BACKGROUND OF THE INVENTION

Thermoplastic polymers are useful in a wide variety of applications, including, for example, various electrical, automotive, medical, consumer, industrial, and packaging applications. Thermoplastic polymers are advantaged over thermoset plastics in that thermoplastic polymers can be easily melt processed into a variety of useful articles.

Different types of thermoplastic polymers have different properties that make them desirable for certain end uses. Elastomeric thermoplastic polymers generally have glass transition temperature values below room temperature and low modulus values making them suitable for applications requiring flexibility and stretchability. In contrast, rigid thermoplastic polymers generally have glass transition temperature values above room temperature and high modulus values making them suitable for applications requiring stiffness and strength.

Polyesteramides are one class of thermoplastic polymers which are formed from the polycondensation of diacids, diols, and diamines (e.g., WO2008112833, U.S. Pat. Nos. 5,672,676, 2,281,415, CA2317747). Polyesteramides have attracted strong industrial interest primarily because of their excellent heat resistance properties (U.S. Pat. No. 5,672,676), their amenability to processing and their potential for biodegradability (e.g., WO2008112833).

The present application discloses novel polyesteramides comprising diols such as TMCD and/or CHDM having tunable properties by adjusting the monomer ratios and varying the reaction conditions. The polyesteramides are useful in a variety of engineering plastics applications wherein chemical resistance, UV resistance, moisture barrier, surface energy, heat resistance, mechanical, optical, and/or melt processability properties are important. One such application includes polymer sheets, layers, interlayers or films.

Polymer sheets can be used as interlayers in multiple layer panels formed by sandwiching the interlayer between two panes of glass. Such laminated multiple layer panels are commonly referred to as “safety glass” and have use in both architectural and automotive applications. One of the primary functions of the interlayer in a safety glass panel is to absorb energy resulting from impact to the panel without allowing penetration of an object through the glass. The interlayer also helps keep the glass bonded when the applied force is sufficient to break the glass in order to prevent the glass from forming sharp pieces and scattering. Additionally, the interlayer can also provide the laminated panel with a higher sound insulation rating, reduce ultraviolet (UV) and/or infrared (IR) light transmission through the panel, and enhance its aesthetic appeal through the addition of color, textures, etc.

Often, when an interlayer exhibits a desirable property, such as rigidity, it may lack other desirable or important properties, such as impact resistance or optical clarity. In some applications safety glass panels may be used as a structural element, but it may also be required to impart aesthetic characteristics to the application. In such cases, an optimal optical performance, rigidity, and impact resistance is not only desirable, but required. Unfortunately, as the rigidity of conventional interlayers is increased, the impact resistance of the resulting panel worsens. Similarly, conventional interlayers formulated for enhanced impact strength often lack necessary rigidity that is required in many applications, such as applications requiring excellent structural support properties.

An emerging market in architectural laminated glass requires interlayers with structural properties such as load bearing ability. Such an interlayer is Eastman's Saflex™ DG structural interlayer, which is made of plasticized polyvinyl butyral (“PVB”). Generally, structural interlayers are stiffer products than standard PVB interlayers and this higher stiffness allows laminates made with structural interlayer to sustain higher loads. Alternatively, structural interlayers can be used to allow a reduction in the glass thickness while achieving the same laminate loading.

Higher performance structural interlayers are desirable as more applications requiring stiffer interlayers are emerging (e.g., single side balcony laminates, canopies, staircases, and support beams). However, some of the commercially-available interlayers exhibit deficiencies in terms of processability and/or functionality. Further, the attraction of glass in many of these structural applications is the clarity of the glass panel. Thus, the layers or interlayers must also not hinder the optical properties of the structural glass articles in which they are incorporated.

Additionally, lighter weight and/or lower cost laminates are desirable for many applications. These lighter weight laminates must still possess the desired physical and optical properties, such as having required impact protection, clarity and other properties. One way to achieve a lighter weight laminate is to reduce the thickness of glass. However, if the thickness of glass is reduced too much, the rigidity of the laminate may be compromised. Higher rigidity interlayers can then be used to restore part of the lost rigidity and result in a lighter weight acceptable laminate. Another way to reduce laminate weight is to eliminate one or more panes of glass and replace them by rigid, transparent plastic pane of sufficiently high rigidity to maintain the integrity of the laminate as well as desirable optical properties.

Thus, a need exists for polymeric interlayers that exhibit strength and rigidity, while still providing sufficient impact resistance. Ideally, such interlayers would also exhibit desirable optical properties, such as low haze and no yellowing. Desirably, these interlayers could be used in multiple layer panels for a wide range of applications, including architectural applications, and would provide an optimized balance of structural, performance, and aesthetic properties.

SUMMARY OF THE INVENTION

One embodiment of the present application concerns an interlayer comprising a layer comprising a polyesteramide composition, the polyesteramide composition comprising: (a) a diamine component comprising: 0.1 to 99 mole % of diamine residues derived from cycloaliphatic diamines, aliphatic diamines, or a combination thereof; (b) a diol component comprising: 0.1 to 99 mole % of diol residues derived from at least one diol which is a cycloaliphatic diol, a mixture of cycloaliphatic diols, or a mixture at least one cycloaliphatic diol with at least one aliphatic diol; and (c) a diacid component comprising: 0.1 to 100 mole % of diacid residues derived from a diacid chosen from HO2C—(C2-40)alkylene-CO2H, or HO2C—(C3-10)cycloalkyl-CO2H; wherein each cycloalkyl is unsubstituted or substituted by (C1-3)alkyl, wherein the total mole % of the diacid component is 100 mole %, and wherein the total mole % of the combined diol and diamine component is 100 mole %.

Another embodiment of the present application concerns a multiple layer interlayer comprising a first layer comprising a polyesteramide composition, the polyesteramide composition comprising: (a) a diamine component comprising: 0.1 to 99 mole % of diamine residues derived from cycloaliphatic diamines, aliphatic diamines, or a combination thereof; (b) a diol component comprising: 0.1 to 99 mole % of diol residues derived from at least one diol which is a cycloaliphatic diol, a mixture of cycloaliphatic diols, or a mixture of at least one cycloaliphatic diol with at least one aliphatic diol; and (c) a diacid component comprising: 0.1 to 100 mole % of diacid residues derived from a diacid chosen from HO2C—(C2-40)alkylene-CO2H, or HO2C—(C3-10)cycloalkyl-CO2H; wherein each cycloalkyl is unsubstituted or substituted by (C1-3)alkyl, wherein the total mole % of the diacid component is 100 mole %, and wherein the total mole % of the combined diol and diamine component is 100 mole %, and a second layer comprising a polymer composition different from the polyesteramide composition of the first layer.

The present application also discloses multilayer panels comprising the interlayers.

