Patent Description:
Sound transmission loss generally increases with an increase in the mass per unit area of a sound dampening material. However, it is desirable to minimize the increase in weight that results from incorporating sound dampening materials into an article. Further, it is desirable to achieve good sound dampening (i.e., increased sound transmission loss) at a range of lower frequencies, such as less than <NUM>, where sound attenuation is more difficult.

<CIT> disclose polyester molded articles including bars which are having enhanced sound and vibration damping.

Accordingly, there is an increasing need to develop cost effective solutions to achieve quieter and more efficient vehicles.

According to an embodiment, a polyester composition comprises, based on the total weight of the polyester composition, a first polyester and a second polyester, wherein a weight ratio of the first polyester to the second polyester is <NUM>:<NUM> to <NUM>:<NUM>, preferably <NUM>:<NUM> to <NUM>:<NUM>; <NUM> to <NUM> weight percent, preferably <NUM> to <NUM> weight percent of a reinforcing filler; and <NUM> to <NUM> weight percent, preferably <NUM> to <NUM> weight percent of an inorganic filler having a specific gravity of greater than <NUM> grams per cubic centimeter, as determined in accordance with ASTM D792, wherein a molded article comprising the polyester composition has a sound transmission loss of greater than <NUM> decibels, preferably <NUM> to <NUM> decibels, more preferably <NUM> to <NUM> decibels, as determined at <NUM> Hertz according to ASTM E1050 using a molded disc with a diameter of <NUM> and a thickness of <NUM>.

According to another embodiment, a multi-layer composite comprises a first layer comprising a first polyester composition; and a second layer comprising a second polyester composition, wherein the first polyester composition and the second polyester composition are the same or different, and are each the polyester composition.

According to still another embodiment, a method for manufacturing the multi-layer composite comprises providing a first layer precursor comprising the first polymer composition and a second layer precursor comprising the second polymer composition; and contacting the first layer precursor and the second layer precursor to provide the multi-layer composite.

In another embodiment, an article comprises the multi-layer composite.

In yet another embodiment, a sound insulating component comprises the article.

Provided herein is a polyester composition that includes a reinforcing filler and an inorganic filler having a high specific gravity. The polyester composition can be molded into articles having desirable sound transmission loss at lower frequencies, such as less than <NUM>. An advantage to using the high specific gravity inorganic filler in combination with the reinforcing filler is that sound transmission loss can be achieved without greatly increasing the mass per unit area of the material. Additionally, articles having polyester compositions of different densities can be co-joined with each other, for example by lamination, gluing, over molding, or the like, to provide laminates with improved sound damping characteristics. These sound damping articles and laminates including the polyester composition(s) combine the freedom of design and speed of manufacturing, for example injection molding, with the structural modulus and strength benefits of the fiber reinforced compositions. The use of polyesters, especially poly(ethylene terephthalate) (PET), also allows for the incorporation of post-consumer recycle (PCR) materials and end of life recovered polyester resins from fiber, film, and packaging operations to be reused in structural sound damping automotive parts. Further, the polyester compositions have the heat capability to withstand automotive painting operations, such as E-coat painting, at <NUM> to <NUM>.

The polyester composition includes a first polyester and a second polyester different from the first polyester. The weight ratio between the first polyester and the second polyester can be varied based on the desired properties of the polyester composition. In an embodiment, the weight ratio of the first polyester to the second polyester is <NUM>:<NUM> to <NUM>:<NUM>, or <NUM>:<NUM> to <NUM>:<NUM>, or preferably <NUM>:<NUM> to <NUM>:<NUM>, or <NUM>:<NUM>.

In some embodiments, the first polyester or the second polyester comprises a poly(alkylene terephthalate). The alkylene group of the poly(alkylene terephthalate) can comprise <NUM> to <NUM> carbon atoms. In particular embodiments, the alkylene group is ethylene, <NUM>,<NUM>-propylene, <NUM>,<NUM>-butylene, <NUM>,<NUM>-pentylene, <NUM>,<NUM>-hexylene, <NUM>,<NUM>-cyclohexylene, <NUM>,<NUM>-cyclohexanedimethylene, or a combination comprising at least one of the foregoing. In some embodiments, the alkylene group is ethylene, <NUM>,<NUM>-butylene, or a combination comprising at least one of the foregoing.

In particular embodiments, the first polyester or the second polyester can each comprise, independently, one or more poly(alkylene terephthalate)s. In an embodiment, the first polyester comprises a first poly(alkylene terephthalate) and a second poly(alkylene terephthalate), preferably a first poly(butylene terephthalate) and a second poly(butylene terephthalate).

The poly(alkylene terephthalate) can also be a copolyester derived from terephthalic acid (or a combination of terephthalic acid and up to <NUM> mole percent isophthalic acid) and a mixture comprising a linear C<NUM>-C<NUM> aliphatic diol, such as ethylene glycol or <NUM>,<NUM>-butylene glycol), and a C<NUM>-C<NUM> cycloaliphatic diol, such as <NUM>,<NUM>-cyclohexane diol, <NUM>,<NUM>-cyclohexanedimethanol, dimethanol decalin, dimethanol bicyclooctane, <NUM>,<NUM>-decane diol, or a combination comprising at least one of the foregoing. The ester units comprising the two or more types of diols can be present in the polymer chain as random individual units or as blocks of the same type of units. Specific esters of this type include poly(<NUM>,<NUM>-cyclohexylene dimethylene co-ethylene terephthalate) (PCTG) wherein greater than <NUM> mole percent of the ester groups are derived from <NUM>,<NUM>-cyclohexanedimethanol; and poly(ethylene-co-<NUM>,<NUM>-cyclohexylenedimethylene terephthalate) wherein greater than or equal to <NUM> mole percent of the ester groups are derived from ethylene (PETG).

The poly(alkylene terephthalate)s can include small amounts (e.g., up to <NUM> weight percent, preferably up to <NUM> weight percent) of residues of monomers other than alkylene diols and terephthalic acid. For example, the poly(alkylene terephthalate) can include the residue of isophthalic acid. As another example, the poly(alkylene terephthalate) can comprises units derived from an aliphatic acid, such as succinic acid, glutaric acid, adipic acid, pimelic acid, <NUM>,<NUM>-cyclohexanedicarboxylic acid, or a combination comprising at least one of the foregoing.

The poly(alkylene terephthalate) can be, but is not limited to, poly(ethylene terephthalate) (PET), poly(butylene terephthalate) (PBT), poly(ethylene naphthanoate) (PEN), poly(butylene naphthanoate) (PBN), poly(cyclohexanedimethanol terephthalate), poly(propylene terephthalate) (PPT), or a combination comprising at least one of the foregoing. In some embodiments, the poly(alkylene terephthalate) is PET, PBT, or a combination comprising at least one of the foregoing. In particular embodiments, the poly(alkylene terephthalate) comprises PBT. In still other embodiments, the first polyester comprises a first PBT and a second PBT, and the second polyester comprises PET. In a preferred embodiment, the poly(alkylene terephthalate) comprises highly crystalline polyesters such as PBT or a combination of PBT and PET.

In polyester compositions having different polyesters, for example a combination of PBT and PET, each polyester can retain its individual crystallinity, which can be observed by differential scanning calorimetry (DSC) as distinct melting points. Polyester compositions having different polyesters that retain their individual crystallinities are preferred over compositions having an appreciable degree of copolymerization between different polyesters as evidenced by a single melting point by DSC.

Dicarboxylic acids (e.g., aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, aromatic dicarboxylic acids, and combinations thereof) and diols (e.g., aliphatic diols, alicyclic diols, aromatic diols, and combinations thereof) can be used to prepare the polyesters. Chemical equivalents of dicarboxylic acids (e.g., anhydrides, acid chlorides, acid bromides, carboxylate salts, or esters) and chemical equivalents of diols (e.g., esters, preferably C<NUM>-C<NUM> esters such as acetate esters) may also be used to prepare the polyesters.

Aromatic dicarboxylic acids that can be used to prepare the polyesters include, but are not limited to, isophthalic acid, terephthalic acid, <NUM>,<NUM>-di(p-carboxyphenyl)ethane, <NUM>,<NUM>'-dicarboxydiphenyl ether, <NUM>,<NUM>'-bisbenzoic acid, and the like, and <NUM>,<NUM>- or <NUM>,<NUM>-naphthalene dicarboxylic acids and the like. A combination of isophthalic acid and terephthalic acid can be used. The weight ratio of isophthalic acid to terephthalic acid may be, for example, <NUM>:<NUM> to <NUM>:<NUM>, or <NUM>:<NUM> to <NUM>:<NUM>. Dicarboxylic acids containing fused rings that can be used to prepare the polyesters include, but are not limited to, <NUM>,<NUM>-, <NUM>,<NUM>-, and <NUM>,<NUM>-naphthalenedicarboxylic acids. Exemplary cycloaliphatic dicarboxylic acids include, but are not limited to, decahydronaphthalene dicarboxylic acids, norbornene dicarboxylic acids, bicyclooctane dicarboxylic acids, and <NUM>,<NUM>-cyclohexanedicarboxylic acids.

Aliphatic diols that can be used to prepare the polyesters include, but are not limited to, <NUM>,<NUM>-ethylene glycol, <NUM>,<NUM>- and <NUM>,<NUM>-propylene glycol, <NUM>,<NUM>-dimethyl-<NUM>,<NUM>-propane diol, <NUM>-ethyl-<NUM>-methyl-<NUM>,<NUM>-propane diol, <NUM>,<NUM>- and <NUM>,<NUM>-pentane diol, dipropylene glycol, <NUM>-methyl-<NUM>,<NUM>-pentane diol, <NUM>,<NUM>-hexane diol, dimethanol decalin, dimethanol bicyclooctane, <NUM>,<NUM>-cyclohexane dimethanol and its cis- and transisomers, triethylene glycol, <NUM>,<NUM>-decane diol, and the like, and combinations thereof. The diol may be ethylene or <NUM>,<NUM>-butylene diol. The diol may be <NUM>,<NUM>-butylene diol. The diol may be ethylene glycol with small amounts (e.g., <NUM> to <NUM> percent) of diethylene glycol. Aromatic diols that can be used to prepare the polyesters include, but are not limited to, resorcinol, hydroquinone, pyrocatechol, <NUM>,<NUM>-naphthalene diol, <NUM>,<NUM>-naphthalene diol, <NUM>,<NUM>-naphthalene diol, <NUM>,<NUM>'-dihydroxybiphenyl, bis(<NUM>-hydroxyphenyl)ether, bis(<NUM>-hydroxyphenyl)sulfone, and the like, and combinations thereof.

In some embodiments, the poly(alkylene terephthalate) is PBT that is obtained by polymerizing a glycol component comprising at least <NUM> mole percent, preferably at least <NUM> mole percent, of tetramethylene glycol (<NUM>,<NUM>-butanediol), and an acid component comprising at least <NUM> mole percent, preferably at least <NUM> mole percent, of terephthalic acid or polyester-forming derivatives thereof. Commercial examples of PBT include those available as VALOX™ <NUM> Resin and VALOX™ <NUM> Resin, manufactured by SABIC.

In some embodiments, the poly(alkylene terephthalate) component comprises a modified PBT, that is, a PBT derived in part from PET, for example recycled PET from used soft drink bottles. The PET-derived PBT polyester (referred to herein for convenience as a "modified PBT") can be derived from a PET component such as PET, a PET copolymer, or a combination thereof. The modified PBT can further be derived from biomass-derived <NUM>,<NUM>-butanediol, e.g., corn-derived <NUM>,<NUM>-butanediol or a <NUM>,<NUM>-butanediol derived from a cellulosic material. Unlike conventional molding compositions containing virgin PBT (PBT that is derived from <NUM>,<NUM>-butanediol and terephthalic acid monomers), the modified PBT contains units derived from ethylene glycol and isophthalic acid. Use of modified PBT can provide a valuable way to effectively use underutilized scrap PET (from post-consumer or post-industrial streams) in PBT thermoplastic molding compositions, thereby conserving non-renewable resources.

The modified PBT can have at least one residue derived from the PET component. Such residue can be selected from the group consisting of ethylene glycol residues, diethylene glycol residues, isophthalic acid residues, antimony-containing residues, germanium-containing residues, titaniumcontaining residues, cobalt-containing residues, tin-containing residues, aluminum, aluminum-containing residues, <NUM>,<NUM>-cyclohexane dimethanol residues, <NUM>,<NUM>-cyclohexane dimethanol residues, alkali salts and alkaline earth metal salts including calcium and magnesium and sodium and potassium salts, phosphorous-containing residues, sulfur-containing residues, naphthalene dicarboxylic acid residues, <NUM>,<NUM>-propanediol residues, and combinations thereof.

Depending on factors such as the types and relative amounts of PET and PET copolymers, the residue can include various combinations. For example, the residue can include mixtures of units derived from ethylene glycol groups and diethylene glycol groups. The residue can also include mixtures of units derived from ethylene glycol, diethylene glycol, and isophthalic acid. The residue derived from PET and PET copolymers can be selected from the group consisting of cis-<NUM>,<NUM>-cyclohexanedimethanol residues, cis-<NUM>,<NUM>-cyclohexane dimethanol residues, trans-<NUM>,<NUM>-cyclohexanedimethanol residues, trans-<NUM>,<NUM>-cyclohexanedimethanol residues, and combinations thereof. The residue can also include a mixture of units derived from ethylene glycol, diethylene glycol, isophthalic acid, cis-<NUM>,<NUM>-cyclohexane dimethanol, trans-<NUM>,<NUM>-cyclohexanedimethanol, or a combination thereof. The residue derived from PET and PET copolymers can also include mixtures of units derived from ethylene glycol, diethylene glycol, cobalt-containing compounds, and isophthalic acid.

Commercial examples of modified PBT resins include those available under the trade name VALOX™ iQ Resin, manufactured by SABIC. The modified PBT can be derived from the PET component by any method that involves depolymerization of the PET component and polymerization of the depolymerized PET component with <NUM>,<NUM>-butanediol to provide the modified PBT. For example, the modified PBT component can be made by a process that involves depolymerizing a PET or PET copolymer, with a <NUM>,<NUM>-butanediol component at a temperature from <NUM> to <NUM>, under agitation, at a pressure that is at least atmospheric pressure in the presence of a catalyst component, at an elevated temperature, under an inert atmosphere, to produce a molten mixture containing an oligomer containing ethylene terephthalate moieties, an oligomer containing ethylene isophthalate moieties, an oligomer containing diethylene terephthalate moieties, an oligomer containing diethylene isophthalate moieties, an oligomer containing butylene terephthalate moieties, an oligomer containing butylene isophthalate moieties, a covalently bonded oligomeric moiety containing at least two of the foregoing moieties, <NUM>,<NUM>-butanediol, ethylene glycol, or a combination thereof; and agitating the molten mixture at subatmospheric pressure and increasing the temperature of the molten mixture to an elevated temperature under conditions sufficient to form a modified PBT containing at least one residue derived from the PET component.

The composition can comprise a combination of virgin poly(alkylene terephthalate) and modified poly(alkylene terephthalate), including a combination of virgin and modified PBT, the latter obtained from recycled PET as described above.

The polyesters can be obtained by interfacial polymerization or melt-process condensation, by solution phase condensation, or by transesterification polymerization wherein, for example, a dialkyl ester such as dimethyl terephthalate can be transesterified with ethylene glycol using acid catalysis, to generate PET. It is possible to use a branched polyester in which a branching agent, for example, a glycol having three or more hydroxyl groups or a trifunctional or multifunctional carboxylic acid has been incorporated. Furthermore, it is sometimes desirable to have various concentrations of acid and hydroxyl end groups on the polyester, depending on the ultimate end use of the composition.

A catalyst component facilitates the reaction, and can be selected from antimony compounds, tin compounds, cobalt compounds, titanium compounds, combinations thereof as well as many other metal catalysts and combinations of metal catalysts that have been disclosed in the literature. The amount of the catalyst will vary depending on the specific need at hand. Suitable amounts of the catalyst range from <NUM> to <NUM>,<NUM> ppm, or more.

In some embodiments, the polyester (e.g., poly(alkylene terephthalate)) has an intrinsic viscosity of <NUM> to <NUM> deciliter/gram (dl/g), as measured in a <NUM>:<NUM> phenol/tetrachloroethane mixture at <NUM>. In some embodiments, the polyester has an intrinsic viscosity of <NUM> to <NUM> dl/g, preferably <NUM> to <NUM> dl/g, as measured in a <NUM>:<NUM> phenol/tetrachloroethane mixture at <NUM>.

In some embodiments, the first polyester and the second polyester have different intrinsic viscosities. In particular embodiments, the first polyester comprises a first poly(butylene terephthalate) and a second poly(butylene terephthalate), wherein the intrinsic viscosity of the first poly(butylene terephthalate) is different than the intrinsic viscosity of the second poly(butylene terephthalate)different intrinsic viscosities, preferably wherein the first poly(butylene terephthalate) has an intrinsic viscosity of <NUM> to <NUM> dl/g and the second poly(butylene terephthalate) has an intrinsic viscosity of <NUM> to <NUM> dl/g, each as measured in a <NUM>:<NUM> phenol/tetrachloroethane mixture at <NUM>.

In some embodiments, the polyester (e.g., poly(alkylene terephthalate)) has a weight average molecular weight (MW) of <NUM>,<NUM> to <NUM>,<NUM> grams per mole (g/mol), preferably <NUM>,<NUM> to <NUM>,<NUM>/mol, as measured by gel permeation chromatography (GPC) using polystyrene standards. If a poly(alkylene terephthalate) having a MW of less than <NUM>,<NUM>/mol is used, the mechanical properties of the articles molded from the polyester composition can be unsatisfactory. On the other hand, if a poly(alkylene terephthalate) having a MW of greater than <NUM>,<NUM>/mol is used, the moldability can be insufficient. The poly(alkylene terephthalate) can also comprise a mixture of two or more poly(alkylene terephthalate)s having different intrinsic viscosities or weight average molecular weights.

In some embodiments, the polyester (e.g., poly(alkylene terephthalate)) has a the carboxylic end group (CEG) concentration of <NUM> to <NUM> millimole equivalents per kilogram (meq/kg), preferably <NUM> to <NUM> meq/kg, more preferably <NUM> to <NUM> meq/kg, as determined according to ASTM D7409-<NUM>.

In some embodiments, the polyester (e.g., poly(alkylene terephthalate)) has a melting temperature of <NUM> to <NUM>, preferably <NUM> to <NUM>, more preferably <NUM> to <NUM>, as determined by differential scanning calorimetry (DSC).

In some embodiments, the polyester comprises a phosphorous compound, for example at least <NUM> ppm of a phosphorous compound, for example <NUM> to <NUM> ppm or <NUM> to <NUM> ppm, which can stabilize melt viscosity and deactivate residual polymerization catalysts. In a preferred embodiment, the polyester comprises a PET that includes at least <NUM> ppm of a phosphorous compound. In other embodiments, the polyester, for example PET, can further include a cobalt compound. Phosphorous compounds and cobalt compounds include, but are not limited to, those provided herein.

The polyester composition further includes a reinforcing filler. In some embodiments, the reinforcing filler is glass fiber, glass flake, fiber glass, chopped glass, mica, or a combination comprising at least one of the foregoing, preferably glass fiber. The reinforcing filler is present in an amount of <NUM> to <NUM> wt%, preferably <NUM> to <NUM> wt%, more preferably <NUM> to <NUM> wt%, based on the total weight of the polyester composition.

In an embodiment, the glass fiber is E, A, C, ECR, R, S, D, or NE glasses, or the like, or a combination comprising at least one of the foregoing. The glass fibers can be made by standard processes, e.g., by steam or air blowing, flame blowing, and mechanical pulling. Exemplary glass fibers are made by mechanical pulling.

The glass fibers can be sized or unsized. Sized glass fibers are coated on their surfaces with a sizing composition selected for compatibility with the polyester components. The sizing composition facilitates wet-out and wet-through of the polyesters upon the fiber strands and assists in attaining desired physical properties in the polyester composition.

In some embodiments, the glass fiber is sized with a coating agent. In a preferred embodiment, the coating agent is present in an amount from <NUM> to <NUM> wt%, preferably <NUM> to <NUM> wt%, based on the weight of the glass fibers. Fiber coating is preferred for better handing of the chopped glass and adhesion to the polyester, which can provide for superior mechanical properties.

In preparing the glass fibers, a number of filaments can be formed simultaneously, sized with the coating agent, and then bundled into what is called a strand. Alternatively the strand itself may be first formed of filaments and then sized. The amount of sizing employed is generally that amount which is sufficient to bind the glass filaments into a continuous strand and ranges from <NUM> to <NUM> wt %, preferably <NUM> to <NUM> wt %, based on the weight of the glass fibers.

In some embodiments, the glass fiber can be continuous or chopped. Glass fibers in the form of chopped strands may have a length of <NUM> millimeters (mm) to <NUM> centimeters (cm), preferably <NUM> to <NUM>, more preferably <NUM> to <NUM>. In certain embodiments, the glass fiber has a length from <NUM> to <NUM>, preferably <NUM> to <NUM>, more preferably <NUM> to <NUM>. In this area, where a thermoplastic composition is reinforced with glass fibers in a composite form, fibers having a length of <NUM> or more are referred to as long fibers, and shorter ones are referred to as short fibers.

In an embodiment, the glass fiber has a round (or circular), flat, or irregular cross-section. Thus, use of non-round fiber cross sections is not excluded. In a further embodiment, the glass fiber has a circular cross-section. In another embodiment, the diameter of the glass fiber is from <NUM> to <NUM> micrometers (µm), preferably <NUM> to <NUM>, more preferably1 to <NUM>, even more preferably <NUM> to <NUM>. In a preferred embodiment, the glass fiber has a diameter of <NUM>. In some embodiments, flat glass fibers may be preferred for low warp high strength articles.

Other suitable reinforcing fillers include, but are not limited to, glass spheres such as hollow and solid glass spheres, silicate spheres, or the like; kaolin, including hard kaolin, soft kaolin, calcined kaolin, kaolin comprising various coatings known in the art to facilitate compatibility with the polymer matrix, or the like; fibers (including continuous and chopped fibers) such as, glass fibers, and carbon fibers; flaked fillers such as glass flakes, flaked silicon carbide, aluminum oxides, or the like; organic fillers such as polytetrafluoroethylene; reinforcing organic fibrous fillers formed from organic polymers capable of forming fibers such as poly(ether ketone), polyimide, polybenzoxazole, poly(phenylene sulfide), polyesters, polyethylene, aromatic polyamides, aromatic polyimides, polyetherimides, polytetrafluoroethylene, acrylic polymers, poly(vinyl alcohol) or the like; as well as mica, clay, talc, wollastonite, feldspar, perlite, tripoli, diatomaceous earth, carbon black, or the like, or combinations comprising at least one of the foregoing. Milled glass, glass flake, glass or ceramic bubbles, and spheres may also be used as less isotropic fillers. Combination of glass fiber with platy fillers such as glass flake or mica may be beneficial in producing molded articles with high strength and reduced warp with better flatness and improved dimensional stability over use of only cylindrical glass fibers alone.

In other embodiments, the reinforcing fillers can be provided in the form of monofilament or multifilament fibers and can be used either alone or in combination with other types of fiber, for example, co-weaving or core/sheath, side-by-side, orange-type or matrix and fibril constructions, or by other methods known to one skilled in the art of fiber manufacture. Suitable cowoven structures include, for example, glass fiber-carbon fiber, carbon fiber-aromatic polyimide (aramid) fiber, and aromatic polyimide fiberglass fiber or the like. Fibrous fillers can be supplied in the form of, for example, rovings, woven fibrous reinforcements, such as <NUM>-<NUM> degree fabrics or the like; non-woven fibrous reinforcements such as continuous strand mat, chopped strand mat, tissues, papers and felts or the like; or three-dimensional reinforcements such as braids.

The polyester composition further includes an inorganic filler. The inorganic filler can be present in an amount of <NUM> to <NUM> wt%, preferably <NUM> to <NUM> wt%, more preferably <NUM> to <NUM> wt%, based on the total weight of the polyester composition.

The inorganic filler has a specific gravity of greater than <NUM> grams per cubic centimeter (g/cm<NUM>), as determined in accordance with ASTM D792. Representatives of such high specific gravity filler materials include metal (or metal alloy) powders, such as tungsten powder, metal salts, and metal complexes, but are not limited thereto. Examples of several suitable inorganic filler materials which can be included and their respective specific gravities are tungsten (<NUM>), bismuth (<NUM>), nickel (<NUM>), molybdenum (<NUM>), iron (<NUM>), copper (<NUM>), brass (<NUM>-<NUM>), bronze (<NUM>-<NUM>), cobalt (<NUM>), zinc (<NUM>), tin (<NUM>), and silver (<NUM>). In an embodiment, the inorganic filler and/or the polymer composition does not include lead, mercury, cadmium, thallium, arsenic, a salt thereof, a complex thereof, or any combination thereof. In another embodiment, the inorganic filler and/or the polymer composition does not include water soluble barium compounds such as barium chloride or barium nitrate. Alloys or blends of these filler materials can also be used, and the materials can be optionally coated with a suitable coating such as C<NUM>. The specific gravities provided herein are exemplary and the materials identified can have different specific gravities depending on the specific material used and tested, and the material's treatment. The particle size may vary from <NUM> to <NUM> microns (µm), preferably from <NUM> to <NUM>, and more preferably <NUM> to <NUM>.

In some embodiments, the inorganic filler is a metal oxide, sulfate, or sulfide salt such as barium sulfate, zinc oxide, zinc sulfide, titanium dioxide, iron oxide, or a combination comprising at least one of the foregoing. The metal salt can be in the form of a naturally occurring species or synthetically derived using suitable synthetic techniques. The particle size may vary from <NUM> to <NUM> microns (µm), preferably from <NUM> to <NUM>, and more preferably <NUM> to <NUM>.

The polyester composition can further include an impact modifier. Suitable impact modifiers are typically high molecular weight elastomeric materials derived from olefins, monovinyl aromatic monomers, acrylic and methacrylic acids and their ester derivatives, as well as conjugated dienes. The polymers formed from conjugated dienes can be fully or partially hydrogenated. The elastomeric materials can be in the form of homopolymers or copolymers, including random, block, radial block, graft, and core-shell copolymers. Combinations of impact modifiers can be used.

A specific type of impact modifier is an elastomer-modified graft copolymer comprising (i) an elastomeric (i.e., rubbery) polymer substrate having a Tg less than <NUM>, preferably less than -<NUM>, or more preferably -<NUM>° to -<NUM>, and (ii) a rigid polymeric superstrate grafted to the elastomeric polymer substrate. Materials suitable for use as the elastomeric phase include, for example, conjugated diene rubbers, for example polybutadiene and polyisoprene; copolymers of a conjugated diene with less than <NUM> wt% of a copolymerizable monomer, for example a monovinylic compound such as styrene, acrylonitrile, n-butyl acrylate, or ethyl acrylate; olefin rubbers such as ethylene propylene copolymers (EPR) or ethylene-propylene-diene monomer rubbers (EPDM); ethylene-vinyl acetate rubbers; silicone rubbers; elastomeric (C<NUM>-<NUM> alkyl) (meth)acrylates; elastomeric copolymers of (C<NUM>-<NUM> alkyl) (meth)acrylates with butadiene or styrene; or combinations comprising at least one of the foregoing elastomers. Materials suitable for use as the rigid phase include, for example, monovinyl aromatic monomers such as styrene and alpha-methyl styrene, and monovinylic monomers such as acrylonitrile, acrylic acid, methacrylic acid, and the C<NUM>-C<NUM> esters of acrylic acid and methacrylic acid, preferably methyl methacrylate.

Specific elastomer-modified graft copolymers include those formed from styrene-butadiene-styrene (SBS), styrene-butadiene rubber (SBR), styrene-ethylene-butadiene-styrene (SEBS), ABS (acrylonitrile-butadiene-styrene), acrylonitrile-ethylene-propylene-diene-styrene (AES), styrene-isoprene-styrene (SIS), methyl methacrylate-butadiene-styrene (MBS), and styrene-acrylonitrile (SAN). In an embodiment, the impact modifier is an alkyl (meth)acrylate copolymer, (meth)acrylic ester-butadiene-styrene, acrylonitrile-butadiene-styrene, styrene-butadiene, styrene-ethylene-butylene-styrene, a poly(ether ester) block copolymer, a polyethylene-α olefin copolymer, styrene-isoprene-styrene triblock copolymer, or a combination comprising at least one of the foregoing.

Impact modifiers can be present in amounts of <NUM> to <NUM> wt%, preferably <NUM> to <NUM> wt%, more preferably <NUM> to <NUM> wt%, based on the total weight of the polymer composition.

In some embodiments, the polyester composition can include various other additives ordinarily incorporated into polymer compositions of this type, with the proviso that the additive(s) are selected so as to not significantly adversely affect the desired properties of the polyester composition. Such additives can be mixed at a suitable time during the mixing of the components for forming the composition. Additives include fillers, reinforcing agents, antioxidants, heat stabilizers, light stabilizers, ultraviolet (UV) light stabilizers, plasticizers, lubricants, mold release agents, antistatic agents, colorants such as carbon black and organic dyes, surface effect additives, radiation stabilizers, flame retardants, and anti-drip agents. A combination of additives can be used, for example a combination of a mold release agent, a stabilizer, and a filler. In general, the additives are used in the amounts generally known to be effective. For example, the total amount of the additives (other than the reinforcing filler, inorganic filler, and optionally the impact modifier) can be <NUM> to <NUM> wt%, based on the total weight of the polyester composition.

Heat stabilizer additives include organophosphites (e.g. triphenyl phosphite, tris-(<NUM>,<NUM>-dimethylphenyl)phosphite, tris-(mixed mono-and di-nonylphenyl)phosphite or the like), phosphonates (e. g, dimethylbenzene phosphonate or the like), or combinations comprising at least one of the foregoing heat stabilizers. The heat stabilizer can be tris(<NUM>,<NUM>-di-t-butylphenyl) phosphite available as IRGAPHOS™ <NUM>.

There is considerable overlap among plasticizers, lubricants, and mold release agents, which include, for example, glycerol tristearate (GTS), phthalic acid esters (e. g, octyl-<NUM>,<NUM>-epoxyhexahydrophthalate), tris-(octoxycarbonylethyl)isocyanurate, tristearin, di- or polyfunctional aromatic phosphates (e. g, resorcinol tetraphenyl diphosphate (RDP), the bis(diphenyl) phosphate of hydroquinone and the bis(diphenyl) phosphate of bisphenol A); poly-alpha-olefins; epoxidized soybean oil; silicones, including silicone oils (e.g., poly(dimethyl diphenyl siloxanes); esters, for example, fatty acid esters (e. g, alkyl stearyl esters, such as, methyl stearate, stearyl stearate, and the like), alkyl amides such as ethylene bis stearamide (EBS), waxes (e. g, beeswax, montan wax, paraffin wax, or the like), or combinations comprising at least one of the foregoing plasticizers, lubricants, and mold release agents.

Fillers can include silicates and silica powders such as aluminum silicate (mullite), synthetic calcium silicate, zirconium silicate, fused silica, crystalline silica graphite, natural silica sand, or the like; boron powders such as boron-nitride powder, boron-silicate powders, or the like; talc, including fibrous, modular, needle shaped, lamellar talc, or the like; wollastonite; surface-treated wollastonite; cenospheres, aluminosilicate (armospheres), or the like; single crystal fibers or "whiskers" such as silicon carbide, alumina, boron carbide, or the like. Hollow or solid glass or ceramic spheres may also be used.

In some embodiments, the polymer composition can further comprise an antioxidant or stabilizer, for example hindered phenol, phosphite, phosphonite, thioester, or a combination comprising at least one of the foregoing. Stabilizers or antioxidants include phosphites such as tris(nonyl phenyl)phosphite, tris(<NUM>,<NUM>-di-t-butylphenyl)phosphite, bis(<NUM>,<NUM>-di-t-butylphenyl)pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, trilauryl phosphite, trioctadecyl phosphite, diisodecyl pentaerythritol diphosphite, tristearyl sorbitol triphosphite, and tetrakis(<NUM>,<NUM>-di-tert-butylphenyl)-<NUM>,<NUM>'-biphenylene diphosphonite; phosphonites such as tetrakis(<NUM>,<NUM>-di-tert-butylphenyl)<NUM>,<NUM>'-biphenylene diphosphonite; sterically hindered phenols such as octadecyl-<NUM>,<NUM>-di-t-butyl-<NUM>-hydroxy hydrocinnamate, tetrakis[methylene(<NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxyhydrocinnamate)] methane, <NUM>,<NUM>-bis(<NUM>,<NUM>-di-t-butyl4-hydroxyhydrocinnamoyl)hydrazine, <NUM>,<NUM>,<NUM>-tris(<NUM>,<NUM>-di-t-butyl-<NUM>-hydroxybenzyl)-s-triazine-<NUM>,<NUM>,<NUM>(<NUM>,<NUM>, <NUM>)trione, <NUM>,<NUM>,<NUM>-tris(<NUM>-t-butyl-<NUM>-hydroxy-<NUM>,<NUM>-dimeth <NUM>,<NUM>,<NUM>-(<NUM>,<NUM>,<NUM>)trione, <NUM>,<NUM>,<NUM>-trimethyl-<NUM>,<NUM>,<NUM>-tris(<NUM>,<NUM>-di-t-butyl-<NUM>-hydroxybenzyl)benzene, <NUM>,<NUM>-di-t-butyl-<NUM>-hydroxyhydrocinnamic acid triester with <NUM>,<NUM>,<NUM>-tris(<NUM>-hydroxyethyl)-<NUM>-triazine-<NUM>,<NUM>,<NUM>(<NUM>,<NUM>,<NUM>)-trione, and bis(<NUM>,<NUM>-bis(<NUM>-hydroxy-<NUM>-t-butylphenyl)butanoic acid)glycolester; thioesters such as bis-dodecyl <NUM>,<NUM>'-thiodipropionate, bis-octadecyl <NUM>,<NUM>'-thiodipropionate, dimyristyl thiodipropionate, ditridecyl thiodipropionate, mixed esters (lauryl and stearyl) of thiodipropionic acid, pentaerythritol tetrakis(<NUM>-(dodecylthio)propionate), and thioesters of di-, tri- or tetra-carboxylic acids; phosphonates such as dimethylbenzene phosphonate or the like, organic phosphates such as trimethyl phosphate; butylated reaction products of para-cresol or dicyclopentadiene; alkylated hydroquinones; hydroxylated thiodiphenyl ethers; alkylidene-bisphenols; benzyl compounds; esters of beta-(<NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxyphenyl)-propionic acid with monohydric or polyhydric alcohols; esters of beta-(<NUM>-tert-butyl-<NUM>-hydroxy-<NUM>-methylphenyl)-propionic acid with monohydric or polyhydric alcohols; amides of beta-(<NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxyphenyl)-propionic acid, or combinations comprising at least one of the foregoing. In particular embodiments, the polyester composition includes <NUM> to <NUM> wt%, preferably <NUM> to <NUM> wt% of the antioxidant stabilizer, based on the total weight of the polyester composition.

Useful flame retardants include organic compounds that include phosphorus, for example organic phosphates and organic compounds containing phosphorus-nitrogen bonds.

Flame retardant aromatic phosphates include triphenyl phosphate, tricresyl phosphate, isopropylated triphenyl phosphate, phenyl bis(dodecyl) phosphate, phenyl bis(neopentyl) phosphate, phenyl bis(<NUM>,<NUM>,<NUM>'-trimethylhexyl) phosphate, ethyl diphenyl phosphate, <NUM>-ethylhexyl di(p-tolyl) phosphate, bis(<NUM>-ethylhexyl) p-tolyl phosphate, tritolyl phosphate, bis(<NUM>-ethylhexyl) phenyl phosphate, tri(nonylphenyl) phosphate, bis(dodecyl) p-tolyl phosphate, dibutyl phenyl phosphate, <NUM>-chloroethyl diphenyl phosphate, p-tolyl bis(<NUM>,<NUM>,<NUM>'-trimethylhexyl) phosphate, and <NUM>-ethylhexyl diphenyl phosphate. Di- or polyfunctional aromatic phosphorus-containing compounds are also useful, for example resorcinol tetraphenyl diphosphate (RDP), the bis(diphenyl) phosphate of hydroquinone and the bis(diphenyl) phosphate of bisphenol A, respectively, and their oligomeric and polymeric counterparts. Flame retardant compounds containing phosphorus-nitrogen bonds include phosphonitrilic chloride, phosphorus ester amides, phosphoric acid amides, phosphonic acid amides, phosphinic acid amides, and tris(aziridinyl) phosphine oxide.

Halogenated materials can also be used as flame retardants, for example bisphenols of which the following are representative: <NUM>,<NUM>-bis-(<NUM>,<NUM>-dichlorophenyl)-propane; bis-(<NUM>-chlorophenyl)-methane; bis(<NUM>,<NUM>-dibromophenyl)-methane; <NUM>,<NUM>-bis-(<NUM>,<NUM>-dichlorophenyl)-ethane; <NUM>,<NUM>-bis-(<NUM>-chloro-<NUM>-methylphenyl)-ethane; <NUM>,<NUM>-bis-(<NUM>,<NUM>-dichlorophenyl)-ethane; <NUM>,<NUM>-bis-(<NUM>-phenyl-<NUM>-bromophenyl)-ethane; <NUM>,<NUM>-bis-(<NUM>,<NUM>-dichloronaphthyl)-propane; and <NUM>,<NUM>-bis-(<NUM>,<NUM>-dichloro-<NUM>-hydroxyphenyl)-propane <NUM>,<NUM> bis-(<NUM>-bromo-<NUM>-hydroxyphenyl)-propane. Other halogenated materials include <NUM>,<NUM>-dichlorobenzene, <NUM>,<NUM>-dibromobenzene, <NUM>,<NUM>-dichloro-<NUM>-hydroxybenzene, and biphenyls such as <NUM>,<NUM>'-dichlorobiphenyl, polybrominated <NUM>,<NUM>-diphenoxybenzene, <NUM>,<NUM>'-dibromobiphenyl, and <NUM>,<NUM>'-dichlorobiphenyl, as well as oligomeric and polymeric halogenated aromatic compounds, such as a copolycarbonate of bisphenol A and tetrabromobisphenol A and a carbonate precursor, e.g., phosgene. Metal synergists, e.g., antimony oxides, can also be used with the flame retardant.

Alternatively, the polyester composition can be essentially free of chlorine and bromine. "Essentially free of chlorine and bromine" is defined as having a bromine or chlorine content of less than or equal to <NUM> ppm, less than or equal to <NUM> ppm, or less than or equal to <NUM> ppm, based on the total weight of the polyester composition.

Anti-drip agents can also be used in the composition, for example a fibril forming or non-fibril forming fluoropolymer such as polytetrafluoroethylene (PTFE). The anti-drip agent can be encapsulated by a rigid copolymer as described above, for example styrene-acrylonitrile copolymer (SAN). PTFE encapsulated in SAN is known as TSAN. Encapsulated fluoropolymers can be made by polymerizing the encapsulating polymer in the presence of the fluoropolymer, for example an aqueous dispersion.

A thermoplastic polymer different from the first and second polyesters can be present. Examples of thermoplastic polymers that can be used include polyacetals (e.g., polyoxyethylene and polyoxymethylene), poly(C<NUM>-<NUM> alkyl)acrylates, polyacrylamides, polyamides, (e.g., aliphatic polyamides, polyphthalamides, and polyaramides), polyamideimides, polyanhydrides, polyarylates, polyarylene ethers (e.g., polyphenylene ethers), polyarylene sulfides (e.g., polyphenylene sulfides), polyarylene sulfones (e.g., polyphenylene sulfones), polybenzothiazoles, polybenzoxazoles, polycarbonates (including polycarbonate copolymers such as polycarbonate-siloxanes, polycarbonate-esters, and polycarbonateester-siloxanes), polyesters (e.g., polyethylene terephthalates, polybutylene terephthalates, polyarylates, and polyester copolymers such as polyester-ethers), polyetheretherketones, polyetherimides (including copolymers such as polyetherimide-siloxane copolymers), polyetherketoneketones, polyetherketones, polyethersulfones, polyimides (including copolymers such as polyimide-siloxane copolymers), poly(C<NUM>-<NUM> alkyl)methacrylates, polymethacrylamides, polynorbornenes (including copolymers containing norbornenyl units), polyolefins (e.g., polyethylenes, polypropylenes, polytetrafluoroethylenes, and their copolymers, for example ethylene-alpha-olefin copolymers), polyoxadiazoles, polyoxymethylenes, polyphthalides, polysilazanes, polysiloxanes, polystyrenes (including copolymers such as acrylonitrile-butadiene-styrene (ABS) and methyl methacrylate-butadiene-styrene (MBS)), polysulfides, polysulfonamides, polysulfonates, polysulfones, polythioesters, polytriazines, polyureas, polyurethanes, polyvinyl alcohols, polyvinyl esters, polyvinyl ethers, polyvinyl halides, polyvinyl ketones, polyvinyl thioethers, polyvinylidene fluorides, or the like, or a combination comprising at least one of the foregoing. In some embodiments no additional polymer is present. Polyvinyl chloride (PVC) and other aliphatic chlorinated polymers are generally avoided since they are not thermally stable under polyester processing conditions (<NUM> to <NUM>). In some embodiments, the polyester composition further includes linear low density polyethylene (LLDPE).

The method of preparing the polyester composition can be carried out using any suitable technique. One convenient method comprises blending the polyesters, reinforcing filler, inorganic filler, and other optional ingredients in powder or granular form, extruding the blend under temperature sufficient to melt the polyesters, and comminuting into pellets or other suitable shapes. The ingredients are combined in any usual manner, e.g., by dry mixing or by mixing in the melted state in an extruder, on a heated mill or in other mixers.

Illustrative examples of equipment used in such melt processing methods include: corotating and counter-rotating extruders, single screw extruders, co-kneaders, disc-pack processors and various other types of extrusion equipment. The temperature of the melt in the present process is preferably minimized in order to avoid excessive degradation of the resins. It is often desirable to maintain the melt temperature between <NUM> and <NUM> in the molten polyester composition, although higher temperatures can be used provided that the residence time of the polyesters in the processing equipment is kept short. In some embodiments the melt processed polyester composition exits processing equipment such as an extruder through small exit holes in a die. The resulting strands of molten resin are cooled by passing the strands through a water bath. The strands can be cut into pellets and further dried before molding.

Despite the high specific gravity and high level of inorganic filler, the polyester compositions can be molded into useful shaped articles by a variety of means such as injection molding, extrusion, rotational molding, blow molding, and thermoforming. For example, good results are obtained in an injection molding machine, e.g. of the <NUM> ton Van Dorn type, with temperatures that depend on the particular polyester blends utilized. If necessary, depending on the molding properties of the polyesters, the amount of additives, and the rate of crystallization of the polyester component, those skilled in the art will be able to make the necessary adjustments in molding cycles to accommodate the polyester compositions. Additives used to enhance polyester crystallization, such as alkaline and alkaline earth carboxylates, for example sodium stearate, potassium oleate, or calcium stearate, and talc, used either alone or in any combination, are useful to speed polyester crystallization. Faster crystallization can result in molded articles with better and more consistent properties and that can be prepared by shorter, more efficient, molding cycles.

The molded article comprising the polyester composition has a sound transmission loss (STL) of greater than <NUM> decibels, preferably <NUM> to <NUM> decibels, more preferably <NUM> to <NUM> decibels, as determined at <NUM> Hertz according to ASTM E1050 using a molded disc with a diameter of <NUM> and a thickness of <NUM>. The STL is a measurement of the reduction of sound intensity, measured in decibels (dB) caused by a sample of the polyester composition at a selected wavelength. Greater STL values indicate more sound loss (i.e., more effective sound blocking).

The molded article comprising the polyester composition can have a melting viscosity of from <NUM> to <NUM> Poise (P), measured in accordance with ISO11443/ ASTM <NUM>-<NUM> at <NUM> and a shear rate of <NUM><NUM>/s.

The molded article comprising the polyester composition can have a tensile modulus of elasticity of from <NUM>,<NUM> MPa to <NUM>,<NUM> MPa, more preferably <NUM>,<NUM> to <NUM>,<NUM> MPa, measured in accordance with ASTM D638, and the tensile strength at yield can be from <NUM> to <NUM> MPa, more preferably <NUM> to <NUM> MPa, measured in accordance with ASTM D638.

The molded article comprising the polyester composition can have a specific gravity of <NUM> to <NUM> grams per cubic centimeter (g/cm<NUM>), as determined in accordance with ASTM D792. In some embodiments, the polyester composition has a specific gravity of <NUM> to <NUM>/cm<NUM>, or <NUM> to <NUM>/cm<NUM>, or <NUM> to <NUM>/cm<NUM>, or <NUM> to <NUM>/cm<NUM>, or <NUM> to <NUM>/cm<NUM>, or <NUM> to <NUM>/cm<NUM>, as determined in accordance with ASTM D792.

The molded article comprising the polyester composition can have a heat deflection temperature of <NUM> to <NUM>, as determined in accordance with ASTM D648 at <NUM> MPa.

The molded article comprising the polyester can have a melt volume flow rate of <NUM> to <NUM><NUM>/<NUM> minutes, as determined at <NUM>/<NUM> in accordance with ASTM-D1238-<NUM>.

Also provided herein is a multi-layer composite that comprises a first layer comprising a first polyester composition and a second layer comprising a second polyester composition. In the composite, the first polyester composition and the second polyester composition are the same or different. In an embodiment, the first and second polyester compositions are the same. In another embodiment, the first and second polyester compositions are different.

In some embodiments, the composite can further include one or more additional layer(s), wherein each additional layer is the same or different, and is a polyester composition that is the same as or different than the first polyester and the second polyester. For example, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> additional layers can be included in the composite to provide a multi-layer composite having <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> total layers.

In particular embodiments, an adhesive layer can be disposed between the first layer and the second layer. Any suitable adhesive material can be used to form the adhesive layer, for example a cyanoacrylate adhesive or the like. The adhesive layer can have a thickness of <NUM> to <NUM>. An adhesive layer can also be used to adhere one or more additional layer(s) to the opposite sides of the first or second layers. Each subsequently added additional layer can then connected to the previously added additional layer using an adhesive layer.

The composite can have any suitable dimensions based on the desired use. In an embodiment, the composite has a total thickness of <NUM> to <NUM>, preferably <NUM> to <NUM>, more preferably <NUM> to <NUM>. In another embodiment, the composite has a length <NUM> to <NUM>, preferably <NUM> to <NUM>, more preferably <NUM> to <NUM>. In still another embodiment, the composite has a width of <NUM> to <NUM>, preferably <NUM> to <NUM>, more preferably <NUM> to <NUM>. Preferably the length and the width are the same or different, and are each independently at least one order of magnitude greater (i.e., ten times greater) than the total thickness.

In a preferred embodiment, the composite has a thickness of <NUM> to <NUM>, a length of <NUM> to <NUM>, and a width of <NUM> to <NUM>. In another embodiment, the composite has a thickness of <NUM> to <NUM>, a length of <NUM> to <NUM>, and a width of <NUM> to <NUM>. In still another embodiment, the composite has a thickness of <NUM> to <NUM>, a length of <NUM> to <NUM> mmm, and a width of <NUM> to <NUM>. In yet another embodiment, the composite has a thickness of <NUM> to <NUM> and a length and width that are each independently <NUM> to <NUM>. In an embodiment, the composite has a thickness of <NUM> to <NUM> and a length and width that are each independently <NUM> to <NUM>.

In some embodiments, the first and second layers include first and second polyester compositions that are substantially the same or similar. In an embodiment, the first polyester composition and the second polyester composition each independently has a specific gravity of <NUM> to <NUM>/cm<NUM>, preferably <NUM> to <NUM>/cm<NUM>, as determined in accordance with ASTM D792.

In other embodiments, the first and second layers include first and second polyester compositions that are different. In an embodiment, the first polyester composition has a specific gravity of <NUM> to <NUM>/cm<NUM>, preferably <NUM> to <NUM>/cm<NUM>and the second polyester composition has a specific gravity of <NUM> to <NUM>/cm<NUM>, preferably <NUM> to <NUM>/cm<NUM>, as determined in accordance with ASTM D792.

In an embodiment, the first and second layers include first and second polyester compositions that are substantially the same or similar, and the composite has an STL of greater than <NUM> decibels, preferably <NUM> to <NUM> decibels, more preferably <NUM> to <NUM> decibels at <NUM> Hertz; greater than <NUM> decibels, preferably <NUM> to <NUM> decibels, more preferably <NUM> to <NUM> decibels at <NUM> Hertz; greater than <NUM> decibels, preferably <NUM> to <NUM> decibels, more preferably <NUM> to <NUM> decibels at <NUM> Hertz; greater than <NUM> decibels, preferably <NUM> to <NUM> decibels, more preferably <NUM> to <NUM> decibels at <NUM> Hertz; and greater than <NUM> decibels, preferably <NUM> to <NUM> decibels, more preferably <NUM> to <NUM> decibels at <NUM> Hertz. The STLs are each determined according to ASTM E1050 using a molded disc with a diameter of <NUM> and a thickness of <NUM>.

In an embodiment, the first and second layers include first and second polyester compositions that are different, and the composite has an STL of greater than <NUM> decibels, preferably <NUM> to <NUM> decibels, more preferably <NUM> to <NUM> decibels at <NUM> Hertz; greater than <NUM> decibels, preferably <NUM> to <NUM> decibels, more preferably <NUM> to <NUM> decibels at <NUM> Hertz; greater than <NUM> decibels, preferably <NUM> to <NUM> decibels, more preferably <NUM> to <NUM> decibels at <NUM> Hertz; greater than <NUM> decibels, preferably <NUM> to <NUM> decibels, more preferably <NUM> to <NUM> decibels at <NUM> Hertz; and greater than <NUM> decibels, preferably <NUM> to <NUM> decibels, more preferably <NUM> to <NUM> decibels at <NUM> Hertz. The STLs are each determined according to ASTM E1050 using a molded disc with a diameter of <NUM> and a thickness of <NUM>.

Also provided is a method for manufacturing the multi-layer composite. The method includes providing a first layer precursor comprising the first polymer composition and a second layer precursor comprising the second polymer composition; and contacting the first layer precursor and the second layer precursor to provide the multi-layer composite. In some embodiments, an adhesive layer can be applied to one or both of the layer precursors prior to the contacting. Additional layers can be added by contacting each additional layer and the first or second layer of the composite, or by contacting each additional layer to another additional layer that has already been added to the composite.

In another embodiment, an article includes the multi-layer composite. In an embodiment, a sound insulating component comprises the article that includes the multi-layer composite. In a preferred embodiment, the sound insulating component is an automotive component. Other non-limiting examples of such articles include instrument enclosures, speaker enclosures, firewalls, instrument panels, trunk partitions, wheel wells, spare tire enclosures, heating and cooling ducts, fans, blowers, body panels, fenders, doors, underbody panels, resonators, muffler shrouds, radiator enclosures, pump casings and impellers, air diverters, valve covers, oil pans, transmission and differential gear casings, head liners, flooring, or the like. This disclosure is further illustrated by the following examples, which are non-limiting.

The materials used for the examples are provided in Table <NUM>.

Samples were prepared as follows. The components were pre-mixed in a paint shaker and then extruded under a minimal vacuum on a single screw extruder having a screw size of <NUM> inches. Resultant pellets were dried for <NUM> to <NUM> hours at <NUM> in a forced air-circulating oven. The compositions were not pre-dried prior to extrusion. Injection molding using the resultant pellets was performed on an <NUM> ton van Dorn injection molding machine at <NUM> to <NUM> with a <NUM> second cycle time and mold temperature of <NUM>.

The extrusion conditions are shown in Table <NUM>.

The following methods were used to evaluate the samples.

Melt viscosity (MV) was determined using a capillary rheometer at <NUM> with a shear rate of <NUM> radians per second (rad/s) according to ASTM D3835-<NUM>. Viscosity is measured in the unit Poise (P). Lower values indicate higher melt flow. All samples are dried for <NUM> hr. at <NUM> prior to testing.

Melting temperature (Tm) of the polyester components in the blend examples were determined by differential scanning calorimetry (DSC) using heating and cooling rates rate of <NUM>/min, and the melting temperatures are taken from the endotherm peak maxima of the second heating cycle.

Carboxylic end group (CEG) concentration was determined by a general equivalencepoint titration according to ASTM D7409-<NUM>. A solid sample is dissolved at reflux in a solution of orthocresol and methylene chloride. After cooling to room temperature, the carboxylic end groups are titrated with <NUM> N-tetrabutylammonium hydroxide/<NUM>,<NUM>,<NUM>-trifluoroethanol. CEG is reported as millimole equivalents per kilogram (meq/kg).

Specific gravity (Sp. ) was measured per ASTM D <NUM>.

Tensile properties were measured on <NUM> millimeter type I bars as per ASTM method D638 at <NUM> with a crosshead speed of <NUM>/min as tangent. Tensile strength is measured at yield. Tensile modulus and tensile strength at yield are reported in MPa (Mega Pascal).

Heat deflection temperature (HDT) was measured on <NUM> bars as per ASTM D648 (<NUM> MPa or <NUM> psi stress) at a heating rate of <NUM>/hr.

Polyester glass transition temperature (Tg) was determined by dynamic mechanical analysis (DMA) and is a composite value of the mix of the polyesters in the sample. DMA was performed on a <NUM> molded part with a <NUM>/min heating rate.

Sound transmission loss (STL) was measured using an impedance tube according to ISO <NUM>-<NUM>/ASTM E1050. The STL is a measurement of the reduction of sound intensity, measured in decibels (dB) caused by the resin sample at a selected wavelength. Greater STL values indicate more sound loss (i.e., more effective sound blocking). STL was determined using samples having a diameter of <NUM> and a thickness of <NUM>. Samples were prepared from molded disks having a diameter of <NUM> inches (<NUM>) and a thickness of <NUM> mil (<NUM>) that were machined to a diameter of <NUM>. The samples were tested at a frequency range of <NUM> to <NUM> hertz (Hz). Sound transmission loss is reported as the average from three test samples.

The impedance tube device measures the ratio of the airborne sound power to the sound power transmitted by a partition comprising the test material. The device includes precision testing tubes that are equipped with microphones and sound sources. The test samples were inserted into the impedance tube at a location between a loudspeaker (sound source) and a receiver (microphone). The loudspeaker in the impedance tube emits precisely quantified sound, and the microphones measure the sound pressure level at specific locations along the length of the tube. The normal incident acoustic properties of the material were calculated based on frequency response functions measured between the various measurement locations.

Sound transmission loss (STL) was calculated in dB using Equation <NUM>. <MAT> wherein SA is the incident sound intensity (dB); and ST is the transmitted sound intensity (dB).

The compositions and properties of Examples <NUM> to <NUM> and Comparative Example <NUM> are provided in Table <NUM>, wherein the amounts are in weight percent.

In Examples <NUM> to <NUM>, PET was blended with PBT to achieve good mechanical/thermal mechanical strength and lower cost in the composition. PET use allows facile incorporation of post-consumer recycle (PCR) with a higher melting point (<NUM>), the PBT allows for fast crystallization giving molded articles with good dimensional stability; that is faithful replication of mold tolerance and less than <NUM>% change in dimensional stability when exposed to heat below <NUM>. The combination of PBT-<NUM> and PBT-<NUM> provides flexibility to adjust the melt flow during the compounding process. DSC analyses showed that the E1 to E6 polyester mixtures all had two distinct melting points at <NUM> and <NUM> on first and second heatings.

The comparative example had a baseline formulation having <NUM> wt% of <NUM> micron diameter glass fiber (Comparative Example <NUM>, C1). Examples <NUM> to <NUM> (E1 to E6) were prepared from the baseline formulation of <NUM> wt% of glass fiber and further including <NUM> wt% of a metal filler having Sp. of greater than <NUM> (Table <NUM>), resulting in composite materials with Sp. in the range of <NUM> to <NUM>/cm<NUM>. The metal oxide fillers such as TiO<NUM> (E3) and ZnO (E4) resulted in composite materials having unfavorable thermal and mechanical properties at <NUM> wt% loading level, which was indicated by a lower HDT temperature (less than <NUM>). Examples <NUM> and <NUM>, which included BaSO<NUM> (E1) and tungsten (E5) respectively, showed greater sound transmittance loss (dB) in the frequency range of <NUM> to <NUM> relative to C1.

Examples <NUM> to <NUM> (E7 to E12) were prepared and evaluated to provide samples having a broader range of BaSO<NUM> or tungsten in a PET-PBT polyester mixture again comprising a high and low Mw PBT to fine tune viscosity. Comparative Example <NUM> (C2) was prepared with a greater loading of glass fiber and without a metal filler. The compositions and properties of E7 to E12 and C2 are provided in Table <NUM>, wherein the amounts are in weight percent.

From the Examples, BaSO<NUM> with glass fiber (E7 to E10) demonstrated a good balance of mechanical and thermal properties, and sound transmittance loss. DSC analyses showed that the E7 to E12 polyester mixtures all had two distinct melting points (on first and second heats) of <NUM> and <NUM>.

The lower loading levels of BaSO<NUM> provided less noise reduction (E7 and E8).

In addition, a <NUM> wt% LLDPE loading was evaluated to determine the sound dampening effect (E11). Greater sound transmittance loss was observed in the frequency range of <NUM> to <NUM> for the sample including the LLDPE.

Tungsten powder was further evaluation in PET-PBT blends for noise reduction. It was found that extrusion became challenging when loading more than <NUM> wt% of tungsten due to the weak melt strength. E12, which was loaded with <NUM> wt% tungsten, demonstrated a significant reduction in sound transmittance, especially at <NUM> (> <NUM> dB) as compared to C1.

In Examples <NUM> to <NUM> and Comparative Example <NUM>, dual layer articles were prepared by connecting layers of the molded composition(s) together. Individual layers were prepared as <NUM> discs of individual composites having <NUM> wt% glass fiber (B), <NUM> wt% GF and <NUM> wt% BaSO<NUM> (HV), or <NUM> wt% GF and <NUM> wt% tungsten (VHV). Two individual layers were connected using a cyanoacrylate adhesive to form a laminated sample, and then machined to provide laminate samples that were <NUM> in diameter and <NUM> in thickness. The laminate samples were evaluated for STL at frequencies from <NUM> to <NUM> as described above.

Laminate samples having identical layers were prepared as C3 (B-B), E13 (HV-HV), and E14 (VHV-VHV). Table <NUM> shows the STL (dB) for laminate samples E14 to E15 and the polyester control C3 (B-B).

Laminate samples were then prepared from individual layers that were dissimilar. The STL for laminate samples E15 (B-HV), E16 (B-VHV), and E17 (HV-VHV) were determined in two configurations for each sample, with first one side exposed to the sound source and then the other side exposed. Surprisingly, both testing configurations gave similar results independent of whether the higher or lower density face was exposed to the sound source.

Table <NUM> shows the measured STL (STLM) for E15 to E17, calculated STL (STLC) for E15 to E17, and the difference (Δ) between the calculated and measured STL for E15 to E17 at frequencies from <NUM> to <NUM>. All values are in dB.

The measured STLs from C3, E13, and E14 were used to determine the calculated STLC for the mixed laminate samples at each wavelength. As an exemplary calculation, the STL of the B-B laminate (C3) was added to the STL of the HV-HV laminate (E13), and the sum was then divided by <NUM> to give the expected (calculated) value for the sound loss of the B-HV mixed laminate (E15). The difference (Δ) between the calculated STLC and the measured STLM were determined at each wavelength. A similar method was used to determine the STLC, STLM, and Δ for E16 and E17.

Surprisingly, at lower wavelengths (e.g., <NUM>, <NUM>, <NUM>, and <NUM>) the STLM of the mixed laminates are from <NUM> to <NUM> dB less than the STLC, meaning a negative Δ was observed. However, at <NUM> and higher wavelengths the STLM of the mixed laminates are from <NUM> to <NUM> dB greater than the STLC. At the higher wavelengths, the positive Δ indicated a positive synergy because the STL was greater than the expected sum of the individual components.

This disclosure further encompasses the following examples.

A polyester composition comprising, based on the total weight of the polyester composition, a first polyester and a second polyester, wherein a weight ratio of the first polyester to the second polyester is <NUM>:<NUM> to <NUM>:<NUM>, preferably <NUM>:<NUM> to <NUM>:<NUM>; <NUM> to <NUM> weight percent, preferably <NUM> to <NUM> weight percent of a reinforcing filler; and <NUM> to <NUM> weight percent, preferably <NUM> to <NUM> weight percent of an inorganic filler having a specific gravity of greater than <NUM> grams per cubic centimeter, as determined in accordance with ASTM D792, wherein a molded article comprising the polyester composition has a sound transmission loss of greater than <NUM> decibels, preferably <NUM> to <NUM> decibels, more preferably <NUM> to <NUM> decibels, as determined at <NUM> Hertz according to ASTM E1050 using a molded disc with a diameter of <NUM> and a thickness of <NUM>.

In another embodiment the first polyester comprises a first poly(butylene terephthalate) and a second poly(butylene terephthalate), and an intrinsic viscosity of the first poly(butylene terephthalate) is different than an intrinsic viscosity of the second poly(butylene terephthalate); or a weight average molecular weight of the first poly(butylene terephthalate) is different than a weight average molecular weight of the second poly(butylene terephthalate); or both the intrinsic viscosity and the weight average molecular weight are different.

In another embodiment the second polyester comprises poly(ethylene terephthalate), poly(butylene terephthalate), poly(ethylene naphthanoate), poly(butylene naphthanoate), poly(cyclohexanedimethanol terephthalate), poly(propylene terephthalate), or a combination comprising at least one of the foregoing.

A In another embodiment the first polyester and the second polyester each independently have a carboxylic acid end group concentration of <NUM> to <NUM> meq/kg, preferably <NUM> to <NUM> meq/kg, more preferably <NUM> to <NUM> meq/kg, as determined according to ASTM D7409; and a melting temperature from <NUM> to <NUM>, preferably from <NUM> to <NUM>, more preferably from <NUM> to <NUM>, as determined by differential scanning calorimetry, preferably wherein the first polyester and the second polyester have at least two separate melting temperatures from <NUM> to <NUM>, as determined by differential scanning calorimetry.

In another embodiment the reinforcing filler comprises glass, glass fibers, glass flakes, mica, or a combination comprising at least one of the foregoing; preferably flat glass, cylindrical glass fibers, glass flakes, mica, or a combination comprising at least one of the foregoing; more preferably flat glass, a combination of cylindrical glass fibers and glass flakes, mica, or a combination comprising at least one of the foregoing.

A In another embodiment the inorganic filler comprises barium sulfate, tungsten, iron, zinc oxide, zinc sulfide, titanium dioxide, iron oxide, or a combination comprising at least one of the foregoing, preferably barium sulfate or tungsten.

In another embodiment, the composition further comprises <NUM> to <NUM> weight percent of a stabilizer, based on the total weight of the polyester composition; preferably <NUM> to <NUM> weight percent of a hindered phenol, phosphite, phosphonite, thioester, or a combination comprising at least one of the foregoing.

In another embodiment, the composition further comprises <NUM> to <NUM> weight percent of an impact modifier, based on the total weight of the polyester composition; preferably <NUM> to <NUM> weight percent of an alkyl (meth)acrylate copolymer, (meth)acrylic ester-butadiene-styrene, acrylonitrile-butadiene-styrene, styrene-butadiene, styrene-ethylene-butylene-styrene, a poly(ether ester) block copolymer, a polyethylene-α olefin copolymer, styrene-isoprene-styrene triblock copolymer, or a combination comprising at least one of the foregoing.

In another embodiment, the molded article has one or more of a specific gravity of <NUM> to <NUM> grams per cubic centimeter, as determined in accordance with ASTM D792; a heat deflection temperature of <NUM> to <NUM>, as determined in accordance with ASTM D648; a tensile strength of <NUM> to <NUM> MPa, as determined in accordance with ASTM D638; a tensile modulus of <NUM>,<NUM> to <NUM>,<NUM> MPa, as determined in accordance with ASTM D638; and a melt viscosity of <NUM> to <NUM> Poise, as determined at <NUM> at a shear rate of <NUM> radians per second in accordance with ASTM-D3835.

A multi-layer composite comprising a first layer comprising a first polyester composition; and a second layer comprising a second polyester composition, wherein the first polyester composition and the second polyester composition are the same or different, and are each the polyester composition of any one or more of aspects <NUM> to <NUM>.

In another embodiment, the composite further comprises an adhesive layer disposed between the first layer and the second layer.

In another embodiment, the composite has a total thickness of <NUM> to <NUM>, preferably <NUM> to <NUM>, more preferably <NUM> to <NUM>; a length <NUM> to <NUM>, preferably <NUM> to <NUM>, more preferably <NUM> to <NUM>; and a width of <NUM> to <NUM>, preferably <NUM> to <NUM>, more preferably <NUM> to <NUM>, preferably wherein the length and the width are the same or different, and are each independently at least one order of magnitude greater than the total thickness.

In another embodiment, the first polyester composition and the second polyester composition each independently has a specific gravity of <NUM> to <NUM> grams per cubic centimeter, preferably <NUM> to <NUM> grams per cubic centimeter, as determined in accordance with ASTM D792.

In another embodiment, the composite has a sound transmission loss of greater than <NUM> decibels, preferably <NUM> to <NUM> decibels, more preferably <NUM> to <NUM> decibels at <NUM> Hertz; greater than <NUM> decibels, preferably <NUM> to <NUM> decibels, more preferably <NUM> to <NUM> decibels at <NUM> Hertz; greater than <NUM> decibels, preferably <NUM> to <NUM> decibels, more preferably <NUM> to <NUM> decibels at <NUM> Hertz; greater than <NUM> decibels, preferably <NUM> to <NUM> decibels, more preferably <NUM> to <NUM> decibels at <NUM> Hertz; and greater than <NUM> decibels, preferably <NUM> to <NUM> decibels, more preferably <NUM> to <NUM> decibels at <NUM> Hertz, wherein the sound transmission loss is determined according to ASTM E1050 using a molded disc with a diameter of <NUM> and a thickness of <NUM>.

In another embodiment, the first polyester composition has a specific gravity of <NUM> to <NUM> grams per cubic centimeter, preferably <NUM> to <NUM> grams per cubic centimeter, as determined in accordance with ASTM D792; and the second polyester composition has a specific gravity of <NUM> to <NUM> grams per cubic centimeter, preferably <NUM> to <NUM> grams per cubic centimeter, as determined in accordance with ASTM D792.

A method for manufacturing the multi-layer composite of any one or more of aspects <NUM> to <NUM>, the method comprising providing a first layer precursor comprising the first polymer composition and a second layer precursor comprising the second polymer composition; and contacting the first layer precursor and the second layer precursor to provide the multi-layer composite.

An article comprising the multi-layer composite as described herein, or made by the method as described herein,.

A sound insulating component comprising the article as described herein,.

In another embodiment, the component is an automotive component.

All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other (e.g., ranges of "up to <NUM> wt%, or, <NUM> to <NUM> wt%", is inclusive of the endpoints and all intermediate values of the ranges of "<NUM> to <NUM> wt%," etc.). "Combinations" is inclusive of blends, mixtures, alloys, reaction products, and the like. The terms "first," "second," and the like, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms "a" and "an" and "the" do not denote a limitation of quantity, and are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. "Or" means "and/or" unless clearly stated otherwise. Reference throughout the specification to "some embodiments", "an embodiment", and so forth, means that a particular element described in connection with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. In addition, it is to be understood that the described elements may be combined in any suitable manner in the various embodiments.

However, if a term in the present application contradicts or conflicts with a term in the reference, the term from the present application takes precedence over the conflicting term from the reference.

The term "alkyl" means a branched or straight chain, unsaturated aliphatic hydrocarbon group, e.g., methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, t-butyl, n-pentyl, s-pentyl, and n- and s-hexyl. "Alkenyl" means a straight or branched chain, monovalent hydrocarbon group having at least one carbon-carbon double bond (e.g., ethenyl (-HC=CH<NUM>)). "Alkoxy" means an alkyl group that is linked via an oxygen (i.e., alkyl-O-), for example methoxy, ethoxy, and sec-butyloxy groups. "Alkylene" means a straight or branched chain, saturated, divalent aliphatic hydrocarbon group (e.g., methylene (-CH<NUM>-) or, propylene (-(CH<NUM>)<NUM>-)). "Cycloalkylene" means a divalent cyclic alkylene group, -CnH2n-x, wherein x is the number of hydrogens replaced by cyclization(s). "Cycloalkenyl" means a monovalent group having one or more rings and one or more carbon-carbon double bonds in the ring, wherein all ring members are carbon (e.g., cyclopentyl and cyclohexyl). "Aryl" means an aromatic hydrocarbon group containing the specified number of carbon atoms, such as phenyl, tropone, indanyl, or naphthyl. "Arylene" means a divalent aryl group. "Alkylarylene" means an arylene group substituted with an alkyl group. "Arylalkylene" means an alkylene group substituted with an aryl group (e.g., benzyl). The prefix "halo" means a group or compound including one more of a fluoro, chloro, bromo, or iodo substituent. A combination of different halo groups (e.g., bromo and fluoro), or only chloro groups can be present. The prefix "hetero" means that the compound or group includes at least one ring member that is a heteroatom (e.g., <NUM>, <NUM>, or <NUM> heteroatom(s)), wherein the heteroatom(s) is each independently N, O, S, Si, or P.

Unless substituents are otherwise specifically indicated, each of the foregoing groups can be unsubstituted or substituted, provided that the substitution does not significantly adversely affect synthesis, stability, or use of the compound. "Substituted" means that the compound, group, or atom is substituted with at least one (e.g., <NUM>, <NUM>, <NUM>, or <NUM>) substituents instead of hydrogen, where each substituent is independently nitro (-NO<NUM>), cyano (-CN), hydroxy (-OH), halogen, thiol (-SH), thiocyano (-SCN), C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, C<NUM>-<NUM> alkynyl, C<NUM>-<NUM> haloalkyl, C<NUM>-<NUM> alkoxy, C<NUM>-<NUM> haloalkoxy, C<NUM>-<NUM> cycloalkyl, C<NUM>-<NUM> cycloalkenyl, C<NUM>-<NUM> aryl, C<NUM>-<NUM> arylalkylene (e.g., benzyl), C<NUM>-<NUM> alkylarylene (e. g, toluyl), C<NUM>-<NUM> heterocycloalkyl, C<NUM>-<NUM> heteroaryl, C<NUM>-<NUM> alkyl sulfonyl (-S(=O)<NUM>-alkyl), C<NUM>-<NUM> arylsulfonyl (-S(=O)<NUM>-aryl), or tosyl (CH<NUM>C<NUM>H<NUM>SO<NUM>-), provided that the substituted atom's normal valence is not exceeded, and that the substitution does not significantly adversely affect the manufacture, stability, or desired property of the compound. When a compound is substituted, the indicated number of carbon atoms is the total number of carbon atoms in the compound or group, including those of any substituents.

Claim 1:
A multi-layer composite, comprising:
• a first layer comprising a first polyester composition; and
• a second layer comprising a second polyester composition,
wherein the first polyester composition and the second polyester composition are different, wherein at least one of the first and the second polyester composition comprises, based on the total weight of the polyester composition,
• a first polyester and a second polyester, wherein a weight ratio of the first polyester to the second polyester is <NUM>:<NUM> to <NUM>:<NUM>, preferably <NUM>:<NUM> to <NUM>:<NUM>;
• <NUM> to <NUM> weight percent, preferably <NUM> to <NUM> weight percent of a reinforcing filler; and
• <NUM> to <NUM> weight percent, preferably <NUM> to <NUM> weight percent, more preferably <NUM> to <NUM> weight percent of an inorganic filler having a specific gravity of greater than <NUM> grams per cubic centimetre, as determined in accordance with ASTM D792,
wherein a moulded article comprising the polyester composition has a sound transmission loss of greater than <NUM> decibels, preferably <NUM> to <NUM> decibels, more preferably <NUM> to <NUM> decibels, as determined at <NUM>,<NUM> Hertz according to ASTM E1050 using a moulded disc with a diameter of <NUM> and a thickness of <NUM>.