Solution

An excellent heat-resistant binder resin that conforms to REACH regulations and does not include restricted substances

NMP-free polyamide-imide resin

HomeSolutionNMP-free polyamide-imide resin
Applicable Business Areas
Automotive parts manufacturers
Target Applications
Binders for sliding part coating

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

 

New PAI resin
(NMP not used)

Conventional PAI resin
(NMP used)

Performances

Same as conventional PAI

・Heat resistance
・Mechanical property
・Durability

ANNEX 14
(Candidate list of substances for authorization)

N/A

Candidate

ANNEX 17
(Candidate list of substances for restriction)

N/A

Applicable

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.

 

Solvent included in the product type

Solvent that can be added

Organic solvent type

Organic solvent type

Organic solvent type

Water-dilutable type

Organic solvent + water type

Organic solvent or water type