Photoinitiator TPO CAS 75980-60-8 is also known as photosensitizer or photocuring agent, is an efficient cleavage free radical photoinitiator with a very broad absorption wavelength array, taking into consideration both surface drying and deep healing, and is used to initiate the UV polymerization reaction of the unsaturated prepolymerization system.
The item has a fast photocuring speed, and it likewise has photobleaching effect, which appropriates for deep treating of thick movies as well as non-yellowing properties of the finish. It has reduced volatility and appropriates for water-based.
Photoinitiator TPO is mainly utilized in white systems, and can be made use of in UV-curable coverings, publishing inks, UV-curable adhesives, optical fiber layers, photoresists, photopolymerization printing plates, stereolithographic materials, composite products, dental fillings, etc.
This kind of initiator has the adhering to three qualities: quick curing, resistance to yellowing, and also reduced odor.
1、It is a photoinitiator, mainly used in screen printing inks, lithographic printing inks, flexographic printing inks, and wood coatings.
TPO can be completely cured on white or high titanium dioxide pigmented surfaces.
2、It is widely used in various coatings. Because of its excellent absorption properties, it is especially suitable for screen printing inks, offset printing, flexographic printing inks, and wood coatings.
The coating does not turn yellow, the post-polymerization effect is low, and there is no residue.
3、It can also be used for transparent coating, especially suitable for products with low odor requirements. Used alone in unsaturated polyester containing styrene system, it has high initiation efficiency.
For acrylate systems, especially colored systems, it usually needs to be used in conjunction with amines or acrylamides, and also with other photoinitiators to achieve complete curing of the system. Especially suitable for low yellowing, white systems and thick film layers.
The curing. The photoinitiator TPO is used in combination with MOB 240 or CBP 393 to improve curing efficiency. It is the best extraction solvent for petroleum aromatics equipment, and it is also used as a formylation reagent in the fine chemical industry.
Photoinitiator TPO is a sort of compound that can soak up a particular wavelength of power in the ultraviolet region (250-420nm) or visible light region (400-800nm), produce cost-free radicals, cationic ions, and so on, therefore triggering monomer cross-linking and curing.
The complete name of photoinitiator TPO is UV curing photoinitiator, which can be separated into 3 categories.
Absorbing ultraviolet quanta emitted by strong ultraviolet illumination, the cross-connection effect occurs, and the liquid forms a solid film (eg, 1173, 184, 907, 369, 1490, 1700, etc.) in a fraction of a second.
Decomposition reactor: After the photoinitiator absorbs light, it changes from the ground state to the generated state, and the Norrish I effect occurs, and the covalent bond between the carbonyl group and the adjacent carbon atoms is extended, weakened and broken to form the primary group.
Recaptures hydrogen to form BP-like groups.
Mechanism of hydrogen deprivation action of photoinitiators. The photoinitiator in the excited state starts to snatch hydrogen atoms from hydrogen atoms such as active monomers and low-element prepolymers to form active groups and initiate aggregation reactions.
Cationic photoinitiators are another important photoinitiator. Including diazonium salts, diaryliodones, triarylsulfur salts, alkylsulfur salts, iron arene salts, sulfonic acid oxyketones, triarylsiloxane ethers.
Its basic function is characterized by photoactivation that makes the molecule in an excited state, a series of disassembly reactions caused by the element, and then the resulting asset (also known as Bronsted acid), as a cationic species, triggers epoxy compounds, vinyl ethers , the polymerization of lactones, acetaldehyde, cyclic ethers, etc.
Cationic photoinitiators can be divided into salts, metal organics and silicones, among which yellow salts and iron aromatics are representative.
Special: The photoinitiator TPO is divided into two categories: radical aggregation photoinitiator and cationic polymerization photoinitiator according to the photodisassembly mechanism. Radical photoinitiators can be divided into split-type photoinitiators and hydrogen-type photoinitiators according to the mechanism of generating free elements.
Mainly used in screen printing inks, lithographic inks, wood coatings, etc.