Why is HHPA (Hexahydrophthalic Anhydride) Preferred in High-End Manufacturing?

HHPA (Hexahydrophthalic Anhydride), with its full name as cis-1,2-cyclohexanedicarboxylic anhydride, is an organic chemical raw material that combines high reactivity and stable performance. Boasting characteristics such as low toxicity, low viscosity, and excellent curing effects, it is widely used in various industrial fields including epoxy resin curing and plasticizer synthesis, and has become a core additive in industries like coatings, electronics, and composite materials.

I. Basic Properties of HHPA: Stable and Highly Compatible

1. Core Physicochemical Parameters

*Chemical Name: cis-1,2-cyclohexanedicarboxylic anhydride (Common Aliases: Hexahydrophthalic Anhydride, cis-Hexahydrophthalic Anhydride)

*CAS No.: 85-42-7; Molecular Formula: C₈H₁₀O₃; Molecular Weight: 154.17

*Appearance: White to off-white crystalline low-melting solid at room temperature; melts into a colorless and clear viscous liquid at 35-36℃, with slight hygroscopicity

*Key Properties: Density 1.18g/mL (40℃); Flash Point 143-152℃; Boiling Point 158℃ (2.7kPa); Easily soluble in organic solvents such as benzene, toluene, acetone, and chloroform, slightly soluble in petroleum ether

*Safety Attribute: Low toxicity (LD50 1200mg/kg), but highly irritating to skin and eyes; proper protection is required during operation

2. Core Chemical Characteristics

*Excellent Reactivity: Can be quickly mixed with epoxy resin at 50-60℃, featuring a long pot life and low curing exotherm, enabling rapid completion of crosslinking reactions

*Outstanding Stability: No double bonds in the molecular structure; the cured product is colorless and transparent, resistant to yellowing and aging

*Strong Compatibility: Compatible with various resins, fillers, and additives, especially suitable for high-filler loading scenarios

II. Core Application Fields of HHPA: Covering Rigid Demand Scenarios Across Industries

1. Epoxy Resin Curing Agent (Core Application)

*As a high-performance alicyclic anhydride curing agent, HHPA is most widely used in epoxy resin systems:

*Advantage Performance: The cured epoxy resin integrates high hardness, high toughness, and excellent electrical insulation. It is colorless and transparent with strong yellowing resistance, outperforming most traditional curing agents.

*Typical Scenarios: Electronic component encapsulation, insulating material molding, composite material preparation, high-end coating curing; especially suitable for products requiring high appearance transparency and weather resistance.

2. Fine Chemical Intermediate

*Plasticizer Synthesis: Used as an intermediate in the production of environment-friendly plasticizers with good compatibility and low migration, suitable for processing materials such as PVC and rubber.

*Functional Additive Preparation: Applied in the synthesis of insect repellents and rust inhibitors, leveraging its chemical stability to extend the service life and application scope of additives.

*Resin Modification: Serves as a modified monomer for polymer materials like alkyd resins, optimizing resin film-forming properties, corrosion resistance, and mechanical strength.

3. Other Industrial Scenarios

*Coating Industry: Used in the preparation of high-end anti-corrosion coatings and high-temperature resistant coatings, enhancing coating density and adhesion.

*Composite Materials: Adapts to the molding processes of carbon fiber, glass fiber, and other composite materials, improving the structural stability and aging resistance of materials.

III. Core Advantages of HHPA: Why It Becomes the Industry Preference

1. Performance Level: Balancing Effectiveness and Stability

*High Curing Efficiency: Low viscosity ensures uniform mixing with epoxy resin, shortens curing cycle, and improves production efficiency.

*Superior Finished Product Quality: The cured product is colorless and transparent without yellowing risk; it resists chemical corrosion and high-low temperature cycles, suitable for complex working conditions.

*Safer Controllability: Low toxicity meets modern environmental requirements, making operation and emission safer.

2. Application Level: Outstanding Compatibility and Cost-Effectiveness

*Wide Application Scope: Meets the performance requirements of high-end fields such as electronics and coatings, and adapts to the production needs of general chemical products.

*Strong Compatibility: No additional compatibilizers are needed for mixing with most resins and fillers, reducing formula adjustment costs.

*Stable Market Supply: Sufficient production capacity ensures long-term cooperative supply.

IV. Selection and Usage Notes

*Selection Matching: According to the epoxy resin model, curing temperature requirements, and product performance needs, confirm the purity (recommended ≥99.0%) and acid value (710-740mg KOH/g) of HHPA.

*Operation Specifications: Avoid direct skin contact; ensure good ventilation in the operating environment; store in a sealed, dry, and cool place to prevent moisture absorption from affecting performance.

*Formula Adjustment: When mixing with epoxy resin, control the temperature at 50-60℃ to ensure fluidity, and adjust the ratio and curing process according to product requirements.

*With its stable performance, wide compatibility, and excellent environmental attributes, HHPA has become an indispensable core chemical raw material in industrial production. Whether for high-end electronic materials, environmental protection coatings, or functional additives, HHPA can create value for customers by optimizing product performance and improving production efficiency.

*If the above information has inspired you, we are deeply honored. Dalian Sinobio Chemistry Co., Ltd. is committed to providing customers with high-quality L-Carnitine and professional solutions. We look forward to becoming your trusted preferred partner for chemicals, offering you efficient one-stop service.   Feel free to contact us anytime.