In the process of rapid development of photopolymer materials towards higher efficiency and environmental friendliness, functional materials with rapid reaction activity and excellent chemical stability are becoming the core elements for UV/electron beam curing coatings, semiconductor photomasks, and high-performance release coatings, etc. The product we have launched, mercapto group modified organosilicon 280, as a modified organosilicon material containing active mercapto functional groups, demonstrates significant industrial application value in numerous high-end application fields such as photopolymer anti-sticking coatings, semiconductor coatings, optical fiber coating, and paper isolation agents, etc., thanks to its unique "mercapto-ene click chemistry" reaction characteristics, UV light-induced rapid crosslinking, and good compatibility with various substrates.


I. Core Physical and Chemical Properties of the Product


Product mercapto group modified organosilicon 280 is a colorless transparent liquid with a low special odor of mercapto functional groups. This product series is available in two specifications: IOTA-280-1 and IOTA-280-3. At 25 degrees Celsius, the viscosity is 100 to 200 millipascal-seconds, and the volatile matter does not exceed 2% at 150 degrees Celsius for three hours. The mercapto content of IOTA-280-1 is 3.50% to 3.70%, and that of IOTA-280-3 is 3.00% to 3.10%. The core reaction characteristics of this product originate from the mercapto functional groups in the molecule. These functional groups can react rapidly with unsaturated double bonds in compounds containing vinyl groups under the presence of a photoinitiator, forming stable thioether bonds. This reaction path has the following key advantages: extremely fast curing rate, with reported curing rates of 1-second photopolymerization for systems containing mercapto/alkene groups in literature, without the need for heating or precious metal catalysts, facilitating the processing of heat-sensitive substrates and the layout of high-speed production lines. During the photopolymerization process, no small molecule by-products are released, avoiding the formation of bubbles and shrinkage cavities. The mercapto-ene click chemistry has high selectivity and conversion rate, resulting in a regular crosslinked network structure, giving the cured film excellent mechanical properties and chemical resistance.


II. Core Reaction Characteristics and Application Value


The application value of product mercapto group modified organosilicon 280 is rooted in the unique reaction chemistry of mercapto groups. Under the irradiation of light with a wavelength of 200 to 400 nanometers, the photoinitiator decomposes to produce free radicals, and the mercapto groups rapidly react with the carbon-carbon double bonds in vinyl silicone oil or resin, forming stable thioether bonds. This reaction path has the following key advantages: extremely fast curing rate, with reported curing rates of 1-second photopolymerization for systems containing mercapto/alkene groups in literature, without the need for heating or precious metal catalysts, facilitating the processing of heat-sensitive substrates and the layout of high-speed production lines. No small molecule by-products are released during the photopolymerization process, avoiding the formation of bubbles and shrinkage cavities. The mercapto-ene click chemistry has high selectivity and conversion rate, and the resulting crosslinked network structure is regular, giving the cured film excellent mechanical properties and chemical resistance.


III. Main Application Areas


Product mercapto group modified organosilicon 280, with its efficient photopolymerization characteristics and excellent film-forming performance, can play an important role in the following key application areas:


1. UV/electron beam curing anti-sticking coatings and release agents. The product is an excellent material for preparing UV/electron beam curing anti-sticking coatings and can be used as release agents and paper isolation agents. Compared with traditional solvent-based, emulsion-based, and platinum-catalyzed addition-based isolation agents, this system does not require heating and can be rapidly cured at room temperature, especially suitable for the production of pressure-sensitive adhesive products on polyethylene, polypropylene, and polyester films with heat sensitivity.


2. UV/electron beam curing crosslinking agents for semiconductor coatings and optical fiber coatings. The product can be used as a crosslinking agent in UV/electron beam curing systems for preparing semiconductor coatings and optical fiber coatings. It has been reported that the photopolymerization of the light-curing optical fiber coating prepared by mixing mercapto group silicone oil and vinyl silicone oil has an extremely fast curing rate and no hydrogen gas release, avoiding the formation of bubble defects. In the semiconductor field, thiol/vinyl type siloxane coatings can solidify into elastic modulus within seconds under the irradiation of high-pressure mercury lamps, with excellent resistance to cold and heat shock ranging from -50 to 200 degrees Celsius. They have good adhesion to materials such as silicon, ceramics, and copper, and help protect semiconductor structures and leads from damage during packaging and usage.


III. Improvement of the curing rate of condensation type sulfurized silicone rubber. This product can be used to improve the curing rate of common condensation type room-temperature cured silicone rubber, overcoming the problem of poor adhesion of photopolymer. Traditional condensation type room-temperature cured silicone rubber has a long deep curing time and is difficult to achieve continuous and rapid curing operations. However, after adding a photopolymer system containing thiol and vinyl groups, it can not only accelerate the curing speed but also overcome the drawback of poor adhesion of photopolymer.


IV. Metal corrosion inhibitors and temperature-resistant durable materials. When thiol silicone oil is combined with the curing agent, the product's temperature resistance and durability can be improved. Adding it to the coating can prevent caking and treating wool can give it durable shrink resistance. Mixing thiol silicone oil with dimethyl silicone oil can also improve the thermal oxidation stability of the latter and be used as a metal corrosion inhibitor and release agent.


IV. Application methods and process suggestions


Mix the product modified with thiol group-containing organosilicon 280 with vinyl silicone oil or resin in the prescribed ratio and mix evenly. Add the photoinitiator (recommended dosage is 5% to 10% of the total weight of the system), stir evenly, and apply it to the substrate surface. Irradiate it with a UV lamp at a wavelength of 200 to 400 nanometers for one to ten seconds to achieve crosslinking and solidification. It is recommended to conduct a small-scale test before curing to determine the optimal ratio and irradiation time.


V. Packaging specifications and storage conditions


Product modified with thiol group-containing organosilicon 280 is available in 1 kg and 5 kg plastic drums. Other specifications can be provided according to customer requirements. This product is non-flammable and non-explosive. Store it in a cool and dry place, keep it sealed. The shelf life is six months. After the expiration date, recheck the product's properties before use.


VI. Quality assurance and market value


Product modified with thiol group-containing organosilicon 280 has established a strict quality control system during production. It conducts full-process detection of key indicators such as appearance, odor, viscosity, and volatile matter to ensure consistency and reliability between batches. As photopolymer technology continues to develop towards high-speed, environmentally friendly, and high-performance directions, the demand for thiol group-modified organosilicon intermediates with high thiol content and excellent photoreaction activity, excellent film-forming performance, and wide substrate applicability is steadily increasing. Product modified with thiol group-containing organosilicon 280, with its rapid photocuring characteristics, flexible adhesive compatibility, and wide substrate applicability, is becoming an important raw material option for UV curing release coatings, semiconductor photolithography resins, and optical fiber coatings, providing strong raw material support for promoting the technological innovation and industrial upgrading of photopolymer materials.