| 配方类型： |
LUBRICANTS AND OILS |
| 配方说明： |
Hydraulic-Brake Fluids |
| 配制方法： |
SOLVENT AND RUBBER-SWELLING INHIBITOR As pointed out before, the solvent and coupling agent must be an excellent mutual solvent for all of the commonly used ingredients in hydraulic-brake fluid formulations, including castor oil. In general, those solvents that are most powerful coupling agents are also the chemicals which swell natural rubber to a greater degree than is permissible for the finished formulation. Fortunately, glycols will inhibit or reduce the swelling of natural rubber by most of the commonly used hydraulic-brake fluid solvents without appreciably reducing their coupling action. Ethylene glycol iss the most effective rubber-swelling inhibitor, followed by propylene glycol, diethylene glycol, dipropylene glycol, and hexylene glycol. It should be pointed out that in castor-oil formulations, ethylene glycol requires a more powerful coupling agent to maintain lowtemperature miscibility than propylene glycol, and so on, down the list. The choice of glycols is usually made on the basis of the best |
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