Search

This paper focuses on the world’s first non-phosgene process using CO2 as starting material succeeded in development and industrialization by Asahi Kasei Corp. The Asahi Kasei Process enables high-yield production of high-quality PC having excellent properties and high-purity monoethylene glycol (MEG), starting from ethylene oxide (EO), by-produced CO2 and bisphenol-A without waste and waste water. The innovative reactive distillation technologies in the monomer production and the innovative gravity-utilized, non-agitation polymerization reactor in the melt polymerization, led the new process to success. The monomer process consists of 3 production steps, ethylene carbonate (EC) from CO2 and EO, dimethyl carbonate (DMC) and MEG from EC and MeOH, and diphenyl carbonate (DPC) and MeOH from DMC and PhOH. All intermediates are recycled. The new type polymerization reactor perfectly overcomes the difficulty based on the extremely high viscosity in the melt polymerization of DPC with Bis-A. The by-produced PhOH is recycled to the monomer process. The reduction of CO2 emissions (0.173t/PC 1t) is also achieved, because CO2 used as raw material is utilized as the main chain components of the products. Four commercial plants (Taiwan: 150,000 t/y, Korea: 2 plants of 65,000 t/y, Russia: 65,000 t/y) using the Asahi Kasei Process are now successfully operating, and the plant of 260,000 t/y in Saudi Arabia will start in 2010.

This review focuses on the world’s first process succeeded in development and industrialization by Asahi Kasei Corp. for producing an aromatic polycarbonate (PC) using CO2 as starting material.1 The carbonate group of PC links directly to the residual aromatic groups of the bisphenol. Until Asahi Kasei’s new process is revealed, all of carbonate groups of PC in the world were derived from CO as starting material. Furthermore, more than about 90% of PC has been produced by so-called “phosgene process”, and the PC contains Cl-impurities. It needs to use not only highly toxic and corrosive phosgene made from CO and Cl2 as a monomer, but also very large amounts of CH2Cl2 and water, and needs to clean a large amount of waste water. The new process enables high-yield production of the two products, Cl-free and high-quality PC and high-purity monoethylene glycol (MEG), starting from ethylene oxide (EO), by-produced CO2 and bisphenol-A. PC produced by the new process has many excellent properties compared with conventional PCs. The new process not only overcomes drawbacks in the conventional processes, but also achieves resource and energy conservation. The reduction of CO2 emissions (0.173 t/PC 1 t) is also achieved in the new process, because all CO2 is utilized as the component consisting main chains of the products. The newly constructed commercial plant of Chimei-Asahi Corp. (Taiwan), a joint venture between Asahi Kasei Corp. and Chi Mei Corp., has been successfully operating at full-production since June 2002. The initial capacity (PC:50,000 t/y) is now increased to 150,000 t/y. A typical example of the Green and Sustainable Chemistry (GSC) contributing to society and mankind has been realized.

Asahi Kasei Corp. has succeeded in the development of a new green process for producing an aromatic polycarbonate based on bisphenol-A (hereafter usually abbreviated as PC) without using phosgene and methylene chloride. The new PC production process is the world's first to use carbon dioxide (CO2) as a starting material. Until Asahi Kasei's new process was revealed, all of the PC in the world has been produced using carbon monoxide (CO) made from cokes or lower hydrocarbons and oxygen as a starting material. Furthermore, more than about 93% of the PC has been produced by the so-called “phosgene process” which uses phosgene made from CO and chlorine (Cl2) as a monomer. However, the phosgene process inherently involves a number of environmental and economic shortcomings in addition to the high toxicity of phosgene itself and the high carcinogenic probability of methylene chloride itself. Asahi Kasei's new process enables high-yield production of the two important products for our citizens’ lives, high-quality PC and high-purity monoethylene glycol (MEG), starting from ethylene oxide (EO), carbon dioxide (CO2) and bisphenol-A. This new technology not only overcomes the environmental and economic problems existing in the phosgene process, but also achieves resource conservation, and energy conservation. Furthermore, the new process contributes to the earth environment by the reduction of CO2 emissions (173 tons per thousand tons of product PC). Commercial application of the new process was carried out at the 50,000 ton year−1 PC plant of Chimei-Asahi Corporation, a joint venture between Asahi Kasei Corporation and Chi Mei Corporation, which was newly constructed in Taiwan and has been successfully operating since June 2002. In recognition of the outstanding advance in ecological and sustainable performance that this technology represents, Japan's Minister of Economy, Trade and Industry conferred the Green and Sustainable Chemistry Award of 2003 on us. Furthermore, the Chairman of Japan Chemical Industry Association also conferred the 35th Japan Chemical Industry Association Award of 2003 on us as an outstanding chemical technology. An outline of this new non-phosgene PC process embodying the spirit of Green and Sustainable Chemistry is given here.

重合後精製され, いったん触媒や溶媒などを除去した高分子溶液や固体成形体に再び重合触媒を混合することによって, 高分子どうしの再重合が起こることを実験的に確かめることと, 再重合の速度などがこれまで観測されている重合挙動と著しい差異が見られないかについて考察を行った. その結果, ポリフェニレンエーテル (PPE) を用いた実験においては重合後, いったん触媒や溶媒を除去して乾燥した高分子を再び同一条件で触媒と溶媒を加えて重合すると, 重合の進行が見られた. またフィルム上に成形した材料でも可塑剤などを含み高分子鎖の運動が確保できるときには再重合により分子量の増大が見られた. これらの結果を踏まえて繰返し力学負荷などで分子量の低下が起こり, そのために材料寿命が短くなる場合にはあらかじめ材料に触媒などを添加することにより能動的防御作用をもつ材料を合成しうる基礎的知見を得た.

The phase separation of PS/SAN/PPE (polystyrene/acrylonitrile-styrene copolymer/polyphenylene ether) immiscible alloy and the distribution of PPE into the separated phases in the alloy have been studied in detail. The profiles of the loss modulus clearly showed the phase separation, and the structure of the alloy could be designed by the assistance of the viscoelastic information. The immiscible alloy composed of PS, SAN, and PPE showed high distortion temperature, good fluidity, and high flexural strength even in the absence of the compatibilizer. PPE distributed into the two phases and played a role of a compatibilizer. The PS/PPE phase led to the high distortion temperature and the SAN/PPE phase brought about the high mechanical strength. The distribution constant of PPE in PS and SAN phases was measured and showed a constant value (K = 0.50) in the whole region of the alloy composition. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 2521–2526, 1998

The miscibility and properties of the alloys composed of polyphenylene ether (PPE), polystyrene (PS), and acrylonitrile-styrene (SAN) polymers have been studied. The heat distortion temperature and flexual strength decreased with increasing AN contents in SAN in PPE/SAN alloys because the mutual solubility was poor in the high-AN content region. However, PPE/PS/SAN alloys showed higher heat distortion temperature and higher flexural strength than the PPE/PS miscible alloy and the PPE/SAN immiscible alloy. Furthermore, the PPE/PS/SAN alloy has excellent fluidity. It is a kind of immiscible alloy without a compatibilizer, which shows the excellent properties. The results suggested that there is a so-called “entanglement phase” between two separated phases and PPE distributed to both phases, and this phase is superior to that in which compatibilizer was added to enhance miscibility. Moreover, it is very useful for recycling materials because it does not contain a sophisticated compatibilizer. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 2515–2520, 1998

コーンカロリメーターによるポリフェニレンエーテル (PPE) とポリスチレン (PS) アロイを中心として高分子燃焼の研究を行い, 燃焼時の高分子の分解および表面状態について考察を行った. PPEの含有量が増大するに従って発熱速度, 最大発熱速度が減少し, PPEの含有量が50 wt%以上ではPPEの含有量の影響が少なかった. コーンカロリメーターの結果と熱重量分析, UL燃焼試験, およびPPEとベンゼン環の相互作用のコンピューター・シミュレーションの研究により, PPEの含有量の少ないときにはPPEとコンプレックスをつくらないPSが材料全体の燃焼を支配し, PPEの含有量がPSに対して1/2以上になるとPSの高分子鎖はPPEとコンプレックスをつくりPPEの燃焼挙動が材料全体を支配すると考えられた.

Poly(oxy-1,4-phenylene-carbonyl-1,4-phenylene-oxy-1,4-phenylene-carbonyl-1,4-phenylene-carbonyl-1,4-phenylene) (PEKEKK) was heated in the presence of potassium carbonate at 340°C to yield another aromatic polyetherketone, which contained not only the original EKEKK repeating unit but also the EK and EKK repeating units. This indicates that trans-etherification reaction occurs between molecules of PEKEKK. Poly(oxy-1,4-phenylene-carbonyl-1,4-phenylene) (PEK) reacted with poly(oxy-1,4-phenylene-sulfonyl-1,4-phenylene) (PES) in the presence of potassium carbonate at 300°C to yield a trans-etherification product, i.e., a block copolymer of P(EK)/(ES). A further reaction decreased the crystallinity of the block copolymer to yield a random copolymer.

There exist considerable literatures on the vascular changes by tolerance dose or over tolerance dose irradiation, but little work has been done to study the effect of under tolerance dose irradiation on capillary changes. The purpose of this study was to observe capillary changes in the periosteum of rats after Co60 irradiation. The vascularity of the periosteum was observed with vascular resin casts and scanning electron microscope at 3 days to 30 weeks after the heads were exposed to 10 Gy or 20 Gy of Co60γray.The results were as follows:1. In rats irradiated with 10 Gy.Leakage of resin from the fine blood vessels was observed at 3 weeks. Decrease in the diameter of small blood vessels and decrease of capillary networks were observed at 5 weeks. These changes improved at 7 weeks.2. In rats irradiated with 20 GyLeakage of resin and decrease in the diameter of the small blood vessels were observed at 2 weeks. The number of small blood vessels was decreased at 4 weeks. These changes improved at 7 weeks.

We carried out SEREX (serological analysis of antigens by recombinant cDNA expression cloning) using sera from patients with Sjogren's syndrome (SjS) and investigated the frequencies of autoantibodies against autoantigens identified by SEREX in the sera of healthy individuals (HI) and patients with SjS, rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). IFI16 and two kelch-like proteins, KLHL12 and KLHL7, were found to be novel autoantigens in SjS by SEREX. A markedly high frequency of anti-IFI16 autoantibodies was observed in the sera of SjS (SjS, 70%; RA, 13%; SLE, 33%; HI, 0%). Interestingly, all serum samples from SjS demonstrated immunoreactivity against one or both of IFI16 and SS-B/La. The presence of autoantibodies against KLHL12 and KLHL7 in the sera was significantly specific to SjS (23% and 17%, respectively), as they were not detected in RA, SLE or HI. Furthermore, we confirmed that transcripts of these autoantigens were expressed preferentially in the salivary glands and immuno-privileged testes. Our results suggest these autoantigens may be useful as serological markers for the clinical diagnosis of SjS and may play a crucial role as organ-specific autoantigens in the aetiopathogenesis of SjS. This study warranted clinical evaluations of autoantibodies against IFI16, KLHL12 and KLHL7 in combination with anti-SS-B/La autoantibodies.

An upper alveolar skeletal reconstruction with closure of the palatal fistula using an osteocutaneous free flap is considered an ideal reconstructive strategy after curative surgery for cancer of the lower maxilla. Although installation of osseointegrated implants into the bone has advantages for utilizing a dental prosthesis, it is often time and cost prohibitive. In the case of 1 patient, we reconstructed and fit the patient with a conventional denture, eliminating the need for installation of osseointegrated implants. The patient underwent upper alveolar reconstruction using a fibular osteoadipofascial flap, followed by a skin graft for creation of an alveololabial sulcus. It was then possible for the patient to wear a conventional denture without implants. One explanation for this success is that the regenerated mucosa on the adipofascial flap and skin graft was immobile, which allowed it to serve as a base for the dental prosthesis. The alveololabial sulcus that had been constructed kept the denture in place. This reconstruction confirmed that a fibular osteoadipofascial flap might be a useful choice in restoring a natural upper alveolar osseous and soft tissue structure.

In this study, the magnetic permeability of a series of metal substituted e-Fe2O3 was first measured. The electromagnetic wave absorption properties were measured in the region of 50–75 GHz (V band), and the materials exhibited absorption peaks at 64 GHz (e-Ga0.51Fe1.49O3), 59 GHz (e-Ga0.56Fe1.44O3), and 55 GHz (e-Ga0.61Fe1.39O3). From the reflectance and transmittance measurements, the magnetic permeability (μ′-jμ″) and dielectric constant (e′-je″) of e-GaxFe2−xO3 were evaluated. The μ″ values of e-GaxFe2−xO3 are the highest values among reported magnetic millimeter wave absorbers in the V-band region.

It is considered that the flow of lymph and its metastasis may occur along the mental region when an inferior labial tumor infiltrates into the white labial portion. For treating this kind of tumor, Martin's method employing the resection of the mental region through vertical incision from the vermillion border down to the lower margin of the mandible is suitable. This method increases the degree of radical treatment for tumors on one hand, but makes difficult to reconstruct the lower lip because of enhanced buccal tone on the other hand.We now apply a modified Martin's method by adding incision on the lower margin of the mandible in the case of resection of inferior labial tumor and/or regional lymph vessel. For the reconstruction of inferior labial defect site, extensive cheek advancement flaps are used according to Fries's myoplastic method and our modifications mentioned above.The method has been applied in three patients with satisfactory results both esthetically and functionally as of 6 months after operation.

We investigated the clinical effects of an OTC dental cone (®Oxytetra Cone “Showa”)(OTC-C), by the double blind method using an inactive placebo (P) and obtained the following results.1. OTC-C was associated with significantly better postoperative granulation from 3 days after teeth extraction.2. OTC-C resulted in significant reductiou of redness in the surrounding gingiva from 3 days after teeth extraction.3. Final overall evaluation showed signification superiority of OTC-C, with an effectiveness rate of 92.8%for OTC-C and 60% for P.4. The rate of usefulness was 89.3% for OTC-C and 63.3% for P, showing significantly high usefulness of OTC-C.5. There were no side effects in any subject.6. The higher usefulness of OTC-C was suggested in relation to greater operative stress including extraction of teeth associated with purulent inflammation and surgical duration.From the above findings, the superior usefulness of Oxytetra Cone “Showa” in clinical settings was confirmed. It seems necessary to take advantage of the dental cone particularly in patients with purulent inflammation or those who had systemic complications and in whom postoperative wound healing or influence on other distant organs is of concern.

A case of cat scratch disease (C. S. D.) in a 7-year-old girl is presented in this paper.The patient showed swelling in left cheek and submandlar area starting 1 week previously.Also, a scratch on medial angle of eye by kitten was found.Investigation including Hanger-Rose Test and histopathological examination gave a diagnosis C. S. D.The diagnotic and treatment course are discussed.