A lightweight, ergonomically beneficial, hydrodynamic, and volumetrically efficient hybrid pressure vessel having at least two longitudinally extending, semi-cylindrical sections with flattened rib portions at a common interface between the sections. Additional longitudinally extending sections may be employed to provide additional internal volume. One or more apertures extend through the ribs to provide communication between sections. The pressure vessel comprises a cast metal material, optionally including exterior reinforcing structure for containing internal pressure.

The use of pressurized gas vessels, or air tanks, for breathable primary or supplemental air supplies has become widely accepted in recreational, industrial and public safety arenas. Air tanks are used underwater for recreational underwater diving, termed "SCUBA" (Self Contained Underwater Breathing Apparatus) diving, which is also applicable to industrial or commercial settings for ship repair, off-shore drilling operations, underwater salvage, pipeline repair, as well as to military applications, search and rescue operations, and underground environments, such as mines. In above-water applications, an air tank used as a Self-Contained Breathing Apparatus (SCBA) is invaluable for personnel working in an environment that poses an Immediate Danger to Life or Health (IDLH). SCBAs are used by fire fighters entering into smoke filled or toxic environments, police working at contaminated crime scenes, underground mine rescue teams entering "bad air" or smoke, HAZMAT teams working in contaminated environments, and industrial maintenance personnel working in confined spaces or in toxic environments. SCBAs are also strategically placed in chemical plants, laboratories, refineries, nuclear facilities, paper mills and underground mines for employees to use as a "self-rescuer" during an emergency.
FIG. 1 depicts a conventional pressure vessel or air tank 10 configured as a cylinder 12 with a domed, or hemispherical, top 18 and a domed, or hemispherical, bottom 20. A rubber or plastic boot 16 disposed over the bottom 20 both protects and stabilizes the cylinder 12 when resting on a surface in an upright position. A gas under pressure such as a breathable air mixture or, less commonly, oxygen, is injected and expelled from the cylinder 12 via a primary valve 14.
Cylinders vary in size depending upon the application. A self-rescue air cylinder may be relatively small; for example a cylinder with an 8 cubic foot equivalent capacity at 3000 PSI, may be 4 inches in diameter and 10 inches long, and can be used to supply sustainable air for about 5 minutes. This provides the user enough time to retreat from a small building or enclosure to a safe environment. An air supply lasting 15 minutes is the minimum requirement for an SCBA to be approved by the National Institute for Occupational Health and Safety (NIOSH) for entering IDLH environments. In order for a SCBA to meet the 15 minute standard the device must have a capacity of 20-24 cubic feet equivalent, when the air is pressurized to 3000 PSI. This requires a single air cylinder with dimensions approximately 5 inches in diameter and 18 inches in length, or the breathable air volume can be split between multiple, smaller cylinders. However, the bulk and size of either of these configurations may become a hindrance if the user is attempting to perform tasks in, or trying to escape from, a confined space. Fire fighters and mine rescue personnel use incrementally larger configurations of SCBAs, allowing for extended forays into IDLH environments, re-supplying breathable air to fellow rescuers or the ability to share breathable air with a victim stranded in the hostile environment. Most SCUBA air cylinders are a so-called standard "80," or a cylinder capable of holding 80 cubic feet of air. Thus, if an additional volume of breathable air is required, most divers will use two tanks or "double-up" tanks. However, 100 cubic foot and larger tanks are also available. The 100 cubic foot tanks are extremely large and, when made from steel, weigh more than 40 lbs. Double tanks or the large, 100 cubic foot tanks are manageable underwater, but can significantly reduce the diver's mobility when negotiating around or within structures such as, by way of example only, rocks or coral, offshore platforms, or sunken ships. Additionally, smaller users may not be physically able to shoulder or handle the larger tanks or multi-tank configurations while above water.
Further, with respect to the use of multiple cylindrical tanks, stacking or aligning cylindrical structures in a single row is an inefficient use of space. Considering cylinders with the same diameter, each cylinder contacts the laterally adjacent cylinder or cylinders tangentially along a line of contact, creating a substantially triangular void between the cylinders on either side of the line of contact. This issue has been addressed in a number of applications for improving the volumetric efficiency of multiple cylinders used for storing propane or natural gas. Most of these multi-cylinder pressure vessels are formed using rolled steel sections which are mated and welded together, such as those described in U.S. Pat. No. 4,946,056 to Stannard, U.S. Pat. No. 3,528,582 to Rigollot and U.S. Pat. No. 3,414,153 to Leroux. Another method used to form multi-cylinder pressure vessels includes interlocking sections, such as a clip and lobe arrangement, shown in U.S. Pat. No. 6,220,779 to Warner et al. U.S. Pat. No. 5,944,215 to Orlowski describes a volumetrically efficient multi-cylinder vessel that may be formed from a plastic as a one-piece or unitary structure. A second one-piece plastic structure designed for use in automotive applications as a vacuum pressure vessel is described in U.S. Pat. No. 4,343,409 to Silver. Each of these plastic vessels are designed for relatively low pressure or vacuum use, the former being designed for at least 5 atmospheres or approximately 75 psi and the latter being described to provide "adequate implosion resistance" when subjected to a vacuum sufficient to actuate automotive features like headlight door covers.
A diving tank is typically attached to a pack-frame using a clamping ring, or the tank is placed into a "clamshell" structure that fully encases the tank and is worn on the diver's back. Originally the pack-frame accommodated the air tank only and the user would need a separate weight-belt and inflatable vest or BC (buoyancy compensator) to achieve neutral or slightly negative buoyancy while in the water. Modern tank packs are now universally referred to as a BC and are configured more like a vest which includes the air tank clamping ring, integrated regulators and gauges, an inflatable bladder, weights and pockets for numerous diving accessories. With both the older pack-frame and a modern BC, the air tank extends well above the diver's back and, since it is behind the diver and out of sight, the diver can easily misjudge the clearance necessary to enter an opening in a reef, cave or wreck, causing damage to the air tank or possibly trapping the diver. This problem is exacerbated when using large or multiple tanks.
Divers manage underwater risk in several ways. One way is by "slinging" their air tank over a single shoulder when diving in a confined space such as wreck or cave, allowing the tank to dangle below the diver, where the tank can be watched and manually manipulated around obstacles. A second way to manage risk and which has been adopted as a modern standard safety feature is the provision of an emergency regulator. Originally, tanks included a single hose from the primary valve to the diver's mouthpiece or regulator. Currently, an additional hose for a backup regulator or "octopus" is attached to the tank. The octopus is available to the diver if the primary regulator fails or malfunctions and may be offered to another diver who is short of air or otherwise in trouble.
It would be desirable to offer a portable air tank system that is volumetrically more efficient than conventional multi-tank systems, is of reduced overall weight for easy handling, is less obtrusive, as well as more compact and hydrodynamic.


In general, embodiments of the technology relate to writing data to and reading data from storage appliances. More specifically, embodiments of the technology describe a method and system whereby a global control mechanism may be established, with delegation of specific translation activities to particular storage media device.

Storage appliances include storage media and provide a mechanism to enable clients to write data to and to read data from the storage media. In some conventional implementations, a logical to physical address translation layer is included with each storage media device. In other conventional implementations, a logical to physical address translation layer is implemented across all storage media devices by a global control mechanism.

Delegated media translation layer in a storage appliance


The present disclosure provides methods of using probiotic arginolytic oral compositions including isolated arginolytic bacterial strains to increase arginolytic activity in the oral cavity, increase ammonia-producing bacteria in the oral cavity, and/or to treat and/or prevent oral disorders, such as caries.

Dental caries is the most prevalent infectious and chronic disease affecting humans, and is associated with costly treatment worldwide. The transition from dental health to dental caries is characterized by compositional and metabolic changes in the complex microbial communities of oral biofilms. Oral biofilms, often called dental plaque, constantly form and grow on all tooth surfaces. Although production of acid by the bacteria in oral biofilms is the direct cause of dental caries, it is noteworthy that increases in the proportions of aciduric organisms, such as the caries-associated Streptococcus mutans, appear to occur at the expense of species that are less acid tolerant (i.e. less "aciduric"). Of particular note, a subset of less aciduric organisms derives protection from plaque acidification by alkali generation, which shows a positive association with dental health.
One of the primary routes for alkali generation by oral bacteria is the arginine deiminase system (ADS), through which arginine is catabolized into ornithine, ammonia and CO2, with the concomitant generation of ATP. Hence, the ADS serves key physiological functions in bacteria, providing protection from the deleterious effects of low pH and ATP for growth and maintenance. The ADS activity in oral biofilms can impact the ecology of oral microbial communities by moderating the pH through ammonia production.
A variety of bacteria that colonize the teeth and oral soft tissues and form oral biofilms express the ADS. An increased risk for dental caries has been associated with a reduced ability of oral biofilms to produce alkali from arginine via the arginine deiminase system (ADS). Specifically, plaque bacteria from caries-free subjects present higher levels of ADS activity when compared to plaque bacteria from caries-active subjects. Moreover, there is a high degree of variability in the rate of alkali production among individuals, in some cases greater than 1000-fold. A better understanding of the microbiological basis of inter-subject variation in ADS activity and methods for improving ADS activity for the improvement of oral health would be beneficial.
Other streptococcal species can also produce and secrete antimicrobial substances that suppress the growth of S. mutans, including hydrogen peroxide (H2O2). For example, Streptococcus sanguinis and Streptococcus gordonii produce sufficient amounts of H2O2 to inhibit growth of S. mutans, mainly via a pyruvate oxidase enzyme (Pox) encoded by the spxB gene. H2O2 production by S. gordonii, but not S. sanguinis, seems to be inversely correlated with carbohydrate availability. S. oligofermentans can also produce H2O2 from lactic acid through lactate oxidase (Lox) and less efficiently using L-amino acid oxidase enzymes (LAAO). Moreover, facultatively anaerobic lactic-acid bacteria, including commensal oral streptococci, were shown to have vigorous oxygen metabolism catalyzed by flavin-containing NADH oxidases, some of which yield H2O2 as an end product.

This patent is subject to a terminal disclaimer.

Probiotic arginolytic oral compositions and methods of making and using probiotic arginolytic oral compositions

University of Florida Research Foundation, Inc.


In an embodiment the present invention provides a dispensing device for introducing a pourable detergent in metered amounts into a treatment chamber of a program-controlled cleaning appliance, in particular a dishwasher, the dispensing device including: a supply container for holding the detergent, the supply container having a reservoir chamber and a metering chamber terminating in a dispensing opening, the metering chamber being provided by a metering element that is movably disposed within the supply container and is movable from a non-metering position to a metering position; and a carrier unit which is rotatable by a motor and is configured to replaceably receive the supply container.

Program-controlled cleaning appliances in general, and dishwashers in particular, are per se well known in the art and, therefore, need not be specifically described herein.
Cleaning appliances of the type in question typically have a washing tub providing a treatment chamber, also called washing chamber. The treatment chamber is accessible to a user via a loading opening which can be closed in a fluid-tight manner by a pivotably mounted washing chamber door. During normal use, the washing tub serves to receive items to be washed which, in the case of a dishwasher, may be dishes, cutlery items and/or the like.
In order to apply wash water, also called wash liquid, to the items to be washed, the cleaning appliance has a spray device disposed inside the washing tub. This spray device generally provides rotatable spray arms, typically two or three such spray arms. During normal use, wash liquid is applied to the items to be washed by rotating spray arms.
In order to achieve optimized cleaning results, process chemicals are used which are delivered into the washing chamber during a cleaning operation. Typically, the process chemicals are added to the wash liquid. Such process chemicals may, for example, be detergents, which are added into the washing chamber of the cleaning appliance in a program-controlled manner at a particular point in time during the operational cycle.
Detergents in liquid and solid form are known in the art. Solid detergents may be in the form of pourable powders or so-called tabs; i.e., in tablet form. However, practice has shown that the comparatively best results can be achieved with pourable detergents in powder form.
When pourable detergents in powder form are used, the user must manually measure out the detergent each time before a cleaning cycle is started. For this purpose, a cleaning appliance typically has a supply container which is disposed on the inner side of the door and has to be charged with a manually selected amount of detergent. During operation, this supply container opens at a particular point in time during the wash cycle, allowing the detergent held in the supply container to be washed out by the wash liquid present in the washing chamber of the cleaning appliance.
To be able to store detergent for a plurality of wash cycles, avoiding the need to manually measure out detergent each time before a wash cycle is started, dispensing devices have been proposed, such as the one described in DE 10 2013 104 391 A1.
This known dispensing device has a replaceable supply container for storing an amount of detergent sufficient for a plurality of wash cycles. The supply container is rotatable about an axis of rotation. During a normal dispensing event, the supply container is rotated in a program-controlled manner. For this purpose, a motor-driven drive device is provided which, when operated, causes rotational movement of the supply container. In the process, the motor-driven drive device cooperates with a carrier unit which replaceably receives the supply container.
To permit release of detergent, the supply container has a dispensing opening. During operation, detergent is released in portions through this opening. Such a release of detergent occurs in response to a rotational movement of the supply container. Each 360° rotation of the supply container causes equal portions of detergent to be fed to the dispensing opening and released from there into the washing chamber of the cleaning appliance via an interposed channel system.
To be able to effect metering of the detergent, the supply container has a reservoir chamber, on the one hand, and a metering chamber, on the other hand. The reservoir chamber is used for storing the detergent, and the metering chamber is used for dispensing the detergent in portions during operation. To this end, the metering chamber is divided into two fluidically connected sections, namely a metering space and a dispensing channel, which are separated by a barrier. The barrier bounds the metering space in such a manner that during a rotational movement of the supply container, first the metering space is filled with an amount of detergent determined by the size of the metering space. During further rotational movement, the amount of detergent introduced into the metering space is conveyed past the barrier into the dispensing channel and toward the dispensing opening without any additional detergent flowing from the reservoir chamber into the metering space. Thus, during normal use, the detergent passes from the reservoir chamber through the passage opening into the metering space of the metering chamber, the size of the metering space determining the portioned amount of detergent. When the supply container is rotated further, the portioned amount of detergent exits the metering space and passes through the dispensing channel to the dispensing opening. During this process, no additional detergent can flow from the reservoir chamber through the passage opening into the metering space of the metering chamber due to the continued rotation of the supply container.
Dispensing devices of the aforedescribed type have proven practical in everyday use. Nevertheless, there is a need for improvement, particularly with respect to increasing the ease of use for the user. It is, therefore, an object of the present invention to improve a dispensing device of the above-mentioned type in such a way that it makes handling easier for the user because of the design.


Disclosed is a method for producing a catalyst, wherein the method comprises: a supplying step of supplying a dispersion containing a palladium-containing fine particle from a supplying part into a reaction container; a preparing step of preparing a copper-palladium-containing complex in which at least part of a surface of the palladium-containing fine particle is covered with copper, by passing the dispersion through a reacting part and bringing the palladium-containing fine particle in the dispersion into contact with a copper-containing member in the reacting part; and a substituting step of substituting the copper in the copper-palladium-containing complex emitted from an emitting part with platinum by bringing the complex into contact with a platinum-containing solution.

Technical Field
The present invention relates to a method for producing a catalyst, which is configured not to require the application of a potential at the time of covering the surface of a palladium-containing fine particle with copper, in the production of a catalyst. The present invention also relates to a production device which is configured to be able to realize the method.
Background Art
As a technique aimed at cost reduction of catalysts, a technique relating to fine catalyst particles is known, which have a structure that includes a core particle and an outermost layer covering the core particle (a so-called core-shell structure). In the fine catalyst particles, by using a relatively inexpensive material for the core particle, the cost of the inside of the particles which does not participate in catalytic reactions can be reduced. In Patent Literature 1, a technique for covering the surface of a fine catalyst particle with copper is disclosed, in which a reaction container is filled with a carbon-containing member; a raw material for fine catalyst particles is passed through the reaction container, with applying a given potential thereto; and the surface of the fine catalyst particle is covered with copper by copper underpotential deposition (Cu-UPD).    Patent Literature 1: Japanese Patent Application Laid-Open (JP-A) No. 2014-128756
However, in the prior art disclosed in Patent Literature 1, a device for applying a potential to the reaction container is additionally required, which will be the cause of an increase in the production cost, especially in the case of expanding the reaction scale.

Method and device for producing a catalyst


New 2,2-dimethylcyclopropanecarbaldehyde dimethyl acetal derivatives of the formula ##STR1## wherein X is --CH.sub.2 OC(O)CH.sub.3, --CH.sub.2 OH, or --CHO are useful chemical intermediates for the preparation of pesticidally active cyclopropanecarboxylates.

1. Field of the Invention
This invention relates to new 2,2-dimethylcyclopropanecarbaldehyde dimethyl acetal derivatives and to a process for the preparation of these derivatives.
2. Description of the Prior Art
It is well known that certain substituted cyclopropanecarboxylic acid derivatives are an important class of pesticides called "pyrethroids". These pyrethroids have been of considerable interest because of their quick knock-down activity, low persistence as toxic residues and their low mammalian toxicity. However, the acid moiety of these pyrethroids has heretofore been fairly expensive to manufacture in the large scale commercial quantities for agricultural and domestic applications.
The hereinafter described process of the invention, and the new intermediates thereof, provide a method for obtaining desired pyrethroids from 3-carene, which is an inexpensive, readily available, naturally occurring terpene found in numerous varieties of pine trees.

2,2-Dimethylcyclopropanecarbaldehyde dimethyl acetal derivatives


An essentially water-free solvent system comprising methoxy acetone and an organic protic solvent is useful as a solvent for. a) a curing agent for an epoxy resin and/or PA1 b) a curing catalyst and/or PA1 c) a cure inhibitor.

The present invention relates to a solvent system and to the use of the solvent system for dissolving one or more curing agents for epoxy resins and/or one or more curing catalysts and/or one or more cure inhibitors.
It is a well known technique to utilize an organic solvent for reducing the viscosity of liquid epoxy resins or liquid curing agents therefore or to solubilize solid resins and/or curing agents in organic solvents in order to facilitate the handling of the epoxy resins and/or of the curing agents.
U.S. Pat. No. 3,679,465 teaches the production of reinforced, hardenable epoxy compositions by continuously passing a reinforcement material through an epoxy solution system, thereby impregnating the reinforcement material with the epoxy solution system. The impregnated reinforcement material is subjected to a heat treatment. The epoxy solution system contains a curable epoxy resin, a curing agent therefore and a low boiling solvent. Various types of conventional curing agents or hardeners as well as accelerators are listed, such as primary and secondary amines, amides, polyamines, polyamides, dicyandiamide, benzoguanamine, imidazole, tetramethyl diamine, etc. As useful low boiling organic solvents are mentioned acetone or methyl ethyl ketone, or a mixture of dimethyl formamide, acetone and water.
It is known that mixtures containing an epoxy resin and certain curing agents therefore, such as dicyandiamide, have excellent storage stability at 20.degree. C. Therefore, these mixtures are useful for producing so-called "one-component systems" which cure upon heating.
East German patent 134 446 teaches that a major disadvantage of known one-component systems is the low solubility of dicyandiamide in the solvents which are used in these systems. The amount of dicyandiamide required for curing the system is often close to or even above its saturation concentration in the solvent. Precipitation of dicyandiamide from the one-component system at low temperature, such as 0.degree. C., is quite frequent. In order to overcome this disadvantage, the East German patent suggests the production of a one-component system by dissolving an epoxy resin and dicyandiamide in a mixture consisting of a glycol ether and water. Water is used in an amount of from 1 to 30 percent, preferably 5 to 15 percent, by the weight of the glycol ether. Useful glycol ethers are said to be ethyl glycol and/or methyl glycol.
WORLD PATENT INDEX, Abstract No. 79-26180B by Derwent Publications Ltd., which abstracts East German patent 133 955, discloses that a hardener for epoxy resins consists of dicyandiamide dissolved in a solvent mixture of glycol ethers, especially ethyl glycol and/or methyl glycol, containing 1 to 50, preferably 5 to 20 wt. -percent, water. It is disclosed that the presence of water doubles the dicyandiamide solubility. Presently, the monomethyl ether and monoethyl ether of ethylene glycol as well as dimethyl formamide are widely used in the industry for dissolving epoxy hardeners like dicyandiamide.
However, the wide use of ethylene glycol monomethyl ether, ethylene glycol monoethyl ether and dimethyl formamide has raised some concern among environmentalists.
It is known from Swiss patent 257,115 to heat an epoxy resin in the presence of a solvent with dicyandiamide and an aldehyde condensation product containing etherified methylol groups, such as alkyl ethers of methylolmelamine or of methylolureas. It is suggested to dissolve the epoxy resin in an organic solvent, such as 2-methyl-pentanediol-(2,4), toluene, cyclohexanol, etc. and to add the other components. Alternatively, the epoxy resin can be combined with a mixture of dicyandiamide, aldehyde condensation product and solvent. From 2 to 20 percent, preferably from 6 to 10 percent, of dicyandiamide is used for curing, based on the weight of the epoxy resin. The Swiss patent teaches that the amount of the aldehyde condensation product must be high enough to enable a complete absorption of dicyandiamide in the resin solution. Lacquer resin solutions are produced which can be used for applying coats of lacquer on metals. These coats of lacquer have good properties, such as good adherence to metals and high resistance to chemicals.
WORLD PATENT INDEX LATEST, Abstract No. 91-003223 by Derwent Publications Limited, abstracting published Japanese patent application JP-A-2,279,776 discloses an ink composite containing an epoxy resin, a hardening agent and a solvent. Dicyandiamide, imidazole compounds, triazine compounds, urea compounds, aromatic amine compounds and one or more kinds of photo-cationic polymerization catalysts are used as a hardening agent. The compound of formula R.sup.1 --(OR.sup.2).sub.n OR.sup.3 and one or more kinds of solvent naphtha are used as a solvent. R.sup.1 is hydrogen or C.sub.1-8 -alkyl, R.sup.2 is methylene or ethylene, R.sup.3 is hydrogen or --C(O)--R.sup.4 wherein R.sup.4 is C.sub.1-8 -alkyl and n is 1 to 4.
Published German patent applications DE-A-2,545,149 and DE-A-2,650,408 suggest the use of a mixture of diacetone alcohol and water for dissolving dicyandiamide. It is recommended to dissolve 3 weight parts of dicyandiamide in 65 weight parts of diacetone alcohol and 13.3 weight parts of water. However, trials made by the Applicants have shown that dicyandiamide dissolves very slowly in the suggested mixture of diacetone alcohol and water. Apparently no more than 3 weight parts of dicyandiamide can be dissolved in the suggested solvent mixture. Furthermore, upon addition of an epoxy resin solution described in detail in the Examples further below, the dicyandiamide solution in diacetone alcohol and water turns turbid. The turbidity is an indication that dicyandiamide crystallizes.
The published Belgian patent application BE-A-677,466 discloses an epoxy resin and 1-cyanoguanidine dissolved in a solvent mixture of a low boiling point. The solvents in the solvent mixture are mainly polar. One solvent mainly serves to dissolve the epoxy resin. Acetone and/or ethyl acetate are suggested. The other solvent mainly serves to dissolve 1-cyanoguanidine. Water or a mixture of water and acetone or a low boiling alcohol, such as methanol and/or ethanol are suggested. However, trials made by the applicants have shown that the solubility of the expoxy resin and 1-cyanoguanidine in several of the suggested solvents, such as water, methanol, ethanol or acetone, is undesirably low.
Accordingly, one object of the present inventions is to find a new solvent system. Another object of the present invention is to find a solvent system which is useful for dissolving a curing agent for an epoxy resin, for dissolving a curing catalyst or a cure inhibitor for dissolving a blend thereof.
Applicants have found that an essentially water-free mixture comprising methoxy acetone and an organic protic solvent is a very useful solvent for a curing agent, such as a dicyandiamide, or for a curing catalyst, such as an imidazole, or for a cure inhibitor, such as boric acid, or for a mixture of two or more of such compounds.
Accordingly, one aspect of the present invention is an essentially water-free solvent system comprising methoxy acetone and an organic protic solvent.
Another aspect of the present invention is a method of preparing a solution of one or more compounds selected from the group consisting of
a) curing agents for an epoxy resin, PA1 b) curing catalysts, and PA1 c) cure inhibitors, PA1 one of the substituents R.sub.1 and R.sub.2 is an alkyl group having from 1 to 12, preferably from 1 to 6, more preferably from 1 to 4 carbon atoms and the other of the substituents R.sub.1 and R.sub.2 is hydrogen, PA1 R.sup.3 in each occurrence independently is methyl or ethyl and PA1 n is from 1 to 4, preferably 1, 2 or 3. PA1 the substituents R.sub.4 and R.sub.5 each independently are an alkyl group having from 1 to 12, preferably from 1 to 6, more preferably from 1 to 4 carbon atoms, PA1 R.sup.3 in each occurrence independently is methyl or ethyl and PA1 n is from 1 to 4, preferably 1, 2 or 3. PA1 a) a curing agent for an epoxy resin; and/or PA1 b) a curing catalyst; and/or PA1 C) a cure inhibitor.
in the indicated solvent system by contacting one or more such compounds with a solvent system comprising methoxy acetone and an organic protic solvent.
Yet another aspect of the present invention is a solution containing the indicated solvent system and one or more such compounds.
Yet another aspect of the present invention is an epoxy resin composition containing the indicated solution of the present invention and an epoxy resin.
The essentially water-free solvent system comprises methoxy acetone and one or more organic protic solvents. By the term "essentially water-free" is meant that the solvent system does not contain an essential amount of water. This means that the water content of the solvent system is not more than about 1 percent, preferably not more than about 0.1 percent, more preferably not more than about 0.01 percent, by the total weight of the solvent system. Most preferably, the solvent system does not contain any extractable amount of water.
The weight percentage of methoxy acetone in the solvent system of the present invention preferably is from about 25 to about 95 percent, more preferably from about 30 to about 65 percent, most preferably from about 40 to about 60 percent, by the total weight of the solvent system. Methoxy acetone, also named 1-methoxy-2-propanone, has the chemical formula H.sub.3 C--C(O)--CH.sub.2 --OCH.sub.3. Methoxy acetone has a boiling point of about 114.degree. C. at atmospheric pressure. The boiling point of the solvent system depends on the amount and kind of the organic protic solvent and of any optional compounds present. Generally, the solvent system has a boiling point of from 100.degree. to 150.degree. C., preferably from 105 to 140.degree. C. This is very favorable because on one side the boiling point is low enough to allow removal of the boiling system after usage without substantial difficulties and on the other hand the boiling point is high enough that premature evaporation of the solvent system and a resulting quality loss generally is not experienced.
Methoxy acetone is a known compound. The author of JP-A-2,279,776 believes that methoxy acetone forms its peroxide under mild conditions. It is suggested to use peroxide-containing methoxy acetone as a radical polymerization initiator. The peroxide-containing methoxy acetone is said to have high dissolving power. Equilibrium constants for addition of water and 3-mercaptopropionic acid to various methyl ketones including methoxy acetone in D.sub.2 O have been made by Th. J. Burkey et al., "Equilibrium studies of water and thiol addition to ketones: substituent and solvent effects for methyl ketones"; Journal of the American Chemical Society, vol. 105, no. 4, 23 Feb. 1983, pages 868-871. The potential biological importance of thiol addition to ketones is discussed in the article.
Preferably, the solvent system comprises from about 5 to about 75 percent, preferably from about 10 to about 70 percent, most preferably from about 10 to about 60 percent of one or more organic protic solvents, based on the total weight of the solvent system. If the solvent system comprises a blend of two or more organic protic solvents, the indicated percentages refer to their total weight. As will be described further below, the solvent system of the present invention may comprise other components in addition to methoxy acetone an an organic protic solvent. Generally, the solubility of an epoxy curing agent, such as dicyandiamide, or of a curing catalyst, such as an imidazole, in the solvent system increases when the content of the organic protic solvent in the solvent system increases. However, if the content of the organic protic solvent in the solvent system is too high, the compound dissolved in the solvent system tends to precipitate if the solution of the compound is mixed with an epoxy resin.
Useful saturated, aliphatic unsaturated or aromatic organic protic solvents generally contain one or more hydroxyl, mercapto, or acid groups, such as carboxyl. Preferably, the organic protic solvent contains one or two, more preferably only one, hydroxyl, mercapto or acid group. The protic organic solvent should be inert, i.e. at the chosen conditions for dissolving a curing agent, curing catalyst and/or cure inhibitor in the solvent system, it should neither undergo a chemical reaction with such compounds to an essential degree nor should it react with an epoxy resin which is chosen for preparing an epoxy resin composition. Based on the present teaching the skilled artisan knows how to select an organic protic solvent that does not react with the chosen curing agent, curing catalyst, cure inhibitor and/or epoxy resin.
Preferred organic protic solvents are monofunctional alcohols, such as saturated open-chain or cyclic alcohols, preferably methanol, ethanol, the propanols, such as n-propanol or isopropanol, the butanols, such as n-butanol or isobutanol, the hexanols, such as n-hexanol or cyclohexanol, the heptanols, octanols, decanols, dodecanols, such as lauryl alcohol, or the octadecanols, such as stearyl alcohol; or unsaturated alcohols, preferably the allyl or furfuryl alcohol. The alcohols preferably have 1 to 12, more preferably 1 to 8, most preferably 1 to 4 carbon atoms. Other useful alcohols are glycols or glycol monoethers. Preferred glycols are ethylene, propylene or butylene glycols, such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol or dibutylene glycol.
Preferred glycol monoethers are the propylene or butylene glycol monoethers, most preferably ethers represented by formula I EQU R.sub.1 O--(CH.sub.2 --CHR.sup.3 O).sub.n --R.sub.2 (I)
wherein
The alkyl groups may be branched or unbranched. Exemplary of the alkyl groups are methyl, ethyl, n-propyl, isopropyl, the butyl groups, such as n-butyl or isobutyl, and the pentyl, hexyl, octyl, decyl or dodecyl groups. Of the propyl and butyl groups n-propyl and n-butyl are preferred. Preferably, one of the substituents R.sub.1 and R.sub.2 independently is methyl or n-butyl.
Preferred monoethers of formula I are propylene glycol methyl ether, propylene glycol n-butyl ether, dipropylene glycol methyl ether and dipropylene glycol n-butyl ether.
Corresponding thiols containing one or more mercapto groups instead of one or more hydroxyl groups in the above-mentioned organic protic solvents are useful as well, such as 1,3-propane dithiol, ethane thiol or propane thiol.
Preferred acid groups are sulfenic, sulfinic or sulfonic acid groups, phosphinic or phosphonic acid groups or the carboxyl group. Carboxylic acids, such as formic acid, acetic acid, propionic acid, butanoic acid or pentanoic acid are preferred.
The preferred organic protic solvent are methanol, ethylene glycol and, most preferably, ethanol.
The solvent system of the present invention may comprise one or more organic protic solvents.
The solvent system may additionally comprise one or more aprotic oxygen-containing solvents other than methoxy acetone. Preferably, methoxy acetone, the organic protic solvent(s) and, if present, the aprotic oxygen-containing solvent other than methoxy acetone together amount to about 90 percent or more, more preferably to about 95 percent or more, most preferably to about 99 percent or more, of the total weight of the solvent system. Most preferably, the solvent system consists essentially of methoxy acetone, the organic protic solvent(s) and, optionally, the aprotic oxygen-containing solvent(s) other than methoxy acetone. In this case the above indicated ranges of the content of the organic protic solvent are based on the total weight of methoxy acetone, the organic protic solvent(s) and aprotic oxygen-containing solvent(s) other than methoxy acetone, if present.
Preferably, the weight ratio between the aprotic oxygen-containing solvent (other than methoxy acetone), if present, and methoxy acetone is from about 0.1:1 to about 2:1, more preferably from about 0.3:1 to about 1.5:1, most preferably from about 0.5:1 to about 1:1. Preferably, the weight ratio between the aprotic oxygen-containing solvent, if present, and the protic organic solvent is from about 0.01:1 to about 30:1, more preferably from about 1:1 to about 20: 1, most preferably from about 2:1 to about 6:1. If the solvent system of the present invention does not comprise an aprotic oxygen-containing solvent (other than methoxy acetone) it preferably comprises from about 25 to about 95 percent, more preferably from about 30 to about 65 percent and most preferably from about 40 to about 60 percent of methoxy acetone and preferably from about 5 to about 75 percent, more preferably from about 35 to about 70 percent and most preferably from about 40 to about 60 percent of an organic protic solvent. If the solvent system comprises an aprotic oxygen-containing solvent in addition to methoxy acetone, it preferably comprises from about 25 to about 80 percent, more preferably from about 30 to about 65 percent and most preferably from about 40 to about 60 percent of methoxy acetone, preferably from about 5 to about 60 percent, more preferably from about 10 to about 45 percent, most preferably from about 10 to about 20 percent of an organic protic solvent and preferably from about 15 to about 70 percent, more preferably from about 25 to about 60 percent and most preferably from about 30 to about 50 percent of an aprotic oxygen-containing solvent (other than methoxy acetone).
Useful aprotic oxygen-containing solvents generally contain one or more ether or carbonyl functionalities. Aldehydes and ketones are preferred, such as formaldehyde, acetaldehyde, acetone, methyl ethyl ketone, methyl iso-butyl ketone or cyclohexanone.
Other useful aprotic oxygen-containing solvents are ethers, preferably propylene or butylene glycol diethers, most preferably ethers represented by formula II EQU R.sub.4 O--(CH.sub.2 --CHR.sup.3 O).sub.n --R.sub.5 (II)
wherein
Preferred alkyl groups are listed above with reference to formula I. Preferred diethers of formula II are propylene glycol dimethyl ether, propylene glycol methyl n-butyl ether, dipropylene glycol dimethyl ether and dipropylene glycol methyl n-butyl ether.
The solvent system may comprise other additives, such as viscosity modifiers, for example N-methyl pyrrolidone, thickeners, for example high molecular polyalkylene glycols, or plasticizers, for example dioctyl phthalate or chlorinated paraffin. If present, their amount preferably is from about 0.1 to about 9 percent, more preferably from about 1 to about 4 percent, based on the total weight of the solvent system.
The solvent system of the present invention is very useful as a solvent for
Curing agents for epoxy resins, commonly also called epoxy hardeners, are well known in the art. Useful classes of curing agents are for example amides, acid anhydrides, boron trifluoride complexes, dicyandiamide, substituted dicyandiamides, polyester resins, novolacs or phenolic hardeners, i.e. compounds containing more than one aromatic hydroxyl group. Another class of curing agents well known in the art comprises prereacted adducts of epoxy resins with amines or anhydrides or dicyandiamide or phenolic resins. Preferred phenolic hardeners are described on pages 6-8 of European patent specification 0,240,565, the teaching of which is incorporated herein by reference. Other known curing agents are primary or secondary amines, hydrazides or hydrazine, preferably the multifunctional, more preferably the di- to hexafunctional primary amines, amides and hydrazides. Such curing agents are listed on column 5, lines 47-68 and column 6, lines 14-19 of U.S. Pat. No. 4,789,690, the teaching of which is incorporated herein by reference.
Further useful curing agents are listed on page 11, lines 41-58 and page 12, lines 1-40 of the published European patent application EP-A-0,458,502, the teaching of which is incorporated herein by reference. Other preferred curing agents are cyanamide, dicyanamide, derivatives of cyanamide or dicyanamide, dihydroxy phenols, biphenols, halogenated bisphenols, alkylated bisphenols, trisphenols, phenol-aldehyde resins, halogenated phenol-aldehyde novolac resins, alkylated phenol-aldehyde novolac resins, hydrocarbonphenol resins, hydrocarbon-halogenated phenol resins, hydrocarbon-alkylated phenol resins or a combination of two or more thereof.
The solvent system of the present invention is particularly useful for dissolving a dicyandiamide, such as a substituted dicyandiamide or non-substituted dicyandiamide (cyanoguanidine). The low solubility of dicyandiamide in other, known solvents or solvent compositions is well known. Therefore, there was a particular need for providing a solvent system in which dicyandiamide can be dissolved to a sufficient extent. It has been found that the solvent system of the present invention is a very good solvent for dicyandiamide. The solvent system of the present invention is also useful for dissolving substituted dicyandiamides, such as dicyandiamides wherein some, but not all, hydrogens bonded to a nitrogen are replaced by alkyl, preferably C.sub.1-6 -alkyl, more preferably methyl, ethyl or the propyl groups; or by aryl, preferably benzyl, more preferably 2-methylbenzyl. Preferably, the dicyandiamide carries only one of the above-listed substituents. Most preferably, the dicyandiamide is not substituted.
The solvent system of the present invention is useful for dissolving two or more of the above-mentioned curing agents for epoxy resins. The term "a curing agent" as used herein also comprises mixtures of two or more compounds which act as a curing agent for an epoxy resin.
If the solvent system is used for dissolving a curing agent, preferably from about 1 to about 20 percent, more preferably from about 2 to about 15 percent, most preferably from about 3 to about 12 percent of a curing agent is dissolved in the solvent system, by the weight of the solvent system. It is to be understood that the solubility of the curing agent in the solvent system of the present invention depends on various factors, such as the type of the curing agent, the specific composition of the solvent system and the amounts and types of compounds which may additionally be dissolved in the solvent system, such as a curing catalyst or a cure inhibitor. The solubility of a specific curing agent in a specific solvent system of the present invention can be evaluated by series trials.
Curing catalysts or curing accelerators which increase the speed of reaction between the curing agent and the epoxy resin are also well known in the art.
Curing catalysts or curing accelerators which increase the speed of reaction between the curing agent and the epoxy resin are also well known in the art. Preferred are tertiary amine-containing or heterocyclic amine containing compounds. Some curing catalysts may have an effect as a curing agent per se, such as benzoguanamidine, imidazoles, benzodimethylamine, metaphenolene diamine, or N,N,N',N'-tetramethyl-1,3-butadiamine. Preferred imidazoles are 2-methyl imidazole, 2-ethyl-4-methyl-imidazole or 2-phenylimidazole. 2-Methyl imidazole is the most preferred curing catalyst. Other curing catalysts which may be dissolved in the solvent system of the present invention are heterocyclic nitrogen compounds, phosphines, sulfides or ammonium, phosphonium or sulfonium containing compounds. Such curing catalysts are listed on page 12, lines 41-50, on pages 13-16 and on page 17, lines 1-22 of the published European patent application EP-A-0,458,502, the teaching of which is incorporated herein by reference. Exemplary of such curing catalysts are ethyltriphenyl phosphonium acetate, ethyltriphenyl phosphonium acetate.acetic acid complex, tetrabutyl phosphonium acetate, tetrabutyl phosphonium acetate.acetic acid complex, ethyltriphenyl phosphonium chloride, ethyl triphenyl phosphonium iodide, tetrabutyl phosphonium chloride, tetrabutyl phosphonium iodide, tetrabutylphosphonium hydroxide, tetramethylammonium hydroxide, ethyltri(2-ethoxyethyl)ammonium hydroxide, triethyl(2-thioethylethyl)ammonium hydroxide, N-methyl-N-methylenemethanaminium acetate, N-methyl-N-methylenemethanaminium acetate.acetic acid complex,-N-methyl-N-methylenemethanaminium chloride, N-methyl-N-methylenemethanaminium iodide, N-methylpyridinium acetate, N-methylpyridinium acetate.acetic acid complex,N-methylpyridinium chloride, N-methylpyridinium iodide, 1-ethyl-2,3-dimethylimidazolium acetate, 1-ethyl-2,3-dimethylimidazolium acetate.acetic acid complex, 1-ethyl-2,3-dimethylimidazolium chloride, 1-ethyl-2,3-dimethylimidazolium iodide, N-methylquinolinium acetate, N-methylquinolinium acetate.acetic acid complex, N-methylquinolinium chloride, N-methylquinolinium iodide, N-methyl-1,3,5-triazinium acetate, N-methyl-1,3,5-triazinium acetate.acetic acid complex, N-methyl-1,3,5-triazinium chloride, N-methyl-1,3,5-triazinium iodide, ethylamine, diethylamine, triethylamine, n-propylamine, di-n-propylamine, tri-n-propylamine, isopropylamine, diisopropylamine, triisopropylamine, butylamine, dibutylamine, tributylamine, methyldibutylamine or an imidazole, an imidazolidine, an imidazoline, an oxazole, a pyrrole, a thiazole, a pyridine, a pyrazine, a morpholine, a pyridazine, a pyrimidine, a pyrrolidine, a pyrazole, a quinoxaline, a quinoazoline, a phthalozine, a quinoline, a purine, an indazole, an indole, an indolazine, a phenazine, a phenarazine, a phenothiazine, a pyrroline, an indoline, a piperidine, a piperazine; or a combination of two or more thereof.
The solvent system of the present invention is useful for dissolving two or more of the above-mentioned curing catalysts. The term "a curing catalyst" as used herein also comprises mixtures of two or more compounds which influence the speed of reaction between an epoxy resin and an epoxy hardener.
If the solvent system is used for dissolving a curing catalyst, generally from about 0.1 to about 40 percent, preferably from about 0.5 to about 35 percent, more preferably from about 1 to about 20 percent and most preferably from about 2 to about 12 percent of a curing catalyst is dissolved in the solvent system, by the weight of the solvent system. It is to be understood that the solubility of the curing catalyst in the solvent system of the present invention depends on various factors, such as the type of curing catalyst, the amount and type of curing agent which is optionally present in the solvent system, the specific composition of the solvent system and the amounts and types of compounds which may additionally be dissolved in the solvent system. The solubility of a specific curing catalyst in a specific solvent system of the present invention can be evaluated by series trials. In the case of imidazoles such as 2-methylimidazole, preferably from about 1 to about 20, more preferably from about 2 to about 12 percent of an imidazole is dissolved in the solvent system, by the weight of the solvent system.
Useful cure inhibitors are boric acid, metaboric acid, boric acid anhydride or maleic acid or a mixture of (meta)boric acid(anhydride) with at least one acid having a weak nucleophilic anion, such as fluoroboric acid (HBF.sub.4). Cure inhibitors are described on page 17, lines 18-50 and page 18, lines 1-38 of the published European patent application EP-A-0,458,502, the teaching of which is incorporated by reference. If a cure inhibitor is dissolved in the solvent system, it is preferably dissolved in the solvent system in an amount of from about 0.1 to about 12 percent, more preferably from about 0.5 to about 6 percent, most preferably of from about 1 to about 4 percent, by the weight of the solvent system.
If the solvent system of the present invention contains substantial amounts of a curing agent, for example between about 3 and about 12 percent of dicyandiamide, the solubility of the curing catalyst and/or the cure inhibitor in the solvent system is generally smaller, usually between about 0.1 and about 3 percent, typically between about 0.5 and about 2 percent, based on the weight of the solvent system.
As indicated above, one aspect of the present invention is a method of preparing a solution of one or more compounds selected from the group consisting of a) curing agents for an epoxy resin, b) curing catalysts, and c) cure inhibitors by contacting one or more such compounds with an effective amount of a solvent system comprising methoxy acetone, an organic protic solvent and, optionally, an oxygen-containing solvent other than methoxy acetone. The solution may be prepared in a known way. Useful curing agents, curing catalyst and cure inhibitors as well as their useful concentrations in the solvent system are indicated above. Generally methoxy acetone, an organic protic solvent and, optionally, an oxygen-containing solvent other than methoxy acetone are mixed in the ratios indicated above at a temperature of from about 1 to about 80.degree. C., preferably from about 15.degree. to about 40.degree. C., until a homogeneous mixture is obtained. Then the desired amount of curing agent(s) and/or curing catalyst(s) and/or cure inhibitor(s) is added to the solvent system and the resulting mixture is stirred until a clear solution is obtained. The compounds to be dissolved can be added together or alternatingly to the solvent system of the present invention. Alternatively, each compound can be dissolved individually in the solvent system and the resulting solutions can be combined if desired. Preferred compositions of the resulting solutions of the present invention are described above.
The above described solutions of a curing agent and/or a curing catalyst and/or a cure inhibitor in the solvent composition of the present invention can be mixed with an epoxy resin for preparing an epoxy resin composition. Typically the epoxy resin is dissolved in a solvent. Although the solvent for the epoxy resin can be added simultaneously or after the epoxy resin has been mixed with the solution of the curing agent, curing catalyst and/or cure inhibitor, the epoxy resin is preferably pre-mixed with the solvent. The epoxy resin solution is then mixed with the solution of the curing agent, curing catalyst and/or cure inhibitor for producing an epoxy resin composition. Such a resin composition is typically designated in the art as "one-component epoxy resin composition".
The epoxy resin composition of the present invention may comprise a wide variety of epoxy resins, provided that they are curable, preferably with dicyandiamide. Curable epoxy resins are well known in the art.
Suitable examples include epoxy resins from the reaction of polyphenols and epihalohydrins, polyalcohols and epihalohydrins, amines and epihalohydrins, sulfur-containing compounds and epihalohydrins, polycarboxylic acids and epihalohydrins, polyisocyanates and 2,3-epoxy-1-propanol (glycide) and from epoxidation of olefinically unsaturated compounds. Preferred epoxy resins are the reaction products of polyphenols and epihalohydrins, or polyalcohols and epihalohydrins or of polycarboxylic acids and epihalohydrins. Mixtures of polyphenols, polyalcohols, amines, sulfur-containing compounds, polycarboxylic acids and/or polyisocyanates can also be reacted with epihalohydrins.
Illustrative examples of epoxy resins useful herein are described in The Handbook of Epoxy Resins by H. Lee and K. Neville, published in 1967 by McGraw-Hill, New York, in appendix 4-1, ppgs through 4-56 and U.S. Pat. Nos. 2,633,458; 3,477,990; 3,821,243; 3,970,719; 3,975,397; 4,071,477; and 4,582,892, and GB Patent Specification No. 1,597,610, all of which are incorporated herein by reference.
Epoxy resins of particular interest include diglycidyl ethers of bisphenol compounds, particularly those compounds represented by the following structure III: wherein each A is independently a divalent hydrocarbon group having from 1 to 8 carbon atoms, preferably methylene or, more preferably, isopropylidene (--C(CH.sub.3).sub.2 --), --C(O)--, --O--, --S--, --S--S--, --S(O)--, --S(O).sub.2 --or a covalent bond; each X is independently hydrogen, an alkyl group of 1 to 6 carbon atoms such as methyl, ethyl, propyl, butyl, pentyl or hexyl, or halogen, preferably chlorine or bromine; and n has an average ##STR1## value of from 0 to 35, preferably from 0 to 10, most preferably from 0 to 2.
The average epoxy equivalent weight is advantageously from 149 to 3000, preferably from 170 to 950, most preferably from 170 to 450. The molecular weight is a weight average molecular weight.
Other polyhydric phenols which may be co-reacted with an epihalohydrin to provide these epoxy polyethers are such compounds as resorcinol, hydroquinone and substituted hydroquinones, e.g. methylhydroquinone.
Further useful liquid epoxy resins are those obtained from the reaction of polyhydric alcohols with epihalohydrins. These alcohols can be polyether polyols or polyester polyols.
Another useful class of polymeric resins includes liquid epoxy novolac resins. The epoxy novolac resins can be obtained by reacting, preferably in the presence of a basic catalyst, e.g. sodium or potassium hydroxide, an epihalohydrin, such as epichlorohydrin, with the resinous condensate of an aidehyde, e.g. formaldehyde, and either a monohydric phenol, e.g. phenol itself, or a polyhydric phenol. Further details concerning the nature and preparation of these epoxy novolac resins can be obtained in Lee, H. and Neville, K., Handbook of Epoxy Resins, McGraw Hill Book Co. New York, 1967. The epoxy resin compositions of the present invention may contain two or more different epoxy resin.
Useful solvents for the epoxy resin are well known in the art. Preferred examples are 2-metyl-pentanediol-(2,4), toluene, o-dichlorobenzene, cyclohexanone, cyclohexanol or, more preferably, methyl ethyl ketone or methyl iso-butyl ketone. Mixtures of different solvents are also useful for dissolving the epoxy resin.
Generally, from about 50 to about 95 percent, preferably from about 60 to about 90 percent, more preferably from about 70 to about 85 percent epoxy resin is dissolved in a suitable solvent, based on the total weight of epoxy resin and solvent.
The epoxy resin composition of the present invention preferably comprises from about 0.5 to about 20 percent, more preferably from about 1 to about 10 percent, most preferably from about 2 to about 6 percent of a curing agent, such as dicyandiamide, based on the weight of the epoxy resin. The epoxy resin composition preferably also comprises from about 0.05 to about 2 percent, more preferably from about 0.08 to about 1 percent, most preferably from about 0.1 to about 0.5 percent of a curing catalyst, such as a 2-methylimidazole, based on the weight of the epoxy resin. The epoxy resin composition may comprise a cure inhibitor, such as boric acid, for modifying the curing catalyst. The amount of such a cure inhibitor, if present, preferably is from about 0.05 to about 2 percent, more preferably from about 0.08 to about 1 percent, most preferably from about 0.1 to about 0.5 percent, based on the weight of the epoxy resin. The epoxy resin composition optionally contains known auxiliary compounds, such as colorants, fillers and the like.
The weight ratio between the epoxy resin and methoxy acetone generally is from 0.5-20:1, preferably from 2-15:1, more preferably from 4-10:1. The weight ratio between the epoxy resin and the organic protic solvent generally is from 1-60:1, preferably from 5-40:1, more preferably from 10-30:1.
The epoxy resin compositions of the present invention are useful for various known applications, for example for preparing electrical laminates, coatings etc. At least the preferred embodiments of the epoxy resin composition of the present invention are homogeneous and generally have a viscosity that is low enough to allow a good impregnation of a reinforcing material, such as glass rovings, reinforcing mats etc. to produce reinforced epoxy compositions which cure upon heating. Techniques of impregnating reinforcing materials with epoxy resin compositions and curing the epoxy resin compositions are well known in the art.


The invention relates to an on-site medical gas production plant (100) comprising a unit (50) for purifying gas, such as air, a first compartment (A) for storing purified gas, and a main gas line (10) fluidically connecting the gas purification unit (50) to the said first storage compartment (A). It furthermore comprises an actuated valve (304) arranged on the main gas line (10) upstream of the first storage compartment (A), and furthermore connected to the secondary purifying device (306), as well as an operating device (4) which controls at least the actuated valve (304), and at least a gas analysis device (D2) in fluid communication with the main line (10), and which is in communication with said operating device (4).

Embodiments of the invention relate to a plant for medical air production on-site, that is to say in a hospital building or the like, employing a three-way solenoid valve adapted to discharge product gas contaminated by impurities to the atmosphere via a purge line connected to one of the ports of the solenoid valve and/or to send the produced gas contaminated by the impurities to an in-line filter or purifier for removal of said impurities, and to a method for controlling or operating such a plant.
The medical air used in hospitals, clinics, treatment centres, emergency or incident units, or the like, for patients' respiration is a medicament whose composition is specified by recognized Pharmacopoeia.
For example, European Pharmacopoeia standards typically define medical air as ambient air that has been compressed to a pressure above atmospheric pressure, typically several bars, or to tens or even hundreds of bars and contains (by volume) from 20.4% to 21.4% oxygen, at most 500 ppm CO2, at most 5 ppm CO, at most 1 ppm SO2, at most 2 ppm NO and NO2, at most 67 ppm water and at most 0.1 mg/m3 oil; the oil vapours possibly present essentially come from the compression of the air. For medical oxygen, U.S. Pharmacopeia standards require oxygen of not less than 90% and not more than 96% by volume, max 10 ppm CO, and max 300 ppm CO2.
It should be noted that, other than oxygen, the components mentioned above (i.e. COx, NOx, water, or oil etc.) are in fact impurities whose presence is tolerated within the limits of the Pharmacopoeia but which ideally are not present therein.
Medical air furthermore contains nitrogen, and may also contain other compounds, such as argon.
Currently, medical air is delivered to hospitals or the like in three forms, namely, depending on the case:                direct delivery in the form of compressed air, for example at an absolute pressure of from 200 to 300 bar, in cylinders, that is to say bottles or canisters of gas, or containers comprising a plurality of bottles;        production on-site by mixing oxygen and nitrogen so as to create nitrogen/oxygen mixtures, and        direct production on-site from ambient air treated, in particular, by compressors and filtration/purification systems.
Of these, the production of air directly on-site by compressors and filtration systems is the most widespread solution. Such a method is described, for example, in the document EP-A-864818.
The ambient air is taken in and compressed by compressors to a pressure range extending from 1 bar to 80 bar relative. This compressed air is then filtered, that is to say purified, by means of one or more treatment steps, for example by a set of filters and/or by employing a pressure swing adsorption method (PSA).
The medical air produced in this way may be stored in one or more intermediate buffer compartments, then sent through the network of pipes which passes through the hospital building in order to provision the treatment rooms, bedrooms or the like with medical air. It is quite clearly possible, and even indispensable in certain cases, to carry out intermediate expansion of the gas, for example in order to change from a pressure of about 10 bar in the storage compartment to a pressure of 5 or 8 bar in the network.
In general, any break in medical air provision is overcome by using medical air taken from a reserve or backup source in which the air is kept in gaseous form.
The other medical gases used in hospitals or treatment centres, such as oxygen, are also delivered in a similar way to the air. The compositions of these other gases are also specified by the European or US Pharmacopoeia.
Thus, oxygen may also be produced on-site by a PSA method by using specific adsorbents, such as lithium-exchanged zeolites X, making it possible to retain the nitrogen contained in the air and thus produce gaseous oxygen having a purity typically greater than 90%, or even 93% by volume, as is known from the document EP-A-297542.
However, the methods for producing medical air or other medical gases used on-site (also referred to as on-site methods) present certain drawbacks.
First, these methods do not permit easy monitoring of the reliability of the manufacturing process.
Thus, when an on-site medical air production unit is operating autonomously, the manufacturing process is not overseen continuously and the interventions on the plant take place on the basis of planning, that is to say preventive maintenance, or when an error or a problem arises in the plant, that is to say curative maintenance.
These interventions are therefore carried out independently of the status of the plant and its reliability, which is not optimal because they are carried out either too soon, and therefore without actual need, or too late, and therefore with an impact on the production process and possibly on the final product.
Next, pollutant blockages in the main pipe occur when the gas produced is not compliant. This is because in existing plants, the control solenoid valve is a so called "2-way" solenoid valve which is arranged on the main line.
Although it makes it possible to stop possible pollution upstream of the valve, this pollution nevertheless remains blocked in the main line and necessitates a total purge of the system upstream of the valve. This is not ideal because it entails a shutdown of the gas production and manual intervention.
Furthermore, in the event of short-term breaks in the air provision due, for example, to temporary contamination at the inlet, the backup source is resorted to directly. However, this poses a problem because the backup volume is limited and therefore, if the frequency of the breaks in provision is high, there is then a risk of draining the backup source. In other words, it would be highly beneficial to be able to avoid this drawback by reducing the extent to which the backup source is used, so as to increase its autonomy over time.
Lastly, the air produced by the current methods and plants is in general neither analyzed nor validated in pharmaceutical terms, which may raise obvious problems of compliance and quality. Furthermore, when it is analyzed, in the event of "noncompliance" this usually leads either to immediate interruption of the production and changeover to a backup source air, which may entail overuse of the backup air liable to cause a possible total break in the air provision, or to continuous provision of noncompliant air and parallel triggering of an alarm in order to warn the user, who then needs to intervene manually. It will be understood that these solutions are not ideal either.
In summary, there is currently no method of validating air produced on-site which makes it possible to ensure that the air produced is in fact compliant with the required specifications and which makes it possible to ensure effective and reliable provision of medical air.
In other words, the problem which arises is to provide a plant for continuous on-site production of a medicament gas, particular medical air, in accordance with good manufacturing practice (GMP) and a method for controlling or operating such a plant, which permit in particular:                supervision of the reliability of the manufacturing process with rapid detection of any anomaly,        monitoring of the various production steps and in particular the final production with, for each step, the possibility of a purge thus making it possible to stop any contamination or noncompliance of the gas produced, in particular medical air, and/or        the use of the backup sources to be reduced to a minimal level.

On-site medical gas production plant and associated operating method


A safety post assembly includes a flat mounting plate adapted to rest on a support surface, an upright post fixed in an upstanding relationship on a central portion of the mounting plate, a pair of elongated narrow anchoring straps having inner portions positioned over a pair of peripheral edge portions of the mounting plate and outer portions extending outwardly from the inner portions and the mounting plate so as to overlie portions of the support surface located adjacent to the mounting plate, and a plurality of fasteners adapted to attach the mounting plate and anchoring straps upon the support surface. The mounting plate has a plurality of holes defined therein along peripheral edge portions of the plate and in spaced relationship to one another. The anchoring straps also have pluralities of openings defined therein, some being in a spaced relationship to one another which matches the spaced relationship between the holes in the mounting plate. The fasteners are adapted to extend through openings in the anchoring straps and through holes in the mounting plate being aligned with the openings in the anchoring straps and then to be threadable into the support surface.

1. Field of the Invention
The present invention generally relates to safety equipment for use at construction sites and, more particularly, is concerned with a safety post assembly.
2. Description of the Prior Art
The construction of most commerical building and residential homes typically involves considerable risk to craftsmen and others moving around the building site during the early stages of construction. Until framing of the structure is finished there is really no way to protect these persons as they work near edges of floors and staircases.
Regulations of the Occupational, Safety and Health Administration (OSHA) of the U.S. Government require the introduction of safety structures along locations which entail risk of fall for persons on the site. To satisfy OSHA regulations, these structures must exceed certain minimum lateral load requirements without experiencing permanent deformation or component failure. One safety rail system which has been tried in the past employed a safety post construction which included a rigid tubular metal post fixedly mounted upright on a flat rectangular plate which is screwed to the flooring. However, this safety post construction failed to withstand the minimum lateral load during testing and thus is unacceptable under current OSHA regulations.
Consequently, a need still exists for improvements in the design of safety rail systems so as to meet OSHA regulations.


A method is disclosed for analyzing ions by mass spectrometry by repeatedly executing a data acquisition cycle to acquire product ion data across a precursor mass range of interest. The data acquisition cycle comprises performing, for each of a plurality of isolation windows having different mass ranges, steps of (i) isolating precursor ions within the mass range of the isolation window, (ii) fragmenting the isolated precursor ions to generate product ions, and (iii) mass analyzing the product ions. The step of mass analyzing the product ions includes concurrently mass analyzing product ions corresponding to N isolation windows, N being an integer greater than or equal to one, wherein N is changed at least once across the data acquisition cycle.

Data independent acquisition (DIA) is a mass spectrometry technique in which MS/MS data is acquired for substantially all precursor ions across a mass (m/z) range of interest. An implementation of DIA is symbolically depicted in FIG. 1. Within an acquisition cycle, an isolation window is stepped across a mass range of interest in a series of MS/MS events. For each MS/MS event, ions within a mass window are isolated (i.e., mass selected), fragmented (e.g., by collisionally activated dissociation), and an MS/MS spectrum is acquired of the resultant product ions. The isolation windows are set such that they sequentially span the precursor ion mass range of interest. In the example depicted, the precursor range of interest is 500-1000 Thomson (m/z units, abbreviated Th), and 25 isolation windows of 20 Th width are used. After the isolation window has been stepped across the entire range of interest, the acquisition cycle is repeated. As depicted in FIG. 1, each acquisition cycle may be initiated by a full range MS scan (a "survey scan") to obtain a spectrum of the precursor ions. DIA has the advantage of producing a rich data set without requiring a priori knowledge of targets, and the data set can be revisited to investigate hypotheses generated post-acquisition.
The selection of the isolation window width in DIA involves balancing competing performance considerations. In general, using narrower window widths reduces the number of different precursor ion species fragmented together in an MS/MS event, rendering the resultant product ion spectra relatively clean and easy to interpret (noting that since each MS/MS spectra will typically include ions from a number of precursor ion species, some sort of deconvolution to assign product ions in the spectra to a corresponding precursor ion species will typically be required). However, because the number of MS/MS events in a DIA cycle is inversely proportional to the window width, each DIA cycle will take a relatively long time to complete when narrow window widths are utilized. This reduces the number of DIA cycles that can be completed across a chromatographic peak, which in turn compromises the ability to reliably and accurately quantify sample components, particularly when elution peaks are narrow. Conversely, wide isolation windows permit a relatively large number of acquisition cycles to be performed across a chromatographic peak, but the resultant MS/MS spectra are highly complex and difficult to interpret due to the multiplicity of different precursor ion species present in an MS/MS scan; this complexity may be particularly problematic for samples in the form of a biological matrix such as blood plasma. The selection of an appropriate window width is made more difficult by the fact that precursor ion species produced from a sample will not typically be distributed evenly across the m/z range of interest, and information regarding their distribution may not be available prior to running the analysis.

Data independent acquisition with variable multiplexing degree


A motion converter used with an input element rotatable about an axis and an output element displaceable axially relative to the input element has an axially nondisplaceable support provided with a first external screwthread of predetermined diameter, pitch, and hand centered on the axis and a second external screwthread provided on the output element centered on the axis and of the same diameter and pitch as the first screwthread but of opposite hand. A roller having respective first and second ridged portions respectively meshing with the screwthreads has a mechanical coupling for maintaining the first and second roller portions aligned axially with each other. Formations between the first and second roller portions axially couple them to each other and to the rotary input element so that on roling of the roller portions on the screwthreads the roller portions and input element are displaced axially a predetermined distance relative to the support and the output element is displaced through twice this distance.

In a power chuck or the like it is frequently necessary to convert a rotation into linear movement. This is done, for instance, to open or close the jaws of a chuck. Such a converter typically has coaxial input and output elements, the former being axially displaceable and the later rotatable. Rollers or the like engaged between them perform the necessary movement conversion.
German patent document 3,937,448 Hubert Bald et al uses balls as motion-converting members. Thus the rotatable elements are axially braced via these balls on an axially non-displaceable support member. Thus the support element must move both axially and rotationally.
The use of such a converter on rapidly rotating lathes creates several problems, namely:
1. To reduce throw the length and diameter must be as small as possible.
2. The converter must be able to transmit and convert considerable forces.
3. No matter what the position of the device its center of mass must not move to prevent throw and vibration.
4. Large mechanical advantage must be obtained even in a system capable of transmitting considerable force, even in a relatively small unit.
Furthermore it is necessary that the converter be of relatively simple and, therefore, inexpensive construction. In particular the screwthread guides that are essential in such a device much be designed so that they can be manufactured inexpensively.

Gedib Ingenieurburo Und Innovations-Beratung GmbH


An exhaust gas recirculation mixer includes a convergent nozzle in a flow path from an air inlet of the mixer to an outlet of the mixer. The convergent nozzle is oriented converging toward the outlet of the mixer. The nozzle accelerates the flow to high velocity, which is released as a free-jet. The mixer includes an exhaust gas housing having an exhaust gas inlet into an interior of the exhaust gas housing, and a convergent-divergent nozzle having an air-fuel-exhaust gas inlet in fluid communication to receive fluid flow from the convergent nozzle (i.e., the free-jet), the interior of the exhaust gas housing, and a fuel supply into the mixer.

Exhaust gas recirculation, especially cooled EGR, can be added to internal combustion engine systems to reduce NOx emissions and reduce knock tendency. In such a system, an amount of exhaust gas is added to the air and/or fuel mixture within the air-intake manifold of the engine. The challenge is that there is a cost to deliver the cooled EGR (cEGR), especially for high efficiency engines which generally are most efficient when the exhaust manifold pressure is lower than the intake manifold pressure. The pressure difference creates a positive scavenging pressure difference across the engine which scavenges burn gas from the cylinder well and provides favorable pressure-volume pumping loop work. It is particularly challenging to deliver cEGR from its source at the exhaust manifold to the intake manifold without negatively impacting the residual gas scavenging and efficiency of the engine cycle via the pumping loop. The "classic" high pressure loop cEGR system plumbs the exhaust gas directly to the intake manifold, which requires either design or variable turbocharging to force the engine exhaust manifold pressure to be higher than the intake manifold, which in turn, unfavorably reduces scavenging of hot burned gases and engine P-V cycle and loses efficiency. It is particularly counterproductive since the purpose of the cEGR is to reduce the knock tendency to improve efficiency and power density. But, this classic method to drive EGR actually increases the knock tendency through residual gas retention and reduces efficiency thru negative pressure work on the engine—in a manner of diminishing returns, i.e., two steps forward to reduce knock with cEGR, but one step back due to how it is pumped, leading to a zero gain point where the cost of driving cEGR counteracts the benefits of delivering it.

Passive pumping for recirculating exhaust gas