Polyester imide film for optoelectronic devices

The patent employs composite materials by combining diamine and dianhydride monomers to form polyimide polymers with superior comprehensive performance. The specific combination of aromatic diamines (providing heat resistance and mechanical strength) and aromatic dianhydrides (providing transparency and flexibility) creates a synergistic effect that achieves all four desired properties simultaneously, resolving the contradiction between comprehensive performance and manufacturing cost.

The patent applies parameter changes by systematically varying the chemical structures of monomers (different aromatic rings, substituent groups, and molecular weights) to optimize the balance between comprehensive performance and manufacturing cost. By adjusting parameters such as the type of aromatic ring, position of substituents, and chain length, the invention achieves high transparency, heat resistance, mechanical strength, and flexibility while maintaining cost-effectiveness through selective monomer combinations.

The patent applies local quality by assigning different functional roles to specific molecular segments within the polyimide structure. The aromatic diamine portions (with rigid aromatic rings) provide mechanical strength and flexibility, while the aromatic dianhydride portions (with specific carbonyl group arrangements) provide transparency and optical performance. This localized functional distribution within the polymer chain resolves the contradiction between optical performance and mechanical properties.

The invention uses composite material principles by creating a polyimide polymer that integrates two distinct functional components: diamine units contributing mechanical strength and flexibility, and dianhydride units contributing transparency and optical properties. The alternating copolymer structure ensures both sets of properties are present and synergistically integrated, resolving the trade-off between optical performance and mechanical strength.

The patent applies this principle by using commercially available, relatively inexpensive diamine and dianhydride monomers as starting materials. Rather than employing complex, expensive specialty chemicals, the invention uses readily obtainable aromatic diamines and dianhydrides that can be procured at lower costs, thereby achieving high heat resistance and durability without proportionally increasing production cost.

The invention uses parameter changes by selecting monomers with optimal balances between performance and cost. By carefully choosing aromatic rings, substituent types, and molecular weights within specific ranges, the patent achieves high heat resistance and durability while avoiding excessively expensive materials. The parameter optimization ensures cost-effective synthesis of high-performance polyimide polymers.