C5 Hydrocarbon Resin

I. Physical and Chemical Properties

Low Softening Point and Thermoplastic Balance

The softening point of C5 resin is typically between 70-120°C (adjustable through the polymerization process), lower than that of other petroleum resins such as C9 resin. While C5 hydrocarbon resin is a brittle solid at room temperature, it exhibits excellent fluidity when heated to its softening point and rapidly solidifies and forms upon cooling. This “low-temperature softening and room-temperature curing” characteristic eliminates the need for high-temperature processing in applications such as hot-melt adhesives and coatings, reducing energy consumption while preventing thermal damage to the substrate.

Excellent Solubility and Compatibility

The lack of polar groups in its molecular structure makes it highly compatible with a variety of non-polar solvents (such as toluene, xylene, gasoline, and mineral oil) and polymers (such as natural rubber, styrene-butadiene rubber, EVA, and polyethylene). For example, when added to rubber products, C5 hydrogenated petroleum resin disperses evenly within the rubber matrix, improving the product’s viscosity and elasticity without delamination or sedimentation. In inks, it blends seamlessly with pigments and binders, improving printability.

Strong Chemical Stability

The backbone is primarily composed of carbon-carbon single bonds, with only a small amount of unsaturated double bonds, resulting in outstanding acid, alkali, and water resistance. The resin structure is resistant to hydrolysis or degradation in environments with a pH of 3-11. Its water absorption rate is less than 0.1% upon contact with water, making it suitable for outdoor adhesives or coatings, and its long-term performance is not susceptible to degradation due to changes in ambient humidity.

II. Processing and Application Performance: Adaptable to Various Production Needs

Excellent Viscosity Adjustment

As a core category of “tackifying resins,” C5 resins form weak interactions with substrate surfaces through the unsaturated bonds in their molecular chains, significantly improving both initial and sustained tack. For example, adding 10%-30% of C5 resin to a pressure-sensitive adhesive can increase the peel strength from 5N/25mm to over 15N/25mm without compromising aging resistance.

Easy to Control Flowability

Its molecular weight distribution is narrow (typically between 1.5 and 3.0), and its melt viscosity is stable after heating. The flowability can be precisely controlled by adjusting the processing temperature (e.g., 120-160°C) or adding plasticizers. This characteristic enables it to evenly coat complex substrates in precision casting or coating, forming a film of consistent thickness without the formation of bubbles or cavities.

Excellent synergy with fillers

The non-polar groups in its molecular structure can form adsorption interactions with the surfaces of inorganic fillers such as calcium carbonate and talc, improving the filler’s dispersion within the polymer matrix. For example, adding a C5 petroleum resin and calcium carbonate composite system to plastic modification can increase the composite’s impact strength by 20%-30%, while reducing production costs and maintaining molding efficiency.

III. Environmental Resistance and Safety: Balancing Practicality and Environmental Protection

Moderate Aging Resistance

Compared to high-performance resins like epoxy resins, C5 resin has weaker UV aging resistance (it tends to yellow after long-term exposure to sunlight). However, by combining it with antioxidants and UV absorbers, its aging lifespan can be significantly improved. For example, adding 0.5%-1% of antioxidant 1010 to C5 resin in outdoor paint can extend the coating’s weathering resistance from one year to over three years, meeting the needs of mid-range and low-end outdoor applications.

Low Toxicity and Environmental Protection

No toxic monomers such as formaldehyde and benzene are released during the polymerization process. The volatile organic compound (VOC) content in the finished product is less than 50g/L, complying with environmental standards such as the EU RoHS and China’s GB 18583-2008. When used in applications such as children’s toys and food packaging adhesives, it poses no risk to human health and can be disposed of via incineration or landfill after disposal, minimizing environmental pollution.

Limited Temperature Range

Long-term operating temperatures typically range from -20°C to 80°C. Above 80°C, C5 aliphatic hydrocarbon resin is prone to softening and deformation, while temperatures below -20°C may cause brittle cracking. This limitation makes it unsuitable for high-temperature applications (such as those surrounding automotive engine components). However, its performance stability fully meets operational requirements in ambient or medium-low temperature environments (such as interior decoration and daily necessities packaging).

With the continuous development of the global economy and the accelerated advancement of industrialization, the market demand for C5 petroleum resin continues to grow. Especially in industrial fields such as coatings, inks and rubber, the demand for high-performance and environmentally friendly C5 petroleum resin is growing. In the future, with the continuous advancement of technology and the upgrading of industries, the market prospects of C5 petroleum resin will be broader.