1 Overview

Silane oligomers are synthesized from specific silane coupling agents as the base material, combined with selected end-capping agents, catalysts, and stabilizers, resulting in a polymerization degree of 3–5. Compared to conventional silane coupling agents, they feature longer molecular chains, enhanced chain flexibility, improved system stability, and offer superior adhesion, boiling water resistance, chemical resistance, abrasion resistance, heat resistance, weatherability, and unique flexibility.

Amino silane oligomers are low-molecular-weight polymers formed by controlled hydrolysis and condensation of amino silane monomers. They combine the reactivity of organic amine groups with the excellent properties of the siloxane backbone. Compared to traditional silane monomers, they provide more uniform film formation, higher storage stability, and improved functionality, acting as a “molecular bridge” between organic systems and inorganic substrates. They hold irreplaceable value in various industrial fields such as metal surface treatment, baking paints, and waterborne coatings.

2 Applications

2.1 Metal Surface Treatment

Metal surfaces are prone to oxidation and corrosion in humid environments and exhibit weak interfacial adhesion with organic coatings and adhesives. Amino silane oligomers form a dense protective film on metal surfaces through chemical interaction while enhancing interfacial compatibility. They are key additives for metal surface modification, widely used in the treatment of steel, aluminum alloys, copper, and other metals, and are particularly suitable for environmentally friendly processes such as chromium-free passivation.

The mechanism involves two aspects: first, the siloxane groups (Si–O–Si) in the amino silane oligomer hydrolyze to form silanol groups (Si–OH), which undergo condensation with hydroxyl groups (–OH) on the metal surface, forming stable Si–O–Metal covalent bonds and creating a uniform, dense silane film. Second, the amino groups (–NH₂) are highly polar and can react with reactive groups (such as epoxy and isocyanate) in subsequent coatings or adhesives, further enhancing interfacial bonding strength.

Shenzhen Haolong New Material Technology Co., Ltd. published a patent titled A Composite Film Conversion Treatment Agent for Magnesium Alloy Surfaces and Its Application, disclosing a treatment agent consisting of three components: phosphorus-free and chromium-free A agent, B agent, and C agent. The A agent contains the silane coupling agent KH550. This treatment enables chromium-free and phosphorus-free chemical conversion, with stable performance and environmentally friendly waste liquid. The resulting film exhibits high corrosion resistance (salt spray resistance exceeding 48 hours) and good conductivity, showing promising application in the production of 3C magnesium alloy mobile phone frames.

Hefei Puqing New Material Technology Co., Ltd. published a patent titled A High-Adhesion, Low-Viscosity, Chromium-Free Fingerprint-Resistant Liquid for Galvanized Aluminum-Zinc Steel Sheets. By adding silane coupling agents KH550 and KH560 in a specific sequence, combined with a composite matrix of waterborne epoxy resin, acrylic resin, and polyurethane resin, and reinforced with nano-silicon solution, a three-dimensional crosslinking network is formed. The resulting coating shows no detachment in tape peel tests, no black spots after 120 hours of salt spray, and viscosity below 30 seconds, offering excellent corrosion resistance, conductivity, and processability, effectively resolving the black spot defect caused by coating detachment in galvanized aluminum-zinc steel sheets.

2.2 Waterborne Coatings

Waterborne coatings use water as the dispersion medium, offering environmental friendliness, solvent-free safety, and non-toxicity. They have been widely adopted in construction, furniture, automotive, and industrial anticorrosion sectors as replacements for solvent-based coatings. However, they suffer from inherent drawbacks such as poor water resistance, insufficient adhesion, and suboptimal film-forming properties. Amino silane oligomers serve as multifunctional additives to effectively address these limitations while enhancing overall coating performance, making them a key component in waterborne coating formulations, including primers, topcoats, adhesives, and sealants.

Xinlongtu Environmental Technology (Dalian) Co., Ltd. published a patent titled A Waterborne Organic-Inorganic Hybrid Zinc-Rich Coating and Its Preparation Method, disclosing a coating composition comprising water-soluble acrylic resin, dispersant, substrate wetting agent, defoamer, cosolvent, anti-settling agent, zinc powder, waterborne inorganic resin, and amino silane coupling agent. The coating forms a dense film through organic-inorganic hybrid crosslinking, providing long-term anticorrosion and durability. It also addresses issues such as cracking, sagging during application, and challenges related to zinc powder dispersion and dust pollution commonly associated with existing waterborne inorganic zinc-rich coatings.

Beijing Oriental Yuhong Waterproof Technology Co., Ltd. published a patent titled A Waterborne Asphalt Coating and Its Preparation Method, involving a composition comprising 40–80 wt% emulsified modified asphalt, 10–60 wt% polymer emulsion, 0.1–0.5 wt% amino silane solution, and 0–30 wt% filler. The resulting coating exhibits significantly improved mechanical properties compared to conventional waterborne asphalt coatings and can be used in combination with membranes for sidewall waterproofing.

Hunan Kaisili New Material Co., Ltd. published a patent titled A Catalytic Method and Application Method for Waterborne Inorganic Nanocoatings, describing a process involving mixing a coupling agent with a catalyst, adding the mixture to a nano-oxide sol, stirring and reacting at 35–70°C for 0.5–5 hours, diluting with water to achieve a solid content of 30–50%, and cooling to obtain a liquid waterborne inorganic nanocoatings. Curing is achieved through heating or by using amino silane or its hydrolysate. This method eliminates the need for pH adjustment using acids or bases, expanding the coating’s application range while improving solubility and stability.

2.3 Waterborne Baking Paints

Baking paints offer high decorative appeal and durability and are widely used in automotive, furniture, home appliances, instrumentation, and other fields. Key requirements include strong adhesion to substrates, smooth surfaces, scratch resistance, aging resistance, and chemical resistance. Amino silane oligomers function as adhesion promoters, crosslinking agents, and leveling agents in baking paints, effectively addressing common issues such as poor adhesion, inadequate leveling, and insufficient weather resistance. They are particularly compatible with mainstream baking paint systems such as epoxy, polyurethane, and acrylic resins.

Taiwan Dachamp Paint Products Co., Ltd. published a patent titled A Boiling-Water-Resistant High-Temperature Baking Glass Protective Coating and Its Preparation Method. The formulation incorporates a waterborne amino silane coupling agent, which provides strong adhesion to glass substrates and meets the requirements for adhesion and resistance to 1-hour boiling water exposure. The preparation method is characterized by simplicity, low production cost, and suitability for large-scale production.

3 Product Introduction

Wuhan Hugarise New Material Co., Ltd. offers a silane oligomer product: Amino Silane Oligomer, which is positioned as a counterpart to imported products such as Evonik Dynasylan® HYDROSIL 1151 and Momentive Silquest Y-15744.