Polymer interlayers with improved optical performance

Abstract

A interlayer is disclosed that is at least a bilayer, for use as a component for an electromagnetically reflective interlayer. The interlayer includes a first layer comprising a reflection layer and a second layer comprising PVB resin plasticized with plasticizer to form plasticized PVB, the second layer having a flow value DF135 of not more than 145 µm and the PVB for the second layer having a polydispersity index (PDI) of more than 4.2. An electromagnetically reflective interlayer and a multilayer rigid laminated composite are also described.

Description

POLYMER INTERLAYERS WITH IMPROVED OPTICAL PERFORMANCEFIELD OF THE INVENTION

[0001] The present invention is related to the field of polymer interlayers and interlayer components, and more specifically to polymer interlayers useful in the manufacture of laminated glass composite.BACKGROUND OF THE INVENTION

[0002] Angstrom-thick or thicker layers of metals, metal compounds, and other agents have conventionally been used in multiple layer glass panels to reflect heat-producing infra-red solar radiation while transmitting visible light. These layers can be arranged in sequence as stacks, and can be disposed on any appropriate substrate, such as biaxially stretched, thermoplastic polyethylene terephthalate) (PET) film or similar material. One form, known as an interference filter, comprises at least one layer of reflective metal sandwiched between reflection-suppressing or anti-reflective dielectric layers.

[0003] When an IR-reflection film such as an interference filter is combined with glass in a multiple layer glass laminate, for example in a vehicle windshield, at least one shock-dissipating interlayer of plasticized poly(vinyl butyral) (PVB) is usually included to absorb a blow from the head of an occupant within the vehicle or from a foreign object from outside the vehicle without allowing penetration through the windshield. In a typical arrangement, a single layer of a polyethylene terephthalate)-type coated reflection film is disposed between two layers of a poly(vinyl butyral)-type material to form a three-layer structure that is subsequently disposed between two layers of glass. The finished multiple layer glass composite has the combined benefit of safety and electromagnetic radiation transmission control.

[0004] Certain challenges may arise in the process for manufacturing these interlayers and related multilayer composites that include the interlayers sandwiched between rigid substrates such as glass. For example, processingconditions for the glass composite lamination process can result in one or more of IR-reflection film wrinkling; so-called “short vinyl” in which vinyl pulls in of the vinyl from the edge of the glass before it is bonded to the glass; and issues in achieving proper “edge deletion” to avoid the risks of corrosion of the layer reflecting infrared radiation. In a finished glass composite, each of these can lead to delamination, optical issues and other product defects and is unacceptable.

[0005] An additional optical quality defect that can be particularly noticeable at oblique viewing angles can occur in such safety glass panels as a visually apparent, isotropic, wave-like reflected image estimated to have an amplitude of about 0.002 to 0.012 mm and a wavelength of 2.5-7.5 mm. It is referred to in the art and hereinafter by the term “applesauce.” A number of theories as to the cause of applesauce have been proffered, As described in US 9,452,958, assigned to a entity related to the assignee of the present invention, applesauce may occur because the polyethylene-type layer, which reflects light at oblique viewing angles, conforms to the poly(vinyl butyral)-type layer during lamination and will assume any non-linearity, also referred to as waviness or non-planarity, that may be present on that poly(vinyl butyral)-type layer.

[0006] Several attempts to mitigate the severity of applesauce have been reported (see, for example, U.S. Pat. Nos. 4,465,736, 4,973,511 , 6,455,141 , 5,091 ,258 and 9,248,628); however, further methods of reducing applesauce are needed. Accordingly, further improved compositions and methods are needed to enhance the characteristics of polymer and poly(vinyl butyral) sheets that are used in conjunction with a polymer film layer, and specifically polyethylene terephthalate), without adversely affecting the optical and other required performance characteristics of the resulting laminated glass composites.SUMMARY OF THE INVENTION

[0007] In one aspect, the invention relates to a bilayer for use as a component for an electromagnetically reflective interlayer. The bilayer includesa first layer comprising an electromagnetic energy-reflecting layer, said electromagnetic energy-reflecting layer reflection layer comprising a base surface and a top surface; and a second layer having a thickness of 0.3-0.55 mm and comprising PVB resin plasticized with plasticizer to form plasticized PVB, said second layer having a contact surface adjacent the top surface of said electromagnetic energy-reflecting layer; wherein (a) the second layer has a flow value DF135 of no more than 145pm and wherein (b) the PVB of the second layer has a PDI of more than 4.2.

[0008] In one aspect, the invention relates to an electromagnetically reflective multilayered interlayer for multilayer rigid laminated composites. The electromagnetically reflective multilayered interlayer includes a first layer comprising an electromagnetic energy-reflecting layer, said electromagnetic energy-reflecting layer reflection layer comprising a base surface and a top surface; a second layer having a thickness of 0.3-0.55 mm and comprising PVB resin plasticized with plasticizer to form plasticized PVB, the second layer having a contact surface adjacent said top surface of said electromagnetic energy-reflecting layer; and a third layer comprising PVB plasticized with plasticizer to form plasticized PVB, the third layer having a contact surface adjacent said base surface of said energy-reflecting layer reflection layer; wherein (a) the second layer has a flow value DF135 of no more than 145pm and wherein (b) said PVB of the second layer has a PDI of more than 4.2.

[0009] In one aspect, the invention relates to a multilayer rigid laminated composite. The multilayer rigid laminated composite of the present invention includes the electromagnetically reflective interlayer of the present invention sandwiched between first and second rigid sheets. The laminated composite construction may be characterized by a ROSA score of 125 pixels or less.

[0010] Other aspects of the invention are as disclosed and claimed herein.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a partial, sectional view of an exemplary embodiment of the bilayer of the present invention;

[0012] Figure 2 is a partial, sectional view of an exemplary embodiment of the electromagnetically reflective interlayer of the present invention;

[0013] Figure 3 is a partial, sectional view of an exemplary embodiment of the multilayer rigid laminated composite of the present invention; and

[0014] Figure 4 is a schematic diagram of an embodiment of an exemplary device for analyzing the ROSA score of a multilayer rigid laminated composite.DETAILED DESCRIPTION

[0015] In order to facilitate a more comprehensive understanding of the present description, the meaning of certain terms and / or phrases, as used herein, are described or defined below. Notwithstanding, the definitions and descriptions should not be taken or interpreted to limit these terms as they are understood by one of ordinary skill, but simply to provide for improved understanding of how certain terms are used herein.

[0016] The terms “polymer interlayer” “interlayer,” “polymer layer”, “layer” and “sheet” as used herein, may designate a single-layer sheet or a multilayered assembly. A “single-layer sheet,” as the name implies, is a single polymer layer extruded as one layer. A “bilayer” designates at least two but optionally more than two layers, including separately extruded layers, coextruded layers, or any combination of separately and co-extruded layers. A multilayered assembly, may comprise multiple layers, including separately extruded layers, co-extruded layers, or any combination of separately and coextruded layers. By way of non-limiting example, a multilayered interlayer could comprise, for example: two or more single-layer sheets combined together (“plural-layer 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 single-layer sheet and at least one co-extruded sheet; and a combination of at least one plural-layer sheet and at least one co-extruded sheet. In various embodiments of the present invention, a multilayered interlayer comprises at least two polymer layers (e.g., a single layer or multiple layers co-extruded) disposed in contact with each other, wherein each layer comprises a polymer resin.

[0017] The term “resin,” as utilized herein refers to the polymeric component (e.g., poly(vinyl acetal) such as poly(vinyl butyral) often referred to as PVB) of a layer or polymer layer. Generally, resins may be combined with plasticizer, such as those discussed more fully below, to result in a plasticized polymer such as plasticized PVB. Additionally, and as exemplified herein, plasticized resin may have other components or ingredients in addition to the polymer or resin and plasticizer.

[0018] The term ’’adjacent”, used herein to describe the spacial relationship of elements such as coatings, surfaces or layers, is intended to include such elements contacting each other or adjoining as well as such elements that may be indirectly bonded to each while separated by one or more coatings, films or additional layers. In contrast, “contacting” is intended to describe elements in direct physical contact.

[0019] It should also be noted that, while poly(vinyl butyral) (“PVB”) may be specifically discussed as a polymer resin for polymer layers or interlayers in the present application, it should be understood that other thermoplastic resins besides PVB are contemplated and are within the spirit and scope of the present invention. Contemplated resins or polymers include, but are not limited to, polyurethane, polyvinyl chloride, polyethylene vinyl acetate) and combinations thereof. These polymers can be utilized alone, or in combination with other polymers. Accordingly, it should be understood that when ranges, values, characteristics and / or methods are given for elements such as PVB resins and layers herein, (e.g., plasticizer component percentages, thickness and characteristic-enhancing additives), those ranges, values and / or methods also apply, where applicable, to the other polymers and polymer blends disclosed herein or could be modified, as would be known to one of ordinary skill, to be applied to different materials.

[0020] In one aspect, the present invention is directed to a bilayer that is useful or usable as a component for an electromagnetically reflective interlayer. The electromagnetically reflective interlayer may in turn be useful or usable as an interlayer for a laminated composite wherein the interlayer is sandwiched between two rigid sheets. With reference to Figure 1 , the bilayer 5 may includea first layer 10 and a second layer 20. The first layer 10 may include or be referred to as an electromagnetic energy-reflecting layer and may include a base surface 13 and a top surface 15. In one or more exemplary embodiments, the first layer 10 may have a thickness from about 12 microns to about 125 microns. In one or more exemplary embodiments, the electromagnetic energyreflecting layer 10 includes a substrate 12 having a base surface 13 and a coated surface 14 supporting an electromagnetic energy-reflecting coating 16 thereon. The substrate 12 may be formed from any suitable film-forming polymer. Suitable polymers for forming substrate 12 may include polyesters such as polyethylene terephthalate (PET), polycarbonate, polyamides, and the like. The substrate may have a thickness of from about 12 microns to about 125 microns or 25 microns to 76 microns.

[0021] The electromagnetic energy-reflecting coating 16 on the top surface or coated surface 14 of first layer 10 may be a single layer or multilayer coating of any material which reflects incident electromagnetic energy. The electromagnetic energy-reflecting coating 16 may in one or more exemplary embodiments have a thickness from about 10nm to 250 nm. In one or more exemplary embodiments, the electromagnetic energy-reflecting coating 16, or more generally the reflection layer 10, reflects electromagnetic energy in the visible range or the infrared range or a wavelength range of from 780 nm to 2,500 nm. . In one or more exemplary embodiments, the coating may include a metal layer or a metal oxide layer or a combination thereof or a plurality of metal layer or a plurality of metal oxide layers or a combination thereof. In one or more exemplary embodiments, the electromagnetic energy-reflecting coating 16 includes alternating layers of a high refractive index material and a low refractive index material.

[0022] The electromagnetic energy-reflecting coating 16 and, in applicable embodiments, its various layers, may be formed from or applied to the substrate 12 using known and publicly available coating deposition techniques. Nonlimiting examples of suitable coating deposition techniques include sputtering, vacuum deposition, solvent or solution coating and the like. The electromagnetic energy-reflecting coating 16 may be vacuum-depositedcoating, meaning that the coating layer or (in a multilayer coating embodiment) all layers of the coating are deposited via vacuum deposition.

[0023] In one or more exemplary embodiments, the reflection layer may be a coated reflection film. Such reflection films are known in the art and commercially available, for example from the assignee of the present invention under the tradename XIR™. Suitable reflection films and their structures are also described for example in U.S. Patent No. 10,946,619, the contents and disclosure of which are hereby incorporated herein by reference.

[0024] In one or more exemplary embodiments, the electromagnetic energyreflecting layer 10 includes a multilayer organic alternating refractive index construction as described for example in U.S. Patent No. 5,103,337, the contents and disclosure of which are hereby incorporated herein by reference.

[0025] The bilayer of the present invention may include a second layer 20 that includes a contact surface 21 contacting the top surface 15 of the reflection layer 10. The second layer 20 may include PVB resin plasticized with plasticizer to form plasticized PVB. The second layer may have a thickness of from 0.30 to 0.55 mm. In one or more exemplary embodiments, the second layer 20 has a flow value DF135 of no more than 145pm or no more than 142pm or no more than 140pm or no more than 135pm or no more than 130pm or no more than 120pm or no more than 1 10pm or no more than 100pm or no more than 90pm or no more than 80pm or no more than 75pm or no more than 70 pm or from 60pm to 145pm or from 60pm to 135pm or from 60pm to 130pm or from 60pm to 120pm or from 60pm to 100pm or from 60pm to 90pm or from 60pm to 80pm or from 60 pm to 70pm. In general, DF135 is a quantifying parameter with testing protocol to quantify or describe bilayer or interlayer flow under simulated lamination conditions, with higher DF135 values generally indicative of better flow during autoclave lamination conditions. In analyzing flow characteristics of the present invention, a DF135 was measured as the deformation (reduction of sample thickness normalized according to the standard interlayer thickness 0.76 mm) when a certain load pressure (i.e., 11 .5 psi) is applied onto the sample surface in the thickness direction and the sample is being heated from 23° C. to 140° C. at 10° C. / min heating rate. The flow iscommonly measured as the DF 135 by a thermo-mechanical analysis apparatus. As an example, a sheet sample of 0.76 mm in thickness is cut into discs having a diameter of 8 mm, and the discs are subjected to the DF 135 testing. A flow value of 0.242 mm means that an interlayer with 0.76 mm thickness will deform 0.242 mm in the thickness direction. The flow value is calculated by subtracting the thickness at 135° C. from the thickness at 45° C. measured under the aforementioned conditions to get the deformation value. This value is then normalized to the standard interlayer thickness 0.76 mm.

[0026] In one or more exemplary embodiments, the contact surface 21 of the second layer 20 may have a surface roughness value Rz of less than 45 pm or less than 35 pm or less than 25 pm or less than 20 pm or less than 15 pm. The second layer 20 may also include a lamination surface 22 opposite the contact surface 21 and in one or more embodiments the laminating surface may have an Rz value of 20 or more pm. In general, Rz is a known quantifying parameter with a commercially utilized testing protocols to quantify or describe the roughness of a surface in terms of surface peak heights. In measuring the surface roughness Rz of the contact surface 21 for the present invention, as well as for measuring the MD Rsm described below, surface roughness was measured under a Mahr M1 500 Perthometer with each sample measured at both top and bottom surfaces of the sample and five traces run on each measurement location in both the machine and cross machine directions. The recorded surface roughness value Rz in the examples was the averaged value from both directions at the top or bottom surface of the sheet, where MD Rsm is the averaged value in the machine direction.

[0027] In one or more exemplary embodiments, the contact surface 21 of the second layer 20 may have a machine direction surface roughness value (MD Rsm) of 200 to 900 or less than 1000. In general, MD Rsm is a known quantifying parameter with a commercially utilized testing protocols to quantify or describe the roughness of a surface in terms of distance between surface peaks. The recorded surface roughness value MD Rsm was the average value from the five machine direction (MD) measurements at the top or bottom side of the sheet.

[0028] In one or more exemplary embodiments, the contact surface of said second layer is a non-embossed surface such that surface roughness is created exclusively through known melt facture methods or techniques. In one or more exemplary embodiments, the contact surface of said second layer is an embossed surface such that surface roughness is created through a combination of known embossing methods or techniques and known melt facture methods or techniques.

[0029] In one or more exemplary embodiments, the second layer has a warm shrinkage of 8% or less. In general, the phrase “warm shrinkage” is intended to describe the dimension change of a layer or sheet or film after exposure thereof to a temperature of 54 °C for 10 minutes. For purposes of the present invention, warm shrinkage was measured using the following protocol: 20 cm sheet samples were cut out from an extruded layer roll immediately after extrusion, measured in the machine direction using a calibrated ruler, marked using a template to indicate as an original sample length a 10cm distance from an edge in the machine direction, and then placed on a cardboard sheet. The samples on the carboard were placed on a rack in an oven whose temperature was pre-set at 54°C. The samples were then removed from the oven after 10 minutes, placed on the benchtop to allow to cool down to room temperature for a minimum of 5 minutes. The sample length in the machine direction was measured using the calibrated ruler before and after 54°C oven treatment. The shrinkage was calculated as the percentage of the length change in the machine direction relative to the original length prior to the oven treatment.

[0030] The second layer 20 includes PVB resin. The PVB resin of the second layer may be produced by known aqueous or solvent acetalization processes by reacting polyvinyl alcohol (“PVOH”) with butyraldehyde in the presence of an acid catalyst, separation, stabilization, and drying of the resin. Such acetalization processes are disclosed, for example, in U.S. Pat. Nos. 2,282,057 and 2,282,026 and Wade, B. (2016), “Vinyl Acetal Polymers”, Encyclopedia of Polymer Science and Technology, pp. 1 -22 (John Wiley & Sons, Inc.), the entire disclosures of which are hereby incorporated herein by reference.

[0031] While generally referred to herein as “poly( vinyl acetal)” or “poly(vinyl butyral)”, the PVB resins described herein may include residues of any suitable aldehyde, including, but not limited to, isobutyraldehyde. In some embodiments, one or more poly(vinyl acetal) resin can include residues of at least one Ci to C10 aldehyde, or at least one C4 to CB aldehyde. Examples of suitable C4 to Cs aldehydes can include, but are not limited to, n-butyraldehyde, isobutyraldehyde, 2-methylvaleraldehyde, n-hexyl aldehyde, 2-ethylhexyl aldehyde, n-octyl aldehyde, and combinations thereof.

[0032] A parameter useful in describing the PVB resin components of the present invention is residual hydroxyl content (as vinyl hydroxyl content or poly(vinyl alcohol) (“PVOH”) content). Residual hydroxyl content refers to the amount of hydroxyl groups remaining as side groups on the chains of the polymer after processing is complete. For example, PVB can be manufactured by hydrolyzing poly(vinyl acetate) to poly(vinyl alcohol), and then reacting the poly(vinyl alcohol) with butyraldehyde to form PVB. In the process of hydrolyzing the poly(vinyl acetate), typically not all the acetate side groups are converted to hydroxyl groups. Further, the reaction with butyraldehyde typically will not result in all the hydroxyl groups being converted into acetal groups. Consequently, in any finished PVB, there will typically be residual acetate groups (such as vinyl acetate groups) and residual hydroxyl groups (such as vinyl hydroxyl groups) as side groups on the polymer chain. Generally, the residual hydroxyl content of a polymer can be regulated by controlling the reaction times and reactant concentrations, among other variables in the polymer manufacturing process. When utilized as a parameter herein, the residual hydroxyl content is measured on a wt. % basis per ASTM D-1396.

[0033] In various embodiments, the PVB resin comprises about 8 to about 35 wt. % (wt. %) residual hydroxyl groups calculated as PVOH, about 13 to about 30 wt. % residual hydroxyl groups calculated as PVOH, about 8 to about 22 wt. % residual hydroxyl groups calculated as PVOH, or about 15 to about 22 wt. % residual hydroxyl groups calculated as PVOH; and for some of the high rigidity interlayers disclosed herein, for one or more of the layers, the poly(vinyl butyral) resin comprises greater than about 19 wt. % residual hydroxyl groupscalculated as PVOH, greater than about 20 wt. % residual hydroxyl groups calculated as PVOH, greater than about 20.4 wt. % residual hydroxyl groups calculated as PVOH, and greater than about 21 wt. % residual hydroxyl groups calculated as PVOH.

[0034] In various embodiments, the PVB resin includes a residual hydroxyl content of at least about 18, at least about 18.5, at least about 18.7, at least about 19, at least about 19.5, at least about 20, at least about 20.5, at least about 21 , at least about 21 .5, at least about 22, at least about 22.5 wt. % and / or not more than about 30, not more than about 29, not more than about 28, not more than about 27, not more than about 26, not more than about 25, not more than about 24, not more than about 23, or not more than about 22 wt. %, measured as described above.

[0035] The resin can also comprise less than 35 wt. % residual ester groups, less than 30 wt. %, less than 25 wt. %, less than 15 wt. %, less than 13 wt. %, less than 11 wt. %, less than 9 wt. %, less than 7 wt. %, less than 5 wt. %, or less than 1 wt. % residual ester groups calculated as polyvinyl ester, e.g., acetate, with the balance being an acetal, preferably butyraldehyde acetal, but optionally including other acetal groups in a minor amount, for example, a 2 ethyl hexanal group (see, for example, U.S. Patent No. 5,137,954, the entire disclosure of which is incorporated herein by reference). The residual acetate content of a resin may also be determined according to ASTM D-1396.

[0036] In some embodiments, as described above, one or more of the polymer layers of the interlayer may be formed from poly(vinyl acetal) resin. Such poly(vinyl acetal) resin may have a residual acetate content of at least about 1 , at least about 3, at least about 5, at least about 7 wt. % and / or not more than about 15, not more than about 12, not more than about 10, not more than about 8 wt. %, measured as described above.

[0037] Other parameters useful in describing the PVB resin components of the present invention relate to its molecular weight. As known in the art, molecular weight may be quantified as weight average molecular weight (Mw) or number average molecular weight (Mn). The weight average molecular weight of a PVB resin of the present invention may be in the range of from about50,000 to about 600,000, about 70,000 to about 450,000, or about 100,000 to about 425,000 or about 180,000 to 250,000 Daltons. A related parameter, polydispersity index (PDI), characterizes particle size distributions of a sample and is calculated as the ratio of weight average by number average molecular weight (Mw / Mn). The PVB resin of the present invention may have a PDI of more than 2.5 or more than 3.0 or more than 3.5 or more than 4.0 or more than than 4.2 or from 2.5 to 7.0. or from 4.0 to 7.0. For testing described herein, molecular weight (kg / mol) of PVB resins was measured by gel permeation chromatography (GPC) in Hexafluoroisopropanol (HFIP solvent) with 20mM Potassium Trifluoroacetate at 40 °C. (Flow rate: 1 .0 ml / min; Sample solution: 20 mg sample in 10 ml of Hexafluoroisopropanol with 20mM of potassium trifluoroacetate + 10 pl Isopropanol flow rate marker; Injection volume: 10 pl; Column set: Polymer Laboratories 5 pm HFIP gel guard and Mixed HFIP gel). Following are more details for detection and instrumentation. For the detection part, the refractive index is set to 40 °C with attenuation setting at 31250nRIU and zero offset setting at 5%. The calibrants were monodisperse polymethylmethacrylate standards with Mw from 580 to 3,000,000 g / mol.

[0038] The second layer, as well as other components or elements of the present invention, includes PVB resin plasticized with plasticizer to form plasticized PVB. In generally, plasticizers may be added to the polymer resins in the formation of polymer layers or interlayers to for example increase the flexibility and durability of the resultant product. Plasticizers generally function by embedding themselves between chains of polymers, spacing them apart (increasing the “free volume”) and thus significantly lowering the glass transition temperature (Tg) of the polymer resin, making the material softer. In this regard, the amount of plasticizer in the second layer can be adjusted to tune and establish a desirable glass transition temperature (Tg) for the plasticized PVB. The glass transition temperature (Tg) is the temperature that marks the transition from the glassy state of the interlayer to the rubbery state. In general, higher amounts of plasticizer loading can result in lower Tg.

[0039] Suitable plasticizers for the plasticized PVB of the second layer may generally include, but are not limited to, esters of a polybasic acid, a polyhydricalcohol, triethylene glycol di-(2-ethylbutyrate), triethylene glycol di-(2- ethylhexonate) (known as “3-GEH”), triethylene glycol diheptanoate, tetraethylene glycol diheptanoate, dihexyl adipate, dioctyl adipate, hexyl cyclohexyladipate, mixtures of heptyl and nonyl adipates, diisononyl adipate, heptylnonyl adipate, dibutyl sebacate, and polymeric plasticizers such as oil- modified sebacic alkyds and mixtures of phosphates and adipates, and mixtures and combinations thereof. 3-GEH is particularly preferred. Other examples of suitable plasticizers can include, but are not limited to, tetraethylene glycol di-(2-ethylhexanoate) (“4-GEH”), di(butoxyethyl) adipate, and bis(2-(2-butoxyethoxy)ethyl) adipate, dioctyl sebacate, nonylphenyl tetraethylene glycol, and mixtures thereof.

[0040] Other suitable plasticizers may include blends of two or more distinct plasticizers, including but not limited to those plasticizers described above. Still other suitable plasticizers, or blends of plasticizers, may be formed from aromatic groups, such polyadipates, epoxides, phthalates, terephthalates, benzoates, toluates, mellitates and other specialty plasticizers. Further examples 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, diethylene glycol di-o-toluate, triethylene glycol di-o-toluate, dipropylene glycol di-o-toluate, 1 ,2- octyl dibenzoate, tri-2-ethylhexyl trimellitate, di-2-ethylhexyl terephthalate, bisphenol A bis(2-ethylhexaonate), ethoxylated nonylphenol, and mixtures thereof. In some embodiments, the plasticizer can be selected from the group consisting of dipropylene glycol dibenzoates, tripropylene glycol dibenzoates, and combinations thereof.

[0041] Generally, plasticizer content of plasticized PVB resins for polymer layers and interlayers may be measured in the art in parts per hundred resin parts (“phr”) on a weight per weight basis. For example, if 30 grams of plasticizer is added to 100 grams of polymer resin, the plasticizer content of the resulting plasticized polymer would be 30 phr. When the plasticizer content ofa polymer layer is given in this application, the plasticizer content of the particular layer is determined in reference to the phr of the plasticizer in the melt that was used to produce that particular layer.

[0042] In one or more exemplary embodiments, the second layer of the bilayer of the present invention may have a total plasticizer content of no more than 40 phr or no more than 38 phr or no more than 36 phr or no more than 34 phr or no more than 32 phr or no more than 30 phr. In some embodiments, the total plasticizer content of the second layer of the bilayer may be from about 18 to about 40 phr, about 20 to about 38 phr, or about 25 to about 35 phr.

[0043] As indicated above, another parameter that may be useful in describing plasticized PVB for the present invention is glass transition temperature (Tg). As known in the art, glass transition temperature may be determined by a dynamical mechanical thermal analysis (DMTA) in shear mode wherein the DMTA measures the storage (elastic) modulus (G’) in Pascals, loss (viscous) modulus (G”) in Pascals, tan delta (=G” / G’) of the specimen as a function of temperature at a given oscillation frequency and temperature sweep rate. The Tgis then determined by the position of the tan delta peak on the temperature scale in °C with the tan delta peak value sometimes referred to as tan delta or peak tan delta. In quantifying glass transition temperature for the present invention, a frequency of 1 Hz and temperature sweep rate of 3°C / min were used. As used herein, “tan delta”, “peak tan delta”, “tan 6” and “peak tan 5” may be used interchangeably. In one or more exemplary embodiments, the plasticized PVB resin of the present invention has a glass transition temperature of less than 40°C or less than 39°C or less than 38°C or from 30 to 40°C or higher than 32°C or higher than 35°C or from 31 °C to 38°C.

[0044] The plasticized PVB may include one or more additional and / or optional ingredients. For example, adhesion control agents (“ACAs”) can also be added to the plasticized PVB. ACAs generally function to alter and / or improve the adhesion of an interlayer to the rigid sheets such as glass when forming a laminated composite. Contemplated ACAs include, but are not limited to, magnesium carboxyl ates / salts. In addition, contemplated ACAs may also include those ACAs disclosed in U.S. Patent 5,728,472, incorporated byreference herein in its entirety, such as residual sodium acetate, potassium acetate, and / or magnesium bis(2-ethyl butyrate).

[0045] Other additives may be incorporated into the plasticized PVB to enhance its performance in a final product and / or impart certain additional properties. Such additives include, but are not limited to, dyes, pigments, stabilizers (e.g., ultraviolet stabilizers), antioxidants, anti-blocking agents, flame retardants, IR absorbers or blockers (e.g., indium tin oxide, antimony tin oxide, lanthanum hexaboride (LaB6) and cesium tungsten oxide), processing aides, flow enhancing additives, lubricants, impact modifiers, nucleating agents, thermal stabilizers, UV absorbers, UV stabilizers, dispersants, surfactants, chelating agents, coupling agents, adhesives, primers, reinforcement additives, and fillers, among other additives known to those of ordinary skill in the art.

[0046] In another aspect, the present invention is directed to an electromagnetically reflective multilayered interlayer for multilayer laminated rigid composites. With reference to Figure 2, the interlayer 25 of the present invention includes a first layer 10 comprising a reflection layer, the reflection layer including a substrate 12 having a base surface 13 and a coated surface 14 and an electromagnetic energy-reflecting coating 16 on the coated surface 14 of substrate 12; a second layer 20 comprising PVB plasticized with plasticizer to form plasticized PVB, with the second layer 20 having a contact surface 21 adjacent the electromagnetic energy-reflecting coating 16; and a third layer 30 comprising PVB plasticized with plasticizer to form plasticized PVB, with the third layer having a contact surface 31 adjacent the base surface 13 of the substrate. In one or more exemplary embodiments, the second layer has a flow value DF135 of no more than 145 pm. In one or more embodiments, the PVB of the second layer has a PDI of at least 2.7 or at least 3.0 or at least 3.5. In one or more embodiments, the second layer 20 includes a lamination surface 22 opposite its contact surface 21 and third layer 30 similarly includes a lamination surface 32 opposite its contact surface 31. One or both of lamination surfaces 22 and 32 may have a surface roughness Rz of at least 20 pm.

[0047] Third layers for the interlayer of the present invention may vary widely in form, features or construction. In one or more exemplary embodiments, the third layer may be clear or transparent. In one or more exemplary embodiments, the third layer may be colored or tinted. In one or more exemplary embodiments, the third layer may be or include a single-layer or monolithic sheet or a multilayered assembly, a plural-layer sheet; a coextruded sheet); two or more co-extruded sheets combined together; a combination of at least one single-layer sheet and at least one co-extruded sheet; and a combination of at least one plural-layer sheet and at least one coextruded sheet. In one or more embodiments, the third layer may have a thickness of from 0.3 mm to 1 .3 mm. In one or more embodiments, the third layer may be a multilayer construction having sound damping properties, such as described in U.S. Patent No. 9,460,702, the contents and disclosure of which are hereby incorporated herein by reference.

[0048] Preceding descriptions regarding for example PVB resin type and characterization, plasticizer type and amount, plasticized PVB resin details and other elements of the second layer 20 may each be the same as or different from those elements as present in the third layer 30. More generally, and for avoidance of doubt and to improve clarity of description, the present invention is described herein with respect to various interrelated aspects and embodiments and one of ordinary skill will understand and appreciate that elements or features used to describe one aspect or embodiment may be applicable and useful in describing other embodiments. Accordingly, descriptions and disclosure relating to elements or features of an aspect or embodiment of the present invention are hereby expressly relied on to describe and support those elements or features in other aspects or embodiments. More particularly, descriptions and disclosure relating to elements or features of the bilayer of the present invention such as PVB resin, plasticizer and plasticized PVB as described herein are hereby expressly relied on to describe and support those elements or features in the electromagnetically reflective multilayered interlayer for laminated composites as described herein, and vice versa.

[0049] It is contemplated that the second and third layers, and more generally the bilayers and interlayers, as described herein may be produced by any suitable process known to one of ordinary skill in the art of producing polymer interlayer sheets that are capable of being used in a multiple layer rigid composite (such as a glass laminate). For example, it is contemplated that the polymer interlayer sheets may be formed through solution casting, compression molding, injection molding, melt extrusion, melt blowing or any other procedures for the production and manufacturing of a polymer interlayer sheet known to those of ordinary skill in the art. Further, in embodiments where multiple polymer interlayers are utilized, it is contemplated that these multiple polymer interlayers may be formed through co-extrusion, blown film, dip coating, solution coating, blade, paddle, air-knife, printing, powder coating, spray coating or other processes known to those of ordinary skill in the art. The final multilayer glass composites of the present disclosure may be formed using processes known in the art.

[0050] In one non-limiting method, the bilayer 5 of the present invention is pre-formed as an intermediate component of a multilayer interlayer, with the bilayer combinable with a second plasticized PVB resin sheet layer 30 as shown in Figure 2 disposed in contact with base surface 13 of the substrate 12 of the reflecting layer 10, thereby forming a three-layer construct that can then be disposed or sandwiched between two rigid sheets 40 and 50 as shown in Figure 3 to form a multilayer rigid laminated composite 60. A suitable exemplary method of manufacture in this regard is described in U.S. Patent No. 8,551 ,600, assigned to the assignee of the present invention, the contents and disclosure of which are hereby incorporated herein by reference.

[0051] In an exemplary extrusion process, thermoplastic resin and plasticizers, including any of those resins and plasticizers described above, are generally pre-mixed and fed into an extruder device. Additives such as colorants and UV inhibitors (in liquid, powder, or pellet form) may be used and can be mixed into the thermoplastic resin or plasticizer prior to arriving in the extruder device. These additives are incorporated into the thermoplastic polymer resin, and by extension the resultant polymer sheet, to enhance certainproperties of the polymer interlayer sheet and its performance in the final multiple layer composite product.

[0052] In the extruder device, the particles of the thermoplastic raw material and plasticizers, including any of those resins, plasticizers, and other additives described above, are further mixed and melted, resulting in a melt that is generally uniform in temperature and composition. Embodiments of the present invention may provide for the melt temperature to be approximately 200°C. Once the melt reaches the end of the extruder device, the melt is propelled into the extruder die. The extruder die is the component of the extruder device which gives the final polymer interlayer sheet product its profile. The die will generally have an opening, defined by a lip, that is substantially greater in one dimension than in a perpendicular dimension. Generally, the die is designed such that the melt evenly flows from a cylindrical profile coming out of the die and into the product’s end profile shape. A plurality of shapes can be imparted to the end polymer interlayer sheet by the die so long as a continuous profile is present. Generally, in its most basic sense, extrusion is a process used to create objects of a fixed cross-sectional profile. This is accomplished by pushing or drawing a material through a die of the desired cross-section for the end product.

[0053] In another aspect, the present invention is directed to a multilayer rigid laminated composite. In general, the multilayer rigid laminated composite of the present invention includes the interlayer aspect of the present invention sandwiched between first and second rigid sheets 40 and 50. Rigid sheets 40 and 40 may be inorganic or formed from glass or similar material or organic and formed from polymers such polycarbonates or acrylics. Sheets 40 and 50 may have a thickness of from 0.4 mm to 3.0 mm in one or more exemplary embodiments. In one or more embodiments, thicknesses for sheets 40 and 50 may be substantially constant along their length or may vary along their lengths. Rigid sheets may include coatings or additives, for example to improve optical performance or toughness, such as infrared or UV absorbers. With reference to Figure 3, the multilayer rigid laminated composite 60 includes a first layer 10 comprising a reflection layer; a second layer 20 having a thickness of 0.3-0.55 mm and comprising PVB resin plasticized with plasticizer to form plasticizedPVB, said layer having a lamination surface and a contact surface contacting said electromagnetic energy-reflecting coating; a third layer 30 comprising PVB plasticized with plasticizer to form plasticized PVB, said third layer having a lamination surface 32 and a contact surface 31 adjacent said base surface 13 of said energy-reflecting layer reflection layer; a fist rigid sheet 40 adjacent said lamination surface 22 of said second layer 20; and a second rigid sheet 50 adjacent said lamination surface 32 of said third layer 30.

[0054] In one or more exemplary embodiments, the laminated rigid composite may have a ROSA score of 125 pixels or less or 110 pixels or less or 90 pixels or less or 80 pixels or less or 75 pixels or less or 70 pixels or less, or from 25 to 145 pixels or from 25 to 125 pixels or from 35 to 125 pixels or from 45 to 125 pixels or from 50 to 125 pixels. Reflective orange skin analyzer (ROSA) measurement was developed to quantify the severity of “applesauce” (or orange skin / orange peel) using a glancing light reflectance model. With reference to Figure 4, an LED light source was used to generate a signal and a camera was used to image the reflectance of sample. The instrument includes a Smart Vision Lights S30-WHI-W Spot Light (LED, Barrel, 30mm, White, "Prox Light", Wide Lens Option, 24V) and Balsler camera (avA1900-50gm; Aviator - KAI-02150, 2 / 3", C-Mount, 1920x1080, 51 fps, Mono, CCD, GigE) fitted with a Fujinon lens (HF12.5HA-1 B, 12.5 mm, 2 / 3" Format, C-Mount, with manual focus, iris and locking screws, 1 .4 f-stop). The instrument was configured such that the projector illuminates the sample at an oblique angle and the reflection detected by the camera as outlined in the schematic of Figure 4. The measurements were run in an enclosure to block the other light sources besides the LED light of the instrument. A sample reflectance image from testing as described herein is depicted in Figure 4.

[0055] An image analysis algorithm was then applied to the reflectance image. The size of the image is 1000 x 1000 pixels with the lateral dimension of 65 x 65mm. The grayscale image obtained from the ROSA is converted to an FFT (Fast Fourier Transform) of the image using the National Instruments Vision Development Module function called “IMAQ FFT”. The FFT creates a complex image in which high frequencies are grouped at the center, while lowfrequencies are located at the edges. The FFT is then truncated using the National Instruments Vision Development Module function called “IMAQ Complex Truncate”. The truncation frequency is set to 1 .00%. The truncation frequency % is the percentage of the frequencies that are retained within a Fourier-transformed image. The function is set so that the high pass frequencies are truncated. The filtered FFT is converted back into an image using the National Instruments Vision Development Module function called “IMAQ Inverse FFT”. The image is then equalized using the National Instruments Vision Development Module function called “IMAQ equalize”. This function produces a histogram equalization of an image. Redistributing the pixel values of an image to linearize the accumulated histogram. The grayscale image obtained equalization is converted to an FFT of the image using the National Instruments Vision Development Module function called “IMAQ FFT”. The FFT is then truncated using the National Instruments Vision Development Module function called “IMAQ Complex Truncate”. The truncation frequency is set to 50.00%. The function is set so that the low pass frequencies are truncated. The filtered FFT is converted back into an image using the National Instruments Vision Development Module function called “IMAQ Inverse FFT”. The image is then thresholded using the National Instruments Vision Development Module function called “IMAQ threshold”. The function converts an image to a binarized image based on a manual threshold. All pixels with intensities between 128 and 255 for an 8-bit image are set to a value of 1. All pixels with intensities below 128 are given a value of 0 in the binarized image. The image is then filtered using the National Instruments Vision Development Module function called “IMAQ Particle Filter 3”. The filter is set to keep particles in the binarized image with an area between 3 and 10,000,000 pixels2. The areas of all particles in the image are then determined using National Instruments Vision Development Module function called “IMAQ Particle Analysis”. The function produces an array of each particles’ area. The National Instruments LabVIEW function called “Mean” is used to calculate the “Average Area (pixels)” value or average particle size value, which is the ROSA score reported in this invention. In general, a higher ROSA score represents thehigher level of “applesauce” for the sample. Typically, when the ROSA score is higher than 125 but less than 250, the applesauce defects in the laminate are observable under the reflection light and treated as light level. When the ROSA score is higher than 250 but less than 600, the applesauce defects in the laminate are noticeable under the reflection light and treated as medium level. When the ROSA score is higher than 600, the applesauce defects in the laminate are conspicuous under the reflection light and treated as the severe level.

[0056] The following offers a simplified description of the manner in which laminated rigid composites may generally be produced in combination with the interlayers. The formed interlayer may be placed between two glass substrates and any excess interlayer is trimmed from the edges, creating an assembly. It is not uncommon for multiple polymer interlayer sheets or a polymer interlayer sheet with multiple layers (or a combination of both) to be placed within the two glass substrates creating a multiple layer glass panel with multiple polymer interlayers. Then, air is removed from the assembly by an applicable process or method known to one of skill in the art; e.g., through nip rollers, vacuum bag or another deairing mechanism. Additionally, the interlayer is partially press- bonded to the substrates by any method known to one of ordinary skill in the art. In a last step, in order to form a final unitary structure, this preliminary bonding is rendered more permanent by a high temperature and pressure lamination process, or any other method known to one of ordinary skill in the art such as, but not limited to, autoclaving.

[0057] As mentioned previously, the present invention is described herein with respect to various interrelated aspects and embodiments and one of ordinary skill will understand and appreciate that elements or features used to describe one aspect or embodiment may be applicable and useful in describing other embodiments. Accordingly, descriptions and disclosure relating to elements or features of an aspect or embodiment of the present invention are hereby expressly relied on to describe and support those elements or features in other aspects or embodiments. More particularly, descriptions and disclosure relating to elements or features of the bilayer and / or electromagneticallyreflective multilayered interlayer of the present invention such as for example PVB resin, plasticizer and plasticized PVB, are hereby expressly relied on to describe and support those elements or features in the laminated glass composite described herein, and vice versa.

[0058] The following example(s), while provided to illustrate with specificity and detail the many aspects and advantages of the present invention, are not to be interpreted as in any way limiting its scope. Variations, modifications and adaptations which do not depart of the spirit of the present invention will be readily appreciated by one of ordinary skill in the art.

[0059] Exemplary plasticized PVB sheets of 0.38 mm thickness useful as the second layer in the bilayer of the present disclosure (designated as “Disclosed Layers” and as shown as DL 1 -6 in Table 1 below) and control conventional second layers in the bilayer (designated as “Conventional Layers” and as shown as CL 1-3 in Table 1 below) were prepared. These plasticized PVB sheets were produced by mixing and melt-extruding 100 parts of PVB resin and various amounts of plasticizer, as shown in Table 1. A roughness pattern was embossed on the lamination surface (designated as 1x in Table 1 below) or both the contact and lamination surfaces (designated as 2x in Table 1 below) of the extruded PVB sheets for some samples as indicated in the Table by using rollers having a roughness pattern. The first or reflection layer for the prepared samples was a coated electromagnetic energy-reflecting film commercially available from Eastman Chemical under the trade name XIR® 70.48. The warm shrinkage, DF135, Tg, Mw and PDI of the plasticized PVB sheets were also determined and are listed in Table 1 .

[0060] The electromagnetic energy-reflecting coating side of the reflection film, also referred to as the first layer, was lightly bonded to the contact surface of the pre-formed 0.38 mm- thickness PVB sheet in Table 1 ,also referred to as the second layer, to form a bilayer. The lamination surface of the second layer was then placed on one glass pane, and another 0.38 mm thickness PVB sheet, which is the same as the one used in the bilayer, was then placed on the base surface of the reflection film as the third layer. Finally, another glass pane was placed on the lamination surface of the third layer. For the second layer, thesurface roughness (Rz and MD Rsm) of the side adjacent the electromagnetic energy-reflecting coating side of the reflection layer were determined and are set forth in Table 1 as Rz_1 and MD Rsm_1 , while the surface roughness (Rz and MD Rsm) of the lamination surface were determined and are listed in Table 1 as Rz_2 and MD Rsm_2.

[0061] The multilayer stack was loaded into a vacuum bag with target vacuum level greater than 25” of Hg. After staying 20 min at 23 °C, the vacuum bag with the stack was processed for 20 min at 95 °C to de-air and form an almost transparent pre-laminate. This pre-laminate was then processed in an autoclave at 140 °C, 185 psi for a period of 60 min to form the multilayer rigid laminated composite The applesauce level was quantified by the ROSA score by imaging the glass laminates with electromagnetic energy-reflecting coating side facing towards the light source.Table 1

[0062] While the invention has been disclosed in conjunction with a description of certain embodiments, including those that are currently believed to be the preferred embodiments, the detailed description is intended to be illustrative and should not be understood to limit the scope of the present disclosure. As would be understood by one of ordinary skill in the art, embodiments other than those described in detail herein are encompassed by the present invention. Modifications and variations of the described embodiments may be made without departing from the spirit and scope of the invention.

[0063] It will further be understood that any of the ranges, values, or characteristics given for any single component of the present disclosure can be used interchangeably with any ranges, values or characteristics given for any of the other components of the disclosure, where compatible, to form an embodiment having defined values for each of the components, as given herein throughout. For example, a polymer layer can be formed comprising plasticizer content in any of the ranges given in addition to any of the ranges given for residual hydroxyl content, where appropriate, to form many permutations that are within the scope of the present invention but that would be cumbersome to list.

Claims

THAT WHICH IS CLAIMED IS:

1. A bilayer for use as a component for an electromagnetically reflective interlayer; said bilayer comprising: a first layer comprising an electromagnetic energy-reflecting layer, said electromagnetic energy-reflecting layer comprising a base surface and a top surface; and a second layer having a thickness of 0.3-0.55 mm and comprising PVB resin plasticized with plasticizer to form plasticized PVB, said second layer having a contact surface adjacent said top surface of said electromagnetic energy-reflecting layer; wherein (a) said second layer has a flow value DF135 of no more than 145pm and wherein (b) said PVB has a PDI of more than 4.2.

2. The bilayer of claim 1 wherein said contact surface of said second layer has an Rz value less than 45 pm.

3. The bilayer of claim 1 wherein said plasticized PVB has a glass transition temperature of higher than 35°C.

4. The bilayer of claim 1 wherein said PVB resin has a weight average molecular weight from about 180,000 to about 250,000.

5. The bilayer of claim 3 wherein said plasticizer is present in an amount of 18 to 40 phr.

6. The bilayer of claim 5 wherein said plasticizer comprises 3-GEH.

7. The bilayer of claim 2 wherein said contact surface of said second layer is a non-embossed surface.

8. The bilayer of claim 1 wherein said first layer has a thickness of from about 12 microns to about 125 microns.

9. The bilayer of claim 8 wherein said polyester substrate has a thickness of from about 12 microns to about 125 microns.

10. The bilayer of claim 8 wherein said electromagnetic energy-reflecting coating has a thickness from about 10nm to 250 nm.1 1 . The bilayer of claim 10 wherein said electromagnetic energy-reflecting coating is a vacuum-deposited coating.

12. The bilayer of claim 1 1 , wherein said vacuum-deposited coating comprises alternating layers of a high refractive index material and a low refractive index material.

13. The bilayer of claim 1 , wherein the electromagnetic energy-reflecting layer comprises at least one metal layer or at least one metal oxide layer or a combination thereof.

14. The bilayer of claim 1 , wherein the electromagnetic energy-reflecting coating comprises a plurality of metal layers or a plurality of metal oxide layers or a combination thereof.

15. The bilayer of claim 1 wherein said second layer exhibits a warm shrinkage of no greater than 8%.

16. The bilayer of claim 2 wherein said second layer further comprises a lamination surface having a surface roughness Rz of at least 20 pm opposite said contact surface.

17. An electromagnetically reflective multilayered interlayer, said interlayer comprising: a first layer comprising an electromagnetic energy-reflecting layer, said electromagnetic energy-reflecting layer comprising a base surface and a top surface; a second layer having a thickness of 0.3-0.55 mm and comprising PVB resin plasticized with plasticizer to form plasticized PVB, said second layer having a contact surface adjacent said top surface of said electromagnetic energy-reflecting layer; and a third layer comprising PVB plasticized with plasticizer to form plasticized PVB, said third layer having a contact surface adjacent said base surface of said energy-reflecting layer reflection layer; wherein (a) said second layer has a flow value DF135 of no more than 145pm and wherein (b) said PVB of said second layer has a PDI of more than 4.

218. A multilayer rigid laminated composite comprising: the electromagnetically reflective interlayer of claim 17 sandwiched between first and second rigid sheets, said multilayer rigid laminated composite characterized by a ROSA score of 125 pixels or less.

19. A multilayer rigid laminated composite comprising: a first layer comprising an electromagnetic energy-reflecting layer, said electromagnetic energy-reflecting layer comprising a base surface and a top surface; a second layer having a thickness of 0.3-0.55 mm and comprising PVB resin plasticized with plasticizer to form plasticized PVB, said second layer having a lamination surface and an opposing contact surface adjacent said top surface of electromagnetic energy-reflecting layer; wherein (a) said second layer has a flow value DF135 of no more than 145pm and wherein (b) said PVB of said second layer has a PDI of more than 4.2;a third layer comprising PVB plasticized with plasticizer to form plasticized PVB, said third layer having a lamination surface and an opposing contact surface adjacent said base surface of said electromagnetic energyreflecting layer; a first rigid sheet adjacent said lamination surface of said second layer; and a second rigid sheet adjacent said lamination surface of said third layer.

Images