1. Market Pain Points
In modern tire manufacturing, sidewall markings—such as brand logos, size indicators, homologation codes, and decorative patterns—are not merely aesthetic features. They are critical for product identification, legal compliance, and brand differentiation. However, the colored rubber compounds used for these markings have long suffered from a set of persistent problems that compromise tire quality and shorten service life.
When searching for a reliable tire sidewall marking rubber compound, manufacturers often struggle to find a product that balances durability, processability, and environmental compliance. The most common pain points include:
- Rapid yellowing and fading — White or light colored sidewall markings turn yellow or brown after only a few months of exposure to sunlight, heat, and ozone. This is why an anti yellowing sidewall rubber factory is in high demand.
- Poor wear and scratch resistance — Markings become illegible due to abrasion from road debris, curbs, and tire cleaning brushes. A wear resistant tire marking rubber compound is essential to maintain legibility.
- Cracking and chalking under UV/weather exposure — The colored layer degrades, leading to surface cracks and a powdery appearance.
- Processing difficulties — Scorching (premature vulcanization) during co extrusion causes rejects and production downtime.
- Environmental compliance pressure — Many conventional colorants and curatives contain restricted substances (e.g., heavy metals, phthalates), failing RoHS, REACH, or other regional regulations. Manufacturers need a colored rubber compound for tire sidewall that meets global standards.
These issues directly impact tire manufacturers: increased warranty claims, customer complaints, and brand image erosion. For premium and electric vehicle tires, where sidewall appearance is a key selling point, the problem is even more acute. Consequently, selecting a trusted Tire Sidewall Compound supplier and Tire Sidewall Marking Rubber manufacturer has become a strategic decision for tire makers worldwide. As a leading Colored Rubber Compound Manufacturer, Sanezen Rubber addresses all these challenges with its advanced NC55 formulation.
2. Root Cause Analysis
Understanding why traditional colored rubber fails is essential to developing a reliable solution.
| Pain Point | Root Cause |
| Yellowing / fading | Use of low grade natural or synthetic rubber with insufficient antioxidant and antiozonant protection. Conventional curing systems (e.g., sulfur accelerator) leave unreacted double bonds that oxidize and form colored chromophores under heat/UV. |
| Poor wear & scratch resistance | Low rubber content or excessive filler loading (e.g., calcium carbonate, clay) reduces abrasion resistance. Inadequate crosslink density leads to low modulus and poor tear strength. |
| Weather/UV degradation | Lack of UV stabilizers and hindered amine light stabilizers (HALS). Traditional white pigments like TiO₂ can photocatalyze degradation if not properly coated. |
| Scorching during co extrusion | Mismatched curing kinetics between the colored compound and the black NR sidewall compound. Too short scorch time (T5) causes premature vulcanization in the extruder head. |
| Environmental non compliance | Use of banned plasticizers (e.g., certain phthalates), lead based stabilizers, or non compliant colorants. |
Moreover, many colored compounds are designed without considering the specific demands of sidewall co extrusion — high shear, elevated temperatures (typically 100–120°C at the extruder head), and the need for identical cure rates with the black base compound. When the colored layer cures faster or slower than the black sidewall, interfacial adhesion fails or surface defects appear.
3. Solution: Color Rubber NC55
To address these market pain points, Sanezen Rubber developed Color Rubber NC55, an eco friendly, NR based compounded rubber specifically engineered for tire sidewall marking applications. It represents the ideal white rubber compound for tire sidewall marking that does not yellow, while also serving as an eco friendly colored rubber for tire sidewall co extrusion and a wear resistant white natural rubber for tire logo sidewall.
3.1 What is NC55?
NC55 is a white colored, high rubber content compound based on natural rubber (NR). It incorporates a composite curing system that balances scorch safety, cure rate, and final mechanical properties. Unlike conventional colored compounds, NC55 is designed for co extrusion with black NR sidewall compounds — meaning it cures at the same rate and temperature (e.g., 160°C × 30 minutes) as the surrounding black rubber, ensuring perfect interfacial bonding. Moreover, NC55 is a uv stable colored tire marking compound with high elongation, making it resistant to both UV degradation and mechanical deformation.
3.2 How It Works
The composite curing system in NC55 achieves three simultaneous goals:
- Extended scorch time (T5 > 19 min at 125°C) — Safe processing even in long run co extrusion lines.
- Matched cure rate (TC90 ~ 622 sec at 160°C) — Synchronized vulcanization with standard black sidewall compounds.
- High crosslink density — Resulting in improved wear, scratch, weather, and UV resistance.
The compound is supplied as a B mix (containing curing package) with a 1 month shelf life at <25°C, or as an A mix (without curatives) for extended storage. This flexibility allows tire manufacturers to manage inventory and production schedules efficiently.
4. Product Features and Key Benefits
Based on the Technical Data Sheet (TDS SZ0322 2024 16 V2), NC55 delivers the following verified advantages:
4.1 High Rubber Content & Mechanical Strength
- Tensile strength ≥12 MPa (typical 13.58 MPa) — excellent resistance to tear and dynamic fatigue.
- Elongation at break ≥550% (typical 721%) — allows the colored layer to deform with the sidewall without cracking.
- 300% Modulus 3.53 MPa typical — balanced stiffness for good processing and durability.
4.2 Superior Wear, Scratch & Weather Resistance
The composite curing system and optimized filler package give NC55 outstanding resistance to:
- Abrasion from road contact and cleaning brushes.
- Scratching during tire mounting and normal use.
- UV radiation — no yellowing or chalking after extended sunlight exposure. In fact, NC55 is a true UV resistant white tire marking rubber compound that retains its brightness even under intense solar radiation.
- Ozone and thermal aging — retains whiteness and mechanical integrity.
4.3 Anti Aging Properties
NC55 contains a synergistic stabilizer package that prevents discoloration caused by high temperature and sunlight. Even after accelerated aging tests (e.g., 70°C × 7 days or UV exposure), the white color remains stable — a critical requirement for premium tire brands. This makes it an excellent anti aging white rubber for tire sidewall pattern area as well as an effective Anti aging colored rubber for tire sidewalls in general.
4.4 Safe Scorch Time & Processability
- Mooney ML (1+4) @125°C = 39.6 (within 37–45 specification) — consistent viscosity for stable extrusion.
- Scorch T5 @125°C = 19.42 min (range 16–26 min) — ample safety margin for co extrusion lines.
- Cure characteristics: TC30 = 305 sec, TC90 = 622 sec at 160°C — well matched to typical NR sidewall compounds.
4.5 Environmental Compliance
NC55 is formulated to meet:
- RoHS (Restriction of Hazardous Substances)
- REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals)
It contains no heavy metals (lead, cadmium, mercury, hexavalent chromium), no restricted phthalates, and no polycyclic aromatic hydrocarbons (PAHs). This makes it a rohs reach compliant rubber for white sidewall stripes and a certified REACH and RoHS compliant colored rubber compound. Furthermore, NC55 is an Eco friendly natural rubber based compound that aligns with the sustainability goals of modern tire manufacturers. It is suitable for tires sold in the EU, North America, Japan, and other regulated markets.
4.6 Typical Physical Properties
| Testing Items | Specification | Typical Value | Test Method |
| Hardness, Shore A | 55 ± 3 | 54 | ASTM D2240 |
| Modulus 300%, MPa | 3.5 | 3.21 | ASTM D412 |
| Tensile Strength, MPa | ≥12 | 13.58 | ASTM D412 |
| Elongation, % | ≥550 | 721 | ASTM D412 |
| Specific Gravity, g/cm³ | 1.27–1.33 | 1.318 | ASTM D297 |
| Mooney ML (1+4) @125°C | 37–45 | 39.6 | ASTM D6204 |
| Scorch T5/min @125°C | 16–26 | 19.42 | ASTM D6204 |
5. Application Guidelines
5.1 Typical Use
NC55 is applied to the tire sidewall area for marking purposes. It is co extruded with black natural rubber (NR) sidewall compound, either as a continuous stripe, lettering, or sidewall pattern inserts. Thanks to its formulation as a wear resistant white natural rubber for tire logo sidewall, logos and brand marks remain crisp and legible throughout the tire’s service life.
5.2 Processing Recommendations
- Extrusion temperature: 80–100°C (barrel), 90–110°C (head)
- Curing condition: 160°C × 30 minutes (adjustable based on tire cure cycle)
- Storage (B mix): Below 25°C, away from direct sunlight and moisture. Use within 1 month of production date.
- Storage (A mix): Up to 6 months at <25°C; add curatives just before use.
5.3 Compatibility
NC55 has excellent adhesion to standard NR sidewall compounds. For best results, ensure that the black sidewall compound does not contain excessive process oils that could migrate into the colored layer. A pre test on a small extrusion line is recommended before full production.
6. Packing, Storage & Shelf Life
- Packing: Palletized continuous sheets, stacked in rows, fixed with stretch wrap. Approximately 1000 kg/pallet.
- Custom packaging available upon request (e.g., smaller rolls, bags).
- Shelf life (B mix): 1 month from production date when stored below 25°C.
- Extended shelf life option: A mix (without curing package) can be stored for up to 6 months; curing package is added later by the user or upon request.
7. Frequently Asked Questions (FAQs)
FAQ 1: Can NC55 be used for other tire components besides sidewall markings?
Answer: While NC55 is optimized for sidewall co extrusion with NR compounds, it can also be used for sidewall pattern areas, small decorative inserts, or even colored tread stripes in specialty tires (e.g., classic car tires, bicycle tires). However, it is not recommended for the tread base or cap where high temperature resistance or low rolling resistance is critical. For other applications, please contact Sanezen for a custom formulation.
FAQ 2: How do we prevent scorching during long production runs?
Answer: NC55 has a safe scorch time (T5 = 19.4 min at 125°C), which is longer than most conventional colored compounds. To further minimize scorch risk:
- Maintain extruder barrel temperature below 100°C and head temperature below 110°C.
- Use a screw design with low shear and efficient cooling.
- Avoid long idle periods where the compound remains hot in the extruder.
- If using the A mix, ensure the curing package is uniformly blended and that the mix is used within 8 hours after adding curatives.
FAQ 3: The shelf life of B mix is only 1 month — can we extend it?
Answer: Yes. The 1 month shelf life applies to the B mix (with curing package). For longer storage, order the A mix (without curing package). A mix can be stored for up to 6 months under recommended conditions (<25°C, away from humidity). When ready to use, simply blend in the separate curing package provided by Sanezen or compound it in house according to the supplied recipe. This is a common practice among tire manufacturers who produce colored sidewall markings infrequently.
FAQ 4: Is NC55 available in other colors besides white?
Answer: The standard NC55 is white (based on titanium dioxide and white fillers), which is the most common requirement for tire markings. However, Sanezen’s Color Rubber Series can be customized to produce red, blue, yellow, or black colored compounds for specific branding or safety markings. Minimum order quantities and lead times apply for custom colors. Please contact our technical sales team for details.
8. Contact Us
For technical inquiries, sample requests, or to discuss a custom colored rubber formulation for your tire application, please reach out to Sanezen Rubber.
Plant Address:
Baishou Road, North District of Xuan Zhou Economic Development Zone
Xuancheng City, Anhui Province, China
Commercial Office (International Sales):
Room 1606 1608, Boda Commercial Buildings
No. 11 Puhuitang Road, Xuhui District
Shanghai, China 200030
Tel: +86- 1367 164 1995
Email: yorichen@sanezen.comWebsite:www.sanezenrubber.com
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