JP2010190919A - Optical lens and method of manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plastic lens manufactured from a plant-derived raw material and having high heat resistance, high transparency, a high Abbe number, high strength, high dyeability, and low birefringence. <P>SOLUTION: An optical lens such as a spectacle lens is obtained by injection molding using a material having a main component of polycarbonate resin which has a structure unit derived from a dihydroxy compound (isosorbide or the like) represented by formula (1) and which has reduced viscosity of 0.2 to 1.5 dl/g. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a plastic lens produced from a plant-derived raw material, having high transparency, high heat resistance, high Abbe number, high strength, high dyeability and low birefringence. Specifically, the present invention relates to an optical lens made of an aliphatic polycarbonate having a specific structure.

  Conventionally, inorganic glass has been the mainstream material for eyeglass lenses, but plastics now account for more than 80% of eyeglass lenses due to molding processability, light weight, and impact resistance. Thus, unlike inorganic glass lenses, plastic lenses are widely used as optical elements such as eyeglass lenses and camera lenses because they are lightweight and difficult to break.

  Examples of resins that are currently widely used as plastic lens materials include acrylic resins, diethylene glycol carbonate resins, and polycarbonates.

  Among these plastic materials, polydiethylene glycol bisallyl carbonate, typified by CR-39, is excellent in transparency and has heat resistance that can withstand various treatments.

  However, since this resin is a thermosetting resin, it requires 15 to 20 hours for casting polymerization in a glass mold and has the problem of poor productivity, and has low impact resistance and safety. This is also insufficient.

  On the other hand, in order to improve productivity, it is also attempted to make a spectacle lens by injection molding or injection compression molding with a thermoplastic resin, and spectacle lenses made of polymethyl methacrylate and spectacle lenses made of polycarbonate are commercially available.

  Of these, polymethylmethacrylate is a material with low distortion and excellent transparency, but it has poor heat resistance and is insufficient in terms of impact resistance.

  Polycarbonate resin (hereinafter abbreviated as PC) is a polymer in which bisphenol is linked by a carbonic acid ester. Among them, polycarbonate resin obtained from 2,2-bis (4-hydroxyphenyl) propane (commonly called bisphenol A) is transparent. It has excellent properties and mechanical properties such as impact resistance. For this reason, in the optical field such as various lenses and optical discs, their characteristics such as impact resistance, transparency and low water absorption are attracting attention and are used as optical materials.

  However, the PC derived from bisphenol A has a problem that blurring of an image or the like occurs due to low Abbe number and birefringence. In addition, eyeglass lens materials are strongly required to be easily dyeable by a simple dyeing method, but PC has a problem that dyeability is very poor in a general dyeing method using a disperse dye or the like. For this reason, when a spectacle lens is manufactured by a PC, it is necessary to go through complicated steps such as providing a coat layer on the lens with a dyeable hard coat material and dyeing the coat layer.

  In addition, these resins are generally manufactured using raw materials derived from petroleum resources. However, in recent years, there is a concern about the depletion of petroleum resources, and global warming due to increased accumulation of carbon dioxide emissions. Since there is a fear of causing fluctuations and the like, there is a demand for a plastic material made from plant-derived monomers that are carbon neutral even after disposal after use.

Examples of plastic materials made from plant-derived monomers include copolymer polycarbonates of heterocyclic diols such as isosorbide and bisphenol (Patent Document 1), and copolymer polycarbonates of isosorbide and aliphatic diols (Patent Document 2, Patent Documents). 3) Copolycarbonates of dihydroxy compounds having an undecane structure and isosorbide have been proposed (Patent Document 4).
However, satisfactory plastic lenses made of plant-derived materials having all of the high Abbe number, high strength, high dyeability, and low birefringence required for spectacle lenses have not yet been developed.

Japanese Patent Laid-Open No. 56-110723 JP 2003-292603 A International Publication No. WO2004 / 111106 Japanese Patent Laid-Open No. 2006-232897

  An object of the present invention is to solve the problems associated with the prior art, and is manufactured from plant-derived raw materials and has high heat resistance, high transparency, high Abbe number, high strength, and high dyeability. An object of the present invention is to provide a plastic lens having a low birefringence.

As a result of intensive studies, the present inventors have found the fact that an aliphatic polycarbonate having a specific structure can solve the above-mentioned problems brilliantly, and have completed the present invention.
That is, the present invention relates to the following optical lens.
1) It is made of a material for an optical lens containing a structural unit derived from a dihydroxy compound represented by the following formula (1) and having as a main component a polycarbonate resin having a reduced viscosity of 0.2 to 1.5 dl / g. Optical lens.

2) The optical lens according to (1), wherein the carbohydrate represented by the formula (1) is isosorbide.
3) The optical lens according to (1), wherein the carbohydrate represented by the formula (1) is isomannide.
4) The optical lens according to any one of (1) to (3), which is dyed with a disperse dye.
5) The optical lens according to any one of (1) to (4), which is a spectacle lens.

6) A method for producing an optical lens according to any one of (1) to (5), comprising the following step (a) and optionally (b): .
(A) An optical lens material comprising as a main component a polycarbonate resin containing a structural unit derived from a dihydroxy compound represented by the following formula (1) and having a reduced viscosity of 0.2 to 1.5 dl / g Injection molding step for molding by injection molding (b) Dyeing step for dyeing the injection molded body obtained in the injection molding step with a disperse dye in a medium

According to the present invention, an excellent optical lens having high heat resistance, high transparency, high Abbe number, high strength, and high dyeability and no optical distortion can be obtained. The optical lens of the present invention can be injection-molded and has high productivity, and is useful for lenses such as cameras, telescopes, binoculars, and particularly spectacle lenses.
The optical lens of the present invention is manufactured from a plant-derived raw material that has not existed until now, and is a carbon-neutral plastic material.

(1) Polycarbonate resin The optical lens of the present invention contains a structural unit derived from a dihydroxy compound represented by the following formula (1) (hereinafter referred to as “structural unit (1)”) and has a reduced viscosity of 0. An optical lens mainly composed of a polycarbonate resin of 2 to 1.5 dl / g (30 ° C., phenol: 1,1,2,2-tetrachloroethane = 1: 1 wt% in a mixed solution of 1.0 g / dl). It consists of materials for use.

  The dihydroxy compound represented by the above formula (1) is easily made from renewable resources such as sugars and starch, and three isomers are known. Specifically, the isomers include 1,4: 3,6-dianhydro-D-sorbitol (hereinafter referred to as “isosorbide”) represented by the following formula (2), and 1,4 represented by the following formula (3). : 3,6-dianhydro-D-mannitol (hereinafter referred to as “isomannide”), and 1,4: 3,6-dianhydro-L-iditol (hereinafter referred to as “isoidide”) represented by the following formula (4): It is.

  Isosorbide, isomannide, and isoidide are obtained from D-glucose, D-mannose, and L-idose, respectively. That is, it can be obtained by hydrogenating each corresponding sugar and then dehydrating using an acid catalyst.

  The polycarbonate resin used in the present invention has a reduced viscosity of 0.2 to 1.5 dl / g, preferably 0.4 to 1.0 dl / g. When the reduced viscosity is less than 0.20 gdl / g, the lens brittle fracture occurs, and when it exceeds 1.5 dl / g, the moldability is reduced and residual birefringence is exhibited, so that the range is limited to the above range. The reduced viscosity in the present invention is measured by using a Ubbelohde viscometer in a 1: 1 (weight ratio) mixed solution (concentration: 1.0 g / dl) of phenol and 1,1,2,2-tetrachloroethane as a solvent. It is a value measured at 30 ° C.

  In addition, it is preferable that the glass transition temperature (Tg) of the polycarbonate resin used for this invention is 145-160 degreeC. If the glass transition temperature is within this range, it has sufficient heat resistance to withstand the processing conditions as a spectacle lens and can be injection molded.

  In order to obtain the desired effect of the present invention, the polycarbonate resin used in the present invention is particularly preferably a homopolycarbonate resin consisting only of the structural unit (1) and containing no other structural unit. However, the polycarbonate resin used in the present invention may contain a small amount of other structural units other than the structural unit (1) as carbonate-forming units as long as the physical properties thereof are not impaired. In this case, the proportion of the structural unit (1) in the total structural units constituting the polycarbonate resin is usually 50 mol% or more, preferably 70 mol%, more preferably 80 mol% or more, and still more preferably 90 mol. % Or more.

When the other structural unit is contained, the other structural unit may contain one kind or two or more different kinds.
Thus, when the polycarbonate resin used in the present invention contains two or more types of carbonate-forming units, the copolymer structure may be any of random, block, and alternating copolymer structures.

  Examples of the structural unit other than the structural unit (1) used in the present invention include a structural unit derived from a dihydroxy compound other than the dihydroxy compound represented by the above formula (1). Examples of such dihydroxy compounds include various known aromatic dihydroxy compounds. Copolymerization with an aliphatic diol is not preferable because it causes a decrease in Tg and heat resistance.

Examples of the aromatic dihydroxy compound include bis (4-hydroxyphenyl) methane, 1,1-bis (4′-hydroxyphenyl) ethane, 1,2-bis (4′-hydroxyphenyl) ethane, and bis (4- Hydroxyphenyl) phenylmethane, bis (4-hydroxyphenyl) diphenylmethane, bis (4-hydroxyphenyl) -1-naphthylmethane, 1,1-bis (4′-hydroxyphenyl) -1-phenylethane, 2,2- Bis (4′-hydroxyphenyl) propane (abbreviation bisphenol A), 1,1-bis (4′-hydroxyphenyl) cyclopentane, 1,1-bis (4′-hydroxyphenyl) cyclohexane, 1,1-bis ( 3'-methyl-4'-hydroxyphenyl) cyclohexane,
4,4′-dihydroxydiphenyl ether 4,4′-dihydroxydiphenyl sulfide, 4,4′-dihydroxydiphenyl sulfone, bis (4-hydroxyphenyl) ketone, α, α′-bis (4-hydroxyphenyl) -1,4 -Diisopropylbenzene (abbreviated bisphenol P), 6,6'-dihydroxy-3,3,3 ', 3'-tetramethyl-1,1'-spirobiindane, 9,9-bis (4'-hydroxyphenyl) fluorene, Examples thereof include dihydroxy compounds such as 4,4′-dihydroxybiphenyl, hydroquinone and resorcin.

  The polycarbonate resin according to the present invention can be produced by a known melt polycondensation method in which a dihydroxy compound and a carbonic acid diester are reacted in the presence of a mixed catalyst comprising a basic compound catalyst, a transesterification catalyst, or both. Examples of the carbonic acid diester include diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, m-cresyl carbonate, and the like. Of these, diphenyl carbonate is particularly preferred. The carbonic acid diester is preferably used in a ratio of 0.97 to 1.20 mol, more preferably 0.98 to 1.10 mol, relative to a total of 1 mol of the dihydroxy compound.

  Examples of the basic compound catalyst include alkali metal compounds, alkaline earth metal compounds, and nitrogen-containing compounds.

  Examples of such compounds include organic acid salts such as alkali metal and alkaline earth metal compounds, inorganic salts, oxides, hydroxides, hydrides or alkoxides, quaternary ammonium hydroxides and salts thereof, amines, and the like. Are preferably used, and these compounds can be used alone or in combination.

  Specific examples of the alkali metal compound include sodium hydroxide, potassium hydroxide, cesium hydroxide, lithium hydroxide, sodium bicarbonate, sodium carbonate, potassium carbonate, cesium carbonate, lithium carbonate, sodium acetate, potassium acetate, acetic acid. Cesium, lithium acetate, sodium stearate, potassium stearate, cesium stearate, lithium stearate, sodium borohydride, sodium phenyl borohydride, sodium benzoate, potassium benzoate, cesium benzoate, lithium benzoate, hydrogen phosphate Disodium, dipotassium hydrogen phosphate, dilithium hydrogen phosphate, disodium phenyl phosphate, disodium salt of bisphenol A, 2 potassium salt, 2 cesium salt, 2 lithium salt, sodium salt of phenol, potassium salt Cesium salt, lithium salt or the like is used.

  Specific examples of the alkaline earth metal compound include magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, magnesium hydrogen carbonate, calcium hydrogen carbonate, strontium hydrogen carbonate, barium hydrogen carbonate, magnesium carbonate, calcium carbonate. Strontium carbonate, barium carbonate, magnesium acetate, calcium acetate, strontium acetate, barium acetate, magnesium stearate, calcium stearate, calcium benzoate, magnesium phenyl phosphate, and the like are used.

  Specific examples of nitrogen-containing compounds include alkyl, aryl, groups, etc. such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and trimethylbenzylammonium hydroxide. Secondary ammoniums such as quaternary ammonium hydroxides, triethylamine, dimethylbenzylamine and triphenylamine, secondary amines such as diethylamine and dibutylamine, primary amines such as propylamine and butylamine, 2-methylimidazole, 2 -Imidazoles such as phenylimidazole and benzimidazole, or ammonia, tetramethylammonium borohydride, tetrabutylammonium borohydride, Tetrabutylammonium tetraphenylborate, basic or basic salts such as tetraphenyl ammonium tetraphenylborate, or the like is used.

  As the transesterification catalyst, zinc, tin, zirconium and lead salts are preferably used, and these can be used alone or in combination.

  Specific examples of the transesterification catalyst include zinc acetate, zinc benzoate, zinc 2-ethylhexanoate, tin (II) chloride, tin (IV) chloride, tin (II) acetate, tin (IV) acetate, and dibutyltin. Dilaurate, dibutyltin oxide, dibutyltin dimethoxide, zirconium acetylacetonate, zirconium oxyacetate, zirconium tetrabutoxide, lead (II) acetate, lead (IV) acetate and the like are used.

  These catalysts are used in a ratio of 1 × 10 −9 to 1 × 10 −3 mol, preferably 1 × 10 −7 to 1 × 10 −4 mol, per 1 mol of the total of dihydroxy compounds. .

  The melt polycondensation method according to the present invention is a method in which melt polycondensation is carried out using the above-mentioned raw materials and catalyst while removing by-products by a transesterification reaction under normal pressure or reduced pressure. The reaction is generally carried out in a multistage process of two or more stages.

  Specifically, the reaction at the first stage is allowed to react at a temperature of 120 to 260 ° C., preferably 180 to 240 ° C. for 0.1 to 5 hours, preferably 0.5 to 3 hours. Next, the reaction temperature is increased while raising the degree of vacuum of the reaction system to react the dihydroxy compound and the carbonic acid diester, and finally, 0.05 to 2 hours at a temperature of 200 to 350 ° C. under a reduced pressure of 133.3 Pa or less. Perform polycondensation reaction. Such a reaction may be carried out continuously or batchwise. The reaction apparatus used for carrying out the above reaction is equipped with paddle blades, lattice blades, glasses blades, etc. even with vertical types equipped with vertical stirring blades, Max blend stirring blades, helical ribbon stirring blades, etc. It may be a horizontal type or an extruder type equipped with a screw, and it is preferable to use a reaction apparatus in which these are appropriately combined in consideration of the viscosity of the polymer.

  In the polycarbonate resin according to the present invention, the catalyst may be removed or deactivated after the polymerization reaction in order to maintain thermal stability and hydrolysis stability. In general, a method of deactivating a catalyst by adding a known acidic substance is preferably performed. Specific examples of these substances include esters such as butyl benzoate, aromatic sulfonic acids such as p-toluenesulfonic acid, and aromatic sulfonic acids such as butyl p-toluenesulfonate and hexyl p-toluenesulfonate. Esters, phosphoric acids such as phosphorous acid, phosphoric acid, phosphonic acid, triphenyl phosphite, monophenyl phosphite, diphenyl phosphite, diethyl phosphite, di-n-propyl phosphite, phosphorous acid Phosphorous esters such as di-n-butyl, di-n-hexyl phosphite, dioctyl phosphite, monooctyl phosphite, triphenyl phosphate, diphenyl phosphate, monophenyl phosphate, dibutyl phosphate, phosphorus Phosphate esters such as dioctyl acid and monooctyl phosphate, phosphones such as diphenylphosphonic acid, dioctylphosphonic acid and dibutylphosphonic acid , Phosphonic acid esters such as diethyl phenylphosphonate, phosphines such as triphenylphosphine and bis (diphenylphosphino) ethane, boric acids such as boric acid and phenylboric acid, and aromatics such as tetrabutylphosphonium dodecylbenzenesulfonate Organic halides such as aromatic sulfonates, stearic acid chloride, benzoyl chloride, p-toluenesulfonic acid chloride, alkyl sulfuric acids such as dimethyl sulfate, and organic halides such as benzyl chloride are preferably used. These deactivators are used in an amount of 0.01 to 50 times mol, preferably 0.3 to 20 times mol for the amount of catalyst. When the amount is less than 0.01 times the amount of the catalyst, the deactivation effect is insufficient, which is not preferable. Moreover, when it is more than 50 times mole with respect to the amount of catalyst, since heat resistance falls and it becomes easy to color a molded object, it is not preferable.

  After deactivation of the catalyst, a step of devolatilizing and removing the low boiling point compound in the polymer at a pressure of 13.3 to 133.3 Pa and a temperature of 200 to 350 ° C. may be provided. A horizontal apparatus equipped with a stirring blade excellent in surface renewability, such as a glasses blade, or a thin film evaporator is preferably used.

  The polycarbonate resin used in the present invention is desired to have as little foreign matter content as possible, and filtration of the molten raw material and filtration of the catalyst solution are suitably performed. The filter mesh is preferably 5 μm or less, more preferably 1 μm or less. Furthermore, filtration with the polymer filter of the resin to produce | generate is implemented suitably. The mesh of the polymer filter is preferably 100 μm or less, more preferably 30 μm or less. Also, the step of collecting the resin pellets must naturally be a low dust environment, and is preferably class 1000 or less, more preferably class 100 or less.

(2) Optical lens material (i) Other polymer The optical lens material for forming the optical lens of the present invention is mainly composed of the specific polycarbonate resin of the present invention containing the structural unit (1) described above. In addition to the specific polycarbonate resin, a small amount of other polymers can be blended within a range not impairing the physical properties.

  In this case, the standard of the amount of the other polymer is preferably 1 to 40% by weight, more preferably 1 to 35% by weight, based on the total amount of the optical lens material forming the optical lens of the present invention.

  Examples of such other polymers include polycarbonate resins made of aromatic dihydroxy compounds and polycarbonate resins made of aliphatic dihydroxy compounds. Specific examples of such a polycarbonate resin include polycarbonate made of bisphenol A, polycarbonate made of bisphenoxyethanol fluorene, polycarbonate made of biscresol fluorene, and the like.

  In addition, polymers other than polycarbonate resin, such as polyethylene, polypropylene, polystyrene, ABS resin, polymethyl methacrylate, polytrifluoroethylene, polytetrafluoroethylene, polyacetal, polyphenylene oxide, polybutylene terephthalate, polyethylene terephthalate, polyamide, polyimide, It is also possible to blend polyamideimide, polyetherimide, polysulfone, polyethersulfone, paraoxybenzoyl polyester polyarylate, polysulfide, and the like.

Moreover, it is desirable to add various known additives to the optical lens material of the present invention depending on the purpose within a range that does not impair the physical properties.
Examples of such additives include antioxidants, ultraviolet absorbers, mold release agents, flame retardants, antistatic agents, pigments, dyes and the like, and these can be used alone or in combination as necessary.

  Examples of the antioxidant include triphenyl phosphite, tris (4-methylphenyl) phosphite, tris (4-t-butylphenyl) phosphite, tris (monononylphenyl) phosphite, tris (2-methyl- 4-ethylphenyl) phosphite, tris (2-methyl-4-t-butylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, tris (2,6-di-t -Butylphenyl) phosphite, tris (2,4-di-t-butyl-5-methylphenyl) phosphite, tris (mono, dinonylphenyl) phosphite, bis (monononylphenyl) pentaerythritol-di-phos Phyto, bis (2,4-di-t-butylphenyl) pentaerythritol-di-phosphite, bis 2,6-di-tert-butyl-4-methylphenyl) pentaerythritol-di-phosphite, bis (2,4,6-tri-tert-butylphenyl) pentaerythritol-di-phosphite, bis (2, 4-di-t-butyl-5-methylphenyl) pentaerythritol-di-phosphite, 2,2-methylenebis (4,6-dimethylphenyl) octyl phosphite, 2,2-methylenebis (4-t-butyl- 6-methylphenyl) octyl phosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite, 2,2-methylenebis (4,6-dimethylphenyl) hexyl phosphite, 2,2 -Methylenebis (4,6-di-t-butylphenyl) hexyl phosphite, 2,2-methylenebis (4,6-di-) Phosphite compounds such as -butylphenyl) stearyl phosphite; pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3 -(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 1,3,5-trimethyl- 2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate ], 9,9-bis {2- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1 , 1-dimethylethyl} -2,4,8,10-tetraoxaspiro [5,5] undecane, 1,1,3-tris [2-methyl-4- (3,5-di-t-butyl- Hindered phenolic compounds such as 4-hydroxyphenylpropionyloxy) -5-t-butylphenyl] butane; 5,7-di-t-butyl-3- (3,4-dimethylphenyl) -3H-benzofuran-2 -ON etc. are mentioned. These may be used alone or in combination of two or more.

  The amount of these antioxidants added is preferably 0.005 to 0.1 parts by weight, more preferably 0.01 to 0.00 parts by weight per 100 parts by weight of the polycarbonate resin containing the structural unit (1) of the present invention. It is 08 weight part, More preferably, it is 0.01-0.05 weight part. If the added amount of the antioxidant is too small, the desired effect, for example, undesirable coloring during molding and the effect of suppressing the decrease in molecular weight may not be obtained, and if it is excessive, the heat resistance and mechanical properties may be reduced, which may not be appropriate. .

  Examples of the ultraviolet absorber include 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole. 2- (3,5-di-tert-butyl-2-hydroxyphenyl) benzotriazole, 2- (3-tert-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- ( 3,5-di-t-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-t-amyl-2-hydroxyphenyl) benzotriazole, 2- (2′-hydroxy -5'-t-octylphenyl) benzotriazole, 2,2'-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6-[(2H -Benzotriazol-2-yl) phenol]], 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol, 2,4-di Examples include hydroxobenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, 2-hydroxy-4-methoxy-2′-carboxybenzophenone. These may be used alone or in combination of two or more.

  As the mold release agent, commonly used ones may be used, such as natural, synthetic paraffins, silicone oil, polyethylene wax, beeswax, stearic acid, stearic acid monoglyceride, stearyl stearate, palmitic acid monoglyceride, behenine. Examples include fatty acid esters such as acid behenine, pentaerythritol distearate, and pentaerythritol tetrastearate. These may be used alone or in combination of two or more.

(3) Optical Lens and Manufacturing Method Thereof The optical lens of the present invention can be obtained by molding the above-described optical lens material, preferably by injection molding or injection compression molding. Further, the present optical lens material can be molded by vacuum molding or compression molding.
More preferably, the optical lens of the present invention can be produced by a method including the following step (a) and optionally (b).
(A) An injection molding process for molding the optical lens material mainly composed of the specific polycarbonate resin of the present invention described above by injection molding. (B) An injection molded product obtained by the injection molding process is dispersed in a medium. Dyeing process

(I) Injection molding process In the injection molding process, an injection molding machine or an injection compression molding machine is used for injection molding into a lens shape to obtain a molded article for an optical lens.
In order to avoid the entry of foreign matter into the optical lens as much as possible, the molding environment must of course be a low dust environment, preferably class 1000 or less, more preferably class 100 or less.

  The molding conditions in the injection molding are not particularly limited, and known injection molding conditions can be employed. For example, resin temperature: 250-320 ° C., mold temperature: 60-120 ° C., injection pressure: 100-210 MPa, cooling time: about 20-60 seconds.

The thickness of the optical lens molded body thus obtained can be appropriately selected depending on the application, but is preferably about 1 to 5 mm.
The optical lens of the present invention is preferably used in the form of an aspheric lens as necessary. Since an aspheric lens can substantially eliminate spherical aberration with a single lens, there is no need to remove spherical aberration with a combination of a plurality of spherical lenses, thus reducing weight and reducing production costs. It becomes possible.

  On the surface of the optical lens of the present invention, a coating layer such as an antireflection layer or a hard coating layer may be provided as necessary. The antireflection layer may be a single layer or a multilayer, and may be organic or inorganic, but is preferably inorganic. Specific examples include oxides or fluorides such as silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, cerium oxide, magnesium oxide, and magnesium fluoride.

(Ii) Dyeing Step The molded article for optical lenses obtained in the injection molding step can be used as it is as the optical lens of the present invention, but can be dyed by various known dyeing methods as necessary. As a typical dyeing method, for example, there is a method of dyeing using a dye or pigment such as a disperse dye in an aqueous medium or an organic solvent, or a mixed solvent thereof.

When carried out in an aqueous medium, examples of the aqueous medium used include water and water-methanol mixed solvents.
When performing in an organic solvent, there are no particular limitations on the organic solvent to be used, and various known organic solvents that are generally used are used. However, a water-soluble solvent such as an alcoholic solvent or the like rather than a non-aqueous organic solvent or A mixture of it and water is preferred. Among them, preferred is an aqueous medium, and particularly preferred is water.

Dyes and pigments are not particularly limited, and various known dyes and pigments used for dyeing fibers, resins and the like are preferably used. Of these, disperse dyes are particularly preferred.
Examples of disperse dyes include azo dyes, quinophthalone dyes, anthraquinone dyes, and the like. Although there is no restriction | limiting in particular as the usage-amount of a disperse dye, It is a density | concentration of 0.5-30 g / L by a normal washing bath density | concentration.

Examples of the dyes that can be used include the following (where CI is an abbreviation for color index):
(1) Blue dye Dianics Blue AC-E Dianics Blue RNE (CI Disperse Blue 91), Dianics Blue GRE (CI Disperse Blue 81), Sumikaron Blue ER (C.I.) I. Disperse Blue 91), Kayalon Polyester Blue GR-E (C.I. Disperse Blue 81),
(2) Red color dye Dianics Red AC-E Diamond Shelton Fast Red R (CI Disper Thread 17), Diamond Shelton Fast Scarlet R (CI Disper Thread 7), Diamond Shelton Fast Pink R (C.I. I. Disper Thread 4), Sumicaron Rubin SE-RPD Kayalon Polyester Rubin GL-SE200 (CI Disper Thread 73),
(3) Yellow-based dye Dianics Yellow AC-E Diamondix Yellow YL-SE (CI Disperse Yellow 42), Sumikaron Yellow SE-RPD Diamond Shelton Fast Yellow GL (CI Disperse Yellow 33), Kayalon Fast Yellow GL (CI Disperse Yellow 33), Kayalon Micro Ester Yellow AQ-LE,
(4) Orange dye Dianics Orange B-SE200 (CI Disperse Orange 13), Diamond Shelton Fast Orange GL (CI Disperse Orange 3), Miketone Polyester Orange B (CI Disperse) Orange 13),
Sumikaron Orange SE-RPD Sumikaron Orange SE-B (CI Disperse Orange 13),
(5) Purple dye Dianics Violet 5R-SE (CI Disperse Violet 56), Sumikaron Violet E-2RL (CI Disperse Violet 28).

Although there is no restriction | limiting in particular as the usage-amount of a pigment, Usually, it is a density | concentration of 0.1 to 10 weight%.
Examples of the pigment include CI pigment white 6, CI pigment blue 15: 4, CI pigment green 7, CI pigment violet 23, CI pigment yellow 42, and CI pigment brown (where CI is an abbreviation for color index). .

  As a method for dyeing with a disperse dye in an aqueous medium, for example, a disperse dye is dispersed in an aqueous medium, and various known additives (for example, surfactant, pH adjuster, disperse leveling agent, dyeing) Examples thereof include a method of adding a promoter and the like, adjusting the dyeing bath while maintaining the dyeing concentration, and immersing the lens in the dyeing bath for a predetermined time.

  The optical lens of the present invention can be used in a wide range of optical devices such as spectacle lenses, automobile and train headlights, airplane sign towers, search lamps, and OHP. Among these, it is particularly suitable as a spectacle lens.

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In addition, the measured value in an Example was measured using the following method or apparatus.
1) Reduced viscosity: It was determined by measuring a phenol / 1,1,2,2-tetrachloroethane (1: 1 wt%) mixed solution having a concentration of 1.0 g / dl at 30 ° C. using an Ubbelohde viscometer.
2) Glass transition temperature (Tg): TMA manufactured by Seiko Electronics Co., Ltd. was used by a penetration method under a temperature rising rate of 20 ° C./min.
3) Refractive index nD, Abbe number νD: A rectangular parallelepiped having a thickness of 3 mm × 8 mm × 8 mm was cut out and measured with a refractometer manufactured by ATAGO.
4) Injection molding machine: The product name “SH50” manufactured by Sumitomo Heavy Industries, Ltd. was used.
5) Impact resistance: The weight of the steel ball is shown as the weight of the steel ball that spontaneously drops from a height of 7 cm toward the center of the lens and breaks the test piece.
6) Birefringence: Measured using a JASCO ellipsometer.
7) Dye density: calculated using “(transmittance before staining−transmittance after staining) / transmittance before staining × 100”. The transmittance was measured with a Hitachi spectrophotometer (trade name “U-2910”).

<Example 1>
Isosorbide (hereinafter abbreviated as “ISB”) 5.846 kg (40 mol), diphenyl carbonate (hereinafter abbreviated as “DPC”) 8.869 kg (41.40 mol), and sodium hydrogen carbonate 0.00123 g (1 .46 × 10 ⁻⁵ mol) was placed in a 50 liter reactor equipped with a stirrer and a distillation apparatus, and heated to 215 ° C. over 1 hour under a nitrogen atmosphere of 101325 Pa and stirred.

Thereafter, the degree of vacuum was adjusted to 1998. 3 Pa over 30 minutes, and the transesterification reaction was carried out by maintaining for 40 minutes under the conditions of 215 ° C and 1998.3 Pa. Further, the temperature was raised to 240 ° C. at a rate of 37.5 ° C./hr, and held at 240 ° C. and 1998.3 Pa for 10 minutes.
Then, it adjusted to 15998.6 Pa over 10 minutes, and hold | maintained at 240 degreeC and 15998.6 Pa for 70 minutes. Then, it adjusted to 13332.2 Pa over 10 minutes, and hold | maintained at 240 degreeC and 13332.2Pa for 10 minutes.
Furthermore, it was set to 133.3 Pa or less over 40 minutes, and the polymerization reaction was performed with stirring for 30 minutes under the conditions of 240 ° C. and 133.3 Pa or less.

  After completion of the reaction, nitrogen was blown into the reactor to increase the pressure, and pelletized while extracting the produced polycarbonate resin. The obtained polycarbonate resin had a reduced viscosity = 0.64 dL / g and Tg = 160 ° C.

  10.0 kg of this polycarbonate resin is vacuum-dried at 100 ° C. for 24 hours, and an antioxidant (trade name “IRGANOX1010”, manufactured by Ciba Japan Co., Ltd.) is 500 ppm for the resin, and glycerin monostearate is used as a release agent. 300 ppm was added, and the mixture was kneaded at 260 ° C. by an extruder and pelletized to obtain pellets. The MI value of the pellets was 14.8 g / 10 min at 260 ° C. and a 2.16 kg load.

  The pellets were vacuum-dried at 100 ° C. for 24 hours and then injection molded at a cylinder temperature of 265 ° C. and a mold temperature of 105 ° C. to obtain a plano lens having a diameter of 75 mm and a thickness of 3.0 mm. When the birefringence of the resin lens was measured, it was 33 nm, and it was confirmed that the resin lens was a lens having very little birefringence and substantially no optical distortion.

  The total light transmittance of the lens was 91.0%, and the impact resistance was 160 g. Further, the refractive index nD of the resin was 1.501 and the Abbe number was 60.1. The measurement results of various physical properties are shown in Table 1.

  Further, 5 g of a trade name “BPI brown” (manufactured by Brain Power Incorporated) as a disperse dye was added to 1 L of pure water and kept at 90 to 91.5 ° C. to obtain a brown dyeing solution. The lens obtained above was soaked at about 90 ° C. for 1 hour for a dyeing test. The dyeing test results are shown in Table 2.

<Example 2>
The reaction was performed in the same manner as in Example 1 except that isomannide was used instead of isosorbide (ISB). The polycarbonate resin obtained had a reduced viscosity = 0.55 dL / g and Tg = 166 ° C. 10.0 kg of this polycarbonate resin is vacuum-dried at 100 ° C. for 24 hours, and an antioxidant (trade name “IRGANOX1010”, manufactured by Ciba Japan Co., Ltd.) is 500 pm, and glycerin monostearate is used as a release agent. 300 ppm was added, and the mixture was kneaded at 260 ° C. by an extruder and pelletized to obtain pellets. The MI value of the pellets was 11.8 g / 10 min at 260 ° C. and a load of 2.16 kg. The pellets were vacuum dried at 100 ° C. for 24 hours, and then injection molded at a cylinder temperature of 265 ° C. and a mold temperature of 105 ° C. to obtain a plano lens having a diameter of 75 mm and a thickness of 3.0 mm.

  When the birefringence of the resin lens was measured, it was 38 nm, and it was confirmed that the lens had a very small birefringence and substantially no optical distortion. The total light transmittance of the lens was 91.0%, and the impact resistance was 160 g. Further, the refractive index nD of the resin was 1.501 and the Abbe number was 60.1. These results are shown in Table 1. Further, a dyeing test was conducted in the same manner as in Example 1. The results are shown in Table 2.

<Comparative Example 1>
The product name “Iupilon H-4000” (manufactured by Mitsubishi Engineering Plastics Co., Ltd.) was used as the polycarbonate resin composed of bisphenol A. The MI of the pellet was 25.0 g / 10 min at 255 ° C. and a 5.00 kg load. The glass transition temperature was 145 ° C. The pellets were vacuum-dried at 100 ° C. for 24 hours and then injection molded at a cylinder temperature of 255 ° C. and a mold temperature of 95 ° C. to obtain a plane lens having a diameter of 70 mm and a thickness of 3.0 mm. The total light transmittance of the lens was 89.0%, and it was 510 g or more in the falling ball impact test. In addition, the refractive index of the resin was nD = 1.586, and the Abbe number = 29.7. When the birefringence of the resin lens was measured, it was 1240 nm, and it was confirmed that the lens had a large birefringence and a large distortion. These results are shown in Table 1. Further, a dyeing test was conducted in the same manner as in Example 1. The results are shown in Table 2.

<Comparative example 2>
Add 100 parts by weight of diethylene glycol bisallyl carbonate and 3 parts by weight of diisopropyl peroxydicarbonate, pour into a plano-lens mold having a diameter of 75 mm and a thickness of 3.0 mm, and hold in an oven at 40 ° C. for 24 hours under a nitrogen atmosphere. did. Then, it was kept at 80 ° C. for 4 hours and further at 120 ° C. for 2 hours to complete curing. The total light transmittance was 91.0%, and it was 15.8 g in the falling ball impact test. In addition, the refractive index of the resin was nD = 1.499 and the Abbe number = 58.1. The birefringence of the resin lens was measured and found to be 44 nm. These results are shown in Table 1. Further, a dyeing test was conducted in the same manner as in Example 1. The results are shown in Table 2.

  According to the present invention, an excellent optical lens produced from a plant-derived raw material, which has not existed until now, has high heat resistance, high transparency, high Abbe number, high strength, high dyeability and no optical distortion is obtained. be able to. The optical lens of the present invention can be injection-molded and has high productivity, and is useful for lenses such as spectacle lenses, cameras, telescopes, and binoculars, and is particularly useful for spectacle lenses. The optical lens of the present invention can also be used in a wide range of optical devices such as automobile and train headlights, airplane sign towers, search lamps, and OHP.

Claims (6)

An optical lens made of a material for an optical lens containing as a main component a polycarbonate resin containing a structural unit derived from a dihydroxy compound represented by the following formula (1) and having a reduced viscosity of 0.2 to 1.5 dl / g .

  The optical lens according to claim 1, wherein the carbohydrate represented by the formula (1) is isosorbide.   The optical lens according to claim 1, wherein the carbohydrate represented by the formula (1) is isomannide.   The optical lens according to claim 1, wherein the optical lens is dyed with a disperse dye.   The optical lens according to claim 1, which is a spectacle lens. A method for producing an optical lens according to any one of claims 1 to 5, comprising the following step (a) and optionally (b).
(A) An optical lens material comprising as a main component a polycarbonate resin containing a structural unit derived from a dihydroxy compound represented by the following formula (1) and having a reduced viscosity of 0.2 to 1.5 dl / g Injection molding step for molding by injection molding (b) Dyeing step for dyeing the injection molded body obtained in the injection molding step with a disperse dye in a medium