CA2095703A1 - Method for producing photochromic plastic lens - Google Patents
Method for producing photochromic plastic lensInfo
- Publication number
- CA2095703A1 CA2095703A1 CA002095703A CA2095703A CA2095703A1 CA 2095703 A1 CA2095703 A1 CA 2095703A1 CA 002095703 A CA002095703 A CA 002095703A CA 2095703 A CA2095703 A CA 2095703A CA 2095703 A1 CA2095703 A1 CA 2095703A1
- Authority
- CA
- Canada
- Prior art keywords
- plastic lens
- photochromic dye
- dye solution
- photochromic
- lens
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 239000004033 plastic Substances 0.000 title claims abstract description 38
- 229920003023 plastic Polymers 0.000 title claims abstract description 38
- 238000004519 manufacturing process Methods 0.000 title abstract description 8
- 238000000034 method Methods 0.000 claims abstract description 45
- 238000010438 heat treatment Methods 0.000 claims abstract description 33
- 150000001875 compounds Chemical class 0.000 claims description 14
- 239000002904 solvent Substances 0.000 claims description 11
- 229920008347 Cellulose acetate propionate Polymers 0.000 claims description 10
- 229920006217 cellulose acetate butyrate Polymers 0.000 claims description 9
- -1 poly(methyl methacrylate) Polymers 0.000 claims description 9
- 239000011347 resin Substances 0.000 claims description 8
- 229920005989 resin Polymers 0.000 claims description 8
- 229920001187 thermosetting polymer Polymers 0.000 claims description 8
- 229920003229 poly(methyl methacrylate) Polymers 0.000 claims description 7
- 239000004926 polymethyl methacrylate Substances 0.000 claims description 7
- 229920001169 thermoplastic Polymers 0.000 claims description 7
- 239000004416 thermosoftening plastic Substances 0.000 claims description 7
- 239000011248 coating agent Substances 0.000 claims description 6
- 238000000576 coating method Methods 0.000 claims description 6
- HKQOBOMRSSHSTC-UHFFFAOYSA-N cellulose acetate Chemical compound OC1C(O)C(O)C(CO)OC1OC1C(CO)OC(O)C(O)C1O.CC(=O)OCC1OC(OC(C)=O)C(OC(C)=O)C(OC(C)=O)C1OC1C(OC(C)=O)C(OC(C)=O)C(OC(C)=O)C(COC(C)=O)O1.CCC(=O)OCC1OC(OC(=O)CC)C(OC(=O)CC)C(OC(=O)CC)C1OC1C(OC(=O)CC)C(OC(=O)CC)C(OC(=O)CC)C(COC(=O)CC)O1 HKQOBOMRSSHSTC-UHFFFAOYSA-N 0.000 claims description 5
- 239000004417 polycarbonate Substances 0.000 claims description 5
- 229920000515 polycarbonate Polymers 0.000 claims description 5
- JHQVCQDWGSXTFE-UHFFFAOYSA-N 2-(2-prop-2-enoxycarbonyloxyethoxy)ethyl prop-2-enyl carbonate Chemical compound C=CCOC(=O)OCCOCCOC(=O)OCC=C JHQVCQDWGSXTFE-UHFFFAOYSA-N 0.000 claims description 4
- 238000007598 dipping method Methods 0.000 claims description 3
- 238000005507 spraying Methods 0.000 claims description 3
- 150000001338 aliphatic hydrocarbons Chemical class 0.000 claims description 2
- 150000004945 aromatic hydrocarbons Chemical class 0.000 claims description 2
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 claims 2
- 238000002791 soaking Methods 0.000 claims 2
- 238000005406 washing Methods 0.000 claims 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims 1
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 claims 1
- 238000004528 spin coating Methods 0.000 claims 1
- 238000004043 dyeing Methods 0.000 abstract description 8
- 239000000975 dye Substances 0.000 description 36
- 239000000243 solution Substances 0.000 description 13
- 239000000463 material Substances 0.000 description 8
- DNIAPMSPPWPWGF-UHFFFAOYSA-N Propylene glycol Chemical compound CC(O)CO DNIAPMSPPWPWGF-UHFFFAOYSA-N 0.000 description 6
- 239000011521 glass Substances 0.000 description 5
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 4
- 238000001746 injection moulding Methods 0.000 description 4
- 239000000178 monomer Substances 0.000 description 4
- 239000007790 solid phase Substances 0.000 description 4
- 239000000758 substrate Substances 0.000 description 4
- MTHSVFCYNBDYFN-UHFFFAOYSA-N diethylene glycol Chemical compound OCCOCCO MTHSVFCYNBDYFN-UHFFFAOYSA-N 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- JUJWROOIHBZHMG-UHFFFAOYSA-N Pyridine Chemical class C1=CC=NC=C1 JUJWROOIHBZHMG-UHFFFAOYSA-N 0.000 description 2
- 230000003213 activating effect Effects 0.000 description 2
- 238000005266 casting Methods 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 239000007791 liquid phase Substances 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 239000007800 oxidant agent Substances 0.000 description 2
- 239000002685 polymerization catalyst Substances 0.000 description 2
- 239000003505 polymerization initiator Substances 0.000 description 2
- 238000009987 spinning Methods 0.000 description 2
- 241001301450 Crocidium multicaule Species 0.000 description 1
- VVQNEPGJFQJSBK-UHFFFAOYSA-N Methyl methacrylate Chemical compound COC(=O)C(C)=C VVQNEPGJFQJSBK-UHFFFAOYSA-N 0.000 description 1
- 241000080590 Niso Species 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- JKJWYKGYGWOAHT-UHFFFAOYSA-N bis(prop-2-enyl) carbonate Chemical compound C=CCOC(=O)OCC=C JKJWYKGYGWOAHT-UHFFFAOYSA-N 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 238000005034 decoration Methods 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000004980 dosimetry Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 150000002334 glycols Chemical class 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D11/00—Producing optical elements, e.g. lenses or prisms
-
- 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
- G02B1/041—Lenses
-
- G—PHYSICS
- G02—OPTICS
- G02C—SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES
- G02C7/00—Optical parts
- G02C7/02—Lenses; Lens systems ; Methods of designing lenses
- G02C7/021—Lenses; Lens systems ; Methods of designing lenses with pattern for identification or with cosmetic or therapeutic effects
Landscapes
- Physics & Mathematics (AREA)
- Ophthalmology & Optometry (AREA)
- Health & Medical Sciences (AREA)
- Engineering & Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- General Health & Medical Sciences (AREA)
- Eyeglasses (AREA)
- Surface Treatment Of Optical Elements (AREA)
- Coloring (AREA)
- Optical Filters (AREA)
- Electrochromic Elements, Electrophoresis, Or Variable Reflection Or Absorption Elements (AREA)
Abstract
METHOD FOR PRODUCING PHOTOCHROMIC PLASTIC LENS of the Invention: A method for producing photochromic plastic lenses is presented. In accordance with the method of the present invention a photochromic property is imparted to a plastic lens (e.g., by dyeing the surface of the lens with a photochromic dye solution) at high temperatures by microwave heating for a predetermined amount of time.
Description
7 ~ 3 METHOD FOR PRODUCING PHOTOCHROMIC P~ASTIC LENS
Back~round sf the Invention: ;
The present invention relates to photochromic plastic lenses. More particularly, the present invention relates to a fast and efficient method for producing photochromic lenses by microwave heating.
Photochromic materials have many potential applications in the fields of self-developing photography, dosimetry, optical siynal processing, data display, decoration, control of radiation intensity and others. The most widely used and commercially successful photochromic material technology i5 in eyewear for protecting against sunlight and controlling of sunlight intensity. Currently, the majority of the photochromic eyewear lenses are made of silver halide based glasses. However, photochromic plastic lenses based on spirooxazine photochromic compounds have made some lnroad.
: ~, :: ~, , . :
Back~round sf the Invention: ;
The present invention relates to photochromic plastic lenses. More particularly, the present invention relates to a fast and efficient method for producing photochromic lenses by microwave heating.
Photochromic materials have many potential applications in the fields of self-developing photography, dosimetry, optical siynal processing, data display, decoration, control of radiation intensity and others. The most widely used and commercially successful photochromic material technology i5 in eyewear for protecting against sunlight and controlling of sunlight intensity. Currently, the majority of the photochromic eyewear lenses are made of silver halide based glasses. However, photochromic plastic lenses based on spirooxazine photochromic compounds have made some lnroad.
: ~, :: ~, , . :
2~7~3 The spiroo~azine compounds are a member of a Eamily of photochromic compounds ~ith inherently excellent photodurab;li-ty. They are the preferred photochromic compounds ~Ised for producing eyewear glasses (both ophthalmic and sunglass lenses). This is due to their photofatigue resistance and their colorless hue in the unactivated form (i.e., in the absence of the activating ultraviolet light).
Many methods are known to impart the photoch~omic property to a material. The commonly used methods include dyeing, casting, coating and injection molding. The method of ~pplication depends strongly on the substrate material. For example, the spirooxazine dyes are sensitive to certain chamicals such as polymerization initiators and oxidants, and is unstable at high temperatures (e.g., at injection molding temperatures).
The commonly used plastics for eyewear included poly~methyl methacrylate) (PMMA), cellulose aceta-te hutyrate (CAB), polycarbonate~ and cellulose acetate propionate (CAP) and diethylene glycol bis(allyl carbonate) (CR~39). The first four are thermoplastics while CR-39 is a thermoset plastic. Since the methods for photochromic treatment depend on the nature of the lens substrate, some methods applicable -to the thermoplastics may not be useful ~or the thermoset plastics. For example, the photochromic dye cannot be mixed into CR-39 monomer to be polymerized along with the monomers to obtain a product with the dye uniformly dispersed, since the polymerization catalyst will destroy the dye.
The dyeing process is generally performed in a high boiling organic solvent bath. The solvents commonly used are alcohols, glycols, aromatic or aliphatic hydrocarbons. The thermoset plastic lens is .
~ "
~ , ; ! , . ;
7 ~ ~
Many methods are known to impart the photoch~omic property to a material. The commonly used methods include dyeing, casting, coating and injection molding. The method of ~pplication depends strongly on the substrate material. For example, the spirooxazine dyes are sensitive to certain chamicals such as polymerization initiators and oxidants, and is unstable at high temperatures (e.g., at injection molding temperatures).
The commonly used plastics for eyewear included poly~methyl methacrylate) (PMMA), cellulose aceta-te hutyrate (CAB), polycarbonate~ and cellulose acetate propionate (CAP) and diethylene glycol bis(allyl carbonate) (CR~39). The first four are thermoplastics while CR-39 is a thermoset plastic. Since the methods for photochromic treatment depend on the nature of the lens substrate, some methods applicable -to the thermoplastics may not be useful ~or the thermoset plastics. For example, the photochromic dye cannot be mixed into CR-39 monomer to be polymerized along with the monomers to obtain a product with the dye uniformly dispersed, since the polymerization catalyst will destroy the dye.
The dyeing process is generally performed in a high boiling organic solvent bath. The solvents commonly used are alcohols, glycols, aromatic or aliphatic hydrocarbons. The thermoset plastic lens is .
~ "
~ , ; ! , . ;
7 ~ ~
-3-immersed in the solvent ba-th ~hich normally contains between 1% to 10% photochromic dye. The dye ba-th is maintained in the range of 90 to 120C and the immersion ti~e is normally one to several hou~s. This will ensure that an adequate amount of dye is dif~ed into.the lens surface for sufficient photochromic durability. Thermal stability of the dye in the dyeing bath is a major ~roblem because of the cost associated with high d~e concentration and lo~g dyeing time.
Two other known processes for application of photochromic d~e to the surfaces of a lens include vapor-liquid phase transfer and solid phase transfex.
In the vapor-liquid phase transEer, the lens is heated in the presence of vapors of photochromic dye. In the solid phase transfer, the photochromic dye and a film-forming resin are dissolYed in a solven-t. The resulting solution is applied to the surface of a lens by any of the commonly used techniques such as dipping, spinning or spraying. The coated lens is heated to a high temperature kelow the melting point OE the dye for a sufficient length of time to allow diffusion of the dye from the resin ilm to the lens ~ubstrate.
Generally, the heating tempera-ture is in the range of 110 to 150C from several minutes to hours depending on the hardness of the lens. After the heat treatment st8p, the resin-film is removed. The heating source for these two photochromic processes is a conventional heat oven.
Hea~ing by conventional ovens is convenient, but not cost efective, especially for hard cured lenses.
To obtain adequate amounts of dye transferred to the 18ns, several hours of heating time is required.
SummarY of the _nvention:
The above-discussed and other problems and deficiencies o~ the prior art are overcome or alleviated by the method for producing photochromic plastic lenses of the present invenkion. In accordance with the present invention, a phot~chromic proper~y is imparted to a plastic lens ~e.g., by dyeing the surface of the lens with a photochrGmic dye solution) at high temperature by microwave heating for a predetermined amount of time.
The microwave heating, in accordance with the present invention, considerabl~ reduces the heating time as compared to the convection heating used by the prior art. Accordingly, the microwave heating results in an efficient, cost effective method for producing photochromic plastic lenses.
The above-discussed and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description.
Description of the PreEerred Embodiment:
A novel method for producing a photochromic plastic lens is presented. The plastic lens is comprised of any optical grade plastic material, such as poly(methyl methacrylate) (PMMA), cellulose acetate butyrate (CAB), polycarbonate, cellulose acetate propionate (CAP) or diethylene glycol his(allyl carbonate) (CR-39). The first four are thermoplastics while CR-39 is a thermoset plastic. Other plastic materials having a refractive index greater than CR-39 have been developed for eyewear application. For e~ample, CR-400s materials from PPG and MR-6 from Mitsui Toatsu.
.
7 ~ ~
As was noted in the prior art, spiroo~azine photochromic compounds are being used for photochromic plastic lenses and such is contemplated by the present invention. The spirooxazine compounds are a member of a family of photochromic compounds with inherently excellent photodurability. They are the preferred photochromic compounds used for producing eyewear glasses (both ophthalmic and sunglass lenses). This is due to their photofa-tigue resistance and their colorless hue in the unactivated form ~i.e., in the absence of the activating ultraviolet light).
Representative spiroo~a~ine fasnily of pho-tochromic compounds can be classified into several subclasses, which are spiroindolinonaphthoxazines (NISO), spiroindolinopyridobenzoxazines (QIS0), spiroindolinobenzoxazines (BISO) and spiroindolinoanthrylo~azines (AISO).
In accordance with the present invention a photochromic property is imparted to the lens by dyeing the lens in photochromic dye solution. The lens is immersed in the photochromic dye ~olution which is then heated for a predetermined amount oE time. After heating the lens may remain in the heated photochromic dye solution to soak. The lens is then removed and washed with a solvent.
The heat treatment step is accomplished by microwave heating. The microwave heating has been found to be very efEicient and cost effective as compared to the prior art method. The heat treatment step in the prior art was accomplished by conventional heatinq. Heat treatment using the conventional ovens re~uired a heating temperature in the range of 110 to 150C (for CR-39 lenses) for several minutes to hours depending on the hardness of the lens. Heating by a conventional oven is convenient, but not cost ' ' .
effective especially for hard high cured lenses. To obtain an adequate arnount of dye transferred to the lens, several hours of heating time is required.
Microwave heating, in accordance with the present invention, considerably reduces the heating time as can be seen from the examples p~ovided below.
The lenses used in the below exa~ples were high cured AOli ~e CR-39 plano le~ses having a diameter cf 76 mm ~manufactured by American Optical Corporation, the assignee o~ the present invention). The photochromic dye used was a mixture of 1,3,3,4,5- and - 1,3,3,5,5-pentamethyl-9'-methoxy NISQ isomer mi~ture.
Further, in order to determine the amount of dye being transferred to the lens substrate, the absorhences of the lens at 360 nm was measured be~ore and after photochromic treatment.
EXAMPLE l In a first prior art e~ample, 1.2 kg of propylene glycol was added in a 1.5 L glass beaker. The solvent was heated to 115C with a hot plate. Twenty-four (24) g of photochromic dye were added to the solvent.
Two AOllte lenses were used, one lens was immersed in the dye bath or 1 hour and the o-ther or 2 hours. The absorbence change at 360 nm before and after treatment for the first lens (i.e., 1 hour treatment) was 0.18 and for the second lens (i.e., 2 hour treatment) was 0.25.
:
In a second prior art example, a 2% dye bath solution was made in a metal pan and heated to 152C
by a hot plate. Two AOlite lenses were dyed by immersing them in the dye bath for 1 hour. The dye uptake as measured by the absorbence change at 360 nm was 0.46 for both lenses.
:-'~ i . . , .; ' . ~ ~ ' ' . . , . . ` . . ' ' ' ~J~ 3 E~AMPLE 3 In a first e~cample in accordance with the present invention, a 1 L glass beaker containing 500 g propylene glycol and 10 g photochromic dye wa~ placed in a microwave oven (e.g., Goldstar, 800 watt model) with a lens therein and heated for 6 minutes. The lens was then soaked in the heated solution for 15 minutes.
The lens was then rernoved and washed with acetone. The temperature of the solution after heating was 167 C.
The absorbence change of the lens a-t 360 nm was 0.37.
In a second example in accordance with the present invention, 5 g more dye was added to the solution o-f Example 3 to make a 3% dye solution. A lens was dyed by immersing it in the solution and heating the solution with the lens therein or 6 minutes, using the microwave oven. The lens was then soaked in the heated solution for 15 minutes. I'he lens was then rernoved and washed with acetone. The absorbence change of the lens at 360 nm was 0.60.
The method of the presen-t invention obtains comparable results -to that of the prior art in significantly less time. This is clearly seen by comparing the time required in the prior art examples 1 and 2 to examples 3 and 4 which are in accordance with the present invention.
While the preferred method of imparting the photochromic property to the lens is dyeing, other known methods, such as casting, coating and injection molding may be employed. The method of application is dependent on the lens material used. For example, spirooæazine dyes are sensitive to certain chemicals, such as polymerization initiators and oxidants, and is unstable at high temperatures (e.g., at injection molding temperatures). Further, sorne methods applicable to the thermoplastics ma~ not be useful for the thermoset plastics. For e~ample, the photochromic dye cannot be mixed into CR-39 monomer to be polymerized along with the monomers to obtain a product with the dye uniformly dispersed since the polymerization catalyst will destroy the dye.
Alternately, the aforementioned solid phase transfer process for applying the photochromic dye to the surface of the lens may be used in the method of the present invention. In the solid phase transfer, the photochromic dye and a film-forming resin are dissolved in a solvent. The resulting solution is applied to the surface of a lens by any of the commonly used techniques SUCil as dipping, spinning or spraying.
The coated lens is then heated to a high temperature below the melting point of the dye for a sufficient length of time to allow the diffusion of the dye from the resin film to the lens substrate.
While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.
What is claimed is:
. .' -. ,.
Two other known processes for application of photochromic d~e to the surfaces of a lens include vapor-liquid phase transfer and solid phase transfex.
In the vapor-liquid phase transEer, the lens is heated in the presence of vapors of photochromic dye. In the solid phase transfer, the photochromic dye and a film-forming resin are dissolYed in a solven-t. The resulting solution is applied to the surface of a lens by any of the commonly used techniques such as dipping, spinning or spraying. The coated lens is heated to a high temperature kelow the melting point OE the dye for a sufficient length of time to allow diffusion of the dye from the resin ilm to the lens ~ubstrate.
Generally, the heating tempera-ture is in the range of 110 to 150C from several minutes to hours depending on the hardness of the lens. After the heat treatment st8p, the resin-film is removed. The heating source for these two photochromic processes is a conventional heat oven.
Hea~ing by conventional ovens is convenient, but not cost efective, especially for hard cured lenses.
To obtain adequate amounts of dye transferred to the 18ns, several hours of heating time is required.
SummarY of the _nvention:
The above-discussed and other problems and deficiencies o~ the prior art are overcome or alleviated by the method for producing photochromic plastic lenses of the present invenkion. In accordance with the present invention, a phot~chromic proper~y is imparted to a plastic lens ~e.g., by dyeing the surface of the lens with a photochrGmic dye solution) at high temperature by microwave heating for a predetermined amount of time.
The microwave heating, in accordance with the present invention, considerabl~ reduces the heating time as compared to the convection heating used by the prior art. Accordingly, the microwave heating results in an efficient, cost effective method for producing photochromic plastic lenses.
The above-discussed and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description.
Description of the PreEerred Embodiment:
A novel method for producing a photochromic plastic lens is presented. The plastic lens is comprised of any optical grade plastic material, such as poly(methyl methacrylate) (PMMA), cellulose acetate butyrate (CAB), polycarbonate, cellulose acetate propionate (CAP) or diethylene glycol his(allyl carbonate) (CR-39). The first four are thermoplastics while CR-39 is a thermoset plastic. Other plastic materials having a refractive index greater than CR-39 have been developed for eyewear application. For e~ample, CR-400s materials from PPG and MR-6 from Mitsui Toatsu.
.
7 ~ ~
As was noted in the prior art, spiroo~azine photochromic compounds are being used for photochromic plastic lenses and such is contemplated by the present invention. The spirooxazine compounds are a member of a family of photochromic compounds with inherently excellent photodurability. They are the preferred photochromic compounds used for producing eyewear glasses (both ophthalmic and sunglass lenses). This is due to their photofa-tigue resistance and their colorless hue in the unactivated form ~i.e., in the absence of the activating ultraviolet light).
Representative spiroo~a~ine fasnily of pho-tochromic compounds can be classified into several subclasses, which are spiroindolinonaphthoxazines (NISO), spiroindolinopyridobenzoxazines (QIS0), spiroindolinobenzoxazines (BISO) and spiroindolinoanthrylo~azines (AISO).
In accordance with the present invention a photochromic property is imparted to the lens by dyeing the lens in photochromic dye solution. The lens is immersed in the photochromic dye ~olution which is then heated for a predetermined amount oE time. After heating the lens may remain in the heated photochromic dye solution to soak. The lens is then removed and washed with a solvent.
The heat treatment step is accomplished by microwave heating. The microwave heating has been found to be very efEicient and cost effective as compared to the prior art method. The heat treatment step in the prior art was accomplished by conventional heatinq. Heat treatment using the conventional ovens re~uired a heating temperature in the range of 110 to 150C (for CR-39 lenses) for several minutes to hours depending on the hardness of the lens. Heating by a conventional oven is convenient, but not cost ' ' .
effective especially for hard high cured lenses. To obtain an adequate arnount of dye transferred to the lens, several hours of heating time is required.
Microwave heating, in accordance with the present invention, considerably reduces the heating time as can be seen from the examples p~ovided below.
The lenses used in the below exa~ples were high cured AOli ~e CR-39 plano le~ses having a diameter cf 76 mm ~manufactured by American Optical Corporation, the assignee o~ the present invention). The photochromic dye used was a mixture of 1,3,3,4,5- and - 1,3,3,5,5-pentamethyl-9'-methoxy NISQ isomer mi~ture.
Further, in order to determine the amount of dye being transferred to the lens substrate, the absorhences of the lens at 360 nm was measured be~ore and after photochromic treatment.
EXAMPLE l In a first prior art e~ample, 1.2 kg of propylene glycol was added in a 1.5 L glass beaker. The solvent was heated to 115C with a hot plate. Twenty-four (24) g of photochromic dye were added to the solvent.
Two AOllte lenses were used, one lens was immersed in the dye bath or 1 hour and the o-ther or 2 hours. The absorbence change at 360 nm before and after treatment for the first lens (i.e., 1 hour treatment) was 0.18 and for the second lens (i.e., 2 hour treatment) was 0.25.
:
In a second prior art example, a 2% dye bath solution was made in a metal pan and heated to 152C
by a hot plate. Two AOlite lenses were dyed by immersing them in the dye bath for 1 hour. The dye uptake as measured by the absorbence change at 360 nm was 0.46 for both lenses.
:-'~ i . . , .; ' . ~ ~ ' ' . . , . . ` . . ' ' ' ~J~ 3 E~AMPLE 3 In a first e~cample in accordance with the present invention, a 1 L glass beaker containing 500 g propylene glycol and 10 g photochromic dye wa~ placed in a microwave oven (e.g., Goldstar, 800 watt model) with a lens therein and heated for 6 minutes. The lens was then soaked in the heated solution for 15 minutes.
The lens was then rernoved and washed with acetone. The temperature of the solution after heating was 167 C.
The absorbence change of the lens a-t 360 nm was 0.37.
In a second example in accordance with the present invention, 5 g more dye was added to the solution o-f Example 3 to make a 3% dye solution. A lens was dyed by immersing it in the solution and heating the solution with the lens therein or 6 minutes, using the microwave oven. The lens was then soaked in the heated solution for 15 minutes. I'he lens was then rernoved and washed with acetone. The absorbence change of the lens at 360 nm was 0.60.
The method of the presen-t invention obtains comparable results -to that of the prior art in significantly less time. This is clearly seen by comparing the time required in the prior art examples 1 and 2 to examples 3 and 4 which are in accordance with the present invention.
While the preferred method of imparting the photochromic property to the lens is dyeing, other known methods, such as casting, coating and injection molding may be employed. The method of application is dependent on the lens material used. For example, spirooæazine dyes are sensitive to certain chemicals, such as polymerization initiators and oxidants, and is unstable at high temperatures (e.g., at injection molding temperatures). Further, sorne methods applicable to the thermoplastics ma~ not be useful for the thermoset plastics. For e~ample, the photochromic dye cannot be mixed into CR-39 monomer to be polymerized along with the monomers to obtain a product with the dye uniformly dispersed since the polymerization catalyst will destroy the dye.
Alternately, the aforementioned solid phase transfer process for applying the photochromic dye to the surface of the lens may be used in the method of the present invention. In the solid phase transfer, the photochromic dye and a film-forming resin are dissolved in a solvent. The resulting solution is applied to the surface of a lens by any of the commonly used techniques SUCil as dipping, spinning or spraying.
The coated lens is then heated to a high temperature below the melting point of the dye for a sufficient length of time to allow the diffusion of the dye from the resin film to the lens substrate.
While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.
What is claimed is:
. .' -. ,.
Claims (26)
- CLAIM 1. A process for producing a photochromic plastic lens, comprising the steps of:
mixing a photochromic dye solution;
immersing a plastic lens in said photochromic dye solution;
microwave heating the photochromic dye solution with the plastic lens therein for a predetermined amount of time;
removing the plastic lens from the heated photochromic dye solution after a predetermined amount of time has elapsed; and washing the plastic lens with a solvent. - CLAIM 2. The process of claim 1 wherein said photochromic dye solution comprises a spirooxazine compound.
- CLAIM 3. The process of claim 2 wherein said spirooxazine compound comprises spiroindolinonaphthoxazines, spiroindolinopyridobenzoxazines, spiroindolinobenzoxazines or spiroindolinoanthryloxazines.
- CLAIM 4. The process of claim 1 wherein said step of microwave heating comprises microwave heating using a microwave oven.
- CLAIM 5. The process of claim 1 wherein said plastic lens comprises a thermoplastic or a thermoset plastic.
- CLAIM 6. The process of claim 1 wherein said plastic lens comprises poly(methyl methacrylate) (PMMA), cellulose acetate butyrate (CAB), polycarbonate, cellulose acetate propionate (CAP) or diethylene glycol bis(allyl carbonate) (CR-39).
- CLAIM 7. The process of claim 2 wherein said photochromic dye solution includes from about 1% to about 10% of a photochromic dye.
- CLAIM 8. A process for producing a photochromic plastic lens, comprising the steps of:
mixing a photochromic dye solution;
immersing a plastic lens in said photochromic dye solution;
microwave heating the photochromic dye solution with the plastic lens therein for a predetermined amount of time;
soaking the plastic lens in the heated photochromic dye solution for a predetermined amount of time;
removing the plastic lens from the heated photochromic dye solution after the predetermined amount of time for soaking has elapsed; and washing the plastic lens with a solvent. - CLAIM 9. The process of claim 8 wherein said photochromic dye solution comprises a spirooxazine compound.
- CLAIM 10. The process of claim 9 wherein said spirooxazine compound comprises spiroindolinonaphthoxazines, spiroindolinopyridobenzoxazines, spiroindolinobenzoxazines or spiroindolinoanthryloxazines.
- CLAIM 11, The process of claim 8 wherein said step of microwave heating comprises microwave heating using a microwave oven.
- CLAIM 12. The process of claim 8 wherein said plastic lens comprises a thermoplastic or a thermoset plastic.
- CLAIM 13. The process of claim 8 wherein said plastic lens comprises poly(methyl methacrylate) (PMMA), cellulose acetate butyrate (CAB), polycarbonate, cellulose acetate propionate (CAP) or diethylene glycol bis(allyl carbonate) (CR-39).
- CLAIM 14. The process of claim 8 wherein said photochromic dye solution includes from 1% to about 10%
of a photochromic dye. - CLAIM 15. A process for producing a photochromic plastic lens, comprising the steps of:
coating the surface of a plastic lens with a photochromic dye solution;
microwave heating the coated plastic lens for a predetermined amount of time, whereby a photochromic dye is diffused from a resin film to the surface of the plastic lens; and removing the resin film. - CLAIM 16. The process of claim 15 wherein said step of coating comprises dipping the lens in the photochromic dye solution.
- CLAIM 17. The process of claim 15 wherein said step of coating comprises spin coating the surface of the plastic lens with the photochromic dye solution.
- CLAIM 18. The process of claim 15 wherein said step of coating comprises spraying the surface of the plastic lens with the photochromic dye solution.
- CLAIM 19. The process of claim 15 wherein said plastic lens comprises a thermoplastic or a thermoset plastic.
- CLAIM 20. The process of claim 15 wherein said plastic lens comprises poly(methyl methacrylate) (PMMA), cellulose acetate butyrate (CAB), polycarbonate, cellulose acetate propionate (CAP) or diethylene glycol bis(allyl carbonate) (CR-39).
- CLAIM 21. The process of claim 15 wherein said photochromic dye solution comprises said photochromic dye and said resin dissolved in a solvent.
- CLAIM 22. The process of claim 21 wherein said photochromic dye comprises a spirooxazine compound.
- CLAIM 23. The process of claim 22 wherein said spirooxazine compound comprises spiroindolinonaphthoxazines, spiroindolinopyridobenzoxazines, spiroindolinobenzoxazines or spiroindolinoanthryloxazines.
- CLAIM 24. The process of claim 21 wherein said solvent comprises an alcohol, a glycol, an aromatic hydrocarbon or an aliphatic hydrocarbon.
- CLAIM 25. The process of claim 15 wherein said step of microwave heating comprises microwave heating using a microwave oven.
- CLAIM 26. The process of claim 15 wherein said step of removing comprises removing the resin film using a solvent.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US94421592A | 1992-09-11 | 1992-09-11 | |
| US944,215 | 1992-09-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2095703A1 true CA2095703A1 (en) | 1994-03-12 |
Family
ID=25481008
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002095703A Abandoned CA2095703A1 (en) | 1992-09-11 | 1993-05-06 | Method for producing photochromic plastic lens |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPH06108384A (en) |
| KR (1) | KR940006752A (en) |
| CN (1) | CN1093813A (en) |
| BR (1) | BR9302073A (en) |
| CA (1) | CA2095703A1 (en) |
| DE (1) | DE4328675A1 (en) |
| FR (1) | FR2695732A1 (en) |
| GB (1) | GB2270576A (en) |
| IL (1) | IL105147A0 (en) |
| MX (1) | MX9302645A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000014325A1 (en) * | 1998-09-03 | 2000-03-16 | Ryser Christophe U | Tinting plastic articles |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5708064A (en) * | 1993-10-15 | 1998-01-13 | Ppg Industries, Inc. | High refractive index photochromic ophthalmic article |
| AU770553B2 (en) * | 1999-08-02 | 2004-02-26 | Essilor International Compagnie Generale D'optique | Process for the manufacture of a crosslinked, transparent, hydrophilic and photochromic polymeric material, and optical and ophthalmic article obtained |
| KR100379257B1 (en) * | 2000-04-27 | 2003-04-08 | 주식회사 듀얼인텍 | Photochromic resin and producing method of the same |
| US20030164563A1 (en) * | 2002-03-04 | 2003-09-04 | Olin Calvin | Use of microwave energy to disassemble, release, and hydrate contact lenses |
| KR20040011703A (en) * | 2002-07-30 | 2004-02-11 | 주식회사 유진텍 이십일 | A Process For Producing Photochromic Lens |
| KR20040011701A (en) * | 2002-07-30 | 2004-02-11 | 주식회사 유진텍 이십일 | A Coating Composition For Plastic Photochromic Lens |
| KR20040011702A (en) * | 2002-07-30 | 2004-02-11 | 주식회사 유진텍 이십일 | A Coating Composition For Photochromic Contact Lens |
| KR100649348B1 (en) * | 2006-03-30 | 2006-11-28 | (주)유브이테크인터내셔날 | Dyeing method of photochromic spectacles lens |
| JP4518170B2 (en) * | 2008-03-26 | 2010-08-04 | セイコーエプソン株式会社 | Plastic lens dyeing method |
| CN103091866A (en) * | 2012-12-18 | 2013-05-08 | 上海甘田光学材料有限公司 | Penetration type photochromic lens and manufacturing method thereof |
| KR102102929B1 (en) * | 2019-09-20 | 2020-04-22 | (주)자이언 | coating apparatus and method using microwave |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4043637A (en) * | 1973-06-15 | 1977-08-23 | American Optical Corporation | Photochromic light valve |
| FR2415318A1 (en) * | 1978-01-18 | 1979-08-17 | Essilor Int | PROCESS FOR THE INTEGRATION OF A PHOTOCHROMIC SUBSTANCE INTO A BASE SUBSTRATE TRANSLUCENT IN ORGANIC MATTER, AND BASIC TRANSPARENT SUBSTRATE |
| US4289497A (en) * | 1980-09-02 | 1981-09-15 | American Optical Corporation | Gradient photochromic lens and method selectively reducing photochromic activity |
| GB8432563D0 (en) * | 1984-12-21 | 1985-02-06 | Banks P J | Apparatus for handling information |
| AU554441B2 (en) * | 1985-03-29 | 1986-08-21 | Ppg Industries Ohio, Inc. | Photochromic plastic lenses |
| JPS6210605A (en) * | 1985-07-09 | 1987-01-19 | Seiko Epson Corp | Photochromic optical material |
| US4880667A (en) * | 1985-09-24 | 1989-11-14 | Ppg Industries, Inc. | Photochromic plastic article and method for preparing same |
| US5130353A (en) * | 1990-03-07 | 1992-07-14 | Ppg Industries, Inc. | Method for preparing photochromic plastic article |
| JPH03269507A (en) * | 1990-03-20 | 1991-12-02 | Nippon Sheet Glass Co Ltd | Plastic lens having dimming property |
-
1993
- 1993-03-24 IL IL105147A patent/IL105147A0/en unknown
- 1993-04-13 CN CN93104381A patent/CN1093813A/en active Pending
- 1993-05-04 MX MX9302645A patent/MX9302645A/en unknown
- 1993-05-06 CA CA002095703A patent/CA2095703A1/en not_active Abandoned
- 1993-05-24 KR KR1019930008951A patent/KR940006752A/en not_active Application Discontinuation
- 1993-05-26 BR BR9302073A patent/BR9302073A/en not_active Application Discontinuation
- 1993-06-30 JP JP5162486A patent/JPH06108384A/en active Pending
- 1993-07-28 GB GB9315620A patent/GB2270576A/en not_active Withdrawn
- 1993-08-26 DE DE4328675A patent/DE4328675A1/en not_active Withdrawn
- 1993-09-09 FR FR9310734A patent/FR2695732A1/en not_active Withdrawn
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000014325A1 (en) * | 1998-09-03 | 2000-03-16 | Ryser Christophe U | Tinting plastic articles |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2695732A1 (en) | 1994-03-18 |
| IL105147A0 (en) | 1993-07-08 |
| JPH06108384A (en) | 1994-04-19 |
| DE4328675A1 (en) | 1994-03-17 |
| CN1093813A (en) | 1994-10-19 |
| MX9302645A (en) | 1994-05-31 |
| BR9302073A (en) | 1994-03-22 |
| GB9315620D0 (en) | 1993-09-08 |
| KR940006752A (en) | 1994-04-25 |
| GB2270576A (en) | 1994-03-16 |
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| Date | Code | Title | Description |
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| FZDE | Discontinued |