To provide a chipping-resistant interlaminar coating material which, even when applied as an underlayer of a water-based intermediate coating, can assure a beautiful coating appearance without causing the yellowing of the water-based intermediate coating even when heated afterward and can attain sufficient chipping resistance and excellent storage stability.
The chipping-resistant interlaminar coating material comprises a blocked isocyanate compound and a powdery amine compound of an amine value of 300-1,200, the ratio between the content of the blocked isocyanate compound and that of the powder amine compound being such that the NCO/amine ratio is 1.0-3.0. The chipping-resistant interlaminar coating materials (examples 1-4) of compositions satisfying these requirements had such chipping resistance that no chipping occurred at a nut drop weight of 4 kg or larger, such thermal yellowing resistance that the b value of a coating film of a water-based intermediate coating was below 1.0 after two repeated 160C30 min keepings, and such storage stability that the rate of viscosity change was below 30% after 40C10 day storage.
GOTO TETSUO
SHIBATA SEISHI
TOYOTA MOTOR CORP
| JPH02614A | 1990-01-05 | |||
| JPH04332780A | 1992-11-19 | |||
| JP2004010879A | 2004-01-15 |