In weatherproof waterproof sealing of building skylights and stone curtain walls, ordinary acidic silicone sealants release acetic acid during curing, easily corroding carbonate stones like marble and granite, causing surface stains and efflorescence that ruin architectural appearance. Some one-part sealants with insufficient control over penetration pollution on porous stone allow plasticizers or low-molecular substances to migrate into the stone, forming hard-to-remove stain bands, especially conspicuous on light-colored stone. Low-movement-capability sealants (e.g., 12.5 class) suffer fatigue failure under thermal and structural displacement in skylights, leading to water leakage. Ordinary sealants lack weather aging resistance; long-term UV exposure hardens, cracks and powders them, losing elastic recovery. For specifications demanding "neutral cure non-corrosive, non-staining to stone, 20-class elastic movement, weatherproof waterproof", a strictly quality-controlled neutral silicone stone sealant places long-term joint protection at the construction source. Addressing this, Anhui IOTA Silicone Oil Co., Ltd. launches Neutral Silicone Stone Sealant IOTA 997. Characterized by "one-part, neutral cure; good adhesion to marble, granite and other building materials with no pollution; good elasticity and elongation; good weather aging and high-low temperature resistance; colors black, gray or specified; standard GB/T 23261-2009 20HM; packaging 300ml cartridge, 500ml sausage; typical properties: slump vertical ≤3mm (actual 0), horizontal no deformation; extrusion ≥80ml/min (actual 373); skin time ≤3h (actual 1.2h); elastic recovery ≥80% (actual 96%); 23℃ tensile modulus ≥0.4MPa (actual 0.74); movement class 20 (actual 20); tension-compression amplitude ±20% (actual ±20%); static extension adhesion, immersion extension adhesion, cyclic extension-compression adhesion all non-destructive; staining depth ≤2.0mm (actual 0), width ≤2.0mm (actual 0); mass loss ≤5.0% (actual 3.0%); storage below 27℃ dry ventilated cool place, 12 months from production date; cannot be used as structural sealant; not for materials exuding oil/plasticizer/solvent, unventilated spaces, frosted/damp surfaces, continuous immersion; substrate surface temperature below 4℃ or above 50℃ not suitable; full cure and maximum bond strength achieved after 21 days", backed by "neutral non-stain + elastic weathering + stone compatibility", it serves as a neutral silicone stone sealant dedicated to skylight and stone engineering. System Positioning: Neutral Silicone Stone Sealant Among Sealant Families Within building sealant families, IOTA 997 is a one-part neutral-cure silicone stone sealant, distinct from silicone structural sealants (load-bearing, cannot substitute), acidic silicone sealants (release acetic acid corroding carbonate stone, causing discoloration), polyurethane sealants (limited UV resistance, prone to yellowing), and general-purpose neutral silicone weatherproof sealants (not specifically optimized for stone stain resistance). Designed for porous stones like marble, granite and skylights, IOTA 997 has 20HM movement capability (GB/T 23261-2009). It positions as a dedicated sealant for "building skylight weatherproof waterproof sealing + stone joint non-staining protection", rather than structural bearing or interior low-demand caulking. Molecular Architecture: Hydroxy-Terminated Polysiloxane + Neutral Crosslinking + Non-Stain Formulation + Elastic Siloxane Network IOTA 997 uses α,ω-hydroxy-terminated polydimethylsiloxane as base polymer, with nano-calcium carbonate reinforcing fillers, neutral crosslinker (oxime or alcohol type, no acidic release), catalyst and pigments, forming a one-part non-sag paste. The neutral cure system avoids acidic by-products like acetic acid that corrode carbonate stones, fundamentally preventing surface stains and efflorescence. Optimized formulation reduces low-molecular plasticizers and selects stone-compatible polymers, achieving actual staining depth and width of 0mm, completely solving stone pollution. The siloxane backbone provides high elongation and elastic recovery (actual 96%), adapting to ±20% displacement cycles from temperature difference and wind load in skylights; slump actual 0mm ensures no sag on vertical and overhead applications; extrusion actual 373ml/min ensures smooth application. Performance Leap: From "Acid Corrosion Stain, Low Movement Aging" to "Neutral Non-Stain Elastic Weathering" With IOTA 997, skylight and stone sealing improve: non-staining—staining depth and width actual 0mm, meeting high appearance demands of light marble and granite; elastic movement—20HM class, ±20% tension-compression amplitude, elastic recovery actual 96% (std ≥80%), cyclic extension-compression non-destructive, adapting to structural displacement; application—extrusion actual 373ml/min (std ≥80), skin time actual 1.2h (std ≤3h), slump 0mm, easy tooling; weathering life—weather aging and high-low temp resistance, immersion extension non-destructive, mass loss actual 3.0% (std ≤5.0%), long-term outdoor elasticity; broad adhesion—good adhesion to ceramics, granite, brick, wood, steel and most plastics (compatibility test needed), no primer required; 23℃ tensile modulus actual 0.74MPa (std ≥0.4) provides sufficient support while retaining flexibility. Application Penetration: From Skylight Engineering to Stone Curtain Wall Non-Stain Sealing IOTA 997 covers two core scenarios. Building skylight weatherproof waterproof sealing: roof skylight joints of glass-metal-stone combinations—emphasizing waterproofing, elastic movement and weathering; joint width per design code, surface cleaning before application. Stone curtain wall and decoration joints: exterior and interior marble, granite joints—emphasizing non-staining, anti-corrosion, elastic weathering; new materials require bond compatibility testing. ⚠️ Taboo: cannot be used as structural sealant; not for materials exuding oil/plasticizer/solvent (e.g., oiled wood); not for unventilated spaces (curing needs moisture); not for frosted/damp surfaces (poor adhesion); not for continuous immersion or year-round wet places; substrate surface temperature below 4℃ or above 50℃ not suitable; reseal unused cartridges/sausages to prevent skinning. IOTA Technical Guide: Clean Substrate, Temperature Control, 21-Day Full Cure IOTA 997 is a one-part paste, packaged in 300ml cartridge or 500ml sausage. Before application, clean substrate surface with solvent or other method to remove oil, dust and loose particles; use caulking gun to extrude sealant into joint, ensuring full fill and no air bubbles; tool before skin formation to ensure close contact; cure schedule: chemical reaction starts upon air contact from surface inward, full cure and maximum bond strength achieved after 21 days; avoid severe displacement within initial 24h; prevent touching or contamination before skin formation. Store below 27℃ in dry, ventilated, cool place; shelf life 12 months from production date; check appearance and extrudability if expired; qualified can continue use. Industry Insight: The key to neutral silicone stone sealant for skylight and stone protection is not just filling the joint, but using neutral cure for stone safety, staining for appearance quality, movement class for joint life, and elastic recovery for fatigue durability. For building and curtain wall engineers, IOTA 997 uses one one-part neutral cure silicone sealant across skylight weatherproofing and stone non-staining sealing, taking 20HM movement, zero pollution, and elastic weathering as batch-checkable anchors, reducing acidic corrosion on stone, ordinary sealant yellow staining, and low-movement cracking rework.