A Message Storage and Deliver System (MSDS) is connected to the public switched telephone network (PSTN) and receives incoming calls with these calls being facsimile, voice, or data transmissions. The MSDS detects the type of call and stores the message signal in a database. The MSDS is also connected to the Internet and has a hyper-text transfer protocol deamon (HTTPD) for receiving requests from users. The HTTPD forwards requests for certain files or messages to a network server which transmits at least part of the message to the HTTPD and then to the user. In addition to requests for certain documents, the HTTPD may also receive a request in the form of a search query. The search query is forwarded from the HTTPD to an application program for conducting the search of the database. The results of the search are forwarded through the HTTPD to the user. The user may then select one or more files or messages from the search results and may save the search for later reference.

This invention relates to system(s) and method(s) for storing and delivering messages and, more particularly, to system(s) and method(s) for storing messages and for delivery the messages through a network, such as the Internet, or a telephone line to an intended recipient. In another aspect, the invention relates to system(s) and method(s) for storing, delivering, and managing messages or other files, such as for archival purposes or for document tracking.
Even though the facsimile machine is heavily relied upon by businesses of all sizes and is quickly becoming a standard piece of office equipment, many businesses or households cannot receive the benefits of the facsimile machine. Unfortunately, for a small business or for a private household, a facsimile machine is a rather expensive piece of equipment. In addition to the cost of purchasing the facsimile machine, the facsimile machine also requires toner, paper, maintenance, as well as possible repairs. These expenses may be large enough to prevent many of the small businesses and certainly many households from benefiting from the service that the facsimile machine can provide. For others who are constantly traveling and who do not have an office, it may be impractical to own a facsimile machine. In fact, the Atlanta Business Chronicle estimates that 30% of the small businesses do not have any facsimile machines. Therefore, many businesses and households are at a disadvantage since they do not have access to a facsimile machine.
Because a facsimile machine can be such an asset to a company and is heavily relied upon to quickly transmit and receive documents, a problem exists in that the machines are not always available to receive a facsimile message. At times, a facsimile machine may be busy receiving another message or the machine may be transmitting a message of its own. During these times, a person must periodically attempt to send the message until communication is established with the desired facsimile machine. This inability to connect with a facsimile machine can be frustrating, can consume quite a bit of the person""s time, and prevent the person from performing more productive tasks. While some more advanced facsimile machines will retry to establish communication a number of times, a person will still have to check on the facsimile machine to ensure that the message was transmitted or to re-initiate the transmission of the message.
In addition to labor costs and a reduction in office efficiency, a facsimile machine may present costs to businesses that are not readily calculated. These costs include the loss of business or the loss of goodwill that occurs when the facsimile machine is not accessible by another facsimile machine. These costs can occur for various reasons, such as when the facsimile machine is out of paper, when the machine needs repairing, or when the facsimile machine is busy with another message. These costs occur more frequently with some of the smaller businesses, who are also less able to incur these expenses, since many of them have a single phone line for a telephone handset and the facsimile machine and thereby stand to lose both telephone calls and facsimile messages when the single line is busy. In fact, the Atlanta Business Chronicle estimated that fewer than 5% of the small businesses have 2 or more facsimile machines. Many of the larger companies can reduce these losses by having more than one facsimile machine and by having calls switched to another machine when one of the machines is busy. These losses, however, cannot be completely eliminated since the machines can still experience a demand which exceeds their capabilities.
A main benefit of the facsimile machine, namely the quick transfer of documents, does not necessarily mean that the documents will quickly be routed to the intended recipient. The facsimile machines may be unattended and a received facsimile message may not be noticed until a relatively long period of time has elapsed. Further, even for those machines which are under constant supervision, the routing procedures established in an office may delay the delivery of the documents. It is therefore a problem in many offices to quickly route the facsimile message to the intended recipient.
The nature of the facsimile message also renders it difficult for the intended recipient to receive a sensitive message without having the message exposed to others in the office who can intercept and read the message. If the intended recipient is unaware that the message is being sent, other people may see the message while it is being delivered or while the message remains next to the machine. When the intended recipient is given notice that a sensitive message is being transmitted, the intended recipient must wait near the facsimile machine until the message is received. It was therefore difficult to maintain the contents of a facsimile message confidential.
In an office with a large number of employees, it may also be difficult to simply determine where the facsimile message should be routed. In light of this difficulty, some systems have been developed to automatically route facsimile messages to their intended recipient. One type of system, such as the one disclosed in U.S. Pat. No. 5,257,112 to Okada, can route an incoming call to a particular facsimile machine based upon codes entered with telephone push-buttons by the sender of the message. Another type of system, such as the one disclosed in U.S. Pat. No. 5,115,326 to Burgess et al. or in U.S. Pat. No. 5,247,591 to Baran, requires the sender to use a specially formatted cover page which is read by the system. This type of system, however, burdens the sender, who may very well be a client or customer, by requiring the sender to take special steps or additional steps to transmit a facsimile message. These systems are therefore not very effective or desirable.
Another type of routing system links a facsimile machine to a Local Area Network (LAN) in an office. For instance, in the systems disclosed in the patents to Baran and Burgess et al., after the system reads the cover sheet to determine the intended recipient of the facsimile message, the systems send an E-mail message to the recipient through the local network connecting the facsimile machine to the recipient""s computer. Other office systems, such as those in U.S. Pat. No. 5,091,790 to Silverberg and U.S. Pat. No. 5,291,546 to Giler et al., are linked to the office""s voice mail system and may leave a message with the intended recipient that a facsimile message has been received. Some systems which are even more advanced, such as those in U.S. Pat. No. 5,317,628 to Misholi et al. and U.S. Pat. No. 5,333,266 to Boaz et al., are connected to an office""s local network and provide integrated control of voice messages, E-mail messages, and facsimile messages.
The various systems for routing facsimile messages, and possibly messages of other types received in the office, are very sophisticated and expensive systems. While these office systems are desirable in that they can effectively route the messages at the office to their intended recipients, the systems are extremely expensive and only those companies with a great number of employees can offset the costs of the system with the benefits that the system will provide to their company. Thus, for most businesses, it still remains a problem to effectively and quickly route messages to the intended recipients. It also remains a problem for most businesses to route the messages in a manner which can preserve the confidential nature of the messages.
Even for the businesses that have a message routing system and especially for those that do not have any type of system, it is usually difficult for a person to retrieve facsimile messages while away from the office. Typically, a person away on business must call into the office and be informed by someone in the office as to the facsimile messages that have been received. Consequently, the person must call into the office during normal business hours while someone is in the office and is therefore limited in the time that the information in a facsimile message can be relayed.
If the person away on business wants to look at the facsimile message, someone at the office must resend the message to a facsimile machine accessible to that person. Since this accessible machine is often a facsimile machine at another business or at a hotel where the person is lodging, it is difficult for the person to receive the facsimile message without risking disclosure of its contents. Further, since someone at the person""s office must remember to send the message and since someone at the accessible facsimile machine must route the message to the person away from the office, the person may not receive all of the facsimile messages or may have to wait to receive the messages.
The retrieval of facsimile messages, as well as voice mail messages, while away from the office is not without certain costs. For one, the person often must incur long distance telephone charges when the person calls the office to check on the messages and to have someone in the office send the messages to another facsimile. The person will then incur the expenses of transmitting the message to a fax bureau or hotel desk as well as the receiving location""s own charges for use of their equipment. While these charges are certainly not substantial, the charges are nonetheless expenses incurred while the person is away from the office.
Overall, while the facsimile machine is an indispensable piece of equipment for many businesses, the facsimile machine presents a number of problems or costs. Many businesses or households are disadvantaged since they are unable to reap the benefits of the facsimile machine. For the businesses that do have facsimile machines, the businesses must incur the normal costs of operating the facsimile machine in addition to the costs that may be incurred when the facsimile machine or machines are unable to receive a message. Further, the facsimile messages may not be efficiently or reliably routed to the intended recipient and may have its contents revealed during the routing process. The costs and problems in routing a facsimile message are compounded when the intended recipient is away from the office.
Many of the problems associated with facsimile messages are not unique to just facsimile messages but are also associated with voice mail messages and data messages. With regard to voice messages, many businesses do not have voice mail systems and must write the message down. Thus, the person away from the office must call in during normal office hours to discover who has called. The information in these messages are usually limited to just the person who called, their number, and perhaps some indication as to the nature of the call. For those businesses that have voice mail, the person away from the office must call in and frequently incur long distance charges. Thus, there is a need for a system for storing and delivery voice messages which can be easily and inexpensively accessed at any time.
With regard to data messages, the transmission of the message often requires some coordination between the sender and the recipient. For instance, the recipient""s computer must be turned on to receive the message, which usually occurs only when someone is present during normal office hours. Consequently, the recipient""s computer is usually only able to receive a data message during normal office hours. Many households and also businesses may not have a dedicated data line and must switch the line between the phone, computer, and facsimile. In such a situation, the sender must call and inform the recipient to switch the line over to the computer and might have to wait until the sender can receive the message. The retransmission of the data message to another location, such as when someone is away from the office, only further complicates the delivery. It is therefore frequently difficult to transmit and receive data messages and is also difficult to later relay the messages to another location.
A standard business practice of many companies is to maintain records of all correspondence between itself and other entities. Traditionally, the correspondence that has been tracked and recorded includes letters or other such printed materials that is mailed to or from a company to the other entity. Although tracking correspondence of printed materials is relatively easy, non-traditional correspondence, such as facsimile messages, e-mail messages, voice messages, or data messages, are more difficult to track and record.
For example, facsimile messages may be difficult to track and record since the messages may be received on thermal paper, which suffers from a disadvantage that the printing fades over time. Also, accurate tracking of facsimile messages is difficult since the facsimile messages may only be partially printed at the facsimile machine or the messages may be lost or only partially delivered to their intended recipients. Facsimile messages also present difficulties since they are often delivered within an organization through different channels than ordinary mail and thus easily fall outside the normal record keeping procedures of the company.
Voice mail messages are also difficult to track and record. Although voice messages can be saved, many voice mail servers automatically delete the messages after a certain period of time. To maintain a permanent record of a voice message, the voice message may be transcribed and a printed copy of the message may be kept in the records. This transcribed copy of the voice message, however, is less credible and thus less desirable than the original voice message since the transcribed copy may have altered material or may omit certain portions of the message.
In addition to facsimile and voice mail messages, data messages are also difficult to track and record. A download or upload of a file may only be evident by the existence of a file itself. A file transfer procedure normally does not lend itself to any permanent record of what file was transferred, the dialed telephone number, the telephone number of the computer receiving the file, the time, or the date of the transfer. It is therefore difficult to maintain accurate records of all data transfers between itself and another entity.
It is an object of the invention to reliably and efficiently route messages to an intended recipient.
It is another object of the invention to route messages to the intended recipient while maintaining the contents of the message confidential.
It is another object of the invention to enable the intended recipient to access the messages easily and with minimal costs.
It is a further object of the invention to permit the simultaneous receipt of more than one message on behalf of the intended recipient.
It is a further object of the invention to enable the intended recipient of a message to access the message at any time and at virtually any location world-wide.
It is yet a further object of the invention to enable the intended recipient of a message to browse through the received messages.
It is yet a further object of the invention to quickly notify an intended recipient that a message has been received.
It is still another object of the invention to receive messages of various types.
It is still another object of the invention to deliver messages according to the preferences of the intended recipient.
It is still a further object of the invention to record and track correspondence, such as facsimile messages, voice mail messages, and data transfers.
Additional objects, advantages and novel features of the invention will be set forth in the description which follows, and will become apparent to those skilled in the art upon reading this description or practicing the invention. The objects and advantages of the invention may be realized and attained by the appended claims.
To achieve the foregoing and other objects, in accordance with the present invention, as embodied and broadly described herein, a system and method for storing and delivering messages involves receiving an incoming call and detecting an address signal associated with the incoming call, the address signal being associated with a user of the message storage and delivery system. A message accompanied with the address signal is then received and converted from a first file format to a second file format. The message is stored in the second file format within a storage area and is retrieved after a request has been received from the user. At least a portion of the message is then transmitted to the user over a network with the second file format being a mixed media page layout language.
In another aspect, a network message storage and delivery system comprises a central processor for receiving an incoming call, for detecting an address signal on the incoming call, for detecting a message on the incoming call, and for placing the message in a storage area. The address signal on the incoming call is associated with a user of the network message storage and delivery system. A network server receives the message from the storage area, converts the message into a mixed media page layout language, and places the message in the storage area. When the network server receives a request from the user over the network, the network server transmits at least a portion of the message over the network to the user.
Preferably, the network storage and delivery system can receive facsimile messages, data messages, or voice messages and the network is the Internet. The messages are converted into a standard generalized mark-up language and the user is notified that a message has arrived through E-mail or through a paging system. A listing of the facsimile messages may be sent to the user in one of several formats. These formats include a textual only listing or a listing along with a full or reduced size image of the first page of each message. A full or reduced size image of each page of a message in the listing may alternatively be presented to the user.
According to a further aspect, the invention relates to a system and method for managing files or messages and involves storing message signals in storage and receiving requests from a user for a search. The search preferably comprises a search query that is completed by a user and supplied to a hyper-text transfer protocol deamon (HTTPD) in the system. The HTTPD transfers the request through a common gateway interface (CGI) to an application program which conducts the search. The results of the search are preferably returned through the HTTPD to the computer in the form of a listing of all messages or files satisfying the search parameters. The user may then select one or more of the listed messages or files and may save the search for later references.

Systems and methods for storing, delivering, and managing messages


In one embodiment, one or more computing systems executes a computer program defining (1) a bound value that references a bound variable and (2) a terminating bound value that references computation instructions for deriving a runtime value from at least the bound value of the bound variable. A computation orchestration layer of a programming framework initializes, according to the computer program, a subscription tracker that tracks subscription relationships between the bound variable and the terminating bound value. The computation orchestration layer uses, in response to receiving an indication of an update to the bound value of the bound variable, the subscription tracker to determine that the terminating bound value subscribes to updates to the bound value of the bound variable. The computation orchestration layer sends an update stream associated with the update to a callback function associated with the terminating bound value.

In computer programming, a software framework is an abstraction in which software providing generic functionality can be selectively changed by additional user-written code, thus providing application-specific software. It provides a standard way to build and deploy applications and is a universal, reusable software environment that provides particular functionality as part of a larger software platform to facilitate the development of software applications, products and solutions. Software frameworks may include support programs, compilers, code libraries, toolsets, and application programming interfaces (APIs) that bring together all the different components to enable development of a project or system.

System and method of utilizing data binding to propagate data changes


Disclosed are compositions for shortstopping free radical emulsion polymerizations and stabilizing polymers produced from the corresponding emulsion processes. Such compositions include at least one hydrophillic radical scavenger (i.e, shortstopper) and at least one hydrophobic radical scavenger. The compositions are preferably targeted for applications in the emulsion processes of rubber latexes. These compositions exhibit excellent performance not only as shortstoppers of free radical emulsion polymerizations but also as stabilizers of the corresponding polymers. Thus, the compositions prevent additional polymerization in the particles without requiring additional stabilizer even after such polymers are steam stripped. They do so without the use of chemicals which carry a high safety, health, or environmental risk.

This invention relates to compositions for shortstopping of free radical polymerizations and stabilization of polymers produced therein; the compositions include at least one hydrophilic component and at least one hydrophobic component.
In emulsion polymerization processes such as those used to synthesize rubber latices, chain growth is often terminated at a designated conversion to prevent the formation of polymer gel and ensure the quality of the resulting polymer. The termination is accomplished by employing a free radical scavenger, commonly referred to as a shortstopper. The action of a shortstopper is to provide hydrogen atoms which combine with the reactive center to terminate growing polymer chains. It is desirable for a shortstopper to destroy any radical initiator remaining in the latex as well.
It is advantageous for a single shortstopping composition to offer both efficient reaction quenching and effective latex stabilization. This avoids the need for complicated equipment and procedures to introduce first the shortstopper and then the latex stabilizer. However, the chemistry of shortstoppers and that of SBR latices precludes any single molecule from performing both functions.
The efficiency of all shortstoppers, and alkylhydroxylamine shortstoppers especially, depends primarily on the ease of active hydrogen atom removal and the degree of access (lack of hindrance) to the active hydrogen atom by the chain radical. Both of these decrease with increasing substitution and increasing alkyl chain length. Thus diethylhydroxylamine (DEHA) is a less active shortstopper than monoethylhydroxylamine, and less active than dimethylhydroxylamine (DMHA). However, minimizing the number of carbons in the molecule also has the effect of raising its volatility and water solubility. These are the properties least desirable for a latex stabilizer, which must persist in the hydrophobic particles when monomers are stripped from the latex. It is often required that the shortstopper have sufficient volatility to inhibit formation of xe2x80x9cpopcornxe2x80x9d polymer caused by volatile monomer radicals collecting on the walls of stripping columns, and this is defeated by segregation in the particle.
Nitroxides and phenolic compounds have also been studied as shortstoppers for Styrene-Butadiene Rubber (SBR) emulsion polymerizations and as stabilizers for SBR latexes. These compounds can provide good stability for synthetic rubber latexes during storage but do not perform well as shortstoppers for most free radical emulsion processes. Further, most nitroxides and phenolic compounds are costly or toxic, or both, and lack the ability to inhibit overhead popcorn formation.
In order to provide full functionality, shortstoppers have been formulated as binary mixtures of xe2x80x9cstopperxe2x80x9d and stabilizer. One such mixture, DEHA and sodium dimethyldithiocarbamate (SDDC), was found to be effective in cost and performance. However, as chemical products and processes have come to be more carefully scrutinized, weaknesses in this formulation were exposed. Upon stripping, SDDC emits CS2, a toxic and highly regulated chemical, requiring a scrubber to be installed. In addition, dimethylamine, a potential nitrosamine forming molecule, is emitted. Recently, a formulation containing N-isopropylhydroxylamine (NiPHA) and polysulfides was described. The odor of polysulfides is one drawback to this invention. Another is the lack of overhead popcorn prevention.
The objective of this invention is to offer a shortstopping composition that not only effectively shortstops free radical emulsion polymerization reactions and destroys initiators, but also provides improved stability for the resulting rubber latices without incurring any negative safety, health, or environmental impacts.
The literature discloses many variations on the concept of shortstopping compositions for free radical emulsion polymerizations containing hydroxylamines. In U.S. Pat. No. 3,222,334, Demme discloses the use of N,N-dialkylhydroxylamines as shortstopping agents for use in emulsion processes of synthetic rubber latexes involving dienes and monoolefins. Haines et al. in U.S. Pat. No. 3,296,177, disclose bis-oxalate salts of N-monoalkyl and N,N-dialkylhydroxylamines as effective shortstoppers for both hot and cold emulsion polymerization processes for synthetic rubber latices. Albert et al. discloses a process for shortstopping emulsion polymerizations using dithiocarbamate salt/alkylhydroxylamine mixtures in both hot and cold emulsion styrene-butadiene rubber (SBR) processes in U.S. Pat. No. 3,341,487 and the use of N,N-dialkyl-N,Nxe2x80x2-methylenebishydroxylamines as shortstoppers for both hot and cold synthetic rubber emulsion processes in U.S. Pat. No. 3,402,138. Albert et al. disclose the use of diethylaniline-N-oxide as a shortstopper for emulsion process synthetic rubber in U.S. Pat. No. 3,567,700.
Haines et al. describe mixtures of N-alkyl-N-arylhydroxylamines as shortstoppers for hot and cold SBR emulsion polymerizations and as popcorn inhibitors in U.S. Pat. No. 3,697,470.
Mixtures of DEHA with a phenolic antioxidant are claimed as shortstoppers for emulsion polymerization processes involving chloroprene by Tsuyoshi et al. in JP 06,298,813.
In U.S. Pat. No. 5,384,372, Lattime discloses the use of N-isopropylhydroxylamine (NiPHA) or its salts as shortstoppers for SER emulsion polymerizations wherein the formation of nitrosamines is suppressed. Maestri et al., U.S. Pat. No. 5,504,168, describe the use of mixtures of isopropylhydroxylamine (or salts thereof) and sodium polysulfide as shortstoppers for free radical emulsion polymerizations; the shortstopping composition is alleged not to yield nitrosamines in the resulting rubber latices.
Compositions have been developed for shortstopping free radical emulsion polymerizations and stabilizing polymers produced from the corresponding emulsion processes.
Such compositions include at least one hydrophillic radical scavenger (i.e, shortstopper) and at least one hydrophobic radical scavenger.
The compositions are preferably targeted for applications in the emulsion processes of rubber latexes.
These compositions exhibit excellent performance not only as shortstoppers of free radical emulsion polymerizations but also as stabilizers of the corresponding polymers. Thus, the compositions prevent R1 and R2 may each be the same or different, straight, cyclic or branched, and can be hydrogen, C1-20-alkyl, hydroxy-C1-20 alkyl, C1-10 alkoxy-C1-10 alkyl, or sulfonated C1-20-alkyl groups, with the proviso they may not both be H, or a H and a methyl, and the total carbon number of R1 and R2 together is between 2-20.
The salt forms of the hydroxylamines can also be used. These may be based on carboxylic acids such as formate, acetate, propionate, butyrate, isobutyrate, and valerate. An example would be diethylhydroxylamine formate.
Hydroxylamine salts produced from inorganic acids such as mono- or dialkylhydroxylamines hydrochloride, sulfate, phosphate, perchlorate, carbonate, hydrosulfate and hydrophosphate. N-isopropylhydroxylamine hydrochloride will also be effective shortstop.
Whether the hydroxylamine compound is hydrophilic or hydrophobic depends on the total carbon number: R1+R2. As a rule of thumb, the alkylhydroxylamine is likely hydrophilic if the total carbon number is 0-6, and likely hydrophobic if the total carbon number greater than 6.
Typical examples of the hydrophillic shortstopper useful in the present invention include diethylhydroxylamine (DEHA), N-isopropylhydroxylamine (NiPHA), and dimethylhydroxylamine (DMHA).
The most preferred hydrophilic alkylhydroxylamine is DEHA.
The hydrophobic free radical scavengers of invention can be based on phenol, nitroxide, and hydroxylamine compounds.
Phenolic compounds useful in the present invention have the general formula:
where R3 and R5 may be the same or different, and each group could be hydrogen, alkyl, hydroxyl, or alkaryl groups; R4 could be C1-C20 alkyl, alkaryl, alkylamino, amine, and alkanoic acid ester groups.
The most preferred phenol is 4-methyl-2,6-di-tert-butyl phenol (BHT).
Nitroxide compounds useful in the present invention have the general formula:
where R6 could be hydrogen, hydroxyl, alkyl, hydroxyalkyl, alkoxyalkyl, and sulfonated alkyl groups. Such nitroxide compounds are usually hydrophobic, and they are based on 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO).
Typical examples of the hydrophobic shortstopper include DBHA, dibenzylhydroxylamine (DBzHA), and 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) and its analogs. The most preferred are DBHA and DBzHA.
In a variant of the present invention, each shortstopping component can be introduced into the polymerization system separately, and one or more solvents could be used to deliver each component. Such components could also be added to the rubber latexes after being steam stripped to provide additional latex stability.
A blend of DEHA (hydrophilic) and DBHA (hydrophobic), for example, exhibits excellent overall performance both as a shortstopper for the emulsion process of SBR and as stabilizer for SBR latexes during storage. The obtained latexes, even after being steam-stripped, do not require additional stabilizer to maintain high latex stability. An additional advantage for such a composite shortstopper is that it does not generate any odorous or toxic gases that are subject to environmental regulations.
The disclosed composite shortstoppers can be altered in that their composition could be changed, and various amine, nitroxide, phenolic free radical scavengers could be used.
The disclosed shortstopping technology is applicable to a variety of emulsion processes of preparing synthetic rubber latexes. Such polymerization processes typically involve conjugated dienes, particularly, 1,3-butadiene, isoprene, chloroprene and the like, and optionally monoolefin compounds such as styrene, acrylonitrile, acrylic acid, vinyl chloride and the like.
These alternatives are presented based on theory, analogy, and limited experiments.
While the following examples illustrate the use of various materials in embodiments of the invention, it should be clear that there is no intention of so limiting the scope of the invention. On the contrary, it is intended that the breadth of the invention illustrated by reference to the following examples will apply to other embodiments which would be obvious to those skilled in the art.

Compositions for shortstopping free radical emulsion polymerizations and stabilizing latices made therefrom


The present invention is a method for alleviating at least one climacteric symptom in a climacteric subject using an anticholinergic agent. To illustrate the instant invention, homatropine was shown to relieve hot flushes in peri-menopausal and post-menopausal women.

Hot flushes, also known as hot flashes, and night sweats are common and salient symptoms experienced by menopausal woman that typically occur during the transition time from peri-menopause to menopause. They can continue to occur to up to 5 years post-menopause (75% of women experience hot flushes, and of those, 25% experience them for more than 5 years; Belchetz (1994) New Engl. J. Med. 330:1062-71). The "hot flush" is a result of sudden or acute drop in estrogen levels. This sudden drop can be due to natural events (menopause), or as a result of surgical (oophorectomy) or medical (hormone therapy, chemotherapy) removal of ovarian function. It is estimated that 80% of women undergoing natural or iatrogenic menopause experience hot flushes. Over time, the frequency and intensity of hot flushes do diminish, but they are still present in up to 50% of women for up to 5 years.
A hot flush is subjectively described as a sensation of intense warmth lasting as little as 30 seconds or as long as 5 minutes. It can be accompanied by tachycardia or palpitations, headache, faintness, or vertigo, and typically ends in profuse sweating and a cold sensation. At night, the frequency and severity of hot flushes increase, affecting a woman's sleep and ultimately her overall quality of life.
Estrogen therapy has been the mainstay of treatment for menopausal symptoms over the years, but concerns about the risks of hormone replacement therapy have made the search for alternative therapies critical for many women.
Mild symptoms may be improved by avoidance of triggering substances or situations. Caffeine, alcohol, spicy foods, and hot beverages may trigger hot flushes. Exercise, lowering stress levels, and smoking cessation are thought to help relieve the symptoms. Dressing in layers, wearing breathable clothing such as cotton and natural linen, and using fans, may also aid in comfort.
Studies investigating the benefits of dietary soy and vitamin E have mixed results as to the benefits on hot flashes (Krebs, et al. (2004) Ob. Gyn. 104:824-836). There is up to a 40% placebo effect in most studies on hot flashes, and randomized, blinded studies involving phytoestrogens derived from soy or red leaf clover do not show additional benefit (Fitzpatrick (2003) Med. Clin. N. Am. 87:1091-1113; Tice, et al. (2003) JAMA 290:207). There is a concern that phytoestrogens are not risk-free as they stimulate cellular activity in breast cysts and can contribute to postmenopausal bleeding.
Black cohash is an herbal supplement which has been shown to have benefit for hot flashes without altering FSH levels or endometrial thickness (Fitzpatrick (2003) supra; Tice, et al. (2003) supra). Side effects such as nausea, headaches, dizziness and liver toxicity have been reported (Fitzpatrick (2003) supra; Tice, et al. (2003) supra). A black cohash/St John's Wort combination has been shown to reduce the Menopause rating scale by 50% and the Hamilton Depression Scale by 41% (Uebelhack, et al. (2006) Ob. Gyn. 107:247-55).
There are no prescription medications that are as effective as estrogen for the treatment of hot flushes, but many have a positive impact in some women. Unfortunately, all have side effects that balance their clinical use. Venlafaxine, paroxetine, and fluoxetine have all shown an approximate 60% reduction in hot flushes but with side effects common to the SSRI's. Veralipride reduces hot flushes but caused weight gain and galactorrhea.
Clonidine has a 50% reduction in symptoms, but causes dry mouth, sedation and hypotension. Gabapentin has a 45% reduction in frequency, and 54% decrease in severity but can cause somnolence, fatigue, tremors, nausea, edema and ataxia. High dose progestins or megace may help, but can cause PMS symptoms, depression and fluid retention. Bellergal was used in the past, but has addictive potential (Fitzpatrick (2004) Ob. Gyn. 104:106s-117s).
The Women's Health Initiative (WHI) was the largest placebo controlled study of hormone replacement therapy to date, and showed an increase in thromboembolism, stroke, and breast cancer in the estrogen-progestin group, leaving many women with the uncomfortable feeling that they were compromising their long-term health by using hormone therapy.
In certain severe cases, medication is prescribed by a physician. Progestins such as megestrol acetate (Megace) have been prescribed. The hormone estrogen is the most effective treatment for hot flushes. It can help not only in this aspect, but also in lubricating the vagina and urinary tract, improving sexual function, and decreasing and preventing the incidence of urinary tract infections.
However, drawbacks of standard estrogen replacement therapy include the potential for increased risk of breast cancer, cardiovascular disease, general discomfort, and ineffectiveness. Recent studies have linked hormone replacement therapy to an increase risk of breast cancer. Furthermore, not all women can or want to take HRT, depending on their medical history and family history. Documenting the effectiveness of alternative treatments, and the development of new, non-hormonal treatments with low incidence of side effects and lower costs are desirable (Belchetz (1994) supra; Krebs, et al. (2004) supra; Fitzpatrick (2003) supra; Tice, et al. (2003) supra; Uebelhack, et al. (2006) supra; Fitzpatrick (2004) supra) At present, other than SSRI's which are marginally effective, there are no pharmaceutical or over the counter products that offer effective palliation of hot flushes.
U.S. Pat. Nos. 6,395,757 and 5,962,505 disclose the use of glycopyrrolate and glycopyrrolate analogs for alleviating menopausal hot flashes.
Accordingly, there is a need in the art for effective treatment regimes for relieving symptoms of the climacteric. The present invention meets this long-felt need.

Method for alleviating climacteric symptoms


A polymer composition comprises at least one substantially non-conductive polymer and at least one electrically conductive filler and in the form of granules, the granules preferably being in the size range up to 1 mm and more preferably between 0.04 mm and 0.2 mm, with the volume ratio of conductor to polymer preferably being at least 3:1.

This invention relates to a polymer composition including a finely divided electrical conductor, particularly comprising such a composition in an advantageous physical form.
The use of such a composition has been proposed for devices for controlling or switching electric current, to avoid or limit disadvantages such as the generation of transients and sparks which are associated with the actuation of conventional mechanical switches. In particular, co-pending application PCT/GB98/00206 dated Jan. 23, 1998 and subsequently published under serial number WO98/33193, discloses such a composition and switches based on it. That application discloses for the first time a granular composition containing polymer and conductive filler. The present application relates to a polymer composition in that form and to further developments thereof.
DE-A-4315382, to which corresponds U.S. Pat. No. 5,589,222, discloses hydrophobic flowable granules comprising hydrophilic inorganic powder and 0.03 to 15% w/w of hydrophobic polyorganosiloxan and a process of producing them by mixing the powder in a granulator with an aqueous emulsion of the polyorganosiloxan and drying the resulting product at elevated temperature. Among the powders listed are metals and alloys. The granules are, however, for use in enamelling; there is no disclosure that they might form part of an electrical circuit or, further, that they could be electrically insulating when quiescent but conducting when subject to mechanical stress or electrostatic field.
According to the present invention there is provided an electrical conductor composite providing conduction when subjected to mechanical stress or electrostatic charge but electrically insulating when quiescent comprising a granular composition each granule of which comprises at least one substantially non-conductive polymer and at least one electrically conductive filler and is electrically insulating when quiescent but conductive when subjected to mechanical stress or electrostatic charge.
The granules are typically in the size range up to 1 mm, especially 0.04 to 0.2 mm. Thus the smaller granules behave as powders. These ranges are based on measuring the greater diameter of the granules if not regularly spherical. To suit user""s requirements, the granules may be for example in an approximate Poisson size distribution, or sieved to a skewed distribution or a narrow spread (for example, largest granules no greater than 2xc3x97smallest) or classified so that small granules fill the spaces between larger granules.
Within the granules the conductor:polymer volumetric ratio (tapped bulk:voidless solid) is suitably at least 3:1. For the ratio of conductive medium to polymer small changes will be required to account for differences in relative surface tensions of types and grades of polymer and the various surface energies of the different conductive oxides and other solids present. Changes of this ratio have an effect on the piezo-charge properties, the overall resistance range, the recovery hysteresis and the pressure sensitivity of the granules.
In general the conductive material can be one or more metals, other conductive or semiconductive elements and oxides or intrinsically conductive or semiconductive organic or inorganic polymers. Thus it is suitably selected from powdered forms of the metallic elements or their electrically conductive alloys or reduced oxides either on their own or together. More specifically it is one or more of titanium, tantalum, zirconium, vanadium, niobium, hafnium, aluminium, silicon, tin, chromium, molybdenum, tungsten, lead, manganese, beryllium, iron, cobalt, nickel, platinum, palladium, osmium, iridium, rhenium, technetium, rhodium, ruthenium, gold, silver, cadmium, copper, zinc, germanium, arsenic, antimony, bismuth, boron, scandium and metals of the lanthanide and actinide series and, if appropriate, at least one electroconductive agent. The conducting filler can be the basic element in the unoxidised state; or can be a layer on a carrier core of powder, grains, fibres or other shaped forms. The oxides can be mixtures comprising sintered powders of an oxycompound. The alloy may be for example titanium diboride.
The micro-structure of the conductor particles is of substantial importance. Thus dendritic, filamentous, and spiked forms of the conductive materials have been shown to be capable of producing particularly sensitive granules when coated with a polymer such as silicone. Generally the conductor particles are rough-surfaced with smaller and spikier powders producing more sensitive granules. Preferably the particles comprise metal having at least one of these characteristics:
(i) spiky and/or dendritic surface texture;
(ii) filamentary structure, with a three-dimensional chain-like network of spiky beads, the chains being on average 2.5-3.5 microns in cross-section and possibly more than 15-20 microns in length.
Generally these characteristics are present in the conductor particles before mixing with polymer, and mixing is controlled to substantially preserve them.
As described further below, preferred conductor particles comprise carbonyl-derived metallic nickel. Other examples include dendritic copper.
The polymer constituent of the granules can be chosen from a wide range of materials, the only limitation being that the polymer or a precursor thereof should be available in a form sufficiently mobile to permit incorporation of conductor particles. In an extreme case it can be a fully or partly cured resin, such as a formaldehyde condensate, epoxy resin, maleimide resin or 3-dimensional olefin resin. Polymers having flexibility, such as linear thermoplasts, are of more general application. Very suitably the polymer constituent is an elastomer. Since elastomers are preferred in certain composites including the granules, they will be described further below.
The invention provides a method of making the granules by mixing conductor particles with liquid-form polymer in granule-forming conditions. The liquid-form polymer may be, for example, a precursor subject to polymerization or to cross-linking during the granule-forming step or later. Liquid-form means sufficiently flowable to undergo mixing with the conductor particles. The polymer may be very viscous. A liquid may be present to modify the viscosity of the polymer as an aid to mixing. It may be added, for example, by pre-mixing with the polymer or with the conductor powder. The liquid should of course be chemically inert with respect to the conductor and polymer. Preferably it is volatile, that is, has an atmospheric pressure boiling point under 120xc2x0 C., to assist removal during and after mixing. Hydrocarbons, such as petroleum distillates, are very suitable. Before or during mixing there may be added a hydrophobising agent. This is believed to act by displacing adsorbed water from the surfaces of the components of the mix, for example the conductor particles, solid additives such as those described below, especially fumed silica, and possibly of newly exposed polymer and newly formed granules. The agent may also act as a lubricant limiting friction-at mixer surfaces. Since it can act by formation of very thin, even unimolecular layers, the quantity to be used is very small, for example 10-1000 ppm w/w of the mix. Examples of the agent are liquid hydrocarbons carrying groups favouring chemisorption on metals, and fluorocarbons.
The granules are made by coating conductive particles with a layer of polymer in a controlled mixing regime that imparts only sufficient force to the components of the mix to achieve the coating process and avoids additional force which has been found to have a degrading effect on the electrical properties of the final polymer composition. The relationship between filler, binder, mixing energy, time, rate of shear, temperature and pressure determine the particle size-distribution and electromechanical properties of the resulting granule. It appears likely that the conductor particles act as nuclei for granule formation. Such mixing is preferably at a low level of shear, so that the conductor particles remain structurally intact. Suitably a dish-granulator, blunger, coaxial cylinder mixer (rotary ablation) can be used. In the granule-forming step it appears that the total shear can be of the same order as in the production of bulk composition but applied at greater intensity for a shorter time. Granule formation is preferably accompanied by some cross-linking of the polymer. The polymer formulation is chosen and the conditions of mixing are controlled so that breakage of the mixture into granules is synchronized with cross-linkage of the polymer sufficient for a non-sticky state. This is especially convenient using RTV silicone. The process may if desired be controlled to produce a precursor of the granules in which the polymer may be subjected to further cross-linking to develop elastomerism. Use of HTV silicone affords more scope in making such precursors. The silicone very suitably is one subject to high shrinkage for example by 10-20% on cross-linking. This makes possible a relatively high conductor to polymer volume ratio in granules without an inconveniently high ratio at the start of mixing.
If the silicone content of the mix is increased, sensitivity is decreased and agglomeration increases. If high silicone content is required, silicone may be applied to previously made granules of lower silicone content. In rotary ablation the clearance setting of the pestle against the mortar, and the pressure applied to the pestle, are mechanically adjusted to achieve the required conditions. This pressure affects the time taken to achieve the granulated state and is important to the coating thickness, the eventual size of the granule and the amount of agglomeration between individual granules. Too much pressure produces destructive shear forces.
The resulting granules can be comminuted to provide a desired range. They can be screened to separate the different sized agglomerations if required. Different sized granules show different sensitivities; granule sizes can be separated and remixed in different proportions to alter the final sensitivity of the granule composite. It has also been found possible to combine different conductive materials, conductive, semi-conductive or non-conductive powders, prior to the granule-forming agglomeration/coating process to obtain the required conduction or other electrical and mechanical properties in the final granule form.
The invention provides also a composite comprising the granules. Generally the granules can be used by containing them in a device which limits peripheral movement but allows the input of an electrical or mechanical pressure in order to activate it. They may be mixed with or coated onto other bulk or foamed polymers to form solid, semi-flexible or flexible composite structures. For one type of structure, the granules can be extruded or pressed into sheet, pellet or fibre form or can be cast into moulds. In the course of the shaping process they can be milled or cryogenically powdered. Energy imparted during mixing and moulding the polymer composition in the uncured state may, however, affect the physical and electrical performance of the composite.
For a second type of composite, the granules may be associated with a containing means. This may be a fibre or sheet, for example of polymer fibre film, plate or cloth and may carry granules on one or both faces. The polymer sheet may already contain or carry conductor particles as described for example in Example 7 of the co-pending application. The sheet may comprise or carry an adhesive for the granules.
In another method of forming such a composite, precursor granules (as specified above) can be pressed into the surface or surfaces of the un-cross-linked carrier polymer and permanently bonded to the carrier polymer when it is cross-linked. This produces a pressure sensitive or EM screening layer on the carrier polymer.
For a third type of composite the granules are associated with a three-dimensional matrix. The matrix may be electrically non-conducting, but could be composed, for example, of polymer having conductor particles dispersed in it, such as described in the co-pending application or in prior-published documents. Several variants of this type are possible, for example:
(i) added granules individually conducting or non-conducting or mixed;
(ii) matrix material differing in degree of cross-linking from granule polymer;
(iii) matrix material may enter spaces between granules or may be just a containment bag.
In a particular example of the third type, in which the polymer composition may be in bulk form as described in the co-pending application or, preferably, introduced in granule form as follows:
in a composite structure for generation, detection and relay of electrical signals internal connectivity is provided in the form of an integrated electrically conductive member for example a layer such as metal film or sheet especially continuous metallised cloth, typically polyester based. The cloth increases the tactile sensitivity (increase in resistance drop versus mass loading) of the conductive polymer composition by providing a hard fibre anvil for elastomeric distortion and provides an electron bridge between zones of low resistance within the composite. The polymer composition can be bonded to or formed on the conductive member.
Whereas the composite may be a simple device for switching on when deformed, more complicated electrical circuits may be built into the layer, for example, of the metallised cloth structure. The metal coated fabric is typically manufactured by application of metal by vapour deposition, sputtering or similar means to a woven polyester cloth.
Electrical circuits, analogous to those etched onto a conventional printed circuit board, may be created by masking and etching the pre-metallised cloth or preferably by masking the target cloth at the point of metallisation.
In the latter example the metal coating will only be deposited where the mask allows and by this process a conductive circuit layout can be produced.
Composites incorporating the circuit cloth show true flexibility, are solid state and may be made extremely sensitive to touch or other operating forces. They may be used for digital and analogue switching and control, may incorporate PTC load control or heat production capability and have the capacity to carry substantial electric currents.
Whichever type of composite is in view, a particularly useful one comprises the granules and includes means for the input of electrical and/or mechanical deformation to activate it. Thus the sheet or matrix would comprise ohmic conductor(s) connecting the granule assembly electrically.
The granules can also be used as a component of other conductive and electromagnetic shielding materials either alone or in combination with other powders or granules or other non-conductive, semiconductive or conductive materials.
Granule-coated surfaces can be particularly sensitive to applied pressure, increasing in pressure sensitivity with increasing surface loading. Granules on their own and granule-coated surfaces can show a drop in electrical resistance of more than 1012 ohms with an applied force within the range 0.01-6 N/cm2.
Whichever type of composite is being made, it is preferred to have hydrophobising agent, as above described, present when an assembly of the granules is being set up.
Composites containing the granules as a film or heterogeneous mixture with other polymers and materials tend to show greater repeatability, sensitivity and linearity of resistance change than can be obtained with bulk pressure sensitive polymer compositions as in the co-pending application. Like the bulk composition, the granules return to a quiescent resistance state when the operating force is removed.
For the granules and/or the matrix (especially if conducting), very suitably the polymer constituent is an elastomer, especially having the general properties:
i) low surface energy typically in the range 15-50 dyne/cm but especially 22-30 dyne/cm;
ii) a surface energy of wetting for hardened elastomer higher than its uncured liquid;
iii) a low energy of rotation (close to zero) giving extreme flexibility;
iv) excellent pressure sensitive tack both to the filler particles and electrical contacts to which the composite may be attachedxe2x80x94that is, possess a high ratio of viscous to elastic properties at time spans comparable to bonding times (fraction of a second);
v) high on the triboelectric series as a positive charge carrier (conversely, will not carry negative charge on its surface);
vi) chemically inert, fire extinguishing and effective as a barrier to oxygen and air ingress.
Silicone elastomer rubbers are typically but not exclusively based on polydimethylsiloxane, polysilamine and allied silicone backbone polymers, with leaving groups, cross-linkers and cure systems based on:
meet all the above mentioned property criteria. The elastomer can be mixtures comprising cured elastomers selected from the group comprising one, two or more component silicones, one, two or more component polygermanes and polyphosphazines and at least one silicone agent. In such polymer mixtures, the silicone component exceeds other polymer components.
Other additives are included with the silicone for the purpose of modifying the physical and/or electrical properties of the uncured or cured polymer composition. Such additives can include at least one property modifier from the group comprising: alkyl and hydroxyalkycellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, polyacrylamide, polyethylene glycol, poly (ethylene oxide), polyvinyl alcohol, polyvinylpyrrolidone, starch and its modifications, calcium carbonate, fumed silica, silica gel and silicone analogues and at least one silica analogue or silicone analogue modifier. Fumed silica is an example of a modifier as commonly used in elastomer technology. For this invention, in proportions of between 0.01-20% by weight of the final polymer composition, it acts as a recovery-enhancing filler, that is, it increases the resilience of the polymer composition to accelerate the return of the composition to its quiescent state after any applied force is released. A preferred example of a silicone system is manufactured from high strength room temperature cured fumed silica loaded (RTV) silicone polymer. Another example uses high temperature cured HTV silicone filled with fumed silica to provide interstitial structure, useful strength, pressure tack and life, cross-linked at an elevated temperature in the presence of a peroxide or other catalyst, that may typically but not exclusively be 2,4 dichloro dibenzoyl peroxide. Such HTV products may be stored for prolonged periods in the uncured state prior to processing into sheet, rod, foam, fibre, press moulded or other forms.
Another usable class of elastomer is the natural or synthetic hydrocarbon rubbers. Especially for matrix material, such rubber may be introduced in latex form.
The resulting composites may display a piezo-charge affect and will change their inherent electrical resistance in response to both pressure and strain forces. Working resistance is around the range 1012 to 10xe2x88x921 ohms and the composite have excellent current carrying capability; typically a 2 mm thick sample of the composite on a heat-sink can control AC or DC currents of 3 A/cm2. The initial application of pressure or force to a sample of the high-resistance composite results in the generation of an electrostatic charge; increasing the pressure or force decreases the electrical resistance of the composite. The composites can be flexible and can reassert themselves when the force or pressure is removed. As this occurs the electrical resistance will increase towards a quiescent value and a pronounced electrostatic charge will develop. The electrostatic effect can provide digital switching indications or provide a voltage source. The electrical resistance change can provide an analogue of the applied pressure or force. Alternatively, the resistance range can be used to provide digital switching especially but not essentially at its upper and lower limits. Sensitive versions of composite which are close to conduction, can be changed into a fully conducting state by applying an electrostatic charge, typically that generated by a piezoelectric spark generator and greater than 0.5 kV.
The composite may consist of the granules held within a matrix. Within the granules the conductive particles are of such a size distribution as to provide for a close packed structure with interstitial particle infilling. Voids present in the bulk conductor powder become infilled with elastomer during mixing and conductor particles become set in close proximity during curing. In order to achieve this structural arrangement the elastomer will have a low surface energy relative to the powder phase and uncured liquid surface energy less than cured elastomer surface energy. Such polymer compositions will include silicones, polygermanes and polyphosphazines. In the stressed state the distortion takes place such that the average entrapped inter-particle distance decreases. For metal particles this corresponds to an increase in electrical conductivity, for other types of particle other effects may be generated (change in ferromagnetism, piezoelectricity, ionic conduction, etc.).
For metal filled compositions over the transition from unstressed to stressed state, bulk conductivity will change from that of the elastomer to that of the entrapped conductor particles. At a certain level of distortion the number of particle-to-particle open-circuit tracks results in a conductivity tending towards that of the bulk metal resistivity. Since this effect is ultimately related to distortion of the bulk composite, and since the bulk material is highly elastomeric and therefore energy absorbing, low xe2x80x98metallicxe2x80x99 conductivity may only be achieved for thin sections (less than 2 mm in lateral dimension) of the composite material or upon application of high external stress or strain or torque. Upon removal of external force the material reverts to its original structure whereby entrapped particles are held apart within an elastic insulating network.
Surprisingly, the assembly of granules is capable of carrying significant electrical current. Up to 30 amps continuous load has been carried by a 2xc3x972 cm conductor to date when in a compressed state. This unique property may be explained by the fact that in the compressed state conduction occurs principally through the metal bridges described above. So for the purpose of explaining conduction the materials are best described in terms of a heterogeneous mixture in which the insulative encapsulant dominates electrical property in the quiescent state; and tending towards that of the conductor bridges (having a local resistivity tending to that of the conductor typically 1-1000 microhm-cm), in the compressed state (typically having a bulk resistivity greater than 1 milliohm-cm). Electron conduction is further confined to the conductor filler by the inability of the encapsulant to hold negative xe2x80x98electronxe2x80x99 charge (typically the encapsulant is the optimal positive triboelectric charge carrier). For fixed composition the statistical chance of bridge formation is directly related to composite thickness. Thus both the sensitivity to distortion and current carrying capability increase with reduction in thickness with the thinnest films limited by the filler size distribution. For the mixtures described below the filler size distribution will typically limit thickness to  greater than 10-40 microns.
By incorporation of zirconium particles (or other ionic conducting materials) into a silicone elastomer, within and/or between granules, the composite may be made to conduct both electrons and, in the presence of gaseous oxygen, oxygen ions. By control of bulk material stress (for example by the incorporation of static or externally resonated xe2x80x98stress gridsxe2x80x99 into the bulk composition) conduction of electrons and oxygen may be made to occur in different planes or different parts of the bulk structure. Such properties may be of particular interest in the design of fuel cell systems. It has also been found that internal ohmic heating may affect the internal structure of the composite. So for example in compositions encompassing nickel as conductive filler, RTV silicone encapsulant and fumed silica skeletal modifier, it is found that the differential expansion of the encapsulant relative to the conductor is of such proportion (typically, the encapsulant expands fourteen times faster than the conductor) that upon passage of high current, sufficient to create ohmic heating, differential expansion alters the stress/strain versus resistance transition. This effect may be induced at low differential temperatures (typically less than 100xc2x0 C.). This effect (which induces a positive temperature coefficient of resistance (PTC) in the composite phase) may be conveniently employed for the purpose of regulating current flow. Onset of PTC may be regulated by increasing or decreasing mechanical pressure on the polymer composition. Alternatively, for composites that have a low electrical resistance (typically  less than 100 ohms) in the quiescent state, ohmic heating switches by virtue of the PTC effect between conducting and insulating states in a composition that is under little or no compressive force. This effect allows these polymer compositions to be used as switches or fuses which switch sharply to a high resistance state in response to excess current and which, because of their elastomeric nature, will return to a conductive state without the removal of power when the current flow returns to a set value. This PTC effect can also be used in self-regulating heating elements where heat levels can be set by applying mechanical pressure to keep the polymer composition close to its PTC point at the required temperature. The polymer composition will maintain a relatively steady temperature by cycling in and out of the PTC phase. The composition has wide temperature tolerance and good thermal conductivity.
A nickel powder used in the invention was INCO Type 287 which has the following properties: beads are on average 2.5-3.5 microns in cross-section; chains may be more than 15-20 microns in length. It is a filamentary powder with a three-dimensional chain-like network of spiky beads having a high surface area.

Peratech Limited of a Company of Great Britain and Northern Ireland


A method for sealing a gap (4) between a leadthrough (2) provided in a constructional element (1) and an object (3) extending through the leadthrough (2), the method including placing in the gap (4) a plurality of elongate sealing elements, formed as hot melt elements (5) provided with heat-activated blowing agent, and applying heat to the hot melt element from outside; and a sealing element used by the method.

1. Field of the Invention
The present invention relates to a method of sealing a gap between a leadthrough provided in a constructional component and an object extending therethrough and including placing a sealing element into the gap. The present invention also relates to a sealing element for use in sealing a gap.
2. Description of the Prior Act
Gap sealing is necessary in the regions of housing leadthroughs through which tubes, pipes, cables are passed through from outside through openings in the walls. A gap between a tube or a cable and a leadthrough wall can be sealed by different methods. E.g., a mechanical seal, with which a rigid sealing element fills the gap and seals it by forming a form-locking connection with the wall and the tube or cable or by being pressed into the gap, can be used. Also a chemical seal can be used. With a chemical seal, the gap is filled with reactive system which hardens and closes the gap. As reactive systems, e.g., inorganic systems, such as mortar, or organic systems such as, e.g., sealing masses, polymer foams, and the like, can be used. Also, a chemical-mechanical seal can be used. With this seal, as a rule, a casing is placed in a gap and is filled with a chemical system of the type discussed above.
Mechanical solutions are expensive and time-consuming and require the use of tubes, cables, and leadthroughs having a predetermined diameter. This drawback is absent in chemical systems filling the gaps, such as sealing mass, foam, mortar. However, the chemical systems do not provide a lasting sealing against fluids or water. In addition, the treatment of liquid chemical components is often accompanied by soiling, contamination, increased health risks, ecological problems, presence of dirt residues, and the like.
Accordingly, an object of the present invention to provide a method of and a sealing element for sealing gaps which would insure a more rapid and easier sealing of gaps in leadthroughs having different diameters and with different diameter tubes extending therethrough, without affecting, in any significant manner, the environment.
This and other objects of the present invention, which will become apparent hereinafter, are achieved by providing a method of sealing a gap between a leadthrough provided in a constructional element and an object extending through the leadthrough and including placing in the gap at least one sealing element formed as a hot melt element provided with heat-activated blowing agent, and applying heat to the hot melt element from outside; and by providing a sealing element consisting of a hot melt mass provided with a heat-activated blowing mass.
Solid, e.g., elongate bar-shaped, hot melt elements, which are formed of an expandable material, are inserted in a gap between the leadthrough wall and at least one object extending through the leadthrough and are stacked there. The number of the hot melt elements insertable in a gap depends on the gap size. After the gap has been filled with the hot melt elements to a most possible extent, the elements are heated. The hot melt elements melt, expand and, then, become hardened again. As a result, the remaining empty spaces of the gap become sealed and lastingly closed. The hot melt material resists most of the fluids and, in particular, water, so that the sealed gap is also fluid-tight.
The hot melt element according to the present invention is formed of hot melt polymers, e.g., on epoxy or PUR basis. The hot melt element can be produced in bar-shaped form or any other suitable form. In addition, the hot melt element contains a heat-activated blowing agent. As a blowing agent, any substance can be used which contains components that, upon being heated, assume a gaseous form that splits off. E.g., nitrogen can be used as a blowing agent. Thus, as a heat-activated blowing agent, solid substances can be used which, upon reaching a predetermined temperature, decompose as a result of separation of the heated gas. The blowing agent should be uniformly distributed in the hot melt element. Blowing agent compositions, which contain organic compounds or nitrogen, e.g., such as azoic compounds, hydrazial, and the like, can be used.
However, microencapsulated fluid motive agents can also be used as a heat-activable flowing agents. To this type of agents, such compounds as pentan, i-butan, etc. belong.
According to an advantageous embodiment of the present invention, the hot melt element contains a heat-activated or blocking hardener that insures that after solidification in its expanded condition, the condition of the seal becomes irreversible. As a temperature activated or blocking hardener, e.g., a chemical blocking hardener such as a hidden amine, or a mechanical blocking hardener that, e.g., is microencapsulated, can be used.
For activation of a hot melt element, a heat should be applied thereto and uniformly distributed over the entire element. For distribution of heat in a hot melt element, e.g., metallic fibers can be embedded therein. In this case, the heat can be applied from outside, e.g., in a form of hot air supplied by a drier. The heat would propagate through the hot melt element in its longitudinal direction through the metallic fibers in a form of a heat flux. After the application of heat from outside, the heat is distributed through the metallic fibers uniformly over the hot melt element and melts it. In the melt, the heat-activated blowing agent is activated, which results in an increase of the volume of the hot melt element. In case a hardener is present, it becomes activated upon the temperature reaching a pre-determined value. Upon cooling, the foam-shaped material of the hot melt element solidifies, and the leadthrough becomes firmly and fluid-tightly closed.
According to a further embodiment of the present invention, the hot melt element can contain thermal cells. These cells can contain chemicals which, upon being activated, react exothermally and give up heat. This heat likewise can be distributed over the element through the metallic fibers. In an ideal case, the reaction of the hot melt element polymers with the heat-activated or blocking hardener releases, as a result of an exothermal reaction, so much heat that this heat is sufficient for initiation of a further autonomous reaction in form of a chain reaction. The activation of the thermal cells can again be effected by feeding heat from outside for a short time.
To facilitate handling of the bar-shaped sealing elements or the hot melt elements, they are connected with each other in form of a belt along their longitudinal edges. In this case, they can be placed around of a rod-shaped object between the object and the leadthrough wall one or more times, dependent on the size of the gap. Thus, a sample placing of sealing elements in the gap is insured.
The novel features of the present invention, which are considered as characteristic for the invention, are set forth in the appended claims. The invention itself, however, both as to its construction and its mode of operation, together with additional advantages and objects thereof, will be best understood from the following detailed description of preferred embodiments, when read with reference to the accompanying drawings.

Method of and a sealing element for sealing a gap