Abstract: A powder that contains microparticles formed from an aromatic polyester is provided. The mean size of the microparticles is generally from about 0.1 to about 40 micrometers. The microparticles may also have a shape that is generally spherical in nature. Regardless of the actual size and shape, however, the size distribution of the microparticles may be consistent throughout the powder. For example, at least about 50% by volume of the microparticles may have a mean size within a range of from about 0.1 to about 200 micrometers. Without intending to be limited by theory, the present inventor believes that a certain size and/or size distribution can improve the quality of coatings formed from the powder.

Abstract: An aromatic polyester that contains one or more aromatic ester repeating units and one or more biphenyl repeating units is provided. While a wide variety of aromatic ester repeating units may be employed, the polymer is nevertheless “low naphthenic” to the extent that it contains a minimal content of repeating units derived from naphthenic hydroxycarboxylic acids and naphthenic dicarboxylic acids. Despite the absence of a high level of conventional naphthenic acid repeating units, the present inventors have discovered that selective control over the type and relative concentration of the biphenyl repeating units can lead to “low naphthenic” polymers that are not only soluble in certain solvents, but also capable of exhibiting good mechanical properties. Thus, the ability of the resulting polymer to be dissolved or dispersed in various solvents can be enhanced without sacrificing performance.

Abstract: A method for forming a high molecular weight thermotropic liquid crystalline polymer is provided. The method includes melt polymerizing two or more monomers in the presence of a unique aromatic amide oligomer to form a prepolymer, and then solid-state polymerizing the prepolymer to achieve a target molecular weight. The present inventors have discovered that a unique aromatic amide oligomer can be employed to help increase the “low shear” complex viscosity of the resulting solid-state polymerized composition. This allows for the attainment of higher than conventional “low shear” complex viscosity values and/or a substantial reduction in the solid-state polymerization time needed to achieve a target complex viscosity. In addition, the oligomeric flow aid can also accelerate the extent to which the “high shear” melt viscosity is increased during solid-state polymerization, which may also contribute to a substantial reduction in the solid-state polymerization time needed to achieve a certain molecular weight.

Abstract: A thermoplastic composition that comprises a thermotropic, liquid crystalline polymer and a combination of certain types of flow modifiers is provided. More particularly, one type of flow modifier that is employed in the composition is a functional compound (e.g., hydroxy-functional, carboxy-functional, etc.) that can react with the backbone of the polymer. In certain cases, for instance, the functional compound can initiate chain scission of the polymer, which reduces the molecular weight, and in turn, the melt viscosity of the polymer under shear. An additional non-functional compound is also employed to help reduce the melt viscosity to the desired “ultralow” levels without having a significant impact on the mechanical properties. The non-functional compound is, more specifically, an aromatic amide oligomer that can alter intermolecular polymer chain interactions without inducing chain scission to any appreciable extent, thereby further lowering the overall viscosity of the polymer matrix under shear.

Abstract: A molded part having a predetermined shape is provided. The molded part may be formed by casting a liquid crystalline polymer composition into a mold cavity at a relatively low shear rate. Due to the use of a relatively low shear rate, the polymer composition does not generally undergo extensive shear orientation, which can allow the resulting part to be further processed using standard finishing techniques. The ability to use relatively low shear rates during casting is achieved in the present invention through the use of an aromatic amide oligomer. More particularly, the present inventors have discovered that the aromatic amide oligomer can serve as a flow aid by altering intermolecular polymer chain interactions, thereby lowering the overall viscosity of the polymer matrix to “ultralow” levels without having a significant impact on the mechanical properties.

Abstract: A thermotropic liquid crystalline polymer melt polymerized in the presence of a viscosity modifier that can help increase the “low shear” viscosity of the resulting composition is provided. The increased “low shear” viscosity can minimize drooling of the polymer composition during processing and also allow it to possess a greater melt strength, which facilitates its ability to be processed in a wide variety of applications without losing its physical integrity. Despite having a relatively high “low shear” viscosity, the present inventors have discovered that the viscosity modifier does not substantially increase the “high shear” melt viscosity of the polymer composition. In this regard, the ratio of the “low shear” viscosity to the melt viscosity is generally very high, such as within a range of from about 50 to about 1000.

Abstract: A method for forming a high molecular weight thermotropic liquid crystalline polymer is provided. The method includes melt polymerizing two or more monomers in the presence of a unique aromatic amide oligomer to form a prepolymer, and then solid-state polymerizing the prepolymer to achieve a target molecular weight. The present inventors have discovered that a unique aromatic amide oligomer can be employed to help increase the “low shear” complex viscosity of the resulting solid-state polymerized composition. This allows for the attainment of higher than conventional “low shear” complex viscosity values and/or a substantial reduction in the solid-state polymerization time needed to achieve a target complex viscosity. In addition, the oligomeric flow aid can also accelerate the extent to which the “high shear” melt viscosity is increased during solid-state polymerization, which may also contribute to a substantial reduction in the solid-state polymerization time needed to achieve a certain molecular weight.

Abstract: A polymer composition that contains a thermotropic liquid crystalline polymer, fibrous filler (e.g., glass fibers), and a flow aid is provided. The flow aid is in the form of an aromatic amide oligomer which, due to its unique nature and properties, has the ability to dramatically reduce melt viscosity with only a minimal degree of blending with the polymer. More particularly, the fibrous filler is supplied to an extruder in conjunction with the polymer and/or at a location downstream thereof so that the polymer is still in a solid or solid-like state when it initially contacts the filler. In this manner, the fibrous filler and polymer are allowed to mix together while the composition still has a relatively high melt viscosity, which helps to uniformly disperse the fibrous filler within the polymer matrix. After a certain period of time, the aromatic amide oligomer is then supplied to the extruder at a location downstream from the fibrous filler to reduce the melt viscosity of the composition.

Abstract: A method for forming a high molecular weight liquid crystalline polymer is provided. The method include melt polymerizing two or more precursor monomers (e.g., acetylated or non-acetylated) in the presence of an aromatic amide oligomer. The present inventors have discovered that such an oligomer can lower the melt viscosity of the viscous polymer as it is formed. The ability to lower melt viscosity in situ during melt polymerization enables the formation of high molecular weight polymers that display low melt viscosity and can still be removed from the reactor vessel without solidifying therein. This not only improves the ease of processing, but also allows molecular weights to be reached that are even higher than conventionally practical.

Abstract: A thermotropic liquid crystalline polymer composition capable of exhibiting both a low melting temperature and good heat resistance without the use of conventional naphthenic acids is provided. The melting temperature may, for example, range from about 250° C. to about 400° C. Even at such low melting temperatures, the present inventors have surprisingly discovered that the ratio of the deflection temperature under load (“DTUL”), a measure of short term heat resistance, to the melting temperature may remain relatively high. The specific DTUL values may range from about 200° C. to about 300° C. The ability to form a polymer composition with the properties noted above may be achieved, at least in part, by the use of an aromatic amide oligomer.

Abstract: A liquid crystalline polymer composition that contains a liquid crystalline polymer and an aromatic amide oligomer is provided. The oligomer can serve as a flow aid by altering intermolecular polymer chain interactions, thereby lowering the overall viscosity of the polymer matrix under shear. The oligomer is also not easily volatized or decomposed during compounding, molding, and/or use, which minimizes off-gassing and the formation of blisters that would otherwise impact the final mechanical properties of a part made from the polymer composition. While providing the benefits noted, the aromatic amide oligomer does not generally react with the polymer backbone of the liquid crystalline polymer to any appreciable extent so that the mechanical properties of the polymer are not adversely impacted.

Abstract: An aromatic amide compound having the following general formula (I) is provided: wherein, X1 and X2 are independently C(O)HN or NHC(O); G1, G2 and G3 are independently hydrogen, C(O)HN-phenyl, or NHC(O)-phenyl, wherein at least one of G1, G2 and G3 is C(O)HN-phenyl or NHC(O)-phenyl; Q1, Q2, and Q3 are independently hydrogen, C(O)HN-phenyl, or NHC(O)-phenyl, wherein at least one of Q1, Q2, and Q3 is C(O)HN-phenyl or NHC(O)-phenyl; R5 is halo, haloalkyl, alkyl, alkenyl, aryl, heteroaryl, cycloalkyl, or heterocyclyl; and m is from 0 to 4.

Abstract: A melt-extruded substrate that can be readily thermoformed into a shaped, three-dimensional article is provided. The substrate is formed from a polymer composition that contains a thermotropic liquid crystalline polymer and a unique aromatic amide oligomer. The present inventors have discovered that the oligomer can help increase the “low shear” complex viscosity of the resulting polymer. The ability to achieve enhanced low shear viscosity values can lead to polymer compositions with an increased melt strength, which allows the resulting substrate to better maintain its shape during thermoforming without exhibiting a substantial amount of sag. Due to its relatively high degree of melt strength, the polymer composition is particularly well suited for forming thin extruded substrates for use in thermoforming processes.

Abstract: A method for lowering melt viscosity of a liquid crystalline polymer as it is formed in a reactor vessel. More particularly, a reaction mixture is initially supplied to the reactor vessel that contains two or more precursor monomers (e.g., acetylated or non-acetylated). The reaction mixture is heated to an elevated temperature under agitation to initiate formation of the polymer. After a certain period of time, an aromatic amide oligomer is added to the reaction mixture. Among other things, the present inventors have discovered that such an oligomer can serve as a flow aid by altering intermolecular polymer chain interactions, thereby lowering the overall viscosity of the polymer matrix under shear. This minimizes the likelihood of “freeze off” of the polymer within the reactor vessel and limits the impact of process disruptions on the production of the liquid crystalline polymer.

Abstract: A liquid crystalline polymer composition that contains a liquid crystalline polymer and an aromatic amide oligomer is provided. The oligomer can serve as a flow aid by altering intermolecular polymer chain interactions, thereby lowering the overall viscosity of the polymer matrix under shear. The oligomer is also not easily volatized or decomposed during compounding, molding, and/or use, which minimizes off-gassing and the formation of blisters that would otherwise impact the final mechanical properties of a part made from the polymer composition. While providing the benefits noted, the aromatic amide oligomer does not generally react with the polymer backbone of the liquid crystalline polymer to any appreciable extent so that the mechanical properties of the polymer are not adversely impacted.