In high-temperature masking tape, insulation tape, and many industrial tapes,
silicone pressure-sensitive adhesive systems are among the most important pressure-sensitive adhesives on the market. These silicone pressure-sensitive adhesives (often shortened to silicone PSA or silicone PSAs) are widely used where a wide temperature range, high heat resistance, excellent cold resistance, and strong chemical resistance are required.
Compared with acrylic pressure-sensitive adhesives or rubber-based pressure-sensitive systems, a silicone pressure-sensitive adhesive offers several key advantages:
A much wider service temperature range, from very low temperatures up to extreme high heat
Excellent resistance to chemicals, solvents, moisture, and even fungus or mildew in demanding environments
The ability to bond to low energy surfaces and difficult substrates, such as fluoropolymers, polyolefins, and silicone release liners
Good clarity and optical properties for films, protective films, display films, and plastic films
However, for these pressure sensitive adhesive systems to deliver the right adhesive properties, adhesion, cohesion strength, and clean removability, the choice of silicone resin—especially MQ silicone resin and methyl/phenyl silicone resins—is critical.
1. What is the backbone of silicone PSA?
1. What is the backbone of silicone PSA?
A typical solvent-based silicone pressure-sensitive adhesive is built from two core raw material components:
(1) High Molecular Weight Silicone Gum
Methyl silicone gum or methyl/phenyl copolymer gum
Provides flexibility, low-temperature performance, and good bonding to various surfaces and substrates
(2) Highly Branched MQ Silicone Resin (MQ Resin)
Composed of M units (SiO₀.₅R₃) and Q units (SiO₂)
R can be methyl, phenyl, or other organic groups, providing a versatile, wide array of design options
Has a high glass transition temperature (Tg) and a rigid structure
It is essential to build cohesive strength, adhesive strength, and high temperature stability.
In a suitable solvent system (often toluene, aliphatic hydrocarbons, or their blends), silicone gum and MQ resin are formulated and processed together. Under the right catalyst and curing process, they condense and later crosslink to form a three-dimensional network. The coating is then applied as a coating onto backings such as polyester, polyimide, cloth, or release papers, and further cured to build the final adhesive performance.
For the formulation engineer, selecting and adjusting the type and level of silicone resin allows fine-tuning of:
Tack, peel, and adherence (peel adhesion)
Cohesive strength (internal cohesion strength) and high temperature shear
Clean removability after heat aging or long-term insulation use
Adhesion to different surfaces and substrates (metals, plastics, films, foams, and textiles)
In simple words:
Silicone gum determines whether it sticks; silicone resin determines how strongly it sticks, how it behaves at high temperature, and how cleanly it can be removed.
XJY-301 Silicone pressure-sensitive adhesives
It is made from the specific structure of silicone resin and high molecular weight polydimethylsiloxane in cooperation with organic adhesive, which is suitable for specific scene conditions.
Compared with natural rubber, it is characterized by heat resistance, high stability, good electric insulation, good transparency, high peel adhesion, and chemical resistance etc. It has a wide range of applications in industrial product processing, electronic processing, optical materials, health care, and mica tapes, splicing tapes, protective films, and other fields.
2. Methyl vs. Phenyl – Balancing Performance and Cost
In high-temperature-resistant silicone PSA tapes, two major families of silicones are used:
Methyl silicone pressure-sensitive adhesive systems
Phenyl silicone pressure-sensitive adhesive systems
The main difference is whether phenyl groups are introduced into the backbone or side chains.
Phenyl silicone PSAs typically provide:
Even better, high heat resistance and thermal stability
Improved performance at very high temperatures, where vibration, thermal cycling, and aggressive chemicals are present
However:
Phenyl silicone gum and phenyl silicone resins are more expensive compared with pure methyl systems
This raises the cost of the total pressure-sensitive adhesive system
Methyl silicone PSAs usually offer:
More competitive cost, especially for large-volume industrial applications
A good compromise between adhesive properties, adhesive strength, and cost
With the right silicone resin and MQ silicone pressure-sensitive formulation, they can reach excellent resistance to heat, moisture, solvents, and chemicals
Many tape makers, therefore, ask:
“How can we use methyl silicone pressure sensitive adhesives to get performance closer to phenyl systems, while still controlling cost?”
The answer is to optimize the resin package: using well-designed MQ silicone resins and methyl/phenyl silicone resins to assist the engineer in improving anchorage, improving bond strength, and enhancing high-temperature performance.
3. What is the real value of silicone resins in applications?
End users care less about theory and more about concrete tape applications. Their typical questions are:
“What kind of silicone resin is suitable for my application?”
“Which raw material can help me reduce residue and improve high temperature adhesion?”
Below are several key fields where silicone pressure-sensitive adhesive systems and silicone resins are widely supplied and used.
(1) Electronics & Electrical – High Temperature Soldering and Insulation Tapes
In electronics and electrical insulation, silicone PSAs are used in:
Solder masking tapes for PCB and FPC
High temperature insulation tape for motors and transformers
Protective films and special film applications for displays and sensitive electronic parts
These products must offer:
Reliable high-temperature adhesive performance during soldering, reflow, curing, and other harsh processing steps
Strong adhesion and cohesive strength to PI and PET films, copper, stainless steel, and other substrates
Excellent electrical insulation, chemical resistance, and moisture resistance
Clean removability, with minimal or zero residue
Here, MQ silicone resin is key to:
Build internal cohesion strength so that the coated adhesive layer does not slide or split under stress and vibration
Maintain adhesive properties and reliability over a wide temperature range
Work with suitable primer systems to improve anchorage to difficult surfaces
When formulated correctly, these silicone PSA systems show high stability in contact with solvents, fluxes, and various chemicals encountered in electronic processing.
(2) Automotive – Engine Compartment, Wire Harness, and Paint Masking
In the automotive sector, high-temperature tapes are used for:
Masking around engines and exhaust components
Fixing and bundling wire harnesses in areas exposed to heat and vibration
Body paint and bake masking tape on polyester, steel, and other backings
EV battery pack insulation and protection
In these applications, the adhesive must combine:
High adhesive strength and secure bonding to many substrates
Long-term stability at elevated temperatures, including exposure to oil, chemicals, and moisture
Easy, clean removability without damaging the surfaces or leaving heavy residue
By using optimized silicone resins and MQ silicone resins, automotive tape producers can achieve:
Better high temperature resistance and cohesive stability
Controlled peel, tack, and adherence to painted metals, plastics, and composites
Durable performance under vibration, temperature cycling, and outdoor sunlight
Compared with many standard acrylic pressure-sensitive adhesives from big brands such as Dow, a well-designed silicone pressure-sensitive adhesive often delivers superior temperature and chemical resistance and is more suitable for under-the-hood environments.
(3) Powder Coating & Industrial Coating – High Temperature Masking and Clean Removal
In metal finishing, industrial powder coating, and baking coating lines, silicone pressure-sensitive masking tapes are required to:
Resist high curing temperatures in powder coating ovens
Maintain line clarity and sharp masking edges
Offer clean removability even when removed hot
If the pressure-sensitive adhesive is not heat-resistant enough, the adhesive may soften, flow, or degrade, leading to:
Dirty edges and poor masking quality
Adhesive residue on metal surfaces and films
Extra processing steps and cleaning to remove adhesives
By choosing high Tg silicone resin and a well-balanced MQ resin package, powder coating masking tapes can be formulated to:
Provide strong internal cohesion, strength, and high temperature resistance
Work on polyimide, polyester, and cloth backings as well as papers
Offer a reliable balance between tack, peel, and clean removability
These advantages help coaters and fabricators reduce rework and discover more stable production windows.
4. What Should Formulators Look for When Selecting Silicone Resins?
As a silicone resin and silicone PSA raw material supplier, we often hear:
“My high temperature masking tape has poor shear and residue issues – which silicone resin can assist with that?”
“I want to move from a phenyl system to a more economical methyl silicone pressure sensitive adhesive – which MQ resin is suitable?”
Formulators should pay attention to several key factors when choosing silicone resins:
Resin Type and Structure
Pure methyl MQ silicone resins, methyl/phenyl MQ silicones, and other silicone resins
Each structure influences Tg, rigidity, compatibility, and overall adhesive properties
Resin / Gum Ratio (R/G Ratio)
Controls adhesive strength, cohesive strength, and high temperature resistance
Too low: insufficient cohesion strength and heat stability
Too high: lower tack and flexibility, difficult processing
Functionality, Catalyst and Cure Mechanism
Silanol, vinyl and other functional groups must fit the chosen catalyst and cure process
Impacts crosslink density, volatility, and the ability to resist solvents, aliphatic hydrocarbons and other chemicals
Solvent System and Dilution
Compatibility with solvents like toluene, xylene, and diluted blends
Viscosity and solids must match your coating and drying process so the adhesive layer is evenly coated
Target Applications and Backings
Electronics and electrical insulation tapes
Automotive high-temperature masking and insulation tapes
Industrial and powder coating masking tapes, protective films, and plastic films
Specialty applications on polyimide, polyester, cloth, and paper backings
Matching the silicone pressure-sensitive system to the real application is essential to get the best properties and long-term reliability.
5. What Can a Silicone Resin Supplier Offer to Tape Manufacturers?
From a raw material supplier’s perspective, we do more than just sell “a resin in a solvent.” Our goal is to help you formulate a better sensitive adhesive system.
For customers developing or upgrading high temperature silicone pressure-sensitive adhesives and tapes, a professional silicone resin partner can:
Supply a portfolio of MQ silicone resins and related silicones, with different M/Q ratios and functionalities
Offer resin solutions optimized for electronics, industrial insulation, powder coating masking, and automotive applications
Recommend combinations of silicone pressure-sensitive materials, primer systems, and backings to improve anchorage, bonding, and adherence
Work with your coating and curing process to optimize viscosity, solids, cure schedule, and oven profile
By adjusting the resin package, you can:
Increase high-temperature cohesive strength and adhesive strength
Maintain strong adhesion yet still get clean removability
Improve overall reliability and stability of the adhesive system, even under sunlight, chemicals, moisture, and mechanical vibration
6. How to make silicone PSA perform better?
Whether you are working in electronics, automotive, or industrial coating, the demand for high-performance pressure-sensitive adhesives and high-temperature tape is growing. Customers expect:
Strong, durable adhesion on a wide variety of substrates and surfaces
A wide temperature range, plus high heat resistance and cold resistance
Excellent chemical resistance, moisture resistance, and resistance to solvents and chemicals
Reliable, clean removability with minimal residue
In all of these areas, silicone pressure-sensitive adhesives formulated with the right silicone resin and MQ silicone PSA technology can outperform many conventional systems.
XJY Silicones is one of the leading silicone MQ resin and VMQ silicone manufacturers in China, with more than 30 years of R&D and manufacturing experience in the silicone industry, as well as more than 15 related patents and technical support. Our silicone raw material products can meet the needs of the silicone coating field and support the provision of diversified customized solutions.