A polymer dispersion is disclosed. The polymer dispersion includes a liquid crystal polymer powder, a polyamide acid, and a solvent. A solid content of the polymer dispersion includes the liquid crystal polymer powder and the polyamide acid. The liquid crystal polymer powder has a mass ratio of 20% to 30% in the solid content. The polyamide acid has a mass ratio of 70% to 80% in the solid content. The polyamide acid is obtained by mixing two kinds of diamines and two kinds of dianhydrides together, causing the diamines and the dianhydrides to be polymerized with each other. Both two kinds of diamines and two kinds of dianhydrides comprise a liquid crystal structure and a flexible structure respectively. A method of preparing the polymer dispersion, and a method for preparing a polymer composite film using the polymer dispersion are also disclosed.

Example methods and articles of manufacture related to electrospun aramid nanofibers are provided. One example method may include forming a resultant solution by reacting a solution of aramids dissolved in a solvent with an electrophile. In this regard, the electrophile may perform a side chain substitution on the dissolved aramids. The example method may further include electrospinning the resultant solution to form an aramid nanofiber.

Provided are a photosensitive resin composition which has excellent pattern processabilities (high sensitivity and high resolution) and is excellent in chemical resistance and thermal resistance after thermally treated; a heat-resistant resin or heat-resistant resin precursor used for the composition; and a diamine compound which is a raw material of the resin and the precursor. The diamine compound is a diamine compound represented by a general formula (1).

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Provided are a novel polyamide polymer obtained by polymerizing monomers including aromatic diamine substituted with a nitrile group and an amide group and an aromatic dibasic acid compound, a spinning dope comprising the same, and a polyamide molded article. A fiber obtained using the novel polyamide polymer according to the present invention, particularly, a fiber obtained by spinning the polymer according to the present invention may have high strength and high elasticity, such that the fiber may be applied to various industrial fields.

Provided are a novel polyamide polymer obtained by polymerizing monomers including aromatic diamine substituted with a nitrile group and an amide group and an aromatic dibasic acid compound, a spinning dope comprising the same, and a polyamide molded article. A fiber obtained using the novel polyamide polymer according to the present invention, particularly, a fiber obtained by spinning the polymer according to the present invention may have high strength and high elasticity, such that the fiber may be applied to various industrial fields.

A hardcoat film includes: a substrate; and a hardcoat layer, in which the hardcoat film satisfies the following Formulas (i) and (ii), (i) E′.sub.(0.4)HC×d.sub.HC≥8,000 MPa.Math.μm, (ii) E′.sub.(4)HC×d.sub.HC≤4,000 MPa.Math.μm, E′.sub.(0.4)HC is an elastic modulus of the hardcoat layer obtained in a case where an elongation rate is 0.4%, E′.sub.(4)HC is an elastic modulus of the hardcoat layer obtained in a case where an elongation rate is 4%, and d.sub.HC is a film thickness of the hardcoat layer.

A poly(amide-imide) block copolymer that includes: a first segment including a structural unit represented by Chemical Formula 1C, and a second segment including a structural unit represented by Chemical Formula 2: ##STR00001## In Chemical Formula 1C and Chemical Formula 2, R.sup.5 to R.sup.13, and n3 to n8 are the same as in the specification.

A poly(amide-imide) block copolymer that includes: a first segment including a structural unit represented by Chemical Formula 1C, and a second segment including a structural unit represented by Chemical Formula 2: ##STR00001## In Chemical Formula 1C and Chemical Formula 2, R.sup.5 to R.sup.13, and n3 to n8 are the same as in the specification.

A process for manufacturing a display device, an optical device or an illuminating device includes casting a polyamide solution onto a base at temperature below 200° C. to obtain a film, heating the film on the base at temperature sufficient to make the film solvent resistant and obtain a polyamide film, forming on a surface of the polyamide film one of a display element, an optical element and an illumination element to form a display device, an optical device or an illumination device, and de-bonding the base from the display device, the optical device or the illuminating device. The polyamide solution comprises a solvent, an aromatic polyamide dissolved in the solvent, and a multifunctional epoxyde, where the aromatic polyamide comprises at least one functional group that reacts with an epoxy group, the aromatic polyamide comprises a first repeat unit of formula (I) and a second repeat unit of formula (II)

##STR00001##

A process for manufacturing a display device, an optical device or an illuminating device includes casting a polyamide solution onto a base at temperature below 200° C. to obtain a film, heating the film on the base at temperature sufficient to make the film solvent resistant and obtain a polyamide film, forming on a surface of the polyamide film one of a display element, an optical element and an illumination element to form a display device, an optical device or an illumination device, and de-bonding the base from the display device, the optical device or the illuminating device. The polyamide solution comprises a solvent, an aromatic polyamide dissolved in the solvent, and a multifunctional epoxyde, where the aromatic polyamide comprises at least one functional group that reacts with an epoxy group, the aromatic polyamide comprises a first repeat unit of formula (I) and a second repeat unit of formula (II)

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