Polyisocyanate Composition for Polyurethane Resin Properties

The patent uses a composite polyisocyanate composition containing multiple components: isocyanurate derivative of xylylene diisocyanate (5-95 parts by mass), biuret derivative of aliphatic polyisocyanate (5-95 parts by mass), and optionally polyol-modified xylylene diisocyanate (5-90 parts by mass). This composite approach combines the advantages of different polyisocyanate derivatives to achieve excellent optical characteristics, quick-drying properties, quick-curing properties, weatherability, and mechanical properties that cannot be obtained with single-component polyisocyanates

The patent optimizes the mass ratio parameters of different polyisocyanate components to achieve the desired balance of properties. Specifically, the isocyanurate derivative content is controlled at 5-95 parts by mass and biuret derivative at 5-95 parts by mass relative to 100 parts by mass of total polyisocyanate composition. This parameter optimization enables simultaneous improvement of optical characteristics, drying speed, curing speed, weatherability, and mechanical properties

The composite polyisocyanate composition strategically combines isocyanurate derivative (which provides quick-curing properties through high reactivity) with biuret derivative (which contributes to mechanical strength and optical clarity). The balanced formulation ensures that quick-drying and quick-curing properties are achieved without sacrificing optical characteristics and mechanical properties, as each component compensates for the limitations of the others

The patent assigns different functional roles to different components within the polyisocyanate composition. The isocyanurate derivative primarily provides quick-curing activity, while the biuret derivative contributes to mechanical strength and optical properties. This functional differentiation allows each component to excel at its specific function while the composite achieves overall balance across all required properties