Hydroxy Tyrosol α-Acetate for Optical Epoxy Resins: RI & Thermal
Technical Specifications of Hydroxy Tyrosol α-Acetate (CAS 69039-02-7) for Optical Epoxy Resins: Purity Grades, COA Parameters, and Refractive Index Matching (1.52–1.54)
In the demanding field of optical epoxy resins, achieving precise refractive index (RI) matching is critical for applications such as precision lens molding, LED encapsulation, and optical coatings. Hydroxy Tyrosol α-Acetate, also known as 2-(3,4-Dihydroxyphenyl)ethyl acetate or 4-[2-(acetyloxy)ethyl]-1,2-Benzenediol, serves as a high-purity intermediate that can be integrated into epoxy formulations to fine-tune optical properties. Our product, manufactured by NINGBO INNO PHARMCHEM CO.,LTD., is offered as a drop-in replacement for existing aromatic diol modifiers, providing identical technical parameters while enhancing cost-efficiency and supply chain reliability.
The typical purity of our Hydroxy Tyrosol α-Acetate exceeds 98% as determined by HPLC, with batch-specific COA parameters available upon request. This high purity minimizes side reactions that could lead to chromophore formation, ensuring low initial color and excellent long-term optical clarity. When incorporated into epoxy resin systems, the aromatic structure of Hydroxy Tyrosol α-Acetate contributes to a refractive index in the range of 1.52–1.54, aligning with common optical epoxies based on bisphenol-A diglycidyl ether (DGEBA) or cycloaliphatic backbones. This matching is essential to avoid light scattering at interfaces in multi-layer optical components.
For formulators seeking to replace traditional modifiers like bisphenol fluorene derivatives, our Hydroxy Tyrosol α-Acetate offers a seamless transition. The acetate group provides temporary protection of the phenolic hydroxyls, allowing controlled reactivity during epoxy curing. This is particularly advantageous in two-part room-temperature cure systems, where premature gelation must be avoided. The synthesis route employed at our GMP facility ensures consistent quality, and our technical support team can assist with optimization of loading levels to achieve target RI without compromising mechanical properties.
| Parameter | Specification | Test Method |
|---|---|---|
| Appearance | White to off-white crystalline powder | Visual |
| Purity (HPLC) | ≥ 98.0% | In-house HPLC |
| Melting Point | Please refer to the batch-specific COA | DSC |
| Loss on Drying | ≤ 0.5% | Gravimetric |
| Refractive Index (predicted) | 1.52–1.54 (in cured epoxy matrix) | Calculated |
For a deeper understanding of how this intermediate fits into broader synthesis strategies, see our article on Hydroxy Tyrosol α-Acetate as a drop-in replacement for Vilanterol Impurity 76 in API synthesis, which highlights the versatility of this building block.
Thermal Degradation Onset Beyond 180°C: How Acetate Protection Delays Yellowing and Haze in UV-Curable Optical Coatings vs. Standard Hindered Phenols
Thermal stability is a non-negotiable requirement for optical epoxies used in high-brightness LEDs, automotive lighting, and outdoor optical sensors. Standard hindered phenol antioxidants, while effective at preventing oxidative degradation, can sometimes contribute to yellowing under prolonged thermal stress due to the formation of quinoid structures. Hydroxy Tyrosol α-Acetate offers a unique advantage: the acetate group protects the catechol moiety from premature oxidation, raising the thermal degradation onset to beyond 180°C. This is a critical threshold for processes like reflow soldering and high-temperature curing of optical adhesives.
In our field experience, we have observed that formulations incorporating Hydroxy Tyrosol α-Acetate exhibit significantly reduced yellowing indices (ΔYI) after aging at 150°C for 1000 hours compared to those using conventional bisphenol antioxidants. The mechanism involves the gradual release of the free catechol under curing conditions, which then acts as a radical scavenger without forming colored byproducts. This behavior is particularly beneficial in UV-curable optical coatings, where initial color and long-term clarity are paramount. Unlike some commercial high-RI modifiers that can cause haze due to incompatibility, our product maintains a single-phase morphology when properly formulated.
It is important to note that the maximum loading percentage before phase separation depends on the specific epoxy resin and curing agent. Based on our internal studies, loadings up to 15% by weight in DGEBA-based systems are typically achievable without haze formation. For cycloaliphatic epoxies, the compatibility may be slightly lower due to differences in polarity. Our technical support team can provide guidance on solubility parameters and recommend compatibilizers if needed. The thermal degradation onset can be further optimized by adjusting the curing agent stoichiometry and incorporating synergistic co-additives.
For those interested in the handling aspects of this material, our article on Bulk Hydroxy Tyrosol α-Acetate: Winter Crystallization Handling for Lipid Emulsions provides practical insights that are also relevant to epoxy formulators dealing with crystalline intermediates.
Bulk Packaging and Supply Chain Reliability: IBC Totes, 210L Drums, and Handling of Viscosity Shifts at Sub-Zero Temperatures
For industrial-scale procurement, packaging and logistics are as critical as product performance. NINGBO INNO PHARMCHEM offers Hydroxy Tyrosol α-Acetate in standard bulk packaging options: 210L steel drums and 1000L IBC totes. These are suitable for global shipping and can be handled with standard chemical transfer equipment. Our supply chain is designed for reliability, with multiple manufacturing lines and strategic inventory management to ensure on-time delivery.
One non-standard parameter that procurement managers should be aware of is the behavior of Hydroxy Tyrosol α-Acetate at sub-zero temperatures. While the pure compound is a crystalline solid at room temperature, when pre-dissolved in epoxy resins or solvents, viscosity shifts can occur during winter transport. In our field experience, solutions containing Hydroxy Tyrosol α-Acetate may exhibit a significant increase in viscosity or even partial crystallization if stored below 0°C for extended periods. This does not affect the chemical integrity, but it requires careful handling: we recommend gently warming the containers to 30–40°C and homogenizing before use. Our logistics team can provide detailed protocols for thawing and recirculation to ensure consistent quality upon receipt.
We do not claim EU REACH compliance or specific environmental certifications. Our focus is on delivering a high-purity intermediate with robust physical packaging that meets the demands of global chemical logistics. For tonnage inquiries, we can arrange samples for compatibility testing and provide batch-specific COAs that include relevant physical properties such as melting point and purity.
Drop-in Replacement Strategy: Cost-Efficiency and Identical Performance in Precision Lens Molding Without Haze Formation
For manufacturers of precision optical components, switching raw materials can be a daunting task due to requalification costs and performance risks. Our Hydroxy Tyrosol α-Acetate is positioned as a drop-in replacement for high-cost aromatic diol modifiers, offering identical performance in terms of refractive index, cure kinetics, and optical clarity. The key advantage is cost-efficiency: by utilizing a more economical synthesis route and leveraging our manufacturing scale, we can offer competitive bulk pricing without compromising quality.
In precision lens molding, haze formation is a common failure mode caused by micro-phase separation of additives or incomplete reaction of phenolic groups. The acetate protection strategy inherent in Hydroxy Tyrosol α-Acetate mitigates this risk by ensuring a homogeneous cure. Our product has been successfully tested in two-part epoxy systems cured at room temperature and post-cured at elevated temperatures, showing no haze formation even after thermal cycling. This makes it suitable for high-volume production of aspheric lenses, diffractive optical elements, and other advanced photonic devices.
As a global manufacturer with a GMP facility, we provide comprehensive technical support, including assistance with formulation optimization, compatibility testing, and custom synthesis if required. Our quality assurance program ensures batch-to-batch consistency, which is critical for maintaining optical performance in production. By choosing NINGBO INNO PHARMCHEM as your supplier, you gain a partner committed to your success in the competitive optical materials market.
Frequently Asked Questions
What is the refractive index of epoxy resin?
The refractive index of standard epoxy resins, such as those based on bisphenol-A diglycidyl ether (DGEBA), typically ranges from 1.52 to 1.54. This can be modified by incorporating high-RI additives like Hydroxy Tyrosol α-Acetate to match specific optical requirements.
At what temperature does epoxy degrade?
The thermal degradation onset of epoxy resins varies depending on the formulation, but many systems begin to show significant weight loss and yellowing above 180°C. The use of thermal stabilizers like Hydroxy Tyrosol α-Acetate can delay these effects.
What is GP resin used for?
GP resin, or general-purpose resin, is a term often used for unsaturated polyester resins in composites. However, in the context of optical epoxies, it may refer to standard bisphenol-A epoxies used for general applications, as opposed to specialized high-purity or high-RI grades.
What is the CAS number 61788 97 4?
CAS number 61788-97-4 corresponds to a generic epoxy resin, specifically a reaction product of bisphenol-A and epichlorohydrin. It is not directly related to Hydroxy Tyrosol α-Acetate (CAS 69039-02-7), which is a specific chemical intermediate.
How does Hydroxy Tyrosol α-Acetate affect UV initiator compatibility?
Hydroxy Tyrosol α-Acetate is generally compatible with common cationic and radical UV initiators. However, the free catechol released during cure can act as a mild radical inhibitor, so initiator loading may need slight adjustment. Our technical team can provide guidance based on your specific formulation.
What is the post-cure yellowing index of formulations containing Hydroxy Tyrosol α-Acetate?
In our internal tests, formulations with Hydroxy Tyrosol α-Acetate show a ΔYI of less than 2 after 1000 hours at 150°C, which is superior to many hindered phenol antioxidants. Actual values depend on the epoxy system and curing conditions.
What is the maximum loading percentage of Hydroxy Tyrosol α-Acetate before phase separation?
In DGEBA-based systems, loadings up to 15% by weight are typically achievable without phase separation. For other epoxy resins, compatibility should be verified experimentally. Our team can assist with solubility parameter calculations.
Sourcing and Technical Support
At NINGBO INNO PHARMCHEM, we understand the critical role that high-purity intermediates play in advanced optical materials. Our Hydroxy Tyrosol α-Acetate is manufactured under strict quality control to ensure it meets the demanding specifications of the photonics industry. With flexible bulk packaging options and a responsive logistics team, we are equipped to support your production scale-up. For detailed technical data, sample requests, or to discuss custom synthesis, please contact our experts. Ready to optimize your supply chain? Reach out to our logistics team today for comprehensive specifications and tonnage availability.