Abstract: A resin including a unit represented by Chemical Formula 1, a method for preparing the same, a resin composition including the same, and a molded article including the resin composition is described: wherein all the variables are described herein.

Abstract: A resin includes a unit represented by Chemical Formula 1, a method for preparing the same, a resin composition including the same, and a molded article including the resin composition in Chemical Formula 1, Ar1, Ar2, R1, r1, X1 to X4, Z1, Z2, a and b are described herein.

Abstract: The present application relates to a resin including a unit represented by Chemical Formula 1, a method for preparing the same, a resin composition including the same, and a molded article including the resin composition.

Abstract: An analysis method is provided, wherein a measurement sample containing a diamine and an acid dianhydride can be obtained without a separate methyl derivatization process. The analysis method includes pretreating a polyimide film including the polyimide which is a poorly soluble polymer with DMAc after hydrolysis, and determining an amount of monomers contained in the polyimide film.

Abstract: The present invention relates to the production of a polyimide precursor, whereby, by using an amide-based organic solvent having a positive-number partition coefficient (Log P) and a density of at most 1 g/cm3, an interaction between the organic solvent and polyamic acid, which is a polyimide precursor, may be mitigated, thereby enabling the decrease of the viscosity of a polyimide precursor solution, and thus enabling a polyimide precursor solution having high solid content and low viscosity to be obtained.

Abstract: According to the present invention, damage such as film tearing during a rolling process can be reduced by using, as a substrate for a flexible display, a polyimide film having the thickness of 5-10 ?m, modulus of 3-8 GPa, the absolute value of out-of-plane retardation (Rth) of 200-600 nm, and a strain, at a tensile force of 100 MPa, of 10% or less. In addition, since the polyimide film has low residual stress with respect to inorganic substrates, the occurrence of defects during a TFT process is reduced. As a result, processing reliability for a flexible display can be improved. In addition, the saturated static electricity half-life of the polyimide film is controlled to be 250 seconds or more so as to minimize the voltage loss ratio of saturated static electricity and reduce the current drop during a TFT operation, and, as a result, enables a display having improved luminosity to be provided.

Abstract: The laminate for manufacturing a flexible substrate according to the present invention is formed by using a polyimide having a high absorbance to a UV laser in an organic sacrificial layer for delaminating a flexible substrate from a carrier substrate. Therefore, it is possible that the laser energy density required in the delaminating process using laser irradiation is reduced and the amount of as generated by the delaminating process is remarkably reduced so that the efficiency of the process, the permeability of the flexible substrate is improved and the reliability of the device is improved.

Abstract: According to the present invention, damage such as film tearing during a rolling process can be reduced by using, as a substrate for a flexible display, a polyimide film having the thickness of 5-10 ?m, modulus of 3-8 GPa, the absolute value of out-of-plane retardation (Rth) of 200-600 nm, and a strain, at a tensile force of 100 MPa, of 10% or less. In addition, since the polyimide film has low residual stress with respect to inorganic substrates, the occurrence of defects during a TFT process is reduced. As a result, processing reliability for a flexible display can be improved. In addition, the saturated static electricity half-life of the polyimide film is controlled to be 250 seconds or more so as to minimize the voltage loss ratio of saturated static electricity and reduce the current drop during a TFT operation, and, as a result, enables a display having improved luminosity to be provided.

Abstract: The present invention provides a polyimide film which, by having a fluorine structure adopted into a rigid polyamide chain structure, exhibits not only superb heat resistance but also enhanced optical properties. Additionally, the polyimide according to the present invention, by having the particular structure, exhibits excellent transparency, heat-resistance, mechanical strength and flexibility, and thus can be utilized in a variety of functions such as an element substrate, display cover substrate, optical film, integrated circuit (IC) package, adhesive film, multi-layered flexible printed circuit (FPC), tape, touch panel, and protective film for optical disks.

Abstract: A method for producing a device substrate by obtaining a laminate comprising a carrier substrate with a first polyimide film disposed on at least one surface of the carrier substrate, a second polyimide film disposed on the first polyimide film, applying a physical stimulus to the second polyimide film without causing chemical changes in the first polyimide film such that the adhesive strength of the first polyimide to the second polyimide film decreases and separating the second polyimide film from the first polyimide film formed on the carrier substrate to obtain the device.

Abstract: The present invention relates to a polyimide-based solution that can be used to produce an isotropic transparent polyimide-based film with high heat resistance and excellent mechanical properties as well as high transmittance. A coating of the polyimide-based solution on a substrate has a haze of 1% or less after storage at a temperature of 30° C. and a humidity of 70% for 30 minutes.

Abstract: The present invention relates to the production of a polyimide precursor, whereby, by using an amide-based organic solvent having a positive-number partition coefficient (Log P) and a density of at most 1 g/cm3, an interaction between the organic solvent and polyamic acid, which is a polyimide precursor, may be mitigated, thereby enabling the decrease of the viscosity of a polyimide precursor solution, and thus enabling a polyimide precursor solution having high solid content and low viscosity to be obtained.

Abstract: The laminate for manufacturing a flexible substrate according to the present invention is formed by using a polyimide having a high absorbance to a UV laser in an organic sacrificial layer for delaminating a flexible substrate from a carrier substrate. Therefore, it is possible that the laser energy density required in the delaminating process using laser irradiation is reduced and the amount of as generated by the delaminating process is remarkably reduced so that the efficiency of the process, the permeability of the flexible substrate is improved and the reliability of the device is improved.

Abstract: Disclosed is a polyimide precursor composition for the production of a flexible board of a photoelectronic device. The polyimide precursor composition includes a polyimide precursor derived from a diamine or acid dianhydride including a structure of Formula 1: wherein R1 to R8, m1, m2, and m3 are as defined in the specification. Also disclosed is a polyimide film produced from the polyimide precursor composition. The polyimide film is obtained by applying the precursor composition to a substrate and curing the composition. The polyimide film has high transparency and good heat resistance. In addition, the polyimide film exhibits good dimensional stability because the substrate does not undergo an increase in stress even during high-temperature heat treatment.

Abstract: An analysis method is provided, wherein a measurement sample containing a diamine and an acid dianhydride can be obtained without a separate methyl derivatization process. The analysis method includes pretreating a polyimide film including the polyimide which is a poorly soluble polymer with DMAc after hydrolysis, and determining an amount of monomers contained in the polyimide film.

Abstract: The present invention relates to a laminate and a device fabricated using the laminate. The laminate includes a debonding layer including a polyimide resin between a carrier substrate and a flexible substrate. The adhesive strength of the debonding layer to the flexible substrate is changed by a physical stimulus. According to the present invention, the flexible substrate can be easily separated from the carrier substrate without the need for further processing such as laser or light irradiation. Therefore, the use of the laminate facilitates the fabrication of the device having the flexible substrate. The device may be, for example, a flexible display device. In addition, the device can be prevented from deterioration of reliability and occurrence of defects caused by laser or light irradiation. This ensures improved characteristics and high reliability of the device.

Abstract: The present invention relates to a polyimide-based solution that can be used to produce an isotropic transparent polyimide-based film with high heat resistance and excellent mechanical properties as well as high transmittance. A coating of the polyimide-based solution on a substrate has a haze of 1% or less after storage at a temperature of 30° C. and a humidity of 70% for 30 minutes.

Abstract: The present invention provides a polyimide film which, by having a fluorine structure adopted into a rigid polyamide chain structure, exhibits not only superb heat resistance but also enhanced optical properties. Additionally, the polyimide according to the present invention, by having the particular structure, exhibits excellent transparency, heat-resistance, mechanical strength and flexibility, and thus can be utilized in a variety of functions such as an element substrate, display cover substrate, optical film, integrated circuit (IC) package, adhesive film, multi-layered flexible printed circuit (FPC), tape, touch panel, and protective film for optical disks.

Abstract: The present invention relates to a polyimide-based solution that can be used to produce an isotropic transparent polyimide-based film with high heat resistance and excellent mechanical properties as well as high transmittance. A coating of the polyimide-based solution on a substrate has a haze of 1% or less after storage at a temperature of 30° C. and a humidity of 70% for 30 minutes.

Abstract: A method for producing a device substrate by obtaining a laminate comprising a carrier substrate, a first polyimide film comprising a first polyimide resin disposed on at least one surface of the carrier substrate, a second polyimide film disposed on the first polyimide film opposite to the surface of the first polyimide film formed on a surface of the carrier substrate; applying a physical stimulus to the second polyimide film without causing chemical changes in the first polyimide film such that the cross-sections of the second polyimide film are exposed and cross-sectional surfaces of the first polyimide film are not exposed and no physical stimulus is applied to the surface of the carrier substrate, wherein the adhesive strength of the first polyimide to the second polyimide film decreases when the second polyimide film in the laminate is cut to expose cross-sectional surfaces of the second polyimide film; and separating the second polyimide film from the first polyimide film formed on the carrier substra