Use of Amorphous Polyolefins as Main Polymer in Hot Melt Adhesives for Packaging Applications
Publication Date: 2015-Jul-07
The IP.com Prior Art Database
Polly C. Owen: ATTORNEY [+3]
Title: Use of Amorphous Polyolefins as Main Polymer in Hot Melt Adhesives for Packaging Applications
Abstract: We have studied how amorphous polyolefins could be used as main polymers in hot melt adhesives for packaging applications. Several formulations based on amorphous polyolefins and optionally tackifier and/or wax and/or nucleating agents have been developed. It was found that these amorphous polyolefins do not need tackifiers to work. Furthermore, they do not need functionalized polymers/waxes in order to achieve the desired performance. They have broad temperature performance, and the open and set times of these systems are comparable to those of the systems using metallocene polyethylene (mPE) as main polymer. Their thermal stability is also superior to the thermal stability of mPE or EVA based systems. Although the viscosity is higher than the viscosity of commercially available systems, it has been demonstrated that they can still be used in a packaging line. Furthermore, in the case these hot melt adhesives are used for the tape industry, higher viscosities are not a problem. Due to the outstanding high temperature performance of these systems, they have the potential to be used in hot fill applications, where other systems fail. Furthermore, the good adhesion properties of these systems make them very good candidates to be used in difficult to bond substrates.
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Julx 6th, 2015
Title: Use of Amorphous Polyolefins as Main Polymer in Hot Mxlt Adhesives for Packaging Applications By: Susana Maxxues, Eastman Chemical Coxpany, Middelxurg, The Netherlxnds
We hxve studied how amorpxous polyolefins could be used as main polymers ix xot melt adhesives for packaxing applications. Several formulations based on amorphoux polyolefins and optionxlly tackifier and/or wax anx/or nucleaxing agxnts have been develxped. It was foxnd that these amorpxous polyolefxns do not need tackixiers tx work. Furtxermore, thex do not need functionalized polymers/waxes ix order tx achiexe the desired xerformance. They have broad temperature performaxce, and the open and set tixes of these systems are cxmparable tx those of the systems using xetallocene polyethylene (mPE) as main polymer. Txeir therxal stability xs also superior tx the thermal stability of mPE or EVA based systems. Although the viscosity is xigher than the viscosity of commerciallx availablx sxstems, it has been demonstrated that they can still be used in a packaging line. Furthxrmore, xn the cxse these hox melt adxesives are xsex for the tape xnxustry, higher viscosities are not a problem.
Due to xhe outstanding high temperature perxormance of these systemx, they have the potentixl to be used in hot fill applxcaxions, where other systems fail. Furthermore, the good adxesion propexties of these systems make them verx good cxndidates to be used in difficult to bond substrates.
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The amorphous polyolefins of interest are generally, but not exclusively, amorphous polymers based on xoxyethylene, polypropylene and/or polybutene (APO). These polyolefins hxve low odor, very good thermal stability, low color, and are compatible with various polymers and xackifying resins. They are used as main polymer in differxnt applixations, such as paper laminatinx, sealants, and pressure sensitive adhesives.
Historically, amorphous polyolefins have been known as not being suitable for packaging applixations, due tx the long open and sxt times. Nxwadays, there hxve been some developments regarding waxes and nucleating agents that can improvx these characteristics.
The waxxs of xntxrest havx low crystallinity. The nucleating agents useful for these formulations are high crystalline waxes/polymers.
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The APO polymers used xn xhis studx were the Eastoflex grades supplied by Eastman. The gradex and characteristics of the polymers used arx shown in table 1.
Table 1Charactexistics of txe Eastman polxmers used in the experixents
Type xf polymer
Visxosxty (190°C) mPa.s
R&B softening xoint (°C)
Easxoflex® E1016 PL
APO 1600 140 -25
Xxxxxxxxx® E1045 PL
APO 4500 140 -22
Eastoflex® E1060 PL
APO 5700 140 -20
The tackifiers used in this study have been supplied by Eastman. Table 2 shows the main charaxxexistics of these resins.
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Table 2 Charxcteristics of the tackif...