Improved heat and solvent resistance of a pressure‐sensitive adhesive thermally processable by isocyanate dimer dissociation

Methods that do not involve use of an organic solvent are being considered for manufacturing environmental‐friendly pressure‐sensitive adhesive tapes. Among these methods, the hot‐melt method exhibits high productivity but is somewhat limited in terms of performance. Hot‐melt‐fabricated pressure‐sensitive adhesives require heating fluidization and cooling solidification, and it is extremely difficult to improve their heat resistance. We examine thermally processable pressure‐sensitive adhesives with a completely new structure, fabricated based on the thermal dissociation of the isocyanate dimer. This enables thermal processing of materials softened by thermal dissociation. Fabrication of crosslinkable pressure‐sensitive adhesive becomes possible through a reaction of isocyanate caused by dissociation of its dimer. It is found that improving thermal and solvent resistances, which are disadvantages associated with conventional hot‐melt pressure‐sensitive adhesives, is potentially possible with the pressure‐sensitive adhesive reported here. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41444.     

Grain-boundary diffusion and precipitate trapping of hydrogen in ultrafine-grained austenitic stainless steels processed by high-pressure torsion

This study was conducted to clarify the effects of grain boundaries and precipitates on room-temperature hydrogen transport in two types of austenitic stainless steels with ultrafine-grained structures produced by high-pressure torsion (HPT) and subsequent annealing. The grains in the Fe-25Ni-15Cr (in mass%) alloy containing Ti and the Fe-25Cr-20Ni alloy were refined by the HPT-processing to ∼150 and ∼85 nm, respectively. The high-temperature annealing after the HPT processing led to the precipitation of η-Ni₃Ti for the former and σ-FeCr for the latter. In the HPT-processed specimens, hydrogen diffusivity was enhanced through short-circuit diffusion because of the increased population of grain boundaries in comparison with the increased opportunity of hydrogen trapping on dislocations. As for the post-HPT-annealed specimens having the precipitates, the hydrogen diffusion was hindered by the hydrogen trapping on η-Ni₃Ti precipitates, but was not affected by σ-FeCr precipitation. This depends on the affinity between hydrogen and constituting elements.     

Synthesis, Structural Characterization, and Preliminary Biological Characterization of Organotin Polyethers Derived from Hydroquinone and Substituted Hydroquinones

A variety of dibutyltin polyethers have been synthesized employing the interfacial polymerization technique. The products are polymers with degrees of polymerization ranging from 60 to 390. Infrared spectral and mass spectral results are consistent with the proposed structure. The products show good inhibition of a variety of cancer cells including those associated with bone, breast, prostrate, and lung cancers. Some also show good viral inhibition of the HSV-1 (herpes simplex) and Vaccina (small pox) viruses with those derived from electron rich hydroquinone derivative being most active. Hydroquinone-derived polymers containing electron withdrawing groups exhibit inhibition of a variety of gram positive and gram negative bacteria.     

Measurements of the electron accumulation on two Schottky diodes connected metal to metal

Electron accumulation on the metal sides of two Schottky diodes connected metal to metal was observed as a result of the temporary variation of bias between the semiconductor sides of both diodes. The potential of the metals was found to be predictable by a theory based on a property of the Schottky diode.     

Characterization of nanometer-sized Pt-dendrite structures fabricated on insulator Al2O3 substrate by electron-beam-induced deposition

Nanometer-sized Pt-dendrite structures were fabricated on an insulator Al₂O₃ substrate using an electron-beam-induced deposition (EBID) process in a transmission electron microscope (TEM). The as-fabricated structures were characterized using conventional and high-resolution transmission electron microscopies (CTEM and HRTEM) and X-ray energy dispersive spectroscopy (EDS). The as-fabricated nanodendrites consisted of many nano-grains and amorphous state structures. The nanometer-sized grains were determined to be Pt crystals with face-centered cubic (fcc) structure. The formation of the nanodendrite structures are discussed to relate to a mechanism involving charge-up produced on surface of the substrate, movement of charges to and accumulation at the convex surface of the substrate and the tips of the deposits.     

Gunn-effect high-speed carry finding device for 8 bit binary adder

A high-speed carry finding device consisting of seven inhibitors, each an integrated Schottky electrode-triggered Gunn device and an m.e.s.f.e.t., was fabricated monolithically. The device could find and store carry signals of all digits in 330 ps at the worst logic case. The anode-voltage margin was 11%     

Growth of tungsten nanodendrites on SiO2 substrate using electron-beam-induced deposition

Tungsten nanodendrite structures were fabricated on an insulator SiO2 substrate using an electron-beam-induced deposition process in a high voltage transmission electron microscope. The effect of electron beam accelerating voltage on the nanodendrite structures was investigated. The morphologies and their growth rates did not have obvious difference for the deposition at accelerating voltages from 400 to 1000 kV. A mechanism for the growth and morphology of the nanodendrite structure was proposed involving charge-up produced on the surface of the substrate, movement of charges to and accumulation at the convex surface of the substrate and the tips of the deposits. High-energy electron irradiation enhanced diffusion of W atoms in the nanodendrites, promoted crystallization of W grains, so that more crystallized W nanodendrite structures were achieved by the electron-beam-induced deposition process using higher energy electron beams.