Seeking Below 100°C Curing Technology for Water-based Coating

A SpecialChem Client is looking for a technology which is able to react as a crosslinker at low temperatures (

State of the art crosslinking chemistries in waterborne coating systems are melamine and isocyanate based systems. However, the SpecialChem Client is looking for a solution beyond these established crosslinking mechanisms.

The desired solution (crosslinking molecule) will have to meet the following criteria:

• The final overall system (pigments, polyol and crosslinker) should not have more than 20% organic solvents (VOC)
• The final overall system must be liquid. The low shear viscosity (reciprocal seconds) of a final coating containing pigments, binder and the crosslinker should be less than 8 Pa*s and sprayable (Air-assisted). This should be considered when searching for a suitable crosslinking molecule
• Sufficient thermal crosslinking of polyols within 20 minutes, for a waterborne pigmented coating, at temperatures between 80-100°C (175-210°F)
• Onset of reaction (crosslinker + polyol) should be around 60°C (140°F)
• Crosslinkable groups are primary or secondary polyalcohols (for example polyester, polyacrylates)
• Chemicals (i.e. crosslinker) used for the reaction must not be carcinogenic, mutagenic or reprotoxic (non-CMR)
• Chemicals used for the reaction must be colorless.

The technology (crosslinking molecule) may be applied in a 1-part (only 1 component is applied as a coating) or 2-part (crosslinker is mixed with polyol prior to application) system.

• For a 1-part solution, the mixture should be stable at ambient temperatures (below 40°C – 105°F) for 3 months
• For a 2-part system, the mixture of crosslinker and polyol must be stable for at least 1 hour.

The ability to provide samples for initial performance evaluation (minimum 100 g), upon request by the SpecialChem Client, is preferred.

Where possible, the proposed solution should provide routes for material synthesis.

The proposal should provide sound scientific explanation to critical aspects, such as the choice of specific material chemistries, which aim to fulfill the abovementioned solution criteria.

The SpecialChem Client is interested in the low temperature curing technology only as he will be formulating the final coating.

The SpecialChem Client is open to consider diverse approaches and chemistries, except for those mentioned below in section “Solutions that are not of interest”.

The following chemistries or technologies will not be considered:

• (Alkylated) Melamine Formaldehydes – crosslinking starts at temperatures above 100°C
• Isocyanates – toxicity issues

1-2 years, depending on the maturity of the proposed technology.

The SpecialChem Client is motivated to find a working solution, and welcomes suggestions about preparing formulations and coating samples in ways that will maximize potential of proposed technology.

Ideally, the proposed technology is a scalable and cost effective solution for commercialization.

Input and feedback from the value chain (OEM) of the Coatings industry, regarding the technical viability of this challenge would be appreciated by the SpecialChem Client.