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Volume 63, Issue 9
Displaying 1-12 of 12 articles from this issue
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Review Articles
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Ken-ichi FUKUKAWA, Mitsuru UEDA2006 Volume 63 Issue 9 Pages 561-576
Published: 2006
Released on J-STAGE: September 21, 2007
JOURNAL FREE ACCESSPhotosensitive polyimides (PSPIs) and polybenzoxazoles (PSPBOs) have been attracting great attention as insulating materials or protecting packages in microelectronics industries because they can be directly patterned by the action of UV irradiation. The photolithographic method of PI and PBO is advantageous due to simplified process steps as well as their outstanding properties. This article reviews developments of PSPIs and PSPBOs produced by a lot of researchers up to date. After brief introductions are given on PI and PBO, a typical patterning process out of photosensitive polymers in respect of both negative- and positive-working is described, Next details on each resist system involving PSPI and PSPBO are reviewed. Especially, what and how to form the patterns under UV exposure and heat treatment is the core subject of this review article. Each of their chemical processes can be understood in various ways.View full abstractDownload PDF (761K)
Original Papers
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Takehiko YAMASHITA, Shinya KIDA, Tomoyuki ISHIKAWA, Kunihiko TAKEDA2006 Volume 63 Issue 9 Pages 577-585
Published: 2006
Released on J-STAGE: September 21, 2007
JOURNAL FREE ACCESSThe combustion and flame retardancy of polylactic acid, one of the non-petroleum polymers, have been studied. Red phosphorous, which is used as a flame retardant for polyesters prepared from petroleum, does not restrain its combustion, whereas a halogen flame retardant shows its effect by stopping radical chain reactions in the gas phase. Some metal-organic complexes, especially iron and copper complexes and their catalysts on porous silica show excellent results. The lower the degradation temperature in the initial stage and at 50% degradation are, the shorter the combustion times are. The ignition times are not affected by the degradation temperature. These tendencies are different from those observed during the combustion test of the polyesters prepared from petroleum. The combustion is retarded because the concentration of the degradation products in the lower temperature is too low for ignition and because the average molecular weight of the products is low.View full abstractDownload PDF (1120K) -
Kan HIRAI, Kouji SUENAGA, Jun-ichi SHINTANI2006 Volume 63 Issue 9 Pages 586-592
Published: 2006
Released on J-STAGE: September 21, 2007
JOURNAL FREE ACCESSPoly[oxy-1,4-phenylenecarbonylimino (2-chloro-5-methyl-1,4-phenylene) iminocarbonyl-1,4-phenylene] (P-1) was prepared by the low-temperature solution polycondensation of 2-chloro-5-methyl-p-phenylenediamine with bis (4-chloroformylphenyl) ether in 1-methyl-2-pyrrolidinone (NMP). The inherent viscosity of P-1 was 1.77 dL/g in sulfuric acid (0.5g/100mL, 25°C). In order to enhance the tensile properties of P-1 film, the film was drawn in a N,N'-dimethylacetamide (DMA) /water mixture (80 : 20, v/v, 50°C) and subsequently heat-treated under tension in nitrogen atmosphere, the temperature being raised from room temperature to 300°C at a heating rate of 15°C/min. The tensile strength (T), elongation (E), and tensile modulus (M) of the drawn and heat-treated film were 1.2 GPa, 13.9%, and 15 GPa, respectively. These values changed to 0.82 GPa (T), 6.59% (E), and 11 GPa (M) after 2 hours of aging at 300°C under release condition in air. After 2 hours of aging at 300°C under condition of constant length, the values changed to 1.1 GPa, 13.7%, and 15 GPa, respectively. The results show that the drawn and heat-treated Aramid films have high-temperature durability.View full abstractDownload PDF (315K) -
Yoshihiro YAMASHITA, Toshimitsu TAKAHASHI, Shunsuke KASUGAI, Akira TAN ...2006 Volume 63 Issue 9 Pages 593-600
Published: 2006
Released on J-STAGE: September 21, 2007
JOURNAL FREE ACCESSThe reinforcement effect of carbon nano fiber prepared by vapor-phase method (VGCF) was examined for various resins. The modulus of elasticity and yield stress of crystalline nylon-6 became 1.5 times and 1.6 times as large, respectively, upon addition of only 0.1 wt% VGCF. The reinforcement effect of VGCF was observed also with polypropylene. On the other hand, the reinforcement effect was not observed with non-crystalline polymers such as polystyrene and polycarbonate. An optimal mixing rule was investigated to explain the reinforcement mechanism of VGCF. A model in which fiber/matrix series and single matrices are parallely arranged best explains the experimental results. The present result is extremely important in the future design of VGCF reinforced composites. It was also found that the use of ultrasonic wave irradiation together with mechanical mixing was the best way to obtain the dispersibility of VGCF.View full abstractDownload PDF (607K) -
Makoto YUASA, Kenichi OYAIZU, Hidenori MURATA, Ken TANAKA, Masakuni YA ...2006 Volume 63 Issue 9 Pages 601-606
Published: 2006
Released on J-STAGE: September 21, 2007
JOURNAL FREE ACCESSCarbon nanoparticles modified with a cobalt-adsorbed polypyrrole film (Co/PPy/C) were found to be a good electrocatalyst for O2 reduction. The Co/PPy/C catalyst was synthesized by a multiple modification method for the purpose of obtaining Co-N4 structure in high density. The conventional Co/PPy/C catalyst was prepared by electropolymerization of pyrrole onto the surface of carbon particles dispersed in the electrolyte solution containing pyrrole, followed by complexation using cobalt acetate. The new Co/PPy/C catalyst was prepared by repeating the above operation. Compared with those of the conventional catalyst, the cobalt ions and nitrogen atoms constituting active centers increased remarkably. The carbon nanoparticles prepared by the multiple modification method was suspended in a Nafion solution, and pseudo MEA (Membrane Electrode Assembly) was made by casting the solution onto an edge-plane pyrolytic graphite electrode. It was revealed that the new catalyst reduced O2 mainly with four electrons, the number of electrons transferred n being 3.3 at a positive potential (Ep=0.31 V vs. SCE). In addition, the catalytic activity of the catalyst was improved by optimizing the heat-treatment conditions (n=3.8 at Ep=0.42 V vs. SCE). These results show the potential use of the present catalyst as a novel cathode catalyst in the fuel cell.View full abstractDownload PDF (398K) -
Makoto YUASA, Kenichi OYAIZU, Hidenori MURATA, Mizuki KITAO, Kenji FUJ ...2006 Volume 63 Issue 9 Pages 607-612
Published: 2006
Released on J-STAGE: September 21, 2007
JOURNAL FREE ACCESSmeso-Substituted cobalt porphyrins adsorbed on carbon materials were prepared by using a homogenizer in mixing cobalt tetraethylporphyrin and various carbon materials. These electrocatalysts gave rise to electroreduction of O2 at a remarkably positive potential (Ep = 0.44 V versus saturated calomel electrode (SCE)) and showed a high selectivity for the four-electron reduction (n = 3.9). The catalyst heat-treated at 600°C showed higher potential (Ep = 0.44 V vs. SCE). Electrochemical study and X-ray photo spectroscopy (XPS) analysis revealed that the adsorbed amount of cobalt-porphyrin molecules caused highly effective catalysts for electroreduction of O2.View full abstractDownload PDF (299K) -
Kohei SHIRAISHI, Megumi OHDAN, Kazuma MAEDA, Kazuo SUGIYAMA, Katsuyuki ...2006 Volume 63 Issue 9 Pages 613-620
Published: 2006
Released on J-STAGE: September 21, 2007
JOURNAL FREE ACCESSIn order to develop a novel cell cultured material capable of thermal stimulating cell detachment from its surface, we studied the biocompatible and thermosensitive copolymer consisting of N-(2-hydroxypropyl) methacrylamide (HPMA) and methyl methacrylate (MMA) [poly(HPMA-co-MMA) : HPMA/MMA = 100/27.6 (molar ratio)]. With N-isopropylacylamide (NiPAAm) as a control of thermosensitive polymer, the copolymers were grafted onto poly (ethyleneterephthalate) (PET) by Ar plasma irradiation-post polymerization technique. From the contact angle (θ) measurements to water at 25°C, the θ values of poly (HPMA-co-MMA) grafted PET (g-PET-I: amount of grafted polymer = 0.125 mg cm-2) and poly (NiPAAm) grafted PET (g-PET-II: 0.109 mg cm-2) decreased from θ = 80° (the original PET) to θ = 52° and θ = 50°, respectively. HeLa cells attached and proliferated on g-PET-I and g-PET-II at 37°C, above the lower critical solution temperature of poly (HPMA-co-MMA). After the cultivation of HeLa cells, the thermal stimuli-exfoliation was also examined at 4°C for 2 h. The ratios of the number of thermal stimuli-exfoliation cells to the total number of attached cells on g-PET-I or g-PET-II were 73% and 45%, respectively, while little thermal stimuli-exfoliation was observed in the case of untreated PET.View full abstractDownload PDF (563K) -
Mariko SHIBAIKE, Junko YOKOYAMA, Hiroki IKAKE, Shigeru SHIMIZU, Kimio ...2006 Volume 63 Issue 9 Pages 621-625
Published: 2006
Released on J-STAGE: September 21, 2007
JOURNAL FREE ACCESSThe synthesis and characterization of random copolymers of Disperse Red 1 acrylate (DR1A, 2-ethyl-4,4'-nitrophenyl azophenyl ester) and butyl methacrylate (BMA) or methyl methacrylate (MMA) have been carried out. The copolymers exhibit the orientation of azobenzene groups through photochemical trans-cis isomerization in tetrahydrofuran solution with linearly polarized argon ion laser. The response rate was estimated by using a biexponential equation. The response rate of the DR1A/BMA copolymer was found to be slower than that of DR1A/MMA copolymer.View full abstractDownload PDF (306K) -
Tetsuo TAKAYAMA, Mitsugu TODO, Hideto TSUJI, Kazuo ARAKAWA2006 Volume 63 Issue 9 Pages 626-632
Published: 2006
Released on J-STAGE: September 21, 2007
JOURNAL FREE ACCESSThe blends of poly (lactic acid) (PLA) and poly (ε-caprolactone) (PCL) were prepared by melt blending using lysine triisocyanate (LTI) as a compatibilizer to improve blend miscibility. Critical J-integral at crack initiation, Jin, was measured as a fracture energy parameter, and crystallinity, xc, PLA, and molecular weight, Mw, were evaluated by DSC and GPC, respectively. Jin and Mw tend to increase, while xc, PLA decreases, as the LTI content increase. Increased Mw and reduced xc, PLA are both considered to be due to crosslinking reaction of added LTI. It is also found that the decreased size of spherical PCL phase results in the improvement of Jin indicating that the size change of dispersed PCL phase due to LTI addition plays an important role in determining Jin value.View full abstractDownload PDF (907K) -
Osamu WATANABE, Takashi UEMATSU, Masakazu SUZUKI, Takahiro UTSUGI, Izu ...2006 Volume 63 Issue 9 Pages 633-640
Published: 2006
Released on J-STAGE: September 21, 2007
JOURNAL FREE ACCESSThe surface of metallic zinc was coated with polyhydric phenols (urushiol and tannic acid) occurring in plants. The coating properties were evaluated by contact angles and corrosion resistance. The urushiol coating showed a high water-repellent property with a contact angle of over 90 degrees. The tannic acid coating was cross-linked with a diamine, giving a tough surface with improved corrosion resistance. The salt spray test showed that the exposure time with no rust formation extends over 48 hours. The above treatments were carried out in water for several tens of seconds at ambient temperature under atmospheric pressure. It was thus shown that the use of polyhydric phenols is a useful method of metal surface modification in view of recent interest in environmental protection against harmful chemicals.View full abstractDownload PDF (439K)
Notes
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Masahiro WADA, Yoshiharu KAGAMI, Suguru HORINOUCHI2006 Volume 63 Issue 9 Pages 641-644
Published: 2006
Released on J-STAGE: September 21, 2007
JOURNAL FREE ACCESSA DNA-lipid complex, where cationic surfactants are bonded to DNA, was synthesized and its optical property was examined by doping rare-earth chelates. The DNA lipid complex films to which several kinds of rare-earth chelates were doped were prepared, and their fluorescence quantum yields were examined. A 2 to 10-fold increase in quantum yield was observed as compared with conventional PMMA similarly doped. The improvement of the fluorescence quantum yield indicates that the use of DNA is promising in the development of new optical functional materials.View full abstractDownload PDF (315K) -
Hiromasa ADACHI2006 Volume 63 Issue 9 Pages 645-648
Published: 2006
Released on J-STAGE: September 21, 2007
JOURNAL FREE ACCESSFor evaluation of thermal endurance of elastomers and foamed plastics, the time dependences of compression dynamic modulus of thermosetting polyurethane elastomers, and of micro-cell, hard and flexible polyurethane foams were investigated by dynamic viscoelastic measurements. In the temperature range of interest, 140∼290°C, compression dynamic modulus of each elastomer and each foam lessened gradually with time, which is presumably due to thermal degradation of the elastomers and foams. The logarithm of the time t at which the compression dynamic modulus came to be 50% of its value at the beginning of the dynamic measurement was found to be a linear function of reciprocal temperature T-1. Therefore, thermal endurance characteristics of thermosetting polyurethane elastomers and polyurethane foams can be evaluated as well as closed-celled polyethylene foams from the linear relations between T-1 and the logarithm of time t at which the compression dynamic modulus came to be 50% of its initial value. The loss tangent of elastomer differs from that of foam. Thermal degradation is determined by compression deformation in elastomers that have no cells and by the bending deformation in foam that have closed or open cells.View full abstractDownload PDF (260K)
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