1、 Molecular structure and properties of polybutyl titanate
Polybutyl titanate (ld-1090) is an oligomer compound formed by condensation reaction of several butyl titanate units. Its molecular structure is usually composed of titanium oxide bond (Ti-O) and butoxy group (C4H9O -) alternately connected. Compared with the traditional monomer butyl titanate (such as tetrabutyl titanate, the molecular formula is Ti (OC4H9) 4), the oligomer structure of ld-1090 gives it higher molecular weight and more complex crosslinking network. This structural feature makes it show the following core characteristics in the coating:
1. multi functional group reactivity: each titanium atom can combine multiple organic groups to provide more reaction sites and form chemical bonds with resins, fillers, etc.
2. excellent thermal stability: the oligomer structure is not easy to decompose at high temperature, and can withstand the environment above 300 ℃. It is suitable for heat-resistant coatings.
3. hydrolysis stability: compared with monomer butyl titanate, ld-1090 is less sensitive to moisture and has more relaxed storage and processing conditions.
4. solubility and dispersibility: soluble in alcohol, ether, benzene and other organic solvents, and can effectively disperse inorganic fillers (such as titanium dioxide, aluminum powder) to reduce agglomeration.
2、 Core functions of polybutyl titanate in coatings industry
1. improve coating adhesion and mechanical strength
The titanium oxygen bond of ld-1090 can react with hydroxyl (-oh) on the surface of metal, glass and other substrates to form stable ti-o-si or ti-o-m (metal) bonds, which significantly enhance the interface adhesion between the coating and the substrate. For example, adding 0.5% -1.5% ld-1090 to automotive primer or building exterior wall coating can improve the wet adhesion by more than 30%, and significantly enhance the peel resistance.
In addition, ld-1090 can also be crosslinked with the active groups (such as hydroxyl and amino) of resins (such as epoxy resin and polyurethane), forming a three-dimensional network structure, and improving the hardness (up to 2H) and wear resistance of the coating.
2. enhance heat resistance and corrosion resistance
In high-temperature coatings (such as industrial equipment protective paint and automobile exhaust pipe coating), ld-1090 plays a role through the following mechanisms:
Thermal stability: ld-1090 decomposes into titanium dioxide (TiO2) at high temperature to form a dense ceramic protective layer to block the penetration of oxygen and corrosive medium.
Synergistic corrosion protection: when combined with aluminum powder or zinc powder, ld-1090 can promote the directional arrangement of metal particles, form a "labyrinth effect", and extend the diffusion path of corrosive medium. The experiment shows that the corrosion resistance life of aluminum powder coating containing ld-1090 can reach more than 2000 hours in salt spray test.
3. optimize the weather resistance and decoration of the coating
UV shielding: the titanium oxide structure of ld-1090 has excellent UV absorption ability (wavelength 200-400 nm), which can reduce the chalking and fading of the coating caused by photoaging.
Gloss and leveling: as a leveling agent, ld-1090 can reduce the surface tension of the coating, promote the uniform spreading of the coating, reduce orange peel, shrinkage and other defects, and give the coating high gloss (60 ° gloss>90) and rainbow effect.
4. promote solidification and energy saving
In polyester enamelled wire paint or silicone resin paint, ld-1090 as a curing accelerator can reduce the baking temperature (e.g. from 200 ℃ to 150 ℃) and shorten the curing time by 30% -50%. The mechanism is to reduce energy consumption and improve production efficiency through the condensation polymerization of Lewis acid catalytic resin with titanium atom.
3、 Typical application scenarios and technical cases
1. high temperature resistant industrial coatings
Formula example: epoxy resin (40%), ld-1090 (1.2%), aluminum powder (15%), solvent (surplus).
Performance: the coating has no crack after continuous working at 500 ℃ for 100 hours, and its salt spray resistance reaches 2500 hours. It is suitable for petrochemical pipelines, boilers and other equipment.
2. environment friendly waterborne coatings
Technical breakthrough: through the blending modification of ld-1090 and waterborne polyurethane, the pain points of poor adhesion and water resistance of waterborne coatings were solved. After adding 1% ld-1090, the adhesion of the coating to PVC substrate was improved from level 2 to level 0 (cross cut method), and the water immersion time was extended from 24 hours to 72 hours.
3. functional special coatings
Antistatic coating: ld-1090 is compounded with conductive fillers (such as carbon nanotubes) to form a conductive network, and the surface resistivity can be reduced to 10 Ω/sq, which is used for the coating of electronic plants and medical equipment.
Self cleaning coating: ld-1090 is compounded with nano titanium dioxide to decompose surface pollutants through photocatalytic action, which is suitable for building curtain walls and solar panels.
4、 Technical challenges and future directions
1. environmental protection trend: develop low VOC ld-1090 derivatives to meet the environmental protection requirements of waterborne coatings and high solid content systems.
2. multi function integration: give ld-1090 additional functions such as flame retardant and antibacterial through molecular design, and expand its application in marine coatings, food packaging and other fields.
3. intelligent application: ld-1090 based intelligent coating is developed in combination with Internet of things technology to realize temperature response discoloration or corrosion self-warning function.
5、 Summary
With its unique oligomer structure and multi-functional group characteristics, polybutyl titanate shows irreplaceable technical value in the coating industry. Ld-1090 is gradually becoming the core additive of high-performance coatings, from improving adhesion to realizing high-temperature protection, from optimizing decoration to promoting environmental protection. In the future, with the deep integration of material science and application needs, its application boundary will be further expanded to provide continuous power for the innovation of coating technology.
Yangzhou Lida Resin Co.,Ltd. Copyright(C) 2019
