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Applicable Business AreasResin manufacturers
Target ApplicationsResin materials for photoresists, adhesives, and coatings
Expanding Resin Design Flexibility with Dual‑Functional (Meth)acryloyl–Isocyanate Monomers
Karenz MOI and Karenz AOI are monomers that incorporate a (meth)acryloyl group and an isocyanate group within a single molecule. Because these functional groups react via different mechanisms, they allow control over crosslink density, copolymerization between different resin systems, and multi-stage curing processes, thereby providing greater flexibility in resin material design.
In resin material design, the selection of resin systems and components, as well as control of crosslinked structures, directly influences the targeted properties and functions. For example, acrylic resins widely used in adhesives can achieve both low glass transition temperature and shape retention or heat resistance through the design of crosslinked structures. In photosensitive resists, combining different resin systems and adjusting crosslink density enables multiple functions to coexist, such as solubility contrast, substrate adhesion, and process durability.
As these examples illustrate, resin materials are required to balance multiple functions according to their application while meeting increasingly demanding performance requirements. Consequently, resin design must consider not only composition but also processing aspects.
Fig 1. Isocyanate (meth)acrylate monomers supplied by Resonac1)
- 1) In addition to the standard products, the lineup includes long-chain types incorporating ethylene glycol (Karenz MOI‑EG), multifunctional acrylate types (Karenz BEI), and isocyanate-protected types (Karenz MOI‑BP, Karenz MOI‑BM).
Solution
Enabling Copolymerization of Different Resin Systems and Multi‑Step Curing in Resin Design
MOI and AOI feature a radical‑polymerizable (meth)acryloyl group and an isocyanate group capable of addition reactions with functional groups containing active hydrogen. By utilizing the differences in these reaction mechanisms, these monomers enable formulation design that combines different resin systems as well as process design through multi‑step curing, providing a broad range of options for resin material development.
When the (Meth)acryloyl Group Is Utilized First
In copolymerization with monofunctional acrylates, appropriate selection of monomers and composition ratios enables the synthesis of acrylic polyisocyanates with targeted properties and crosslinking sites. Subsequent combination of these copolymers with monomers or polymers containing active‑hydrogen functional groups forms crosslinked structures via addition reactions. Furthermore, controlling the initiation point of these addition reactions allows flexibility in process design.
Fig 2. Example of acrylic poly-isocyanate synthesis
When the Isocyanate Group Is Utilized First
Isocyanate groups undergo addition reactions with functional groups containing active hydrogen, such as alcohols, amines, thiols, carboxylic acids, amides, and oximes. This approach enables the introduction of (meth)acryloyl groups into a wide range of resin systems—including acrylics, epoxies, and polyimides—making it possible to incorporate radical polymerization into the curing process of resin materials.
Fig 3. Addition reactions between isocyanate groups and active hydrogen functional groups
Fig 4. Example of introducing an acryloyl group into active hydrogen containing compounds
Features
Radical Polymerization Reactivity Comparable to MMA
Table 1 shows the Q–e values of 2 isocyanatoethyl (meth)acrylates (MOI and AOI) and general purpose acrylates. The Q value relates to monomer radical stability, while the e value depends on monomer polarity; together, these values are useful for predicting copolymer structure and composition. Because MOI has Q–e values close to those of MMA and AOI to those of MA, and because their steric environments around the double bond are identical, MOI and MMA, as well as AOI and MA, can be considered to exhibit equivalent radical polymerization behavior.
Table 1. Q–e values of isocyanate (meth)acrylates and general purpose acrylates
2) Source: L. J. Young, Journal of Polymer Science, 54, 411-455 (1961)
Note: The data shown are representative examples of measurement and calculation results and do not guarantee quality.
Addition Reactivity Comparable to Aromatic Isocyanates
The addition reactions of MOI and AOI with alcohols were monitored over time, and reactivity was evaluated based on isocyanate conversion. The reactivity of MOI and AOI was higher than that of aliphatic isocyanates such as hexamethylene diisocyanate (HDI) and iso-phorone diisocyanate (IPDI), and comparable to that of the aromatic isocyanate toluene diisocyanate (TDI).
Fig 5. Time dependent conversion of NCO groups in addition reactions with alcohols
Experimental Conditions:
n-Butanol was diluted in toluene and maintained at 60 °C. Each isocyanate monomer (MOI, AOI‑VM, MOI‑EG, BEI, TDI, HDI, and IPDI) was then added, and addition reactions were carried out.
Samples were taken at predetermined reaction times, and the conversion of isocyanate groups was determined by GPC
Column: KF‑801, Eluent: THF, Flow rate: 0.8 mL/m, Oven temperature: 40 °C, Detector: RI, UV (210 nm)
Note: The data shown are representative examples of measurement and calculation results and do not guarantee quality.
Updated: July 13, 2026
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