Eastman water based resin dispersions provide improved adhesion to various substrates with minimal impact on cohesive properties. Our broad product line provides formulating flexibility to meet your polymer and application requirements.

Figures 1–4 show typical performance ranges for commercial general purpose labels for peel adhesion, shear resistance, and quick stick (tack).

The concentration of tackifier resin dispersion added is a critical factor for optimum PSA performance in any one base polymer.

Table 1: Composition Ranges for Tackifier Additions to Common Latex Polymers

Polymer Latex Type	Cohesion	Tackifier Level	Emulsion Stability
Acrylic	Low/Medium	0–40%	Excellent
Natural rubber	High	20–60%	Limited
Styrene butadiene rubber	Medium	20–60%	Excellent

The addition of Tacolyn 3179 H resin dispersion tackifier to an acrylic latex such as Acronal V205 will influence the adhesive properties of the coated label. Figure 5 below shows how increasing the tackifier concentration will raise the peel adhesion to both polyethylene and cardboard to a level at which either the substrate or the label backing fails. As the tackifier concentration increases, however, the shear force resistance of the system decreases as shown in Figure 6. The loop tack results shown in Figure 7 generally increase as resin concentration increases, although the effect is highly dependant on the substrate used. The data used to produce these figures is summarized in Table 2. These examples illustrate the dilemmas that the adhesive formulator often faces. Frequently, in order to improve one property such as peel, it is necessary to accept a trade-off in another property such as shear resistance.

Figure 5: Peel of Acronal V205/Tacolyn 3179H Blends		Figure 6: Shear of Acronal V205/Tacolyn 3179H Blends
Figure 7: Loop Tack of Acronal V205/Tacolyn 3179H Blends

Table 2: Adhesive Properties for Blends of Acronal V205 and Tacolyn 3179H

 PS = Paper Strain, PF = Paper Failure

Hydrocarbon-based and rosin-based resin dispersions can also be blended for optimized PSA properties. Figure 8 shows how using different ratios of two types of resin dispersions at a 30% concentration in the same acrylic latex can produce adhesive properties very different from either of the tackifiers alone.