Phenolic resin 551 is a heat-reactive alkyl phenolic resin used to synthesize neoprene adhesive. 551 formulated adhesive has lower initial viscosity and excellent viscosity stability than similar adhesives. Among neoprene adhesives, 551 shows good bond strength at room temperature.
Product Parameters
| Exterior: | Transparent irregular sheet or block | Exterior: | Transparent irregular sheet or block |
| proportion: | 1.03 | proportion: | 1.03 |
| Melting point (capillary method): (Capillary), (° F): | 170—195 | Melting point (capillary method): (Capillary), (° F): | 170—195 |
| Softening point, spherical ring method (B & R), (℃): | 100—110 | Softening point, spherical ring method (B & R), (℃): | 100—110 |
| Color, GARDNER-Holdt, 60% soluble in toluene: | 0—8 | Color, GARDNER-Holdt, 60% soluble in toluene: | 0—8 |
Product Application
The main function of 551 is to make neoprene adhesives have a low initial viscosity and maintain the stability of viscosity. This kind of adhesives rely on the interaction of elastomers and metal oxides at room temperature and high temperature to produce high cohesive strength. The typical formula is as follows:
| Part A | Part B | ||
| Neoprene | 100.0 | 551 | 45.0 |
| Antioxidant | 1.0 | water | 1.0 |
| Magnesium oxide | 8.0 | Solvent | 480.0 |
| Zinc oxide | 5.0 |
Part A-Preheat the rollers of the heat refiner to 50 ° C and add magnesium oxide, zinc oxide and antioxidants in sequence. Part B-Dissolve the resin in solvent and water. Part C-(After the resin is completely dissolved in the solvent) Mix Part A and Part B until the solution is uniform and single. Adding a portion of water helps optimize viscosity stability without significantly affecting the bond strength at high temperatures. Adding more water can continue to improve the viscosity stability, but it will greatly weaken the cohesive strength at high temperatures. The solvent system composed of the same weight of toluene, n-ethane and methyl ethyl ketone (MEK) makes the adhesive have a low initial viscosity and good stability.