Selective ion implantation on the respective polysilicon is performed by utilizing a low temperature accelerated oxidation phenomenon in polysilicon with a high impurity concentration and the dependence of an accelerated energy of the impurity projection range in the ion implantation, so that formation of a mask resist pattern by photoetching is not necessary for each incorporation step of an impurity.. A base (source drain) electrode is formed by polysilicon separated by a selective oxidation method and a selective oxide film in connection with an emitter (gate) region is removed to form a side wall spacer on the inner surface of the emitter (gate) region, thus loading to formation of the emitter (gate) in a reduced size.

In the fields of semiconductor integrated circuit devices which are applied particularly as required for high speed workability, it is usual to employ ECL/CML bipolar semiconductor integrated circuit devices. In the ECL/CML circuits, when power consumption and logical amplitude are made constant, the operating speed is determined depending on the parasitic capacitance of elements and interconnections which constitute the circuit and the base resistance and the gain-bandwidth product of a transistor. Of these, for the reduction of the parasitic capacitance, it is necessary to reduce the junction capacitance between the base and the collector of the transistor which greatly contributes to the operating speed. To this end, it is effective to use polysilicon in order that a base electrode is lead out to outside an element region thereby reducing the area of the base. In addition, it is generally adopted to use a method wherein polysilicon resistors and interconnections are formed on a thick field oxide film to reduce the parasitic capacitance thereof.
On the other hand, for the reduction of the base resistance, it is necessary that an extrinsic base layer be made low in resistance and is provided as closely to the emitter as possible and also to make the emitter shallow so that an intrinsic layer beneath the emitter is reduced with respect to the resistance. In order to enhance the gain-bandwidth product, it is effective to make a shallow junction between the emitter and the base along with a thin epitaxial layer of the collector.
As a prior technique which has been proposed for the purpose of realizing these modifications, a fabrication method disclosed in Japanese Patent Application No. 62-095358 is described.
FIGS. 4(A)-(F) are, respectively, sectional views of the steps of the technique. FIG. 5(a)-(f) are, respectively, enlarged views of peripheries of base and emitter regions for illustrating the steps of FIGS. 4(C)-(F) in more detail. It will be noted that part of the films is omitted in order to avoid complication of the drawings.
FIG. 4(A) shows a state wherein after element isolation, an about 3,000 angstrom thick polysilicon is formed and oxidized at approximately 200 angstroms on the surface thereof (not shown), followed by a selective formation of 1,000-2,000 angstrom thick nitride film at portion where a base electrode and a collector electrode are to be formed. Indicated at 401 is a P.sup.- -type silicon substrate, at 402 is an N.sup.+ -type buried diffusion layer formed on the silicon substrate 401, at 403 is an N.sup.- -type epitaxial layer formed on the buried diffusion layer 402, at 404 is an element isolation oxide film formed on the silicon substrate 401 and the buried diffusion layer 402, at 406 is polysilicon formed on the epitaxial layer 403 and the element isolation oxide film 404, and at 407 is a nitride film formed on the polysilicon 406.
Next, as shown in FIG. 4(B), the polysilicon 406 is selectively oxidized to form polysilicon regions 406a, 406c and 406d. Reference numeral 409 indicates an oxide film of the polysilicon 406. Subsequently, the nitride film 407 on the collector electrode is selectively removed and phosphorus is subjected to ion implantation into the polysilicon 406d of the collector electrode and thermally treated to form an N.sup.+ -type region 405 for reduction of the resistance of the collector. Thereafter, boron is ion implanted into the base electrode polysilicon 406a, 406c through the nitride film 407 at approximately 1-5.times.10.sup.15 cm.sup.-2, followed by annealing at a temperature of approximately 900.degree. C., thereby uniformizing the concentration of the boron in the base electrode polysilicon 406a, 406c. Then, the emitter-forming region of the polysilicon oxide film 409 is selectively removed and the inner wall is oxidized to form an approximately 200 angstrom thick inner wall oxide film 414. Through diffusion from the polysilicon 406a, 406c, a P.sup.+ -type extrinsic base 410 is formed. This state is shown in FIGS. 4(C) and 5(a).
Next, BF.sup.2 is ion implanted at approximately 1-5.times.10.sup.13 cm.sup.-2 to form an active base 411, after which as shown in FIG. 4(D) and 5(b), an approximately 1,000 angstrom thick oxide film 415 and an approximately 2,000 angstrom thick polysilicon 416 are formed by CVD over the entire surface. It will be noted that in FIG. 4(D), the oxide film 415 formed by CVD is not shown.
Subsequently, reactive ion etching is used to etch the polysilicon 416, followed by further etching of the oxide film 414, 415 to make an opening in the emitter as shown in FIGS. 4(E) and 5(c). The polysilicon 416 and the CVD oxide film 415 are left only on the side walls as shown in FIG. 5(C), thereby allowing an emitter, which is smaller than the opening of the nitride film 407, to be self-alignedly opened. At the same time, as shown in FIG. 4(E), the collector electrode polysilicon 406d is exposed.
Next, as shown in FIG. 5(d), an approximately 3,000 angstrom thick polysilicon 417 is deposited over the entire surface and after oxidation of the surface thereof in approximately 200 angstroms in thickness, arsenic is ion implanted at approximately 10.sup.16 cm.sup.-2.
As shown in FIG. 5(e), the oxide film 418, the polysilicon 417 and the nitride film 407 are etched, followed by thermal treatment to form an emitter 412 in the intrinsic base 411 by diffusion from the polysilicon 417.
A thin oxide film 418 is removed from the polysilicon 406a, 406c and 417, after which platinum is vacuum deposited, followed by thermal treatment to form a platinum silicide 419 on the surfaces of the polysilicon. At portions such as of a resistor which do not undergo any silicidation, the thin oxide film is left as it is. The platinum left unreacted on the oxide film is removed by aqua regia. Then, a CVD oxide film is deposited over the entire surface as shown in FIG. 5(f).
Finally, as shown in FIG. 4(F), contact holes are made to form an interconnection 413.
As described hereinabove, according to the fabrication method of the above technique, the emitter is formed in the selective oxide region of the polysilicon and the highly concentrated extrinsic base is formed through diffusion from the polysilicon left adjacent to the oxide region, so that the distance between the highly concentrated extrinsic base and the emitter can be significantly reduced. This allows easy formation of the emitter which is smaller in width than one attained by a minimum dimension of design. In addition, since the surface of the polysilicon with which the base electrode is brought to outside of the element region is converted to a silicide to an extent near the emitter and is thus rendered low in resistance, the base region is sufficient to be three times the minimum dimension of design, so that the base-collector junction capacitance can be reduced. Almost all the emitter junction is a junction with the intrinsic base with a low concentration, leading to the reduction of the emitter-base junction capacitance with the aid of the reduction in the width of the emitter.
Because the maximum depth of the junction can be made at not larger than 0.3 .mu.m, the epitaxial layer can be made as thin as 1 .mu.m or below, thereby shortening the transit time of the carrier through the depletion layer of collector. Moreover, the reduction in the junction capacitance results in shortage of the time constants of the collector and the emitter, thereby improving the gain-bandwidth product. Since, as described above, the base resistance and the parasitic capacitance of the transistor can be reduced and the gain-bandwidth product can be improved, remarkable speeding up can be achieved.
However, for the construction of high speed large capacity information communication systems, it is essential to realize high speed high integration LSIs of the analog digital hybird type. To this end, complementary devices are essential. In the above technique, for example, where a PNP transistor is used in combination with an NPN transistor used as a main element, it is inevitable to select:
(1) a lateral PNP transistor which has a structure of an NPN transistor from which an intrinsic base is eliminated and which includes one of P.sup.+ -type diffusion layers (an extrinsic base of the NPN transistor) as an emitter, the other as a collector, and an N.sup.- -type epitaxial layer (a low concentration collector of the NPN transistor) as a base:
(2) a vertical PNP transistor which has a structure of an NPN transistor from which an emitter is eliminated and which includes a P.sup.+ -type diffusion layer (a base of the NPN transistor) as an emitter, an N.sup.- -type epitaxial layer (a low concentration collector of the NPN transistor) as a base and a substrate as a collector; and
(3) a complementary transistor wherein emitters, bases separately formed through ion implantation masking using a photoresist. With (1) and (2), however, since the gain of the PNP transistor is small, matching in characteristics between the NPN transistor an the PNP transistor is not possible. With (3), it involves the problem that as a photoetching step increases, the productivity (yield, throughput) is lowered, thus impeding realization of highspeed high integration LSIs of the analog digital hybrid type.
In the fields of semiconductor integrated circuit devices requiring the high speed high integration. Consideration is generally given to MOS devices. Because of the fineness of the element, the device not only improves the scale of the integration, but also can reduce the speed-power product according to the scaling rule. The improvement of the integration scale brings about an effect of reducing the delay of interconnection accompanied by the shortage of critical path of the interconnection within integrated circuits, thus leading not only to the high operating speed of the element, but also to an improvement in the operating speed of the integrated circuit as a whole.
Since such high speed and high integration brings about the miniaturization and high performance of the devices in the applied fields, lower consumption power becomes important. As a consequence, the main current of MOS devices are now being changed to CMOS (complementary MOS) devices.
However, recent approaches to scaling down of the MOS devices depend on the photoetching technique and particulary, on the exposure technique. As a pattern size comes close to a wavelength of exposure light, studies have been made on utilization of light with a shorter wavelength (Deep-UV coherent light, X-rays) and charged particles (EB: electron beam, FIB: focussed ion beam). However, the utilization of such light rays inevitably need a large-sized (high cost) exposure apparatus and lowers productivity (throughput), making the practical utility difficult and thus producing an obstacle on the scaling down.
As a measure for solving the above problem, the present applicant disclosed a technique in a previous patent application, which is now described hereinbelow. FIGS. 2 are sectional views of steps of the technique and the steps are illustrated one by one.
(a) First, boron and arsenic are diffused in a P-type silicon substrate 201 having a crystal plane of 111 to form a P.sup.+ -type diffusion layer 202 with 800-1000.OMEGA./.quadrature. and an N.sup.+ diffusion layer 203 with 20-30.OMEGA./.quadrature.. Thereafter, an N.sup.- epitaxial layer 203 with 5-10.OMEGA./.quadrature. is grown in a thickness of about 0.8 .mu.m. The silicon substrate is oxidized to form an about 500 angstrom thick oxide film (not shown), on which an about 2000 angstrom thick nitride film (not shown) is deposited. The nitride film on the oxide film in a region on which an isolation oxide film is to be formed is removed, and the silicon substrate at the region is etched to a depth of about 4000 angstroms. Using a known high pressure oxidation technique, an about 1 .mu.m thick isolation oxide film 205 is formed. The nitride film is completely removed by etching with phosphoric acid. Thereafter, boron is ion implanted at a dose of 1-5.times.10.sup.15 ions/cm.sup.2 at an energy of 100 KeV, followed by thermal treatment at 1200.degree. C. to form a P well layer 222. After removal of the about 500 angstrom thick oxide film, a first polysilicon 206 having a thickness of about 3000 angstroms is deposited. The thermal oxidation at 900.degree. C. causes the surface of the polysilicon 206 to be converted to an about 200 angstrom thick oxide film 207. An about 500 angstrom thick nitride film 208 is deposited on the oxide film, followed by using a known lithographic technique to remove the nitride film 208 in regions for separation of electrodes and for a gate of the transistor.
(b) The polysilicon 206 which has not been covered with the nitride film 208 is thermally oxidized according to a known high pressure oxidation technique for conversion into an about 8000 angstrom thick oxide film 209. By utilizing a photoresist, arsenic is ion implanted into polysilicon 210 used as an N channel transistor electrode under conditions of 150 KeV and 1-5.times.10.sup.15 ions/cm.sup.2 and boron is ion implanted into polysilicon 211 used as a P channel transistor electrode under conditions of 100 KeV and 1-5.times.10.sup.15 ions/cm.sup.2. In order not to implant unnecessary ions, care should be taken such that when arsenic is ion implanted, the polysilicon 211 is covered with a photoresist and when boron is ion implanted, the polysilicon 210 is covered with a photoresist.
(c) The oxide film 209 which separates the N channel transistor electrode 210 and the P channel transistor electrode 211 therewith is covered with a photoresist, followed by removal of the other thick polysilicon oxide films by the use of hydrofluoric acid. After removal of the photoresist, thermal oxidation at 800.degree. C. is performed to form an about 200 angstrom thick oxide film 216. The regions on which the P channel transistor and the N channel transistor are to be formed are alternately covered with photoresists, followed by ion implantation of boron and arsenic successively under conditions of 40 KeV and 0.5-1.times.10.sup.12 ions/cm.sup.2. Annealing in an atmosphere of N.sub.2 at 800.degree.-900.degree. C. allows formation by diffusion of source and drain regions 212 and a channel region 213 of the N channel transistor, source and drain regions 214 and a channel region 215 of the P channel transistor.
(d) Using a known LPCVD technique, an about 1000 angstrom thick oxide film 217 is grown up, followed by growth of second polysilicon 218 with a thickness of about 2000 angstroms by the same method as indicated above.
(e) A gas mainly composed of CF.sub.4 is used for anisotropic etching of the second polysilicon 218 and the oxide films 217, 216 according to a known reactive-ion-etching method wherein the nitride film 208 and the single crystal silicon of the substrate serve as a stopper for the etching, thereby obtaining a configuration shown in the sectional view of this figure.
(f) By thermal oxidation at 800.degree. C., an about 150 angstrom thick gate oxide film is formed along with the second polysilicon 218 at the side walls being oxidized. Third polysilicon 220 is subjected to LPCVD in a thickness of about 3000 angstroms. The polysilicon in the P channel transistor region is covered with a photoresist, under which arsenic is ion implanted. The ion implantation conditions include 40 KeV and 1.times.10.sup.16 ions/cm.sup.2. Similarly, a photoresist is used to cover the polysilicon in the N-channel transistor region, under which boron is ion implanted under conditions of 40 KeV and 1.times.10.sup.16 ion/cm.sup.2. According to a known lithographic technique, the third polysilicon 220 and the nitride film 208 are patterned by dry etching. After annealing at 900.degree. C., an about 1500 angstrom thick oxide film is deposited according to LPCVD method. Openings are formed in part of the oxide film 221 on the third polysilicon 220 and the oxide films 221, 216 on the transistor electrodes 210, 211 according to a known lithographic technique, followed by sputtering of an aluminum-silicon alloy (not shown). Moreover, according to a known lithographic technique, the aluminum-silicon alloy is patterned and finally thermally treated at 500.degree. C. in an atomosphere of H.sub.2.
Features of the above technique reside in that the gate, source and drain regions are self-alignedly determined and that side walls are formed within the region where the selective oxide film of the polysilicon is removed, whereby a gate which is shorter in size than a minimum dimension of design can be formed.
In the above technique, however, when impurities are incorporated in the polysilicon serving as the source and drain electrodes and diffusion source, it is necessary to provide a masking for ion implantation such as by photolithography with respect to the N channel MOSFET and the P channel MOSFET. This presents a problem on the lowering of productivity (yield, thoughput) owing to the repetition of the photolithography procedure.
In addition, since any substrate (well) contact for giving a substrate (well) potential is not provided, limitation is placed on the range of application.
Further, since the electrodes of the gate, source and drain are formed of the polysilicon, a great resistance results. Accordingly, a great drop of voltage takes place owing to the passage of a great current at the time of switching, thus impeding an effect of improving the switching speed by the reduction in length of the gate.
The present invention has been accomplished in order to solve the above problems and has for its object the provision of a method for fabricating in high productivity (1) complementary bipolar transistors applicable to analog digital hybrid-type high speed integration LSIs and (2) complementary MOS transistors applicable to high speed high integration LSIs while removing the production and performance problems with respect to the formation method and structure of source drain electrodes.

Method for fabricating a semiconductor device


Corpectomy device including an outer component, an inner component and a riser. The outer component includes a first endplate and first structure. The first structure includes a window and seat in communication with the window. The inner component includes a second endplate and second structure at least partially disposed in the first structure in a first configuration, wherein the second structure defines a first terminal surface. The riser has a third tubular structure that defines a second terminal surface, wherein the riser is to be received through the window into the seat so that the second terminal surface engages at least a portion of the first terminal surface enabling the riser to support the inner component in a second configuration with respect to the outer component.

Field of Technology
This application relates generally to spinal fusion. More specifically, this application is directed to a pre-packed corpectomy device and method of bridging vertebrae with the corpectomy device to improve fusion.
Brief Description of Related Art
Spinal surgery frequently requires reconstruction of the anterior spinal column. Spinal vertebrae are bony cylindrical structures that are located in front of the spinal cord and nerves; they contribute to the structural support of the axial skeleton. A vertebra can be damaged or destroyed by disease or trauma, resulting in the compression of the spinal cord and/or loss of structural integrity of the spinal column. When the vertebra is removed during spinal surgery to decompress the spinal cord and/or restore structural integrity of the spinal column, it is necessary to reinforce and stabilize the anterior spinal column. A bone graft (e.g., from patient's hip) has traditionally been inserted into a defect site to bridge or fuse the vertebrae above and below the removed vertebra.
While there have been significant efforts to develop artificial weight-bearing devices, the materials that are suitable for the manufacture of these devices do not allow for bone integration. Accordingly, the devices need to have sufficient amount of interior space to pack grafting material, which can facilitate bone integration between the vertebrae. During spinal surgery, a surgical corridor is formed to the defect site, e.g., the diseased or damaged vertebra of the anterior spinal column. The corridor is generally as narrow as possible because there are sensitive and vital structures in front of the anterior spinal column that can be damaged.
To accommodate the materials and the surgical corridor, weight-bearing devices have been designed to have telescoping components that provide vertical expansion from a collapsed state during insertion to an expanded state after insertion into the defect site. Various expansion mechanisms have been designed to facilitate expansion and locking of the telescoping components with respect to one another. Generally, weight-bearing devices that have expansion mechanisms, which are easiest to actuate in the defect site, have the bulkiest exterior dimensions and/or take up the most interior space in the weight-bearing devices, negatively affecting fusion as they do not have sufficient amount of interior space to pack grafting material.
Accordingly, the following characteristics are desirable in an artificial weight-bearing device. It should have proper structural (or weight-bearing) properties. It should have a modulus of elasticity that is close to bone. It should be low profile to facilitate insertion. It should have the ability to expand after insertion into the defect site to accommodate defect sites of various patients. The expansion mechanism should be low profile and easy to actuate. The weight-bearing device should have a sufficient interior space to accommodate grafting material in order to achieve bone integration. It should further facilitate pre-packing of the grafting material before insertion into the defect site. Further, the pre-packed grafting material should be packed tightly after expansion of the device in the defect site.
Currently available artificial weight-bearing devices do not meet the foregoing criteria and require significant improvement. One of the most critical shortcomings is that there is little interior space for pre-packing of grafting material while the device is in a collapsed state. Further, when the device is expanded in the defect site into its expanded state, the grafting material loses its packing inside the interior space of the device. Post-packing the interior space of the device—while the device is expanded in the defect site—is not desirable and presents a danger of dislodging the device or impacting the device into the vertebrae.

Pre-packed corpectomy device to improve fusion


The use of a chromium-containing martensitic alloy for plastic molds is described. The use properties of a thermally treated plastic mold of a hardness of at least 45 Rockwell C are improved by an iron-based alloy including, in weight-%,. ______________________________________ C 0.25 to 1.0, preferably 0.4 to 0.8; N 0.10 to 0.35, preferably 0.12 to 0.29; Cr 14.0 to 25.0, preferably 16.0 to 19.0; Mo 0.5 to 3.0, preferably 0.8 to 1.5; and V 0.04 to 0.4, preferably 0.05 to 0.2, ______________________________________. where the sum of the concentration of carbon and nitrogen results in a value of, in weight-%, at least 0.5 and no more than 1.2, preferably at least 0.61 and no more than 0.95, the remainder including iron and melt-related impurities.

1. Field of the Invention
The invention relates to the use of a chromium-containing, martensitic iron-based alloy for plastic molds.
2. Discussion of the Background of the Invention and Material Information
Iron-based alloys with a chromium content of more than 12% are generally used in the production of corrosion-resistant plastic molds for processing chemically-reactive molding compounds. Depending on the required (or desired) hardness of the material, heat-treatable Cr steel with 13.0% Cr and 0.2 or 0.4 weight-% C, for example in accordance with DIN Material Number 1.2082 and 1.2083, are employed. These iron-based alloys essentially containing carbon and chromium are easily and economically usable for less stressed molds, but they have the disadvantage that a sufficient service life of the mold (or tool) cannot be attained when subjected to highly corrosive molding compounds with wear-causing additives.
Iron-based alloys, for processing of plastics, which are more corrosion-resistant can be obtained by increasing the chromium content to 14.5 weight-% and increasing the carbon content to 0.48 weight-%, and adding 0.25 weight-% of molybdenum in accordance with DIN Material Number 1.2314. In practical use, such materials are mostly sufficiently resistant to chemical reactions but have, particularly in connection with molding materials containing mineral fibers, insufficient resistance to wear.
Improved use properties of plastic molds with respect to oxidation/corrosion and wear can be attained by comparably large chromium contents, large carbon contents and molybdenum and vanadium content of the steel used. The material No. 1.2361 in accordance with DIN constitutes an iron-based alloy typical for this use in connection with highly-stressed plastic molds. However, in the course of producing molds or tools from this alloy, it is possible that material distortion or uneven dimensional changes may occur, which often requires expensive finishing work or discarding of the worked part. As one skilled in the art knows, such uneven dimensional changes are essentially caused by a deformation texture or a linear arrangement of the carbides. If now, as has been proposed in the prior art, the carbon content and thus the carbide portion in the matrix is reduced, the wear resistance of the material in particular is also reduced. Further, the wear of the mold under large directional stress is increased and the service life reduced. A further disadvantage of a high carbon content is the low stretching ability and the reduced toughness of the steel.


A thrust reverser actuator system fitting and a v-blade may be coupled to a track beam. A portion of the load between a translating sleeve and a fan case may be transmitted through the track beam. The thrust reverser actuator system fitting may comprise an integral v-blade.

A nacelle for a turbofan propulsion system on a typical commercial airliner is a structure which surrounds the engine and provides smooth aerodynamic surfaces for airflow around and into the engine. The nacelle also helps define a bypass air duct through the propulsion system. The nacelle may also include a thrust reverser which can deploy and provide reverse thrust to help slow the aircraft after touchdown. The thrust reverser may create a large load which is transferred at least in part through an actuator. The actuator is typically coupled to a torque box, and load from the actuator is transferred through the torque box and to a v-blade which engages matching geometry on the fan case. The large load may drive the design of the torque box to be large and heavy.

Thrust reverser track beam with integrated actuator fitting


A control system is provided for a conveyor bridge with a plurality of segments and equipped with individual traveling gears for the cyclic traveling (moving) on a surface in travel straight ahead and in a curve. The control system follows a process including the steps of: detecting positions of both ends of the segments of a conveyor bridge on terrain; calculating target coordinates for the control of the conveyor bridge; simultaneous switching on of the drives of all traveling gears; synchronously controlling the drives of all traveling gears; during the travel movement, constantly measuring the distance covered by each traveling gear; constantly measuring angular deviations from the straight line between two adjacent segments during the travel movement; providing a lateral slope compensation between the traveling gear and the support frame of each segment; and providing a fine alignment of all segments after reaching the target coordinates.

A conveyor comprising a plurality of segments, which is provided with a means, which indicates a possible deviation of the segments from the straight line after the moving back of the conveyor together with progressive reduction in mining, is known from the patent DE 1 262 945. This means consists of a tensioned wire cable, which is functionally connected to measuring points arranged at the segments and these measuring points indicate to a monitoring person the extent of the deviations from the straight line. This measurement may then bring about a correction of the position of the respective segment, so that all segments are in a line with the necessary accuracy at the end of the alignment process.
Furthermore, a conveyor bridge traveling on crawler traveling gears (continuous track or crawler track vehicle propulsion), which comprises a plurality of segments, is known from the U.S. Pat. No. 6,155,400. It is equipped with a conveyor belt that is guided over the entire length of the conveyor bridge. The individual segments are connected to one another in an articulated manner and will travel by a certain extent simultaneously during a moving process. The moving takes place with untensioned conveyor belt. When traveling in a straight line and in curves, it is not possible, in spite of a synchronous control of the drives for the crawler traveling gears on an uneven subsoil, to achieve that all segments move in a line jointly during the moving process. In order not to permit excessively great deviations from the ideal line between the individual segments, the angle deviations from one another are measured by sensors. If a maximum preset deviation is exceeded, the drives are so affected that a correction of their positions in relation to one another is brought about by reducing the speed or by stopping the hurrying ahead section and/or an acceleration of the speed or a moving on of the section that has remained behind. After reaching the end positions of the two outer sections, a fine alignment of the inner sections is made. Then follows a tensioning of the conveyor belt. After that, the conveyor bridge can be operated again. This solution is not suitable for a pivoting of the entire conveyor bridge by 180°, since the differentiated control of the two outer sections necessary for this is not guaranteed.
It is known from a plurality of literature sources to use the Global Positioning System (GPS) in opencast mining to determine the positions of large apparatuses. Thus, e.g., in the technical journal BRAUNKOHLE—Surface-Mining, vol. 48 (1996), No. 4, July/August, pages 413 to 421 under the title "SATAMA—Automated Opencast Site Measuring by Means of High-Precision Real-Time GPS Measurements on Bucket Wheel Excavators," it is disclosed how the excavated masses can be determined by the progression of mining by an extraction apparatus on opencast mining terrain. Moreover, the Global Positioning System (GPS) is in the meantime used aside from pure survey use in opencast mining in the operating technique there as well. The applications extend from automatic documentation of the respective positions of the apparatuses, monitoring and disposition of their movements up to support of the control tasks of these apparatuses. An overall view is given in the same technical journal BRAUNKOHLE—Surface-Mining, vol. 52 (2000), No. 5, September/October, pages 469 to 479 under the title, "GPS—State of the Art and Its Applications in the Mining Industry."
In the patent DE 10 2004 040 394 A1, the application of the Global Positioning System (GPS) in a generalized manner is provided for the control of a conveyor bridge comprising a plurality of segments for the control of the two outer segments, wherein the traveling gear of one segment is the master traveling gear and the traveling gear of the other segment is the slave traveling gear, which follows the segment with the master traveling gear. The segments arranged between them are moved approximately at the same speed. Due to unevennesses of the subsoil and other external effects, the individual segments do not form a straight line in their entire line direction in relation to one another during the moving process. This joint moving back proves to be even more difficult when the entire conveyor bridge shall be moved in a curved path. The necessary correction of all segments in relation to one another is only performed when the end positions were reached with the two outer segments.

Control system of a traveling multi-segment conveyor bridge


Methods, systems, and apparatus, including computer programs encoded on computer storage media, for determining 3D printing customizations for a user. One of the methods includes receiving data indicating a selection of a product design by a user for creation of a three-dimensional product that includes a plurality of attributes, determining a style which includes values for some of the plurality of attributes and that is associated with the user, for each of the plurality of attributes determining whether the style includes a value for the respective attribute, and upon determining that the style includes a value for the respective attribute, customizing the product design using the value for the respective attribute, or upon determining that the style does not include a value for the respective attribute, customizing the product design using a default value for the respective attribute, and providing data for the customized product design for the three-dimensional product.

The industrial revolution reduced cost for many products by virtue of mass production and economies of scale. But the products made using mass production techniques are generally not made for a specific user.
3D printing manufacturing systems may enable companies to manufacture products on-demand (often after receiving payment for the product), reduce or eliminate tooling costs, launch new products rapidly, have faster product evolution, reduce product inventory, introduce supply chain simplification and savings, have design and assembly simplification via reduced part count, perform manufacturing locally, reduce shipping and waste, and increase local recycling and material re-use.

User specific design customization for 3D printing


A data carrier provides health related information regarding a patient, and facilitates compliance with HIPAA by the obscuring the association between the name of the patient and the health related information when the data carrier is to be discarded. The data carrier includes a release liner, a health information label having an upper surface and a lower surface, the label including a first area on the upper surface for indicia specifying health related information and a second area on the upper surface for indicia specifying the identity of a patient, and a pressure sensitive adhesive coating on the lower surface of the health information label, securing the health information label to the release liner. A masking label is either integral with the health information label, or the liner. By various arrangements the masking label is either removed from the health information label, thereby disassociating the patient identity and the health related information, or the masking label is secured to the health information label so as to cover and obscure the name of the patient or the information, or both.

The Health Insurance Portability and Accountability Act of 1996 (HIPAA) Privacy Rule created national standards to protect individuals' medical records and other personal health information. It protects all individually identifiable health information that is held or transmitted by a covered entity or its business associate, in any form or media, whether electronic, paper or oral.
It is considered important to minimize even the incidental disclosure of patient information to the extent possible. Health care providers have adopted a number of changes in their standard operating procedures to limit the incidental disclosure of patient health information beyond what is required to provide medical services to the patient in an effective and efficient manner. For example, most health care facilities take steps to make sure patient information is not retrievable by unauthorized individuals from discarded documents, records, and other materials containing identifiable patient information. Many organizations now require that such materials be shredded or incinerated to avoid the risk of disclosure. These materials may include empty plastic pill vials, discarded patient ID bracelets, and used plastic bags having patient labels. This requires that bins for collecting these materials be located through the facility, and that employees spend time to empty the bins and shred or burn the contents. As an alternative, some organizations mark through the name of the patient with a marking pen at the time that the material is discarded. This is also time consuming and may not be completely effective in rendering the name of the patient illegible.
It is seen, therefore, that there is a need for a data carrier for providing health information related to a patient in which the health information and the identity of the patient can be simply and efficiently disassociated.

Data carrier for health related information


A heat retaining knit fabric is comprised of a knit textile design for outer clothing exposed in an open air wherein heat is retained inside a knit structure and a dispersion of heat is prevented when using heat of wetting generating fiber which generates heat by water adsorption and steam adsorption in a interlock stitch of plating stitch comprising minute space surrounded by two kinds of yarn at the front and the back of each knitted loop in a knit-loop portion.

1. Field of the Invention
The present invention relates to a textile design of knit fabric (hereafter abbreviated as textile design) in order to bring out specific functions of yarn efficiently.
2. Description of the Related Art including information disclosed under 37 CF R 1.97 and 1.98
It has been known that fiber, such as natural fiber generates heat of adsorption when adsorbing moisture or steam. Also, wool and animal hair have been known as fibers in which heating value of wetting is rather high. As for an example, there is a report on heat of wetting of sheep wool, "Sheep wool: Secrets of Generating Heat When Getting Wet With Water" in page 5 of `Industrial Material and Functional Fabric` as hand out materials of an open seminar by Japan Fabric Machinery Society in Jul. 6, 1984.
While advocating said function as heat of wetting generating of synthetic fiber, the textile design of fabric disclosed in the present invention has to generate a few times as much of heat value of wetting as wool because in general, wool has not been identified as a heat of wetting generating fiber. Therefore, fiber with as much heat building-up as wool is not generally identified as a fiber possessing a heat of wetting generating function, rather, it is only now expressing this characteristic as if this function is a new function.
Synthetic fiber of the polyacrylate series has been known as one kind of synthetic fiber which generates heat by water adsorption or steam adsorption. Polyacrylate indicates polymer of acrylic acid or polymerizated ester of acrylic acid.
Therefore, from this point of view, all kinds of polyacrylate do not possess the heat of wetting generating function. Since fiber in polymer of acrylic acid soda series classified in polyacrylate has 2 to 3 times as much heat of wetting generating function as wool, said fiber can be said to possess the heat of wetting generating function.
If certain fiber has such heat of wetting generating function, it generates heat with moisture content from sweating when worn and with moisture content of steam in such a surrounded atmosphere, and therefore, the generated heat can be felt on the skin.
Yet in order to make fiber using acrylic acid soda polymer series as a base, this limitation cannot be made only to simple fiber in acrylic acid soda of polymer series because of a restriction in making fiber and polymer plans such as making polymer easy to swell with water adsorbing function and restraining the swelling function whilst leaving the water adsorbing function. Therefore, the base of fiber in the present invention is expressed as a polyacrylate series fiber with the heat of wetting generating function.
Using these kinds of fiber with the heat of wetting generating function as a heat retaining material in batting and lining has been made public in prior art such as Tokkaihei-6-294006. Basically, retaining of heat is a purpose when using these kinds of fiber in related materials of batting since these kinds of fiber comprise primarily a structure wherein the heat of wetting does not easily disperse and have an additional effect of the heat of wetting in generating heat of wetting with moisture content from sweating when worn.
Further, if the heat of wetting generating fiber is used in products such as underclothing and mufflers, with their purpose being the retaining of heat, are also worn in order to protect heat from dispersion, the additional advantages of the effects of the heat of wetting can be obtained.
Similarly, since a lining made out of the heat of wetting generating fiber is also used inside of outer clothing, the same effect as above can be expected.
After all, most fiber products with their main purpose being heat retaining within their structure or in ways of wearing are those which aim to obtain the additional effect of heat of wetting by using the heat of wetting generating fiber partly in the existing circumstances.
Generation of heat caused by the heat of wetting generating fiber with moistness is known as heat generated by adsorption wherein water being in a different state from normal free water adsorbed and fixed inside the heat of wetting generating fiber when the water immerses in the fiber. In a case of steam, condensation heat of steam is added to this.
The heating value of wetting generated by fiber of polyacrylate series with the heat of wetting generating function is about 1400 J (335 cal) per 1 g of the fiber in an atmosphere of 25.degree. C., 80% RH, which is very small value being about 5% of the heating value, 2500 J (6000 cal), which would be generated in combustion of such fiber.
This value can only be obtained under an ideal situation. It gets much less an amount with an effect of water cooling caused by lacking of moistness, by excess of moistness or with endothermic reaction of latent heat of evaporation.
Therefore, promoting the heat of wetting generating fiber becomes meaningless unless it is a fiber product which is planned with the consideration that the generation of heat will be very small.
Fiber products comprising a structure aiming at retained heat with the additional effect of generated heat of wetting by using the heat of wetting generating fiber, wherein a very small amount of generated heat of wetting with moisture of sweating can be used as effective as it can be, are such clothing products protecting from coldness which comprise a structure preventing a dispersion of heat or are worn in order to prevent dispersion of heat.
In spite of that, the dispersion of heat cannot be avoided in a case of using the heat of wetting generating fiber as outer clothing like sweaters and vests because the clothing is exposed to the open air directly.
Particularly in a case of a knit fabric, the most of additional effect of the generated heat of wetting would not appear simply with swapping a normal yarn with a yarn made out of the heat of wetting generating fiber since the structure of a knit fabric is rather rough when comparing to a woven fabric.
Therefore, as for a knit fabric for outer clothing which is exposed to the open air directly, an invention of a knit fabric structure wherein the generated heat of wetting can be added effectively when using the heat of wetting generating fiber as in using a yarn.


Modern subsea wells utilise an electrohydraulic control system which switches hydraulic power to various control components in dependence on received control signals. The mounting and interconnection of the control components tends to be complicated. The invention provides a manifold comprising a first manifold body 6 having a number of openings and flow passageways therethrough. The manifold body is selectively configurable by selecting predetermined openings in order to achieve a desired configuration of flow passageways between control devices 1, 2, 13, 4. The manifold simplifies the interconnection of the hydraulic components and provides greater flexibility in the location of the components. The manifold body also provides a platform for mounting the control devices.

This invention relates to the control of hydrocarbon wells, such as subsea wells.
Subsea wells incorporate a multiplicity of devices requiring controlled operation. Modern wells utilise an electrohydraulic control system, typically located on the Christmas tree situated above the well bore. An umbilical from the surface provides hydraulic power, electrical power and electrical or optical control signals to the control system. The control system switches hydraulic power to various control components, in dependence on the received control signals. Components controlled by the control system may include safety valves, packers and flow control devices such as chokes.
A difficulty which may be encountered with the design and manufacture of such control systems is that the mounting and interconnection of the multiplicity of components tends to be complicated, particularly with regard to the hydraulic pipework needed to transmit hydraulic power to and between the components.
The invention provides a manifold arrangement for distributing hydraulic fluid to control devices, the arrangement comprising a manifold body having a plurality of openings and flow passageways therethrough, the manifold body being selectively configurable by selection of predetermined openings so as to achieve a desired configuration of flow passageways between the control devices.
The provision of a configurable manifold greatly simplifies the interconnection of hydraulic components and provides greater flexibility in the location of components.


A three-dimensional porous polyurethane scaffold for repairing central nerve injuries and a preparation method are disclosed. The scaffold includes three-dimensional porous polyurethane, wherein the compression modulus of the three-dimensional porous polyurethane is 0.001-10.0 MPa and the pore diameter is 10-200 μm. The three-dimensional porous polyurethane scaffold has an efficient central nerve repair function without additionally inoculating functional cells or factors and can partially restore the original nerve function of tested animals, the preparation method is simple and it has a great prospect of application.

Generally, the regeneration ability of adult's nervous systems is limited. As a result, different extents of losses in sensory or movement functions and neuropathic pains will be caused once people suffer nerve injuries.
Nerve transplantation is a "Golden Rule" for treating nerve injuries at current. However, due to shortage of donors and certain risks in surgeries, it is very difficult to popularize this treatment approach. More importantly, its treatment effect is not very satisfactory.
It is highly concerned in recent years to promote repair of damaged nerves by using tissue engineering technology, especially by using artificial nerve tissue engineering scaffolds, and a series of eye-striking achievements are obtained.
However, current researches mainly focus on the aspect of low-difficulty peripheral nerve repair. There are few researches on the aspect of high-difficulty central nerve repair. This is because the regeneration ability of the central nervous system is obviously weaker than the regeneration ability of the peripheral nervous system (J. W. Fawcett, R. A. Asher, The glial scar and central nervous system repair, Brain Res. Bull. 49 (1999) 377-391). At the same time, after central nerve fibers are damaged, it is considered that they cannot be regenerated at present (Sabrina Morelli, Antonella Piscioneri, Neuronal growth and differentiation on biodegradable membranes, J Tissue Eng Regen Med (2012)). Therefore, methods applicable to repairing the peripheral nervous system at present are almost not applicable to repairing the central nervous system. As a result, no major breakthrough has been made in many years in researches on repairing damaged central nerves by using the existing tissue engineering technology. However, by comparison, remarkable effects have already been achieved in the aspect of repairing the peripheral nervous system by using tissue engineering scaffolds.
In researches on repairing the peripheral nervous system by using artificial nervous tissue engineering scaffolds, people find that the repair possibility of nerves depends on factors such as scaffold structure and chemical or biological induced stimulation, scaffolds such as hollow tubes and electrospun fiber membranes are prepared under this finding by using degradable natural macromolecular materials (such as collagen, chitosan and alginate) and synthetic degradable materials (such as polylactic acid-polyglycollic acid copolymer, polycaprolactone and polypyrrole), and certain peripheral nerve repair effects are achieved. On this basis, by inoculating some functional cells (such as Schwann cells, olfactory ensheathing cells and neural stem cells) or growth factors (such as nerve growth factors, brain-derived neurotrophic factors and glia-derived neurotrophic factors), better peripheral nerve repair effects are realized.
However, in regard to the repair of the central nervous system, no applicable artificial nerve tissue engineering scaffolds with remarkable effects have been found. As reported at present, researchers generally use gel only for a scaffold for repairing the central nervous system, and a certain effect can be achieved only under the joint effect of the inoculated cells and carried factors. It is worthy of being pointed out that the holding time of the gel scaffold in vivo is very short and a long-time repair effect cannot be provided. More importantly, as known up to now, any current research achievements cannot enable the original nerve function of tested animals to be restored. In other words, the current research achievements mainly stay at a level of in-vitro experiments, and it is still a major challenge in researches in this field to find a central nervous system repairing scaffold which has an actual application value.
In order to overcome the disadvantage that the holding time of gel is short, researchers try to use polyhydroxyalkanoate (PHA) three-dimensional nano-fibers as a scaffold for repairing the central nervous system, and the obtained achievement solves the problem that the holding time of the scaffold is short to a certain extent. However, the repair effect thereof depends on the inoculated neural stem cells (NSCs). More importantly, it still stays at a level of in-vitro experiments and no obvious practical prospect is shown.
For the medical field, when the practical prospect of a certain technology is judged, it is a fundamental indicator whether the in-vivo experiment result is effective and the repeatability is good. For cell-containing scaffolds, since the exertion of the function of cells is greatly influenced by the environment, in the process that the scaffold is implanted and the effect is shown after the scaffold is implanted, the implantation operation steps, the surrounding environment of implantation parts and the physiological environment therein will all influence the superiority of the repair effect. Therefore, the existing central nervous system repair methods not only do not show any expectable excellent animal experiment results, but also are very difficult to implement.
To sum up, it is urgent to find a tissue engineering scaffold for repairing the central nervous system, which can repair damaged central nerves, has good animal experiment effects and has a low difficulty in implementation.

Three-dimensional porous polyurethane scaffold for repairing central nerve injuries and preparation method thereof


Some embodiments provide a non-transitory machine-readable medium that stores a program executable by at least one processing unit of a first device. The program establishes a collaboration session with a second device. The program also receives, from the second device, analytics data shared through the collaboration session and contextual data associated with the analytics data. The program further provides additional data for display on the first device based on the contextual data associated with the analytics data.

Today, there are many tools that may be used to allow people to collaborate with one another. For example, audio communication (e.g., a telephone call, an audio conference, etc.) tools allow people to talk to one another. Visual tools such as video conferencing, shared workspace applications, etc. allow people to view, share, demonstrate information. Many other tools may be used also, such as e-mail, messaging/chat, discussion boards, etc. for collaboration purposes.

Context-based analytics for collaboration tools


An event notification system for distributed processing systems provides for replacement of event identifiers associated with transient objects, such as processes within the processing system. An event management interface receives a notification from an event producer that an identifier of an event produced by the event producer is no longer valid. The event management interface blocks event notification for the event and dissociates an event registration entry associated with the event from the event identifier. A new event identifier is received from the event producer by the event management interface, which associates the registration entry with the new event identifier. Event notification for the event is then resumed.

1. Field of the Invention
The present invention is related to handling of event notification in computer systems, and more specifically to changing of event identifiers for transient events so that registration of a new event is not required.
2. Description of Related Art
In large-scale distributed computer systems, such as those using distributed software models to perform tasks, multiple nodes provide independent execution of sub-tasks. In order to keep such a system operational, and further, to provide indication of events occurring at one node that either require a reaction from another node or indicate to the other node that either an erroneous operating condition has occurred, or that a phase of processing is complete. In particular, event notification and event logging are operations used to indicate system health to system administrators or software applications, including operating systems components.
Health monitoring techniques employed in distributed processing systems perform an important function in that connections to other nodes must be reliable and all of the active nodes that have been assigned tasks need to perform those tasks in order to ensure that the totality of the processing requirements are met, and in a timely fashion. The health of a node-based distributed processing system is typically monitored by: 1) a heartbeat messaging system, which passes messages between the nodes and a central monitoring component; and 2) an event notification system that signals interested nodes when events occur on other nodes. Event notification systems in node-based distributed processing systems typically require an interested application (a consumer) to register to receive event notifications either with a centralized event manager, or with the processes or objects that generate the events (an event producer).

Changing an event identifier of a transient event in an event notification system

International Business Machines Corporation


Hard magnetic poles made of a permanent magnet and soft magnetic poles are alternately disposed on the periphery of a cylindrical rotor of a permanent magnet type synchronous motor. The arcuate length of the hard magnetic poles is equal to that of the intervals between the hard magnetic poles, thereby enabling an increase in the ratio of reluctance torque. Therefore, the number of permanent magnets used can be reduced, making production economical, and a back electromotive force can also be lowered. Further, one magnetic pole consists of six slots, and the arcuate length of hard and soft magnetic poles corresponds to a 3-slot pitch, thereby enabling a reduction in cogging torque.

1. Field of the Invention
This invention relates to a permanent magnet type synchronous motor having magnetic poles of a permanent magnet arranged on a rotor and having magnetic poles of a soft magnetic material which are alternately arranged with the magnetic poles of the permanent magnet, and particularly to the arrangement of the above two types of magnetic poles and their sizes.
2. Description of the Prior Art
Today, permanent magnet type synchronous motors, which have magnetic poles of a permanent magnet on a rotor and use a rotating magnetic field generated by a stator to rotate the rotor, are used in various fields. Such permanent magnet type synchronous motors are superior to an induction motor which has a winding on its rotor in enabling an increase in magnetic flux density per unit volume, thereby reducing the outside dimensions of the motors.
However, a hard magnetic material for use as a permanent magnet is generally expensive, and therefore, it is desired to use the hard magnetic material in a small quantity. In view of the circumstances, a rotor 1 having the cross section shown in FIG. 1 may be used. The rotor 1 has four permanent magnets on the outer wall of a rotor body 2 which is made of a hard magnetic material. These permanent magnets form hard magnetic poles 3. Between these adjacent hard magnetic poles 3, a magnetic pole 4 (hereinafter referred to as the soft magnetic pole) made of a soft magnetic material and being integral with the rotor body 2 is disposed. These soft magnetic poles 4 are made of the same soft magnetic material as used for the rotor. The hard magnetic poles 3 and the soft magnetic poles 4 have the same thickness radially, and are alternately arranged in the circumferential direction of the rotor 1. Hence, the rotor 1 has a cylindrical appearance.
Also, in a case of an ordinary 3-phase motor which has three slots per pole, arcuate lengths of the hard magnetic poles in the circumferential direction are about two times the slot pitch of a stator, and arcuate lengths of the soft magnetic pole are equal to the slot pitch.
A motor having the above rotor 1 generates torque with the hard magnetic poles 3 attracted by a rotating magnetic field generated by the stator and torque with the soft magnetic poles 4 attracted by the above rotating magnetic field. Therefore, this motor can generate greater torque compared with a motor using a rotor which disposes hard magnetic poles only on the outer wall of a cylindrical rotor without disposing the soft magnetic poles.
On the other hand, in the permanent magnet type synchronous motor, a back electromotive force is generated within the stator coil by rotation of permanent magnets. This phenomenon occurs in the motor having the soft magnetic poles 4 as shown in FIG. 1 and also in a motor without them. The back electromotive force increases as the motor rotates faster. When the back electromotive force becomes equal to the power voltage, the rotation cannot be further increased. Therefore, in order to obtain a faster rotation by means of the permanent magnet type synchronous motor, the stator is controlled to generate a magnetic field which counteracts the magnetic field of the above permanent magnet. This control is generally called a field-weakening control.
For the above permanent magnet type synchronous motor, its rotation torque may be increased by increasing the quantity of the permanent magnets to enhance a magnetic flux. However, it has a disadvantage that a motor cost is increased when quantity of the hard magnetic material is increased because the hard magnetic material for the permanent magnets is generally expensive as described above. Besides, there are disadvantages that the enhanced magnetic flux increases a voltage of the back electromotive force and lowers the upper limit of the rotating speed when the field-weakening control is not conducted. Also, when the quantity of the hard magnetic material is increased and the field-weakening control is required, the control range is increased and the power consumption is also increased. Besides, when a failure in a control circuit during the field-weakening control suspends the field control, there is a problem that the voltage of the back electromotive force exceeds a withstand voltage of the power circuit, causing a damage in the circuit.

Synchronous motor having magnetic poles of permanent magnet and magnetic poles of a soft magnetic material


There is provided an apparatus and a method of evaluating an effect of chroma downsampling in a compression process of an input image. According to examples of the presently disclosed subject matter the method can include: computing an error for a target chroma downsampling (“CDS”) block based on characteristics of DCT coefficients in the U and/or V planes of a respective CDS candidates group in the input image, and further based on a diversity of the DCT coefficients in the U and/or V planes of the respective CDS candidates group in the input image; and computing an estimated perceptual effect of CDS over the input image based on a plurality of target CDS blocks error values.

It is widely acknowledged that the human visual system is much more sensitive to variations in brightness than color. Chroma downsampling is based on this principle. Chroma downsampling involves encoding images by implementing lower resolution for Chroma information than for Luma information and is widely adopted in the field of digital image compression. Many digital SLR cameras use 2×1 chroma subsampling, and some point and shoot digital cameras use 2×2 chroma subsampling. Some graphics programs (such as Photoshop) sometimes use 2×2 (4:2:0) chroma subsampling.
In Towards Better Chroma Subsampling (published in SMPTE Motion Imaging Journal, 2008 5/6 May/June), Glenn Chan submits that chroma downsampling is not visually lossless in all situations and examines sources of chroma subsampling artifacts. Chen discloses a technique for extracting higher quality from existing chroma subsampled signals by minimizing out of gamut colors.

Method of classifying a chroma downsampling error


An ETFE powder having a viscosity factor xcfx86 of at most 1xc3x97104 Paxc2x7sec, an anelasticity factor xcex5 of at most 5xc3x9710xe2x88x924 Paxe2x88x921, an average particle diameter of from 5 to 1,000 xcexcm and an apparent density of at least 0.5 g/cc, is deposited on a substrate surface, followed by heat melting and cooling for solidification to form a film.

The present invention relates to a molding method or an ethylene/tetrafluoroethylene type copolymer (hereinafter referred to also as ETFE) powder. Particularly, it relates to a molding method for an ETFE powder whereby a coating film excellent in the surface smoothness can be obtained, and an ETFE powder therefor.
ETFE is excellent in heat resistance and chemical resistance and is therefore widely used as a material suitable for corrosion resistant lining or corrosion resistant containers, etc. As a processing method for corrosion resistant lining, there is a method wherein ETFE is powdered and subjected to a known method such as electrostatic powder coating, fluid bed coating or rotational molding to form coating films on various substrates. Further, as a processing method for corrosion resistant containers, there is a method wherein: ETFE is powdered and subjected to a mold, whereby a bottle molded product having any shape is obtained by a molding method such as rotational molding.
However, in a molding method for a powder, it sometimes tends to be difficult to increase the smoothness of the surface of the coating film, since no external shearing stress is exerted during the melting and solidification of a resin.
The present invention has an object to provide a molding method for a novel ETFE powder, whereby the surface smoothness of the coating film thereby obtained, can be remarkably improved. The present invention provides an ETFE powder which is made of ETFE of ethylene, tetrafluoroethylene and a fluorine-containing vinyl monomer copolymerizable therewith, said copolymer having a viscoelastic property represented by the formula (1) wherein the viscosity factor xcfx86 in the formula (1) is at most 1xc3x97104 Paxc2x7sec, and the anelasticity factor xcex5 represented by the formula (2) as the sum of xcex5i in the formula (1) is at most 5xc3x9710xe2x88x924 Paxe2x88x921, and which has an average particle diameter of from 5 to 1,000 xcexcm and an apparent density of at least 0.5 g/cc:                               J                                (            t            )                          =                              t            /            φ                    +                                    ∑                              i                =                1                            6                                                  xe2x80x83                                                  [                                                ϵ                  i                                                                  (                                      1                    -                                          exp                                                                    (                                                                              -                            t                                                    /                                                      τ                            i                                                                          )                                                                              )                                                                                (1)                                ϵ        =                              ∑                          i              =              1                        6                                          xe2x80x83                                          ϵ            i                                              (2)
provided that in the formulae (1) and (2), J(t) is the amount of strain per unit stress under a predetermined stress, xcfx86 is a viscosity factor, t is time, xcex5 is an anelasticity factor, i is an integer of from 1 to 6, and xcfx84i is a constant (xcfx841=0.135 sec, xcfx842=0.368 sec, xcfx843=1.000 sec, xcfx844=2,718 sec, xcfx845=7.389 sec, xcfx846=20.086 sec)
Further, it provides a molding method for an ETFE powder characterized by depositing the above ETFE powder on a substrate surface, followed by heat melting and cooling for solidification to form a coating film.
ETFE to be used in the present invention is one obtained by copolymerizing tetrafluoroethylene (hereinafter referred to as TFE), ethylene and a fluorine-containing vinyl monomer copolymerizable therewith, wherein the molar ratio of polymer units based on TFE/polymer units based on ethylene is preferably 90 to 50/10 to 50. If the molar ratio of polymer units based on TFE/polymer units based on ethylene is lower than 50/50, the decomposition temperature tends to be low, whereby the moldability tends to be impaired. On the other hand, if this molar ratio exceeds 90/10, by-product polytetrafluoroethylene is likely to be present in ETFE, and the formed coating film is likely to form gels, or the high surface smoothness intended by the present invention, tends to be impaired.
The fluorine-containing vinyl monomer to be used in the present invention is a fluorine-containing vinyl monomer copolymerizable with TFE and ethylene, and the following ones may, for example, be mentioned. The fluorine-containing vinyl monomers may be used alone or in combination as a mixture of two or more of them.
Poly (or mono) fluoroethylenes such as CF2xe2x95x90CFCl, and CF2xe2x95x90CH2.
Poly (or mono) fluoropropylenes such as CF2xe2x95x90CFCF3, and CF2xe2x95x90CHCF3.
(Poly (or mono) fluoroalkyl) ethylenes such as CH2xe2x95x90CH(CF2)2F, and CH2xe2x95x90CH(CF2)4F.
Poly (or mono) fluoroalkyl fluoroethylenes wherein the poly (or mono) fluoroalkyl group has from 2 to 10 carbon atoms, such as CH2xe2x95x90CF(CF2)4F, and CH2xe2x95x90CF(CF2)3H.
Perfluorovinyl ethers such as CF2xe2x95x90CFO(CF2CFXO)mRf (wherein Rf is a C1-6 perfluoroalkyl group, X is a fluorine atom or a trifluoromethyl group, and m is an integer of from 0 to 5).
Vinyl ethers having a carboxyl group or a sulfonate group, such as CF2xe2x95x90CFO(CF2)3COOCH3, and CF2xe2x95x90CFOCF2CF (CF3) OCF2CF2SO2F.
The proportion of polymer units based on the fluorine-containing vinyl monomer is usually from 1 to 10 mols, preferably from 2 to 7 mols, per 100 mols of the total amount of polymer units based on TFE and polymer units based on ethylene.
For ETFE in the present invention, it is important that the viscosity factor xcfx86 defined by the above formula (1) is at most 1xc3x97104 Paxc2x7sec, and the an elasticity factor xcex5 defined by the above formula (2) is at most 5xc3x9710xe2x88x924 Paxe2x88x921.
The above formula shows the relation between the strain and the time when a very small stress is exerted in a molten state of the polymer heated at a temperature of at least the melting point. If the molten liquid is a Newtonian fluid, the strain increases linearly with time. Namely, it is considered to be a fluid whereby xcex5=0 in the formula (2). Whereas, ETFE is an agglomerate of linear molecules, and the molten liquid will not take an ideal Newtonian fluid behavior, since the molecules are entangled, and it shows a viscous behavior and an elastic behavior simultaneously against a very small stress, whereby the strain-time curve becomes non-linear. Namely, it is considered to be a fluid whereby xcex5 greater than 0 in the formula (2). If such ETFE is melted and left to stand still, the surface of the molten liquid becomes smooth and flat by free movement of molecules and the own weight of the molten liquid itself, while it shows an elastic behavior as the linear molecules are entangled one another, which prevents the surface from becoming completely flat and smooth.
ETFE in the present invention has a viscosity factor xcfx86 of at most 1xc3x97104 Paxc2x7sec, preferably from 500 to 7,000 Paxc2x7sec. When the viscosity factor xcfx86 is at most 1xc3x97104 Paxc2x7sec, mutual free movement of the molecules can be promoted. If the viscosity factor xcfx86 is larger than 1xc3x97104 Paxc2x7sec, free movement of molecules will be suppressed, and a large stress and time will be required to obtain a smooth surface, and it tends to be difficult to obtain a smooth surface.
Further, ETFE to be used in the present invention has an anelasticity factor xcex5 of at most 5xc3x9710xe2x88x924 Paxe2x88x921, preferably from 1xc3x9710xe2x88x925 to 1xc3x9710xe2x88x924 Paxe2x88x921. By adjusting the anelasticity factor xcex5 to be at most 5xc3x9710xe2x88x924 Paxe2x88x921, elastic resistance can be made small. If the anelasticity factor xcex5 is larger than 5xc3x9710xe2x88x924 Paxe2x88x921, the mutual entangling effect of molecules tends to be large, and it tends to show a more elastic behavior, whereby it tends to be difficult to obtain a smooth surface.
ETFE having a viscosity factor xcfx86 of at most 1xc3x97104 Paxc2x7sec can be obtained by controlling the molecular weight. If the molecular weight is too large, slipping of ETFE molecules one another will be suppressed, whereby the viscosity tends to be large, and the value of the viscosity factor xcfx86 will not be satisfied. Specifically, the control of the molecular weight of ETFE can be accomplished by e.g. the temperature, the pressure and/or the addition of a chain transfer agent during the polymerization. Further, as an index of the molecular weight of ETFE, the melt index (MI) is employed.
Further, ETFE having an anelasticity factor xcex5 of at most 5xc3x9710xe2x88x924 Paxe2x88x921 can be obtained by adjusting so that the proportion of polymer units based on the fluorine-containing vinyl monomer in ETFE will be usually within a range of from 1 to 10 mols per 100 mols of the total amount of polymer units based on TFE and polymer units based on ethylene.
Further, ETFE having an anelasticity factor xcex5 of at most 5xc3x9710xe2x88x924 Paxe2x88x921 can be obtained by charging the fluorine-containing vinyl monomer all at once at the initial stage of the polymerization, followed by the polymerization. The reason for this is not clearly understood, but is assumed to be such that the larger the number of polymer units based on the fluorine-containing vinyl monomer having a side chain, and the more uniform the distribution thereof in ETFE, the larger the mutual entangling effect of ETFE molecules, whereby the anelasticity factor xcex5 will be large.
Accordingly, it is considered that by carrying out the polymerization by charging the fluorine-containing vinyl monomer all at once at the initial stage of the polymerization, the proportion of polymer units based on the fluorine-containing vinyl monomer in ETFE formed at the initial stage of the polymerization, is large, and as the polymerization approaches the terminal stage, ETFE having a small proportion of polymer units based on the fluorine-containing vinyl monomer will be formed. Thus by making the distribution of polymer units of the fluorine-containing vinyl monomer to be non-uniform, it is possible to obtain ETFE having a suitable anelasticity factor xcex5.
The ETFE powder of the present invention is a powder having an average particle diameter of from 5 to 1,000 xcexcm, preferably from 10 to 700 xcexcm and an apparent density of at least 0.5 g/cc, preferably from 0.6 to 1.0 g/cc.
If the average particle diameter is smaller than 5 xcexcm, the powder particles are likely to form agglomerates having air internally occluded by an electrostatic action. If such a powder is melted and solidified, the coating film will be one having air occluded therein, whereby the appearance and the surface smoothness as an object of the present invention will be impaired. If the average particle diameter is larger than 1,000 xcexcm, it causes hard spots when it is melted and solidified, whereby the surface smoothness as the object of the present invention will be impaired. Further, if the apparent density is smaller than 0.5 g/cc, air present among the powder particles will be substantial, and when it is melted and solidified, it forms a coating film having air occluded, whereby the appearance and the surface smoothness as the object of the present invention will be impaired.
As a method for powdering ETFE, various conventional powdering methods may be employed. For example, there may be mentioned a method wherein ETFE is subjected to a mechanical pulverizer such as a pin mill or an impeller mill for powdering by an action of e.g. impact or shearing force, a method wherein a liquid having ETFE dispersed in a solvent, is sprayed in an atmosphere of at least the melting point for powdering, or a method wherein ETFE is subjected to a granulating machine such as a Henschel mixer, a high speed mixer or a mechanofusion for granulation and powdering.
The ETFE powder of the present invention has a feature that the melt flow property is high under a low shearing stress and is capable of realizing an extremely high surface smoothness even when melted and solidified under a static condition such as a powder molding.
In the molding method for the ETFE powder of the present invention, the ETFE powder is deposited on a substrate surface, followed by heat melting and cooling for solidification to form a coating film.
As a specific method for depositing the ETFE powder on the substrate surface, there may, for example, be mentioned a method wherein by an electrostatic powder coating machine, the powder is deposited on the substrate surface by an electrostatic action, a method wherein the powder is subjected to a fluidized tank and the powder is melt-deposited on a heated substrate surface, or a method wherein the powder is charged into a hollow substrate, which is subjected to a rotational molding machine for rotation to deposit the powder on the substrate surface.
The heat melting of the ETFE powder deposited on the substrate surface can be carried out by various conventional heating means. For example, heating in an electric furnace, heating in a gas burner furnace, heating by direct flame, or a continuous system electric furnace, may be mentioned. The temperature for heat melting may be a temperature where the ETFE powder will melt, and it is usually from 250 to 350xc2x0 C.
Further, the heat-melted ETFE powder is cooled for solidification, and the cooling for solidification may be carried out at a temperature where the heat-melted ETFE powder will be solidified, and it is usually carried out at a temperature of at most the melting point, specifically from room temperature to about 200xc2x0 C.
The thickness of the coating film formed by the ETFE powder is usually at least 30 xcexcm, preferably from 50 to 5,000 xcexcm.
The coating film to be formed by the present invention may be of a single layer or of multilayers.
A method for making the coating film to be of multilayers may, for example, be a method wherein on a substrate surface, at least one layer of a coating film layer formed by the ETFE powder used in the present invention or a layer formed by other ETFE, or a composite multilayer comprising at least one member from each of the two layers, is preliminarily coated, and the ETFE powder of the present invention is deposited thereon, followed by heat melting and cooling for solidification to form a coating film. The ETFE powder of the present invention has good compatibility with other ETFE in a molten state and is capable of forming a multilayer coating film which is scarcely peeled.
Other ETFE layer may be a coating film formed by depositing other ETFE powder on a substrate surface, followed by heat melting and cooling for solidification, or a coating film formed on a substrate surface by a coating material containing other ETFE, or having a molded product such as a sheet or a film of other ETFE laminated on a substrate surface.
Other ETFE is ETFE other than ETFE to be used in the present invention, and specifically, it is a copolymer of ethylene with TFE, or a copolymer of ethylene, TFE and a fluorine-containing vinyl monomer copolymerizable therewith, whereby the viscosity factor xcfx86 in the formula (1) exceeds 1xc3x97104 Paxc2x7sec, the anelasticity factor xcex5 of the formula (2) exceeds 5xc3x9710xe2x88x924 Paxe2x88x921, the average particle diameter is less then 5 xcexcm or more than 1,000 xcexcm, or the apparent density is less than 0.5 g/cc. The copolymerizable fluorine-containing vinyl monomer may be the same as described above.
The coating film to be formed by the present invention, may be made to have a surface smoothness of at most 0.1 xcexcm as measured by the surface roughness Ra.
The substrate to be used in the present invention is not particularly limited. For example, those made of various materials such as inorganic materials such as metals, concrete or ceramics or organic materials such as heat resistant plastics, may be mentioned.
Now, the present invention will be described in detail with reference to Examples (Examples 1 to 4) and Comparative Examples (Examples 5 and 6), but the present invention is not thereby limited. Further, in the following Examples, the physical properties and characteristics of ETFE, its powder and coating films, were measured by the following methods.
(1) Melt viscoelasticity: Using a Rotary rheometer (CS rheometer, manufactured by BOHLIN Company), the strain was measured under a load of 50 Pa at a temperature of 300xc2x0 C. with a plate diameter of 25 mm and a plate clearance of 1 mm, and by the curve fitting of the formula (1), the viscosity factor 4 and the anelasticity factor xcex5 were obtained.
(2) Melt index (MI): Using a Meltindexer (manufactured by Takara Kogyo K.K.), it was measured under a load of 5 kg at 297xc2x0 C. in accordance with ASTM D3159.
(3) Average particle size: Using an average diameter distribution measuring apparatus of a laser diffraction system (HELOS and RODOS, manufactured by Simpatec Company), it was measured by a dry method.
(4) Apparent density: Measured in accordance with JIS K6891.
(5) Film thickness: A magnetic substrate was measured by means of an electromagnetic system film thickness meter, and a non-magnetic substrate was measured by means of an eddy current system film thickness meter.
(6) Surface roughness: Measured by means of a contact system surface roughness meter.

Ethylene/Tetrafluoroethylene/fluorinated vinyl monomer copolymer powder and molding method therefor