DK162976B - LAMINATED SAFETY PANEL - Google Patents

Abstract

1. A laminated pane comprising a glass sheet, a transparent intermediate layer based on polyurethane having energy-absorbing properties, and a transparent coating layer of self-healing plastics material, notably based on a thermosetting polyurethane, characterised in that the intermediate layer based on polyurethane having energy-absorbing properties is formed essentially of a polyurethane obtained by reactive casting on a flat horizontal support of a reaction mixture of an isocyanate component of viscosity less than 5 Pas at 40 degrees C and a polyol component, the isocyanate component comprising at least one aliphatic or cycloaliphatic di-isocyanate or an isocyanate prepolymer, the isocyanate component containing urea functions, the content of urea being up to 10% of the total weight of isocyanate component, the content of urea preferably being from 5 to 7%, the polyol component comprising at least one long difunctional polyol of molecular weight from 500 to 4000 and at least one short diol as a chain lengthening agent, the ratio of isocyanate group equivalents to hydroxyl group equivalents is about 1, the proportions of the different polyols are selected such that the number of hydroxyl group equivalents due to the short polyol represents from 20 to 70% of the total hydroxyl groups, and this layer having at a thickness of about 0.5 mm, a flow stress sigma y at -20 degrees C not exceeding 3 daN/mm**2 , a rupture stress sigma R at 40 degrees C of at least 2 daN/mm**2 , a lengthening at rupture vepsiln R at + 20 degrees C from 250 to 500%, and a tear resistance Ra at + 20 degrees C of at least 9 daN/mm.

Description

DK 162976 B

The invention relates to a laminated pane containing a glass lamella, a transparent intermediate layer based on a polyurethane having energy absorbing properties and a transparent coating layer of self-healing resin, in particular on the basis of a thermosettable polyurethane which, at a thickness of approx. 0.5 mm, in the intermediate layer has a flow threshold voltage σ at -20 ° C equal to or 2 y o · lower than 3 daN / mm, a breaking voltage uD at 40 C equals

2 K

with or higher than 2 daN / mm, a rupture extension 10 at 20 ° C in the range 250-500% and a resistance to initial tearing R at 20 ° C equal to or higher than 9 daN / mm.

In particular, the vehicle windshields include a rigid transparent silicate glass support, a transparent plastic layer with energy-absorbing properties (layer AE) and a transparent coating material of scratch-resistant and abrasive material, which is referred to as self-healing layers or inner protective layer (layer PI), since in case of 20 a windshield faces the interior of the cab.

Laminated panes of said type are known. For example, French Patent No. 2,134,255 discloses a laminated pane comprising a glass lamella, a plastic layer having energy absorbing properties, in particular a layer of plasticized polyvinyl butyral, and a relatively soft protective coating based on one. aliphatic polyurethane.

Such a laminated pane was not fully satisfactory, since after a certain time varying from a few days to several months a deterioration of the adhesive properties, especially between the glass and the interlayer, resulted in the loosening of the elements of the laminated pane and thus a deterioration of the optical qualities of the pane with the formation of unclear zones. These deteriorations are apparently due to a moisture uptake of the layer of plasticized polyvinyl butyral.

From French Patent No. 2,398,606 a laminated pane of the type described above is known in which the intermediate layer having energy absorbing properties is a thermoplastic

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2 polyurethane recovered from at least one aliphatic diisocyanate and at least one polyester diol or polyether diol, the ratio of the equivalent groups NCO to the equivalent groups OH being preferably between 0.8 and 0.9.

5 This pane retains its good optical properties and the adhesion remains good between the elements under highly variable temperature and humidity conditions, but the pane's biomechanical properties and in particular the shock resistance are not fully satisfactory.

In European Patent Specification No. 0.054,491, a laminated pane of the structure described above is known, and wherein the intermediate resin layer having energy absorbing properties is based on a polyurethane polyurea having a linear structure and a urea group content of the order of 1-20. % polyurethane-polyurea is the reaction product of a prepolymer derived from a polyol component and an isocyanate component used in excess with at least one diamine. This intermediate layer is made by extruding a polyurethane-polyurea resin or by pouring a solution of said resin and evaporation of the solvents, which in both cases requires several successive operations.

In the case of extrusion, it is necessary to perform a prior synthesis of the resin in order to extrude it.

In addition, to obtain the optical quality required for the intended use, it is necessary to "post-process" the slat. However, the optical quality thus obtained is generally not of longer durability, since the resin material is characterized by its manufacturing process and the quality obtained by the "finishing" decreases over time.

Furthermore, the extrusion of the layer with energy absorbing properties presents a problem in the assembly of the self-healing layer.

In the case where a solution is poured, it is also necessary to carry out a prior synthesis.

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3 view of the resin. This must then be dissolved in a solvent, after which the solution must be poured and the solvent evaporated, and this must be repeated to obtain a layer of a thickness compatible with the desired energy absorbing character. Further, the evaporation of the solvent gives rise to nuisance.

The invention addresses the aforementioned disadvantages and provides a safety pane, particularly for use as a vehicle windshield, which has good optical and bio-mechanical properties and retains these properties under variable temperature and humidity conditions.

The pane of the invention, like the above-mentioned panes, contains a glass lamella, a plastic layer with energy-absorbing properties and a self-healing coating layer which is resistant to scratches and abrasion, and the peculiar consists in the choice of the plastic layer with energy-absorbing properties.

Accordingly, the laminated pane of the invention is characterized in that the intermediate layer on the basis of a polyurethane having energy absorbing properties is formed mainly by a polyurethane obtained by reactive pouring onto a planar horizontal support of a reaction mixture of an isocyanate component having a viscosity lower. than 5000 centipoise at 40 ° C and a polyol component, the isocyanate component containing at least one aliphatic or cycloaliphatic diisocyanate or an isocyanate prepolymer, the isocyanate component containing urea functions, and the amount of urea reaching 10 % of the total weight of the isocyanate component and preferably is between 5 and 7% and the polyol component contains at least one long difunctional polyol having a molecular weight between 500 and 4000 and at least one short diol as a chain extender, the ratio of isocyanate equivalents to hydroxy equivalents is approximately equal to 1, and the ratio of the different polyols is chosen such that the number of hydroxy equivalent groups from the short diol constitutes 20-70% of the total hydroxy groups.

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4

The mixing ratios of the components of the polyurethane are chosen such that a stoichiometric equilibrated system is preferably obtained, i.e. the ratio of the ash valentine groups NCO provided by the diisocyanate component to the equivalent groups OH originating from the polyol component, i.e. the long polyol (s) and the short diol (s) are of the order of 1.

When the ratio of NCO / OH is less than 1, the more it decreases, the more quickly the unsatisfactory mechanical properties required for the application of 10 to 10 will be used. When all the components of the polyurethane are difunctional, the lower limit of the ratio of NCO / OH to obtain satisfactory mechanical properties is located at approx. 0.9. When one of the components 15 is at least trifunctional, said lower limit may be lowered to approx. 0.8. When the ratio of NCO / OH is greater than 1, the more it increases, the more certain mechanical properties of the layer obtained by reactive pouring are reinforced, for example, the layer becomes stiffer, but then iso <- · 20 cyanate component is more expensive than the polyol component, the choice of the ratio of NCO / OH is approximately equal to 1, a good compromise between obtained properties and costs.

The mixing ratio of the long polyol to the short diol may vary as a function of the desired properties and also to the ratio of equivalent groups, but the number of equivalent groups OH derived from the short diol generally represents 20 to 70% of the total equivalent groups in the mixture forming the polyol component, in the case where the ratio of the 30 equivalents of NCO to the equivalents of OH is of the order of 1. As the amount of the short diol is raised, the layer is hardened and its modulus generally increased.

In particular, the diisocyanates useful in the present invention are selected from the following difunctional aliphatic isocyanates: hexa-methylene diisocyanate (HMDI), 2,2,4-trimethyl-1,6-hexanedisocyanate (TMDI), bis 4-isocyanatocyclohexylmethane (Hylene W), bis-3-methyl-4-isocyanatocyclohexylmethane, 2.2-

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5 bis (4-isocyanatocyclohexyl) propane, 3-isocyanatomethyl 3,5,5-trimethylcyclohexyl isocyanate (IPDI), m-xylylenedi isocyanate (XDI), m- and p-tetramethylxylylene diisocyanate (m- and p-TMXDI), trans-cyclohexane-1,4-diisocyanate (CHDI) 5 and 1,3- (diisocyanatomethyl) -cyclohexane (hydrogenated XDI).

Preferably, IPDI is used, especially because of the fabrication price.

According to a feature of the invention, an isocyanate component containing urea functions is used. These urea functions enhance certain mechanical properties of the layer. The content of urea can represent up to approx. 10% of the total weight of the isocyanate component with urea functions. The urea content is preferably located between 5 and 7% of the total weight of said component. For the above reason, 3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate containing urea functions (IPDI and derivatives) is preferably used.

The suitable long polyols are selected from polyether diols or polyester diols having a molecular weight of 500-4000, the polyester diols being the products of esterification of a diacid such as adipic acid, succinic acid, palmitic acid, azalanic acid, sebacic acid or ophthalic acid, and a diol such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, the dg of the polyether diols having the general formula H-f0 (CH₂) OH OH, where η = 2-τβ, and m as the molecular in nm weight is in the range 500-4000, or the polyether CH-3 I3 diols have the general formula H-fOCH -CHO} OH where m 2 m as the molecular weight is in the range 500-4000 .

Polycaprolactone diols can also be used.

Preferably, a polytetramethylene glycol (n = 4) having a molecular weight of 1000 is used.

The suitable chain elongating agents are short diols 35 having a molecular weight lower than ca. 300 and preferably lower than 150 such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-, 1,3- or 1,4-butanediol, 2,2-dimethyl-1,3-propanediol ( neopentylglycol), 1,5-pentanediol, 1.6-

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6 hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, cyclohexanedimethanol, bisphenol A, 2-methyl-2,4-pentanediol, 3-methyl-2,4-pentanediol, 2- ethyl-1,3-hexane-diol, 2,2,4-trimethyl-1,3-pentanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, 2-butyn-1,4-diol, 1,4-butenediol and decyndiol, the three latter optionally substituted and / or etherified hydroquinone bis hydroxyethyl ether, bisphenol A etherified with two or four propylene groups, dimethylol proponic acid. In general, the shorter the diol, the harder the layer is.

Preferably, 1,4-butanediol is used, which is a good compromise for obtaining a layer that is neither too hard nor too soft as desired for the present energy absorbing application.

A characteristic of the layer with energy absorbing properties is that it is obtained by reactive pouring on a flat horizontal support. This reactive pour, in which one embodiment has been previously described, for example, in French Patent Specification No. 2,442,128 to obtain a thermoset polyurethane layer from a mixture of trifunctional components, surprisingly provides in the case of the invention with di. functional starting components a layer that is not completely thermoplastic when the NCO / OH group ratio is approximately equal to 1.

The reactive pouring involves a rapid polymerization reaction in order for the layer to be formed over a period compatible with an industrial fabrication. This necessitates an elevated temperature, of the order of approx. 80-140 ° C, at which temperature secondary branching reactions occur, providing, for example, allophanate and / or biuret groups between the urethane chains, such as

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7 - R - NH - CO - O - R '- 0 -

OCN - R - NCO

- R-NH-CO-O-R '- O - 5 ~ - R ^ N-COYO-R' - O - I / 1 t CO in aVlophanate

{NH

v V 7

10 NH

CO

- R - N - CO - R '- O - or 15 - R "- NH - CO - NH - R" -

OCN - R - NCO

- R "- NH - CO - NH - R" - 20 - R "- N - CO" - NH / R "-

/ / S

t CO

t I -.

«NH biuret v Jj. - i

R

/

NH

CO

- R "- N - CO - NH - R" -

Under these. operating conditions, the product obtained, even with difunctional components, when the NCO / OH ratio is approximately equal to 1 above, is not completely thermoplastic and is in fact immiscible and insoluble in most solvents for polyurethanes such as tetrahydrofuran or dimethyl. formamide. This is not a disadvantage as the film or the la-35 is already formed. On the contrary, as an advantage, improved mechanical properties of the same composition are obtained as compared to an equivalent system polymerized by

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8 low temperature where only linear polycondensation takes place.

When the ratio in NCO / OH is lower than 1 and of the order of 0.8-0.9, only 5 insignificant cross-linking of the type shown above takes place.

In a method of preparing the polyurethane layer with energy-absorbing properties, the polyol component may contain a small amount of at least one polyol having higher functionality than two and in particular monomeric aliphatic 10 triols such as glycerol, trimethylol propane, polyether chain triols, polycaprolactone triols, these molecular weights. generally located between 90 and 1000, mixed polyether / polyester polyols with functionality higher than 2, for example functionality located between 2 and 3. Addition of a polyol with functionality higher than 2 promotes further bridging between the polyurethane chains and thus improve the cohesion of the layer.

The mixing ratios of the long polyol, the 20 short diol and optionally the polyol with functionality higher than 2 may vary according to the desired properties.

Generally, such blending ratios are chosen that, for one equivalent of hydroxyl, the long polyol represents approx. 0.30-0.45 equivalent, the short diol approx. 0.2-0.7 equivalent and the polyol with functionality higher than 2 approx. 0-0.35 equivalent. Under these conditions, the layer shows mechanical characteristics as mentioned in claim 11, the characteristic part and measured according to the standards AFNOR NFT 46.002, 51.034 and 54.108.

According to another preparation of layer AE of the invention, the isocyanate component may contain, in limited amounts, for example, less than 15% in NOC equivalent, at least one triisocyanate such as a biuret of isocyanate or a triisocyanurate.

According to a feature of the invention, a portion of the polyol component may be replaced by a product with other active hydrogens such as an amine.

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9

An important advantage of the layer AE used according to the invention is that it can be formed by reactive pouring onto a first plastic material layer which is already polymerized or is about to complete its polymerization, in particular the self-healing plastic layer, without it being necessary to treat the support layer.

The self-healing, scratch-resistant plastic coating layer, which in the application of the invention is also referred to as inner protective layer (layer PI), is, for example, that described in French Patent Nos. 2,187,719 and 2,251,608. This self-healing layer has, under normal temperature conditions, a high capacity for elastic deformation, a low modulus of elasticity, lower than 2 2000 daN / cm and preferably lower than 200 daN / cm, and a fracture elongation higher than 60% with less than 2% plastic deformation and preferably a fracture elongation higher than 100% with less than 1% plastic deformation. The preferred layers of this type are thermoset polyurethane with a modulus of elasticity of approx. 25-200 daN / cm and an extension of approx. 100-200% with less than 1% plastic deformation.

Examples of monomers suitable for the preparation of these thermoset polyurethanes are partly di-. functional aliphatic isocyanates such as 1,6-hexanedisocyanate, 2,2,4-trimethyl-1,6-hexanedisocyanate, 2,4,4-trimethyl-1,6-hexanedisocyanate, 1,3-bis (isocyanate atom) -thyl) benzene, bis- (4-isocyanatocyclohexyl) methane, bis- (3-methyl-4-isocyanatocyclohexyl) methane, 2,2-bis- (4-isocyanatocyclohexyl) propane and 3-isocyanatomethyl-3,5, 5-tri-methylcyclohexyl isocyanate, as well as biureter isocyanurates and prepolymers of these compounds having a functionality of 3 or more, and partly polyfunctional polyols, e.g. the branched polyols such as the polyester polyols and polyether polyols obtained by reaction of 35 polyfunctional alcohols, in particular 1,2,3-propanetriol (glycerol), 2,2-bis (hydroxymethyl) -1-propanol (trimethylolethane), 2 , 2-bis (hydroxymethyl) -1-butanol (trimethylol propane), 1,2,4-butane triol, 1,2,6-hexane triol,

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2,2-bis (hydroxymethyl) -1,3-propanediol (pentaerythritol) and 1,2,3,4,5,6-hexane-hexole (sorbitol), with aliphatic diacids such as malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid and sebacic acid, or with cyclic ethers such as ethylene oxide, 1,2-propylene oxide and tetrahydrofuran.

Preferably, the molecular weight of the branched polyols is approx. 250-4000 and preferably of approx. 450-2000. Mixtures of various monomeric polyisocyanates and 10 polyols can be used. A particularly preferred thermosettable polyurethane is that described in French Patent No. 2,251,608.

The choice of the thickness of the layer with energy absorbing properties (layer AE) and of the self-healing layer (layer PI) 15 and the relationship between these two thicknesses are important factors. According to the invention, the total thickness of the two superimposed layers is greater than 0.5 mm with a thickness of at least 0.4 mm for the layer having energy absorbing properties.

In addition, the adhesion between this layer and the glass slab must be greater than approx. 2 daN / 5 cm, which value is measured by the peel test described below. However, this adhesive force must not be too great, especially when using a layer AE having a relatively small thickness, close to the applicable lower limit of approx. 0.4 mm.

The layer having energy absorbing properties may contain various additives which generally serve to facilitate its fabrication by reactive pouring, or which may further improve some of the properties of the layer.

It may contain a catalyst such as a tin catalyst, for example, dibutyltin dilaurate, tributyltin oxide, tin octoate, an organo-mercury catalyst, e.g., phenylmercury ester, an amine catalyst, for example, diazabicyclo- (2,2,2) -octane. , 1- (1,8-diazabicyclo- (5.4.0)) - 7-decene.

The layer may contain a stabilizer such as bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate and a phenolic antioxidant.

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11

The layer may also contain a covering layer such as a silicone resin, a fluoroalkylated ester or an acrylic resin.

A two-layer lamella can be prepared in the following manner.

First, a first layer may be prepared which may be either the adhesive layer having energy absorbing properties (layer AE) or the self-healing plastic layer for inner protection (layer PI) made in particular of a thermosetting polyurethane. On this first layer, the second layer is then formed.

Thus, a thermoset polyurethane layer can first be prepared by pouring the component mixture onto a pouring support. After polymerization of the 15 monomers and forming a thermosettable layer with a thickness which can vary between 0.1 and 0.8 mm, the reaction mixture of the components is poured into the layer with energy absorbing properties.

The reverse preparation can also be used, i.e. first forming the layer with energy absorbing properties (layer AE) and then forming layer PI.

To produce the laminated pane, the elements are assembled using pressure, for example, by squeezing between calender rolls, and by the action of heat, the layer AE always being located between the glass and the layer PI.

It is possible to further improve the bonding of the elements by subjecting the laminated pane to a period in autoclave, for example, one hour at a temperature of approx. 100-140 ° C and at a pressure of approx. 3-15 bar, or for a period in the oven.

The invention is further described by the following examples.

Example 1 On a mobile continuous glass carrier coated with a separation agent, which may be, for example, that described in French Patent No. 2,383,000,

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12, namely an ethylene oxide modified product, a homogeneous mixture is poured with the following mixing ratios: - 1000 g of a polyether having a molecular weight of approx. 450 obtained by condensation of 1,2-propylene oxide with 2,2-bis (hydroxymethyl) -1-butanol and having a free hydroxy group content of approx. 10.5-12%, containing 1% by weight of a stabilizer, 0.05% by weight of a catalyst, namely dibutyltin dilaurate, and 0.1% by weight of a coating agent, - 1020g of a biuret of 1.6 hexane diisocyanate with a content of free isocyanate groups of approx. 23.2%.

A pouring head is used as described in French Patent No. 2,347,170. A uniform layer is formed which, after polymerization under the influence of heat, e.g. 15 minutes at 120 ° C, has a thickness of approx. 0.19 mm and self-healing properties.

To prepare the layer with energy absorbing properties, the polyol component is prepared by mixing a polytetramethylene glycol with a molecular weight of 1000 (for example, the product sold under the designation Polymeg 1000 by QUAKER OATS) with 1,4-butanediol, two excipients are such that the polytetramethylene glycol provides 0.37 equivalent of hydroxy groups, while the 1,4-butanediol provides 0.63 thereof.

In the polyol component, a stabilizing agent is incorporated in an amount of 0.5% by weight of the total mass of the polyol component and the isocyanate component, a coating agent in an amount of 0.05 weight calculated in the same manner and a catalyst , namely dibutyltin dilaurate, in an amount of 0.02% by weight calculated in the same manner as above.

The isocyanate component used is 3-isocyanato-methyl-3,5,5-trimethylcyclohexylisocyanate (IPDI) transmitting urea functions, obtained by partial hydrolysis of IPDI, and having a content of NCO groups of approx. 31.5% by weight.

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13

The components are used in such quantities that the ratio NCO / OH is 1.

After deaeration of the components in vacuo, it becomes approx. 40 ° C applied mixture by means of a pouring head, such as that described in French Patent 2,347,170, poured onto the preformed self-healing polyurethane layer. In this way, a layer with a thickness of approx. 0.53 mm, subjected to a polymerization period consisting of 25 minutes of heating at approx. 120 ° C.

The two-layer lamella is taken by the glass carrier and can be easily handled, stored or used immediately afterwards for the preparation of laminated panes according to the invention.

To make the pane, the two-layer lamina 15 is obtained above assembled with a cured glass lamella of thickness 2.6 mm. The glass may be hardened or hardened. As mentioned above, the assembly can take place in two stages, a first stage consisting of a preliminary assembly obtained by passing the incoming elements in the space between two calender rolls, for which purpose, for example, the apparatus described in European patent specification no. 0.015,209, the layer AE being disposed against the inner glass surface, and a second stage consisting of placing the laminated product obtained in an autoclave, where it is for approx. 1 hour is exposed to a pressure of approx. 10 bar at a temperature of approx. 135 ° C. This autoclave period can optionally be replaced by an oven period without pressure.

The won pane exhibits excellent optical quality and perfect transparency.

The adhesion obtained between the glass slab and the energy absorbing layer is measured on the fabricated pane by a peel test described below.

A ribbon with a width of 5 cm is cut off the two-layer covering slat. The end of the belt is separated and a pull is applied to the belt perpendicular to the surface of the pane at a pulling speed of 5 cm per minute. The operation is performed at 20 ° C. The mean tensile force needed to separate the belt is noted. By this method

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14 there was a traction of 10 daN / 5 cm.

Shock resistance tests at various temperatures were performed on the pane made according to the example.

5 The first shock resistance test was conducted with a steel ball weighing 2,260 kg (large ball test), which was allowed to fall on the central one of a sample of laminated pane with a 30.5 cm side held on a rigid frame. The approximate height was determined at 10 which 90% of the samples tested at the selected temperature withstood the drop of the ball without being penetrated.

For the laminated pane according to the example, the value obtained was 8 meters.

Another shock resistance test was performed with a steel ball of 0.227 kg and a diameter of 38 mm. One test was conducted at a temperature of -20 ° C and another was conducted at a temperature of + 40 ° C. The values obtained were 11 and 13 meters, respectively.

According to current European standard R 43, the desired 20 results are at least 4 meters with the big ball, at least 8.5 meters with the small ball at -20 ° C and at least 9 meters with the small ball at + 40 ° C .

In addition, the layer PI shows surface properties sufficient for use in a laminated pane and in particular a scratch resistance, measured with ERICHSEN type 413 apparatus, of more than 20 g and a wear resistance according to European standard R 43 with a deviation of clarity (Δ clarity) lower than 4%.

The pane according to the invention shows all the characteristics which make it suitable for use as a vehicle windshield.

comparison Example

The same procedure as in Example 1 35 was used with the same starting components and the same mixing ratios for the preparation of layer AE, except that this layer was not watered by reactive pouring, but by several successive pourings of a solution of polyethylene.

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15 urethane prepared by synthesis in solution to obtain a thickness of 0.53 mm.

Shock resistance tests under the same conditions as in Example 1 gave the following values: 5 3.5 meters for large ball, 4 meters and 3 meters for small ball at -20 ° C and + 40 ° C, respectively.

The peel sample gave the value 8 daN / 5 cm.

These values are insufficient, showing that the reactive pouring used in Example 1 imparts to the layer AE the desired properties.

Example 2

The same procedure as in Example 1 15 was used except that layers of other thicknesses were made, namely a self-healing layer (PI) having a thickness of 0.41 mm and a layer of AE with a thickness of 0.29 mm.

The laminated pane won showed the following characteristics: The peel test gave the value 10 daN / 5 cm. The big ball test and the two small ball tests gave the values 3.5 m, 9 m and 9 m respectively, which is inadequate. These poor values are due to the insufficient thickness of the layer with energy absorbing properties.

Example 3

The same procedure as in Example 1 was used except that a layer of PI 30 having a thickness of 0.315 mm and a layer of AE with a thickness of 0.415 mm were prepared.

The peel test gave a value of 10 daN / 5 cm.

The large-ball and small-ball tests yielded the values of 4.5 m, 10 m and 13 m, respectively, which is fully satisfactory.

Example 4

The same procedure was used as in Example 1 except that a layer of PI was prepared

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16 with a thickness of 0.32 mm and a layer of AE with a thickness of 0.42 mm and that the glass surface prior to assembly was subjected to a classical treatment with an adhesion promoting agent such as silanes to obtain a higher adhesion value.

The peel test gave a value of 20 daN / 5 cm.

The large ball test yielded a value of 3.5 m. This insufficient value for the shock resistance is due to an excessive adhesion of the layer AE to the glass in the case where this layer exhibits a relatively small thickness. This example is to be compared with Example 3 which, despite using layers of the same thickness, provided a satisfactory pane due to a lower adhesion force.

Example 5 The same procedure as in Example 1 was used except that a layer PI of 0.46 mm thickness and a layer AE of 0.56 mm thickness were prepared and the glass prior to assembly was treated as in Example 4.

The 20 peel test gave a value of 20 daN / 5 cm, while the large and small ball tests gave values of 8 m, 11.5 m and 13 m respectively.

This example should be compared with Example 4.

It shows that despite a strong adhesion, application of a layer of AE of high thickness provides satisfactory mechanical resistance values.

Example 6

The same procedure as in Example 1 30 was used except that the polyol starting component of layer AE consisted of a mixture of polytetramethylene glycol having a molecular weight of 1000, 1,4-butanediol and polycaprolactolitriol (e.g. the product sold under the name Niax 301 of the company UNION CARBIDE) in such respective mixing ratios that one equivalent of hydroxyl 0.35, 0.55 and 0.10 equivalent of each of the polyols was used.

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17

Layers having a thickness of 0.160 mm were made for the layer PI and a thickness of 0.660 mm for the layer AE.

The won pane showed fully satisfactory optical and mechanical characteristics. The values measured at the various 5 tests were as follows: an adhesion of 3 daN / 5 cm, ball test values of 9 m, 13 m and 13 m.

Example 7

The same procedure was used as in Example 6 10 except that the mixing ratios of the different polyols were 0.35 equivalent OH for Polymeg 1000, 0.45 equivalent OH for 1,4-butanediol and 0.20 equivalent OH for Niax 301, respectively. .

Layers of 0.31 mm thickness were made for layer PI and 0.48 mm for layer AE.

The values measured by the tests were as follows: an adhesion of 3 daN / 5 cm and ball test values of 4.5 m, 10 m and 12 m, which is satisfactory.

Example 8

The same procedure as in Example 7 was used except that thicknesses of 0.39 mm were used for layer PI and 0.39 mm for layer AE.

The measured values were as follows: an adhesion of 4 and 25 ball test values of 3 m, 8 m and 8 m, which is inadequate.

This example, when compared to Example 7, shows that for the same thickness of the two-layer slat there is a thickness ratio between layer AE and layer PI, which, by value, provides a satisfactory or unsatisfactory pane.

Example 9

The same procedure as in Example 1 35 was used except that the polymerization of layer AE was carried out at a temperature of only 60 ° C for 20 hours.

Shock resistance tests conducted under the same conditions as in Example 1 gave the following values:

Claims (11)

1. A laminated pane containing a glass lamella, a transparent intermediate layer based on a polyurethane having energy-absorbing properties and a transparent coating layer of self-healing resin, in particular on the basis of a thermosettable polyurethane which, at a thickness of 0.5 mm, exhibits a flow threshold stress 2 15. at -20 ° C equal to or lower than 3 daN / min, a yo breaking voltage σ „at 40 C equal to or higher than 2 daN / min, a rupture extension ε_ at 20 ° C in the range of 250-500% and a resistance to initial tearing R CL at 20 ° C equal to or greater than 9 daN / mm, characterized in that the polyurethane-based interlayer with energy absorbing properties is formed mainly of a polyurethane obtained by reactive pouring on a plane horizontal carrier of a reaction mixture of an isocyanate component having a viscosity lower than 5000 centipoise at 40 ° C and a polyol component, the isocyanate component containing at least one aliphatic component. or cycloaliphatic diisocyanate or an isocyanate prepolymer, the isocyanate component containing urea functions, and the amount of urea reaching up to 10% of the total weight of the isocyanate component and preferably being between 5 and 7% and polyol component contains at least one long difunctional polyol having a molecular weight between 500 and 4000 and at least one short diol as a chain extender, the ratio of isocyanate. 35 equivalents and hydroxy equivalents are approximately equal to 1, and the mixing ratio of the various polyols is chosen such that the number of hydroxy equivalent groups from the short diol constitutes 20-70% of the total hydroxy groups. Laminated pane according to claim 1, characterized in that the polyol component contains at least one polyol with a functionality higher than 2. Laminated pane according to claim 1 or 2, characterized in that the isocyanate component contains 3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate. Laminated pane according to any one of claims 1-3, characterized in that the isocyanate component consists mainly of 3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate containing urea groups, and the polyol component mainly consists of polytetramethylene glycol. having a molecular weight of about 1000 and 1,4-butanediol. Laminated pane according to any one of claims 2-4, characterized in that the polyol having a functionality higher than 2 is a triol. Laminated pane according to any one of claims 1-5, characterized in that of one hydroxy equivalent in total to the polyol component of the polyurethane having energy absorbing properties, the long polyol represents 0.30 to 0.45 equivalent, while the short diol represents 0.2 to 0.7 equivalent, and polyol having a functionality higher than 2 represents 0 to 0.35 equivalent. Laminated pane according to any one of claims 1-6, characterized in that the polyurethane layer with energy absorbing properties contains additives such as a catalyst, a coating agent or a stabilizing agent. Laminated pane according to any one of claims 1-7, characterized in that the thickness of the polyurethane layer with energy absorbing properties plus the thickness of the coating layer is greater than 0.5 mm, wherein the layer with energy absorbing properties has a thickness of at least 0.4 mm. DK 162976 B Laminated pane according to any one of claims 1-8, characterized in that the adhesion between the layer with energy absorbing properties and the glass slab is greater than 2 daN / 5 cm. Laminated pane according to any one of claims 1-9, characterized in that the polyurethane layer with energy absorbing properties is obtained by polymerization at a polymerization temperature higher than 80 ° C during the reactive pouring. Laminated pane according to any one of claims 1-10, characterized in that the isocyanate component further contains at least one triisocyanate.