Lg Chem, Ltd

Bora Shin

Dong Hyun Kim

Jaesoon Bae

Kyungjun Kim

Hye Won Jeong

Cheolmin Yun

Hangah Park

Jinho Lee

Kyoung Hoon Kim

Chan Hyo Park

MiRa Im

Jung Ho Jo

Byoung Hyoun Kim

Su Youn Han

Jong Hee Kim

Il Hwan Choi

Jinyoung Park

Hyeonah Shin

Seung Yup Lee

Danbi Choi

Min Suk Jung

Dongmyung Kim

Seung W Chu

Jun Sik Suh

Yong Jeong Kim

Kwonyoung Choi

Dong Myung Oh

Soo Ah Nam

Kyeongmun Kim

Hye Jin Yim

Kyeongmin Kim

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.

Method for quantitative analysis of monomers in polyimide film

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.

Polyimide precursor solution and polyimide film produced using same

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 &#x3bc;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.

Polyimide film, flexible substrate using same, and flexible display comprising flexible substrate

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.

Laminate for manufacturing flexible substrate and method for manufacturing flexible substrate by using same

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.

Polyimide precursor solution and method for producing same

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.

Laminate, and element comprising substrate manufactured using same

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&#xb0; C. and a humidity of 70% for 30 minutes.

Polyimide-based solution and polyimide-based film produced using same

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: 

Composition for the production of polyimide film for flexible board of photoelectronic device

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.

Laminite, and element comprising substrate manufactured using same

The present invention relates to a laminate and a device fabricated using the laminate. The laminate includes a first polyimide resin layer between a carrier substrate and a second polyimide resin layer, wherein the first polyimide resin layer has a coefficient of thermal expansion (CTE) equal to or lower than the CTE of the second polyimide-based resin layer at a temperature of 100 to 200&#xb0; C., and the adhesive strength of the first resin layer to the second resin layer decreases when a physical stimulus causing no chemical changes in the first resin layer is applied to the laminate. 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.

The present invention relates to a laminate and a device fabricated using the laminate. The laminate includes a debonding layer including a polyimide resin having a similarity score not greater than 0.5, as calculated by Equation 1 defined in the detailed description, between a carrier substrate and a flexible substrate. 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.

The present invention relates to a polyamic acid polymer composite and a method for producing the same, and more specifically, a polyamic acid polymer composite, which can be applied to display substrate production due to its high transparency and low thermal expansion of glass-level, and a method for producing same. The polyamic acid polymer composite comprises 50 to 99 wt % of a polyamic acid polymer having a repeating unit of Chemical Formula 1; and 1 to 50 wt % of a silica-based particle: 

Polyamic acid polymer composite and preparation method thereof

Provided is a secondary battery comprising a cathode active material having low-electrolyte wettability as a main ingredient, which is capable of improving high-rate discharge properties by an addition of a perfluorinated sulfonamide substituent-containing polymer ('additive') to a cathode mix and/or an electrolyte.

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Daejeon, South Korea

Bora Shin