Powder coating material and a recoat steel plate
US5252670A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 1992 |
| Grant date | Oct 12, 1993 |
| Priority date | — |
| Expiry date | Nov 12, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31605
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A powder coating composition comprises 100 weight parts of the total of a polyester resin having a hydroxyl value in the range from 20 to 100 KOH mg/g and a blocked polyisocyanate compound, 0.01 to 3 weight parts of an organotin compound and 0.01 to 10 weight parts of a carboxylic acid compound having an acid value of 1000 KOH mg/g or less which can form a complex compound by reaction with the organotin compound. The amount of the polyester resin is in the range from 95 to 50 weight % and the amount of the blocked polyisocyanate compound is in the range from 5 to 50 weight % respectively based on the total of the polyester resin and the blocked polyisocyanate compound. A precoat steel plate is prepared by coating the powder coating composition described above on a steel plate by a electrostatic powder coating method to form a coating layer having a thickness in the range from 20 to 120 .mu.m and curing the coating composition by baking at a temperature in the range from 190.degree. to 300.degree. C. for a time in the range from 20 seconds to 10 minutes. The powder coating composition can be cured without formation of blisters and pin holes under a desired condition by controlling t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.