Organic silicon thermal conductive gasket is a composite material, which is prepared by mixing an additive organic silicon elastomer that provides high elasticity and a thermal conductive filler that provides thermal conductivity. So the main influencing factors are as follows:

1. Excessive crosslinking agent (this factor is the highest and also the most prone to problems):
Generally speaking, when adding hydrogen containing silicone oil, the molar ratio of hydrogen to vinyl group should be controlled at (1.2-1.8): 1, where hydrogen containing silicone oil includes side hydrogen and end hydrogen. Many people mistakenly believe that adding a little more hydrogen to the silicone oil will increase its strength and decrease its hardness, so they will add too much hydrogen to the silicone oil. As a result, the rebound elasticity of the gel decreases, the surface viscosity decreases, and the hardness increases rapidly after aging.

2. The volatile components in hydrogen containing silicone oil are generally high, up to about 12%. Some of these volatile components are cyclic siloxane monomers (DMC), while others are hydrogen containing small molecule monomers (linear or cyclic). The characteristics of these hydrogen containing small molecules are low activity at medium and low temperatures, and slow reaction at high temperatures, resulting in increased hardness in later stages or after aging.

3. When the volatile matter in vinyl silicone oil and hydrogen containing silicone oil is high, these small molecules will escape during the aging process, which is equivalent to a decrease in the amount of system oil. This not only causes the gasket to harden, but also reduces the thermal conductivity. After volatilization, the contact interface of the gasket will dry out and the surface viscosity will decrease.

4. The powder factor is due to the different chemical additives added to the raw materials, resulting in different quality and extraction standards for each type of powder. Therefore, one of the factors that cause quality problems with silicone rubber gaskets is also included.

How to solve this problem?
Calculate the molar ratio of hydrogen to vinyl and control it at (1.2-1.8): 1. The amount of hydrogen silicone oil added should not be too high, generally below 0.9 relative to vinyl. This can ensure stable hardness and maintain product resilience.

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