Silicones: Production route
Every silicone starts with one copper-catalysed reaction
What this tab covers How it is made: the main production routes or, for product families, the main product types and technologies, compared on share of supply, inputs per tonne, plant scale, yield, co-products and unit cost.Every commercial silicone starts with the direct process, which joins silicon metal and methyl chloride. The resulting chlorosilanes are distilled and hydrolysed to siloxane intermediates (DMC), which are polymerised. The family then splits into four product types: fluids and emulsions, elastomers (HTV, LSR and RTV), resins and coatings, and functional silanes. Upstream integration into silicon metal and methyl chloride decides cost; downstream formulation and qualification decide margin.
Routes compared
| Route | Share of supply | Inputs per tonne | Typical scale | Yield | Co-products | Unit cost |
|---|---|---|---|---|---|---|
| Silicone fluids and emulsions (PDMS oils, antifoams, personal care) | about 30-35% of silicone volume (indicative) | about 1 t siloxane intermediate; siloxane needs about 0.44 t silicon metal and 0.95 t methanol (stoichiometric with yield losses, indicative) | upstream monomer plants 100-500 kt/yr (indicative) | direct process about 85-90% selectivity to dimethyldichlorosilane (indicative) | methyltrichlorosilane, trimethylchlorosilane and high boilers (used for resins and fumed silica) | DMC cash cost about CNY9,000-10,000/t in China in 2025 (derived, indicative: 0.44 t Si at about CNY8,500-9,000/t plus 0.95 t methanol plus conversion) |
| Silicone elastomers (HTV, LSR, RTV sealants) | about 35-40% (indicative) | gum plus 20-40% fumed silica; platinum catalyst at ppm levels (indicative) | compounding plants 10-100 kt/yr | not published | acetic acid or oxime from some RTV cures | finished products typically $4,000-10,000/t (indicative) |
| Silicone resins and coatings | about 10% (indicative) | methyltrichlorosilane and phenyl silanes (indicative) | 5-50 kt/yr | not published | HCl recycled | not published |
| Functional silanes and specialty (coupling agents, fumed silica) | about 10-15% (indicative) | trichlorosilane and organic reactants (indicative) | 5-50 kt/yr | not published | HCl | not published |
How each route works
Silicone fluids and emulsions (PDMS oils, antifoams, personal care)Cyclic or linear siloxanes are ring-opened and equilibrated with end-blockers to set chain length and viscosity, then stripped of volatiles. Emulsions are made by dispersing fluid in water.
High volume; commoditised at the DMC level.
SMM, Jun 2025; silicon and methanol tiles; indicative Silicone elastomers (HTV, LSR, RTV sealants)High-molecular-weight gums are compounded with fumed silica and cured by peroxide (HTV) or platinum-catalysed addition (LSR); RTV sealants cure at room temperature with moisture.
High value and sticky customers; needs approvals in auto, medical and construction.
indicative Silicone resins and coatingsTri- and tetra-functional chlorosilanes are co-hydrolysed into branched resins for heat-resistant paints, electrical varnishes, pressure-sensitive adhesives and masonry water repellents.
Uses direct-process co-products; specialty margins.
indicative Functional silanes and specialty (coupling agents, fumed silica)Silanes with amino, epoxy or sulphur groups couple silica to rubber in green tyres and bond glass fibre to resins; fumed silica is made by burning chlorosilanes.
Grows with green tyres and composites.
indicative Unit economics are indicative ranges from the sources named; costs move with feedstock and energy prices, plant size and region.