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| [1] The adhesiveness of S-LEC B/K differs according to the degree of polymerization
and the composition. Generally, low polymers have stronger adhesion, and materials
with a certain amount of variation in the degree of polymerization prove to be
better adhesives than those with uniform dispersion. [2] Film coated with S-LEC
B/K, if immersed in water, absorbs 5 to 8% of water, but no more, even after long
periods of immersion. When dried, it returns to its original state. Repeated wetting
and drying does not cause fragility or peeling of the film. This characteristic
may seem to be a drawback, but on the other hand, in textile processing it gives
very good touch and feel. The fact that insulation shows a constant value when
the material is hygroscopicly saturated gives a favorable rust preventing property
to wash primers. [3]After baking S-LEC B/K coating at different temperatures,
we performed a series of tests, the results of which are shown in Table1 below
(clear lacquer is listed for comparison) |
Table1: properties of S-LEC B/K Coating |
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N.B.1:BM-2, BM-S = 12%; BL-1 = 20% N.B.2:Refer to the Painting Manual
for the Testing method.
Iso-propanol-toluene solution (1:1) coated twice.
++ Excellent; + Good; +- Ordinary - - Poor
The characteristics of S-LEC B/K as a coating are excellent.
By raising the baking temperature, resistance to hot water is considerably improved.
Combination with compatible resins will further improve the performance.
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| The relationship between coating thickness and etching hardness of S-LEC B/K
with differing degrees of polymerization is given in Table 2 and Fig. 2. |
| Table2 Coating thickness vs. etching hardness |
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| Fig. 2 Curves of coating thickness and etching hardness |
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| In the case of low polymers like BL and BM, the coating thickness is about
0.02 mm and the etching hardness does not deviate much, but in BH (high polymer),
it increases in proportion to the number of coatings. As a coating material, S-LEC
BM is the best, as it has well harmonized adhesiveness and toughness. The etching
hardness of differing over-coating combinations and differing coating mixes of
S-LEC BL, BM and BH are shown in Tables 3 and 4. |
| Table 3 Etching hardness of over-coating |
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| N.B.: n-Butanol- Toluene solution (1:1) is coated and baked at
100
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