In an image forming apparatus, three or more (four in this case) cylindrical photosensitive members 1 to 4 on which latent images are formed and developed through use of toner to thereby produce toner images, are arranged so as to share a tangential line in common, and a cylindrical intermediate transfer member 51 is provided. Alternatively, a first unit containing one or more image carriers is positioned next to a first transfer member and a second unit containing one or more image carriers is positioned next to a second transfer member such that there is reflectional symmetry between the first and second units and the transfer members.

1. Field of the Invention
The present invention relates to an image forming apparatus which forms a color image by the steps of forming a latent image, e.g., an electrostatic latent image, for each of colors, developing the latent image through use of each color toner to thereby produce a monochrome image, superimposing the monochrome images on each other on predetermined paper, and fixing them, and also relates to an image forming method for use with the image forming apparatus. More particularly, the present invention relates to an image forming apparatus which forms a color image by adoption of an image forming method such as an electrophotographic recording method, an electrostatic recording method, ionography, or a magnetic recording method, and also relates to an image forming method for use with the apparatus.
2. Description of the Related Art
Image forming apparatuses which form a color image have widely been in actual use in recent years. Particularly, a color image forming apparatus equipped with a plurality of image carriers has been developed taking full advantage of its superior productivity as a rival to an existing color image forming apparatus which creates one copy by a plurality of rotations (e.g., four rotations). In the color image forming apparatus equipped with a plurality of image carriers (hereinafter referred to as a tandem-type image forming apparatus), the plurality of image carriers, e.g., a plurality of photosensitive members in the case of an electrophotographic color image forming apparatus, are likely to be arranged substantially linearly. For this reason, a charging device, an exposure device, a developing device, and a cleaner, all of which are disposed around each photosensitive member, can be designed so as to have substantially the same construction in common according to the type of the device. Accordingly, the tandem-type image forming apparatus has the advantages of compactness, a low price, and high reliability. Conversely, the apparatus has the disadvantage of the extremely difficulty of registration of color images which is the most important factor in determining color picture quality.
FIG. 21 shows one example of the construction of an existing color image forming apparatus which comprises four photosensitive members 1, 2, 3, 4 and a belt-like transfer member 5 extended across them. A charging device 11, an exposure device 12, a developing device 13, and a cleaner 14 are disposed around the photosensitive member 1; a charging device 21, an exposure device 22, a developing device 23, and a cleaner 24 are disposed around the photosensitive member 2; a charging device 31, an exposure device 32, a developing device 33, and a cleaner 34 are disposed around the photosensitive member 3; and a charging device 41, an exposure device 42, a developing device 43, and a cleaner 44 are disposed around the photosensitive member 4. The belt-like transfer member 5 may be formed into a so-called intermediate transfer member on which toner images are directly placed or into a so-called transfer paper carrier in which toner images are transferred onto the paper sucked by the belt-like transfer member 5.
Next, with reference to the case of the intermediate transfer belt, the formation of an image is described in detail. To begin with, after having been evenly electrostatically charged by the charging device 11, the photosensitive member 1 is exposed to light by the exposure device 12, whereby an electrostatic latent image is formed. The thus-formed latent image is developed and visualized through use of monochrome toner to thereby produce a toner image. The toner image, or the first toner image, is then transferred to the intermediate transfer belt 5 at the position where the toner image comes into contact with the intermediate transfer belt 5. Another color toner image which is similarly formed on the photosensitive member 2 in synchronization with the travel of the first toner image to the position where the first toner image comes into contact with the photosensitive material 2 is superimposed as the second toner image on the first toner image. Similarly, the third and fourth toner images are further superimposed on the thus-superimposed toner images to thereby 4-color superimposed images. These images are transferred as a single image to and fixed on paper (not shown), whereby a color image is formed on the paper.
While passing by the positions where the intermediate transfer belt 5 comes into contact with the respective four photosensitive members 1, 2, 3, and 4, the intermediate transfer belt 5 does not successfully travel along the positions, because it extends/contracts or snakes it's way by dint of the tensile force stemmed from the driving of the intermediate transfer belt 5. As a result, the color toner images become slightly offset from each other, thereby resulting in an undesirable image. Various methods have already been adopted to position the toner images. With one of the methods, a predetermined image is developed, and the position of this developed image is read by an image detection sensor. After the positions of respective color images have been calculated, for example, the starting point for writing operations of the laser light source or the position of a reflection mirror of the light source is finely adjusted. However, this methods requires a very complicated mechanism, thereby resulting in an inevitable increase in the cost.
There is proposed another method in which a plurality of photosensitive members are arranged around a larger cylindrical roll- or drum-shaped rotary transfer member for purposes of preventing dislocation. This method is illustrated in FIG. 22. A rotary transfer member 51 may be an intermediate transfer member or a paper carrier. For the roll- or drum-shaped rotary transfer member 51, it does neither extend/contract nor snake in contrast with the belt. Hence, the rotary transfer member 51 rotates around a drive shaft in a very stable manner, thereby rendering the mutual registration of images comparatively easy. In connection with this method, there is a more desirable method disclosed in Utility Model Publication (Kokoku) No. Hei-6-18364, by which the surface velocity of each of the photosensitive members (image carriers) comparatively easily differs from the surface velocity of the rotary transfer member. The difference in surface velocity between the photosensitive members and the rotary transfer member is intended to prevent the rotary transfer member from receiving a different speed from each of the four photosensitive members while following the rotations of the photosensitive members. The rotary transfer member has the advantage of easy speed control. However, as can be seen from FIG. 22, there is the need for the use of a rotary transfer member having a very large diameter. Further, components to be provided around the respective photosensitive members 1, 2, 3, 4, e.g., the charging devices 11, 21, 31, 41, the exposure devices 12, 22, 32, 42, the developing devices 13, 23, 33, 43, and the cleaners 14, 24, 34, 44 are different in position from each other with reference to the direction of gravity. Therefore, it is impossible to achieve the commonality of components, thereby posing serious problems with regard to cost, reliability, or size. Although it is possible to use a member having a smaller diameter for the rotary transfer member 51, the difficulty of achieving the commonality of constituent components to be provided around the photosensitive member is multiplied greatly.

Color image forming apparatus and method using plural photosensitive drums


A battery packaging assembly having safety features that reduce the risk of thermal propagation is disclosed. The battery packaging assembly may include a foam layer having a plurality of cutout trenches, the foam layer configured to engage battery cells in a press-fit relationship. In addition, the battery packaging assembly may include a tray configured to receive the foam layer, the tray enclosing a compartment configured for receiving a plurality of battery cells. Further, the battery packaging assembly may include a ventilation cavity in fluid communication with the plurality of trenches of the foam layer.

Any number of battery cells may be combined to form a battery module, the battery cells being surrounded by a battery module housing. And in turn, a plurality of such battery modules may be combined in another housing or assembly to form a battery pack. Such battery packs are increasingly used in mobile and stationary applications. Uses include hybrid and electric drive vehicles, as well as stationary power generation. For example, a machine such as a hydraulic excavator, an articulated truck, a locomotive or a generator may be powered by large battery packs carried onboard. Battery powered electric drive machines may be particularly advantageous in underground mining applications where they may reduce the required mine ventilation and cooling, thereby making viable the extraction of ore bodies that would not be economically feasible with diesel powered machines. Mobile applications require secure packaging of battery packs due to the shock and vibration introduced by movement of the vehicle over roads or terrain; and heavy-duty applications such as underground mining and construction require an even higher amount of protection.
High amounts of battery energy are built into such heavy-duty equipment in order to maximize performance and productivity. For example, lithium battery systems have successfully and safely been implemented into multiple industries. A battery management system may be required to maintain control and keep such batteries in a safe working state. For example, a control system may be employed to actively monitor cell voltage, temperature and currents, and may take action to derate power limits or open the battery contactors when necessary. The control system, control components and safety features of typical battery packs help to prevent battery cell failure, which may result in the release of high-temperature, high-intensity gases and/or flames outside of the battery, also known as thermal runaway.
Thermal runaway may be caused by a short circuit within the cell, improper cell use, physical mishandling, manufacturing defects or the exposure of the cell to extreme external temperatures. And because of the close packaging of battery cells within a battery module or pack, thermal runaway in a single battery cell is capable of triggering a thermal runaway in an adjacent battery cell if enough heat is absorbed from the initial failed cell. A single cell failure, therefore, may start a thermal runaway chain reaction throughout a battery pack causing numerous adjacent batteries fail, one after another. This is known as fire or thermal propagation, and may cause significant collateral damage to the equipment as well as endanger the safety of personnel. Patent application US 2016/0248061 to Brambrink et al. describes a battery module having a burn through safety wall through which a flame from a single failed battery may escape. Likewise, the battery pack housing of the Brambrink et al. disclosure may also have a burn through safety wall corresponding to the module safety wall, thereby allowing a flame from a failed cell to also escape the battery pack. While the Brambrink et al. design may help to avoid the corruption of battery cells adjacent a failed single cell, the Brambrink et al. design requires the burning and destruction of the safety wall material, and may allow for the escape of hot gasses or flames from the battery pack, thereby presenting the risk of additional damage to equipment outside of the battery pack.
In addition to battery packaging methods that protect battery cells from excessive vibrations and shocks that may physically damage the batteries and cause failure, it would also be advantageous to have a battery packaging design where a single cell thermal runaway is managed so as not to result in damage to adjacent, normal cells, thereby preventing thermal propagation throughout the entirety of the battery pack, and where the escaping high-heat energy is contained so as not to risk damage to other equipment components. The presently disclosed battery packaging assembly and methods address one or more of the above-described problems and/or other problems in the art.

Battery packaging assembly with safety features to reduce thermal propagation


A composition for inhibiting corrosion in hydrocarbon wells includes a pyranopyrazole derivative. The pyranopyrazole derivative includes a pyrazole moiety, a dihydropyran moiety, and a phenyl moiety. The dihydropyran moiety is bound to the pyrazole moiety. The phenyl moiety is bound to the dihydropyran moiety. The composition can be flowed into a wellbore formed in a subterranean formation, thereby inhibiting corrosion in the wellbore.

Corrosion can occur in oil and gas processing equipment and piping. Corrosion can occur due to factors such as temperature, the presence of carbon dioxide, the presence of hydrogen sulfide, the presence of electrolytes, and flow conditions. Corrosion can be detrimental if left untreated. For example, untreated corrosion can result in an asset becoming inefficient, unreliable, and in some cases, unsafe. A common solution is to use corrosion inhibitor, which can form a protective barrier against corrosive attack.

King Fahd University of Petroleum & Minerals


A small slider unit having a size effectively reduced in the longitudinal direction is equipped with a rail 22; a slide table 23 moving on the rail 22; a screw shaft 26 coupled to the slide table 23 and situated parallel to the rail 22; a motor M for rotating the screw shaft 26; a coupling member 31 for providing the coupling between a rotating shaft 32 of the motor M and the screw shaft 26; and a bearing 29 supporting the screw shaft 26. The screw shaft 26 is rotated by driving the motor M, whereupon the rotation of the screw shaft 26 moves the slide table 23 in the axis direction of the rail 22. The screw shaft 26 has a holding portion 27a, and the bearing 29 is held between the holding portion 27a and the coupling member 31.

1. Field of the Invention
This invention relates to a small slider unit having a slide table linearly moving by use of a rotational force generated by a screw shaft rotated by a motor.
2. Description of the Related Art
An example of conventional slider units is described with reference to FIG. 3 and FIG. 4.
As shown in FIG. 3, a rail 2 is mounted on a mounting base 1 and a slide table 3 moves along the rail 2. Specifically, C-shaped cross-section guide members 4 are provided on the two sides of the slide table 3 and slidably straddle the rail 2 to allow for the movement of the slide table 3 along the rail 2.
The slide table 3 has a hole extending therethrough in the axis direction of the rail 2. A ball nut 5 is screwed in the hole, and then is engaged with a threaded portion 6a of a screw shaft 6. When the screw shaft 6 is rotated, the rotational force moves a combination of the ball nut 5 and the slide table 3 along the rail 2.
The screw shaft includes the threaded portion 6a having a screw groove formed, and a supporting portion 6c made up of a round bar having a diameter lager than that of the threaded portion 6a, and additionally a flange 6c is interposed between the threaded portion 6a and the supporting portion 6b.
A casing 7 having a hole through which the supporting portion 6b is secured on the mounting base 1. An angular bearing 8 is built in the casing 7. A lid member 9 is secured to an opening of the casing 7 to prevent the angular bearing 7 from falling out of the casing 7.
The angular bearing 8 has an inner ring 8a through which the supporting portion 6b of the screw shaft 6 passes. The inner ring 8a has an end adjoining the flange 6c and the other end adjoining a collar 10. The inner ring 8a of the angular bearing 8 is pressed between the collar 10 and the flange 6c by a bearing nut 11 fixedly screwing into the screw groove formed on the supporting portion 6b. In this manner, the inner ring 8a is fixedly interposed between the flange 6c and the collar 10 to inhibit the screw shaft 6 from rattling in the axis direction.
One of the opposing ends of the supporting portion 6b is coupled to the threaded portion 6a , and at the other end an interlock portion 6d of a smaller diameter than that of the supporting portion 6b is provided. The leading end of the interlock portion 6d faces a rotating shaft 12 of a motor M. The interlock portion 6d of the screw shaft 6 is connected through a coupling member 13 to the rotating shaft 12. As a result, the motor M is driven so as to rotate the rotating shaft 12, whereupon the screw shaft 6 rotates concurrently with the rotating shaft 12. Then, the rotation of the screw shaft 6 moves the slide table 3 along the rail 2.
Upon the movement of the slide table 3, a reaction acts on the screw shaft 6, so that the screw shaft 6 attempts to move in the direction opposite to the direction of movement of the slide table 3. Similarly, when any external force acts on the screw shaft 6, the screw shaft 6 may possibly move in the axis direction. If the screw shaft 6 is caused to move in the axis direction as described above, the slide tale 3 will be moved to an incorrect position.
For example, the above-described slider unit is employed as a positioning apparatus for use in the manufacturing process for semiconductor devices, the slide tale 3 on which a semiconductor is mounted is moved to various positions in which the semiconductor undergoes predetermined treatments. For this purpose, high precision is required to stop the movement of the slide table 3 in a correct position. In particular, for producing small workpieces such as semiconductors, a very high degree of precision in microns is required. Accordingly, in a small slider unit, the screw shaft 6 is inhibited from moving in the axis direction by use of the bearing nut 11 to secure the flange 6c and the collar 10 to prevent play from being created in an area between the flange 6c and the collar 10.
Such a slider unit as described above is disclosed in Japanese Patent No. 3927285, for example.
As described above, for conveying a small workpiece such as a semiconductor, the slider unit itself is required to be reduced in size. For example, the slide table 3 of the slider unit used in the manufacturing process of the semiconductor devices moves a short distance ranging from about 20 mm to about 50 mm, so that a short screw shaft 6 is sufficient for use. Also, the load-carrying capacity is not much required. Because of this, the slide tale 3 and the mounting base 1 can be reduced in size. In some slider units, the width of the slid table 3 and the mounting base 1 is reduced to about 10 mm to about 20 mm.
However, conventional slider units must have space for placing the collar 10 and the bearing nut 11 for the purpose of inhibiting the movement of the screw shaft 6 in the axis direction. In addition, another space is required for the coupling member 13 which provides connection between the rotating shaft 12 and the screw shaft 6 (interlock portion 6d). In this manner, the collar 10 and the bearing nut 11 or the coupling member 13 must be arranged in the axis direction of the screw shaft 6. As the next logical step, the length of the screw shaft 6 is increased, resulting in an increase in the length of the entire unit.
That is, in conventional slider units, even though the movement range of the slide tale 3 is very short, it is disadvantageously necessary to restrain a reduction in size of the slider unit in the longitudinal direction.


Disclosed is a safety sensor provided with a plurality of input signal lines for inputting signals for setting. Specifically disclosed is a safety sensor wherein at least one input signal line is provided with a high-level detection circuit and a low-level detection circuit. In an initialization process wherein setting of an operation mode is permitted, a CPU registers in a memory the on-off states of detection signals from the respective detection circuits on condition that the on-off states of detection signals are mutually opposite, and the CPU identifies the connection state of the input signal line on the basis of the on-off states and sets an operation mode corresponding to the connection state. After setting the operation mode is completed, the CPU monitors the detection signals from the respective detection circuits and determines, when at least either of the detection signals comes into a state different from the states registered in the memory, as occurrence of abnormality in the connection state of the input signal line.

A multiple-optical-axis photoelectric sensor used to control supply of power to a machine in a dangerous region is configured to turn off an output in order to ensure safety, when an object is detected, and when occurrence of an abnormality is detected in the sensor (for example, refer to Patent Document 1).
Some of this type of sensors are designed to allow switching of operation mode according to an installation environment, a use application, and the like. For example, in a multiple-optical-axis photoelectric sensor developed by an applicant, the operation mode for an interlock function is set by a combination of connection states of two signal lines (see Non-Patent Document 1)
FIG. 10 illustrates a wiring method disclosed in Non-Patent Document 1 regarding the operation mode of the interlock function. Here, one of an automatic reset mode and a manual reset mode is selected by a function selecting signal line P4 and a reset-signal inputting signal line P2.
The automatic reset mode provides automatic return of the sensor output to, an on-state after an optical axis is blocked to stop the output of the sensor, according to release of the light obstruction state. When the automatic reset mode is set, as illustrated in FIG. 10(1), the reset signal inputting signal line P2 is short-circuited to a 24-V (high-level) power supply line 3H through a normally-closed switch S1 while the function selecting signal line P4 is connected to the 0-V (low-level) power supply line 3L.
The manual reset mode maintains an output off-state after the light obstruction state is released and the output is returned to the on-state from input of the reset signal. When the manual reset mode is set, as illustrated in FIG. 10(2), the reset-signal inputting signal line is connected to the 24-V power supply line 3H through a normally-open switch S2, while the interlock function selecting signal line is connected to the 24-V power supply line 3H.
According to the above configuration, the automatic reset mode is set when the low-level signal is input from the signal line P4 while the high-level signal is input from the signal line P2, and the manual reset mode is set when the high-level signal is input from the signal line P4 while the low-level signal is input from the signal line P2. An error state occurs when a different combination of input signals from the two combinations described above is input.

Safety sensor and method for detecting abnormality in safety sensor


A push service device for balancing message loads includes: a service provider (SP) interworking unit to connect with a service providing device; a controller to route a push message received from the service providing device through the SP interworking unit to one or more corresponding client devices; and a client interworking unit to transmit the push message transferred from the controller to the one or more corresponding client devices, to receive a keep-alive message from at least one of the one or more corresponding client devices, and to transmit a keep-alive configuration message to the one or more corresponding client devices to disperse reception time points of the keep-alive message for a predetermined transmission period of the keep-alive message when the reception time points of the received keep-alive message are synchronized.

The statements in this section merely provide background information related to the present disclosure and do not constitute prior art.
As smart phones have come into wide use, and various applications have appeared due to the smart phone environment, the use of wireless resources is greatly increasing. In particular, always-on type applications, such as an Instant Messaging (IM) service, a Web service, and a Widget service, which always connect with a network in order to receive a push message or a push notification in real time are rapidly increasing. Since the always-on type applications are preparing to receive a push service while maintaining connections with service providers, the inventor(s) has experienced that excessive traffic is caused, and batteries are rapidly exhausted.
A push server according to the related art has adopted a method in which a service provider and a client are not directly connected, and when the service provider maintaining connection with the push server through a daemon constructed in the client transmits a push message or a push notification, the intermediary push server receives and transmits it to the corresponding client.

Push service providing system and method for balancing message loads


Cyclodextrin derivatives and inclusion complexes having increased solubility and stability are provided. Cyclodextrin derivatives include amino and other modified cyclodextrins, and linked cyclodextrins. Inclusion complexes comprising the foregoing cyclodextrins, and processes for making the cyclodextrin derivatives are disclosed. Also disclosed are cyclodextrin derivatives comprising otherwise substituted or unsubstituted cyclodextrins covalently bonded to agents such as pharmaceuticals. The covalent bond, when broken, yields the agent in active form. Pharmaceutical compositions and methods of treating an animal host are also described, as well as chromatographic compositions and a method for separating racemic mixtures.

This invention relates to derivatives of the cyclodextrins (which are cyclic oligosaccharides), inclusion complexes comprising cyclodextrin derivatives, and to processes for preparing and using the derivatives and complexes. This invention also relates to cyclodextrin derivatives useful as synthetic intermediates, and to processes for preparing such intermediates. This invention also relates broadly to pharmaceutical, pesticidal, herbicidal, agricultural, cosmetic or personal care agent compositions comprising the cyclodextrin derivatives and inclusion complexes. This invention further relates to pharmaceutical compositions, and to processes for treating animals, including humans. This invention also relates to chromatographic compositions, and to a method for separating racemic mixtures.
Inclusion complexes are chemical species consisting of two or more associated molecules in which one of the molecules, the "host", forms or possesses a cavity into which it can admit a "guest" molecule, resulting in a stable association without formation of any covalent bonds. Secondary forces are alone responsible for maintenance of the integrity of all inclusion complexes.
Over the past twenty-five years, interest in the physical and chemical properties of inclusion complexes has grown considerably. The cyclodextrins, because they are nontoxic and are able to form complexes with numerous small organic molecules, perhaps the most important of all compounds capable of acting as host components. The three most important cyclodextrins are the .alpha.-, .beta.- and .gamma.-cyclodextrins, which respectively consist of six, seven and eight .alpha.-D-gluco-pyranosyl residues. Cyclodextrins are not perfectly cylindrical molecules, but are somewhat coneshaped, with all of the secondary hydroxyl groups situated at one end of the annulus (the larger diameter end) and all of the primary hydroxyl groups at the other, as illustrated in FIG. 1.
Each glucopyranose residue contains three hydroxyls which are of varying reactivity. The primary or C6 hydroxyl is the most reactive by virtue of its position on the C6 carbon, which is the only primary carbon. The secondary or C2 and C3 hydroxyls are less reactive because of their location on the C2 and C3 carbons, which are secondary carbons. Thus, synthetic reactions will usually involve one or more of the C6 hydroxyls unless steps are taken to proceed via the C2 and/or C3 hydroxyls.
The numbering system and structure of .beta.-cyclodextrin are shown in FIG. 2. Viewing the secondary end of the cyclodextrin, each glucopyranosyl residue is labelled clockwise from A to F, G or H (for .alpha.-, .beta.- and .gamma.-cyclodextrins, respectively). The A residue is determined by the substitution which takes priority. Thus each substituent is assigned a prefix indicating the number of the carbon to which the substituent is attached and the letter of the glucopranose residue. For example, 6.sup.A -o-toluenesulfonyl-.beta.-cyclodextrin indicates that a toluenesulfonyl is attached to the oxygen on the C6 carbon of the A-glucopyranose residue.
The cavity of a cyclodextrin is relatively apolar and thus cyclodextrins will normally preferentially include apolar or hydrophobic molecules (or portions thereof) in their cavities, while excluding polar or hydrophilic molecules or portions thereof. The molecular dimensions and solubility of .alpha.-, .beta.-, and .gamma.-cyclodextrin are provided in Table 1.
TABLE 1 ______________________________________ Physical Properties of Cyclodextrins Number of Solubility Cavity D-glucosyl Molecular in water width residues Name weight (g/100 mL) (pm) ______________________________________ 6 alpha 972 14.5 470-520 cyclodextrin 7 beta 1135 1.85 600-640 cyclodextrin 8 gamma 1297 23.2 750-830 cyclodextrin ______________________________________
As shown in Table 1, the space within the cyclodextrin cavity increases with the number of D-glucopyranosyl residues. Thus, as would be expected, the stability of an inclusion complex depends to a large degree on the relative sizes of the cyclodextrin cavity and the portion of the guest molecule to be included. For example, a molecule may be too large to fit within the cavity of .alpha.-cyclodextrin, but might form a complex with the larger .beta.-cyclodextrin. A further discussion of the molecular interaction of inclusion complexes is provided in R. J. Clarke, J. H. Coates and S. F. Lincoln, "Inclusion Complexes of the Cyclomalto-Oligosaccharides (Cyclodextrins)", Advances in Carbohydrate Chemistry and Biochemistry, Vol 46, pp 205-249 (1988), which is expressly incorporated herein by reference.
Cyclodextrins have been widely investigated for use in the pharmaceutical industry because of their reported ability to solubilize and stabilize drugs and to increase bioavailability. This ability has led to many scientific publications, and numerous worldwide patents and published applications relating to the use of cyclodextrins with pharmaceuticals. See, for example, U.S. Pat. No. 4,727,064 to Pitha and U.S. Pat. No. 4,707,472 to Inagaki et al., U.S. Pat. No. 4,774,329 to Friedman, and U.S. Pat. No. 4,432,802 to Harata et al., U.S. Pat. Nos. 4,518,588 and 4,274,985 to Szejtli et al., U.S. Pat. No. 4,722,815 to Shibanai, U.S. Pat. No. 4,598,070 to Ohwaki et al., and U.S. Pat. No. 4,424,209 to Tuttle, and the references cited therein.
Despite all of this research activity, the commercial use of cyclodextrins to deliver drugs has remained relatively low for a few reasons. First, while each type of cyclodextrin can form inclusion complexes by including other molecules in the annulus, for a variety of drugs in common usage the .beta.-cyclodextrin annulus is the most appropriate size. Although .beta.-cyclodextrin is the most readily available and least expensive cyclodextrin, it is also the lowest in solubility (1.85 g/100 ml) which substantially decreases its utility as a drug delivery system. This is especially true when the drug is itself substantially insoluble; the resulting inclusion complex generally having a solubility somewhere between the solubility of the drug and cyclodextrin. Thus, one of the main benefits of cyclodextrins, i.e., the ability to solubilize otherwise insoluble drugs, is lost when .beta.-cyclodextrin is used to include the drug.
Another main benefit of cyclodextrins, i.e., the ability to stabilize and increase the bioavailability of drugs, stems from the ability of cyclodextrins to strongly include a drug molecule. These benefits are particularly important where (1) the drug is rendered inactive by hydrolysis in the acidic environment of the stomach, which has a pH of generally less than about 3, (2) the drug irritates the gastrointestinal lining such as, for example, non-steroidal anti-inflammatory compounds, or (3) the drug has a short half-life such that it is immediately absorbed through the lining of the small intestine, and within a few hours, is no longer present in effective serum concentrations. It is the ability of cyclodextrins to form highly stable inclusion complexes which in fact prevents the drug from being freely available to undergo hydrolysis, irritate the stomach lining or absorb too quickly into the blood stream. This ability, however, depends upon whether the molecular dimensions of the drug molecule happen to fit one of the three cyclodextrins, so that a strong intermolecular attraction exists resulting in a high stability constant.
The stability constant (or association constant), K, of cyclodextrin inclusion complexes is a measure of the proportions of free drug and free cyclodextrins in solution versus the concentration of drug-cyclodextrin inclusion complex (or included drug). ##EQU1##
When the stability constant is high only a small proportion of the drug is in the free state in the gastrointestinal tract. Thus only a small proportion of the drug will be exposed to hydrolysis and will be available to cause gastrointestinal irritation, and in the case of a drug of low solubility, to precipitate. However, as the drug is absorbed in the small intestine, further drug will be rapidly released in a controlled manner, from the drug-cyclodextrin inclusion complex, so that a continuous absorption of the drug by the small intestine occurs.
Obviously, when the stability constant is low the proportion of the drug free in the gastrointestinal tract will be high. This exposes a large proportion of the drug to hydrolysis. A large proportion of the drug is also available to cause irritation of the gastrointestinal tract. If the free drug is of low solubility, precipitation of solid drug will occur in the gastrointestinal tract.
While there have been some fairly high stability constants reported (e.g., up to 3.7.times.10.sup.4 for some .gamma.-cyclodextrin-steroid systems; Uekama et al., Int. J. Pharmaceuticals, Vol. 10 (1982) pp 1-15), most known cyclodextrin-drug inclusion complexes have stability constants only on the order of from less than about 10.sup.3 M.sup.-1 up to about 10.sup.4 M.sup.-1 (especially for smaller drug molecules), and it is for this reason that cyclodextrins have not gained widespread popularity. Moreover, given the wide range of molecular sizes exhibited by drug molecules, only a fraction of the drugs needing a superior delivery system will be of correct size to form an inclusion complex of high stability with one of the three naturally occurring cyclodextrin molecules.
It is apparent that high stability constants are required to ensure a high proportion of included drug molecules and thus why cyclodextrins have yet to achieve widespread commercial use. A perspective of stability constants can be gained from the following model, which follows Habon, et al., J. Pharmazie, Vol 39, pp 830-834 (1984) and assumes a drug solubility of 10.sup.-4 M (relatively insoluble) and a 1:1 drug/CD complex solubility of 10.sup.-3 M, with a total of 10.sup.-4 mole of drug/CD complex present. If one assumes a stability constant of 10.sup.4 M.sup.-1 (relatively high) and a total volume of solution of 100 ml, (approximately an unfilled human stomach, e.g., before a meal), 40% of the drug would be present as undissolved (i.e., insoluble) solid drug, 10% as dissolved drug and only 50% as dissolved complex. For a stability constant of 10.sup.4 M.sup.-1 and a total volume of 1000 ml (approximately a filled human stomach), 62% of the drug would be present as dissolved pure drug and only 38% as a dissolved drug/CD complex. For a stability constant of 10.sup.2 M.sup.-1 and a total volume of 1000 ml, 99% of the drug would be present as dissolved pure drug and only 1% a drug/CD complex.
In attempts to overcome these problems, researchers have tried using either modified cyclodextrins, which have groups or pendant arms substituted onto the cyclodextrins, or polymeric cyclodextrins which generally comprise either randomly polymerized cyclodextrins, or cyclodextrins randomly attached to a preformed polymer backbone.
There have also been other attempts to prepare modified cyclodextrins, although the study of many such modified cyclodextrins has been confined mostly to observing interactions with dyes or other agents which are not pharmaceutical, pesticidal, herbicidal or agricultural. Moreover, the descriptions of the synthetic procedures in some instances appear insufficient to enable others of ordinary skill to reproduce the reported work.
In the case of modified cyclodextrins, those that are currently available are characterized by having some or all of their hydroxyl hydrogens replaced by methyl, ethyl, hydroxyethyl or hydroxypropyl. Such modifications lead in some cases to enhanced solubility of the cyclodextrin and its inclusion complexes formed with poorly soluble drug molecules, but do not address the problem of increasing the drug-cyclodextrin stability constants. Moreover, many of these modified cyclodextrins are the products of modifications which can be controlled only to a limited extent, and which yield a relatively inseparable mixture of mono-, di- and other randomly multisubstituted cyclodextrins. The cyclodextrin product is thus identifiable only in terms of a "degree of substitution." In the case of cyclodextrin polymers, it can also be likewise difficult to control the reaction and thus one cannot generally be certain of the product. Moreover there is also a problem with efficiency, i.e., large amounts of cyclodextrin are required to deliver only small amounts of included drug, resulting in the patient having to swallow many capsules or tablets to obtain a normal dose of a drug.
Another type of modification has been the covalent linking of two cyclodextrin molecules as reported by Fujita et al., J. Chem. Soc., Chem. Commun., (1984) 1277-1278, and Chemistry Lett., (1985) 11-12; Harada et al., Polymer J., Vol. 12 (1980) pp 29-33; and Tabushi et al., J. Am. Chem. Soc., Vol. 101 (1979) pp 1614 et seq. However, no further works has been performed to determine whether linked cyclodextrins are useful for including pharmaceuticals or other useful agents which can have intended bio-affecting activity, for example, pesticides, herbicides and agricultural products.
In a modification reported by Tabushi et al., J. Am. Chem. Soc., Vol. 108 (1986) 4514-4518, .beta.-cyclodextrin was doubly substituted with amine and carboxylic acid pendant arms. These functionalities allowed for an increased association with the amino acid, tryptophan, which was included in the cyclodextrin annulus. Again, there have been no attempts to form such associations with, for example, associable groups of pharmaceutical agents for delivering drugs into human or other host animals.
Kojima et al. reported covalently bonding the vitamin nicotinamide to a cyclodextrin. Tetrahedron Lett., Vol. 21 (1980) 2721. However, the resulting cyclodextrin derivative would not have been suitable for delivery of the vitamin to a host animal because the tertiary amine bond created between the nicotinamide and the cyclodextrin, if broken, would not yield the nicotinamide in active form. Moreover, that bond would not break in a host animal under the conditions normally found, for example, the acidic conditions of the stomach.
In summary, despite the large volume of research relating to modified and unmodified cyclodextrins, there remains a long felt need for cyclodextrin derivatives and inclusion complexes which have good solubility properties and which can deliver problem drugs in a pharmacologically acceptable manner. This long felt need has been accompanied by the need for processes and intermediates by which such derivatives and complexes can be readily prepared.
It is against this background that the present invention is brought forth. While much of the foregoing discussion has dealt with the use of cyclodextrins to deliver drugs, those skilled in the art, upon reading this disclosure, will recognize many other commercial applications for this invention such as, for example, delivery systems for pesticides, herbicides, agricultural products such as feeds and fertilizers, and food additives, to name only a few.

Compositions and methods for drug delivery and chromatography

Australia Commercial Research & Development Limited


Apparatuses and methods for vacuuming floors and other surfaces can include a vacuum cleaner head having a first chamber in communication with a first inlet positioned on a bottom surface of the vacuum cleaner head and a first outlet connected to a vacuum line, a second chamber in communication with a second inlet positioned on at least one side of the vacuum cleaner head and a second outlet connected to the vacuum line, and a divider separating the first chamber from the second chamber.

Vacuum cleaners commonly employ a downward-facing nozzle to apply suction to a carpet or other surface being cleaned. A long-standing difficulty with such an arrangement, however, is the inability to clean effectively in areas very close to a wall or other obstruction. For example, the edge of a carpeted area where it meets the wall often forms a crevice which tends to collect dirt and debris that conventional nozzle assemblies have difficulty removing.
Vacuum cleaner designers have attempted to deal with this problem by positioning the ends of the intake opening as close as possible to the lateral edges of the nozzle assembly. Even when the nozzle assembly is made as thin as possible, however, the end wall of the opening and the end support for the roller brush always create a gap that prevents the cleaning action from reaching into the crevice. In some instances, designs have small channels that extend laterally from the main airflow opening and under the roller brush end supports in an effort to generate some suction along the edges of the nozzle assembly, but these solutions often must be quite limited in size or else they will compromise the ability of the assembly to generate an upwards suction force with sufficient airflow when moving over the floor in areas away from the wall. Alternatively, many vacuum cleaners are provided with a separate "crack tool" or "crevice tool", which can be a flat, narrow nozzle that is mounted on the end of a suction hose. Although these tools usually work adequately, they add an additional step to the edge-cleaning process.
Accordingly, there exists a need for a vacuum cleaner assembly that provides an effective cleaning action along at least one lateral edge thereof so as to effectively remove dirt and debris along the junctures between the floor and walls or other obstructions. Furthermore, there exists a need for such an assembly to provide effective edge-cleaning without compromising the ability of the assembly to provide a vertical suction against floor surfaces when cleaning in areas away from the wall. In addition, there exists a need for such an assembly that is structurally simple, economical to manufacture, and durable in use.

Dual suction vacuum apparatuses and methods for use


The invention relates to monoreactive mesogenic compounds of formula I

The invention relates to monoreactive mesogenic compounds, to polymerizable liquid crystal compositions comprising the monoreactive mesogenic compounds, to linear or crosslinked liquid crystal polymers obtainable from the monoreactive mesogenic compounds and the polymerizable compositions comprising them, and to the use of the monoreactive mesogenic compounds and the polymerizable compositions and polymers obtainable thereof in optical elements, liquid crystal displays, adhesives, synthetic resins with anisotropic mechanical properties, cosmetics, diagnostics, liquid crystal pigments, decorative and security applications, nonlinear optics and optical information storage:
Polymerizable mesogenic compounds, which are also known as reactive mesogenic compounds, have been described in prior art for various purposes. For example, they can be aligned in their liquid crystal phase and subsequently polymerized in situ, to give linear or crosslinked liquid crystal polymer films with uniform orientation of high quality. These films can be used for example as optical elements, like polarization filters as described in EP 0 397 263, broadband circular polarizers as described in EP 0 606 940 and WO 97/35219, or compensation or retardation films as described in WO 98/00475, WO 98/04651 and WO 98/12584.
The polymerizable mesogenic compounds described in prior art, however, do often exhibit liquid crystalline phases only in a small temperature range or do not show mesophase behavior at all.
Therefore, often mixtures of two or more polymerizable compounds are used for the preparation of oriented liquid crystal polymer films.
When preparing oriented liquid crystal polymer films for the uses as described above, it is especially desired to have available polymerizable compositions exhibiting a nematic liquid crystal phase at room temperature, so that it is possible to carry out aligment and polymerization of the composition at low temparatures. For this purpose, it is advantageous if the single polymerizable components exhibit broad liquid crystalline phases, too.
Thus, there is a demand for polymerizable mesogenic compounds with a broad liquid crystalline phase, which can be used for the preparation of oriented liquid crystal polymer films for optical applications.
Furthermore, regarding the broad range of applications for polymerizable mesogenic compounds it is desirable for the expert to have available further compounds of this type which are easy to synthesize and fulfill the various requirements as described above.
It was an aim of the invention to provide polymerizable mesogenic compounds with advantageous properties, thus extending the pool of reactive mesogenic compounds available to the expert. Other aims of the present invention are immediately evident to the person skilled in the art from the following detailed description.
It was now found that these aims can be achieved by providing monoreactive mesogenic compounds according to the present invention.
The terms reactive or polymerizable mesogenic compound as used in the foregoing and the following comprise compounds with a rod-shaped, board-shaped or disk-shaped mesogenic group, i.e. a group with the ability to induce mesophase behavior. These compounds do not necessarily have to exhibit mesophase behavior by themselves. It is also possible that these compounds show mesophase: behavior only in mixtures with other compounds or when the polymerizable mesogenic compounds or the mixtures comprising them are polymerized.
The compounds according to the present invention are characterized by a mesogenic core which comprises three phenylene rings linked via ester groups, and which is laterally monosubstituted and terminally substituted by polar groups.
Monoreactive mesogenic compounds having a mesogenic core that is substituted with polar groups are disclosed in DE 38 37 936 and EP 0 648 827.
DE 38 37 936 shows monoreactive methacrylates with a mesogenic core that consists of a hydroquinone dibenzoate being laterally substituted with alkyl or alkoxy groups having two or more C atoms and carries a terminal cyano or alkoxy group. However, monoreactive compounds according to the present invention are not disclosed in DE 38 37 936. Furthermore, the compounds shown in DE 38 37 936 do exhibit only narrow or even monotropic nematic phases.
EP 0 648 827 discloses mono- and direactive mesogenic compounds having a mesogenic core with three phenylene rings linked directly or via ester groups, and optionally being laterally substituted with polar groups. However, the monoreactive ester compounds of the present invention are not disclosed in EP 0 648 827, whereas e.g. the compounds of EP 0 648 827 with directly linked phenylene groups (terphenyls) show a tendency to smectic phase behavior .
A particularly preferred aspect of the invention relates to the use of the inventive monoreactive mesogenic compounds in polymerizable compositions for the preparation of a liquid crystalline polymer retardation or compensation film with a planar or tilted structure.
In this connection, the term xe2x80x98tilted structurexe2x80x99 means that the optical axis of the retardation film forms a tilt angle between 0 and 90xc2x0 with the plane of the film. The term xe2x80x98planar structurexe2x80x99 means that the optical axis of the retardation film is oriented substantially parallel to the plane of the film. For sake of simplicity, an optical retardation film (ORF) with a tilted structure or a planar structure is hereinafter shortly referred to as xe2x80x98tilted ORFxe2x80x99, and xe2x80x98planar ORFxe2x80x99, respectively.
A tilted ORF is described for example in WO 98/12584, a planar ORF is described for example in WO 98/04651, the entire disclosure of these documents being incorporated into this application by way of reference.
Planar and tilted ORFs as described above are usually prepared from a polymerizable liquid crystal composition by coating a thin layer of the composition onto a substrate, aligning the liquid crystal molecules in the layer in the desired orientation, and fixing the orientation by polymerization.
Thus, in case of a planar ORF, it is required to achieve highly uniform alignment of the polymerizable compounds, with the mesogenic groups oriented substantially parallel to the substrate, i.e. with a low tilt angle or preferably without any tilt, whereas in case of a tilted ORF, the polymerizable compounds have to be aligned such that the mesogenic groups form the desired tilt angle with the plane of the substrate.
The inventors have found that, when using a monoreactive prior art mesogenic compound with a polar terminal group in a polymerizable composition, such as e.g. the compound
the methacrylate homologue of which is described in EP 0 445 629, the resulting composition has a relatively narrow nematic phase with a low nematic isotropic phase transition temperature (clearing temperature), and shows a relatively low tilt angle.
On the other hand, when adding a monoreactive prior art compound with an non-polar terminal alkyl group to the polymerizable composition, such as e.g. the compound
which is known from WO 97/34862 and exhibits a broad nematic phase, the clearing temperature of the composition is increased, however at the same time the tilt angle is increased.
Therefore, due to the above described arbitrating effects it is difficult, by using known compounds, to increase the clearing temperature of a polymerizable composition without altering the tilt angle.
The inventors now found that, when using one or more monoreactive mesogenic compounds according to the present invention in a polymerizable liquid crystal composition as described above, it is possible at the same time to increase the clearing point of the composition whereas the tilt angle remains substantially the same.
Thus, the inventive monoreactive mesogenic compounds can be used in a polymerizable liquid crystal composition that shows planar orientation with low tilt when coated onto a substrate, in order to improve the nematic phase behavior of the composition. On the other hand, the inventive compounds can also be used in a polymerizable liquid crystal composition that shows a tilted orientation when coated onto a substrate, in order to increase the clearing point without negatively affecting the tilt angle. The advantageous effects of the inventive compounds will be further demonstrated in the examples below.
One object of the present invention are monoreactive mesogenic compounds of formula I
wherein
P is CH2=CWxe2x80x94COOxe2x80x94, WCHxe2x95x90CHxe2x80x94Oxe2x80x94,
or CH2xe2x95x90CHxe2x80x94 Phenyl-(O)kxe2x80x94 with W being H, CH3 or Cl and k being 0 or 1,
Sp is a spacer group having 1to 20 C atoms,
X is xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94COOxe2x80x94, xe2x80x94OCOxe2x80x94, xe2x80x94COxe2x80x94NHxe2x80x94, xe2x80x94NHxe2x80x94COxe2x80x94, xe2x80x94CH2CH2xe2x80x94, xe2x80x94OCH2xe2x80x94, xe2x80x94CH2Oxe2x80x94, xe2x80x94SCH2xe2x80x94, xe2x80x94CH2Sxe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94COOxe2x80x94,xe2x80x94OCOxe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94Cxe2x89xa1Cxe2x80x94, or a single bond,
n is 0 or 1,
Y1 and Y2 are each independently F, Cl, CN, OH, NO2, OCH3, COR1, COOR1 or a fluorinated alkyl or alkoxy group having 1 to 4 C atoms,
R1 is an alkyl group with 1to 3C atoms, which is optionally fluorinated,
r1, r2and r3are 0or 1, with r1+r2+r3=1,
Z1, Z2 are each independently xe2x80x94COOxe2x80x94 or xe2x80x94OCOxe2x80x94.
Another object of the invention is a polymerizable liquid crystal composition comprising at least two polymerizable compounds, at least one of which is a compound of formula I.
Another object of the invention is a linear or crosslinked polymer obtainable by polymerization of one or more compounds of formula I or of a polymerizable composition comprising one or more compounds of formula I.
Yet another object of the invention is the use of a compound of formula I, or a polymerizable composition or polymer obtainable thereof, in optical elements such as polarizers, optical retardation or compensation films, alignment layers, color filters or holographic elements, in liquid crystal displays such as PDLC, polymer gel or polymer stabilized cholesteric texture (PSCT) displays, in adhesives, synthetic resins with anisotropic mechanical properties, cosmetics, diagnostics or liquid crystal pigments, for decorative and security applications, and for nonlinear optics or optical information storage.
Formula I covers the following subformulae
wherein P, Sp, X, n, Y1, Y2, Z1 and Z2 have the meaning of formula I.
Particularly preferred are compounds of subformulae Ia, Ic, Ie and If.
Further preferred are monoreactive compounds of formula I, wherein
n is 1 and Sp is alkylene with 1 to 15 C atoms.
P is an acryl, methacryl or epoxy group.
Y1 and Y2 are selected from F, Cl, OH, OCH3, COCH3, COC2H5, COOCH3, COOC2H5, CF3, OCF3, OCHF2 and OC2F5.
P in formula I and its subformulae is preferably an acrylate group, a methacrylate group, a vinyl or vinyloxy group, an epoxy group, a styrene group or a propenyl ether group, in particular an acrylate, methacrylate, vinyloxy or epoxy group, very preferably an acrylate or epoxy group.
Particularly preferred are compounds of formula I wherein n is I.
As for the spacer group Sp in formula I and its subformulae, all groups can be used that are known for this purpose to the skilled in the art. The spacer group Sp is preferably a linear or branched alkylene group having 1 to 20 C atoms, in particular 1 to 12 C atoms, in which, in addition, one or more non-adjacent CH2 groups may be replaced by xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94NHxe2x80x94, xe2x80x94N(CH3)xe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94Sxe2x80x94COxe2x80x94, xe2x80x94Oxe2x80x94COOxe2x80x94, xe2x80x94COxe2x80x94Sxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94CH(halogen)xe2x80x94 or xe2x80x94CH(CN)xe2x80x94.
Typical spacer groups are for example xe2x80x94(CH2)oxe2x80x94, xe2x80x94(CH2CH2O)pxe2x80x94CH2CH2xe2x80x94, xe2x80x94CH2CH2xe2x80x94Sxe2x80x94CH2CH2xe2x80x94 or xe2x80x94CH2CH2xe2x80x94NHxe2x80x94CH2CH2xe2x80x94, with o being an integer from 2 to 12 and p being an integer from 1 to 3.
Preferred spacer groups are ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, octadecylene, ethyleneoxyethylene, methyleneoxybutylene, ethylene-thioethylene, ethylene-N-methyl-iminoethylene, 1-methylalkylene, ethenylene, propenylene and butenylene for example.
Especially preferred are inventive compounds of formula I and its subformulae wherein Sp is denoting an alkyl or alkoxy group with 2 to 8 C atoms. Straight-chain alkyl or alkoxy groups are especially preferred.
In another preferred embodiment of the invention the chiral compounds of formula I comprise at least one spacer group Sp that is a chiral group of the formula II:
wherein
Q1 is an alkylene or alkylene-oxy group with 1 to 8 C atoms or a single bond,
Q3 is halogen, a cyano group or an alkyl or alkoxy group with 1 to 4 C atoms different from Q1, and
Q4 is an alkylene or alkyleneoxy group with 1 to 7 C atoms or a single bond, and is different from Q1.
In case Q4 in formula II is an alkylene-oxy group, the O atom is preferably adjacent to the chiral C atom.
X in formula I and its subformulae is preferably xe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94COOxe2x80x94, xe2x80x94OCOxe2x80x94 or a single bond, in particular xe2x80x94Oxe2x80x94 or a single bond.
Y1 and Y2 in formula I and its subformulae preferably denote, independently of each other, F, Cl, CN, NO2, OH, CH3, C2H5, OCH3, OC2H5, COCH3, COC2H5, COOCH3, COOC2H5, CF3, OCF3, OCHF2 or OC2F5, in particular F, Cl, OCH3 or OCF3, most preferably Cl or OCH3.
The inventive compounds of formula I can be synthesized according to or in analogy to methods which are known per se and which are described in standard works of organic chemistry such as, for example, Houben-Weyl, Methoden der organischen Chemie, Thieme-Verlag, Stuttgart. Some specific methods of preparation can be taken from the examples.
The invention also relates to a polymerizable liquid crystal composition comprising at least two polymerizable components, at least one which is a compound of formula I, and to linear or crosslinked polymers prepared from the inventive compounds and compositions.
Suitable polymerizable mesogenic compounds that can be used as co-components of the polymerizable liquid crystal composition, together with the inventive compounds of formula I, are disclosed for example in WO 93/22397; EP 0,261,712; DE 195,04,224; WO 95/22586 and WO 97/00600. The compounds disclosed in these documents, however, are to be regarded merely as examples that shall not limit the scope of this invention.
Typical examples representing such polymerizable mesogenic compounds are shown in the following list of compounds, which should, however, be taken only as illustrative and is in no way intended to restrict, but instead to explain the present invention:
In the above formulae, P has one of the meanings of formula I and its preferred meanings as mentioned above, x and y are each independently 1 to 12, A is 1,4-phenylene or 1,4-cyclohexylene, v is 0 or 1, Z0 is xe2x80x94COOxe2x80x94, xe2x80x94OCOxe2x80x94, xe2x80x94CH2CH2xe2x80x94 or a single bond, Y is a polar group, R0 is a non-polar alkyl or alkoxy group, Ter is a terpenoid radical like e.g. menthyl, Chol is a cholesteryl group, and L1 and L2 are each independently H, F, Cl, CN or an optionally halogenated alkyl, alkoxy or carbonyl group with 1 to 7 C atoms.
In a preferred embodiment of the invention the polymerizable liquid crystalline composition comprises at least one monoreactive compound of formula I and at least one di- or multireactive polymerizable compound, i.e. a mesogenic compound having two or more polymerizable groups. Especially preferred are direactive compounds, i.e. compounds comprising two polymerizable groups. Very preferred are direactive compounds of formulae V1, V2 and V3 above.
It is also possible for the inventive polymerizable liquid crystalline composition to comprise one or more non-polymerizable chiral compounds, which may be mesogenic or non-mesogenic, in addition or alternatively to chiral polymerizable compounds. For example, commercially available dopants, like e.g. R 811 or R 1011 (from Merck KGaA, Germany) can be used for this purpose.
Polymerizable liquid crystalline compositions are preferred that comprise 1 to 6, preferably 1 to 3 compounds of formula I.
In a preferred embodiment of the present invention the polymerizable liquid crystalline composition comprises 1 to 80% by weight, preferably 2 to 60%, in particular 5 to 50% by weight of one or more compounds of formula I.
In the polymerizable compositions comprising direactive mesogenic compounds, the total concentration of these compounds is preferably 1 to 50%, in particular 1 to 25%, very preferably 2 to 10% by weight of the total mixture. Especially preferably the polymerizable composition contains not more than 6% by weight of direactive mesogenic compounds.
Particularly preferred are polymerizable compositions comprising
a1) 5 to 70%, very preferably 10 to 50% by weight of up to five, preferably one, two or three monoreactive mesogenic compounds of formula I,
a2) 5 to 60%, very preferably 10 to 40% by weight of up to five, preferably one, two or three monoreactive mesogenic compounds having a non-polar terminal alkyl or alkoxy group,
a3) 5 to 40%, very preferably 5 to 30% by weight of one, two or three monoreactive polymerizable mesogenic compounds having a polar terminal group,
b) 0 to 25%, very preferably 1 to 10% by weight of a direactive polymerizable mesogenic compound,
c) 0.5 to 10%, very preferably 1 to 7% by weight of a polymerization initiator,
d) 0 to 5%, very preferably 0.1 to 2% by weight of a surfactant.
The compounds of component a2) are preferably selected from the above formulae V6 to V15, in particular from formulae V6 to V10.
The compounds of component a3) are preferably selected from the above formulae V4 and V5.
The compounds of component b) are preferably selected from the above formula V1 and V2.
The term polar group as used in the foregoing and the following means a group selected from halogen, CN, NO2, OH, OCH3, OCN, SCN, an optionally fluorinated carbonyl or carboxyl group with up to 4 C atoms or a mono- oligo- or polyfluorinated alkyl or alkoxy group with 1 to 4 C atoms. Especially preferred polar groups are those as defined for Y1 in formula I, including its preferred meanings.
The term non-polar group means an alkyl group with 1 or more, preferably 1 to 12 C atoms or an alkoxy group with 2 or more, preferably 2 to 12 C atoms.
In addition to the components mentioned above, the polymerizable composition may also comprise one or more other suitable components such as e.g. catalysts, stabilizers, chain-transfer agents, co-reacting monomers or surface-active compounds. In particular the addition of stabilizers is preferred in order to prevent undesired spontaneous polymerization of the polymerizable material e.g. during storage.
In a preferred embodiment of the present invention, one or more surfactants are added to the polymerizable composition in order to improve planar alignment, i.e. an orientation wherein the mesogens are aligned substantially parallel to the plane of the layer, with a low tilt angle or even with zero tilt.
Suitable surfactants are described for example in J. Cognard, Mol.Cryst.Liq.Cryst. 78, Supplement 1, 1-77 (1981). Particularly preferred are non-ionic surfactants, such as mixtures of non-ionic fluoroalkylalkoxylate surfactants selected from formula III and IV
CnF2n+1SO2N(C2H5)(CH2CH2O)xCH3xe2x80x83xe2x80x83III
CnF2n+1(CH2CH2O)xHxe2x80x83xe2x80x83IV
wherein n is an integer from 4 to 12 and x is an integer from 5 to 15. Upon using these surfactants it is possible to produce polymerized films with a very low tilt angle.
The surfactants of formula III are commercially available under the trade name Fluorad 171 (from 3M Co.), the surfactants of formula IV under the trade name Zonyl FSN (from DuPont).
Polymerizable mesogenic compositions of this preferred embodiment contain preferably from 500 to 2500 ppm, in particular from 1000 to 2500 ppm, very preferably from 1500 to 2500 ppm of surfactants. Further preferred compositions contain 0.01 to 5%, in particular 0.1 to 3%, very preferably 0.2 to 2% by weight of surfactants.
It is also possible, in order to increase crosslinking of the polymers, to add up to 20% of a non-mesogenic compound with two or more polymerizable functional groups to the polymerizable composition alternatively or additionally to di- or multireactive mesogenic compounds.
Typical examples for difunctional non-mesogenic monomers are alkyldiacrylates or alkyldimethacrylates with alkyl groups of 1 to 20 C atoms. Typical examples for non mesogenic monomers with more than two polymerizable groups are trimethylpropanetrimethacrylate or pentaerythritoltetraacrylate.
Liquid crystalline polymers can be obtained from the inventive polymerizable compounds and compositions e.g. by solution polymerization or by in-situ polymerization.
For example, solution polymerization can be carried out in a solvent like dichloromethane, tetrahydrofuran or toluene using AIBN as an initiator and heating for 24 hours at 30 to 60xc2x0 C.
The in-situ polymerization of polymerizable liquid crystalline compounds and compositions is described in detail by D. J.Broer et al., Makromol.Chem. 190, 2255ff. and 3202ff. (1989).
The polymerizable liquid crystal compounds and compositions according to this invention are preferably polymerized in situ as described in the foregoing and the following.
The inventive compounds and polymerizable liquid crystalline compositions are particularly useful for the preparation of anisotropic polymer films, such as nematic or cholesteric polymer films, with uniform molecular orientation.
Thus, another object of the invention is an anisotropic polymer film with an oriented liquid crystalline phase that is obtainable by polymerizing a polymerizable liquid crystalline composition comprising at least one monoreactive polar mesogenic compound of formula I.
To prepare an anisotropic polymer film with uniform orientation, an inventive polymerizable mesogenic composition is preferably coated onto a substrate, aligned and polymerized in situ by exposing them to heat or actinic radiation. Alignment and curing are preferably carried out in the liquid crystalline phase of the composition.
Actinic radiation means irradiation with light, like UV light, IR light or visible light, irradiation with X-rays or gamma rays or irradiation with high energy particles, such as ions or electrons. As a source for actinic radiation for example a single UV lamp or a set of UV lamps can be used. Another possible source for actinic radiation is a laser, like e.g. a UV laser, an IR laser or a visible laser.
When polymerizing by means of UV light, for example a photoinitiator can be used that decomposes under UV irradiation to produce free radicals or ions that start the polymerization reaction.
It is also possible to use a cationic photoinitiator, when curing reactive mesogens with for example vinyl and epoxide reactive groups, that photocures with cations instead of free radicals.
As a photoinitiator for radical polymerization for example the commercially available Irgacure 651, Irgacure 184, Darocure 1173 or Darocure 4205 (all from Ciba Geigy AG) can be used, whereas in case of cationic photopolymerization the commercially available UVI 6974 (Union Carbide) can be used.
Preferably the polymerizable liquid crystalline composition comprises 0.01 to 10%, in particular 0.05 to 8%, very preferably 0.1 to 6% by weight of a photoinitiator, especially preferably a UV-photoinitiator.
In a preferred embodiment of the invention the polymerization of the polymerizable composition is carried out under an atmosphere of inert gas, preferably under a nitrogen atmosphere.
As a substrate for example a glass or quartz sheet as well as a plastic film or sheet can be used. It is also possible to put a second substrate on top of the coated mixture prior to, during and/or after polymerization. The substrates can be removed after polymerization or not. When using two substrates in case of curing by actinic radiation, at least one substrate has to be transmissive for the actinic radiation used for the polymerization.
Isotropic or birefringent substrates can be used. In case the substrate is not removed from the polymerized film after polymerization, preferably isotropic substrates are used.
Preferably at least one substrate is a plastic substrate such as for example a film of polyester such as polyethyleneterephthalate (PET), of polyvinylalcohol (PVA), polycarbonate (PC) or triacetylcellulose (TAC), especially preferably a PET film or a TAC film. As a birefringent substrate for example an uniaxially stretched plastic film can be used. For example PET films are commercially available from ICI Corp. under the trade name Melinex.
In a preferred embodiment of the present invention, the inventive polymerizable composition is coated as a thin layer on a substrate or between substrates and is aligned in its liquid crystal phase to give a uniform orientation.
A uniform orientation can be achieved for example by shearing the mixture, e.g. by means of a doctor blade. It is also possible to apply an alignment layer, for example a layer of rubbed polyimide or sputtered SiOx, on top of at least one of the substrates. In some cases, the mixtures orient themselves spontaneously on the substrate, or good alignment is achieved already by the act of coating the mixture.
In another preferred embodiment, a second substrate is put on top of the coated material. In this case, the shearing caused by putting together the two substrates is sufficient to give good alignment.
It is also possible to apply an electric or magnetic field to align the coated mixture.
In some cases it is of advantage to apply a second substrate not only to aid alignment of the polymerizable mixture but also to exclude oxygen that may inhibit the polymerization. Alternatively the curing can be carried out under an atmosphere of inert gas. However, curing in air is also possible using suitable photoinitiators and high lamp power. When using a cationic photoinitiator oxygen exclusion most often is not needed, but water should be excluded.
For the preparation of anisotropic polymer gels, e.g. for use in switchable liquid crystal display devices, the polymerizable compounds or compositions can be polymerized in situ as described above, however, in this case alignment of the polymerizable mixture is not necessarily required, although it may be desired for specific applications.
The invention also relates to the use of inventive compounds, compositions and polymers such as polarizers, optical retardation or compensation films, alignment layers, colour filters or holographic elements, in liquid crystal displays such as PDLC, polymer gel or polymer stabilized cholesteric texture (PSCT) displays, in adhesives, synthetic resins with anisotropic mechanical properties, cosmetics, diagnostics or liquid crystal pigments, for decorative and security applications, and for nonlinear optics or optical information storage. Inventive compounds comprising a chiral spacer group can also be used as chiral dopants.
The inventive compounds of formula I are particularly suitable for the preparation of oriented liquid crystal polymer films that can be used as polarization or compensation films in liquid crystal displays, in particular for the preparation of tilted and planar optical retardation and compensation films.
Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The following preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever.
The entire disclosure[s] of all applications, patents and publications, cited above [or below], and of corresponding European application No. 99112807.5, filed Jul. 2, 1999, is hereby incorporated by reference.
In the foregoing and in the following examples, unless otherwise indicated, all temperatures are set forth uncorrected in degrees Celsius and all parts and percentages are by weight.
The following abbreviations are used to illustrate the liquid crystalline phase behavior of the compounds: K=crystalline; N=nematic; S=smectic; Ch=cholesteric; I=isotropic. The numbers between the symbols indicate the phase transition temperatures in xc2x0 C.

Abstract: wherein P, Sp, X, n, Y1, Y2, r1, r2, r3, Z1 and Z2 are defined herein.

Merck Patent Gesellschaft mit beschraenkter Haftung


A wafer prober system includes a host computer, and a prober device. The prober device includes a plurality of prober circuits, and a plurality of touch screens, each connected to the prober circuit for simultaneously displaying image data and display data from said prober circuit, each of the prober circuit including an image processing section for sequentially photographing wafers checked by probes and outputting image data, a display control section for outputting display data according to the checking, and a prober control section for controlling the outputs of the image processing section and display control section. The control section outputs the image data and display data from the prober circuit, so that the image data and display data are displayed on the touch screen at the same time. Image data and display data are selectively provided by one of prober circuits, from image data and display data displayed on each of touch screens, and are simultaneously displayed on the host computer.

1. Field of the Invention
The present invention relates to a wafer prober system comprising a plurality of prober devices each having probers or pins which are to be in contact with test points or conductive pads of a semiconductor circuit, such as a large-scale integrated circuit, formed on a semiconductor wafer.
2. Description of the Related Art
Generally, a system for testing a circuit, such as a large-scale integrated circuit (hereinafter, referred to as "LSI") formed on a semiconductor wafer, has a plurality of test stations which are independently connected to an operation and measuring unit. To each of the test stations, a prober device having an electronics portion with probes, is provided. LSI's are tested by operating a plurality of prober devices independently and simultaneously, while each of the test operations is being monitored on the screen provided to each of the prober devices. For monitoring, an operator or operators must work for each prober device to check whether each prober device is normally working or not. Thus, the conventional system mentioned is significantly disadvantageous in view of labor cost.


Methods and system for a centralized unit and a distributed unit of a base station to operatively cooperate with each other are disclosed. In one embodiment, a method performed by a first communication node includes: sending a first message to a second wireless communication node upon determining to switch a third wireless communication node to a radio resource control inactive mode. The first and second wireless communication nodes cooperate to serve as a first base station in a wireless network.

Due to mass connection and higher rate requirements from users in the 5G New Radio (NR) communication network (5G network), there is a big challenge to the transmission capacity of the fronthaul interface CPRI (Common Public Radio Interface) between a BBU (Baseband Unit) and a RRU (Radio Remote Unit) in the LTE (Long-Term Evolution) communication network. Because the CPRI interface transmits an I/Q (real/imaginary) signal that has been processed by physical layer coding, the CPRI interface has a tighter requirement on the transmission delay and bandwidth. If the 5G F1 interface rate is increased to tens of giga-bits per second (Gbps), the traffic demand on the CPRI interface will rise to tera-bits per second (Tbps) levels, which will increase both the cost and difficulty of network deployment. Therefore, in the 5G network, there is a need to redefine divisions of the fronthaul interface, in consideration of transmission capacity, transmission delay, ease of deployment, and other aspects. For example, taking into account a non-ideal fronthaul transmission, when dividing a base station (BS), one can put delay-insensitive network functions in a first network element, such as a Centralized Unit (CU), and put delay-sensitive network functions in a second network element, such as a Distributed Unit (DU). There is an ideal and/or non-ideal fronthaul transmission between the first and second network element.
Moreover, since the 5G network can support a diverse range of applications such as, for example, Massive Machine-Type Communications (M-MTC), Ultra-Reliable and Low Latency Communications (URLLC), Enhanced Mobile Broadband (eMBB), etc., it is expected that an increasing number of user equipment devices (UE's) to be used in some of the above applications will be powered by batteries. Thus, power consumption of UE's in the 5G network has become one of the anticipated parameters to optimize or decrease. To this end, and additionally, to reduce signaling overheads between a random access network (RAN) and a core network (CN) in the 5G network, a new radio resource control (RRC) state, "RRC INACTIVE state," has been proposed. It is understood that a UE may be requested by a corresponding RAN (e.g., a BS) to switch to the RRC INACTIVE state after the UE has been inactive for a certain period of time. Different from the known RRC IDLE state, when the UE is in the RRC INACTIVE state, the UE can still move around and process paging messages.
To date, however, no research has been conducted regarding how the BS, when divided as CU and DU, switches the UE to the RRC INACTIVE state. In addition, when the UE, under the RRC INACTIVE state, moves into a new area (e.g., a random access network (RAN) notification area), no research has been conducted regarding how the CU and DU handle a process to update such a new RAN notification area. Thus, there is a need for a method and system for the CU and DU to cooperate with each other to handle such scenarios so as to meet the anticipated demands of the 5G network.

Method and systems for exchanging messages in a wireless network