IOTA M7140 is a two-component transparent thermosetting liquid silicone rubber specifically designed for electronic buttons. Its core selling points include long lifespan, high resilience, excellent electrical insulation, and fatigue resistance. It has passed RoHS certification. Product introduction: Unlike the previous food-grade materials, M7140 is positioned for the consumer electronics sector and does not involve food contact compliance requirements.
Key performance data (after curing, 23±2℃, 24 hours of vulcanization)
Performance Values Testing method
Performance Values Testing method
Density 1.09 g/cm³ ISO 2781
Hardness 40 Shore A DIN 53505
Tensile strength 6.0 MPa DIN 53504
Elongation 320% DIN 53504
Tear strength 15 KN/m —
Unvulcanized product viscosity: Component A 150 mPa·s, Component B 100 mPa·s, mixed 125 mPa·s (23℃, ISO 3219). Technical parameters: This viscosity is much lower than the M6020/M6750 series (280–380 Pa·s), with better fluidity, making it suitable for injection molding of precise thin-walled buttons.
Core differences from M6020/M6750
Comparison item M7140 M6020/M6750
Comparison item M7140 M6020/M6750
Core positioning Electronic buttons, keyboard protective cover Food contact, baby care, kitchenware
Compliance certification RoHS BfR, FDA, RoHS
Viscosity 125 mPa·s (low viscosity, high flow) 280–380 Pa·s
Hardness Single 40 HA 20–70 HA multiple levels
Tensile strength 6.0 MPa 7–10 MPa
Elongation 320% 340–650%
Tear strength 15 KN/m 20–40 KN/m
VOC Not labeled ≤0.4–0.5%
The mechanical properties (tensile, elongation, tear) of M7140 are significantly lower than those of M6020/M6750. This is because electronic buttons prioritize resilience, fatigue resistance, and touch sensation rather than extreme tensile/tear strength. Product Introduction
Key verification items for electronic key selection
Key lifespan (fatigue resistance)
The core selling point of M7140 is "long lifespan", but the specific number of presses is not provided in the materials. For consumer electronic remote controls and household appliances, it usually requires 100,000 - 1,000,000 presses, while for industrial control and vehicle keys, it requires 500,000 - 2,000,000 presses. Specific lifespan test data should be obtained from the supplier and verified on the actual product.
Compression permanent deformation
Whether the key can return to its original position after repeated pressing depends on the compression permanent deformation rate. High-quality silicone keys should have a deformation rate of ≤15% and a rebound rate of ≥95% at a compression rate of 150℃/22h/25%. The data is not provided in the materials and needs to be obtained from the supplier.
Contact resistance (if it is a conductive silicone key)
If used for conductive silicone keys (such as remote controls and keyboards), the initial contact resistance (usually ≤100–150 Ω) and the resistance drift after 1 million presses (usually <1000 Ω) need to be verified. The M7140 materials do not label the conductive performance, and if a conductive function is required, it needs to be confirmed whether it is a conductive version.
Touch force and rebound time
The touch force of consumer keyboards is usually 100–400 gf, and the rebound jitter ≤5 ms. The feel should be tested on the actual mold to confirm if it meets the product requirements.
Electrical insulation performance
The materials state "excellent electrical insulation performance", but no specific values are provided. Industrial-grade silicone keys typically require an insulation resistance of ≥10¹² Ω (500 V DC). Specific test data should be obtained from the supplier.
Complete selection decision table for five materials
Model Core positioning Hardness level Compliance certification Typical scenarios Key differences
Model Core positioning Hardness level Compliance certification Typical scenarios Key differences
M3054 Low compression permanent deformation No complete data provided Not labeled Long-term static sealing Optimal pressure variation performance
M3055 General sealing component No complete data provided Not labeled General sealing components, accessories Lower cost advantage
M6020 General two-stage vulcanization-free type 25–70 HA BfR, FDA, RoHS Infant care, food contact 省去后烘工序
M6040K General two-stage vulcanization-free + high bite force No data provided BfR， FDA， RoHS Reinforced molding， insert injection Stronger adhesion to base material
M6750 Cookware-specific food grade 20–70 HA BfR， FDA， RoHS Cookware， baking molds Minimum VOC (≤0.4%)
M7140 Electronic key-specific 40 HA (single) RoHS Electronic keys， keyboard protectors Low viscosity， high flow， fatigue resistance
How to verify from samples to mass production
Obtain complete TDS
Request the complete technical parameters of M7140 from the supplier to confirm key data such as compression permanent deformation， rebound rate， and electrical insulation performance.
Key lifespan test
Carry out pressing lifespan tests according to GB/T 4967-95 or customer standards to verify if it reaches the target number (such as 1，000，000 times).
Feel and touch force test
Test touch force， rebound time， and feel on the actual mold to confirm if it meets the product feel requirements.
Conductive performance verification (if applicable)
If used for conductive keys， test the initial contact resistance and resistance drift after 1 million presses.
Environmental reliability test
Conduct tests such as high and low temperature cycling (-40℃~+85℃)， wet heat aging， etc. to verify the stability of long-term use.
What information to prepare before inquiring from the supplier
Provide non-confidential application summary： product type (remote control keys/keyboard protector/3C sealing)， target hardness， whether a conductive function is required， expected key lifespan number， temperature range of use， injection or molding process， and estimated purchase quantity. When there are specific requirements for lifespan, compressive permanent deformation and contact resistance, the testing methods and acceptance standards should also be specified simultaneously.
FAQ
Can M7140 be used for food-contact products?
No. The M7140 is only RoHS certified and does not have BfR, FDA or GB 4806.16-2025 compliance labels. If used for food contact, the M6020 or M6750 should be chosen. Product introduction, 4
2. Why are the mechanical properties of M7140 lower than those of M6020?
Electronic buttons place more emphasis on resilience, fatigue resistance and touch sensation rather than extreme tensile/tear strength. The formula of M7140 has been optimized for high resilience and fatigue resistance. Product Introduction
3. Is M7140 conductive silicone?
The documentation does not clearly indicate this. M7140 is labeled as having "excellent electrical insulation properties". If a conductive function is required (such as for remote control buttons), it is necessary to confirm with the supplier whether there is a conductive version available.
4. What is the exact number of button lifetimes?
The documentation does not provide a specific value. Consumer electronic buttons typically require 100,000 to 1 million cycles. Specific test data should be obtained from the supplier.
5. Why is catalyst poisoning avoided?
When platinum-based catalytic systems come into contact with substances such as sulfur, phosphorus, nitrogen, and organic tin, they may not cure or become sticky on the surface. Important matters include checking the base material, release agent, and pigment in advance.