In the addition-cure LSR glass-cloth coating spectrum, the "vinyl PDMS molecular weight distribution" and "H-silicone crosslinker active-H density" jointly dictate wetting-spread speed on glass-fiber/sponge, post-vulc shear-bond strength at fiber interface, and "second-level cure" window for high-speed continuous production. Conventional RTV condensation coatings need 24h room-temp cure—extremely slow; standard LSR cures fast but tear <5kN/m and needs primer for glass. As glass-fiber coated fabric (fire curtain/expanding seal), sponge coating (aging-resistant breathable), and industrial conveyor belt demand "1:1 easy-mix, 15Pa·s low-visc fast-wet, 31A hardness, 10kN/m tear, 48h RT pot-life, 9-month shelf," sourcing a transparent/semi-transparent, A/B=1:1, A 15/B 15Pa·s, density 1.09g/cm³, 3.5MPa tensile, 400% elongation, 200kg drum/20L pail product has become the core gap for domestic glass-cloth coating LSR localization.
Addressing this "fiberglass coat" pain point,
Anhui IOTA Silicone Oil Co., Ltd. (IOTA) officially launches
Fiberglass-Coated Silicone Rubber IOTA LSR 3430 (mid-hardness coating-dedicated two-part addition LSR in IOTA 34 series). Characterized by "transparent, A/B=1:1, A 15/B 15Pa·s, 31 Shore A, density 1.09g/cm³, 3.5MPa tensile, 400% elongation, 10kN/m tear, 48h pot-life@25℃, recommend meter-mix + vacuum degas, ≤32℃ original 9-month shelf, 200kg steel/20L PE, no amine/sulfur/tin," and backed by "vinyl PDMS fast crosslink + graded H-silicone cure + glass-fiber self-bond," it serves as the "coating silicone anchor" for glass-cloth/sponge coating, fire-expanding seals, and industrial conveyor belt covering.
Molecular Architecture: Vinyl PDMS + Graded H-Crosslink + Glass-Fiber Self-Bond 3D Logic
The core competitiveness of IOTA LSR 3430 stems from its "vinyl-terminated PDMS base (A) + H-silicone crosslinker + Pt catalyst + fumed silica reinforcement" two-part architecture:
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Vinyl PDMS Fast Crosslink: A-component vinyl gum hydrosilylates with B Si-H under Pt at elevated temp—seconds-level cure (typical 100℃×tens of sec tack-free); vinyl density matches 15Pa·s low-visc for deep fiber penetration without sag.
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Graded H-Crosslink: B H-silicone active-H density precisely tuned—crosslink network forms gradient from surface to inner; surface skins first (anti-stick), inner continues reacting for deep glass-fiber anchoring; post-cure tear 10kN/m (above series 3425's 8), survives repeated flex.
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Glass-Fiber Self-Bond: Built-in adhesion promoter (similar mechanism to prior IOTA 3954 but optimized for E-glass) forms Si-O-Si covalent with glass surface—peel breaks rubber not interface, no KH-560 primer needed.
Performance Leap: From "Condensation RTV 24h" to "Addition Sec-Cure 10kN/m"
Incorporating IOTA LSR 3430 enables qualitative leaps:
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Glass-Fire Curtain: Fiberglass cloth dip 15Pa·s → 100-120℃ oven 30-60sec tack-free → roll; 50-100μm coat, intumesces on fire for insulation, flexible foldable at ambient.
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Sponge Coating: Open-cell PU sponge dip/knife-coat → 120℃×2min cure; silicone fills cell walls, breathable water-repellent, UV-aging resistant, for auto seat vent/filtration.
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Industrial Conveyor Belt: Glass-fiber mesh coat → heat cure → smooth wear-resistant non-stick surface, fits food/pharma lines.
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Intumescent Seal: Blend with expandable graphite/vermiculite coat on glass cloth—silicone ceramifies + expands on fire, dual barrier.
Application Penetration: From Fire Curtain to Food Conveyor
IOTA LSR 3430 covers sectors triply sensitive to "fast vulc + glass self-bond + mid-hard high-tear":
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Building Fire: Fire-roll door glass-fabric, intumescent seals, damper gaskets.
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Auto Interior: Sponge breathable coat, seat vent pad, acoustic material laminate.
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Industrial Conveyor: Food-grade belt (FDA-compliant blend needed), antistatic silicone-glass tape for electronics.
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New Energy: Battery-pack fire blanket coating, charging-pile heat-shield curtain.
IOTA Technical Guide: Meter-Mix + Vac Degas, No Amine/Sulfur/Tin
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Mixing: A:B=1:1 by weight—strongly recommend meter-mix pump (no air entrain); if hand-stir introduces bubbles, vacuum degas (-0.095MPa×3-5min).
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Cure: Heat fast—typical 100-120℃ tunnel tens of sec tack-free; thick parts can RT 48h full cure (within pot-life); higher temp = faster, but contact with amine/sulfur/tin molds inhibits cure.
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Substrate Prep: Preheat glass cloth to drive moisture (120℃×10min); sponge surface dry, no mold-release; for stronger bond pair with IOTA 3954.
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Taboo Red Line: No amine/sulfur/organotin contact—Pt catalyst poison causes no-cure; uncured silicone removable with hydrocarbon solvents (heptane/toluene/white oil), NOT ketones/alcohols.
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Storage: 55-gal steel drum (200kg) / 20L PE pail (20kg); ≤32℃ original unopened; shelf 9 months (from prod date), retest appearance/viscosity/cure and extend if qualified; general chemical manage.
Industry experts note that under building fire-code upgrades, NEV battery fire-blanket mandates, and industrial conveyor "no-primer + sec-cure" trends, glass-cloth coating LSRs are upgrading from "Momentive/Wacker/Shin-Etsu import followers" to "fast-vulc self-bond reference coating rubbers." IOTA LSR 3430, with its "1:1 mix + 15Pa·s + 31A + 10kN/m tear + 48h pot-life + 9-month shelf" hard metrics,
fills the domestic supply chain gap for glass-cloth coating LSRs in fire/conveyor/NEV fields, providing a mass-producible path to replace imported Momentive LR, Wacker ELASTOSIL® LR for downstream coaters and fire-material enterprises. This confirms domestic coating LSRs are advancing steadily along "condensation RTV → general addition → glass-self-bond fast-vulc type," with growing technical say in glass-fiber coating key materials.
