JP4742603B2 - Manufacturing method of plastic lens - Google Patents

Description

  The present invention relates to a plastic lens and a manufacturing method, and more particularly, to a plastic lens having excellent light resistance and suppressing color change.

In recent years, plastic lenses are widely used in spectacle lenses and the like where fashionability is important because they have characteristics such as light weight, resistance to breakage, and easy dyeing compared to inorganic glass lenses. This plastic spectacle lens has a disadvantage that it is inevitable that the edge thickness of the minus lens and the center thickness of the plus lens are thicker than those of the glass lens. For this reason, development of plastic lens materials with higher refractive index has been promoted, and many proposals have been made.
Among these proposals, a plastic lens obtained by polymerizing a compound having two or more episulfide groups in one molecule has a refractive index of 1.70 or more and an Abbe number of 30 or more. Resins having comparable optical properties have been proposed (see, for example, Patent Document 1).

In addition, in plastic lenses, in order to improve the scratch resistance, a hard coat film is generally formed on the surface, or a multilayer film is provided for the purpose of preventing reflection. In this case, if the refractive indexes of the plastic lens substrate and the hard coat film are different, interference fringes are likely to occur, and the fashionability of the glasses may be impaired.
Therefore, in order to prevent the occurrence of interference fringes, for example, fine particles of various high refractive index metal oxides such as Ti, Al, Sn, Ta, Zr, Ce, Sb, W, and Fe are mainly used in the hard coat film. Inclusion as a component has been performed. Of these, composite oxide fine particles mainly composed of titanium dioxide are generally used. In particular, titanium dioxide has an anatase type crystal structure.

Japanese Patent Laid-Open No. 9-110979

  However, titanium dioxide is a metal oxide having photoactivity, and in particular, the anatase type crystal structure has the property of easily expressing photoactivity, and when used as a coating for a plastic spectacle lens, it causes abnormal coating film. Often come. On the other hand, so-called episulfide-based resins having a refractive index of 1.70 or more have the property of being easily yellowed by receiving light, and color tone change is a problem in long-term use, particularly in dyed lenses.

  Under such circumstances, the present invention has good optical performance such as Abbe number, transparency and antireflection properties, reduced generation of interference fringes, and excellent surface hardness, weather resistance and moisture resistance. Another object of the present invention is to provide a plastic lens having a water resistance, a chemical resistance, etc., particularly excellent in light resistance, and suppressed in color change, and a manufacturing method.

  As a result of intensive research to develop a plastic lens having excellent performance, the present inventors have formed a specific hard coat film on the surface of a plastic lens substrate obtained by cast polymerization of a specific monomer. It was found that the object can be achieved by providing an antireflection film made of a multilayer inorganic oxide film, and the present invention has been completed based on this finding.

In the method for producing a plastic lens of the present invention, on the surface of a plastic lens substrate obtained by cast polymerization of a monomer mainly composed of bis (2,3-epithiopropyl) disulfide,
Composite oxide fine particles composed of a core particle composed of titanium dioxide and tin dioxide having a rutile crystal structure, and a coating layer composed of a mixed particle of zirconium dioxide and silicon oxide around the core particle, and organic A hard coat film forming step of applying a hard coat film forming coating solution containing a silicon compound as a main component and curing to form a hard coat film; and at least one layer of SiO ₂ on the hard coat film An antireflective film forming step of forming a multilayer inorganic oxide film including a layer, wherein in the antireflective film forming step, a film is formed by a vacuum deposition method, and the degree of vacuum at the time of film formation is 5.0. It is characterized by being set to x10 ⁻⁵ mbar or more and 4.0 × 10 ⁻⁶ mbar or less.
The rutile-type crystal structure has a photochromic action that develops a very light blue color when exposed to light, so that the compound that has an episulfide group undergoes yellowing when receiving light. It is possible to correct the color tone and to prevent the color change of the plastic lens from turning yellow. Furthermore, by forming the antireflection film made of a multilayer inorganic oxide on the hard coat film, the photochromic action that the hard coat film develops color due to the oxygen blocking effect of the antireflection film can be maintained.
According to the present invention, since the antireflection film is a multilayer inorganic oxide film including at least one layer made of SiO ₂ , the antireflection film has an oxygen blocking effect and is formed under the antireflection film. In addition, the photochromic effect that the hard coat film receives light and develops an extremely light blue color can be maintained. Generally, SiO ₂ of metal oxides that form an antireflection film can control the film density by the degree of vacuum at the time of film formation, but it is easy to improve the film density with TiO ₂ , ZrO _2, etc. Instead, the film density of the antireflection film as a whole depends on the SiO ₂ layer. Therefore, by forming an antireflection film comprising at least one layer of SiO ₂ ,
Sustains the property that the oxygen barrier effect is exhibited and the hard coat film develops a very light blue color.
Is possible.
According to the present invention, optical performance such as Abbe number, transparency, and antireflection properties is good, generation of interference fringes is reduced, and excellent surface hardness, weather resistance, moisture resistance, water resistance, chemical resistance In particular, a plastic lens with excellent light resistance and suppressed color tone change can be obtained.

In addition, according to the manufacturing method of the present invention, the degree of vacuum during vacuum deposition for forming the antireflection film is formed under a high vacuum condition of 5.0 × 10 ⁻⁵ mbar or more, thereby providing a good oxygen barrier. An antireflection film having an effect can be obtained. In a low vacuum environment where the degree of vacuum is less than 5.0 × 10 ⁻⁵ mbar, the mean free path of the vapor deposition material becomes small, and this reduces the film density on the lens surface, so that a good oxygen blocking effect cannot be obtained. That is, the photochromic action of the hard coat film cannot be sustained, and the color tone change cannot be suppressed. Moreover, the film thickness of the layer made of SiO ₂ obtained by the above method is preferably 10 nm to 300 nm. If the thickness is less than 10 nm, a sufficient oxygen blocking effect cannot be obtained, and if it exceeds 300 nm, sufficient antireflection properties cannot be obtained, and the internal stress of the thin film itself increases, resulting in a decrease in heat resistance.

The lens base material of the plastic lens of the present invention can be obtained by cast polymerization of a monomer having as a main component a compound having two or more episulfide groups in one molecule.
Here, examples of the compound having two or more episulfide groups in one molecule include compounds represented by the following general formula (I).

（式中、ｍは０〜６の整数、ｎは０〜４の整数である。）
この中でｍ＝０、ｎ＝１で表されるビス（２，３−エピチオプロピル）ジスルフィドが好適に用いることができる。この一般式（Ｉ）で表される化合物は、公知の方法（特許文献１参照）により、容易に製造することができる。

(In the formula, m is an integer of 0-6, and n is an integer of 0-4.)
Of these, bis (2,3-epithiopropyl) disulfide represented by m = 0 and n = 1 can be preferably used. The compound represented by the general formula (I) can be easily produced by a known method (see Patent Document 1).

  Further, one or more of the compounds represented by the above general formula (I) and one or more of copolymerizable monomers can be mixed and used. Further, a curing polymerization catalyst, a polymerization accelerator, an ultraviolet absorber, an antioxidant and the like can be added to these monomers as desired.

  Examples of the copolymerizable monomer include epithio groups such as other episulfide compounds, epoxy compounds, polycarboxylic acids, polycarboxylic anhydrides, mercaptocarboxylic acids, polymercaptans, mercaptoalcohols, polyphenols, amines and amides. Functional group capable of reacting with an episulfide group such as an epoxy compound having an unsaturated group, an episulfide compound having an unsaturated group, a carboxylic acid having an unsaturated group or a derivative thereof One or more compounds having one or more homopolymerizable functional groups, one glycidyl ester, glycidyl thioester, glycidyl ether, glycidyl thioether, or other episulfide group capable of reacting with one homopolymerizable functional group To mention compounds Kill.

  Examples of the curing polymerization catalyst include amines, phosphines, mineral acids, Lewis acids, organic acids, silicic acids, and tetrafluoroboric acid. Examples of the polymerization accelerator include radical polymerization initiators such as organic peroxides, azo compounds, and known photopolymerization catalysts.

And a plastic lens base material is manufactured by inject | pouring such a monomer into glass and a metal shaping | molding die, and polymerizing and hardening it.
The polymerization temperature for the polymerization and curing is usually -10 to 160 ° C, preferably -10 to 140 ° C. The polymerization time depends on the polymerization temperature and cannot be determined in general, but is generally about 0.1 to 100 hours, preferably about 1 to 48 hours. Further, after the polymerization and curing, in order to remove the distortion of the plastic lens substrate, it is preferable to anneal at a temperature in the range of 50 to 150 ° C. for about 10 minutes to 5 hours.

The plastic lens substrate obtained by polymerizing and curing in this way is a plastic lens substrate having a refractive index (nd) of 1.65 or more and an Abbe number of 33 or more.
A hard coat film and an antireflection film are sequentially formed on the surface of the plastic lens substrate thus obtained, thereby completing the plastic lens of the present invention.

First, the hard coat film formed on the surface of the plastic lens substrate will be described.
The hard coat film is composed of composite oxide fine particles mainly composed of titanium dioxide having a rutile crystal structure (hereinafter referred to as “a” component), and a compound containing an organosilicon compound as a main component (hereinafter referred to as “b” component) Notation).

  Since the rutile type crystal structure in the component (a) has significantly less photoactivity than the anatase type crystal structure, a hard coat film excellent in light resistance can be formed. In addition, the rutile crystal structure has a property of receiving a light and temporarily developing a very light blue color, that is, a photochromic action. This photochromic action is a reversible reaction between color development due to light and fading due to oxygen exchange. However, especially when an antireflection layer is provided on the upper layer of the hard coat film, only the color development action is manifested by the oxygen blocking effect of the antireflection layer. Thus, it is possible to maintain the characteristic of exhibiting an extremely light blue color. This characteristic leads to correcting the property that the compound having an episulfide group is yellowed by receiving light from the relationship of complementary colors to an achromatic color, and due to yellowing during actual use when used in an optical article. Color tone change can be prevented.

  Preferred examples of the component B include those composed of “nuclear fine particles obtained by doping titanium oxide with tin oxide” and “mixed fine particles of zirconium oxide and silicon oxide” coated on the periphery thereof. The “mixed fine particles of zirconium oxide and silicon oxide” include not only a mixture of zirconium oxide fine particles and silicon oxide fine particles, but also those having zirconium oxide as a nucleus and coated with silicon oxide.

  Further, the core fine particles constituting the component (a) are titanium oxide doped with tin oxide. Doping refers to adding tin oxide to titanium oxide. The added tin oxide may be in a state where it is physically mixed with titanium oxide, or may be in a state where tin oxide has entered the titanium oxide molecular chain by chemical reaction such as atomic substitution. By using such core fine particles obtained by doping tin oxide with titanium oxide, a rutile-type crystal structure is obtained, and chemical properties such as weather resistance (non-coloring property) and water resistance of the hard coat film are improved.

  The other component constituting the component A is a mixed fine particle of zirconium oxide and silicon oxide coated around the core fine particle. By using zirconium oxide as a component of the mixed fine particles coated around the core fine particles, the weather resistance (non-coloring property) and chemical properties such as water resistance of the resulting hard coat film are further improved. To do. The reason why silicon oxide is used together with zirconium oxide is that it is only zirconium oxide. When this oxide composite fine particle is mixed with the organosilicon compound of the below-described component, it is easy to bond and aggregate, and the resulting hard This is because cloudiness is likely to occur in the coating film, but the use of silicon oxide prevents such agglomeration problem and ensures dispersion uniformity of the coating liquid for forming the hard coating film. In addition, silicon oxide has a function of increasing the bonding strength with a compound containing an organosilicon compound as a main component as a main component, and can improve the weather resistance and scratch resistance of the hard coat.

In addition, as described above, the component A is composed of core fine particles and mixed fine particles coated around the core fine particles. When titanium and tin in the core fine particles are converted into TiO ₂ and SnO ₂ , respectively, TiO _{2 2} / SnO ₂ (weight ratio) is preferably in the range of 1 / 9.9 to 14/1. Within such a range of TiO ₂ / SnO ₂ , the core fine particles become a solid solution oxide having a high refractive index and a highly crystalline rutile structure. On the other hand, when TiO ₂ / SnO ₂ (weight ratio) is less than 1 / 9.9, a sufficient refractive index cannot be obtained, and when TiO ₂ / SnO ₂ (weight ratio) exceeds 14/1. May not be easily obtained as a solid solution oxide having a highly crystalline rutile structure, and may be a mixed crystal of rutile and anatase types. Further, the core fine particles may contain silicon oxide and zirconium oxide together with titanium oxide and tin oxide.

On the other hand, when silicon and zirconium in the coating layer are converted into SiO ₂ and ZrO ₂ , respectively, the SiO ₂ / ZrO ₂ (weight ratio) is preferably in the range of 50/50 to 99/1. On the other hand, when SiO ₂ / ZrO ₂ (weight ratio) is less than 50/50, stability and weather resistance cannot be obtained, and when SiO ₂ / ZrO ₂ (weight ratio) exceeds 99/1. Stability and water resistance may not be obtained. It is preferable to use such core fine particles and a coating layer in a composite form in the range of 100 / 0.5 to 100/100 by weight ratio of the core fine particles / the coating layer.

  Moreover, the average particle diameter of the component A is preferably in the range of 1 to 200 nm. If the average particle size is less than 1 nm, the fine particles are likely to aggregate, and the resulting coating is inferior in scratch resistance, and the refractive index cannot be increased. Conversely, if it exceeds 200 nm, it is difficult to obtain a transparent hard coat film. Therefore, the average particle diameter is more preferably in the range of 1 to 100 nm, and particularly preferably in the range of 1 to 20 nm.

Moreover, in order to maintain the dispersion | distribution state stably or to improve water resistance, you may process the surface with various organic acids, an alkali, an organosilicon compound, a silicon oxide, etc.
Examples of the organic acid include citric acid and tartaric acid. Examples of the alkali include aqueous solutions of alkali metal hydroxides or salts thereof such as sodium and potassium, ammonia, and organic amines.
Examples of the organosilicon compound include silane coupling agents such as γ-glycidoxypropyltrimethoxysilane and γ-methacryloxypropyltrimethoxysilane, and organic silanes such as methyltrichlorosilane and tetramethoxysilane.
Such composite oxide fine particles having a rutile crystal structure can be produced by a known method such as a pulverization method, a gas phase method, an ion exchange method, or a hydrolysis method.

On the other hand, examples of the component B include compounds represented by the following general formula (II).
(R ₁ ) _a (R ₂ ) _b Si (OR ₃ ) _{4- (a + b)} (II)
(Here, R ₁ and R ₂ are an alkyl group having 1 to 10 carbon atoms, an aryl group, an alkyl halide, an aryl halide, an alkenyl, or an epoxy group, a (meth) acryloxy group, a mercapto group, or a cyano group. R ₃ is an alkyl group having 1 to 6 carbon atoms, an alkoxyalkyl group or an acyl group, and a and b are 0, 1 or 2 And a + b is 1 or 2.)

  Examples of the organosilicon compound represented by the general formula (II) include methyltrimethoxysilane, methyltriethoxysilane, methyltrimethoxyethoxysilane, methyltriacetoxysilane, methyltripropoxysilane, methyltributoxysilane, Ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, vinyltrimethoxyethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriacetoxysilane, γ-chloropropyl Trimethoxysilane, γ-chloropropyltriethoxysilane, γ-chloropropyltripropoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, γ-glycidoxypropylto Limethoxysilane, γ-glycidoxypropyltriethoxysilane, γ- (β-glycidoxyethoxy) propyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4 -Epoxycyclohexyl) ethyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, Trialkoxy or triacyloxysilanes such as N-β (aminoethyl) -γ-aminopropyltrimethoxysilane and β-cyanoethyltriethoxysilane, and dimethyldimethoxysilane, phenylmethyldimethoxysilane, dimethyl Diethoxysilane, phenylmethyldiethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylphenyldimethoxysilane, γ-glycidoxypropylphenyldiethoxy Silane, γ-chloropropylmethyldimethoxysilane, γ-chloropropylmethyldiethoxysilane, dimethyldiacetoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-mercaptopropylmethyldimethoxysilane , Γ-mercaptopropylmethyldiethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, methylvinyldimethoxysilane, methyl Examples thereof include dialkoxysilanes such as vinyldiethoxysilane and diacyloxysilanes.

These organosilicon compounds can be used alone or in combination of two or more. Furthermore, various tetraalkoxysilanes that can be used in combination with an organosilicon compound, although not used alone. Examples of tetraalkoxysilanes include methyl silicate, ethyl silicate, n-propyl silicate, isopropyl silicate, n-butyl silicate, sec-butyl silicate, t-butyl silicate, and the like.
The hydrolyzate can be obtained by partially or completely hydrolyzing the organosilicon compound of formula (II) or tetraalkoxysilane in the presence of an inorganic acid such as hydrochloric acid or sulfuric acid or an organic acid such as acetic acid. . At this time, an organic solvent may be used in order to perform hydrolysis uniformly.

  As these organosilicon compounds as the component B, the compounds represented by the general formula (II) may be used alone or in combination of two or more. In addition, one or more hydrolysates of these compounds may be used, or one or more compounds represented by the general formula (II) may be used in combination with one or more hydrolysates thereof. Good.

  The content ratio of component A and component B described above is appropriately selected according to the type of plastic lens substrate used, the predetermined refractive index of the hard coat film to be formed, etc. The component B is preferably in the range of 10 to 500 parts by weight with respect to 100 parts by weight of the component B. If the amount of the component A is less than 10 parts by weight, the refractive index of the hard coat film to be formed may be lowered, and if it exceeds 500 parts by weight, the transparency of the hard coat film tends to be lowered. From the viewpoint of the balance between the refractive index and transparency of the hard coat film, the more preferable content of the component A is in the range of 20 to 100 parts by weight.

  In addition, the component B and component B used for forming the hard coat film can contain various additive components as long as the object of the present invention is not impaired. As an additive component, for example, a curing agent for accelerating the curing reaction at the time of hard coat film formation, a fine inorganic material for matching the refractive index with the plastic lens substrate, and a coating liquid for forming a hard coat film on the substrate. Surfactant (surface smoothing agent) to improve wettability and hard coat film smoothness during application, resin such as epoxy resin, acrylic resin and urethane resin to improve dyeability and flexibility Further, UV absorbers, antioxidants and the like can be contained as desired.

Examples of curing agents include amines such as allylamine and ethylamine, various acids and bases such as Lewis acid and Lewis base, specifically organic carboxylic acid, chromic acid, hypochlorous acid, boric acid, perchloric acid, Examples thereof include acids such as bromic acid, selenious acid, aluminate, and carbonic acid and salts thereof, metal alkoxides such as aluminum, zirconium, titanium, and magnesium, and metal chelate compounds such as aluminum acetylacetonate.
Examples of the particulate inorganic material include silicon oxide, zirconium oxide, antimony oxide, tin oxide, tungsten oxide, composite fine particles of tin oxide and tungsten oxide, composite fine particles of tin oxide, zirconium oxide, and tungsten oxide. It is done.
Such a hard coat film preferably has a thickness in the range of 1 to 5 μm and a refractive index close to that of the substrate.

Next, the antireflection film formed on the surface of the hard coat film will be described.
The antireflection film is a film made of a multilayer inorganic oxide and is not particularly limited. For example, the antireflection film is made of at least one selected from oxides of Si, Ti, Zr, Al, Ta, Nb, and Y. An antireflection layer having a multilayer structure is preferred. Of these, a multilayer film in which oxides made of Si, Zr, Ti, Ta, and Nb are formed by vacuum deposition is preferable in terms of reflectivity, transparency, durability, productivity, and availability. is there. Or what consists of a combination of the surface reinforcement layer mentioned later and the antireflection layer of the multilayered structure provided on it is mentioned. Among these, the antireflection film having the latter configuration is preferable because surface enhancement and enlargement of the antireflection area are achieved.

As the antireflection layer having a multilayer structure, for example, a multilayer structure in which low refractive index layers and high refractive index layers shown below are alternately laminated is preferable.
That is, an optical film thickness of 0.09λ to 0.14λ composed of at least one selected from tantalum oxide, zirconium oxide, and yttria oxide in this order from the hard coat film formed on the plastic lens substrate or the surface reinforcing layer side. An optical film comprising at least one selected from a low refractive index composite layer comprising tantalum oxide, a silicon oxide layer having a thickness of 0.04λ to 0.07λ, tantalum oxide, zirconium oxide and yttria oxide A multilayer structure composed of a high refractive index layer having a thickness of 0.24λ to 0.28λ and a low refractive index layer having an optical film thickness of 0.24λ to 0.28λ made of silicon oxide is preferable.

In addition, as described above, the antireflection layer needs to block the supply of oxygen to the rutile-type titanium oxide sol and maintain the colored state, so it is necessary to control the degree of vacuum during film formation and to control the film formation density. is there. Therefore, the degree of vacuum at the time of film formation should be 5.0 × 10 ⁻⁵ mbar or higher, preferably 2.0 × 10 ⁻⁵ mbar or higher, more preferably 9.0 × 10 ⁻⁶ mbar or higher. There is. In an actual vacuum deposition apparatus, the degree of vacuum is considered to be about 4.0 × 10 ⁻⁶ mbar, and therefore it is preferable to form a film with as high a degree of vacuum as possible.

Moreover, it can form as a part of antireflection film as a surface reinforcement | strengthening layer between a hard-coat film and the antireflection layer of a multilayered structure. By forming the surface reinforcing layer, the scratch resistance, moisture resistance, water resistance and the like are further improved, and the antireflection area is expanded. The surface hardened layer is composed of a first layer having an optical film thickness of 0.25λ or less, zirconium oxide, tantalum oxide, aluminum oxide made of at least silicon oxide (SiO ₂ , SiO, or a mixture thereof) from the hard coat film side. , Titanium oxide, cerium oxide and yttrium oxide (ZrO ₂ , Ta ₂ O ₅ , Al ₂ O ₃ , TiO ₂ , TiO, Ti ₂ O ₅ , CeO ₂ , and Y ₂ O ₃ ) It is preferable to include a second layer having an optical film thickness of 0.25λ or less and a third layer having an optical film thickness of 0.25λ or more made of silicon oxide (SiO ₂ , SiO, or a mixture thereof). it can.

Next, the manufacturing method of the plastic lens of this invention is demonstrated.
In the method for producing a plastic lens, first, a monomer mainly composed of a compound having two or more epithio groups in one molecule is cast polymerized to produce a plastic lens substrate. Then, a hard coat film forming process is performed in which a hard coat film forming coating solution is applied to the surface of the polymerized plastic lens base material and cured to form a hard coat film, and reflected on the formed hard coat film. The antireflection film forming step for forming the antireflection film is sequentially performed and completed.

  Prior to the hard coat film forming step, the polymerized plastic lens substrate can be pretreated as desired for the purpose of improving the adhesion with the hard coat film and cleaning. Examples of the pretreatment include chemical treatment with acid, alkali, organic solvent, etc., physical treatment with plasma or ultraviolet light, washing treatment with various cleaning agents, and primer treatment with various resins.

  In the hard coat film forming step, first, a coating liquid for forming a hard coat film is prepared. This coating liquid for forming a hard coat film is represented by the above-mentioned general formula (II) in a predetermined organic solvent and composite oxide fine particles (a component) mainly composed of titanium dioxide having a rutile-type crystal structure. An organic silicon compound (component B) and a hydrolyzate thereof are added at a predetermined ratio, and various additional components are added as necessary.

  Then, this hard coat film forming coating solution is applied to the surface of the surface-treated plastic lens substrate so that the thickness after curing becomes a predetermined value. As the coating method, for example, a dipping method, a spin coating method, a spray method, or the like can be used. From the viewpoint of surface accuracy, the dipping method and the spin coating method are preferable.

Then, the plastic lens substrate coated with the hard coat film forming coating solution is cured by hot air drying or irradiation with active energy rays. In the case of curing by hot air drying, it is preferably performed in hot air at 50 to 200 ° C. In particular, it is more preferably carried out in hot air at 70 to 130 ° C. In the case of active energy ray irradiation, far infrared rays or the like can be used as the active energy ray. When active energy ray irradiation is used, damage caused by heat can be kept low.
In this way, a hard coat film is formed on the surface of the plastic lens substrate.

Next, the plastic lens substrate on which the hard coat film is formed in the hard coat film forming process moves to the antireflection film forming process.
In the antireflection film forming step, a multilayer antireflection layer comprising an inorganic oxide film, preferably a surface reinforcing layer and a multilayer antireflection layer, is formed on the hard coat film formed in the hard coat film forming step. An antireflection film is formed by sequentially forming the layers by vapor deposition.

  In the case of providing a surface enhancement layer and a multilayer antireflection layer on the formed hard coat film, for example, a first layer having an optical film thickness of 0.25λ or less made of at least silicon oxide in order on the hard coat film, A second layer having an optical film thickness of 0.25λ or less made of at least one selected from zirconium oxide, tantalum oxide, aluminum oxide, titanium oxide, cerium oxide, and yttrium oxide, and an optical film thickness of 0.25λ or more made of silicon oxide A surface enhancement layer made of the third layer is formed by vapor deposition or the like. Then, the multilayer antireflection layer described above is sequentially formed on the formed surface enhancement layer by vapor deposition or the like. As a vapor deposition method, a vacuum vapor deposition method, a sputtering method, a physical vapor deposition method (PVD method) such as an ion plating method, a chemical vapor deposition method (CVD method), or the like can be employed.

  Examples and comparative examples based on this embodiment will be described below.

Example 1
(1) Production of plastic lens substrate After preparing about 500 g of bis (2,3-epithiopropyl) disulfide as a compound having two or more episulfide groups in one molecule and cooling it to −15 ° C., A 0.5 μm membrane capsule cartridge filter made of polytetrafluoroethylene (hereinafter referred to as PTFE) (manufactured by Advantech, model number: CCF-050-C1B) was put into a pressurized tank, and the nitrogen pressure was about 2.5 kgf / Pressurization and filtration were performed at a pressure of about cm ² .
4,8or4,7or5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithia was added to 90.0 g of this pressurized and filtered bis (2,3-epithiopropyl) disulfide. Add 10.0 g of undecane, 0.02 g of N, N-dimethylcyclohexylamine, 0.10 g of N, N-dicyclohexylmethylamine and 0.25 g of 2 (2'-hydroxy-5'-t-octylphenyl) benzotriazole The raw material mixture was prepared in a room temperature environment.

  Then, the prepared raw material mixture was poured into a glass mold for a plastic lens set to a center thickness of 1.2 mm, and the temperature was raised from 30 ° C. to 120 ° C. over 24 hours in an air polymerization furnace to be polymerized and cured. . Thereafter, the plastic lens was released from the glass mold, and was annealed by heating at 130 ° C. for 2 hours to obtain a plastic lens substrate. The obtained plastic lens substrate had a refractive index (nd) = 1.74 and an Abbe number of 33.

(2) Formation of hard coat film First, a coating liquid for forming a hard coat film is prepared. In a stainless steel container, 1045 parts by weight of γ-glycidoxypropyltrimethoxysilane as the component B and 200 parts by weight of γ-glycidoxypropylmethyldiethoxysilane as the component B are added, and the mixture is stirred while stirring. A silane hydrolyzate was obtained by adding 299 parts by weight of 01 mol / liter hydrochloric acid and continuing stirring all day and night.

  In another container, a composite fine particle sol mainly composed of titanium oxide, tin oxide, and silicon oxide as a component (methanol dispersion, total solid content 20% by weight, manufactured by Catalyst Kasei Kogyo Co., Ltd., OPTRAKE 1120Z 8RU- 25.A17) 4000 parts by weight and 830 parts by weight of isopropanol were added and mixed by stirring. Further, a silicone surfactant as a surface smoothing agent (manufactured by Nihon Unicar Co., Ltd., L-7001), 4 parts by weight, and a curing agent. 100 parts by weight of aluminum acetylacetonate was added and stirring was continued for a whole day and night. And after stirring all day and night, it combined with the silane hydrolyzate prepared previously, and also stirred all day and night. Thereafter, filtration was performed with a 3 μm filter to obtain a coating liquid A for forming a hard coat film.

Next, a hard coat film was formed on the plastic lens substrate obtained in (1) above.
In the formation of the hard coat film, first, an alkali treatment was performed on the plastic lens substrate. In the alkali treatment, neutralization was performed by immersing in a 2.0 N aqueous potassium hydroxide solution maintained at 50 ° C. for 5 minutes and then immersed in 0.5 N sulfuric acid maintained at 25 ° C. for 1 minute. Then, after the alkali treatment, pure water was washed, dried and allowed to cool. Then, after dipping in the prepared coating liquid A for forming a hard coat film for 20 seconds, it is pulled out from the liquid at a pulling rate of 20 cm / min, and further heated in an oven set at 120 ° C. for 2 hours to form a hard coat film. And obtained a plastic lens.
The formed hard coat film contains composite oxide fine particles (component B) having a rutile type crystal structure made of titanium oxide, tin oxide, and silicon oxide, and an organosilicon compound (component B).

(3) Formation of antireflection film An antireflection film was formed on the plastic lens having the hard coat film obtained in (2) above. In the formation of the antireflection film, first, a plastic lens having a hard coat film formed thereon is put into a vapor deposition apparatus, heated to 85 ° C. while being evacuated, and subjected to ion gun treatment (carrier gas: oxygen, voltage: 400 eV, treatment time: 30 seconds). Then, after evacuation to a vacuum degree of 5.0 × 10 ⁻⁵ mbar, a deposition material was deposited by an electron beam heating method, and from the hard coat film side, SiO ₂ (30 nm) / TiO ₂ (21 nm) / SiO _{2 An} antireflection film composed of 7 layers of ₂ (34 nm) / TiO ₂ (53 nm) / SiO ₂ (20 nm) / TiO ₂ (35 nm) / SiO ₂ (94 nm) was formed. Thereby, a plastic lens provided with a hard coat film and an antireflection film was produced.

(Example 2)
(1) Production of Plastic Lens Base Material A plastic lens base material having a refractive index (nd) = 1.74 and an Abbe number of 33 was obtained in the same manner as in Example 1.

(2) Formation of primer film and hard coat film First, a coating solution for forming a primer film is prepared. Add 3700 parts by weight of methyl alcohol, 250 parts by weight of water, and 1000 parts by weight of propylene glycol monomethyl ether in a stainless steel container, and after stirring well, composite fine particle sol (methanol containing mainly titanium oxide, tin oxide and silicon oxide) 2800 parts by weight of dispersion, total solid content 20% by weight, manufactured by Catalyst Kasei Kogyo Co., Ltd., OPTRAICK 1120Z 8RU-25 / A17), and mixed by stirring. Further, 2200 parts by weight of a polyester resin was added and mixed by stirring. 2 parts by weight of a system surfactant (manufactured by Nippon Unicar Co., Ltd., L-7604) was added and stirring was continued for a whole day and night, followed by filtration with a 3 μm filter to obtain a primer film forming coating solution B.

  Next, 1300 parts by weight of butyl cellosolve and 800 parts by weight of γ-glycidoxypropyltrimethoxysilane were put into a stainless steel container and stirred and mixed. Then, 220 parts by weight of 0.01 mol / liter hydrochloric acid was added while stirring. Then, stirring was continued for a whole day and night to obtain a silane hydrolyzate.

  In this silane hydrolyzate, composite fine particle sol mainly composed of titanium oxide, tin oxide and silicon oxide as a component (methanol dispersion, total solid content 20% by weight, manufactured by Catalyst Kasei Kogyo Co., Ltd., OPTRAIK 1120Z 8RU-25 · A17) 7000 parts by weight, stirred and mixed, 500 parts by weight of epoxy compound (manufactured by Nagase Kasei Kogyo Co., Ltd., EX-313), and a silicone surfactant as a surface smoothing agent (this Unicar) Co., Ltd., L-7001) 30 parts by weight and iron (III) acetylacetonate 20 parts by weight as a curing agent were added and stirred for one day. Thereafter, the mixture was filtered through a 3 μm filter to obtain a coating liquid C for forming a hard coat film.

Next, a primer film and a hard coat film were formed on the plastic lens substrate obtained in (1) above.
In forming the primer film and the hard coat film, the plastic lens substrate was first subjected to alkali treatment. In the alkali treatment, neutralization was performed by immersing in a 2.0 N aqueous potassium hydroxide solution maintained at 50 ° C. for 5 minutes, and then immersed in 0.5 N sulfuric acid maintained at 25 ° C. for 1 minute. And pure water washing | cleaning, drying, and standing to cool were performed. Then, after being immersed in the primer film forming coating solution B for 20 seconds, it was pulled up from the solution at a pulling rate of 30 cm / min and baked at 80 ° C. for 30 minutes. Subsequently, after being immersed in the coating liquid C for forming a hard coat film for 20 seconds, it was lifted from the liquid at a pulling rate of 30 cm / min and baked at 80 ° C. for 30 minutes. And it heated in the oven set to 120 degreeC for 2 hours, the primer film | membrane and the hard-coat film | membrane were formed, and the plastic lens was obtained.
The formed hard coat film contains composite oxide fine particles (component B) having a rutile type crystal structure made of titanium oxide, tin oxide, and silicon oxide, and an organosilicon compound (component B).

(3) Formation of antireflection film An antireflection film was formed on the plastic lens having the hard coat film obtained in (2) above. The antireflection film was formed under the same conditions and procedure as in Example 1.
Thereby, a plastic lens provided with a hard coat film and an antireflection film was produced.

(Example 3)
(1) Production of plastic lens base material By the same operation as in Example 1, a plastic lens base material having a refractive index (nd) = 1.74 and an Abbe number of 33 was obtained.
(2) Formation of primer film and hard coat film By the same operation as in Example 2, a primer film and a hard coat film were formed on a plastic lens substrate.
(3) Formation of Antireflection Film An antireflection film having the same layer structure as that of Example 1 was formed on the plastic lens having the hard coat film obtained in (2) above. The antireflection film was formed under the same conditions and procedures as in Example 1 except that the evacuation was continued until the degree of vacuum was 2.0 × 10 ⁻⁵ mbar.

Example 4
The same conditions and procedures as in Example 3 were followed, except that evacuation was continued to a vacuum degree of 9.0 × 10 ⁻⁶ mbar.
(Example 5)
The same conditions and procedures as in Example 3 were followed, except that the evacuation was continued until the degree of vacuum was 4.0 × 10 ⁻⁶ mbar.
(Example 6)
The same conditions and procedures as in Example 1 were performed except that an antireflection film composed of a single layer of SiO ₂ (30 nm) was formed.

(Comparative Example 1)
Instead of the composite fine particle sol mainly composed of titanium oxide, tin oxide, and silicon oxide as the component B in the coating liquid A for forming the hard coat film used in Example 1, the main component is titanium oxide, zirconium oxide, and silicon oxide. The coating liquid D for forming a hard coat film is prepared using an anatase type crystal structure composite fine particle sol (methanol dispersion, total solid content 20% by weight, manufactured by Catalyst Kasei Kogyo Co., Ltd .; Prepared. The compounds other than the composite fine particle sol, the preparation conditions, and the preparation procedure were all the same as in Example 1.
Then, a hard coat film and an antireflection film were provided under the same conditions and procedures as in Example 1 except that the hard coat film forming coating liquid D was used instead of the hard coat film forming coating liquid A. A plastic lens was produced.

(Comparative Example 2)
In Example 1, except that the degree of vacuum in the vapor deposition apparatus when forming the antireflection film was 1.0 × 10 ⁻⁴ mbar, the hard coat film and the antireflection film were all subjected to the same conditions and procedures as in Example 1. A plastic lens provided with was manufactured.

(Comparative Example 3)
In Example 2, the same conditions as in Example 2 except that the hard coat film was formed using the hard coat film forming coating liquid D prepared in Comparative Example 1 instead of the hard coat film forming coating liquid C. The plastic lens provided with the primer film, the hard coat film, and the antireflection film was prepared by the above and procedures.

  The plastic lenses obtained in the above Examples and Comparative Examples were evaluated by the evaluation methods shown below. The results are shown in Table 1. Evaluation items were evaluated by 8 items of appearance, refractive index, scratch resistance, adhesion, moisture resistance, warm water resistance, light resistance, and alkali resistance. Hereinafter, an evaluation method for each evaluation item will be described.

(1) Appearance (1-1) Interference fringes: A plastic lens was held over a three-wavelength fluorescent lamp, and the state of occurrence of interference fringes on the lens surface was visually evaluated by the following ○ and ×.
○: No interference fringes.
X: Interference fringes clearly understood.
(1-2) Cracks: After applying a hard coat film or an antireflection film, the state of occurrence of cracks was evaluated by the following ○ and ×.
○: No crack occurred.
X: A crack occurred.
(1-3) Transparency: Under a fluorescent lamp in a dark room, the degree of transparency was evaluated visually by the following ○ and ×.
○: Good transparency.
X: The transparency is not good.

(2) Refractive index: The spectral reflectance of the hard coat film was measured with a spectrophotometer, and the refractive index was calculated from the obtained value. Based on the value of the refractive index (nd) obtained by the calculation, the evaluation was performed by the following ◯ and ×.
○: Refractive index of 1.67 or more.
X: Refractive index less than 1.67.
(3) Scratch resistance test: after 10 reciprocations of 3-4 cm distance on the surface of the plastic lens with a load of 1 kg using steel wool # 0000 Evaluation was made in five stages.
A: There is no scratch.
B: 1 to 5 scratches are confirmed.
C: 6-20 scratches are confirmed.
D: There are 21 or more scratches but it does not appear cloudy.
E: A state in which there are many scratches and it is almost cloudy.

(4) Adhesion test: The surface of the plastic lens was cross-cut with 100 meshes at intervals of about 1 mm, and an adhesive tape (manufactured by Nichiban Co., Ltd., cello tape (registered trademark)) was firmly attached to the cross-cut portion. Thereafter, the adhesive tape was rapidly peeled off from the surface of the plastic lens, and the peeled state of the film was evaluated by the following ○ and ×.
○: No film peeling at all on the base after the adhesive tape was peeled off.
X: The film peeled off on the base after the adhesive tape was peeled off.

  (5) Moisture resistance test: After placing a plastic lens in a constant temperature and humidity furnace (setting value: 60 ° C., 98 RH%) for 10 days, the lens is taken out and stored indoors, and an adhesion test is performed after one day. , ○, × evaluated (see (4) Adhesion test).

(6) Warm water resistance test: After being immersed in a 90 ° C. hot water bath for 1 hour, an adhesion test was performed and evaluated by ○ and × (see (4) Adhesion test).
(7) Light resistance test: After irradiation for 200 hours using a xenon long life weather meter (manufactured by Suga Test Instruments Co., Ltd.), color change by visual inspection and adhesion test were conducted. (For the adhesion test evaluation, see (4) Adhesion test).
○: The color tone hardly changed.
Δ: Some yellowing is observed.
X: Remarkably yellowing is observed.

(8) Alkali resistance: The plastic lens was immersed for 30 minutes in a 10% by weight sodium hydroxide aqueous solution at 20 ° C., and the peeled state of the film was evaluated by the following ○ and ×.
○: No film peeling.
X: The film was peeled off.

表１の結果より、耐光性試験において、実施例１〜５は黄変が見られず、かつ密着性も良好であるのに対して、比較例１〜３は黄変が見られると共に、比較例１，３においては、膜剥がれが発生した。
このことから、ハードコート膜がルチル型の結晶構造を有する二酸化チタンを主成分とする複合酸化物微粒子および有機ケイ素化合物を主成分として含有することにより、黄変する色調変化を防止すると共に、良好な密着性を得ることができる。

From the results of Table 1, in the light resistance test, Examples 1 to 5 show no yellowing and good adhesion, while Comparative Examples 1 to 3 show yellowing and are compared. In Examples 1 and 3, film peeling occurred.
As a result, the hard coat film contains a composite oxide fine particle mainly composed of titanium dioxide having a rutile-type crystal structure and an organic silicon compound as a main component, thereby preventing a change in yellowing color tone and being good. Good adhesion can be obtained.

On the other hand, when the hard coat film contains composite fine particles having an anatase type crystal structure mainly composed of titanium oxide, zirconium oxide, and silicon oxide, yellowing is observed (Comparative Examples 1 to 3) and film peeling occurs. (Comparative Examples 1 and 3).
In particular, in Comparative Example 3, yellowing and film peeling occur despite the formation of a primer film having a rutile crystal structure. In Comparative Example 2, the degree of vacuum at the time of film formation of the antireflection film formed on the hard coat film is a low vacuum environment lower than 5.0 × 10 ⁻⁵ mbar. The performance was extremely low, and film peeling occurred in the alkali resistance test.

In addition, as a plastic lens substrate, in Examples 1 and 2 and Comparative Examples 1 to 3, a monomer mainly containing a compound having two or more episulfide groups in one molecule, particularly bis (2,3-epi By comprising a thiopropyl) disulfide compound, it was excellent in appearance, refractive index and various durability (moisture resistance, water resistance), and in particular, a plastic lens having a refractive index of 1.74 and an Abbe number of 33 was obtained.

Claims (1)

On the surface of a plastic lens substrate obtained by casting polymerization of a monomer containing bis (2,3-epithiopropyl) disulfide as a main component,
  Composite oxide fine particles composed of a core particle composed of titanium dioxide and tin dioxide having a rutile crystal structure, and a coating layer composed of a mixed particle of zirconium dioxide and silicon oxide around the core particle, and organic A hard coat film forming step of applying a hard coat film forming coating solution containing a silicon compound as a main component and curing to form a hard coat film;
  At least one layer of SiO on the hard coat film ₂ An antireflection film forming step of forming a multilayer inorganic oxide film including a layer comprising:
Have
  In the antireflection film forming step, film formation is performed by vacuum vapor deposition, and the degree of vacuum at the time of film formation is 5.0 × 10. ^-5 more than mbar 4.0 × 10 ^-6 A method for producing a plastic lens, characterized by being mbar or less.