S-LEC Coating

[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

Table1: properties of S-LEC B/K Coating

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.

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

Table2 Coating thickness vs. etching hardness


N.B.: n-Butanol- Toluene solution (1:1) is coated and baked at 100・


Fig. 2 Curves of coating thickness and etching hardness


Fig. 2 Curves of coating thickness and etching hardness

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


Table 3 Etching hardness of over-coating


N.B.: n-Butanol- Toluene solution (1:1) is coated and baked at 100・