Akron Polymer Systems, Inc.

Akon Polymer Systems, Inc.

Other

Sumitomo Bakelite Company Limited

Limin Sun

Frank Wayne Harris

Dong Zhang

Jiaokai Jing

John D Harvey

Haci Bayram Erdem

Stephen Z D Cheng

Jun Okada

Xiaoliang Joe Zheng

Yusuke Inoue

Zhikuan Lu

Hideo Umeda

Ritsuya Kawasaki

Toshihiko Katayama

Mizuho Inoue

Manabu Naito

Frank Harris

The present invention is directed toward transparent films prepared from soluble aromatic copolyamides with glass transition temperatures greater than 300° C. The copolyamides, which contain pendant carboxylic groups are solution cast into films using N,N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidinone (NMP), or other polar solvents. The films are thermally cured at temperatures near the copolymer glass transition temperature. After curing, the polymer films display transmittances >80% from 400 to 750 nm, have coefficients of thermal expansion of less than 20 ppm, and are solvent resistant. The films are useful as flexible substrates for microelectronic devices.

Aromatic polyamide films for transparent flexible substrates

A class of solvent resistant, flexible copolyimide substrates having high optical transparency (&#x3e;80% from 400 to 750 nm) that is retained after brief exposure to 300&#xb0; C., near-zero birefringence (&#x3c;0.001) and a maximum CTE of approximately 60 ppm/&#xb0; C. is disclosed. The copolyimides are prepared from alicyclic dianhydrides, aromatic cardo diamines, and aromatic diamines containing free carboxyl groups. The substrates are manufactured from solutions of the copolyimides containing multifunctional epoxides in the form of single layer films, multilayer laminates and glass fiber reinforced composite films. The substrates can be used in the construction of flexible optical displays, and other microelectronic and photovoltaic devices that require their unique combination of properties.

Thermally stable, low birefringent copolyimide films

A flexible substrate with a high optical transparency (&#x3e;80% from 400 to 750 nm) that is retained after exposure to 300&#xb0; C., near-zero birefringence (&#x3c;&#xb1;0.001), and a relatively low CTE (&#x3c;60 ppm/&#xb0; C.) is disclosed. The substrate may be manufactured as single layer, polyimide films and as a multi-layer laminate comprising a polyimide layer and a thin glass layer. The polyimides may include alicyclic dianhydrides and aromatic, cardo diamines. The films formed of the polyimides can serve as flexible substrates for optical displays and other applications that require their unique combination of properties.

Thermally stable, flexible substrates for electronic devices

The present invention is directed toward transparent films prepared from soluble aromatic copolyamides with glass transition temperatures greater than 300 C. The copolyamides, which contain pendant carboxylic groups are solution cast into films using N,N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidinone (NMP), or other polar solvents. The films are thermally cured at temperatures near the copolymer glass transition temperature. After curing, the polymer films display transmittances &#x3e;80% from 400 to 750 nm, have coefficients of thermal expansion of less than 20 ppm, and are solvent resistant. The films are useful as flexible substrates for microelectronic devices.

Films with optical transmittance of &#x3e;80% between 400 and 750 nm and with coefficient of thermal expansion less than 20 ppm/&#xb0; C. are prepared from aromatic polyamides that are soluble in polar organic solvents yet have glass transition temperatures &#x3e;300&#xb0; C. The films are cross-linked in the solid state by heating at elevated temperatures for short periods of time in the presence of multifunctional epoxides. Surprisingly, the optical and thermal properties of the films do not change significantly during the curing process. The temperature required for the crosslinking process to take place can be reduced by the presence of a few free, pendant carboxyl groups along the polyamide backbones. The films are useful as flexible substrates for electronic displays and photovoltaic devices.

Aromatic polyamide films for solvent resistant flexible substrates

Solvent resistant, transparent films prepared from solutions of aromatic polyamides and multi-functional carboxylic acids in polar aprotic solvents are described herein. Solvent resistance is achieved by heating the films for a short time above 300&#xb0; C. near the polyamide Tg. The films have CTEs less than 40 ppm/&#xb0; C. and are optically clear displaying transmittance above 75% between 400 and 750 nm. The films are useful as substrates for flexible electronic devices.

Solvent resistant, aromatic polyamide films for transparent flexible substrates

The present disclosure, in one aspect, relates to a polyamide solution including an aromatic polyamide and a solvent, wherein the aromatic polyamide includes at least two types of constitutional units, and a change rate of coefficient of thermal expansion (CTE) of a cast film produced by casting the polyamide solution on a glass plate and CTE of the same cast film after being subjected to a heat treatment at temperature of 200&#xb0; C. to 450&#xb0; C. (=CTE after heat treatment/CTE before heat treatment) is 1.3 or less.

Solution of aromatic polyamide for manufacturing display element, optical element, illumination element or sensor element

Films with optical transmittance of &#x3e;80% between 400 and 750 nm and with coefficient of thermal expansion less than 20 ppm/&#xb0; C. are prepared from aromatic polyamides that are soluble in polar organic solvents yet have glass transition temperatures &#x3e;300&#xb0; C. The films are crosslinked in the solid state by heating at elevated temperatures for short periods of time in the presence of multifunctional epoxides. Surprisingly, the optical and thermal properties of the films do not change significantly during the curing process. The temperature required for the crosslinking process to take place can be reduced by the presence of a few free, pendant carboxyl groups along the polyamide backbones. The films are useful as flexible substrates for electronic displays and photovoltaic devices.

A negative birefringence film prepared from a poly(aryletherimide) which is the reaction product of a dianhydride and a diamine, where the dianhydride is 4,4'-[4,4&#x2032;-(p-phenyleneoxy)isopropylidene]bis(phthalic anhydride) (BisADA), bis(3,4-dicarboxyphenyl)ether dianhydride (ODPA), 4,4&#x2032;-bis(3,4-dicarboxyphenoxy)biphenyl dianhydride (BPEDA), 1,4-bis(3,4-dicarboxyphenyloxy)phenyl dianhydride (BPQDA), 3,3&#x2032;,4,4&#x2032;-tetracarboxylicbiphenyl dianhydride (BPDA), or 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride (6FDA), alone or a mixture with one or more of:

Poly(aryletherimides) for negative birefringent films for LCDs

A class of soluble poly(aryletherimides) (PAEIs) having flexible backbones, useful in the manufacture of polymeric optical films are disclosed. The poly(aryletherimides) are dissolved in organic solvents, such as ketones and ketone solvent mixtures and coated on variety of substrates such as triacetyl cellulose (TAC), to form clear thin-layer films which display negative birefringence. The thin films can serve as compensation layers in liquid crystal displays (LCDs), and can be combined with other types of optical films, such as polarizers, brightness enhancement films, or other compensation films, to from multi-layered films that are especially useful in the manufacture of LCDs.

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Copley, OH, United States of America

Limin Sun