High refractive index polyvinyl acetal resins modified with cyclic aldehydes

Abstract

A modified polyvinyl acetal resin comprising a residue of a cyclic aldehyde is provided for forming an interlayer for use in the manufacture of laminated glass. Interlayers as described herein exhibit desirable optical and acoustic properties and are easier to recover than interlayers that do not contain the modified polyvinyl acetal resin.

Description

Background Art

[0001] Safety glass used in automotive windshields and architectural applications can include two sheets of glass laminated together with a plasticized polymer interlayer between the glass. Polyvinyl butyral ("PVB") can be the main component in the polymer interlayer. Typically, the PVB interlayer can be a single-layer structure, but in recent years, the sales of multi-layer polyvinyl butyral interlayers for laminated glass have been increasing in the market. The multi-layer interlayer can provide enhanced sound insulation by setting a softer "core" layer between two harder "skin" layers. Typically, the PVB resin in the core layer has a different composition of ingredients than the PVB compound in the skin layer, and may, for example, have a different residual hydroxyl content and / or acetyl content.

[0002] During the production of monolithic interlayers, unqualified materials and / or scraps are often reused in the board manufacturing process because the monolithic interlayers only include one type of polyvinyl butyral. However, due to the different polyvinyl butyral compositions between the skin and core layers of the multilayer PVB interlayers, the multilayer film waste cannot be re-extruded. If it is, the resulting blended resin composition exhibits a high level of haze, resulting in unacceptable visual quality of the final interlayer product. Therefore, large-scale recycling of multilayer interlayer materials has not been successfully achieved.

[0003] Therefore, it is desirable to have a commercial-scale process and system for recycling multilayer polyvinyl butyral waste (e.g., from off-spec finished products, scrap from the manufacturing process, and even discarded laminated glass) in an economically and ecologically efficient manner. It is desirable to have resin compositions (including PVB resin compositions) that can be used in multilayer interlayers that do not exhibit haze when re-extruded and are therefore more recyclable. Summary of the invention

[0004] In one aspect, the present technology relates to a polyvinyl acetal resin composition comprising: a polyvinyl acetal resin component comprising the residue of at least one cyclic aldehyde having an unsaturated 5-membered or 6-membered ring group and another polyvinyl acetal resin component comprising the residue of at least one C3 to C8 aliphatic aldehyde; and at least one plasticizer.

[0005] In one aspect, the present technology relates to a polyvinyl acetal resin composition comprising: one or more polyvinyl acetal resins, wherein the polyvinyl acetal resin comprises at least one polyvinyl acetal resin component, the polyvinyl acetal resin component comprising a residue of at least one cyclic aldehyde comprising at least one heterocyclic group; and at least one plasticizer, wherein the composition comprises less than 5 weight percent of a resin other than the polyvinyl acetal resin.

[0006] In one aspect, the present technology relates to an interlayer comprising: a first resin layer comprising a first polyvinyl acetal resin and at least one plasticizer; and a second resin layer comprising a polyvinyl acetal resin component comprising the residue of at least one cyclic aldehyde, another polyvinyl acetal resin component comprising the residue of at least one C3 to C8 aliphatic aldehyde, and at least one plasticizer, wherein the cyclic aldehyde comprises (a) a conjugated 5-membered or 6-membered ring and / or (b) a heterocyclic ring.

[0007] In one aspect, the present technology relates to a method for making a polyvinyl acetal resin component, the method comprising at least one of the following steps (a) and (b): (a) acetalizing polyvinyl alcohol with at least one C3 to C8 aliphatic aldehyde and at least one cyclic aldehyde to form a modified polyvinyl acetal resin, wherein the cyclic aldehyde contains (i) an unsaturated 5-membered or 6-membered ring and / or (ii) a heterocycle; and / or (b) blending a polyvinyl acetal resin containing residues of a cyclic aldehyde and / or a heterocycle with another polyvinyl acetal resin containing at least 50 weight percent residues of a C3 to C8 aliphatic aldehyde to form a blended polyvinyl acetal resin composition.

[0008] In one aspect, the present technology relates to a blended polyvinyl acetal resin composition comprising: a first polyvinyl acetal resin having a residual hydroxyl content of at least 16 weight percent; a polyvinyl acetal resin component having residues of at least one cyclic aldehyde, wherein the cyclic aldehyde comprises (a) an unsaturated 5-membered or 6-membered ring and / or (b) a heterocyclic ring; and at least one plasticizer, wherein the resin composition has a haze value of less than 1. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Various embodiments of the present technology are described in detail below with reference to the accompanying drawings, in which:

[0010] Figure 1 is a block flow diagram illustrating the major steps / areas of a process / facility for producing modified polyvinyl acetal resins according to an embodiment of the present technology; and

[0011] Figure 2 is a cross-section of a multilayer interlayer according to an embodiment of the present technology. DETAILED DESCRIPTION

[0012] We have found a polyvinyl acetal resin composition suitable for forming an interlayer suitable for use in a variety of applications, which interlayer can also be recycled in large quantities. Specifically, we have found that a multilayer interlayer having a core resin layer with a higher refractive index can exhibit a lower haze value when blended with other polyvinyl acetal resins (such as resins used to form a skin layer). Therefore, this multilayer interlayer can be recycled by, for example, combining multilayer waste with a skin layer resin and re-extruding the combination to form a recycled interlayer. The new polyvinyl acetal resin for the core layer contains cyclic aldehyde side groups extending from the polymer backbone. The modified polyvinyl acetal resin can be formed by co-acetalizing at least one cyclic aldehyde with at least one C3 to C8 aliphatic aldehyde, and the resulting modified polyvinyl acetal resin can be blended with at least one plasticizer to form a modified resin composition suitable for the multilayer interlayer.

[0013] Initially go to Figure 1 , provides a block flow diagram illustrating the main steps / areas of a process / facility for forming a modified polyvinyl acetal resin according to an embodiment of the present technology. Figure 1 As shown, vinyl acetate can be polymerized to provide polyvinyl acetate, and then polyvinyl acetate can be hydrolyzed to provide polyvinyl alcohol. Then at least a portion of the polyvinyl alcohol can be reacted with at least one cyclic aldehyde to form a modified polyvinyl acetal resin. The acetalization reaction can be carried out by suspension or solution polymerization in the presence of a catalyst (which can be an acid or a base). Then, the modified polyvinyl acetal resin obtained can be separated, stabilized and dried according to known methods (such as, for example, U.S. Patents No. 2,282,057 and No. 2,282,026 and Wade, B.2016, Vinyl Acetal Polymers, Encyclopedia of Polymer Science and Technology.1–22 (online, copyright 2016 John Wiley & Sons, Inc.)).

[0014] When used in this article, the term "modified polyvinyl acetal resin" refers to a polyvinyl acetal resin including the residue of at least one cyclic aldehyde. Unless otherwise specified, the modified polyvinyl acetal resin may have a total acetalization percentage of at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90 weight percent measured according to ASTM D-1396. The total amount of aldehyde residues in the polyvinyl acetal resin can be collectively referred to as the acetal component, and the balance of the polyvinyl acetal resin is the residual vinyl alcohol (hydroxyl) group and the residual acetate (acetyl) group, which will be discussed in more detail below. As used herein, the term "unmodified polyvinyl acetal resin" refers to a polyvinyl acetal resin that does not include the residue of a cyclic vinyl acetal monomer and contains at least 99 weight percent of vinyl acetate, polyvinyl alcohol and the residue of at least one aldehyde.

[0015] The modified polyvinyl acetal resin may contain at least 1, at least 2, at least 5, at least 10, at least 15, or at least 20 weight percent and / or no more than 50, no more than 45, no more than 40, no more than 35, no more than 30, no more than 25, or no more than 20 weight percent of the residues of one or more cyclic aldehydes, based on the total moles of aldehyde residues in the polyvinyl acetal resin. Alternatively, the modified polyvinyl acetal resin may contain at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, at least 95, or at least 99, or up to 100 weight percent and / or no more than 99, no more than 95, no more than 90, no more than 85, no more than 80, no more than 75, no more than 70, no more than 65, no more than 60, no more than 55, or no more than 50 weight percent of the residues of the cyclic aldehydes, based on the total weight of the aldehyde residues in the modified polyvinyl acetal resin.

[0016] Cyclic aldehyde can comprise at least one, two or three cyclic groups.One or more cyclic groups can comprise individually each ring at least 5, at least 6, at least 8 or at least 10 atoms and / or be no more than 30, be no more than 28, be no more than 24, be no more than 22, be no more than 20, be no more than 18, be no more than 16, be no more than 14, be no more than 12, be no more than 10, be no more than 8, be no more than 6, be no more than 5, be no more than 4 or be no more than 3 carbon atoms.In some cases, ring may only comprise carbon atom.At least one cyclic group can be undersaturated, and in some cases, it can be conjugated, or even aromatic.In some cases, cyclic aldehyde can comprise at least one undersaturated 5 yuan or 6 yuan cyclic groups.

[0017] In some embodiments, the cyclic aldehyde may include a heterocycle having at least one atom other than carbon in the main ring structure. When a heterocycle, the ring group may include at least one heteroatom selected from sulfur (S), phosphorus (P), nitrogen (N) and oxygen (O). In some cases, the heterocycle may be unsaturated, and in other cases, it may be conjugated. The heterocycle may be saturated. The cyclic aldehyde may include one or more heterocycles.

[0018] Examples of specific cyclic aldehydes suitable for use in embodiments of the present technology may include, but are not limited to, furfural, substituted furfurals, hydroxymethylfurfural (HMF), 2-thiophenecarboxaldehyde, 3-thiophenecarboxaldehyde, 2-pyridinecarboxaldehyde, 2-acetylthiophene, 2-pyrrole-2-carboxaldehyde, 5-bromo-2-thiophenecarboxaldehyde, benzo(b)thiophene-2-carboxaldehyde, 4-pyridinecarboxaldehyde, and 3-pyridinecarboxaldehyde. In some embodiments, the cyclic aldehyde may not be furfural or a derivative thereof.

[0019] The cyclic aldehyde can have a value of at least 1.500, at least 1.505, at least 1.510, at least 1.515, at least 1.520, at least 1.525, at least 1.530, at least 1.535, at least 1.540, at least 1.545, at least 1.550, at least 1.555, at least 1.560, at least 1.565, at least 1.570, at least 1.575, at least 1.580, at least 1.585, at least 1.590, at least 1.595, at least 1.600, at least 1.605, at least 1.610, at least 1.615, at least 1.620, at least 1.625, at least 1.630, at least 1.635, at least 1.640, at least 1.645, at least 1 .650, at least 1.655, at least 1.660, at least 1.665, at least 1.670, or at least 1.675 and / or a refractive index of no more than 2.000, no more than 1.950, no more than 1.900, no more than 1.850, no more than 1.800, no more than 1.750, no more than 1.700, no more than 1.650, no more than 1.600, no more than 1.590, no more than 1.580, no more than 1.575, no more than 1.570, no more than 1.565, no more than 1.560, no more than 1.555, no more than 1.550, no more than 1.545, no more than 1.540, no more than 1.535, no more than 1.530, or no more than 1.525.

[0020] In some embodiments, the polyvinyl acetal resin of modification can include at least one C1 to C10 aliphatic aldehyde, C3 to C8 aliphatic aldehyde, C3 to C6 aliphatic aldehyde or C4 aliphatic aldehyde residue in addition.The example of suitable aldehyde can include but not limited to n-butyraldehyde, isobutyraldehyde, 2-methylpentanal, n-hexyl aldehyde, 2-ethylhexyl aldehyde, n-octanal and combination thereof.The polyvinyl acetal resin of modification can include at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90 or at least 95 weight percents or one or more C3 to C8 aliphatic aldehyde residues in the range of 20 to 90 weight percents, 30 to 80 weight percents or 40 to 70 weight percents. Alternatively, the modified polyvinyl acetal resin may include less than 50, less than 45, less than 40, less than 35, less than 30, less than 25, less than 20, less than 15, less than 10, less than 5, less than 2, less than 1, or less than 0.5 weight percent of one or more C3 to C8 aliphatic aldehyde residues based on the total weight of aldehyde residues in the polyvinyl acetal resin. In some cases, the modified polyvinyl acetal resin may not include C3 to C8 aliphatic aldehyde residues.

[0021] Although a single polyvinyl acetal resin having residues (or moieties) of two or more aldehydes is generally described herein, it should be understood that in some cases, an equivalent physical blend of two polyvinyl acetal resins (each including residues of an aldehyde) will provide similar results as a single modified polyvinyl acetal resin. As used herein, the term "polyvinyl acetal resin component" may refer to a single polyvinyl acetal resin present in a physical blend of two or more resins, or to the acetal moieties present on a single polyvinyl acetal resin.

[0022] In some cases, at least one resin composition, layer or interlayer described herein may include a polyvinyl acetal resin component including a residue of a cyclic aldehyde and another polyvinyl acetal resin component that does not include a residue of a cyclic aldehyde (and may, for example, include a residue of a C3 to C8 aliphatic aldehyde). This polyvinyl acetal resin component may refer to (1) a blend of two different polyvinyl acetal resins (e.g., one having a cyclic aldehyde residue and one not having a cyclic aldehyde residue), or (2) a single polyvinyl acetal resin having two different acetal moieties (e.g., one having a cyclic aldehyde residue and one not having a cyclic aldehyde residue). In either case, the polyvinyl acetal resin component (as a single polyvinyl acetal resin or as a blend of two or more resins) may be combined with one or more plasticizers and optional other additives to provide a single plasticized composition, layer or interlayer according to an embodiment of the present technology. As described above, a polyvinyl acetal resin including a residue of a cyclic aldehyde may be referred to as a "modified polyvinyl acetal resin" regardless of whether it includes a residue of another aldehyde (e.g., a C3 to C8 aliphatic aldehyde). When blended, the polyvinyl acetal resin having the residue of another aldehyde may have similar properties (eg, hydroxyl content, acetate content, etc.) to the modified polyvinyl acetal resin present in the blend.

[0023] When forming a modified polyvinyl acetal resin including residues (or moieties) of a cyclic aldehyde and another aldehyde (e.g., a C3 to C8 aliphatic aldehyde), the cyclic aldehyde and the other aldehyde (e.g., a C3 to C8 aliphatic aldehyde) may be introduced into the acetalization step / zone ( Figure 1 ) or may be combined as shown in Figure 1 The aldehydes are added separately as shown. When added separately, the aldehydes can be added simultaneously or sequentially. For example, in some cases, the C3 to C8 aliphatic aldehyde can be added after the cyclic aldehyde has been added and at least partially reacted with the polyvinyl alcohol. When the modified polyvinyl acetal resin only includes the residue of the cyclic aldehyde, the resin can be added to the reaction at any suitable time, and the C3 to C8 aldehyde may not be added.

[0024] The modified polyvinyl acetal resin may have a residual hydroxyl content of at least 8, at least 8.5, at least 9, at least 9.5, at least 10, at least 10.5, at least 11, at least 11.5, at least 12, or at least 12.5 weight percent and / or no more than 16, no more than 15.5, no more than 15, no more than 14.5, no more than 14, no more than 13.5, no more than 13, no more than 12.5, or no more than 12 weight percent. Additionally, or alternatively, the modified polyvinyl acetal resin may have a residual acetate content of at least 0.5, at least 1, at least 1.5, at least 2, at least 5, at least 10, at least 15, or at least 18 weight percent and / or no more than 35, no more than 30, no more than 25, no more than 20, no more than 15, no more than 10, no more than 8, no more than 6, no more than 5, no more than 3, no more than 2.5, or no more than 2 weight percent.

[0025] As used herein, the terms "residual hydroxyl content" and "residual acetate content" refer to the amount of hydroxyl and acetate groups remaining on the polyethylene resin after the acetalization reaction is completed, respectively. In the process of hydrolyzing polyvinyl acetate, generally not all acetate groups are converted into hydroxyl groups, and residual acetate groups remain on the resin. Similarly, in the process of acetalizing polyvinyl alcohol, not all hydroxyl groups are converted into acetal groups, which also leaves residual hydroxyl groups on the resin. Therefore, most polyvinyl acetal resins include both residual hydroxyl groups (as vinyl hydroxyl groups) and residual acetate groups (as vinyl acetate groups) as part of the polymer chain. Unless otherwise stated, the residual hydroxyl content and the residual acetate content are expressed as weight percentages based on the weight of the polymer resin and are measured according to ASTM D-1396.

[0026] In some embodiments, the modified polyvinyl acetal resin may contain less than 5, less than 3, less than 2, less than 1, or less than 0.5 weight percent of residues other than residual hydroxyl groups, residual acetate groups, and aldehyde residues in the polymer backbone. For example, the modified polyvinyl acetal resin may include less than 5, less than 3, less than 2, less than 1, or less than 0.5 weight percent of residues of acrylic resin, butadiene, imide, and combinations thereof.

[0027] The modified polyvinyl acetal resin can have at least 30,000, at least 50,000, at least 70,000, at least 100,000, at least 250,000, at least 500,000 Daltons and / or no more than 1,000,000, no more than 750,000, no more than 600,000, no more than 550,000, no more than 500,000, no more than 450,000 or no more than 425,000 Daltons of molecular weight, the molecular weight is measured by size exclusion chromatography using the small angle laser light scattering (SEC / LALLS) method of Cotts and Ouano. As used herein, the term "molecular weight" refers to the weight average molecular weight. The molecular weight of the polyvinyl acetal resin can be in the range of 50,000 to 1,000,000 Daltons, 100,000 to 750,000 Daltons or 250,000 to 750,000 Daltons.

[0028] The modified polyvinyl acetal resin may not be cross-linked. That is, in some cases, it may include less than 250, less than 200, less than 150, less than 100, less than 50, less than 25, less than 10, less than 5, less than 3, less than 2, or less than 1 parts per million (ppm) of dialdehyde cross-linking agent by weight. In addition, or in an alternative example, the modified polyvinyl acetal resin may include less than 2, less than 1, less than 0.5, or less than 0.25 weight percent of an acidic cross-linking agent. In some cases, during the process of forming the modified polyvinyl acetal resin discussed herein, little or no (e.g., less than 5, less than 2, less than 1, or less than 0.5 phr) of these cross-linking agents may be added to the resin or its precursor.

[0029] The modified polyvinyl acetal resin may have a molecular weight of at least 1.480, at least 1.485, at least 1.486, at least 1.490, at least 1.495, at least 1.500, at least 1.505, at least 1.510, at least 1.515, at least 1.520, at least 1.525, at least 1.530, at least 1.535, at least 1.540, at least 1.545, at least 1.550 and / or no more than 1.600, no more than 1.695, no more than 1.706, no more than 1.710, no more than 1.725, no more than 1.730, no more than 1.740, no more than 1.755, no more than 1.760, no more than 1.775, no more than 1.780, no more than 1.790, no more than 1.800, no more than 1.815, no more than 1.820, no more than 1.830, no more than 1.840, no more than 1.855 A refractive index exceeding 1.580, not exceeding 1.575, not exceeding 1.570, not exceeding 1.565, not exceeding 1.560, not exceeding 1.555, not exceeding 1.550, not exceeding 1.545, not exceeding 1.540, not exceeding 1.535, not exceeding 1.530, not exceeding 1.525, not exceeding 1.520, not exceeding 1.515, not exceeding 1.510, not exceeding 1.505, not exceeding 1.500, not exceeding 1.495, not exceeding 1.490 or not exceeding 1.488.

[0030] Now go to Figure 2 , showing a schematic cross-section of an interlayer according to various embodiments of the present technology. Figure 2 The interlayer shown is a multilayer interlayer (multilayer interlayer) having, for example, a first resin layer 1, a second resin layer 2, and a third resin layer 3. As used herein, the terms "first", "second", "third" and the like are used to describe various elements, but these elements should not be unnecessarily limited by these terms. These terms are only used to distinguish one element from another element, and do not necessarily imply a specific order or even a specific element. For example, an element may be considered a "first" element in the specification and a "second" element in the claims without contradiction. It is consistent in the specification and for each independent claim, but this nomenclature does not necessarily require consistency between them. In some cases, the interlayer may include four or more layers ( Figure 2 Implementation not shown).

[0031] like Figure 2 As shown, the second resin layer 2 may be located between and adjacent to the first resin layer 1 and the third resin layer 3. The second resin layer 2 may be referred to as a "core" or "inner" layer, while the first resin layer 1 and the third resin layer 3 may be referred to as a "surface" or "outer" layer. When the interlayer includes more than three layers, the outermost layer may be referred to as a skin layer, and the innermost layer may be referred to as a core layer.

[0032] In one or more embodiments, at least one resin layer (e.g., Figure 2 The skin layers 1 and 3 and / or the core layer 2 shown may include at least one modified polyvinyl acetal resin as described above. The modified polyvinyl acetal resin may be present in the skin layer and the core layer in the same or different amounts, while in other cases, the modified polyvinyl acetal resin may be present only in the skin layer or the core layer. In some embodiments, the skin layers 1 and 3 may contain at least 85, at least 90, at least 95, at least 97, or at least 99 weight percent of unmodified polyvinyl acetal resin, while the core layer 2 may contain at least 85, at least 90, at least 95, at least 97, or at least 99 weight percent of at least one modified polyvinyl acetal resin containing cyclic vinyl monomer residues. As used herein, the term "unmodified polyvinyl acetal resin" refers to a polyvinyl acetal resin that does not include residues of cyclic vinyl acetal monomers and contains at least 99 weight percent of residues of vinyl acetate, polyvinyl alcohol, and at least one aldehyde.

[0033] In some embodiments, at least one of the resin layers of the multilayer interlayer may include at least one thermoplastic polymer other than polyvinyl acetal (or modified polyvinyl acetal) resin. Examples of suitable thermoplastic polymers may include, but are not limited to, polyvinyl acetal resins, polyurethanes (PU), poly(ethylene co-vinyl acetate) (EVA), polyvinyl chloride (PVC), poly(vinyl chloride co-methacrylate), polyethylene, polyolefins, ethylene acrylate copolymers, poly(ethylene co-butyl acrylate), silicone elastomers, epoxy resins, and acid copolymers (such as ethylene / carboxylic acid copolymers and ionic polymers thereof) derived from any of the previously listed polymers, and combinations thereof.

[0034] In some cases, the core layer 2 and / or the skin layers 1, 3 may substantially exclude resins other than polyvinyl acetal resin (or modified polyvinyl acetal resin). In some embodiments, at least one of the core layer and / or the skin layer may include resins other than polyvinyl acetal resin (or modified polyvinyl acetal resin) in an amount of no more than 20, no more than 15, no more than 10, no more than 5, no more than 4.5, no more than 4, no more than 3.5, no more than 3, no more than 2.5, no more than 2, no more than 1.5, no more than 1, no more than 0.5, no more than 0.1, or no more than 0.05 weight percent based on the combined weight of all resins, or the layer may include less than 0.5, less than 0.3, less than 0.25, less than 0.20, less than 0.15, less than 0.10, less than 0.05, or less than 0.01 phr of resins other than polyvinyl acetal resin, or resins (e.g., polyolefins, acrylic resins, and block copolymers, etc.). In some cases, at least one of the layers may include only a single polyvinyl acetal resin, while in other cases, one or more of the layers may include a blend of two or more polyvinyl acetal resins. One or more of the skin layers 1, 3 and the core layer may be a continuous layer that does not include islands or particles of other polymeric materials dispersed therein.

[0035] The polyvinyl acetal resin (or resin component or modified polyvinyl acetal resin or component) used in one or more layers of the multilayer interlayer can include the residue of any suitable aldehyde, and in some embodiments can include at least one, or at least two, or three or more C1 to C10 aldehydes, at least one C3 to C8 aldehyde, at least one C3 to C6 aldehyde, or C4 to C8 or C4 aliphatic aldehyde residues. Examples of suitable aldehydes can include, but are not limited to, propionaldehyde, n-butyraldehyde, isobutyraldehyde, 2-methylpentanal, n-hexanal, 2-ethylhexyl aldehyde, n-octyl aldehyde and combinations thereof. In some embodiments, the one or more polyvinyl acetal resins used in the layer or layers may include at least 20, at least 30, at least 40, at least 50, at least 60, or at least 70 weight percent of residues of at least one C3 to C8 aldehyde based on the total weight of the aldehyde residues of the resin, and / or may include no more than 90, no more than 85, no more than 80, no more than 75, no more than 70, or no more than 65 weight percent of at least one C3 to C8 aldehyde, or at least one C3 to C8 aldehyde in the range of 20 to 90 weight percent, 30 to 80 weight percent, or 40 to 70 weight percent. The C3 to C8 aldehyde may be selected from the group listed above, or it may be selected from n-butyraldehyde, isobutyraldehyde, 2-ethylhexyl aldehyde, and combinations thereof.

[0036] In some embodiments, the polyvinyl acetal resin may be a polyvinyl butyral (PVB) resin or component (or a modified PVB resin or component). In other embodiments, the polyvinyl acetal resin may be a polyvinyl n-butyral resin comprising primarily residues of n-butyraldehyde, and may, for example, include residues of aldehydes other than n-butyraldehyde in an amount of no more than 50, no more than 40, no more than 30, no more than 20, no more than 10, no more than 5, or no more than 2 weight percent based on the total weight of all aldehyde residues of the resin.

[0037] When the polyvinyl acetal resin present in one or more layers comprises a PVB resin, the molecular weight of the resin can be at least 30,000, at least 50,000, at least 70,000, at least 100,000, at least 250,000, at least 500,000 Daltons and / or no more than 1,000,000, no more than 750,000, no more than 600,000, no more than 550,000, no more than 500,000, no more than 450,000, or no more than 425,000 Daltons, measured as previously described. The molecular weight of the polyvinyl acetal resin can be in the range of 50,000 to 1,000,000 Daltons, 100,000 to 750,000 Daltons, or 250,000 to 750,000 Daltons.

[0038] One or more layers of interlayer (e.g., Figure 2The at least one polyvinyl acetal resin present in the first layer 1 and the third layer 3 shown can have a residual hydroxyl content of at least 16, at least 16.5, at least 17, at least 17.5, at least 18, at least 18.5, at least 19, at least 19.5, at least 20, or at least 20.5 weight percent and / or no more than 30, no more than 29, no more than 28, no more than 27, no more than 26, no more than 25, no more than 24, no more than 23, no more than 22, no more than 21, no more than 20, or no more than 19.5 weight percent.

[0039] Additionally, or in the alternative, one or more layers (e.g., Figure 2 The at least one polyvinyl acetal resin present in the first layer 1 and the third layer 3) shown can have a residual acetate content of at least 0.5, at least 1, at least 1.5, at least 2, at least 5, at least 10, at least 15, or at least 18 weight percent and / or no more than 35, no more than 30, no more than 25, no more than 20, no more than 15, no more than 10, no more than 8, no more than 6, no more than 5, no more than 3, no more than 2.5, or no more than 2 weight percent.

[0040] In some cases, one or more polyvinyl acetal resins (including modified polyvinyl acetal resins) may contain less than 5, less than 3, less than 2, less than 1, less than 0.5, less than 0.1, or less than 0.05 weight percent of residues other than residual hydroxyl groups, residual acetals, and aldehydes (e.g., olefin residues, acrylic acid residues, butadiene residues, imide residues, etc.). In some cases, at least one polyvinyl acetal resin may include less than 5, less than 4, less than 3, less than 2, less than 1, or less than 0.5 weight percent of residues of any cyclic vinyl monomer described herein.

[0041] According to some embodiments, two or more layers in the multilayer interlayer may have different compositions. For example, in some embodiments, one or both of the outer skin layers may be formed from at least a first polyvinyl acetal resin or resin component (e.g., an unmodified polyvinyl acetal resin), while the core layer or inner layer may be formed from at least a second polyvinyl acetal resin or resin component (e.g., a modified polyvinyl acetal resin or component). In some embodiments, the residual hydroxyl content and / or residual acetate content of at least one polyvinyl acetal resin used to form the first layer may be higher or lower than the residual hydroxyl content and / or residual acetate content of at least one second polyvinyl acetal resin used to form the second layer by at least 2, at least 3, at least 4, at least 5, at least 6, or at least 8 weight percent.

[0042] In some cases, the difference between the residual hydroxyl content of the polyvinyl acetal resin in two or more layers (e.g., the first layer and the second layer and / or the second layer and the third layer) in the layer can also be at least 2, at least 5, at least 10, at least 12, at least 15, at least 20, or at least 30 weight percent and / or no more than 30, no more than 25, no more than 20, no more than 15, no more than 10, or no more than 8 weight percent. As used herein, the term "weight percentage is different" or "the difference is at least ... weight percentage" refers to the difference between two given weight percentages, which is calculated by subtracting one number from another. For example, the residual hydroxyl content of a polyvinyl acetal resin having a residual hydroxyl content of 12 weight percent is 2 weight percent lower than that of a polyvinyl acetal resin having a residual hydroxyl content of 14 weight percent (14 weight percent-12 weight percent=2 weight percent). As used herein, the term "different" can refer to a value being higher or lower than another value.

[0043] In some embodiments, at least one of the polyvinyl acetal resins used to form, for example, two different layers within an interlayer may have a different residual acetate content than the other. For example, in some embodiments, the difference (or maximum difference) between the residual acetate content of the two polyvinyl acetal resins (or any layer of the interlayer) may be at least 2, at least 3, at least 4, at least 5, at least 8, at least 10 weight percent and / or no more than 15, no more than 13, no more than 10, no more than 8, no more than 6, no more than 4, no more than 2, no more than 1, or no more than 0.5 percent. One of the polyvinyl acetal resins may have a residual acetate content of less than 15, no more than 13, no more than 12, no more than 10, no more than 8, no more than 6, no more than 5, no more than 4, no more than 3, no more than 2, no more than 1, or no more than 0.5 weight percent, measured as described above.

[0044] In some embodiments, at least one of the polyvinyl acetal resins used to form the interlayer may have a residual acetate content of at least 5, at least 8, at least 10, at least 12, at least 14, at least 16, at least 18, at least 20, or at least 30 weight percent. The difference in residual vinyl acetate content between the polyvinyl acetal resins used in two or more resin layers may be within the ranges provided above, or the difference may be less than 3, no more than 2, no more than 1, or no more than 0.5 weight percent.

[0045] In some embodiments, the difference between the residual acetate content of the polyvinyl acetal resins used in two or more layers may be less than 2, no more than 1, no more than 0.5 weight percent, and the difference in residual acetate content between the polyvinyl acetal resins used in two or more layers may be at least 3, at least 5, at least 8, at least 15, at least 20, or at least 30 weight percent. In other embodiments, the difference in residual acetate content of the polyvinyl acetal resins in two or more layers may be less than 3, no more than 2, no more than 1, or no more than 0.5 weight percent, and the difference in residual hydroxyl content of the same polyvinyl acetal resin may be at least 2, at least 5, at least 10, at least 12, at least 15, at least 20, or at least 30 weight percent.

[0046] In some embodiments, one or more of the layers may include at least one plasticizer. Figure 2 Each resin layer shown can include a polyvinyl acetal resin and at least one plasticizer. Depending on the specific composition of the layer, one or more plasticizers can be present in an amount of at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, or at least 70 parts per hundred parts of resin (phr) and / or no more than 120, no more than 110, no more than 105, no more than 100, no more than 95, no more than 90, no more than 85, no more than 80, no more than 75, no more than 70, no more than 65, no more than 60, no more than 55, no more than 50, no more than 45, no more than 40, or no more than 35, or in the range of 5 to 120, 10 to 110, 20 to 90, or 25 to 75 phr. These amounts may refer to a single plasticizer, a blend of plasticizers, or one plasticizer in a blend of two or more plasticizers.

[0047] As used herein, the term "parts per hundred parts of resin" or "phr" refers to the amount of plasticizer present relative to one hundred parts of resin by weight. For example, if 30 grams of plasticizer are added to 100 grams of resin, the plasticizer will be present in an amount of 30 phr. If a layer includes two or more resins, the weight of the plasticizer is compared to the combined amount of all resins present to determine the parts per hundred parts of resin. In addition, when the plasticizer content of a layer is provided herein, the plasticizer content is determined by reference to the amount of plasticizer in the mixture or melt used to produce the layer.

[0048] Examples of suitable plasticizers may include, but are not limited to, triethylene glycol di(2-ethylhexanoate) ("3GEH"), triethylene glycol di(2-ethylbutyrate), triethylene glycol diheptanoate, tetraethylene glycol diheptanoate, tetraethylene glycol di(2-ethylhexanoate) ("4GEH"), dihexyl adipate, dioctyl adipate, cyclohexylhexyl adipate, diisononyl adipate, heptylnonyl adipate, di(butoxyethyl) adipate and bis(2-(2-butoxyethoxy)ethyl) adipate, dibutyl sebacate, dioctyl sebacate, and mixtures thereof. The plasticizer may be selected from triethylene glycol di(2-ethylhexanoate) and tetraethylene glycol di(2-ethylhexanoate), or the plasticizer may comprise triethylene glycol di(2-ethylhexanoate).

[0049] Additionally, or alternatively, the plasticizer may include one or more of the following plasticizers: dipropylene glycol dibenzoate, tripropylene glycol dibenzoate, polypropylene glycol dibenzoate, isodecyl benzoate, 2-ethylhexyl benzoate, diethylene glycol benzoate, butoxyethyl benzoate, butoxyethoxyethyl benzoate, butoxyethoxyethoxyethyl benzoate, propylene glycol dibenzoate, 2,2,4-trimethyl-1,3-pentanediol dibenzoate, 2,2,4- Trimethyl-1,3-pentanediol benzoate isobutyrate, 1,3-butylene glycol 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-ethylhexanoate), di(butoxyethyl) terephthalate, di(butoxyethoxyethyl) terephthalate, and mixtures thereof.

[0050] In some embodiments, at least one layer (e.g., Figure 2 The outer layers 1, 3) in the embodiment may include at least one plasticizer in an amount of at least 20, at least 25, at least 30, or at least 35 phr and / or no more than 45, no more than 40, or no more than 35 phr. In addition, or in an alternative example, at least one other layer (e.g., Figure 2 The core layer 2) in may include at least one plasticizer in an amount of at least 50, at least 55, at least 60, at least 65, or at least 70 phr and / or no more than 95, no more than 90, no more than 85, no more than 80, or no more than 75 phr.

[0051] At least one of the plasticizers used in a layer or interlayer may have a refractive index of at least 1.435, at least 1.440, at least 1.445, at least 1.450, at least 1.460, at least 1.470, at least 1.475, at least 1.480, at least 1.490, or at least 1.500 and / or no more than 1.530, no more than 1.525, no more than 1.520, no more than 1.515, no more than 1.510, no more than 1.505, no more than 1.500, no more than 1.495, no more than 1.490, or no more than 1.485.

[0052] In some cases, at least one resin layer (e.g., Figure 2 The core layer 2 shown may have a total plasticizer content in the range of 20 to 120 phr, 30 to 90 phr, 45 to 85 phr, or 55 to 80 phr. Optionally, or in addition, at least one resin layer (e.g., Figure 2 The outer layers 1, 3) shown may have a total plasticizer content in the range of 20 to 45 phr or 30 to 40 phr. The plasticizer content refers to the total amount of plasticizer in the interlayer and may be the amount of one or two or more plasticizers included in the interlayer.

[0053] Resins with higher or lower residual hydroxyl content and / or residual acetate content may also ultimately include different amounts of plasticizers when combined with at least one plasticizer. Therefore, layers formed by polyvinyl acetal resins of different compositions may also have different properties within a single interlayer. Although not wishing to be bound by theory, it is assumed that the compatibility of a given plasticizer with a polyvinyl acetal resin may depend at least in part on the composition of the polymer, particularly its residual hydroxyl content. In general, polyvinyl acetal resins with higher residual hydroxyl content tend to exhibit lower compatibility (or capacity) for a given plasticizer compared to similar resins with lower residual hydroxyl content. Therefore, polyvinyl acetal resins with higher residual hydroxyl content tend to have lower plasticization and exhibit higher stiffness than similar resins with lower residual hydroxyl content. On the contrary, polyvinyl acetal resins with lower residual hydroxyl content may tend to incorporate higher amounts of plasticizers when plasticized with a given plasticizer, which may result in a softer resin layer that exhibits a lower glass transition temperature compared to similar resins with higher residual hydroxyl content. Depending on the specific resin and plasticizer, these trends may be reversed.

[0054] The type of plasticizer used in the skin layer and the core layer can be the same or different. In some embodiments, at least one plasticizer can also be a blend of two or more plasticizers. In addition, in some embodiments, the two outer skin layers (e.g., Figure 2The outer layers 1 , 3 ) shown may have almost the same or identical composition to each other (including the type and / or amount of plasticizer), whereas the core layer may comprise a different amount of plasticizer.

[0055] In some embodiments, the plasticizer content difference between two or more resin layers can be at least 2, at least 5, at least 8, at least 10, at least 12, or at least 15, at least 20, at least 25, at least 30, or at least 35 phr. In some cases, the resin layer including the resin with lower hydroxyl content can have a higher plasticizer content. In order to control or retain other characteristics of the resin layer or interlayer, the plasticizer content difference between the two layers can be no more than 75, no more than 70, no more than 65, no more than 60, no more than 55, no more than 50, no more than 45, no more than 40, no more than 30, no more than 25, no more than 20, or no more than 17 phr. In other embodiments, the plasticizer content difference between the two resin layers can be at least 25, at least 30, at least 35, at least 40, at least 50, at least 60, at least 70 phr, or at least 80 phr. In some embodiments, the outer skin layer (e.g., the first layer 1 and the third layer 3) can have a plasticizer content lower than the plasticizer content of the inner core layer (e.g., the second layer 2).

[0056] The glass transition temperature or Tg is the temperature at which the tagged polymer changes from a glassy state to its rubbery state. At least one plasticized resin layer (e.g., core layer 2) may have a glass transition temperature greater than -15°C, greater than -12°C, greater than -10°C, greater than -5°C, greater than -2°C, or 0°C and / or no more than 20°C, no more than 15°C, no more than 12°C, no more than 10°C, no more than 5°C, no more than 2°C, no more than 0°C, or no more than -1°C. Alternatively, or in addition, at least one resin layer (e.g., such as Figure 2 At least one of the epidermal layers 1 or 3) shown may have a glass transition temperature of at least 20°C, at least 22°C, at least 25°C, at least 27°C, at least 29°C, or at least 30°C and / or no more than 55°C, no more than 50°C, no more than 45°C, no more than 40°C, no more than 35°C, or no more than 32°C.

[0057] The glass transition temperature of the layers described herein is determined by dynamic mechanical thermal analysis (DMTA). DMTA measures the storage (elastic) modulus (G') (in Pascals), the loss (viscous) modulus (G") (in Pascals), and the loss tangent (G" / G') of the sample, which varies with temperature at a given oscillation frequency and temperature scan rate. The glass transition temperature is then determined by the position of the loss tangent peak on the temperature scale. The glass transition temperatures provided herein are measured in shear mode at an oscillation frequency of 1 Hz and a temperature scan rate of 3°C / min.

[0058] In some embodiments, the two resin layers may have different glass transition temperatures, particularly when the two resin layers have resins with different hydroxyl or acetate and / or plasticizer contents. Figure 2 The difference in glass transition temperature between one of the outer layers 1, 3 shown and the core layer 2) can be at least 2°C, at least 3°C, at least 5°C, at least 8°C, at least 10°C, at least 12°C, at least 15°C, at least 18°C, at least 20°C, at least 22°C, at least 25°C, at least 30°C, or at least 35°C and / or no more than 60°C, no more than 55°C, no more than 50°C, no more than 45°C, no more than 40°C, no more than 35°C, no more than 30°C, or no more than 25°C.

[0059] In some cases, the outer layer or layers of the multilayer interlayer may have a higher Tg and thus may be considered a "hard" outer layer, while the inner layer of the multilayer interlayer may have a lower Tg and may be considered a "soft" interlayer. In some embodiments, the outer skin layer may have a Tg that is at least 2°C, at least 5°C, at least 10°C, at least 15°C, at least 20°C, at least 25°C, at least 30°C, or at least 35°C higher than the Tg of the inner core layer and / or no higher than 100°C, no higher than 90°C, no higher than 75°C, no higher than 70°C, no higher than 65°C, no higher than 60°C, no higher than 55°C, no higher than 50°C, no higher than 45°C, or no higher than 40°C, no higher than 35°C, no higher than 30°C, or no higher than 25°C.

[0060] In terms of optical properties, one or more plasticized resin layers may have a refractive index of at least 1.465, at least 1.470, at least 1.472, at least 1.474, at least 1.475, at least 1.480, at least 1.485, at least 1.490, at least 1.495, at least 1.500, at least 1.505, at least 1.510, at least 1.525 and / or no more than 1.600, no more than 1.590, no more than 1.580, no more than 1.570, no more than 1.560, no more than 1.550, no more than 1.540, no more than 1.530, no more than 1.520, no more than 1.510, no more than 1.500, no more than 1.490, no more than 1.482, no more than 1.480, or no more than 1.479.

[0061] Two or more layers in the interlayer may have different refractive indices based on the specific composition of each layer. For example, the type and amount of plasticizer, and the specific polyvinyl acetal resin present in each layer. In some cases, even when one layer (e.g., core layer 2) includes a modified polyvinyl acetal resin and another layer (e.g., one or more skin layers 1, 3) includes an unmodified polyvinyl acetal resin or does not include any modified polyvinyl acetal resin, the refractive index difference between the two layers in the interlayer (e.g., skin layer and core layer) may be at least 0.0001, at least 0.005, at least 0.0010, and / or no more than 0.0100, no more than 0.0075, no more than 0.0050, or no more than 0.0025.

[0062] In some cases, at least one layer (e.g., first resin layer 1 and / or third resin layer 3) may have a refractive index of at least 1.470, at least 1.472, at least 1.474, and / or no more than 1.482, no more than 1.480, or no more than 1.479, while at least one layer among the other layers (e.g., second resin layer 2) may have a refractive index of at least 1.465, at least 1.470, at least 1.475, at least 1.480, at least 1.485, at least 1.490, at least 1.495, at least 1.500, at least 1.505, at least 1.510, or at least 1.525 and / or a refractive index of no more than 1.600, no more than 1.590, no more than 1.580, no more than 1.570, no more than 1.560, no more than 1.550, no more than 1.540, no more than 1.530, no more than 1.520, no more than 1.510, no more than 1.500, or no more than 1.490.

[0063] In some embodiments, the interlayer as a whole can have a refractive index of at least 1.480, at least 1.482, at least 1.485, at least 1.487, at least 1.490, at least 1.500, at least 1.510, at least 1.520, at least 1.525 and / or no more than 1.700, no more than 1.675, no more than 1.650, no more than 1.625, no more than 1.600, no more than 1.575, no more than 1.550, no more than 1.525, no more than 1.500, no more than 1.495, no more than 1.490, or no more than 1.485.

[0064] In addition, one or more layers of the multilayer interlayer may include at least one type of additive that can impart specific properties or characteristics to the polymer layer or interlayer. Such additives may include, but are not limited to, dyes, pigments, stabilizers (such as UV stabilizers), antioxidants, antiblocking agents, flame retardants, IR absorbers or blockers (such as indium tin oxide, antimony tin oxide, lanthanum hexaboride (LaB6) and cesium tungsten oxide), processing aids, flow enhancement additives, lubricants, impact modifiers, nucleating agents, thermal stabilizers, UV absorbers, dispersants, surfactants, chelating agents, coupling agents, adhesives, initiators, reinforcing additives, fillers and adhesion control agents (ACAs). The specific type and amount of such additives may be selected based on the final properties or end use of the particular interlayer, and may be used to the extent that the additive or additives do not adversely affect the final properties of the interlayer or the windshield using the interlayer configured for the specific application.

[0065] In some cases, one or more resin layers (or the entire interlayer) may not include a solid refractive index (RI) additive. As used herein, the term "solid RI additive" refers to an additive for adjusting the refractive index of a polyvinyl acetal resin, a resin layer, or an interlayer, which is solid under ambient conditions of 25°C and 1 atmosphere. One or more or all of the resin layers in the interlayer may include less than 0.5, less than 0.25, or less than 0.10 phr. Examples of solid RI additives include, but are not limited to, polyadipate, polystyrene having a molecular weight of less than 2500, epoxides, phthalates, benzoates, inorganic oxides (such as, for example, zirconium oxide), halogenated additives, and silicon-containing additives, and combinations thereof.

[0066] In some embodiments, one or both of the outer skin layers may include a gradient color band near one or both edges of the interlayer. Such a gradient color band may be embedded in the outer skin layer of the interlayer or all or part of the outer skin layers of the interlayer, and may have a thickness between 0.025mm and 0.375mm, between 0.125mm and 0.325mm, or between 0.225mm and 0.300mm. The thickness of the outer skin layer on one or both sides of the interlayer may be 0.0125mm to 0.075mm, 0.025mm to 0.05mm, or 0.03mm to 0.04mm. As used herein, the term "external skin layer" includes the gradient color band (if present).

[0067] According to some embodiments, at least one surface of a layer or interlayer may be textured to facilitate the formation of an interlayer or glass. For example, at least a portion of at least one surface of one or more layers in a layer or interlayer may have a surface roughness (Rz) of at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, or at least 50 microns and / or no more than 150, no more than 140, no more than 130, no more than 120, no more than 110, no more than 100, no more than 90, no more than 80, no more than 75, no more than 70, no more than 65, no more than 60 microns, or no more than 40 microns.

[0068] As used herein, Rz is a measure of the surface topography of a polymer layer and is an indicator of the degree to which the surface deviates from a plane. In addition, the surface roughness of a layer can also be described by its Rsm, which is a measure of the distance between peaks in the surface topography of a polymer layer. Further description of how to determine Rz and Rsm is provided in U.S. Patent No. 7,883,761, the entire contents of which are incorporated herein by reference to the extent not in conflict with the present disclosure. Such roughness can be achieved by any suitable method, including but not limited to embossing, melt fracturing, and combinations thereof.

[0069] The interlayer may have a profile of any suitable shape, including, for example, a planar profile having a substantially uniform thickness or a wedge-shaped profile having a constant or variable thickness variation. When the interlayer has a planar profile, at least 90, at least 92, at least 95, at least 97, at least 99, or all perpendicular cross-sections of the layer or interlayer have a uniform thickness. Such an interlayer may be non-wedge-shaped and may have a wedge angle of about zero or less than 0.05 milliradians (mrad).

[0070] When the interlayer has a constant thickness distribution (e.g. Figure 2 When the interlayer is arranged in a constant thickness distribution (generally shown), each layer of the interlayer can be flat, or two or more layers can have a wedge-shaped distribution and can be arranged so that the overall distribution of the interlayer is flat (embodiment not shown). The total thickness of the constant thickness distribution interlayer can be at least 25, at least 27, or at least 30 mils and / or no more than 37, no more than 35, or no more than 34 mils. Each layer can have an average thickness of at least 1, at least 2, at least 3, at least 5, or at least 6 mils and / or no more than 20, no more than 15, no more than 10, no more than 8, or no more than 6 mils, wherein the core layer has a thickness of 1 to 8 mils or 2 to 6 mils and the skin layers each have a thickness of 1 to 15 mils or 2 to 12 mils. As used herein, the term "average thickness" refers to the thickness of a layer or interlayer, measured at 10 evenly spaced locations over the entire vertical height of the interlayer and then averaged (i.e., divided by 10).

[0071] In some cases, the resin used to form the skin layer may include 50 to 95 weight percent or 85 to 92 weight percent of the total interlayers, while the resin used to form the core layer may include 5 to 50 weight percent or 8 to 15 weight percent of the total interlayers.

[0072] In some embodiments, the interlayer may have an overall wedge-shaped or wedge-shaped profile. As used herein, the term "wedge-shaped" or "wedge-shaped" refers to having a cross-sectional geometry, at least a portion of which increases from a relatively thin dimension to a relatively thick dimension. In some cases, the thickness of the thinnest edge of the wedge-shaped portion (e.g., the tapered region) of the interlayer can be at least 0.50, at least 0.55, at least 0.60, at least 0.65, or at least 0.70 mm and / or no more than 1.1, no more than 1.0, no more than 0.95, no more than 0.90, no more than 0.85, no more than 0.80, no more than 0.75, or no more than 0.70 mm, and the thickness of the thickest edge of the wedge portion of the wedge-shaped portion of the interlayer can be at least 0.60, at least 0.65, at least 0.70, at least 0.75, at least 0.80, at least 0.85, or at least 0.90 mm and / or no more than 2.0, no more than 1.95, no more than 1.90, no more than 1.85, no more than 1.80, no more than 1.75, no more than 1.70, no more than 1.65, no more than 1.60, no more than 1.55, or no more than 1.50 mm. The total interlayer thickness at any point is the combined thickness of all layers at that point.

[0073] When at least one layer of the interlayer (or the interlayer itself) is wedge-shaped, at least a portion of the interlayer can have at least one wedge angle of at least 0.05, at least 0.10, at least 0.13, at least 0.15, at least 0.20, at least 0.25, at least 0.30, at least 0.35, or at least 0.40 milliradians (mrad) and / or no more than 1.0, no more than 0.90, no more than 0.85, no more than 0.80, no more than 0.75, no more than 0.70, no more than 0.65, or no more than 0.60 mrad. In some embodiments, the interlayer can have a total wedge angle of at least 0.3, at least 0.35, at least 0.40, at least 0.45, at least 0.50, at least 0.55, at least 0.60, at least 0.65, at least 0.70, at least 0.75 mrad and / or no more than 0.80, no more than 0.75, no more than 0.70, no more than 0.65, no more than 0.60, no more than 0.55, no more than 0.50, no more than 0.45, no more than 0.40, no more than 0.35, no more than 0.30 mrad.

[0074] In some embodiments, when the interlayer is a multi-layer interlayer, one or more of the skin or core layers can be wedge-shaped. In some cases, only the outer skin layer can be wedge-shaped, while the inner core layer can be flat or substantially flat. In other cases, one of the skin layers can be wedge-shaped, while the other skin layer can be flat. In some cases, both the outermost skin layer and the innermost core layer can be wedge-shaped, and the wedge angles can be similar or different. In another case, the outer layer can be flat, while the inner core layer is wedge-shaped. In other cases, the outer skin layer can be wedge-shaped, while the inner core layer can be wedge-shaped or flat.

[0075] When the interlayer is a wedge-shaped interlayer, it may have at least one constant wedge angle that does not change over the entire or a portion of the interlayer, while in other cases, the wedge angle may vary continuously over the entire or a portion of the non-uniform thickness region. Specific embodiments of interlayers with different tapered zone configurations are described in detail in U.S. Patent Application Publication No. 2017 / 0285339, the entire contents of which are incorporated herein by reference to the extent not inconsistent with the present disclosure.

[0076] Whether the interlayer has a flat or wedge-shaped outline, the outer epidermis ( Figure 2 The outer skin layers (shown as layer 1 and layer 3 in FIG. 1 ) may have similar or different thicknesses. When the outer layers have similar thicknesses, the maximum difference between the thicknesses of the two outer layers may be no more than 5, no more than 3, no more than 2, no more than 1, or no more than 0.5 percent. In some cases, the two outer skin layers may have the same nominal thickness.

[0077] In other embodiments, at least a portion of one outer skin layer 1 or 3 may be thicker than at least a portion of the other outer skin layer 3 or 1. For example, in some embodiments, one of the outer skin layers 1, 3 may be at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45%, or at least 50 percent thicker than the other outer skin layer at one or more locations on the interlayer. Alternatively, or in addition, at least a portion of one outer skin layer 1 or 3 may be no more than 90, no more than 85, no more than 80, no more than 75, no more than 70, no more than 65, no more than 60, no more than 55, no more than 50, or no more than 45 percent thicker than the other outer skin layer 3 or 1 at one or more locations along the interlayer.

[0078] The interlayer described herein can be formed by any suitable method. For example, in some embodiments, the multilayer interlayer can be formed by coextrusion. In such a process, at least three resin streams (including the first surface resin stream, the second surface resin stream and the inner core resin stream between the first surface resin stream and the second surface resin stream) can be extruded from the mold at the same time to form a coextruded resin sheet. In other embodiments, the multilayer interlayer can be formed by extruding each of the first surface resin stream, the second surface resin stream and the core layer resin stream respectively to form three separate layers, and then these layers are laminated to form a multilayer interlayer. In some cases, coextrusion and lamination can be used to form a multilayer interlayer. In some cases, coextrusion can be used to form a multilayer sheet having, for example, at least 2 layers, at least 3 layers, or 4 layers or more layers. Then, the sheet can be laminated to another sheet including 1 or more other layers to form a multilayer interlayer. In some cases, one or more layers of the sheet can be flat, and one or more layers of the sheet can be wedge-shaped. In some embodiments, the multilayer sheet can have a planar profile and can be laminated to a single-layer sheet with a wedge-shaped profile to provide a wedge-shaped multilayer interlayer.

[0079] Compared to interlayers formed from conventional polymer layers, interlayers configured and formed according to embodiments of the present technology can exhibit enhanced optical and / or acoustic properties. For example, in some embodiments, the interlayer can have a speckle value of no more than 3.5, no more than 3.25, no more than 3, no more than 2.75, no more than 2.5, no more than 2.25, no more than 2, no more than 1.75, no more than 1.5, or no more than 1. The speckle is a measure of optical quality that is detected as texture or granularity. When the speckle is too high or too severe, it can result in an unpleasant visual appearance in the interlayer or glass.

[0080] The spot values ​​provided herein are measured using a clear spot analyzer (CMA) including a xenon arc lamp, a sample holder, a projection screen, and a digital camera. The xenon arc lamp is used to project a shadow map of the laminated sample onto a screen, and the camera is configured to capture an image of the resulting shadow map. The image is then digitally analyzed using computer imaging software, and the image is compared with an image of a previously captured standard sample to determine the spots of the sample. The method of measuring spots using CMA is described in detail in U.S. Patent No. 9.311,699.

[0081] Clarity is another optical parameter for describing the performance of interlayer as described herein, and can be measured by measuring haze value or percentage.Haze value represents the quantification of the light scattered by the sample compared with the incident light.In some embodiments, resin blends, layers and interlayer as described herein may have a haze value less than 5 percentages, less than 4 percentages, less than 3 percentages, less than 2 percentages, less than 1 or less than 0.5 percentages, which is measured under the observer angle of 2 degrees using illuminator C according to ASTM D1003-13-Procedure B. The test is carried out using a spectrophotometer (such as Hunterlab UltraScan XE instrument (commercially available from Hunter Associates in Reston, Virginia)) to a polymer sample having a thickness of 0.76 mm, and the sample has been laminated between two sheets of transparent glass having a thickness of 2.3 mm each (commercially available from Pittsburgh Glass Works in Pennsylvania).

[0082] In some embodiments, the interlayer may have a visual transmittance (% TvisK) of at least 65, at least 70, at least 75, at least 80, at least 81, at least 82, at least 83, at least 84, at least 85, at least 85.5, at least 86, at least 86.5, at least 87, at least 87.5, at least 88, or at least 88.5 percent. Additionally or alternatively, the interlayer may have a total solar energy transmittance (% Tts) of no more than 75, no more than 70, no more than 65, no more than 60, no more than 55, no more than 50, or no more than 45% as measured according to ISO 13837.

[0083] The interlayers as described herein may also exhibit ideal acoustic properties. For example, in some embodiments, the interlayers according to the embodiments of the present technology may have a loss tangent value of at least 0.70. The loss tangent is the ratio of the loss modulus (G") (in Pascals) to the storage modulus (G') (in Pascals) of a sample measured by dynamic mechanical thermal analysis (DMTA). DMTA is performed in shear mode with an oscillation frequency of 1 Hz and a temperature scan rate of 3°C / min. The peak of the G" / G' curve at the glass transition temperature is the loss tangent value. The loss tangent of the interlayer described herein may be at least 1.0, at least 1.05, at least 1.10, at least 1.25, at least 1.50, at least 1.75, at least 2.0, or at least 2.25 and / or no more than 5, no more than 4.75, no more than 4.5, no more than 4.25, no more than 4, no more than 3.75, no more than 3.5, no more than 3.25, no more than 3, or no more than 2.5.

[0084] In addition, the interlayer may have a damping loss factor or loss factor of at least 0.10, at least 0.15, at least 0.17, at least 0.20, at least 0.25, at least 0.27, at least 0.30, at least 0.33, or at least 0.35. The loss factor is measured by mechanical impedance measurement as described in ISO Standard 16940. The polymer sample is laminated between two sheets of transparent glass, each sheet having a thickness of 2.3 mm and prepared to have a width of 25 mm and a length of 300 mm. The polymer sample is then laminated between two sheets of transparent glass, each sheet having a thickness of 2.3 mm and prepared to have a width of 25 mm and a length of 300 mm. The polymer sample is then laminated using the method described in Brüel and The laminated samples were excited at the center point by a commercially available vibrator (Brüeland, The Netherlands) and the impedance head (Brüeland, The Netherlands) was used. ) The force and vibration velocity required to excite the rod to vibrate were measured. The resulting transfer function was recorded on a National Instruments data acquisition and analysis system, and the half-power method was used to calculate the loss factor in the first vibration mode.

[0085] According to embodiments of the present technology, an interlayer having at least one resin layer comprising a modified polyvinyl acetal resin as described herein can be more easily recycled and / or recycled in larger quantities than a similar interlayer that does not include the modified polyvinyl acetal. For example, in some cases, a multilayer interlayer comprising at least one pair of outer skin layers and an inner core layer comprising a modified polyvinyl acetal resin can be more easily recycled than a similar multilayer interlayer having the same skin layers and a core layer that does not contain the modified polyvinyl acetal resin.

[0086] The recycling of the interlayer can be carried out by any known process, and in some cases produces a blend of two or more polyvinyl acetal resins (e.g., a skin resin and a core resin), typically with at least one plasticizer. In some cases, due to the increased refractive index of the modified polyvinyl acetal resin compared to a similar unmodified polyvinyl acetal resin, a larger amount of the modified polyvinyl acetal resin can be recycled than would be expected for the unmodified resin, and the recycled composition can still maintain desirable properties, including optical properties. The recycled interlayer can include post-consumer waste, post-industrial waste, and / or pre-consumer waste.

[0087] For example, in some cases, the recycled blended composition can include at least one polyvinyl acetal resin and at least one modified polyvinyl acetal resin, as described herein. The two resins can have different hydroxyl contents within one or more ranges herein, and therefore can have different plasticizer contents and / or refractive indices. The modified polyvinyl acetal resin can be present in the blended composition in an amount of at least 1.2, at least 1.5, at least 2, at least 5, at least 10, at least 12, or at least 15 weight percents and / or no more than 30, no more than 25, no more than 20, no more than 17, no more than 15, or no more than 10 weight percents based on the total weight of the resin in the composition.

[0088] In some cases, the total amount of the modified polyvinyl acetal resin composition (e.g., the plasticized polyvinyl acetal resin described herein) can be present in the blend composition in an amount of at least 1, at least 2, at least 5, at least 10, at least 12, or at least 15 weight percent and / or no more than 50, no more than 45, no more than 40, no more than 35, no more than 30, no more than 25, no more than 20, or no more than 15 weight percent based on the total weight of the blend composition (e.g., resin and plasticizer). Even with higher amounts of different polyvinyl acetal resins, the blend composition can still exhibit a haze of less than 2, less than 1.5, or less than 1.

[0089] In some cases, at least a portion of the mixed composition can be used to form a recycled component interlayer. Such interlayers may include, for example, at least 1, at least 5, at least 10, at least 15, at least 20, or at least 25 percent based on the gross weight of the interlayer and / or no more than 75, no more than 70, no more than 65, no more than 60, no more than 55, no more than 50, or no more than 45 percent recycled component materials. In some cases, at least a portion of the outer skin layer of the recycled component interlayer may include recycled component resin (including, for example, recycled component modified PVB resin) and at least one plasticizer, and may have one or more characteristics discussed herein. The interlayer may be a multilayer interlayer, and other layers may include or may not include recycled component resin.

[0090] The interlayers described herein can be used to form glass.Glass (or laminates or panels) can be formed by sandwiching an interlayer according to embodiments of the present technology between a first rigid substrate and a second rigid substrate and laminating the construction to form multiple layers of glass.

[0091] As described herein, multilayer glass or plate generally comprises a first rigid substrate sheet with a first substrate thickness and a second rigid substrate sheet with a second substrate thickness. The first substrate and the second substrate can both be formed by rigid materials (such as glass), and can be formed by the same operation or different materials. In some embodiments, at least one of the first substrate and the second substrate can be a glass substrate, and in other embodiments, at least one of the first and second can be formed by another material (including, for example, rigid polymers, such as polycarbonate, copolyester, acrylic acid, polyethylene terephthalate and combinations thereof). In embodiments, the rigid substrates are all glass. Depending on the desired performance and characteristics, any suitable type of non-glass material can be used to form this substrate.

[0092] Any suitable type of glass can be used to form the rigid glass substrate, and in some embodiments, the glass can be selected from aluminosilicate glass, borosilicate glass, quartz or fused quartz glass, and soda-lime glass. The glass substrate may be annealed, heat strengthened or tempered, chemically tempered, etched, coated, or ion exchange strengthened when used, or it may have been subjected to one or more of these treatments. The glass itself may be rolled glass, float glass, or flat glass. In some embodiments, the glass may not be chemically treated or strengthened by ion exchange, and in other embodiments, the glass may not be aluminosilicate glass. When the first substrate and the second substrate are both glass substrates, the type of glass used to form each substrate may be the same or different.

[0093] The rigid substrate can have any suitable thickness. In some embodiments, when the rigid substrates are both glass substrates, the nominal thickness of at least one of the glass sheets (the first glass or the second glass) ranges from 0.1 mm to 12.7 mm, and the multiple layer glass panel includes any combination of the first glass sheet and the second glass sheet (and any other glass sheets or rigid sheets, if desired). In some embodiments, the nominal thickness of the first substrate and / or the second substrate can be at least 0.4, at least 0.5, at least 0.7, at least 0.75, at least 1.0, at least 1.25, at least 1.3, at least 1.6, at least 1.9, at least 2.2, at least 2.5, or at least 2.8 and / or less than 3.2, less than 2.9, less than 2.6, less than 2.5, less than 2.3, less than 2.0, less than 1.75, less than 1.7, less than 1.5, less than 1.4, or less than 1.1 mm.

[0094] In addition, or in the alternative, the first substrate and / or the second substrate can have a nominal thickness of at least 2.3, at least 2.6, at least 2.9, at least 3.2, at least 3.5, at least 3.8, or at least 4.1 and / or less than 12.7, less than 12.0, less than 11.5, less than 10.5, less than 10.0, less than 9.5, less than 9.0, less than 8.5, less than 8.0, less than 7.5, less than 7.0, less than 6.5, less than 6.0, less than 5.5, less than 5.0, or less than 4.5 mm. Other thicknesses may be appropriate depending on the application and desired properties.

[0095] When a multilayer sheet includes two substrates having the same nominal thickness, such a sheet may be referred to as a "symmetrical configuration" because the ratio of the nominal thickness of one substrate to the nominal thickness of the other substrate is equal to 1. When a multilayer sheet includes two substrates having different nominal thicknesses, such a sheet may be referred to as an "asymmetrical configuration" because the ratio of the nominal thickness of one substrate to the nominal thickness of the other substrate is not equal to 1. In some cases, the thicker rigid substrate or sheet may have a nominal thickness that is at least 1.05 times, at least 1.5 times, at least 2 times, at least 2.5 times, at least 3 times, or at least 5 times and / or no more than 10 times, no more than 8 times, no more than 6 times, no more than 5 times, no more than 3 times, no more than 2 times, or no more than 1.5 times thicker than the nominal thickness of the thinner rigid substrate or sheet.

[0096] In some embodiments, one or both substrates may be wedged. When one or both rigid substrates are wedge-shaped substrates, the substrates may define a wedge angle of at least 0.05, at least 0.10, at least 0.15, at least 0.20, at least 0.25, at least 0.30, or at least 0.35 milliradians and / or no more than 1, no more than 0.95, no more than 0.90, no more than 0.85, no more than 0.80, no more than 0.75, no more than 0.70, no more than 0.65, no more than 0.60, no more than 0.55 milliradians. When both substrates are wedge-shaped, the substrates may have substantially similar wedge angles within 0.001 milliradians, within 0.005 milliradians, or within 0.01 milliradians of each other. Alternatively, when both wedge-shaped substrates are wedged, one of the wedge-shaped substrates may have a different wedge angle than the other.

[0097] Examples of suitable types of multilayer panels may include windows for automotive applications, including but not limited to windshields, side windows and skylights. Examples of suitable types of multilayer panels for architectural applications include but are not limited to windows, laminated glass panels for doors, walls, ceilings and walkways, and the like.

[0098] Example

[0099] Example 1 - High refractive index polyvinyl acetal resin

[0100] Several polyvinyl acetal resins, referred to as comparative or control resins CR1 to CR6 in Table 1 below, were prepared by acetalizing polyvinyl alcohol with one or more aldehydes, including n-butyraldehyde (n-ButCHO; RI=1.377) and benzaldehyde (BzCHO; RI=1.545). Benzaldehyde was used as the controlling aromatic monomer for the polyvinyl acetal to illustrate the low reactivity of benzaldehyde with polyvinyl alcohol due to its fully conjugated structure. Alkyl, aryl or halogen substitution on the aromatic ring of benzaldehyde can increase its reactivity with polyvinyl alcohol.

[0101] In addition, several polyvinyl alcohol acetal resins according to embodiments of the present invention were synthesized. The resins of the present invention, labeled IR1 to IR5 in Table 1, were prepared by acetalizing polyvinyl alcohol with a mixture of n-butylaldehyde and various high refractive index aldehydes, including 4-methylbenzaldehyde (4-MBzCHO, RI=1.545), cinnamaldehyde (CCHO, RI=1.620), 2-hydroxy-1-naphthaldehyde (2-Hy-1-NCHO, RI=1.652).

[0102] Table 1. Different cyclic aldehydes used in the resins of the invention, and benzaldehyde and n-butyraldehyde used in comparative resins.

[0103]

[0104] Example 2 - Synthesis of polyvinyl acetal and cyclic aldehyde

[0105] Polyvinyl acetal was synthesized in a jacketed 2L autoclave reactor equipped with an overhead stirrer, condenser, addition funnel, and temperature probe for temperature monitoring. 115 g of polyvinyl alcohol (99% hydrolyzed) was dissolved in 1323 g of water by stirring at 150 rpm at 90° C. for 1 hour to give a clear solution. After the polyvinyl alcohol was dissolved, the reaction mixture was cooled to 8° C. 149.5 g of n-butyraldehyde was then added via the addition funnel over 1 minute and stirred at 8° C. and 150 rpm for 30 minutes.

[0106] A concentrated mineral acid catalyst solution (24.058 g concentrated mineral acid catalyst + 24.058 g deionized water) was added quickly via an addition funnel over approximately 2 minutes, and the reaction mixture was stirred at 750 rpm for 15 minutes at 8°C until the agitator torque point dropped sharply to a minimum (solution viscosity decreased). After an additional 15 minutes of stirring, the bath temperature was set to 70-80°C to heat the reaction mixture for an additional 2-2.25 hours. The reaction mixture was cooled to room temperature and the polyvinyl acetal resin was collected by vacuum filtration. The resin was then washed with 1.6 L of deionized water, and the resin was neutralized with potassium hydroxide solution to remove residual acid by mixing the solid resin with deionized water under continuous stirring and adding KOH solution dropwise to a pH of 7-7.4. After the resin was neutralized, the resin was collected by vacuum filtration and dried overnight in a 55°C vacuum oven and then precipitated using a ZM 200 ultracentrifugal mill. The dried resin was ground to 1 mm particle size.

[0107] According to Table 2, polyvinyl acetal resins using a mixture of aliphatic and aromatic aldehydes were similarly prepared for CR2 to CR6 and IR1 to IR5 resins.

[0108] Table 2: Weight composition of aliphatic and cyclic aldehydes of polyvinyl acetal resins.

[0109]

[0110]

[0111] Example 3 - Characterization of polyvinyl acetal resin

[0112] use 1 The composition of the resulting resin was measured by H-NMR quantitative analysis. The sample was prepared by dissolving 20-30 mg of PVB in 1 mL of deuterated DMSO. Then 100 μL of 1,4-dimethoxybenzene solution (DMB, 19.6 mg per 3 mL of DMSO-d6) was added for use as a chemical shift reference. The sample was heated and stirred at 80°C until completely dissolved. The sample was then transferred to an NMR tube while hot and run on a Bruker Avance III 600MHz instrument. (64 scans, 20 second delay time, 80°C temperature). The 600MHz BBFO probe was used according to 1 The samples were analyzed by H-NMR spectroscopy. The amounts of aliphatic and aromatic polyvinyl acetal in the resin were determined by comparing the integrals of the signals at 0.5 ppm to 7.5 ppm.

[0113] The thermal properties of the resulting resin were determined by differential scanning calorimetry with a scan range of -55°C to 250°C and a scan rate of 10°C / min (ASTM D3418-21). The instrument used was a TA Instruments Q2000 DSC with an RCS cooling unit. A standard aluminum pan and a non-sealed lid were used. The sample size was 3-7 mg. A preliminary thermal cycle was performed, heating the sample from -55°C to 255°C at a rate of 10°C / min to eliminate the previous thermal history and record it. The temperature was maintained for 2 minutes. (See Note 6. ASTM D3418-21). The sample was suddenly cooled to at least -55°C below the transition temperature of interest. The temperature was maintained for 0.5 minutes. The heating rate of 10°C / min was repeated and the heating curve was recorded until all desired transitions were completed. Tg was determined by the midpoint of the change in baseline heat flow with temperature in the second heating cycle.

[0114] The weight average molecular weight (kg / mol) of PVB resin was measured by gel permeation chromatography (GPC) in hexafluoroisopropanol (HFIP solvent) containing 20 mM potassium trifluoroacetate at 40°C (flow rate: 1.0 ml / min; sample solution: 20 mg sample in 10 ml hexafluoroisopropanol (containing 20 mM potassium trifluoroacetate + 10 μl isopropanol flow rate marker); injection volume: 10 μl; column set: Polymer Laboratories 5 μm HFIP gel protection and mixed HFIP gel).

[0115] The following information provides more details about the test and instrumentation:

[0116] ■Detection

[0117] ●The refractive index is set to 40℃

[0118] Peak width setting> 0.2 minutes (4S response time) (2.28Hz)

[0119] ●Attenuation 31250nRIU

[0120] Zero offset 5%

[0121] ● Calibrator: Monodisperse polymethyl methacrylate standards, MW = 580 to 3,000,000 g / mol

[0122] ■Instrument:

[0123] ●Autosampler: Agilent 1100 series autosampler

[0124] ● Column oven: Agilent 1100 series column oven

[0125] ●Pump: Agilent 1100 series isocratic pump

[0126] ●Detector: Agilent series refractive index

[0127] The refractive index of the polyvinyl acetal resin film containing 75 percent plasticizer was measured. Plasticized resin film was prepared by weighing 20g resin and 15g TEG-EH (triethylene glycol bis (2-ethylhexanoate)) plasticizer in a plastic cup. The resin and plasticizer were fully mixed, and then the mixture was compounded in a Brabender mixer at 170°C with 50rpm for 7 minutes. The resin and plasticizer compound were then pressed into a 30 mil thick film using a hydraulic or pneumatic press. The pressing temperature was then set to 180°C. PET film (5 mils) was placed on a first metal plate, and then a 3"x3" 30 mil gasket was placed on the PET film. 5g of compounded resin and plasticizer mixture were weighed, and the compounded resin was spread on the gasket. A second PET film was placed on the gasket containing the resin / plasticizer compound, and then a second metal plate was placed above it. The assembly was placed in a press and pressed for 5 minutes at 180°C and 2000psi. The press was cooled to about 40-50°C, then the pressure was released and the assembly was removed from the press. The resulting 3 inch x 3 inch 30 mil thick pressed film was removed from the metal shim and cut into 1-2 square inch pieces for RI measurement. For RI measurement, a Metricon Model 2010 prism coupler was used. The sample size is preferably 1-2 square inches, or cut as needed. The sample was then wiped with a Kim wipe and clamped into the instrument by a plunger, which pushed the sample flat against the prism. The plunger pressure was adjusted depending on the rigidity or softness of the sample (higher pressure for rigidity and lower pressure for elasticity). The refractive index of the polyvinyl acetal film was measured at a wavelength of 589.3nm. These RI values ​​were then compared with the RI of the PVB skin resin. The skin resin is a polyvinyl butyral resin containing 18.5% PVOH, which is used as the top interlayer in a three-layer series. The RI of the PVB skin resin without plasticizer at 589.3 nm was 1.490, while the RI of the PVB skin containing 38 phr plasticizer at 589.3 nm was 1.483.

[0128] The glass transition temperature of a 30 mil thick plasticized PVB film (PVB resin + 75 phr plasticizer) was measured by dynamic mechanical thermal analysis (DMTA) with an oscillation frequency of 1 Hz in shear mode and a temperature scanning rate of 3 °C / min over a range of -40 °C to 80 °C. DTMA measures the loss tangent of the sample as it changes with temperature at a given oscillation frequency and temperature scanning rate. The peak of the loss tangent curve is considered to be the glass transition temperature.

[0129] The analysis results and compositions of the comparative resin and the resin of the present invention are shown in Table 3 below.

[0130] Table 3: Analysis results and composition of comparative and inventive polyvinyl acetal resins

[0131]

[0132]

[0133] Additional films were made by blending the skin resin with the selected resins (CR1, IR2, IR5) (secondary resin) from Table 1 and a plasticizer using the above procedure. The haze values ​​of the pressed films were then measured using a Hunterlab UltraScan Vis instrument in the range of 360-780 nm, with an illuminant of C / 2, and a total transmission mode type conforming to ASTM D1003 Procedure B Part 8. The results are shown in Table 4.

[0134] Methods and procedures:

[0135] 1. Standardize the instrument using air.

[0136] 2. Check the air standards to ensure the instrument is properly standardized.

[0137] 3. Use a lint-free cloth to clean the PVB film, making sure there are no fingerprints or other stains on it.

[0138] 4. Place the PVB film against the transmission port and analyze to obtain the haze value.

[0139] Table 4: Haze measurement of plasticized polyvinyl acetal resin layer

[0140]

[0141] The haze value of the skin layer with plasticizer (38 phr) but without the second resin (containing n-butyraldehyde) was 0.05%.

[0142] in conclusion

[0143] 1. Polyvinyl acetals made from aromatic (cyclic) aldehydes exhibit a higher refractive index at 589.3 nm compared to aliphatic aldehyde (CR1) resins.

[0144] 2. Polyvinyl acetal made from aromatic (cyclic) aldehydes increases the molecular weight and glass transition temperature of the resin.

[0145] 3. Plasticized polyvinyl acetal made with aromatic (cyclic) aldehydes increases the glass transition temperature.

[0146] 4. Benzaldehyde was used as a comparative example of aromatic (cyclic) aldehydes, and the NMR results confirmed that it exhibited poor reactivity with polyvinyl alcohol. This occurred due to its conjugated structure. However, the addition of benzaldehyde increased the refractive index of the polyvinyl acetal resin.

[0147] 5. Alkyl and aryl substitution on the benzaldehyde ring increases reactivity with polyvinyl alcohol. 4-Methylbenzaldehyde exhibits excellent refractive index increment (DR2, DR4 and DR5). With the resin of the present invention, the refractive index (skin-core) difference is reduced. (DR2, DR3, DR4 and DR5). However, the DR3 cyclic aldehyde exhibits lower reactivity with polyvinyl alcohol.

[0148] 6. Some of the other cyclic aldehydes that can increase the refractive index and decrease the skin-core RI are 4-methoxybenzaldehyde (MeBzCHO, RI=1.578) and p-phenylbenzaldehyde (P-PhBzCHO, RI=1.5994).

[0149] 7. There is a difference in the composition of polyvinyl butyral between the skin layer and the core layer of the multilayer PVB interlayer, and the multilayer film scrap cannot be re-extruded. If it is, the resulting blended resin composition exhibits a high level of haze, resulting in unacceptable visual quality of the final interlayer product. Therefore, large-scale recycling of multilayer interlayer materials has not been successfully achieved. The haze values ​​of these interlayers / films can be improved by adding polyvinyl acetal resins containing cyclic aldehydes to the skin resin.

[0150] 8. The haze (Table 4) of films made by blending the skin resin with selected resins from the aromatic / cyclic aldehyde containing secondary resins (Examples 15, 16, 17) was significantly improved compared to films made by blending the skin resin with a control resin (Examples 12, 13, 14).

[0151] definition

[0152] It should be understood that the following is not intended to be an exhaustive list of defined terms. Additional definitions may be provided, such as, for example, in the foregoing description where context accompanies the use of a defined term.

[0153] As used herein, the term "modified polyvinyl acetal resin" refers to a polyvinyl acetal resin including a residue of at least one cyclic aldehyde.

[0154] As used herein, the term "polyvinyl acetal resin component" may refer to a single polyvinyl acetal resin present in a physical blend of two or more resins, or the acetal moiety present on a single polyvinyl acetal resin.

[0155] As used herein, the term "polymer backbone" or "main chain" refers to the longest continuous chain of atoms bonded together in a polymer compound.

[0156] As used herein, the term "pendent group" or "pendant group" refers to a group of two or more atoms bonded together and extending from a polymer backbone.

[0157] As used herein, the term "substituted" refers to a molecule in which at least one atom or functional group in the molecule is replaced with a different atom or functional group to form a new compound.

[0158] As used herein, the term "ring" or "cyclic compound" refers to at least three atoms bonded to each other in the form of a ring or circle.

[0159] As used herein, the term "unsaturated" means having at least one CC double bond.

[0160] As used herein, the term "saturated" refers to the absence of CC double bonds.

[0161] As used herein, the term "conjugated" refers to having at least two CC double bonds separated by a CC single bond.

[0162] As used herein, the term "cyclic vinyl monomer" refers to a monomer including a vinyl group (--CH2=CH-) and at least one cyclic group.

[0163] As used herein, the term "heteroatom" refers to an atom other than carbon in the ring of a cyclic compound.

[0164] As used herein, the term "heterocycle" refers to a ring group including at least two different types of atoms within the ring.

[0165] As used herein, the term "5-membered ring" refers to a molecule having a ring structure formed by 5 atoms bonded to each other.

[0166] As used herein, the term "6-membered ring" refers to a molecule having a ring structure formed by 6 atoms bonded to each other.

[0167] As used herein, the term "aromatic" refers to a planar unsaturated ring structure.

[0168] As used herein, the term "derivative" refers to a chemical compound that is derived from another chemical compound by chemical modification.

[0169] As used herein, the term "polymer backbone" or "main chain" refers to the longest continuous chain of atoms bonded together in a polymer compound.

[0170] As used herein, the term "pendent group" or "pendant group" refers to a group of two or more atoms bonded together and extending from a polymer backbone.

[0171] As used herein, the term "refractive index" refers to the ratio of the speed of light in a vacuum to the speed of light through the material under consideration. Unless otherwise specified, the refractive index is measured according to ASTM D542 at a wavelength of 589 nm and 25°C.

[0172] As used herein, the term "glass transition temperature" or "Tg" is the temperature that marks the transition of a polymer from a glassy state to a rubbery state. The glass transition temperatures described herein are determined by dynamic mechanical thermal analysis (DMTA). DMTA measures the (elastic) modulus (G') (in Pascals), the loss (viscous) modulus (G") (in Pascals), and the loss tangent (G" / G') of a sample, which changes with temperature at a given oscillation frequency and temperature scan rate. The glass transition temperature is then determined by the position of the loss tangent peak on the temperature scale. Unless otherwise stated, the specific glass transition temperatures provided herein are determined in shear mode at an oscillation frequency of 1 Hz and a temperature scan rate of 3°C / min.

[0173] As used herein, the term "parts per hundred parts of resin" or "phr" refers to the amount of a component (eg, plasticizer, additive, etc.) present in a composition compared to one hundred parts of resin by weight.

[0174] As used herein, the term "residual hydroxyl content" refers to the amount of hydroxyl groups remaining on the polyvinyl acetal resin after processing. Unless otherwise specified, the residual hydroxyl content is expressed as a weight percent based on the weight of the polyvinyl acetal resin and is measured herein according to ASTM D-1396.

[0175] As used herein, the term "residual acetyl content" refers to the amount of acetyl groups remaining on the polyvinyl acetal resin after processing. Unless otherwise specified, the residual acetyl content is expressed as a weight percentage based on the weight of the polyvinyl alcohol carboxylic acid resin and is measured herein according to ASTM D-1396.

[0176] As used herein, the term "residue" or "moiety" refers to a portion of a polymer, typically derived from the reaction of one or more monomers.

[0177] As used herein, the term "aliphatic" refers to molecules that include saturated or unsaturated molecules but do not include any aromatic groups.

[0178] As used herein, the term "haze" or "haze value" refers to a quantitative value representing the light scattered by a sample compared to the incident light. Unless otherwise specified, haze is measured according to ASTM D1003-13—Procedure B using illuminant C at a 2 degree observer angle. The test is performed using a spectrophotometer (such as a Hunterlab UltraScan XE instrument (commercially available from Hunter Associates in Reston, Virginia)) on a polymer sample having a thickness of 0.76 mm, which has been laminated between two sheets of clear glass having a thickness of 2.3 mm (commercially available from Pittsburgh Glass Works in Pennsylvania).

[0179] As used herein, the term "resin composition" refers to a composition including one or more polymer resins.

[0180] As used herein, the term "resin layer" refers to one or more polymer resins, optionally in combination with one or more plasticizers, that have been formed into a polymer sheet.

[0181] As used herein, the term "interlayer" refers to a single or multi-layer polymeric sheet suitable for use with at least one rigid substrate to form a multi-layer board.

[0182] As used herein, the terms "monolithic" interlayer and "monolithic" interlayer refer to an interlayer formed from a single resin sheet.

[0183] As used herein, the terms "multiple layer" and "multilayer" interlayer refer to an interlayer having two or more resin sheets coupled to each other by coextrusion, lamination, or other means.

[0184]

[0043] As used herein, unless otherwise indicated, the term "molecular weight" or "MW" refers to weight average molecular weight as measured by size exclusion chromatography using the low angle laser light scattering (SEC / LALLS) method of Cotts and Ouano.

[0185] As used herein, the term "different" may refer to a value that is higher or lower than another value, and the value is calculated by subtracting one value from another value.

[0186] As used herein, the term "vertical cross-section" refers to a cross-section taken between the upper and lower edges of the interlayer when the interlayer is arranged for laminate installation in a windshield or other end use.

[0187] As used herein, the term "Cx" or "Cx hydrocarbon" or "Cx component" refers to a hydrocarbon compound that includes a total of "x" carbons per molecule, and encompasses all olefins, paraffins, aromatics, heterocyclic compounds, and isomers having the stated number of carbon atoms. For example, n-butane, isobutane, and tert-butane, as well as each of the butene and butadiene molecules, fall within the general description of "C4" or "C4 component".

[0188] As used herein, the term "primarily" means greater than 50 weight percent. For example, a stream, composition, feedstock, or product that is primarily propane is a stream, composition, feedstock, or product that contains greater than 50 weight percent propane.

[0189] As used herein, the terms "a", "an" and "the" mean one or more than one.

[0190] As used herein, the term "and / or," when used in a list of two or more items, means that any one of the listed items may be used alone, or any combination of two or more of the listed items may be used. For example, if a composition is described as containing components A, B, and / or C, the composition may contain only A; only B; only C; a combination of A and B; a combination of A and C, a combination of B and C; or a combination of A, B, and C.

[0191] As used herein, the phrase "at least a portion" includes at least a portion and up to and including the entire amount or time period.

[0192] As used herein, the terms "comprising," "comprises," and "comprise" are open transition words that are used to transition from an object recited before the term to one or more elements recited after the term, wherein the one or more elements listed after the transition word are not necessarily the only elements that make up the subject matter.

[0193] As used herein, the terms "including, include, and included" have the same open-ended meaning as "comprising, comprise, and comprise" provided above.

[0194] As used herein, the term "recycled content" refers to a composition that is or contains a composition that is directly and / or indirectly derived from recycled materials. Recycled content is generally used to refer to physical recycled content and credit-based recycled content. Recycled content is also used as an adjective to describe materials that have physical recycled content and / or credit-based recycled content.

[0195] As used herein, the term "polyvinyl acetal resin component" may refer to a single polyvinyl acetal resin present in a physical blend of two or more resins, or the acetal moiety present on a single polyvinyl acetal resin.

[0196] As used herein, the term "unmodified polyvinyl acetal resin" refers to a polyvinyl acetal resin that does not include residues of cyclic vinyl acetal monomers and contains at least 99 weight percent residues of vinyl acetate, polyvinyl alcohol, and at least one aldehyde.

[0197] The claims are not limited to the disclosed embodiments

[0198] The preferred forms of the present invention described above are intended to be used as illustrations only and should not be used in a limiting sense to interpret the scope of the present invention. Those skilled in the art may easily make modifications to the above exemplary embodiments without departing from the spirit of the present invention.

[0199] The inventors hereby declare that they intend to determine and assess the reasonable and fair scope of the present invention under the doctrine of equivalents as it relates to any device that does not materially depart from the literal scope of the present invention as set forth in the following claims.

Claims

1. A polyvinyl acetal resin composition, comprising: a polyvinyl acetal resin component comprising a residue of at least one cyclic aldehyde having an unsaturated 5-membered or 6-membered ring group and another polyvinyl acetal resin component comprising a residue of at least one C3 to C8 aliphatic aldehyde; and At least one plasticizer.

2. A method for producing a polyvinyl acetal resin component, the method comprising at least one of the following steps (a) and (b): (a) acetalizing polyvinyl alcohol with at least one C3 to C8 aliphatic aldehyde and at least one cyclic aldehyde to form a modified polyvinyl acetal resin, wherein the cyclic aldehyde contains (i) an unsaturated 5-membered or 6-membered ring and / or (ii) a heterocyclic ring; and / or (b) blending a polyvinyl acetal resin comprising residues of cyclic aldehydes and / or heterocycles with another polyvinyl acetal resin comprising at least 50 weight percent of residues of C3 to C8 aliphatic aldehydes to form a blended polyvinyl acetal resin composition.

3. The composition, layer, interlayer or method of any one of the preceding claims, wherein the cyclic aldehyde comprises a saturated ring.

4. The composition, layer, interlayer or method of any one of the preceding claims, wherein the cyclic aldehyde comprises an unsaturated ring.

5. The composition, layer, interlayer or method of any preceding claim, wherein the cyclic aldehyde is a heterocyclic aldehyde.

6. The composition, layer, interlayer or method of any of the preceding claims, wherein the cyclic aldehyde comprises a ring having no more than 30 carbon atoms.

7. The composition, layer, interlayer or method of any one of the preceding claims, wherein the cyclic aldehyde comprises a ring of only carbon atoms.

8. The composition, layer, interlayer or method of any one of the preceding claims, wherein the cyclic aldehyde comprises a conjugated ring.

9. The composition, layer, interlayer or method of any of the preceding claims, wherein the residue of the cyclic aldehyde is present in the polyvinyl acetal resin in an amount of at least 1 weight percent and / or no more than 50 weight percent, based on the total aldehyde residues of the polyvinyl acetal resin.

10. The composition, layer, interlayer or method of any preceding claim, wherein the cyclic aldehyde or the heterocyclic aldehyde has a refractive index of at least 1.

500.

11. A composition, layer, interlayer or method according to any one of the preceding claims (claim 3 and dependent claims) wherein the second polyvinyl acetal resin has a refractive index (RI) of at least 1.

480.

12. The composition, layer, interlayer or method of any of the preceding claims, wherein the second polyvinyl acetal resin has a residual hydroxyl content of at least 8.5 weight percent and / or less than 16 weight percent.

13. The composition, layer, interlayer or method of any of the preceding claims, wherein the first polyvinyl acetal resin and / or the second polyvinyl acetal resin has a weight average molecular weight (Mw) of at least 100,000 Daltons and / or no more than 1,000,000 Daltons.

14. The composition, layer, interlayer or method of any of the preceding claims, wherein the first polyvinyl acetal resin comprises at least 0.5 weight percent and / or no more than 35 weight percent residual acetyl groups.

15. The composition, layer, interlayer or method of any of the preceding claims, wherein the polyvinyl acetal resin composition or the first polyvinyl acetal resin layer and / or the second polyvinyl acetal resin layer comprises at least one plasticizer having a refractive index of at least 1.435 and / or not more than 1.530 at 589 nm.

16. The composition, layer, interlayer or method of any of the preceding claims, wherein the plasticizer is selected from the group consisting of triethylene glycol di(2-ethylhexanoate), triethylene glycol di(2-ethylbutyrate), triethylene glycol diheptanoate, tetraethylene glycol diheptanoate, tetraethylene glycol di(2-ethylhexanoate), dihexyl adipate, dioctyl adipate, cyclohexylhexyl adipate, diisononyl adipate, heptylnonyl adipate, di(butoxyethyl) adipate and bis(2-(2-butoxyethoxy)ethyl) adipate, dibutyl sebacate, dioctyl sebacate and mixtures thereof. (Reserved) 17. The composition, layer, interlayer or method of any of the preceding claims, wherein the plasticizer is selected from dipropylene glycol dibenzoate, tripropylene glycol dibenzoate, polypropylene glycol dibenzoate, isodecyl benzoate, 2-ethylhexyl benzoate, diethylene glycol benzoate, butoxyethyl benzoate, butoxyethoxyethyl benzoate, butoxyethoxyethoxyethyl benzoate, propylene glycol dibenzoate, 2,2,4-trimethyl-1,3-pentanediol dibenzoate, 2,2,4-Trimethyl-1,3-pentanediol benzoate isobutyrate, 1,3-butylene glycol 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-ethylhexanoate), terephthalic acid di(butoxyethyl) ester, terephthalic acid di(butoxyethoxyethyl) ester and mixtures thereof. (Reserved)? 18. The composition, layer, interlayer or method of any one of the preceding claims, wherein the first polyvinyl acetal resin layer and the second polyvinyl acetal resin layer have a refractive index difference of no more than 0.0100.

19. The composition, layer, interlayer or method of any of the preceding claims, wherein the plasticizer is present in the first polyvinyl acetal resin composition or layer in an amount of at least 20 phr and / or no more than 45 phr.

20. The composition, layer, interlayer or method of any preceding claim, further comprising a blended polyvinyl acetal resin layer comprising the blended resin composition.

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