CA1225579A - Laminated transparent polarizing glasses and method of making - Google Patents

Abstract

Abstract of the Invention This invention is directed to the production of laminated, transparent, polarizing glass articles. The inventive method contemplates five basic steps:
(1) forming parallel microgrooves on a surface of a glass support;
(2) washing and drying said surface;
(3) depositing on said surface a mixture of organic colorants corresponding to the three primary colors and exhibiting a nematic state to yield a coating displaying polarizing properties;
(4) treating the polarizing coating with an aqueous solution of inorganic salts having an acid pH; and (5) applying a continuous, optically transparent, composite film upon the polarizing coating and bonding it thereto.

Description

S~79 Transparent, laminated, light polarizing glasses are used extensively in the making of medical, ophthalmic, sun, and protective spectacle lenses, but they could also be utilized in other fields as, for example, instrument lenses, windows for vehicles of all kinds (air, sea, land), wi~dows for buildings, and the like.
The manufacture of polarizing glasses raises various problems related to the solubility of the polarizing materials (generally the polarizing particles) in the surrounding environments (water, chemical products even in weak concen-trations, etc.), as well as their very low mechanical strength. This has led researchers to devise various means of protection as, for example, by incorporating the polarizing particles in a polymer film.
In general, the products are recognized as having very low surface hardness, a very marked sensitivity to scratching, and an incompatibility with the majority of the current cosmetic products.
For all that, attempts to obtain glass lenses have consisted in associating an organic polarizing film of the polyvinyl alcohol type with one or two ("sandwich") elements of glass. These attempts have come up against a n~mber of dif~iculties such as:
the complexity of bonding the polarizing film to an optical su~strate with~ut deforming the direction o polarization, as indicated in French Patent ~o. 76.18891, filed June ~, 1976 by American Optical Corporation;

12~557g the weight of the assemblies thus obt~ined are not compatible wit~, for e~ample, the conventional lenses utilized in spectacles C10-25 grams); and the extremely high cost o such products which is a result of their complexity.
For these reasons, t~ese products are not much used for application~ of the "general public" type such as spectacle making.
~ore recently, attempts were conducted to provide polariz~ng films of the polyvinyl acetate or ~olyvinyl butyrate type bonded onto the concave face of an inorganic spectacle glass. This approach also proved fruitless because of t~ree ma~or dïfficulties:
the very poor optical $uality of such ~ilms;
the necessity for protecting them from moisture; and t~eir sensitivity to scratching.
In spite of all these handicaps, a product o~ this type is available in commerce under the name of "POLAROID"
lenses. In this product the ~olarizing material is contained in polyvinyl ~ilms laminated front and back to thin ~ilms of celluiose and protected by ~ thin strip of melamine.
As with all materials of this type, the gre~t disad~an-tage in using this type of product is its very great sensi-tivity to scratching when compared to conventional products which are inorganic qlasses.
In addition to all this, all the products curr~ntly (or formerly~ on the mar~et do not satisfy a present need of consumers which is to have at ~eir disoosal inorsanic photochromic glasses (tha~ i3 ~0 say an op~ical ~-ansmission which varies wi~h ~he conditions of lighting~ and ~olari2ing, colorable, and/or filtering if it i5 needed~ ~uch a product in order to be perfectly suitable, should not b~ subjec~ ~o * trade mark.

iZ~2~579 any limitation a~out the design o~ the shape and the radius of curvature in order to satisfy, without any restriction, all the needs for making medical, ophthalmic, a~d ~rotective spectacles.

Summary of the Invention The present invention aims to provide a laminated, transparent, polarizing glass which is free of the deficiencies reviewed above and permits satisfaction of the above-mentioned needs.

More precisely, the invention is concerned with a laminated, transparent, polarizing glass characterized in that it comprises:
(a) a support of inorganic or organic glass;
~ ) a coating with polarizing properties deposited upon one of the faces of the support; and ~ c~ an optically transparent, continuous composite film constituted on one side by a thickness of thermoplastic polyurethane with adhesive properties, and on t~e other side by a thickness of thermosetting polyurethane with anti-lacerating and self-healing properties, the thermoplastic polyurethane side adhering to the coating with polarizing properties.
The invention is also concerned with a process for o~taining such a laminated, transparent, polarizing glass characterized in that it comprise3 the following steps:
(a). forming parall~l microgrooves on a sur~ace of an inorganic or organic glass support which is to receive the polarizing coating, these grooves frequently being ma~e with the aid of a very gentle a~rasion of the afore~aid su~port carefully washing the surface of the sup~ort which is to receive the polari2ing coating and drying this ~urface;

~ ~4f~"~5579 (c~ depositing on the washed and dried surface of the support a mixture o~ three organic colorants corresponding to the thres primary colors and exhibiting a nematic state to form a coating demonstrating polarizing ~roperties;
~ d) treating the resulting polarizing coating with an a~ueous solution of inorganic salts having an acid pH
(normaily ~y immersing into said solution~ in order to reduce the water solu~ility of the aforesaid polarizing coating; and (e) applying the composite film of polyurethane by subjecting it first to moderate temperature and pressure conditions in o~er to insure a ~rinkle-~ree and gradual flow or spreading out and an adherence o the film upon the polarizing coating, and thereafter to ele~ated temperature and pressure conditions to reinforce the mechanical ~ond between the fi}m and the coating and to complete the cross-linking of the composite film.

Brief Descri~tion of the Drawings FIGURE 1 is a view in cross section of a laminated polarizing glass according to the invention; and - FIGURE Z is a schematic ~Lew illustrating the protection of the edge of a spectacle glass lens according to the invention through a coating of polymerized resin.
As is illustrated LQ FIGURE 1, the support 1 can be composed of an inorganic or organic glass of any composition and shape. ~L~i5 can be, among others, a glass ~Yh_~iting photochromic properties; in particular, a blank of sPectacle glass (corrective, solar, or protective~.
The polari2ing coating can ~e of ~arious types. One type of suitable polari2ing coating is ormed of a mixture of three colorants corresponding to the three primary colors blue-red-yellow and exhi~iting a nematic state. Th~ colorant 12255~79 molecules ar~ oriented spontaneously on t~e ~ase support through the grace of a pr~-alignm~nt created by a very slight a~rasive parallel brushing of the surrace of the support to ~e coated. This brushing creates parallel micro-grooves of very little depth and width (less than 0.5 ~).
The coating ohtained exhibits a dichroic effect in the.
vicinity of 10 and a high water solubility. One can reduce this water solubility by a surface stabilization treatment with the aid of an aqueous solution of inorganic salts having an acid pH. Suitable organic colorants are sold by, among others, the 3M Company of 5t. Paul, ~nnesota, U.S.A., under the brand name ~3M Veri-light 25".
Techni~ues concerning this type of polarizing coating can also ~e found in U.S. Patents Nos. 2,544,659 and 2,481,830.
The composite film (3) is advantageously composed of the composite film described in British Patent ~o. 1,576,3~4.
According to a preferred embodiment, a continuous com-posite ~ilm is constituted on one side by a thickness of thermoplastic polyurethane, and on the other side by a thickness of thermosetting polyurethane, the aforesaid thermoplastic polyurethane being joined to the coating exhibiting polarizing properties and being formed from an aliphatic diisocyanate and an aliphatic diacid polyester diol or a polyglycol ether diol, each of said diols ha~ing a molecular weight of 50a-4000, and said thermosetting ?oly-urethane being the product of (a~`a polyglycol ether resulting fro~ the combination of epoxy-1,2 propane with 2,2-bis ~ydroxy-methyl)l-butanol and containing 1~5-12~ by weight of ~ree hydroxyls, and tb~ a biuret of 1,6-hexamethylane diisocyanate ! 30 containing 21-22% by weight of isocyanate groups, the weight of said biuret being composed o~ between 0.9 and 1~1 times _5_ 12~5579 the weight of said polyglycol ether, the thickness of the thermoplastic polyurethane ranging a~out ~.01-0.8 mm and the thickness of t~e thermosetting polyurethane ranging about 0.2-Q.~ mm.
The application of this composite film (3) upon the polarizing coating (2~ i~ effected through the ap~lication of heat and pressure, as will be described in more detail below.
Once the laminated transparent glass with three ~lies 1-2-3 is completed, it can be subjected to any pQssibly necessary finishing operations. For example, in the case where the laminated glass is a blank or a spectacle lens, it can ~e subjected to the operation called "edging" (finishing`
of the contour in order to fit the gla~s to the shape of the frame into which it is to be affixed~.
This edging operation has the disadvantage of breaking the thin skin layer formed upon the polarizing coating at the level of the edge of the glass so that there exists a risk that moisture may penetrate into the laminate and eventually bring about a destruction of the polarizing layer through unsticking, as tests of resistance to atmospheric agents have shown. In order to surmount this difficulty it is advisable, according to the invention, to protect the edge of the glass, after edging the latter, wi~h a coating of a resin which is polymerized in situ.
The inventive laminated glasses exhibit polarizing effects ranging between ;0-98% and optical transmissions at

2 mm ranging between 25-45~, those values being a function of the quantities of polarizing molecules, ~heir structure, and their dichroic efect. These prod~cts conform pèrCect~y to all the prevailing standaras in the field Q~ s?ectacle ma~ing.
It is fitting to note, in passing, th~ the inven~ive laminated glasses can then b~ colored, if desired, b~ the l~Z5579 process described in French Patent No. 81.22718 filed by the present applicant on December 4, 1981; now French Patent Publication 2,517,712 (1984). In this manner, it is possible to easily produce new and desirable products, namely, photochromic polyarizing glasses which are easily tinta~le and which are able to cut off ultraviolet radiation and have the widest variety of shapes and curvatures without any limitation.
Finally, although in the present application refere~ce ~s made more specially to a laminated glass destined for spectacle making, this application is not so lLmited. As a matter of fact, such glass can find perfect application in other fields, for example, as windows for vehicles (automobiles, boats, trucks~ or for buildings, or as reading windows of digital indicators utilized i~ electronic instrumentation or timepieces under the name ~liquid crystal display". Generally speaking, the invention is useful in all fields where polarization of incident.or reflected light can provide comfort or increased technical possibilities to the user.
~e description which follows, presented with respect to the attached drawings, given by way of non-limiting examples, will make it easy to understand how the invention can be carried out, the particularities which appe~_ both in the drawings and in the text do, of course, form ~ar~ of the said invention.

- DescriPtion of Praferred Embodiments In FIGURE 1 is shown a laminated polarizing glass according to ~he invention: more precisely, a ~lank for a spectacle glass machined according ~o th requisite optical 1~5579 specifications. T~e glass is comprised of a support 1 of an inorganic or organic glass with or without photochromic properties, a polarizing coating 2 deposited upon the conc~ve face of the.support, and an optically transparent, continuous composite film ~ composed of a layer 4 of thermoplastic polyurethane having adhesive properties and a layer 5 of thermosetting polyurethane having anti-lac~rating and self-healing properties, the thermoplastic polyurethane adhering to coating 2.
In FIGURE 2 is shown a spectacle glass lens made into the desired shape through edging the blan~ of FIGURE 1. The glass is provided on i~s edge with a coating 6 of resin polymerized in situ for protection against the penetration of water.
A glass support endowed with photochromic properties constitutes a pre~erred embodiment of carrying o~t the invention.
The following is a non-limiting e~ample illustrating the invention.

Example ~ he application of the polarizing coating upon an inorganic photochromic glass support is effected as follows in eight phases:

Phase 1: Preparation of the Surface This step has the objective of permitting a pre-alisnmen~
of the organic molecules to he deposited through a very sl~ght abrasi~e brushing of the surface to be covered~ To this end one.can utili2e, for ex~mple, a thick ro~ary disc, preferably polyester foam impregnated with an abrasive, such 1~5579 as an oxide of the zirconia type (ZrO2) or, preferably, alumina (A12O3~ in suspension in water. The edge of the disc is applied against the surfàce so as to foa~n parallel microgrooves in the latter. The duration of thè operation can take, by way of illustration, a~out 3-30 seconds, the time being a function of the surface hardness of the support to be covered. Ordinarily, 10 seconds will be sufficient for inorganic glasses.

Phase 2: First Washing of the Surface This operation has the objective of clearing the surface of the inorganic oxide residues utilized in the preceding step. This can be effected, for example, by brushing the surface with apparatus similax to the preceding step but wherein the a~rasive in suspension is replaced with natural water at ambient temperature. This operation lasts, for example, a~out 10-30 seconds.

Phase 3: Second Washinq of the Surface This operation has the objective of chemically preparing the surface to be covered to give it a high level of cleanli-ness. In this operation the support, preferably subjectedto a movement of horizontal rotation (for example at ;Q0 rpm), is continuously sprayed with deionized water ha~ing a resistivity of about 10-17 ohm cm which, depending upon the support, may or may not contain a small proportion of a surface tension agent (for example 1~ by volume alcoholl.
The duration of this operation às, for example, on the order of 5-10 seconds.

iZ~S5~79 Phase 4: Drying of the Surface One dries the surface of the support, previously prepared by a ~ery clean rinse, ~or example by exposure of the support, while rotating, under a 75-watt ~.R. lamp for several seconds (for example 5-10 seconds).

Phase 5: Stabilization of the Su~port In this operation the support to be covered is sta~ilized to temperature and humidity for about 1 minute 30 seconds in a cabinet.at 30Cl1C and 50~l5% humidity. The same cabinet is utilized for the following phase.

Phase 6: Deposition of the Polarizing Coating In this phase organic molecules of the "nematic" type, comprised o~ a mixture of three azo-based colorants ~lue-red-yellow) in solution in water, are deposited and oriented.
; The proportion of the three colorants (marketed by the 3~
Company under the name n 3M Vari-Light 25"1 is determined so as to obtain a maximum polarizing effect, which effect is linked to the formation of elongated crystals in very precise ranges of temperatures and humidities (30+1C and 5Q+5~
relative humi~i~y~. The resulting coating has a slight gray color. A slightly alkaline wetting agent is generally associated with the mixture of colorants, its role being to promote the formation of aggregates of organic molecules.
The concentrations of the recommended wetting agent are on the order of a few percent, pre~erably 1-2~ hy volume.
In this phase the support is sprinkled wi~h the solution of organic molecule~ in the ratio of about 1.5-5 ml or li~uid for a support ha~ing a diameter between 5a-80 ~m.
~he support is set in a hori20ntal rotation, for e~ample, , ~

~ ~ 5579 1000 rpm, during, for example, 30-45 seconds, in order to orient the organic molecules according to the pre-alignment generated previously through brushing, and to evapora~e through centriugation the solvent o~ the initial solution.
The deposit obtained exhibits a dichroic effect in the vicinity of 10 and a high solubility in water. The quantity of the solution of organic molecules and the speed of centri-fugation impart to the support a level of polarization ranging ~etween about 90~ and 50~ for optical transmissions at 550 nm ranging between 25% and 45%.

Phase 7: Stabilization ?reatment of the Surface This step has the objective to reduce the water soiu-bility o the previously formed, oolarizing coating. To accomplish this the supports are treated by immersion for 10 seconds into an aqueous solution of inorganic salts having an acid pH (for example 3.2~. The inorganic saLts generally employed are mixtures of iron and calcium salts in aqueous solution. This produces an ionic diffusicn in the surface with the formation, with the organic colorant molecules, of a metal sulfonate which is insoluble in water. Other salts which are usable are described ln above-cited U.S. paten~s.

hase ~: Last Rinsing of the Surface In this step the product obtained is rinsed through total immersion into natural water at ambient temperature.
The lens produced is polarizing and the treatment of the surface operates to impart an ~frective insensitivity to water to t~e surface of the polarizing coating.
The application of the composite polyurethane iLm can be effected as described in the British oatent previously cited, but it is preferably produced as described in French -lL-i~25579 patent No. 81.18678, filed October 5, 1981, by the applicant under the title "Laminated Ophthalmic Glass and Method of Makingl';
now French Patent Publication 2,513,940, except that the opera-tion of cleaning the glass lens is omitted. Briefly, this process consists in placing the thermoplastic polyurethane side of the composite film into contact with the polarizing coating carried by the support, pressing the composite fiLm against said coating at ambient ~emperatur~ or at a moderately elevated temperature (40-80C for example~ and under a moderately elevated pressure ~-5 bars for example), in order to insure a uniformly progressive flow or spreading free from wrinkles and an adherence of the film upon the coating, and then subjecting the resulting laminate to elevated temperatures and pressures ~75-150C and S-25 bars, for example~ for a sufficient length of time ~0.5-4 hours, for example) in order to reinforce the mechanical bond between the composite film and the polarizing coating, and to eliminate gaseous inclusions.
The resulting laminated glass lens blank can be subjected, if necessary, to edging. This edging is carried out on a blank previously heated to 110C+10C for about 30 minutes in order to temporarily increase the adherence of the polarizing coating to the composite film.
Ater edging, a thin layer of organic resin capable of being polymerized in situ is applied to the edge o~ the glass lens in order to physically protect the ~olarizing coating against possible penetration of water. It is possible to use, for example, a resin polymerizable by ultrAviolet radiation such as the resin LOCTITE~ mar~eted in France by the Society F~AMET in Senlis. ~ treatment of S seconds with a 1500-watt xenon ultra~iolet lamp suffic~s to harden thi~
resin.

1~5579 The protective coating of resin is polymerized to a thickness of a few hundredths of a millimeter and is perfectly transparent ànd colorless. The finished glass obtained can then be mounted in spectacles without any fear of deteriora-tion, as de~onstrated by tests of more than 252 hours at 50C and 98~ relative humidity in a weathering chamber followed by an extended immersion in water (several weeks ) .

Claims (14)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A laminated, transparent, polarizing glass article comprising:
(a) a support of inorganic or organic glass;
(b) a coating exhibiting polarizing properties deposited on one face of said support;
(c) a continuous, optically transparent composite film consisting on one face thereof of a layer of thermoplastic urethane having adhesive properties and on the other face of a layer of thermo-setting polyurethane having anti-lacerating and self-healing properties, said thermoplastic poly-urethane layer being adhered to said coating exhibiting polarizing properties.

2. A glass article according to claim 1 wherein said support is glass displaying photochromic properties.

3. A glass article according to claim 1, wherein the polarizing coating comprises a mixture of three organic colorants corresponding to the three primary colors blue-red-yellow and exhibits a nematic state, the polarizing coating having as a result of a treatment with an aqueous solution of inorganic salts reduced solubility in water.

4. A glass article according to claim 2, wherein the polarizing coating comprises a mixture of three organic colorants corresponding to the three primary colors blue-red-yellow and exhibits a nematic state, the polarizing coating having as result of a treatment with an aqueous solution of inorganic salts reduced solubility in water.

5. A glass article according to one of claims 1, 2 or 3 wherein said thermoplastic poly-urethane layer of composite film is formed from an aliphatic diisocyanate and an aliphatic diacid polyester diol or a polyglycol ether diol, each of said diols having a molecular weight of 500-4000 and said thermosetting polyurethane is the product (a) of a polyglycol ether resulting from the com-bination of epoxy-1,2 propane with 2,2-bis(hydroxy-methyl) 1-butanol and containing 10.5-12% by weight of free hydroxyls, and (b) a biuret 1,6-hexamethylene diisocyanate containing 21-22% by weight of isocyanate groups, the weight of said biuret being composed of between 0.9-1.1 times the weight of said polyglycol ether, the thickness of the thermoplastic poly-urethane layers ranging about 0.01-0.8 mm and the thickness of the thermosetting polyurethane layer ranging about 0.2-0.8 mm.

6. A glass article according to claim 4 wherein said thermoplastic polyurethane layer of composite film is formed from an aliphatic diisocyanate and an aliphatic diacid polyester diol or a poly-glycol ether diol, each of said diols having a molecular weight of 500-4000 and said thermosetting polyurethane is the product (a) of a polyglycol ether resulting from the combination of epoxy-1,2 propane with 2,2-bis(hydroxymethyl) 1-butanol and containing 10.5-12% by weight of free hydroxyls, and (b) a biuret 1,6-hexamethylene diisocyanate containing 21-22% by weight of isocyanate groups, the weight of said biuret being composed of between 0.9-1.1 times the weight of said polyglycol ether, the thickness of the thermoplastic polyurethane layers ranging about 0.01-0.8 mm and the thickness of the thermosetting polyurethane layer ranging about 0.2-0.8 mm.

7. A glass article according to one of claims 1, 2 or 3, wherein the composite film has been subjected to a coloring treatment.

8. A glass article according to claim 4 or 6 wherein the composite film has been subjected to a coloring treatment.

9. A glass article according to claim 1 which is destined for use as a blank for a spectacle lens which blank is subjected to an edging operation, wherein the edge of said blank has a coating of resin thereon which is polymerized in situ.

10. A method for making a laminated, transparent, polarizing glass article as claimed in claims 3 or 4 comprising the following steps:
(a) forming parallel microgrooves on a surface of a support of inorganic or organic glass which is to receive a polarizing coating by a very gentle abrasion of said surface;
(b) carefully washing and then drying said surface;
(c) depositing on said surface a mixture of three organic colorants corresponding to the three primary colors and exhibiting a nematic state;
(d) treating said polarizing coating with an aqueous solution of inorganic salts having an acid pH to reduce the water solubility thereof;
(e) applying a continuous, optically transparent, composite film consisting of a layer of thermoplastic polyurethane having adhesive properties and a layer of thermosetting polyurethane having anti-lacerating and self-healing properties to said polarizing coating by first subjecting it to moderate temperature and pressure conditions in order to insure a wrinkle-free and gradual spreading out and an adherence of the film upon the polarizing coating, and then subjecting it to elevated temperature and pressure conditions to reinforce the mechanical bond between the film and the coating and to complete the cross linking of the composite film.

11. A method for making a laminated, transparent, polarizing glass article as claimed in claim 9 comprising the following steps:
(a) forming parallel microgrooves on a surface of a support of inorganic or organic glass which is to receive a polarizing coating by a very gentle abrasion of said surface:
(b) carefully washing and then drying said surface;
(c) depositing on said surface a mixture of three organic colorants corresponding to the three primary colors and exhibiting a nematic state;
(d) treating said polarizing coating with an aqueous solution of inorganic salts having an acid pH to reduce the water solubility thereof;
(e) applying a continuous, optically transparent, composite film consisting of a layer of thermoplastic polyurethane having adhesive properties and a layer of thermosetting polyurethane having anti-lacerating and self-healing properties to said polarizing coating by first subjecting it to moderate temperature and pressure conditions in order to insure a wrinkle-free and gradual spreading out and an adherence of the film upon the polarizing coating, and then subjecting it to elevated temperature and pressure conditions to reinforce the mechanical bond between the film and the coating and to complete the cross linking of the composite film;

(f) after having subjected the said blank to an edging operation, coating the edge of said blank with a resin which is polymerized by ultra violet radiation and subjecting said resin to ultra violet radiation to effect the polymerization thereof.

12. A method for making a laminated, transparent, polarizing glass article consisting essentially of the following steps:
(a) forming parallel microgrooves in a surface of a support of inorganic or organic glass through gentle abrasion of said surface by brushing with a thick rotary disc of polyester foam impregnated with an abrasive selected from the group of ZrO2 and A12O3 suspended in water;
(b) carefully washing said surface by first brushing with a thick rotary disc of polyester foam impreg-nated with water and thereafter spraying with water and then drying said surface;
(c) stabilizing said support to a temperature of 30°C+1°C and a humidity of 50%+5%;
(d) at said temperature and humidity depositing on said surface a mixture of three organic colorants corres-ponding to the three primary colors and exhibiting a nematic state to form a coating demonstrating polarizing properties, and thereafter rotating said support in order to orient the organic molecules according to the pre-alignment generated previously through the parallel microgrooves and to dry said coating;
(e) treating said polarizing coating with an aqueous solution of metal salts having an acid pH to produce an ionic diffusion in said surface with the formation of, with the organic molecules, a metal sulfonate which is insoluble in water to reduce the water solubility of said polarizing compound;
(f) rinsing said polarizing coating and then drying; and (g) applying a continuous, optically transparent, composite film consisting of a layer of thermoplastic polyurethane having adhesive properties and a layer of thermosetting polyurethane having anti-lacerating and self-healing properties to said polarizing coating by first subjecting it to moderate temperature and pressure conditions in order to insure a wrinkle-free and gradual spreading out and adherence of the film upon the polarizing coating, and then subjecting it to elevated temperature and pressure conditions to reinforce the mechanical bond between the film and the coating and to complete the cross linking of the composite film.

13. A glass article according to claim 2 which is destined for use as a blank for a spectacle lens which blank is subjected to an edging operation, wherein the edge of said blank has a coating of resin thereon which is polymerized in situ.

14. A glass article according to claim 3 which is destined for use as a blank for a spectacle lens which blank is subjected to an edging operation, wherein the edge of said blank has a coating of resin thereon which is polymerized in situ.