DE2240580A1 - Laminated windscreen with a polyurethane layer - to protect it against shatt-ering on impact, for aircraft and armoured vehicles - Google Patents

Abstract

The windscreen has a relatively solid layer, 0.13-6.4mm thick, of a transparent material, specif. a polycarbonate resin, a first open surface to which is bonded an optically smooth layer, 0.076-3.8 mm thick, of a polyurethane, thus forming a new open surface, which is in-facing towards the structure contg. the windscreen.

Description

Multi-layer windows.

The invention relates to .the protection of transparent windows and in particular windows that have a layer that has an outwardly facing surface made of relatively strong transparent material that is sensitive against scratches, splinter damage and other damage, such as a polycarbonate, a polyester, an acrylic or a glass or the like. Such windows can consist essentially of a monolithic disc of the type used is used to protect crane operators, or they can be made off too consist of a laminate of glass or plastic that is glued together with the help of a thermoplastic material such as plasticized polyvinyl butyral or Polyurethane; Such windows are used as aircraft windows or for armored windows Vehicles used. Such laminated windows are preferably with a innermost layer made of a relatively thin and strong, transparent material provided, as in section 3. Glass, its polycarbonate, a polyester resin or a methyl methacrylate, that is not attached to the frame of the aircraft where the rest of the window is which it is in defl0 US Patent No. 3,009,845, particularly column 3, lines 14 to 1 and column 4, lines 4 to lo, is described.

Such a freely mounted innermost layer has the purpose of the occupants of the vehicle in which the window is installed, ahead at high speed to protect flying fragments of glass and the like that arise when an external object hits the window glass at high speed.

Possess polycarbonates, expanded acrylics, and other polyester resins well-known resistance to breakage upon impact by external objects, e.g. Birds hitting the window of an airplane. It would be desirable to have one relatively solid, still flexible, transparent pane, e.g.

a polycarbonate pane, as a window, or as an interior component of a window because of its resistance to breakage. However, polycarbonate panes have been used as the inner panes of multilayer windows Limited until new days, as the polycarbonate surfaces are light on the outside scratched and decomposed when washed. Typical multilayer windows, which have a polycarbonate pane laminated between the outer panes of glass are in U.S. Patents No. 3.388.o32, No. 3.38ß.o33 and No. 3.388.o34 shown.

When glass panes to the larger surfaces of a polycarbonate pane be laminated, underneath the polycarbonate surfaces from abrasion, scratching, and facing The resulting laminate has to protect against chemical or solvent attack a layer of glass facing up that is likely to shatter if a Object hits the multi-layer window, causing the polycarbonate pane to to yield and to be deformed over the below degree of flexibility for glass panes out. As a result, the glass cover panel splinters, even though the polycarbonate panel deflects in response to the impact, and with it small glass particles spray on the inmates. The same result occurs when other polyester resins and Acrylic plastics by means of other layers of transparent material Abrasion that is more resistant to abrasion, such as e.g.

Glass.

If solid, transparent plastic materials, the more resistant against the strike through impact, as glass, such as polycarbonate, polyacrylate, Polyester and the like, are wrapped at a speed sufficient to in order to allow penetration of the projectile, a plug made of plastic material is used separated from the material layer in the vicinity of the impact of the projectile and becomes a dangerous projectile while it is with the projectile inside s Area that is enclosed by the window that is one layer comprising this solid, transparent plastic material as a component.

This separation of a plastic stopper is called a kind of fragmentation considered as both splintering and plug separation from the impact against one side of a glass or plastic washer, with one or several fragments of the hit target leave the target away from the side, which is opposite the impact side. Transparent glass and / or solid windows transparent material, including monolithic and laminated panes, unexpectedly have better properties in terms of reducing the Splintering when a thin polyurethane coating on the side of the relatively solid, transparent material is applied, which is opposite to the side of the Impact, in such a way that good optical transparency of the Polyurethane resin protected window is maintained.

The present invention avoids the need to use polycarbonate, Acrylic dthe other polyester resin surfaces that are susceptible to chipping and related Subject to dangers to protect with the help of Laminate Matorial. This is achieved adding one or more surfaces to a relatively solid yet flexible Disc made of a transparent material, such as a polycarbonate, Polyester or acrylic pane, coated with a self-healing plastic that is transparent, can be washed and has improved resistance to Shows abrasion and chemical attack, as the surface of the polycarbonate, acrylic or polyester disc covering it.

The state of the art protected windows from splinter damage of flying glass particles according to US Pat. 3oo9,845 by creating a thin innermost layer of glass or polyester resin or methyl methacrylate, which is laminated to an inner layer of polyvinyl butyral of a multilayer window is. However, when such structures fail on impact, the innermost Layer a projectile that is dangerous to the occupants of the aircraft.

Other laminates of glass and polycarbonates such as those described in US patents No. 3,458,388, no. 3.388.o32, No. 3,388,033 and No. 3,388,034 disclosed outward glass surfaces on the final product. Such after External glass surfaces necessarily create splinters if they are struck will.

U.S. Patent No. 2,871,218 discloses a method for application a polyurethane coating on glass or others Materials through Application of a solution and evaporation of the solvent. Unfortunately grab it the solvents suggested in this patent to form a sootless solution including ketones such as cyclohexanone, tetramethylurea, dimethylformamide and the like, certain substrates, such as 3. Polycarbonate disks and make them opaque before the solvent evaporates. As a result, this procedure is unsuitable to apply a protective layer of polyurethane, the predetermined optical Possesses properties.

U.S. Patent No. 3,580,881 also suggests a polyurethane resin to be applied in the form of a solution to protect a surface in which the solvent evaporated. The solvents suggested in this patent, acetone, cyclohexanone, butyl acetate and ethyl acetate also grip a substrate / this base layer made of polycarbonate and make opaque.

In accordance with the present invention, it has been determined that many Polyurethane compositions are useful to make polycarbonates and other transparent ones Protect surfaces. Clear, transparent polyurethane compositions become preferred to provide suitable optical transparency for the window. The present Invention coats an outwardly facing polycarbonate or other relatively solid, transparent surface with a layer of sufficient Thinness to be transparent and of sufficient thickness to be complete Eliminate erosion due to abrasion during the expected lifetime of the window. As a result, polyurethane films with good optical properties and with a thickness of about 0.08 mm to 3.8 mm (3 mils to 150 mils) is preferred.

The preferred type of self-healing, transparent resin is a polyurethane composition, preferably from the group of polyurethanes settlements produced by the reaction of an organic polyisocyanate with a material is derived, which has a variety of active hydrogen residues, such as .B.

a polyether-polyalcohol and / or a polyester-polyalcohol.

Suitable polyether-polyalcohols are disclosed in US Patent No. 3,509,015 disclosed. This group of polyurethanes has come to be used as an intermediate layer used for multilayer safety glass windows. Others used previously Polyurethane compositions useful in the present invention Hydroxyl terminated polyester of those described in U.S. Patent No. 2,871,218 Art.

Other suitable polyurethane resins are described in Book 1, Polyurethanes Chemistry and Technology "by J. S. Saunders K. C. Frisch, published by Interscience Publishers in 19-64.

The polyurethane protective layer is preferably applied to the surface a polycarbonate poured on and then cured.

Thin coatings can be removed by wiping off a poured Coating can be made before curing. One preferably used Group of polyurethane compositions consists of a reaction product of a Poly (tetramethylene oxide) @ glycol with an average molecular weight of approximately 55o to about 1800, a diisocyanate and a curing agent that is at least contains three hydroxyl groups and one diol.

A preferred composition is prepared by first making a Terminal prepolymer containing isocyanate groups from the reaction of a diisocyanate and a poly (tetramethylene oxide) glycol is formed. This prepolymer forms a pack of a two-pack system, the curing system consisting of the polyalcohol and and the other pack consists of the diol. While resinous compositions, made from poly (tetramethylene oxide) glycols from the above Fall out of the molecular weight range, they have good optical clarity and good adhesion to relatively light, transparent materials such as e.g. acrylic or polyester resin or polycarbonate panes, but they can be used for commercial acceptable safety washers cannot be used as they have a very low value Degree of bin slay energy absorption at either very low or very high Temperatures exhibit. If the poly (tetramethylene oxide) glycol having a molecular weight below.550, the resinous compositions will too brittle at low temperatures, and when the poly (tetramethylene oxide) glycol having a molecular weight in excess of 1,800 possess the resinous compositions insufficient strength at high temperatures, so not sufficient Impact resistance is obtained :.

The poly (tetramethylene oxide) glycols are commercially available in the form of a "Prepolymer" obtained, that is a reaction product of the said glycol with diisocyanate, The Adiprenreihen, a trade name for poly (tetramethylene oxide) glycol toluene diisocyanate prepolymers, is a source that has been found to be particularly useful for making of self-healing protective layers. The properties that these resin compounds have particularly desirable for use as a protective layer for a polycarbonate surface make, are obtained from the straight-chain poly (tetramethylene oxide) glycols, which fall within the stated molecular weight range. In other words, the only one ste and most important factor in making the resin compounds that are capable are cast and hardened on the outward-facing surface of a disc is the critical molecular weight range of poly (tetramethylene oxide) glycol.

Various polyesters based on polyurethanes made by Mobay Chemical under various trade names such as Mondur and Multrethan are sold are suitable. While the exact chemical compositions these materials are covered by trade secrets, it is believed that they on esters of dicarboxylic acids mlt 2-lo; Carbon atoms per carboxyl group, are based, such as adypsic acid, sebacic acid, azelaic acid and succinic acid, die'mit one Di-alcohol have reacted with 2 to 10 carbon atoms, such as ethylene glycol, 1,4-butanediol and 1,5-pentanediol, etc., with an excess of diol so that there is there is an excess of alcoholic hydroxyl groups compared to carboxyl groups, so that the terminal polyester contains alcoholic hydroxyl groups.

In forming the prepolymer, it is preferable to use the toluene diisocyanate is used because of its low cost.

As far as effectiveness is concerned, however, there can be large numbers various organic diisocyanates can be used in this reaction, including aromatic, aliphatic and cycloaliphatic diisocyanates and combinations these guys. Representative compounds include m-phenyl diisocpanate, 4-chloro-1,3-phenyl diisocyanate, 4,4'-diphenyl diisocyanate, b, 5-naphthyl diisocyanate, 1,4-tetramethylene diisocyanate, l, 6-hexamethylene diisocyanate, l, lo-decamethylene diisocyanate, l, 4-cyclohexyl diisocyanate, 4,4', methylene bis (cyclohexyl isocyanate) and 1,5-tetrahydronaphthyl diisocyanate.

Aryi diisocyanates, i.e. isocyanates in which each of the two isocyanate groups directly linked to an aromatic ring are preferred. The steric hindered species, e.g.

3,5-diethyl-methyl-bis- (4-phenyl isocyanate) and o, o'-diethyl para-phenyl diisocyanate, in which the two isocyanate groups differ greatly in their reactivity, are also of interest. The diisocyanates can have other substituents, which do not react with isocyanate groups. In the case of aromatic compounds, the isocyanate groups can either be the same or different Be connected to wrestling. Dimers of the monomeric diisocyanates and di (isocyanatoaryl) ureas, such as die- (3-isocyanato-4-methyl-phenyl) -urea can be used.

The curing systems for the polyurethane resins consist of a polyalcohol, which acts as a crosslinking agent, and may also contain a di-alcohol, which acts as a chain extender when such an effect is desired.

Any of a wide variety of di-alcohols is effective as a chain extender, e.g. the glycols with lower molecular weights, such as ethyl, propyl butyl, pentyl glycol and the higher substituted alkyl di-alcohols and the various hydroxyl-substituted aryl compounds.

Particularly useful are 1,4-butanediol, 2,2-bis (4-hydroxycyclohexane) -Propane, 1,5-pentanediol and 2-methyl-2-n-propyl-1,3-propanediol.

The polyalcohols to be used as crosslinking agents preferably have 3 or more labile hydrogen atoms in the molecule and as a requirement they must be compatible with the reaction system, i.e. they must be in the reaction mass be soluble. In theory, there is no real limit to how many the hydroxyl groups per molecule. As a practical matter, the size of the molecules would be however, eventually affect properties such as solubility, etc. and therefore exclude their use.

Polyalcohols with up to 8 and almost 10 hydroxyl groups per molecule, were found to be effective. Examples of these are more common polyalcohols Trimethylolpropane, trimethylolheptane, trimethylolethane, sorbital alcohol, castor oil, the reaction products of allyl alcohol with styrene and the reaction products of various polyalcohols with alkylene oxides.

For best results, mix the mixture to be hardened in to use such amounts that the total sum of the la-} i.len hydrogen atoms is approximately the same stoichiometrically to the number of free isocyanate groups of the prepolymer.

Able to work. However, results are obtained when using this amount within 5% above the stoichiometric point or within a lot below of the stoichiometric point is varied, preferably within 3% of the stoichiometric Amount lies. To get the best results with the different molecular weights To obtain within the above range, certain diol-polyol ratios are required should be used, e.g. for the higher, molecular weights (1250 to 1800) approximately 3.5 equivalents of diol to 1 equivalent of polyol are used while about 6 equivalents of the dialcohol to 1 equivalent of the polyalcohol at the lower end average molecular weights (650 to 850) are used, and approximately 9 equivalents of dialcohol to 1 equivalent of polyalcohol for the lower Molecular weights (approximately 550 to 650). It is possible to have effective resinous interlayer compositions obtainable with ratios of Dz alcohol to polyalcohol in the range of 1.5: 1 to lo: l.

If you look at the extreme values of the molecular weight range of poly (tetramethylene oxide) glycol is working. it is possible to increase the physical properties to some extent change by using a dialcohol, the plasticizing properties the final polymer, or those which the final polymer Give strength, with a straight chain poly (butylene oxide) glycol being an example for the former and a 2,2-bis- (4-hydroxy-cyclohexane) -propane is an example for the latter is.

The resinous layer is simply prepared by first adding the Heat the 'w prepolymer' to about 100 ° C (212 ° F) and for about 1 to 2 hours is kept under vacuum.

The 11Preepolymer "is then with the polyol-diol curing system in mixed in a suitable vessel. The mixture is then in a temperature range maintained under a vacuum from about 65 ° C to about 95 ° g (150 to 200 ° F), to remove any gases that may be present or that may be present during mixing and to create a viscous liquid. Further heating, e.g. an additional curing for 6 hours at 140 ° C (1850F), followed by extrusion, creates polymerized layers that have all the necessary properties that are required in the case of an intermediate layer for a glass-plastic laminate with the Except for suitable adhesion to solid materials such as glass and polycarbonates. The additional curing can be accelerated by doing this step on a is performed at a higher temperature and can be terminated at a lower temperature will, if a longer curing time can be accepted.

Fully cured layers absorb small amounts of moisture, but they have poor adhesive properties once completely off are hardened.

Having described the polyurethanes suitable for the protective layers are described in the following organic compounds that form a protective coating require.

The polycarbonate pane, the surface of which needs protection, such as it is described in the present invention may be any suitable Polycarbonate disc, such as that disclosed in US Pat. 3, o28,365 and 3,117,019, and is preferably prepared by the reaction of di (monohydroxyaryl) alkane with derivatives of carboxylic acid, e.g. phosgene and bischlorocarboxylic acid esters of di (monohydoxyaryl) alkanes.

The aryl radicals of the di (monohydroxyaryl) alkanes can be identical or different be. The aryl radicals can also carry substituents that are incapable of are to react in the conversion to polycarbonates, such as halogen atoms or Alkyl groups, e.g. the methyl, ethyl, propyl or tert-butyl group. The alkyl radical the di (monohydroxyaryl) alkane, which connects the two bazole rings, can be an open chain or a cycloaliphatic ring, and may be substituted, if desired, for example by an aryl radical.

Suitable di (monohydroxyaryl) alkanes are e.g. (4,4'-dihydroxydiphenyl) methane, 2,2- (4,4'-dihydroxy-diphenyl) -propane, 1,1- (4'-dihydroxy-diphenyl) -cyclohexane, 1,1- (4,4'-dihydroxy-3,3'-dimethyl -diphenyl) -cyclohexane, 1,1- (2,2'-Dihydroxy-4,4'-dimethyl-diphenyl) -butane, with a boiling point between 185-188 ° C under a pressure of 0.5 mm Hg column), 2,2 (2,2'-dihydroxy-4,4'-di-tert. -Butyl-Diphenyl) -Propnn or 1,1 '- (4,4'-Dihydroxy-Diphenyl) -l-Phenyl-Ethane; Farther Methane derivatives which carry an alkyl radical in addition to two hydroxyaryl groups, with at least two carbon atoms and a second alkyl radical with one or more carbon atoms, such as.

2,2- (4,4'-dihydroxy-diphenyl) butane, 2,2- (4,4'-dihydroxy-diphenyl) -pentane (Melting point 149-150 ° C), 3,3- (4,4'-dihydroxy-diphenyl) -pentane, 2,2- (4,4'-dihydroxy-diphenyl) -Hexane, 3,3- (4,4'-dihydroxy-diphenyl) -hexane, 2,2- (4,4'-dihydroxy-diphenyl) -4-methyl-pentane (Melting point 151-152 ° C.), 2,2- (4,4'-Dihydroxy-diphenyl) -IIeptane (boiling point 198-200 ° C.) under a pressure of 0.33 mm Ilg column) 4,4- (4,4'-dihydroxy-diphenyl) heptane (melting point 148-1490C) or 2,2- (4,4'-dihydroxy-diphenyl) -tridecane. Suitable di (monohydroxyaryl) -Alkanes in which the two aryl radicals differ are, for example 2,2- (4,4'-dihydroxy-3'-methyl-diphenyl) propane and 2,2- (4,4'-dihydroxy-3-methyl-3'isopropyl-diphenyl) butane, suitable di (monohydroxyaryl) alkanes, in which the aryl radicals carry halogen atoms are, for example, 2,2- (3,5,3 ', 5'-tetrachloro-4,4'-dihydroxy-diphenyl) propane, 2,2- (3,5,3 ', 5'-tetrabromo-4,4'-dihydroxy-diphenyl) propane, (3,3'-dichloro-4,4'-dihydroxy-diphenyl) methane and 2,2'-dihydroxy-5'-difluoro-diphenyl-methyne. - Suitable di (monohydroxyaryl) alkanes, where the alkyl group connects the two benzene rings through an aryl group is replaced, for example (4,4'-dihydroxy-diphenyl) -phenyl-methane and l, l- (4,4'-dihydroxy-diphenyl) -1-Phenylethane In order to achieve special properties, mixtures of different Di (monohydroxyaryl) aikanes can be used, mixed polycarbonates being obtained will.

The conversion of the di (monohydroxyaryl) alkanes listed above into high molecular weight polycarbonates by .e 1 reaction with the carboxylic acid derivatives listed above takes place according to known procedures. For example, the di (monohydroxy aryl) alkanes be re-esterified with carboxylic acid diesters, for example with dimethyl, diethyl, Dipropyl, dibutyl, diamyl, dioctyl, dicyclohexyl, diphenyl and di-o-tolyl or di-p-tolyl carbonate at elevated temperatures of about 50 up to about 320 ° C and especially in the temperature range from 120 to about 28o0C.

The polycarbonates can also be obtained by introducing Phsgen in solutions of DI (monohydroxyaryl) alkanes in organic solvents, such as dimethylaniline, diethylaniline, trimethylamine and pyridine, or inerts organic solvents such as petroleum ether, ligroin, cyclohexane, methylcyclohexane, Benzene, toluene, xylene, chloroform, methylene chloride, carbon tetrachloride, trichlorethylene, Dichloroethane, methyl acetate and ethyl acetate, with an acid-binding one at the same time ! Ettel is added as indicated above.

A particularly suitable process for the production of polycarbonates consists in introducing phosgene into an aqueous solution or suspension of the Al potassium salts, such as the lithium, sodium, potassium and calcium salts of the di (monohydroxyaryl) alkanes, preferably in the presence of an excess of alkali, such as lithium, sodium, Potassium and calcium hydroxide or carbonate. The polycarbonates then fall as a precipitate on the aqueous solution.

The reaction in aqueous solution is enhanced by the addition of indifferent solvents of the type specified above, the phosgene and possibly be able to loosen the polycarbonate produced ..

The phosgene can be added in equimolar amounts; usually however, preference is given to using an excess of Phssgen.

Finally, it is also possible that the di (monohydroxyaryl) alkanes with approximately equimolar amounts of bischlorocarboxylic acid esters of the di- (mohohydroxyaryl) -Alkanes react under appropriate conditions.

In the production of polycarbonates according to the various processes it is advantageous to use small amounts of reducing agents, for example sodium, or potassium sulfide, sulfite and dithionite, or free phenol and p-tert-butylphenol add by adding monofunctional compounds with phosgene or with the end groups of the polycarbonates, which chlorocarboxylic acid ester groups contain, react, and which limit the chains, it is possible to limit the molecular weight to control the polycarbonates in a wide range; such compounds are e.g. Phenol, tert-butyl phenol, cyclohexylphenol, 2,2- (4-hadroxyphenol + LMethoxyphen '; l) -Propane, still aniline and methylaniline.

The reaction of the di (monohydroxyaryl) alkanes with phosgene or with the chlorocarboxylic acid esters of the di (monohydroxyaryl) alkanes can be used at room temperature or are carried out at lower or higher temperatures; i.e. at Temperatures between the melting point and the boiling point of the mixture.

(See U.S. Patent No. 3.o28,365, column 1, line 31 to column 3, line 1). The polycarbonates preferably have a thickness of about 0.08 to about 6.35 mm (3 to 250 mils) and more preferably from about 1.3 to 3.8 mm (50 up to 15o mils). In some cases it may be desirable to use copolymers of different To use dihydroxy-aryl-propane to achieve special properties.

Other clear materials are in US Patent No. 3.069.30l on column 1, lines 62-68. These materials are also strong and durable against scratching and largely not hygroscopic.

Other suitable organic materials in place of the carbonates can be used are stretched acrylates, such as wolymethyl methacrylate, Polymethyl-alphachloro-acrylate and similar ones made by stretching up the apparatus according to re-pending U.S. Patent No. 24,978 and other acrylates and polyester resins according to US Pat. 3,009,845.

The present invention relates to the protection of the surface of any Window showing an exposed pane of poly.

carbonate or other solid transparent material included with low resistance to abrasion and / or chipping, with one exposed Disc with one or more transparent ones made of glass or known substitutes for glass is laminated. The glass preferably consists of an alkali.

silicate mixture or a borosilicate mixture that is easily chemically can be tempered.

An increase in resistance to impact, breakage, penetration and the like is used for glass articles, in particular lime-soda-silicate glass articles, such as window panes, decorative panes, and other panes of glass for the Use as a shop window or similar glass closures, for parts of buildings or transportable compartments, is achieved by making the glass article with a potassium salt at high temperatures, preferably above 470 ° C (875%), for short Time to be brought into contact. The duration for the touch treatment at Temperatures above 470 ° C hardly exceed 25 to 40 minutes, the duration however, it is longer at lower temperatures. Typical chemical tempering processes are in U.S. Patent No. 3.396.o75 disclosed.

In those cases in which the glass mixer wag significant amounts of lithium or sodium salt or a mixture of sodium and potassium salts a series of treatments, first with a molten sodium salt and then with a molten Kaliu: asalz can be used to achieve a TemperWlg. It is assumed that an ion exchange takes place during this chemical tempering, in which in the surface area of the glass article, an alkali metal ion having a larger Diameter is replaced by an alkali metal ion with a smaller diameter. This Ion exchange leads to a compressive stress in the surface area and increases the strength of the glass.

The strength of glass can also be increased by thermal annealing will. The latter technique consists of putting a sheet of glass over the deformation point addition to heat to a temperature close to the softening point and then the glass Suddenly and violently to be deterred to a temperature below the deformation point. This treatment results in compression tension in the surface area over the main area of the body that is subjected to tension.

It is also possible to strengthen the glass by first a thermal tempering of the glass and then a chemical tempering of the previous one thermally tempered glass is carried out using this glass one or more Times immersed in molten alkali metal salts at elevated temperatures however, these temperatures are below the thermal annealing temperature.

Various solid plastic materials, especially acrylic Plastic, can be used to make one or more inner sheets of laminated glass Replace window. Expanded poly (ethyl methacrylate) discs are well known as components of laminated aircraft windows.

In addition, it can be used as an alternative to the stretched acrylic plastics Polycarbonates of the type listed above instead of one or more internal ones Panes can be used in laminated windows.

In the case of laminated windows, adjacent panes of glass can be used or the substitutes for glass sheets are glued together using of typical interlayer materials, such as polyurethane compositions, as listed above or other well known interlayer compositions, such as plasticized polyvinyl butyral, polyvinyl butyral is manufactured by Reaction of butyl aldehyde with polyvinyl alcohol. The alcohol groups that are unreacted Remaining are calculated as the percent of vinyl alcohol remaining in the polymer. The known safety glass laminates are made using intermediate layers manufactured, whose essential Ilarz constituent from polyvinyl alcohol, which partially is condensed with butyl aldehyde, so that this resin 15 to 308 unreacted Contains hydroxyl groups, which are calculated as percent by weight of vinyl alcohol, furthermore, this resin contains less than 3% by weight of ester groups, expressed as percent by weight Vinyl acetate can be calculated, with the remainder consisting of acetal groups, which are used as Vinyl butyral will be charged. This material is commonly called "polyvinyl butyral" referred to or more precisely as partial polyvinyl butyral ". Usually contains such polyvinyl butyral as is used in safety glass laminates, plasticizers.

In general. the plasticizers used are insoluble in water Esters of polybasic acids or they consist of a polyalcohol with free hydroxyl groups. Particularly desired plasticizers for the present Invention are trethylene glycol di (2-ethyl butyrate), dibutyl sebacate, di (beta-butoxy-ethyl) adipate, and dioctyl phthalate.

Other suitable plasticizers include fully esterified one Triethylene glycol with a mixture of 80 to. 90% caprylic acid and lo to 20% capric acid, as in U.S. Patent No. 2.372T522 described, furthermore dimethyl phthalate, Dibutyl phthalate, di (butoxyethyl) sebacate, methyl p almi -tinate, methoxy palmitinate, Triethylene glycol diacetate, tricresyl phosphate, triethyl citronate, butyl butyryl lactonate, Ethyl para-toluene sulfonamide, dibutyl sulfone, lauryl alcohol, oleyl alcohol, glycerine tri-ricinoleate, Methyl lauroyl glycolate, butyl octanoyl glycolate and butyral laurinate. The - above List of plasticizers listed does not include all known plasticizers Suitable for the present invention are Example I Various disks from Bis-phenol-type polycarbonate on the order of 40 to 80 cm2 (6 to 12 inches square) and with a thickness of 6 mm was made with a polyurethane resin of the present invention. This is used to coat the solid disks Polyurethane elastomers used in polycarbonate were created in the reaction between a prepolymer, which consists of a mixture of prepolymer with terminal Diisocyanate groups and consisted of 2,4-toluene diisocyanate or mixtures thereof and up to 35% by weight 2,6-toluene diisocyanate contained, with a curing mixture, which consists of a mixture consisted of 1,4-butanediol and l, l, l-trimethylolpropane. This mixture of 1,4-butanediol and 1,1,1-trimethylolpropane had a ratio of 5 to 6.5 parts by weight of 1,4-butanediol to 1 part by weight of the trimethylolpropane. The prepolymer with the terminal Diisocyanate and the 2,4-toluene diisocyanate and the 2,6-toluene diisocyanate present in such proportions that the isocyanate groups between 12 and Constituted 15% by weight of the mixture of these components.

The prepolymer was created in the reaction between polytetramethylene ether-glycol with a molecular weight of about 1,000 with an excess of 2,4-toluene diisocyanate or with mixtures thereof containing up to 35% by weight of 2,6-toluene diisocyanate. The excess 2,4-toluene diisocyanate and the excess 2,6-toluene diisocyanate were extracted, leaving behind polytetramethylene ether glycol, its terminal Groups were saturated with 2,4- and 2,6-toluene diisocyanate. This structure with Terminal toluene diisocyanate groups have been referred to above as prepolymer.

In the case of the polyurethane elastomers used to coat polycarbonate was the total number of equivalents of prepolymer plus toluene diisocyanate (2,4- and 2,6-toluene diisocyanate) approximately equal to the total number of equivalents of 1,4-butanediol plus l, l, .l-trimethylolpropane. However, it is possible to change the number of Materials containing isocyanate groups (toluene diisocyanate plus prepolymer) to be used in an excess of up to solder or also in a deficit of up to 3%, without serious adverse consequences for the properties of the cured polyurethane elastomer.

The reactants were brought to a temperature between 430 and 820C (llo to 180 ° F) preheated. During the preheating, all components were carefully under vacuum. degassed. The time and temperature for curing was in the range from 22 hours at 80 ° C (175 ° F) and 5 to 6 hours at 150 ° C (300 ° F). All the higher the temperature, the less time it took for complete curing.

Any bis-phenol type polycarbonate resin sheet as shown below under the trade name LEXAN, was at least for 48 hours at 80 ° C (175 0F) preheated or preheated to 930C (200 ° F) for at least 24 hours, before a test mixture of polyurethane on the polycarbonate surface at a Temperature of the substrate of at least 80 ° C (175 ° F) and preferably above 930C (200 ° F) was applied. A glass cover plate was coated over the top Surface attached about 6 ram (1/4 inch) apart, the cover serves as a dust cover. The Abdedpltte remained after curing the coated polycarbonate panes in place; those needed for curing Minimum times and temperatures were at least 22 hours at 88 0C (1750F) or at least 18 hours at 930C (2000F) or at least 16 hours at 107 ° C (225 ° F), or at least 12 hours at 1210C (250 ° F).

The cured coated samples were removed from the oven and cooled down. All samples treated in this way had a smooth coating good optical properties.

A more detailed description of the polyurethane compositions follows, which were used in the particular example: A first composition, the consisted of freshly set mixtures of prepolymer A and curing mixture B, was manufactured according to the following procedure.

For the production of prepolymer A, 85.73% by weight of the reaction product were required of toluene diisocyanate (80% 2,4-isomer and 20% 2,6-isomer) and poly (oxytetramethylene) glycol (Molecular weight around 10000), available under the trade name ADIPRENE L-167 with 13.27% by weight toluene diisocyanate (80% 2,4-isomers and 20% 2,6-isomes) available under the trade name llYLENE TM, mixed. The mixture was degassed in vacuo.

To prepare curing mixture B, 11.02% by weight of -1,4-buthynediol were used and 1.82% by weight trimethylolpropane mixed and degassed. The ingredients were mixed at a maximum temperature of 63 0C (145 ° F) and the resultant liquid reaction product after further degassing on the surface of a polycarbonate pane, which is to be protected, applied. Then the coated polycarbonate sheet cured for 6 hours at about 14oOC (2850F).

The product used to manufacture the protective coating is in hereinafter referred to as Polyurethane AB.

A second composition, hereinafter referred to as polyurethane CD-, was made by mixing prepolymer C with curing mixture D accordingly of the following regulation.

To produce prepolymer C, 78.93% by weight of the reaction product were required from toluene diisocyanate and poly (oxytetramethylene) glycol with 21.07% by weight of toluene diisocyanate (80% 2,4-isomer and 20% 2,6-isomer) mixed. The prepolymer C was in vacuo degassed at 66 ° C (150 ° F) and cooled to 49 ° C (120 ° F) before proceeding with the curing mixture D was mixed.

Curing mixture D was produced using 13.78% by weight of 1,4-butanediol mixed with 2.288 wt% trimethylolpropah.

The mixture was degassed at 66 0C (15o0F) and heated to 49 ° C (120 ° F) cooled down. Prepolymer C and Cure Mixture D were heated at 930C (200 ° F) mixed, degassed and then evacuated for 10 minutes in a vacuum desiccator. Alternatively, prepolymer C was mixed with curing mixture D at 48 ° C (118 0F) mixed and the mixture cured at 710C (16o0F). The mix was degassed in vacuo, stirring was carried out for 4 minutes and then the degassing under further evacuation continued without stirring for 1/2 minute.

The degassed mixture was applied to various polycarbonate panes applied, and is referred to below as polyurethane CD.

The following samples were subjected to a known abrasion test ( Abrasion Resistance Test No, 17 of the American Standard Safety Code for Safety Glazing Materials for Glazing Motor Vehicles Operating on Land Highways), with the Exception that haze and permeability avenge different numbers of Revolutions were measured, and the average of 4 samples reported in each case became. Uncoated polycarbonate control samples also became the same Subjected to abrasion testing to the results with coated polyurethane samples to to compare. The automatic, rotatable ball-veil measuring device according to Gardner was Used with the light source filter "A" to reduce haze and transmission measured as indicated in Table I.

T A B E L L E I Abrasion test H = haze in% T = permeability in% revolutions control samples CD1 CD2 CD3 AB1 AB2 H T H T H T H T H T H T 0 2.25 86.3 1.62 82.8 3.27 81.8 2.97 83.0 4.81 85.2 6.28 84.5 5 1.49 86.3 10 1.85 86.4 5.92 84.2 6.62 84.3 20 2.57 86.2 5.82 84.1 6.22 84.4 30 3.43 86.2 40 4.17 86.1 50 4.80 85.9 5.63 84.1 6.08 83.6 100 8.57 85.9 2.17 81.5 4.27 81.5 3.46 81.9 5.86 83.8 6.01 83.8 1100 7.46 84.0 From the results of Tallile I is to see that the amount of fogging (corresponds to the loss of resistance against abrasion) for the control samples made of .unprotected polycarbonate after 100 revolutions has risen to an average of 7 times, while the various With polyurethane coated samples a lot after only 100 revolutions in the same test device showed less increase in fogging, what the greater resistance to Abrasion covered.

Example II Various control samples consisting of test laminates from a sheet of floated glass with a nominal thickness of about 3 mm (1/8 inch), a sheet of polycarbonate with a nominal thickness of about 3mm (1/8 inch) and an intermediate layer of polyurethane with a nominal thickness about 3mm (1/8 inch) were made. Additional test samples were also used manufactured with the same total thickness for glass, polycarbonate and polyurethane with the exception that the entire thickness of the polyurethane in the Test samples were divided into a first layer between layers of glass and polycarbonate and ion a second polyurethane layer on the larger surface the polycarbonate layer and the total thickness of the two polyurethane layers the Thickness of the polyurethane interlayer from the control samples corresponded, and that each of the samples produced had a surface area of approximately 930 cm2 (1 foot square).

Each of the control samples and each of the test samples were tested by that a bullet made of titanium hits a free glass surface at a controlled speed the sample was spun. The bullet had a weight of 150 g, a diameter of 41 mtn (1,620 inches) and a hemispherical shaped nose on its front End. The speed of each bullet that hits or hits the control sample one . Test sample was applied using a high speed electronic timepiece measured; the time measurement is started when the projectile has a first electronic Barrier crosses and exits when the projectile crosses a second electronic barrier which is about 30 cm (1 foot) away from the first barrier and which Trajectory cuts.

The test was carried out at three different temperatures; at For the first test, the samples were at about 210C (70 ° F), for the second For the third test, the samples were kept at -10C (30F) and the third test was within maintain a temperature gradient of the sample across the thickness of the laminate, in which the free glass surface is opposite to a cooled one Wall located at a temperature approximated between -180C to -230C (00 to -lo ° F) was held while at the same time the coated or uncoated plastic surface Was exposed to room temperature; this simulated the conditions that a window, which is installed in the cockpit of a commercial or military aircraft, is exposed.

In all of these tests, both for the test samples and for the control samples, the bullet was thrown onto the glass surface of the samples.

At a temperature of 21 0C (7off) there was no significant Difference in resistance between in control samples and test samples; however, at the other two temperature conditions listed above, the Test samples clearly superior to control samples in terms of the Impact resistance, particularly dramatic differences between control samples and There were test samples under the condition (3) in which a temperature gradient across the Thickness of the samples tested was maintained.

When attempted to impact at -10C (30 ° F) using a bullet with an impact speed of about 43m / sec.

(96.5 miles per hour) became a stake with a diameter from knocked out approximately 51 mm (2 inches) from the polycarbonate layer of the control sample, while under the same conditions the test samples did not penetrate and no chipping of the back surface of the test samples occurred either.

In the tests with differently cooled samples, the glass surface was cooled by exposure to the atmosphere opposite a cooled wall, while the free plastic surface was exposed to room temperature so that the Glass surface a temperature between approximately -7 to + 40C (20 to 40F) to dcn Time of the impact, while the opposite room area at Room temperature (between approximately 15 and 270C) was maintained. Under these test conditions the control samples were at an impact speed of about 50 m / sec. (111 miles per hour) penetrate while the test samples, which have an intermediate layer Made of polyurethane with a thickness of 2.8 mm (o.llo inch) and an outer polyurethane layer ia with a thickness of 0.4 mm (0.15 inches) even at an impact speed of about 59 m / sec. (132 miles per hour) were not penetrated, and neither were any Chipping occurred even though the polycarbonate layer cracked into three parts; Test samples, a first intermediate layer of polyurethane with a thickness of 1.5 mm (0.06 inch) and an outer second polyurethane layer with a thickness of also 1.5 mm were not penetrated when the projectile hit a velocity at about 55 m / sec (128 miles per hour), although a stake with a About 51 mm (2 inches) in diameter punched through the polycarbonate layer became; -other test samples with an intermediate layer of polyurethane with a thickness of 0.8 mm (0.030 inch) and a free polyurethane layer with a thickness of Von approximately 2.5 mm (0.100 inches) was taken from a projectile at impact velocity of about 68 m / sec. (153 miles per hour) did not penetrate, nor did a chipping occur on, although at this impact a stake with a diameter of about 76 mm (3 inches) were knocked out of the polycarbonate sheets of the test samples.

Example III Further impact tests were made with control samples floati.extem glass about 3.2 mm (1/8 inch) thick and with test samples made of floated glass of the same thickness, those with different polyurethane layers Thick were coated. In these latter tests, a steel ball was used weighing about 230 g (1/2 pound) onto the uncoated glass surface hurled.

In these latter impact tests, the control samples were turned off uncoated, floated glass approximately 3.2 mni (1/8 inch) thick of one Steel ball weighing approximately 1/2 pound (230 g) punctures if this Steel ball fell from a mean height of about 1 m (3 1/2 feet) what an impact speed of about 4.6 m / sec.

(l0.2 miles per hour) corresponded to; in contrast, test samples were on floated glass panes of the same thickness, covered with a polyurethane resin coating of a thickness of approximately 1.0 mm (ooo4 inch) on the point of impact opposite surface does not pierce if the same steel ball comes out heights did not hit the test specimens less than 1.8 to 2.4 m (6 to 8 feet), which a Deflection speed from about G to 6.9 m / sec. (13.4 to 15.5 miles per hour) corresponded to; Floated glass test specimens approximately 3.2 mm thick, the covered with a polyurethane layer with a thickness of about 1.5 mm (o.o. inch) were not penetrated by the same steel ball when it came out of a height of over 9 m (30 feet) impacted on aje test specimens, which corresponds to an impact speed of more than 13.4 m / sec. (30 miles per hour).

The results of these tests indicated that a polyurethane plastic coating with a thickness between about 0.1 mm and 2.54 mm (o.oo4 to o.loo inch), which is applied to the surface of a window opposite the impact side is, the ability of such a window, the impact of an external object, that strikes at considerable speed, to resist improves.

Example IV To the patented structures of the US patent No. 3,388, o32, were six control laminates consisting of five individual layers passed and had a surface area of approximately 77 cm2 (12 inches square), produced, the successive layers of glass, a polyurethane-polyester mixture, made of polycarbonate, polyurethane-polyester and glass, with respective Thicknesses of 3.2 mm, o, 75 mm, 3.2 mm, o, 76 mm and 3.2 mm (1/8 inch or

30 miles! Two of these samples were each under the different Subjected the temperature conditions of Example II to the above impact tests. at there was significant chipping from the glass layer on all six control laminates opposite the service layer on; at about 210C (70F) delivered the tested ones Laminates 31.4 g of splinters, which corresponded to 4.32 of the mass of the glass layer the impact layer made of glass at an impact speed of about 39.8 m / SeR. (89 miles per hour); at a speed of about 136 m / sec. (306 miles per hour) were 296 g or 40.7% of the mass of said opposite Chipped glass layer; a control laminate that has been tested at -10C (30 ° F) provides 33.8 g of splinters, which corresponded to 4.7% of the mass of the opposite glass shift with a surcharge.

speed of 49 m / sec, (109 miles per hour), while the other Control laminate at an impact speed of 136 m / sec. (306 miles per hour) was completely penetrated; for control laminates that meet the above were exposed to the temperature conditions listed under (3), i.e. it passed a temperature gradient across the thickness of the laminates, was determined by the opposite of the The glass layer lying on the top layer was 38 g, which corresponded to 5.2% of its mass Glass layer chipped off at an impact speed of about 47.8 m / sec.

(107 miles per hour); another test laminate was among these Temperature conditions at an impact speed of 48.3 m / sec. (1o8 miles per hour) 53 g or 7.3% of the mass of the opposite glass layer chipped off.

These results contrast with the results for the test samples, where in the area for impact speeds of 43 m / sec. up to 68 m / sec. (96.5 to 153 miles per hour) no chipping was observed.

Example V An attempt was made as described in US Pat No. 2.o68, o82 to manufacture the article described using polyvinyl butyral as synthetic resin. Such laminates delaminated fairly easily in an atmosphere with high humidity and the same disadvantage was found with laminates which Contained discs made of polyvinyl butyral with different plasticizer content; such disks are described in US Pat. 2,184,876.

Cellulose nitrate according to U.S. Patent No. 2,068,082 is dangerous and easily flammable under the lamination conditions as they are at present in the manufacture of laminated windshields for automobiles.

Cellulose nitrate and other cellulose esters that-originally used to larainize of glass used'wurden are replaced by polyvinyl butyral, since the cellulose ester discolor in the course of their use and also unacceptable for other reasons are.

To find the best designs for laminates follow the two above listed US patents with similar structures to compare which Containing free layers of polyurethane, control samples made of glass and polyvinyl butyral were used manufactured, and the impact resistance and the chipping resistance in comparison determined to the test samples; all samples had a surface area of about 77 cm2 (12th century) inches square) and in each test test samples and control samples had the same Thickness of all equivalent layers with the exception of the control samples the free, outwardly protruding layer was made of polyvinyl butyral, while .in the control samples this free layer consisted of polyurethane, according to the present invention.

The control samples consisted of a 3.2 mm thick glass layer a layer of polyvinyl butyral, the 21 wt-l of triethylene glycol di-2-ethyl butyrate contained polyvinyl butyral as a plasticizer to 100 parts, and this layer contained one Thickness of o.76 mm (30 miles), composed of a second layer of glass and a second Layer of polyvinyl IButyral with the same plasticizer content, each of these second layers were the same thickness as the first layer; the samples were largely identical to the control samples with the difference that the second Layer of polyvinyl butyral with a tile maker through a layer 0.76 mm thick was replaced by polyurethane. Both the control samples and the test samples were Impact tests on the first glass surface using the apparatus described above under use different impact speeds Exposed to room temperature; the control samples showed at impact speeds of about 45.5 m / sec. (102 miles per hour) some cracks while in the control samples at this impact speed also not a trace of cracking to be observed was; on another trial, a control sample showed at an impact speed of about 50.8 m / s (114 miles per hour) more chipping than a test sample at an impact speed of about 55.3 m / sec.

(124 miles per hour).

The above test proves the superiority of the structure present invention has similar structures to U.S. Patent No. 2,068,082.

In a similar test, the structures according to the US Pat No. 2,184,876 compared to the structures of the invention; this was a Control laminate made up of one 3.2 mm thick sheet of glass and two each 76 mm thick washer of polyvinyl butyral, one of which was the glass adjacent disc e one twenty parts of the plasticizer listed above on loo Parts contained polyvinyl butyral, and the other disk made of polyvinyl butyral adjacent the plasticized disc was relatively hard as it was only seven parts by weight of the above plasticizer per / contained 100 parts by weight of polyoinyl butyral, and a test laminate in which 0.76 mm thick layers of polyurethane-polyester instead of the two layers of polyvinyl butyral in the control samples used were, and thus corresponded to the structure according to the invention; and wherein the test laminate and control laminate continuously subjected to higher impact speeds using the equipment described above until the projectile was either penetrated the control laminate or the test laminate, causing chipping became.

The control laminate restrained the bullet, which was at a rate of impact of about 50 m / sec.

(112 miles per hour) while the projectile was impacting at of about 53.6 mJsec. (120 miles per hour) occurred which punctured the control laminate.

In contrast, the test laminate held the impacting bullet at impact speeds up to 79.4 m / sec. (178 miles per hour) and left the projectile even at impact speeds up to 93.4 m / sec. (209 miles per hour) do not penetrate the test laminate, what the superiority of the structure according to the invention over the structures according to the U.S. Patent No. 2.184.876 proves.

Various methods have been used to make solid panes of glass or from a polycarbonate resin, the solid panes either from the outer Layer of a laminate or a free disk with a polyurethane elastomer to cover. The first procedure results in a cell build-up.

The surface of the solid disc to be coated forms a surface the cell and a release plate forms the other Surface. the The release plate contains a washer or a coating made of a material that is attached to the not glued to the cured polyurethane Suitable materials for manufacture of release plates are silicone, gunmi, polyethylene, polypropylene, silicone grease, Polyvinyl fluoride, polytetrafluoroethylene as a solid pane and as a cover, completely fluorinated copolymers of ethylene and propylene, again as a solid disc and coating, and various silicone-based coatings that are sprayed or otherwise applied will.

The release plate is pulled through from the surface of the solid disc Separate spacers around the outer edges. The strength of the spacers determines the thickness of the coating. Suitable materials for the spacers are such as silicone rubber, polytetrafluoroethylene and fully fluorinated copolymers of ethylene and propylene. After the spacers are attached, the outer Edge around the spacers sealed with tape to prevent leakage to prevent the mixture during pouring and hardening.

The liquid reaction mixture is introduced through an opening in the seal poured or pumped into the cell. The filled cell is then placed in a Oven brought so that Polyurethane hardens at elevated temperatures.

After complete curing, the release plate is removed and the coating of polyurethane on the polycarbonate or the one coated with polyurethane Glass is exposed. Coatings with a thickness of 38 mm (ozone inch) and higher are used obtain.

A second method of coating a solid disk is in pouring the liquid mixture on it. In this procedure, the flat The disc to be coated is placed on a flat release plate. The The release plate and the fixed disc are carefully aligned. The alignment is best done in that the arrangement with the solid layer as the end face on a molten trap bach floats, the arrangement is built so that the solid disc forms the top surface of the assembly. The reaction mixture is poured onto the fixed pane and can be placed over the edges of the fixed pane flow away onto the release plate. The thickness of the polyurethane coating can be somewhat through different release agents on the release plate and through change the distance of the surface of the fixed disc from the release plate can be controlled. The rules for curing are the same as for the cell structure. It coatings with a thickness between 2.0 and 2.54 mm (o.o80 to o.loo inch) are used obtain.

A third method is similar to the second. Instead of overflowing of the fixed disc, a dam is built around the edges of the fixed disc. The dam holds the liquid resin in place until it has hardened enough to overflow is impossible. The advantages of this process are that it allows thicker polyurethane coatings can be easily obtained.

With this technique, coatings with a thickness of over 2.45 mm (o.loo inch) received.

A fourth method consists in following the procedure 2 or 3 attached solid disc to smear the liquid resin with a doctor blade. This technique is used to create coatings with different thicknesses of 0.076 ms (o.oo3 inch) to any desired thickness.

A fifth method is to make a pre-made arch Polyurethane with the fixed pane made of glass or polycarbonate or similar in an autoclave at high temperatures (9o - 15o0C (200 - 3000F) and under superatmospheric Laminate pressures up to about 14 kg / cm2 (200 pounds per square inch).

In all of these 'listed methods, the polycarbonate was pre-applied of the coating for at least 24 hours Temperature between preheated to around 80 and 128 0C (175-25o0F).

The articles made by this process consisted of a relatively solid, transparent pane with a thickness in the range of approximated o, 13 mm to approximately 6.4 mm (5-250 mils), the free surface of which with one above laid layer of self-healing resin made of polyurethane with a thickness in the range from approximately 0.076 mm to more than 3.8 mm (3 to 150 mils) coated.

The following drawings depict various embodiments of the present invention.

The figures show: FIG. 1, partially in section, an arrangement made of laminated Glass with an outer pane made of polycarbonate covered by a thin layer Polyurethane resin is protected according to the present invention; Fig. 2 partially in section a disk made of polycarbonate, both surfaces with a polyurethane resin are protected according to the present Brfindwlg; Figures 3 and 4 are views from the side and from above on a casting cell, which is used to apply a protective coating made of polyurethane on another exposed surface of a pane made of polycarbonate, which in turn forms part of a glass-plastic larainate is used will; Fig. 5 as a schematic representation of how a protective coating of the same thickness Poured onto the surface of a structure with a polycarbonate interface with the structure floatingly supported, and Fig. 6 as a schematic Representation of a protective coating with a thickness greater than the equilibrium thickness is applied through this.

FIGS. 1 and 2 describe structures with an end face Polycarbonate having a protective coating according to the present invention; the Fig. 1 shows a glass-plastic arrangement lo with alternating layers of glass 12 and thermoplastic adhesive intermediate layers 14, only three of these Layers are mapped while the number and thickness of the layers changed according to the intended use of the finished laminate. The layers of glass 12th can through transparent plastic layers, such as methacrylate be replaced and the intermediate adhesive layers 14 are either made of polyvinyl butyral with a corresponding plasticizer content or made of polyurethane. A polycarbonate pane 16, which usually serves as a splinter protection for the laminated arrangement, normally forms the inwardly facing face of the assembly like this is proposed in US Patent No. 3oo9,845, but with the modification, that according to the invention a protective coating 18 made of polyurethane is provided which the free surface of the polycarbonate pane 16 completely covered.

Fig. 2 shows a polycarbonate pane 16, both surfaces are covered with protective coatings 18; this arrangement is preferred by multiple Dipping or spraying on several times.

never FIGS. 3 to 6 show different processes for producing the Desired protective coverings made of polyurethane on polycarbonate panes as shown in Fig. 1. 3 and 4 show a G-eating cell with the glass-plastic arrangement lo Glass panes 12 with alternating adhesive intermediate layers 14 and a splinter plate 16 made of polycarbonate. zin circumferential sealing ring 20 as a spacer is round around three sides of the circumference of the free Surface of the polycarbonate pane 16 attached that an upwardly open cavity 22 is formed. A release plate 24 forms an outer wall of the cavity 22 with the seal 20 as a bottom and Sidewalls. The above-described polyurethane resin AB or CD or the like Resin is poured into the cavity that is open at the top. As. Spacer acting seal 20 and the release plate 24 are made of a material that The polyurethane does not stick to it during the curing process. Such materials are polyethylene or others described in the examples above.

In FIG. 5, the structure lo with the end face is made of polycarbonate oriented so that the polycarbonate sheet 16 is facing up and away from the release plate 24 is supported. The latter floats on a molten metal bath 26, to ensure that the surface of the polycarbonate pane is horizontal The polyurethane resin 18 flows over the top surface of the polycarbonate pane 16 on the Ab16 "s plate 24 and forms a film of the same thickness. How described above, heating to cure results in a visually acceptable one Coating made of polyurethane, which protects the polycarbonate pane 16 from abrasion.

Fig. 6 corresponds to Fig. 5 with the modification that a dam 28 is provided, which prevents the polyurethane resin from going beyond the boundaries of the polycarbonate pane 16 to flow out when the equilibrium thickness is reached. Dam 28 exists just like the seal 20 acting as a spacer or the release plate 24 made of a material that does not stick to the cured polyurethane.

In those cases where a protective coating on a laminated glass-plastic arrangement was applied with a splitter protection made of polycarbonate, impact tests showed that a protective coating of polyurethane over the exposed polycarbonate surface the Effectiveness of the arrangement to protect against penetration increases. In contrast increased the addition of an admixture layer of polyurethane with an outermost one Layer of glass on the free surface of the polycarbonate reduces the risk of splinters.

It will be understood that the various methods described above for the production of a protective coating for structures with end faces made of polycarbonate allow a number of modifications that are familiar to the expert. Hence are a number of modifications are possible without deviating from the essentials of the invention.

Claims (15)

Claims 1. Laminated window with a relatively solid layer of transparent Material with a thickness of approximately 0.13 mm to approximately 6.4 mm (5 to 250 mils) and with a first free surface, y e k e n n z e i c h n e t d u r c h a polyurethane layer with an optically smooth appearance and a thickness of approximately 0.076 mm to approximately 3.8 mm (3 to 150-miis), whichever with the first Surface connected to form a new free surface for the window is, with the new free surface in the interior of a structure in which the window is installed, directed, with the application of the polyurethane layer as a new free surface, the window's resistance to splintering from the first surface when an object hits the larger divider Surface area facing the first surface of the window is increased. 2. Laminated window according to claim 1, d a d u r c h g e k e-n n note that the relatively strong layer is made of a polycarbonate resin. 3. Laminated window according to claim 1, d a d u r c h g e k e n n notices that the relatively solid layer is on the opposite side of the free surface Side glued to a pane of glass via a thermoplastic intermediate layer is, the thermoplastic intermediate layer made of polyurethane or of polyvinyl butyral with an appropriate softener content. 4. Laminated window according to one of claims 1 to, g e k e n n draws a multitude of layers of transparent material, including a continuous pane of polycarbonate with a thickness between o, 13 mm and 6.4 mm (5 and 250 mils) and with a first free surface and with a layer of self-healing polyurethane resin with an optically smooth surface and with a thickness between approximately 0.076 and approximately 3.8 min (3 and 15c mils), which covers the first free surface of the polycarbonate pane to form a newly free surface, with the uE-bring the polyurethane layer as new free surface the resistance of the window against splintering from the first surface, when an object hits the larger part of the Surface of the window, which is opposite to the first surface, increased. 5. Laminated window according to claim 4, d a d u r c h g e k e n n indicates that the layer of polyurethane resin approximates at least a thickness 1.27 mm (50 mils). 6. Laminated window according to claim 4 ,. d a d u r c h e k e n n n notes that the polyurethane resin is made from the reaction product of poly (oxypolymethylene) glycol with an organic polyisocyanate and with a curing agent. 7. Laminated window according to claim 6, d -a d u r c h g e k e n n I would like to point out that the polyurethane resin is a Polyz.theraddukt with terminal isocyanate groups contains a reaction product of poly (oxypolymethylene) glycol with an organic Diisocyanate and with a curing agent which has at least two active hydrogen groups per molecule, and the poly (oxypolymethylene) glycol contains oxypolymethylene groups with a linear chain of about 3 to about 6 carbon atoms, each separated by an adjacent pair of oxygen atoms. 8. Laminated window according to claim 6 d a d u r c h g e k e n n notes that the polyurethane resin is made from the reaction product of a polyester a dicarboxylic acid which contains 2 to 10 carbon atoms per carboxyl group, with an excess of a dialcohol with 2 lis lo carbon atoms. 9. Laminated window according to claim 4, g e k e n n -z e i c h n e t through a multitude of layers of transparent material including an outer layer made of glass and an intermediate layer made of an organic material, consisting of polyurethane or polyvinyl buty.ral with the appropriate * 4chmacher content, wherein the intermediate layer connects the glass pane and the polycarbonate pane. lo. Laminated window according to claim 9, g e-k e-n n -z e i c h n e t d u r c h at least two layers of glass and at least two consecutive Intermediate layers. 11. Laminated window according to claim 1, g e k e n nz e i c h n e t is a transparent window that consists essentially of a transparent window Polycarbonate disc with a free surface and with a thickness approximated between o, 13 mm and approximately 6.4 mm and furthermore from a free layer of a transparent, self-healing polyurethane resin with a thickness between approximately 0.076 mm and approximately 3.8 mm, with the polyurethane layer with the free surface the polycarbonate pane is connected and the application of the polyurethane layer the resistance of the window to damage to the exposed polycarbonate surface is increased by abrasion, scratching and by the influence of chemicals or solvents. 1: 2. Laminated window according to claim 11, d a d u.r-c h g e k e n It should be noted that the layer of polyurethane resin is at least thick approximately 1.27 mm. 13. Laminated window according to claim 11, d a d u r c h g e k e n It is noted that the polyurethane resin is made from the reaction product of poly (oxypolymethylene) -Glycol with an organic polyisocyanate and a curing agent. 14. Laminated window according to claim 13, d a d u r c h g e k e n It is noted that the polyurethane resin consists of a polyether adduct with terminal Isocyanate groups exist as a reaction product of a poly (oxypolmethylene) glycol with an organic diisocyanate and with a - curing agent, which at least Contains 2 active hydrogen groups per molecule, and the poly (oxypolymethylene) glycol Contains oxypolymethylene groups, with a linear chain from about 3 to about 6 carbon atoms, each separated by a pair of adjacent oxygen atoms are. 15. Laminated window according to claim 11, d a d u r c h g e k e n It is noted that the polyurethane resin is made from the reaction product of a polyester from a -dicarboxylic acid, which contains 2 to 10 oxygen atoms per carboxyl group, with an excess of a dialcol with 2 to 10 carbon atoms. 16 * Laminated window according to claim 1, d u r c h q g e k e n It is noted that the relatively solid layer is made of transparent material consists of an organic composition, such as polycarbonates, polyester resins, made of acyl plastics and the like.