The effects of molecular orientation on the dynamic viscoelastic properties of the biaxially stretched polyvinylchloride films were investigated. The specimens were prepared by stretching of T-die extruded films to various ratio by different methods at 95°C at a rate of 400%/min in a circulating hot-air bath. The stretching methods of films were uniaxial with the free or constant width, two-way successively biaxial and simultaneously biaxial stretching.
The temperature dependence of tan δ, dynamic modulus E′ and dynamic loss E″, of the stretched films were measured at 100Hz by a Viscoelastic Junior Spectrometer.
The following results were obtained:
(1) The stretched films by different process show changes of characteristic dynamic viscoelastic properties due to the orientation.
(2) The peak values of tan δ, E′ and E″ along the stretching direction (MD) were higher than those along the transverse direction (TD) for the uniaxially stretched films. These tendency is observed also in the two-way successively biaxially stretched films. However, the values along MD and TD are equal when the films is biaxially stretched in equal extent along MD and TD. This is same for all stretch ratios in the case of the simultaneous biaxial stretching.
(3) The molecular chain in uniaxially and biaxially stretched films seem to be similarly extended, which is different from the crystalline polymer films.
(4) The temperature of tan δ _max which corresponds to the glass transition changes depending on the stretching conditions. This is due to the fact that the temperature depends not only on the degree of orientation but on the orientation mode and the orientation direction.

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The effects of molecular orientation and crystallization on the dynamic viscoelastic properties of the biaxially stretched polypropylene films were investigated.
The specimens were prepared by stretching T-die extruded films to various ratio by various methods at 145°C at a rate of 1600%/min in a circulating hot-air bath. The stretching methods of films were uniaxial under the conditions of free and/or constant width, two-way successivebly biaxial and simultaneously biaxial stretching.
The temperature dependence of tanδ, dynamic modulus, E′, and dynamic loss, E″, of the stretched films were measured at 100 c. p. s. using a Viscoelastic Junior Spectrometer.
The following results were obtained:
(1) The stretched films by each process show characteristic dynamic viscoelastic properties due to the orientation and crystallization.
(2) The peak value of tan δ in the α_a-absorption region, E′ and E″ values, of the stretching direction (MD) were higher than those of transverse direction (TD) for the uniaxially stretched films. These tendency is observed in the two-way successively biaxially stretched films. These values of MD and TD are some for the simultaneously biaxially stretched films.
(3) The molecular chains in the biaxially stretched films seem to be more extended than in the uniaxially stretched films.
(4) The temperature of tan δ_max changes with the stretching conditions. This is due to the fact that the temperature depends not only on the degree of orientation but on the orientation mode and the orientation direction.

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複数色のカラー画像を感光体上に重ね現像した後，記録媒体に一括転写するIOI（Image-on-Image）カラープロセスは高速，高画質でコンパクトなカラープリンタを実現できる可能性を有している．しかしながら，乾式トナーを用いたIOI プロセスでは幾つかの本質的な課題を抱えており，高画質カラーの実現は困難と思われる．我々は液体トナーを用いることにより，乾式IOI における問題点を解決し，オフセット印刷機並みの高画質なカラー画像を実現した．本稿では，液体トナーIOI プロセスが理想的なカラープロセスであることを，乾式との比較を交え，実験と理論の両面から明らかにする．また，本プロセスを用いた2種類のプロトタイプ機を紹介する．

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液体トナーを用いた電子写真記録技術により解像度の極めて高い高精細な画像出力を実現することができた．同技術は，露光装置としての2540dpiの解像度を有するレーザ・スキャニング・ユニット（LSU）と，電界を一切使用しない画像転写方式を採用する．筆者らは高精細な画像の出力にあたり，これら高解像度露光技術の最適化手法を検討し，転写技術の有効性確認を行った．その結果，高解像度LSU のビーム特性を考慮した理論解析においては，ビームプロファイルのMTF と最大パワーから得られる評価値が，出力サンプルの解析からは輝度分布の標準偏差が，最適なフォーカス状態の決定指標になることを突き止めた．さらに転写前後の画像状態を比較することにより，本転写技術も高精細な画像出力に大きく寄与していることが分かった．高精細画像出力のためのこれら技術を最適化してフルカラー画像の出力を行ったところ，オフセット印刷と同等以上の高画質なカラー画像を得ることができた．

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In the previous report (part 10) in this series, the changes in structure and mechanical properties of the biaxially hot stretched poly (ethylene terephthalate) films were reported. In this paper the orientation behavior of crystalline films stretched biaxially is discussed in relation to the mechanical properties.
The samples and stretching conditions were the same as those described in the previous paper. The orientation of crystallites was studied by means of X-ray diffractometry.
The following results were obtained:
(1) In the case of uniaxial stretching under free width, the c-axis orients preferentially parallel to the stretching direction with cylindrical symmetry around the stretching axis.
(2) When the films were stretched under a constant width the crystallites show a uniplanar-axial orientation where the c-axis orients parallel to the stretching direction and the (100) plane parallel to the film surface as in a rolled film.
(3) The crystalline orientation in the two-way successively biaxial stretching is characterized as follows; In the successive stretching of film to the transverse direction, the degree of planar-orientation always increases, whereas the c-axis orientation decreases with the successive stretching ratio to pass through the state of random orientation and then increases to approach the uniplanar-axial orientation along the transverse direction.
(4) The crystalline orientation of simultaneously biaxially stretched films shows a uniplanar orientation at any stretch ratio; i.e. the (100) plane which is parallel to the phenyl ring orients nearly parallel to the film plane and the c-axis orients randomly within the plane.

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In this report, the orientation mode in the film plane and the relationship between the molecular structure and the surface state are discussed for the uniaxially stretched and simultaneously biaxially stretched poly (ethylene terephthalate) films prepared by wet-process.
Sample films used in this study were the T-die extruded film with 140μ thickness. The uniaxial and the biaxial stretching of the films were done using a film-stretcher in a recirculating hot glycerin bath.
The following results were obtained:
(1) The crystalline orientation of simultaneously biaxially stretched films was random in the plane, however, that of two-way successively biaxially stretched films was selective to some extent.
(2) The selective planar orientation parameter of the simultaneously biaxally stretched films was larger as compared with that of the uniaxially under constant width stretched films, in the machine direction and same stretch ratio.
(3) The tautness-parameter of molecular chain in the simultaneously biaxially stretched films was smaller than in the two-way successively biaxially stretched films, but this tendency was reversed by the heat treatment under the fixed length.
(4) The size of crystallite in the simultaneously biaxially stretched films was nearly equal in both the machine and the transverse directions.
(5) On the electromicroscopic observation, the simultaneously biaxially stretched films with lower stretch ratio showed no charactristic surface structure, however, these films with higher stretch ratio represented the fibril-like structure.
The molecular chain is locally uniaxially oriented in various directions in the plane, but the orientation is totally cancelled by averaging in the thickness direction which is due to the multilayer structure. That is, the simultaneously biaxially stretched films shows the uniplanar orientation.

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液体現像技術は，電子写真技術においてオフセット印刷に近似の高画質が得られる可能性を持ち，その優れた潜在能力は広く認められている．しかしながら，乾式電子写真プロセスを用いたPOD (Print On Demand) 技術による商業印刷業界への進出が目覚しい中，現時点において液体現像プロセスを用いた同様の製品は非常に限られたものでしかないのが現状である．また，これまでに液体現像方式を用いた試作モデルがいくつか提案されており，実用化されていないものも含めて多様なアプリケーションに向けた研究がなされているものの，本格的に市場に投入されるにいたっていない．大きな可能性を持った液体現像技術が真に実用化されるためにはどのようなアプローチが必要であるのか，液体現像技術の変遷を振り返りながら，その技術的な特徴について整理し，今後取り組むべき課題についてまとめた．

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2540dpiの単一画点という微小な領域に対する液体トナーの現像過程を理論的に解析した．その結果，画点形成の素過程において，周辺部から中心に向かって徐々にトナー粒子が凝縮していくということがわかった．このような挙動は，粒子の自由度が高い液体現像特有の現象であると思われる．さらに，本解析から得られた画点径の現像バイアス依存性は，実際に出力した画像から得られたデータと良く一致しており，その妥当性が確認できた．また，線幅10μm のマルチラインの現像についても解析を行い，ライン画像特有の現象を見出すと共に，さらなる高解像度化への指針を得た．このように，直径10μm 以下という微小な画点や，線幅10μmのマルチラインを再現できる液体トナープロセスの優位性を理論と実験の両面から証明した．

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To investigate the relations between flow structure and velocity fluctuations in the vortex growth in bounded jet flow, the full Navier-Stokes equations with the primitive variables are solved by a finite difference method, and the process of vortex growth is visualized by marker particles. The vortex growth in. bounded jet flow can be distinctive. Firstly, to attract the feature, two-dimensional jet flows are investigated. Then, in comparison with the two-dimensional case the bounded jet flows are discussed. The vortex growth in a wall shear layer may be explained by same manner as in a free shear layer. From this point of view, three-dimensional vortex structure in the bounded jet flow can be explained.

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液体トナー電子写真では転写プロセスでの画質劣化という課題があった．新たに開発した転写方法は，感光体上に順次，現像，多重された液体カラートナーを，溶融してフィルム化することなしに，ずり応力と圧力を働かせて中間転写媒体上に移し取り（一次転写），さらに転写媒体上で加熱された液体カラートナー自身の粘着性と圧力の働きで記録媒体へ転写する（二次転写）．この全く電界力を使わない転写方法により，微粒子，高濃度という液体トナーの特徴を活かした高画質の出力が可能になった．しかし，その現象と特性には，いくつかの謎があった．筆者らは有限要素法を使い，中間転写媒体である弾性体の挙動を解析した．その結果，この転写方法のメカニズムは転写媒体のタック力（あるいは粘着力）の作用ではなく，主に，弾性力と摩擦力の作用であることが分かった．

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シアリング転写は，感光体上に順次，多重，現像された液体カラートナー画像を，ずり応力を加える作用により中間転写媒体上へ移動させる．この方法により，安定に高画質画像を出力する液体カラートナー電子写真が実現した．
　この転写技術のメカニズムは既に発表している．しかし，なぜ液体トナーが適度に湿った状態であるときに最良の性能を発揮し，乾燥が不充分の状態や，逆に乾燥しすぎた状態では性能が低下するのかということを説明できなかった．そこで現象の解析を行なった．その結果，この現象は，トナー粒子間の凝集力とトナー中の液体含有量とシアリング転写性能の全てに関係する液体ブリッジ形成の効果であることが分かった．

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近年，ポストテンション方式の既設PC橋におけるグラウト充てん不足部に，凍結防止剤に起因するCl^-が侵入し，構造安全性を確保する上で重要なPC鋼材において腐食や破断が報告されている。そこで，筆者らはこれらの腐食したPC鋼材に対して，亜硝酸リチウム水溶液の注入と亜硝酸リチウム添加補修材の充てんによる新しい補修方法を提案した。本稿では，本補修方法の腐食抑制効果実験の概要と実橋への適用事例について紹介する。

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Films of poly-l-lactic acid were stretched under a novel dry-process. In the case of uniaxial stretching with free width, the stretching attained a stretch ratio up to MD×TD=3.5×1', in the case of uniaxial stretching with constant width, up to 3.0×1.0, and in the case of simultaneous-biaxial stretching, up to 2.5×2.5.
The crystalline phase of uniaxially stretched films with free width had uniaxial orientation, like a fiber. For the uniaxially stretched films with constant width, however, the crystalline phase had uniplanar-axial orientation, And, the crystalline phase of simultaneous-biaxially stretched films, showed uniplanar orientation at all stretch ratios.
The mechanical properties, transparency, crystallinity and degree of molecular orientation of the films were improved by this novel dry stretching process. Particularly, tensile strength and Young's modulus to machine direction increased for all the stretched films.

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In this report effects of spherulite size and of various stretching processes on the characteristics of the deformation and fracture of polypropylene spherulites were investigated at both the room and higher temperature in connection with the stretchability of films. The exfoliatical property of biaxially stretched film is discussed in terms of spherulite deformation.
Film containing spherulite of various sizes were prepared by hot-press technique under the various cooling conditions. These films were stretched with the film-stretcher, in the open bath or the hot-air bath. The following stretching methods were adopted: uniaxial stretchings under the free or constant width, and two-way successive or simultaneous biaxial stretchings.
The biaxial stretchability is higher in the films with small size spherulites than in the films with large size.
The deformation and the fracture mechanisms of spherulite could be phenomelogically classified as follows: (1) brittle break-down, (2) fracture with the cleavage of interfacial boundary, (3) uniaxial plastic deformation, (4) deformation with necking, (5) deformation with pleating, (6) deformation into fibril structure, and (7) biaxial plastic deformation.
The characteristis of the deformation and the fracture of spherulites are summarized in Table 1.
We have deduced that the appearance of exfoliatical property as mica was owing to the multilayer structure of the spherulite and the planar orientation of molecular chains and crystalls in the film.

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This paper deals with an experimental study on the influence of cooling conditions at the cavity walls on the sink generation appearing in an injection molded polymer product. By employing a test mold which has two transparent windows, the processes of sink generation and solidification of the injection molded polymer were observed under various molding conditions. The observed results showed that sinks appear on the surface just before the whole polymer solidifies. This means that the development of sinks must be influenced by the rigidity of the solidified layer generated at the beginning of the cooling stage. This implies that the sink generation can be controlled by the temperature of the cavity walls.
In order to confirm whether the sink location can be controlled by the cooling rate of the cavity walls, sink generation was examined in tests using asymmetrical cooling of the cavity walls. The results are summarized as follows:
(1) When the temperature of one cavity wall is 10-20K higher than that of opposite wall, sinks appear only on the surface adjacent to the hotter wall.
(2) On the contrary, if the hot wall temperature exceeds the glass-transition temperature of the polymer, the sinks appear on the opposite cold surface.
It was thus concluded that the location of sink can be controlled by the cooling rate of the cavity walls.

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