UV cured UV blocking compositions and methods for making and using the same

[0001] The invention is in the field of blocking Ultraviolet (UV) radiation with UV curable compositions. In particular, the invention relates to preventing UV transmission through glass and other transparent articles by applying one or more layers of a UV curable composition onto such articles, followed by curing such composition by exposure to UV radiation.

[0002] Ultraviolet radiation refers to invisible electromagnetic radiation between visible violet light and X rays. It ranges in wavelength from about 4 to about 400 nm and in frequency from about 10¹⁵ to 10¹⁷ Hz. It is a component of the sun's radiation and is also produced artificially in arc lamps, e.g., in the mercury arc lamp.

[0003] The UV radiation in sunlight is divided into three bands: UV-A (320-400 nanometers), UV-B (280-320 nanometers), and UV-C (below 280 nanometers). Much UV-B and most UV-C radiation is absorbed by the ozone layer of the atmosphere before it can reach the earth's surface.

[0004] Ultraviolet radiation from the sun is a significant cause of damage to cells and degradation in many materials. It is known that UV-A radiation can cause skin damage and may cause melanomatous skin cancer; and that UV-B radiation can cause sunburn and most common skin cancer; and that UV-C is the most potent and harmful form of UV radiation. It has also well-known that art, photographic works, and paper deteriorate when exposed for long periods to sunlight.

[0005] A number of technologies have been developed in order to screen out the UV radiation to minimize the damage and degradation caused by UV radiation. However, none of these methods is very satisfactory in terms of performance, cost, efficiency, and/or durability. Therefore, there remains a clear need for an improved method and composition for blocking transmission of UV radiation. Specifically, there is a need to develop an improved method and composition for blocking transmission of UV radiation through transparent substrates such as glass. More specifically, there is a need to develop an improved method and composition for blocking a substantial percentage of transmission of UV radiation over an extended period of time.

[0006] The present invention is directed to UV blocking compositions suitable for transparent substrates, particularly glass, which when UV cured to the substrate are capable of blocking a significant amount of UV radiation. Thus, one object of the present invention is to provide a UV blocking composition by combining one or more UV blocking ingredients with one or more UV curable ingredients.

[0007] Another object of the present invention is to provide a method for reducing UV transmission through a transparent substrate such as glass by application of a UV blocking composition onto the substrate wherein the UV blocking composition is cured by UV radiation.

[0008] Yet another object of the present invention is to provide a glass or other transparent substrate which is capable of blocking a significant amount of UV radiation. Said glass or transparent substrate is coated with one or more UV cured UV blocking layers.

[0009] Yet still another object of the present invention to provide a process for making a glass or other transparent substrate capable of blocking a significant amount of UV radiation. Said glass or transparent substrate is made by coating (ink) with one or more UV cured UV blocking layers. Preferably the UV blocking compositions absorb more than 90% of UV transmission between 300-400 nm and more than about 97% of UV transmission between 300-385 nm.

[0010] FIG. 1: UV transmission of Samples A, B, C and Comparison Sample.

[0011] FIG. 2: UV transmission of sample over various length of time.

[0012] Unless otherwise specified, all % referred to weight% of the total UV curable, UV blocking coating composition (ink composition).

[0013] The invention is directed to compositions and methods for blocking the transmission of UV radiation through glass or other transparent substrates. More specifically, the present invention is directed to UV blocking compositions suitable for transparent substrates, particularly glass, which when UV cured to the substrate are capable of blocking a significant amount of UV radiation. Thus, one object of the present invention is to provide a UV blocking composition by combining one or more UV blocking ingredients with one or more UV curable ingredients.

[0014] Another object of the present invention is to provide a method for reducing UV transmission through a transparent substrate such as glass by application of a UV blocking composition onto the substrate wherein the UV blocking composition is cured by UV radiation.

[0015] Yet another object of the present invention is to provide a glass or other transparent substrate which is capable of blocking a significant amount of UV radiation. Said glass or transparent substrate is coated with one or more UV cured UV blocking layers.

[0016] Yet still another object of the present invention to provide a process for making a glass or other transparent substrate capable of blocking a significant amount of UV radiation. Said glass or transparent substrate is made by coating with one or more UV cured UV blocking layers. Preferably the UV blocking compositions absorb more than 90% of UV transmission between 300-400 nm and more than about 97% of UV transmission between 300-385 nm.

[0017] In one embodiment of the present invention, UV transmission is blocked by applying one or more layers of a coating composition comprising one or more UV blocking ingredients and one or more UV curable ingredients.

[0018] In a preferred embodiment, an adhesion promoter is applied between the transparent substrate and the one or more layers of UV blocking coating composition.

[0019] In another preferred embodiment, the coating composition comprises 2-(2hydroxy-5methacryloxyethylphenyl)-2H-benzotriazole (tradename: NORBLOC, made by Janssen Pharmaceutica, Titusville, N.J. 08560, USA).

[0020] In another preferred embodiment, the coating composition comprises bis (2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidinyl) ester (tradename: TUNIVIN 123, made by Ciba-Geigy).

[0021] In another preferred embodiment, the coating composition comprises 2-(2H-benzotriazol-2-yl)-6-dodecyl-4-methyl-phenol (tradename: TINUVIN 171, made by Ciba-Geigy).

[0022] In another preferred embodiment, the coating composition comprises the UV-blocking ingredient(s) contained in TINUVIN 99, which is made by Ciba-Geigy.

[0023] In still another preferred embodiment, the coating composition comprises a combination of any of the above.

[0024] In a highly preferred embodiment, the coating composition comprises a 2-(2hydroxy-5methacryloxyethylphenyl)-2H-benzotriazole (NORBLOC), bis (2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidinyl) ester (TINUVIN 123), 2-(2H-benzotriazol-2-yl)-6-dodecyl-4-methyl-phenol (TINUVIN 171), and TINUVIN 99.

[0025] In another embodiments, the invention includes transparent substrates coated with the above identified compositions as well as methods of making and using the UV curable compositions.

[0026] UV blocking ingredients are commonly referred to as UV blockers. UV blockers are also referred to as UV absorbers or UV stabilizers. Any UV blocker(s) known or combination thereof can be used in the present invention. Examples of such UV blocker include, but are not limited to, Cyagard 1164L, Cyagard 3638, Cyagard UV 531, Cyagard UV 5411, Cyagard UV 9, Cyasorb 1084, Cyasorb 1164, Cyasorb 284, Cyasorb UV 1988, Cyasorb UV 2098, Cyasorb UV 2126, Cyasorb UV 24, Cyasorb UV 2908 (Cyasorb is a trademark owned by Cytec Technology Corp., 11 05 North Market St. Suite 1300, Wilmington, Del. 19801); Eastman Inhibitor RMB (Resorcinol Monobenzoate, available through Bio-Rad); Givsorb UV-1, Givsorb UV-2, Givsorb UV-13, Givsorb UV-14, Givsorb UV-15, Givsorb UV-16 (Givsorb is a trademark registerd to Givaudan Corporation, 100 Delawanna Avenue, Clifton, N.J., 07014); Mark 1535, Mark 446 (available through Bio-Rad), Maxgard 200, Maxgard 800 (Maxgard is a trademark registered to Garrison Industries, Inc., 135 Louis Hurley Road, El Dorado, Ak. 71731); Norbloc 6000, Norbloc 7966 (Norbloc is a trademark registered to Johnson & Johnson, One Johnson & Johnson Plaza New Brunswick N.J. 08933-7001); Quercetin; Sanduvor 3206, Sanduvor EPU, Sanduvor VSU (Sanduvor is a trademark registered to Sandoz Ltd., Lichtstrasse 35 Basle, Switzerland); Seesorb 201 (phenyl salicylate); Syntase 1200 (Neville-Synthese Organics, Inc., 2800 Neville Road, Pittsburgh Pa., 15225), THPE BZT, Tinuvin P (2-(2-Hydroxy-5-methylphenyl)benzotriazole 2-(2H-Benzotriazol-2-yl)-4-methylphenol 2-(2H-benzotriazol-2-yl)-p-cresol), Tinuvin 123, Tinuvin 171, Tinuvin 5055, Tinuvin 5151, Tinuvin 99-2, Tinuvin 144, Tinuvin 292, Tinuvin 384-2, Tinuvin 5050, Tinuvin 5060, Tinuvin 99, Tinuvin 109, Tinuvin 1130, Tinuvin 120, Tinuvin 1545, Tinuvin 1577FF, Tinuvin 320, Tinuvin 326, Tinuvin 327, Tinuvin 328, Tinuvin 384, Tinuvin 400, Tinuvin 400-2, Tinuvin 571, Tinuvin 840, Tinuvin 900, Tinuvin 928, Tinuvin P (Tinuvin is a trademark registered to Ciba-Geigy Corporation, 444 Saw Mill River Road, Ardsley, N.Y., 10502); Uvinul 3035, Uvinul 3039, Uvinul 3048, Uvinul 400, Uvinul D 49, Uvinul D 50, Uvinul P 25, Uvinul T-150 (Uvinul is trademark owned by BASF Corporation, 100 Cherry Hill Road Parsippany N.J. 07054).

[0027] Preferably, the UV blocker comprises Norbloc 7966 (chemical name: 2-(2hydroxy-5methacryloxyethylphenyl)-2H-benzotriazole (Janssen Pharmaceutica, Titusville, N.J. 08560, USA; a subsidiary of Johnson & Johnson).

[0028] Also preferably, the UV blocker comprises bis (2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidinyl) ester (tradename: TINUVIN 123, made by Ciba-Geigy).

[0029] Also preferably, the UV blocker comprises 2-(2H-benzotriazol-2-yl)-6-dodecyl-4-methyl-phenol (tradename: TINUVIN 171, made by Ciba-Geigy).

[0030] Also preferably, the UV blocker comprises the UV-blocking ingredient(s) contained in TINUVIN 99, which is made by Ciba-Geigy.

[0031] More preferably, the UV blocker comprises a mixture of two or more components selected from Norbloc 7966, Tinuvin 123, Tinuvin 99, and Tinuvin 171.

[0032] Most preferably, the UV blocker comprising a mixture of Norbloc 7966, Tinuvin 123, Tinuvin 99, and Tinuvin 171.

[0033] The total weight percentages of the UV blocker(s) range from about 0.00001% to about 50%, preferably from about 0.1% to about 30%, more preferably from about 0.5% to about 20%, even more preferably from about 5% to about 15%, still more preferably from about 5% to about 12%, and most preferably about 10%.

[0034] The weight percentages of the each individual UV blocker(s) range from about 0.00001% to about 50%, preferably from about 0.1% to about 20%, more preferably from about 0.5% to about 15%, even more preferably from about 1% to about 10%, still more preferably from about 3% to about 8%, and most preferably from about 5%.

[0035] The UV curable components used in the present invention may contain about 5-95%, preferably about 10-85%, more preferably about 15-75% of polymerizable reactants such as radiation curable monomers, oligomers, or low molecular weight homo- or copolymers, terpolymers, or graft or block copolymers which do not contain free acid groups. Examples of suitable monomers include epoxides, cycloaliphatic epoxides, vinyl chloride, styrene, ethyl acrylate, vinyl acetate, difunctional acrylic monomers such as hydroxy alkyl acrylates, or hydroxy alkyl methacrylates, vinyl butyrate, vinyl methyl ether, methyl methacrylate, isobornyl acrylate, acrylonitrile, or mixtures thereof. Suitable polymers include oligomers, homo- or copolymers, terpolymers, graft copolymers of the above monomers provided they have a molecular weight of less than about 50,000, otherwise it is too difficult to effect polymerization, i.e. curing. Preferred are acrylate homopolymers or acrylate or methacrylate copolymers, preferably acrylate or methacrylate copolymers. Examples of such acrylate or methacrylate copolymers include epoxy acrylates, copolymers of propylene glycol and a dicarboxylic acid, urethane acrylates, and the like. Preferably, the compositions contain one or more polymerizable reactants selected from the group consisting of urethane acrylate copolymers, tripropylene glycol acrylate, epoxy acrylate, and mixtures thereof.

[0036] Preferably, the radiation curable compositions of the invention contain about 5-95% by weight of acrylate or methacrylate monomers, or homo- or copolymers which do not contain acid functional groups.

[0037] The compositions used in the invention can optionally contain pigments. The amount of pigments can range from 1-95%, preferably 1-50%, more preferably 1-10% by weight of the total composition of pigment. A wide variety of pigments are suitable including organic and inorganic pigments. Examples of such pigments are set forth in U.S. Pat. No. 5,178,952 and U.S. Pat. No. 6,093,455, which are hereby incorporated by reference. Inorganic pigments include extender pigments such are baryites, barium sulfate, calcium carbonate, talc, clay, alumina, titanium dioxide,.white carbon, chinese white, zinc sulfide, lithopone, ultramarine, Prussian blue, cobalt, chrome oxide, viridian chrome green yellows, oranges, and reds, cadmium, chromium, iron oxides, carbon black, metallic pigments, aluminum powder, bronze powder, zinc chromate, strontium chromate, zinc dust, copper, and so on. Examples of suitable organic pigments include azo pigments, indolinones, isoindolinones, vat pigments, the Lakes, pthalocyanine pigments and so on. The preferred pigment to impart white color to the ink composition is titanium dioxide. Preferred red and yellow pigments are isoindolinones and pyrrolopyrrols as disclosed in U.S. Pat. Nos. 4,415,685; 4,579,949; 4,791,204; 4,666,455; 5,074,918; 4,783,540; 4,914,211; 4,585,878; as well as U.S. Pat. No. 5,571,359 of Kamen, et. al., all of which are hereby incorporated by reference. These pyrrolopyrrols are generally of the formula:

[0038] wherein R₁ and R₂ are each independently alkyl, arylalkyl, aryl, substituted or unsubstituted isocyclic or heterocyclic aromatic radicals; R₃ and R₄ are each independently H, substituted or unsubstituted alkyl, alkoxycarbonyl, aroyl (e.g. benzoyl), arylalkyl (e.g. benzyl), aryl (e.g. phenyl), alkanoyl, C_5-6 cycloalkyl, alkenyl, alkynyl, carbamoyl, alkylcarbamoyl, arylcarbamoyl, or alkoxycarbonyl; and X is O or S. Preferred is a compound wherein R₁ and R₂ are each independently phenyl or naphthyl, R₃ and R₄ are hydrogen, and X is O. Particularly preferred as a red pigment is pyrrolo 3,4-C pyrrol-1,4-dione, 2,5-dihydro-3,6-di-4-chlorophenyl which has a CAS number 84632-65-5 and is known by the common name C.I. pigment red 254. This pigment is commercially available from Ciba-Geigy Pigments Division, Newport, Del., under the tradename Irgazin DPP Red 80. Other Ciba-Geigy red pigments sold under the tradename Irgazin are also suitable.

[0039] Suitable isoindolinones are as set forth in U.S. Pat. Nos. 3,884,955, 3,867,404, 4,978,768, 4,400,507, 3,897,439 and 4,262,120 and 5,194,088 all of which are hereby incorporated by reference. Preferred isoindolinones are tetrachlorocyanobenzoic acid alkyl esters, particularly benzoic acid, 2,3,4,5-tetrachloro-6-cyano-methyl ester which is reacted with 2-methyl-1,3-benzenediamine and sodium methoxide. This pigment composition has the common name C.I. Pigment Yellow 109 and is available commercially from Ciba-Geigy Pigments Division, Newport Del. under the tradename Irgazin yellow 2GLTE. Other pigments in the Irgazin Yellow series as manufactured by Ciba-Geigy are also suitable.

[0040] Particularly suitable are blue pigments marketed by Ciba-Geigy under the tradename Irgazin Blue X-3367, or by Whittaker, Clark, & Daniels under the tradename Ultramarine Blue 5009.

[0041] Pigment(s) can be added for multiple purposes. It can added to provide color. It can also be added to mask undesirable color caused by other ingredients of the composition. For example, Norbloc 7966 has a yellowish color which is often undesirable. To blend or mask this yellowish color, a small amount of blue pigment is often added.

[0042] The ink compositions used in the invention also optionally contain about 0.01-10% of a defoaming agent, preferably a polyether-containing defoaming agent, which will cause the ink to apply smoothly on the glass substrate without bubbles or unevenness. A wide variety of defoamers are suitable, but preferred are defoamers sold by BYK Chemie under the BYK tradename. Examples of such defoaming agents are alkylvinyl ether polymers set forth in U.S. Pat. No. 5,187,201 and U.S. Pat. No. 6,093,455, which are hereby incorporated by reference. Examples of other defoamers include polyethers such as BYK-052, BYK-053, and BYK-033. BYK-052 and -053 are polyethers such as polyethylene or polypropylene glycol ethers, and in particular, polyvinyl ethers. Also suitable is BYK-354 which is a polyacrylate solution, and BYK-022 which is a mixture of hydrophobic solids and foam destroying polysiloxanes in polyglycol. Preferably the polyether defoaming agent is an alkoxylated alkyl phenol, more particularly a mixtures of petroleum distillates and an ethoxylated alkyl phenol, such as that sold by BYK-Chemie under the tradename BYK-033.

[0043] The ink compositions used in the invention also preferably contain about 0.01-25%, preferably about 0.05-15%, more preferably about 0.1-5% of a silane adhesion promoter which will enhance adhesion of the cured resin to the glass surface. Details on composition and application of these adhesion promoter can be found in U.S. Pat. No. 6.093,455 and U.S. Pat. No.6,136,382. Examples of silanes are silane esters, vinyl silanes, methacryloxy silanes, epoxy silanes, sulfur silanes, amino silanes, or isocyanoto silanes. Suitable silanes include organofunctional silanes of the formula:

[0044] X is each independently CH₃, Cl, OCOCH₃, OC₂ H₄ OCH₃, (OC₂ H₄)₂ OCH₃, or OR, where R is a C_1-20 straight or branched chain alkyl, preferably methyl or ethyl.

[0045] Silanes having this formula are commercially available under the Dynasylan trademark from Huls, America, Inc., Piscataway, N.J. or Osi Specialities Inc. Other organofunctional silanes such as those disclosed in U.S. Pat. No. 5,221,560, U.S. Pat. No. 6,136,382 and U.S. Pat. No. 6,093,455, which are hereby incorporated by reference, are also suitable. Such organosilanes are acryloxyfunctional silanes including 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 2-methacryloxyethyltrimethyoxysilane, 2-acryloxyethyltrimethyoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethyoxysilane, 3-acryloxypropyltriethoxysilane, 2-methacryloxyethyltriethoxysilane, 2-methacryloxyethyltriethoxysilane, 2-acryloxyethyltriethoxysilane, etc. Suitable glycidoxy silanes include 3-glycidoxypropyltrimethoxysilane, 2-glycidoxyethyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-glycidoxyethyltriethoxysilane, 3-glycidoxypropyltrimethyl silane, and so on. Preferred for use in the compositions of the invention are acryloxy-functional silanes, isocyanato silanes, and amino silanes. The preferred acryloxy-functional silane is 3-methacryloxypropyl trimethoxy silane, which is sold by Huls America, Inc. under the tradename DYNASYLAN MEMO. The preferred amino silane is sold by Huls America, Inc. under the tradename DYNASYLAN TRIAMO. The preferred isocyanoto silane is sold by Osi Specialities Inc., under the tradename A-1310. In the preferred ink compositions of the invention a mixture of the three silanes is preferred, generally 0.01-2% by weight of each.

[0046] The adhesion promoter can be applied in a various ways known. For example, the adhesion promoter applied to the transparent substrate before the UV curable composition is applied. Alternatively, the adhesion promoter can be mixed as part of the UV curable composition.

[0047] The ink compositions also can optionally contain 0.01-20%, preferably 0.5-10%, more preferably 1-5% by weight of a fluorinated surfactant. The term fluorinated surfactant means a fluorine containing compound having at least one liphophilic group or portion and at least one hydrophilic group or portion. In particular, fluorocarbon or fluorosilicone surfactants are most desireable. Suitable surfactants include those set forth in U.S. Pat. No. 4,961,976 and U.S. Pat. No. 6,093,455 which are hereby incorporated by reference. Preferred are fluorocarbon surfactants, such as those marketed under the Fluorad trademark by 3M Company. These fluorochemical surfactants include fluorinated alkyl esters, fluorinated alkyl polyoxyethylene ethanols, and the like. Particularly preferred are nonionic fluorinated alkyl alkoxylates e.g. those marketed by 3M under the trademark FC-171. Preferred are fluroinated C_1-30 alkyl ethoxylates and propoxylates.

[0048] The ink compositions preferably contain a photoinitiator which catalyzes the polymerization of the monomers upon exposure to the radiation by which the monomers are curable. There are generally two types of photoinitiators: free radical and cationic. Free radical initiators are more commonly used with ethylenically unsaturated monomers and oligomers, while cationic photoinitiators are used with epoxy or vinyl ether functional resins. Preferably, the compositions used in the invention contain free radical photoiniators. Suitable free radical-type photoiniators include carbonyl compounds such as ketones, acetophenones, benzophenones, and derivatives thereof. Examples of such materials include, for example, methyl ethyl ketone; benzophenone; benzyl dimethyl ketal;

[0049] 1-hydroxycyclohexylphenylketone; diethyoxyacetophenone;

[0050] 2-methyl-1-(methylethiophenyl)-2-(4-morpholinyl)-1-propanone;

[0051] 2-benzyl-2-N,N-dimethylamino-1,4(4-morpholinophenyl)-1-butanone;

[0052] 2,2-dimethoxy-2-phenyl acetophenone;

[0053] 2-methyl-1-4-(methylthio)phenyl-2-morpholino propan-1-one;

[0054] 2-hydroxy-2-methyl-1-phenyl-propan-1-one;

[0055] 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-methylpropyl)ketone; and a mixture of bis(2,6-dimethyoxybenzoyl)-2-4-4-trimethylpentyl phosphine oxide and 2-hydroxy-2-methyl-1-phenyl-propan-1-one. Preferred is a mixture of 25% bis(2,6-dimethyoxybenzoyl)-2-4-4-trimethylpentyl phosphine oxide and 75% 2-hydroxy-2-methyl-1-phenyl-propan-1-one, which is sold under the tradename Irgacure 1700 by Ciba-Geigy.

[0056] Small amounts of cationically curable monomers or oligomers may be used in the compositions of the invention, for example less than about 10%, preferably less than about 5% by weight of the ink composition. Various types of cationic photoinitiators are suitable. Both ionic cationic photoinitiators such as onium salts or organometallic salts are suitable as well as non-ionic cationic photoinitiators such as organosilanes, latent sulphonic acids and the like. Preferred are photosensitive onium salts, in particular, onium salts such as those disclosed in U.S. Pat. Nos. 4,058,401, 4,138,255, 4,161,478, 4,175,972, all of which are hereby incorporated by reference. Triaryl sulphonium salts are most preferred, in particular triaryl sulphonium salts such as those sold by Union Carbide under the tradename Cyracure UVI 6990 and 6974. Also suitable are ferrocenium salts such as those sold under the Irgacure tradename by Ciba-Geigy, in particular Irgacure 261. Sulphonyloxy ketones and silyl benzyl ethers are also good cationic photoinitiators. A detailed analysis of the mechanism of cationic curing is disclosed in Photosensitized Epoxides as a Basis for Light-Curable Coatings by William R. Watt, American Chemical Society Symposium, Ser. 114, Epoxy Resin Chemistry, Chapter 2, 1979, and in Chemistry and Technology of UV and EB Formulation for Coatings, Inks, and Paints, Volume 3, entitled Photoinitiators for Free Radical and Cationic Polymerization, K. K. Dietliker, pages 332-374 (1991), both of which are hereby incorporated by reference.

[0057] Photosensitive onium salts are used as photoinitators in cationic curing, in particular, onium salts such as those disclosed in U.S. Pat. Nos. 4,058,401, 4,138,255, 4,161,478, 4,175,972, all of which are hereby incorporated by reference. Triaryl sulphonium salts are most preferred, in particular triaryl sulphonium salts such as those sold by Union Carbide under the tradename Cyracure UVI 6990 and 6974. The photoiniator is generally present at about 0.1-15%, preferably about 0.5-12%, more preferably about 0.5-10% by weight of the total composition.

[0058] Any transparent material can be used as the substrate for the coating. Non-limiting examples include glass and polycarbonate.

[0059] In a preferred embodiment, the substrate is glass. All types of glass can be used for this invention. Suitable glass can be a wide variety of densities and optical characteristic.

[0060] Non-limiting examples of glass include architectural glass, acoustical glass, temper-resistent glass, clear glass, or tinted glass, display glass and insulating glass.

[0061] The substrate can be any size and shape.

[0062] The UV curable, UV blocking coating composition can be applied in any methods known.

[0063] As non-limiting examples, the coating composition can be applied by silk screening or rolling on.

[0064] In a preferred embodiment, an adhesion promoter is applied onto the substrate prior to the application of the coating composition. Adhesion promoter is discussed in detail above.

[0065] The coating can be of various thickness. The thickness of the coating ranges from about 0.5 micron to about 50 micron. In a preferred embodiment, the coating thickness is from about 2 to about 30 micron. In a more preferred embodiment, the coating thickness is from about 5 to about 20 micron. In a still more preferred embodiment, the thickness is from about 9 to about 20 micron. In a most preferred embodiment, the thickness is about 15 micron.

[0066] When a mesh screen is used to apply the coating, the thickness of the coating depends on the mesh size. For example, a sample prepared by using 255 mesh screen is about 15 micron, whereas a sample prepared by using 390 mesh screen is about 10 microns thick.

[0067] Generally speaking, the thicker the coating layer, the better UV blockage. However, as the thickness increases, the cost of coating increases. Furthermore, some UV blocking ingredients such as Norbloc 7966 has a yellowish color, so as the thickness of the coating increases, the coating would be more yellowish which may not be desirable.

[0068] The UV blocking coating can be cured using any methods known. One of skill in the art would know how to adjust the time, speed, intensity, temperature, wavelength, and various other factors to obtain desirable curing.

[0069] In a preferred embodiment, the wavelength of the UV radiation for curing ranges from about 300 nm to about 415 nm. In a more preferred embodiment, the wavelength ranges from about 350 to 415 nm. In a even more preferred embodiment, about 390 to 410 nm. In a most preferred embodiment 390 to 400 nm.

[0070] In a preferred embodiment, the UV curing lamp is about 600 W, and the curing speed is about 200 ft/min.

[0071] Various publications are cited herein, the disclosures of which are incorporated by reference in their entirety for all purposes.

[0072] Having described the invention, the following examples are included to illustrate the benefits of the present invention. The examples are only illustrative and are not meant to unduly limit the scope of the present invention.

[0073] A UV blocking coating composition of the present invention is prepared with the following ingredients

	Ingredient	Weight (gram)
	SR399	18.272
	CN104	4.568
	Eb5129	6.395
	SR238	6.395
	Tinuvin 123	0.457
	Norbloc 7966	0.914
	Tinuvin 99	3.0
	Tinuvin 171	1.0
	Solution of CAB 531-1	3.0
	HS 40	0.4
	D-62	1.0
	D-604	0.25
	Rad 2250	1.0
	I-500	0.3
	I-184	0.5
	D-1173	0.7
	I-1700	1.0
	CN384	0.85
	FC 171	0.25
	TOTAL	50.3

[0074] SR399 is Dipentaerythritol pentaacrylate, available from Sartomer Company, Inc. CN104 is Epoxy acrylate available from Sartomer Company, Inc. Eb5129 is urethane diacrylate available from UCB Chemical. SR238 is 1,6-Hexanediol Diacrylate available from Sartomer Company, Inc. Norbloc 7966 is 2-(2hydroxy-5methacryloxyethylphenyl)-2H-benzotriazole, available from Janssen Pharmaceutica. Tinuvin 123 is decanedioic acid, bis (2,2,6,6,-tetra methyl-4-piperidinyl) ester reaction products with 1,1-dimethyl ethyl hydroperxoide and octane made by Ciba-Geigy. Tinuvin 99 is 3(2H-Benzotriazole-2-yl) 5-(1,1-dimethyl ethyl)-4-hydroxybenzenepropanoic acid, C7-9-branched alkyl esters. Tinuvin 171 is 2(2H-Benzotrizaol-2-yl)-6-(dodecyl)-4-methylphenol, branched and liner, made by Ciba-Geigy. HS 40 is an additive made by Air Products and Chemicals. D-62 is a defoamer made by Air Products and Chemicals. D-604 a surfactant made by Air Products and Chemicals. FC171 is a flurochemcial surfactant made by 3M. CN384 is acrylated amine acrylic ester made by Sartomer. Solution if CAB 531-1 is a 20% CAB 531-1 (Cellulose Acetate Butyrate) and 80% SR285 (Sartomer). I-1700 is a mixture of 25% by weight bis(2,6-dimethoxybenzoyl)-2,4-,4-trimethylpentyl phosphine oxide and 75% by weight 2hydroxy-2-methyl-1-phenyl-propan-1-one. I-500 is 1-hydroxyacryciohexyl pentyl ketone made by Ciba-Geigy. I-184 is 1-hydroxy cyclohexyl pentyl ketone by Ciba-Geigy. D-173 is oxy-2-methyl-1-phenyl-1 propanone.

[0075] This coating composition contains about 1.8% Norbloc 7966, about 0.9% Tinuvin 123, about 6% Tinuvin 99 and about 2% Tinuvin 171. The total percentage of UV blocking ingredients is about 10.7%.

[0076] The coating composition detailed in Example 1 was applied onto glass substrates by screening. Prior to the application of the coating, the glass substrate were sprayed with a solution of adhesion promoter comprising silane. Three different mesh size were used for the application of the coating composition resulting three coated glass samples of different coating thickness.

		Thickness of coating
Sample	Mesh Screen Size	(micron)
A	255	15
B	390	11
C	508	9

[0077] The UV transmission of coated glass samples A-C described in Example 2 were measured from wave length 275 nm to 425 nm. The numerical results are attached herewith in Exhibit A.

[0078] The transmission/absorption spectrum of each of these samples were also plotted as FIG. 1 (Sample A: ; Sample B: ; Sample C: ). For comparison, a commercially available sample () is also plotted in the same figure. The result indicates that Sample A has much better UV blocking performance than the commercially available product up to the wavelength of about 388 nm.

[0079] To demonstrate that the UV blocking ability of the composition of the present invention is long-lasting, UV transmission of the Sample B was measured at different times, earliest at Dec. 22, 2000, followed by Feb. 9, 2001, Feb. 23, 2001, and Mar. 9, 2001. The results are plotted in FIG. 2. The result indicates that the UV blocking capability remained relatively constant over an extended period of time. The UV transmission of clear glass without any coating is also plotted in FIG. 2 for comparison.

[0080] Another UV blocking coating composition of the present invention is prepared with he following ingredients.

	Ingredient	Weight (gram)
	SR399	36
	CN104	10
	Eb5129	10
	SR238	15
	Tinuvin 123	1.2
	Norbloc 7966	3.6
	Tinuvin 99	6.6
	Tinuvin 171	2.42
	Solution of CAB 531-1	6.0
	HS 40	0.8
	D-62	1.6
	D-604	0.4
	I-500	0.7
	I-184	1.0
	D-1173	1.4
	I-1700	2.0
	CN384	1.7
	FC 171	0.4
	TOTAL	100.82

[0081] This coating composition contains about 3.6% Norbloc 7966, about 1.2% Tinuvin 123, about 6.6% Tinuvin 99 and about 2.4% Tinuvin 171. The total percentage of UV blocking ingredients is about 13.8%.

A		B	C
275	0.037		275	0.017	275	0.001
276	0.021		276	0.016	276	0.002
277	0		277	0.015	277	0.001
278	0.009		278	0.02	278	0.006
279	0.016		279	0.01	279	0.004
280	0.046		280	0.007	280	0.009
281	0.003		281	0.02	281	0.005
282	0.005		282	0.03	282	0.001
283	0.005		283	0.029	283	0.022
284	0.031		284	0.038	284	0.006
285	0.018		285	0.032	285	0.011
286	0.016		286	0.032	286	0.012
287	0.008		287	0.034	287	0.005
288	0.026		288	0.026	288	0.011
289	0.018		289	0.035	289	0.014
290	0.003		290	0.031	290	0.008
291	0.002		291	0.021	291	0.017
292	0.004		292	0.016	292	0.024
293	0.027		293	0.013	293	0.021
294	0.055		294	0.005	294	0.047
295	0.013		295	0.01	295	0.023
296	0.053		296	0.025	296	0.003
297	0.023		297	0.039	297	0.007
298	0.011		298	0.007	298	0.018
299	0.018		299	0.035	299	0.02
300	0.007		300	0.013	300	0.005
301	0.006		301	0.02	301	0.017
302	0.014		302	0.042	302	0
303	0.007		303	0.008	303	0.011
304	0.004		304	0.03	304	0.004
305	0.041		305	0.047	305	0.037
306	0.02		306	0.004	306	0.023
307	0.02		307	0.007	307	0.012
308	0.011		308	0.025	308	0.015
309	0.005		309	0.006	309	0.03
310	0.009		310	0.033	310	0
311	0.046		311	0.03	311	0.007
312	0.016		312	0.025	312	0.01
313	0.017		313	0.042	313	0.038
314	0.028		314	0.04	314	0.006
315	0.037		315	0.045	315	0.009
316	0.055		316	0.049	316	0.017
317	0.006		317	0.049	317	0.008
318	0.045		318	0.082	318	0.079
319	0.022		319	0.038	319	0.012
320	0.018		320	0.056	320	0.015
321	0.04		321	0.071	321	0.003
322	0.062		322	0.055	322	0.019
323	0.047		323	0.104	323	0.019
324	0.044		324	0.072	324	0.033
325	0.012		325	0.104	325	0.051
326	0.019		326	0.071	326	0.019
327	0.092		327	0.071	327	0.038
328	0.004		328	0.065	328	0.03
329	0.003		329	0.083	329	0.054
330	0.004		330	0.076	330	0.025
331	0.016		331	0.06	331	0.035
332	0.01		332	0.071	332	0.037
333	0.008		333	0.074	333	0.038
334	0.015		334	0.074	334	0.043
335	0.008		335	0.06	335	0.028
336	0.011		336	0.049	336	0.024
337	0.003		337	0.065	337	0.034
338	0.006		338	0.067	338	0.044
339	0.006		339	0.055	339	0.036
340	0.01		340	0.051	340	0.055
341	0.003		341	0.058	341	0.047
342	0.003		342	0.069	342	0.037
343	0.013		343	0.067	343	0.048
344	0.009		344	0.069	344	0.054
345	0.014		345	0.071	345	0.067
346	0.002		346	0.068	346	0.065
347	0.003		347	0.088	347	0.058
348	0.011		348	0.095	348	0.067
349	0.001		349	0.095	349	0.066
350	0.002		350	0.118	350	0.071
351	0.002		351	0.125	351	0.095
352	0.016		352	0.136	352	0.117
353	0.013		353	0.175	353	0.12
354	0.013		354	0.199	354	0.152
355	0.006		355	0.23	355	0.173
356	0.012		356	0.262	356	0.212
357	0.011		357	0.299	357	0.249
358	0.009		358	0.352	358	0.307
359	0.008		359	0.428	359	0.366
360	0.018		360	0.5	360	0.425
361	0.008		361	0.603	361	0.52
362	0.007		362	0.729	362	0.613
363	0.027		363	0.873	363	0.769
364	0.012		364	1.064	364	0.959
365	0.02		365	1.286	365	1.164
366	0.025		366	1.572	366	1.422
367	0.046		367	1.929	367	1.769
368	0.057		368	2.358	368	2.155
369	0.089		369	2.883	369	2.666
370	0.125		370	3.53	370	3.268
371	019		371	4.339	371	4.052
372	0.283		372	5.271	372	4.922
373	0.406		373	6.443	373	6.054
374	0626		374	7.811	374	7.367
375	0.932		375	9.425	375	8.96
376	1.354		376	11.321	376	10.791
377	1.946		377	13.511	377	12.967
378	2.779		378	16.068	378	15.451
379	3.874		379	18.848	379	18.224
380	5.319	0.233728	380	22.008	380	21.307
381	7.179		381	25.471	381	24.759
382	9.51		382	29.244	382	28.503
383	12.306		383	33.131	383	32.374
384	15.691		384	37.282	384	36.563
385	19.568		385	41.636	385	40.912
386	23.842		386	45.943	386	45.242
387	28.377		387	50.092	387	49.421
388	33.207		388	54.202	388	53.549
389	38.16		389	58.11	389	57.489
390	43.043		390	61.721	390	61.138
391	47.882		391	65.109	391	64.579
392	52.521		392	68.212	392	67.717
393	56.94		393	71.055	393	70.57
394	60.91		394	73.517	394	73.094
395	64.638		395	75.767	395	75.39
396	67.929		396	77.718	396	77.376
397	70.938		397	79.456	397	79.139
398	73.53		398	80.915	398	80.615
399	75.886		399	82.246	399	81.986
400	77.901	8.899901	400	83.36	400	83.124
401	79.605		401	84.239	401	84.079
402	81.138		402	85.1	402	84.926
403	82.372		403	85.75	403	85.57
404	83.46		404	86.319	404	86.171
405	84.354		405	86.818	405	86.653
406	85.141		406	87.219	406	87.11
407	85.758		407	87.545	407	87.437
408	86.317		408	87.831	408	87.736
409	86.781		409	88.055	409	87.961
410	87.14		410	88.245	410	88.168
411	87.462		411	88.416	411	88.315
412	87.722		412	88.542	412	88.469
413	87.944		413	88.63	413	88.583
414	88.167		414	88.791	414	88.718
415	88.325		415	88.845	415	88.773
416	88.457		416	88.941	416	88.87
417	88.6		417	89.039	417	89
418	88.724		418	89.088	418	89.037
419	88.86		419	89.181	419	89.137
420	88.911		420	89.222	420	89.161
421	89.021		421	89.237	421	89.2
422	89.08		422	89.299	422	89.269
423	89.127		423	89.299	423	89.252
424	89.216		424	89.408	424	89.351
425	89.285		425	89.421	425	89.391