• Polymer(Korea)
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• v.37 no.2
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• pp.184-195
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• 2013

Acrylic pressure sensitive adhesive (PSA) tapes were used for the automotive, the electrical and the electronic industries and the display module junction. In this study, the manufacture of high-strength structural tape used 2-ethylhexyl acrylate (2-EHA) and acrylic acid (AAC), and UV irradiation for photo-polymerization, and the semi-structural properties of acrylic PSA tape with the AAC content and inorganic filler $SiO_2$ content were investigated. The initial adhesion strength was lowered by the rigidity of molecule chains due to the use of AAC, and the adhesion strength increased with increasing wetting time. The wetability, contact angle, and SEM images of PSA tapes with various contents of AAC were determined. Without filler, the peel strength and dynamic shear strength of PSA tape showed inverse correlation but the peel strength and dynamic shear strength increased with increasing filler content. From these correlations the PSA tapes could be optimized for the applications requiring high performance.

• Journal of Adhesion and Interface
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• v.15 no.4
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• pp.145-150
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• 2014

Dicyclopentadiene (DCPD)-based hydrocarbon resins are widely used as tackifiers in many applications. In particular, hydrogenated DCPD-based hydrocarbon resins are widely used in premium hot-melt-type adhesives such as hot melt adhesives (HMAs) and/or hot melt pressure-sensitive adhesives (HMPSAs), because are water-white in color and possess excellent stability to light and heat. This article discusses the adhesive performance of various hydrogenated DCPD resins when they are used as tackifiers in styrene-block-copolymer (SBC)-based HMPSAs. This article shows the correlation between the characteristics of tackifiers and the adhesive performance of SBC-based HMPSAs. The higher the softening point of the tackifier, the higher is the $T_g$, softening point, and crossover temperature of the PSAs. High aromatic H wt% content reduces the high-temperature resistance of PSAs, as suggested by the decrease in the crossover temperature and softening point of the PSAs.

• Journal of Adhesion and Interface
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• v.14 no.1
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• pp.43-48
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• 2013

The physical properties of the acrylic pressure sensitive adhesives (PSAs) can be easily controlled by a proper functional monomer which has functional groups for crosslinking. This study was to investigate the effect of crosslinking agents, isocyanate and epoxy types, of acrylic PSAs on adhesive properties. 2-Ethylhexyl acrylate, acrylic acid (AA), and 2-hydroxy ethyl methacrylate as monomer were used. The obtained samples with different AA contents were partially crosslinked with epoxy- or isocyanate-typed agent. Peel strength, balltack, holding power test and contraction percentage of the obtained PSA were evaluated. Most properties of acrylic PSAs were increased with AA content and acrylic PSAs with epoxy-typed crosslinking agent (4 crosslinking sites) which produces flexible link (ether), showed better properties than those of isocyanate-typed one (3 crosslinking sites).

• Journal of Adhesion and Interface
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• v.18 no.4
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• pp.166-170
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• 2017

In this study, acrylic rubber pressure sensitive adhesives was polymerized with 2-ethylhexyl acrylate, styrene, butadiene, 2-hydroxyethyl acrylate, and acrylic acid by controlling the initiator content. The initial tackiness, peel strength, holding power, and heat resistance of the PSAs were investigated by changing the content of tackifier and curing agent. The results showed that the initial tackiness and peel strength increased as the content of tackifier increased, whereas the holding power decreased. Also, the results exhibited that that the initial tackiness, peel strength, and heat resistance decreased as the content of curing agent increased, whereas the holding power and decreased.

• Polymer(Korea)
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• v.39 no.2
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• pp.281-286
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• 2015

UV-cured acrylic copolymer pressure sensitive adhesive (PSA) having different amounts of crosslinking agents were prepared and adhesion properties were investigated. 0.01 wt% of MMT clay was dispersed in 2-ethylhexyl acrylate (2-EHA)/acrylic acid (AA) monomer mixture containing 0, 0.05, 0.1 and 0.3 wt% 1,6-hexandiol diacrylate (HDDA) for crosslinking. It was investigated that the curing behavior and surface chemistry of PSAs were merely affected by the presence of MMT clays. On the other hand, adhesive properties were influenced by the MMT addition; a cohesive failure was restrained due to improved molecular elasticity even in uncrosslinked acrylic PSAs. However, it was also appeared that combination of 0.3 wt% crosslinking agent and MMT loading might result in the damage of adhesion properties of PSAs possibly due to the lack of chain flexibility. In our studies, it is suggested that the 2-EHA/AA PSAs incorporating 0.01 wt% of MMT and crosslinked with 0.05 wt% of HDDA exhibited the balanced adhesion properties without severe cohesive failure during strip.

• Polymer(Korea)
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• v.38 no.5
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• pp.682-686
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• 2014

To prepare transparent acrylic pressure sensitive adhesives (PSAs), terpolymer syrups were photopolymerized from 2- ethylhexyl acrylate and 2-hydroxyethyl acrylate with third monomer having different chemical structure. After polymerization, 1,6-hexanediol diacrylate as a crosslinker and a photoinitiator were added and then UV-irradiated to prepare the PSAs. The adhesion performances and optical characteristics of the PSAs were investigated. Their adhesion performance was dependent on the composition of monomers in the polymer chain but optical properties were maintained at a suitable level. The PSAs prepared by bulky and heteroatom-containing monomers such as IBOA, THFA, and ACMO showed better adhesion performance than others.

• Elastomers and Composites
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• v.44 no.4
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• pp.429-435
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• 2009

The pressure sensitive adhesives (PSA) were synthesized by soap-free emulsion polymerization of acrylic monomers such as butyl acrylate, 2-ethyl hexyl acrylate, and acrylic acid in the presence of starch as a protective colloid and copolymer. The peel strength and holding power of PSA were increased with starch contents due to the enhancement of gel content, But the initial tackiness of PSA was decreased with starch contents. The contact angle analysis of PSA indicated that the wettability was increased with starch contents owing to the increase of polarity by hydroxy group in starch. In the pH measurement of emulsion with time for biodegradability, the starch in the PSA accelerated the lowering of pH due to the formation of organic acids followed by decomposition of starch.

• Elastomers and Composites
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• v.49 no.3
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• pp.210-219
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• 2014

In this study, the acrylic pressure sensitive adhesive (PSA) for the optical functionality sheet was prepared by blending liquid isoprene rubber. The acrylic PSA was synthesized with butyl acrylate, acrylic acid, 2-ethylhexyl acrylate and 2-hydroxyethyl methacrylate. Toluene was used to a solvent for polymerization. Liquid isoprene rubber (LIR-50) was blended with the acrylic PSA and blend ratio was 0 ~ 50 wt%. According to the results, the adhesive transfer, which was the big problem of acrylic adhesive, was reduced with the addition of LIR-50. The secondary bonding of LIR-50 with substrate did not occurred due to absence of polar group in LIR-50. The peel strength and adhesive transfer were decreased by UV curing and the degreed of decrease depended on the amounts of photoinitiator and UV irradiation time. On the other hand holding power increased drastically by increasing amounts of photoinitiator and UV irradiation time.

• Journal of Adhesion and Interface
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• v.17 no.3
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• pp.89-95
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• 2016

An environmentally friendly water-based pressure sensitive adhesive (PSA) was designed in an attempt to replace the solvent-based adhesive for dry lamination used in flexible food packaging films. Instead of using a low molecular weight surfactant, which may have variable material properties, a high molecular weight dispersant was used for emulsification. A polymeric nano-dispersant (PND) was synthesized using solution polymerization, and it was used as a micelle seed in the surfactant, resulting in the synthesis of a core/shell grafted acrylic adhesive. The shell and core exhibited different $T_g$ values, so that the initial adhesion strength and holding power were complemented by the film's flexibility, which is required to provide good adhesion of thin films. Results showed that the PSA designed in this study using the PND instead of traditional low molecular weight surfactant had adhesive properties applicable to the flexible packaging with appropriate tack.

• Journal of Adhesion and Interface
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• v.20 no.4
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• pp.135-139
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• 2019

In this work, flame retardant acrylic emulsion pressure sensitive adhesives were newly polymerized combining phosphorous flame retardant monomer and acrylic monomer like butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, acrylic acid, and 2-hydroxyethyl methacrylate. The process of polymerization showed 100% of conversion at solid content of 65%, and viscosity of acrylic emulsion was increased up to 5500 cps when phosphorous flame retardant monomer was added into acrylic emulsion. The structure of flame retardant acrylic emulsion was identified using FT-IR and thermal properties like glass transition temperature (Tg) were checked by differential scanning calorimeter (DSC). Acrylic emulsion without phosphorous flame retardant monomer had Tg of -44.1℃ and peel strength of 2,100gf/inch, however, flame retardant acrylic emulsion showed maximum Tg (-31.4℃) and peel strength of 200gf/inch when 15 part of phosphorous flame retardant monomer was added. Flammability test was also conducted to confirm the application of flame retardant acrylic emulsion as the flame retardant addtive.