Optical article comprising an external water- and/or oil-repellent coating coated with a temporary coating

[0001] The invention relates generally to the field of optical products, in particular ophthalmic lenses, provided with an outer coating with hydrophobic and / or oleophobic properties (top coat).

[0002] These external hydrophobic and / or oleophobic coatings are well known in the art.

[0003] These hydrophobic and / or oleophobic outer coatings, which are generally associated with anti-reflective coatings, aim to make the ophthalmic lens less soiling. Most often this applies to materials of the fluorosilane type, which reduces surface energy to avoid the adherence of greasy dirt, which is therefore easier to remove.

[0004] One of the problems caused by these hydrophobic and / or oleophobic outer coatings is that they achieve such efficiency that adhesion to the adhesive surface of the adhesive block / hydrophobic and / or oleophobic coating needed for lens assembly during rounding operations turns out changed and even threatened.

[0005] Rounding is the final stage of finishing an ophthalmic lens and is an operation that involves machining the lens edge or perimeter in such a way as to match the nucleus of the dimensions and form required to match the lens to the spectacle frame in which it is intended to be placed.

[0006] Rounding is performed on an automated grinding machine comprising diamond grinding discs which perform the machining described above and therefore it is necessary to keep the rounded lens stationary in the grinding machine.

[0007] To do this, the first phase is to clamp the vise in the center of the convex lens surface with an adhesive block, such as a double-surface adhesive block.

[0008] The vise to which the lens adheres via an adhesive block is then mechanically secured in the assembly axis of the grinder and the axial arm begins to block the lens by applying a central force to the lens surface opposite the vise.

[0009] During rounding, the lens should not be subjected to an axis displacement of more than 2 °, preferably at most 1 °, and consequently the adhesion of the block to the lens surface is essential to obtain satisfactory rounding.

[0010] To overcome these difficulties of rounding lenses equipped with an external hydrophobic and / or oleophobic coating, it has been proposed to form a hydrophobic and / or oleophobic coating with a temporary organic or mineral coating. For example, European patent applications EP 1 392 613 and EP 1 633 684, on behalf of ESSILOR, describe the use of a temporary coating, of an organic or mineral nature, which increases surface energy and thus allows the optician to perform reliable rounding of the lens. After rounding, the temporary coating should be removed to restore the surface properties of the outer hydrophobic and / or oleophobic coating. It is understood that after the withdrawal of the temporary coating, the outer hydrophobic and / or oleophobic coating should have surface properties as close as possible to their initial properties.

[0011] Although the temporary coatings described in European patent applications EP 1 392

613 and EP 1 633 684 lead, after their withdrawal, to external hydrophobic and / or oleophobic coatings having good surface properties and a high angle of static contact with water (in a typical case 112 °), it is desirable to increase this value of the contact angle.

[0012] Alternatively, after the rounding operation of the primary optical product, one may want to perform the rounding repair and / or drilling operation of the glass, the drilling area being the attachment point of the frame of the spectacle frame.

[0013] For these last stages, in particular glass drilling, it is essential that the vise / adhesive block holding unit stays in position on the surface of the product, since it provides a landmark for positioning drills for drilling holes.

[0014] The film described in patent application WO 05/015 270 allows to provide substantial rounding, but it is systematically found that the holding unit: vise / adhesive block detaches spontaneously within seconds following this basic rounding operation.

[0015] From the beginning of the rounding operation, it appears that the water falling on the product during this rounding operation, penetrates under the temporary film, which rotates around itself. Under these conditions, it is therefore impossible to perform subsequent rounding or glass drilling repairs.

[0016] Patent application WO 03/05 7641 provides for the deposition of organic material on a MgF2 layer. Consequently, a temporary film of organic material is not deposited directly on the outer hydrophobic and / or oleophobic coating.

[0017] The object of the present invention is therefore to provide an optical article, in particular an ophthalmic lens, comprising an external hydrophobic and / or oleophobic coating directly coated with a temporary layer which:

- after withdrawing the temporary layer, it allows to recover the outer hydrophobic and / or oleophobic coating having properties practically identical to the initial properties and in particular the angle of static contact with water practically equal to the initial angle of static contact with water; and / or

- allows, possibly, a rounding repair operation; and / or

- allows drilling glass, the drilling area being used as an attachment point to the frame of the spectacle frame.

[0018] According to the invention, these objects are achieved by an optical article having on one of its main surfaces an outer hydrophobic and / or oleophobic coating with low surface energy, characterized in that the temporary layer of the dried polyurethane latex composition is directly deposited on the outer hydrophobic coating and / or oleophobic.

[0019] The temporary layer, preferably peelable, is generally 10-40 mm thick, preferably 15-30 mm and more preferably 15-20 mm thick, and preferably has an elongation at break equal to or less than 200%, more preferably equal to or less than 150% .

[0020] According to the method of depositing a temporary layer, the thickness of the layer may locally vary. In particular, in the case of deposition by dip coating (immersion) of the coating composition in the liquid bath, the thickness is higher at the bottom of the glass (the part first coming into contact with the liquid of the temporary coating composition and the last leaving the bath when the glass is removed).

[0021] The average thickness of the temporary layer is the average of 3 measured thicknesses at 3 surface points: two opposite points: top point (about 5 mm from the edge of the glass), middle and bottom point (about 5 mm from the edge of the glass), when deposited by " dip "(immersion).

[0022] The average thickness ranges are the same as the thickness ranges mentioned above.

₂ [0023] Preferably, the temporary layer has a surface energy higher than or equal to 15 mJ / m², 22 more preferably equal to or higher than 20 mJ / m², even more preferably equal to or higher than 30 mJ / m². Even more preferably, the temporary layer has a polar surface energy component of less than 26 mJ / m².

[0024] In the present application, the term "optical article" means a substrate of organic or mineral glass, optically transparent, treated or not, according to which it comprises one or more coatings of different nature or which remains uncovered.

[0025] Surface energies are calculated according to the Owens-Wendt method described in the following reference: "Estimation of a surface force energy of polymers" OWENS DK, WENDT RG

(1969) J. Appl. POLIM. SCI, 13, 1741-1747.

[0026] Optical products according to the invention are optical products, in particular ophthalmic lenses, which contain an external hydrophobic and / or oleophobic coating and preferably optical products simultaneously containing an external hydrophobic coating and / or oleophobic coating deposited on a mono- or multilayer anti-reflective coating.

[0027] Indeed, hydrophobic and / or oleophobic outer coatings are generally used for optical products containing an anti-reflective coating, in particular of mineral material, to reduce their pronounced tendency to contaminate, for example with respect to fatty deposits.

[0028] As is known, external hydrophobic and / or oleophobic coatings are obtained by applying, on the surface of the anti-reflective coating, compounds reducing the surface energy of an optical product.

[0029] Such compounds are widely described in the art, for example in US Patent Nos. 4,410,563, EP 0 203 730, EP 749 021, EP 844 265, and EP 933 377.

[0030] Silane-based compounds containing fluorinated moieties, in particular perfluorocarbons or perfluoropolyethers, are most commonly used.

[0031] By way of example, silazan, polysilazane or silicone compounds may be cited which include one or more fluorinated moieties such as those previously cited.

[0032] A known method is the deposition on the anti-reflective coating of compounds having fluorinated moieties and Si-R moieties, where R is -OH or a precursor thereof, preferably an alkoxy group. Such compounds can effect polymerization and / or crosslinking reactions on the surface of the anti-reflective coating, directly or after hydrolysis.

[0033] The application of compounds that reduce the surface energy of an optical article is classically done especially by immersion in a solution of the compound, by centrifugation or vapor deposition.

[0034] In general, the outer hydrophobic and / or oleophobic coating has a thickness less than 10 nm, and more preferably even less than 5 nm.

[0035] In general, a low surface energy hydrophobic and / or oleophobic coating₂ has surface energy equal to or less than 14 mJ / m², preferably equal to or less than 13 mJ / m², more preferably equal to or less than 12 mJ / m².

[0036] As indicated previously, the temporary layer of the invention is a dried layer of a polyurethane latex composition deposited directly on the outer hydrophobic and / or oleophobic coating.

[0037] As is well known, latex is a dispersion in an aqueous environment of polymeric or copolymeric particles. The aqueous medium may be water, for example distilled water or demineralized water, or a mixture of water and one or more solvents, especially water and an alkanol, generally a C1-C6 alkanol, and preferably ethanol.

[0038] In the present invention, the term "polyurethane" simultaneously includes polyurethane (co) polymers as such, i.e. polymers obtained by condensation of at least one polyisocyanate and at least one polyol and optionally a chain extender, and polyurethane-urea, i.e. ) polymers obtained by condensation of at least one polyisocyanate and polyamine, and optionally a chain extender, and mixtures thereof.

[0039] Preferably, the polyurethanes and polyurethane-urea according to the invention result from the condensation of diisocyanate with a diol and / or diamine. Even more preferably, the polyurethanes and polyurethane urea according to the invention are linear or cyclic aliphatic polyurethanes and polyurethane urea, i.e. obtained by condensation of aliphatic, linear or cyclic polyisocyanates with polyols and / or linear or cyclic aliphatic polyamines.

[0040] Among the polyisocyanates useful for forming the polyurethanes and polyurethane urea according to the invention, and especially preferred diisocyanates, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2, 4'-diisocyanate, paraphenylene diisocyanate, biphenyldiisocyanate, 3,3'-dimethyl-4,4'-diphenylenediisocyanate, tetramethylene-1,4-diisocyanate, hexamethylene-1,6-diisocyanate, 2,2,4-trimethylhexane-1,6-diisocyanate . lysine methyl ester diisocyanate, bis (isocyanoethyl) fumarate, isophorone diisocyanate (IPDI), ethylenediisocyanate, dodecane-1,12-diisocyanate, cyclobutane-1,3-diisocyanate, cyclohexane-1,3-diisocyanate, cyclohexano-1,4-cyclohexanoate diisocyanate, hexahydro-toluene-2,4-diisocyanate, methylcyclohexyl diisocyanate, hexahydrotoluene-2,4-diisocyanate, hexahydrotoluene-2,6-diisocyanate, hexahydrophenylene-1,3-diisocyanate, hexahydroisanoate perhydrodiphenylmethane-2,4'-diisocyanate, perhydrodiphenylmethane-2,4'-diisocyanate, perhydrodiphenylmethane-2,4'diocyanate, perhydrophenylmethane-4,4'-diisocyanate (or bis- (4-isocyanatocyclohexyl) methane, or 'dicyclohexycimethane diisocyanate) and mixtures thereof.

[0041] Preferred polyisocyanates are aliphatic diisocyanates such as hexamethylene-1,6-diisocyanate, isophorone diisocyanate, ethylene diisocyanate, dodecane-1,12-diisocyanate, cyclohexane-1,3-diisocyanate, bis- (4-isocyanate) methane and mixtures thereof. The preferred diisocyanate is isophorone diisocyanate.

[0042] Other polyisocyanates suitable for the polyurethanes and polyurethane urea according to the invention are described in detail in WO 98/37 115.

[0043] Among the polyols suitable for the polyurethanes of the invention, mention may be made of pentaerythritol, trimethylol ethane, trimethylolpropane, di (triethylolpropane) -dimethylolpropionic acid, ethylene glycol, 1,2- and 1,3-propylene glycol, 1,2-butanediol, 1,4 -butenodiol, 1,3-butanediol, 2,3-butanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,5-pentanediol, 2,4-pentanediol, 1,6-hexanediol, 2 , 5-hexanediol, 1,8-octanediol, 2-methyl-1,3-pentadiol, 2,4-heptanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 1,4-cyclohexanediol, 2,2-dimethyl-3-hydroxypropyl-2,2-dimethyl-3-hydroxypropionate, 1, 2,6-hexanetriol, 1,2,4-butanetriol, glycerin, sorbitol, mannitol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, dibutylene glycol, 1,4-bis (hydroxymethyl) cyclohexane, 1, 2bis (hydroxymethyl) cyclohexane, 1,2-bis (hydroxyethyl) cyclohexane, bis (hydroxypropyl) lantoin, tris-hydroksyetyloizocyjanuran.

[0044] Preferred polyols are aliphatic diols, in particular polypropylene glycol.

[0045] Another class of polyols suitable for polyurethanes and polyurethane urea according to the invention are polyether polyols such as polyoxyalkylene polyols, polyalkoxylated polyols such as poly (oxytetramethylene) diols and mixtures thereof.

[0046] Preferred polyamines are diamines, in particular linear and cyclic aliphatic diamines. [0047] Among the diamines, mention may be made of diaminomethane, ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane, 1,4-diaminocyclohexane, 4,4'diaminodicyclohexylmethane, 1-amino-3 -aminomethyl-3,5,5-trimethylcyclohexane, trimethylamine.

[0048] Also suitable for the production of polyurethanes and polyurethane urea are amino alcohols suitable for the invention, such as monoethanolamine, diethanolamine.

[0049] Polyurethanes and their method of preparation are described, inter alia, in US Pat. No. 6,187,444. [0050] Preferably, the polyurethanes of the invention do not include acrylic or methacrylic functions, and in particular a polymerizable acrylic or methacrylic function.

[0051] Polyurethane latexes suitable for the present invention are commercially available, for example from BAXENDEN under the names W 234i W 240 (polyurethane-urea) or under the name Pellimer TC^TM (polyurethane-urea) from SOCOMOR and PROXR 910® (polyurethane) from SYNTRON. [0052] The TC pellimer will then be used after dilution with water (a mixture of 80 wt% Pellimer TC to 20 wt% water is prepared). This mixture obtained will hereinafter be referred to as TC80F.

[0053] The polyurethane latex compositions according to the invention can of course be mixtures of polyurethane latex, in particular commercial polyurethane latex.

[0054] In a particular embodiment of the invention, the polyurethane latex composition also comprises a low content, up to 10% by weight of the composition, of (meth) acrylic latex, preferably acrylic latex. Preferably, the weight proportion of (meth) acrylic latex varies from 0.1 to 10% by weight and more preferably from 2 to 6% by weight based on the total weight of the latex composition.

[0055] The dry weight proportion of the acrylic latex relative to the total dry weight of the composition also preferably varies from 0.1 to 10% by weight, and more preferably from 2 to 6% by weight.

[0056] The presence of (meth) acrylic latex has the advantage of reducing the nature of the hydrophyte material on the one hand, and of making the final dry layer more rigid on the other, and reducing its elongation at break.

[0057] These (meth) acrylic latexes are commercially available, especially from SYNTRON under the names PROXAM 185 RS® (acrylic resin), PROXAM 157® (acrylic copolymer), PROXAM N 360^® (acrylic copolymer).

[0058] Preferably, the PU latex compositions of the invention are free of demineral colloidal or magnesium particles.

[0059] Obtaining favorable results according to the invention, in particular the adhesion of the adhesive block, does not require the presence of colloidal oxygen or magnesium colloids.

[0060] In the general case, the PU latex compositions of the invention preferably contain one or more surfactants, generally 0.5 to 10% by weight based on the total weight of the latex composition, preferably 0.5 to 6% by weight.

[0061] In general, the PU latex compositions of the invention have a dry matter content of 25 to 55% by weight, preferably 25 to 50%, more preferably 25 to 45% by weight, based on the total weight of the latex composition.

[0062] Their viscosity at ambient temperature varies preferably from 5 to 50 cp, more preferably from 7 to 46 cp.

[0063] The temporary layers according to the invention can be deposited on a hydrophobic and / or oleophobic coating with any type of agent, but preferably by dip coating, centrifugation, powdering, or application with a brush coating, preferably by dipping. [0064] Embedding may be done on the entire surface of the lens intended to receive the holding adhesive block or on a part of it, in particular in the central part of the lens.

[0065] In one embodiment, the temporary layer can be applied to the middle part with a brush.

[0066] Preferably, no other coating is placed on the surface of the temporary layer, in other words the temporary layer is preferably a monolayer and during rounding, the holding adhesive stick comes into direct contact with the surface of the polyurethane-based latex layer.

[0067] Preferably, the temporary layer is optically active, that is to say power measurement allowed by conventional measuring means such as a confocometer.

[0068] After application, the latex composition of the invention is dried, generally by heating at temperatures varying typically from 40 ° C to 80 ° C, for a period of several minutes to several hours.

[0069] Advantageous results of the invention are obtained by simple drying and do not require any active radiation.

[0070] It is not necessary for the composition to contain a photoactive polymerization initiator.

[0071] Preferably, the latex composition is dried in a single step, by heating or maintaining at ambient temperature.

[0072] The following examples illustrate the present invention. In the examples, unless otherwise indicated, all parts and percentages are by weight.

1. Latex compositions used in the examples [0073] Latex compositions used in the examples are given in Table I below.

TABLE I

<td colspan="7">Latex compositions</td>

<td rowspan="2">Composition No.</td><td colspan="3">Latex type (%)</td><td rowspan="2">Surfactant (%)</td><td rowspan="2">Solvent</td><td rowspan="2">Dry weight (%)</td>

<td>PU</td><td>PU-urea</td><td>Acrylic</td>

<td>1a</td><td> -</td><td>W234 (99.33%)</td><td> -</td><td>A (0.67%)</td><td>water</td><td> 31%</td>

<td>1b</td><td> -</td><td>W234 (95.24%)</td><td> -</td><td>M (4.76%)</td><td>water</td><td> 31,4%</td>

<td>1c</td><td> -</td><td>W234 (94.57%)</td><td> -</td><td>A (0.67%) + M (4.76)</td><td>water</td><td> 31,5%</td>

<td>2a</td><td> -</td><td>TC80F (100%)</td><td> -</td><td> -</td><td>water</td><td> 29%</td>

<td>2b</td><td> -</td><td>TC80F (99.33%)</td><td> -</td><td>A (0.67%)</td><td>water</td><td> 29,5%</td>

<td>2c</td><td> -</td><td>TC80F (95.24%)</td><td> -</td><td>M (4.76%)</td><td>water</td><td> 28,75%</td>

<td>2d</td><td> . -</td><td>TC80F (94.57%)</td><td> -</td><td>A (0.67%) + M (4.76%)</td><td>water</td><td> 29,4%</td>

<td>3a</td><td>PROX R910 (100%)</td><td> -</td><td> -</td><td> -</td><td>water</td><td> 40%</td>

<td>3b</td><td>PROX R910 (99.33%)</td><td> -</td><td> -</td><td>A (0.67%)</td><td>water</td><td> 39,8%</td>

<td>3c</td><td>PROX R910 (95.24%)</td><td> -</td><td> -</td><td>M (4.76%)</td><td>water</td><td> 39,96%</td>

<td>3d</td><td>PROX R910 (94.57%)</td><td></td><td></td><td>A (0.67%) + M (4.76%)</td><td>water</td><td> 40,51%</td>

<td>4a</td><td> -</td><td> -</td><td>PROXAM 185 RS (100%)</td><td> -</td><td>water</td><td> 50%</td>

<td>4b</td><td> -</td><td> -</td><td>PROXAM 185 RS (99.43%)</td><td>A (0.67%)</td><td>water</td><td> 49,72%</td>

<td>4c</td><td> -</td><td> -</td><td>PROXAM 185 RS (95.24%)</td><td>M (4.76%)</td><td>water</td><td> 49,61%</td>

<td>4d</td><td> -</td><td> -</td><td>PROXAM 185 RS (94.57%)</td><td>A (0.67%) + M 4.76%)</td><td>water</td><td> 49,2%</td>

<td> 5</td><td></td><td></td><td>PROXAM 157 (100%)</td><td></td><td>water</td><td> 49,73%</td>

<td> 6</td><td></td><td></td><td>PROXAM N 360 R (100%)</td><td></td><td>water</td><td> 45,62%</td>

<td> 7</td><td>PROX R 910 (94.6%)</td><td></td><td>PROXAM185 RS (4.7%)</td><td>A (0.7%)</td><td>water</td><td> 40,5%</td>

<td> 8</td><td>PROX R 910 (91.05%)</td><td></td><td>PROXAM 185 RS (3.5%)</td><td>A (0.67%) + M (4.76%)</td><td>water</td><td> 41%</td>

A = ACTIRON F 487® - surfactant, biodegradable (SYNTRON)

M = MODAREZ PW 336® - surfactant based on acrylic copolymer (SYNTRON) [0074] The values ​​in brackets in the table correspond to the quantities of liquid components used (liquid latex, surfactant, ..).

[0075] The total dry weight values ​​of the obtained compositions and starting products are given in the right column of Table I.

Preparation of latex compositions No. 7 and 8 [0076] A weighed amount of PROX R 910® is placed in a beaker and the weighed amounts of PROX AM 185 RS®, ACTIRON F 487® are successively added, and, optionally, MODAREZ PW 336®, the mixture is mixed in RAYNERIE (35 mm diameter deflector turbine) starting at low speed and then progressively increasing the speed up to 1800 rpm and mixing is continued for about 2 and a half hours.

[0077] It is allowed to stand overnight (elimination of microbubbles) before use.

3. Determination of surface energy characteristics of temporary layers of dried latex compositions

- Sample Preparation [0078] Latex compositions are deposited by dip coating on an uncoated substrate, in two planes, on a base 6, with an ethylene diglycol copolymer - bis allyl carbonate (CR 39® from PPG -ORMA® from ESSILOR) using a dipping coater at a dehumidification rate 1 mm / s and a break time of 10 seconds. The coated samples are then oven dried at 50 ° C for 2 hours.

- Determination of surface energy characteristics [0079] Surface energy characteristics, total energy, dispersion component and polar component are determined by the Owens-Wendt method using a DIGIDROP GBX apparatus.

[0080] By way of comparison, the surface energy characteristics of two hydrophobic and / or oleophobic coatings, namely OPTOOL DSX® from DAIKIN and KY 130 from SHINETSU are also given.

[0081] The results are given in Table II below.

TABLE II

<td rowspan="2">Layer character</td><td rowspan="2">Thickness (mm)</td><td colspan="3">Surface energy (mJ / m¹)</td>

<td>altogether</td><td>Dispersion component</td><td>Polar component</td>

<td>1a</td><td></td><td> 39,7</td><td> 34,3</td><td> 5,4</td>

<td>1b</td><td></td><td> 37,6</td><td> 35,5</td><td> 2,1</td>

<td>1c</td><td></td><td> 38,1</td><td> 34,8</td><td> 3,3</td>

<td>2a</td><td> 19</td><td> 43,6</td><td> 34,0</td><td> 9,5</td>

<td>2b</td><td></td><td> 44,2</td><td> 35,6</td><td> 8,6</td>

<td>2c</td><td></td><td> 43,6</td><td> 35,8</td><td> 7,8</td>

<td>2d</td><td></td><td> 39,0</td><td> 28,0</td><td> 10,9</td>

<td>3a</td><td></td><td> 43,4</td><td> 34,5</td><td> 8,9</td>

<td>3b</td><td></td><td> 39,8</td><td> 37,2</td><td> 2,6</td>

<td>3c</td><td></td><td> 37,5</td><td> 33,7</td><td> 3,8</td>

<td>3d</td><td></td><td> 36,4</td><td> 32,4</td><td> 4,0</td>

<td>4a</td><td></td><td> -</td><td> -</td><td> -</td>

<td>4b</td><td></td><td> -</td><td> -</td><td> -</td>

<td>4c</td><td></td><td> 41,3</td><td> 32,6</td><td> 8,7</td>

<td>4d</td><td></td><td> 47,1</td><td> 26,8</td><td> 20,3</td>

<td> 5</td><td></td><td> 36,8</td><td> 34,8</td><td> 2,0</td>

<td> 6</td><td></td><td> 40,9</td><td> 33,1</td><td> 7,8</td>

<td> 7</td><td></td><td> 40,5</td><td> 33,3</td><td> 7,2</td>

<td> 8</td><td> 19</td><td> 43,5</td><td> 31,6</td><td> 12,1</td>

<td>OPTOOLD SX</td><td>2,6nm</td><td> 11,3</td><td> 11,1</td><td> 0,2</td>

<td>KY130</td><td></td><td> 13,1</td><td> 13,0</td><td> 1,0</td>

[0082] Examples 1 to 10 and comparative examples C1 to C6.

[0083] Temporary layers were created as described above

- ORMA® substrate (sphere: -5.00, cylinder: +2.00, diameter 65 mm and thickness in the middle of 1.9 mm)

- polycarbonate base (sphere: -8.00, cylinder: + 2.00, diameter 65mm and thickness in the middle of 1.3mm)

- ORMIX® 1.6 substrate (sphere: -8.00, cylinder: + 2.00, diameter 65m and thickness in the middle 1.1 mm) previously coated, in the order indicated, with an anti-abrasive coating, an anti-reflective coating and an external hydrophobic and / or oleophobic coating (OPTOOL DSX , thickness 2.6 nm) as described in Example 1 of EP 1 392 613. Visually creating a temporary layer was found and rounding and drilling of samples was performed. Characteristics of temporary layers and results are given in Table III.

Protocol for measuring the axis shift of the lens subjected to rounding operations

I- Description of the test [0084] The rounding test is performed on an Esilor Kappa grinder.

[0085] The lenses are rounded to give them the size of a particular frame (see below).

[0086] The following equipment is needed to perform the test:

Essilor CLE 60 front-focus meter (for lens setting and final inspection)

Essilor Kappa numeric line (positioning remote control / locking device and grinder)

Overall dimensions of the Charmant frame reference number 8320, model 05, size 51 control pseudo-frame.

Adhesive plate or adhesive block for holding LEAP Il with a diameter of 24 mm GAM200 from 3M

Essilor vise to accept an adhesive plate.

II- Sampling and assembly parameters.

[0087] The stored assembly data are as follows:

Height: half the housing height either

PD (right and left) = 32 mm and axis = 90 ° [0088] The trimming cycle used is the material-adapted cycle (plastic cycle for low index, polycarbonate cycle for PC and cycle for medium with medium refractive index MHI). The pressure maintained is the pressure corresponding to the capacity of the brittle glass of the grinder.

III- Control tests [0089] After rounding, a control test is performed to determine if the rounding operation has been performed satisfactorily.

[0090] Control tests are performed using a CLE 60 front-focus meter by positioning the lenses in pseudo-fixtures. Axes are detected during this phase.

[0091] If the lens cannot be inserted into the pseudo-frame after the rounding operation, or if the lens can be inserted into the pseudo-frame but has an axis shift of more than 2 °, the lens is incompatible and has not passed the test. It is denoted by - in the scoreboard.

[0092] If the glass exhibits an axis shift of less than 2 °, the lens passes the test and is marked in the scoreboard by X.

Drilling after rounding [0093] After the rounding operation, the lens and vise / adhesive block assembly, with the vise / adhesive block permanently adhering to the lens, is placed in an Optodrill or Minima2 drilling machine and held by a locking device.

[0094] Then the lens is pierced

- or manually with a Minima 2 drill equipped with a 2.2 mm drill bit, rotational speed 3500 rpm.

- Or automatically an Optidrill Evo drill equipped with a 2.2 mm drill bit with a rotational speed of 12,000 rpm.

[0095] After drilling, the fixation system is unscrewed and the drilled lens and vise / stick are removed.

[0096] Next, the vice is removed and the bored lens is removed.

[0097] While the lens can be positioned in the drilling device and due to this fact undergoes a drilling operation, it is marked as X in table III. In the opposite case, it is marked as -.

[0098] For the lenses of examples 1 to 8 and C1 toC6, the adhesive block loses its adhesion after the rounding operation and does not allow drilling.

[0099] For the lenses of examples 9 and 10, the adhesive block remains permanently retained on the lens after the rounding operation and allows positioning the lens in the drilling device and performs the correct drilling.

TABLE III

<td rowspan="2">Prov. No.</td><td colspan="2">Temporary layer</td><td rowspan="2">Layer creation</td><td rowspan="2">rounding simple</td><td rowspan="2">rounding complete</td><td rowspan="2">Drilling after complete rounding</td>

<td>Composition latex</td><td>Thickness (Mm)</td>

<td> 1</td><td>2a</td><td> 19</td><td>X</td><td>X</td><td> -</td><td> -</td>

<td> 2</td><td>2b</td><td></td><td>X</td><td>X</td><td> -</td><td> -</td>

<td> 3</td><td>2c</td><td></td><td>X</td><td>X</td><td> -</td><td> -</td>

<td> 4</td><td>2d</td><td></td><td>X</td><td>X</td><td> -</td><td> -</td>

<td> 5</td><td>3a</td><td></td><td>X</td><td>X</td><td> -</td><td> -</td>

<td> 6</td><td>3b</td><td></td><td>X</td><td>X</td><td>X</td><td></td>

<td> 7</td><td>3c</td><td></td><td>X</td><td>X</td><td>X</td><td></td>

<td> 8</td><td>3d</td><td></td><td>X</td><td>X</td><td>X</td><td></td>

<td> 9</td><td> 7</td><td></td><td>X</td><td>X</td><td>X</td><td>X</td>

<td> 10</td><td> 8</td><td> 19</td><td>X</td><td>X</td><td>X</td><td>X</td>

<td>C1</td><td>4a</td><td></td><td> -</td><td> -</td><td> -</td><td> -</td>

<td>C2</td><td>4b</td><td></td><td> -</td><td> -</td><td> -</td><td> -</td>

<td>C3</td><td>4c</td><td></td><td> -</td><td> -</td><td> -</td><td> -</td>

<td>C4</td><td>4d</td><td></td><td> -</td><td> -</td><td> -</td><td> -</td>

<td>C5</td><td> 5</td><td></td><td> -</td><td> -</td><td> -</td><td> -</td>

<td>C6</td><td> 6</td><td></td><td> -</td><td> -</td><td> -</td><td> -</td>

<td colspan="7">X = yes - = no</td>

[0100] The contact angle with water of the external hydrophobic coating and / or oleophobic coating of example 8 after removal of the temporary layer is also measured relative to the value of this contact angle for the same hydrophobic and / or oleophobic coating prior to deposition of the temporary layer. By comparison, the angle of contact with water was measured for a Platinum® commercial product (substrate refractive index 1.56) from HANDOK OPTEC.

[0101] The measurements were repeated after caustic soda treatment on the hydrophobic and / or oleophobic coating. [0102] The results are given in Table IV

TABLE IV

<td rowspan="2"></td><td rowspan="2">The nature of a hydrophobic and / or oleophobic coating / withdrawn temporary layer</td><td colspan="2">Water contact angle (°)</td>

<td>Without caustic soda treatment</td><td>After caustic soda treatment</td>

<td>Example 11 (invention)</td><td>OPTOOL DSX 2.6 nm / latex 8 (example 10)</td><td> 117°- 120°</td><td> 114°- 115°</td>

<td>Ref. 1</td><td>OPTOOL DSX- 3 nm</td><td> 117°- 120°</td><td> 113°</td>

<td>Ref. 2</td><td>KY 130</td><td> 110°</td><td> 109°</td>

<td>Comparative Example 1</td><td>Platinum® product</td><td> 111°</td><td> -</td>

[0103] The contact angle is measured using a KROSS goniometer DSA Reference No. 10 by depositing 5 drops of demineralized water (4 ml per drop) on the cleaned and dried lens surface, one inside and four others 20mm from that.

[0104] Caustic treatment, which aims to check the resistance of a hydrophobic and / or oleophobic coating based on immersion of the lens for 1 minute in a 0.1N soda solution, followed by rinsing with water and isopropyl alcohol, drying, contact measurements, re-immersion for 29 minutes in soda solution 0.1N, rinsing and drying again and contact measurements. The contact angle value is the average of the results.

[0105] Glass is considered to have passed the caustic treatment successfully when the mean contact values ​​without soda treatment and the contact angle after soda treatment are close to the target values ​​set out below:

<td rowspan="2">The nature of the hydrophobic and / or oleophobic coating / temporary layer withdrawn</td><td colspan="2">Target values ​​«Contact angle» with water (°)</td>

<td>Without caustic soda treatment</td><td>After caustic soda treatment</td>

<td>OPTOOL DSX ~ 3nm</td><td> 117°-120°</td><td></td>

<td>KY 130 (20 nm set)</td><td> 110°</td><td> 109°</td>

[0106] The temporary coating according to the invention has the advantage that it can be applied by a liquid route, which makes it possible to mark the glasses on the temporary layer, can keep the surface energy of the hydrophobic and / or oleophobic coating low, in particular better to keep the contact angle after reversing the temporary coating and multivalent, it can be deposited on various hydrophobic and / or oleophobic layers.