Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C39/00—Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor
  • B29C39/22—Component parts, details or accessories; Auxiliary operations
  • B29C39/44—Measuring, controlling or regulating
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
  • G02B1/04—Optical elements characterised by the material of which they are made; Optical coatings for optical elements made of organic materials, e.g. plastics

Definitions

• the present disclosure relates to a method for manufacturing an optical material.
• a method for producing a resin used in an optical material for plastic lenses for example, there is a cast polymerization method in which a polymerizable composition containing a monomer is injected into a mold and cured by heating.
• the polymerizable composition is injected into a mold (mold), heat-cured (polymerization reaction), and the product is removed from the mold (mold release). ) and annealing to obtain optical materials (for example, lenses, semi-finished blanks, etc.).
• US Pat. No. 6,201,403 discloses a process for preparing a molded optical article comprising: a) introducing two separate reactive components A and B each from separate supply vessels into a mixing chamber having a volume of 200 mL to 2000 mL; b) mixing the components together in a mixing chamber for 50-200 seconds to form a reaction mixture, c) injecting the reaction mixture into a mold at a temperature of up to 130° C., d a) holding the reaction mixture in a mold at a temperature and for a time sufficient to cure the reaction mixture and form a molded optical article; and e) removing the article from the mold.
• Patent Document 1 Patent No. 5735663
• the polymerizable composition for optical materials may be produced by mixing two or more different monomers for optical materials and polymerization catalysts in one supply vessel.
• the polymerizable composition for optical materials comprises a first raw material containing part of two or more different monomers for optical materials, a second raw material containing the remainder of two or more different monomers for optical materials, and a polymerization catalyst. It may be made by mixing.
• the present inventors have found that the following problems exist when a polymerizable composition for optical materials is produced by such a method. That is, when the first raw material and the second raw material are mixed to prepare the polymerizable composition for optical materials, they may not be well mixed, and unevenness may occur in the polymerizable composition for optical materials.
• striae may occur (in the present disclosure, such striae are also referred to as "casting striae"). say).
• the unevenness in the polymerizable composition for optical materials, which causes casting striae, is likely to occur, for example, when either one of the first raw material and the second raw material has a high viscosity, or when both have a high viscosity.
• striae tend to be caused by the occurrence of convection in the polymerizable composition for optical materials due to uneven heating temperature during polymerization of the polymerizable composition for optical materials.
• This commonly known striae is a striae that causes wrinkles in the optical material.
• the casting striae found by the present inventors tends to be caused mainly by unevenness due to poor mixing when a plurality of raw material compositions are mixed.
• the casting striae include, for example, U-shaped striae formed across the optical material, striae formed substantially linearly from the casting port of the optical material, and the like.
• the U-shaped striae are often large in shape, distinct in shape, and dark in color, and are therefore likely to impair the quality of the optical material. Therefore, it is required to suppress the U-shaped striae.
• Patent Literature 1 does not discuss suppression of casting striae.
• a problem to be solved by an embodiment of the present disclosure is to provide a method for producing an optical material that can suppress casting striae in the obtained optical material.
• the standard deviation is obtained by putting a mixture of the first raw material and the second raw material into a quartz cell having an optical path length of 8 mm, an area of 360 mm 2 and a thickness of 12 mm, and a shutter of 1/5000 (sec) and gamma
• An image was measured using a glass striae inspection device under the conditions of correction 100, sharpness 500, contrast and brightness 0, and the image was analyzed by image analysis software (ImageJ). is assumed to be a normal distribution with luminance.
• ImageJ image analysis software
• the first raw material is obtained by mixing part of the two or more different optical material monomers and at least part of the polymerization catalyst, and at least part of the two or more different optical material monomers
• the two or more different optical material monomers are an isocyanate compound (A) containing two or more isocyanate groups, a polythiol compound having two or more mercapto groups, one or more mercapto groups and one a hydroxythiol compound having at least one hydroxyl group, a polyol compound having two or more hydroxyl groups, and an active hydrogen compound (B) containing at least one selected from the group consisting of an amine compound ⁇ 1> to The method for producing an optical material according to any one of ⁇ 4>.
• ⁇ 6> Any one of ⁇ 1> to ⁇ 5>, wherein the polymerization catalyst contains at least one selected from the group consisting of a basic catalyst having a pKa value of 4 to 8 and an organometallic catalyst.
• ⁇ 7> The method for producing an optical material according to any one of ⁇ 1> to ⁇ 6>, wherein the polymerization catalyst contains at least one selected from the group consisting of an amine-based catalyst and an organic tin-based catalyst.
• the polymerization catalyst contains 3,5-lutidine, 2,4,6-collidine, triethylenediamine, N,N-dimethylethanolamine, triethylamine, N-ethylmorpholine, dibutyltin dichloride, dimethyltin dichloride, dibutyltin dilaurate and The method for producing an optical material according to any one of ⁇ 1> to ⁇ 7>, containing at least one selected from the group consisting of dibutyltin diacetate.
• a numerical range represented using “to” means a range including the numerical values described before and after “to” as lower and upper limits.
• the amount of each component in the composition is the total amount of the multiple substances present in the composition unless otherwise specified. means.
• the upper limit or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range described step by step. .
• the upper or lower limits of the numerical ranges may be replaced with the values shown in the examples.
• the term "step” includes not only independent steps, but also if the intended purpose of the step is achieved even if it cannot be clearly distinguished from other steps. .
• a polymerizable composition for an optical material containing two or more different monomers for an optical material and a polymerization catalyst is produced by mixing a first raw material and a second raw material.
• the method for producing an optical material of the present disclosure includes the first step described above, so that casting striae in the obtained optical material can be suppressed.
• the present inventors suppress the unevenness of the polymerizable composition for optical materials by setting the standard deviation to 60 or less. I have learned that it is possible. Therefore, by producing an optical material using the polymerizable composition for an optical material according to the present disclosure, casting striae can be suppressed in the resulting optical material.
• the method for producing an optical material of the present disclosure is a method for producing an optical material using a polymerizable composition for optical materials containing two or more different types of monomers for optical materials and a polymerization catalyst.
• the polymerizable composition for optical materials contains two or more different monomers for optical materials and a polymerization catalyst.
• Monomers for optical materials include an isocyanate compound containing two or more isocyanate groups, a polythiol compound containing two or more mercapto groups, a hydroxythiol compound containing one or more mercapto groups and one or more hydroxyl groups, and two Polyol compounds and amine compounds having the above hydroxyl groups can be mentioned.
• the two or more different optical material monomers are an isocyanate compound (A) containing two or more isocyanate groups, a polythiol compound having two or more mercapto groups, one or more mercapto groups and one or more hydroxyl groups. , a polyol compound having two or more hydroxyl groups, and an active hydrogen compound (B) containing at least one selected from the group consisting of an amine compound.
• isocyanate compound (A) containing two or more isocyanate groups examples include aliphatic isocyanate compounds, alicyclic isocyanate compounds, aromatic isocyanate compounds, heterocyclic isocyanate compounds, and the like. Used. These isocyanate compounds containing two or more isocyanate groups may include dimers, trimers and prepolymers. Examples of isocyanate compounds containing two or more isocyanate groups include compounds exemplified in International Publication No. 2011/055540. In the present disclosure, an alicyclic isocyanate compound refers to an isocyanate compound that contains an alicyclic structure and may contain a heterocyclic structure.
• An aromatic isocyanate compound refers to an isocyanate compound that contains an aromatic structure and may contain an alicyclic structure and a heterocyclic structure.
• a heterocyclic isocyanate compound refers to an isocyanate compound that contains a heterocyclic structure and does not contain an alicyclic structure or an aromatic structure.
• the isocyanate compound (A) containing two or more isocyanate groups preferably contains at least one selected from aliphatic isocyanate compounds, alicyclic isocyanate compounds, aromatic isocyanate compounds and heterocyclic isocyanate compounds. More preferably, it contains at least one of a cyclic isocyanate compound and an aromatic isocyanate compound.
• the isocyanate compound (A) containing two or more isocyanate groups is 2,5-bis(isocyanatomethyl ) bicyclo-[2.2.1]-heptane, 2,6-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane, m-xylylene diisocyanate, 2,4-tolylene diisocyanate, 2 ,6-tolylene diisocyanate, dicyclohexylmethane diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, isophorone diisocyanate, 1,6-hexamethylene diisocyanate, 1,5- It preferably contains at least one selected from pentamethylene diisocyanate and isocyanurate of 1,5-pentamethylene diiso
• Active hydrogen compounds (B) include polythiol compounds having two or more mercapto groups, hydroxythiol compounds having one or more mercapto groups and one or more hydroxyl groups, polyol compounds having two or more hydroxyl groups, and amines. compound etc. can be mentioned.
• an oligomer of the above active hydrogen compound and a halogen-substituted product for example, a chlorine-substituted product, a bromine-substituted product, etc.
• the active hydrogen compound (B) may be used alone or in combination of two or more.
• a polythiol compound is a compound having two or more mercapto groups, and can include compounds exemplified in International Publication No. 2016/125736.
• the polythiol compound is 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, 5,7 -dimercaptomethyl-1,11-dimercapto-3,6,9-trithiundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiundecane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiundecane mercaptomethyl-1,11-dimercapto-3,6,9-trithiundecane, pentaerythritol tetrakis (3-mercaptopropionate), bis (mercaptoethyl) sulfide, pentaerythritol tetrakis (3-mercaptoprop
• thiol compounds having a hydroxy group examples include 2-mercaptoethanol, 3-mercapto-1,2-propanediol, glycerin bis(mercaptoacetate), 4-mercaptophenol, 2,3-dimercapto-1-propanol, and pentaerythritol.
• examples include tris(3-mercaptopropionate), pentaerythritol tris(thioglycolate) and the like, but the compound is not limited to these exemplary compounds.
• Polyol compound having two or more hydroxyl groups include one or more aliphatic or cycloaliphatic alcohols. Specifically, linear or branched aliphatic alcohols, alicyclic alcohols, alcohols obtained by adding at least one selected from the group consisting of ethylene oxide, propylene oxide and ⁇ -caprolactone to these alcohols etc. More specific examples include compounds exemplified in International Publication No. 2016/125736.
• Polyol compounds are preferably ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,2-cyclopentanediol, 1,3-cyclopentanediol, 1,2-cyclohexanediol, 1 ,3-cyclohexanediol and 1,4-cyclohexanediol.
• Amine compounds include ethylenediamine, 1,2- or 1,3-diaminopropane, 1,2-, 1,3- or 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,10-diaminodecane, 1,2-, 1,3- or 1,4-diaminocyclohexane, o-, m- or p-diaminobenzene, 3 ,4- or 4,4'-diaminobenzophenone, 3,4- or 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 3,3' or 4,4 '-diaminodiphenylsulfone, 2,7-
• the active hydrogen compound (B) preferably contains a polythiol compound having two or more mercapto groups.
• the content of the polythiol compound having two or more mercapto groups is preferably 60% by mass or more, more preferably 70% by mass or more, based on the total mass of the active hydrogen compound (B). % by mass or more is more preferable.
• the total content of 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane and pentaerythritol tetrakis(3-mercaptopropionate) is It is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more, relative to the total mass of the active hydrogen compound (B).
• the hydroxyl group (OH group) and mercapto group (SH group) in the active hydrogen compound relative to the isocyanate group (NCO group) in the isocyanate compound (A) containing two or more isocyanate groups are preferably 0.8 to 1.2, more preferably 0.85 to 1.15, and 0.9 to 1.5. 1 is more preferred.
• the first raw material preferably contains at least one compound selected from the group consisting of polyisocyanate compounds, epoxy compounds and epithio compounds.
• the second raw material is a polythiol compound having two or more mercapto groups, a hydroxythiol compound containing one or more mercapto groups and one or more hydroxyl groups, a polyol compound containing two or more hydroxyl groups, and It preferably contains at least one active hydrogen compound selected from the group consisting of amine compounds.
• polymerization catalyst is not particularly limited, basic catalysts, organometallic catalysts, zinc carbamates, ammonium salts, sulfonic acids and the like can be used, for example. Only one kind of the polymerization catalyst may be used, or two or more kinds thereof may be used in combination.
• basic catalyst examples include amine-based catalysts and imidazole-based catalysts. Specifically, triethylenediamine, N,N-dimethylethanolamine, triethylamine, tertiary amine catalysts such as N-ethylmorpholine, 2-methylpyrazine, pyridine, ⁇ -picoline, ⁇ -picoline, ⁇ -picoline, 2 ,6-lutidine, 3,5-lutidine, 2,4,6-collidine, 3-chloropyridine, N,N-diethylaniline, N,N-dimethylaniline, hexamethylenetetramine, quinoline, isoquinoline, N,N- dimethyl-p-toluidine, N,N-dimethylpiperazine, quinaldine, 4-methylmorpholine, triallylamine, trioctylamine, 1,2-dimethylimidazole, 1-benzyl-2-methylimidazole and the like.
• amine-based catalysts examples include amine
• an amine-based catalyst is preferable.
• amine-based catalysts include tertiary amine-based catalysts such as 3,5-lutidine, 2,4,6-collidine, triethylenediamine, N,N-dimethylethanolamine, triethylamine, and N-ethylmorpholine. .
• the amine-based catalyst preferably contains at least one selected from 3,5-lutidine, 2,4,6-collidine, triethylenediamine, N,N-dimethylethanolamine, triethylamine and N-ethylmorpholine.
• the basic catalyst preferably contains a compound represented by the following general formula (2) and/or a compound represented by the following general formula (3).
• R 1 represents a straight-chain alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or a halogen atom, and there are a plurality of them. R 1 may be the same or different.
• Q represents a carbon atom or a nitrogen atom.
• m represents an integer of 0 to 5;
• R 2 , R 3 and R 4 each independently represent a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, or a cycloalkyl group having 3 to 20 carbon atoms. or represents an allyl group
• the basic catalyst preferably has a pKa value of 1-9, more preferably 3-8, even more preferably 4-8.
• the pKa value (acid dissociation index) is, for example, described in (a) The Journal of Physical Chemistry vol. 68, number 6, page 1560 (1964); c) The acid dissociation index and the like described in the Chemical Handbook edited by the Chemical Society of Japan (3rd revised edition, June 25, 1984, published by Maruzen Co., Ltd.) can be used.
• organometallic catalysts examples include organotin catalysts; organic acid salts such as iron, nickel and zinc; acetylacetonate complexes; catalyst compositions comprising carboxylic acid metal compounds and quaternary ammonium salt compounds; bicyclic tertiary A catalyst composition comprising an amine compound and a quaternary ammonium salt compound; a metal catalyst in which an alkoxy group, a carboxy group, or the like is coordinated to titanium or aluminum; Among the above organometallic catalysts, organotin catalysts are preferable. Examples of organotin catalysts include dibutyltin dichloride (DBC), dimethyltin dichloride (DMC), dibutyltin dilaurate (DBTDL), and dibutyltin diacetate.
• DBC dibutyltin dichloride
• DMC dimethyltin dichloride
• DBTDL dibutyltin dilaurate
• dibutyltin diacetate examples include di
• the organotin catalyst preferably contains at least one selected from dibutyltin dichloride, dimethyltin dichloride, dibutyltin dilaurate and dibutyltin diacetate.
• the polymerization catalyst preferably contains at least one selected from the group consisting of basic catalysts with a pKa value of 4 to 8 and organometallic catalysts.
• the polymerization catalyst preferably contains at least one selected from the group consisting of amine-based catalysts and organic tin-based catalysts.
• Polymerization catalysts include 3,5-lutidine, 2,4,6-collidine, triethylenediamine, N,N-dimethylethanolamine, triethylamine, N-ethylmorpholine, dibutyltin dichloride, dimethyltin dichloride, dibutyltin dilaurate and dibutyltin diacetate. It is also preferable to include at least one selected from the group consisting of
• the polymerizable composition for optical materials preferably contains a total of 100 parts by mass of two or more different monomers for optical materials and 0.010 to 2.0 parts by mass of a polymerization catalyst. That is, in the method for producing an optical material of the present disclosure, it is preferable to use 0.010 to 2.0 parts by mass of a polymerization catalyst with respect to a total of 100 parts by mass of two or more different optical material monomers.
• the amount of the polymerization catalyst used in the present disclosure is large compared to the conventional method for producing an optical material.
• reaction heat of the polymerizable composition for optical materials can be generated in a short time when the monomer for optical materials in the polymerizable composition for optical materials is polymerized in the curing step.
• the polymerization reaction can be favorably promoted, and a high-quality optical material in which striae are suppressed can be obtained in a shorter period of time than conventionally.
• the polymerization reaction can be favorably promoted, and striae can be suppressed in a short time.
• a high-quality optical material can be obtained.
• the polymerization catalyst is preferably used in an amount of 0.015 parts by mass or more, more preferably 0.038 parts by mass or more, with respect to 100 parts by mass of two or more different optical material monomers. It is more preferable to use 0.10 parts by mass or more, and it is particularly preferable to use 0.17 parts by mass or more.
• the content range of the polymerization catalyst described above may be appropriately changed depending on the type of the optical material monomer and the polymerization catalyst.
• optical material monomers are 2,5(6)-bis(isocyanatomethyl)-bicyclo-[2.2.1]-heptane, pentaerythritol tetrakis(3-mercaptopropionate), and 4-mercaptomethyl -1,8-dimercapto-3,6-dithiaoctane
• the polymerization catalyst is 0.10 parts per 100 parts by mass of two or more different optical material monomers. It is preferable to use 0.17 parts by mass or more, and it is more preferable to use 0.17 parts by mass or more.
• optical material monomers include m-xylylene diisocyanate, 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiundecane, 4,7-dimercaptomethyl-1,11- Dimercapto-3,6,9-trithiaundecane and 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, when the polymerization catalyst contains 3,5-lutidine
• the polymerization catalyst is preferably used in an amount of 0.015 parts by mass or more, more preferably 0.020 parts by mass or more, with respect to 100 parts by mass of two or more different optical material monomers.
• the polymerization catalyst contains 2 It is preferable to use 0.010 parts by mass or more, more preferably 0.015 parts by mass or more, based on 100 parts by mass of optical material monomers having different species or more.
• the optical material monomers are dicyclohexylmethane diisocyanate, 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, and 4,7-dimercaptomethyl-1,11-dimercapto - a mixture of 3,6,9-trithiaundecane and 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, the polymerization catalyst comprising 3,5-lutidine
• the polymerization catalyst is preferably used in an amount of 1.0 parts by mass or more, more preferably 1.5 parts by mass or more, with respect to 100 parts by mass of two or more different optical material monomers.
• the optical material monomer includes 1,3-bis(isocyanatomethyl)cyclohexane, pentaerythritol tetrakis(2-mercaptoacetate) and 2,5-bis(mercaptomethyl)-1,4-dithiane, and the polymerization catalyst is
• the polymerization catalyst is preferably used in an amount of 0.03 parts by mass or more, preferably 0.07 parts by mass or more, with respect to 100 parts by mass of two or more different optical material monomers. is more preferred.
• the handling property when casting the polymerizable composition for optical materials into a mold is improved.
• the polymerization catalyst may be used in an amount of 1.0 parts by mass or less, or 0.3 parts by mass or less, with respect to 100 parts by mass of two or more different optical material monomers. may be used, and may be used in an amount of 0.15 parts by mass or less.
• the amount of the polymerization catalyst depends on the type of polymerization catalyst, the type and amount of monomers used (isocyanate compounds containing two or more isocyanate groups, active hydrogen compounds, other components, etc.), and the desired molded product. It can be appropriately set depending on the shape.
• the polymerization catalyst preferably satisfies Condition 1 below.
• Condition 1 -Ea/R is -7100 or more and -2900 or less.
• Ea is the activation energy calculated by Arrhenius plot from the reaction rate constants of two or more different optical material monomers at two or more different temperatures, and R is the gas constant (8.314 J / mol / K) is.
• the value of Ea is calculated by the following method.
• a composition 1 containing an optical material monomer and a predetermined amount of a polymerization catalyst is heated and kept at a plurality of temperatures, the physical property value 1a derived from the functional group of the optical material monomer before heating and the predetermined
• a polymerizable composition for optical materials containing two or more different monomers for optical materials and a polymerization catalyst is prepared by mixing a first raw material and a second raw material, and the following A step of obtaining a polymerizable composition for optical materials having a standard deviation of 60 or less as measured under Condition 1 and a viscosity of 30 mPa ⁇ s to 1000 mPa ⁇ s as measured with a Brookfield viscometer at 25° C. and 60 rpm. .
• a polymerizable composition for optical materials having a viscosity of 30 mPa ⁇ s to 1000 mPa ⁇ s measured at 60 rpm can be obtained.
• the polymerizable composition for an optical material has a viscosity of 30 mPa ⁇ s to 1000 mPa ⁇ s measured with a Brookfield viscometer under conditions of 25° C. and 60 rpm (in the present disclosure, also simply referred to as “viscosity”).
• the polymerizable composition for optical materials should have a viscosity of 30 mPa ⁇ s to 1000 mPa ⁇ s measured at 25° C. and 60 rpm with a Brookfield viscometer. is preferred.
• the viscosity of the polymerizable composition for optical materials is set within an appropriate range, and striae are suppressed in the resulting optical material. can be done.
• the viscosity of the polymerizable composition for optical materials is preferably 40 mPa ⁇ s or more, more preferably 70 mPa ⁇ s or more, further preferably 80 mPa ⁇ s or more, and 100 mPa ⁇ s or more. s or more is particularly preferable, and 120 mPa ⁇ s or more is even more preferable.
• the viscosity of the polymerizable composition for optical materials is preferably 700 mPa ⁇ s or less, more preferably 400 mPa ⁇ s or less, from the viewpoint of maintaining good handleability when molding the optical material into a desired shape. preferable.
• the rotor number is 2 when measuring viscosity with a Brookfield viscometer.
• the method for adjusting the viscosity of the polymerizable composition for optical materials is not particularly limited.
• the viscosity of the polymerizable composition for optical materials may be adjusted by adding a high-viscosity compound, heating, stirring, or the like.
• Viscosity Va measured under the conditions of 25 ° C. 60 rpm (revolutions per minute) with a Brookfield viscometer of the first raw material The absolute value V (also referred to as viscosity difference V) of the difference between the viscosity Vb of the second raw material measured with a Brookfield viscometer at 25° C. and 60 rpm may be 10 mPa ⁇ s or more.
• the viscosity difference V may be 20 mPa ⁇ s or more, or may be 100 mPa ⁇ s or more.
• the viscosity difference V is preferably 1500 mPa ⁇ s or less, more preferably 1000 mPa ⁇ s or less, and 500 mPa ⁇ s or less. is more preferable, and 300 mPa ⁇ s or less is particularly preferable.
• the viscosity difference V may be, for example, 10 mPa ⁇ s or more and 1500 mPa ⁇ s or less.
• Va is the viscosity of the first raw material before mixing
• Vb is the viscosity of the second raw material before mixing
• the viscosity Va of the first raw material measured at 25° C. and 60 rpm with a B-type viscometer is preferably in the range of 10 mPa s to 2000 mPa s, and preferably in the range of 50 mPa s to 1500 mPa s. more preferably 100 mPa ⁇ s to 1000 mPa ⁇ s.
• the polymerizable composition for optical materials contains two or more different monomers for optical materials and a polymerization catalyst. Also, the polymerizable composition for optical materials is obtained by mixing the first raw material and the second raw material. Therefore, the first raw material and the second raw material as a whole include two or more different optical material monomers and a polymerization catalyst.
• Each of the first raw material and the second raw material may be a single compound or a composition containing a plurality of compounds.
• the first raw material and the second raw material are compositions, it is preferable that the first raw material and the second raw material are not compositions having the same composition.
• the first raw material and the second raw material may contain different types of optical material monomers, and at least one of the first raw material and the second raw material may contain the polymerization catalyst.
• the first raw material and the second raw material are not particularly limited as long as they contain two or more different optical material monomers and a polymerization catalyst as a whole.
• the first raw material and the second raw material may be ready-made products, or may be prepared by mixing an optical material monomer and a polymerization catalyst.
• the mixing method is not particularly limited, and known methods can be used.
• the temperature at which the above components are mixed is not particularly limited, but is preferably 30° C. or lower, more preferably room temperature (25° C.) or lower. From the viewpoint of the pot life of the prepared polymerizable composition for optical materials, it may be preferable to set the temperature even lower than 25°C. However, if the solubility of the additives such as the internal release agent and the above components is not good, the above components may be heated in advance to dissolve the additives in the above components. .
• the remainder of the two or more different optical material monomers may be mixed in a single step or in multiple steps. May be mixed.
• Specific aspects for obtaining the first raw material and the second raw material include, for example, the following aspects.
• a part of the optical material monomer and an additive are added to prepare a mixed solution. After stirring this mixture at 25° C. for 1 hour to completely dissolve each component, a portion of the remainder of the optical material monomer is added and stirred to form a homogeneous solution. This solution is defoamed to obtain the first raw material. Then, the rest of the optical material monomer and the catalyst are stirred at 25° C. for 30 minutes to completely dissolve and form a homogeneous solution. This solution is defoamed to obtain the second raw material.
• an additive for example, an internal release agent
• the first raw material is obtained by mixing a portion of two or more different optical material monomers and at least a portion of a polymerization catalyst, and polymerizing at least a portion of the two or more different optical material monomers. It preferably contains a prepolymer that is Including the prepolymer in the first raw material increases the viscosity of the first raw material, making it difficult to mix the first raw material and the second raw material. In other words, unevenness tends to occur in the polymerizable composition for optical materials, and the problem of the present disclosure becomes more pronounced.
• the method for producing an optical material of the present disclosure may further include a filtering step of filtering the mixture of the first raw material and the second raw material or the polymerizable composition for optical materials.
• the filtering step can be performed using a filter.
• a filter for example, a capsule filter can be used.
• the filtration accuracy of the filter is preferably 1.0 ⁇ m to 4.5 ⁇ m.
• the filtering step is preferably provided at least either before or after the stirring step.
• the polymerizable composition for optical materials has a standard deviation of 60 or less as measured under Condition 1 below.
• the standard deviation was obtained by putting a mixture of the first raw material and the second raw material into a quartz cell with an optical path length of 8 mm, an area of 360 mm 2 and a thickness of 12 mm, a shutter of 1/5000 (sec), gamma correction of 100, The image is measured using a glass striae inspection device under the conditions of sharpness 500, contrast and brightness 0, and the image is analyzed by image analysis software (ImageJ). Calculated assuming a normal distribution.
• the standard deviation is 60 or less, unevenness in the polymerizable composition for optical materials can be suppressed, and casting striae in the resulting optical material can be suppressed.
• the standard deviation is preferably 50 or less, more preferably 40 or less.
• the standard deviation is preferably 5 or more, more preferably 10 or more, even more preferably 20 or more, from the viewpoint of handling properties of the polymerizable composition for optical materials. It is also preferable that the standard deviation is 5 or more and 60 or less.
• the standard deviation is measured according to Condition 1 above.
• Examples of the glass striae examination device include FG100-RT-L3 (manufactured by Kato Koken Co., Ltd., observation effective diameter: 100 mm, length at opening: 300 mm).
• the dimensions of the quartz cell are preferably, for example, 12 mm wide, 49 mm high, and 12 mm thick, and the dimensions of the liquid passing portion are preferably 8 mm wide, 45 mm high, and 8 mm thick, for example. .
• the standard deviation is calculated as the average value for 15 seconds by taking 30 images in 1 second, measuring the standard deviation for each image.
• the method for producing the optical material of the present disclosure preferably includes at least one of the following shearing step and stirring step. This makes it easier to keep the above standard deviation within the above range.
• the method for producing an optical material of the present disclosure preferably includes both the following shearing step and stirring step, for example, in the first step.
• the shearing step is a step of applying a shearing force to a mixture of the first raw material and the second raw material (simply referred to as raw material mixture).
• shear force force applied in a direction transverse to the direction of flow
• shearing applying force primarily in a direction transverse to the direction of flow
• “Making it flow” means, for example, sending the raw material mixture from the tank to the power mixer, sending the raw material mixture from the power mixer to the stirring tank, etc. to make the raw material mixture flow.
• the flow rate of the raw material mixture is preferably 3 g/s or more, more preferably 6 g/s or more, from the viewpoint of increasing productivity while suppressing an increase in the viscosity of the polymerizable composition for optical materials. is more preferable, and 9 g/s or more is even more preferable.
• the flow rate of the raw material mixture is preferably 30 g/s or less, and preferably 25 g/s or less, from the viewpoint of suppressing unevenness in the polymerizable composition for optical materials and suppressing casting striae of the optical materials. is more preferably 20 g/s or less.
• the rotation speed in the shearing step is preferably 200 rpm or more, more preferably 400 rpm or more, and even more preferably 500 rpm or more.
• the rotation speed in the shearing step is preferably 3000 rpm or less, more preferably 2500 rpm or less, and even more preferably 2000 rpm or less.
• a stirring process is a process of applying stirring force to the mixture of a 1st raw material and a 2nd raw material.
• a force applied in a direction substantially parallel to and opposite to the flow direction is also referred to as a stirring force.
• the preferable range of the flow rate of the raw material mixture when applying force in a direction substantially parallel to and opposite to the flow direction is the same as the preferable range of the flow rate of the raw material mixture in the ⁇ shearing step> described above.
• the rotation speed in the stirring step is preferably 50 rpm or more, more preferably 100 rpm or more, and even more preferably 200 rpm or more.
• the rotation speed in the stirring step is preferably 800 rpm or less, more preferably 600 rpm or less, and even more preferably 400 rpm or less.
• the method for producing an optical material of the present disclosure includes a shearing step and a stirring step, so that a uniform polymerizable composition for optical materials can be continuously produced. This makes it possible to better suppress casting striae in the resulting optical material.
• the method for producing an optical material of the present disclosure preferably includes a shearing step and a stirring step in this order.
• the second step is a step of producing an optical material using the polymerizable composition for optical materials. This makes it possible to obtain an optical material in which casting striae are suppressed.
• the second step may be a step of casting the polymerizable composition for optical materials into a mold and curing to produce an optical material.
• Casting may be performed by a multi-screw method or by a mixing method just before casting.
• the casting method may be manual casting or automatic casting by machine.
• the method of automatic casting may be pressure feeding using nitrogen, or may be liquid feeding using a pump (diaphragm pump, gear pump, etc.).
• pressure for example, back pressure
• nitrogen or the like to cast the polymerizable composition for optical materials into a mold.
• Curing can be performed by polymerizing two or more different optical material monomers in the polymerizable composition for optical materials in the mold.
• An optical material can be produced by polymerizing the polymerizable composition for an optical material.
• the method of polymerization is not particularly limited, but a known method of heating to generate a polymerization reaction may be used.
• a method of injecting the polymerizable composition into a molding mold (mold) held by a gasket, tape, or the like and gradually raising the temperature while heating to promote the polymerization reaction may be used.
• a method of conducting a polymerization reaction without heating may be used. That is, the polymerizable composition for optical materials may be cured by polymerization by allowing the polymerizable composition for optical materials to stand still.
• the environment in which the curing is performed is not particularly limited, and the mold can be heated from outside the mold for curing. It is preferable to cure the polymerizable composition for optical materials by allowing the polymerizable composition to stand in a closed space. By allowing the polymerizable composition for optical materials to stand still in the closed system space, it is possible to prevent the heat generated by the self-heating of the polymerizable composition for optical materials from being released to the outside. As a result, the heat generated by self-heating can be retained in the closed system space, so that the polymerization reaction can be promoted more efficiently, and the optical material can be produced in a shorter time.
• a closed system space includes, for example, an adiabatic environment.
• An adiabatic environment refers to an environment in which heat is retained inside and heat conduction between the inside and the outside is suppressed.
• the environment in which heat conduction between the inside and the outside is suppressed means that, when the polymerizable composition for optical materials is allowed to stand in the closed space, the heat conduction between the inside and the outside of the closed space is high. It means an environment in which the polymerizable composition for optical materials can be cured.
• the insulating environment can be formed, for example, using insulating materials. That is, by allowing the polymerizable composition for optical materials to stand still in a heat-insulating container made of a heat-insulating material, heat can be retained inside the heat-insulating container and heat conduction between the inside and the outside can be suppressed. .
• the thermal conductivity of the heat insulating material is preferably 0.50 W/mK or less, more preferably 0.10 W/mK or less, and further preferably 0.05 W/mK or less. preferable.
• the density of the heat insulating material is preferably 10 kg/m 3 or more, more preferably 15 kg/m 3 or more, and even more preferably 20 kg/m 3 or more.
• the polymerization reaction due to the reaction heat of the polymerizable composition for optical materials is hindered, or the polymerization reaction of the polymerizable composition for optical materials is excessively promoted by external heating. It is preferable to heat the adiabatic reaction vessel to a constant temperature state (constant temperature reaction vessel) within a range in which the temperature does not increase. As a result, the environmental temperature in the reaction tank (constant temperature reaction tank) in which the mold is placed can be kept warm or constant according to the temperature rise due to the self-heating of the optical material monomer. It can favorably promote the polymerization reaction.
• the adiabatic environment can be, for example, an adiabatic or isothermal reactor as described above.
• adiabatic polymerization in an adiabatic environment using an adiabatic reaction tank can be carried out according to the following procedure. can.
• the inner surface of the vacuum container is covered with a member having heat insulation and heat retention such as urethane foam or cork, and the mold into which the monomer is injected is wrapped with a member such as waste cloth as necessary. Then, the mold filled with the monomer is left still in the vacuum vessel.
• the curing step may be a step of curing the polymerizable composition for optical materials by allowing the polymerizable composition for optical materials to stand without externally heating the composition.
• the present disclosure does not necessarily require heating of the polymerizable composition for optical materials.
• a device may be used, which may increase the economic burden. If the method does not require heating from the outside, the optical material can be produced by a simple method, and the economic burden can be reduced.
• the curing step is preferably a step of curing the polymerizable composition for optical materials by allowing the polymerizable composition for optical materials to stand for 2 to 10 hours. In the curing step, it is more preferable to leave the polymerizable composition for optical materials at rest for 8 hours or less.
• the polymerizable composition for optical materials is preferably allowed to stand still for 2 hours or longer, and more preferably allowed to stand for 3 hours or longer.
• a microwave irradiation step of irradiating the polymerizable composition for optical materials with microwaves for a predetermined period of time may be provided.
• One aspect of the curing step includes an aspect including the following steps a and b.
• Step a Injecting (casting) a polymerizable composition for an optical material into a mold (into a mold cavity).
• Step b The mold into which the polymerizable composition for optical materials has been injected is allowed to stand still in a closed system space for a predetermined period of time for adiabatic polymerization.
• Step a First, the polymerizable composition is injected into a molding mold (mold) held by a gasket, tape, or the like. At this time, depending on the physical properties required for the optical material to be obtained, it is preferable to perform defoaming treatment under reduced pressure, filtration treatment under increased pressure or reduced pressure, or the like, if necessary.
• the polymerization conditions are not particularly limited, but are preferably adjusted according to the composition of the polymerizable composition for optical materials, the type and amount of the catalyst used, the shape of the mold, and the like.
• the mold into which the polymerizable composition for optical materials has been injected may be allowed to stand still in an adiabatic environment for 2 to 4 hours for polymerization.
• a heating step may be added after the adiabatic polymerization process in which the mold filled with the polymerizable composition for optical materials is allowed to stand in an adiabatic environment for a certain period of time.
• step b in parallel with the step of leaving the mold into which the polymerizable composition for optical materials has been injected in an adiabatic environment (adiabatic polymerization), continuously or intermittently in the adiabatic polymerization process Heat the mold filled with the polymerizable composition for optical materials at a temperature that does not exceed the self-heating generated by the polymerizable composition for optical materials, or heat the inside of the adiabatic reaction tank to maintain the environmental temperature in the adiabatic reaction tank. You may
• the method for producing an optical material of the present disclosure may optionally include an annealing step of annealing the cured polymerizable composition for optical materials.
• the temperature for the annealing treatment is generally 50 to 150.degree. C., preferably 90 to 140.degree. C., more preferably 100 to 130.degree.
• the optical material produced by the method for producing an optical material of the present disclosure can be used for plastic lenses, prisms, optical fibers, information recording substrates, filters, light-emitting diodes, and the like.
• the optical material can be suitably used for plastic lenses, and more suitably for spectacle plastic lenses.
• the molded article was projected by an ultra-high pressure mercury lamp (light source type OPM-252HEG, manufactured by Ushio Inc.), and the transmitted image was visually observed and evaluated according to the following criteria.
• Examples 1 to 2 and Comparative Examples 1 to 3 (Production of composition) 1.5 parts by mass of Tinuvin 329 [ultraviolet absorber] and 50.7 parts by mass of m-xylylenediisocyanate [monomer for optical materials] were charged to prepare a mixed solution. The mixture was stirred at 25° C. for 1 hour for complete dissolution.
• FIG. 1 is a schematic diagram for explaining shearing and stirring of a raw material mixture.
• a power mixer 1 was used to apply a shearing force to the raw material mixture.
• Capsule Filter 2 manufactured by F-Tech Co., Ltd.
• the raw material mixture After passing through the capsule filter 2, the raw material mixture is sent to a buffer tank 4 (stirring tank) having a water bath 3, and stirred in the buffer tank 4, so that the raw material mixture flows in a direction substantially parallel and opposite to the flow direction. was vigorously stirred. At that time, back pressure was applied using nitrogen from the liquid surface side of the stirring tank. A second standard deviation measuring point 52 was provided after the capsule filter 2 and before the buffer tank 4 .
• the raw material mixture was stirred with a static mixer (32) 6 (the number of elements: 32) or a static mixer (48) 7 (the number of elements: 48) while adjusting the flow rate with the pinch valve 5.
• a third standard deviation measuring point 53 was provided after the buffer tank 4 and before the static mixer (32) 6 and the static mixer (48) 7 .
• a fourth standard deviation measuring point 54 is provided after the static mixer (32) 6.
• a fifth standard deviation measuring point 55 is provided after the static mixer (48) 7.
• Table 1 shows the measurement points of the standard deviation in each example and comparative example.
• the flow cell 8 When measuring the standard deviation at each of the above measurement points, the flow cell 8 is installed at each measurement point, and the raw material mixture at the measurement point is made to flow through the flow cell 8 as a polymerizable composition for optical materials, and the standard deviation is measured. bottom.
• the raw material mixture sampled at each measurement point was cast as a polymerizable composition for optical materials into a lens-producing mold having a diameter of 78 mm, four curves, and a center thickness of 10 mm. That is, the polymerizable composition for optical materials used in each example and comparative example is a raw material mixture at each measurement point, and the mixed state of the polymerizable composition for optical material used in each example and comparative example is at each measurement point. It is the same as the mixed state of the raw material mixture.
• a polymerization reaction was carried out by the following method. - The mold after casting was placed in a heat-insulated container at 25°C and allowed to stand still for adiabatic polymerization for 2 hours. After that, the cast product was taken out from the heat-insulating container, and heat polymerization was further performed at 120° C. for 1 hour.
• the mold was allowed to cool naturally, the cured molded article was released from the mold, and annealing was performed at 120°C for 2 hours to obtain a molded article (lens).
• Examples 3 to 4, and Comparative Examples 4 to 6 A molded body (lens) was obtained in the same manner as in Example 1, except that the first raw material and the second raw material were changed to the following first raw material and second raw material.
• Table 1 shows the viscosity Va of the viscosity of the first raw material. 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiundecane and 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiundecane; 41.9 parts by mass of a mixture of 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane was charged, and the mixture was subjected to desorption at 400 Pa and 20° C. for 1 hour. A second raw material was obtained. Table 1 shows the viscosity Vb of the second raw material.
• Comparative Example 7 In Comparative Example 7, the following composition was used as the polymerizable composition for optical materials without producing the first raw material and the second raw material.
• composition 0.008 parts by mass of dimethyltin (II) dichloride (also referred to as DMC), 0.1 parts by mass of an internal release agent for MR manufactured by Mitsui Chemicals, Inc., 0.6 parts by mass of each of the ultraviolet absorbers Tinuvin 329 and Seesorb 709, A mixed solution was prepared by charging 50.7 parts by mass of m-xylylene diisocyanate. This mixed solution was stirred at 25° C. for 1 hour to dissolve completely.
• the resulting polymerizable composition for optical materials was passed through a capsule filter (manufactured by F-Tech Co., Ltd.) and filtered. A standard deviation measurement point was provided after the capsule filter. After filtering, the polymerizable composition for optical materials was cast into a lens-making mold having a diameter of 78 mm, four curves, and a center thickness of 10 mm.
• a polymerization reaction was carried out by the following method. - Using an oven, the mold after casting was heated from 20°C to 120°C over time, and heat polymerization was performed over 30 hours.
• the mold was naturally cooled, the cured molded product was released from the mold, and the molded product was annealed at 120° C. for 2 hours to obtain a molded product (lens).
• a polymerizable composition for optical materials containing two or more different monomers for optical materials and a polymerization catalyst by mixing a first raw material and a second raw material Obtaining a polymerizable composition for an optical material having a standard deviation of 60 or less measured under Condition 1 of No. 1 and a viscosity of 30 mPa s to 1000 mPa s measured with a Brookfield viscometer at 25° C. and 60 rpm. and the second step of producing an optical material using the polymerizable composition for an optical material. Casting striae in optical materials could be suppressed.
• Example 5 and Comparative Example 8 A molded body (lens) was obtained in the same manner as in Example 1, except that the first raw material and the second raw material were changed to the following first raw material and second raw material.
• Table 2 shows various physical property values, types of catalysts, concentrations of catalysts, measurement locations of standard deviations, standard deviations, and evaluations.
• This mixed liquid was degassed at 400 Pa and 25° C. for 1 hour to obtain a second raw material.
• Table 2 shows the viscosity Vb of the second raw material.
• a polymerizable composition for optical materials containing two or more different monomers for optical materials and a polymerization catalyst by mixing the first raw material and the second raw material Obtaining a polymerizable composition for an optical material having a standard deviation of 60 or less measured under Condition 1 of No. 1 and a viscosity of 30 mPa s to 1000 mPa s measured with a Brookfield viscometer at 25° C. and 60 rpm. and the second step of producing an optical material using the polymerizable composition for an optical material. Casting striae in optical materials could be suppressed.
• Comparative Example 8 in which the standard deviation was more than 60, was inferior in evaluation of casting striae, and casting striae could not be suppressed in the resulting optical material.
• Example 6 to 7 A molded body (lens) was obtained in the same manner as in Example 1, except that the first raw material and the second raw material were changed to the following first raw material and second raw material.
• Table 3 shows various physical property values, types of catalysts, concentrations of catalysts, measurement locations of standard deviations, standard deviations, and evaluations.
• a polymerizable composition for optical materials containing two or more different monomers for optical materials and a polymerization catalyst by mixing the first raw material and the second raw material Obtaining a polymerizable composition for an optical material having a standard deviation of 60 or less measured under Condition 1 and a viscosity of 30 mPa s to 1000 mPa s as measured with a Brookfield viscometer at 25°C and 60 rpm and the second step of producing an optical material using the polymerizable composition for an optical material. Casting striae in optical materials could be suppressed.

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• 2023
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