KH-550 vs KH-560 vs KH-570: Which Silane Coupling Agent Do You Need?
Key takeaways
- KH-550 is an amino silane (CAS 919-30-2), KH-560 an epoxy silane (CAS 2530-83-8) and KH-570 a methacryl silane (CAS 2530-85-0).
- Match the organic group to your resin: KH-570 for free-radical cure, KH-560 for epoxy and polyurethane, KH-550 as an amine-functional adhesion promoter.
- China reference prices on 11 November 2026: about RMB 23.5, 32.5 and 26/kg for KH-550, KH-560 and KH-570 respectively. Not SUNCHEM quotations or FOB export prices.
- Order by CAS number, ask for measured purity, colour, water and chloride, and keep drums sealed. KH-570 also needs protection from heat and light.
By David, Founder & Sales Director, SUNCHEM — 25 years in chemical export sales.
Published: November 2026
KH-550 vs KH-560 vs KH-570 is really a choice between three organic groups. All three silanes bond glass, silica and mineral fillers to polymers; what differs is the group that reacts with the resin. Free-radical systems point to KH-570, epoxy and polyurethane systems to KH-560, and amine-functional adhesion promotion to KH-550. "KH" is a trade designation, not a specification, so confirm the chemical name and CAS number on every quote, certificate of analysis (COA) and drum label.
Contents
Product comparison: chemistry, uses and substitution
A silane coupling agent has two ends. The alkoxy groups on silicon hydrolyse to silanols, which bond to glass, silica and many mineral surfaces. The organic group at the other end has to react with, or mix into, your polymer. If it does not match the resin, you pay for the silane without getting the adhesion.
| KH-550 | KH-560 | KH-570 | |
|---|---|---|---|
| Chemical name | 3-Aminopropyltriethoxysilane | 3-Glycidoxypropyltrimethoxysilane | 3-Methacryloxypropyltrimethoxysilane |
| CAS number | 919-30-2 | 2530-83-8 | 2530-85-0 |
| Functional group | Primary amine (basic) | Epoxy (glycidoxy) | Methacrylate (C=C double bond) |
| Alkoxy group / by-product | Ethoxy / ethanol | Methoxy / methanol | Methoxy / methanol |
| Main applications | Adhesion promoter in silane-terminated polyether and polyurethane sealants and in primers; filler and pigment treatment | Filler treatment and adhesion in epoxy, urethane, melamine, EPDM and polysulfide systems; adhesives, sealants, coatings | Glass-fibre-reinforced and filler-modified plastics; co-monomer in binders; free-radical-curing adhesives, sealants and primers |
| Can it replace the others? | Sometimes, in epoxy and polyurethane systems (trial against KH-560); not in free-radical cure | Often the first alternative to KH-550 when the amine shortens pot life or raises pH; trial first | Not a drop-in for the other two; it is the one that copolymerises in free-radical cure |
Chemical data and applications are taken from producers' technical data sheets and the Chinese industry standards listed under Sources. Always check them against your supplier's own technical data sheet (TDS).
So the three are not interchangeable. If you want to swap KH-550 for KH-560 in an epoxy or polyurethane system, run a side-by-side trial in your own formulation: cure speed and adhesion will change, and neither replaces KH-570 in free-radical cure. The alkoxy group matters too: methoxy silanes (KH-560, KH-570) react faster than the ethoxy KH-550 and release methanol instead of ethanol. For silica in sulfur-cured tyre treads, none of the three is the usual choice; see our note on silanes for rubber and tyre applications.
Indicative prices in China (11 November 2026)
| Product | Domestic China price, about (RMB/kg) | USD assessment, range (USD/kg) |
|---|---|---|
| KH-550 | 23.5 | 3.04–3.17 |
| KH-560 | 32.5 | 4.23–4.36 |
| KH-570 | 26 | 3.30–3.57 |
Source: a Chinese industry price-assessment service, figures for 11 November 2026, checked by SUNCHEM. Latest verified assessment checked on 12 November 2026. RMB figures are approximate domestic China delivered-price mid-points including VAT; the separately displayed USD assessment ranges exclude 13% VAT. These dated assessments are not current quotations.
Treat these numbers as a market reference, not an offer. They are not SUNCHEM quotations and not FOB export prices: an export price must also cover export packaging, any dangerous-goods handling, inland freight, port charges and documents, and China taxes domestic and export sales differently. Prices also move with time, grade and volume. The KH-550 assessment assumes at least 97% content; higher-purity grades, small lots and small packs usually cost more. Compare offers on the same specification and packaging; our guide on how to compare Chinese silane suppliers covers what else to check.
Quality standards and what to ask for on the COA
China has a chemical industry standard for each family, all in force since 1 July 2016: HG/T 4892-2016 for amino silane coupling agents (KH-550), HG/T 4893-2016 for epoxy silane coupling agents (KH-560) and HG/T 4894-2016 for unsaturated silane coupling agents (KH-570). Each sets requirements, test methods, inspection rules, and marking, packaging and storage rules for several products. They are recommended standards, so ask which standard and grade the COA refers to, and write tighter limits into the contract if you need them. For each lot, ask for measured values rather than "conforms":
| Indicator | What it tells you | What to ask for |
|---|---|---|
| GC purity | Share of the main molecule measured by gas chromatography (GC); the rest is by-products or oligomers | Measured %; international data sheets typically state more than 97% |
| Colour (Pt-Co) | Good product is a clear, near-colourless liquid; rising colour can point to impurities or ageing | Limit and measured value |
| Water | Water in the drum starts hydrolysis before you use the product, which can show up as haze or higher viscosity | Karl Fischer result, and how the drum is sealed |
| Hydrolysable chloride | Depends on the production route; often specified for electronics and metal-contact uses | Measured mg/kg; published KH-570 limits are typically below 30 mg/kg |
| Epoxy content (KH-560) | Confirms the epoxy ring is intact and reactive | Measured %; producers' data sheets give about 17.5% |
Density and refractive index are useful quick identity checks. Also make sure the CAS number matches: 3-aminopropyltrimethoxysilane (CAS 13822-56-5) is a different, methoxy-based amino silane, not KH-550. It reacts faster and releases methanol, so put the CAS number on your purchase order.
Packaging, storage and shelf life
Common packs are 25 kg plastic drums, 180–200 kg drums and 950–1,000 kg IBCs, with 5 kg pails for small orders. All three silanes react with moisture, so keep them in the sealed original drum, in a cool, dry, ventilated area away from heat; a typical storage specification is no more than 30 °C and below 75% relative humidity. Reseal part-used drums promptly according to the product-specific SDS/TDS and manufacturer's handling instructions. Do not assume a nitrogen blanket is suitable: methacryloxy silanes such as KH-570 may need oxygen to maintain inhibitor effectiveness, so follow the manufacturer's inhibition and oxygen guidance.
Published shelf life is usually 12 months unopened, but figures vary: the KH-570 data we reviewed range from 6 to 24 months. Ask for the supplier's figure and the manufacturing date on the label and COA. Product past its date is not necessarily unusable, but re-test it first.
KH-570 needs extra care. Its methacrylate double bond can polymerise, and producers describe it as light- and heat-sensitive. Reagent grades are typically sold stabilised with BHT, a polymerisation inhibitor; ask whether your industrial grade contains one, keep it away from sun and peroxides, and avoid long storage in hot warehouses or containers. Haze, rising viscosity or gel mean stop and test.
Shipping classes differ too. KH-550 usually ships as a corrosive (UN 2735, Class 8); KH-560 is classified differently by different producers (for example UN 3082 or UN 1993), so book freight from your own supplier's safety data sheet (SDS). Our article on silane packaging, storage and export covers drums, IBCs and dangerous-goods paperwork in more detail.
About SUNCHEM
SUNCHEM is a China-based specialty chemicals supply-chain partner for international buyers. For KH-550, KH-560 and KH-570 we can help you discuss which grade fits your resin system, coordinate TDS, SDS and COAs from producers, compare Chinese suppliers' offers on the same specification and packaging, and handle quotation requests. Specific services, specifications and supply terms are confirmed for each enquiry.
Email david@sunchemgroup.com or use our contact page.
More silane and silicone guides are in our Silicones & Silanes section. If you also buy silicone fluids, see our pages for polydimethylsiloxane fluid and cyclopentasiloxane.
Sources
- National Public Service Platform for Standards Information: HG/T 4892-2016 Amino silane coupling agents
- HG/T 4893-2016 Epoxy silane coupling agents (chemical industry standard of the People's Republic of China, in force since 1 July 2016)
- National Public Service Platform for Standards Information: HG/T 4894-2016 Unsaturated silane coupling agents
How this guide was made: chemical names, CAS numbers, properties, applications and handling notes come from the Chinese industry standards above and from producers' technical data sheets; prices come from a Chinese industry price-assessment service. It consolidates information from three earlier SUNCHEM notes on silane coupling agents. This article was drafted with AI assistance and reviewed by SUNCHEM before publishing.
