Resin composition, spectacle lens, and spectacles

Abstract

[Problem] To provide a resin composition suitable for a spectacle lens, and a spectacle lens and spectacles having excellent characteristics. [Solution] One aspect of the present invention provides a resin composition for a spectacle lens, the resin composition containing a styrene resin (A) containing a styrene monomer unit, a mold release agent (B), and an anthraquinone colorant (C), wherein the content of the anthraquinone colorant (C) is 0.1-1,000 ppb inclusive relative to 100 parts by mass of the styrene resin (A).

Description

Resin composition, eyeglass lenses, and eyeglasses

[0001] This invention relates to a resin composition, eyeglass lenses, and eyeglasses.

[0002] Traditionally, materials used for optical lenses have included highly transparent acrylic resins, diethylene glycol bisallyl carbonate resins, polystyrene, and polycarbonate. Of these resins, thermosetting resins, such as diethylene glycol bisallyl carbonate, are widely used in eyeglass lenses. However, thermosetting resins require a relatively long curing time, resulting in low productivity. Therefore, thermoplastic resins that can be injection molded are selected for eyeglass lenses due to their high productivity. Among such thermoplastic resins, polymethyl methacrylate, which has excellent transparency, is particularly suitable.

[0003] However, with the growing awareness of carbon neutrality, including climate change countermeasures, there is a demand for further reductions in energy consumption during molding and transportation. Therefore, the development of lighter and more moldable materials is necessary. To this end, copolymers incorporating styrene or acrylonitrile structures with good moldability have been proposed (see Patent Document 1). However, acrylonitrile is considered carcinogenic, and the health risks of residual acrylonitrile in the resin cannot be denied. Furthermore, conventional resins do not provide resins for eyeglass lenses that have high transparency (light transmittance) and excellent hue and moldability.

[0004] On the other hand, the frame material for eyeglass lenses mainly utilizes cellulose derivatives. However, when cellulose derivatives are heated alone, they melt and simultaneously discolor and decompose. To prevent this, plasticizers are often added to cellulose derivatives. From the standpoint of performance and economic considerations, phthalate ester plasticizers and the like are used as such plasticizers. However, if the plasticizer bleeds out from the frame during use and comes into contact with the lens, cracking may occur depending on the lens material. For example, although polymethyl methacrylate has high transparency, it has low resistance to plasticizers, and cracking due to plasticizers can occur. Therefore, research is currently underway to develop plasticizers that are less prone to bleeding out (see Patent Document 2).

[0005] Japanese Patent Publication No. 9-124739 Japanese Patent Publication No. 2000-212224

[0006] In view of the above circumstances, the present invention aims to provide, for example, a resin composition suitable for use in eyeglass lenses, eyeglass lenses having excellent properties, and eyeglasses.

[0007] According to one aspect of the present invention, a resin composition for eyeglass lenses is provided, comprising a styrene-based resin (A) containing styrene monomer units, a mold release agent (B), and an anthraquinone-based coloring agent (C), wherein the content of the anthraquinone-based coloring agent (C) is 0.1 ppb or more and 1000 ppb or less per 100 parts by mass of the styrene-based resin (A).

[0008] According to this embodiment, for example, a resin composition suitable for use in eyeglass lenses can be provided.

[0009] The following describes embodiments of the resin composition, spectacle lenses, and eyeglasses. The various features shown in the embodiments below can be combined with each other. <Resin Composition> A resin composition is preferred as the composition of this embodiment. The resin composition of this embodiment is a resin composition for spectacle lenses and contains a styrene-based resin (A), a mold release agent (B), and an anthraquinone-based coloring agent (C).

[0010] The following describes each component in turn. <<Styrene Resin (A)>> Styrene resin (A) contains styrene monomer units and optionally contains (meth)acrylic acid ester monomers. Such styrene resin (A) imparts high chemical resistance and excellent light transmittance (transparency) to the resin composition, and also has the function of lowering the specific gravity and raising the refractive index of the resin composition.

[0011] The content of styrene monomer units in the styrene resin (A) is preferably 5% by mass or more and 95% by mass or less, more preferably 15% by mass or more and 90% by mass or less, even more preferably 30% by mass or more and 85% by mass or less, and particularly preferably 50% by mass or more and 80% by mass or less. By setting the content of styrene monomer units within the above range, the specific gravity of the styrene resin (A) (and consequently the specific gravity of the resin composition) can be reduced. As a result, the molded articles obtained from such resin compositions can be made lighter. Furthermore, the rigidity, moldability, and chemical resistance of the resin composition can be improved.

[0012] When the styrene resin (A) contains a (meth)acrylic acid ester monomer, the content of the (meth)acrylic acid ester monomer is preferably 5% by mass or more and 95% by mass or less, more preferably 10% by mass or more and 75% by mass or less, even more preferably 15% by mass or more and 55% by mass or less, and particularly preferably 20% by mass or more and 35% by mass or less. By setting the content of the (meth)acrylic acid ester monomer within the above range, the light transmittance and hue of the styrene resin (A) can be sufficiently increased. Hereinafter, in this specification, the content (by mass) of X in Y is the proportion of X when the total Y is considered to be 100% by mass.

[0013] Styrene monomer units are units derived from styrene monomers. Examples of these styrene monomers include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, ethylstyrene, and p-t-butylstyrene. These styrene monomers may be used individually or in combination of two or more. The styrene monomer is preferably styrene.

[0014] (Meth)acrylic acid ester monomer units are units derived from (meth)acrylic acid ester monomers. Examples of these (meth)acrylic acid ester monomers include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, isoamyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and lauryl (meth)acrylate, as well as alkyl (meth)acrylates such as phenyl (meth)acrylate and benzyl (meth)acrylate. Examples include aryl esters of (meth)acrylates, cyclohexyl (meth)acrylate, 4-t-butylcyclohexyl (meth)acrylate, 2-norbornyl (meth)acrylate, isobornyl (meth)acrylate, adamantan-1-yl (meth)acrylate, 2-methyladamantan-2-yl (meth)acrylate, 2-ethyl-2-adamantyl (meth)acrylate, tricyclodecanyl (meth)acrylate, alicyclic alkyl (meth)acrylates, glycidyl (meth)acrylate, and dicyclopentanyl (meth)acrylate. These (meth)acrylate ester monomers may be used individually or in combination of two or more. The (meth)acrylate ester monomer is preferably an alkyl (meth)acrylate, and more preferably methyl methacrylate.

[0015] Furthermore, the styrene resin (A) may be a copolymer obtained by copolymerizing a styrene monomer with a monomer copolymerizable with a (meth)acrylic acid ester monomer. Examples of such copolymerizable monomers include (meth)acrylic acids such as acrylic acid and methacrylic acid, α,β-ethylene unsaturated carboxylic acids such as maleic anhydride and fumaric acid, and imides such as phenylmaleimide and cyclohexylmaleimide. These monomers may be used individually or in combination of two or more.

[0016] The weight-average molecular weight (Mw) of styrene resin (A) is 5 × 10 ４ 40 x 10 ４ It is preferable that it be approximately 10 x 10 ４ The above 35 x 10 ４ It is more preferable that the values ​​be within the following ranges. Furthermore, the ratio (Mw / Mn) of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) of the styrene resin (A) is preferably between 1 and 3.5, and more preferably between 1.5 and 3. By setting Mw and Mw / Mn within these ranges, it is possible to achieve both improved moldability of the resin composition and improved mechanical strength of the resulting molded article.

[0017] Furthermore, the weight-average molecular weight (Mw) is 5 × 10 ４ In the above case, the mechanical strength of the molded body is likely to be sufficient, 40 x 10 ４ The moldability of the resin composition is easily improved when the following conditions are met. Furthermore, when the ratio of weight-average molecular weight (Mw) to number-average molecular weight (Mn) (Mw / Mn) is 1 or greater, the moldability of the resin composition is easily improved, and when it is 3.5 or less, the mechanical strength of the molded article is easily improved. Herein, in this specification, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) are polystyrene equivalent values ​​measured by gel permeation chromatography (GPC).

[0018] Since such a styrenic resin (A) is a thermoplastic resin, a resin composition containing the same can be molded using a mold (for example, a metal mold). Therefore, after molding with the mold, it is preferable that a molded article obtained from the resin composition can be easily taken out from the mold (that is, can be separated) in order to prevent defects, breakage, and the like of the molded article. Accordingly, a release agent (B) is added (compounded) to the resin composition of the present embodiment.

[0019] <<Release Agent (B)>> The release agent (B) has a function of easily separating (releasing) a molded article obtained from the resin composition from the mold. Examples of the release agent (B) include aliphatic alcohols such as myristyl alcohol, cetyl alcohol, and stearyl alcohol; fatty acids such as lauric acid, myristic acid, palmitic acid, and stearic acid; fatty acid amides such as stearic acid amide, erucic acid amide, and ethylene bisstearic acid amide; and fatty acid glycerides such as lauric acid monoglyceride, palmitic acid monoglyceride, stearic acid monoglyceride, and behenic acid monoglyceride.

[0020] Among these, the release agent (B) preferably contains at least one selected from the group consisting of aliphatic alcohols and fatty acids. By using these release agents (B), the ease of taking out a molded article obtained from the resin composition from the mold (release property) can be further improved. The content of the release agent (B) is preferably about 200 ppm or more and 5000 ppm or less, more preferably about 300 ppm or more and 2500 ppm or less, still more preferably about 400 ppm or more and 2000 ppm or less, and particularly preferably about 500 ppm or more and 1500 ppm or less, relative to 100 parts by mass of the styrenic resin (A). In this case, sufficient release properties can be imparted to the molded article without reducing the processability of the resin composition.

[0021] <<Anthraquinone Colorant (C)>> The anthraquinone colorant (C) is a component called a so-called bluing agent, and has a function of adjusting the hue (particularly the YI value) of a molded article obtained from the resin composition. The anthraquinone colorant (C) is preferably a compound represented by the following general formula (1).

[0022] Here, in the general formula (1), R １ is a group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group, and an alkoxy group. R ２ to R ８ are each independently a group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group, an alkoxy group, a hydroxyl group, a halogen group, an amino group, a sulfo group, a carboxyl group, a cyano group, a nitro group, -COR ９ , -COOR ９ , -NR ９ R １０ , -NR ９ COR １０ , -NR ９ SO ２ R １０ , -CONR ９ R １０ , -SO ３ R ９ , -CONHSO ２ R ９ , -SO ２ NR ９ R １０ , and -SO ２ NHCOR ９ is a group selected from the group consisting of the foregoing. R ９ and R １０ are each independently a group selected from the group consisting of a hydrogen atom, an aliphatic carbon group, an aromatic group, and a heterocyclic group. When the structure contains -SO ３ H and / or -CO ２ H, these may form a salt such as a sodium salt or a potassium salt.

[0023] R １ to R ８Examples of the alkyl group having 1 to 10 carbon atoms in include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an isopropyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an isopentyl group, a neopentyl group, and a 2-ethylhexyl group. These alkyl groups may have a substituent such as a hydroxyl group, a halogen group, an amino group, a sulfo group, a carboxyl group, a cyano group, a nitro group, or a nitrile group. R １ to R ８ Examples of the cycloalkyl group having 3 to 10 carbon atoms in include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a tricyclodecyl group. These cycloalkyl groups may have a substituent such as a hydroxyl group, a halogen group, an amino group, a sulfo group, a carboxyl group, a cyano group, a nitro group, or a nitrile group.

[0024] R １ to R ８ Examples of the aryl group in include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a cumyl group, a xylyl group, a propylphenyl group, an n-butylphenyl group, and a 4-tert-butylphenyl group. These aryl groups may have a substituent such as a hydroxyl group, a halogen group, an amino group, a sulfo group, a carboxyl group, a cyano group, a nitro group, or a nitrile group. R １ to R ８ Examples of the alkoxy group in include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a tert-butoxy group, a phenoxy group, and a naphthoxy group. These alkoxy groups may have a substituent such as a hydroxyl group, a halogen group, an amino group, a sulfo group, a carboxyl group, a cyano group, a nitro group, or a nitrile group.

[0025] Specific examples of anthraquinone-based colorants (C) include the following. Note that the names listed below are color index names. Disperse Violet4, Disperse Violet8, Disperse Violet17, Disperse Violet26, Disperse Violet28, Disperse Violet31, Disperse Blue3, Disperse Blue14, Disperse Blue60, Disperse Blue72, Disperse Blue134, Disperse Blue181, Disperse Blue197, Solvent Violet11, Solvent Violet12, Solvent Violet13, Solvent Violet26, Solvent Violet31, Solvent Violet33, Solvent Violet34, Solvent Violet36, Solvent Violet37, Solvent Violet38, Solvent Violet48, Solvent Violet51, Solvent Violet59, Solvent Violet60, Solvent Blue11, Solvent Blue12, Solvent Blue13, Solvent Blue14, Solvent Blue16, Solvent Blue18, Solvent Blue35, Solvent Blue36, Solvent Blue45, Solvent Blue58, Solvent Blue59, Solvent Blue59:1, Solvent Blue63, Solvent Blue67, Solvent Blue68, Solvent Blue74, Solvent Blue76, Solvent Blue78, Solvent Blue79, Solvent Blue83, Solvent Blue90, Solvent Blue94, Solvent Blue95, Solvent Blue97, Solvent Blue98, Solvent Blue101, Solvent Blue102, Solvent Blue104, Solvent Blue105, Solvent Blue111, Solvent Blue112,Solvent Blue122, Solvent Blue128, Solvent Blue132, Solvent Blue136, Solvent Blue146, Acid Blue27, Acid Blue43, Acid Blue47, Acid Blue49, Acid Blue51, Acid Blue55, Acid Blue145, Mordant Blue23, Mordant Blue27, Disperse Green6:1, Solvent Green3, Solvent Green20, Solvent Green28, Solvent Green33, Acid Green25. ,

[0026] The content of the anthraquinone-based colorant (C) is preferably about 0.1 ppb to 1000 ppb, more preferably about 1 ppb to 500 ppb, even more preferably about 5 ppb to 250 ppb, and particularly preferably about 10 ppb to 200 ppb, per 100 parts by mass of the styrene resin (A). In this case, the molded article obtained from the resin composition can be given sufficient optical properties while suppressing variations in hue and a decrease in brightness.

[0027] <<Other Components>> The content of t-butylcatechol (TBC) in the resin composition is preferably about 10 ppm or less, and more preferably about 5 ppm or less. The lower limit of this content is not particularly limited, but is usually about 0.1 ppm. Therefore, the content of t-butylcatechol in the resin composition can be, for example, 0.1 ppm or more and 10 ppm or less. From such a resin composition, a molded article (especially an eyeglass lens) with excellent hue and light transmittance can be obtained.

[0028] The content of 6-tert-butyl-2,4-xylenol (TBX) in the resin composition is preferably about 10 ppm or less, and more preferably about 5 ppm or less. The lower limit of this content is not particularly limited, but is usually about 0.1 ppm. Therefore, the content of 6-tert-butyl-2,4-xylenol in the resin composition can be, for example, 0.1 ppm or more and 10 ppm or less. From such a resin composition, a molded article (especially an eyeglass lens) with excellent hue and light transmittance can be obtained.

[0029] The resin composition of this embodiment may contain antioxidants such as phosphorus-based antioxidants, phenol-based antioxidants, sulfur-based antioxidants, and lactone-based antioxidants, as well as ultraviolet absorbers, heat stabilizers, weathering agents, light stabilizers, fluorescent whitening agents, processing stabilizers, antistatic agents, hydrophilic additives, liquid paraffin (mineral oil), polyethylene wax, microcrystalline wax, etc., to the extent that the above effects are not impaired. Furthermore, the resin composition of this embodiment may be in any shape, such as pellets, granules, powder, or lumps.

[0030] Eyeglass lenses made from the resin composition of this embodiment can be used as is, but they can also be fitted with a scratch-resistant hard coat layer, an impact-resistant hard coat layer, an anti-fog hard coat layer, etc. These hard coat layers can be applied using any known primer composition and hard coat composition and by known methods. Examples of primer compositions include compositions containing polyurethane resin compounds, polyester resin compounds, and compositions obtained by adding a high refractive index sol containing metal oxide fine particles to these compounds. Examples of hard coat compositions include compositions obtained by adding an organosilicon compound and / or a high refractive index sol containing metal oxide fine particles, and compositions mainly composed of a curing agent.

[0031] Furthermore, the hard coat layer can be formed on the surface of the spectacle lens by applying and drying it using methods such as dip coating, spin coating, or spray coating. The hard coat composition may also contain various additives as needed, such as solvents, antioxidants, light- and heat-resistant stabilizers, UV absorbers, oil-soluble dyes, disperse dyes, pigments, fluorescent whitening agents, photochromic compounds, leveling agents, disperse stabilizers, defoamers, thickeners, antistatic agents, and conductive materials.

[0032] <Physical Properties of Resin Composition> <<Melt Mass Flow Rate (MFR)>> The MFR of the resin composition, measured under test conditions of a temperature of 200°C and a load of 49N, is preferably between 0.5 g / 10 min and 10 g / 10 min, and more preferably between 1 g / 10 min and 5 g / 10 min. Resin compositions having an MFR in this range have high molding stability, and the molded articles obtained therefrom have sufficient mechanical strength. In this specification, the MFR can be measured in accordance with JIS K 7210:1999 (ISO 1133:1997).

[0033] <<Vicat Softening Temperature>> The Vicat softening temperature, measured under test conditions of a heating rate of 50°C / hr and a load of 50N for the resin composition, is preferably between 90°C and 110°C, and more preferably between 95°C and 105°C. Molded articles obtained from resin compositions having a Vicat softening temperature within this range can exhibit sufficient heat resistance, and thus deformation can be prevented or suppressed regardless of the usage environment. In this specification, the Vicat softening temperature can be measured in accordance with JIS K 7206:2016 (ISO 306:2013).

[0034] <<Average Transmittance>> A molded body with a length of 115 mm, manufactured by injection molding under molding conditions of a cylinder temperature of 200°C and a mold temperature of 60°C, preferably has an average transmittance of 80% or more, more preferably 82% or more, and even more preferably 84% or more. A molded body having such an average transmittance can be judged to have excellent light transmittance (transparency).

[0035] <<YI Value (Yellow Index)>> A molded body produced by injection molding preferably has a YI value of approximately -10 to 10 at an optical path length of 115 mm, more preferably -5 to 5, and even more preferably -2.5 to 2.5. A molded body having such a YI value can be judged to have an appropriate color tone (chromaticity).

[0036] <<Release Resistance>> A box-shaped molded body manufactured by injection molding preferably has a release resistance of approximately 1500 N or less, more preferably approximately 1300 N or less, even more preferably approximately 1100 N or less, and particularly preferably approximately 900 N or less. The lower limit of the release resistance is not particularly limited, but is usually around 500 N. Therefore, the release resistance can be, for example, between 500 N and 1500 N. A molded body having such a release resistance can be judged to have excellent release properties.

[0037] <<Chemical Resistance>> In the evaluation of the chemical resistance of a resin composition using a phthalate ester plasticizer, the critical strain ε is preferably about 0.3% or more, more preferably about 0.4% or more, even more preferably about 0.5% or more, and particularly preferably about 0.6% or more. The upper limit of the critical strain ε is not particularly limited, but is usually about 1.2%. Therefore, the critical strain ε can be, for example, about 0.3% to 1.2%. A resin composition having such a critical strain ε can be judged to have excellent chemical resistance. In this embodiment, among phthalate ester plasticizers, dioctyl phthalate (DOP) is preferably used. By using a phthalate ester plasticizer (especially dioctyl phthalate), the chemical resistance of the resin composition can be evaluated more appropriately.

[0038] <<Refractive Index>> The refractive index of the resin composition is preferably about 1.5 or higher, more preferably about 1.52 or higher, even more preferably about 1.54 or higher, and particularly preferably about 1.56 or higher. The upper limit of the refractive index is not particularly limited, but is usually about 1.6. Therefore, the refractive index can be, for example, between 1.5 and 1.6. Resin compositions having such a refractive index are particularly suitable for use in manufacturing eyeglass lenses. In this specification, the refractive index can be measured in accordance with JIS K 7142:2014.

[0039] <<Abbe Number>> The Abbe number of the resin composition is preferably around 30 or higher, more preferably around 32 or higher, even more preferably around 34 or higher, and particularly preferably around 36 or higher. The upper limit of the Abbe number is not particularly limited, but is usually around 45. Therefore, the Abbe number can be, for example, between 30 and 45. Resin compositions having such an Abbe number are particularly suitable for use in manufacturing eyeglass lenses. In this specification, the Abbe number can be measured in accordance with JIS K 7142:2014.

[0040] <<Density>> The density of the resin composition is 1.19 g / cm³.３ Preferably, it should be around 1.17 g / cm³. ３ It is more preferable that the following is the case: 1.15 g / cm³ ３ It is even more preferable that the following is the case: 1.09 g / cm³ ３ The following is particularly preferable. The lower limit of density is not particularly limited, but is usually 1.05 g / cm³. ３ It is approximately 1.05 g / cm³. Therefore, the density is, for example, 1.05 g / cm³. ３ 1.19g / cm or more ３ The density can be as follows. By using a resin composition having such density, the resulting molded article can be made lighter. In this specification, density can be measured in accordance with JIS K 7112-1:2023.

[0041] <Method for producing the resin composition> For polymerization of the styrene-based resin (A), for example, bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, etc., can be used. From the viewpoint of quality and productivity, bulk polymerization and solution polymerization are preferred methods for polymerization of the styrene-based resin (A), and continuous polymerization is also preferred. For example, alkylbenzenes such as benzene, toluene, ethylbenzene, and xylene, ketones such as acetone and methyl ethyl ketone, aliphatic hydrocarbons such as hexane and cyclohexane can be used as solvents.

[0042] During the polymerization of styrene-based resin (A), polymerization initiators, chain transfer agents, crosslinking agents, or other polymerization aids may be used as needed. As polymerization initiators, radical polymerization initiators are preferred, such as peroxyketals like 1,1-di(t-butylperoxy)cyclohexane, 2,2-di(t-butylperoxy)butane, 2,2-di(4,4-di-t-butylperoxycyclohexyl)propane, and 1,1-di(t-amylperoxy)cyclohexane; hydroperoxides like cumene hydroperoxide and t-butyl hydroperoxide; alkyl peroxides like t-amylperoxyisononanoate; t-butylcumyl peroxide, di-t-butyl peroxide, dicumyl peroxide, and di-t-hexyl peroxide. Examples include dialkyl peroxides such as t-butyl peroxyacetate, t-butyl peroxybenzoate, and t-butyl peroxyisopropyl monocarbonate, peroxycarbonates such as t-butyl peroxyisopropyl carbonate and polyethertetrakis(t-butyl peroxycarbonate), and azobisnitriles such as N,N'-azobis(cyclohexane-1-carbonilate), N,N'-azobis(2-methylbutyronitrile), N,N'-azobis(2,4-dimethylvaleronitrile), and N,N'-azobis[2-(hydroxymethyl)propionitrile]. These polymerization initiators may be used individually or in combination of two or more. The polymerization initiator content is preferably about 5,000 ppm or less, more preferably about 1,000 ppm or less, even more preferably about 500 ppm or less, and particularly preferably about 300 ppm or less, at the concentration added to the raw material solution (concentration based on mass relative to the total monomer) as described later. The polymerization initiator content is preferably about 0 ppm or more, more preferably about 10 ppm or more, even more preferably about 50 ppm or more, and particularly preferably about 80 ppm or more, at the concentration added to the raw material solution (concentration based on mass relative to the total monomer) as described later.

[0043] Examples of chain transfer agents include aliphatic mercaptans such as n-dodecyl mercaptan and tert-dodecyl mercaptan, aromatic mercaptans, thiocarboxylic acids such as thioglycolic acid and mercaptopropionic acid, polyfunctional mercaptans in which the hydroxyl group of polyhydric alcohols such as ethylene glycol, tetraethylene glycol, neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol, tripentaerythritol, and sorbitol is esterified with thioglycolic acid or mercaptopropionic acid, pentaphenylethane, α-methylstyrene dimer, and terpinolene. Among these, the chain transfer agent is preferably selected from the group consisting of aliphatic mercaptans, aromatic mercaptans, thiocarboxylic acids, and polyfunctional mercaptans because it allows for easy adjustment of the molecular weight of the styrene resin (A). The content of the chain transfer agent is preferably about 5000 ppm or less, more preferably about 2500 ppm or less, even more preferably about 1000 ppm or less, and particularly preferably about 600 ppm or less, at the concentration added to the raw material solution described later (concentration based on mass relative to the total monomer). The content of the chain transfer agent is preferably about 0 ppm or more, more preferably about 10 ppm or more, even more preferably about 50 ppm or more, and particularly preferably about 80 ppm or more, at the concentration added to the raw material solution described later (concentration based on mass relative to the total monomer).

[0044] When styrene-based resin (A) is manufactured (synthesized) by continuous polymerization, it can be produced through a polymerization process, a defoliation process, and a granulation process. First, in the polymerization process, the polymerization reaction is controlled by adjusting the polymerization temperature, etc., using a fully mixed stirring tank or a tower reactor, etc., to achieve the target molecular weight, molecular weight distribution, and reaction conversion rate. Next, the polymerization solution containing the polymer obtained in the polymerization process is transferred to the defoliation process, where unreacted monomers and polymerization solvents are removed. The defoliation process consists of a vacuum defoliation tank with a heater or a defoliation extruder with a vent. After that, the molten polymer obtained in the defoliation process is transferred to the granulation process. In the granulation process, the molten resin is extruded in strand form from a porous die and processed into pellet form by a cold cut method, air hot cut method, underwater hot cut method, etc.

[0045] The resin composition can be produced by mixing a styrene resin (A) with a release agent (B) and an anthraquinone colorant (C). The release agent (B) and the anthraquinone colorant (C) may be added to the raw material solution before polymerization of the styrene resin (A), or they may be mixed in an extruder or static mixing device installed after the production of the styrene resin (A) and before granulation. Alternatively, the pellets granulated from the styrene resin (A) may be dry-blended with the release agent (B) and the anthraquinone colorant (C) and then melt-kneaded. Alternatively, a pellet-shaped masterbatch may be prepared by melt-kneading the release agent (B) and the anthraquinone colorant (C) together with a small amount of styrene resin (A) beforehand, and this masterbatch may be further dry-blended with the styrene resin (A) and then melt-kneaded.

[0046] <Eyeglass Lens> The eyeglass lens of this embodiment is composed of the resin composition described above. This eyeglass lens has high chemical resistance and excellent light transmittance (transparency), and can be made thin. Such an eyeglass lens can be formed by various molding methods, but preferably by injection molding. That is, the eyeglass lens of this embodiment is preferably an injection-molded article of a resin composition. For this reason, the eyeglass lens has excellent productivity. It is also suitable for producing a wide variety of eyeglass lenses with different shapes. Furthermore, the eyeglass lens of this embodiment has excellent release properties.

[0047] <Eyeglasses> The eyeglasses of this embodiment have the above-mentioned eyeglass lenses and a frame that holds the eyeglass lenses. The frame may be made of any material, but it is preferably made of a resin material containing a plasticizer. By using a resin material containing a plasticizer, the processability of the frame can be improved and frames of various shapes can be easily manufactured. Furthermore, even if the plasticizer (for example, phthalate ester plasticizer, etc.) bleeds out from the frame, the eyeglass lenses have excellent chemical resistance, so damage such as cracking is unlikely to occur. Furthermore, the eyeglasses may be provided in the following embodiments.

[0048] (1) A resin composition for eyeglass lenses, comprising a styrene resin (A) containing styrene monomer units, a mold release agent (B), and an anthraquinone coloring agent (C), wherein the content of the anthraquinone coloring agent (C) is 0.1 ppb or more and 1000 ppb or less per 100 parts by mass of the styrene resin (A).

[0049] (2) The resin composition described in (1) above, wherein the mold release agent (B) comprises at least one selected from the group consisting of aliphatic alcohols and fatty acids.

[0050] (3) A resin composition according to (1) or (2) above, wherein the content of the mold release agent (B) is 200 ppm or more and 5000 ppm or less per 100 parts by mass of the styrene resin (A).

[0051] (4) A resin composition according to any one of (1) to (3) above, wherein the styrene resin (A) further comprises a (meth)acrylic acid ester monomer.

[0052] (5) The resin composition described in (4) above, wherein the content of the styrene monomer units in the styrene resin (A) is 5% by mass or more and 95% by mass or less, and the content of the (meth)acrylic acid ester monomer is 5% by mass or more and 95% by mass or less.

[0053] (6) A resin composition according to any one of (1) to (5) above, wherein the molded article produced by injection molding has a YI value of -10 or more and 10 or less at an optical path length of 115 mm.

[0054] (7) A resin composition according to any one of (1) to (6) above, wherein a box-shaped molded body produced by injection molding has a mold release resistance of 1500 N or less.

[0055] (8) A resin composition according to any one of (1) to (7) above, wherein the critical strain ε in the chemical resistance evaluation using a phthalate ester plasticizer is 0.3% or more.

[0056] (9) Eyeglass lens, comprising the resin composition described in any one of (1) to (8) above.

[0057] (10) In the eyeglass lens described in (9) above, the eyeglass lens is an injection-molded article of the resin composition.

[0058] (11) Eyeglasses having eyeglass lenses as described in (9) or (10) above and a frame for holding the eyeglass lenses.

[0059] (12) Eyeglasses as described in (11) above, wherein the frame is made of a resin material containing a plasticizer.

[0060] (13) A composition comprising a styrene resin (A) containing styrene monomer units, a mold release agent (B), and an anthraquinone coloring agent (C), wherein the content of the anthraquinone coloring agent (C) is 0.1 ppb or more and 1000 ppb or less per 100 parts by mass of the styrene resin (A). Of course, this is not limited to this.

[0061] Finally, while various embodiments of this disclosure have been described, these are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents. The composition of this embodiment can be suitably used not only for spectacle lenses, but also for various transparent molded articles and various optical components that require light transmittance, hue, chemical resistance, release properties, and moldability.

[0062] The resin compositions will be described in more detail below using the following examples and comparative examples, but these are not limited to the following examples.

[0063] 1. Preparation of raw materials 1-1. Monomers: Styrene: t-butylcatechol (TBC) concentration = 11 μg / g Methyl methacrylate (MMA): 6-tert-butyl-2,4-xylenol (TBX) concentration = 7 μg / g 1-2. Solvent: Ethylbenzene

[0064] 1-3. Polymerization initiator: t-butyl peroxyisopropyl monocarbonate [manufactured by NOF Corporation, "Perbutyl I"] 1-4. Chain transfer agent: n-dodecyl mercaptan [manufactured by Arkema Corporation] 1-5. Comparative resin: polymethyl methacrylate (PMMA) [manufactured by Mitsubishi Chemical Corporation, "Acrypet VH001"]

[0065] 1-6. Release Agents (B) ・Release agent (B-1): Fatty acid mixture (12 carbon atoms ≤ 1% by mass, 14 carbon atoms ≤ 2% by mass, 16 carbon atoms = 56-62% by mass, 18 carbon atoms = 37-42% by mass, 18 carbon atoms or more ≤ 1% by mass) [Manufactured by Emery Co., Ltd., "EDENOR ST05M MY"] ・Release agent (B-2): Stearic acid [Manufactured by Kao Corporation, "Lunaq S-90"] ・Release agent (B-3): Docosanol [Manufactured by Tokyo Chemical Industry Co., Ltd., "1-Docosanol"] ・Release agent (B-4): Ethylene bisstearyl amide [Manufactured by Kao Corporation, "Kaowax EB-P"] ・Release agent (B-5): Myristyl alcohol [Manufactured by Kao Corporation, "Calcol 4098"]

[0066] 1-7. Anthraquinone-based colorants (C) ・C. I. Solvent Violet 13 (SV13): 1-hydroxy-4-(4-methylphenylamino)anthracene-9,10-dione [manufactured by LANXESS, "Macrolex Violet B Gran"] ・C. I. Solvent Violet 33 (SV33) [manufactured by Mitsubishi Chemical Corporation, "Dia Resin Blue J"] ・C. I. Solvent Blue 45 (SB45): 3,3'-[(9,10-dihydro-9,10-dioxo-1,4-anthracene)diimino]bis[N-cyclohexyl-2,4,6-trimethylbenzenesulfonamide] [manufactured by EPSILON, "Transparent Blue S-RLS"]

[0067] 2. Production of Resin Composition (Example 1) A apparatus was constructed by connecting a first reactor, which is a fully mixed stirred tank, and a second reactor, which is a plug-flow type reactor with a static mixer, in series. A polymerization process was carried out using this apparatus to produce a styrene-based resin (A). The capacity of each reactor was 30 L for the first reactor and 12 L for the second reactor.

[0068] First, t-butyl peroxyisopropyl monocarbonate and n-dodecyl mercaptan were added at the inlet of the first reactor to a raw material solution containing 65% by mass of styrene, 25% by mass of methyl methacrylate, and 10% by mass of ethylbenzene. Subsequently, this raw material solution was continuously supplied at 8.0 kg / h to the first reactor, which was set to 135°C. The concentrations of t-butyl peroxyisopropyl monocarbonate and n-dodecyl mercaptan added to the raw material solution (concentration based on mass relative to the total monomer) were adjusted to 100 ppm and 150 ppm, respectively.

[0069] Next, the obtained polymerization solution was continuously supplied to the second reactor to complete the polymerization. The monomer polymerization rate at this time was 70%. In the second reactor, a temperature gradient was set along the direction of flow, with the temperature in the middle section at 135°C and the temperature at the outlet section at 145°C. Subsequently, the solution containing the polymer continuously extracted from the second reactor was introduced into a vacuum defloration tank with a preheater, consisting of two stages in series. The temperature of the preheater was adjusted so that the polymer temperature reached 240°C, and unreacted styrene, methyl methacrylate, and ethylbenzene were separated at a pressure of 1.0 kPa.

[0070] Subsequently, the obtained molten polymer was continuously supplied to an extruder, and 1000 ppm of release agent (B) and 107 ppb of anthraquinone-based coloring agent (SV13) were added to 100 parts by mass of polymer through the additive feed port. After mixing at a set temperature of 220°C, the mixture was extruded in strand form from a porous die, and the strands were cooled and cut using a cold-cut method to produce pellets.

[0071] (Examples 2-15 and Comparative Examples 1-6) Resin compositions were produced in the same manner as in Example 1, except that the composition of the raw material solution and polymerization conditions were changed as shown in Table 1, and the formulation of the release agent (B) and anthraquinone-based colorant (C) was changed as shown in Tables 2-5. In Example 15, adding 5500 ppm of the release agent (B-1) at once resulted in poor dispersibility and strand disorder. Therefore, first, 2750 ppm of the release agent (B-1) was added to obtain pellets, then another 2750 ppm of the release agent (B-1) was dry-blended, and finally, the mixture was kneaded again in a single-screw extruder (IKG Corporation, "MS-40") set to 220°C until the total amount of the release agent (B-1) reached 5500 ppm to obtain the resin composition.

[0072]

[0073] 3. Evaluation and Measurement 3-1. Measurement of Melt Mass Flow Rate (MFR) The MFR of each styrene resin (A) and each resin composition was measured in accordance with JIS K 7210:1999 under test conditions of a temperature of 200°C and a load of 49N. 3-2. Measurement of Vicat Softening Temperature The Vicat softening temperature of each styrene resin (A) and each resin composition was measured in accordance with JIS K 7206:2016 under test conditions of a heating rate of 50°C / hr and a load of 50N.

[0074] 3-3. Measurement of Average Molecular Weight The weight-average molecular weight (Mw), Z-average molecular weight (Mz), and number-average molecular weight (Mn) of each styrene resin (A) were measured by gel permeation chromatography (GPC) under the following conditions: GPC model: Showa Denko K.K. Shodex GPC-101 Column: Polymer Laboratories PLgel 10 μm MIXED-B Mobile phase: Tetrahydrofuran Sample concentration: 0.2 mass% Temperature: Oven 40°C, inlet 35°C, detector 35°C Detector: Differential refractometer The molecular weight was calculated by determining the molecular weight at each elution time from the elution curve of monodisperse polystyrene and then calculating the molecular weight in polystyrene equivalent.

[0075] 3-4. Measurement of Average Transmittance and YI Value First, pellets of each resin composition were used to produce molded bodies measuring 115 mm (length) x 80 mm (width) x 3 mm (thickness) using molds polished to a mirror finish at a cylinder temperature of 200°C and a mold temperature of 60°C. Next, using an ultraviolet-visible spectrophotometer [JASCO Corporation, "V-670"], incident light with dimensions of 20 mm x 1.6 mm and a divergence angle of 0° was directed onto the end face of the molded body, and the spectral transmittance in the wavelength range of 350 nm to 800 nm was measured with an optical path length of 115 mm. The YI value was then calculated in accordance with JIS K 7375:2008 under the condition of a 2° field of view with a C light source. The average transmittance was determined as the average value of the spectral transmittance in the wavelength range of 380 nm to 780 nm.

[0076] 3-5. Measurement of Mold Release Resistance First, a 100t injection molding machine [manufactured by Japan Steel Works, "J100E-P"] was prepared, equipped with a mold for mold release resistance (box-shaped molded product dimensions: 60 mm long, 130 mm wide, 45 mm deep, 2 mm thick) with load cells attached to the ejector pins. Next, each resin composition was continuously molded with the cylinder temperature set to 230°C and the mold temperature to 40°C, and the ejection force of the ejector pins when the molded body was released during mold opening was measured. The mold release resistance value was defined as the maximum mold release resistance value (N).

[0077] 3-6. Evaluation of Chemical Resistance First, molded bodies measuring 350 mm in length, 20 mm in width, and 2 mm in thickness were produced by press molding of each resin composition. Next, these molded bodies were placed and fixed along the curved surface of a Bergen-type quarter-ellipse jig, and the target chemical was uniformly applied. The bodies were then left for 48 hours at 23°C and 55% RH humidity. Dioctyl phthalate (DOP) [manufactured by Tokyo Chemical Industry Co., Ltd.] was used as the chemical. The occurrence of crazing and cracking in the molded bodies was then checked, and the critical strain ε (%) was calculated using the following formula and evaluated according to the following evaluation criteria.

[0078] [Here, in the above formula, a is the long axis of the jig (=250 mm), b is the short axis of the jig (=150 mm), t is the thickness of the molded body (=2 mm), and X is the distance (mm) along the length direction between the end of the crack closest to the upper edge of the curved surface and the upper edge of the curved surface.] [[Evaluation Criteria]] A: Critical strain ε was 0.6% or more. B: Critical strain ε was 0.3% or more and less than 0.6%. C: Critical strain ε was less than 0.3%.

[0079] 3-7. Measurement of refractive index and Abbe number For a molded body with a thickness of 3 mm, prepared in the same manner as in "3-4" above, the refractive index and Abbe number were measured in accordance with JIS K 7142:2014 using a multi-wavelength Abbe refractometer [ATAGO Corporation, "DR-M4"].

[0080] 3-8. Density Measurement A sample measuring 10 mm in length, 80 mm in width, and 3 mm in thickness was cut from each molded body prepared in the same manner as described in "3-4" above. The density of this sample was measured using the water displacement method in accordance with JIS K 7112-1:2023. These results are shown in Tables 2 to 6 below.

[0081]

[0082]

[0083]

[0084]

[0085]

Claims

1. A resin composition for eyeglass lenses, comprising a styrene-based resin (A) containing styrene monomer units, a mold release agent (B), and an anthraquinone-based coloring agent (C), wherein the content of the anthraquinone-based coloring agent (C) is 0.1 ppb or more and 1000 ppb or less per 100 parts by mass of the styrene-based resin (A).

2. The resin composition according to claim 1, wherein the mold release agent (B) comprises at least one selected from the group consisting of aliphatic alcohols and fatty acids.

3. The resin composition according to claim 1, wherein the content of the mold release agent (B) is 200 ppm or more and 5000 ppm or less per 100 parts by mass of the styrene resin (A).

4. The resin composition according to claim 1, wherein the styrene-based resin (A) further comprises a (meth)acrylic acid ester monomer.

5. The resin composition according to claim 4, wherein the content of the styrene monomer units in the styrene resin (A) is 5% by mass or more and 95% by mass or less, and the content of the (meth)acrylic acid ester monomer is 5% by mass or more and 95% by mass or less.

6. The resin composition according to claim 1, wherein the molded article produced by injection molding has a YI value of -10 or more and 10 or less at an optical path length of 115 mm.

7. The resin composition according to claim 1, wherein the box-shaped molded body produced by injection molding has a mold release resistance of 1500 N or less.

8. The resin composition according to claim 1, wherein the critical strain ε in the chemical resistance evaluation using a phthalate ester plasticizer is 0.3% or more.

9. Eyeglass lens, comprising the resin composition described in any one of claims 1 to 8.

10. An eyeglass lens according to claim 9, wherein the eyeglass lens is an injection-molded article of the resin composition.

11. Eyeglasses, comprising eyeglass lenses as described in claim 9 and a frame for holding the eyeglass lenses.

12. Eyeglasses according to claim 11, wherein the frame is made of a resin material containing a plasticizer.

13. A composition comprising a styrene resin (A) containing styrene monomer units, a mold release agent (B), and an anthraquinone coloring agent (C), wherein the content of the anthraquinone coloring agent (C) is 0.1 ppb or more and 1000 ppb or less per 100 parts by mass of the styrene resin (A).

Images