News

Knowledge

Company News

Application Mind Map

Test Report

Technical Article

Industry News

Introduction to Common Photoinitiators for UV-Curing Systems

Release time:

2014-09-16 09:12

Introduction to Common Photoinitiators for UV-Curing Systems
Introduction to Common Photoinitiators for UV-Curing Systems

With the vigorous development of the UV industry in China, an ever-growing variety of photoinitiators have come into our view—so numerous and diverse that they seem to be blooming in full splendor. However, this abundance also brings challenges: For many beginners who are new to the UV industry, choosing and combining photoinitiators in a way that’s truly tailored to their products has become a significant hurdle. To help address this issue, I’ve put together a brief summary here. We’d love to hear from everyone—feel free to join in and share your thoughts and experiences!

 

TPO
Chemical name 2,4,6-(Trimethylbenzoyl) diphenyl phosphine oxide
Appearance Pale yellow powder Absorption wavelength 269,298,379,393 nm
App Introduction TPO is a highly efficient free-radical (I) type photoinitiator, particularly well-suited for colored systems and applications involving thick coating films. Due to its broad absorption spectrum, TPO can be widely used in various coatings. Thanks to its excellent absorption performance, it is especially suitable for screen-printing inks, offset printing inks, flexographic printing inks, and wood coatings. When used together with 184, it is also ideal for adhesive products. The dosage of this product should be determined based on actual experimental results; the recommended addition level is 0.5–4% by weight.

 

TPO-L
Chemical name Ethyl 2,4,6-trimethylbenzoylphosphonate
Appearance Pale yellow liquid Absorption wavelength 273,370 nm
App Introduction A photoinitiator with an extremely rapid curing speed; TPO-L is a liquid photoinitiator that is particularly well-suited for formulations requiring low yellowing and low odor. Due to its relatively broad absorption spectrum, TPO-L can also be used to cure white coatings. To enhance the surface curing effect, TPO-L is often used in combination with other photoinitiators, such as 184, 1173, and benzophenone. The recommended usage concentration of TPO-L is 0.3% to 5%.

 

907
Chemical name 2-Methyl-1-[4-methylthiophenyl]-2-morpholinyl-1-propanone
Appearance White to slightly yellowish crystalline powder Absorption wavelength 232,307 nm
App Introduction It works exceptionally well when used in conjunction with ITX, and the product is particularly effective for deep curing in colored systems. 907 is a highly efficient free-radical (Type I) photoinitiator. It finds applications in adhesives, composites, lithographic printing inks, flexographic printing inks, offset screen-printing inks, and varnishes, as well as in the electronics industry (e.g., photoresists and solder mask inks) and in printing plates. The recommended addition level is 2–6% by weight.

 

ITX
Chemical name 2-Isopropylthioxanthon (mixture of 2,4 isomers)
Appearance Yellow crystalline powder Absorption wavelength 258,382 nm
App Introduction ITX is a highly efficient free-radical (Type II) photoinitiator; when used in combination with anionic photoinitiators, it acts as a synergist. It exhibits excellent performance when used in conjunction with 907. ITX is particularly suitable for layer-wise curing of corresponding resins along with tertiary amine co-initiators. As a highly effective photoinitiator, ITX is widely employed in transparent or colored UV-curable screen-printing inks, copy coatings, offset printing inks, flexographic printing inks, electronic products, wood coatings, adhesives, and photoresists. It is typically used in combination with the amine synergist EDB, and the recommended addition level is 0.2–2% by weight.

 

EDB
Chemical name Ethyl 4-dimethylaminobenzoate
Appearance White solid powder Absorption wavelength 228,308 nm
App Introduction EDB is a highly effective amine co-initiator that, when used in conjunction with free-radical (Type II) photoinitiators, is suitable for UV polymerization of monomers and oligomers with either single or multiple functional groups. EDB is a solid amine synergist commonly employed in sub-products such as offset printing inks, adhesives, silk-screen printing inks, and solder mask inks. It is typically used in combination with ITX or 907, and the recommended addition level is 2–5% by weight.

 

184
Chemical name 1-Hydroxy-cyclohexyl-phenyl ketone
Appearance White crystalline powder Absorption wavelength 246,280,333 nm
App Introduction 184 performs exceptionally well when used in combination with TPO in surface-curing systems. It is typically added together with other photoinitiators and, if necessary, can be used in conjunction with UV absorbers. The recommended dosage in the final product is 2-5% by weight.

 

1173
Chemical name 2-Hydroxy-2-methyl-1-phenyl-1-propanone
Appearance Light yellow liquid Absorption wavelength 245,280,331 nm
App Introduction The liquid is highly compatible and easy to blend. 1173 is suitable for surface-curing systems. It is particularly well-suited for acrylic UV-curable varnish systems, such as those used on wood, metal, paper, plastics, and other substrates. 1173 is especially recommended for UV-curable coatings that need to withstand prolonged exposure to sunlight and exhibit excellent resistance to yellowing. The recommended addition level is 1–4% by weight.

 

BDK
Chemical name Benzoin dimethyl ether
Appearance White crystalline solid Absorption wavelength 205,253 nm
App Introduction The BDK additive is applicable to colored systems and is widely used in various UV-curing systems. It exhibits strong absorption properties in UV ink systems such as PCB inks and clear-coat systems. The recommended addition level is 2-5% by weight.

 

OMBB
Chemical name Methyl benzoate
Appearance White crystalline powder Absorption wavelength 253nm
App Introduction Low-odor curing system; OMBB is widely used in odorless and non-toxic packaging for paper and food packaging. When used in combination with TPO, it can enhance curing efficiency.

 

CBP
Chemical name 4-Chlorobenzophenone
Appearance White crystalline powder Absorption wavelength 254nm
App Introduction CBP is widely used in odorless and low-toxicity packaging applications for paper and food packaging. When used in combination with TPO, it can enhance curing efficiency and provide a low-odor curing system.

 

PBZ
Chemical name 4-Phenylbenzophenone
Appearance Pale yellow crystals Absorption wavelength 289nm
App Introduction Highly efficient Type II free radical photoinitiator, suitable for low-odor applications.

 

BI-751
Chemical name -
Appearance Colorless liquid Absorption wavelength -
App Introduction BI-751 is an internationally newly developed liquid photoinitiator that exhibits excellent resistance to yellowing and provides deep-cure performance. It boasts superior yellowing resistance, low odor, and the ability to achieve deep curing. As a liquid product, it is extremely convenient to use and can be readily blended with other components in formulations, demonstrating excellent formulation compatibility. It is widely used in UV adhesives, UV clear coats, UV white plastics coatings, silk-screen white inks, and other applications requiring resistance to yellowing. Currently, only Guangzhou Boxing Chemical offers this product for sale.

 

Share to:

Previous page

Development Trends of Water-Based Wood Coatings Over the Next Ten Years

Regarding oligomers, an introduction to oligomers in UV-curable coatings

Next page

Related News

Regarding oligomers, an introduction to oligomers in UV-curable coatings

In light-curable coatings, oligomers serve as the equivalent of resins in conventional coatings—they are both film-forming substances. Their properties play a crucial role in determining the overall performance of the coating. Structurally, oligomers must possess photopolymerizable groups, such as various unsaturated double bonds or epoxy groups, and thus belong to the category of photosensitive resins. Among all the components of a light-curable coating, oligomers constitute the main body of the formulation; their properties essentially dictate the key performance characteristics of the cured material. Therefore, the synthesis and selection of oligomers undoubtedly represent an important step in the formulation design of light-curable coatings.

Application of UV-Curing Technology in Mobile Phones

With the remarkable advancements in wireless communications in recent years, mobile phones have come in an ever-growing variety of styles. Not only have their functions become increasingly powerful, but their designs have also become more and more attractive—some dazzlingly vibrant, others refreshingly serene, some impeccably sleek and mirror-like, and others elegantly understated yet richly textured, leaving viewers dazzled and captivated. These transformations are made possible by the application of ultraviolet (UV)-curing coatings in mobile phone manufacturing.

UV Varnish Performance Testing Items and Methods

Testing the performance of UV varnishes is one of the crucial steps in the UV varnish production process. Conducting performance tests on UV varnishes ensures the quality and stability of their performance. The following are the UV varnish performance testing items and methods.