Phthalonitrile Resin Market Size & Forecasts 2026-2035, By Segments (Type, Sales Channel, End Use Industries, Product Application), Growth Opportunities, Innovation Landscape, Regulatory Shifts, Strategic Regional Insights (U.S., Japan, China, South Korea, UK, Germany, France), and Competitive Dynamics (Cytec Industries, Huntsman Corporation, Lonza Group, Sichuan Jiuneng New Material, Shanghai Kaitai New Material)