The role of silane coupling agent in coatings and inks


4. Silane coupling agent as hardener


Amino functional silane coupling agent can be used as hardener of traditional epoxy resin and polyurethane (ethyl) ester (usually silicone resin). They have an additional effect, that is, the silanol groups react with each other to form a silicon-oxygen bond (Si-O-Si), a process called condensation reaction. The crosslinking result of this silane coupling agent improves the strength and wear resistance of the coating due to the stable Si-O-Si silicon oxide network.


V. Silane Coupling Agent as Copolymer


Organic functional silane coupling agent is used in solvent-based resin synthesis and solvent-based coatings. Organic functional silane coupling agent can be used as copolymer in solvent-based resin synthesis, cross-linking accelerator and adhesion accelerator in solvent-based coatings. The following results can be achieved:


(1) Weatherability


(2) UV stability


(3) adhesion promotion


(4) The organic functional group Y of Chemical-Resistant silane coupling agent must react with other monomers. Cross-linking occurs through the bonding of Si-OH functional group with substrate.


Six. Silane coupling agents are applied to emulsion synthesis and waterborne coatings:


With the progress of society and the improvement of people's quality of life, in order to meet the requirements of environmental protection, more and more water is required as solvent in coatings.


Although silane coupling agents produce hydrolysis in the presence of water, this does not mean that they can not be used in water systems at all.


For example, YDH-550 aminosilane coupling agent is a very good bonding promoter and hardener. It is completely soluble in water, very stable in aqueous solution, and has many organic resin phase agents.


Organic functional silane coupling agents are applied to acrylic emulsion synthesis and waterborne coatings:


(1) Improving water resistance and solvent resistance;


(2) Improve the abrasion resistance, scratch resistance and wear resistance;


(3) Improving durability and aging resistance;


(4) Improve adhesion and hardness.


Acrylic ester and styrene monomer can be copolymerized with silane coupling agent to synthesize silane coupling agent based acrylic emulsion, so that it can be made into room temperature crosslinking curable acrylate coating (vinyl three isopropyl silane coupling agent silane coupling agent). It is a vinyl silane coupling agent used for crosslinking acrylic acid and vinyl rubber latex. Body. It can be used in OEM products and building coatings. The silane coupling agent can be easily copolymerized into the backbone of acrylic acid and vinyl latex. Hard and highly cross-linked coatings can be obtained after curing with a formula containing the recommended catalyst. The unique structure of the silane coupling agent enables it to have good stability in the water-based system and does not react or cross-link before the coating is condensed. A water-based coating formulation containing vinyl three isopropane silane coupling agent silane coupling agent silane coupling agent remained stable and effective after one year of aging. The typical step of emulsion synthesis is that the reaction is highly exothermic. Typically, only a few copolymer premixes are polymerized in the reactor, and then the remaining parts are slowly added from a buffer tank.


Typical steps are as follows:


1. Adding water, surfactant and retarder to the reactor.


2. Adding 5%-10% copolymer premix (without silane coupling agent) to the reactor.


3. Heating the mixture above to the optimum temperature that the manufacturer has, the typical temperature is controlled at about 65-75 degrees Celsius.


4. Adding all the catalysts and initiators to the reactor.


5. Controlling the adding rate of residual copolymer monomer premix to the reactor, the typical time range is 4-6 hours.


6. Additional silane coupling agent is added to the buffer tank when the pre-mixture of copolymer monomer is still 10%. The silane coupling agent and the remaining 10% copolymer monomer premix were completely mixed and continued to be added to the reactor at the controlled rate.


7. After adding the pre-mixtures of copolymer monomers, enough time is maintained to obtain the maximum degree of polymerization.


Note: 1. Delayed monomer polymerization is used to improve the properties of the emulsion. 2. If the typical dosage of 151, 172 and 570 is less than 1% of the total weight of the monomer, higher dosage may reduce the storage life of the product.


Conversion from Ipax Coupling Agent