C5 Resin: Properties, Uses and Supplier Guide

C5 resin is a light-colored, thermoplastic aliphatic tackifier made by polymerizing the reactive C5 stream—often rich in piperylene—from steam-cracked naphtha. It is selected mainly to increase tack, wetting and peel in adhesives and to bind thermoplastic road-marking compounds, while retaining low acidity and practical melt-processing behavior.

What is C5 aliphatic petroleum resin?

The name C5 describes the refinery or petrochemical feedstream, not one pure five-carbon monomer. Steam cracking of naphtha produces a C5 fraction containing reactive olefins and diolefins. Piperylene is usually an important component; isoprene, cyclopentadiene and related molecules may also contribute, depending on the feed and process. Controlled polymerization converts that mixed stream into a low-molecular-weight, glassy solid.

Because its backbone is predominantly aliphatic, C5 petroleum resin has low polarity. It is insoluble in water but dissolves or blends in many hydrocarbon media and nonpolar polymer systems. It is not normally the structural polymer in an adhesive. Instead, it modifies the base polymer: lowering melt viscosity, improving substrate wetting and moving the balance among initial tack, peel and cohesive strength.

“C5 resin,” “C5 hydrocarbon resin,” “C5 petroleum resin” and “aliphatic hydrocarbon resin” are often used interchangeably in purchasing. They still do not define a complete grade. Feed composition, aromatic modification, hydrogenation, molecular-weight distribution and softening point can materially change performance. For the broader product family, see our hydrocarbon resin guide.

Typical C5 resin properties

The values below are a screening guide compiled from representative commercial technical data sheets, not a universal sales specification. WESTCO lists 95–105°C and 105–115°C grades, Gardner color limits of 4–7, acidity of 0.5–1.0 mg KOH/g and typical specific gravity of 0.94. A separate C5 TDS distributed by Ravago reports 95–105°C, Gardner 5 maximum and acid value 0.6 mg KOH/g maximum.¹²

Typical values — commercial unhydrogenated C5 resin

Property	Typical value or range	Why buyers check it
Appearance	Light-yellow granules	Feeding, handling and visual consistency
Softening point, ring-and-ball	90–110°C	Heat response, tack window and processing
Gardner color	≤7; low-color grades commonly ≤5	Finished adhesive or coating color
Acid value	≤1.0 mg KOH/g	Formulation stability and lot consistency
Specific gravity	About 0.94–0.98	Volume-to-mass calculations
Melt viscosity at 200°C	Often about 70–250 mPa·s	Mixing, pumping and coating behavior

Test method and sample preparation matter. Gardner color may be measured in solution or molten resin, while melt viscosity must state temperature and method. Softening point is not a true melting point; hydrocarbon resin softens over a range. Compare supplier limits, methods and a certificate of analysis rather than comparing one headline number.

C5 resin vs rosin and terpene tackifiers

Natural-origin tackifiers are not automatically better or worse. Their polarity, oxidation behavior and polymer compatibility differ, and hydrogenated or chemically modified versions can behave very differently from the base family.

Selection factor	C5 hydrocarbon resin	Rosin / rosin ester	Terpene resin
Feedstock	Petrochemical C5 cracking stream	Pine-derived gum, wood or tall-oil rosin; often esterified	Terpene feedstocks such as alpha-pinene, beta-pinene or limonene
General polarity	Low	Higher; esterification reduces rosin acidity	Low to moderate, grade-dependent
Common strengths	Fast tack, good wetting, low acid value, economical formulation	Strong wetting and broad adhesion, especially where more polarity helps	High tack and useful compatibility in selected elastomer systems
Heat and color behavior	Good for standard industrial use; hydrogenated grades improve color and oxidation resistance	Unmodified rosin is more oxidation-sensitive; stabilized or hydrogenated esters perform better	Depends strongly on monomer, softening point and hydrogenation
Practical caution	Standard C5 may not suit polar polymers or water-white requirements	Acid value and odor require attention; raw rosin is not equivalent to a rosin ester	Supply and cost may be less favorable; confirm polymer compatibility

The right comparison is formulation-specific. Screen tackifiers at equal resin loading, then measure viscosity, cloud point, color, loop tack, peel, shear and heat aging. A lower-cost resin is not economical if it forces more polymer, slows the coating line or misses the end-use specification.

Core applications

Hot-melt adhesives

In hot-melt adhesive formulations, C5 resin provides tack and promotes wetting while helping control melt viscosity. It is commonly evaluated with:

• EVA: compatibility depends on vinyl-acetate content, resin chemistry and wax package. Standard aliphatic C5 is often a better fit with lower-VA EVA; modified C5 may widen the window.
• SIS: C5 resin has strong affinity for the rubbery polyisoprene phase and is a common starting tackifier for hot-melt PSAs. Published research has observed complete compatibility between a C5 resin and the polyisoprene blocks in the SIS system studied.³
• SBS: usable compatibility is grade-dependent. C5/C9 or styrene-modified grades can be worth screening where a straight aliphatic resin gives haze, phase separation or an unsuitable tack–cohesion balance.

Do not select on softening point alone. Run a drawdown or coating trial and compare melt viscosity, open time, set speed, peel, heat resistance and color after aging.

Thermoplastic road-marking paint

In road-marking paint, C5 resin acts as the binder that holds pigment, mineral filler, glass beads and additives together. It supports hot flow, pavement adhesion and rapid film formation on cooling. A practical formulation window is 10–22 wt% C5 resin in the total dry blend, but the correct loading depends on the governing road specification and the balance of aggregate, pigment, beads, wax and plasticizer.

That range should be treated as formulation guidance, not a universal standard. An Exxon road-marking patent describes 10–30 wt% resin and a preferred 13–22 wt% petroleum-resin range relative to resin plus aggregate.⁴ Kolon’s published comparison uses 15 wt% C5 resin in its test formulation, alongside 60% calcium carbonate, 20% glass beads, 3% titanium dioxide, 1% wax and 1% oil.⁵ Validate flow, softening behavior, color stability, abrasion and adhesion under the applicable local method.

Pressure-sensitive adhesives

For tapes, labels and nonwoven assembly, C5 resin helps build quick stick and peel in SIS-, SBS- and rubber-based PSAs. Lower-softening grades can favor wetting and low-temperature tack; higher-softening grades may support heat response and cohesive balance. Those are starting tendencies, not guaranteed outcomes. Polymer architecture, oil level, resin loading, antioxidant package and coating weight all interact.

Milorez C5 grades

Milorez supplies MR-series petroleum resins as a transparent export trading partner based in Fujian, China. The two standard C5 selection points are:

Typical values — grade selection

Grade	Nominal softening point	Suggested first screen	Grade page
MR-C5100	100°C	General adhesive and road-marking development requiring balanced processing	MR-C5100 details
MR-C5110	110°C	Formulations beginning with a higher softening-point target	MR-C5110 details

Nominal softening point is not the full acceptance specification. Request the current TDS and confirm the agreed limits for color, acid value, melt viscosity and test methods before commercial approval.

Buying, packing and wholesale supply

When comparing C5 petroleum resin suppliers, send one written requirement to every bidder. Include the end use, polymer system, target softening point, maximum Gardner color and acid value, viscosity test condition, trial quantity, annual demand and destination. This prevents a nominal “100°C C5” from being compared with a chemically modified or differently tested product.

Milorez’s commercial MOQ is 1×20’FCL, with FOB Xiamen or FOB Qingdao shipment terms. A free sample is available for laboratory evaluation. Packing format, bag construction, net bag weight, palletization and container payload should be confirmed in the quotation and pro forma invoice; do not infer the shipment configuration from another supplier’s TDS. This is especially important for C5 petroleum resin wholesale orders, where pallets and moisture protection affect usable container weight and warehouse handling.

For a meaningful price request, provide:

1. MR-C5100, MR-C5110 or your target specification;
2. adhesive, PSA, road-marking or other application;
3. destination port and requested Incoterm;
4. packing and pallet preference;
5. trial timing and expected annual volume; and
6. any benchmark resin, test recipe and pass/fail data.

Request a formulation-matched C5 resin sample

Tell Milorez what you formulate, which polymer or road-marking standard you use, and the property you need to improve. We can align the initial screen with MR-C5100 or MR-C5110, provide a free sample and quote one 20-foot FCL FOB Xiamen or Qingdao. For a hydrogenated benchmark, review the Escorez 5300 equivalent guide before requesting a match.

Frequently asked questions

What is C5 resin made from?

It is made by polymerizing reactive components in the C5 stream generated during naphtha cracking, commonly including piperylene and related aliphatic olefins and diolefins. Feed composition and process conditions shape the final resin.

What is the difference between C5 and C9 resin?

C5 is predominantly aliphatic and is widely used for tack in nonpolar adhesive and road-marking systems. C9 is predominantly aromatic and often fits coatings, inks, rubber or polymers needing aromatic compatibility. Modified C5/C9 resins bridge parts of that gap; test the actual grade.

Is standard C5 resin equivalent to Escorez 5300?

No. ExxonMobil describes Escorez 5300 as a water-white hydrogenated cycloaliphatic resin with a typical softening point of 105°C.⁶ Standard unhydrogenated C5 resin differs in chemistry, color and aging profile. Use our Escorez 5300 comparison to define the full benchmark rather than matching only softening point.

Which Milorez grade should I test first?

Start with MR-C5100 when 100°C nominal softening gives the desired balance of tack and processing. Screen MR-C5110 when your formulation calls for a nominal 110°C grade. Confirm performance in your complete recipe.

What is the MOQ?

The minimum commercial order is one 20-foot full-container load. FOB Xiamen and FOB Qingdao are available. Milorez provides free samples for pre-purchase evaluation.

How can I get a current price?

Send your grade or specification, application, destination port, packing preference, trial schedule and expected volume. C5 resin pricing is quotation-based, so a defined requirement produces a more useful and comparable offer than a request for a generic per-ton figure.

Sources

Footnotes

1. Western Reserve Chemical, WESTCO HRT Aliphatic C5 Hydrocarbon Resins technical data. ↩

2. Ravago Australia / Nurchem, C5 Hydrocarbon Resin YH-1288 technical data. ↩

3. Royal Society of Chemistry, Synthesis and structure–property relationships of SIS-g-PB copolymers, RSC Advances (2018). ↩

4. Exxon Chemical Patents Inc., Road marking compositions, US Patent 4,690,958. ↩

5. Kolon Industries, HIKOREZ for hot-melt road-marking applications. ↩

6. ExxonMobil Product Solutions, Escorez 5300 product data sheet. ↩