WO2020040994A1 - Thin laminate structures with enhanced acoustic performance - Google Patents

Abstract

A glass laminate article having improved acoustic performance characteristics is provided, as well as a vehicle having such a laminate article. The laminate includes a first substrate having a first thickness, a second substrate having a second thickness, the second thickness being about 1.0 mm or less, a third substrate having a third thickness, a first interlayer between the first and second substrates, and a second interlayer between the second and third substrates. The laminate exhibits a transmission loss of greater than about 40 dB over a frequency range from about 4000 Hz to about 8000 Hz.

Description

THIN LAMINATE STRUCTURES WITH ENHANCED ACOUSTIC PERFORMANCE

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority under 35 U.S.C. § 119 of U.S.

Provisional Application Serial No. 62/720,567 filed on August 21, 2018 the content of which is relied upon and incorporated herein by reference in its entirety.

TECHNICAL FIELD

[0002] The disclosure relates generally to thin laminated structures having improved acoustic properties and vehicles that incorporate such structures.

BACKGROUND

[0003] Laminates can be used as windows and glazing in architectural and transportation applications (e.g., vehicles including automobiles and trucks, rolling stock, locomotive and airplanes). Laminates can also be used as panels in balustrades and stairs, and as decorative panels or covering for walls, columns, elevator cabs, kitchen appliances and other applications. The laminates may be transparent, semi-transparent, translucent or opaque and may comprise part of a window, panel, wall, enclosure, sign or other structure. Common types of such laminates may also be tinted or colored or include a component that is tinted or colored.

[0004] Conventional vehicle laminate constructions may consist of two plies of 2 mm soda lime glass (heat treated or annealed) with a polyvinyl butyral PVB interlayer. These laminate constructions have limited impact resistance, and usually have a poor breakage behavior and a higher probability of breakage when getting struck by impacts such as roadside stones, vandals and others.

[0005] In many transportation applications, fuel economy is a function of vehicle weight. It is desirable, therefore, to reduce the weight of laminates for such applications without compromising their strength, acoustic, and thermal properties. However, acoustic performance is also important. Thus, laminates that possess or exceed the durability and sound-damping performance properties associated with conventional laminates are desirable. SUMMARY

[0006] A first aspect of this disclosure pertains to a laminate exhibiting improved acoustic performance. In one or more embodiments, the laminate includes a first substrate including a first thickness defined as a distance between opposing major surfaces of the first substrate; a second substrate including a second thickness defined as a distance between opposing major surfaces of the second substrate, the second thickness being about 1.0 mm or less; a third substrate including a third thickness defined as a distance between opposing major surfaces of the third substrate; a first interlayer disposed between the first and second substrates; and a second interlayer disposed between the second and third substrates. In an aspect of one or more embodiments, the laminate exhibits a transmission loss of greater than about 40 dB over a frequency range from about 4000 Hz to about 8000 Hz.

[0007] In some embodiments, the laminate exhibits a transmission loss of greater than about 35 dB, greater than about 36 dB, or greater than about 37dB over a frequency range from about 2500 Hz to about 6300 Hz.

[0008] In one or more embodiments, the laminate exhibits a plate bending stiffness of less than about 200 Nm over a frequency range from about 400 Hz to about 8000 Hz, less than about 150 Nm over a frequency range from about 1000 Hz to about 8000 Hz, less than about 100 Nm over a frequency range from about 2500 Hz to about 8000 Hz, and/or less than about 50 Nm from a frequency range from about 6000 Hz to about 8000 Hz. The first, second, and third thicknesses may be equal. In some embodiments, the first, second, and third thicknesses are about 0.7 mm or less.

[0009] According to some embodiments, the laminate exhibits a coincidence dip frequency above 1000 Hz. The laminate exhibits a damping loss factor of greater than about 0.1 over a frequency range from about 100 Hz to about 8000 Hz, greater than about 0.15 over a frequency range from about 160 Hz to about 8000 Hz, greater than about 0.2 over a frequency range from about 250 Hz to about 8000 Hz, greater than about 0.25 over a frequency range from about 400 Hz to about 8000 Hz, greater than about 0.3 over a frequency range from about 630 Hz to about 8000 Hz, greater than about 0.35 over a frequency range from about 900 Hz to about 8000 Hz, greater than about 0.4 over a frequency range from about 1250 Hz to about 8000 Hz, greater than about 0.45 over a frequency range from about 2500 Hz to about 5000 Hz, and/or greater than about 0.4 over a frequency range from about 5000 Hz to about 8000 Hz. [0010] In one or more embodiments, the laminate exhibits a peak damping loss factor of about 0.45 or more, or about 0.46 or more over a frequency range from about 100 Hz to about 8000 Hz, or over a range of from about 2000 Hz to about 6300 Hz.

[0011] According to one or more embodiments, at least one of the first, second, and third substrates includes a strengthened glass material. The strengthened glass material may be chemically or thermally strengthened. In one or more embodiments, at least one of the first, second, and third substrates comprises an alkali aluminosilicate glass or an alkali aluminoborosilicate glass. The first and third substrates may include soda lime glass.

[0012] In one or more embodiments, the laminate exhibits a plate bending stiffness of about 1400 Nm or less over a frequency range from about 100 Hz to about 8000 Hz, about 1200 Nm or less over a frequency range from about 315 Hz to about 8000 Hz, about 1000 Nm or less over a frequency range from about 500 Hz to about 8000 Hz, about 800 Nm or less over a frequency range from about 800 Hz to about 8000 Hz, about 600 Nm or less over a frequency range from about 1250 Hz to about 8000 Hz, about 400 Nm or less over a frequency range from about 2500 Hz to about 8000 Hz, and/or about 300 Nm or less over a frequency range from about 4000 Hz to about 8000 Hz.

[0013] In some embodiments, the laminate exhibits a damping loss factor of about 0.2 or more over a frequency range from about 125 Hz to about 8000 Hz, about 0.25 or more over a frequency range from about 200 Hz to about 8000 Hz, about 0.3 or more over a frequency range from about 315 Hz to about 6300 Hz, about 0.35 or more over a frequency range from about 500 Hz to about 5000 Hz, and/or about 0.4 or more over a frequency range from about 630 Hz to about 3150 Hz. The laminate may exhibit a peak damping loss factor of about 0.44 or more, or about 0.45 over a frequency range from about 100 Hz to about 8000 Hz.

[0014] According to one or more embodiments, the first and second interlayers include polyvinyl butyral (PVB). The PVB may be acoustic polyvinyl butyral.

[0015] In one or more embodiments, the laminate is disposed in a vehicle and comprises a windshield, a sidelite, a rearlite, a sunroof, or other vehicle glazing.

[0016] In another embodiment, a vehicle is provided that includes a body having at least one opening and an interior; and a laminate according to any one of the embodiments of this disclosure, the laminate being disposed in the at least one opening.

[0017] Additional features and advantages will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments as described herein, including the detailed description which follows, the claims, as well as the appended drawings. [0018] It is to be understood that both the foregoing general description and the following detailed description are merely exemplary, and are intended to provide an overview or framework to understanding the nature and character of the claims. The accompanying drawings are included to provide a further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiment(s), and together with the description serve to explain principles and operation of the various embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a perspective view of a vehicle according to one or more embodiments;

[0020] Figure 2 is a side view of a laminate according to one or more embodiments;

[0021] Figure 3 is a graph of SPL levels of laminates according to one or more embodiments;

[0022] Figure 4 is a graph of plate bending stiffness of laminates according to one or more embodiments;

[0023] Figure 5 is a graph of laminate damping according to one or more embodiments;

[0024] Figure 6 is a graph of STL of laminates according to one or more embodiments;

[0025] Figure 7 is a graph of plate bending stiffness of laminates according to one or more embodiments;

[0026] Figure 8 is a graph of laminate damping according to one or more embodiments;

[0027] Figure 9 is a graph of STL of laminates according to one or more embodiments;

[0028] Figure 10 is a graph of change in STL for laminate constructions according to one or more embodiments;

[0029] Figure 11 is a graph of STL of laminates according to one or more embodiments;

[0030] Figure 12 is a graph of STL of laminates according to one or more embodiments;

[0031] Figure 13 is a graph of SPL of laminates according to one or more embodiments;

[0032] Figure 14 is a graph of change in SPL of laminates according to one or more embodiments;

[0033] Figure 15 is a graph of SPL of laminates according to one or more embodiments;

[0034] Figure 16 is a graph of change in SPL of laminates according to one or more embodiments;

[0035] Figure 17 is a graph of SPL of laminates according to one or more embodiments; [0036] Figure 18 is a graph of change in SPL of laminates according to one or more embodiments;

[0037] Figure 19 is a graph of SPL of laminates according to one or more embodiments; and

[0038] Figure 20 is a graph of change in SPL of laminates according to one or more embodiments

DETAILED DESCRIPTION

[0039] Reference will now be made in detail to the present preferred embodiment(s), examples of which are illustrated in the accompanying drawings. Aspects of the present disclosure pertain to thin laminated or laminate structures having improved acoustic properties and vehicles and architectural panels that incorporate such structures. An example of a vehicle 100 that includes such a laminate structure 200 is shown in Figure 1. The vehicle includes a body 110 with at least one opening 120. The laminate 200 is disposed in the at least one opening 120. As used herein, the term“vehicle” may include automobiles (e.g., cars, vans, trucks, semi-trailer trucks, and motorcycles), rolling stock, locomotives, train cars, airplanes, marine craft, and the like. The opening 120 is a window within which a laminate is disposed to provide a transparent covering or glazing. It should be noted that the laminates described herein may be used in architectural panels such as windows, interior wall panels, modular furniture panels, backsplashes, cabinet panels, and/or appliance panels.

[0040] In vehicle windshields and windows, glass laminates typically consist of two glass substrates separated by a polymer interlayer, typically polyvinyl butyral (PVB). PVB comes in acoustic and standard varieties, where acoustic PVB (or APVB) is specifically designed to help attenuate sound and improve acoustic performance of laminates, and may include three co-extruded layers consisting of two outer, thicker layers and a thin, soft core layer. The soft core is considered to provide acoustic damping at temperatures around 20 °C. APVB is typically used in sheets having thicknesses of 0.76 mm, 0.81 mm, or 0.84 mm.

[0041] Vehicle laminates not only provide an optically transparent barrier between the interior and exterior of a vehicle, but may also provide an acoustic barrier. This may be the case in a typical windshield or vehicle glazing where it is desirable to control the vehicle interior climate relative to the exterior climate, but it may also be true in certain vehicles where mechanical components of the vehicle generate heat and noise that can enter the vehicle interior or passenger compartment. For example, some high-performance automobiles have engine compartments located just behind the passenger compartment. Such an engine compartment can create noise and heat. Therefore, it is desirable to place a barrier between the engine compartment and the passenger compartment.

[0042] Conventional vehicle laminates consist of two layers of relatively thick soda lime glass separated by an interlayer, such as PVB. With a desire to decrease weight and improve optics, newer laminates have attempted to replace one layer of soda lime glass in typical vehicle glazing with a layer of thin, chemically strengthened glass, such as Coming® Gorilla® Glass. For example, a laminate having a soda layer with thickness of 2.1 mm, a PVB (or APVB) layer with thickness of 0.81 mm, and thin, chemically strengthened glass layer with thickness of 0.55 mm, resulting in a total laminate thickness of 3.46 mm. These laminates are sometimes referred to as“asymmetric hybrid laminates.”

[0043] Asymmetric hybrid laminates made using a relatively thick soda lime glass outer ply (thickness typically ranges between l.8mm to 3.5mm) with a thin chemically

strengthened Gorilla Glass inner ply (thickness ranging between 0.5 to 0.7mm) have a number of advantages over traditional windshields made using two plies of annealed soda lime glass (SLG) with thicknesses ranging between l.6mm to 3.0mm. Advantages are greater in-use durability and significant weight reduction compared to traditional annealed soda lime glass laminated windshields.

[0044] For example, asymmetric hybrid laminates typically have 2x greater resistance to sharp impact and 3-4x greater resistance to blunt impact. Higher impact resistance is related to the thin chemically strengthened inner ply. Because of the thin inner ply, asymmetric hybrid laminates tend to deflect and bend more than thick annealed soda lime glass laminates upon impact. Greater bending results in more viscous energy dissipation in the PVB interlayer instead of energy dissipation through crack formation and propagation in the glass. However greater bending causes increased tensile stress on the inside surface of the laminate (sometimes referred to as“surface 4” or“S4”). Because of chemical strengthening of the thin inner ply and associated high intrinsic compressive stress, high level of bending induced tensile stress does not cause breakage. The use of thin annealed soda lime glass inner plies in an asymmetric hybrid laminate configuration is not feasible because such glass would break under bending induced tensile stress because of low intrinsic compressive stress.

[0045] Another advantage of thin asymmetric hybrid laminates is the significant weight savings they afford. A traditional 2. lmmSLG/ PVB/ 2. lmmSLG laminate has surface density of 11.4 kg/m², whereas a thin asymmetric hybrid laminate of construction

2. lmmSLG/ PVB/ 0.55mmGG has surface density of 7.5 kg/m². As used in examples herein, “SLG” refers to soda lime glass, and“GG” refers to strengthened alkali aluminosilicate or alkali aluminoborosilicate glass, such as Coming® Gorilla® Glass. This constitutes a weight savings of 34%. Benefits of light weighting are better fuel economy, reduced CO2 emissions, lower center of gravity for better handling, and faster defogging/defrost.

[0046] However, a challenge to the wide spread adoption of thin light weight asymmetric hybrid laminates for automotive applications is acoustics. As the surface density of a panel is reduced sound transmission through the panel increases in the mass law frequency range which typically extends from about 200 Hz up to lOOOHz (the exact extent of this range depends on laminate construction). In this frequency range sound transmission depends only on panel surface density, lower surface density means more sound transmission.

[0047] In view of the above, improved laminates are needed that satisfy thermal and acoustic requirements.

[0048] Above the mass law range there is the coincidence frequency range which often lies within the peak hearing sensitivity frequency range. The coincidence frequency range is characterized by the coincidence dip, which is a range of frequencies where sound transmission through a panel increases. In this important frequency range sound

transmission through a laminated panel depends on damping, higher damping means a less pronounced coincidence dip and less sound energy transmission. In automotive laminates significant damping is provided by the viscoelastic polyvinyl butyral (PVB) interlayer that binds glass plies together. Specially designed acoustic PVB (APVB) interlayers that provide high damping in the coincidence frequency range are commercially available and widely used in the auto industry to reduce sound transmission through laminated auto glass in the coincidence frequency range. The coincidence frequency range typically extends from 2000 Hz up to 6300 Hz.

[0049] According to some embodiments, the coincidence dip frequency can be controlled by laminate stiffness: less stiff laminates have higher coincidence dip frequencies. An advantage of thin asymmetric hybrid laminates is that they are less stiff than traditional thick annealed soda lime glass laminates so their coincidence dips occur at higher frequencies often time outside the range of peak hearing sensitivity.

[0050] According to embodiments of this disclosure, laminate constructions are provided that have high damping and low high frequency stiffness to simultaneously cause the coincidence dip frequency to be shifted out of the range of peak hearing and to minimize the increase in sound transmission caused by the coincidence dip. For example, some embodiments include laminate 5 -layer constructions of glass/acoustic PVB/0.7mmGG/acoustic PVB/glass. It has been found that particular embodiments of these 5 -layer laminate constructions have higher damping, lower stiffness, and consequently less sound transmission in the 2000 Hz to 5000 Hz frequency range as compared to traditional three-layer laminates consisting of glass/APVB/glass or glass/two layers of APVB/glass.

This frequency range is particularly important because it corresponds to the frequency range of most sensitive human hearing. Minimizing sound transmission in the coincidence frequency range can partially compensate for increased sound transmission in the mass law range.

[0051] Referring to Figure 2, the laminate 200 of one or more embodiments includes a first substrate 210 and a second substrate 211 as outer glass layers of the laminate 200, as well as a third substrate 230 disposed between the first and second substrates 210, 211. A first interlayer 220 is disposed between the first and third substrates 210, 230, and a second interlayer 221 is disposed between the second and third substrates 211, 230.

[0052] The sound transmission property of laminates according to embodiments of this disclosure is characterized herein by sound transmission loss (STL) vs. frequency curves.

STL is the ratio of sound incident on a panel to sound transmitted through a panel. Higher STL means less sound transmission. The coincidence dip appears in STL vs. frequency curves as dips or reductions in sound transmission that typically occur between 2000 Hz and 6300 Hz but for some laminate constructions described in the present disclosure the coincidence dip occurs above 10000 Hz. The mass law frequency range is the straight-line portion of STL vs. frequency curves that occur at lower frequencies. Above the coincidence dip frequency, the STL vs. frequency is largely governed by laminate stiffness.

[0053] In some of the examples discussed herein, the 5-layer laminates are abbreviated using just the component glass thickness. For example: 2. lslg/apvb/0.7gg/apvb/0.7gg is abbreviated as 2.lslg/0.7gg/0.7gg. It is understood that APVB separates the glass layers, unless otherwise noted.

[0054] Figure 3 shows STL vs. frequency of a 3 layer 2. lslg / APVB/ 0.7gg laminate and a 5 layer 0.7gg / APVB/ 0.7gg / APVB/ 0.7gg laminate. STL for the 5 layer construction is up to 5 dB greater than the three layer construction despite lower surface density. The coincidence dip of the 5 layer laminate shown in Figure 1 is shifted to high frequency, above 10000 Hz, because of reduced high frequency stiffness of the 5 layer laminate compared to 3 layers. This is shown in Figure 4 where plate bending stiffness vs. frequency is plotted for both laminates. Plate bending stiffness is calculated using WaveFEA software that calculates laminate bending stiffness and damping loss factors vs. frequency based on measured frequency dependent acoustic PVB shear storage modulus and loss factors. At high frequency, stiffness of the 5 layer laminate is much less than the 3 layer laminate so that the coincidence dip of the 5 layer laminate is shifted above 10000 Hz. At lower frequencies the difference in bending stiffness is much less so the 5 layer laminate will have similar resistance to low frequency (quasi-static) mechanical deformation as the 3 layer construction.

[0055] In addition to the advantageous shift of coincidence dip to higher frequencies that are outside of the range of peak hearing sensitivity, the laminate damping loss factor (DLF) of the 5 layer construction is much greater than that of the 3 layer construction. DLF vs. frequency is plotted in Figure 5. Higher DLF reduces coincidence depth resulting in higher STL through the coincidence frequency range. The coincidence dip frequency range is quite often in the frequency range of peak hearing sensitivity so increasing STL by decreasing coincidence dip depth results in substantial improvement (increase) in articulation index (AI). Without wishing to be bound by theory, it is believed that the cause of increased damping, decreased high frequency stiffness and reduced coincidence dip for 5 layer laminates is reduction of thickness of the thick SLG ply by redistributing across 3 glass plies to increase laminate symmetry.

[0056] Figure 6 shows another example of how decreasing thickness of the thick SLG ply and increasing laminate symmetry increases STL through the coincidence frequency range. Reducing thickness of the outer laminate ply from 3T5mm to 2.lmm and increasing thickness of the inner ply from 0.7mm to 2. lmm increases laminate symmetry. Greater symmetry lowers stiffness and increases damping. Lower stiffness results in shift of the coincidence frequency to higher frequency while increased damping reduces coincidence dip depth. The net result of both of these effects is higher STL across the coincidence dip frequency range.

[0057] Bending stiffness results are given in Figure 7. Note the lower high frequency stiffness and higher low frequency stiffness of 2. lslg/07gg/2. lslg. Higher low frequency stiffness suggests that 2.lslg/0.7gg/2.lslg will have less deflection under loads than

3. l5slg/0.7gg/0.7gg. Lower high frequency stiffness causes the coincidence dip to be shifted to higher frequencies. Figure 8 shows that 2. lslg/0.7gg/2. lslg has higher laminate damping than 3. l5slg/0.7gg/0.7gg resulting in higher STL in the coincidence dip frequency range for 2.slgl/0.7gg/2.lslg laminate.

[0058] Data shown in Table 1 compares STL at a frequency in the mass law range (800 Hz), at a frequency in the coincidence range (2500 Hz) and at a frequency just above the coincidence frequency (6300 Hz) range for laminates with two layers of APVB and two layers of APVB separated by 0.7mm GG. Also shown is the reduction in surface density of each construction compared to 3.85slg/ APVB/ 3.85slg.

Table 1.

[0059] At 2500 Hz the 5 layer laminates have higher STL than the 3 layer laminate with two layers of APVB (2xAPVB) and higher STL than the baseline 3.85slg/ APVB/ 3.85slg. Comparing 3.15SLG/0.7GG/3.15SLG with 3.50slg/2xAPVB/3.50slg, which have similar surface densities, shows the 3T5slg/0.7gg/3. l5slg has 0.9 dB higher STL than

3.50slg/2xAPVB/3.50slg. Surprisingly the lower surface density 2.5slg/0.7gg/2.5slg laminate has the highest STL at 2500 Hz. Figures 9 and 10 show the STL and ASTL plots, respectively, for the laminate constructions in Table 1.

[0060] Figure 11 shows STL curves for two 5 layer laminates with the same surface density but where an APVB layer was replaced by an SPVB layer. Also shown is the STL curve for a laminate with the same surface density with a single layer of APVB. Replacing APVB with SPVB results in reduced damping and reduced STL in the coincidence frequency range. STL between the two laminate configuration are identical through the mass controlled (200 Hz - 1000 Hz) and stiffness controlled (6300 Hz - 10000 Hz) frequency ranges. The 2.5/APVB/0.7/SPVB/2.5 laminate behaves like a single layer APVB laminate up through 3150 Hz. At higher frequencies the 3.0/APVB/3.0 laminate has higher STL because of added glass thickness to the laminate outer plies.

[0061] Figure 12 contains plots of STL curves comparing all APVB and SPVB interlayer in the 0.7/0.7/0.7 laminate configuration. Replacement of APVB with SPVB results in reduction of STL by 8.6 dB at 5000 Hz.

[0062] The discussion so far has focused on sound transmission loss of glazing panels individually. In order to get an indication of how different glazing panels affect acoustics in a full vehicle environment, full vehicle interior cabin SPL was calculated using transparency and wind noise models. The transparency model simulates the situation where a full vehicle is placed in a reverberant room such that the same acoustic energy level is incident on all glazing positions. It is analogous to sound transmission loss but at a full vehicle level. The wind noise model employs calibrated wind noise sources. Each glazing position has a unique source level determined by the external turbulent air flow environment, which is different at each glazing position. The sources were calibrated at 80 mph using a BMW SUV.

[0063] The glazing configuration used for both transparency and wind noise full system models is given in Table 2.

Table 2.

[0064] Results of transparency model calculations are shown in Figures 13 and 14. In Figure 13 are plots of interior cabin SPL vs. frequency for front side lites consisting of 3.85mm monolithic baseline, 2.1/2.1 laminates or 0.7/0.7/0.7 laminates. Figure 14 shows data in Figure 13 plotted in a difference format, where differences in SPL vs. frequency of 2.1/2.1 laminates and 0.7/0.7/07 laminates relative to the 3.85mm baseline are plotted. There is little difference in interior cabin SPL between heavier 2.1/2.1 laminates (11.4 kg/m2) front side lites and lighter 0.7/0.7/0.7 laminates (6.84 kg/m2). The most significant difference is between laminates and 3.85mm monoliths (9.63 kg/m2) where interior cabin SPL is 1.2 dB less for laminated front side lites that the 3.85mm monolithic baseline. This reduction in SPL is caused by acoustic damping provided by the APVB interlayer, which reduces the coincidence dip effect of the 3.85mm monoliths. 0.7/0.7/0.7 front side lites provide comparable improvement in vehicle acoustics (reduction in SPL) to 2.1/2.1 front side lites but at 40% lower weight. 0.7/0.7/0.7 front side lites have significantly lower cabin interior SPL than 3.85mm monoliths at 29% weight savings.

[0065] Similar plots for wind noise induced interior cabin SPL are shown in Figures 15 and 16. Again both laminated front side lites have similar improvement over 3.85mm monoliths. However in the case of wind noise the input acoustic source strength is very high on the front side lites because of turbulence induced by the A-pillar resulting in a greater sensitivity of interior cabin SPL on the type of window than for transparency. For wind noise, interior cabin SPL with both laminated front side lite constructions is almost 6 dB less that for 3.85mm monoliths at 3150 Hz. The difference plot in Figure 16 clearly shows the improvement of laminated front side lites over monoliths. In particular, comparable improvement (reduction in SPL) can be achieved at much lower weight using 0.7/0.7/0.7 front side lites.

[0066] Table 3 shows articulation index for three front side lite constructions discussed above. Articulation index is a weighted average of SPL vs. frequency from 200 Hz to 6300 Hz. It is a measure of speech recognition in an environment with background noise (wind noise in this case). Articulation index ranges between 0% and 100%. 0% corresponds to complete inability to understand speech above the background noise, 100% corresponds to complete speech recognition. Results in Table 3 show that articulation index is much improved over 3.85mm monoliths by using 0.7/0.7/0.7 front side lites with significant weight savings. Articulation index of 0.7/0.7/0.7 is only slightly less than 2.1/2.1 at 40% lower weight.

[0067] Figures 17 and 18 compare the interior cabin sound pressure level, calculated using the Golf VII transparency model, of 0.7/0.7/0.7 and 2.1/0.7 front side lites. Results plotted in Figure 17 show that both laminate constructions have lower SPL than the 3.85mm monolith baseline front side lites between 2000 and 4000 Hz. Data in Figure 17 is plotted in a difference format in Figure 18 where it is seen that the 0.7/0.7/0.7 laminates have 0.5 dB lower SPL than 2.1/0.7 at 6300 Hz. 2.1/0.7 front side lite laminates have between 0.1 to 0.2 dB lower SPL between 200 and 1600 Hz because of slightly higher surface density.

[0068] Figure 19 and 20 compare interior cabin sound pressure levels, calculated using the Golf VII wind noise model, of 0.7/0.7/0.7, 2.1/0.7, 3.85mm monolithic and 4.85mm monolithic front side lites. Because of the relatively high source level incident on the front side lites in the wind noise model, the effect of different front side lite types is much more pronounced than in transparency. Results plotted in Figure 19 show that both laminate types have lower SPL than either 3.85mm or 4.85mm monolith front side lites between 2000 and 4000 Hz. The difference plot in Figure 20 clearly shows that interior cabin SPL with 0.7/0.7/0.7 front side lites is lower than for 2.1/0.7, 3.85mm or 4.85mm front side lites. The maximum difference occurs in the coincidence frequency range of 2.1/0.7, 3.85mm or 4.85mm front side lites.

[0069] Table 4 summarizes AI and weight savings relative to 3.85mm monolithic front side lite baseline. The 0.7/0.7/0.7 front side lite case has 1.4% lower AI than the heavy acoustic 2.1/2.1 laminate but is 5.8 kg lighter. The AI of 0.7/0.7/0.7 is higher than all of the other front side lite options. Note the large increase in AI and weight savings when

0.7/0.7/0.7 is substituted for monolithic front side lites.

Table 4. Articulation index and weight c lange compared to 3.85mm FSLs

(Windshield in all cases was 2.1/0.55)

[0070] In some embodiments, the laminate exhibits a transmission loss of greater than about 31 dB (e.g., 32 dB or greater, 35 dB or greater, 38 dB or greater, 40 dB or greater, or 42 dB or greater) over a frequency range from about 2500 Hz to about 6300 Hz. In some embodiments, the transmission loss is even greater over specific frequency ranges. For example, over the frequency range from about 2500 Hz to about 4000 Hz, the laminate exhibits a transmission loss of greater than 35 dB, or over 40 dB.

[0071] Referring to the construction of the laminate 200, the first and second substrates 210, 230 may have the same thickness or differing thicknesses. In Figure 2, the first substrate 210 is shown having a greater thickness than the second substrate 230. In some

embodiments, the thickness of the first substrate 210 may be in the range from about 0.3 mm to about 4 mm (e.g., from about 0.4 mm to about 4 mm, from about 0.5 mm to about 4 mm, from about 0.55 mm to about 4 mm, from about 0.6 mm to about 4 mm, from about 0.7 mm to about 4 mm, from about 0.8 mm to about 1 mm, from about 0.9 mm to about 4 mm, from about 1 mm to about 4 mm, from about 1.2 mm to about 4 mm, from about 1.5 mm to about 4 mm, from about 1.8 mm to about 4 mm, from about 2 mm to about 4 mm, from about 2.1 mm to about 4 mm, from about 2.5 mm to about 4 mm, from about from about 1 mm to about 4 mm, from about 0.3 mm to about 3 mm, from about 0.3 mm to about 2.1 mm, from about 0.3 mm to about 2 mm, from about 0.3 mm to about 1.8 mm, from about 0.3 mm to about 1.5 mm, from about 0.3 mm to about 1 mm, from about 0.3 mm to about 0.7 mm, or from about 1.2 mm to about 1.8 mm, and all ranges and sub-ranges therebetween).

[0072] In one or more embodiments, the thickness of the second substrate 230 may be less than the thickness of the first substrate 210. In some embodiments, the second substrate 230 is about 1 mm or less, 0.7 mm or less, 0.5 mm or less or about 0.4 mm or less. In some embodiments, the thickness of the second substrate 230 may be in the range from about 0.3 mm to about 4 mm (e.g., from about 0.4 mm to about 4 mm, from about 0.5 mm to about 4 mm, from about 0.55 mm to about 4 mm, from about 0.6 mm to about 4 mm, from about 0.7 mm to about 4 mm, from about 0.8 mm to about 1 mm, from about 0.9 mm to about 4 mm, from about 1 mm to about 4 mm, from about 1.2 mm to about 4 mm, from about 1.5 mm to about 4 mm, from about 1.8 mm to about 4 mm, from about 2 mm to about 4 mm, from about 2.1 mm to about 4 mm, from about 2.5 mm to about 4 mm, from about from about 1 mm to about 4 mm, from about 0.3 mm to about 3 mm, from about 0.3 mm to about 2.1 mm, from about 0.3 mm to about 2 mm, from about 0.3 mm to about 1.8 mm, from about 0.3 mm to about 1.5 mm, from about 0.3 mm to about 1 mm, from about 0.3 mm to about 0.7 mm, and all ranges and sub-ranges therebetween). In embodiments in which the first substrate 210 has a thickness greater than the second substrate, the second substrate may have a thickness of about 1.5 mm or less, about 1 mm or less or about 0.7 mm or less.

[0073] The first and second interlayers may have a thickness of 4 mm or less, about 3 mm or less, about 2 mm or less, or about 1 mm or less. In some embodiments, the thickness of the interlayer structure 220 may be about 1.6 mm or more, about 1.96 mm or more, about 2.0 mm or more, about 2.4 mm or more. In one or more particular embodiments, the thickness of the interlayer 220 is about 1.2 mm or more, or about 1.62 mm.. [0074] As used herein,“acoustic PVB” or“APVB” refers to commercially available acoustic PVB that is designed for better acoustic performance, as would be understood by a person of ordinary skill in the art. As used herein,“standard PVB” or“SPVB” refers to commercially available standard PVB that is not specifically designed for better acoustic performance, as would be understood by a person of ordinary skill in the art.

[0075]

[0076] The interlayers may be formed from a variety of materials. In one or more embodiments, the interlayers may be formed from polymers such as polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA) and thermoplastic polyurethane (TPU), polyester (PE), polyethylene terephthalate (PET) and the like. The interlayers may include any one or more of pigments, UV absorbers, infrared absorbers, adhesion control salts, and other stabilizers.

[0077] The laminate 200 of one or more embodiments may exhibit a relatively low deflection stiffness, compared to other laminates exhibiting acoustic dampening, at room temperature. In one or more embodiments, the laminate 200 may exhibit a deflection stiffness of less than about 150 N/cm at room temperature. This deflection stiffness is measured before the laminate is shaped or otherwise bent (i.e., the laminate is planar and flat). The deflection stiffness may be measured using a three-point bend test. Without being bound by theory, it is believed that the increase in flexibility (or decrease in deflection stiffness) facilitates shearing between at least the first interlayer and the other substrates and/or layers of the laminate.

[0078] In one or more embodiments, the laminate may be characterized in terms of optical properties. In one or more embodiments, the laminate may be transparent and exhibit an average transmittance in the range from about 50% to about 90%, over a wavelength range from about 380 nm to about 780 nm. As used herein, the term“transmittance” is defined as the percentage of incident optical power within a given wavelength range transmitted through a material (e.g., the article, the substrate or the optical film or portions thereof). The term “reflectance” is similarly defined as the percentage of incident optical power within a given wavelength range that is reflected from a material (e.g., the article, the substrate, or the optical film or portions thereof). Transmittance and reflectance are measured using a specific linewidth. In one or more embodiments, the spectral resolution of the characterization of the transmittance and reflectance is less than 5 nm or 0.02 eV.

[0079] Optionally, the laminate may be characterized as translucent or opaque. In one or more embodiments, the laminate may exhibit an average transmittance in the range from about 0% to about 40%, over about over a wavelength range from about 380 nm to about 780 nm.

[0080] The color exhibited by the laminate in reflection or transmittance may also be tuned to the application. In one or more embodiments, the potential colors may include grey, bronze, pink, blue, green and the like. The color may be imparted by the substrates 210, 230 or by the interlayer structure 220. Such colors do not impact the acoustic performance of the laminate and vice versa.

[0081] In one or more embodiments, the acoustic performance of the laminates described herein is achievable while also exhibiting low or no optical distortion. In other words, the laminates provided herein simultaneously exhibit the improved acoustic performance and exhibit low or no optical distortion that can arise during manufacture.

[0082] The materials used in the laminate may vary according to application or use. In one or more embodiments, the substrate 210, 230 may be characterized as having a greater modulus than the interlayers. In some embodiments, the first and second substrates 210, 230 may be described as inorganic and may include an amorphous substrate, a crystalline substrate or a combination thereof. Either one or both the first and second substrates 210,

230 may be formed from man-made materials and/or naturally occurring materials. In some specific embodiments, the substrate 210,230 may specifically exclude plastic and/or metal substrates.

[0083] In one or more embodiments, the first, second, and third substrates 210, 211, 230 may be amorphous and may include glass, which may be strengthened or non-strengthened. Examples of suitable glass include soda lime glass, alkali aluminosilicate glass, alkali containing borosilicate glass and alkali aluminoborosilicate glass. In some variants, the glass may be free of lithia. In one or more alternative embodiments, the substrates 210, 211, 230 may include crystalline substrates such as glass ceramic substrates (which may be strengthened or non-strengthened) or may include a single crystal structure, such as sapphire. In one or more specific embodiments, the substrate includes an amorphous base (e.g., glass) and a crystalline cladding (e.g., sapphire layer, a poly crystalline alumina layer and/or or a spinel (MgAbOi) layer).

[0084] The substrate 210, 211, 230 may be provided using a variety of different processes. For instance, where the substrate includes an amorphous substrate such as glass, various forming methods can include float glass processes and down-draw processes such as fusion draw and slot draw. [0085] Once formed, the substrates 210, 211, 230 may be strengthened to form a strengthened substrate. As used herein, the term "strengthened substrate" may refer to a substrate that has been chemically strengthened, for example through ion-exchange of larger ions for smaller ions in the surface of the substrate. However, other strengthening methods known in the art, such as thermal strengthening (i.e., by a rapid quench after heating), or mechanical strengthening (i.e., utilizing a mismatch of the coefficient of thermal expansion between portions of the substrate to create compressive stress and central tension regions), may be utilized to form strengthened substrates. In some embodiments, the substrates 210,

211, 230 may be strengthened using a combination of methods including any two or more of chemical strengthening, thermally strengthening and mechanical strengthening methods. For example, the substrates 210, 211, 230 may be thermally strengthened followed by chemically strengthened to form a thermally and chemically strengthened substrate.

[0086] Where a substrate is chemically strengthened by an ion exchange process, the ions in the surface layer of the substrate are replaced by - or exchanged with - larger ions having the same valence or oxidation state. Ion exchange processes are typically carried out by immersing a substrate in a molten salt bath containing the larger ions to be exchanged with the smaller ions in the substrate. It will be appreciated by those skilled in the art that parameters for the ion exchange process, including, but not limited to, bath composition and temperature, immersion time, the number of immersions of the substrate in a salt bath (or baths), use of multiple salt baths, additional steps such as annealing, washing, and the like, are generally determined by the composition of the substrate and the desired compressive stress (CS), and depth of compressive stress layer (DOC) of the substrate that result from the strengthening operation. By way of example, ion exchange of alkali metal-containing glass substrates may be achieved by immersion in at least one molten bath containing a salt such as, but not limited to, nitrates, sulfates, and chlorides of the larger alkali metal ion. The temperature of the molten salt bath typically is in a range from about 380°C up to about 450°C, while immersion times range from about 15 minutes up to about 40 hours. However, temperatures and immersion times different from those described above may also be used.

[0087] In addition, non-limiting examples of ion exchange processes in which glass substrates are immersed in multiple ion exchange baths, with washing and/or annealing steps between immersions, are described in U.S. Patent Application No. 12/500,650, filed July 10, 2009, by Douglas C. Allan et al, entitled“Glass with Compressive Surface for Consumer Applications” and claiming priority from U.S. Provisional Patent Application No.

61/079,995, filed July 11, 2008, in which glass substrates are strengthened by immersion in multiple, successive, ion exchange treatments in salt baths of different concentrations; and U.S. Patent 8,312,739, by Christopher M. Lee et al, issued on November 20, 2012, and entitled“Dual Stage Ion Exchange for Chemical Strengthening of Glass,” and claiming priority from U.S. Provisional Patent Application No. 61/084,398, filed July 29, 2008, in which glass substrates are strengthened by ion exchange in a first bath is diluted with an effluent ion, followed by immersion in a second bath having a smaller concentration of the effluent ion than the first bath. The contents of U.S. Patent Application No. 12/500,650 and U.S. Patent No. 8,312,739 are incorporated herein by reference in their entirety.

[0088] In one or more embodiments, either one or both the first and second substrates 210, 230 may be thermally strengthening using conventional thermally strengthening processes that include heating the substrate in a radiant energy furnace or a convection furnace (or a “combined mode” furnace using both techniques) to a predetermined temperature, then gas cooling (“quenching”), typically via convection by blowing large amounts of ambient air against or along the glass surface. This gas cooling process is predominantly convective, whereby the heat transfer is by mass motion (collective movement) of the fluid, via diffusion and advection, as the gas carries heat away from the hot glass substrate.

[0089] In one or more embodiments, either one or both of the first and second substrates 210, 230 may be thermally strengthened using very high heat transfer rates. In particular embodiments, after heating the substrate as to a predetermined temperature, the thermal strengthening process may utilize a small-gap, gas bearing in the cooling/quenching section that allows processing thin glass substrates at higher relative temperatures at the start of cooling, resulting in higher thermal strengthening levels. This small-gap, gas bearing cooling/quenching section achieves very high heat transfer rates via conductive heat transfer to heat sink(s) across the gap, rather than using high air flow based convective cooling. This high rate conductive heat transfer is achieved while not contacting the glass with liquid or solid material, by supporting the glass on gas bearings within the gap.

[0090] The degree of strengthening achieved may be quantified based on the parameters of central tension (CT), surface CS, and either one or both of depth of compression (DOC) and depth of layer (DOE). It should be noted that DOL and DOC, as defined herein, are not always equal, especially where compressive stress extends to deeper depths of a substrate.

As used herein, the terms“depth of compression” and“DOC” refer to the depth at which the stress within the glass-based article changes compressive to tensile stress. At the DOC, the stress crosses from a positive (compressive) stress to a negative (tensile) stress and thus exhibits a stress value of zero. DOL is distinguished from DOC by measurement technique in that DOL is determined by surface stress meter using commercially available instruments such as the FSM-6000, manufactured by Luceo Co., Ltd. (Tokyo, Japan) (“FSM”), or the like, and known techniques using the same (often referred to as FSM techniques). In some embodiments, DOL indicates the depth of the compressive stress layer achieved by chemical strengthening, whereas DOC indicates the depth of the compressive stress layer achieved by thermal strengthening and/or mechanical strengthening.

[0091] Surface CS may be measured near the surface or within the strengthened glass at various depths. A maximum CS value may include the measured CS at the surface (CS_s) of the strengthened substrate. The CT, which is computed for the inner region adjacent the compressive stress layer within a glass substrate, can be calculated from the CS, the physical thickness t, and the DOL. CS may be measured using those means known in the art such as by the measurement of surface stress using an FSM or the like. Methods of measuring CS and DOL are described in ASTM 1422C-99, entitled“Standard Specification for Chemically Strengthened Flat Glass,” and ASTM 1279.19779“Standard Test Method for Non- Destructive Photoelastic Measurement of Edge and Surface Stresses in Annealed, Heat- Strengthened, and Fully-Tempered Flat Glass,” the contents of which are incorporated herein by reference in their entirety. Surface stress measurements rely upon the accurate measurement of the stress optical coefficient (SOC), which is related to the birefringence of the glass substrate. SOC in turn is measured by those methods that are known in the art, such as fiber and four point bend methods, both of which are described in ASTM standard C770- 98 (2008), entitled“Standard Test Method for Measurement of Glass Stress-Optical

Coefficient,” the contents of which are incorporated herein by reference in their entirety, and a bulk cylinder method. The relationship between CS and CT is given by the expression (1):

CT = (CS · DOL)/(t - 2 DOL) (1), wherein t is the physical thickness (pm) of the glass article. In various sections of the disclosure, CT and CS are expressed herein in megaPascals (MPa), physical thickness t is expressed in either micrometers (pm) or millimeters (mm) and DOL is expressed in micrometers (pm).

[0092] In one embodiment, a strengthened substrate can have a surface CS in the range from about 50 MPa to about 800 MPa (e.g., about 100 MPa or greater, about 150 MPa or greater, about 200 MPa or greater, of 250 MPa or greater, 300 MPa or greater, e.g., 400 MPa or greater, 450 MPa or greater, 500 MPa or greater, 550 MPa or greater, 600 MPa or greater,

650 MPa or greater, 700 MPa or greater, or 750 MPa or greater). [0093] The strengthened substrate may have a DOL in the range from about 35mih to about 200 mih (e.g., 45 mih, 60 mih, 75 mih, 100 mih, 125 mih, 150 mm or greater). In one or more specific embodiments, the strengthened substrate has one or more of the following: a surface CS of about 50 MPa to about 200 MPa, and a DOL in the range from about 100 mih to about 200 mih; a surface CS of about 600 MPa to about 800 MPa and a DOL in the range from about 35 mih to about 70 mih.

[0094] For strengthened glass-based articles in which the compressive stress layers extend to deeper depths within the glass-based article, the FSM technique may suffer from contrast issues which affect the observed DOL value. At deeper DOL values, there may be inadequate contrast between the TE and TM spectra, thus making the calculation of the difference between TE and TM spectra - and determining the DOL - more difficult.

Moreover, the FSM technique is incapable of determining the compressive stress profile (i.e., the variation of compressive stress as a function of depth within the glass-based article). In addition, the FSM technique is incapable of determining the DOL resulting from the ion exchange of certain elements such as, for example, lithium.

[0095] The techniques described below have been developed to yield more accurately determine the depth of compression (DOC) and compressive stress profiles for strengthened glass-based articles.

[0096] In U.S. Patent Application No. 13/463,322, entitled“Systems And Methods for Measuring the Stress Profile of Ion-Exchanged Glass(hereinafter referred to as“Roussev I”),” filed by Rostislav V. Roussev et al. on May 3, 2012, and claiming priority to U.S. Provisional Patent Application No. 61/489,800, having the same title and filed on May 25, 2011, two methods for extracting detailed and precise stress profiles (stress as a function of depth) of tempered or chemically strengthened glass are disclosed. The spectra of bound optical modes for TM and TE polarization are collected via prism coupling techniques, and used in their entirety to obtain detailed and precise TM and TE refractive index profiles HTM(Z) and HTE(Z). The contents of the above applications are incorporated herein by reference in their entirety.

[0097] In one embodiment, the detailed index profiles are obtained from the mode spectra by using the inverse Wentzel-Kramers-Brillouin (IWKB) method.

[0098] In another embodiment, the detailed index profiles are obtained by fitting the measured mode spectra to numerically calculated spectra of pre-defmed functional forms that describe the shapes of the index profiles and obtaining the parameters of the functional forms from the best fit. The detailed stress profile S(z) is calculated from the difference of the recovered TM and TE index profiles by using a known value of the stress-optic coefficient (SOC):

S(z) = [n_TM(z) - n n (z)|/SOC (2).

[0099] Due to the small value of the SOC, the birefringence htM(z) - nn (z) at any depth z is a small fraction (typically on the order of 1%) of either of the indices htM(z) and htE(z). Obtaining stress profiles that are not significantly distorted due to noise in the measured mode spectra requires determination of the mode effective indices with precision on the order of 0.00001 RIU. The methods disclosed in Roussev I further include techniques applied to the raw data to ensure such high precision for the measured mode indices, despite noise and/or poor contrast in the collected TE and TM mode spectra or images of the mode spectra. Such techniques include noise-averaging, filtering, and curve fitting to find the positions of the extremes corresponding to the modes with sub-pixel resolution.

[00100] Similarly, U.S. Patent Application No. 14/033,954, entitled“Systems and Methods for Measuring Birefringence in Glass and Glass-Ceramics (hereinafter“Roussev II”),” filed by Rostislav V. Roussev et al. on September 23, 2013, and claiming priority to U.S.

Provisional Application Serial No. 61/706,891, having the same title and filed on September 28, 2012, discloses apparatus and methods for optically measuring birefringence on the surface of glass and glass ceramics, including opaque glass and glass ceramics. Unlike Roussev I, in which discrete spectra of modes are identified, the methods disclosed in Roussev II rely on careful analysis of the angular intensity distribution for TM and TE light reflected by a prism-sample interface in a prism-coupling configuration of measurements.

The contents of the above applications are incorporated herein by reference in their entirety.

[00101] Hence, correct distribution of the reflected optical intensity vs. angle is much more important than in traditional prism-coupling stress-measurements, where only the locations of the discrete modes are sought. To this end, the methods disclosed in Roussev 1 and Roussev II comprise techniques for normalizing the intensity spectra, including normalizing to a reference image or signal, correction for nonlinearity of the detector, averaging multiple images to reduce image noise and speckle, and application of digital filtering to further smoothen the intensity angular spectra. In addition, one method includes formation of a contrast signal, which is additionally normalized to correct for fundamental differences in shape between TM and TE signals. The aforementioned method relies on achieving two signals that are nearly identical and determining their mutual displacement with sub-pixel resolution by comparing portions of the signals containing the steepest regions. The birefringence is proportional to the mutual displacement, with a coefficient determined by the apparatus design, including prism geometry and index, focal length of the lens, and pixel spacing on the sensor. The stress is determined by multiplying the measured birefringence by a known stress-optic coefficient.

[00102] In another disclosed method, derivatives of the TM and TE signals are determined after application of some combination of the aforementioned signal conditioning techniques. The locations of the maximum derivatives of the TM and TE signals are obtained with sub pixel resolution, and the birefringence is proportional to the spacing of the above two maxima, with a coefficient determined as before by the apparatus parameters.

[00103] Associated with the requirement for correct intensity extraction, the apparatus comprises several enhancements, such as using a light-scattering surface (static diffuser) in close proximity to or on the prism entrance surface to improve the angular uniformity of illumination, a moving diffuser for speckle reduction when the light source is coherent or partially coherent, and light-absorbing coatings on portions of the input and output facets of the prism and on the side facets of the prism, to reduce parasitic background which tends to distort the intensity signal. In addition, the apparatus may include an infrared light source to enable measurement of opaque materials.

[00104] Furthermore, Roussev II discloses a range of wavelengths and attenuation coefficients of the studied sample, where measurements are enabled by the described methods and apparatus enhancements. The range is defined by <¾l < 250ps_d, where as is the optical attenuation coefficient at measurement wavelength l, and o_s is the expected value of the stress to be measured with typically required precision for practical applications. This wide range allows measurements of practical importance to be obtained at wavelengths where the large optical attenuation renders previously existing measurement methods inapplicable. For example, Roussev II discloses successful measurements of stress-induced birefringence of opaque white glass-ceramic at a wavelength of 1550 nm, where the attenuation is greater than about 30 dB/mm.

[00105] While it is noted above that there are some issues with the FSM technique at deeper DOL values, FSM is still a beneficial conventional technique which may utilized with the understanding that an error range of up to +/-20% is possible at deeper DOF values. The terms“depth of layer” and“DOF” as used herein refer to DOF values computed using the FSM technique, whereas the terms“depth of compression” and“DOC” refer to depths of the compressive layer determined by the methods described in Roussev I & II. DOC and CT may also be measured using a scatered light polariscope (SCALP), using techniques known in the art.

[00106] The strengthened substrate may have a DOC in the range from about 35 pm to about 200 pm (e.g., 45 pm, 60 pm, 75 pm, 100 pm, 125 pm, 150 pm or greater). In one or more specific embodiments, the strengthened substrate has one or more of the following: a surface CS of about 50 MPa to about 200 MPa, and a DOC in the range from about 100 pm to about 200 pm; a surface CS of about 600 MPa to about 800 MPa and a DOC in the range from about 35 pm to about 70 pm.

[00107] Example glasses that may be used in the substrate may include alkali

aluminosilicate glass compositions or alkali aluminoborosilicate glass compositions, though other glass compositions are contemplated. Such glass compositions are capable of being chemically strengthened by an ion exchange process. One example glass composition comprises S1O2, B2O3 and Na20, where (S1O2 + B2O3) > 66 mol. %, and Na20 > 9 mol. %.

In an embodiment, the glass composition includes at least 6 wt.% aluminum oxide. In a further embodiment, the substrate includes a glass composition with one or more alkaline earth oxides, such that a content of alkaline earth oxides is at least 5 wt.%. Suitable glass compositions, in some embodiments, further comprise at least one of K2O, MgO, and CaO.

In a particular embodiment, the glass compositions used in the substrate can comprise 61-75 mol.% Si02; 7-15 mol.% AI2O3; 0-12 mol.% B2O3; 9-21 mol.% Na₂0; 0-4 mol.% K2O; 0-7 mol.% MgO; and 0-3 mol.% CaO.

[00108] A further example glass composition suitable for the substrate comprises: 60-70 mol.% S1O2; 6-14 mol.% AI2O3; 0-15 mol.% B2O3; 0-15 mol.% L12O; 0-20 mol.% Na₂0; 0- 10 mol.% K2O; 0-8 mol.% MgO; 0-10 mol.% CaO; 0-5 mol.% Zr0₂; 0-1 mol.% Sn0₂; 0-1 mol.% Ce02; less than 50 ppm AS2O3; and less than 50 ppm Sb203; where 12 mol.% < (L12O + Na20 + K2O) < 20 mol.% and 0 mol.% < (MgO + CaO) < 10 mol.%.

[00109] A still further example glass composition suitable for the substrate comprises: 63.5- 66.5 mol.% S1O2; 8-12 mol.% AI2O3; 0-3 mol.% B2O3; 0-5 mol.% L12O; 8-18 mol.% Na₂0; 0-5 mol.% K2O; 1-7 mol.% MgO; 0-2.5 mol.% CaO; 0-3 mol.% Zr0₂; 0.05-0.25 mol.%

Sn02; 0.05-0.5 mol.% Ce02; less than 50 ppm AS2O3; and less than 50 ppm Sb203; where 14 mol.% < (L12O + Na20 + K2O) < 18 mol.% and 2 mol.% < (MgO + CaO) < 7 mol.%.

[00110] In a particular embodiment, an alkali aluminosilicate glass composition suitable for the substrate comprises alumina, at least one alkali metal and, in some embodiments, greater than 50 mol.% S1O2, in other embodiments at least 58 mol.% S1O2, and in still other AI₂03 5,0,

> 1

mod ifiers

embodiments at least 60 mol.% SiCh, wherein the ratio

^J , where in the ratio the components are expressed in mol.% and the modifiers are alkali metal oxides. This glass composition, in particular embodiments, comprises: 58-72 mol.% SiCh; 9-17 mol.% AI2O3; 2-12 mol.% B2O3; 8-16 mol.% Na20; and 0-4 mol.% K2O, wherein the ratio

0₃ B₂O₃ > 1

mod ifiers

[00111] In still another embodiment, the substrate may include an alkali aluminosilicate glass composition comprising: 64-68 mol.% SiCh; 12-16 mol.% Na20; 8-12 mol.% AI2O3; 0- 3 mol.% B2O3; 2-5 mol.% K2O; 4-6 mol.% MgO; and 0-5 mol.% CaO, wherein: 66 mol.% < SiCh + B2O3 + CaO < 69 mol.%; Na₂0 + K2O + B2O3 + MgO + CaO + SrO > 10 mol.%; 5 mol.% < MgO + CaO + SrO < 8 mol.%; (Na20 + B2O3) - AI2O3 < 2 mol.%; 2 mol.% < Na20 - AI2O3 < 6 mol.%; and 4 mol.% < (Na20 + K2O) - AI2O3 < 10 mol.%.

[00112] In an alternative embodiment, the substrate may comprise an alkali aluminosilicate glass composition comprising: 2 mol% or more of AI2O3 and/or Zr02, or 4 mol% or more of AI2O3 and/or Zr02.

[00113] Where a substrate 210, 230 includes a crystalline substrate, the substrate may include a single crystal, which may include AI2O3. Such single crystal substrates are referred to as sapphire. Other suitable materials for a crystalline substrate include poly crystalline alumina layer and/or spinel (MgAhOr).

[00114] Optionally, the crystalline substrate 210, 230 may include a glass ceramic substrate, which may be strengthened or non-strengthened. Examples of suitable glass ceramics may include Li20-Ak03-Si02 system (i.e. LAS-System) glass ceramics, Mg0-Ah0₃-Si02 system (i.e. MAS-System) glass ceramics, and/or glass ceramics that include a predominant crystal phase including b-quartz solid solution, b-spodumene ss, cordierite, and lithium disilicate. The glass ceramic substrates may be strengthened using the chemical strengthening processes disclosed herein. In one or more embodiments, MAS-System glass ceramic substrates may be strengthened in L12SO4 molten salt, whereby an exchange of 2Li⁺ for Mg²⁺ can occur.

[00115] In one or more embodiments, the first substrate is unstrengthened, while the second substrate is strengthened. In some embodiments, the first substrate may include a soda lime glass. Optionally, the first substrate may include a soda lime glass that is strengthened. In another embodiment, the first substrate may include an alkali aluminosilicate glass that is strengthened. [00116] The laminates described herein may include one or more films, coatings or surface treatments to provide added functionality. Examples of such films and/or coatings include anti-reflective coatings, UV absorbing coatings, IR reflecting coatings, anti-glare surface treatments, and the like.

[00117] The laminates described herein may be formed using known techniques in the art including hot bending (i.e., forming the substrates separately or together in a furnace or heated environment), cold forming (i.e., shaping at room temperature) and the like.

[00118] The laminate may be disposed in an opening of a vehicle or within an architectural panel by adhesives and other means to secure the laminate thereto.

[00119] According to an aspect (1) of the present disclosure, a laminate is provided. The laminate comprises: a first substrate comprising a first thickness defined as a distance between opposing major surfaces of the first substrate; a second substrate comprising a second thickness defined as a distance between opposing major surfaces of the second substrate, the second thickness being about 1.0 mm or less; a third substrate comprising a third thickness defined as a distance between opposing major surfaces of the third substrate; a first interlayer disposed between the first and second substrates; and a second interlayer disposed between the second and third substrates, wherein the laminate exhibits a transmission loss of greater than about 40 dB over a frequency range from about 4000 Hz to about 8000 Hz.

[00120] According to an aspect (2) of the present disclosure, the laminate of aspect (1) is provided, wherein the laminate exhibits a transmission loss of greater than about 35 dB, greater than about 36 dB, or greater than about 37dB over a frequency range from about 2500 Hz to about 6300 Hz.

[00121] According to an aspect (3) of the present disclosure, the laminate of any of aspects (l)-(2) is provided, wherein the laminate exhibits a plate bending stiffness of less than about 200 Nm over a frequency range from about 400 Hz to about 8000 Hz, less than about 150 Nm over a frequency range from about 1000 Hz to about 8000 Hz, less than about 100 Nm over a frequency range from about 2500 Hz to about 8000 Hz, and/or less than about 50 Nm from a frequency range from about 6000 Hz to about 8000 Hz.

[00122] According to an aspect (4) of the present disclosure, the laminate of aspect (3) is provided, wherein the first, second, and third thicknesses are equal.

[00123] According to an aspect (5) of the present disclosure, the laminate of any of aspects (3)-(4) is provided, wherein the first, second, and third thicknesses are about 0.7 mm or less. [00124] According to an aspect (6) of the present disclosure, the laminate of any of aspects (l)-(5) is provided, wherein the laminate exhibits a coincidence dip frequency above 1000 Hz.

[00125] According to an aspect (7) of the present disclosure, the laminate of any of aspects (l)-(6) is provided, wherein the laminate exhibits a damping loss factor of greater than about 0.1 over a frequency range from about 100 Hz to about 8000 Hz, greater than about 0.15 over a frequency range from about 160 Hz to about 8000 Hz, greater than about 0.2 over a frequency range from about 250 Hz to about 8000 Hz, greater than about 0.25 over a frequency range from about 400 Hz to about 8000 Hz, greater than about 0.3 over a frequency range from about 630 Hz to about 8000 Hz, greater than about 0.35 over a frequency range from about 900 Hz to about 8000 Hz, greater than about 0.4 over a frequency range from about 1250 Hz to about 8000 Hz, greater than about 0.45 over a frequency range from about 2500 Hz to about 5000 Hz, and/or greater than about 0.4 over a frequency range from about 5000 Hz to about 8000 Hz.

[00126] According to an aspect (8) of the present disclosure, the laminate of any of aspects (l)-(7) is provided, wherein the laminate exhibits a peak damping loss factor of about 0.45 or more, or about 0.46 or more over a frequency range from about 100 Hz to about 8000 Hz, or over a range of from about 2000 Hz to about 6300 Hz.

[00127] According to an aspect (9) of the present disclosure, the laminate of any of aspects (7)-(8) is provided, wherein the first, second, and third thicknesses are equal.

[00128] According to an aspect (10) of the present disclosure, the laminate of any of aspects (7)-(9) is provided, wherein the first, second, and third thicknesses are about 0.7 mm or less.

[00129] According to an aspect (11) of the present disclosure, the laminate of any of aspects (1)-(10) is provided, wherein the laminate is symmetrical with respect to a plane that is through the center of the laminate and that is parallel to the first, second, and third substrates.

[00130] According to an aspect (12) of the present disclosure, the laminate of any of aspects (l)-(l 1) is provided, wherein the first thickness and the third thickness are equal.

[00131] According to an aspect (13) of the present disclosure, the laminate of any of aspects (l)-(l2) is provided, wherein the second thickness is less than the first and third thicknesses.

[00132] According to an aspect (14) of the present disclosure, the laminate of any of aspects (l)-(l2) is provided, wherein the second thickness is equal to the first and third thicknesses.

[00133] According to an aspect (15) of the present disclosure, the laminate of any of aspects (l)-(l4) is provided, wherein at least one of the first, second, and third substrates comprises a strengthened glass material. [00134] According to an aspect (16) of the present disclosure, the laminate of aspect (15) is provided, wherein the strengthened glass material is chemically or thermally strengthened.

[00135] According to an aspect (17) of the present disclosure, the laminate of any of aspects (l)-(l6) is provided, wherein at least one of the first, second, and third substrates comprises an alkali aluminosilicate glass or an alkali aluminoborosilicate glass.

[00136] According to an aspect (18) of the present disclosure, the laminate of any of aspects (l)-(l7) is provided, wherein the first and third substrates comprise soda lime glass.

[00137] According to an aspect (19) of the present disclosure, the laminate of aspect (18) is provided, wherein the second substrate comprises a chemically strengthened alkali aluminosilicate glass or an alkali aluminoborosilicate glass.

[00138] According to an aspect (20) of the present disclosure, the laminate of any of aspects (18)-(19) is provided, wherein the first and third thicknesses are less than about 3.0 mm or are about 2.1 mm, and the second thickness is about 0.7 mm or less.

[00139] According to an aspect (21) of the present disclosure, the laminate of any of aspects (l8)-(20) is provided, wherein the laminate exhibits a plate bending stiffness of about 1400 Nm or less over a frequency range from about 100 Hz to about 8000 Hz, about 1200 Nm or less over a frequency range from about 315 Hz to about 8000 Hz, about 1000 Nm or less over a frequency range from about 500 Hz to about 8000 Hz, about 800 Nm or less over a frequency range from about 800 Hz to about 8000 Hz, about 600 Nm or less over a frequency range from about 1250 Hz to about 8000 Hz, about 400 Nm or less over a frequency range from about 2500 Hz to about 8000 Hz, and/or about 300 Nm or less over a frequency range from about 4000 Hz to about 8000 Hz.

[00140] According to an aspect (22) of the present disclosure, the laminate of any of aspects (18)-(21) is provided, wherein the laminate exhibits a damping loss factor of about 0.2 or more over a frequency range from about 125 Hz to about 8000 Hz, about 0.25 or more over a frequency range from about 200 Hz to about 8000 Hz, about 0.3 or more over a frequency range from about 315 Hz to about 6300 Hz, about 0.35 or more over a frequency range from about 500 Hz to about 5000 Hz, and/or about 0.4 or more over a frequency range from about 630 Hz to about 3150 Hz.

[00141] According to an aspect (23) of the present disclosure, the laminate of any of aspects (l8)-(22) is provided, wherein the laminate exhibits a peak damping loss factor of about 0.44 or more, or about 0.45 over a frequency range from about 100 Hz to about 8000 Hz.

[00142] According to an aspect (24) of the present disclosure, the laminate of any of aspects (l)-(23) is provided, wherein the first and second interlayers comprise polyvinyl butyral. [00143] According to an aspect (25) of the present disclosure, the laminate of aspect (24) is provided, wherein at least one of the first and second interlayers are acoustic polyvinyl butyral.

[00144] According to an aspect (26) of the present disclosure, the laminate of any of aspects (l)-(25) is provided, wherein the second substrate comprises a thickness of about 0.55 mm or less.

[00145] According to an aspect (27) of the present disclosure, the laminate of any of aspects (l)-(26) is provided, wherein the laminate is disposed in a vehicle and comprises a windshield, a sidelite, a rearlite, a sunroof, or other vehicle glazing.

[00146] According to an aspect (28) of the present disclosure, a vehicle is provided. The vehicle comprises: a body having at least one opening and an interior; and the laminate of any of aspects (l)-(27) disposed in the at least one opening.

[00147] It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit or scope of the present disclosure.

Claims

What is claimed is:

1. A laminate comprising:

a first substrate comprising a first thickness defined as a distance between opposing major surfaces of the first substrate;

a second substrate comprising a second thickness defined as a distance between opposing major surfaces of the second substrate, the second thickness being about 1.0 mm or less;

a third substrate comprising a third thickness defined as a distance between opposing major surfaces of the third substrate;

a first interlayer disposed between the first and second substrates; and

a second interlayer disposed between the second and third substrates,

wherein the laminate exhibits a transmission loss of greater than about 40 dB over a frequency range from about 4000 Hz to about 8000 Hz.

2. The laminate of claim 1, wherein the laminate exhibits a transmission loss of greater than about 35 dB, greater than about 36 dB, or greater than about 37dB over a frequency range from about 2500 Hz to about 6300 Hz

3. The laminate of claim 1 or claim 2, wherein the laminate exhibits a plate bending stiffness of less than about 200 Nm over a frequency range from about 400 Hz to about 8000 Hz, less than about 150 Nm over a frequency range from about 1000 Hz to about 8000 Hz, less than about 100 Nm over a frequency range from about 2500 Hz to about 8000 Hz, and/or less than about 50 Nm from a frequency range from about 6000 Hz to about 8000 Hz.

4. The laminate of any one of the preceding claims, wherein the first thickness and the third thickness are equal.

5. The laminate of any one of the preceding claims, wherein the second thickness is less than the first and third thicknesses.

6. The laminate of any one of claims 1-4, wherein the second thickness is equal to the first and third thicknesses.

7. The laminate of any one of claims 1-4, wherein the first, second, and third thicknesses are equal.

8. The laminate of claim 7, wherein the first, second, and third thicknesses are about 0.7 mm or less.

9. The laminate of any one of the preceding claims, wherein the laminate exhibits a coincidence dip frequency above 1000 Hz.

10. The laminate of any one of the preceding claims, wherein the laminate exhibits a damping loss factor of greater than about 0.1 over a frequency range from about 100 Hz to about 8000 Hz, greater than about 0.15 over a frequency range from about 160 Hz to about 8000 Hz, greater than about 0.2 over a frequency range from about 250 Hz to about 8000 Hz, greater than about 0.25 over a frequency range from about 400 Hz to about 8000 Hz, greater than about 0.3 over a frequency range from about 630 Hz to about 8000 Hz, greater than about 0.35 over a frequency range from about 900 Hz to about 8000 Hz, greater than about 0.4 over a frequency range from about 1250 Hz to about 8000 Hz, greater than about 0.45 over a frequency range from about 2500 Hz to about 5000 Hz, and/or greater than about 0.4 over a frequency range from about 5000 Hz to about 8000 Hz.

11. The laminate of any one of the preceding claims, wherein the laminate exhibits a peak damping loss factor of about 0.45 or more, or about 0.46 or more over a frequency range from about 100 Hz to about 8000 Hz, or over a range of from about 2000 Hz to about 6300 Hz.

12. The laminate of any one of the preceding claims, wherein the laminate is symmetrical with respect to a plane that is through the center of the laminate and that is parallel to the first, second, and third substrates.

13. The laminate of any one of the preceding claims, wherein at least one of the first, second, and third substrates comprises a strengthened glass material.

14. The laminate of claim 13, wherein the strengthened glass material is chemically or thermally strengthened.

15. The laminate of any one of the preceding claims, wherein at least one of the first, second, and third substrates comprises an alkali aluminosilicate glass or an alkali aluminoborosilicate glass.

16. The laminate of any one of the preceding claims, wherein the first and third substrates comprise soda lime glass.

17. The laminate of claim 16, wherein the first and third thicknesses are less than about 3.0 mm or are about 2.1 mm, and the second thickness is about 0.7 mm or less.

18. The laminate of any one of claims 16-17, wherein the laminate exhibits a plate bending stiffness of about 1400 Nm or less over a frequency range from about 100 Hz to about 8000 Hz, about 1200 Nm or less over a frequency range from about 315 Hz to about 8000 Hz, about 1000 Nm or less over a frequency range from about 500 Hz to about 8000 Hz, about 800 Nm or less over a frequency range from about 800 Hz to about 8000 Hz, about 600 Nm or less over a frequency range from about 1250 Hz to about 8000 Hz, about 400 Nm or less over a frequency range from about 2500 Hz to about 8000 Hz, and/or about 300 Nm or less over a frequency range from about 4000 Hz to about 8000 Hz.

19. The laminate of any one of claims 16-18, wherein the laminate exhibits a damping loss factor of about 0.2 or more over a frequency range from about 125 Hz to about 8000 Hz, about 0.25 or more over a frequency range from about 200 Hz to about 8000 Hz, about 0.3 or more over a frequency range from about 315 Hz to about 6300 Hz, about 0.35 or more over a frequency range from about 500 Hz to about 5000 Hz, and/or about 0.4 or more over a frequency range from about 630 Hz to about 3150 Hz.

20. The laminate of any one of the preceding claims, wherein the first and second interlayers comprise polyvinyl butyral.

21. The laminate of claim 20, wherein at least one of the first and second interlayers are acoustic polyvinyl butyral.

22. The laminate of any one of the preceding claims, wherein the second substrate comprises a thickness of about 0.55 mm or less.

23. The laminate of any one the preceding claims, wherein the laminate is disposed in a vehicle and comprises a windshield, a sidelite, a rearlite, a sunroof, or other vehicle glazing.

24. A vehicle comprising:

a body having at least one opening and an interior; and

the laminate according to any one of the preceding claims disposed in the at least one opening.