Insulating glazing comprising laminated glazing with controlled internal adhesion and tear resistance

Abstract

The invention relates to an insulating glazing unit (1) comprising an assembly of parallel glazing units, two consecutive glazing units in the assembly being separated by a cavity enclosing a gas layer (4), said insulating glazing unit (1) comprising at least one laminated glazing unit (3), the at least one laminated glazing unit (3) comprising two glass sheets (5a, 5b) between which is laminated an interlayer adhesive layer (6) of thickness e, in which the laminated glazing unit (3) has a thickness of between 3 and 6 mm, the value of the glass (5a, 5b) - interlayer adhesive layer (6) adhesion measured by the TCT method at 33 mm.s-1 and 20°C is between 4 kJ / m2 + 8 kJ / m3 xe(mm) and 14 kJ / m2 + 8 kJ / m3 xe(mm), and the interlayer adhesive layer (6) has a resistance to tear opening and propagation greater than 30 kJ / m2. Figure for abstract Figure 1.

Description

Title of the invention: Insulating glazing comprising laminated glazing with controlled internal adhesion and tear resistance

[0001] The present invention relates to the field of glazing, and relates more particularly to insulating glazing having improved impact resistance, i.e. having an increased capacity to completely absorb the kinetic energy of an object impacting the glazing, i.e. also to stop this object without it perforating the glazing, as well as good retention of glass shards, in order to avoid injuries to people.

[0002] Insulating glazing is typically composed of an assembly of several parallel glazings, separated by a cavity containing a layer of gas, often insulating gas.

[0003] In the field of construction in particular, in which these insulating glazings are widely used for reasons of acoustic insulation and thermal insulation, there is an increasing desire to increase their resistance to impacts / perforation, with the aim of giving them an anti-burglary / anti-vandalism character, of protecting people from broken glass and the risks resulting from a fall against the glazing, or even with the aim of guaranteeing resistance to violent weather (hail), in particular for insulating glazings for roof windows.

[0004] Although the impact / perforation resistance is better for insulating glazing than for single monolithic glazing, it appears, however, that insulating glazing composed solely of monolithic glazing does not have sufficient impact / perforation resistance to provide burglary / vandalism resistance or to protect people from broken glass and the risks resulting from falling against the glazing, or to guarantee resistance to violent weather.

[0005] Laminated glazing, consisting of two sheets of glass between which an interlayer adhesive layer is laminated, has good impact / perforation resistance in some cases.

[0006] In particular, there is a need for glazing with good thermal and acoustic insulation properties, which also ensure the safety of residents, while not being too thick and heavy to install. The inventors have focused on the design of insulating glazing that meets multiple requirements.

[0007] In accordance with a first requirement, the insulating glazing of the invention meets the maximum level of personal protection performance 1B1 of the EN 12600 standard, a level frequently required as for example in the French AFNOR Standard, NF DTU 39 - Building works - Glazing works - mirrors, 2017, which concerns glazing that guarantees people do not fall into a void. In the definition of the maximum performance level above, the first "1" of "1B1" corresponds to a drop height of 1.20 m from an impactor at which the glazing either did not break or broke safely with or without disintegration (disintegration after breakage being typical of toughened glass); the second "1" corresponds to a drop height of 1.20 m from an impactor at which the glazing either did not break or broke safely without disintegration, i.e. with very limited perforation and detachment of debris, according to EN 12600 paragraph 4.a). The letter "B" indicates breakage similar to that of a laminated glass, the letter "C" indicates breakage similar to that of toughened glass. There are levels with the letter "A" indicating breakage similar to that of annealed glass. In the EN 12600 standard there are lower levels “2B2”, “2C2”...for a drop height of 0.45 m from an impactor. The insulating glazing of the invention is designed to meet classification 1 of standard EN 12600 corresponding to a drop height of 1.20 m from an impactor. More generally, the ability of glazing to absorb shocks and stop an impactor without being perforated while retaining the glass shards must be precisely known and understood because this ability is critical for the safety of people and the security of property.

[0008] On the other hand, the EN 356 standard defines eight performance classes based on tests representing the ability of glazing to resist throwing objects (levels 1 to 5 or PI A to P5A of the EN 356 standard) or attempted break-ins using a sledgehammer or an axe (levels 6 to 8 or P6B to P8B of the EN 356 standard). The thicker the glass sheets of the laminated glazing, the better the EN 356 performance class. To increase the resistance of an insulating glazing unit, it may be advantageous for one of the glazing units to be a laminated glazing unit.Compliance with the P1A level, the least demanding of the EN 356 standard (protection against manual attack), is currently measured by a method known as the hard body drop test, which consists of successively dropping three steel balls of 10 cm diameter and a mass of 4.1 kg from a certain height onto the glass; the three balls are dropped in an equilateral triangle with sides of 13 cm centered on the glazing. To achieve the PI A level, three samples of a glass must each withstand three successive ball drops from a height of 1.5 m.

[0009] From a statistical point of view, it is very difficult to draw clear conclusions about a glass performance due to the limited number of samples (determination of a probability of failure at 1.5 m with only three samples).

[0010] A more robust method for evaluating the performance of laminated glass according to EN 356 has been developed by the Applicant Company and is the mean break height with three balls -MBH3-). This method consists of dropping three balls successively from a certain height onto a laminated glass sample. If the sample passes the test without being punctured by the three balls, then another laminated glass of the same type is tested, dropping the three balls from a greater height corresponding to the height of the previous test plus a fixed increment value. If the sample does not pass the test, then another laminated glass of the same type is tested, dropping the three balls from a lower height corresponding to the height of the previous test minus a fixed increment value.By repeating this test, we will converge and then naturally oscillate around the average perforation height of the glazing by three balls, in other words the height at which half of the samples are perforated and the other half are not, which makes it possible to precisely quantify the impact resistance of the laminated glass, i.e. its ability to stop an impactor without it perforating the glazing. We will preferably choose the starting height close to the average perforation height expected for the glazing tested, the fixed increment value (plus or minus) being preferably close to the standard deviation of the probability distribution examined by the test (probability of failure in the three-ball test as a function of the drop height of the balls). For a PI A performance test with laminated glazing, we will therefore choose a starting height of 2.1 m and an increment value of 0.3 m.A statistical treatment of this method shows that the mean perforation height and the associated standard deviation and the 95% confidence interval on the value of the mean perforation height can be defined and calculated (see Dixon W.J. Mood A., "A method for obtaining and analyzing sensitivity data", Journal of the American Statistical Association, 43, 1948). Once the mean perforation height and the associated standard deviation are obtained, it can then be estimated whether the difference between the mean perforation height and the target height (e.g. 1.5 m for P1A) is sufficiently large compared to the standard deviation of the distribution to ensure that the probability of failure at the target height is sufficiently low.For example, if the target height is 1.5 m, the mean perforation height is 2.1 m and the standard deviation is 0.3 m, this means that the difference of 0.6 m is twice the standard deviation, and the probability of failure at 1.5 m is then 2.3% for a normal (Gaussian) distribution. Thus, in accordance with a second requirement, the insulating glazing of the invention meets the P1A level of the EN 356 standard assessed by the three-ball mean perforation height method (MBH3).

[0011] In addition, the inventors have endeavored to design an insulating glazing unit comprising a laminated glazing unit with a thickness as close as possible to that of a standard monolithic insulating glazing unit, making it possible to replace this monolithic glass unit with this laminated glazing unit, without the need to replace the frame, the spacers or the seal of the insulating glazing, and / or one or more elements of its host structure (building bay... Such a thickness of monolithic glass of standard insulating glazing, in many targeted applications, is relatively thin, between 3 and 6 mm. For example, the aim is to replace one glass in a 24 mm thick double glazing with two 4 mm thick glasses separated by a 16 mm thick gas blade.

[0012] An insulating glazing meeting both requirements and the significant additional advantage described above has been obtained. The invention therefore relates to an insulating glazing unit comprising an assembly of parallel glazing units, two consecutive glazing units in the assembly being separated by a cavity containing a gas layer, said insulating glazing unit comprising at least one laminated glazing unit, the at least one laminated glazing unit comprising two sheets of glass between which is laminated an interlayer adhesive layer of thickness e, characterized in that the laminated glazing unit has a thickness of between 3 and 6 mm, the value of the glass - interlayer adhesive layer adhesion measured by the TCT method at 33 mm.s 1 and 20°C is between 4 kJ / m2 + 8 kJ / m3 xe(mm) and 14 kJ / m2 + 8 kJ / m3 xe(mm), and the interlayer adhesive layer has a resistance to opening and tear propagation greater than 30 kJ / m2.

[0013] The insulating glazing of the invention is in particular double glazing (one gas blade), or triple glazing (two gas blades).

[0014] The TCT method (acronym for Through-Cracked-Tensile (TCT) test) is a method for measuring the energy absorbed per unit area created between the crack lips of broken glass, a surface created due to delamination at the glass-interlayer interface and due to the deformation of the latter. This method is notably described in the document "Mechanical behavior in tension of cracked glass bridged by an elastomeric ligament", S. Muralidhar, A. Jagota, SJ Bennison, S. Saigal, Acta Materialia, Volume 48, numbers 18-19, December 1, 2000, pages 4577-4588, a document which also highlights the importance for energy dissipation (and therefore for the absorption of the kinetic energy of an object impacting the glazing) of these delamination mechanisms at the glass-interlayer interface and of deformation of the latter.The glass - interlayer adhesive layer adhesion value measured by the TCT method at 33 mm.s 1 and 20°C between 4 kJ / m2 + 8 kJ / m3 xe(mm) and 14 kJ / m2 + 8 kJ / m3 xe(mm) corresponds substantially, at the thickness values of the interlayer adhesive layer used, to values between 4 and 7 on the Pummel scale, not too low to guarantee good retention of the glass fragments, to prevent them from detaching, but not too high to allow delamination, . thus allowing substantial energy absorption during an impact, without the interlayer tearing. In this application, any reference to TCT tests also refers to the document “Adhesion rupture in laminated glass: influence of adhesion on the energy dissipation mechanisms”, P. Fourton, K. Piroird, M. Ciccotti and E. Barthel, Glass Structures & Engineering, vol. 5, pp. 397-410, 2020.

[0015] The tear opening and propagation resistance are measured as follows. Twenty 5 x 10 cm2 samples of interlayer are cut before lamination. Two slits are cut from two opposite edges in the middle of each sample, so as to separate the rectangle into two squares of 5 x 5 cm2 each. The separation is however incomplete, because there remains an intact ligament between the two cuts. Each sample has a different ligament length 1. All samples have the same thickness b (e.g. 0.76 mm). A tensile test is carried out at 20 °C and 100 mm / min until complete rupture on each sample. For each sample, the work W until rupture is measured. The diagram of W / 1b versus 1 is a straight line that is extrapolated for 1 = 0. The extrapolated value, in J / m2, is the intrinsic resistance of the interlayer to opening and tear propagation, independent of the geometry of the sample.A resistance to opening and tear propagation of at most 30 kJ / m2 is manifested by a failure in the pendulum test for interlayers whose glass - interlayer adhesive layer adhesion value measured by the TCT method at 33 mm.s 1 and 20 °C is between 4 kJ / m2 + 8 kJ / m3 xe(mm) and 14 kJ / m2 + 8 kJ / m3 xe(mm) and whose thickness is between 0.7 and 0.8 mm.

[0016] The invention is based on the fact that an insulating glazing unit, in particular of standard thickness, comprising a laminated glazing unit as thin as 3 to 6 mm thick, having both a glass-interlayer adhesive layer adhesion value and a resistance to opening and tear propagation of the interlayer adhesive layer described above, satisfy levels 1B1 of standard EN 12600 and P1A of standard EN 356.

[0017] Preferably, the laminated glazing has a thickness of between 3.5 and 4.5, preferably 3.8 and 4.2, and particularly preferably 3.9 and 4.1 mm, and the interlayer adhesive layer has a thickness e of between 0.4 and 1.9 mm.

[0018] Preferably, the insulating glazing consists of double glazing whose gas blade has a thickness of between 10 and 18 mm.

[0019] Preferably, the insulating glazing consists of double glazing with a thickness of between 18 and 26 mm.

[0020] Preferably, the two glass sheets have identical or different thicknesses of between 1.05 and 3.1 mm, are made of mineral glass such as float, soda-lime, aluminosilicate, borosilicate, possibly thermally toughened or chemically reinforced. The glass is colorless or tinted.

[0021] In this case, at least one of the two glass sheets advantageously carries at least one transparent functional layer or stack of layers such as obtained by magnetron-assisted cathode sputtering, by chemical vapor deposition (CVD), by liquid means such as sol-gel, consisting of a thermal control, anti-solar, low-emissivity, anti-reflective layer or stack, a surface tension modification layer, hydrophobic, hydrophilic, photocatalytic self-cleaning, an electrically conductive layer connected to a source of electric current, anti-frost, anti-fog heating.

[0022] Preferably, the interlayer adhesive layer is made of polyvinyl butyral (PVB), including acoustic trilayer (described in more detail in the examples below), and structural (relatively hard and poorly plasticized PVB, as marketed by Eastman Company under the reference DG 41, or by Kuraray Company under the reference Extra Stiff), ethylene-vinyl acetate (EVA), ionomer resin (as marketed by Kuraray Company under the registered trademark SentryGlas®), polyethylene terephthalate (PET), thermoplastic polyurethane (TPU), cast resin, alone or in combination of several of them, in particular in the form of a tough core layer (for example PET) between two softer skin layers (for example PVB).

[0023] The invention will be better understood in light of the following exemplary embodiments, and the appended drawings in which

[0024] [Fig.l] represents a sectional view of an insulating glazing unit according to the present invention; [Fig.2] represents a sequence of research and determination of the average perforation height with three balls (MBH3) of a laminated glazing unit described below, intended to be used in the constitution of an insulating glazing unit according to the invention.

[0025] With reference to [Fig.l], the insulating glazing 1 consists of an assembly of a monolithic glazing 2 and a laminated glazing 3 separated by a cavity 4 containing an insulating gas. The laminated glazing 3 consists of two monolithic glass sheets 5a, 5b separated by an interlayer adhesive layer 6.

[0026] Although [Fig.l] represents an insulating glazing unit consisting of a single monolithic glazing unit and a single laminated glazing unit, the invention is not limited in this respect, and the insulating glazing unit could contain more than one laminated glazing unit, more than two glazing units, whether laminated or monolithic, the laminated glazing unit(s) having any place in the assembly constituting the insulating glazing unit.

[0027] To constitute a laminated glazing intended to be used in the constitution of an insulating glazing according to the invention, laminated glazings are formed in Jumbo size (6 x 3.21 m2) by bonding two sheets of 1.6 mm thick glass marketed by the Saint-Gobain Glass Company under the registered trademark Planiclear® by means of a 0.76 mm thick layer of acoustic polyvinyl butyral (PVB) marketed by the Eastman Company under the reference QS 41, which is made up of a 0.12 mm thick core layer of more flexible (more plasticized) PVB between two surface layers of more rigid (hard) PVB (less plasticized).

[0028] Six samples of 1938 x 876 mm2 of this laminated glazing are tested at a drop height of 0.45 m (level 2B2 of the EN 12600 standard) and six other samples are tested at a drop height of 1.2 m (level 1B1, the highest of the EN 12600 standard): no sample is perforated by the impacts, all the samples pass the tests.

[0029] Ten 1100 x 900 mm2 samples of this laminated glazing are tested at a drop height of 1.5 m: none are perforated by the impacts, satisfying the PI A level of the EN 356 standard. Thirty-four other samples are tested according to a sequence of research and determination of the average perforation height with three balls (MBH3), as described previously, starting at a drop height of 2.1 m. The results are shown in [Fig.2]. On the abscissa are indicated the order numbers of the perforation tests with three balls, between 1 and 34. On the ordinate are indicated the drop heights of the three balls for each of the tests. The result is each time represented in the form of a disc in case of success (no perforation) or a cross in case of failure (perforation).If successful, the following test is carried out at a drop height of the three balls increased by the value of an increment (30 cm), if unsuccessful, at a height reduced by the value of the increment. The value of the average perforation height obtained is 2.83 + / - 0.32 m (95% confidence interval represented by the dashed line in [Fig.2]), which is not far from the performance of a thicker standard 22-2 laminated glazing (two 2.1 mm thick panes and a 0.76 mm thick interlayer - two thicknesses of 0.38 mm -): average perforation height of 2.92 m, average over 5 different batches of at least 30 panes each of 1100 x 900 mm2.

[0030] The measured value of the adhesion between the Planiclear® glass and the 0.76 mm thick layer of acoustic PVB, (measured by the TCT method at 33 mm.s 1 and 20°C) is 13.1 kJ / m2. For standard PVB, this measured value is between 12.1 and 16.6 kJ / m2 (minimum and maximum on 13 batches).

[0031] The measured value of resistance to opening and tear propagation of the 0.76 mm thick acoustic PVB layer is between 33 and 46 kJ / m2 (minimum and maximum over 4 batches). For standard PVB, it is between 35 and 60 kJ / m2 (minimum and maximum over 10 batches).

[0032] The acoustic performances of four double glazings of different compositions defined below, comprising a 4 mm thick monolithic glass, a 16 mm thick gas blade and a second glazing, are described by the values of Rw, Ra and Ratr, recorded in the following table.

[0033] [Tables 1] Double glazing composition Rw (dB) Ra (dB) Ratr (dB) 1 34 33 29 2 34 32 29 3 32 31 27 4 31 30 27

[0034] In these double glazing compositions, the second glazing consists of: - composition 1: two 2.1 mm glasses glued by a 0.76 mm layer of acoustic PVB described previously;

[0035] - composition 2: two 1.6 mm glasses glued by a 0.76 mm layer of PVB acoustic (i.e. the laminated glazing described above at the beginning of these examples); - composition 3: two 2.1 mm panes of glass bonded by a 0.76 mm layer of standard PVB; and - composition 4: 4 mm monolithic glass.

[0036] The table shows that double glazing compositions 1 to 4 are classified by decreasing acoustic performance. In particular, composition 2 using a 4 mm laminated glazing is better than composition 4 using a 4 mm monolithic glass, and even than composition 3 using a 5 mm laminate with standard PVB. Composition 1 is better than composition 2 from an acoustic point of view, but the thickness of the 5 mm laminate is unfavorable for integration into a standard 24 mm double glazing with two 4 mm glazings and a 16 mm gas gap.

[0037] The wind behavior of two double glazings of 0.96 x 1.56 m2 is compared, the first of composition 4 above (two 4 mm monolithic glasses) and the second of composition 2 above in accordance with the invention (one 4 mm monolithic glass and one 4 mm laminated glazing). The deflection of the double glazings is measured under an increasing wind load. It is found that the values calculated according to the EN 16612 standard never vary, for each of the two double glazings, by more than 10% of the actual values measured. On the other hand, the deflection of the double glazing with two monolithic glasses remains less than 10% lower than that of the double glazing of the invention comprising 4 mm laminated glazing.

[0038] On the other hand, the breakage limits of these two double glazings are tested. In a batch of 10 double glazings with two 4 mm monolithic glasses, none breaks below 4200 Pa (wind speed of 290 km / h). In a batch of 13 double glazings including a 4 mm laminated glass, none breaks below 2800 Pa (wind speed of 240 km / h). 4 of these 13 double glazings resisted a wind speed of 420 km / h without breaking. 3 of these double glazings including a 4 mm laminated glass were subjected to additional load cycles, consisting of: - 20 cycles between 0 and +4200 Pa (1.5 times the theoretical limit of 2800 Pa of the EN 16612 standard for this size and composition of glazing), and - 20 cycles between -4200 and 0 Pa, with a cycle period of 8 seconds. None of these three double glazing units broke.

[0039] Double glazings in accordance with the invention and comprising a laminated glazing different from that described previously in the examples, were tested: - a double glazing differing from that described previously only in that the two glasses of the laminate are of different thicknesses, 1.1 mm and 2.1 mm instead of 2 x 1.6 mm, and therefore bonded to each other by an acoustic PVB of 0.76 mm; - a double glazing with laminated glazing of thickness substantially equal to 4 mm, the interlayer adhesive layer of which, of a nature chosen from those described above, is of thickness between 0.4 and 1.9 mm (for example 2.86 + / - 0.1 mm of glass - for example 2 panes of 1.4 mm - and 1.14 + / - 0.03 mm of interlayer, 2.48 + / - 0.1 mm of glass - for example 2 panes of 1.2 mm - and 1.52 + / - 0.04 mm of interlayer, 2.1 + / - 0.1 mm of glass - for example 2 panes of 1.05 mm - and 1.9 + / - 0.05 mm of interlayer); it should be noted that three-layer acoustic PVBs of 0.5 - 0.6 mm thickness are marketed; - double glazing with laminated glazing of a thickness approximately equal to 5 mm, for example two 2.1 mm panes glued by a 0.76 mm spacer; - double glazing with laminated glass of a thickness approximately equal to 6 mm, for example a 3.1 mm pane and a 2.1 mm pane bonded by a 0.76 mm spacer.

[0040] All these glazings comply with the invention with regard to the values of glass-interlayer adhesive layer adhesion and resistance to opening and tear propagation of the interlayer adhesive layer. All these glazings satisfy levels IB 1 of standard EN 12600 and PI A of standard EN 356, and have good impact resistance properties.

Claims

Claims

1. Insulating glazing (1) comprising an assembly of parallel glazings, two consecutive glazings in the assembly being separated by a cavity enclosing a gas layer (4), said insulating glazing (1) comprising at least one laminated glazing (3), the at least one laminated glazing (3) comprising two sheets of glass (5a, 5b) between which is laminated an interlayer adhesive layer (6) of thickness e, characterized in that the laminated glazing (3) has a thickness of between 3 and 6 mm, the value of the glass (5a, 5b) - interlayer adhesive layer (6) adhesion measured by the TCT method at 33 mm.s 1 and 20°C is between 4 kJ / m2 + 8 kJ / m3 xe(mm) and 14 kJ / m2 + 8 kJ / m3 xe(mm), and the interlayer adhesive layer (6) has a resistance to opening and tear propagation greater than 30 kJ / m2, in that the laminated glazing (3) has a thickness between 3.5 and 4.5 mm, and the interlayer adhesive layer (6) has a thickness e between 0.4 and 1.9 mm.

2. Insulating glazing (1) according to claim 1, characterized in that the laminated glazing (3) has a thickness of between 3.8 and 4.2, preferably 3.9 and 4.1 mm.

3. Insulating glazing (1) according to one of the preceding claims, characterized in that it consists of double glazing whose gas blade (4) has a thickness of between 10 and 18 mm.

4. Insulating glazing (1) according to one of the preceding claims, characterized in that it consists of double glazing with a thickness of between 18 and 26 mm.

5. Insulating glazing (1) according to one of the preceding claims, characterized in that the two sheets of glass (5a, 5b) have identical or different thicknesses of between 1.05 and 3.1 mm, are made of mineral glass such as float, soda-lime, aluminosilicate, borosilicate, possibly thermally toughened or chemically reinforced.

6. Insulating glazing (1) according to claim 5, characterized in that at least one of the two glass sheets (5a, 5b) carries at least one transparent functional layer or stack of layers as obtained by magnetron-assisted cathode sputtering, by chemical vapor deposition (CVD), by liquid means such as sol-gel, consisting of a thermal control, anti-solar, low-emissivity, anti-reflective layer or stack, a surface tension modification, hydrophobic, hydrophilic, photocatalytic self-cleaning layer, an electrically conductive layer connected to an electric current source, anti-frost, anti-fog heating.

7. Insulating glazing (1) according to one of the preceding claims, characterized in that the interlayer adhesive layer (6) consists of polyvinyl butyral (PVB), including acoustic and structural trilayer, ethylene-vinyl acetate (EVA), ionomer resin, poly(ethylene terephthalate) (PET), thermoplastic polyurethane (TPU), cast resin, alone or in combination of several of them, in particular in the form of a tough core layer between two more flexible skin layers.

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