Tackifier Resin for Hot Melt Adhesives | Milorez

A tackifier resin makes a hot-melt adhesive wet and grip the substrate while the base polymer supplies cohesive strength and wax controls viscosity and set speed. For EVA packaging, start with C5 or C5/C9; for color- and odor-sensitive hygiene systems, screen a fully hydrogenated grade. Milorez can shortlist an MR-* resin and provide a free sample.

Last reviewed: July 20, 2026

What the tackifier does in a three-component hot melt

The three main hot melt adhesive raw material groups are polymer, tackifier and wax or oil, normally with a small antioxidant package. The tackifier changes wetting, specific adhesion, melt viscosity and the polymer’s bonding window. H.B. Fuller identifies the same functional components in packaging hot melts.¹

Typical values — functional roles in a non-reactive hot-melt adhesive

Component	Primary job	Too little or poor selection	Too much or poor selection
Base polymer	Cohesion, flexibility, strength and service-temperature framework	Weak film or inadequate holding power	High melt viscosity, poor wetting or difficult machining
Tackifier resin	Wetting, hot tack, specific adhesion and tack–cohesion balance	Low grab, poor substrate wet-out or weak peel	Excessive softness, creep or reduced cohesive strength
Wax or process oil	Viscosity, set speed, open time and application behavior	Slow set or difficult pumping, depending on system	Brittle bond, short useful open time or lower strength

Choose the resin by hot-melt system

Selecting a petroleum resin for hot melt adhesive production begins with the base polymer. EVA vinyl-acetate content changes polarity; in SIS or SBS, the tackifier may favor the rubbery midblock or styrenic end blocks. This shortlist directs trials but does not guarantee performance.

Typical values — tackifier selection directions by adhesive system

Hot-melt system and use	First resin screen	Why it is shortlisted	Confirm in the finished adhesive
EVA case and carton packaging	C5 or C5/C9 copolymer	C5 supports tack and wetting; aromatic modification can widen EVA compatibility	Blend clarity, fiber tear, set speed, open time and hot-aging color
SIS/SBS pressure-sensitive adhesive	C5 or hydrogenated hydrocarbon resin	Favors elastomer-phase tack; hydrogenation improves color and thermal stability	Loop tack, peel, shear, SAFT, viscosity and oil balance
Disposable hygiene construction or elastic attachment	Fully hydrogenated, water-white resin	Low color, low odor and stable hot-melt processing are priorities on white nonwovens	Sprayability, creep, peel, emissions, odor and applicable documentation
EVA bookbinding	C9 or C5/C9 copolymer	Aromatic character can improve compatibility and adhesion in suitable EVA systems	Page pull, spine flexibility, heat response, open time and color

Use the C5 resin guide for aliphatic options and the hydrogenated hydrocarbon resin guide when appearance, odor or thermal color stability leads the brief. KOLON’s current product guidance also positions C5/C9 copolymers as tackifiers for EVA, SIS, HMA and HMPSA systems.²

Three indicators that decide whether a resin works

1. Compatibility and cloud point

Compatibility comes first. For EVA, test the actual polymer because vinyl-acetate content and melt index alter resin affinity. For SBCs, avoid plasticizing hard styrene domains when midblock tackification is the goal.

State the cloud-point method. MMAP and DACP characterize resin behavior, while an EVA/wax blend cloud point evaluates one formula; the values are not interchangeable. Record haze, separation and viscosity too.

2. Softening point and open time

Ring-and-Ball softening point (SP) is not the adhesive’s melting point or service limit. Within a compatible series, lower SP often favors wetting; higher SP can support cohesion and heat response.

Open time is the useful bonding window after application. Polymer and wax crystallization, coating temperature, bead mass, substrate temperature and compression timing can outweigh resin SP. Set and test the two targets separately.¹

3. Color, odor and hot stability

Standard C5 resin is usually pale; unhydrogenated C9 is normally more amber. Full hydrogenation can deliver water-white color, lower odor and stronger resistance to discoloration during heated storage. Synthomer describes its fully hydrogenated Regalite R1100 in those terms for hot-melt applications.³ These are formulation benefits, not evidence of hygiene, food-contact or medical approval.

Starting formulation ranges

Tackifier loading of 30–50 wt% is a practical trial window for many conventional hot melts. It is not a universal recipe, and every column must be normalized to 100%.

Typical values — formulation starting ranges, wt% of total adhesive

System	Base polymer	Tackifier resin	Wax or process oil	Antioxidant / other modifier
EVA packaging or bookbinding	25–40%	30–50%	15–30% wax	0.2–5%
SIS/SBS PSA or hygiene hot melt	25–35%	40–50%	10–25% oil; wax may be absent	0.2–10%

Published recipes support the range while showing why it must remain application-specific. A 2022 University of Campinas study used 30% EVA, 49.5% hydrocarbon resin, 20% wax and 0.5% antioxidant for packaging-wax comparisons.⁴ A National Starch patent gives a representative 30% EVA / 40% rosin ester / 30% wax case-sealing composition.⁵ A published SIS elastic-attachment example used 30% SIS, 50% hydrogenated DCPD tackifier, 15% mineral oil and 5% end-block resin.⁶

Milorez grade starting points

Typical values — grade-selection directions; request the current TDS

Application target	Milorez candidate	Selection reason
General EVA packaging or SIS screening	MR-C5100	C5 resin with nominal 100°C SP for balanced tack and processing
Higher-SP C5 trial	MR-C5110	C5 option when the starting target is nominally 110°C
EVA bookbinding or broader aromatic compatibility	MR-5920	Medium-aromatic C5/C9 copolymer starting point
Aromatic EVA bookbinding screen	MR-C9110	C9 candidate where color and EVA compatibility are acceptable
Elastomer-rich PSA	MR-5910	Lower-aromatic C5/C9 starting point for tack-led screening
Water-white hygiene, clear packaging or low-color PSA	MR-H100	Fully hydrogenated resin with nominal 100°C SP

For a deeper decision tree, use the hot-melt tackifier selection guide. If the incumbent is an Eastotac grade, define chemistry, SP, color, cloud point and finished-adhesive tests with the Eastotac equivalent guide; no alternative should be approved from a trade name alone.

Free sample and technical-support process

1. Send the formulation brief. Include polymer grade, EVA VA content or SBC type, current recipe, substrate, application temperature, open/set-time target, test methods, incumbent resin, destination and expected volume.
2. Review the shortlist. Milorez compares suitable MR-* candidates and states its role as a Fujian export trading supplier; it does not claim to own the factory.
3. Test a free sample. Hold the incumbent loading and process constant first, then run a controlled dosage ladder if needed.
4. Compare complete performance. Record compatibility, melt viscosity, tack or fiber tear, peel, shear, open/set time, heat aging, color and odor.
5. Confirm commercial supply. Put the accepted specification, packing, source continuity and documents into the quotation. The MOQ is 1 × 20’ FCL.

Send your polymer system, target properties and incumbent TDS to [email protected], or request a free sample. Milorez will propose a technically relevant resin rather than quote an undefined “100°C tackifier.”

Frequently asked questions

Which tackifier for EVA hot melt?

Start with C5 for lower-VA EVA and straightforward packaging tack, or C5/C9 when more aromatic compatibility is needed. Choose fully hydrogenated resin when water-white color, low odor or hot-aging stability leads the specification. Confirm with the exact EVA, wax and substrate.

How much tackifier resin goes into a hot-melt adhesive?

Use 30–50 wt% as a first screening window. Some HMPSAs exceed it, but more resin can dilute the polymer network and reduce cohesion. Normalize the formula to 100% and test resin, polymer, wax or oil as one balance.

Is hydrocarbon resin better than rosin ester?

Neither wins universally. C5 resin is low-acid and often suits nonpolar elastomers; rosin ester is more polar and broadly compatible with EVA. Compare cloud point, viscosity, tack, peel, shear, odor, color, heat aging, supply and total formulation cost.

Does higher tackifier softening point mean longer open time?

No. Higher SP can improve heat response in a compatible system, but open time depends on the whole cooling and crystallization profile. Wax type, polymer, application temperature, bead size, substrate temperature and line timing can outweigh neat-resin SP.

Why choose fully hydrogenated resin for hygiene hot melt?

It is the first screen when water-white appearance, low odor and thermal color stability matter. Those properties do not prove skin-contact or medical compliance. Review the exact raw-material documents and validate emissions, odor, sprayability, peel and creep in the finished article.

Are samples free, and what is Milorez’s MOQ?

Samples are free for formulation evaluation; courier arrangements are confirmed before dispatch. The commercial MOQ is 1 × 20’ FCL. Share the polymer, application, current grade, pass/fail targets, destination and annual demand so the sample and quotation refer to the same requirement.

Sources

Footnotes

1. H.B. Fuller, Packaging Hot Melt Adhesives 101, 2020 (accessed July 20, 2026). ↩ ↩²

2. KOLON Industries, HIKOREZ C5–C9 Copolymer Resins, current product guide, accessed July 20, 2026. ↩

3. Synthomer, REGALITE R1100 Hydrocarbon Resin Technical Data Sheet, revision April 11, 2022 (accessed July 20, 2026). ↩

4. University of Campinas, Estudo do efeito de ceras em adesivos hotmelt, master’s thesis, 2022 (accessed July 20, 2026). ↩

5. National Starch and Chemical Investment Holding Corporation, Hot Melt Adhesive Composition, US 6,794,443 B2, issued September 21, 2004 (accessed July 20, 2026). ↩

6. Adhesives & Sealants Industry, New High-Efficiency Styrenic Block Copolymers, Tackifier for Adhesives, 2008 product-development report (accessed July 20, 2026). ↩