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.

The objective of the present invention is to provide a spiral-type separation membrane element having superior oxidant resistance relative to the prior art, and a salt-blocking rate that tends not to decrease. The spiral-type separation membrane element is characterized in including: a supply-side flow-path material; a composite semipermeable membrane in which a skin layer is formed on the surface of a porous support, the skin layer containing a polyamide resin obtained by interfacial polymerization of a polyfunctional amine component and a polyfunctional acid halogen component; and a permeation-side flow-path material, wherein the polyfunctional amine component contains N,N-dimethyl-meta-phenylenediamine and the permeation-side flow-path material has a porosity of 40 to 75%.

The objective of the present invention is to provide a spiral-type separation membrane element having superior oxidant resistance relative to the prior art, and a salt-blocking rate that tends not to decrease. The spiral-type separation membrane element is characterized in including: a supply-side flow-path material; a composite semipermeable membrane in which a skin layer is formed on the surface of a porous support, the skin layer containing a polyamide resin obtained by interfacial polymerization of a polyfunctional amine component and a polyfunctional acid halogen component; and a permeation-side flow-path material, wherein the polyfunctional amine component contains N,N-dimethyl-meta-phenylenediamine and the permeation-side flow-path material has a porosity of 40 to 75%.

In the process of forming the meta-aramid polymer, alkyl is introduced among macromolecules through alkylation, such that adjacent molecular chains are linked by a chemical bond so as to form a grid structure. A coating slurry prepared from the meta-aramid polymer with a grid structure, a pore-forming agent and a cosolvent are coated on the surface of a polyolefin porous separator so as to obtain a high-performance lithium battery coated separator. Compared with a coated separator prepared by a traditional method, the coated separator prepared by the present disclosure has higher heat resistance, thermal shrinkage resistance and puncture strength, has better wettability with an electrolyte, and thus can prolong a cycle life of a battery. The coated separator of the meta-aramid with a grid structure can further improve the oxidation resistance, is beneficial to realizing high potential and improves energy density.