Some knowledge about photoinitiator TPO

Photoinitiator TPO is a good free radical photoinitiator, which has a wide absorption wavelength range, takes into account surface drying and deep curing, and is used to initiate UV polymerization of unsaturated prepolymerization system. This initiator has the following three characteristics: fast curing, resistance to yellowing and low odor.

Photoinitiator TPO manufacturers consider any material that produces free radicals and further initiates polymerization by light irradiation as photoinitiator. Photoinitiator is also known as photosensitizer or photocuring agent. In the light curing system, including UV glue, UV paint, UV ink, etc. After receiving or absorbing external energy, chemical changes occur and decompose into free radicals or cations, thus initiating polymerization reactions. According to different initiation mechanisms, photoinitiators can be divided into free radical polymerization photoinitiators and cationic photoinitiators, among which the free radical polymerization photoinitiators are widely used.

Photoinitiator TPO manufacturers believe that the so-called lytic free radical photoinitiator, refers to the photoinitiator molecules in the absorption of light energy, transition to the excited singlet state, and then to the excited triplet state. When the singlet state or triplet state is excited by the photoinitiator, the molecular structure is in an unstable state, and the weak bonds in the photoinitiator will be evenly broken, generating primary active radicals, and triggering polymerization cross-linking of oligomers and active diluents.

The photoinitiator TPO is an acyl phosphine oxide free radical photoinitiator, and its photolysis products are trimethylbenzoyl group and benzoyl phosphine acyl group, both of which are highly active free radicals. The absorption peak of TPO is at 380nm, and there is absorption at 430nm in the visible light region, so TPO is particularly suitable for light curing of colored system. The absorption wavelength of the photolysis product can move to short wave, which has photobleaching effect and is conducive to ultraviolet light transmission, so it is suitable for curing thick coating. Excellent thermal stability, no chemical reaction when heated to 180, good storage stability. Although light yellow, but after photolysis becomes colorless, will not turn yellow. Photoinitiator TPO is widely used in light curing of color coatings, thick coatings and coatings with poor light transmittance. Because TPO also absorbs visible light, light should be avoided during manufacturing, storage, and transportation.

The photoinitiator TPO can be used in UV-curable coatings and acrylate-based ink formulations for paper, wood, metal, plastic and glass substrates. It can be used as a single initiator or in combination with other photoinitiators such as -hydroxy ketones, such as 4265 (50% TPO/50 73). 0.3 to 3% of the weight of the formula is recommended. Store in a cool, ventilated and dry place, away from heat and sunlight; Avoid contact with alkaline additives and water. If stored at room temperature, the shelf life is about 24 months.

The above is about the photoinitiator TPO some knowledge points, I hope you can seriously learn to understand the relevant knowledge.