One cannot simply rely on the IOTA GNJ 3128H having a transmittance of ≥93% or its two-component room-temperature curing silicone gel structure to directly conclude that it is suitable for all moisture-proofing of electronic components, internal encapsulation of integrated circuits, or bonding of optical instruments. One must first confirm the substrate type, surface cleanliness, mixing ratio, degassing process, curing conditions, and environmental cleanliness, and then determine whether the problem lies in the decrease in transmittance, poor curing, insufficient bonding strength, or poor compatibility with the substrate and operating environment. IOTA GNJ 3128H can be considered as a candidate for benzene-based silicone gel elastic bonding and moisture-proof protection, but it must be confirmed through small-scale tests, transmittance tests, and actual working conditions verification.


Why does room-temperature curing silicone gel often fail to achieve the expected results in electronic moisture-proofing or optical bonding?


Inaccurate mixing ratio or uneven mixing, with the A/B component ratio deviating from 1:1, leads to incomplete curing or uneven crosslink density.


The gel comes into contact with organic compounds such as N, P, S or ionic compounds such as Sn, Pb, Hg, As, causing poisoning of the platinum catalyst and poor curing.


If the substrate surface is not cleaned or contaminated, it affects the adhesion and transmittance of the silicone gel to the substrate.


Insufficient vacuum degassing, with residual bubbles in the gel layer, affects transmittance and moisture-proof performance.


The operation time exceeds 240 minutes, causing the viscosity of the mixed material to increase after mixing, affecting the uniformity of application and penetration.


Insufficient curing temperature or time, with 24 hours at room temperature not fully curing, or the heating curing conditions not being optimized.


The benzene content does not match the refractive index of the substrate, resulting in optical interface reflection loss and decreased transmittance.


Improper storage conditions, with A/B components absorbing moisture or deteriorating, affecting the performance and curing quality after mixing.


When used for optical instrument bonding, the long-term yellowing resistance performance is not evaluated, and the transmittance decreases under high temperature or UV conditions.


When switching from other silicone gels, the mixing ratio, curing conditions, and degassing process are not re-adjusted.


What are the public parameters of IOTA GNJ 3128H?


Parameter IOTA GNJ 3128H
Pre-mixing viscosity (A/B, 22℃, cp) 600±200
Mixing ratio (weight ratio) A:B=1:1
Post-mixing color Transparent
Post-mixing viscosity (22℃, cp) 600±200
Operation time (min) ≤240
Curing time (22℃, h) 24
Curing after Shore A00 25±5
Curing after density (g/ml) 0.98
Curing after transmittance (%) ≥93
Volume resistivity (Ω·cm) >1.0×10¹⁴
Operating temperature range -59℃～200℃
The above data is from Aytota's current public product information. Formal procurement and batch acceptance should be based on the valid TDS, specification documents, and COA of the delivery batch confirmed by both parties.


Which application directions is IOTA GNJ 3128H suitable for?


Application direction Candidate direction Still needs verification
Electronic component moisture-proofing Provide waterproof and moisture-proof protection and anti-aging protection Adjusting curing conditions, bonding strength, volume resistivity
Transistor and integrated circuit internal coating Used as an internal coating material to protect chips and circuits Transmittance, low stress, temperature resistance, curing uniformity
Optical instrument elastic bonding Provide high transmittance elastic bonding Matching refractive index, anti-yellowing, bonding strength
Precision electronic assembly Provide low stress protection for precision components Adjusting curing shrinkage, thermal expansion matching, ion impurity control
Optical lens and window bonding High transmittance elastic bonding Transmittance retention rate, interface reflection, long-term stability


What are the key differences in the selection of IOTA GNJ 3128H compared to similar silicone gels?


Comparison direction: IOTA GNJ 3128H (phenyl silicone gel) vs. ordinary methyl silicone gel vs. epoxy potting compound. Selection boundary.
Curing mechanism: Platinum-catalyzed addition polymerization, no by-products. Platinum-catalyzed addition polymerization. Selection depends on substrate and process.
Transmittance: ≥93% vs. usually 90% - 93% vs. usually <90%. Phenyl silicone gel has better transmittance.
Temperature range: -59°C to 200°C vs. -50°C to 200°C vs. -40°C to 150°C. Selection depends on operating temperature.
Stress: Low stress, Shore A00 25±5 vs. medium vs. high stress. Silicone gel suitable for protection of precision components.
Yellowing resistance: Long-term yellowing resistance vs. general vs. poor. Phenyl silicone gel suitable for optical applications.
Curing by-products: No vs. no vs. possible. Addition polymerization silicone gel has no by-products.
Catalyst poisoning sensitivity: Sensitive to N, P, S, Sn, Pb, Hg, As vs. equally sensitive. Not involved. Need to strictly control environmental cleanliness.
Operation time: ≤240min vs. varies by product vs. varies by product. Selection depends on construction window.
Storage stability: 6 months vs. 6 months vs. 6 - 12 months. All need to be sealed, cool, dry storage.
Why is it still necessary to conduct complete tests for compatibility with substrate and operating environment?


Aydota's public information states that IOTA GNJ 3128H is used for moisture protection of electronic components, encapsulation of transistors and integrated circuits, and elastic bonding agent for optical instruments. However, when used in actual systems, there may still be:


Differences in substrate type and surface treatment.


Environmental cleanliness and control of catalyst poisons.


Mixing ratio and degassing process.


Matching of curing temperature and time.


Match between phenyl content and substrate refractive index.


Long-term yellowing resistance and light transmittance retention rate.


Storage conditions and packaging sealing.


Matching of operation time and construction process.


Effect of ionic impurities on volume resistivity and light transmittance.


Appearance transparency or short-term non-layering does not prove stability during long-term storage, thermal cycling, or long-term operation. Verification using the complete formula and actual materials should be conducted before use.


What parameters should be confirmed when using IOTA GNJ 3128H?


Parameter category Information to be confirmed
Application direction Electronic moisture protection, encapsulation of integrated circuits, optical instrument bonding
Substrate type Glass, metal, plastic, ceramic, chip, etc.
Surface treatment Cleaning method, drying degree, presence of contaminants
Mixing ratio A:B = 1:1 (weight ratio), uniformity of mixing
Degassing process Vacuum degassing conditions, time, vacuum degree
Operation time ≤240min, matching with construction process
Curing conditions 24h at room temperature or rapid heating curing conditions
Environmental cleanliness Avoid N, P, S, Sn, Pb, Hg, As, etc. poisons
Storage conditions Sealed, cool, ventilated, dry place, 6 months
Acceptance indicators Light transmittance, volume resistivity, Shore A00, bonding strength, yellowing resistance
What should be primarily verified when using IOTA GNJ 3128H?


Mixing uniformity and degassing effect.


Light transmittance and haze after curing.


Shore A00 hardness and low stress characteristics.


Volume resistivity and electrical insulation performance.


Bonding strength to substrate.


Long-term yellowing resistance and light transmittance retention rate.


High and low temperature cycling performance.


Match between refractive index of substrate.


Storage viscosity and curing activity.


Impact of environmental cleanliness on curing quality.


Batch consistency and repeatability.


How to design tests before using IOTA GNJ 3128H?


Establish a current silicone gel benchmark, record model, batch, mixing ratio, curing conditions and failure performance.


Unified test conditions: substrate, surface treatment, mixing ratio, defoaming process, curing temperature and time.


Set candidate samples: current silicone gel, IOTA GNJ 3128H, different curing condition gradients.


Complete the entire process test: mixing → defoaming → coating → curing → performance testing.


Evaluate actual results: transmittance, volume resistivity, hardness, bonding strength, color resistance.


Test items Unified requirements
Substrate type and surface treatment Keep consistent
Mixing ratio A:B = 1:1
Defoaming process Keep consistent
Curing conditions Set gradient according to test design
Environmental cleanliness Avoid catalyst poison contamination
Measurement methods Transmittance, volume resistivity, hardness, bonding strength, color resistance are consistent
Which situations are not suitable for directly using IOTA GNJ 3128H?


If the substrate surface is not cleaned or there are contaminants, it will affect the bonding strength and transmittance.


If there are N, P, S organic compounds or ionic compounds such as Sn, Pb, Hg, As in the environment, it will cause catalyst poisoning.


If the mixing ratio is inaccurate or not uniform, it will lead to incomplete curing.


If the vacuum defoaming is insufficient, there will be residual bubbles in the adhesive layer, affecting transmittance and moisture-proof performance.


It requires specific food contact, medical or other industry approval, but the corresponding materials have not been obtained yet.


If there are strict requirements for transmittance, but the refractive index matching verification has not been conducted.


Only know the substrate type, but do not know the mixing ratio, defoaming process and curing conditions.


The customer requests to directly mix it into the current system, but cannot control the mixing ratio and defoaming conditions.


The operation time exceeds 240 minutes, the viscosity of the adhesive layer increases, affecting the uniformity of coating.


The storage conditions do not meet the requirements of sealing, coolness and dryness, and the product absorbs moisture or deteriorates.


For optical instrument bonding, the long-term color resistance performance has not been evaluated.


For integrated circuits encapsulation, the low stress and thermal expansion matching has not been verified.


What selection support can Aytota provide?


As a "provider of the organic silicone全产业链 solutions"， Aytota can assist in comparing the applicability of phenyl silicone gel in different substrates， curing conditions and application scenarios for IOTA GNJ 3128H.


For electronic moisture-proof， integrated circuit encapsulation or optical instrument bonding projects that require both transmittance， low stress， thermal stability and moisture-proof performance， before selection， the following should be provided：


Substrate type and surface treatment method.


Target transmittance and refractive index matching requirements.


Mixing ratio and defoaming process conditions.


Curing temperature and time requirements.


Operating temperature range and color resistance requirements.


Volume resistivity and bonding strength requirements.


Current silicone gel model and curing conditions.


Failure manifestations and acceptance methods.


After receiving complete materials， it can be determined whether to prioritize testing IOTA GNJ 3128H or choose other silicone gel or encapsulation adhesive routes.


Common misunderstandings


A transmittance of ≥ 93% can be directly used for all optical bonding
Transmittance also depends on the refractive index matching of the substrate， the thickness of the adhesive layer， interface treatment and curing conditions， and requires special verification.


The mixing ratio can be slightly deviated
A:B = 1：1 is a weight ratio， deviation may lead to incomplete curing or performance decline， it needs to be precisely controlled.


The operation time can be adjusted freely within 240 minutes
The operation time is affected by environmental temperature， after exceeding the time， the viscosity increases， affecting the uniformity of coating and permeability.


It can be directly added to the current system if it is compatible with the substrate
It is still necessary to confirm the surface cleanliness， defoaming process， curing conditions and long-term stability.


The performance at 25℃ is the same， it can be replaced in equal quantities
Different silicone gels have different phenyl contents， refractive indices and curing characteristics， replacement requires re-verification.
Contact with N, P, S organic compounds or Sn, Pb, Hg, As and other ionic compounds in the gel will cause poor curing. The environmental cleanliness must be strictly controlled.


The 24-hour room temperature curing is the same as the heating curing performance.
Heating curing can increase the production rate and the adhesion of the substrate, but the curing conditions need to be verified according to the substrate and the process.


It can still be used normally after storage for 6 months.
The storage conditions should be in a cool, ventilated and dry place. After the expiration, the mixing ratio, viscosity and curing activity need to be retested.


IOTA GNJ 3128H can replace all silicone gels.
The phenolic silicone gel is suitable for high light transmittance, low stress and yellowing resistance requirements. For systems with high hardness or high bonding strength requirements, other silicone gels or potting resins may need to be selected.


Recommended selection steps


Confirm the application direction: electronic moisture protection, integrated circuit inner coating or optical instrument bonding.


Confirm the type of substrate and the surface treatment method.


Confirm the matching requirements for the target light transmittance and refractive index.


Confirm the mixing ratio and degassing process conditions.


Confirm the curing temperature and time requirements.


Confirm the operating temperature range and yellowing resistance requirements.


Select IOTA GNJ 3128H or other silicone gels based on the application scenario.


Set up different curing condition gradients for small tests.


Test light transmittance, volume resistivity, hardness, bonding strength and yellowing resistance.


Verify the compatibility with the substrate and the environment.


Complete the storage stability and batch consistency verification.


Confirm that the environmental cleanliness control (avoiding catalyst toxins) is in place.


After multiple batch verifications, determine the official usage plan.