Laminated glazing with improved sound insulation properties

Abstract

A laminated glazing having improved sound or acoustic properties is disclosed. The laminated glazing includes two rigid substrates and a multilayer polymer interlayer, the laminated glazing having an improved sound or acoustic properties per glazing area (1 / m2) measured directly on the laminated glazing. 2 ) has a damping loss factor (η) of at least 0.0450.

Description

[Technical Field]

[0001]

[0001] This disclosure relates to the field of polymer interlayers for double-glazed panels and double-glazed panels having at least one polymer interlayer sheet. More specifically, this disclosure relates to the field of double-glazed panels comprising a polymer interlayer having improved acoustic properties, such as improved attenuation, when measured on a windshield glass. [Background technology]

[0002]

[0002] A multi-layer panel is generally a panel consisting of two sheets of a substrate (for example, but not limited to, glass, polyester, polyacrylate, or polycarbonate) and one or more polymer interlayers sandwiched between them. Multi-layer glass panels are commonly used in architectural window applications, in automotive and aircraft windows, and in photovoltaic solar panels. The first two applications are generally referred to as laminated safety glass. The main function of the interlayer in laminated safety glass is to absorb energy from impacts or forces applied to the glass, to maintain the bonded layers of glass even when force is applied and the glass breaks, and to prevent the glass from breaking into sharp shards. In addition, the interlayer can provide the glass with a higher sound insulation rating, reduce the transmission of UV and / or IR light, and enhance the aesthetic appeal of the associated window. With respect to solar cell applications, the main function of the interlayer is to enclose the photovoltaic panel used to generate and supply electricity in commercial and residential applications.

[0003]

[0003] To achieve certain properties and performance characteristics of glass panels, it has become common practice to utilize multilayer or multilayer interlayers. In this specification, the terms “multilayer” and “multilayer” mean interlayers having two or more layers, and multilayer and multilayer may be used interchangeably. Multilayer interlayers typically contain at least one soft layer and at least one hard layer. Interlayers having one soft “core” layer sandwiched between two more rigid or harder “skin” layers have been designed with sound insulation properties of glass panels in mind. Interlayers having the opposite configuration, i.e., one hard layer sandwiched between two softer layers, have been shown to improve the impact performance of glass panels and can also be designed with sound insulation in mind. Other examples of multilayer interlayers include those having at least one "transparent" or uncolored layer, at least one colored layer or at least one conventional layer, such as a non-acoustic layer, and at least one acoustic layer (i.e., a layer having acoustic properties, or the ability to provide sound insulation or reduce sound transmission, as further defined below). Another example of a multilayer interlayer is one having at least two layers having various colors for aesthetic appeal. The colored layer typically contains a pigment or dye or some combination of pigments and dyes.

[0004]

[0004] Interlayers are generally produced by mixing a polymer resin, such as poly(vinyl butyral), with one or more plasticizers and melting the mixture into a sheet by any applicable process or method known to those skilled in the art, for example, by extrusion molding, but not limited to these methods. Multilayer interlayers can be produced by processes such as co-extrusion molding or lamination, and the layers are combined together to form a single structure. Optionally, other additional components may be added for a variety of other purposes. After being formed, the interlayer sheets are typically assembled and rolled up for transport and storage and for later use in multilayer glass panels, as described below.

[0005]

[0005] A brief description follows of how a multilayer glass panel is generally manufactured in combination with an interlayer. First, at least one polymer interlayer sheet (single or multilayer) is placed between two substrates, and any excess interlayer is trimmed from the edges to create an assembly. It is not uncommon to place multiple polymer interlayer sheets or polymer interlayer sheets with multiple layers (or a combination of both) within two substrates to create a multilayer glass panel with multiple polymer interlayers. Next, air is removed from the assembly by applicable processes or methods known to those skilled in the art, for example, via a nip roller, vacuum bag or other degassing mechanism. In addition, the interlayer is partially pressed onto the substrate by any method known to those skilled in the art. In the final step, to form a final integral structure, this pre-bonding is made more permanent by high-temperature, high-pressure lamination or any other method known to those skilled in the art, for example, by autoclave, but not limited to.

[0006]

[0006] Multilayer interlayers, such as a three-layer interlayer having a soft core layer and two harder skin layers, are commercially available. The hard skin layers provide handling, processability, and mechanical strength of the interlayer; the soft core layers provide acoustic attenuation properties.

[0007]

[0007] The windshield and side laminates occupy a large portion of the vehicle's cabin area and are the main pathways for external noise (e.g., wind noise, traffic noise, tire noise, engine noise) entering the vehicle's cabin. Therefore, the vibration damping characteristics of the windshield and side laminates are important for the vehicle's cabin noise level. By having highly vibration-damping windshields and side laminates, external noise or sound can be absorbed more effectively, keeping the cabin quieter.

[0008]

[0008] There is a need to maximize the attenuation of windshield glass while meeting the industrial safety requirements for windshield glass applications. The present invention discloses an interlayer that, when measured directly on the windshield glass, provides the maximum attenuation loss coefficient necessary to provide a safe windshield glass, and also meets the required impact resistance.

[0009]

[0009] In short, it is common to use multilayer interlayers to provide high-performance laminates. In this field, there is a need to develop multilayer interlayers that have desirable good optical, mechanical, and acoustic properties. More specifically, in this field, there is a need to develop multilayer interlayers that have good acoustic properties, such as the damping loss coefficient, when measured directly on windshield glass. [Overview of the project] [Means for solving the problem]

[0010]

[0010] Because of these and other problems in the art, in particular, what is described herein is: a laminated glazing comprising a first rigid substrate; a multilayer polymer interlayer; and a second rigid substrate; the multilayer polymer interlayer comprising: a first poly(vinyl acetal) resin having a first residual hydroxyl content and a first residual acetate content, and a first plasticizer, with a glass transition temperature (T) higher than 26°C. g A first layer having ) a second poly(vinyl acetal) resin having a second residual hydroxyl content and a second plasticizer comprising a glass transition temperature (T) of less than 20°C. g A second layer having ) and a third poly(vinyl acetal) resin having a third residual hydroxyl content and a third plasticizer, comprising a glass transition temperature (T) higher than 26°C. g The laminated glazing includes a third layer having ), the second layer is located between the first and third layers, and when measured according to procedure 1, the laminated glazing has a glazing area per glazing area (1 / m²) measured directly in the laminated glazing. 2The laminated glazing has a damping loss coefficient (η) of at least 0.0450 (0.0500, 0.0550, 0.0600, 0.0650, 0.0700, 0.0750, 0.0800, 0.0850).

[0011]

[0011] In one embodiment, the windshield glass comprises: a first glass substrate; a multilayer polymer interlayer; and a second rigid substrate; the multilayer polymer interlayer comprises a first poly(vinyl acetal) resin having a first residual hydroxyl content and a first residual acetate content, and a first plasticizer, and has a glass transition temperature (T) higher than 26°C. g A first layer having ) a second poly(vinyl acetal) resin having a second residual hydroxyl content and a second plasticizer comprising a glass transition temperature (T) of less than 20°C. g A second layer having ); a third poly(vinyl acetal) resin having a third residual hydroxyl content and a third plasticizer, comprising a glass transition temperature (T) higher than 26°C. g The windshield includes a third layer having ), the second layer is located between the first and third layers, and when measured according to procedure 1, the windshield has a windshield area (1 / m²) measured directly on the windshield. 2 The damping loss coefficient (η) of the ) is at least 0.0450 (0.0500, 0.0550, 0.0600, 0.0650, 0.0700, 0.0750, 0.0800, 0.0850).

[0012]

[0012] In this embodiment, the first poly(vinyl acetal) resin and the third poly(vinyl acetal) resin are the same. In this embodiment, the first plasticizer and the third plasticizer are the same. In another embodiment, the second plasticizer is the same as at least one of the first plasticizer or the third plasticizer.

[0013]

[0013] In the embodiment, the difference between the first residual hydroxyl content and the second residual hydroxyl content is at least 2.0 (2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0) weight percent.

[0014]

[0014] In an embodiment, the multilayer intermediate film is a tapered intermediate film. In an embodiment, one type of layer of the multilayer intermediate film has a tapered outer shape, and in other embodiments, all layers of the multilayer intermediate film have a tapered outer shape.

[0015]

[0015] In an embodiment, the intermediate film has a gradient color band. In an embodiment, the intermediate film contains an IR absorber in at least one type of layer.

[0016]

[0016] In an embodiment, the intermediate film further includes a non-poly(vinyl acetal) layer.

[0017]

[0017] In an embodiment, the intermediate film has a MIM loss factor (LF) at 20 °C measured by ISO16940 of at least 0.29 (0.30, 0.31, 0.32, 0.33, 0.34).

[0018]

[0018] A method for producing a polymer intermediate film as disclosed herein is also disclosed.

[0019]

[0019] In an embodiment, the laminated glazing is a vehicle windshield, side lite, sunroof or other window. In an embodiment, the laminated glazing is used in head-up display applications.

[0020]

[0020] In certain embodiments, the rigid substrate (or substrate) is glass.

Brief Description of the Drawings

[0021] [Figure 1]

[0021] It is a figure which shows an example of the vibration response curve with respect to the excitation for measuring the windshield damping loss factor (η) in a 1st vibration mode. [Figure 2]

[0022] It is a graph showing the attenuation loss coefficient (η) of the windshield glass compared with the laboratory MIM loss coefficient (LF) for the windshield glass 2. [Figure 3]

[0023] It is a graph showing the attenuation loss coefficient (η) of the windshield glass compared with the laboratory MIM loss coefficient (LF) for the windshield glass 1. [Figure 4]

[0024] It is a graph showing the attenuation loss coefficient (η) per unit area (1 / m2) of the windshield glass compared with the laboratory MIM loss coefficient (LF) for both windshield glasses.

Mode for Carrying Out the Invention

[0022]

[0025] In particular, what is described in this specification is a laminated glazing composed of a first rigid substrate, a second rigid substrate, and a multilayer polymer interlayer. The laminated glazing of the present disclosure has improved acoustic or sound insulation properties when measured by the attenuation loss coefficient. The laminated glazing of the present invention has an attenuation loss coefficient (η) per unit area (1 / m 2 ) of the laminated glazing directly measured of at least 0.0450 (0.0500, 0.0550, 0.0600, 0.0650, 0.0700, 0.0750, 0.0800, 0.0850).

[0023]

[0026] A multilayer glass panel including an interlayer is also described. The multilayer interlayer of the present invention can be used for safety glass in multilayer glass panel applications, for example, in windshield glass, side windows, sunroofs, and roofs and windows of buildings among several applications.

[0024]

[0027] Each layer of a multilayer polymer interlayer can be made by mixing one or more polymer resins, such as poly(vinyl acetal) resin (e.g., PVB), and one or more plasticizers. Multilayer interlayers generally contain two or more layers and two or more resins of various compositions. For example, poly(vinyl acetal) resins with various residual hydroxyl content and / or various residual acetate content, such as PVB resins, are suitable for layers in a multilayer interlayer composition. In a multilayer containing two layers, at least one of the two layers is a soft layer and the other layer is a hard layer. In this specification, a “soft layer” or “softer layer” is a layer having a glass transition temperature of less than about 20°C. In this specification, a “hard layer” or “harder layer” generally refers to a layer that is harder or more rigid than another layer and generally has a glass transition temperature at least 2°C higher than another layer (e.g., a softer layer).

[0025]

[0028] The multilayer interlayer formed from the composition contains two or more glass transitions, the lowest glass transition occurring at a temperature below 20°C, or below 15°C, or below 10°C, or below 5°C, or below 0°C, or below -5°C, or below -10°C.

[0026]

[0029] Conventional multilayer interlayers, such as three-layer acoustic interlayers, consist of a flexible core layer composed of a single poly(vinyl butyral) ("PVB") resin with a low residual hydroxyl content and a high amount of conventional plasticizer, and two rigid skin layers with significantly higher residual hydroxyl content (see, for example, U.S. Patents 5,340,654, 5,190,826, and 7,510,771). The residual hydroxyl content and amount of plasticizer in the PVB core resin are optimized so that the interlayer provides optimal sound insulation properties under ambient conditions for double-glazed panels such as windshields and windows installed in vehicles and buildings.

[0027]

[0030] Multilayer acoustic interlayers, such as three-layer interlayers, can be designed and manufactured by (1) selecting a plasticizer or a mixture of plasticizers, (2) selecting resins for the skin layer(s) and core layer(s), (3) maintaining plasticizer equilibrium between the core layer(s) and skin layer(s) (for example, by selecting resins having specific properties), and (4) combining the core layer(s) and skin layer(s) by applicable methods such as co-extrusion or lamination to form the multilayer interlayer. The resulting multilayer acoustic interlayer provides excellent transparency and sound insulation without sacrificing other preferred and desirable features of conventional multilayer interlayers, such as the optical properties and mechanical strength of glass panels made from multilayer acoustic interlayers.

[0028]

[0031] This section explains some technical terms and common components found in both general interlayers and the interlayers of this disclosure, as well as in their formation. The terms “polymer interlayer sheet,” “interlayer,” and “polymer melt sheet” as used herein may generally specify a monolayer sheet or a multilayer interlayer. A “monolayer sheet,” as its name implies, is a single polymer layer extruded as a single layer. A multilayer interlayer, on the other hand, may include multiple layers, such as separately extruded layers, co-extruded layers, or any combination of separately extruded and co-extruded layers. Thus, a multilayer interlayer may include, for example: two or more monolayer sheets combined together ("multilayer sheet"); two or more layers co-extruded together ("co-extruded sheet"); two or more co-extruded sheets combined together; a combination of at least one monolayer sheet and at least one co-extruded sheet; a combination of a monolayer sheet and a multilayer sheet; and a combination of at least one multilayer sheet and at least one co-extruded sheet. In various embodiments of this disclosure, a multilayer interlayer comprises at least two polymer layers (e.g., single-layer or co-extruded multilayers and / or jointly laminated multilayers) arranged in direct contact with each other, each layer comprising a polymer resin as further detailed below. In this specification, for a multilayer interlayer having at least three layers, “skin layer” generally refers to the outer layer of the interlayer, and “core layer” generally refers to the inner layer(s). Thus, one exemplary embodiment is skin layer / / core layer / / skin layer. In a multilayer interlayer having a skin layer / / core layer / / skin layer configuration, in some embodiments the skin layer may be more rigid and the core layer may be more flexible, and in other embodiments the skin layer may be more flexible and the core layer may be more rigid.

[0029]

[0032] Poly(vinyl acetal) resins are produced by known acetalization methods, which involve reacting polyvinyl alcohol ("PVOH") with one or more aldehydes, such as butyraldehyde, in the presence of an acid catalyst, followed by separation, stabilization, and drying of the resin. Such acetalization methods are disclosed, for example, in U.S. Patent Nos. 2,282057 and 2,282026, and in Wade, B. 2016, Vinyl Acetal Polymers, Encyclopedia of Polymer Science and Technology, pp. 1-22 (online, copyright 2016 John Wiley & Sons, Inc.), the entirety of which is incorporated herein by reference. The resins are commercially available in various forms, for example, as Butvar® resin by Solutia Inc., a wholly owned subsidiary of Eastman Chemical.

[0030]

[0033] In this specification, the residual hydroxyl content of poly(vinyl acetal) resin (calculated as % by weight of vinyl alcohol or % by weight of PVOH) refers to the amount of hydroxyl groups remaining in the polymer chain after processing is complete. For example, PVB can be produced by hydrolyzing poly(vinyl acetate) to polyvinyl alcohol (PVOH), and then reacting the PVOH with butyraldehyde. In the hydrolysis of polyvinyl acetate, typically not all acetate side groups are converted to hydroxyl groups. Furthermore, the reaction with butyraldehyde typically does not convert all hydroxyl groups to acetal groups. As a result, in any finished PVB resin, typically, residual acetate groups (as vinyl acetate groups) and residual hydroxyl groups (as vinyl hydroxyl groups) are present as side groups in the polymer chain. In this specification, the residual acetate content (calculated as % vinyl acetate content in poly(vinyl acetal) or % by weight of poly(vinyl acetate) (PVAc)) refers to the amount of residual groups remaining in the polymer chain. In this specification, the residual hydroxyl content and residual acetate content are measured in weight percent (wt.%) according to ASTM D1396.

[0031]

[0034] In one embodiment, when the multilayer interlayer of the present invention consists of three layers, the core layer is a soft layer and the skin layer is a hard layer. In another embodiment, the core layer is hard and the skin layer is softer. Other combinations and other numbers of layers are also possible.

[0032]

[0035] In various embodiments, when the interlayer is a multilayer interlayer such as a three-layer interlayer, the soft (or core) layer contains a poly(vinyl acetal) resin (or first resin) containing approximately 7 to approximately 16 wt.%, approximately 7 to approximately 14 wt.%, approximately 9 to approximately 14 wt.%, or approximately 8.5 to approximately 12 wt.% of hydroxyl groups calculated as PVOH%, or, in a particular embodiment, a poly(vinyl acetal) resin (or first resin) containing approximately 11 to approximately 13 wt.% of hydroxyl groups calculated as PVOH%, but other amounts are also possible. The resin may also contain less than 30 wt.% of residual acetate groups calculated as poly(vinyl acetate), less than 25 wt.% of residual acetate groups, less than 20 wt.% of residual acetate groups, less than 15 wt.% of residual acetate groups, less than 13 wt.% of residual acetate groups, less than 10 wt.% of residual acetate groups, less than 7 wt.% of residual acetate groups, less than 5 wt.% of residual acetate groups, or less than 1 wt.% of residual acetate groups, or less than 0.5 wt.% of residual acetate groups, or less than 30 wt.% of residual acetate groups, 1 to 3 The content may be in the range of 0 wt.%, 2-25 wt.%, 5-20 wt.%, or 7-15 wt.%, with the remainder being an acetal, such as butyraldehyde (which contains an isobutyraldehyde acetal group), but optionally another acetal group, such as a 2-ethylhexanal acetal group, or a mixture of a butyraldehyde acetal group and a 2-ethylhexanal acetal group.

[0033]

[0036] In various embodiments, when the interlayer is a multilayer interlayer such as a three-layer interlayer, the hard (or skin) layer(s) The resin comprises a poly(vinyl acetal) resin having wt.%, at least 16 wt.%, at least 17 wt.%, at least 18 wt.%, at least 19 wt.%, or at least 20 wt.%, or more residual hydroxyls, wherein the resin in the skin layer contains about 15 to about 35 wt.%, about 15 to about 30 wt.%, or about 17 to about 22 wt.%, of residual hydroxyl groups calculated as PVOH%; for certain embodiments, it may contain about 17.25 to about 22.25 wt.%, but other amounts are possible depending on the desired properties.

[0034]

[0037] This difference between poly(vinyl acetal) resins is calculated by subtracting the residual hydroxyl content of the resin with the lower residual hydroxyl content from the residual hydroxyl content of the resin with the higher residual hydroxyl content. In this specification, the terms “weight percentage difference” or “the difference is at least ……… weight percent” refer to the difference between two given weight percentages, calculated by subtracting one number from the other. For example, a poly(vinyl acetal) resin with a residual hydroxyl content of 12 weight percent has a residual hydroxyl content less than 2 weight percent lower than a poly(vinyl acetal) resin with a residual hydroxyl content of 14 weight percent (14 weight percent - 12 weight percent = 2 weight percent). In this specification, the term “various” can refer to a value higher or lower than another value. One or more other poly(vinyl acetal) layers may also be present in the interlayer and may have residual hydroxyl within the ranges indicated above. In addition, the residual hydroxyl content of one or more other poly(vinyl acetal) resins may be the same as or different from the residual hydroxyl content of the first poly(vinyl acetal) resin and / or the second poly(vinyl acetal) resin.

[0035]

[0038] In various embodiments, the poly(vinyl acetal) resin for the soft layer or the poly(vinyl acetal) resin for the hard layer(s) may contain less than 30 wt.% of residual acetate groups calculated as poly(vinyl acetate), less than 25 wt.% of residual acetate groups, less than 20 wt.% of residual acetate groups, less than 15 wt.% of residual acetate groups, less than 13 wt.% of residual acetate groups, less than 10 wt.% of residual acetate groups, less than 7 wt.% of residual acetate groups, less than 5 wt.% of residual acetate groups, or less than 1 wt.% of residual acetate groups, the remainder being acetal, such as butyraldehyde (which includes isobutyraldehyde acetal groups), but optionally, as described above, another acetal group, such as 2-ethylhexanal acetal groups, or a mixture of butyraldehyde acetal groups and 2-ethylhexanal acetal groups.

[0036]

[0039] In some embodiments, the first poly(vinyl acetal) resin and the second poly(vinyl acetal) resin can have varying residual acetate content. For example, in some embodiments, the difference between the residual acetate content of the first poly(vinyl acetal) resin and the residual acetate content of the second poly(vinyl acetal) resin can be at least about 2 weight percent, at least about 3 weight percent, at least about 4 weight percent, at least about 5 weight percent, at least about 6 weight percent, at least about 7 weight percent, at least about 8 weight percent, at least about 9 weight percent, at least about 10 weight percent, at least about 12 weight percent, at least about 14 weight percent, at least about 16 weight percent, at least about 18 weight percent, at least about 20 weight percent, at least about 24 weight percent, or at least 29 weight percent. One of the poly(vinyl acetal) resins can have a residual acetate content of about 4 weight percent or less, about 3 weight percent or less, about 2 weight percent or less, or about 1 weight percent or less, when measured as described above. In some embodiments, one of the first poly(vinyl acetal) resin and the second poly(vinyl acetal) resin may have a residual acetate content of at least 4 weight percent, at least about 5 weight percent, at least about 6 weight percent, at least about 7 weight percent, about 8 weight percent, at least about 10 weight percent, at least about 12 weight percent, at least about 14 weight percent, at least about 16 weight percent, at least about 18 weight percent, at least about 20 weight percent, at least about 25 weight percent, or at least about 30 weight percent.In other embodiments, the first poly(vinyl acetate) resin and the second poly(vinyl acetate) resin may both have a residual acetate content of at least 4 weight percent, at least about 5 weight percent, at least about 6 weight percent, at least about 7 weight percent, about 8 weight percent, at least about 10 weight percent, at least about 12 weight percent, at least about 14 weight percent, at least about 16 weight percent, at least about 18 weight percent, or at least about 20 weight percent. The difference in residual acetate content between the first poly(vinyl acetal) resin and the second poly(vinyl acetal) resin may be within the above range, or the difference may be less than about 3 weight percent, about 2 weight percent or less, about 1 weight percent or less, or about 0.5 weight percent or less. The additional poly(vinyl acetal) layer present in the interlayer may have the same residual acetate content as the first poly(vinyl acetal) resin and / or the second poly(vinyl acetal) resin, or a different residual acetate content.

[0037]

[0040] The poly(vinyl acetal) resins of this disclosure, for example, one or more poly(vinyl butyral) (PVB) resins typically have a molecular weight greater than 50,000 daltons, less than 500,000 daltons, or about 50,000 to about 500,000 daltons, or about 70,000 to about 500,000 daltons, or about 100,000 to about 425,000 daltons, as measured by size exclusion chromatography using a low-angle laser light scattering detector, differential refractometer, or UV detector. In this specification, the term "molecular weight" means weight-average molecular weight.

[0038]

[0041] To control the adhesion of the interlayer sheet to the glass, various adhesion control agents ("ACAs") can be used in the interlayers of this disclosure. In various embodiments of the interlayers of this disclosure, the interlayer may contain about 0.003 to about 0.15 parts by weight of ACA per 100 parts by weight of resin; about 0.01 to about 0.10 parts by weight of ACA per 100 parts by weight of resin; and about 0.01 to about 0.04 parts by weight of ACA per 100 parts by weight of resin. Such ACAs include, but are not limited to, ACA disclosed in U.S. Patent No. 5,728,472 (the entire disclosure of which is incorporated herein by reference), sodium acetate, potassium acetate, magnesium bis(2-ethyl butyrate), and / or magnesium bis(2-ethylhexanoate).

[0039]

[0042] Other additives can be incorporated into the interlayer to enhance its performance in the final product and impart certain additional properties to the interlayer. Such additives include, but are not limited to, a number of additives known to those skilled in the art, such as dyes, pigments, stabilizers (e.g., UV stabilizers), antioxidants, antiblocking agents, flame retardants, IR absorbers or IR blockers (e.g., indium tin oxide, antimony tin oxide, lanthanum hexaboride (LaB6), and cesium tungsten oxide), processing aids, flow-enhancing additives, lubricants, impact modifiers, nucleating agents, thermal stabilizers, UV absorbers, dispersants, surfactants, chelating agents, coupling agents, adhesives, primers, enhancing additives, and fillers.

[0040]

[0043] In various embodiments, the plasticizer may be selected from a high refractive index plasticizer, a mixture of two or more high refractive index plasticizers, or a mixture of a conventional plasticizer and one or more high refractive index plasticizers.

[0041]

[0044] In this specification, plasticizers having a refractive index of approximately 1.450 or less are referred to as "conventional plasticizers." Conventional plasticizers include, but are not limited to, triethylene glycol di-(2-ethylhexanoate) ("3GEH"), triethylene glycol di-(2-ethylbutyrate), triethylene glycol diheptanoate, tetraethylene glycol diheptanoate, tetraethylene glycol di-(2-ethylhexanoate), dihexyl adipate, dioctyl adipate, hexylcyclohexyl adipate, diisononyl adipate, heptylnonyl adipate, di(butoxyethyl) adipate, and bis(2-(2-butoxyethoxy)ethyl) adipate, dibutyl sebacate, dioctyl sebacate, and mixtures thereof. These plasticizers have a refractive index of approximately 1.442 to approximately 1.449. In comparison, PVB resin has a refractive index of approximately 1.485–1.495. In interlayers produced for a variety of properties and applications, 3GEH (refractive index = 1.442) is one of the most common plasticizers available.

[0042]

[0045] In various embodiments, one or more high-refractive-index plasticizers may be used. In embodiments, for both the core layer and / or skin layer, the high-refractive-index plasticizers may be selected such that the refractive index of the plasticizer is at least about 1.460, or higher than about 1.460, or higher than about 1.470, or higher than about 1.480, or higher than about 1.490, or higher than about 1.500, or higher than 1.510, or higher than 1.520. In this specification, “high-refractive-index plasticizer” is a plasticizer having a refractive index of at least about 1.460. In some embodiments, the high-refractive-index plasticizers may be used in conjunction with a conventional plasticizer, and in some embodiments, if included, the conventional plasticizer is triethylene glycol di-(2-ethylhexanoate) ("3GEH"), and the refractive index of the plasticizer mixture is at least 1.460. In this specification, the refractive index of plasticizers or resins used throughout this disclosure is measured according to ASTM D542 at a wavelength of 589 nm and 25°C, or as reported in literature in accordance with ASTM D542.

[0043]

[0046] Examples of plasticizers with high refractive indices that may be used include, but are not limited to, polyadipates (RI approximately 1.460 to 1.485); epoxides (RI approximately 1.460 to 1.480); phthalates and terephthalates (RI approximately 1.480 to 1.540); benzoates (RI approximately 1.480 to 1.550); and other special plasticizers (RI approximately 1.490 to 1.520). Detailed examples of suitable high refractive index plasticizers include, but are not limited to, dipropylene glycol dibenzoate, tripropylene glycol dibenzoate, polypropylene glycol dibenzoate, isodecyl benzoate, 2-ethylhexyl benzoate, diethylene glycol benzoate, propylene glycol dibenzoate, 2,2,4-trimethyl-1,3-pentanediol dibenzoate, 2,2,4-trimethyl-1,3-pentanediol benzoate isobutyrate, 1,3-butanediol dibenzoate, and diethylene glycol dibenzoate. Examples include chol di-o-toluate, triethylene glycol di-o-toluate, dipropylene glycol di-o-toluate, 1,2-octyl dibenzoate, tri-2-ethylhexyl trimellitate, bis-phenol A bis(2-ethylhexanate), ethoxylated nonylphenol, nonylphenyltetraethylene glycol, dioctyl phthalate, diisononyl phthalate, di-2-ethylhexyl terephthalate, mixtures of benzoic acid esters of dipropylene glycol and diethylene glycol, and mixtures thereof.

[0044]

[0047] The total plasticizer content in the interlayer may be in the range of 0 to 120 phr, or higher than 0 phr, or higher than 5 phr, or higher than 10 phr, or higher than 15 phr, or higher than 20 phr, or higher than 25 phr, or higher than 30 phr, and / or 120 phr or less, or 115 phr or less, or 110 phr or less, or 105 phr or less, or 100 phr or less, or 95 phr or less, or 90 phr or less, or 85 phr or less, or 80 phr or less, or 75 phr or less, or 70 phr or less, or 10 to 100 phr, or 20 to 80 phr, or 30 to 70 phr. In various embodiments of the interlayers of this disclosure, the interlayer contains a total plasticizer content greater than 5 phr, approximately 5 to approximately 120 phr, approximately 10 to approximately 90 phr, approximately 20 to approximately 70 phr, approximately 30 to approximately 60 phr, or less than 120 phr, or less than 90 phr, or less than 60 phr, or less than 40 phr, or less than 30 phr. While the total plasticizer content is shown above, the plasticizer content of the skin layer(s) or core layer(s) may differ from the total plasticizer content. In addition, as disclosed in U.S. Patent No. 7,510,771 (the whole disclosure of which is incorporated herein by reference), the plasticizer content of each layer in equilibrium state is determined by the residual hydroxyl content of each layer, so the skin layer(s) and core layer(s) can have a variety of plasticizer types and a variety of plasticizer content within the ranges described above. For example, if the combined thickness of the skin layers is equal to the thickness of the core layer, and the total amount of plasticizer in the interlayer is approximately 45.4 phr, then in equilibrium, the interlayer may contain two skin layers, each containing 30 phr of plasticizer, and a core layer containing 65 phr of plasticizer. For thicker or thinner skin layers, the total amount of plasticizer in the interlayer will vary accordingly. Where the plasticizer content of an interlayer is given herein, the plasticizer content is determined by reference to the phr of the plasticizer in the mixture or melt used to produce the interlayer.

[0045]

[0048] The amount of plasticizer in the interlayer depends on the glass transition temperature (T) of the interlayer. g ) and can be adjusted to affect the final acoustic performance. Glass transition temperature (T g ) is the temperature at which the transition from the glassy state to the rubbery state of the interlayer occurs. Generally, a higher amount of plasticizer filling leads to a lower T g This will result in the use of conventional interlayers, which have been used for some time, generally have a temperature range of approximately -10 to 25°C for acoustic (noise reduction) interlayers. g , and for hurricane and aircraft (more rigid or structural) interlayer applications, up to approximately 45°C T g It had a glass transition temperature (T g ) can be determined by dynamic mechanical thermal analysis (DMTA) of the shear mode. DMTA measures the storage modulus (elastic) (G') (Pascals), loss modulus (viscous) (G'') (Pascals), and tan delta (=G'' / G') of the specimen as a function of temperature at a given frequency and temperature sweep rate. In this specification, a frequency of 1 Hz and a temperature sweep rate of 3 °C / min were used. Then T g The value is determined by the position of the tan delta peak on a temperature scale (°C), and the tan delta peak value is referred to as tan delta or peak tan delta. In this specification, "tan delta," "peak tan delta," "tanδ," and "peak tanδ" can be used interchangeably.

[0046]

[0049] Glass transition temperature of the interlayer (T gThe glass transition temperature (GDR) is also related to the rigidity of the interlayer; generally, the higher the glass transition temperature, the harder the interlayer. Generally, interlayers with a glass transition temperature of 30°C or higher increase the mechanical strength and torsional rigidity of the windshield. On the other hand, softer layers or interlayers (generally characterized by layers or interlayers having a glass transition temperature of less than 20°C) contribute to the sound reduction effect (i.e., acoustic properties). The interlayers of this disclosure may have a glass transition temperature of about 26°C or higher, or about 35°C or higher, for the harder layer(s), and about 20°C or lower, or 15°C or lower, or 10°C or lower, or about 5°C or lower, or 0°C or lower, or about -5°C or lower, or about -10°C or lower, for the softer layer(s), although other glass transition temperatures are possible depending on the desired performance and properties.

[0047]

[0050] In some embodiments, the multilayer interlayers of the present disclosure combine these two advantageous properties (i.e., strength and acoustics) by utilizing a harder or harder skin layer (e.g., hard / / soft / / hard) laminated with a softer core layer. In various embodiments, the multilayer interlayers generally include a harder layer(s) containing poly(vinyl acetal) resin(s)

[0048]

[0051] The final interlayer, formed by extrusion or co-extrusion or by lamination of multiple layers, generally has a random rough surface topography because it is formed by melt fractures of the polymer melt as it exits the extrusion die, and furthermore, the random rough surface on one or both sides (e.g., the skin layer) can be embossed by any embossing method known to those skilled in the art.

[0049]

[0052] All methods for producing polymer interlayer sheets known to those skilled in the art are considered as possible methods for producing the polymer interlayer sheets described herein, but this application focuses on polymer interlayer sheets produced by extrusion and co-extrusion methods. The final multilayer glass panel laminate of the present invention is formed using lamination methods known in the art.

[0050]

[0053] Generally, the thickness or gauge of polymer interlayer sheets ranges from about 15 mil to 100 mil (approximately 0.38 mm to 2.54 mm), about 15 mil to 60 mil (approximately 0.38 mm to 1.52 mm), about 20 mil to 50 mil (approximately 0.51 mm to 1.27 mm), and about 15 mil to 35 mil (approximately 0.38 mm to 0.89 mm). In various embodiments, each layer of the multilayer interlayer, for example, the skin layer and the core layer, can have a thickness of about 1 mil to 99 mil (approximately 0.025 mm to 2.51 mm), about 1 mil to 59 mil (approximately 0.025 mm to 1.50 mm), about 1 mil to about 29 mil (approximately 0.025 mm to 0.74 mm), or about 2 mil to about 28 mil (approximately 0.05 mm to 0.71 mm), although other thicknesses may be selected depending on the desired performance and characteristics.

[0051]

[0054] Many of the embodiments described below refer to PVB polymer resins, but it will be understood by those skilled in the art that the polymer may be any polymer suitable for use in multilayer panels. Typical polymers include, but are not limited to, polyvinyl acetal (PVA) (e.g., poly(vinyl butyral) (PVB) or poly(vinyl isobutyral), isomers of poly(vinyl butyral) also called PVisoB), aliphatic polyurethane (PU), poly(ethylene-co-vinyl acetate) (EVA), polyvinyl chloride (PVC), poly(vinyl chloride-co-methacrylate), polyethylene, polyolefin, ethylene acrylate ester copolymer, poly(ethylene-co-butyl acrylate), silicone elastomers, epoxy resins, and acid copolymers, such as ethylene / carboxylic acid copolymers and their ionomers derived from any of the aforementioned possible thermoplastic resins, and combinations thereof. PVB and its isomers polyvinyl isobutyral, polyvinyl chloride, ionomers, and polyurethanes are generally suitable polymers for interlayers, with PVB (including its isomer PVisoB) being particularly preferred.

[0052]

[0055] Examples of exemplary multilayer interlayer configurations include, but are not limited to, PVB / / PVisoB / / PVB (the PVisoB layer comprises two or more resins or various polymer compositions having varying residual hydroxyl content and / or varying residual acetate content); PVC / / PVB / / PVC, PU / / PVB / / PU, ionomer / / PVB / / ionomer, ionomer / / PU / / ionomer, ionomer / / EVA / / ionomer (the core layer PVB (including PVisoB), PU, ​​or EVA may contain one resin with one glass transition or two or more resins with various glass transitions). Alternatively, the skin layer and core layer may all use the same or different raw material resins, PVB having the same or different residual hydroxyl content and / or residual acetate content, and the same or different plasticizers. Other combinations of resins and polymers will become apparent to those skilled in the art.

[0053]

[0056] Although commonly referred to as poly(vinyl acetal) or poly(vinyl butyral), any poly(vinyl acetal) resin may contain any suitable aldehyde residue, such as isobutyraldehyde, as described above. In some embodiments, one or more poly(vinyl acetal) resins may contain at least one C1-C 10 It may contain an aldehyde or at least one C4-C8 aldehyde residue. Suitable examples of C4-C8 aldehydes include, but are not limited to, n-butyraldehyde, isobutyraldehyde, 2-methylbarrelaldehyde, n-hexylaldehyde, 2-ethylhexylaldehyde, n-octylaldehyde, and combinations thereof. At least one of the first poly(vinyl acetal) resin and the second poly(vinyl acetal) resin may contain at least one C4-C8 aldehyde residue in an amount of at least about 20 weight percent, at least about 30 weight percent, at least about 40 weight percent, at least about 50 weight percent, at least about 60 weight percent, or at least about 70 weight percent, and / or may contain at least one C4-C8 aldehyde in an amount of about 90 weight percent or less, about 85 weight percent or less, about 80 weight percent or less, about 75 weight percent or less, about 70 weight percent or less, or about 65 weight percent or less, or may contain at least one C4-C8 aldehyde in an amount of about 20 to about 90 weight percent, about 30 to about 80 weight percent, or about 40 to about 70 weight percent. C4-C8 aldehydes may be selected from the group listed above, or from the group consisting of n-butyraldehyde, isobutyraldehyde, 2-ethylhexylaldehyde, and combinations thereof.

[0054]

[0057] In various embodiments, one or more poly(vinyl acetal) resins may be poly(vinyl butyral) (PVB) resins. In other embodiments, one or more poly(vinyl acetal) resins may be poly(vinyl butyral) resins mainly containing n-butyraldehyde residues, for example, the resin may contain aldehyde residues other than butyraldehyde in amounts of about 50% by weight or less, about 40% by weight or less, about 30% by weight or less, about 20% by weight or less, about 10% by weight or less, about 5% by weight or less, or about 2% by weight or less, relative to the total weight of all aldehyde residues in the resin.

[0055]

[0058] In this specification, a multilayer panel may include a single substrate, such as glass, acrylic, or polycarbonate (or other rigid substrate), along with a polymer interlayer sheet placed thereon, and most commonly, a polymer film further placed across the polymer interlayer. The combination of the polymer interlayer sheet and the polymer film is generally referred to in the art as a two-layer. A typical multilayer panel having a two-layer structure is (glass) / / (polymer interlayer sheet) / / (polymer film), where the polymer interlayer sheet can contain a number of interlayers as described above. The polymer film provides a smooth, thin, rigid substrate that gives better optical properties than the polymer interlayer sheet alone would normally obtain, and functions as an improved layer. The polymer film differs from the polymer interlayer sheets used herein in that it does not itself provide the required penetration resistance and glass retention properties, but rather provides performance improvements, such as infrared absorption properties. Poly(ethylene terephthalate) ("PET") is the most commonly used polymer film. In general, in this specification, the polymer film is thinner than the polymer sheet, for example, with a thickness of about 0.001 to 0.2 mm, but other thicknesses may be used.

[0056]

[0059] The interlayers of this disclosure are most commonly used in multilayer panels comprising two substrates, for example, a pair of glass sheets (or other rigid materials known in the art, such as polycarbonate or acrylic), and an interlayer placed between the two substrates. An example of such a structure is (glass) / / (polymer interlayer sheet) / / (glass), where, as described above, the polymer interlayer sheet may include the multilayer interlayer. These examples of multilayer panels are not intended to be limiting, but are intended to make it readily apparent to those skilled in the art that numerous structures other than those described above can be fabricated with the interlayers of this disclosure.

[0057]

[0060] A typical glass lamination process includes the following steps: (1) assembling two substrates (e.g., glass) and an interlayer; (2) briefly heating the assembly by IR radiation or convection; (3) passing the assembly through a pressurized nip roll for a first degassing; (4) a second heating of the assembly to about 60°C to about 120°C to give the assembly sufficient temporary adhesion to seal the edges of the interlayer; (5) passing the assembly through a second pressurized nip roll to further seal the edges of the interlayer and allow for further handling; and (6) autoclaving the assembly for about 30 to 90 minutes at a temperature of about 135°C to about 150°C and a pressure of about 180 psig to about 200 psig. Actual steps, times, and temperatures can be varied as needed, as is known to those skilled in the art.

[0058]

[0061] Other methods (steps 2-5) used in the degassing of interlayer-glass interfaces that are known and commercially practiced in this field include the vacuum bag method and the vacuum ring method, which utilize vacuum to remove air.

[0059]

[0062] The laboratory damping loss coefficient (LF) was measured by mechanical impedance measurement (MIM) (also referred to as the laboratory MIM loss coefficient) as described in ISO 16940. A laminated glass rod sample, 25 mm wide and 300 mm long, with a pair of 2.3 mm clear glass panes, was prepared and excited at the center of the rod by a vibrating shaker (Bruel-Kjær). Using an impedance head (Bruel-Kjær), the force used to excite the rod to vibrate and the velocity of the vibration were measured, and the resulting transfer function was recorded using a National Instruments data acquisition and analysis system. The loss coefficient for the first vibration mode was calculated using the half-power method. The laminate was conditioned at room temperature for 4 weeks after lamination and then conditioned at the test temperature (e.g., 20°C) for at least 4 hours before conducting the laboratory MIM test.

[0060]

[0063] The measurement of the windshield damping loss coefficient (η) was performed according to the following procedure. Procedure 1: The windshield is conditioned at a test temperature of 20+ / -1°C for at least 4 hours prior to the test. The windshield is suspended by a long (>40cm) string (e.g., hemp string) at the center of the rearview mirror base to minimize damping associated with the support. The windshield is excited on its outer surface by a Bruel-Kjær impulse impact hammer at a position 400mm from the top of the windshield and 400mm from the side closer to the driver. The panel response to the excitation is acquired by an accelerometer at the same location, but inside the windshield surface. The accelerometer and the cable connected to it should be as light as possible so as not to distort the windshield vibration response. By knowing the precise excitation force and response, the frequency response function was generated by a Fast Fourier Transform program, as shown in Figure 1. The damping loss coefficient (η) in the first vibration mode is calculated from the frequency response function using the half-power method: η = Δf / f0 = (f2-f1) / f0.

[0061]

[0064] An example of a response curve is shown in Figure 1. When the response curve is highly asymmetric and f2 cannot be determined, the steeper side of the peak (usually the left side of the peak) can be used and reflected on the right side of the peak. Therefore, the damping loss coefficient (η) is η = Δf / f0 = 2 * It can be calculated as (f0-f1) / f0.

[0062]

[0065] In various embodiments, the interlayer of the present invention is measured directly on the windshield glass and has a per-windshield area (1 / m²). 2 The windshield attenuation loss coefficient (η) is at least 0.0450 (0.0500, 0.0550, 0.0600, 0.0650, 0.0700, 0.0750, 0.0800, 0.0850).

[0063]

[0066] For many of the following examples, the attenuation loss coefficient (LF), also referred to as the laboratory MIM loss coefficient, was similarly measured in the laboratory on small laminated samples (size (2.54 cm × 30.48 cm (1 inch × 12 inches)) by mechanical impedance measurements in accordance with ISO 16940. The laboratory MIM loss coefficient LF may correlate with the windshield attenuation loss coefficient η. Where possible, it is desirable to have the attenuation loss coefficient measured and characterized on actual windshields using the aforementioned procedure (Procedure 1), which is more representative of actual windshield applications. However, measuring a complete windshield may not always be possible or practical, and therefore it is understood that smaller laminated glazings and smaller samples may be measured as described herein.

[0064]

[0067] The mean fracture height (MBH) (impact resistance) was measured at a temperature of 29.4°C according to ANSI / SAE Z26.1-1996. The test was measured at known thicknesses and, if necessary, normalized to a constant thickness (e.g., 30 mils or 45 mils) so that various interlayers could be compared at the same interlayer thickness. The laminates tested were made of 2.3 mm annealed glass and the interlayers described in the following examples. A 2.27 kg (5 lb) steel ball was used in the impact test. The mean fracture height delta shown below is the difference between the respective Example MBH and Comparative Example 1 MBH, given by the formula: Mean fracture height delta (meters) = Example MBH - Comparative Example 1 MBH.

[0065]

[0068] The present invention also includes the following embodiments, as shown below.

[0066]

[0069] One embodiment is a laminated glazing comprising: a first glass substrate; a multilayer polymer interlayer; and a second rigid substrate; wherein the multilayer polymer interlayer comprises: a first poly(vinyl acetal) resin having a first residual hydroxyl content and a first residual acetate content, and a first plasticizer, and having a glass transition temperature (T) higher than 26°C. g A first layer having ) a second poly(vinyl acetal) resin having a second residual hydroxyl content and a second plasticizer comprising a glass transition temperature (T) of less than 20°C. g A second layer having ); a third poly(vinyl acetal) resin having a third residual hydroxyl content and a third plasticizer, comprising a glass transition temperature (T) higher than 26°C. g The laminated glazing includes a third layer having ), the second layer is located between the first and third layers, and when measured according to procedure 1, the laminated glazing has a glazing area per glazing area (1 / m²) measured directly in the laminated glazing. 2The laminated glazing includes a damping loss coefficient (η) of at least 0.0450 (0.0500, 0.0550, 0.0600, 0.0650, 0.0700, 0.0750, 0.0800, 0.0850). The laminated glazing may be a windshield, for example, a windshield for an automobile or other vehicle. The laminated glazing or windshield may be used in head-up display applications in vehicles.

[0067]

[0070] In embodiments, the interlayer in the laminated glazing or windshield glass may include an interlayer in which the first poly(vinyl acetal) resin and the third poly(vinyl acetal) resin are the same. In embodiments, the difference between the first residual hydroxyl content and the second residual hydroxyl content is at least 2.0 (2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0) weight percent.

[0068]

[0071] In some embodiments, the first plasticizer and the third plasticizer are the same. In other embodiments, the second plasticizer is the same as at least one of the first or third plasticizer. In some embodiments, at least one plasticizer may be a mixture of two or more plasticizers. In some embodiments, at least one plasticizer may be a high refractive index plasticizer as defined herein.

[0069]

[0072] In the embodiment, the multilayer interlayer is a tapered interlayer. The tapered interlayer may have one tapered layer, two tapered layers, three (or more) tapered layers, or all layers may be tapered.

[0070]

[0073] In one embodiment, the interlayer has a gradient color band, while in another embodiment, the interlayer contains an IR absorber in at least one layer. In one embodiment, the interlayer may have a gradient color band and may contain an IR absorber in at least one layer.

[0071]

[0074] In one embodiment, the interlayer further comprises at least one non-poly(vinyl acetal) layer. In another embodiment, the interlayer comprises an interlayer bonding layer.

[0072]

[0075] In the embodiment, the interlayer has a MIM loss coefficient (LF) at 20°C measured according to ISO 16940 of at least 0.29 (0.30, 0.31, 0.32, 0.33, 0.34).

[0073]

[0076] Any of the properties described herein can be combined with any other properties. For example, a laminated glazing or windshield may include a non-poly(vinyl acetal) layer and an interlayer having a gradient color band, or the interlayer may include an IR absorber in at least one layer and may be a tapered interlayer, or the interlayer may be made of the same poly(vinyl acetal) resin for the first and third poly(vinyl acetal) resins, and the difference between the first and second residual hydroxyl content may be at least 2.0 (2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0) weight percent. Other combinations of properties are also included and considered. [Examples]

[0074]

[0077] Exemplary multilayer interlayers were manufactured by melt extrusion molding, as shown in Table 1, by mixing 100 parts by weight of poly(vinyl butyral) resin with various amounts of plasticizers and other common additives (as described above). For the disclosed examples, a mixture of 3GEH plasticizer and DPG dibenzoate plasticizer was used, and the amount (%) of 3GEH in the mixture is shown in Table 1. The three PVB resins used are as follows:

[0078] PVB1: PVB resin with a residual PVOH content of approximately 18.5% by weight.

[0079] PVB2: PVB resin with a residual PVOH content of approximately 9% by weight.

[0080] PVB3: PVB resin with a residual PVOH content of approximately 10.5% by weight.

[0081] In addition, commercially available acoustic trilayer comparative examples (Saflex® Q series PVB interlayer from Eastman Chemical (Comparative Example 1), and commercially available competing standard acoustic PVB samples (Comparative Example 2)) were also used, as shown in the table below.

[0075]

[0082] Next, various laminates and windshields were constructed using multilayer interlayers, as shown in the table and fully described below.

[0076]

[0083] Improvements in the acoustic properties of windshield glass, such as the damping loss coefficient (η), can be most easily understood by comparing laminates containing multilayer (triple-layer) interlayers. As shown and explained below, these examples demonstrate the damping characteristics of windshield glass when certain modifications are made to the multilayer interlayer.

[0077]

[0084] For each interlayer, the laboratory MIM loss factor (LF) at 20°C was measured. As mentioned earlier, the laboratory MIM loss factor refers to the MIM loss factor tested on laboratory-scale samples (size (2.54 cm × 30.48 cm (1'' × 12''))) made of 2.3 mm annealed glass, rather than on large laminates such as complete windshields. Impact resistance was also measured on laminates made using the interlayer, as mentioned earlier. The results are shown in Table 1 below.

[0078] [Table 1]

[0079]

[0085] Some of the interlayers shown in Table 1 were used in the windshield attenuation loss coefficient (η) test. The glass thickness and size of the tested windshields are shown in Table 2 below. (Per unit area of ​​windshield or glazing measured directly on the windshield (1 / m²)2 The damping loss coefficient (η) of ) is shown in Table 2 below.

[0080] [Table 2]

[0081]

[0086] A correlation was found between the laboratory MIM loss coefficient (LF) and the windshield attenuation loss coefficient (η). Figure 2 shows the windshield attenuation loss coefficient (η) for windshield 2 compared to the laboratory MIM loss coefficient (LF), and Figure 3 shows the windshield attenuation loss coefficient (η) for windshield 1 compared to the laboratory MIM loss coefficient (LF). As shown in Figures 2 and 3, the windshield attenuation loss coefficient (η) increases as the laboratory MIM loss coefficient increases.

[0082]

[0087] The correlation between the laboratory MIM loss coefficient (LF) and the windshield attenuation loss coefficient (η) can be further illustrated in Figure 4. Figure 4 shows the comparison of the laboratory MIM loss coefficient (LF) for both windshields, normalized by the windshield area (1 / m²). 2 This shows the windshield attenuation loss coefficient (η). As shown in Figure 4, (1 / m²) is the attenuation loss coefficient per unit area of ​​the windshield. 2 The attenuation loss coefficient (η) of the windshield glass increases as the laboratory MIM loss coefficient increases.

[0083]

[0088] There are several ways to affect or change the MIM loss coefficient (and thereby affect or change the windshield attenuation loss coefficient (η)). For example, the MIM loss coefficient can increase with increasing core layer thickness. For instance, comparing interlayers 3D, 3B, 3A, and 3C, the MIM loss coefficient increases as the core layer thickness increases. Also, comparing interlayers 2A, 2B, 2C, and 1A, 1B, and 1C, it has been shown that the MIM loss coefficient increases as the core layer thickness increases.

[0084]

[0089] The MIM loss coefficient can also be increased by changing the type of plasticizer and the core resin. Comparing the interlayer 3D with Comparative Example 1, it is shown that the MIM loss coefficient increases from 0.284 to 0.302 by using a mixture of two plasticizers (3GEH and DPG-dibenzoate) and by changing the resin used in the core (PVB3 to PVB2).

[0085]

[0090] Increasing the amount of plasticizer in the skin layer also improves the MIM loss coefficient. Comparing interlayers 4A, 2A, and 1A with interlayers 4B, 2B, and 1B, it is shown that the MIM loss coefficient increases as the plasticizer level in the outer (skin) layer increases.

[0086]

[0091] In some cases, as shown in Examples 4A, 4B, and 4C, the laboratory MIM LF does not always increase with core layer thickness, and it is clear that there is an optimal core layer thickness in the multilayer that can yield the maximum laboratory MIM LF at a given skin plasticizer level.

[0087]

[0092] In some cases, as shown in Interlayer Examples 1C, 2C, and 4C, the laboratory MIM LF does not always increase with the amount of plasticizer in the skin layer. It is also clear that there is an optimal level of plasticizer in the skin layer in a multilayer that can yield the maximum laboratory MIM LF for a given core thickness.

[0088]

[0093] As shown by comparing Examples 4A, 4B, and 4C, by comparing Examples 2A, 2B, and 2C, and by comparing Examples 1A, 1B, and 1C, impact resistance decreases with increasing core layer thickness. As shown by comparing Samples 1A, 1B, and 1C, which have better impact resistance and less plasticizer, with Samples 2A, 2B, and 2C, and by comparing Samples 2A, 2B, and 2C with Samples 4A, 4B, and 4C, it became possible to reduce the loss of impact resistance due to increased core layer thickness by reducing the amount of skin plasticizer filling.

[0089]

[0094] In conclusion, laminated glazing including the multilayer interlayer according to the present invention, such as automotive windshield glass, exhibits improved damping compared to other laminated glazing. Other advantages will be readily apparent to those skilled in the art.

[0090]

[0095] The present invention has been disclosed in conjunction with descriptions of certain embodiments, including those currently considered to be preferred embodiments. These detailed descriptions are intended to be illustrative and should not be understood as limiting the scope of this disclosure. Embodiments other than those described herein are encompassed by the present invention, as will be understood by those skilled in the art. Modifications and alterations of the described embodiments may be made without departing from the spirit and scope of the present invention.

[0091]

[0096] It is further understood that any range, value, or characteristic given to any one component of this disclosure may be used interchangeably with any range, value, or characteristic given to any other component of this disclosure, if they are compatible, in order to form embodiments having the respective values ​​of each component given herein. For example, to form many substitutions within the scope of this disclosure, although it would be cumbersome to enumerate them all, an interlayer can be formed containing a poly(vinyl butyral) having a residual hydroxyl content of any of the given ranges, in addition to containing a plasticizer of any of the given ranges. Furthermore, unless otherwise indicated, the ranges given for classes or categories, such as phthalates or benzoates, may also be applied to chemical species within a class or category, such as dioctyl terephthalate. The present invention includes the following embodiments. [1] First rigid base material; Multilayer polymer interlayers; and Second rigid base material; A laminated glazing including, The aforementioned multilayer polymer interlayer is: A first poly(vinyl acetal) resin having a first residual hydroxyl content and a first residual acetate content, and a first plasticizer, comprising a glass transition temperature (T) higher than 26°C. g A first layer having ) The material comprises a second poly(vinyl acetal) resin having a second residual hydroxyl content and a second plasticizer, and has a glass transition temperature (T) of less than 20°C. g ) a second layer having; and A third poly(vinyl acetal) resin having a third residual hydroxyl content and a third plasticizer, comprising a glass transition temperature (T) higher than 26°C. g ) has a third layer Includes, The second layer is located between the first layer and the third layer. When measured according to Procedure 1, the laminated glazing is measured per glazing area (1 / m²) directly measured in the laminated glazing. 2 A laminated glazing having a damping loss coefficient (η) of at least 0.0450. [2] The laminated glazing according to [1], wherein the first poly(vinyl acetal) resin and the third poly(vinyl acetal) resin are the same. [3] The laminated glazing according to [1] or [2], wherein the difference between the first residual hydroxyl content and the second residual hydroxyl content is at least 2.0 weight percent. [4] The laminated glazing according to any one of [1] to [3], wherein the multilayer interlayer is a tapered interlayer. [5] The laminated glazing according to any one of [1] to [4], wherein one of the layers of the multilayer interlayer has a tapered outer shape. [6] The laminated glazing according to any one of [1] to [5], wherein the interlayer film has a gradient color band. [7] The laminated glazing according to any one of [1] to [6], wherein the interlayer film comprises an IR absorber in at least one layer. [8] The laminated glazing according to any one of [1] to [7], wherein the interlayer further comprises a non-poly(vinyl acetal) layer. [9] The laminated glazing according to any one of [1] to [8], wherein the interlayer has a MIM loss factor (LF) of at least 0.29 at 20°C as measured by ISO 16940.

[10] The laminated glazing according to any one of [1] to [9], wherein the laminated glazing is a side light, sunroof or other window of a vehicle.

[11] First glass substrate; Multilayer polymer interlayers; and Second rigid base material; A windshield glass that includes, The aforementioned multilayer polymer interlayer is: A first poly(vinyl acetal) resin having a first residual hydroxyl content and a first residual acetate content, and a first plasticizer, comprising a glass transition temperature (T) higher than 26°C. g A first layer having ) The material comprises a second poly(vinyl acetal) resin having a second residual hydroxyl content and a second plasticizer, and has a glass transition temperature (T) of less than 20°C. g ) a second layer having; and A third poly(vinyl acetal) resin having a third residual hydroxyl content and a third plasticizer, comprising a glass transition temperature (T) higher than 26°C. g ) has a third layer Includes, The second layer is located between the first layer and the third layer. When measured according to Procedure 1, the windshield glass has a value per unit area of ​​the windshield glass measured directly on the windshield glass (1 / m²). 2 A windshield glass having a damping loss coefficient (η) of at least 0.0450.

[12] The windshield glass according to

[11] , wherein the first poly(vinyl acetal) resin and the third poly(vinyl acetal) resin are the same.

[13] The windshield according to

[11] or

[12] , wherein the difference between the first residual hydroxyl content and the second residual hydroxyl content is at least 2.0 weight percent.

[14] The windshield glass according to any one of

[11] to

[13] , wherein the multilayer interlayer is a tapered interlayer.

[15] A windshield according to any one of

[11] to

[14] , wherein one of the layers of the multilayer interlayer has a tapered outer shape.

[16] The windshield glass according to any one of

[11] to

[15] , wherein the interlayer has a gradient color band.

[17] The windshield glass according to any one of

[11] to

[16] , wherein the interlayer comprises an IR absorber in at least one layer.

[18] The windshield glass according to any one of

[11] to

[17] , wherein the interlayer further comprises a non-poly(vinyl acetal) layer.

[19] The windshield glass according to any one of

[11] to

[18] , wherein the interlayer has a MIM loss coefficient (LF) of at least 0.29 at 20°C as measured by ISO 16940.

[20] A windshield glass as described in any of

[11] to

[19] , used for head-up display applications in vehicles.

Claims

1. First rigid base material; Multilayer polymer interlayers; and Second rigid base material; A laminated glazing including, The aforementioned multilayer polymer interlayer is: A first poly(vinyl acetal) resin having a first residual hydroxyl content and a first residual acetate content, and a first plasticizer, comprising a glass transition temperature (T) higher than 26°C. ｇ A first layer having ) The material comprises a second poly(vinyl acetal) resin having a second residual hydroxyl content and a second plasticizer, and has a glass transition temperature (T) of less than 20°C. ｇ A second layer having ) and The present invention comprises a third poly(vinyl acetal) resin having a third residual hydroxyl content and a third plasticizer, and has a glass transition temperature (T) higher than 26°C. ｇ The third layer has Includes, The second layer is located between the first layer and the third layer. When measured according to Procedure 1, the laminated glazing is measured per glazing area (1 / m²) directly measured in the laminated glazing. ２ The damping loss coefficient (η) of ) is at least 0.0450, At least one of the first plasticizer, the second plasticizer, and the third plasticizer comprises a plasticizer having a refractive index of 1.450 or less and a plasticizer having a refractive index of at least 1.

460. The laminated glazing having a second residual hydroxyl content of 9% by weight or less.

2. The laminated glazing according to claim 1, wherein the first poly(vinyl acetal) resin and the third poly(vinyl acetal) resin are the same.

3. The laminated glazing according to claim 1, wherein the difference between the first residual hydroxyl content and the second residual hydroxyl content is at least 2.0 weight percent.

4. The laminated glazing according to claim 1, wherein the multilayer interlayer is a tapered interlayer.

5. The laminated glazing according to claim 1, wherein one of the layers among the multilayer interlayers has a tapered outer shape.

6. The laminated glazing according to claim 1, wherein the interlayer film has a gradient color band.

7. The laminated glazing according to claim 1, wherein the interlayer film contains an IR absorbent in at least one layer.

8. The laminated glazing according to claim 1, wherein the interlayer further comprises a non-poly(vinyl acetal) layer.

9. The laminated glazing according to claim 1, wherein the interlayer has a MIM loss factor (LF) of at least 0.29 at 20°C as measured by ISO 16940.

10. The laminated glazing according to claim 1, wherein the laminated glazing is a side light, sunroof or other window of a vehicle.

11. First glass substrate; Multilayer polymer interlayers; and Second rigid base material; A windshield glass that includes, The aforementioned multilayer polymer interlayer is: A first poly(vinyl acetal) resin having a first residual hydroxyl content and a first residual acetate content, and a first plasticizer, comprising a glass transition temperature (T) higher than 26°C. ｇ A first layer having ) The material comprises a second poly(vinyl acetal) resin having a second residual hydroxyl content and a second plasticizer, and has a glass transition temperature (T) of less than 20°C. ｇ A second layer having ) and The present invention comprises a third poly(vinyl acetal) resin having a third residual hydroxyl content and a third plasticizer, and has a glass transition temperature (T) higher than 26°C. ｇ The third layer has Includes, The second layer is located between the first layer and the third layer. When measured according to Procedure 1, the windshield glass has a value per unit area of ​​the windshield glass measured directly on the windshield glass (1 / m²). ２ The damping loss coefficient (η) of ) is at least 0.0450, At least one of the first plasticizer, the second plasticizer, and the third plasticizer comprises a plasticizer having a refractive index of 1.450 or less and a plasticizer having a refractive index of at least 1.

460. The windshield glass having a second residual hydroxyl content of 9% by weight or less.

12. The windshield glass according to claim 11, wherein the first poly(vinyl acetal) resin and the third poly(vinyl acetal) resin are the same.

13. The windshield glass according to claim 11, wherein the difference between the first residual hydroxyl content and the second residual hydroxyl content is at least 2.0 weight percent.

14. The windshield glass according to claim 11, wherein the multilayer interlayer is a tapered interlayer.

15. The windshield glass according to claim 11, wherein one of the layers of the multilayer interlayer has a tapered outer shape.

16. The windshield glass according to claim 11, wherein the interlayer has a gradient color band.

17. The windshield glass according to claim 11, wherein the interlayer contains an IR absorbent in at least one layer.

18. The windshield glass according to claim 11, wherein the interlayer further comprises a non-poly(vinyl acetal) layer.

19. The windshield glass according to claim 11, wherein the interlayer has a MIM loss coefficient (LF) of at least 0.29 at 20°C as measured by ISO 16940.

20. The windshield glass according to claim 11, for use in head-up displays in vehicles.

Images