Can Eastoflex™ amorphous polyolefins be used as extenders in hot-melt elastomeric adhesive formulations?

Eastoflex™ P1023, E1060, and E1003 amorphous polyolefins (APO) are effective extenders for styrenic block copolymers such as SIS (styrene-isoprene-styrene) and SEBS (styrene-ethylene-butylene-styrene) elastomers. Up to about 25% of the elastomer can be replaced with one of the APOs without a significant loss in properties. The choice of APO depends primarily on the desired viscosity.

Can Eastoflex™ amorphous polyolefins be used as extenders for polyisobutylene in hot-melt adhesive and sealant formulations?

Eastoflex E1003 is a low-molecular-weight, tacky, amorphous copolymer with a high resistance to moisture vapor and is generally resistant to oxygen and ozone. Although tensile strength and lap shear properties may be slightly reduced, weathering, peel strength, and moisture vapor transmission properties can be improved when Eastoflex E1003 is substituted for polyisobutylene.

Can Eastoflex™ amorphous polyolefins be used in applications requiring FDA approval for direct food contact?

None of the current Eastoflex amorphous polyolefins can lawfully be used as primary adhesive components where FDA approval for direct food contact is required. If used as a minor component, the overall formulation will need to be tested and confirmed for approval.

Are Eastoflex™ amorphous polyolefins soluble in organic solvents?

Eastoflex E1003, Eastoflex E1060, and Eastoflex P1023 amorphous polyolefins are soluble at the 10% level in a number of aromatic and chlorinated solvents.

What is the specific heat and thermal conductivity of Eastoflex™ amorphous polyolefins?

The specific heat of a substance is not constant. It depends on the temperature at which it is measured. For Eastoflex™ amorphous polyolefins, it varies from about 0.38 to 0.59 Btu/lb/°F over a range of 20° to 175°C (as estimated by DSC data). The typical thermal conductivity of Eastoflex amorphous polyolefins is about 3 Btu/(hr)(sq ft)(°F/in). For more information, refer to Eastman publication WA-35.

How can the peel adhesion and probe tack properties of pressure-sensitive adhesives based on amorphous polyolefins be improved?

Increased concentrations (up to about 30%) of Eastotac™ H-100R hydrocarbon resin with Eastoflex™ E-1060 amorphous polyolefin (APO) have been shown to significantly improve both peel and probe properties of APO pressure-sensitive blends. In this work, the peel adhesion improved up to about 112 g/mm and the probe tack improved up to about 1200 gms using a 70/30 blend of APO/tackifier. But as the tackifier portion was increased beyond 30%, both properties were noted to decline.

Do Eastoflex™ amorphous polyolefins contain an antioxidant stabilizer for improved thermal stability?

Yes. Eastoflex™ amorphous polyolefins contain a proprietary amount of an antioxidant, but additional antioxidant is usually required when formulating with these products.

Are there any substitutes for polyisobutylene (PIB) in pressure-sensitive adhesives?

Eastoflex™ E-1003 amorphous polyolefin (APO) has been found to be a useful substitute for polyisobutylene (PIB) in pressure-sensitive adhesives. Depending on the end-use requirements, this product can be an economical replacement.

Do Eastotac™ hydrocarbon resins contain a stabilizer?

Yes. Eastotac™ hydrocarbon resins do contain a small amount of a proprietary antioxidant.

How much tackifier should be used when formulating packaging adhesives with polyethylene polymers?

Generally, 15%-30% of the formulation should be tackifier. Excess tackifier can result in a brittle adhesive with reduced cold-temperature resistance, and insufficient amounts of tackifier can result in very short open times and reduced hot tack or green strength properties.

What FDA approvals do Eastotac™ hydrocarbon resins have?

In the United States, Eastotac™ hydrocarbon resins are lawful for use in food packaging under the conditions defined under Food Additive Regulation CFR 175.105. None are currently available for use in direct food contact applications.

How can elevated temperature shear properties of a natural rubber-based pressure-sensitive adhesive be improved?

The use of higher-softening-point resins has been shown to greatly improve the shear adhesion failure temperature (SAFT) as well as both room temperature and 50°C holding power of natural rubber-based pressure-sensitive adhesives (PSAs), although some tack properties such as rolling-ball tack may decrease when using higher-melting-point tackifying resins. The exact improvement will depend on the specific formulation and testing conditions. But as much as 10°C improved SAFT and 5 times the room temperature and 50°C shear was found to result in lab work using a 1.2:1 ratio of tackifier to natural rubber polymer with 10% plasticizing oil when Eastotac H-130E was substituted for Eastotac H-100E resin.

Will the addition of rosin ester improve tack properties of natural rubber-based pressure sensitive adhesives formulated with Eastotac™ H-100R resin?

While the partial substitution of rosin ester for Eastotac™ H-130R can improve the adhesion properties of polyethylene-based hot melt adhesives, no significant improvement was found using a similar substitution with natural rubber in a toluene system. The addition of rosin ester does not appear to be worthy in formulating natural rubber based adhesives with Eastotac™ resins.

How can probe tack of an SIS (styrene-isoprene-styrene)-based pressure-sensitive adhesives (PSAs) be improved?

Lab work has found that probe tack of SIS-based PSAs is primarily a direct linear function of tackifier concentration (higher tackifier = higher probe tack) and inversely related (more oil = reduced probe tack) to plasticizing oil concentration. It should be noted that under these conditions, probe tack was found to behave inversely to rolling-ball tack.

Can rolling-ball tack properties of SIS (styrene-isoprene-styrene)-based pressure-sensitive adhesives be improved by increasing the tackifier concentration?

Results of lab work using an SIS polymer with Eastotac™ H-100R hydrocarbon resin indicates increasing amounts of tackifier can result in improved rolling-ball tack up to a point, but beyond a certain level, excessive tackifier can actually reduce the rolling-ball tack. About 1:1 to 1.2:1 ratios of tackifier to polymer is a good optimization range, but the exact concentration will depend on the specific components and their concentrations. It should be noted that rolling-ball tack was also found to be inverse to probe tack, so a balance in properties may be required. Increased amounts of plasticizing oils and lower-melting-point resins can also help to improve rolling-ball tack.

What are some ways to improve the shear adhesion failure temperature (SAFT) and shear properties of SIS (styrene-isoprene-styrene)-based pressure-sensitive adhesives (PSAs)?

Shear properties of SIS-based PSAs can be improved by using higher-melting-point tackifiers (Eastotac H-130R or Eastotac H-115R vs. Eastotac H-100R, for example), by increasing the amount of polymer in the formulation, and/or by reducing the concentration of plasticizing oil. The percentage tackifier is generally not as important as its softening point.

How can loop tack and quick stick properties of SIS (styrene-isoprene-styrene)-based pressure-sensitive adhesives (PSAs) be improved?

Loop tack and quick stick properties tend to follow similar trends in that too little or too much tackifier can reduce these properties. Although higher softening point resins such as Eastotac H-115R or Eastotac H-130R can improve SAFT, shear, and probe tack properties, they can also reduce quick stick and loop tack. Optimum resin concentration will depend on the desired balance in properties as well as the type and amount of assisting components, but around a 1:1 to 1.2:1 ratio of a low-softening-point resin such as Eastotac H-100R to polymer with perhaps 3%-12% plasticizing oil is a good starting point with SIS polymer.

Does Eastman manufacture cyanoacrylate adhesives?

Although Eastman discovered the chemistry and filed the initial patents for the manufacture of cyanoacrylate adhesives during the late 1950s, this technology was sold to the Permabond division of National Starch during the mid 1970s. Eastman is no longer a manufacturer or supplier of cyanoacrylate adhesives.

Which solventborne adhesion promoters are recommended for use as stir-in additives to paints, inks, or adhesives?

Eastman chlorinated polyolefin 343-3 and Eastman chlorinated polyolefin 515-2


What are some end uses of highly sulfonated polyesters?

Highly sulfonated polyesters, as defined by being self-dispersible in water (usually hot water), are used in cosmetics, coatings, inks, and adhesives.

An attempt was made to disperse sulfonated polyester pellets in hot water, but the material clumped up. How can I correct this problem in the future?

To avoid clumping, best results are obtained when the pellets are gradually added rather than making a rapid, single addition of all the material to the mixing tank. A high-speed mixer helps keep the pellets agitated while dispersing in water and should keep them from settling to the bottom of the tank. If settling does occur, continue mixing until the material dissolves. Heating the water will lower the time needed for dispersing.

How can solid sulfonated polyester (pellets) be dispersed?

Polyester that is highly sulfonated is water dispersible. These products are sold under the name Eastman AQ™ polymers. A dispersion is prepared by mixing the solid material (pellets) in hot water at 71°C (160°F) or higher with agitation for about 30 minutes for most Eastman AQ™ products. After cooling, the dispersion will remain stable as long as the concentration does not go above 30% weight for most Eastman AQ™ water-dispersible polyesters.

An exception to this is Eastman AQ™ 48 polymer, which should be dispersed at a maximum temperature of 50°C. When using Eastman AQ™ 48 polymer in formulations that are intended to remain clear, the Eastman AQ™ 48 polymer dispersion should be used as soon as possible to make the final formulation.

What is Eastman triacetin, and how is it used?

Eastman triacetin (glyceryl triacetate) is a plasticizer for cellulose resins and is compatible in all proportions with cellulose acetate, nitrocellulose, and ethyl cellulose. Eastman triacetin imparts plasticity and flow to laminating resins, particularly at low temperature, and is also a plasticizer for vinylidene polymers and copolymers. As a specialty solvent, this product has low volatility and low toxicity. In some pharmaceutical preparations, this product is a solvent and a carrier for flavoring agents. Applications also include compounding perfumes as a solvent and a fixative. Eastman triacetin can also be used in inks for printing on plastics and nonabsorbent surfaces.

How can plasticizers be used as emulsion modifiers for adhesives?

In compounding waterborne adhesives, the formulator can modify the system by adding a plasticizer. In general, the addition of selected plasticizers can increase viscosity, reduce the glass transition temperature (Tg), and increase T-peel strength, especially in a PVA system. Another purpose in adding a plasticizer is to extend its open or working time properties. Open time was judged as the time at which the adhesive became too dry to form a paper-tearing bond. The open time of all plasticized systems was observed to be equal to or greater than the open time for unplasticized base polymer. What plasticizer is used widely in adhesives? Eastman DBP (dibutyl phthalate) is a colorless, odorless liquid commonly used as a solvent and plasticizer. It is miscible with most organic solvents and insoluble in water. This plasticizer is used extensively in the adhesives industry to plasticize polyvinyl acetate (PVA) emulsions. The low viscosity and compatibility of Eastman DBP make this plasticizer ideally suited for PVA-based adhesives for bonding cellulosic materials. In addition, Eastman DBP is an excellent solvent for many oil-soluble dyes and peroxides and in the coatings industry as a primary plasticizer-solvent for nitrocellulose lacquers.

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