13 сентября, 2015 
Malyar A. New Flexible Cyanoacrylates
New cyanoacrylate compounds exhibit good adhesion to various plastics and elastomeric surfaces, such as Mylar, copper foil, and vinyl films. These products show better impact resistance and good flexibility compared to standard cyanoacrylates, good resistance to cracking under flexing or bending, and a longer open time than that of standard products.
B. New Cure-Through-Gap Cyanoacrylates
Through changes in the manufacturing process, cyanoacrylates can now be highly purified. This added purification step has led to the development of a group of materials that can cure through a gap without the typical reduction in shear strength and overall performance. More traditional formulations show a dramatic reduction in shear strength as the gap increases (see Fig. 6). Table 5 shows cure through a gap and the corresponding shear strength for these new, highly purified cyanoacrylates.
|
Time |
Gap-filling |
Regular |
|
(h) |
cyanoacrylate |
cyanoacrylate |
|
2 |
25 |
13 |
|
24 |
100 |
40 |
|
72 |
100 |
100 |
|
Table 6 Set Time Across a 0.004-in. Gap |
||
|
Time (s) |
||
|
Product |
Surface-insensitive |
Ethyl |
|
viscosity (cP) |
cyanoacrylate |
cyanoacrylate |
|
100 |
6-8 |
55 |
|
500 |
7-12 |
>60 |
|
1500 |
8-12 |
>60 |
|
8000 |
8-12 |
n. a.a |
|
aNot applicable. |
Опубликовано в рубрике 