• Elastomers and Composites
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• v.52 no.2
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• pp.136-142
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• 2017

Using various compositions of thermally conductive inorganic fillers with boron nitride (BN) and aluminum oxide ($Al_2O_3$), solventless UV-curable thermally conductive acrylic pressure sensitive adhesives (PSAs) were prepared. The base of the PSAs consists of 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, and isobornyl acrylate.The compositions of the thermally conductive inorganic fillers were 10, 15, 20, and 25 phr in case of BN, and 20:0, 15:5, 10:10, 5:15, and 0:20 phr in case of $BN/Al_2O_3$. The adhesion properties like peel strength, shear strength, and probe tack, and the thermal conductivity of the prepared PSAs were investigated with different thermally conductive inorganic filler contents. There were no significant changes in photo-polymerization behavior with increasing BN or $BN/Al_2O_3$ content. Meanwhile, the conversion rate and transmittance of the PSAs decreased and their thermal stabilities increased with increasing BN content. Their adhesion properties were also independent of the BN or $BN/Al_2O_3$ content. The dispersibility of BN in the acrylic PSAs was better than that of $Al_2O_3$ and it ranked the thermal conductivity in the following order: BN > $BN/Al_2O_3$ > $Al_2O_3$.

• Polymer(Korea)
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• v.38 no.2
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• pp.199-204
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• 2014

To prepare acrylic pressure sensitive adhesives (PSAs), quaternary copolymer syrups were photopolymerized from 2-ethylhexyl acrylate and 2-hydroxyethyl acrylate as default constituents and isobornyl acrylate and tetrahydrofurfuryl acrylate (THFA) as variable constituents. After polymerization, 1,6-hexanediol diacrylate and photoinitiator were added and then crosslinked by UV-irradiation to prepare the PSAs. The characteristics of the syrup such as viscosity, molecular weight, and solid content were investigated. As increasing THFA contents, the relationship between molecular weight and solid content of the syrup was reciprocal. Also, the relationship between peel strength and surface energy of the PSAs showed the same tendency. All the PSA samples showed high transmittance (more than 92%), low haze (less than 1.0%) and low color-difference (less than 1.0).

• 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).

• 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.

• 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.

• Journal of Adhesion and Interface
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• v.8 no.2
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• pp.15-21
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• 2007

To prepare a natural rubber-based pressure-sensitive adhesive (PSA) for protection film of opto- functionalized sheet, natural rubber (NR) was blended with a DCPD type tackifier and three types of aliphatic hydrocarbon resins, respectively. Also, to supply low cohesion strength of NR, in the fixed ratio of tackifier, synthetic rubber, styrene-isoprene-styrene (SIS) block copolymer was blended with NR as a function of SIS contents. PSA performance of prepared PSAs was evaluated using probe tack and peel strength. Probe tack of NR/tackifier blends was increased with increasing tackifier contents, and showed maximum peak. In addition, probe tack of NR/tackifier blends slightly increased with increasing softening point of aliphatic hydrocarbon resins. Their peel strength increased up to 50 wt% of tackifier contents, but in the over contents of tackifier, they showed stick-slip failure mode. Finally, probe tack of NR/SIS/tackifier blends showed the maximum values at 20~40 wt% of tackifier contents, but at 20 wt% of tackifier contents, they showed fibrillation. For this reason, peel strength showed maximum values at 40 wt% of tackifier contents.

• Journal of Convergence for Information Technology
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• v.7 no.4
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• pp.75-81
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• 2017

The design trend of information technology is quickly changed with the times. The design trend of information display is a bezel-less display, recently. The bezel-less display or edge-less display is a new trend of mobile phone display. In this study, the shading tape was manufactured for assembling process of touch panel display with the high screen-to-body ratio so-called bezel-less display. The shading tape was fabricated on PET film with the UV curable acrylic pressure sensitive adhesive(PSA) by roll-to-roll process. The UV curable PSA was synthesized with the eco-friendly toluene-less manufacturing method. The adhesive power of manufactured shading tape was investigated by motorized tensile testing machine. The thixotropic, maintaining property of cutting shape, was characterized by field emission scanning electron microscope. As results, the shading tape exhibits high adhesive power and good thixotropic performance suitable for assembly process of touch panel display. The functional shading tape will be expected to improve productivity of assembly process of touch panel display.

• Korean Chemical Engineering Research
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• v.48 no.5
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• pp.609-614
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• 2010

In this study, emulsion polymerizations for synthesizing acrylic pressure-sensitive adhesive(PSA) were carried out using 2-ethylhexyl acrylate(2-EHA), n-butyl acrylate(n-BA), methyl metacrylate(MMA) as fundamental monomers and acrylic acid(AAc) as a functional monomer in the presence of anionic SLS (sodium lauryl sulfate). To obtain the optimized synthetic condition in the polymerization, we analyzed the polymerization variables such as the effect of surfactant concentration and hydrophilic lipophilic values(HLB). At the same time, the final adhesive properties were also analyzed by the function of the initiator concentration and buffer concentration. In the results, the most stable emulsion was obtained at the surfactant concentrations between 3 and 5 wt%. It was also determined the effect of HLB value of nonionic surfactant and the initiator concentrations on the gel content. Stable emulsion is obtained using the surfactant having HLB value of 12.3. The rate of emulsion polymerization was increased at the initiator concentration greater than 1 wt%, but the stability of the emulsion was decreased. Finally, the effect of the buffer concentrations on the pH and the conversion of the acrylic emulsion product were experimentally measured. At the sodium bicarbonate concentration above 0.4 wt%, the buffer infulence was apparent. The buffer effect was fully acceptable at the concentrations between 0.6 and 0.8 wt% regardless of the monomer composition.

• Journal of Adhesion and Interface
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• v.18 no.1
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• pp.25-32
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• 2017

For application to display module junction process, the silk screen printing based on UV curable acrylic pressure sensitive adhesive(PSA) with silica nano-particles and the rheological properties were studied to investigate the effect on printability and adhesion. The monomers for PSA were based on 2-ethylhexyl acrylate(2-EHA) and acrylic acid(AA) 93:7, butyl acylate(BA), 2-hydroxyethyl acrylate(2-HEA) and tetrahydrofurfuryl acrylate(THFA) were added. Additionally, hydrophobic and hydrophilic nano-particles AEROSIL R974 and AEROSIL 200 were added, respectively. When the ratio of nano-particle was used above 4 or 7 phr, G' and ${\eta}^*$ were increased significantly. When the ratio of AEROSIL 200 was used above 7 phr, the penetration property was decreased during the silk screen printing. We found that the adhesion was decreased with increasing the nano-particle content, and it was decreased in the case of the hydrophilic nano-particle AEROSIL 200.

• Journal of Adhesion and Interface
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• v.22 no.2
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• pp.31-38
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• 2021

In this study, a nonionic reactive emulsifier with aromatic and acryl group was synthesized by using polyoxyethylene(10) dodecylphenyl ether with 3-butenoic acid. The synthesized nonionic reactive emulsifier was confirmed by ¹H-NMR and FT-IR. In addition, the reactive emulsifier synthesized in the preparation of aqueous acrylic adhesives base emulsion was used and the properties of the solid content, conversion, particle size distribution, peel strength and high temperature holding force were compared to those of nonionic emulsifiers without aromatic group. The particle size was distributed from 370 nm to 698 nm, and the peel strength were measured in the range of 1.507~1.802 kg_f. The high temperature holding force of prepared adhesives base emulsion were measured in the range of 0.50~2.00 mm. Especially, in the result of synthesized nonionic reactive emulsifier with aromatic group, it was confirmed that high temperature holding force results were the most excellent than the case of using other nonionic reactive emulsifiers, and it can be useful for water-based acryl pressure sensitive adhesive.