Graphite-Filled Silicone Rubber Elastic Layer Thermal Conductivity
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Solution Overview
Problem
Existing electrophotographic members with elastic layers containing addition-curable liquid silicone rubber face challenges in achieving high thermal conductivity due to difficulties in curing when graphite is used as a filler, as it inhibits the curing process, particularly when graphite particles have high dibutyl phthalate (DBP) oil absorption numbers.
Innovation Solution
Incorporating organopolysiloxane with active hydrogen bonded to silicon as a crosslinking agent with a weight average molecular weight of 5,500 to 65,000 to suppress absorption by graphite particles, ensuring sufficient curing and enhancing thermal conductivity of the elastic layer by using graphite particles with DBP oil absorption numbers between 80 cm3/100 g to 150 cm3/100 g.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If graphite particles with high DBP oil absorption number are used to increase thermal conductivity, then thermal conductivity is improved, but curing of the addition-curable liquid silicone rubber mixture is inhibited
Solution Approach 1:
The patent changes the molecular weight parameter of the organopolysiloxane crosslinking agent to a specific range (5,500 to 65,000) to optimize the balance between curability and thermal conductivity. This parameter adjustment allows the crosslinking agent to effectively cure the silicone rubber while maintaining the thermal conductive properties of graphite particles.
Solution Approach 2:
The patent creates a composite material system combining addition-curable liquid silicone rubber, graphite particles with specific DBP oil absorption numbers (80-150 cm³/100g), and organopolysiloxane crosslinking agents. This composite approach allows the synergistic combination of curing capability and thermal conductivity enhancement.
2Temperature
If graphite is incorporated into addition-curable liquid silicone rubber to enhance thermal conductivity, then thermal conductivity is improved, but the elastic layer cannot be sufficiently cured
Solution Approach 1:
The patent specifies a weight average molecular weight range (5,500 to 65,000) for the organopolysiloxane crosslinking agent to ensure adequate curing of the elastic layer while maintaining high thermal conductivity. This precise parameter control resolves the contradiction between curing completeness and thermal performance.
Solution Approach 2:
The patent references and builds upon previous research findings regarding graphite's thermal conductive properties, applying the same graphite particle characteristics (DBP oil absorption number range) while introducing the molecular weight optimization for the crosslinking agent to achieve both curing and thermal conductivity goals.
3Temperature
If graphite particles are used as filler in the elastic layer, then thermal conductivity is enhanced, but the curing process is inhibited particularly when DBP oil absorption number is high
Solution Approach 1:
The patent optimizes the molecular weight parameter of the crosslinking agent to fall within 5,500 to 65,000, which enables the curing process to proceed effectively even in the presence of graphite particles with high DBP oil absorption numbers, thus improving both manufacturability and thermal conductivity.
Solution Approach 2:
The organopolysiloxane crosslinking agent acts as an intermediary that facilitates the curing process in the presence of graphite particles. By selecting crosslinking agents with specific molecular weights, the patent enables the crosslinking reaction to occur effectively despite the graphite particles' tendency to absorb curing agents.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively increases the thermal conductivity of the elastic layer to 1.1 W/(m·K) to 5.0 W/(m·K) and ensures adequate curing, leading to improved heat transfer and image quality in electrophotographic applications.
Implementation Method 1
the elastic layer having high thermal conductivity in the thickness direction
Implementation Method 2
an electrophotographic member including a substrate and an elastic layer on the substrate, the elastic layer containing a cured product of an addition-curable liquid silicone rubber mixture
Data Source
AI summary
Provided is an electrophotographic member, the member including an elastic layer that is formed by graphite particles dispersed in a silicone rubber and has high thermal conductivity in the thickness direction. The electrophotographic member has a substrate and an elastic layer on the substrate, in which the elastic layer contains a cured product of an addition-curable liquid silicone rubber mixture including graphite particles, the dibutyl phthalate (DBP) oil absorption number of the graphite particles is from 80 cm3/100 g to 150 cm3/100 g, the thermal conductivity in the thickness direction of the elastic layer is from 1.1 W/(m·K) to 5.0 W/(m·K), and the modulus in tension of the elastic layer is from 0.1 MPa to 4.0 MPa.