Method for evaluating scratch resistance of plastic resins

1. A method for evaluating a scratch resistance of a plastic resin, comprising:

scratching a surface of a test sample of the plastic resin using a scratch apparatus to form a scratch on the surface having a scratch profile;

scanning the scratched test sample with a surface profile analysis apparatus to measure the scratch profile; and

determining a scratch resistance evaluation index based on the measured scratch profile to evaluate the scratch resistance of the test sample,

wherein said scratch profile comprises (a) a scratch width, (b) a scratch depth, (c) a maximum hill-to-valley range and (d) a profile area, and wherein said scratch resistance evaluation index is based upon the measured scratch width, scratch depth, maximum hill-to-valley range and profile area of the scratch index.

2. The method of claim 1 , wherein said scratch apparatus scratches the surface of the test sample with a load ranging from about 1 g to about 3,000 g and at a rate less than or equal to about 300 mm/min.

3. The method of claim 1 , wherein said surface profile analysis apparatus is a contact type or a non-contact type surface profile analysis apparatus.

4. The method of claim 3 , wherein said contact type surface profile analysis apparatus scans said scratched surface of said test sample with a metal stylus tip having a diameter ranging from about 0.5 μm to about 2 μm to measure said scratch profile.

5. The method of claim 3 , wherein said non-contact type surface profile analysis apparatus is a three-dimensional microscope or an optical analyzer.

6. The method of claim 3 , wherein said surface profile analysis apparatus has a horizontal scan length ranging from about 1 mm to about 30 mm, a vertical scan length ranging from about 1 μm to about 100 μm and a vertical resolution ranging from about 1 Å to about 30 Å.

7. The method of claim 1 , wherein (a) said scratch width ranges from about 0 μm to about 1,400 μm, (b) said scratch depth ranges from about 0 μm to about 300 μm, (c) said maximum hill-to-valley range ranges from about 0 μm to about 500 μm and (d) said profile area ranges from about 0 μm 2 to about 155,000 μm 2 .

8. The method of claim 1 , wherein said scratch resistance is evaluated by measuring the scratch profile at least about 2 times to about 5 times, and calculating an average value of the scratch resistance evaluation index.