INTERLAYER FOR AN ACOUSTICALLY INSULATING GLAZING UNIT

Abstract

The present invention relates to a viscoelastic plastic interlayer (1) for a laminated glazing unit (2) having vibro-acoustic damping properties, the interlayer (1) comprising a vibro-acoustic damping layer (3), the damping layer (3) having a first thickness e1, the sum of the first thickness e1 and the second thickness e2 being greater than or equal to 0.82 mm and the ratio between the second thickness e2 and the first thickness e1 being greater than or equal to 5.05.

Description

Spacer for acoustically insulating glazing Field of invention

[0001] The present invention relates to a viscoelastic interlayer for glazing, in particular for glazing of a dwelling. The present invention also relates to a method for designing this glazing. State of the art

[0002] It is known to use laminated glazing to manufacture a window for a home, enabling both sound insulation of the home and the window to resist mechanical impacts, for example to prevent intrusions into the home. Document EP 0 842 767 describes, for example, such laminated glazing, comprising two sheets of glass joined by an interlayer having acoustic damping and / or low stiffness properties. However, the use of such an interlayer does not make it possible to obtain good performance both in terms of sound insulation and in terms of impact resistance.

[0003] To this end, it is known to increase the thickness of the interlayer so as to increase the acoustic performance and the resistance of the glazing to mechanical impacts. Document WO2020 / 152416 describes, for example, a glazing having an impact resistance of category P2A of the European standard EN 356. This impact resistance is permitted by increasing the thickness of the interlayer compared to known glazings, for a single-layer or multi-layer interlayer. However, in the case of a multi-layer interlayer, this document does not describe how to choose the thickness of each of the layers of the interlayer. In addition, this document does not describe the contributions of the different layers of an interlayer to acoustic insulation on the one hand and to resistance to mechanical impacts on the other hand.

[0004] An aim of the invention is to provide an interlayer for a glazing having a resistance at least equal to the resistance of a P2A type glazing of the EN 356 standard, the glazing having improved sound insulation properties with respect to the sound insulation properties of a glazing comprising a single-layer interlayer, while limiting the quantity of raw materials necessary to produce the interlayer.

[0005] This object is achieved, at least partially, within the scope of the present invention by means of a viscoelastic interlayer for laminated glazing having vibro-acoustic damping properties, the interlayer comprising:- a vibro-acoustic damping layer, the damping layer having a first thicknesse1, the vibro-acoustic damping layer being formed by a poly(vinyl butyral) (PVB) resin comprising a plasticizer, the mass content of plasticizer being strictly greater than 28.5%,- at least one skin layer, the skin layer or all of the skin layers having a second thicknesse2, the skin layer being formed by a poly(vinyl butyral) (PVB) resin comprising a plasticizer, the mass content of plasticizer being less than 28.5%,- the sum of the first thicknesse1 and the second thicknesse 2étant supérieure ou égale à 0,82 mm,- le rapport entre la deuxième épaisseure2et la première épaisseure1étant supérieur ou égal à 5,05.

[0006] The present invention is advantageously supplemented by the following characteristics, taken individually or in any of their technically possible combinations:

[0007] - the damping layer has a plasticizer mass rate of between 28.5% excluding and 40%,

[0008] - the skin layer has a mass rate of plasticizer between 17% and 28.5%,

[0009] - the interlayer comprises two layers of skin, the vibro-acoustic damping layer being arranged between the two layers of skin,

[0010] - the first thickness e1 is between 0.10 mm and 0.15 mm and preferably between 0.12 mm and 0.14 mm,

[0011] - the second thickness e2 is between 0.64 mm and 0.75 mm and preferably between 0.69 mm and 0.72 mm,

[0012] - the ratio between the second thickness e2 and the first thickness e1 is between 5.05 and 7.00, in particular between 5.05 and 6.00.

[0013] Another aspect of the invention is a laminated glazing having vibro-acoustic damping properties, comprising:- two sheets of glass, and- an interlayer according to one embodiment of the invention, the interlayer being arranged between the two sheets of glass.

[0014] The glazing advantageously has impact resistance greater than or equal to that of category P2A glazing according to European standard EN 356.

[0015] Each of the glass sheets advantageously has a thickness e v greater than 1.8 mm and in particular between 2.8 mm and 3.5 mm.

[0016] Each of the glass sheets advantageously has a thickness e vgreater than 3 mm and in particular between 2.8 mm and 3.5 mm, and - the sum of the first thickness and the second thickness 2est supérieure ou égale à 0,82 mm,- le rapport entre la deuxième épaisseure2et la première épaisseure1est compris entre 5,05 et 6.

[0017] Each of the glass sheets advantageously has a thickness e v between 1.8 mm and 2.8 mm exclusive, and- the sum of the first thicknesse1 and the second thicknesse 2est supérieure ou égale à 0,85 mm,- le rapport entre la deuxième épaisseure2et la première épaisseure1est compris entre 5,5 et 7.

[0018] Another aspect of the invention is a method for designing a glazing, the glazing being a glazing according to an embodiment of the invention, the glazing having a predetermined impact resistance, the method comprising the steps of: - determining the first thickness e1 of the vibro-acoustic damping layer, then - determining the second thickness e2 of the or all of the skin layers, from the first thickness e1 and from the predetermined impact resistance.

[0019] Advantageously, the predetermined impact resistance is chosen so that the glazing belongs to a predetermined category according to European standard EN 356, and in which the determination of the second thickness e2 is implemented from the predetermined category. Description of figures

[0020] Other characteristics, aims and advantages of the invention will emerge from the following description, which is purely illustrative and non-limiting, and which must be read in conjunction with the appended drawings in which:

[0021] - illustrates the acoustic insulation of different laminated glazings,

[0022] - illustrates the average perforation height with three balls of different laminated glazing,

[0023] - schematically illustrates a glazing in section according to an embodiment of the invention,

[0024] - illustrates a domain for the first thickness of a core layer and the second thickness of skin layers of an interlayer according to an embodiment of the invention,

[0025] - schematically illustrates a method of designing glazing according to one embodiment of the invention.

[0026] Throughout the figures, similar elements have identical references. Definitions

[0027] Measurement of impact resistance

[0028] Compliance with category P2A of the EN 356 standard is measured by a ball drop test (or 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 glazing. To achieve category P2A, three samples of a glazing unit must withstand three successive ball drops from a height of 3 m.

[0029] From a statistical point of view, it is very difficult to draw meaningful conclusions about the performance of the tested glazing due to the limited number of samples (determination of a probability of failure at 3 m with only three samples).

[0030] A more robust method for assessing glazing performance according to EN 356 has been developed by the applicant company. This method is the mean break height with three balls (MBH3). This method consists of dropping three balls successively from a certain height onto a glazing sample. If the sample passes the test without being punctured by all three balls, then another glazing 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 glazing 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, the average perforation height of the glazing by three balls is then converged and then oscillated around.This height corresponds to the height at which half of the samples are perforated and the other half are not. The starting height should preferably be close to the expected average perforation height for the glazing units tested, with the fixed increment value (plus or minus) preferably close to the standard deviation of a 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 P2A performance test with laminated glazing, a starting height of 3.6 m and an increment value of 0.3 m should therefore be chosen. A statistical treatment of this method shows that the average perforation height, as well as the associated standard deviation and the 95% confidence interval on the value of the average perforation height, can be defined and calculated (see Dixon WJ 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., 3 m for P2A level glazing) is large enough compared to the standard deviation of the distribution to ensure that the probability of failure at the target height is negligible. For example, if the target height is 3 m, the mean perforation height is 3.6 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 3 m is then 2.3% for a normal (Gaussian) distribution.

[0031] Poly(vinyl butyral) (PVB)

[0032] One layer of the interlayer is formed by a resin comprising poly(vinyl butyral) (PVB).

[0033] The professional knows the following two types of PVB: standard PVB and acoustic PVB.

[0034] Standard PVB is historically the first PVB used for interlayers. In this document, the term "standard PVB" means a resin comprising PVB and comprising a plasticizer, the mass content of the plasticizer in the resin being less than 28.5%, preferably between 17% and 28.5%, in particular between 26.5% and 28.5%. The mass-average molar mass of co-polyvinyl butyral-polyvinyl alcohol may be between 100 and 250 g / mol. For example, the commercial product designated "RB41" from the Eastman company is a single-layer interlayer of standard PVB.

[0035] In this document, the term “acoustic PVB” means a resin comprising PVB and comprising a plasticizer, the mass content of the plasticizer in the resin being between 28.5% exclusive and 50%, preferably between 28.5% exclusive and 40%, in particular between 28.5% exclusive and 30.5%. For example, the commercial product designated “QS41” from the Eastman company is an interlayer comprising a core layer formed by an acoustic PVB. Detailed description of the invention

[0036] Effect of the thickness of an acoustic core layer on an interlayer

[0037] With reference to, a glazing unit may comprise an interlayer and two sheets of glass, each sheet of glass having a thickness equal to 4 mm. The interlayer may be arranged between the two sheets of glass. The interlayer may have a core layer of acoustic PVB and two skin layers of standard PVB, the core layer being arranged between the two skin layers.

[0038] The inventors have discovered that a variation in the thickness of all the skin layers only marginally affects the sound insulation of a glazing unit comprising the interlayer. Curve (a) illustrates the variation in the sound insulation of a glazing unit with frequency, the glazing unit comprising a known interlayer, the interlayer comprising an acoustic PVB core layer having a thickness equal to 0.1 mm and two standard PVB skin layers, the total thicknesses of the skin layers being equal to 0.70 mm. Curve (b) illustrates the variation in the sound insulation of a glazing unit with frequency, the glazing unit comprising an interlayer, the interlayer comprising an acoustic PVB core layer having a thickness equal to 0.1 mm and two standard PVB skin layers, the total thicknesses of the skin layers being equal to 0.35 mm.Curve (c) illustrates the variation of the sound insulation of a glazing unit with frequency, the glazing unit comprising an interlayer, the interlayer comprising an acoustic PVB core layer having a thickness equal to 0.1 mm and two standard PVB skin layers, the total thicknesses of the skin layers being equal to 1.4 mm. Curve (d) illustrates the variation of the sound insulation of a glazing unit with frequency, the glazing unit comprising an interlayer, the interlayer comprising an acoustic PVB core layer having a thickness equal to 0.1 mm and two standard PVB skin layers, the total thicknesses of the skin layers being equal to 2.1 mm.Curve (e) illustrates the variation of the acoustic insulation of a glazing with frequency, the glazing comprising an interlayer, the interlayer comprising an acoustic PVB core layer having a thickness equal to 0.1 mm and two standard PVB skin layers, the total thickness of the skin layers being equal to 2.8 mm.

[0039] [Table 1] below describes the sound reduction indices calculated from the simulations illustrated by the. The indices are calculated following the NF EN ISO 717-1:2013-05 standard. The weighted sound reduction index is noted R W The weighted sound reduction index adapted to a spectrum linked to human activities and air traffic noise is noted R A The weighted sound reduction index adapted to a spectrum linked to road traffic is noted R A,tr . The indices are calculated for different total thicknesses of skin layers.

[0040] Total thickness of skin layers (mm)0.350.71.42.12.8Rw (dB)3737373738R A (dB)3636363737R A,Tr (dB)3434353535

[0041] Thus, the thickness of the core layer of the interlayer can be chosen independently of the other thicknesses, since the thickness of the other layers of the interlayer will only marginally affect the acoustic insulation of the glazing.

[0042] Effect of total interlayer thickness

[0043] With reference to the, the values ​​of the MBH3 test, described above, are measured for glazings comprising an interlayer. The glazing comprises two sheets of glass each having an equal thickness and an interlayer. In particular, curve (f) illustrates a glazing in which each sheet of glass has a thickness equal to 3 mm and curve (g) illustrates a glazing in which each sheet of glass has a thickness equal to 2 mm. The interlayer comprises a core layer having a thickness equal to 0.13 mm. The total thickness of the skin layers varies according to the glazings tested.

[0044] The inventors discovered that the value of the MBH3 test is linear with respect to the total thickness of the interlayer and in particular with respect to the total thickness of the skin layers for a constant core layer thickness, as illustrated by the. Thus, from the chart constructed in the, it is possible to predetermine a total minimum thickness of the interlayer, i.e. the sum of the thickness of the core layer and the thickness of all the skin layers, to exhibit impact resistance according to a predetermined category. Since the thickness of the core layer can be predetermined as seen previously, it is possible to calculate the minimum and sufficient thickness of all the skin layers for the glazing to exhibit impact resistance according to a predetermined category.

[0045] With reference to the, the thicknesses of the interlayer layers for a glazing meeting the criteria of category P2A of standard EN 356 are sought. To ensure that the glazing is not perforated by impacts, the difference between the height H and the value of the MBH3 test must be greater than several times the standard deviation of the heights tested in the MBH sequence, preferably greater than three times the standard deviation, which allows, for a Gaussian statistic, to ensure a failure rate of less than 0.15%. For the glazing illustrated by the, the standard deviation is approximately equal to 0.35 m for a total thickness of the interlayer equal to 0.76 mm. Curve (f) illustrates the MBH3 for a glazing in which each of the glass sheets has a thickness equal to 3 mm. Curve (g) illustrates the MBH3 for a glazing in which each of the glass sheets has a thickness equal to 2 mm.

[0046] Interleaf 1

[0047] With reference to the, one aspect of the invention is a viscoelastic interlayer 1 for a laminated glazing 2 having vibro-acoustic damping properties.

[0048] The interlayer 1 comprises a vibro-acoustic damping layer 3. The damping layer 3 has a first thickness e1. The vibro-acoustic damping layer 3 is formed by a poly(vinyl butyral) (PVB) resin comprising a plasticizer, the mass content of plasticizer being strictly greater than 28.5%. In particular, the damping layer 3 is made of acoustic PVB.

[0049] The interlayer 1 comprises at least one skin layer 4. The skin layer 4 or all of the skin layers 4 have a second thickness e2. The skin layer 4 is formed by a poly(vinyl butyral) (PVB) resin comprising a plasticizer. The mass content of plasticizer is less than 28.5%. In particular, the skin layer 4 is made of standard PVB.

[0050] The sum of the first thickness and the second thickness 2est supérieure ou égale à 0,82 mm. Dans le cas où l’intercalaire comprend uniquement une couche de cœur et une ou plusieurs couches de peau, l’épaisseur de l’intercalaireetotest supérieure ou égale à 0,82 mm. Le rapport entre la deuxième épaisseure2et la première épaisseure1est supérieur ou égal à 5,05. Ainsi, l’intercalaire est adapté à la fabrication d’un vitrage présentant des caractéristiques de résistance aux impacts répondant au moins à la catégorie P2A de la norme EN356, tout en limitant la quantité de matière employée pour fabriquer la couche de cœur, en gardant des caractéristiques d’isolement acoustique équivalentes aux vitrages connus et en limitant la quantité totale de matière employée pour fabriquer l’intercalaire. Notamment, cet effet est atteint pour un vitrage comprenant des feuilles de verre, chaque feuille de verre présentant une épaisseurevsupérieure à 3 mm, notamment comprise entre 3 mm et 3, 5 mm. En particulier, l’épaisseuretotest choisie de sorte que la différence entre une hauteur de perforation moyenne avec trois billes supérieure ou égale à 3 m (MBH3) et 3 m est supérieure à trois fois l’écart type de la distribution des hauteurs. Ainsi, la probabilité d’une rupture de vitrage entraînée par un impact est approximativement nulle. La valeur d’un tel écart type est d’environ 0,35 m, ce qui permet de calculer la condition prédéfinie sur l’épaisseuretot.

[0051] Illustrates the domain (including peas in the) in which the first thickness e1 and the second thickness e2 can be chosen.

[0052] The interlayer 1 may comprise two skin layers 4. The vibro-acoustic damping layer 3 may be arranged between the two skin layers 4. Thus, it is possible to limit the first thickness e1 so as to respect the relationship defined above relating to the ratio between the first thickness e1 and the second thickness e2, while facilitating the manufacture of the interlayer (by preventing a PVB roll from sticking to itself). Alternatively, the interlayer 1 may comprise two layers, including a core layer and a skin layer. Alternatively, the interlayer 1 may comprise a core layer and at least three skin layers. Skin layers may be superimposed so as to choose the second thickness from several films for the manufacture of the skin layer having the same thickness.

[0053] The first thickness e1 may be between 0.10 mm and 0.15 mm and preferably between 0.12 mm and 0.14 mm. Thus, the sound insulation of the glazing 1 can be maximized while limiting the amount of material used to manufacture the core layer. Indeed, as illustrated by the, an increase in the second thickness e2 has only a negligible impact with regard to the sound insulation of the glazing.

[0054] The second thickness e2 may be greater than 0.64 mm, in particular between 0.64 mm and 0.75 mm, and preferably between 0.69 mm and 0.72 mm. The ratio between the second thickness e2 and the first thickness e1 may be between 5.05 and 7.00, in particular between 5.05 and 6.00. Thus, the interlayer is suitable for manufacturing a glazing 1 having mechanical impact resistance properties at least equal to a glazing of category P2A of standard EN 356, while making it possible to reduce, for equal interlayer thickness, the thickness of the core layer.

[0055] Glazing 2

[0056] With reference to the, another aspect of the invention is laminated glazing 2 having vibro-acoustic damping properties. The glazing 2 comprises two glass sheets 5 and an interlayer 1. The interlayer 1 is arranged between the two glass sheets 5.

[0057] Class 2 glazing can have an impact resistance greater than or equal to that of category P2A glazing according to European standard EN 356. In other words, class 2 glazing can have an average perforation height with three balls greater than or equal to 3 m. Thus, class 2 glazing can delay or prevent unwanted intrusion into a home.

[0058] Each glass sheet may be a monolithic glass sheet. The monolithic glass sheet may be formed from at least one material selected from a structural polymer, preferably poly(methyl methacrylate), polycarbonate, structural polyurethane, soda-lime glass, aluminosilicate glass, borosilicate glass. The glass sheet may be thermally toughened or chemically toughened.

[0059] Each sheet of glass 5 can have a thickness vgreater than 1.8 mm and in particular between 1.8 mm and 2.8 mm excluded. Thus, by choosing the thickness range of a predefined glass sheet, and in particular for a sum of the first thicknesse1 and the second thicknesse 2supérieure ou égale à 0,85 mm, et un rapport entre la deuxième épaisseure2et la première épaisseure1compris entre 5,05 et 7,00.le vitrage 2 présente des propriétés de résistance au moins égales à celle d’un vitrage de la catégorie P2A de la norme EN 356, tout en limitant l’épaisseur de la feuille de verre utilisée au regard de vitrages connus présentant la même résistance.

[0060] Each sheet of glass 5 can have a thickness v greater than 2.8 mm and in particular between 2.8 mm and 3.5 mm excluded. Thus, by choosing the thickness range of a predefined glass sheet, and in particular for a sum of the first thicknesse1 and the second thicknesse 2supérieure ou égale à 0,82 mm, et un rapport entre la deuxième épaisseure2et la première épaisseure1compris entre 5,05 et 6,00.le vitrage 2 présente des propriétés de résistance au moins égales à celle d’un vitrage de la catégorie P2A de la norme EN 356, tout en limitant l’épaisseur de la feuille de verre utilisée au regard de vitrages connus présentant la même résistance.

[0061] Glazing design process 2

[0062] With reference to the, another aspect of the invention is a method 6 for designing a glazing 2. The glazing 2 has a predetermined impact resistance. It is for example possible to choose an impact resistance according to a category of the EN 356 standard. It is also possible to choose an impact resistance by predetermining an average perforation height with three balls, according to the aforementioned method.

[0063] The method 6 comprises a step 61 of determining the first thickness e1 of the vibro-acoustic damping layer. The method 6 comprises a subsequent step 62 of determining the second thickness e2 of the or all of the skin layers, from the first thickness e1 and from the predetermined impact resistance.

[0064] When implementing the method 6, the predetermined impact resistance can be chosen so that the glazing 2 belongs to a predetermined category according to the European standard EN 356. The determination of the second thickness e2 can be implemented from the predetermined category. Thus, it is not necessary to determine the first thickness e1 with regard to the desired mechanical resistance properties of the glazing 2, which makes it possible to simplify its design.

Claims

Viscoelastic interlayer for laminated glazing having vibro-acoustic damping properties, the interlayer comprising:- a vibro-acoustic damping layer, the damping layer having a first thicknesse1, the vibro-acoustic damping layer being formed by a poly(vinyl butyral) (PVB) resin comprising a plasticizer, the mass content of plasticizer being strictly greater than 28.5%,- at least one skin layer, the skin layer or all of the skin layers having a second thicknesse2, the skin layer being formed by a poly(vinyl butyral) (PVB) resin comprising a plasticizer, the mass content of plasticizer being less than 28.5%,- the sum of the first thicknesse1 and the second thicknesse 2étant supérieure ou égale à 0,82 mm,- le rapport entre la deuxième épaisseure2et la première épaisseure1étant supérieur ou égal à 5,05. Interlayer (1) according to the preceding claim, in which the damping layer (3) has a mass content of plasticizer of between 28.5% exclusive and 40%. Interlayer (1) according to claim 1 or 2, in which the skin layer (4) has a mass content of plasticizer of between 17% and 28.5%, Interlayer (1) according to one of the preceding claims, the interlayer (1) comprising two skin layers (4), the vibro-acoustic damping layer (3) being arranged between the two skin layers (4). Interlayer (1) according to one of the preceding claims, in which the first thickness e1 is between 0.10 mm and 0.15 mm, preferably between 0.12 mm and 0.14 mm. Interlayer (1) according to one of the preceding claims, in which the second thickness e2 is between 0.64 mm and 0.75 mm, preferably between 0.69 mm and 0.72 mm. Interlayer (1) according to one of the preceding claims, in which the ratio between the second thickness e2 and the first thickness e1 is between 5.05 and 7.

00. Laminated glazing (2) having vibro-acoustic damping properties, comprising:- two sheets of glass (5), and- an interlayer (1) according to one of the preceding claims, the interlayer (1) being arranged between the two sheets of glass (5). Glazing (2) according to the preceding claim, having an impact resistance greater than or equal to that of category P2A glazing according to European standard EN 356. Glazing (2) according to claim 8 or 9, in which each of the glass sheets (5) has a thickness v greater than 1.8 mm. Glazing (2) according to claim 10, in which each of the glass sheets has a thickness e v greater than 3 mm, and in which: - the sum of the first thickness and the second thickness 2est supérieure ou égale à 0,82 mm,- le rapport entre la deuxième épaisseure2et la première épaisseure1est compris entre 5,05 et 6. Glazing (2) according to claim 10, in which each of the glass sheets has a thickness e vbetween 1.8 mm and 2.8 mm exclusive, and in which: - the sum of the first thickness and the second thickness 2est supérieure ou égale à 0,85 mm,- le rapport entre la deuxième épaisseure2et la première épaisseure1est compris entre 5,5 et 7. Method (6) for designing a glazing (2), the glazing (2) being in accordance with a glazing as defined in one of claims 8 to 10, the glazing (2) having a predetermined impact resistance, the method comprising steps of: - determining (61) the first thickness e1 of the vibro-acoustic damping layer, then - determining (62) the second thickness e2 of the or all of the skin layers, from the first thickness e1 and from the predetermined impact resistance. Method (6) for designing a glazing (2) according to the preceding claim, in which the predetermined impact resistance is chosen so that the glazing (2) belongs to a predetermined category according to the European standard EN 356, and in which the determination of the second thickness e2 is implemented from the predetermined category.