A solar collector array is formed of a plurality of solar panels mounted on a frame made of support beams which may be sheet metal channel members. A butyl tape or other glazing material is applied between the back laminate of the solar panel and the beam. Clips are used to clamp the panels to the support beams. The clips have an upper portion that is generally T-shaped in profile, and a retainer in the form of a channel nut or bar, with a threaded hole that receives a bolt or similar threaded fastener. The retainer biases against the inwardly directed flanges of the channel support beam. Electrical wires and mechanical fasteners are concealed within the support beams.

This invention relates to solar energy collection, and is more particular directed towards an arrangement for attaching solar modules to a supporting structure, such as a roof, rack or tracking structure. The invention is more particularly directed to improvements in hardware clips that facilitate the attachment of unframed photovoltaic modules on any of a variety of supporting structures, for the purpose of constructing arrays of photovoltaic modules in a system to produce electricity. The invention may be employed for the attachment of solar thermal panels and non-solar panels as well.
Photovoltaic systems are used for a variety of purposes, including for use as a utility interactive power supply, as a power supply for remote radiotelephone station, or to power an unattended monitoring station, for example.
Photovoltaic systems consist of one or more photovoltaic (PV) modules, arranged in arrays, attached to a supporting surface, and interconnected with electrical wiring to switches, inverters, battery chargers and batteries, etc. This invention relates to a novel method for attaching the PV modules to a variety of supporting structures. PV modules typically consist of a PV laminate and they may also include a frame. The PV laminate typically consists of an assembly of crystalline or amorphous semiconductor devices electrically interconnected and encapsulated between a transparent front cover of glass or plastic and a back cover. Also, a PV module typically includes electrical conductors exiting the laminate edge or back cover which conduct the solar generated current through the electrical circuit including the PV module. The back cover is typically a tough insulating material that is an electrical insulator, is impervious to moisture, and is often made of either flexible Tedlar and/or other foil, film or rigid glass or plastic.
For PV modules that incorporate a frame, the frame often consists of multiple aluminum extrusion elements which are assembled to surround the laminate, and are mechanically interconnected at the module corners. The frame sections often include a channel to capture the laminate, which channel often is filled with a sealant during the frame assembly procedure. The sealant, often a butyl compound in the form of a gunable caulk, tape or putty, acts to promote the sealing of the edge of the laminate, to provide an adhesive attachment between the frame and the laminate, and to provide a cushion to protect the laminate edge from mechanical damage.
For PV modules that incorporate frames, those frames typically include holes which may accommodate fasteners for the attachment of the PV module to a supporting surface. In this way, the PV module may be attached to a variety of supporting structures, including a tracking structure described in U.S. Pat. No. 6,058,930, or attached onto fixed-tilt structures or to the roof of a building such as described in U.S. Pat. No. 6,111,189.
The PV module frame serves many other purposes. In addition to providing laminate edge protection and a means for mounting the PV module, the PV module frame provides a means to grip the PV module to carry and hold that during installation; the frame provides the appearance of a finished perimeter to the PV module; and the frame may be provided with a finish color to blend according to architectural requirements. In some cases, as in U.S. Pat. No. 6,111,189, the frame may provide means to conceal and protect the interconnection wiring in a PV array.
If the frame is made of a conducting material, the frame must be connected to a grounding conductor as a safety precaution in the event that the PV circuit within the PV laminate inadvertently develops an electrical short to the frame. The frame and the conductors and other electrical components and labor required for the grounding of the frame represent significant portions of the cost of the photovoltaic module. These cost elements are accentuated by the historical falling cost of the PV laminate, and represents a barrier to PV generated electricity achieving a cost that is competitive with conventional power sources. The frame typically increases the volume of a PV module, and this reduces the packing density and increases the cost of shipping the PV module. Also, in order to limit the number of product variations that a manufacturer must offer, PV module frames are typically designed such that a single frame design may be used in a variety of xe2x80x9ctypicalxe2x80x9d applications. As a result, the typical frame may not be suitable for applications that have very specific requirements. Manufacturers must therefore also develop custom frames for those applications, and this increases the manufacturer""s cost of operation and the PV module cost.
For these reasons, techniques have been investigated and developed to eliminate the requirement for frames for PV modules. In those cases, a variety of means have been developed to accommodate the attachment of the unframed PV laminate directly to a supporting surface.
In one example, as described in U.S. Pat. No. 5,143,556, mounting brackets are adhesively attached to the laminate back surface. The PV module is attached to the supporting structure by means of conventional fasteners engaging the clips and the supporting surface. This eliminates the cost of the frame and the requirement for grounding, but only partly increases the packing density. However, this introduces additional assembly and adhesive curing steps to the manufacturing process. The frameless PV module also specifically prescribes the required locations for the supporting structure members, and limits the number of attachments, thereby limiting the maximum allowable design pressure that the laminate may tolerate. This also imposes the requirement that the back side of the PV module be accessible during installation and module removal and replacement, which limits the application of this technique in typical building roof applications.
In another example, as described in U.S. Pat. No. 5,762,720, elements are bonded to the PV laminate back surface which elements can slidably engage the open side of a common electrical channel strut, including those marketed under the trademarks UNISTRUT(trademark) and BLINE(trademark). The method of the U.S. Pat. No. 5,762,720 has the advantages that no fasteners are required in order to attach the PV module to the supporting surface, that access is not required of the module back surface during installation, and that the requirement for grounding may be eliminated. One limitation of this technique is that if it becomes necessary to remove or replace only a single one of a number of PV modules that are slidably engaged to a supporting channel, it may be necessary to remove several of the adjacent PV modules as well. That limits the practicality of this technique, particularly in building roof applications. This technique also has the limitations described in the U.S. Pat. No. 5,143,556, above.
Another type of frameless PV module is described in U.S. Pat. No. 6,075,201, intended for use as a curtain wall or roof element.
Another approach pursued for attaching PV modules in building roof and other applications, has been to utilize conventional curtain wall, sloped glazing, skylight and other common building glazing materials and techniques. This approach typically employs conventional aluminum structural elements with glazing gaskets and cover caps. This has been shown to be particularly effective in building applications where the PV laminates are basically substituted for some or all of the conventional building glass or plastic glazing or other building panels, and where there is a significant requirement for weatherproofing the building exterior surfaces. This technique does not require special fixtures or clips permanently affixed to the module, as in U.S. Pat. Nos. 5,143,556 and 5,762,720. In addition, this technique accommodates the removal and replacement of single individual PV modules in an array of modules. However, the cost of such conventional building glazing materials and techniques cannot be economically justified in all PV applications, especially in those applications that do not have the rigorous architectural and weatherproofing requirements of building glazing, wall and roof elements.
The need that now exists is a low cost method for attaching a variety of unframed PV modules to a variety of supporting surfaces, including building surfaces, i.e., roofs and walls, where the applications do not impose strict architectural requirements or requirements for absolute weatherproofing. These applications include many non-building applications, as well as building rain screen architectural applications and building roof and wall applications where the PV modules are placed adjacent to or onto a finished waterproof building roof or wall surface.
Limited efforts have been undertaken to develop such methods for attaching a variety of unframed PV modules to a variety of supporting surfaces. There are a variety of common mounting clips and hardware widely used for other purposes that have self-evident applicability, and have been employed. These clips include those developed for attaching glass mirror panels and other panels to walls and to supporting surfaces. Some well-known clips have been employed for mounting glass mirror panels. Other clips have been developed for mounting other panels to walls and to other surfaces, for example, as described in U.S. Pat. Nos. 4,580,385 and 4,452,027.
The metal clips for surface mounting of glass mirror panels do not require access to the rear surface of the glass mirror panels. Such clips may incorporate flexible rubber cushion pads to protect the edge of the mirror panels and to spread the loads on the mirror back surface. Molded plastic clips function in a manner similar to the metal clip, except that cushions are not required owing to the softer nature of the plastic. The plastic clips may be free to rotate on their fastener, and depend on the clip contact with the edge of the glass mirror panel to properly align the clip to the glass mirror panel.
The clips in U.S. Pat. No. 4,580,385 were developed to accommodate the simultaneous attachment of two adjacent panels to a single supporting surface. Those also achieve attachment without the use of additional fasteners, by engaging a supporting surface consisting of a multiple-pierced hollow closed structural supporting element.
The clips in U.S. Pat. No. 4,452,027 accommodate the attachment of two adjacent panels, where the fastener mounting surface is depressed below the panel surface to accommodate the panel thickness. The clips in this patent also employs a rivet to attach the clip to the supporting element. Those clips align with the panel during installation by their contact with the edge of the attached panel.
Accordingly, the concepts described by these common mirror clips and glass panel clips have been adapted for employment in the mounting of PV modules, as will be described here.
U.S. Pat. No. 4,966,631 describes a xe2x80x9csupported photovoltaic arrayxe2x80x9d which includes the use of clips incorporating some of the features of the common clips. Those clips are mounted from the front of the PV module, and incorporate xe2x80x9ccushionsxe2x80x9d to protect the edge of the PV module and to spread the loads on the PV module back surface. Those clips become properly aligned to the PV module during installation by their contact with the edge of the attached PV module. The clips incorporate a fastener mounting surface that is depressed below the PV module surface to accommodate the PV module thickness.
The arrangement described in this U.S. Pat. No. 4,966,631 has a number of practical limitations.
Firstly, the cushioning pads do not protect the entire interface of the PV module back surface and the supporting surface. In practice, it is often the case that the surface of the structural elements is rough, and without a cushion at the entire interface the rough uncushioned surface of the support can easily damage the PV module back surface and/or lead to stress laminate concentrations that can damage the laminate elements including the laminate cells, electrical interconnections and the laminate back cover. Damage to the PV module back cover can lead to the PV module becoming electrically shorted to the support beam. This leads to a significant safety hazard.
Secondly, the PV module back surface contact with the structural element is not continuous and therefore does not offer complete support to the PV module against loads such as wind pressure impinging on the module front surface. As a result, with loads impinging on the PV module front surface, the PV laminate is allowed to deflect toward the supporting element. That leads to limitations in the maximum design load that the PV module may be exposed to from pressures acting on the PV module front surface.
Thirdly, in the design of U.S. Pat. No. 4,966,631, loads such as wind loads impinging on the PV module back surface are resisted only by these clips, which are acting only at discrete points on the PV module perimeter. This leads to high stress concentrations in the PV laminate front cover under certain loading conditions, and leads to limitations in the maximum design load that the PV module may be exposed to from loads acting on the PV module back surface.
Fourthly, during installation, the PV modules may not initially be placed without the clips in position. Therefore the clips must either be placed first, requiring that the clips be precisely pre-positioned, or that the clips and PV modules be placed simultaneously, which is an awkward maneuver for the installer. This is a particular limitation for building applications where the access to install the PV module may be difficult and awkward on account of the elevation and orientation of the building surface.
Fifth, removal and replacement of a single PV module attached with conventional fasteners would require free access to the space beneath the PV module. Removal and replacement of a PV module attached with rivets would require the awkward and difficult removal of rivets from a position above the PV module to be removed.
Sixth, the arrangement does not provide for the concealment or protection of electrical conductors beneath the PV modules.
Seventh, the clip in U.S. Pat. No. 4,966,631 does not provide a means to conceal the fasteners or other means to provide a more finished, attractive appearance to the clip installation.
Finally, the panels of PV modules mounted in this fashion, as shown in U.S. Pat. No. 4,966,631, have only limited stability against loads, including gravity loads, acting in the plane of the PV modules. This is a significant limitation, since it is common practice to depend on some xe2x80x9clateral stabilityxe2x80x9d sufficient to accommodate the assembly, transport and installation of panels of multiple PV modules. In this case, that stability is limited to that which is developed by the contact pressure developed at the discrete clip connection points. And that contact pressure can lead to stress concentrations in the PV module laminate and front and back covers. In addition, the panels of multiple PV modules may deflect laterally due to their insufficient xe2x80x9clateral stability.xe2x80x9d The structure can deform into a parallelogram, with the mounting clips being brought into closer contact with the PV module laminate edge on one side. This can lead to over-compression and failure of the clip cushion, and can lead to increased stress and mechanical contact between the clip and the laminate. It is well understood that nearly all failures of glass plates, regardless of the specific load condition, are initiated at the edge of the glass plate. As a result, in this instance, the increased stress and/or mechanical contact between the clip and the PV module glass front or rear cover can lead to the PV module failure at lower loads than would have otherwise been anticipated.
Consequently, none of the clips described hereinabove adequately address the requirements of a universal clip or attachment mechanism for the attachment of a variety of unframed PV modules to a various supporting surfaces.
Accordingly, it is the object of this invention to provide a means to attach unframed PV modules or other panels on a variety of supporting surfaces that avoids the limitations of the prior art.
It is another object of this invention to provide an attachment system that limits the stresses in the PV laminate that are induced when structural loads are applied to the PV module front and back surfaces.
It is another object of this invention to simplify the process of safely and expeditiously attaching, removing and replacing PV modules on a supporting surface.
It is yet another object of this invention to provide a means to conceal and protect the electrical conductors in an array of PV modules.
It is still another object of this invention to provide the means to provide lateral stability for a panel of multiple PV modules.
It is a further object of this invention to conceal the fasteners holding the clip in place, and to provide a more finished appearance to the installed clip.
In accordance with an important aspect of the present invention, a row of solar panels or similar panels can be formed using a system of clips, fasteners, glazing material and supporting beams.
In one possible preferred embodiment, the supporting beams may be channel-shaped, i.e., beams with one open slotted side, with the open or slotted side of the channel facing upward toward the back surface of the PV module. The supporting beams may be other shapes as well, including tubes and other common structural shapes such as rods, angles, wide-flange beams, etc. The supporting beams may be attached to the surface of a new or existing roof, or may be attached to any common tracking structure or fixed-tilt structure. When a channel supporting beam is used, the fasteners attaching the channel to the supporting structure or roof may be concealed in the channel beneath the PV module. In a roof application, sealant may be placed on the underside of a channel supporting beam, to facilitate the sealing and waterproofing of the fastener holes in the roof membrane. With the PV modules and clips in place, a channel supporting beam can provide a continuous enclosed space in contact with the PV laminate back surface. With the PV module appropriately positioned, the PV laminate conductors may exit the PV laminate into this space, and in any case the PV module and/or array conductors may be concealed and protected in this enclosed wireway.
A glazing material, such as 3M VHB Acrylic Foam Tape or butyl glazing tape, or equivalent, may be applied to the top surface(s) of the channel (or, equivalently, to the back surface of the PV module) to provide a continuous cushion between the supporting surface (e.g., the channel member) and the PV laminate rear surface. In addition, the glazing tape or equivalent may be supplied with adhesive characteristics that adheres the PV laminates in position during the installation process and before the clips are attached, and provides a fall or partial adhesive attachment of the PV laminate back surface to the supporting element to increase the allowable loads on the PV laminate back surface and the lateral stability of a panel of multiple PV modules.
In several preferred embodiments, the clips may be fabricated as injection molded plastic, however they may be fabricated by alternative methods and from alternative materials such as of extruded and/or machined aluminum, stamped or brake formed steel, etc. If plastic, the plastic material, such as GE Noryl, could be selected for the required strength, with (glass) fillers if necessary, and UV stabilized and electrically insulative properties. The clips may be developed to attach to the supporting beam top surface. In the preferred embodiment the clips may extend beyond the width of the supporting beam as necessary to reduce the stress in the PV laminate under loads impinging on the PV module bottom surface. The clips may be shaped with grooves or extensions that engage the supporting beam elements or edges. This will cause the clips to take the proper orientation without a PV module in place, and will restrain the walls of the channel from buckling laterally and from disengaging the fastener attaching the clip to the supporting beam channel.
In some preferred embodiments, the clips are attached to the channel supporting beam with fasteners and hardware that engage the channel elements such that the clips may be installed anywhere along the channel supporting beam, without providing special holes or receptacles.
In many preferred embodiments, during installation the PV modules may be securely placed and positioned temporarily on the adhesive glazing tape, and removed and repositioned if necessary. The clips are designed to be fastened in place with or without PV modules in position. This facilitates the initial installation of the PV modules. This also facilitates the removal and replacement of the PV modules in future, without having to disturb the adjacent PV modules. Access to the underside of the support structure is unnecessary.


The invention provides a method and compositions for controlling food borne enteric bacterial pathogens in poultry populations. The incidence of the colonization of poultry by enteropathogenic bacteria, and/or the populations of enteropathogenic bacteria within colonized poultry, may by substantially reduced by providing particles of an expanded matrix material to the locus or vicinity of the animals, particularly during the period of feed removal prior to slaughter. The method and compositions are particularly useful for the control of Salmonella species, enteropathogenic Escherichia coli, and Campylobacter species.

1. Field of the Invention
This invention relates to a process for the control of enteric bacterial pathogens in animals using expanded matrix materials.
2. Description of the Prior Art
Despite the efforts of researchers and public health agencies, the incidence of human infections from enteropathogenic bacteria such as Salmonella, E. coli 0157:H7, and Campylobacter has increased over the past 20 years. For example, the number of actual reported cases of human Salmonella infection exceeds 40,000 per year. However, the Communicable Disease Center estimates that the true incidence of human Salmonella infections in the United States each year may be as high as 2 to 4 million. The USDA Economic Research Service has recently reported that the annual cost of the food borne illnesses caused by six common bacterial pathogens, Campylobacter spp., Clostridium perfringens, Escherichia coli 0157:H7, Listeria monocytogenes, Salmonella spp., and Staphylococcus aureus, ranges from 2.9 billion to 6.7 billion dollars (Food Institute Report, USDA, AER, December, 1996). In addition to the impact of enteric pathogens on human health, many of these bacteria also cause significant infections in animals. For example, Salmonella infections in swine alone cost the United States swine industry more than 100 million dollars annually (Schwartz, 1990, xe2x80x9cSalmonellosis in Midwestern Swinexe2x80x9d, In: Proceedings of the United States Animal Health Assoc., pp. 443-449).
Animal food products remain a significant source of human infection by these pathogens. Contamination of meat and poultry products with many bacterial food-borne pathogens, including the particularly onerous pathogens Campylobacter spp., Escherichia coli 0157:H7, and Salmonella spp., often occurs as a result of exposure of the animal carcass to ingesta and/or fecal material during or after slaughter. Any of the above-mentioned pathogens can then be transmitted to humans by consumption of meat and poultry contaminated in this manner.
Preharvest control of enteropathogenic bacteria is a high priority to the food industry. However, few products have been developed to facilitate such efforts. Currently, preharvest pathogen control within the poultry industry is accomplished through use of competitive exclusion cultures or probiotics. In fact, at this time, only one such product, developed by Nisbet et al. of the USDA Agricultural Research Service (U.S. Pat. No. 5,478,557) and sold under the trademark PREEMPT (Milk Specialties Biosciences, Dundee, Ill.), is available commercially in the United States. Moreover, the administration of competitive exclusion cultures is preferably targeted to very young animals. Immune lymphokines (ILK) have also been recently developed for protecting poultry from colonization with enteric pathogens as described by Ziprin et al. (1989, Poult. Sci., 68:1637-1642), McGruder et al. (1993, Poult. Sci., 72:2264-2271), Ziprin et al. (1996, Avian Dis., 40:186-192), and Tellez et al. (1993, Avian Dis., 37:1062-1070), and more recently by Kogut et al. (U.S. Pat. Nos. 5,891,443 and 5,691,200).
Despite these advances, the need persists for technologies for controlling enteric pathogens in animals, and particularly for the treatment of animals immediately prior to slaughter.
We have now discovered a method and compositions for controlling the spread of food borne enteric bacterial pathogens in poultry populations. The incidence of the colonization of poultry by enteropathogenic bacteria, and/or the populations of enteropathogenic bacteria within colonized poultry, may by substantially reduced, by providing particles of an expanded matrix material to the locus or vicinity of the animals, particularly during the period of feed removal prior to slaughter. The method and compositions are particularly useful for the control of Salmonella species, enteropathogenic Escherichia coli, and Campylobacter species.
In accordance with this discovery, it is an object of this invention to provide a method for controlling food borne enteropathogenic bacteria in animals.
Another object of this invention is to provide a method for controlling the spread of enteropathogenic bacteria between animals in a population of poultry.
Yet another object of this invention is to provide a method for significantly reducing the populations of enteropathogenic bacteria in meat producing animals prior to slaughter.
Other objects and advantages of this invention will become readily apparent from the ensuing description.
During the processing of poultry in slaughterhouses, carcasses may become inadvertently exposed to ingesta and/or fecal material. Consequently, contamination of the poultry product may occur if the ingesta or fecal material contain bacterial food-borne pathogens such as Campylobacter spp., Escherichia coli 0157:H7, and Salmonella species. The contamination of carcasses with feces or ingesta in this manner is the primary source of contamination of poultry with these pathogens.
In an effort to reduce bacterial/fecal carcass contamination in the United States, commercially produced poultry are now deprived of feed prior to their transport to the slaughterhouse. However, while this practice successfully reduces the amount of ingesta and fecal material in the bird""s gut and hence decreases fecal contamination levels during processing, bacterial levels in the upper gastrointestinal tract (crop) are increased. In fact, the number of birds with crops contaminated with Salmonella or other pathogens increases from as low as 1-2% prior to feed withdrawal, to as much as 60% or more by the time of slaughter. This increase is primarily due to the birds"" consumption of feces and litter lying in their vicinity; once feed has been withdrawn, the birds characteristically tend to peck at and consume feces and litter on the floor of their enclosure. Thus, bacterial pathogens may be quickly spread throughout the population. Moreover, feed withdrawal also effects an increase in the pH of the crop, providing an environment in the crop more conducive to the growth of the pathogens.
In accordance with this invention, we have discovered that the contamination of poultry with bacterial pathogens may be controlled by providing particles of an expanded matrix material to the locus or vicinity of the poultry population. Interestingly, the poultry will preferentially consume the particulate expanded matrix material rather than the feces and litter, thereby reducing the uptake of the pathogenic bacteria. Either or both of the spread of the bacterial pathogens among the population (i.e., the incidence or number of birds contaminated or colonized with the pathogens), as well as the concentration of the pathogens in the birds, may be significantly reduced in comparison to untreated controls. Moreover, in a preferred embodiment, even greater control of the pathogens may be achieved by incorporating one or more disinfectants or bactericidal agents in the particles.
Virtually any enteropathogenic bacterium may be controlled in accordance with this technique, including but not limited to Salmonella species, enteropathogenic Escherichia coli 0157:H7, and Campylobacter species. While the process may be used for the treatment of a variety of poultry, it is preferred for use with meat producing poultry such as ducks, geese, and particularly chickens and turkeys where large populations are commonly reared in confined pens or enclosures.
In the preferred embodiment, the particles of expanded matrix material are provided to the poultry during any period of feed removal or restriction. In the particularly preferred embodiment, the particles are provided during the period of feed removal which is instituted prior to slaughter (also referred to as processing) and/or transport to the slaughterhouse. Although the precise time of the feed withdrawal may vary between producers, it will typically be within about 1 day prior to slaughter of the poultry, most often within about 12 to 24 hours prior to slaughter, and may be less than or equal to about 10 hours prior to slaughter. As a practical matter, the particles are provided at or shortly before the time that feed is removed to minimize consumption of fecal material and litter by the poultry. It is also understood that the use of the particles of expanded matrix material is not limited to the period prior to slaughter. For instance, the particles may be provided to the poultry to prevent or treat illness within the poultry population.
The particles of the expanded matrix material are provided in the vicinity of the poultry in an amount or density effective to significantly reduce or eliminate their consumption of fecal material and litter relative to an untreated population. Thus, the amount should be sufficient that the particles are readily available for consumption by the birds over the course of the feed withdrawal period, substantially without their reverting to consumption of fecal material and litter. The specific amount may vary with the extent of the period of feed withdrawal, the type floor litter used, and the population density of the birds. However, in the preferred embodiment, the particles are distributed or spread on the floor or ground within the enclosure in which the poultry are maintained in an amount effective to cover approximately 10% or more of the floor area. In a particularly preferred embodiment, a sufficient amount of the particles are provided to cover approximately 25% or more of the floor area.
The particles for use in this invention may be prepared from a wide variety of expanded matrix materials, including but not limited to polymer foams (which may also be referred to as expanded polymers or cellular polymers), syntactic foams, or extruded and expanded grains. As defined herein, the expanded matrices are solid structures comprising voids filled with a gaseous phase derived from a blowing agent or hollow microparticles, which are surrounded or partially surrounded by a solid polymer matrix. The blowing agents may be introduced chemically, physically, or mechanically. A variety of methods for preparing expanded matrix materials from numerous base materials are known in the art and the selection of the particular method and material is not critical. Furthermore, as described in greater detail hereinbelow, other optional solid and/or liquid phase materials may also be included within or on the matrix.
In a first preferred embodiment, the expanded matrix is a polymer foam, prepared from a single polymer or a mix or blend of different polymers, which may be naturally occurring or synthetic polymers or copolymers. Without being limited thereto, examples of naturally occurring polymers which are suitable for use herein include carbohydrates, polysaccharides, celluloses, and starches. Starch derivatives such as modified starches and starch-graft copolymers may also be used. In addition, polystyrene, polyurethanes and other isocyanurate based polymers, polycaprolactams, polycyclopentadienes, polyolefins, polyvinylchlorides (PVC), epoxy resins, urea-formaldehyde resins, latex, silicones, fluoropolymers, and other synthetic polymers may also be suitable for use.
Generally, biodegradable polymers are preferred, particularly starch, modified starch, and starch-graft copolymers, to minimize the accumulation of waste in the poultry house and simplify its disposal. Such biodegradable materials will bioerode relatively quickly in gut, reducing the volume of ingesta and fecal material. Starches may be derived from any available source. However, even though such biodegradable starch-based polymers are generally preferred, their combination with synthetic polymers may provide enhanced strength, structural stability, or other desired properties.
Many techniques have been previously described for the preparation of polymer foams which are suitable for use herein, and particularly for the well-known particulate polymer foams such as loose fill packing or xe2x80x9cpeanutsxe2x80x9d. The selection of the particular technique is not critical and is a matter of choice. Representative non-limiting examples of synthetic polymers and techniques for producing polymer foams which may be used herein are described by Klempner and Frisch (editors, Handbook of Polymeric Foams and Foam Technology, Hanser Publishers, Munich, 1991), Throne (Thermoplastic Foams, Sherwood Publishers, Hinckley, Ohio, 1996), Stober (U.S. Pat. No. 2,576,977), Ropiequet (U.S. Pat. No. 3,961,000), Stochdopole et al. (U.S. Pat. No. 3,723,240) and Holden (U.S. Pat. No. 3,188,264). Examples of several techniques which may be used for producing polymeric foams from starch, starch containing materials, modified starch, or starch-graft copolymers, include but are not limited to those described by Altieri (U.S. Pat. No. 5,153,037), Protzman (U.S. Pat. No. 3,137,592), Fisk (U.S. Pat. No. 5,853,848), Lacourse (U.S. Pat. Nos. 5,043,196 and 5,863,655), Neuman et al. (U.S. Pat. No. 5,208,267) and Ernst (International application WO8302955 or European patent 0087847). The contents of each of the above mentioned publications and patents are incorporated by reference herein.
In an alternative embodiment, the expanded matrix material may be prepared from syntactic foams. Although closely related to polymer foams, syntactic foams are produced by forming the polymer matrix around hollow or gas filled microparticles or microspheres. Techniques for the preparation of syntactic foams are also known in the art and are described by Klempner and Frisch (ibid).
In another preferred embodiment, the expanded matrix may also be prepared from extruded and expanded grains. Briefly, one or more of corn, wheat, rice or other grain are mixed with a binding agent, a blowing agent or water is incorporated therein, and the mixture is then extruded under heat and pressure. Preferred techniques for producing the expanded and extruded grain are described, for example, in Starcevich (U.S. Pat. No. 5,186,990, the contents of which are incorporated by reference herein).
The physical properties of the expanded matrix material are not critical. The expanded matrix may be open or closed cell, or flexible or rigid, although rigid to semi-rigid matrices are preferred. The particle size and shape are also variable, although the particles should be large enough to be readily distinguished by the birds when they are distributed in the holding facility. Accordingly, if the particles are to be spread on a floor which is covered with litter, the particles should be larger than the litter and droppings, preferably greater than or equal to about 0.5 cm in each dimension, with dimensions between about 0.5 to 5.0 cm being preferred (e.g. diameter for substantially cylindrical or spherical particles).
Coloring agents may be incorporated into the matrix or provided on the surface hereof to impart color to the particulate material. Interestingly, poultry typically exhibit a preference for particles which are natural or white (reflecting substantially all wavelengths of light within the visible spectrum at substantially the same reflectance, i.e. the ratio of intensity of incident to reflected light), green (reflecting wavelengths within the visible spectrum only at approximately 530 nm), or black (absorbing substantially all wavelengths of light within the visible spectrum at substantially the same reflectance).
The particles of the expanded matrix material may also function as carriers for delivery of the active agents to the poultry. When used in combination with biodegradable particles, the matrix will bioerode in the upper gastrointestinal tract and crop of the bird, releasing the agents. Thus, in a preferred embodiment, improved control of the enteropathogenic bacteria may be effected by incorporating one or more bactericidal or bacteriostatic agents (compounds) effective against the bacteria into the particles. Without being limited thereto, preferred agents include organic acids, alcohols, organic solvents, and cationic detergents (including cationic bisiguanides such as chlorhexidine and cyclohexidine), iodine, iodophores (i.e. povidoneiodine). Particularly preferred agents include citric acid, lactic acid, and/or limonene. It is also understood that other adjuvants conventional in the art for the treatment of the animals may also be formulated in the particles, such as antitoxins, deworming agents, therapeutic antibiotics, and/or non-therapeutic levels of antibiotics.
The particles used herein are not to be confused with a nutritive feed for the poultry. Rather, the particles are provided to poultry during periods when their access to feed is to be removed or restricted. Thus, substantial amounts of nutrient additives typically found in commercial feeds, particularly supplements which are provided in addition to grains, such as one or more of vitamins, minerals (particularly sodium, calcium, and phosphorous), proteins, and amino acids (particularly lysine and tryptophan), are preferably not incorporated into the particles of this invention. In those embodiments whereon the expanded matrix is prepared from starch or a starch containing material such as flour, or from grains, the amounts of these vitamins, minerals, proteins, and amino acids would be substantially the same as normally present therein without added supplementation.
The following examples are intended only to further illustrate the invention and are not intended to limit the scope of the invention which is defined by the claims.

System for the control of enteropathogenic bacteria in the crops of poultry

The United States of America as represented by the Secretary of Agriculture


A material cutting guide system for cutting predetermined widths of a material. The system includes a frame fixed in location and a pair of spaced apart parallel tracks. At least one horizontal member is movably affixed to the frame and has a distal end extending outwardly therefrom, the distal end being affixed to the tracks. The system includes a motive device adapted to move the tracks in a generally lateral direction to a new location toward the fixed frame in predetermined increments to change the location of the tracks.

Stone cutting is normally initially done at the site of the stone in a quarry and generally utilizes a large wheeled cutting machine that is powered by a motor that both operates the cutting blade as well as the propulsion system that moves the cutting machine in a straight line across the stone in carrying out the cutting operation. In general, the cutting operation may require a plurality of cuts along the straight line of ever deepening cuts in order to cut the stone to the desired depth.
To provide dimensionally accurate stones, therefore, it is necessary to cut the stone by moving the cutting machine into different locations along a lateral direction for the straight cuts, that is, after each straight cut to the desired depth, the cutting machine is moved laterally a specific distance whereupon the cutting machine is again propelled in a straight line to make a subsequent cut parallel to and at a known distance apart from the prior cut.
As such, after the cutting machine has made a plurality of passes along one straight line, that cutting machine then needs to be moved laterally in order to make a second cut and that lateral movement needs to be carried out accurately in order to make the eventual dimension of the stone within acceptable tolerances.
One of the problems, however, in making the multiple passes or cuts is that the terrain generally is uneven and it is difficult to align the subsequent cuts with precision to be the predetermined distance apart from the initial cut, that is, it is difficult to judge the amount of lateral movement that is needed to properly set up the cutting machine for a further cut a predetermined distance away from the immediate preceding cut.
Accordingly, it would, therefore, be desirable to have system that would allow the cutting of dimensionally accurate stone that is robust and can withstand the conditions at a quarry and yet provide an accurate system to make progressive cuts in the stone at predetermined lateral distances between each cut.

Adjustable material cutting guide system

First Concrete Cutters of Wisconsin, Ltd.


A cyanoacrylate adhesive contains an added ester, the ester used being at least one partial and/or full ester of monobasic or polybasic aliphatic carboxylic acids containing 1 to 5 carbon atoms directly attached to one another and monohydric to pentahydric aliphatic alcohols containing 1 to 5 carbon atoms directly attached to one another, the number of carbon atoms directly attached to one another in the other aliphatic groups being at most three where one aliphatic group contains 4 or 5 carbon atoms.

This invention relates to a cyanoacrylate adhesive containing an ester as plasticizer.
Cyanoacrylate adhesives containing an ester as plasticizer are known. Thus, according to DE 34 00 577, up to 25% by weight of a plasticizer is added in addition to 4 to 30% by weight of a vinyl chloride/vinyl acetate copolymer. This plasticizer is an ester of an aromatic monocarboxylic or dicarboxylic acid and a monohydroxy or polyhydroxy compound. According to the document in question, neither the cure rate of the adhesive nor the quality of the bond during curing is significantly affected by the addition of this aromatic plasticizer. However, when these tests were re-run, it was found that the cure rate was clearly reduced. Thus, the setting rate of ethyl cyanoacrylate on EPDM, for example, is slowed from 5 seconds to 35 seconds by a 30% addition of butyl benzyl phthalate.
According to DE 43 17 886 also, the following esters are added to cyanoacrylate adhesives to reduce adhesion to the skin:
1. Aliphatic carboxylic acid esters containing an aliphatic group in which 6 or more carbon atoms are directly attached to one another.
2. Aliphatic carboxylic acid esters containing at least two aliphatic groups in which 4 or more carbon atoms are directly attached to one another.
3. Carboxylic acid esters of a carbocyclic compound which, in a carboxylic acid residue or an alcohol residue, contains an aliphatic group in which 5 or more carbon atoms are directly attached to one another.
The cyanoacrylate adhesives additionally contain polymerization accelerators.
The problem addressed by the present invention was to obviate the disadvantages of known plasticizer-containing cyanoacrylate adhesives and, in particular, to provide a cyanoacrylate adhesive characterized by high stability in storage, useful strength values and virtually the same setting rates.
The solution provided by the invention is defined in the claims and consists essentially in using 1 to 60% by weight of a polymer, based on the adhesive as a whole, in addition to at least one partial and/or full ester of a monobasic or polybasic aliphatic carboxylic acid containing 1 to 5 carbon atoms directly attached to one another and monohydric to pentahydric aliphatic alcohols containing 1 to 5 carbon atoms directly attached to one another, the number of carbon atoms directly attached to one another in the other aliphatic groups being at most 3 where one aliphatic group contains 4 or 5 carbon atoms directly attached to one another.
The alcohol component of the ester is preferably an alcohol containing 1 to 5 and, more particularly, 2 to 4 OH groups and 2 to 5 and, more particularly, 3 or 4 carbon atoms directly attached to one another. The number of carbon atoms not directly attached to one another may be up to 110 and, more particularly, up to 18 carbon atoms.
Examples of monohydric alcohols are methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2,2-dimethyl-1-propanol, 2-methyl-1-propanol, 2,2-dimethyl-1-propanol, 2-methyl-2-propanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 2-methyl-2-butanol, 3-methyl-2-butanol, 1-pentanol, 2-pentanol, 3-pentanol, cyclopentanol, cyclopentenol, glycidol, tetrahydrofurfuryl alcohol, tetrahydro-2H-pyran4-ol, 2-methyl-3-buten-2-ol, 3-methyl-2-buten-2-ol, 3-methyl-3-buten-2-ol, 1-cyclopropyl ethanol, 1-penten-3-ol, 3-penten-2-ol, 4-penten-1-ol, 4-penten-2-ol, 3-pentin-1-ol, 4-pentin-1-ol, propargyl alcohol, allyl alcohol, hydroxyacetone, 2-methyl-3-butin-2-ol.
Examples of dihydric alcohols are ethane-1,2-diol, propane-1,2-diol, propane-1,3-diol, dihydroxyacetone, thioglycerol, 2-methylpropane-1,3-diol, 2-butine-1,4-diol, 3-butene-1,2-diol, butane-2,3-diol, butane-1,4-diol, butane-1,3-diol, butane-1,2-diol, 2-butene-1,4-diol, 1,2-cyclopentane diol, 3-methylbutane-1,3-diol, 2,2-dimethylpropane-1,3-diol, 4-cyclopentene-1,3-diol, 1,2-yclopentane diol, 2,2-dimethylpropane-1,3-diol, pentane-1,2-diol, pentane-2,4-diol, pentane-1,5-diol, 4-cyclopentene-1,3-diol, 2-methylenepropane-1,3-diol, 2,3-dihydroxy-1,4-dioxane, 2,5-dihydroxy-1,4-dithiane.
Examples of trihydric alcohols are glycerol, erythrulose, butane-1,2,4-triol, erythrose, threose, trimethylolethane, trimethylolpropane and 2-hydroxymethylpropane-1,3-diol.
Examples of tetrahydric alcohols are erythritol, threitol, pentaerythritol, arabinose, ribose, xylose, ribulose, xylulose, lyxose, ascorbic acid, gluconic acid-xcex3-lactone.
Examples of pentahydric alcohols are arabitol, adonitol, xylitol.
In one particular embodiment of the invention, the polyhydric alcohols described above may be used in etherified form. The ethers may be prepared from the above-mentioned alcohols, for example by condensation reactions, Williamson""s ether synthesis or by reaction with alkylene oxides, such as ethylene, propylene or butylene oxide. Examples include diethylene glycol, triethylene glycol, polyethylene glycol, diglycerol, triglycerol, tetraglycerol, pentaglycerol, polyglycerol, technical mixtures of the condensation products of glycerol, glycerol propoxylate, diglycerol propoxylate, pentaerythritol ethoxylate, dipentaerythritol, ethylene glycol monobutyl ether, propylene glycol monohexyl ether, butyl diglycol, dipropylene glycol monomethyl ether.
Monobasic carboxylic acids which may be used for the esterification reaction with the alcohols mentioned above include formic acid, acrylic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, 2-oxovaleric acid, 3-oxovaleric acid, pivalic acid, acetoacetic acid, levulinic acid, 3-methyl-2-oxobutyric acid, propiolic acid, tetrahydrofuran-2-carboxylic acid, methoxyacetic acid, dimethoxyacetic acid, 2-(2-methoxyethoxy)-acetic acid, 2-methyl acetic acid, pyruvic acid, 2-methoxyethanol, vinyl acetic acid, allyl acetic acid, 2-pentenoic acid, 3-pentenoic acid, tetrahydrofuran-2-carboxylic acid.
Examples of polybasic carboxylic acids include oxalic acid, malonic acid, fumaric acid, maleic acid, succinic acid, glutaric acid, acetylene dicarboxylic acid, oxaloacetic acid, acetone dicarboxylic acid, mesoxalic acid, citraconic acid, dimethyl malonic acid, methyl malonic acid, ethyl malonic acid.
Other suitable starting materials are hydroxycarboxylic acids, for example tartronic acid, lactic acid, malic acid, tartaric acid, citramalic acid, 2-hydroxyvaleric acid, 3-hydroxyvaleric acid, 3-hydroxybutyric acid, 3-hydroxyglutaric acid, dihydroxyfumaric acid, 2,2-dimethyl-3-hydroxypropionic acid, dimethylolpropionic acid, glycolic acid.
The esterification may be either complete or partial. Mixtures of the above-mentioned acids may optionally be used for the esterification.
The esters to be used in accordance with the invention prepared from the above-mentioned alcohols and carboxylic acids or the corresponding derivatives are preferably free from catalysts, more particularly alkali metals and amines. This can be achieved by treating the esters according to the invention with acids, ion exchangers, acetic acid clays, aluminium oxides, active carbon or other auxiliaries known to the expert. The esters may be dried and further purified by overhead distillation.
Examples of the esters according to the invention include ethyl acetate, butyl acetate, glycerol triacetate, glycerol tripropionate, triglycerol pentaacetate, polyglycerol acetate, diethylene glycol diacetate, 3-hydroxyvaleric acid ethyl ester, lactic acid butyl ester, lactic acid isobutyl ester, 3-hydroxybutyric acid ethyl ester, oxalic acid diethyl ester, mesoxalic acid diethyl ester, malic acid dimethyl ester, malic acid diisopropyl ester, tartaric acid diethyl ester, tartaric acid dipropyl ester, tartaric acid diisopropyl ester, glutaric acid dimethyl ester, succinic acid dimethyl ester, succinic acid diethyl ester, maleic acid diethyl ester, fumaric acid diethyl ester, malonic acid diethyl ester, acrylic acid-2-hydroxyethyl ester, 3-oxovaleric acid methyl ester, glycerol diacetate, glycerol tributyrate, glycerol tripropionate, glycerol dipropionate, glycerol triisobutyrate, glycerol diisobutyrate, glycidyl butyrate, acetoacetic acid butyl ester, levulinic acid ethyl ester, 3-hydroxyglutaric acid dimethyl ester, glycerol acetate dipropionate, glycerol diacetate butyrate, propiolic acid butyl ester, propylene glycol diacetate, propylene glycol dibutyrate, diethylene glycol dibutyrate, trimethylol ethane triacetate, trimethylol propane triacetate, trimethylol ethane tributyrate, neopentyl alcohol dibutyrate, methoxyacetic acid pentyl ester, dimethoxyacetic acid butyl ester, glycolic acid butyl ester.
The boiling point of the esters according to the invention is preferably above 180xc2x0 C. and more preferably above 200xc2x0 C. at normal pressure.
The esters according to the invention are added in a quantity of up to 50% by weight and preferably in a quantity of 1 to 30% by weight, based on the adhesive as a whole. Beyond a concentration of 30 and, more particularly, 40% by weight, the polycyanoacrylates show contact-adhesive properties.
The cyanoacrylate adhesives are essentially based on typical monocyanoacrylic acid esters and/or biscyanoacrylates.
xe2x80x9cTypical monocyanoacrylic acid estersxe2x80x9d in the context of the invention are understood to be compounds corresponding to general formula (I):
H2C=C(CN)xe2x80x94COxe2x80x94Oxe2x80x94Rxe2x80x83xe2x80x83(I)
where R is an alkyl, alkenyl, cycloalkyl, aryl, alkoxyalkyl, aralkyl or haloalkyl group, more especially a methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, pentyl, hexyl, allyl, methallyl, crotyl, propargyl, cyclohexyl, benzyl, phenyl, cresyl, 2-chloroethyl, 3-chloropropyl, 2-chlorobutyl, trifluoroethyl, 2-methoxyethyl, 3-methoxybutyl and 2-ethoxyethyl group. The cyanoacrylates mentioned above are known to the expert on adhesives, cf. Ullmann""s Encyclopedia of Industrial Chemistry, Vol. A1, page 240, Verlag Chemie Weinheim (1985), U.S. Pat. Nos. 3,254,111 and 3,654,340. Preferred monomers are the allyl, methoxyethyl, ethoxyethyl, methyl, ethyl, propyl, isopropyl or butyl esters of 2-cyanoacrylic acid.
xe2x80x9cBiscyanoacrylatesxe2x80x9d are compounds corresponding to general formula (II):
[H2C=C(CN)xe2x80x94COxe2x80x94O]2R1xe2x80x83xe2x80x83(II)
where R1 is a branched or unbranched difunctional alkane group containing 2 to 18 and, more particularly, 6 to 12 carbon atoms which may also contain hetero atoms, such as halogens and oxygen, or aliphatic or aromatic rings. However, R1 is preferably a pure hydrocarbon. It is important that the biscyanoacrylates be particularly pure. This requirement is satisfied, for example, by the following production and purification methods: essentially, monocyanoacrylates are transesterified with diols and the reaction mixtures are subsequently worked up by fractional crystallization.
Accordingly, a suitable process for the production of biscyanoacrylates comprises transesterifying 2-cyanoacrylic acid or an alkyl ester thereof corresponding to general formula (III):
H2C=C(CN)xe2x80x94COxe2x80x94Oxe2x80x94R2xe2x80x83xe2x80x83(III)
where R2 is a branched or unbranched alkyl group containing 1 to 6 carbon atoms,
with diols corresponding to general formula (IV):
[HO]2R1xe2x80x83xe2x80x83(IV)
where R1 is a branched or unbranched difunctional alkane group containing 2 to 18 carbon atoms, which may also contain hetero atoms, such as halogens and oxygen, or aliphatic or aromatic rings,
to form biscyanoacrylates corresponding to general formula II and then purifying the reaction mixture by fractional crystallization.
Accordingly, one starting product is a monofunctional cyanoacrylic acid corresponding to formula III or an alkyl ester thereof. The alkyl group should be selected so that the alcohol formed can be easily removed. Suitable possibilities are known to the expert from the general transesterification reaction. The alcohol is preferably removed by distillation. Accordingly, R2 is a branched or unbranched alcohol radical containing 1 to 6 carbon atoms, preferably 1 or 2 carbon atoms. The monofunctional cyanoacrylic acid ester is stabilized in the usual way.
The diols (formula IV) are dihydric primary or secondary alcohols, preferably primary alcohols. The hydroxyl groups may be in any position to one another, although they are preferably in the alpha/omega position. The diols contain 2 to 18 carbon atoms and preferably 6 to 12 carbon atoms. They may be in a linear, branched or cyclic arrangement. The aliphatic radical may also contain an aromatic group or, besides the hydrogen and carbon atoms, hetero atoms such as, for example, chlorine or oxygen atoms, preferably in the form of polyethylene or polypropylene glycol units. Hexane diol, octane diol, decane diol and dodecane diol are specifically mentioned as diols.
The cyanoacrylic acid ester is used in excess. Accordingly, the molar ratio of monofunctional cyanoacrylic acid ester to diol is at least 2.0:1.0, preferably 2.5:1.0 and, more preferably, 2.2:1.0.
The transesterification is catalyzed by strong acids, more especially sulfonic acids and preferably aromatic sulfonic acids such as, for example, p-toluene sulfonic acid. However, naphthalene sulfonic acid, benzene sulfonic acid and acidic ion exchangers may also be used. The concentration of the transesterification catalyst should be between 1 and 20% by weight, based on the monofunctional cyanoacrylate.
The transesterification reaction is carried out in solution, as is normally the case. Suitable solvents are aromatic hydrocarbons and halogenated hydrocarbons. Preferred solvents are toluene and xylene. The concentration of the solution is 10 to 50% and preferably 10 to 20%.
The monohydric alcohol formed and the water formed are removed in known manner and, preferably, distilled off with the solvent. The conversion of the transesterification reaction is monitored, for example, from NMR spectra. The reaction takes several hours, as is normally the case. Where toluene is used as the solvent and p-toluene sulfonic acid as the catalyst, the reaction is terminated after 10 to 15 hours when there is no further separation of alcohol.
The working up of the reaction mixture is very important. Where acidic ion exchangers are used as the catalyst, they may be simply filtered off. Where soluble sulfonic acids, for example p-toluene sulfonic acid, are used as the catalyst, they are removed by solvent substitution: toluene is replaced by a mixture of hexane, heptane or decane. Pure biscyanoacrylate is obtained after two fractional crystallizations. According to NMR spectra, it has a purity of more than 99%.
The biscyanoacrylate obtained is stable in storage with the usual stabilizers and in the usual concentrations, i.e. there is hardly any change in its melting point after storage for 6 months at 20xc2x0 C.
However, the biscyanoacrylates obtained polymerize very quickly in the presence of bases, preferably at substantially the same rate as the corresponding monocyanoacrylates. As with the monofunctional cyano-acrylates, traces of water are sufficient. A three-dimensionally crosslinked polymer with relatively good thermal properties is formed.
According to the invention, therefore, it is used in known cyanoacrylate adhesives in a quantity of 0.5 to 50% by weight, preferably 1 to 10% by weight and more preferably 2 to 5% by weight, based on the adhesive as a whole.
Besides the plasticizer according to the invention, the adhesive may contain other additives, for example other plasticizers, thickeners, stabilizers, activators, dyes and accelerators, for example polyethylene glycol or cyclodextrin and polymers.
The polymers may be used in a quantity of 1 to 60% by weight, preferably 10 to 50% by weight and more preferably 10 to 30% by weight, based on the formulation as a whole. Suitable polymers are, above all, polymers based on vinyl esters, vinyl ethers, esters of acrylic acid and methacrylic acid, styrene and copolymers and terpolymers derived therefrom with ethene, butadiene. The polymers may be present in liquid, resin-like or even solid form. It is particularly important that the polymers contain no impurities from the polymerization process which could inhibit curing of the cyanoacrylate. If the polymers have an excessive water content, they may have to be dried. Their molecular weight may be scattered over a broad range although the Mw value should be at least 1,500 and at most 1,000,000 because otherwise the final viscosity of the adhesive formulation will be too high. Mixtures of the above-mentioned polymers may also be used. More particularly, a combination of low molecular weight and high molecular weight products has particular advantages in regard to the final viscosity of the adhesive formulation. Examples of suitable polymers based on vinyl acetate include Mowilith types 20, 30 and 60 and Vinnapas types B1.5, B100, B17, B5, B500/20VL, B60, UW10, UW1, UW30, UW4 and UW50. Examples of suitable acrylate-based polymers are Acronal 4F and Laromer types 8912, PE55F and PO33F. Examples of suitable methacrylate-based polymers include Elvacite 2042, Neocryl types B 724, B999 731, B 735, B 811, B 813, B 817 and B722, Plexidon MW 134, Plexigum types M 825, M 527, N 742, N 80, P 24, P28 and PQ 610. An example of a suitable vinyl ether-based polymer is Lutonal A25.
The adhesive is prepared in the usual way by mixing the individual components. In all the cases investigated, the stability of the new adhesives in storage was more than 1 year at room temperature or more than 10 days at 80xc2x0 C.
The cure rate is hardly affected by the plasticizer according to the invention, i.e. it is preferably not doubled and barely exceeds 1 minute in the case of EPDM.
The new cyanoacrylate adhesive according to the invention is particularly suitable for bonding, above all, rubber, metals, wood, ceramics, china, paperboard, paper, cork and plastics other than PE, PP and Teflon and Styropor.
The invention is illustrated by the following Examples.
In order to obtain a comprehensive overview of the changes which the properties of the cyanoacrylates undergo as a result of the addition of plasticizers according to the invention, mixtures of basically stabilized pure ester and mixtures of glycerol triacetate (triacetin) or ethyl acetate in combination with various polymers in the range from 0 to 40% by weight (additives as a whole) were prepared. The basic stabilization consists of hydroquinone (400 to 1,000 ppm) and SO2 (5 to 15 ppm). The samples were homogenized for 6 days in a shaking machine and then measured.

Cyanacrylate adhesive with ester and polymer additives