What are the effects of benzoic acid on silicone products?

- Mar 12, 2018-

        People who make silicone products should understand benzoic acid and it has an important influence on silicone rubber.

1. Control the scorch moment of rubber

a. Improve the scorch function of the rubber compound:

In the rubber compound mixing and thermal refining production process, due to the rubber compound formula, temperature, plastic seed, process and human factors and other factors, the rubber material will appear scorch, glue phenomenon, resulting in unnecessary loss. In this case, 1-2 parts of benzoic acid are added to the rubber compound formulation, and the scorch time of the delayed rubber compound is about 0.5-1 min, which increases the safety function of the rubber compound production.

b. To ensure the scorch time of the rubber compound and to improve the curing degree of the rubber compound:

In the functional requirements of silicone products, there are higher target requirements such as shrinkage, permanent deformation, aging function, elongation, static stiffness, and anti-vulcanization recovery function, and the vulcanization degree of the rubber material is generally higher. When planning compound formulations, the vulcanization system is necessary for toughening. In this way, the coking time T10 of the rubber compound will be relatively short, affecting the safety function of the rubber material, easily exhibiting scorching phenomenon of the rubber material, and decreasing the function of the old-fashioned rubber and rubber products. In order to ensure the function of the rubber compound on the basis of the scorch safety function of the rubber compound, 1-2 parts of the prolonged scorch time of the benzoic acid delay compound are ensured to ensure the safety function of the rubber material and reach the functional goals of the rubber material planning.

2. Increase the activity of plastic material:

In general, the participation of benzoic acid in the formulation of rubber compounds can soften the unvulcanized rubber, which can improve the processing technology and activity of the rubber compound. The rubber material softens on the mixing equipment, shortening the mixing process and the heat refining process. In the rubber vulcanization process, the rubber material is softened, the rubber material activity function is improved, the appearance quality of the rubber product is improved, and the qualified rate of the product is improved. In particular, the effect of the mold in the molded product is more complicated.

3. To improve the mixing and heating of the rubber roll function:

In the mixing process of rubber compound, due to reasons such as rubber compound formula, rubber compound, and rubber mixing equipment, roll off phenomenon sometimes occurs, which can easily result in compound refining, uneven mixing, too long mixing time, etc. As a result, the physical and mechanical functions of the rubber material are reduced, the rubber product is not resistant to aging, and the service life of the product is shortened.

The rubber compound does not include rollers in the hot material process, and the thermal refining process is difficult, and the hot material of the rubber material is not uniform, which greatly affects the process and product quality of the subsequent process.

In order to overcome the above technical disadvantages, adding 0.5-1.0 parts of benzoic acid to the rubber compound can increase the roll function of the compound in the mixing process and the thermal refining process.

PS: The key to increasing benzoic acid is that although benzoic acid has the above effects, the following points should be noted during the application process.

1) Benzoic acid rapidly increases at 100°C, its vapor is very irritating, and it can easily cause coughing after inhalation. Therefore, when the benzoic acid is added during compounding, the mixing temperature must be lower than 100°C.

2) When the number of benzoic acid parts is more than 3 parts, the vulcanized rubber will be hardened and hardened. Especially in rubber containing low rubber content. The use of benzoic acid must depend on the intention of increasing benzoic acid.