A heat-resistant binder resin that conforms to REACH regulations

Polyamide-imide (PAI) resins are used in coating binders for sliding parts such as automotive compressors or engine pistons that require heat resistance. A movement of restriction under the EU REACH regulations on the use of N-Methyl-2-pyrrolidone (NMP), which is generally used as a solvent for this PAI resin, is underway. So far, as a material most suitable for automotive parts, we have aimed at the development of PAI in which the environment and safety are taken into account.

Innovative Solution

No REACH restricted substances, reduce registration cost

For NMP, which is generally used as a solvent for PAI, there is a concern about reproductive toxicity, and NMP is handled as a restricted substance under the REACH regulations. When it is used, various restrictions (requirements), such as the obligation of controlling the amount of worker exposure to NMP, and investment in exhaust/collection equipment for reducing the amount of exposure, must be followed. Related materials such as DMAC^※ and NMP, which are restricted by the REACH regulations, are not used for the new PAI resin we have developed or in any process including the production process. Therefore, various countermeasures for compliance with regulations are unnecessary. Furthermore, as the high heat resistance and mechanical properties, which are the characteristics of PAI resins, are the same as those of conventional materials, high-performance binder films applicable to high-temperature environments can be formed.

• (※ Regulations as of April 2019)

New PAI resin VS Conventional PAI resins: performances and REACH compliancy

Product Features

Strong and hard-to-peel coating is formed

Compared to epoxy, acryl, and urethane resins, which are widely used as binders for sliding part coating, PAI resin has high heat resistance (Tg ≧ 270ºC,heat decomposition temp.＞400ºC) and mechanical property (tensile modulus ≧ 2.5 GPa), as well as excellent durability. Furthermore, thanks to the low linear expansion coefficient, delamination due to temperature changes is reduced.

PAI the optical choice for challenging environments with superior thermal, mechanical and chemical properties

Water-dilutable type to reduce VOC emission and to control humidity

Water-dilutable type PAI resins that can be diluted with water or water-based materials are available. They are produced by controlling solubility in solutions, and can reduce the amount of volatilized solvent during heat curing.
Furthermore, it becomes easy to control the humidity in the coating environment because water- dilutable type reduce absorption of moisture and resist to whitening and solidification.