as) United States
`a2) Patent Application Publication co) Pub. No.: US 2009/0097129 Al
`
`
`(43) Pub. Date:NAITOetal. Apr. 16, 2009
`
`US 20090097129A1
`
`(54) OPTICAL ARTICLE AND PROCESS FOR
`PRODUCING OPTICAL ARTICLE
`
`(75)
`
`Inventors:
`
`Shuji NAITO,Inashi (JP); Yosuke
`SUGIHARA,Suwashi (JP)
`Correspondence Address:
`HOGAN & HARTSONL.L.P.
`1999 AVENUE OF THE STARS, SUITE 1400
`LOS ANGELES, CA 90067 (US)
`
`(73) Assignee:
`
`SEIKO EPSON
`CORPORATION,Tokyo (JP)
`
`Aug. 12,2008
`
`(JP) oo. eeeen renee 2008-208121
`
`Publication Classification
`
`(51)
`
`Int.Cl
`(2006.01)
`GO2B 1/04
`(2006.01)
`B32B 3/22
`(2006.01)
`B32B 18/00
`(2006.01)
`B32B 23/08
`(2006.01)
`B32B 27/06
`(2006.01)
`B29D 11/00
`(52) US. CL wees 359/653; 428/425.9; 428/419;
`428/212; 428/218; 428/414; 428/404; 427/164
`
`(21) Appl. No.:
`
`12/247,073
`
`(57)
`
`ABSTRACT
`
`Filed:
`
`(22)
`
`(30)
`
`Oct. 7. 2008
`,
`Foreign Application Priority Data
`
`Oct. 15,2007
`Jan. 28, 2008
`
`(IP) veecccccceseteeeeteestsneeees 2007-267774
`(IP) vecececccscsseeessseessssesees 2008-016342
`
`An optical article includes a plastic substrate, wherein a
`primerlayer and a hard coat layer are formed on a surface of
`the plastic substrate, and the primerlayer is formed from a
`coating composition containing the following components
`(A) to (C): (A) a polyurethane resin; (B) metal oxide fine
`particles; and (C) an organosilicon compound.
`
`1
`
`14
`
`13
`
` Kili 12
`—L6G
`
`
`
`11
` 10
`
`1
`
`APPLE 1019
`
`APPLE 1019
`
`1
`
`

`

`Patent Application Publication=|Apr.16,2009=US 2009/0097129 Al
`
`ia" i
`VIILillI
`
`SSSpoms
`
`
`FIG. 1
`
`2
`
`

`

`US 2009/0097129 Al
`
`Apr. 16, 2009
`
`OPTICAL ARTICLE AND PROCESS FOR
`PRODUCING OPTICAL ARTICLE
`
`primerlayer, and a hard coat layer, causes almost nointerfer-
`ence fringe, and is excellent in impact resistance, and a pro-
`cess for producing an optical article.
`BACKGROUND
`[0008]Afirst aspect of the invention is directedto an opti-
`[0001]
`1. Technical Field
`cal article composedofa plastic substrate, wherein a primer
`[0002] The present invention relates to an opticalarticle to
`layer and a hard coat layer are formed on a surface of the
`be used as a plastic lens for spectacles, cameras, andthe like,
`plastic substrate, and the primerlayer is formed from a coat-
`and a process for producing an optical article.
`ing composition containing the following components (A) to
`[0003]
`2. Related Art
`(©):
`[0004]
`Plastic lenses are lightweight and excellent in mold-
`[0009] (A)apolyurethaneresin;
`
`ability, processability, dyeability, etc. and less likely to crack
`[0010]
`(B) metal oxidefine particles; and
`and have high safety as compared with glass lenses. There-
`[0011]
`(C) an organosilicon compound.
`fore, their use has rapidly spread in the field of lenses for
`[0012]
`Inaccordance with the aspect ofthe invention, as the
`spectacles and they make up a large portion thereof. Further,
`coating composition for forming the primerlayer, not only a
`recently, in order to meet an additional demandof reducing
`polyurethaneresin and metaloxidefine particles are used, but
`the thickness and weight, a material having a high refractive
`also an organosilicon compound is used in combination.
`index such as a thiourethane resin or an episulfide resin has
`Therefore, a space portion in the primerlayeris filled with the
`been developed. For example, a process for producing an
`organosilicon compound (component (C)), and thus the den-
`episulfide resin having a very high refractive index by poly-
`sity of the entire primerlayer is increased. Accordingly, even
`merization of acompoundhavingan epithio group (an episul-
`withoutusing titanium oxide, or by incorporating only a small
`fide compound) in the presence of sulfur has been proposed
`amountoftitanium oxide therein, the refractive index of the
`(see JP-A-2004-002712 and JP-A-2005-281527). Such an
`primerlayer can be improved, and the occurrenceofinterfer-
`episulfide resin can easily exhibit a high refractive index of
`ence fringe can be prevented. Further, when the used amount
`1.7 or higher and is effective in reducing the thickness of
`of titantum oxide is decreased, the photocatalytic action is
`lenses for spectacles.
`also decreased, andthe light resistance is improved. Further,
`[0005] On the other hand, when the refractive index of a
`a polyurethaneresin is containedin the primerlayer, therefore
`lens substrate is increased, a primer layer and a hard coat layer
`the impactresistance is also superior.
`should have a refractive index equal to that of the lens sub-
`[0013]
`Asthe plastic substrate, a plastic substrate which is
`strate for preventing the occurrenceofinterference fringe. For
`obtained by polymerizing and curing a polymerizable com-
`example, in general, any of various metal oxides is incorpo-
`position containing an episulfide compoundas a main com-
`rated in the hard coatlayerasa filler thereby increasing the
`ponent, and has a refractive index of 1.7 or higheris preferred.
`refractive index. As the metal oxide, fine particles of a simple
`Becausetheplastic substrate hasa high refractive index of 1.7
`substance suchas titanium oxide, zirconium oxide, antimony
`or higher, the reduction ofthe thickness ofthe substrate for an
`oxide or tin oxide or compositefine particles thereof are used.
`optical article is easy, and further, an optical article having
`However, such a metal oxide is generally poor in light resis-
`few interference fringes can be easily provided.
`tance andtendsto be colored. Therefore, from the viewpoint
`[0014]
`Itis preferred that the average particle diameters of
`of transparency andstability in the visible light range and the
`the component (A) and the component (B) in the coating
`like, titanium oxide is mainly used. However,titanium oxide
`composition are from 5 to 50 nm,respectively, and the aver-
`has a property of exhibiting a photocatalytic action under
`age particle diameter of the component(C) is 5 nm.
`ultraviolet radiation. Therefore, when titanium oxide is used
`[0015]
`In accordance with this configuration, the average
`as a filler in the hard coat layer,
`it decomposes a binder
`particle diameters of the component (A) and the component
`component composed of an organic resin therearound, and
`(B), and the averageparticle diameter of the component (C)
`the coat layeris often peeled off. As one of the measures for
`each fall within a predetermined range, and therefore, the
`this problem,it is often the casethat not anatase-type titanium
`refractive index of the primerlayer can be further improved.
`oxide whichis likely to exhibit a photocatalytic action, but
`As a result, even when a plastic substrate having a high
`rutile-type titantum oxide which exhibits a relatively less
`refractive index of 1.7 or higher is used, the occurrence of
`photocatalytic action is adopted as titanium oxide (for
`interference fringe can be effectively prevented.
`example, see JP-A-2007-102096).
`[0016] The mechanism of this action is presumedas fol-
`[0006] However, such rutile-type titanium oxide do not
`lows. In the absence of the component (C), even when the
`completely have a photocatalytic action, and an attempt that
`refractive index of metal oxide fine particles as the compo-
`the photocatalytic action is reduced by coating the surface
`nent (B) is increased or the ratio thereof is increased, the
`thereofwith an insulating material such as silicon dioxide has
`refractive index of the primerlayer is not improved so much.
`also been made,but is not sufficient. Accordingly, whenlight
`Therefore, as the mechanism of action for achieving the
`resistance is considered, amethodof increasing the content of
`above-mentioned effect, because the average particle diam-
`rutile-type titanium oxide in the coating layer could not sim-
`eters ofthe above-mentionedrespective particlesfall within a
`ply increase the refractive index of a hard coat layer or a
`predetermined range, the component (C) enters a space (a
`primerlayer, and whena lens substrate has a refractive index
`space portion) formedbythe particles composed of the com-
`of 1.7 or higher, the occurrence of interference fringe could
`ponent(A) andthe particles composed of the component(B),
`not completely be prevented. Further, a problem has also
`resulting in forming a dense layer at such a portion and
`arisen that the impact resistance is decreased as the thickness
`contributing to the improvementofrefractive index. The aver-
`ofa lens substrate is reduced.
`age particle diameters ofthe above-mentionedrespective par-
`ticles can be obtained bya light scattering method.
`[0017]
`Itis preferred that the optical article accordingto the
`aspectofthe invention hasa first layer whichis in contact with
`
`SUMMARY
`
`[0007] An advantage of someaspects of the invention is to
`provide an optical article which includesa plastic substrate, a
`
`3
`
`

`

`US 2009/0097129 Al
`
`Apr. 16, 2009
`
`the plastic substrate and has a refractive index which
`decreases in the direction away from the plastic substrate; a
`second layer which is in contact with thefirst layer and has a
`refractive index not higherthan thatofthe surface layer of the
`first layer; and a hard coat layer which is in contact with the
`second layer and hasa refractive index lowerthan that of the
`plastic substrate.
`[0018]
`In accordance with this configuration, the optical
`article basically includes a plastic substrate, a hard coatlayer,
`and first and second layers, both of which are sandwiched
`between the plastic substrate and the hard coat layer. There-
`fore, the first and second layers can be allowedto serve as a
`primerlayer, that is, a function including adhesion and impact
`resistance. Further, by allowingthefirst layer having a refrac-
`tive index which decreases in the direction away from the
`plastic substrate to have a function to prevent the occurrence
`of interference fringe through adjustment of the refractive
`index, the need of increasing the refractive index of the sec-
`ondlayer can be relieved. Due to this, in the secondlayer, the
`need of increasing the ratio of metal oxidefine particles can
`be relieved,
`therefore,
`the second layer can sufficiently
`exhibit an impact absorbing function. Further, because the
`needofincreasing therefractive index ofthe second layer can
`berelieved, the need of increasing the refractive index of the
`hard coat layer can also berelieved.
`[0019] That is, in this optical article, by the first layer,
`adhesion and a function to prevent the occurrenceofinterfer-
`ence fringe through adjustment of the refractive index can
`mainly be imparted. By the second layer, impact resistance,
`that is, impact absorbing function can be mainly imparted.
`Further, by providing a hard coat layer which is harder than
`the first and second layers on the secondlayer, scratch resis-
`tance and abrasion resistance can be imparted. Further,
`because the need of increasing the refractive index of the
`second layer and also the need of increasing the refractive
`index of the hard coat layer can be relieved bythefirst layer,
`the refractive indices of the second layer and the hard coat
`layer to be laminatedto thefirst layer can be lower than that
`of the plastic substrate. Accordingly, the constitutions of
`these layers, choices of compositions for forming these layers
`and the degree of freedom of the designing are increased. As
`described above, according to the aspect of the invention, the
`occurrence of interference fringe can be prevented, and an
`optical article which has high durability including impact
`resistance, scratch resistance, and abrasion resistance and
`also has a high refractive index can be provided.
`[0020]
`Itis preferred that the secondlayeris formed from a
`second material containing a urethane,ester, epoxy, acrylic or
`silicone organic resin and metal oxide fine particles.
`[0021]
`In accordance with this configuration, the second
`layer is formed from the second material containing a ure-
`thane,ester, epoxy, acrylic, or silicone organic resin and metal
`oxide fine particles. Therefore, adhesion becomes more
`favorable. Further, among these organic resins, a urethane or
`ester organic resin is preferred. The second layer can be
`formed by, for example, a dip coating method, a spin coating
`method, a spray coating methodorthelike.
`[0022]
`It is preferred that a first material for forming the
`first layer, the second material for forming the second layer
`and a third material for forming the hard coat layer each
`contain metal oxide fine particles and an organicresin, and the
`ratio of the metal oxide fine particles to the organic resin
`
`containedin the first material is greater than the ratio of the
`metal oxidefineparticles to the organic resin containedin the
`second material.
`
`In accordance with this configuration, the first layer
`[0023]
`having a high refractive index in the vicinity of the plastic
`substrate can be obtained and also the second layer having
`high impactresistance can be obtained. Further, in this case,
`the ratio of the metal oxide fine particles to the organic resin
`contained in the third material may be set greater than the
`ratio of the metal oxide fine particles to the organic resin
`contained in the second material.
`
`Itis preferred that the refractive index of the primer
`[0024]
`layer decreases continuously or stepwise from the side of the
`plastic substrate toward the side of the hard coatlayer.
`[0025]
`In accordance with this configuration,therefractive
`index of the primerlayer decreases continuously or stepwise
`from the side of the plastic substrate toward the side of the
`hard coatlayer, therefore, the refractive index ofthe hard coat
`layer can be decreased. That is, even whenthe refractive index
`of the hard coat layer is low, a difference in the refractive
`index with the primer layer can be made small, therefore, the
`occurrence ofinterference fringe can be prevented.
`[0026]
`In the past, in the case where a hard coat layer was
`formed on a surface of an optical article such as an optical
`lens, whentherefractive index of a substrate was high,it was
`necessary that the a primer layer and the hard coat layer
`should have a high refractive index in response thereto. In
`accordance with the aspect of the invention, the refractive
`index of the hard coat layer should not be increased, and
`therefore, the degree of freedom of designing of the hard coat
`layer is increased.
`[0027]
`Itis preferred that a difference betweentherefrac-
`tive index of the primer layer in the vicinity of the plastic
`substrate and the refractive index of the plastic substrate is
`0.01 orless.
`
`In accordance with this configuration, a difference
`[0028]
`betweenthe refractive index ofthe primerlayer in the vicinity
`of the plastic substrate and the refractive index ofthe plastic
`substrate is a predetermined value or less, therefore, the
`occurrence of interference fringe can be effectively pre-
`vented.
`
`Itis preferred that a difference betweentherefrac-
`[0029]
`tive index of the primerlayer in the vicinity of the hard coat
`layer andthe refractive index of the hard coat layer is 0.01 or
`less.
`
`In accordance with this configuration, a difference
`[0030]
`betweenthe refractive index ofthe primerlayer in the vicinity
`ofthe hard coat layer and the refractive index of the hard coat
`layer is a predetermined valueorless, therefore, the occur-
`rence of interference fringe can be effectively prevented.
`[0031]
`Itis preferred that the component(C) is an organo-
`silicon compoundhaving an epoxy group.
`[0032]
`In accordance with this configuration, the organo-
`silicon compoundhas an epoxy group, therefore, the adhe-
`sion of the primerlayer to the plastic substrate and the hard
`coat layer is excellent. Further, the crosslink density of the
`primerlayer is not increased too much andis appropriately
`controlled, therefore, the optical article is excellent in impact
`resistance.
`
`It is preferred that the component (C) is an orga-
`[0033]
`noalkoxysilane compoundand the organoalkoxysilane com-
`poundis used in the form of an unhydrolyzed monomer.
`[0034]
`In accordance with this configuration, the orga-
`noalkoxysilane compoundis used in the form of an unhydro-
`
`4
`
`

`

`US 2009/0097129 Al
`
`Apr. 16, 2009
`
`lyzed monomer,therefore, it is easily filled in a space portion
`in the primer layer as compared with the case where it is
`polymerized by hydrolysis. Accordingly, the refractive index
`of the primerlayeris further improved, and the occurrence of
`interference fringe can be prevented although an episulfide
`plastic substrate having a refractive index of 1.7 or higheris
`used.
`
`can be provided. Accordingly,the plastic lens accordingto the
`aspect of the invention can be widely used as a variety of
`thin-type optical lenses such as lenses for spectacles, lenses
`for cameras,lenses for telescopes, lenses for microscopes and
`collective lenses for steppers.
`[0045] A second aspect of the invention is directed to a
`process for producing an optical article composedof a plastic
`substrate includes a substrate production step of producing a
`Itis preferred that the ratio of the component(C) to
`[0035]
`plastic substrate by polymerizing and curing a polymerizable
`the total components (A) to (C) is from 0.1 to 10% by mass.
`composition; anda surface treatment step offorming a primer
`[0036]
`In accordance with this configuration, the ratio of
`layer and a hard coat layer on a surface ofthe plastic substrate,
`the organosilicon compound as the component(C) is 0.1% by
`wherein in the formation of the primer layer in the surface
`massor more, therefore, the adhesionto the plastic substrate
`treatmentstep, a coating composition containing the follow-
`and the hard coat layer is superior. In addition, because the
`ing components (A) to (C) is used:
`ratio of the organosilicon compound is 10% by massorless,
`a decrease in the refractive index and abrasion resistance is
`[0046] (A)apolyurethaneresin;
`
`[0047]
`(B) metal oxidefine particles; and
`not caused. The upper limit of the component(C)is prefer-
`[0048]
`(C) an organosilicon compound.
`ably 7% by massor less; and more preferably 5% by mass or
`less.
`[0049]
`In accordance with the aspect of the invention, a
`plastic substrate is produced by polymerizing and curing a
`polymerizable composition, therefore, a substrate having a
`different refractive index can be easily obtained. For example,
`whena polymerizable composition containing an episulfide
`compound as a main componentis used, a substrate having a
`high refractive index of 1.7 or higher can be easily obtained.
`Further, because the production process includes a surface
`treatment step of forming a given primer layer and hard coat
`layer, an opticalarticle which has few interference fringes and
`is excellent in scratch resistance and impact resistance can
`easily be produced.
`
`Itis preferred that the component(B) is metal oxide
`[0037]
`fine particles surface-treated with an organosilicon com-
`pound having an alkyl group.
`[0038]
`In accordance with this configuration, by using a
`polyurethane resin and metal oxide fine particles surface-
`treated with an organosilicon compound having an alkyl
`group such as a methyl group, the compatibility between the
`resin componentand the metal oxide fine particle component
`is improved in the primerlayer, andas a result, the homoge-
`neity is improved. Therefore, the occurrence of interference
`fringe is prevented and the impactresistance is also improved.
`Further, when the homogeneity of the primer layer is
`improved, the homogeneity of spaces to be filled with an
`organosilicon compound as the component
`(C)
`is also
`improvedat the sametime, and as a result, the refractive index
`of the primerlayeris further improved and the occurrence of
`interference fringe can be more effectively prevented.
`[0039]
`It is preferred that the component(B) is metal oxide
`fine particles containing titantum oxide having a rutile-type
`crystal structure as a main component.
`[0040]
`In accordance with this configuration, metal oxide
`fine particles containing titantum oxide having a rutile-type
`crystal structure as a main componentare used as the com-
`ponent (B), therefore, not only the refractive index of the
`primer layer is improved, but also the light resistance is
`improved.In particular, a polyurethaneresin to be used asthe
`component (A) greatly contributes to the improvement of
`light resistance.
`[0041]
`Itis preferred thatthe ratio of the component(B) to
`the total components (A) to (C) is from 40 to 80% by mass.
`[0042]
`In accordance with this configuration, the ratio of
`the metal oxide particles as the component(B)to the total
`components (A) to (C)falls within a predetermined range of
`from 40 to 80% by mass,therefore, the refractive index of the
`primer layer can be sufficiently increased, and also the
`crosslink density of the primer layer can be appropriately
`maintained, and further, the hardness and impact resistance
`are not impaired.
`[0043]
`Itis preferred that the optical article according to an
`aspect of the invention is a plastic lens.
`[0044]
`In accordance with this configuration, a substrate
`having a refractive index of 1.7 or higher, i.e., having a high
`refractive index is used, and moreover, a primer layer is
`formed from the above-mentioned components (A) to (C),
`therefore, a plastic lens which is very thin andis excellent in
`impact resistance and causes almost no interference fringe
`
`BRIEF DESCRIPTION OF THE DRAWING
`
`[0050] The invention will be described with reference to the
`accompanying drawing, wherein like numbersreferencelike
`elements.
`
`[0051] TheFIG.1is a view schematically showing aplastic
`lens as an optical article according to a second embodimentof
`the present invention.
`
`DESCRIPTION OF EXEMPLARY
`EMBODIMENTS
`
`[0052] Hereinafter, embodiments ofan optical article anda
`process for producing an opticalarticle of the present inven-
`tion will be described in detail.
`
`First Embodiment
`
`[0053] An optical article of this embodimentis a plastic
`lens for spectacles and hasa plastic lens substrate (hereinafter
`also referred to as merely a “lens substrate”), a primer layer
`formed ona surface of the lens substrate and a hard coat layer
`formed on the uppersurface ofthe primerlayer. Further, in the
`plastic lens ofthis embodiment, furtheran antireflection layer
`is formed on the upper surface of the hard coat layer. Here-
`inafter, the lens substrate, primer layer, hard coat layer and
`antireflection layer will be described.
`
`1. Lens Substrate
`
`[0054] The lens substrate is not particularly limited as long
`as it is a plastic resin, however, in light of reduction of the
`thickness of a lens for spectacles or for obtaining a difference
`in the refractive index with the antireflection layer formed on
`the upperlayer of the surface of the lens substrate, a plastic
`resin having a refractive index of preferably 1.65 or higher,
`
`5
`
`

`

`US 2009/0097129 Al
`
`Apr. 16, 2009
`
`bromide, and quaternary phosphonium salts such as tetram-
`ethyl phosphonium chloride and tetramethyl phosphonium
`bromide.
`
`Further, the catalyst to be used should be selected
`[0063]
`according to the type of monomerto be used, and also the
`addition amount thereof should be adjusted, however, in gen-
`eral, the addition amountthereof is preferably from 0.001 to
`0.1% by mass based onthe total amountofthe lens substrate
`raw material.
`
`[0064] The polymerization temperature is preferably from
`about 5 to 120° C., and the reaction time is from about 1 to 72
`hours. After completion of the polymerization, in order to
`removelens substrate strain, an annealing treatmentat 50 to
`150° C. for about 10 minutes to 5 hours is preferably per-
`formed.
`
`[0065] When the above-mentioned polymerizable compo-
`sition is prepared, it is also preferred that a polyisocyanate
`compound and/or a polythiol compoundare/is further mixed
`as another monomer.
`
`morepreferably 1.7 or higher, further more preferably 1.74 or
`higher, most preferably 1.76 or higheris used.
`[0055] Examples of sucha lens material having a refractive
`index of 1.65 or higher include a polythiourethaneplastic
`producedby reacting a compoundhaving an isocyanate group
`or an isothiocyanate group with a compound having a mer-
`capto group and an episulfide plastic produced by polymer-
`izing and curing a raw material monomer including a com-
`pound having an episulfide group.
`[0056] As the compound having an isocyanate group or an
`isothiocyanate group to be a main componentof a polythio-
`urethane plastic, a known compound can be used. Specific
`examples of the compound having an isocyanate group
`include ethylene diisocyanate,
`trimethylene diisocyanate,
`2,4,4-trimethylhexane diisocyanate, hexamethylene diisocy-
`anate, and m-xylylene diisocyanate.
`[0057] As the compound having a mercapto group, a
`known compoundcan be used, and examples thereof include
`an aliphatic polythiols such as 1,2-ethanedithiol, 1,6-hex-
`anedithiol, and 1,1-cyclohexanedithiol; and aromatic polythi-
`ols such as 1,2-dimercapto benzene and 1,2,3-tris(mercap-
`tomethyl)benzene. In orderto increasethe refractive index of
`aplastic lens, a polythiol containing a sulfur atom in addition
`to a mercapto group is more preferably used, and specific
`examples thereof include 1,2-bis(mercaptomethylthio)ben-
`zene, 1,2,3-tris(mercaptoethylthio)benzene, and 1,2-bis((2-
`mercaptoethy])thio)-3-mercaptopropane.
`[0058]
`Further, a plastic resin obtained by polymerizing
`and curing a polymerizable composition containing an
`episulfide compound as a main componentto havea refrac-
`tive index of 1.7 or higher, preferably higher than 1.7 is also
`preferably used.
`[0059] As the episulfide compound, a known compound
`having an episulfide group can be used without any limita-
`tion. Specific examples thereof include an episulfide com-
`pound obtained by substituting a part or all of oxygen of the
`epoxy group of an existing epoxy compound with sulfur.
`[0069] The primer layer according to the invention is
`Further, in order to increase the refractive index of a lens
`formed from a coating composition containing the following
`substrate, a compoundcontaining a sulfur atom in addition to
`components (A) to (C):
`an episulfide group is preferably used, and specific examples
`[0070] (A)apolyurethaneresin;
`
`thereof include 1,2-bis(6-epithiopropylthio)ethane, bis(p-
`[0071]
`(B) metal oxidefine particles; and
`epithiopropyl)sulfide, —1,4-bis(B-epithiopropylthiomethyl)
`[0072]
`(C) an organosilicon compound.
`benzene,
`2,5-bis(6-epithiopropylthiomethy])-1,4-dithiane,
`[0073] The polyurethaneresin as the component(A) exhib-
`and bis(-epithiopropyl)disulfide. These episulfide com-
`its adhesion to both lens substrate and hard coat layer. Further,
`pounds maybeused aloneor in admixture thereof.
`the polyurethaneresin has a superior effect of improving light
`[0060] The lens substrate can be obtained by mixing the
`resistance as compared with the case where another resin
`above-mentioned episulfide compound as a monomerand a
`such as a polyester resin is used.
`given catalyst and optionally sulfur, casting the resulting mix-
`[0074] The polyurethane resin is not particularly limited,
`ture into a glass or metal mold and effecting so-called cast-
`and a water-soluble or water-dispersible polyurethane resin
`molding polymerization. By performing polymerization in
`obtained by reacting a diisocyanate compound with a diol
`the presenceof sulfur, alens substrate having a high refractive
`compound can be used. Further, one type or two or more types
`index of 1.74 or higher is easily obtained. When sulfur is
`of polyurethane resins can be used. Examplesofthe diisocy-
`mixed, the amountof sulfur is preferably from 0.1 to 25 parts
`anate compound include alicyclic diisocyanate compounds
`by mass, more preferably from 1 to 20 parts by mass based on
`such as hexamethylene diisocyanate, 2,2,4-trimethylhexam-
`100 parts by mass ofthe episulfide compound.
`ethylene diisocyanate, hydrogenerated xylylene diisocyan-
`[0061] Examples of the catalyst to be used in the polymer-
`ate, 1,4-cyclohexane diisocyanate and 4,4-dicyclohexyl-
`ization include amines, phosphines, quaternary ammonium
`methane diisocyanate;
`aromatic
`aliphatic diisocyanate
`salts, quaternary phosphonium salts, tertiary sulfonium salts,
`compoundssuch as xylylene diisocyanate and tetramethylxy-
`secondary iodonium salts, mineral acids, Lewis acids,
`lylene diisocyanate; aromatic diisocyanate compounds such
`organic acids, silicic acids, and tetrafluoroboric acids.
`as toluene diisocyanate and phenylmethane diisocyanate; and
`[0062] Among these, preferred examples of the catalyst
`modified compoundsof these diisocyanates (such as carbo-
`include amines such as aminoethanol and 1-aminopropanol,
`diimide-, uretodione-, and uretoimine-containing modified
`quaternary ammonium salts such as tetrabutyl ammonium
`compounds).
`
`[0066] By allowing not only an episulfide compound, but
`also a polyisocyanate compoundora polythiol compoundto
`participate in polymerization, a lens substrate having more
`excellent dyeability and heat resistance can be obtained.
`[0067]
`Further, in the polymerizable composition, any of
`various known additives such as an ultraviolet absorber, an
`infrared absorber, a light stabilizer, an internal mold release
`agent, an antioxidant, a dye, a photochromic dye, a pigment,
`and an antistatic agent can be blended as needed.
`
`2. Primer Layer
`
`[0068] The primerlayer is formed on the outermost surface
`ofthe lens substrate and is presentat the interface between the
`lens substrate and the hard coat layer, which will be men-
`tionedlater, and basically has a property of exhibiting adhe-
`sion to both lens substrate and hard coat layer and impact
`resistance.
`
`6
`
`

`

`US 2009/0097129 Al
`
`Apr. 16, 2009
`
`[0075] Examples of the diol compoundinclude diol com-
`pounds obtained by (co)polymerization of an alkylene oxide
`such as ethylene oxide or propylene oxide or a heterocyclic
`ether such as tetrahydrofuran. Specific examples of the diol
`compound include polyether diols such as polyethylene gly-
`col, polypropylene glycol, polytetramethylene ether glycol,
`and polyhexamethylene ether glycol; polyester diols such as
`polyethylene adipate, polybutylene adipate, polyneopentyl
`adipate, poly-3-methylpenty] adipate, polyethylene/butylene
`adipate, and polyneopentyl/hexyl adipate; polylactone diols
`such as polycaprolactone diol; and polycarbonate diols.
`Among these, one or more diol compoundsselected from
`polyether diols, polyester diols and polycarbonate diols are
`preferred.
`[0076]
`Preferred examples of the polyurethane resin
`include polyether polyurethane resins, polyester polyure-
`thaneresins, and polycarbonate polyurethaneresins obtained
`by using a polyetherdiol, a polyester diol, or a polycarbonate
`diol as a diol compound. The form of the polyurethane resin
`is also not particularly limited. Typically, an emulsion type,
`for example, a self-emulsified emulsion anda self-stabilized
`emulsion can be exemplified. In particular, among the above-
`mentioned compounds, preferred is a polyurethane resin in
`whicha diol having an acidic group such as a carboxylic acid
`group or a sulfonic acid group is used, or a polyhydroxy
`compound having a low molecular weight is added, or an
`acidic group is introduced, and particularly preferred is a
`polyurethaneresin having a carboxyl group. Further, from the
`viewpoint ofimprovementofgloss, scratch resistance and the
`like, it is preferred that a functional group such as a carboxyl
`group is crosslinked through a crosslinking treatment.
`[0077] The polyurethane resin as the component (A) is
`present in the coating composition as fine particles, and the
`average particle diameter of the polyurethaneresinis prefer-
`ably from 5 to 50 nm, and morepreferably from 20 to 30 nm.
`Whenthe averageparticle diameter of the polyurethane resin
`is less than 10 nm or exceeds 50 nm,a synergistic effect with
`the component (B) or the component (C), which will be
`mentionedlater, cannot be exhibited, and it becomesdifficult
`to effectively improvethe refractive index ofthe primerlayer.
`The particle diameter of the polyurethane resin can be con-
`trolled by the production condition or molecular weightofthe
`polyurethaneresin, the stirring speed for the coating compo-
`sition or the like.
`
`[0078] The average particle diameter of the polyurethane
`resin as fine particles is measured by a light scattering
`method. For example, by using a dynamic light scattering
`particle size distribution analyzer (manufactured by Horiba
`Seisakusho K.K., trade name: LB-550), the particle diameter
`distribution and average particle diameter can be measured.
`[0079] The blending amount of the polyurethane resin is
`preferably from 20 to 60% by mass and more preferably from
`30 to 50% by mass based on the total amount of the compo-
`nents (A) to (C)in the coating composition.
`[0080] When the blending amount of the polyurethane
`resin is less than 20% by mass, the impactresistanceorlight
`resistanceofa final product in the case where a spectacle lens
`is formed as the final product may be insufficient. Further,
`whenthe blending amountof the polyurethane resin exceeds
`60% by mass, the refracti