Composition production method and eyewear lens production method

Abstract

The present invention provides a composition production method whereby it becomes possible to produce a composition which shows a reduced change in viscosity over time and can be cured into a cured film having excellent hardness (particularly scratch hardness). The composition production method according to the present invention includes: a step 1 for heating a mixture comprising a silsesquioxane having a cation-polymerizable group and metal oxide particles to a temperature higher than 60°C; and a step 2 for mixing the mixture obtained in the step 1 with a cation polymerization initiator to produce a composition.

Description

Method for producing composition and method for producing eyeglass lenses

[0001] The present disclosure relates to methods for making compositions and methods for making eyeglass lenses.

[0002] In order to impart scratch resistance to a plastic spectacle lens substrate, a hard coat layer may be disposed on the plastic spectacle lens substrate (for example, Patent Document 1).

[0003] Special Publication No. 2010-515778

[0004] The present disclosure relates to a method for producing a composition, comprising: Step 1: heating a mixture containing a silsesquioxane having a cationically polymerizable group and metal oxide particles at a temperature above 60°C; and Step 2: mixing the mixture obtained in Step 1 with a cationic polymerization initiator to produce a composition.

[0005] The method for producing the composition of the present disclosure will be described in detail below. From the viewpoint of ease of handling, it is desirable for the composition to have little change in viscosity over time. Furthermore, from the viewpoint of application to hard coat layers and the like, it is desirable for the hardness of the cured film formed using the composition to be excellent. The composition produced by the method for producing the composition of the present disclosure has little change in viscosity over time, and the cured film obtained using this composition has excellent hardness (particularly scratch hardness). The method for producing the composition of this embodiment will be described in detail below. In this specification, the symbol "to" is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit.

[0006] [Method for Producing Composition] The method for producing a composition according to the present embodiment includes steps 1 and 2. Step 1 involves heat-treating a mixture containing silsesquioxane having cationically polymerizable groups and metal oxide particles at a temperature above 60°C. Step 2 involves mixing the mixture obtained in step 1 with a cationic polymerization initiator to produce a composition. As will be described later, by carrying out the heat treatment in step 1 prior to step 2, viscosity changes during storage of the composition are suppressed. Furthermore, the composition produced by the method for producing a composition according to the present disclosure contains silsesquioxane having cationically polymerizable groups and metal oxide particles, and therefore has excellent scratch hardness. Each step in the method for producing a composition according to the present embodiment is described in detail below.

[0007] <Step 1> Step 1 is a step of heating a mixture containing silsesquioxane having a cationically polymerizable group and metal oxide particles at a temperature above 60°C. It is presumed that when this step 1 is carried out, a trace amount of acid derived from the metal oxide particles causes polymerization of the cationically polymerizable group of the silsesquioxane, resulting in the prepolymerization of some of the silsesquioxane. Below, first, the materials used in step 1 will be described in detail, and then the procedure of the step will be described in detail.

[0008] (Silsesquioxane Having a Cationically Polymerizable Group) In the above step 1, a silsesquioxane having a cationically polymerizable group (hereinafter also simply referred to as "specific silsesquioxane") is used. Silsesquioxane is generally a silane compound having a basic skeleton represented by formula (1), which is obtained by hydrolyzing a trifunctional silane compound such as an alkoxysilane, a chlorosilane, or a silanol. Known silsesquioxane structures include an irregular form called a random structure, a ladder structure, a cage structure (fully condensed cage structure), and an incomplete cage structure (a partially cleaved cage structure in which some silicon atoms are missing from the cage structure or in which some silicon-oxygen bonds in the cage structure are cleaved). In the following formula (1), R ３ represents an organic group. ３ -SiO３／２ The specific silsesquioxane is represented by R ３ It is preferable that the basic skeleton is an organic group having a cationically polymerizable group.

[0009] The structure of the specific silsesquioxane is not particularly limited, and may be any of the random structure, ladder structure, cage structure, and incomplete cage structure, or may be a mixture of multiple structures.

[0010] The cationic polymerizable group equivalent in the specific silsesquioxane is not particularly limited, but is preferably 50 to 500 g / eq., and more preferably 150 to 300 g / eq., in view of the superior hardness of the cured film that can be formed using the composition.

[0011] The cationically polymerizable group in the specific silsesquioxane is not particularly limited, but examples thereof include an oxetanyl group and an epoxy group.

[0012] The oxetanyl group is a group represented by the following formula (2): ２ represents a hydrogen atom or an alkyl group (for example, a methyl group, an ethyl group, or a propyl group). * represents a bonding position.

[0013]

[0014] The epoxy group is a group represented by the following formula (3): 1 represents a hydrogen atom or an alkyl group (for example, a methyl group, an ethyl group, or a propyl group). * represents a bonding position.

[0015]

[0016] The specific silsesquioxane may be synthesized by a known method, or a commercially available product may be used, such as OX-SQ TX-100, OX-SQ SI-20, OX-SQ HDX, and OX-SQ ME-20, manufactured by Toagosei Co., Ltd.

[0017] (Metal Oxide Particles) In the above step 1, metal oxide particles are used. The type of metal oxide particles is not particularly limited, and known metal oxide particles can be used. Examples of metal oxide particles include particles of at least one metal oxide selected from Si, Al, Sn, Sb, Ta, Ce, La, Fe, Zn, W, Zr, In, and Ti. Among these, from the viewpoint of handleability, metal oxide particles are preferably particles of an oxide containing Si (silicon oxide particles), particles of an oxide containing Sn (tin oxide particles), particles of an oxide containing Zr (zirconium oxide particles), or particles of an oxide containing Ti (titanium oxide particles). In other words, it is preferable that the metal oxide particles contain at least one atom selected from the group consisting of Si, Sn, Zr, and Ti. Note that the metal oxide particles may contain only one of the above-mentioned metals (metal atoms) or two or more metals (metal atoms).

[0018] The average particle size of the metal oxide particles is not particularly limited, but is preferably 1 to 200 nm, and more preferably 5 to 30 nm. Within this range, the dispersion stability of the metal oxide particles in the composition is superior, and whitening of the cured product can be further suppressed. The average particle size is determined by measuring the diameters of 100 or more metal oxide particles using a transmission electron microscope and calculating the arithmetic average. When the metal oxide particles are not perfectly round, the major axis is used as the diameter.

[0019] The metal oxide particles may be used in a colloidal state dispersed in a solvent. For example, when the metal oxide particles contain Si as the metal, they can be used as colloidal silica.

[0020] When colloidal silica is used as the metal oxide particles, examples of commercially available products include the "OSCAL" series manufactured by JGC Catalysts and Chemicals Co., Ltd., the "Snowtex" series manufactured by Nissan Chemical Industries, Ltd., and the "Quattron" series manufactured by Fuso Chemical Co., Ltd.

[0021] In step 1, components other than the specific silsesquioxane and metal oxide particles described above may be used.

[0022] (Solvent) A solvent may be used in Step 1. The solvent may be the solvent added in Step 1, or, if commercially available colloidal metal oxide particles are used, the dispersion medium. The solvent is not particularly limited and may be water or an organic solvent. Examples of organic solvents include alcohol solvents, ketone solvents, ether solvents, ester solvents, hydrocarbon solvents, halogenated hydrocarbon solvents, amide solvents, sulfone solvents, and sulfoxide solvents. Alcohol solvents having 10 or fewer carbon atoms are preferred, and alcohol solvents having 5 or fewer carbon atoms (e.g., isopropanol) are more preferred. The alcohol solvent may also be a polyhydric alcohol having two or more hydroxy groups per molecule.

[0023] In addition to the above-mentioned solvent, other components include, for example, ultraviolet absorbers, surfactants, polymerization inhibitors, antiaging agents, coating film modifiers, light stabilizers, antioxidants, color inhibitors, dyes, fillers, and internal mold release agents.

[0024] (Procedure of Step 1) In the above-mentioned Step 1, a mixture containing the specific silsesquioxane and metal oxide particles is heated at a temperature above 60°C. The method for obtaining the mixture containing the specific silsesquioxane and metal oxide particles is not particularly limited, and the components may be mixed all at once or may be added in portions and mixed. When obtaining the above-mentioned mixture, a stirring treatment may be carried out as necessary.

[0025] The mixing ratio of the specific silsesquioxane and the metal oxide particles in the mixture is not particularly limited, and the mass ratio of the content of the metal oxide particles to the content of the specific silsesquioxane in the mixture is preferably 0.2 to 10.0, more preferably 0.5 to 2.0. The total content of the specific silsesquioxane and the metal oxide particles in the mixture is not particularly limited, but the total content of the specific silsesquioxane and the metal oxide particles relative to the total solid content in the mixture is preferably 80 to 100 mass%, more preferably 90 to 100 mass%. The solid content in the mixture refers to the components in the mixture excluding the solvent. Even if the components are in a liquid state, they are calculated as solids.

[0026] As described above, the mixture may contain components other than the specific silsesquioxane and metal oxide particles. Examples of other components include the solvents described above. The content of the solvent in the mixture is not particularly limited, but is preferably 30 to 60 mass %, more preferably 40 to 60 mass %, based on the total mass of the mixture.

[0027] The method for heating the mixture in step 1 is not particularly limited, and includes known methods, such as methods using known heating devices. Examples of heating devices include electric heaters such as hot plates and mantle heaters, infrared heaters, oil baths and other oil baths, and water baths and other water baths. The heating may be carried out in an open system or a closed system, but is preferably carried out in a closed system because the temperature of the mixture can be raised to a temperature higher than the boiling point of the solvent in the mixture and the mixture can be heated to a high temperature even if volatile components are present in the mixture. Stirring may be carried out during heating, if necessary.

[0028] The heating temperature of the mixture is greater than 60° C., preferably 80° C. or higher, more preferably 100° C. or higher, even more preferably 120° C. or higher, and particularly preferably 140° C. or higher. There is no particular upper limit to the heating temperature, and it is preferably 200° C. or lower. The heating temperature refers to the set temperature of a heating device (such as a hot plate) used to heat the mixture.

[0029] The heating time of the mixture is not particularly limited as long as it is appropriately selected depending on the heating temperature, but is, for example, preferably 1 hour or more, more preferably 3 hours or more, even more preferably 4 hours or more, and particularly preferably more than 4 hours. The upper limit of the heating time is, for example, preferably 12 hours or less, more preferably 10 hours or less, even more preferably 8 hours or less, particularly preferably less than 8 hours, and most preferably 7 hours or less.

[0030] <Step 2> Step 2 is a step of producing a composition by mixing the mixture obtained in Step 1 with a cationic polymerization initiator. First, the materials used in Step 2 will be described in detail below, and then the procedure of the step will be described in detail.

[0031] (Cationic Polymerization Initiator) A cationic polymerization initiator is used in the above step 2. The cationic polymerization initiator is not particularly limited, but examples thereof include a thermal cationic polymerization initiator and a photo-cationic polymerization initiator.

[0032] The type of the thermal cationic polymerization initiator is not particularly limited, and examples thereof include known thermal cationic polymerization initiators. Examples of the thermal cationic polymerization initiator include onium salts such as sulfonium salts, anilinium salts, pyridinium salts, toluidinium salts, phosphonium salts, and iodonium salts. These onium salts include hexafluorophosphate anion (PF ６ － ), tetrafluoroborate anion (BF ４ － ), hexafluoroantimonate anion (SbF ６ － ), and hexafluoroarsenate anion (AsF ６ －) and other anions. The sulfonium cation may be a triarylsulfonium cation, such as a triphenylsulfonium cation, in which the aryl group is a substituted phenyl group having an alkyl group, a thioether group, an alkoxy group, or the like as a substituent. Specific examples of the triarylsulfonium cation include diphenyl[4-(phenylthio)phenyl]sulfonium cation, triphenylsulfonium cation, and alkyltriphenylsulfonium cation. Commercially available examples of the thermal cationic polymerization initiator include Adeka Optron CP-66 manufactured by ADEKA Corporation and San-Aid SI-150L manufactured by Sanshin Chemical Industry Co., Ltd.

[0033] The type of cationic photopolymerization initiator is not particularly limited, and examples thereof include known cationic photopolymerization initiators. Examples of cationic photopolymerization initiators include onium salts such as iodonium salts (e.g., aromatic iodonium salts) and sulfonium salts (e.g., aromatic sulfonium salts), halogen-containing compounds such as s-triazine derivatives, sulfone compounds, sulfonic acid compounds, sulfonimide compounds, and diazomethane compounds. Among these, aromatic sulfonium salts are preferred as cationic photopolymerization initiators in terms of curability.

[0034] (Other Components) In step 2, components other than the cationic polymerization initiator may be used. Examples of the other components include a solvent, an ultraviolet absorber, a surfactant, a polymerization inhibitor, an antiaging agent, a coating modifier, a light stabilizer, an antioxidant, a color inhibitor, a dye, a filler, and an internal mold release agent. Examples of the solvent include the solvents described in step 1 above.

[0035] Examples of the ultraviolet absorber include a hydroxyphenyltriazine-based ultraviolet absorber having a structure in which three hydrogen atoms on the triazine ring are substituted with phenyl groups, and a benzotriazole-based ultraviolet absorber having a benzotriazole structure. Examples of the surfactant include a polyether-modified silicone-based surfactant having a polyether structure.

[0036] (Procedure of Step 2) In Step 2, the mixture obtained in Step 1 is mixed with a cationic polymerization initiator to produce a composition. The method for mixing the mixture with the cationic polymerization initiator is not particularly limited, and the cationic polymerization initiator may be added to the mixture in portions or all at once. During mixing, a stirring treatment may be performed as necessary.

[0037] The amount of the cationic polymerization initiator used is not particularly limited, but as will be described later, it is preferably 0.1 to 2.0 mass %, and more preferably 0.5 to 1.0 mass %, relative to the total amount of the specific silsesquioxane used in step 1 and the metal oxide particles used in step 1.

[0038] In the method for producing a composition of the present embodiment, the amount of the metal oxide particles used in step 1 relative to the total amount of the specific silsesquioxane used in step 1, the metal oxide particles used in step 1, and the cationic polymerization initiator used in step 2 is not particularly limited, but is preferably 40 to 60 mass%, and more preferably more than 40 mass% and less than 60 mass%.

[0039] <Other Steps> The method for producing a composition of the present embodiment may include other steps in addition to step 1 and step 2. As the other step, when the mixture obtained in step 1 contains a solvent, step 3, in which the solvent in the mixture is replaced with another solvent, may be carried out between step 1 and step 2. The procedure of step 3 is not particularly limited, and examples thereof include a method in which a first solvent contained in the mixture obtained in step 1 is removed by evaporation, and a second solvent different from the evaporated first solvent is added to the resulting mixture. Alternatively, a method in which a second solvent different from the first solvent contained in the mixture obtained in step 1 is added to the mixture, and then the first solvent is removed by evaporation from the resulting mixture may be used. The method for volatilizing the solvent is not particularly limited, and examples thereof include a method in which the solvent is volatilized under reduced pressure.

[0040] The solvent (the other solvent) used in step 3 is not particularly limited, and examples thereof include the solvents described above in step 1. Among these, methanol, butyl cellosolve, or methyl ethyl ketone is preferred.

[0041] [Composition] The composition produced by the composition production method of the present embodiment contains a cationic polymerization initiator and can therefore be used as a curable composition. The composition contains the above-mentioned specific silsesquioxane and metal oxide particles. As described above, the composition is also presumed to contain a prepolymerized specific silsesquioxane.

[0042] The content of the specific silsesquioxane in the composition of this embodiment is not particularly limited, but is preferably 35 to 70 mass %, more preferably 35 to 60 mass %, relative to the total solids content in the composition of this embodiment, in order to provide a cured film formed using the composition with superior scratch hardness and with minimal change in viscosity over time. The solids content in the composition refers to the components that constitute the cured film formed using the composition, including the specific silsesquioxane, metal oxide particles, and thermal cationic polymerization initiator described above, and does not include the solvent. Even if a component is liquid, it is still counted as a solid if it constitutes a cured film.

[0043] The content of the metal oxide particles in the composition of the present embodiment is not particularly limited, but is preferably 35 to 70 mass %, and more preferably 35 to 60 mass %, relative to the total solid content in the composition of the present embodiment, in terms of providing a cured film formed using the composition with better scratch hardness and minimizing change in viscosity of the composition over time.

[0044] The content of the cationic polymerization initiator in the composition of the present embodiment is not particularly limited, but is preferably 0.1 to 3.0 mass %, and more preferably 0.2 to 1.5 mass %, relative to the total solid content in the composition of the present embodiment, in terms of providing a cured film formed using the composition with better scratch hardness and minimizing change in viscosity of the composition over time.

[0045] When the composition of this embodiment contains an ultraviolet absorber, the content of the ultraviolet absorber is not particularly limited, but is preferably 0.1 to 10 mass %, more preferably 0.5 to 2.0 mass %, based on the total solid content of the composition of this embodiment. When the composition of this embodiment contains a surfactant, the content of the surfactant is not particularly limited, but is preferably 0.1 to 10 mass %, more preferably 0.5 to 2.0 mass %, based on the total solid content of the composition of this embodiment.

[0046] The viscosity (20°C) of the composition is not particularly limited, but is preferably 60.0 cP or less, more preferably 30.0 cP or less, and even more preferably 20.0 cP or less, from the viewpoint of superior scratch hardness of the cured film formed using the composition or superior workability when forming the hard coat layer. The lower limit is not particularly limited, but is often 5.0 cP or more, and more often 10.0 cP or more. The viscosity can be measured using a known measuring device (for example, a cone-plate type viscometer, etc.).

[0047] The solid content of the composition is not particularly limited, but is preferably 40 to 70% by mass, more preferably 50 to 60% by mass, based on the total mass of the composition.

[0048] The composition can be used, for example, as a composition for forming a cured film on a spectacle lens substrate.

[0049] [Method for manufacturing eyeglass lenses] The present disclosure also includes a method for manufacturing eyeglass lenses, which includes a step of forming a cured film on an eyeglass lens substrate using a composition manufactured by the method for manufacturing a composition of the present embodiment. Below, first, the materials and components used in this step will be described in detail, and then the procedure of the step will be described in detail.

[0050] The composition used in this process is as described above. Examples of spectacle lens substrates used in this process include spectacle lens substrates made of organic or inorganic materials. Examples of spectacle lens substrates include finished lenses in which both the convex and concave surfaces are optically finished and molded to the desired power, semi-finished lenses in which only the convex surface is finished as an optical surface (e.g., spherical, rotationally symmetric aspherical, progressive, etc.), and semi-finished lenses in which the concave surface is processed and polished to match the wearer's prescription. Examples of organic materials (so-called resins) include (meth)acrylic resins, thiourethane resins, allyl resins, episulfide resins, polycarbonate resins, polyurethane resins, polyester resins, polystyrene resins, polyethersulfone resins, poly(4-methylpentene-1) resins, and diethylene glycol bisallyl carbonate resins (CR-39). Examples of inorganic materials include glass.

[0051] A primer layer may be disposed on the spectacle lens substrate.

[0052] The thickness of the spectacle lens substrate may be 1 to 30 mm from the viewpoint of ease of handling. The thickness (average thickness) is determined, for example, by measuring the thickness at any five points and calculating the arithmetic average of the measured values. The spectacle lens substrate is preferably translucent and may be either transparent or opaque. It may also be colored.

[0053] (Step procedure) The method of forming a cured film on a spectacle lens substrate using a composition is not particularly limited, and examples thereof include a method of contacting a spectacle lens substrate with a composition to form a coating film on the spectacle lens substrate, and then curing the coating film to form a cured film. The procedure of the above method will be described in detail below.

[0054] The method for contacting the spectacle lens substrate with the composition is not particularly limited; the composition may be applied to the spectacle lens substrate, or the spectacle lens substrate may be immersed in the composition. The procedure for the curing treatment is not particularly limited, and heat treatment is preferred. The conditions for the heat treatment are not particularly limited, and optimal conditions are selected depending on the type of thermal cationic polymerization initiator used. In particular, the heating temperature is preferably 30 to 120°C, more preferably 50 to 100°C, and the heating time is preferably 5 to 360 minutes, more preferably 10 to 60 minutes.

[0055] The thickness of the cured film is not particularly limited, but can be, for example, 1.0 μm or more, preferably 5.0 μm or more. The upper limit of the film thickness can be, for example, 30.0 μm or less, preferably 20.0 μm or less. The film thickness is an average film thickness, and is measured by measuring the film thickness at any five points on the cured film and calculating the arithmetic average. An optical film thickness meter can also be used.

[0056] The composition of the present disclosure will be explained in more detail below with reference to examples and comparative examples, but the present disclosure is not limited by these examples.

[0057] Example 1 (Preparation of Composition (Step 1)) The composition of Example 1 was prepared by the following procedure. To a glass container equipped with a stirrer, (A) cationically cured silsesquioxane (OX-SQ TX-100, manufactured by Toagosei Co., Ltd.) (27.13 g) as the silsesquioxane, and (B) colloidal silica (OSCAL-1432E, isopropanol dispersion, solids content 30% by mass, manufactured by JGC Catalysts and Chemicals Co., Ltd.) (90.45 g) as the metal oxide particles were added to prepare a mixture. The resulting mixture was stirred for 6 hours while being heated on a hot plate set to 160°C. At this time, the glass container was sealed with a lid, and the solvent in the mixture was in a reflux state.

[0058] (Preparation of Composition (Step 3)) After heating, the resulting reaction solution was cooled to room temperature overnight, and then butyl cellosolve (10.85 g) was added to the cooled reaction solution as a membrane-forming solvent. Next, isopropanol was distilled off from the reaction solution under reduced pressure at 40°C over 2 hours. Methanol (33.40 g) was added to the resulting crude product to obtain Liquid Composition X1.

[0059] (Preparation of Composition (Step 2)) In a glass container equipped with a stirrer, the liquid composition X1 (98.52 g) obtained in the above step 1 and (D) SbF as a cationic polymerization initiator were added. ６ － (F) a hydroxyphenyltriazine-based ultraviolet absorber (manufactured by BASF Japan Ltd.: Tinuvin 477) (0.62 g) as an ultraviolet absorber; and (G) a polyether-modified silicone (manufactured by Dow Corning Toray Co., Ltd.: DOWSIL L-7001) (0.33 g) as a surfactant were added and mixed to obtain Composition 1.

[0060] Examples 2, 5 to 9, Comparative Examples 2 and 3 Compositions 2, 5 to 9, and Compositions C2 and C3 were obtained in the same manner as in Example 1, except that when heating the mixture, the set temperature of the hot plate and the heating time were changed to the values ​​shown in Table 1. Note that Comparative Example 2 corresponds to an example in which the heat treatment in Step 1 was not carried out.

[0061] Example 3 Composition 3 was obtained in the same manner as in Example 1, except that the amount of cation-curable silsesquioxane (OX-SQ TX-100, manufactured by Toagosei Co., Ltd.) used was changed from 27.13 g to 32.56 g, and the amount of colloidal silica (OSCAL-1432E, isopropanol dispersion, solids content 30% by mass, manufactured by JGC Catalysts and Chemicals Co., Ltd.) used was changed from 90.45 g to 72.36 g.

[0062] Example 4 Composition 4 was obtained in the same manner as in Example 1, except that the amount of cation-curable silsesquioxane (OX-SQ TX-100, manufactured by Toagosei Co., Ltd.) used was changed from 27.13 g to 21.71 g, and the amount of colloidal silica (OSCAL-1432E, isopropanol dispersion, solids content 30% by mass, manufactured by JGC Catalysts and Chemicals Co., Ltd.) used was changed from 90.45 g to 108.7 g.

[0063] Comparative Example 1 To a glass container equipped with a stirrer, 19.70 g of 3-glycidoxypropyltrimethoxysilane (KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.) was added as a hydrolyzable silicon compound (C), and 4.50 g of 0.1 N hydrochloric acid was gradually added dropwise while stirring the mixture. After the addition was completed, the mixture was stirred at room temperature for 24 hours. Subsequently, to the resulting mixture, 35.60 g of titanium oxide colloid (NE58, solids content 30% by mass, manufactured by JGC Catalysts and Chemicals Co., Ltd.) as metal oxide particles, 1.60 g of aluminum acetylacetonate (Kishida Chemical Co., Ltd.) as a catalyst, 38.50 g of methanol, and 0.10 g of polyether-modified silicone (DOWSIL L-7001, manufactured by Dow Corning Toray Co., Ltd.) as a surfactant were added and mixed, thereby obtaining a composition C1 of Comparative Example 1.

[0064] <Evaluation> The compositions obtained in the above Examples and Comparative Examples were evaluated as follows. The results are summarized in Table 1 below.

[0065] (Temporal Viscosity Stability) The temporal viscosity stability of the compositions of each Example or Comparative Example was measured by the following method. Before the standing treatment described below, the temperature of the composition was adjusted to 20°C, and the initial viscosity of the composition was measured using a vibration viscometer (VM-100, manufactured by Yamaichi Electronics Co., Ltd.). After measuring the initial viscosity, the composition was allowed to stand for 24 hours at 5°C in the dark, and the viscosity of the composition after the standing treatment was measured as the temporal viscosity in the same manner as in the measurement of the initial viscosity. From the values ​​of the initial viscosity and the temporal viscosity, the rate of change in viscosity over time was calculated as follows, and the temporal viscosity stability was evaluated based on the following evaluation criteria.

[0066] Viscosity change rate over time (%) = 100 x (| (viscosity over time) - (initial viscosity) | / (initial viscosity)) (Evaluation criteria for viscosity stability over time) A: Viscosity change rate over time is 10% or less B: Viscosity change rate over time is more than 10% and 50% or less C: Viscosity change rate over time is more than 50% and 200% or less D: Viscosity change rate over time is more than 200%

[0067] (Evaluation of Pencil Hardness) Using the compositions of each Example or Comparative Example, a plastic eyeglass lens substrate with a cured film was prepared by the following method. First, a lens with a refractive index of 1.60 (Nikon Lite AS Material S-3.00D, manufactured by Nikon Essilor Corporation) was used as the plastic eyeglass lens substrate. The composition of each Example or Comparative Example was applied to one surface of this plastic eyeglass lens substrate by spin coating. Specifically, the plastic eyeglass lens substrate was rotated at 300 rpm for 1 second, and 4 ml of the composition was dripped from the center to the outer periphery of the plastic eyeglass lens substrate during this rotation. The plastic eyeglass lens substrate with the coated composition was then rotated at 300 rpm for 15 seconds, then reached 400 rpm in 5 seconds and rotated for 1 second, then reached 700 rpm in 5 seconds and rotated for 1 second, and then reached 2000 rpm in 9.9 seconds and rotated for 1 second, thereby obtaining a plastic eyeglass lens substrate with a coating film. The resulting plastic eyeglass lens substrate with a coating film was then heated at 100°C for 20 minutes, and then further heated at 100°C for 1 hour to form a cured film, thereby obtaining a plastic eyeglass lens substrate with a cured film. The thickness of the resulting cured film was 15 µm.

[0068] The scratch hardness (pencil hardness) of plastic eyeglass lens substrates with a cured film produced using the compositions of each Example or Comparative Example was evaluated according to the following procedure. Specifically, the pencil hardness of the cured film was measured in accordance with the method specified in JIS K5600-5-4 (1999) and evaluated based on the following evaluation criteria: A: Pencil hardness of 4H or more B: Pencil hardness of 3H or more but less than 4H C: Pencil hardness of 2H or more but less than 3H

[0069] (Scratch Hardness Evaluation) Using the method described in (Pencil Hardness Evaluation), a cured film-coated plastic eyeglass lens substrate was produced using the composition of each Example or Comparative Example. The scratch hardness of the resulting cured film-coated plastic eyeglass lens substrate was evaluated according to the following procedure. Using a friction and wear tester (Tribogear TYPE 40 manufactured by Shinto Scientific Co., Ltd.), a sapphire scratching needle (BH0001-02 manufactured by Shinto Scientific Co., Ltd.) with a tip radius of 0.01 mm and an apex angle of 60° was vertically contacted with the convex surface (the surface on which the cured film was located) of the cured film-coated plastic eyeglass lens substrate produced according to the above procedure, and the scratching needle was moved once over a length of 10 mm at a speed of 60 mm / min while applying a vertical load of 10 g to the scratching needle. Using a scanning white light interference microscope (VS1000 manufactured by Hitachi, Ltd.), the depth of the scratch mark on the convex surface of the cured film-coated plastic eyeglass lens substrate was measured, and the scratch hardness was evaluated according to the following evaluation criteria. A: The depth of the scratch marks is 50 nm or less. B: The depth of the scratch marks is more than 50 nm and 80 nm or less. C: The depth of the scratch marks is more than 80 nm.

[0070] The evaluation results are shown in Table 1. Each numerical value in the table indicates the amount (parts by mass) of each component used in the composition. In the table, the column "B / A+B+D (mass%)" indicates the amount of (B) metal oxide particles used relative to the total amount of (A) silsesquioxane used, (B) metal oxide particles used, and (D) cationic polymerization initiator used in the manufacturing method of the present disclosure (unit: mass%). In the table, the column "Heating Temperature" indicates the set temperature of the hot plate when heating the mixture in Step 1. In the table, the column "Heating Time" indicates the heating time (stirring time) when heating the mixture in Step 1. In the table, the column "Film Thickness" indicates the film thickness of the cured film. The film thickness was measured using an optical film thickness meter. In the table, the column "Hardness-1" indicates the results of the above (evaluation of pencil hardness), the column "Hardness-2" indicates the results of the above (evaluation of scratch hardness), and the column "Viscosity" indicates the results of the above (viscosity stability over time).

[0071]

[0072] As shown in Table 1, the composition of the present disclosure was confirmed to exhibit the desired effects.

Claims

1. Step 1: heating a mixture containing silsesquioxane having a cationically polymerizable group and metal oxide particles at a temperature of more than 60° C.; A step 2 of mixing the mixture obtained in the step 1 with a cationic polymerization initiator to produce a composition.

2. The method for producing a composition according to claim 1 , wherein the heating time is 1 hour or more.

3. The method for producing a composition according to claim 1 , wherein the heating temperature is 100° C. or higher.

4. The method for producing a composition according to claim 1, wherein an amount of the metal oxide particles used is 40 to 60 mass% based on a total amount of the silsesquioxane having a cationic polymerizable group, the metal oxide particles, and the cationic polymerization initiator used.

5. The method for producing a composition according to claim 1 , wherein the metal oxide particles contain at least one atom selected from the group consisting of Si, Sn, Zr, and Ti.

6. The method for producing a composition according to claim 1 , wherein the cationically polymerizable group is an oxetanyl group.

7. A method for producing a spectacle lens, comprising a step of forming a cured film on a spectacle lens substrate using a composition produced by the production method according to any one of claims 1 to 6.