An exemplary apparatus (20), for removing pollutants atop a body of coolant, includes a filter (21), a pollutant removing structure (22), and a pump (23). The filter includes a housing (210), and a filtering unit (211) positioned in the housing for removing the pollutants from the coolant. The filtering unit is separated into a first cavity (2112) and a second cavity (2113) by a partition sheet (213). The partition sheet is spaced apart from a bottom surface of the housing to define a communicating gap (2131) for the first cavity and the second cavity to communicate with each other. The pollutant removing structure is positioned on the filter. The pollutant removing structure includes a removing member (221) for removing the pollutants out of the filter. The pump is configured for pumping the coolant into the first cavity of the filter.

1. Field of the Invention
The present invention generally relates to apparatuses for removing buoyant pollutants, and more particularly, to an apparatus for removing buoyant pollutants having oil and debris floating atop a body of coolant.
2. Discussion of the Related Art
In order to prevent overheating of cutting tools, a coolant is generally applied to the cutting tool to cool it. However, when using the cutting tool, pollutants, such as oil, and debris, such as dust and other particles, may contaminate the coolant in a coolant tank. The oil generally floats atop the coolant. Some of the debris will mix with the coolant, some debris will sink to the bottom of the coolant, and some debris will mix with the oil and float atop the coolant. Because the majority of coolants for cutting tools are viscous, most of the debris will mix with the oil and float atop the coolant.
The coolant tank for receiving the coolant is generally badly ventilated. In badly ventilated environment, contamination of the coolant will increase and because most of the pollutants are buoyant this creates a haven for micro-organisms and the micro-organisms further contaminate the coolant. When the contaminated coolant is applied to the cutting tool, the cutting tool erodes and deteriorates, resulting in poor quality work-pieces machined by the cutting tool. In addition, the contaminated coolant may also be a health hazard. Therefore, the coolant must be changed periodically to prevent contamination. Changing the coolant increases costs and takes time, thus decreasing the work efficiency.
In order to extend the usage life of the coolant, the buoyant pollutants such as debris and oil floating atop a body of the coolant should be removed. A typical apparatus for removing buoyant pollutants, such as oil, floating on top of coolant includes a metallic strip. The metallic strip rotates in the coolant and absorbs oil. Other pollutants mixed in the oil may adhere to and be removed from the coolant by the metallic strip. However, the efficiency of the metallic strip for removing pollutants is relatively low and the metallic strip cannot remove all of the pollutants.
Therefore, a high efficiency apparatus for removing pollutants, is desired.

Apparatus for removing buoyant pollutants

Hong Fu Jin Precision Industry (ShenZhen) Co., Ltd.


There is provided a method for the control of resistant populations of Lepidoptera: Olethreutidae such as Cydia pomonella (L.), Laspeyresia pomonella (L.) Grapholitha molesta (Busck), and the like and the protection of fruit crops therefrom which comprises contacting said Lepidoptera with a toxic amount of flufenoxuron.

Fruit-eating Lepidoptera are an important worldwide pest. Even a small percentage of infestation can be economically more significant than the monetary value of the fruit, due to the increased cost of sorting before packing and the increased infestation potential for the ensuing season. Overwintering larvae, upon emerging from diapause enter fruit after blossom causing the first generation. As many as three generations may occur during a growing season, facilitating Lepidoptera populations to develop resistance to environmental toxins such as insecticides.
Although numerous insecticides may control Lepidoptera effectively, most require frequent application. As a result, the efficacy of the insecticides may be severely compromised by the development of resistant populations such as acylurea-resistant, pyrethroid-resistant, and organophosphate-resistant Lepidoptera.
Therefore, it is an object of this invention to provide a unique and highly effective compound useful for the control of resistant populations of Lepidoptera.
It is another object of this invention to provide a method to enhance the protection of fruit crops from the infestation and attack of acylurea-resistant, pyrethroid-resistant, and organophosphate-resistant Lepidoptera.
It is an advantage of this invention that the method of control of resistant Lepidoptera populations is non-harmful to beneficial insect species and is fairly benign to the environment.
These and other features and objects of the invention will become apparent from the detailed description set forth below.

Method for the control of resistant populations of lepidoptera


A readout arrangement has a base which has a flexible member supporting a probe on a free end thereof so that the probe is movable with respect to the base; a medium in which a superficial data indicative topographical feature can be formed, the superficial data indicative topographical feature being configured to be contacted by the probe, the medium and the base being arranged to be movable relative to one another; and a semiconductor element disposed with one of the base and medium, the semiconductor element being configured to be responsive to an electric field generated in response to interaction between the probe and the superficial data indicative topographical feature.

It has been hitherto been proposed to sense data which is written onto a movable medium using a probe that is supported on a cantilever and used to contact the movable medium. A heated element (heater) is provided in/on the cantilever proximate the probe. The heater is heated by passing a current of electricity therethrough. By using heat transfer characteristics between the movable medium and the probe (or a portion of the cantilever in which the heating element is formed), it is possible to determine minute changes in distance between the movable medium and the cantilever on which the probe is carried, and to use this as a means for reading out the data stored on the movable medium.
The heater in the cantilever can be used for either/both reading and writing. The reading function uses a thermal readback sensor arrangement which exploits a temperature-dependent resistance function. In this arrangement, the resistance (R) may increase with heating power/temperature from (for example) room temperature to a value of 500–700° C. (writing). The peak temperature may be determined by the doping concentration in the heater platform, which may range from 1×1017 to 2×1018. Above the peak temperature, the resistance may drop as the number of intrinsic carriers increases because of thermal excitation.
During sensing, the resistor may operate up to about 300–350° C. This temperature may be selected to not soften the polymer medium but allow thermal conduction through the gas between the cantilever on which the probe is carried, and the moving medium, to remove heat and thus provide a parameter which allows the distance between the cantilever on which the probe is carried and the medium on which the probe is running to be measured.
That is to say, this thermal sensing is based on the fact that the thermal conductance between the heater platform and the storage substrate changes according to the distance between them. The medium between a cantilever and the storage substrate, usually air, transports heat from one side to the other. When the distance between heater and sample is reduced as the probe moves into a bit indentation, heat is more efficiently transported through the air and the heater's temperature and hence its resistance decreases. Thus, changes in temperature of the continuously heated resistor are monitored while the cantilever is scanned over data bits, providing a means of detecting the bits.
Under typical operating conditions, the sensitivity of the thermomechanical sensing may be even better than that of piezoresistive-strain sensing inasmuch as thermal effects in semiconductors can be stronger than strain effects.
Nevertheless, the thermal response has been found to be slower than desired and is slower than the cantilever's ability to follow the data pattern written in the medium. This leads to the system's read performance being slower than it would be if it were not limited to the thermal response of the sensing system.

Hewlett-Packard Development Company, L.P.


A multi-user quantum cryptography system and method are described herein. The system comprises a relay including a quantum information server so configured as to generate quantum information communications having different wavelengths and a multiplexer so configured as to separate the different quantum information communications generated by the quantum information server by their wavelength and to supply each communication to a respective user.

Fibre optic communication is and will be for a long time an essential, integral component of telecommunication systems. For example, telephone networks, the Internet, cable television networks and banking networks routinely use optical fibres to transmit huge quantities of data.
The conveyed data are often of confidential nature, for example a credit card number or a password providing remote access to a computer system. To ensure confidentiality, the conveyed information is ciphered by means of "classical" methods whose security stands from the hypothesis, until now unproven but also not rebutted, that the computational time required to break the cipher is much too long [1]. However, the unforeseeable nature of scientific discoveries as well as the development of the presently known technologies may lead to techniques capable of breaking these classical ciphering methods through a quantum computer [2].
A solution to this problem was discovered in 1984 as reported in an article by C. H. Bennett and G. Brassard [3]. This solution consists of a new method called quantum cryptography (QC) or, more specifically, quantum key distribution. In the foregoing disclosure, we shall make no difference between these two expressions. Since its discovery, feasibility of quantum cryptography with optical fibre signals has been demonstrated many times (see [4] for a review of this domain). The advantage of the quantum cryptography method is that its security is unconditionally warranted by the laws of physics against any possible attack, which overcomes the problems inherent to the above-discussed "classical" ciphering methods. The presently available quantum cryptography concepts are generally designed to allow only two users to communicate with each other under absolute confidentiality.
In view of allowing a greater number of users to use quantum cryptography in an optical network, a new architecture is required.

Multi-user quantum cryptography method and system using wavelength division multiplexing


An image synthesizing system is provided which can output a high-quality image in real time through the texture mapping without preventing the hardware from being increased in speed and reduced in scale. A 3-D image is formed by a game space processing unit (13) and image supply unit (10) to perform a 3-D computation. At a processor unit (30), coordinates for each dot in a polygon and the corresponding texture coordinates are determined. A field buffer unit (40) stores the texture coordinates at an address specified by the coordinates for each dot. A texture data storage unit (42) has stored a rendering data. The texture coordinates are read out from the field buffer unit (40) and then used to read out the rendering data from the texture coordinate storage unit (42) to synthesize and output a pseudo 3-D image. By thus storing the texture coordinates in the field buffer unit (40), the subsampling/interpolation and the like may be carried out.

There are known various image synthesizing systems used as in three-dimensional (3-D) games, airplane or other vehicle simulators and so on. Typically, such image synthesizing systems have information of image relating to a 3-D object 300 as shown in FIG. 33, which has previously been stored therein. Information of image is perspectively transformed into a pseudo 3-D image 308 on a screen 306. As a player 302 makes an operation with a control panel 304 such as rotation, translation or the like, the system responds to the control signal to perform the processing with respect to rotation, translation or the like of the image of the 3-D object 300 in real time. Thereafter, the processed 3-D image is perspectively transformed into the pseudo 3-D image on the screen 306. As a result, the player 302 itself can rotate or translate the three-dimensional objects in real time to experience a virtual 3-D space.
FIG. 34 shows one of such image synthesizing systems. The image synthesizing system will be described as being applied to a 3-D game.
As shown in FIG. 34 the image synthesizing system comprises an operator's control unit 510 a game space processing unit 500 an image synthesizing unit 512 and a CRT 518.
The game space processing unit 500 sets a game space in response to control signals from the operator's control unit 510 and in accordance with a game program which has been stored in a central processing unit 506. Namely the processing is performed with respect to what position and direction the 3-D object 300 should be arranged in.
The image synthesizing unit 512 comprises an image supply unit 514 and an image forming unit 516. The image synthesizing unit 512 performs the synthesization of a pseudo 3-D image in accordance with information of a game space set by the game space processing unit 500.
In this image synthesizing system, 3-D objects in the game space are defined as polyhedrons which are divided into 3-D polygons. As shown in FIG. 33 for example the 3-D object 300 is represented as a polyhedron which is divided into 3-D polygons 1-6 (polygons 4-6 not shown herein). The coordinates and associated data of each vertex in each of the 3-D polygons (which will be referred to "image data of vertices") have been stored in a 3-D image data storage 552.
The image supply unit 514 performs various mathematical treatments such as rotation translation and others and various coordinate conversions such as perspective transformation and others for the image data of vertices in accordance with the setting of the game space processing unit 500. After the image data of vertices has been processed it is permuted in a given order before outputted to the image forming unit 516.
The image forming unit 516 comprises a polygon generator 570 and a palette circuit 30. The polygon generator 570 comprises an outline (polygon edges) point processing unit 324 and a line processor 326. The image forming unit 516 is adapted to perform a process of painting all the dots (pixels) in the polygon with a predetermined color data or the like in the following procedure:
First of all, the outline point processing unit 324 calculates left-hand and right-hand outline points which are intersection points between polygon edges AB, BC, CD, DA and other polygon edges and scan lines, as shown in FIG. 35. Subsequently the line processor 326 paints with specified color data, sections between the left-hand and right-hand outline points, for example, sections between L and Q; Q and R as shown in FIG. 35. In FIG. 35, the section between L and Q is painted by red color data while the section between Q and R is painted by blue color data. Thereafter, the color data used on painting are transformed into RGB data in the palette circuit 580 and then the RGB data in turn is outputted to and displayed in CRT 518.
In such an image synthesizing system of the prior art, all the dots on a single polygon can be painted only by the same color, as described. As can be seen in FIG. 35, for example, the dots on the polygon 1 are only painted by red color; the dots on the polygon 2 are only painted by yellow color; and the dots on the polygon 3 are only painted by blue color. Thus, the formed image is monotonous without reality.
If an object having its complicated surface is to be displayed to avoid such a monotonousness the number of divided polygons must greatly be increased. For example if a 3-D object 332 having a texture of color data as shown in FIG. 36 is to be formed by the image synthesizing system of the prior art, it is required to divide a polyhedron into polygons 1-80 (polygons 41-80 not shown herein) for processing. Namely various processing operations including the rotation, translation and perspective transformation, the treatment of polygon outline, the painting and the like must be performed for all the polygons. It is thus required to treat polygons ten-odd times those of the 3-D object 300 having no texture as shown in FIG. 33. However, the system for synthesizing an image in real time must terminate the drawing of an image to be displayed by treating all the dots for every field (1/60 seconds). In order to draw such a 3-D object 332 having a texture of color data, one requires a hardware having a very increased speed or an increased scale to perform a parallel operation. As the number of polygons to be processed is increased, the memory and data processor of the system is necessarily increased in scale. In image synthesizing systems such as video game machines which are limited in cost and space, it is therefore subsequently impossible to draw a pseudo 3-D image having a delicate texture with high quality.
In the field of computer graphics and the like, there is known a texture mapping technique shown in FIG. 37. The texture mapping separates the image data of a 3-D object 332 into the image data of a polyhedron 334 and the texture data of textures 336 and 338, which are in turn stored in the system. On displaying an image, the texture data of the textures 336, 338 are applied to the polyhedron 334 to perform the image synthesization. (One of the texture mapping type image synthesizing techniques is disclosed in Japanese Patent Laid-Open No. Sho 63-80375, for example).
The texture mapping technique is realized in the field of very large-scale and expensive image processing systems such as exclusive image-processing computers known as graphics work stations, flight simulators and so on. Very few image synthesizing systems which are relatively inexpensive, like video game machines, utilize the texture mapping technique since it is difficult to increase the speed and scale of their hardwares. In addition such video game machines can only display limited numbers and sizes of 3-D objects and the mapping they provide is inaccurate since the operation is performed by a simple approximation. As a result, the reality of the image is very degraded. Furthermore, the real-time display is insufficient since the frequency of updating the scene is low, that is, several frames per second.
In the bit-map type image synthesizing system of the prior art, the color data itself is stored in a memory known as a so-called field buffer unit. Even if the texture mapping technique is applied to such a bit-map type image synthesizing system, thus, the color data itself will be stored in the field buffer unit. As a result, the hardware could not be increased in speed and reduced in scale through the subsampling/interpolation technique. If a plurality of image computing units are used for parallel processing, the scale of the hardware could not be reduced by using a common texture data storage unit in which texture data was stored.
When pseudo 3-D images are to be synthesized to realize a 3-D game or the like, an image formed by a 3-D object which is expressed by polygons must be synthesized with a background image formed by a background. To this end, the image synthesizing system of the prior art newly requires a memory in which background image data have been stored and a circuit for mixing polygon images with background images. It is therefore difficult to increase the processing speed of the hardware and to reduce the scale thereof, according to the prior art.
In view of the aforementioned problems of the prior art, an object of the present invention is to provide an image synthesizing system which can output high-quality images through the texture mapping technique in real time without prevention of the hardware from being increased in speed and reduced in scale.

Image synthesizing system with texture mapping


A high speed digital video network apparatus is implemented on a single integrated circuit chip, and includes a network protocol processing system interconnection, compression/decompression circuits, and encoder/decoder circuits. The interconnection includes a packet conversion logic which converts between a network protocol, such as Asynchronous Transfer Mode (ATM) packets, and the data protocol used to handle large data streams, such as Motion Picture Experts Group (MPEG) packets. The interconnection further includes a Virtual Channel Memory (VCM) for storing ATM cells for segmentation and reassembly, a Direct Memory Access (DMA) controller for connecting the VCR to the compression/decompression circuits, a Parallel Cell Interface (PCI) for connecting the VCM to an ATM network, a Pacing Rate Unit (PCU) for automatically reducing the maximum transmission rate in response to a sensed congestion condition in the network, and a Reduced Instruction Set Computer (RISC) microprocessor for controlling the DMA controller and transfers between the memory, a host and the ATM network, for performing segmentation and reassembly of Conversion Sublayer Payload Data Units (CD-PDUs), and for performing conversion between the ATM Protocol and the MPEG protocol. The compression/decompression and decoder/encoder circuits may utilize MPEG to compress digitized images and motion video into compact data streams that can be moved across networks with bandwidths too narrow to accommodate the uncompressed data. The operating program for the RISC microprocessor is stored in a volatile Instruction Random Access Memory (IRAM) in the form of firmware which can be downloaded at initialization.

Efforts to improve the networking of digital computers and the transmission of digital data have been the object of significant research and development in the past. Networking allows computers to share resources, access huge stores of information, communicate via e-mail, share data, and transfer files. Networking technology and digital data transmission have been subject to a number of bandwidth limitations.
In the past, networking technology has suffered from limitations on data transmission rates which limit the bandwidth of the system. For example, local area networks (LANs) may be connected with cables that have finite limitations on the amount of data they can pass, and the speed at which it can be done. LAN's may be connected to extended wide area networks (WAN's) over transmission lines that have bandwidth limitations. When modems are required for communication over conventional telephone lines, severe limitations may be imposed upon data transmission rates.
Some applications, such as full motion video, require transfer of huge amounts of data. Efforts to reduce the performance requirements upon the data transmission system when large amounts of data must be transferred over the system have resulted in various data compression schemes. For example, video or graphical data may be compressed to occupy less space. Compressed data may then be transmitted and, because the data has been compressed into fewer information bits, fewer bits need to be transmitted, thereby relieving to some extent the loading upon the data transmission system. However, there are limits on the extent to which data may be compressed. In the past, compression imposed computational overhead upon the system and sometimes took too much time to complete. Compressed data must be decompressed at the destination at the other end of the transmission system in order to be useable, which imposes additional computational overhead upon the system. Although compression and decompression may be performed in software, the speeds at which such operations can be performed limit the usefulness of such techniques in some applications such as realtime full motion video. If dedicated hardware is utilized, the additional hardware required to perform compression and decompression has limited the use in some applications where small size and miniaturization are required, and in other instances the cost of such additional hardware may be impractical.
In order for a network to accommodate a number of users efficiently, routing and flow control procedures have to be established. There are many rules that must be followed, and these rules are typically referred to as protocols. Packet-switched networks subdivide digital data messages into packets. The digital data is then transmitted packet by packet. Each packet must contain not only the information bits comprising the digital data that is to be transmitted, but also information bits which are overhead required by the protocol in use, such as information bits which identify the destination of the packet, the source of the packet, and synchronization bits. Overhead bits typically appear in a header and trailer to each packet. In addition, acknowledgement packets must be transmitted over the network to confirm receipt of a packet of data. Alternatively, a protocol may include information in the overhead bits in each packet indicating the number of the packet. This information may be used to reassemble the received packets in the correct order, and if a packet is missing, a negative acknowledgement packet may be sent to request retransmission of the missing packet. Otherwise, data loss could occur and not be detected by the system. In any event, acknowledgement packets and other similar handshaking information which must be transmitted over the network according to the protocol impose some limitations upon the data throughput of the network. While this may be acceptable in many instances, in applications where the transfer of huge amounts of data are required, these bandwidth limitations may render such applications impractical in practice.
It is not uncommon for two or more users on a network to attempt to transmit a packet at the same time. When this occurs, it is referred to as a collision. Neither packet will be received successfully, and both must be retransmitted. Obviously, this reduces the throughput of the network. Different protocols employ various schemes to determine the timing of retransmission attempts in an effort to avoid repeated collisions between the same two users.
Data transmission may sometimes experience data errors, where a digital 11111 is erroneously received as a "0", or vice versa, due to such events as signal fluctuations or noise. Thus, error correction schemes may be employed in an effort to detect data errors. If an error is detected, then a packet must be retransmitted. Of course, when a packet must be retransmitted, it reduces the overall throughput of the network.
Networking technology has suffered from limitations resulting from a proliferation of non-standard protocols, and limitations due to the nature of the protocols and transmission schemes which are employed. Additional overhead may be imposed when conversion from one protocol to another is required. This additional overhead may effectively limit the overall bandwidth of the network.
In addition to limitations on bandwidth, all of the above discussed factors may affect cost, response time, throughput, delay, maximum transmission rates, and reliability.
Television programming is increasingly being delivered to the consumer by means other than traditional terrestrial broadcast. In the United States, the prime broadcast medium is cable (CATV). At the present time, 90 percent of approximately 93 million TV households in the U.S. are passed by cable--in other words, they could receive cable TV if they chose to subscribe to the cable service. Of these, 55 million, or 60 percent, subscribe to at least a basic cable service. In Europe, the picture is different--roughly 20 percent of all households are passed by cable. Of these, about 60 percent are subscribers. Both Germany and the U.K. have installed bases of 2.5 million direct broadcast by satellite (DBS) satellite dishes. In Asia, DBS services are booming, led by the activities of Star TV in Hong Kong.
The U.S. cable industry consists of two main components: program providers and service operators. The program providers produce the programming (MTV, HBO, Showtime, ESPN), which is distributed by satellite. The local service operator (typically one for each town or city in the U.S.) receives the programming through of satellite dish at what is called a cable headend, and re-transmits it by cable to subscribers. Other functions performed at the headend include receiving and re-transmitting local off-the-air services and local insertion of advertising. These local service operators are typically owned by large corporations known as multiple service operators (MSO). The largest MSOs in the U.S. at present are TCI, Time Warner, Viacom and CableVision. These companies also have interests as Program Providers.
Compressed digital video allows more channels to be transmitted without increasing system bandwidth. Typically 4-10 compressed channels (depending on quality and source) can be transmitted in the space of one conventional channel. This allows for reduction of costs and/or increased capacity.
For the CATV industry, compressed digital video is expected to be rolled out in two phases. The first phase will be the utilization of compressed digital video to deliver programming from the provider to the cable headend. This is motivated by both the cost of satellite transponder rental and by a looming shortage of available slots.
The second phase will be the implementation of compressed digital video to the home. Compressed digital video will give cable operators the ability to deliver as many as 500 channels to the home. The most likely use of these channels will be extended pay per view (PPV) services. The huge channel capacity will allow films to be shown on multiple channels separated by a 10-20 minute interval, thus offering near video on demand to the user.
In its present form, the U.S. CATV industry is close to saturation. Recent regulatory events make it difficult to increase revenues by rate hikes so the industry's best chance for growth is to offer new services, allowing it to compete with the video rental industry and perhaps ultimately with the first run cinema industry. An increase in capacity will allow for additional services which should result in increased revenues.
For direct broadcast by satellite, compressed digital video is the enabling technology which will allow that industry to compete with cable services. Assigning multiple channels to the bandwidth previously required for one both reduces the cost and permits a sufficiently large number of channels to compete with cable services. Two operations planned in the U.S. are Hughes DirecTV and the PRlMESTAR service.
An emerging contender in the market for consumer home video consumption is the telephone companies. The combination of compressed digital video and emerging ADSL (asynchronous digital subscriber line) technology will allow the telephone companies to offer "video dial tone" over twisted pair copper cabling. Combined with a "juke box" of movies, the telephone companies' switched services would allow them to offer true video on demand. Recent regulatory changes have cleared the legal barriers to the telephone companies offering these services.
An emerging market in the U.S. is for subscription-based cable radio, which allows subscribers to receive commercial-free near CD-quality audio-only programming. MPEG audio compression will allow the industry to transmit more channels of higher-quality music through traditional cable lines and use fewer satellite transponders. MPEG refers to the Motion Picture Experts Group which has developed draft standards for audiovisual compression/decompression routines.
Direct audio broadcast (DAB) may be a significant advance in the broadcast industry by transmitting CD-quality music to home and car receivers. Europe and Canada are ahead of the U.S. in the development and implementation of such technology, primarily because of the long approval cycle the FCC requires to approve new transmission bands. Outside of the area of broadcast, several other consumer-oriented applications are emerging that are enabled by compressed digital video, such as compact disc interactive (CD-I) from Philips and similar products from Commodore and Tandy, which are intended to be upgradable to offer full motion video using MPEG compression. CD ROM based technology is also finding its way into video games. The combination of compressed digital video and CD ROM will allow games to feature full motion video.
The combination of compact data streams such as MPEG digital video and audio with networking technology will open up new and useful applications which have not heretofore been practical.

High speed single chip digital video network apparatus


A water treatment device and methods of treating water such as cooling tower water, agricultural water, water used in the production of oil and/or gas, swimming pool water, and hot tub or spa water, are described. The water treatment device utilizes ultraviolet radiation, a magnetic field, and ozone fortified air to treat the water, typically resulting in reduced microbial contamination and reduced alkalinity in cooling tower water. Cooling tower water may consequently be run at higher cycles of concentration while reducing or eliminating deposition of minerals on cooling tower components. Swimming pool water and hot tub water treated with the water treatment device typically requires less chlorine, and chlorine levels are typically more stable than without the device.

Water treatment is required to generate or maintain acceptable water quality in systems such as cooling towers, evaporative coolers, heat exchangers, chillers, process recirculation systems, point-of-entry water treatment systems, petroleum and gas production systems, feedlot waters, architectural waters, agricultural waters, recreational waters, hydraulic fracturing waters (for example as used in petroleum and gas producing industries), waters associated with petroleum and gas production (including waters co-produced with petroleum and/or gas, injection waters associated with primary, secondary and tertiary petroleum and/or gas production, and disposal of co-produced waters), flowback waters, and various wastewater treatment systems.
Cooling towers use water as a cooling medium to absorb heat from air conditioning coils or similar heat dumping devices. Water makes an excellent cooling medium due to its relatively high specific heat capacity, its excellent heat conduction in liquid form, and its relatively high heat of vaporization. However, cooling tower water requires extensive treatment to prevent water quality from degrading to unacceptable levels.
Cooling towers that circulate water to dissipate or dispose of heat usually lose substantial quantities of water to evaporation. A typical air conditioning cooling tower loses to evaporation about 3 gallons of water per minute, per 100 tons of air conditioning capacity. A large hospital may have about 1000 tons of air conditioning capacity. Thus the large hospital air conditioning cooling tower loses about 1800 gallons of water per hour through evaporation. Vaporization of cooling tower water leaves behind substantially all of the solids dissolved in the water that becomes vaporized, resulting in increased concentration of dissolved solids in cooling tower water that remains in liquid phase in the tower. Cooling tower water that is hyper-concentrated with solutes (solute laden) and the precipitation or deposition of those solids on cooling tower components is a major problem. Cycle(s) of concentration ("cycle") is a measure of the degree to which dissolved solids concentration in circulating water is increased over that of feed water (also referred to as raw water) as follows: feed water is at 1 cycle of concentration; where dissolved solids in circulating water reach a concentration that is twice that of the feed water, the circulating water is at or has undergone 2 cycles of concentration; at a concentration of 4 times that of feed water, the circulating water is at or has undergone 4 cycles of concentration, etc.
Carbonate precipitation and deposition are typical problems in cooling towers, due at least in part to hyper-concentration of solutes, and to alkalinization. Calcium carbonate and magnesium carbonate are frequently the most common problem species. Carbonate precipitation is exacerbated by highly alkaline cooling tower water because proportions of carbonate to bicarbonate increase with increase in pH, and carbonate is less soluble in water than bicarbonate. Accordingly, a common problem is precipitation of carbonate at higher pH values. Control of alkalinity (i.e. lowering pH) is therefore highly desirable in cooling tower water treatment. Bacterial growth and growth of microorganisms or other organisms in cooling tower water and on cooling tower components is also a substantial problem.
Cooling tower water alkalinity and hyper-concentration of dissolved solids is typically addressed by adding chemicals to the water that help keep the dissolved solids in solution or suspension. However, such chemicals can add substantially to building cooling costs. Chemicals (biocides) are also used to inhibit organism growth, but such chemicals can also be costly, and some biocides are less effective under conditions of increased alkalinity.
Cooling tower water quality is also typically maintained by draining a portion of the water (referred to as bleeding off) and replacing the drained water with feed water that is not hyper-concentrated or substantially biologically contaminated by elevated microorganism levels. Use of chemicals to treat cooling tower water can complicate bleeding off, or limit use of some chemicals, because some chemically treated water may require specialized disposal. Ultraviolet (UV) radiation can be effective as a disinfecting agent, but generally does not help with hyper-concentration and deposition of water borne solids.
High pressure fracturing of rock formations surrounding an oil and/or gas well, typically referred to as fracking, is a water-intensive process. In a fracking process, a mixture of water, sand, and chemicals is injected in a well at high pressures. During the fracking process the pressure is increased until the rock formation surrounding the well fractures and releases the oil and/or gas from the rock, so that they can flow into the well. The fracking waters may contain biological materials, organic materials, inorganic materials or mixtures thereof. The materials may need to be removed from the fracking water to render the water safe for deposal and/or future use. In some instances, the water used to make-up the fracking mixture may need to be treated to remove biological and/or chemicals (such as organic and/or materials) that could contaminant and/or render the fracking mixture unsuitable for the fracking process.
Agriculture waters can include irrigation waters and waters consumed by animals. The agriculture waters can be treated before or after the irrigation process. Animal production facilities, such as but not limited to feedlot facilities, can be a source of water contamination. Feedlot waters can have unsafe levels of nitrates, Samonella, E. Colli, Cryptosporidium, fecal coliform and mixtures thereof.

Water treatment device and methods of use

Silver Bullet Water Treatment Company, LLC


A sensor for monitoring the water content and the acid content in the presence of water in nonaqueous media can be incorporated into a monitoring system for monitoring the quality of nonaqueous fluids in equipment or vehicles. The sensor comprises an insulating substrate; electrodes formed on the substrate in an interdigitated pattern; and a conductive polymer deposited over the interdigitated electrodes which bridges between adjacent digits of the electrodes. The monitoring system incorporating the sensor comprises a control module for measuring the conductivity of the sensor. The control module is preprogrammed to compare the measured conductivity to a predetermined level indicative of an unacceptable level of degradation. The sensor is made by depositing electrodes on an insulating substrate; depositing a conductive polymer over the electrodes in an amount sufficient to bridge between the electrodes; and neutralizing the conductive polymer to an insulating form. A method of sensing water and acid in the presence of water in nonaqueous media exposes an insulating form of a conductive polymer to a nonaqueous medium and monitors the conductivity of said conductive polymer, as the nonaqueous medium is used. The conductive polymer reversibly increases conductivity in measurable amounts with increasing acid and/or water content due to protonation by the acid or hydration by the water.

1. Field of the Invention
The present invention relates to measuring the acid and/or water content of nonaqueous media and measuring the acid content in the presence of water of such nonaqueous media. In particular, the present invention relates to monitoring the quality or condition of engine oil.
2. Description of the Related Art
Acid species in nonaqueous media, such as hydrocarbon-based oil, cause gelling and change the viscosity of the oil so that there is an overall loss of lubricity. Oil in an engine, for example, containing an acid species will not properly coat the engine's moving parts causing the parts to seize up and prematurely fail. Moreover, acid species in hydrocarbon-based oil causes corrosion of the engine's metallic parts.
Water accumulation in engine oil is problematic also. Depending on the geographic region and seasonal weather conditions, water may accumulate in the engine oil faster than it is evaporated. Prolonged exposure of the engine's moving parts to accumulated water will cause corrosion. Moreover, accumulated water in engine oil will remove oil additives and preservatives, which function to neutralize acid species.
The quality of oil is particularly important in the automotive industry. Automobile manufacturers recommend that a vehicle's oil be replaced on a regular basis based on the number of miles the vehicle has been driven. Typically, the actual condition of the oil at the time it is replaced is not known. If the oil should degrade prematurely, the vehicle is operated with the degraded oil at least until the next regularly scheduled oil change. On the other hand, if the vehicle is operated under much less rigorous conditions, including weather conditions, or conditions that are favorable to an extended lifetime for the oil, the oil may be replaced and discarded prematurely, which increases the cost of operation and causes unnecessary environmental problems. With respect to water accumulation, a vehicle driven in a cold winter climate for only a few miles a day, will accumulate water in the engine oil to a much greater extent than a vehicle driven in a warmer climate. Nevertheless, the recommended schedule for changing the oil in the vehicle is the same.
Other important areas of application include diesel engines and automatic transmission fluids. In the former case, diesel fuel contains significant amounts of organo-sulfur compounds, which degrade through use and are oxidized eventually to sulfuric acid. Not only is sulfuric acid highly corrosive, but it causes increased operating temperatures of the oil. Automatic transmission fluids are also hydrocarbon-based materials and they thermally oxidize to carboxylic acids leading to similar eventual operating problems.
It would be desirable if the engine oil in a vehicle could be monitored and replaced only when the oil has degraded to a level which is rated unacceptable to the proper operation of a vehicle.
One monitoring device for indicating when oil has degraded to an unacceptable level is known from U.S. Pat. No. 5,089,780 issued to Megerle on Feb. 18, 1992. Megerle discloses a sensor and system for monitoring the accumulation of contaminants in oil. The contaminants must have an electrical conductivity which is different from the oil. An alternating current conductivity is measured by an electrochemical cell and an indication of the amount of the contaminants present is provided. The conductivity cell includes concentric cylindrical electrodes mounted on a plug or other structure so that they can be immersed in the engine oil. The plug can be mounted in the oil sump, or oil stream, of the engine. One electrode is connected to an AC conductivity measuring device which is connected to a warning light or display device that provides an indication of the oil conductivity. The ability and usefulness of the Megerle device for monitoring the accumulation of water is not known. Moreover, contaminants dissolved in accumulated water in the oil are less likely to be detected with an electrochemical cell.
Conductive polymers have been used as the active material in sensors to detect acidity, or more specifically, pH in aqueous and highly polar systems. Conductive polymer acidity sensors are advantageous because they are compact, simple, inexpensive, and easy to make. A number of high sensitivity prototype sensing devices have been reported using the conductive polymer, polyaniline, as the active sensing material. For example see J-C. Chiang and A. G. MacDiarmid, Synth. Met., Vol. 13, 193 (1986). These range from chemical gas sensors to pH sensors in aqueous solutions.
Yodice et al., U.S. Pat. No. 5,023,133 issued Jun. 11, 1991, discloses an acid sensing device for nonaqueous media, such as motor vehicle lubricating oil. The devices comprise an organic polymer, such as polyaniline or polypyrrole, which is capable of accepting protons. However, Yodice et al. are silent with respect to the ability to monitor water content and acid content in the presence of water.
Y. Maeda, European Patent Application No. 0 442 314 A2, published Aug. 21, 1991, disclose an apparatus for detecting deterioration of lubricating oil. The apparatus comprises a membrane of polyaniline which is treated with an electrical oxidation and an electrical reduction that is immersed in lubricating oil. The electrical resistance of the membrane changes with changes in the amount of acid in the deteriorating lubricating oil. The deterioration is monitored by measuring the electrical resistance between a pair of electrodes.
Maeda et al., like Yodice et al., are silent with respect to a device which comprises a conductive polymer for accurately monitoring water content and acid content in the presence of water in such nonaqueous media.
Therefore, there is a need for a compact, low cost sensor having a conductive polymer as the active element that is adaptable for a method of monitoring acid content, water content, and/or acid content in the presence of water in nonaqueous and nonpolar media, such as hydrocarbon-based oil.

Device and method for sensing water and/or acid in the presence of water in non-aqueous media


The present invention relates to a blend of at least one amorphous ethylene/propylene-derived copolymer, at least one non-stereoregular propylene-derived polymer having a melt viscosity of greater than about 500 Poise, and an optional tackifier that provide pressure-sensitive adhesive compositions in which a good balance of adequate adhesion to both low and relatively high surface energy substrates can be achieved.

The present invention relates to polymer blends comprising ethylene/propylene-derived copolymers and certain other propylene-derived polymers that exhibit pressure-sensitive adhesive properties. The pressure-sensitive adhesives are useful in preparing a wide variety of articles.
A wide variety of references describe blends of xcex1-olefin polymers (i.e., those polymers derived from at least one xcex1-olefin monomer) that are used in hot-melt adhesives and heat-sealing films. However, these references do not teach formulation of such adhesives so that they possess the balance of properties (e.g., shear, peel, and tack) requisite of PSAs. For example, see U.S. Pat. No. 3,492,372 (Flanagan); U.S. Pat. No. 3,798,118 (Jones); U.S. Pat. No. 3,900,694 (Jurrens); U.S. Pat. No. 4,178,272 (Meyer, Jr. et al.); U.S. Pat. No. 4,761,450 (Lakshmanan et al.); U.S. Pat. No. 4,857,594 (Lakshmanan et al.); U.S. Pat. No. 4,957,968 (Adur et al.); U.S. Pat. No. 5,397,843 (Lakshmanan et al.) ; and U.S. Pat. No. 5,834,562 (Silvestri et al.). Further examples include Japanese Patent Publication Nos. 60-120775; 55-069637; 48-066638; and 73-027739.
Pressure-sensitive adhesive (PSA) compositions are well known to those of ordinary skill in the art to possess properties including the following: (1) aggressive and permanent tack, (2) adherence with no more than finger pressure, (3) sufficient ability to hold onto an adherend, and (4) sufficient cohesive strength. Materials that have been found to function well as PSAs are polymers designed and formulated to exhibit the requisite viscoelastic properties resulting in a desired balance of tack, peel adhesion, and shear holding power. Obtaining the proper balance of properties is not a simple process.
The most commonly used polymers for preparing PSAs are natural rubber-, synthetic rubber- (e.g., styrene/butadiene copolymers (SBR) and styrene/isoprene/styrene (SIS) block copolymers), and various (meth)acrylate- (e.g., acrylate and methacrylate) based polymers. With the exception of several (meth)acrylate- and certain xcex1-olefin-based polymers, which are inherently tacky, these polymers are typically blended with appropriate tackifiers to render them pressure-sensitive.
PSA compositions comprising polymers derived from xcex1-olefin monomers are known. Often, such compositions include a single xcex1-olefin polymer, typically a copolymer, which is usually blended with a tackifier. Blending an xcex1-olefin-derived polymer with another polymer when preparing PSAs is known, however. Yet, the relative proportions of the polymers and the physical characteristics of the polymers in these blends is typically not specified.
For example, see European Patent Application No. 0 178 062 (Uniroyal, Inc.) teaches hot melt pressure-sensitive thermoplastic elastomeric adhesive compositions comprising blends of thermoplastic elastomeric polymers made from ethylene and propylene (e.g., those comprising crystalline polypropylene moieties and essentially amorphous elastomeric ethylene-propylene copolymer moieties having a melting point of at least 150xc2x0 C. as measured by differential thermal analysis), tackifiers, and other optional additives, such as plasticizers, fillers, and stabilizers. Amorphous polypropylene having a ring-and-ball softening point of 149-154xc2x0 C. is mentioned as an example of a suitable plasticizer. Plasticizers can comprise 5-50% by weight of the total adhesive.
Also see U.S. Pat. Nos. 3,954,697 and 4,072,812 (McConnell et al.), which teach single component, hot-melt, pressure-sensitive adhesives based on copolymers derived from propylene and 40-60 mole % (based on the copolymer) higher olefin monomers. The copolymers may be used alone or in mixture with other materials, including compatible tackifiers, amorphous polypropylene and amorphous block ethylene/propylene-derived copolymers.
U.S. Pat. No. 4,143,858 (Schmidt, III et al.) teaches amorphous polyolefin homopolymers and copolymers useful in hot-melt PSAs. The amorphous polyolefin polymers may also be blended with up to 20 weight % crystalline polyolefins. The adhesives therein may be used alone or in mixture with other materials such as amorphous polypropylene, amorphous block ethylene/propylene-derived copolymer, etc.
It is also noteworthy that many references describing blends of xcex1-olefin derived polymers with other polymers teach blending xcex1-olefin-derived polymers with other polymers that are rubber-based, containing conjugated dienes. For example, see U.S. Pat. No. 5,859,114 (Davis et al.), where a major amount of an ethylene-propylene-diene terpolymer is blended with a minor amount of at least one fully saturated adhesive-enhancing polymer miscible therewith and at least one tackifier. Examples of adhesive-enhancing polymers taught to be useful therein include: ethylene-vinyl acetate copolymers, ethylene-vinyl chloride copolymers, ethylene-octene copolymers, ethylene-butene copolymers, and propylene-butene-ethylene terpolymers. As described in U.S. Pat. No. 5,504,136 (Davis et al.), ethylene-propylene copolymers, such as those typically having an ethylene content of about 45-65% by weight, are also mentioned as having utility as the adhesive-enhancing polymer in a related invention.
PCT Publication No. WO 98/33,858 (American Tape Co.) describes PSAs comprising a natural or synthetic rubber and a thermoplastic polyolefin blend of ethylene/propylene rubber, hydrogenated polyisoprene, and polypropylene. Each of the constituents making up the thermoplastic polyolefin blend has a relatively low molecular weight (3,000-10,000). The PSA composition also includes a tackifier.
PCT Publication No. WO 97/23,577 (Minnesota Mining and Manufacturing Co.) describes blended PSAs that include at least two components. The first component is a PSA. For example, PSAs useful in the invention include tackified natural rubbers, synthetic rubbers, tackified styrene block copolymers, polyvinyl ethers, acrylics, poly-xcex1-olefins (described as being predominantly amorphous), and silicones. The second component is a thermoplastic material or elastomer. For example, thermoplastic materials useful in the invention include isotactic polypropylene and ethylene/propylene copolymers. It is also taught that useful thermoplastic materials are essentially immiscible in the PSA component at use temperatures. The Abstract describes the blends therein as having a substantially continuous domain (generally the PSA) and a substantially fibrinous to schistose domain (generally the thermoplastic material). Tackifiers may be added.
UK Pat. Application No. GB 2 041 949 (The Kendall Company) discloses PSAs comprising (1) a rubbery copolymer of ethylene, a C3-C14 monoolefin and, optionally, a non-conjugated diene, (2) a polymer of a crystalline ethylene or propylene, and (3) a tackifying agent.
Many compositions derived from diene monomers are relatively unstable over time, such as for example, when exposed to weathering or higher temperatures (e.g., such as when hot-melt processing the compositions). Furthermore, many such compositions are relatively non-polar and do not adhere adequately to both relatively high surface energy substrates and low surface energy substrates. xe2x80x9cLow surface energy substratesxe2x80x9d are those that have a surface energy of less than 45 mJ/m2, more typically less than 40 mJ/m2 or less than 35 mJ/m2. Included among such materials are polyethylene, polypropylene, acrylonitrile-butadiene-styrene, and polyamide.
Ways to effectively adhere to low surface energy materials is a challenge that those of ordinary skill in the art are attempting to overcome. Many times improvements in adherence to low surface energy substrates compromises adherence to higher surface energy substrates or compromises shear strength of the adhesive. As such, further adhesives for adequately adhering to low surface energy surfaces are desired. It is also desired that any such new adhesives will allow for broad formulation latitude and tailorability for particular applications.
It would also be desirable to formulate adhesives using lower cost materials. For example, (meth)acrylate monomers and rubber-based monomers are generally more expensive than xcex1-olefin monomers. The present invention addresses these motivating factors.
The present invention provides an improved pressure-sensitive adhesive composition which comprises a blend of at least one ethylene/propylene-derived copolymer and at least one propylene-derived polymer. Generally, such compositions are advantageous from a cost-standpoint, as opposed to many traditional pressure-sensitive adhesive compositions (e.g., (meth)acrylate and rubber-based adhesive). Furthermore, xcex1-olefin-derived polymers, which include ethylene/propylene-derived copolymers and propylene-derived polymers, are conducive to being recycled, particularly when used in conjunction with other xcex1-olefin-derived polymers (e.g., materials commonly used in packaging). It is beneficial to use materials in adhesive compositions that can be later recycled.
The blends of the present invention are useful in adhering to various substrates including relatively high surface energy substrates, such as glass and metals, as well as low surface energy substrates, such as polyethylene and polypropylene. They may be used in a wide variety of applications, such as in adhesive tapes and sheets and in the application of polymeric films to a wide variety of substrates. They may also be used in the preparation of blown microfiber webs.
Surprisingly, in preferred embodiments of the invention, peel adhesion to low surface energy substrates, such as polyethylene and polypropylene, is enhanced without causing detrimental effects in peel adhesion to high surface energy substrates. For example, certain embodiments of the invention provide substrates, which can be polypropylene, polyethylene, or glass, with the pressure-sensitive adhesive composition at least partially applied thereon. In these embodiments, the 180xc2x0 peel adhesion to the substrate can be as high as at least about 100 N/dm. Useful shear strengths are also realizable using the blends of this invention.
Pressure-sensitive-adhesive (PSA) blends of the present invention comprise at least one ethylene/propylene-derived copolymer and at least one propylene-derived polymer. Preferably, the PSA blend comprises a single domain system. Single domain systems, as well as other terms used throughout, are defined in turn below.
xe2x80x9cSingle Domainxe2x80x9d systems are those where, when analyzed using Dynamic Mechanical Analysis (DMA) in a parallel plate geometry at a temperature increment of 2xc2x0 C./minute, a frequency of 1 radian/second, and a maximum strain of 2%, only one tan delta peak (without a xe2x80x9cshoulderxe2x80x9d) representing a glass transition temperature is present. Typically, these systems involve polymers that form a miscible system at use temperature (e.g., room temperature). xe2x80x9cMiscible systemsxe2x80x9d are those systems comprising at least two materials forming a single domain system. It is advantageous to have single domain systems. For example, single domain systems often do not require additives (e.g., compatibilizers) to ensure storage stability of the system. Also, single domain systems facilitate reproducible compositions (i.e., the compositions have similar mechanical properties), even when the compositions are prepared using a range of different processing equipment.
xe2x80x9cPolymerxe2x80x9d refers to macromolecular materials having at least five repeating monomeric units, which may or may not be the same. The term xe2x80x9cpolymerxe2x80x9d, as used herein, encompasses homopolymers and copolymers. Copolymers of the invention refer to those polymers derived from at least two chemically different monomers. Included within the definition of copolymers are traditional copolymers derived from at least five monomers, which include only two chemically different types of monomers, as well as terpolymers, which include at least three chemically different types of monomers, etc.
In general, a polymer can include more than one type of steric structure throughout its chain length. For example, polymers can include crystalline, stereoregular isotactic and syndiotactic structures, as well as amorphous, atactic structures, or combinations thereof. The steric structure of a polymer can be determined using any suitable method. For example, carbon-13 Nuclear Magnetic Resonance can be used to determine the steric structure (i.e., tacticity) of a polymer.
xe2x80x9cStereoregularxe2x80x9d structures, as defined by Hawley""s Condensed Chemical Dictionary (12th Edition), are those whose molecular structure has a definite spatial arrangement, rather than the random and varying arrangement that characterizes an amorphous polymer. Stereoregular structures include isotactic and syndiotactic structures.
xe2x80x9cIsotacticxe2x80x9d structures, as defined by Hawley""s Condensed Chemical Dictionary (12th Edition), are those whose structure is such that groups of atoms that are not part of the backbone structure are located either all above, or all below, atoms in the backbone chain, when the latter are all in one plane.
xe2x80x9cSyndiotacticxe2x80x9d structures, as defined by Hawley""s Condensed Chemical Dictionary (12th Edition), are those whose structure is such that groups of atoms that are not part of the backbone structure are located in some symmetrical and recurring fashion above and below the atoms in the backbone chain, when the latter are all in one plane.
xe2x80x9cAtacticxe2x80x9d structures, as defined by Hawley""s Condensed Chemical Dictionary (12th Edition), are those whose structure is such that groups of atoms are arranged randomly above and below the backbone chain of atoms, when the latter are all in one plane.
The xe2x80x9cStereoregular Index (S.I.)xe2x80x9d of a polymer is defined as follows: In a perfectly atactic polymer, two homotactic triads, mm and rr, are present in equal amounts (25% each). As the polymer becomes increasingly stereoregular, the relative amounts of mm and rr change so that one increases to be greater than the other. S.I. is the ratio of the larger of mm or rr to the smaller of mm or rr and is always positive and greater than 1. S.I. expresses, in a numerical way, how the steric structure of a polymer shifts away from 1.0 for a random, atactic polymer to larger values characteristic of more stereoregular polymers.
xe2x80x9cNon-stereoregularxe2x80x9d polymers are generally mostly atactic or mostly semi-syndiotactic polymers, rather than mostly isotactic or mostly syndiotactic.
xe2x80x9cSemi-syndiotacticxe2x80x9d polymers are those having structures between mostly syndiotactic polymers and mostly atactic polymers.
In one embodiment, non-stereoregular polymers of the invention have an S.I. of 1 to about 10. In another embodiment, non-stereoregular polymers of the invention have an S.I. of 1 to about 7. In still a further embodiment, non-stereoregular polymers of the invention have an S.I. of 1.5 to about 7. In yet another embodiment, non-stereoregular polymers of the invention have an S.I. of 1 to about 1.1.
xe2x80x9cAmorphousxe2x80x9d polymers are those polymers that are hexane soluble at room temperature. Recognize that such materials may have a small degree of crystallinity, which is detectable, for example, using x-ray or thermal analysis. Amorphous polymers lack a well-defined melting point when measured by Differential Scanning Calorimetry (DSC). Particularly preferred are those amorphous polymers having mostly atactic structures.
Polymers that have less stereoregularity have been found to be preferred for processing and preparing PSAs of the invention, such as for example, by hot-melt processing. Furthermore, materials that are highly isotactic tend to be opaque, while those that are less stereoregular tend to be more transparent. The clarity (i.e., transparency) of materials with low stereoregularity makes them preferred for use in applications where clarity of the adhesive is important. For example, such applications include bonding of glass and transparent plastics.
One advantage of utilizing blends of the invention is the greater formulation latitude that they provide. That is, changes in a wide variety of physical properties of films comprising the blends can be effectuated, for example, by varying the ratio of individual polymers in the blends. Furthermore, cost effectiveness is another advantage of utilizing blends. For example, less expensive polymers can be blended with more expensive polymers. In that way, the less expensive polymers can act as an xe2x80x9cextenderxe2x80x9d for the more expensive polymers. Also, using blends can provide advantageous synergistic effects, wherein, for a certain application, the blend can perform substantially better than either polymer by itself for the same application.
PSA blends of the invention are particularly useful for adhering to both relatively high and low surface energy materials. PSA blends of the invention are capable of providing adequate or improved peel adhesion to such substrates. For example, certain embodiments of the invention provide substrates, which can be polypropylene, polyethylene, or glass, with the pressure-sensitive adhesive composition at least partially applied thereon. In these embodiments, the 180xc2x0 peel adhesion to the substrate can be as high as at least about 100 N/dm. Certain PSA formulations of the invention are also capable of providing compositions having useful shear strengths.
Ethylene/Propylene-Derived Copolymer
Any suitable ethylene/propylene-derived copolymer can be used in the present invention. Generally, however, the ethylene/propylene-derived copolymers of the invention are amorphous. As such, the compositions of the invention are able to have enhanced pressure-sensitive adhesive properties, often without the need for using substantial amounts of additives, such as plasticizers or liquid oils. The ethylene/propylene-derived copolymers themselves may or may not have pressure sensitive-adhesive properties. Furthermore, the use of amorphous ethylene/propylene-derived copolymers facilitates obtaining a single domain system. In contrast, when only crystalline xcex1-olefin polymers are used instead of at least one amorphous ethylene/propylene-derived copolymer, crystallization-induced phase separation may be encountered in the composition, impairing obtainment of a single domain system.
Another preferred aspect of the invention relates to the type of ethylene/propylene-derived copolymer used. While any suitable ethylene /propylene-derived copolymer, including block- and random-copolymers, can be used in accordance with the present invention, the use of at least one random-ethylene /propylene-derived copolymer is preferred. As with using amorphous ethylene/propylene-derived copolymers, the fact that the copolymer is random in a preferred embodiment also facilitates obtainment of a single domain system.
The ethylene/propylene-derived copolymer is derived from at least one ethylene monomer and at least one propylene monomer. While other monomers, including diene monomers, may be copolymerized with the ethylene and propylene monomers, when preparing the ethylene/propylene-derived copolymers, the ethylene/propylene-derived copolymer of the invention is derived from essentially no diene monomers. As discussed previously, many compositions derived from diene monomers are relatively unstable over time, such as for example, when exposed to weathering or higher temperatures (e.g., when hot-melt processing). Furthermore, many compositions derived from diene monomers are relatively non-polar and do not adhere adequately to both relatively high surface energy substrates and low surface energy substrates.
It is preferred that the ethylene/propylene-derived copolymer is derived from a major portion of propylene monomers. That is, the largest mole % of monomers from which the ethylene/propylene-derived copolymer is derived is that for propylene monomers. Similarly, it is preferred that the ethylene/propylene-derived copolymer contains less than about 35% by weight, more preferably less than 30% by weight, even more preferably less than about 25% by weight, and even more preferably less than about 15% by weight repeat monomeric units derived from ethylene monomers.
Any suitable amount of ethylene monomer may be used to prepare the ethylene/propylene-derived copolymer as long as the resulting copolymer is amorphous. Generally, however, the greater the proportion of ethylene monomer used, the more likely it is that the resulting copolymer will not be amorphous.
Particularly useful are the ethylene/propylene-derived copolymers with a glass transition temperature (Tg) of about xe2x88x9250xc2x0 C. to about 0 C., preferably greater than xe2x88x9240xc2x0 C. to about 0xc2x0 C., and more preferably about xe2x88x9230xc2x0 C. to about 0xc2x0 C. Generally, when the Tg of the ethylene/propylene-derived copolymer is lower than xe2x88x9250xc2x0 C., it is because a larger proportion of ethylene monomer was used in preparation of the copolymer. While some such copolymers may be useful for certain embodiments of the invention, as discussed above, these polymers may not be amorphous. Furthermore, it is preferred that the Tg of the ethylene/propylene-derived copolymer is greater than about xe2x88x9250xc2x0 C. in order to reduce the necessity for adding a tackifier, or at least a large amount of tackifier, to the composition in order to obtain PSA properties for room temperature applications. The Tg of a polymer is measurable using Differential Scanning Calorimetry using second heat measurements at 10xc2x0 C. per minute.
Examples of ethylene/propylene-derived copolymers useful in the present invention include polymers commercially available from Eastman Chemical; Kingsport, TN under the EASTOFLEX tradename and polymers commercially available from The International Group; Wayne, PA under the KTAC.tradename. Specific examples of suitable ethylene/propylene-derived copolymers from these companies are those with a Tg of about xe2x88x9233xc2x0 C. to about xe2x88x9223xc2x0 C., such as EASTOFLEX E1060, EASTOFLEX E1200, and KTAC6013.
Propylene-Derived Polymer
Any suitable polymer can be used for the propylene-derived polymer. The propylene-derived polymers themselves, may or may not have PSA properties. Generally, the propylene-derived polymer is non-stereoregular.
The propylene-derived polymer is derived from at least propylene monomer. While other types of monomers may be used in their preparation, preferably, the propylene-derived polymer is derived from at least 60 percent by weight, more preferably at least about 80 percent by weight, and most preferably essentially 100 percent by weight, propylene monomers. As such, it is also preferred that the propylene-derived polymer contains a saturated hydrocarbon backbone. Accordingly, preferably the propylene-derived polymer is derived from essentially no diene monomers. As discussed previously, many compositions derived from diene monomers are relatively unstable over time, such as for example, when exposed to weathering or higher temperatures (e.g., when hot-melt processing). Furthermore, many compositions derived from diene monomers are relatively non-polar and do not adhere adequately to both relatively high surface energy substrates and low surface energy substrates.
Propylene-derived polymers of the invention are of high enough molecular weight that they do not act as a tackifier or plasticizer. That is, the weight average molecular weight of the propylene-derived polymer is at least about 10,000 grams/mole. Preferably, the weight average molecular weight of the propylene-derived polymer is at least about 30,000 grams/mole, even more preferably at least about 50,000 grams/mole, and even more preferably at least about 70,000 grams/mole. Particularly useful are polymers with a weight average molecular weight of about 70,000-1,000,000 grams/mole, preferably about 70,000-200,000 grams/mole.
The preferred Tg of these polymers is about xe2x88x9215xc2x0 C. to about 10xc2x0 C., more preferably about xe2x88x9210xc2x0 C. to about 5xc2x0 C. The use of at least one propylene-derived polymer having such a preferred Tg facilitates formation of a composition having PSA properties. Again, the Tg of a polymer is measurable using Differential Scanning Calorimetry using second heat measurements at 10xc2x0 C. per minute.
The preferred melt viscosity of the propylene-derived polymer is greater than 500 Poise, more preferably greater than about 750 Poise, when measured at 190xc2x0 C. according to the Viscosity Test method in the Examples section, infra. In a further embodiment, the melt viscosity of the propylene-derived polymer is greater than about 2,500 Poise when measured at 190xc2x0 C. according to the Viscosity Test method. In still a further embodiment, the melt viscosity of the propylene-derived polymer is greater than about 10,000 Poise when measured at 190xc2x0 C. according to the Viscosity Test method. Generally, the higher the melt viscosity of the propylene-derived polymer, the more likely it is that the resulting composition will have a higher shear strength in conjunction with improved peel adhesion properties. This is particularly beneficial when preparing PSA compositions of the invention for high performance applications.
Any suitable propylene-derived polymer can be used in blends of the invention. When higher molecular weight propylene-derived polymers are preferred, those polymers prepared using a metallocene catalyst, such as in PCT Publication No. WO 99/20,664, are particularly useful. Typically, polymers prepared using a metallocene catalyst (i.e., metallocene-generated polymers) have a weight average molecular weight of greater than about 70,000 grams/mole, which is typically higher than the molecular weight of many commercially available non-stereoregular propylene-derived polymers. A similar comparison applies when comparing melt viscosities of the polymers. Propylene-derived polymers prepared using metallocene catalysts may be preferred when PSA compositions having higher shear strength are desired in conjunction with improved peel adhesion properties. The higher molecular weight of the propylene-derived polymers prepared using a metallocene catalyst also enables them to be more usefully crosslinked, as compared to those propylene-derived polymers having lower molecular weights. This may be the case, when for example, the PSAs are to be used in a high performance application.
As stated previously, however, one advantage of the present invention is that the blends are tailorable for a wide variety of applications. Higher molecular weight polymers may not always be preferred depending on the application. For example, lower molecular weight polymers may be preferred when using the PSA composition to form a melt-blown fiber. PSA blends of the invention may be advantageously used to prepare blown microfiber webs, for example. Addition of a lower molecular weight polymer to a conventional polymer composition in accordance with the invention tends to lower the melt viscosity of the polymer composition at a given processing temperature. Therefore, the use of polymer blends of the invention may facilitate melt blowing fibers from PSA compositions at lower temperatures than those used to melt-blow fibers from conventional PSA compositions. Also, the use of polymer blends of the invention may facilitate a higher throughput of melt-blown fibers at a given processing temperature.
To facilitate forming a single domain PSA system, it is preferred that the propylene-derived polymer be a non-stereoregular polymer. That is another reason why metallocene-catalyzed propylene-derived polymers, such as those described in PCT Publication No. WO 99/20,664, are useful due to their generally lower stereoregularity. Such polymers are generally either amorphous or semi-syndiotactic. However, in this preferred embodiment, any suitable non-stereoregular polymer can be used.
According to one aspect of the invention, the stereoregularity index (S.I.) of the propylene-derived polymer is about 1.0 to about 5.0. Preferably, when the propylene-derived polymer is amorphous, its S.I. is about 1.0 to about 1.05. Preferably, when the propylene-derived polymer is semi-syndiotactic, its stereoregularity index (S.I.) is about 1.1 to about 4.0.
Optional Tackifier
Tackifiers of the invention have a weight average molecular weight of less than about 10,000 grams/mole and may be a in a solid or liquid state. The compositions of the invention may include a tackifier, where necessary to impart the desired PSA properties. Those of ordinary skill in the art recognize that a wide variety of tackifier are suitable for this purpose. Although a tackifier can be used as understood by one of ordinary skill in the art, generally, if present, the compositions include less than about 60% by weight tackifiers.
Preparation of Blends
PSA compositions of the invention include at least one ethylene/propylene-derived copolymer and at least one propylene-derived polymer. Other additives (e.g., antioxidants and ultraviolet stabilizers) may also be added to the PSA compositions, depending on the desired application and as well known to one of ordinary skill in the art.
Each of the ethylene/propylene-derived copolymer and propylene-derived polymer components of the blend is preferably present in an amount of about 5 weight % to about 95 weight % based on total weight of the blend. More preferably, each of the components is present in an amount of at least about 10 weight % based on total weight of the blend. Typically, however, the ethylene/propylene-derived copolymer component is present in a major portion and the propylene-derived polymer component is present in a minor portion based on total weight of the two components. This ratio of components contributes to cost-effectiveness and easier hot-melt processability of the composition. Furthermore, this ratio of components contributes to obtainment of compositions having adequate adhesion to both relatively high surface energy substrates and low surface energy substrates. It has also been found that this ratio facilitates formation of compositions having PSA properties by helping to lower the overall Tg of the composition.
Blending of the polymers is done by any method that results in a substantially homogeneous distribution of the polymers. The polymers can be blended using several methods. In particular, the polymers can be blended by melt blending, solvent blending, or any suitable physical means.
For example, the polymers can be melt blended by a method as described by Guerin et al. in U.S. Patent No. 4,152,189. That is, all solvent (if used) is removed from each polymer by heating to a temperature of about 150xc2x0 C. to about 175xc2x0 C. at a pressure of about 5 Torr to about 10 Torr. Then, the polymers are weighed into a vessel in the desired proportions. The blend is then formed by heating the contents of the vessel to about 175xc2x0 C., while stirring.
Although melt blending is preferred, the PSA blends of the present invention can also be processed using solvent blending. In that case, the polymers in the blend should be substantially soluble in the solvents used.
Physical blending devices that provide dispersive mixing, distributive mixing, or a combination of dispersive and distributive mixing are useful in preparing homogenous blends. Both batch and continuous methods of physical blending can be used. Examples of batch methods include those methods using BRABENDER (e.g., a BRABENDER PREP CENTER, available from C. W. Brabender Instruments, Inc.; South Hackensack, N.J.) or BANBURY internal mixing and roll milling (available from FARREL COMPANY; Ansonia, Conn.) equipment. Examples of continuous methods include single screw extruding, twin screw extruding, disk extruding, reciprocating single screw extruding, and pin barrel single screw extruding.
Applications
The PSA compositions of the present invention can be readily applied to a substrate. For example, the PSA composition can be applied to sheeting products (e.g., decorative, reflective, and graphical), labelstock, and tape backings. The substrate can be any suitable type of material depending on the desired application. Typically, the substrate comprises a nonwoven, paper, polymeric film (e.g., polypropylene (e.g., biaxially oriented polypropylene (BOPP)), polyethylene, polyurea, or polyester (e.g., polyethylene terephthalate (PET)), or release liner (e.g., siliconized liner).
PSA compositions according to the present invention can be utilized to form tape, for example. The PSA is applied to at least one side of the backing. The PSA may then be crosslinked to further improve the shear strength of the PSA. Any suitable crosslinking method (e.g., exposure to radiation, such as ultraviolet or electron beam) or crosslinker additive (e.g., phenolic and silane curatives) may be utilized.
When double-sided tapes are formed, the PSA is applied to at least a portion of both sides of the backing. Alternatively, a release material (e.g., low adhesion backsize) can be applied to the opposite side of the backing, if desired. Advantageously, the PSA and/or release material, for example, can be coextruded with the film backing for ease of processing.
The PSA can be applied to a substrate using methods well known to one of ordinary skill in the art. For example, the PSA can be applied using melt extrusion techniques. The PSA composition can be applied by either continuous or batch processes. An example of a batch process is the placement of a portion of the PSA composition between a substrate to which the PSA is to be adhered and a surface capable of releasing the PSA to form a composite structure. The composite structure can then be compressed at a sufficient temperature and pressure to form a PSA layer of a desired thickness after cooling. Alternatively, the PSA composition can be compressed between two release surfaces and cooled to form, for example, a transfer tape.
Continuous forming methods include drawing the PSA composition out of a heated film die and subsequently contacting the drawn composition to a moving plastic web or other suitable substrate. A related continuous forming method involves extruding the PSA composition and a coextruded release material and/or backing from a film die and cooling the layered product to form an adhesive tape. Other continuous forming methods involve directly contacting the PSA composition to a rapidly moving plastic web or other suitable preformed substrate. Using this method, the PSA composition is applied to the moving preformed web using a die having flexible die lips, such as a conventional film or sheeting die. After forming by any of these continuous methods, the films or layers can be solidified by quenching using both direct methods (e.g., chill rolls or water baths) and indirect methods (e.g., air or gas impingement). Blown microfibers can also be prepared using another continuous forming method. Examples of this process can be found, for example, in PCT Publication No. WO 99/28,539.
Although coating out of solvent is not preferred, the PSA compositions can be coated using a solvent-based method. For example, the PSA composition can be coated by such methods as knife coating, roll coating, gravure coating, rod coating, curtain coating, and air knife coating. The coated solvent-based PSA composition is then dried to remove the solvent. Preferably, the applied solvent-based PSA composition is subjected to elevated temperatures, such as those supplied by an oven, to expedite drying.
The PSA compositions, coatings, and tapes therefrom are exemplified in the following examples. These examples are merely for illustrative purposes and are not meant to be limiting to the scope of the appended claims. All parts, percentages, ratios, etc. in the examples and the rest of the specification are by weight unless indicated otherwise.

Pressure-sensitive adhesive blends comprising ethylene/propylene-derived polymers and propylene-derived polymers and articles therefrom


A mail cart for use in manual sorting of mail pieces according to the inventions includes a generally rectangular frame and wheels mounted on the frame for rolling support of the cart on a floor. A bottom, substantially horizontal shelf is secured to the frame along with a first inclined shelf secured to the frame above the bottom shelf and spaced from the bottom shelf in a vertical direction, which first inclined shelf extends forwardly and upwardly at an acute angle relative to a horizontal plane. A second inclined shelf is secured to the frame above the first inclined shelf and spaced from the first inclined shelf in a vertical direction. The second inclined shelf extends forwardly and upwardly at an acute angle relative to a horizontal plane, which angle is preferably the same as the angle of first shelf.

Both federal postal services and private couriers face the challenge of sorting, handling and delivering mail pieces that are larger than letter size, such as parcels and flats. Tilt tray sorters and cross belt sorters are often the primary means for automated sorting of such mail pieces, but the output of such sorters often requires manual handling. Little has been done to facilitate such manual handling.
A typical tilt-tray or cross-belt sorter uses a series of carts mounting tilt tray or cross belt mechanisms. See for example Kofoed U.S. Pat. No. 5,690,209. The carts move around a generally oval shaped track or rail system that includes at least one induction area at which new items can be placed on a cart for sorting and a series of unloading zones at which the cart is activated to unload the item to a collection site usually outside of the track on which the carts move. The track is not a true oval but most often a rectangular shape with curved ends.
In connection with a commercial tray sorter known as the RSU tray sorter, the term "virtual sorter" was used to describe a tilt tray sorter with two or more induction points spaced along the perimeter of the oval track with multiple divert points (unloading areas) between induction points. The portion of the sorter that includes one induction point, its associated scanner, and the divert points between the induction point and the next induction point in the direction of travel of the sorter carts is considered one virtual sorter since within that segment the tray sorting machine performs all sorting functions along its length. A virtual sorter as the term is used herein has the foregoing meaning and may make use of any type of closed loop parcel sorting machine such as a cross-belt or tilt-tray sorter, or the equivalent.
Sorting systems such as cross-belt or tilt-tray sorters are often used to unload items to outlet chutes (also called collection chutes) from which items are manually taken and placed in containers or carts for subsequent processing. This operation is limited by the amount of space available around the periphery of the sorting machine's oval track. In one common version of this process, packages and flats are loaded into tubs on adjoining racks or into mail sacks mounted on carts. The carts are lined up in a formation surrounding the sorter. The human worker stands in an five to six foot wide aisle between the sorter track's outlet chutes and the carts or racks, which may be positioned both below the outlet chutes and on the other side of the aisle. The foregoing arrangement makes poor use of the available space. The present invention seeks to provide an improved cart for use with a closed loop parcel sorting machine permitting more efficient manual handling of sorted items.
A number of designs for mail carts and sorting racks are known, including those shown in U.S. Pat. No. 6,715,614 FIGS. 28 and 29. Bags can be described as having length, width and depth dimensions. The plastic bags shown in the '284 publication are oriented edgewise, such that the frontwardly opening mouths of the bags are oriented so that the widthwise dimension of the bag is oriented substantially vertically, presenting an opening that is long vertically and narrow horizontally. Mail carts according this publication use horizontally oriented shelves (FIG. 15) or shelves pitched from side to side (FIG. 19). The present invention takes a different approach to mail cart structure.


A gripping jig for assembling applies a force to a molded body in a direction perpendicular to an assembling direction. When an assembling load is applied to the molded body, the force is adjustable with an adjustment screw such that the molded body is guided to move in the assembling direction. Since the force is applied from a direction different from the assembling direction, the molded body can move in the assembling direction, and as the force is adjustable, application of the assembling load to the molded body and movement of the molded body can be adjusted. Since a plurality of molded bodies are fixed and assembled respectively, when there are variations in size of the molded bodies, if an excessive assembling load is applied, each molded body is guided to move, so that more uniform assembling load is applied to the plurality of molded bodies.

1. Field of the Invention
The present invention relates to a gripping jig for assembling, an assembling device, and a producing method of an assembled body.
2. Description of the Related Art
A gripping jig for assembling has been proposed in which a component member of a ceramic luminous body is set in an electrode reception area so as to fix the component member with a pin (see Patent Document 1, for example). In the gripping jig for assembling described in Patent Document 1, two component members fixed to the electrode reception member are prepared; junctions of the component members are opposed to each other; the junctions are abutted to each other while being simultaneously heated for locally melting a cementing material, so that the junctions are joined together by alternately compressing and extending the boundary region between the two junctions. [Patent Document 1] PCT Japanese Translation Patent Publication No. 2004-519820

Gripping jig for assembling, assembling device, and producing method of assembled body


A heater for wafer processing, such as thin film deposition, includes a first heating unit and a second heating unit. The first heating unit includes a substrate with a top surface for supporting a wafer thereon and a back surface. The second heating unit is disposed proximate the back surface of the substrate and is preferably disposed inside an inner space of a shaft supporting the first heating unit in a processing chamber. The first heating unit and the second heating unit are independently controlled. The second heating unit is designed based on the actual temperature profile and heat loss on the top surface. Therefore, the second heating unit can more effectively compensate the heat loss to achieve a more uniform temperature profile on the top surface.

Electric heaters for heat-treatment of a workpiece, particularly for wafer processing, are generally known in the art. A typical electric heater for wafer processing generally has a dielectric substrate with a heating surface for heating and supporting a wafer and a resistive heating element embedded inside the substrate. The substrate is generally made of ceramic materials due to, among other things, their high thermal conductivity, which facilitates the heat transfer from the resistive heating element to the heating surface and hence the wafer supported thereon. During processing, thin film deposition is to be performed on the wafer when the wafer is heated by the heater. Since a uniform heating/temperature profile on the heating surface is critical to the quality of the deposited film on the wafer, various attempts have been made to achieve a more uniform heating/temperature profile across the heating surface of the substrate.
It has been found that a high degree of uniform heating can be achieved by, among other things, (1) providing an extreme degree of flatness of the supporting surface of the substrate, (2) selecting a thermally conductive substrate with high thermal conductivity, (3) providing a thermally conductive substrate that has rigidity, stiffness, and thermal properties to achieve the desired flatness and thermal conductivity.
Despite these attempts, it is still difficult to realize a heater with an improved uniform heating/temperature profile. The processes for manufacturing a heater, particularly a ceramic heater, are complex. Factors affecting the performance and quality of a completed ceramic heater during manufacturing include, among other things, the inhomogeneous material properties of the substrate and the non-uniform temperature distribution in the manufacturing environment to which the substrate is exposed. These factors complicate the design and manufacturing aspects of a ceramic heater.
Another problem that complicates the design of a ceramic heater is the occurrence of heat loss during operation. Heat losses generally occur at the periphery and the center of the substrate, and it is difficult to predict the amount of heat losses at a specific operating temperature. If the actual heat losses during operation is greater than a maximum design limit, practically nothing can be done to remedy the situation to achieve a more uniform temperature profile once the heater is completed. As a result, the completed ceramic heater with an unsatisfactory heating/temperature profile is often scrapped, thereby increasing manufacturing costs.
It has been proposed that dividing the substrate into multiple heating zones and independently controlling the temperatures of the multiple heating zones may somehow compensate for the heat loss during operation to maintain a more uniform temperature across the heating surface of the substrate, as proposed in U.S. Pat. No. 6,423,949 ("the '949 patent") to Chen et al. However, the proposed heater cannot deal with the situation where any one of the temperature profiles of the individual heating elements deviates significantly from the design requirements. As with a heater with a single heating zone, the heating elements of the '949 patent are embedded inside the substrate and cannot be removed without destroying the heater. Practically, nothing can be done to achieve a more uniform temperature once a heater is completed if any one of the temperature profiles of the multiple heating zones deviates significantly from the design requirements. Moreover, it is difficult to predict the exact locations and areas where hot spots or heat losses occur as well as their degree. As a result, a heater with multiple heating zones as disclosed in the '949 patent does not make the design and manufacturing of a heater less complex than a heater with a single heating zone.

Heater for wafer processing and methods of operating and manufacturing the same