Effect of particle structure on the peel strength and heat resistance properties of vinyl acetate/acrylate latexes laminating adhesives

Abstract

The concept of using particle structure design to prepare emulsion laminating adhesives (LAs) for improving both the peel strength and heat resistance properties has been investigated. The homogeneous particle latices based on vinyl acetate/acrylate copolymer (samples 1-3) were synthesized by seeded semicontinuous emulsion polymerization with different chain transfer agent (CTA) contents but with no functional monomers, while the coreshell structure crosslinkable latices (samples 4 and 5) were prepared through multistage polymerization technique. The emulsion particle structure was investigated by TEM and particle size analyzer. The results indicate that the average emulsion particle diameter is about 130 nm and the particles grow without secondary nucleation. Samples 1 and 2 prepared with 0.7 and 0.5 phm (per hundred gram monomer) CTA respectively, show high peel strength but poor heat resistance property. On the contrary, the sample 3 prepared with 0.1-phm CTA exhibits low peel strength but relatively good heat resistance. However, sample 4, which was synthesized with 0.5-phm CTA and 0.4-phm acetoacetoxy ethyl methacrylate (AAEM) in core but 0.5-phm CTA and 0.6-phm AAEM in shell stages, shows high peel strength (1032.9 g/in.) and good heat resistance property (524.9 g/in.). In addition, sample 5 also demonstrates high peel strength (987.2 g/in.) and good heat resistance property (643.5 g/in.) when it was synthesized using 0.1-phm CTA but no AAEM in core, 0.36-phm CTA and 0.75-phm AAEM in shell stages.

The Relation Between Particle Structure and the Peel Strength of Vinyl Acetate/Acrylate Core-Shell Latexes Laminating Adhesives

“…However, as for conventional emulsion, there are still some deficiencies. A major one is its low peel strength [8,13,14] arising from the competition among film formation, wetting and mechanical film properties [15,16] especially at high temperatures, which limits its further application in the field of adhesives greatly.…”

“…Presently, with increasing attentions of public and government to environmental issues, solvent based laminating adhesives (LAs) used widely in plastic flexible packaging [1][2][3][4] are gradually being replaced by emulsion Las [5][6][7][8] due to the decreased emission of volatile organic compounds [9,10] and low cost [8,11,12] of the latter. However, as for conventional emulsion, there are still some deficiencies.…”

Modification research on the peel strength of the acrylate emulsion pressure‐sensitive adhesives

“…They found that small latex particles gave adhesive films with a higher peel force at short adhesion times, whereas adhesive films from larger particles required more time to achieve their ultimate peel force. 17,18 However, few researchers have paid attention to the effect of NaHCO 3 on the peel strength of the PSAs. They found that the peel adhesion decreased with the MMA content; this was attributed to a reduction in the ability of the adhesive to wet the substrate.…”

Synthesis of poly(butyl acrylate)‐poly(methyl methacrylate) core–shell nanomaterials of anti‐crease‐whitening properties

“…Such composite materials are widely used in various areas. For example, polymer–polymer core–shell particles can be used as effective structures for applications in pigments, fibers, immunological studies, drug delivery systems, baroplastic processing, toughening polymeric materials, transparent conductive thin films, coatings, and adhesives . The combined properties of core and shell polymers are superior to mechanical blends of those polymers.…”