A solvent extraction free, caustic refining free, process for producing refined soybean oil from soybeans includes the steps of heating cleaned, cracked and dehulled soybeans at a temperature of from 220° F. to 600° F. for from 45 to 60 minutes; mechanically pressing the heated soybeans to separate soybean oil; and heating the extracted oil at a temperature of from about 350° F. to about 500° F. under a vacuum to remove free fatty acids from the soybean oil.

(1) Field of the Invention
The present invention relates generally to a process for extracting and refining vegetable oils and to the resultant product, and in particular to the production by a combination of mechanical extraction and physical refining of non-hydrogenated soybean oil having an acceptable frylife similar to that of partially hydrogenated soybean oil.
(2) Description of the Prior Art
Soybean oil production involves several steps that are necessary to render the soybean oil suitable for human consumption. These production steps may be broadly characterized as 1) soybean preparation, 2) oil extraction, and 3) oil refining. Soybean preparation generally includes the steps of cleaning, drying, cracking, and dehulling.
The great majority of commercial soybean oil production processes extract or separate the oil from the soybean meal by a process known as solvent extraction. In the solvent extraction process, the prepared beans are first flaked to provide a large surface area. A solvent, commonly hexane, is then pumped through the soybean flakes to dissolve the oil in the hexane, separating approximately 99.5% of the oil from the meal. The hexane is then separated from the oil and recycled.
The crude oil resulting from the solvent extraction must then be subjected to additional treatments, collectively called "refining", to remove various materials in order for the oil to be suitable for consumption. These materials include hydratable and non-hydratable phospholipids, free fatty acids, and various color and flavor components. Crude soybean oil contains phosphorous compounds called hydratable phospholipids, and small amounts of calcium and magnesium that complex with a portion of the phospholipids to form non-hydratable phospholipids. Hydratable phospholipids are normally removed by a process known as "degumming", in which the oil is agitated or otherwise intimately combined with water to precipitate gums from the oil. The gums are then removed by centrifugation.
These precipitated gums can be used as a feed additive, or evaporated to remove moisture. The end product, lecithin, has various end uses such as in food emulsifiers. The degummed oil is dried under vacuum to remove any water. Removal of non-hydratable phospholipids is considerably more difficult and expensive, requiring further chemical treatment, typically chemical refining, to break the chemical bonds between the calcium or magnesium ions and the phospholipids, followed with extensive bleaching of the oil.
In most processes, free fatty acids are removed from the oil by a process known as caustic refining, also called chemical or alkali refining, in which the oil is mixed with a caustic material, such as sodium or potassium hydroxide, which undergoes a saponification reaction with the acids, forming soaps that are then removed by centrifugation. Non-hydratable phospholipids are removed along with the free fatty acids. Chemical refining soybean oil is an expensive process, requiring a large investment in capital equipment. In addition, a significant quantity of the oil is captured by the soaps, adversely affecting oil yield. Also, the caustic refining process produces soapstock, which has little commercial value, and is difficult to dispose of without environmental problems.
Conventional refining processes also involve some bleaching of the soybean oil to remove color pigments that adversely affect the color of the oil. Finally, chemicals that add flavors to the oil are removed by a process known as "deodorization", which is essentially a form of physical distilling, in which the oil is subjected to high temperatures under a vacuum for a short period of time, which is sufficient to remove the flavor-causing components, but insufficient to break down non-hydratable phospholipids.
A major use of soybean oil is in deep frying of foods, such as chicken, fish, french fries, etc., either in the production of pre-cooked packaged foods, or in the preparation of foods for on-premise or carry-out consumption in restaurants and other commercial establishments. In deep frying, a container or vat is filled with cooking oil that is heated to a frying temperature, normally around 350° to 375° F. The uncooked food is then immersed in the hot oil for a sufficient time to effect the desired cooking, and then removed for serving or packaging.
Some of the oil in the vat is lost during cooking due to absorption and evaporation. The oil is replenished by adding fresh oil to the oil remaining in the vat, and the oil is reused. This procedure is repeated until the oil becomes unusable, as indicated by darkening of the oil and the food cooked in the oil, and/or by the observance of an undesirable taste or appearance in the food being cooked.
Non-hydrogenated soybean oil produced by solvent extraction and caustic refining is unsuitable for use in commercial frying operations due to its limited frylife. Such oil has a maximum frylife of only about 4–5 fry cycles, a cycle being the frying of one batch of food. Replacement of the oil at this frequency is uneconomical. In order to extend the frylife of soybean oil to a commercially acceptable number of fry cycles, preferably at least about 30 fry cycles, refined soybean oil is normally at least partially hydrogenated. Hydrogenation of solvent extracted, caustic refined soybean oil reduces the percentage of C 18:3 acids. It is commonly believed that the presence of C 18:3 acids contribute to the rapid deterioration, and thereby limited frylife, of solvent extracted, caustic refined soybean oil.
Saturation or hydrogenation of C 18:3 acids, however, reduces the healthful properties of soybean oil. Therefore, attempts have also been made to reduce the C 18:3 or linolenic acid content of soybean oil by genetically modifying or selective breeding the soybean, thereby enabling the production of non-hydrogenated soybean oil having a C 18:3 content of significantly less than the 6–8% by weight C 18:3 acids, based on the total content of free fatty acids, found in conventional soybeans. U.S. Pat. No. 5,981,781 to Knowlton, issued Nov. 9, 1999, is an example of these generically modified soybeans. This approach, to date, has met with at most limited success.
Commonly assigned U.S. Pat. No. 6,511,690, issued Jan. 28, 2003 and U.S. Pat. No. 6,753,029, issued Jun. 22, 2004, (herein the "Tysinger et al. patents"), both patents incorporated herein in their entireties by reference, describe an improved refining process combining mechanical extraction with physical refining. As noted in the Tysinger et al. patents, mechanical oil extraction and physical refining were previously known separately, but had not been used in combination, and these resultant properties of the resultant oil had not been appreciated.
In the prior art mechanical oil separation process known as expelling, dehulled beans are extruded through a screw press to frictionally heat the beans and rupture the oil cells. Within the screw press, the beans are subjected to high pressures and frictionally-generated high temperatures for a short period. The crushed, oil-containing meal is then pressed to separate most of the oil from the meal. This process has been rarely used to process soybeans due to the fact that about 25% of the soybean oil is left in the meal.
Physical refining has been used for oils that are naturally low in non-hydratable phospholipids, such as lauric oils, particularly palm oil. In physical refining, the oil is vacuum distilled at high temperatures, e.g., from about 450° F. to about 500° F., to separate more volatile components from the oil. This process is used to remove various flavor components, and will also remove free fatty acids. However, the process alone is not viable for removing free fatty acids from oils such as soybean oil, which contains higher levels, i.e., more than 20 ppm based on elemental phosphorous content, of non-hydratable phospholipids. The high temperatures required for physical refining tend to break down the non-hydratable phospholipids that are present in the soybean oil, producing chemical compounds that cause an unacceptable flavor and color.
In the process described in the Tysinger et al. patents, soybean oil is mechanically separated from prepared soybeans by first rapidly heating the beans to a temperature of from about 300° F. to about 370° F., preferably from about 315° F. to about 335° F., followed by mechanically pressing the oil from the beans. Desirably, the beans are crushed during or after heating to assist in freeing the oil from the remainder of the soybeans, i.e., the meal. After degumming and bleaching, the soybean oil is physically refined to remove free fatty acids and flavor components by heating the oil in a distillation column to a temperature of from about 450° F. to about 500° F., and preferably for from about 460° F. to about 480° F., to distill off the free fatty acids and flavor materials.
Tysinger et al. teach that care should be exercised in heating the soybeans at temperatures above about 350° F., since the oil will tend to scorch, causing an off taste in the final product and a darker color, and that heating the oil to less than 300° F. will fail to destroy sufficient trypsin inhibitors in the meal. Tysinger et al. also note that the time during which the soybeans are heated is also important, and that heating of the beans to the desired temperature in at least 10 seconds has been found to achieve maximum rupture of the oil cells, and thus maximum extraction of oil from the soybeans, while heating of the beans for longer than about 60 seconds degrades the desirable characteristics of the oil.
The restrictions of the Tysinger et al. process with regard to the desired temperature and time ranges requires careful control of the process and restricts the type of equipment that can be used during mechanical extraction. It would be desirable to have a process that was not constrained by these limitations while still producing a mechanically extracted soybean oil that was suitable for physically refining, thereby achieving an improved soybean oil of the type produced in the earlier Tysinger et al. process.

This patent is subject to a terminal disclaimer.


A semiconductor micro-electromechanical system (MEMS) switch provided with noble metal contacts that act as an oxygen barrier to copper electrodes is described. The MEMS switch is fully integrated into a CMOS semiconductor fabrication line. The integration techniques, materials and processes are fully compatible with copper chip metallization processes and are typically, a low cost and a low temperature process (below 400° C.). The MEMS switch includes: a movable beam within a cavity, the movable beam being anchored to a wall of the cavity at one or both ends of the beam; a first electrode embedded in the movable beam; and a second electrode embedded in an wall of the cavity and facing the first electrode, wherein the first and second electrodes are respectively capped by the noble metal contact.

Miniaturization of the front-end of the wireless transceiver offers many advantages including cost, the use of smaller number of components and added functionality allowing the integration of more functions. Micro-electromechanical system (MEMS) is an enabling technology for miniaturization and offers the potential to integrate on a single die the majority of the wireless transceiver components, as described by a paper by D. E. Seeger, et al., presented at the SPIE 27th Annual International Symposium on Microlithography, Mar. 3–8, 2002, Santa Clara, Calif., entitled "Fabrication Challenges for Next Generation Devices: MEMS for RF Wireless Communications".
A micro-electromechanical system (MEMS) switch is a transceiver passive device that uses electrostatic actuation to create movement of a movable beam or membrane that provides an ohmic contact (i.e. the RF signal is allowed to pass-through) or a change in capacitance by which the flow of signal is interrupted and typically grounded.
Competing technologies for MEMS switches include p-i-n diodes and GaAs MESFET switches. These, typically, have high power consumption rates, high losses (1 dB or higher insertion losses at 2 GHz), and are non-linear devices. MEMS switches on the other hand, have demonstrated insertion loss of less than 0.5 dB, are highly linear, and have very low power consumption since they use a DC voltage and an extremely low current for electrostatic actuation. These and other characteristics are fully described in a paper by G. M. Rebeiz, and J. B. Muldavin, "RF MEMS switches and switch circuits", published in IEEE Microwave, pp. 59–71, December 2001.
Patent application Ser. No. 60/339,089 now abandoned, describes a MEMS RF resonator fabrication process which utilizes IC compatible processes for fabrication of MEMS resonators and filters. In particular, the release method and encapsulation processes used are applied to the fabrication of RF MEMS switches.
U.S. Pat. No. 6,876,282 to Deligianni et al., of common assignee, herein incorporated by reference, describes the design of a MEMS RF switch wherein the actuators being totally decoupled from the RF signal carrying electrodes in a series switch. If the actuation and RF signal electrodes are not physically separated and are part of the closing mechanism (by including one of the actuator electrodes) it may cause the switch to close (hot switching), thus limiting the switch linearity by generation of harmonics. This is a known problem for transistor switches such as NMOS or FET. Thus, in order to minimize losses and improve the MEMS switch linearity, it is important to separate entirely the RF signal electrodes from the DC actuator electrodes. U.S. Pat. No. 6,876,282 describes various designs of composite metal-insulator MEMS switches. The preferred metal used is, typically, copper, while the insulator is silicon dioxide, resulting in full separation of the actuators from the RF signal carrying electrodes. In addition, Pat. application Ser. No. 10/315,335 describes the use of a metal ground plane 3–4 microns below the MEMS switch to improve its insertion loss switch characteristics.
As a result of the composite metal-insulator concept, MEMS switches can be fabricated using processes that are similar to the fabrication of copper chip wiring. Integration of MEMS switch with the back-end-of-the-line CMOS process limits the material set selection and the processing conditions and temperature to temperatures no greater than 400° C.
U.S. Pat. No. 5,578,976 to Yao et al. describes a micro-electromechanical RF switch, which utilizes a metal-metal contact in rerouting the RF signal at the switch closure. MEMS metal-to-metal switches have reported problems with increases contact resistance and contact failure during repeated operation, as described by J. J. Yao et al., in the paper "Micromachined low-loss microwave switches", J. MEMS, 8, 129–134, (1999), and in the paper "A low power/low voltage electrostatic actuator for RF MEMS applications", Solid-State Sensor and Actuator Workshop, 246–249, (2000). Switch failure at hot switching reported to be due to contact resistance increase and contact seizure as described by P. M. Zavracky et al. in the papers "Micromechanical switches fabricated using nickel surface micromachining", J. MEMS, 6, 3–9, (1997) and "Microswitches and microrelays with a view toward microwave applications", Int. J. RF Microwave Comp. Aid. Eng., 9, 338–347, (1999). Therein are reported an increased contact resistance and contact seizure, both of which can be associated with material transfer and arcing/welding. An Au—Au contact resistance increase to a value greater than 100 ohms was observed after two billion cycles of cold switching in N2 (no current flow through the switch), while the contact seizure was observed with hot switched samples after a few million cycles in air, as described in the aforementioned first paper.
If the switch is packaged in a hermetic environment, the contamination build up caused switch failure is less likely than when exposed to ambient conditions. When the probability of formation of a contamination film is reduced, increases in contact resistance and/or contact seizure are both due to adhesion at the metal-metal contact. The increase in contact resistance most likely has to do with material transfer caused by surface roughening and results in reduced contact area. In the latter case the two metal surfaces are firmly adhered due to metal-metal bond formation (welding) at the interface. The invention described herein is a method of fabrication of a metal-metal switch with long lifetime and with stable and low contact resistance.
Accordingly, the main thrust for reducing adhesion while gaining adequate contact resistance is: 1) different metallurgy on each side of the contact—lattice mismatch reduces adhesion, and; 2) optimized hardness of the metals in contact—harder metal is expected to give lower adhesion.
The contact metallurgy is selected not only from the group of Au, Pt, Pd as in U.S. Pat. No. 5,578,976, but also from Ni, Co, Ru, Rh, Ir, Re, Os and their alloys in such a manner that it can be integrated with copper and insulator structures. Hard contact metals have lower contact adhesion. Furthermore, hardness of a metal can be changed by alloying. Au has low reactivity, but is soft and can result in contacts that adhere strongly. For instance, to avoid this problem, gold can be alloyed. Adding about 0.5% Co to Au increases the gold hardness from about 0.8 GPa to about 2.1 GPa. Moreover, hard metals such as ruthenium and rhodium are used as switch contacts in this invention. Dual layers, such as rhodium coated with ruthenium, with increasing melting point are used to prevent contact failure during arcing where high temperatures develop locally at the contacts.

Noble metal contacts for micro-electromechanical switches

International Business Machines Corporation


The present invention includes a method of reducing slippage between a mat having a flexible polymer back surface and a substrate surface contiguous to the back surface, the method comprising applying a liquid comprising an aqueous solution of poly(vinyl acetate) to the back surface and contacting the back surface with the liquid thereon to the substrate surface while the aqueous solution is still wet. The method is especially effective where the mat comprises a flexible polymeric back surface comprising a flexible polymer selected from the group consisting of natural rubber, synthetic rubber, natural elastomers and synthetic elastomers. The contacting may be performed before the aqueous solution is completely dried. The aqueous solution may be applied directly to the back surface by spraying said aqueous solution onto said surface. The aqueous solution may be applied directly to the substrate surface. The aqueous solution may, for example, comprise from 1 to 90% by weight of the solution of poly(vinyl acetate) or 1 to 99% by weight of the solution as poly(vinyl acetate).

1. Field of the Invention
The present invention relates to floor mats, particularly to the stabilization of floor mats against slipping and potentially injuring people.
2. Background of the Art
Floor mats are used in a wide variety of locations in many public and private locations. Floor mats are considered to be any surface covering with a rubber, flexible polymer or elastomeric backing or back surface which is placed on the floor. The surface material may be the same as the backing surface (e.g., where a solid cast, molded, extruded or cast mat system such as a Nomad(trademark) mat [manufactured by Minnesota Mining and Manufacturing Co.] is used), or the top surface of the mat may be composed of a substantially different composition or be present in a substantially different form. For example, many floor mats are available with a fabric or fabric appearing surface layer with the rubber, flexible polymer or elastomeric backing or back (hereinafter generally and collectively referred to as a rubber backing) adhered to the bottom or floor contacting side of the mat. The floor mats may be used in entrance ways (e.g., door mats), in transitional areas (e.g., between different rooms or offices), or may be used as decoration or surface protection generally. Many mats are also provided as a safety measure to prevent slippage in areas that may be polished, areas that may become wet and slippery, areas that tend to be slippery because of surfaces which have been worn smooth, and/or to provide antistatic protection. These mats may also referred to as tiles, small area carpets, foot mats and the like in some fields of use.
The rubber, flexible polymer or elastomeric backing or back surface may be comprised of such elastic or elastomeric materials such as those selected from the group consisting of natural rubbers and polymers, blended compositions with natural rubber, synthetic rubbers and polymers (e.g., polyisoprene), and synthetic elastomeric compositions (e.g., polyurethane elastomers, polysiloxane elastomers, and other elastomeric polymeric materials). When a new mat with a rubber backing is first used, it generally tends to display good initial resistance to slippage. When the mat is placed on most surfaces (e.g., concrete, cement, linoleum, vinyl flooring, wood floors, terrazzo, stone, and the like) it resists slipping, even when modest force is applied against the mat with a non-perpendicular (with respect to the floor) component, even when a forty-five degree (50/50 force distribution parallel and perpendicular to the floor) is applied. Unfortunately, rubber backings tend to be subject to various types of deleterious changes with time. They may lose plasticizer, the rubber composition may break down from physical wear (both from flexing and from compression), and chemical changes may occur in the rubber backing because of heat, radiation (especially ultraviolet radiation), and contact with aerial oxygen or cleaners or spilled materials. This change in the properties of the rubber backing often is exhibited as a hardening, cracking, and/or discoloring of the rubber backing, but more importantly, these changes can affect the coefficient of friction between the rubber mat and a floor surface, reducing the ability of the rubber backing to reduce slippage of the mat.
It has been disclosed in the literature to apply adhesives to the rubber back side of the mat when it is first applied and as the mat continues to be used after displaying wear. Typical adhesives used to secure the mats or tiles to a floor include elastomers with tackifying components (e.g., natural gums and resins) as shown in U.S. Pat. No. 3,625,807.
U.S. Pat. No. 3,804,699 describes a mat especially useful for protecting carpeted surfaces which is secured with a bonding resin comprising plastisols based on poly(vinyl chloride) resins, in an amount of from at least 2 pounds per square yard of mat.
U.S. Pat. No. 4,336,293 describes an antislip floor mat used on a floor surface which is useful in food service and industrial areas. The backing layer appears to be an extruded and laminated layer of poly(vinyl chloride), and the surface is a non-slip, abrasive-filled polymeric composition.
U.S. Pat. No. 4,721,641 describes a readily removable antislip floor mat with a thermoformed backing layer comprising high density polyethylene, and an ethylene-vinyl acetate copolymer.
U.S. Pat. No. 4,654,388 describes an adhesive composition for use with flooring comprising an aqueous dispersion of a film forming resin, finely divided filler, diethylene glycol monobutyl ether, and a tackifying agent (such as wood resin and esterified resin). A film-forming vinyl resin is preferred, such as acrylic copolymers and an ethylene-vinyl acetate copolymer. Specific ratios of ingredients are also preferred.
U.S. Pat. No. 3,104,195 describes a rug adapted to be rested on a floor, the rug comprising at least three component layers. A pad is positioned between upper and lower panels, the pad having a coefficient of friction with the floor greater than the coefficient of friction of the panel. This provides for antislip, but slidable contact with the floor.
Japanese Patent No. JP 5 5228067 A describes an antislip bath mat with high friction to the bath floor which eliminates slippage when wet. The composition of the mat is 20-60 parts ethylene-vinyl acetate copolymer having a vinyl acetate content of at least 10% and 40-80 parts by weight of olefin polymer.
Japanese Patent No. JP 08 112880 A2 (JP 94-278399, 94/1017) describes pads useful as carpets or floor mats in which a series of dots comprising ethylene-vinyl acetate copolymer are applied onto the back of a fiber based pad and the copolymer is hot-pressed.
Japanese Patent No. 08 053657, JP 94-209268 describes an adhesive composition used for wood floor material comprising acrylic polymer emulsion, elastomer, and particulates.
Many patents describe particular adhesive compositions which are used to secure flooring materials, whether panels, tiles, mats or the like. Some of these patents include U.S. Pat. No. 5,565,511 describing a stabilized latex (e.g., styrene-butadiene rubber latex) and a caustic agent used to provide good adhesive strength, good aging, and fast drying; U.S. Pat. No. 5,547,741 describes flexible wear layers of poly(vinyl chloride, monomeric ester plasticizer, and urethane polymer; and U.S. Pat. No. 4,810,573 describes a flowable bentonite composition on the back of elastomeric mats which composition can flow into holes and cracks. Some of the Japanese Patents which describe adhesive compositions for use with mats and tiles include, for example, JP 7040777 A describes a mat having a thermoplastic elastomer adhesive having a range of hardness comprising 10-40% styrene and a thermoplastic component free of halogen and sulfur; JP 6057931 A describes the use of vinyl chloride based amorphous particles preferably comprising a vinyl chloride, vinyl chloride/vinyl acetate copolymer, and an UV/heat hardening agent for hardening after application.
Japanese Patent No. JP 4341844 A describes an antislipping sheet for bandages and floor mats produced by applying a foamable liquid coating onto the surface of a substrate paper, heat treating the coated sheet to obtain a foamed sheet, applying an adhesive onto the surface of a substrate to obtain an adhesive sheet, bonding the foamed sheet and the adhesive layer of the adhesive sheet to obtain a layered sheet, and stripping the substrate paper from the layered sheet. The coating liquid (the foamable liquid coating) contains an adhesive component (e.g., esterified starch, poly(vinyl alcohol), polyacrylic acid, or ethylene-maleic anhydride copolymer. The liquid composition is not disclosed as being applied directly to the back side of a mat.
It is often necessary to clean or replace individual mats or tiles after use. When an adhesive has been placed between the mat and the floor, the adhesive seal must be broken, usually leaving residue on the floor and on the backing of the tile or mat. These residues can build-up with each new application of adhesive, an uneven floor surface can develop, mat edges can be forced out of horizontal alignment by the resides, and uneven adhesive securement can exist because the adhesive may locate between segments of the residue and the new adhesive may not contact both the backing and the floor. The use of solvents to remove the residues can damage the floor surface, damage the tile or mat, and alter the adhesive properties of the new application of adhesive if solvent remains on either of the surfaces. An alternative means and composition for securing mats against slipping is desirable.
Mats which have a flexible and/or elastomeric or rubbery backing material may be coated with an aqueous solution of poly(vinyl acetate) before application of the mat to a floor surface (i.e., placement onto the floor). The aqueous solution may be applied to the flexible backing or the floor and the mat contacted with the floor before the solution has completely dried. The solution bonds the backing of the mat to the floor, the dried material is not aggressively tacky, and the dried solution residue may be removed from the mat and the floor by a water wash or mild detergent and water wash. The solution is readily applied to the mat backing by brushing, painting, wiping, or preferably by a spray, either in aerosol or other pressure pump format.
Mats or tiles according to the present invention include any article having a backing layer of flexible polymeric material which article is to be placed on a flat surface such as a floor or counter top. The term polymeric material, as it applies to the backing layer of the mats or tile (hereinafter collectively referred to as xe2x80x9cmatsxe2x80x9d) includes both natural and synthetic polymers and polymeric materials referred to as elastomers. This term would include polymers, copolymers (including those with more than two comonomers, referred to specifically in the art as terpolymers, tetrapolymers, etc.), graft copolymers, block copolymers, blends, solutions and mixtures of polymers (and mixtures with other materials as a composite, as with cork, fiber reinforcement, etc.) and other art recognized equivalents. Typical materials used in forming flexible polymeric backings would include, but not be limited to, natural rubber, synthetic rubber, polyurethane polymers, silicone polymers, polyisoprene, polyacrylates, polyamides, polyolefins, polybutadiene polymers and copolymers, polymers and copolymers of chloroprene rubbers, polymers and copolymers of isobutylene, polyolefin polymers, polystyrene polymers and copolymers, copolymers of butadiene/styrene/acrylonitrile, and the like. The chemical composition of the mat backing is a matter of selection from within the class of flexible polymeric backing materials known within the polymer art, with the description provided being exemplary, but not limiting. The backing may be smooth, ridged, porous, textured or the like and still benefit from the practice of the present invention.
The nature of the surface of the mat away from the poly(vinyl acetate) adhesive is of no criticality to practice of the present invention. The mat surface may comprise the same composition as the backing, either as a distinct layer or as a uniform element (e.g., a single molded article), or may be a completely different material, such as a fabric (printed, dyed or not), a separate polymeric layer (with any manner of decoration desired, such as printed, embossed, laminated, colored, etc.), may have a discontinuous particulate coating (e.g., for decoration or reduced surface slippage), or be provided with or without an edging, etc.
The floor securing composition of the present invention which is applied as a solution/dispersion to the exposed surface of the backing layer of the mat comprises an aqueous solution of poly(vinyl acetate). The floor securing composition may contain at least one percent (1%) by weight solids of poly(vinyl acetate), up to about 90% by weight poly(vinyl acetate). The composition is most readily applied by a spray of the floor securing solution, which would generally use from 1-70% by weight of the solution (including the weight of water) as poly(vinyl acetate). The spray is efficiently applied as from 2-70% by weight, 3-60% by weight, 5-50% by weight poly(vinyl acetate), and the like. More concentrated solutions/dispersion of poly(vinyl acetate) may be applied by brushing, wiping, tray dipping and the like. The coating solution/dispersion may comprise only water and poly(vinyl acetate), or may contain such (convenient additives) which will assist in the drying, application, film forming, stability, appearance or other physical or chemical properties of the aqueous solution. For example, 0.1 to 5% surfactant, coating aids, antistatic agents, cosolvents (e.g., alcohols), UV absorbers, dyes, pigments, fragrances or the like may be present. Some additional binding agent or polymer may be present, but it is desired that the poly(vinyl acetate) be the major (greater than 50% by weight of solids), dominant (e.g., at least 75% by weight), or sole (approximately 100%) polymeric, solid film-forming component in the solution. Agents which tend to harden or crosslink poly(vinyl acetate) may be added, but it is especially desired that the dried solution remain water soluble or water dispersible after they have dried so that the film can be removed easily from floor surfaces and even the back of the mat.
Where a spray application is to be used, especially a hand pump spray or aerosol spray (as opposed to a less desirable but functional mechanically driven spray with greater force and larger vent at the spray head), it is usually desirable to control the particle size, molecular weight of the poly(vinyl acetate) to assure its passage through the spray head with reduced clogging. This consideration is well within the skill of the trade, especially as sprays of poly(vinyl acetate) are commercially available. The polymer particle size should be less than about 90% of the diameter of any nozzle holes in a spray applicator, preferably less than 50% of that spray hole diameter, more preferably less than 10% of the diameter of any nozzle holes in a spray applicator. The particle size is of no significant importance (within obvious physical limits of macrodimensional size limitations) when application is not performed through a nozzle, as where wiping or painting is used.
The present invention includes a method of reducing slippage between a mat having a flexible polymer back surface and a second surface contiguous to the back surface comprising applying a liquid comprising an aqueous solution of poly(vinyl acetate) to said back surface and contacting said back surface with said liquid thereon to said second surface while said aqueous solution is still wet. The method is especially effective where the mat comprises a flexible polymeric back surface comprising a flexible polymer selected from the group consisting of natural rubber, synthetic rubber, natural elastomers and synthetic elastomers. The contacting may be performed before said aqueous solution is completely dried. The aqueous solution may be applied directly to said back surface or directly to said back surface by spraying said aqueous solution onto said back surface. The aqueous solution may applied directly to said second surface, also possibly by spraying. The aqueous solution may, for example, comprise from 1 to 90% by weight of the solution of poly(vinyl acetate) or 1 to 99% by weight of the solution as poly(vinyl acetate).
The method may be practiced where contacting is effected while the aqueous solution, after it has been applied, may still comprise as little as 10% by weight or more (e.g., it will remain tacky at 90% by weight poly(vinyl acetate) in the drying solution) of the solution remaining as water.
The invention also includes a mat having a flexible polymer back surface, said mat being secured in reduced slip orientation to a second surface by a dry layer comprising at least 50% by weight of poly(vinyl acetate). The second surface is usually a floor, but may be a work surface such as a counter top. The dry layer usually comprises at least 90% by weight poly(vinyl acetate), and often at least 99% by weight poly(vinyl acetate). The mat may have an upper surface of the mat which comprises a material which is different from the flexible polymer. The mat may also comprise an antistatic mat which is applied to the floor, with the mat having conductive material (e.g., carbon black, graphite fibers or particles, metallic, conductive polymer, or other conductive material) within a back layer, top layer, a portion of all layers or all layers within the mat. The poly(vinyl acetate) may also contain conductive materials to assure electrical contact or grounding of the mat through the poly(vinyl acetate) adhesive or bonding layer.


Process and economic advantages are achieved by the integration of a Fischer Tropsch process for hydrocarbon liquids production as a retrofit in an installation for the production of ammonia fertilizer from fossil fuel derived syngas. Utilization of most of the CO and part of the H2 in the syngas stream during Fischer-Tropsch synthesis as the first step in the integrated process produces hydrocarbon products while the F-T effluent containing unreacted hydrogen gas at the necessary ratio of H2/N2 is used in the second step of ammonia synthesis. The overall product slate as appropriate for maximum economic performance of the installation is thus achieved.

The invention relates to the discovery of a process integration that interposes a hydrocarbon liquids production process between a fossil fuel-based synthesis gas production process and an ammonia production process in a manner that substantially improves the economics of the overall integrated process. The invention particularly relates to the discovery of a means to enhance the economic feasibility of relatively small scale, syngas based ammonia fertilizer production plants by the integration of compatible liquid hydrocarbon synthesis processes into the ammonia production plant complex utilizing a portion of the fossil fuel-based syngas production as a feedstream to the hydrocarbons production process
The production of ammonia fertilizers by the reduction of nitrogen gas with hydrogen as derived from synthesis gas (syngas) is an established process, well known in the art. The process is of great importance to developed as well as developing countries with the population of ammonia fertilizer plants, both small and large, high in all cases. Typically, the required synthesis gas is produced by partial oxidation or steam reforming of fossil fuels such as coal or natural gas by processes well known and established in the art. When it is readily available, natural gas, of course, is by far the preferred syngas feedstock due to its higher hydrogen to carbon ratio, ease of transportation and cleanliness.
For those countries with an abundance of natural gas reserves, particularly those in the Middle East, the production and export of ammonia fertilizer is a major industry. Very large complexes of ammonia production based on natural gas derived syngas have been built there that enjoy all the economic process advantages attendant upon great plant size and large scale production. As an export commodity, the ammonia fertilizers they produce are exceedingly price competitive, beyond the means of the small, native ammonia plants of importing countries to match, even when their raw material is natural gas. However, the available fossil fuel for these countries is often coal. Ammonia produced from coal-derived syngas is appreciably more costly than an equivalent natural gas/syngas ammonia process. Consequently, the native ammonia fertilizer industry of those importing countries is threatened with native plant obsolescence and long-term dependence upon imported ammonia fertilizer. Hundreds of relatively small, coal-based native ammonia fertilizer plants lie threatened with closure in the face of import competition unless those small plant installations, can be altered to improve the overall plant economics of operation for ammonia production from coal over the economics of imported ammonia fertilizer produced from natural gas. Alternatively, methods need to be found to alter the product slate of the native coal derived syngas-to-ammonia plants to produce a new mix of products that will restore the economic justification for continued operation of coal-based ammonia fertilizer production plants.
There are a number of well known coal gasification processes for the production of nitrogen-containing synthesis gas such as water gas (WG) or semi-water gas (SWG) where the synthesis gas is employed as feedstreams to reactors for the reduction of nitrogen to ammonia. These feedstreams usually have hydrogen gas to carbon monoxide ratios (H2/CO) in the range of 0.6 to 1.5. Typical of these are the Koppers-Totzek, Winkler and Lurgi processes. It is also well known in the art that these syngas processes can be readily modified to adjust the ratios of hydrogen to carbon monoxide in the product stream to provide a ratio that is more suitable for use in the downstream conversion processes of the installation or more compatible with the overall objectives of the product installation. For example, the desired end-product may be a high purity, high BTU SNG gas, a low BTU clean refinery gas, a syngas for methanol production, or, as in the present case, syngas for ammonia production. It is left to the artisan to determine the more preferred syngas process and/or modification of an installed process to meet the overall product goals of the installation and maximize coal utilization.
The problem addressed herein is the discovery of a process modification of small, coal-based syngas-to-ammonia plant installations that would restore the profitability of those plants in competition with imported ammonia costs and make the continued operation of those native plants both feasible and attractive. The specific objective of the instant invention is the realization of a process integration into a syngas-ammonia facility that can utilize a syngas with variable H2/CO ratios first as a feedstock to produce high value liquid hydrocarbons before ammonia production.
For ammonia plants with natural gas-derived syngas as feedstock, the invention as well provides an option of modifying the product slate from only ammonia to integrated fuels/ammonia co-production to cope with changing market demands and to improve plant economics
It has been discovered that the integration into a syngas-to-ammonia process installation of a Fischer-Tropsch process for the production of liquid hydrocarbons can be effectively achieved to both produce ammonia and a slate of liquid hydrocarbons at a substantial benefit to the overall economics of the integrated process. In particular, the process of the invention includes an integrated process for the production of ammonia-based fertilizer and liquid hydrocarbon products from fossil fuel derived synthesis gas by contacting the fossil fuel with steam and oxygen-containing gas under gasification conditions sufficient to produce a synthesis gas after desulfurization. The low sulfur content synthesis gas comprising nitrogen gas, hydrogen gas and carbon monoxide in a mole ratio of hydrogen to carbon monoxide of between 0.6 to 1 and 5 to 1 is directly passed to a catalytic synthesis process under conditions for the conversion of the carbon monoxide gas and a portion of the hydrogen gas to fuel products comprising substantially liquid hydrocarbon products and light hydrocarbon gaseous products.
The synthesis gas does not have to be processed in a water gas shift unit to convert CO into hydrogen as is normally practiced in ammonia plants since CO is not desirable in ammonia production. While CO is a major reactant for Fischer-Tropsch synthesis which essentially uses up the CO and leaves N2 and part of H2 for ammonia production downstream.
The liquid and gaseous hydrocarbon products and by-product CO2, are separated from both the nitrogen gas and the unreacted portion of the hydrogen gas while the valuable hydrocarbon products are recovered. The nitrogen gas and the unreacted hydrogen gas are recovered as a feedstream to a process for the hydrogenation of the nitrogen whereby ammonia-based fertilizer is produced and recovered.
The basic application of the present invention is the integration of a Fischer-Tropsch (F-T) unit into a fossil-fuell derived syngas-to-ammonia plant such that the synthesis gas (water-gas or semi-water gas) is first converted to liquid hydrocarbons before the production of ammonia by reduction of nitrogen (N2) with the unreacted hydrogen gas effluent from the F-T unit. The water gas shift in the syngas reactor originally used to convert CO into hydrogen before ammonia synthesis is no longer necessary and can be eliminated. When the H2/CO molar ratio of the synthesis gas is 0.8-5.2 most of the CO and part of the H2 in the feed gas are converted to hydrocarbon products in the F-T unit,The off-gas from the F-T system contains significant amounts of unconverted hydrogen, N2 and a small amount of CO. These off-gases are converted to ammonia in a second step of the process in the now integrated fertilizer plant with appropriate N2 balancing. The off gas from the F-T system also contains significant amounts of carbon dioxide (CO2). The carbon dioxide can be used to produce ammonium bicarbonate or urea. Accordingly, the hydrogen gas, carbon monoxide and nitrogen in the feed water gas can be fully utilized.
The hydrocarbon products from the F-T synthesis are highly useful, very clean, straight chain liquid hydrocarbons containing no sulfur and nitrogen. They are useful as household fuels such as LPG, liquid transportation fuels such as naphtha comprising an extra clean gasoline component, and diesel fuels having a very high cetane number in the range of 75-80. The liquid hydrocarbons are also valuable chemical feed stocks. For example, naphtha is an excellent feed stock for ethylene production. The liquid hydrocarbons contain about 50 weight percent of alpha-olefins which are high-value chemicals and various grades of solvents can be made from n-alkanes. A small amount of paraffin wax is also generated.
The Fischer-Tropsch process for the conversion of fossil fuel derived syngas to liquid hydrocarbons is well known in the chemical engineering arts and exemplary descriptions of the application of the process are described in xe2x80x9cCoal Conversion Technologyxe2x80x9d by I. Howard-Smith and G. J. Werner, pp 15-17, 29, 52-5, 58, 77 and 92, which descriptions are incorporated herein by reference. The process is particularly well known for its utilization by Germany during WW II where 10 large plants were constructed to produce hydrocarbon fuels. More recently, coal based F-T plants were constructed in South Africa by the South African Coal, Oil and Gas Corporation Ltd (SASOL) and operated long term for the production of hydrocarbon fuels and chemicals. The F-T process is carried out using iron or cobalt as a catalyst at temperatures between 425 and 700xc2x0 F. and medium pressure between 300 and 800 psi.
In a preferred process of the invention, syngas is generated from coal, preferably employing one or the other of the Lurgi gasification process or the Koppers-Totzek (K-T) or similar gasification process. In the Lurgi process, a fixed bed reactor is employed using oxygen or air and steam at about 20-30 atm and temperatures ranging from 560-620xc2x0 C. In the K-T process, gasification takes place at low pressures and much higher temperatures of about 1480xc2x0 C. Optionally, partial oxidation processes known in the art may be employed to produce the required syngas. The product syngas is desulfurized by methods known in the art such as adsorption on activated carbon or reaction with zinc oxide. Water gas shift is no longer required. H2 to N2 ratio in the off-gas can be adjusted by the balancing (addition) of nitrogen.
The unconverted hydrogen and nitrogen are employed to manufacture ammonia by processes well known in the art. Commercial ammonia production is carried out using a catalytic surface based on metallic iron, typically promoted with other oxides. Operating pressures are high, generally in the range of 2,000 to 5,000 psi.

Integrated process for the production of hydrocarbon liquids and ammonia


A flanged-pipe fitting for joining the plain ends of pipe is described. The fitting comprises a tubular body having an interior cylindrical chamber with a first and second openings, an annular ridge located between the first and second openings, an annular recess for receiving a first sealing gasket and an annular flanged portion having a notch for receiving a second sealing gasket. The flanged-pipe fitting is used in conjunction with a gland fitting to join the two ends of the pipe together.

The present invention relates to devices used in the pipeline construction industry. More particularly, this invention relates to devices used to join the plain ends of pipe, as well as certain other ends of pipe.
Generally speaking, in constructing a pipeline, the ends of two pieces of pipe are axially joined to form a single conduit that is used to transport materials from one point to another. Often times, the materials being transported are fluid or gaseous in nature, and, particularly in those circumstances, it is desired that the pipeline be impervious to leaks. In order to accomplish that goal, and to achieve other objectives which will be herein described, those skilled in the business of pipe and pipeline construction are constantly in search of improved means for securing the joints formed by connecting the ends of pipe together.
There are numerous methods currently in use by those in the pipe and pipeline construction industry to obtain a secure joint. These methods employ different types of components and also can be distinguished by the various ways in which such components are employed. The selection of these different methods will usually depend on the overall design requirements of the pipeline. For instant, as mentioned previously, one important design requirement exists when it is desired that the pipe joints be sealed such that the material being transported within the pipeline can not escape and, conversely, foreign materials are prevented from entering the pipeline.
Another important design requirement exists when it becomes necessary to join the pipe components in a restrained manner. This is usually desired in order to prevent the pipe components from separating due to thrust forces that often occur when the pipeline is subjected to internal pressure, and sometimes, when earth tremors or other external events occur. Still another objective is to make assembly of the pipe joints as simple, economical and reliable as possible.
One current method for connecting pipe together employs the use of flanged fittings and gaskets. These are typical components in rigid piping systems, particularly above-ground systems such as water filtration plants, sewage disposal plants, wastewater treatment plants, pumping stations and chemical plants. Often times, the flanged fitting is threaded directly onto the pipe. This is accomplished by threading the plain end of a pipe (sometimes referred to as the spigot end) and threading a compatibly sized flanged fitting. The threaded flanged fitting is then machine-tightened onto the spigot end of the pipe and is often then transported to the field in this joined condition. In addition, it is common in the industry for the pipe and flanged fitting to have been xe2x80x9cfacedxe2x80x9d after proper tightening of the flanged fitting on the pipe. This is done by excising the portion of the threaded pipe that extends from the face of the flanged fitting such that the face of the flanged fitting is flush with the spigot end of the pipe. The threaded flanged pipe is then connected to another flanged pipe, usually by bolting means. In order to obtain a leak-free joint, a gasket is often used between the faces of the two flanged fittings.
The use of threaded flanged fittings presents several limitations as will now be discussed. The threaded flanged fitting is custom machined to accommodate the exact diameter of the pipe and to provide a smooth surface across the end of the pipe and the face of the flanged fitting. Also, extremely high torques are required to tighten properly the flanged fitting onto the threaded pipe. Consequently, one major limitation of this system is that preparation of the flanged fitting and pipe requires sophisticated machinery not usually available on-site where the finished component will be assembled and installed. If assembled at the pipe manufacturing facility before shipment, the presence of the flanged fitting militates against efficient and space-saving packing and reduces the amount of pipe components which can be transported.
In addition, to assure a proper seal, it is important for the threaded portion of the flanged fitting and pipe to be cleaned of all foreign material such as dirt, sand, grit or rust. The presence of foreign materials such as rust can also increase the amount of torque required to install the flanged fitting onto the pipe. Thus, manufacturing and assembling threaded flanged fittings and threaded pipe is very difficult in the field. Still another limitation of this system is that threaded pipe and threaded flanged fittings are individually mated, and the flanged fittings are not interchangeable. Still another limitation of threaded flanged fitting systems is that the pipe walls must be of substantially greater thickness in order to accommodate the threading which will be machined onto its exterior surface.
An alternative method for joining pipe uses unthreaded flanged fittings which are of appropriate diameter and which are fitted onto pipe ends in facing relationship to one another. As with the threaded flanged fitting, a gasket is often deployed between the faces of the flanged fittings to obtain a sealed joint. This is usually accomplished by bolting the flanged fittings together. In order to secure the flanged fitting to the pipe ends, set screws are inserted radially through the collar of the flange into the exterior surface of the pipe ends. One such example of this type of apparatus is disclosed in U.S. Pat. No. 4,480,861, issued Nov. 6, 1984, to Frank E. Cann.
Although the device disclosed by Cann solves some of the problems presented by use of a threaded flanged fitting, it is not without problems of its own. For instance, the flanged fitting in Cann""s device must be mated to one another and therefore limits the choices for joining pipe by those in the field. In addition, as those skilled in the art will appreciate, those assembling the flanged fitting in Cann""s device must be skilled in recognizing the extent to which the set screws should be tightened. Unless care is used in tightening the set screws, they can often damage and even puncture the pipe end. Conversely, if not sufficiently tightened, the set screws used in Cann""s device will cause the flanged fitting to become unstable or dislodged altogether.
A second common method for connecting the ends of pipe involves inserting the spigot end of one pipe into the expanded end of a second pipe the interior profile of which has been specially fabricated to form a socket (the expanded end sometimes being referred to as the xe2x80x9cbell endxe2x80x9d). The bell end is sized to accommodate the spigot end of the pipe to be received. The connection obtained by this method is also known in the industry as a xe2x80x9cpush-on joint.xe2x80x9d
There are several methods used to seal and/or secure the push-on joint. One such method involves inserting a fitted gasket within an annular recess formed within the throat of the socket of the bell. On such gasket is described in U.S. Pat. No. 2,953,398, issued Sep. 20, 1960, to L. Haugen and C. Henrikson. After the gasket is inserted into the annular recess of the socket, the spigot is aligned and forced through the gasket into the bottom of the socket, thereby compressing the gasket and sealing the two pipe ends together.
In order to restrain the spigot within the bell, a specially designed gasket is sometimes used. One such gasket employs stainless steel locking segments vulcanized circumferentially into the gasket as described in U.S. Pat. Nos. 5,295,697 and 5,464,228, issued to J. Weber and L. Jones on Mar. 22, 1994 and Nov. 5, 1995, respectively. The locking segments extend from the interior surface of the gasket, away from the interior surface of the bell end, such that they grip the spigot end of the inserted pipe when the pipeline is subjected to internal pressures.
Still another common method for connecting pipe is sometimes referred to as mechanical joint pipe. The bell end of a pipe has a flanged portion cast on it. The spigot end of a second pipe is fitted with a slidable gland fitting and a gasket that is conically shaped such that one face of the gasket is diametrically larger than the second face of the gasket. The conically shaped gasket is positioned between the gland fitting and the spigot end of the pipe with the smaller, second face of the gasket being closer to the spigot end than the larger, first face of the gasket. The gland fitting has a plurality of apertures for receiving standard bolts. The gland fitting also has an integrally formed, protruding lip which encircles the face of the gland fitting at its inside diameter such that the lip is adjacent to the surface of the pipe and faces the spigot end of the pipe when the gland fitting is positioned on the pipe. The face of the flanged portion has a tapered notch designed to receive the conically-shaped gasket when the spigot end is inserted into the bell. The joint is formed when the spigot is axially inserted into the bell, and the gland fitting and the flanged portion are bolted together, causing the lip of the gland fitting to compress the gasket thus sealing the two pipe pieces. Examples of this type of apparatus is disclosed in U.S. Pat. No. 5,398,980, issued Mar. 21, 1995, to T. Hunter, O. Jackson and M. Pannell; in U.S. Pat. No. 4,878,698, issued Nov. 7, 1995, to R. Gilchrist; and in U.S. Pat. No. 2,832,615, issued Apr. 29, 1958 to A. Summers. Although each of these devices embodies a system that purports to couple pipes in sealing relation to one another, each system requires that conventional metal pipe bells be used, thus limiting the flexibility of those assembling the pipeline, and increasing the transportation and storage difficulties incurred by the pipeline assemblers. There is, consequently, a need in the industry for a compact, lightweight, easy to install pipe fitting which converts plain pipe to various pipe joint configurations such as a flanged or a mechanical joint.
The present invention embodies a significant advancement in the field of pipe manufacture and assembly. The new fitting can be used on standard pipe which needs no special preparation such as welding or threading prior to attachment. As a one-piece pipe fitting, the flanged pipe fitting described herein is simple to manufacture (and therefore economical), is easy to assemble in the field, and is equally or more stable and secure than other alternatives now available. By accomplishing these and other objectives, the disclosed flanged pipe fitting offers those in the business of constructing pipelines with a valuable new component for connecting pipe ends.
The improvements described herein have been achieved in a new flanged pipe fitting to be used in receiving and joining a first pipe and a second pipe. It will be appreciated by those skilled in the art that the fitting is best utilized to mate with a compatible pipe fitting such as a gland fitting attached to another pipe in order to obtain the coupling properties of a standard mechanical joint. The flanged pipe fitting disclosed is a one-piece, tubular casting having an internal chamber and first and second openings at the first and second extremities, respectively, of said tubular casting. The tubular casting is fabricated such that the internal chamber forms a double socket for receiving the spigot ends of pipes. This double socket configuration is accomplished by fabricating an inwardly protruding, annular ridge on the interior surface of the tubular casting and at a point roughly equidistant from the two extremities of the tubular casting thereby forming two socket separated by a cylindrical opening of slightly smaller diameter than the diameter of the spigot ends of pipes to be inserted through the first and second openings at the extremities of the tubular casting.
The surface of the internal chamber is further fabricated such that the throat of at least one of the two sockets formed therein contains an annularly recessed channel designed to receive an internal, cylindrical gasket for sealing, and where desired, for restraining purposes when used to form a push-on joint. One such gasket is disclosed in U.S. Pat. No. 5,464,228.
The tubular casting has a shoulder, or flanged portion, extending radially outward at a substantially right angle to form a cylindrical face encircling the tubular casting. In the preferred embodiment, the flanged portion is located at the extremity of the tubular casting that is farthest from the annular recessed channel, thereby facilitating coupling with the second pipe to be inserted into opening of the tubular casting opposite from the end having the annular recessed channel. The external face of the flanged portion has fabricated at its internal diameter a notch that is tapered perpendicularly from the external face of the flanged portion. It will be appreciated that, so configured, the notch is designed to receive a complementally-shaped gasket used to form mechanical joint pipe when the flanged portion is mated with an appropriately sized gland fitting slidably attached along with the gasket to the spigot end of the second pipe. In a preferred embodiment, the face of the flanged portion has a plurality of apertures for receiving bolts or other connecting means in order to secure the fitting to the appropriately sized and positioned gland. It will be understood by those in the industry that alternative means exist for securing pipe fittings together, and the present invention is not restricted to the use of bolts and bolt apertures.
The new pipe fitting facilitates connections between pipe in the field without the need for sophisticated and time-consuming machining. Also, because the ridge and the recessed channel are fabricated within the new flange component before the joint is assembled, the location of the gasket and the extent to which the spigot must be inserted into the flange component is predetermined, thus eliminating the need for making precise measurements as is required by the invention disclosed by U.S. Pat. No. 3,589,750, issued Jun. 29, 1971 to P. Dunmire. These same features of the present invention also reduce substantially the possibility that the gasket will be displaced or damaged during assembly as is the case with Dunmire. Thus, the instant invention provides a significant improvement over current devices because it is makes assembly of pipeline more efficient, economical and error-free.


The invention relates to a food product comprising 0.1 to 1.5 wt % of one or more anti-spattering agents comprising no native soy lecithin or native soy lecithin in an amount of from 0 to 0.05 wt % on total product, whereby the anti-spattering agent is preferably selected from the group comprising hydrolyzed lecithin, fractionated lecithin, citric acid esters or combinations thereof; optionally one or more emulsifiers in a total amount of from 0 to 0.5 wt %; optionally one or more browning agents in a total amount of from 0 to 0.07 wt %; one or more salts in an amount of from 0.5 to 3 wt %.

The present invention relates to a food product which is a water and oil containing emulsion which comprises an anti-spattering agent. The emulsions are pourable or squeezable products as evidenced by a Bostwick value of equal to or more than 7, preferably more than 10 at 15xc2x0 C. Preferred food products are water in oil emulsions.
Pourable or squeezable food products of a water phase and a fat phase are for example known as liquid frying products which are pourable or squeezable water in oil emulsions at ambient temperature.
These products are for example used in shallow frying. Pourable and squeezable products are considered to be more easily dosed than plastic products for example packed in a wrapper or a tub, and are therefore desired frying products.
The pourability or squeezability of these products is evidenced by a Bostwick value of at least 7 at 15xc2x0 C. For pourable products, a Bostwick value of at least 9 is preferred, even more preferred is a Bostwick value of at least 15, most preferred from 15 to 23.
The method to determine this value is illustrated in the examples.
The invention especially relates to pourable or squeezable water in oil emulsions.
The physical storage stability of pourable or squeezable products is considered an important characteristic.
For example squeezable or pourable emulsions may show formation of an oil layer on top of the emulsion after storage at temperatures between 5 and 25xc2x0 C. The formation of such an oil layer is referred to as oil separation. Pourable products such as liquid frying products preferably show oil separation of less than 7 vol %, more preferred less than 5 vol %, on total product after storage at 25xc2x0 C. for 4 weeks.
As many known water in oil emulsions are often used for frying of food stuff these products usually comprise an anti-spattering agent. Anti-spattering agents are often included in frying products like margarines to improve uniform release of water during heating.
Spattering of a water in oil emulsion is believed to be caused by superheating of water droplets. At a certain point after heating the water droplets explosively evaporate, whereby the product can be spread all over the surroundings of a frying pan in which the emulsion is heated. This may cause danger to the person who fries foodstuff in the heated emulsion and it also often causes a mess in the kitchen.
For example lecithin, especially the phosphatidylcholine component of lecithin, is a well known anti-spattering agent.
Especially pourable or squeezable water in oil emulsions comprising native lecithin as anti-spattering agent are susceptible to undesired oil separation upon storage.
Therefore a desire exists for pourable/squeezable water in oil emulsions that comprise little or no native lecithin.
A further desired characteristic of water in oil emulsions used for frying is that they show the desired signal function. With signal function is meant that during heating the user of the frying medium desirably gets a specific signal at the moment the frying medium is heated sufficiently to temperatures of about 160 to 190xc2x0 C., to put the meat or other foodstuff in.
Foaming of the frying medium as caused by heating, may be one element of a signal function. During heating usually a foam slowly develops. This foaming can be described as the formation of a blanket of gas bubbles on top of the melted frying medium, which is easily identified by eye. The amount of foam that exists is expressed in terms of surface coverage, i.e. in percentage of frying medium surface that is covered by the foam.
The moment at which the maximum surface coverage with the foam is reached, is generally perceived by consumers as the moment to put the food stuff that is to be fried in the hot frying medium.
Desirably foaming is such that a foam with small average gas bubble size of about 0.05 to 1.5 cm develops when the product is heated. Preferably this foam covers 80 to 100% of the frying pan surface. Also preferred is that the foam is not fading immediately but lasts at maximum surface coverage for several seconds, preferably about 15 to 30 seconds, to give a user the time to put frying stuff like meat in the hot frying medium.
Moreover there is a desire among a group of consumers for frying products which do not show browning upon heating but which maintain their yellow-gold colour, even at increased temperatures of for example 160 to 190xc2x0 C.
The colour of a food product, used as a frying medium, can be determined by eye or any other suitable method that is available.
In view of increased awareness among some consumers regarding health and naturalness, these consumers seem to appreciate the maintenance of the yellow colour during frying, in contrast to the often resulting brown or even brown-black colour of many known frying products at increased temperatures.
The increased desire for natural products is also demonstrated by the wish of consumers for food products which are essentially free of additives. Known products like margarine often contain on their packaging material a list of added ingredients such as emulsifiers, flavour components, acidifying agents, stabilisers and the like.
The identification on a product package of these components as additives is often required by national law. In an ingredient list all added ingredients; i.e. those not present naturally in the basic ingredients are summarised. Such law for example exists in Germany, France, The Netherlands.
Ingredients mentioned on this list alert the consumer to the presence of non-natural ingredients. Therefore it is considered that a commercial benefit can be obtained for products that do not have many non-naturally present additives listed on the package.
In summary there is a desire for squeezable or pourable food products which are suitable for shallow frying and which show all the above-indicated characteristics i.e.
a) physical storage stability
b) low spattering
c) foaming as a signal function
d) gold-yellow colour even when heated to high temperatures
e) as little added ingredients on the package as possible.
The prior art discloses products which fulfil part of these characteristics, however none of the products disclosed in the art relates to products which show all these characteristics.
For example GB-A-1,333,938 discloses that oil separation of a water in oil emulsion can be at least partly overcome by incorporating in the emulsion an emulsion-stabilising amount of gas bubbles. However the disclosed products comprise skim milk and it is taught that the optimum stability is obtained by the addition of emulsifiers. These products are believed to show strong browning upon heating and to be less attractive for certain groups of consumers who do not appreciate products with added emulsifier on the package.
Also the spattering and foaming behaviour of these products is believed to be unsatisfactory as these products do not comprise anti-spattering agents.
NL-A-7112119 relates to pourable margarines which have improved stability against oil separation and comprise phosphatides or derivatives thereof to improve spattering behaviour in frying.
According to the examples and the teaching of the description, emulsifiers such as monoglycerides in an amount of about 0.2 wt %, are added to further increase the stability of these products. Nothing is disclosed about the foaming properties.
U.S. Pat. No. 5,756,142 discloses a squeezable spread comprising lecithin.
EP-A-253,429 relates to a surface active composition comprising phosphatidylcholine and phosphatidylethanolamine and at least 3% lysophosphatidylethanolamine and the phosphatide containing composition is further characterised by a specific degree of hydrolysis. The compositions disclosed in the example comprise 1 wt % whey solids which will lead to considerable, undesired, browning.
Furthermore commercial products are known which comprise Bolec ZT(tm) as anti-spattering agent in amounts of for example 0.35 wt %. This amount of a native soy lecithin was found to lead to products which showed considerable oil separation of about 15%.
The elimination of native soy lecithin such as Bolec ZT(tm) leads to a change in foaming behaviour. Native lecithins like Bolec ZT(tm) give rise to the formation of a desired fine foam with an average gas bubble size of from about 0.05 to about 1.5 cm and with a maximum of bubble size distribution at about 0.4-0.9 cm. Such a small average gas bubble size leads to the formation of white or very pale yellow coloured foam which is appreciated by certain groups of consumers.
Moreover the presence of native lecithin influences the velocity of foam formation whereby foam formation was already obtained within 95 seconds. As a further advantage the foam produced in the presence of native lecithin remains at maximum coverage for a period of at least 15 seconds which gives a consumer the time to put meat or other frying stuff in before the foam has disappeared. Furthermore, it was found that the surface coverage with foam at the end of the shallow frying process remains at least 50% for products containing native lecithin.
The removal or severe reduction in native lecithin content in a food product for frying has the problem that it leads to a different foam behaviour, showing none of the indicated foam properties and signal function as nicely as in the presence of native lecithin such as Bolec ZT(tm).
Other known products comprise Bolec MT(tm), a hydrolysed lecithin, at low salt content of 0.1 wt % or less. These show undesired spattering and comprise high amounts of monoglycerides.
It has now surprisingly been found that products comprising a specific combination of anti-spattering agents, emulsifiers, browning agent, salt and fat show all desired characteristics. These products showed the desired foaming behaviour even in the total absence of native lecithin.
Therefore the invention relates to a food product with a Bostwick value of at least 7 at 15xc2x0 C., comprising an aqueous phase and from 40 to 90 wt % of a fat phase on total product, said food product comprising
a) 0.1 to 1.5 wt % of one or more anti-spattering agents comprising no native soy lecithin or native soy lecithin in an amount of from 0 to 0.05 wt % on total product, whereby the anti-spattering agent is preferably selected from the group comprising hydrolysed lecithin, fractionated lecithin, citric acid esters or combinations thereof;
b) optionally one or more emulsifiers in a total amount of from 0 to 0.5 wt %
c) optionally one or more browning agents in a total amount of from 0 to 0.07 wt %, preferably 0 to 0.03 wt %.
d) one or more salts in an amount of from 0.5 to 3 wt %.
Products according to the invention are products with a Bostwick value of at least 7 at 15xc2x0 C.
Products with a Bostwick value at 15xc2x0 C. of below 10 are squeezable products which suffer less from the indicated oil separation compared to pourable products.
Spattering can be measured by determining the spattering value according to the method illustrated in the examples. Preferably food products according to the invention show a primary spattering value, SV1, (spattering upon heating of a frying product such as margarine, without incorporation of a food product to be fried) of from 7 to 10, more preferably from 8.5 to 10. The secondary spattering value, SV2, (spattering upon incorporation of a food product such as meat in a shallow frying product) for products according to the invention is preferably from 5-10.
Preferred anti-spattering agents are selected from the group comprising hydrolysed vegetable lecithin such as Bolec MT(tm), fractionated lecithin such as alcohol soluble lecithin fractions e.g. cetinol(trademark), synthetic anti-spattering agents such as citric acid esters or combinations thereof.
For the purpose of the invention, lecithins, which comprise phosphoacylglycerols, can be divided in three groups according to their preparation. The first group is formed by native lecithins such as Bolec ZT(trademark).
Native lecithins are for example obtained from triglyceride oils which have been filtered, extracted and stripped. The native lecithins can be separated from the oils by use of their affinity for water, this rendering them oil insoluble.
According to another, more preferred definition, native lecithins are those which have a phosphatidylcholine to phosphatidylethanolamine ratio of at most 1.3, in combination with the total amount of lysophosphatides being at most 5 wt % of all phosphatides making up the native lecithin composition.
The second group of lecithins is formed by (partly) hydrolysed lecithins which originate from native lecithins which have been hydrolysed for example by use of the enzyme phospholipase A or by chemical hydrolysis. Hydrolysed lecithins can also be prepared by chemical synthesis.
A third group of lecithins comprises fractionated lecithins such as the alcohol soluble fraction of native lecithins such as cetinol(trademark).
This type of lecithin can be obtained in a process wherein native lecithins are extracted with alcohol.
Examples of these three groups of lecithins are:
native lecithin: Bolec ZT(tm), Adlec(tm), Sterpur PM(tm);
hydrolyzed lecithin BOLEC MT(tm), Sterpur E(tm), Adlec E(tm);
fractionated lecithin: Cetinol(tm), Nathin 3-KE(tm).
For the purpose of the invention lecithins are from vegetable origin.
Lecithins in each group can optionally be de-oiled lecithins.
Suitable amounts of anti-spattering agent were found to range from 0.1 wt % to 1.5 wt %. It will be appreciated that the amount of anti-spattering agent used is dependent on the type of anti-spattering agent used.
Native lecithins such as Bolec ZT(trademark) are well known anti-spattering agents but products comprising this agent show undesired oil separation already at amounts of native soy lecithin of above 0.05 wt %. Therefore the products according to the invention are preferably essentially free of native soy lecithin, although a minor amount of at most 0.05 wt % may be present.
The anti-spattering agents are present in a total amount of from 0.1 wt % to 1.5 wt %. Lower values than 0.1 wt % lead to unsatisfactory spattering behaviour and amounts over 1.5 wt % were found to lead to off taste, coarse foam with high average gas bubble size, and often too much foam which can rise out of the pan.
Preferably the amount of hydrolysed lecithin is carefully chosen between 0.1 and 1 wt % as levels above 1 wt % may lead to taste defects.
Preferably a synthetic anti-spattering agent like citric acid ester is present in an amount of citric acid ester is preferably from 0.1 to 1.5 wt %.
The amount of fractionated lecithin is preferably from 0 to 0.5 wt %, whereby the presence of at least some cetinol is highly preferred.
According to a preferred embodiment, the anti-spattering agent consists of hydrolysed lecithin in an amount of 0.1 to 1 wt %, fractionated lecithin in an amount of 0 to 0.5 wt % and citric acid ester in an amount of 0 to 1.5 wt %.
According to a highly preferred embodiment, the anti-spattering agent consists of 0.1 to 1 wt % hydrolysed lecithin and 0.05 to 0.5 wt % alcohol soluble lecithin.
According to an even more preferred embodiment, the amount of hydrolysed lecithin is from 0.1 to 0.35 wt % and the amount of alcohol soluble lecithin is from 0.05 to 0.2 wt %.
However not all compositions comprising the indicated anti-spattering agents will show the desired foaming behaviour. The addition of these anti-spattering agents to common liquid frying products which are often at least partly based on milk ingredients was found to lead to products which showed a coarse foam with average gas bubble size of between about 0.7 and about 2.5 cm with a maximum from about 1.2 to about 1.8 cm. A coarse foam is a foam with relatively large average gas bubble size of between 0.7 and 2.5 cm wherein also many droplets with size of 1.5-2.5 cm are present. The formation of gas bubbles with such big size is considered undesirable as it does not impart the white look to the product and a yellow view remains. Moreover the large bubbles were found to spatter more severely. Also they are considered less suitable to serve as a signal function.
Furthermore the presence of browning agent such as protein was found to lead to a delay of the start of foaming, a reduction of duration of maximum surface coverage with foam, and a reduction of the foam amount at the end of the shallow frying process.
Browning agents are therefore preferably fully absent but a small amount of up to 0.07 wt % was found to be tolerable. More preferred the amount of browning agent is from 0 to 0.03 wt %.
It will be appreciated that the amount of browning agent such as protein is related to the amount of anti-spattering agent used in view of their combined effect on the formation of a foam.
Besides protein the following compounds are known as browning agents: sugars, combinations of protein and sugar, biopolymers.
In addition to influence on foaming behaviour, the absence or presence of only a low amount of browning agent such as protein was found to lead to products with increased microbiological stability. This is believed to be a considerable advantage; the increase in microbiological stability opens the possibility to reduce or even eliminate preservation agents like potassium sorbate.
The presence of preservation agents is often required to be declared in the ingredient list on the package of a product. The elimination of such ingredients therefore contributes to enhanced perceiving of naturalness by some groups of consumers. This is considered advantageous for commercialisation of a food product in the current age, where many people are considering the presence additives and their amounts while buying food stuff.
To further improve the naturalness of the current products, the product preferably does not comprise an emulsifier other than lecithin or comprises from 0 to 0.5 wt % of an emulsifier other than lecithin. Traditionally emulsifiers are present in spreadable margarines which are traditionally sold in a wrapper or a tub. Emulsifiers are generally believed to effectively increase the stability of an emulsion (Food science and technology, G. Hoffmann, Academic press, 1989, page 147, par A1). Therefore water in oil emulsions, especially those which show a tendency to oil separation, usually comprise emulsifiers to stabilise the emulsions and reduce separation. Examples of emulsifiers are mono- and diglycerides. Combinations thereof are possible.
Also lecithin can function as an emulsifier but for the purpose of the invention the term emulsifier does not include lecithins.
It has now surprisingly been found that emulsifiers (other than lecithin) are no longer needed if products are prepared according to the claimed composition. The specific balance of ingredients thus obtained leads already to products which show no or very limited oil separation. The absence of emulsifiers is considered beneficial in at least two ways. The first benefit being in the cost savings that can be obtained if emulsifiers are no longer added. The second benefit is again in the naturalness of the product, which is increased if no emulsifiers are added. No added emulsifiers means deletion of another item of the common ingredient list for these products.
Although we have found that emulsifiers, other than lecithin, are not necessary and may be fully absent, the presence of a limited amount of emulsifier can be tolerated.
Therefore products according to the invention comprise from 0 to 0.5 wt %, more preferred from 0 to 0.18 wt % of emulsifier. For the purpose of the invention lecithin is not included in this amount.
The potential of our product to show the desired characteristics even in the presence of some emulsifier is beneficial as in almost all cases where oil is used, some partial glycerides like monoglycerides and/or diglycerides will be present. These partial glycerides develop during storage of a triglyceride oil. The level of emulsifier thus obtained is usually below 0.15 wt % so removal is not necessary.
However if the concentration of mono or diglycerides is above 0.5 wt % they are preferably removed from the oil before it is used in product preparation. Undesired effects develop when the amount of emulsifier such as partial glycerides is above 0.5 wt %.
More preferred the amount of emulsifier is from 0 to 0.18 wt %.
The monoglycerides and/or diglycerides which develop during oil storage can be identified by generally known techniques. As these partial glycerides have as a starting source the oil in which they develop, the fatty acid composition of the partial glycerides is similar to that of the stored triglyceride oil.
Emulsifiers that can for example be added are partial glycerides with either saturated and or unsaturated fatty acid chains. Especially the saturated fatty acid partial glycerides are less preferred. It has been found that during temperature cycling of a pourable product the saturated partial glycerides influence the crystallisation behaviour of the fat blend which may influence the pourability of the product. Increased levels of partial glycerides may lead to hardly squeezable products. This effect was especially found if the amount of saturated partial glycerides is above the solubility level of these compounds. The solubility level is generally about 0.1 to 0.2 wt %. Therefore products according to the invention preferably comprise from 0 to 0.2 wt % of partial monoglycerides with saturated fatty acid chains, more preferred the compositions are free of these partial glycerides.
In a preferred embodiment the food products according to the invention are essentially free of added emulsifier. This leads to a shortened ingredient list on the product package in several countries.
For the purpose of the invention added emulsifiers such as mono-or diglycerides are those emulsifiers such as mono-or diglycerides which are added on top of the emulsifiers such as mono- or diglycerides which may be present in the triglyceride oil material.
In an even more preferred embodiment products according to the invention are essentially free of all emulsifier. Again lecithin is not included as this is anyway present to improve spattering behaviour.
Traditionally margarines and like products, and also butter comprise salt. It is generally known that in some countries consumers prefer low salt products (below 0.4 wt %) and in other countries consumers prefer high salt products (above 0.4 wt %).
Known pourable margarines comprise varying amounts of salt, which are tuned to the consumers desires.
It has now been found that the salt level of pourable products which have the indicated balance of ingredients should be between 0.5 to 3, preferably 0.8 to 3 wt % of salt. The salt level was found to influence spattering behaviour. Low salt amounts were found to lead to unsatisfactory spattering behaviour. Preferred levels of salt are from 1 to 2.5 wt %, more preferred from 1.2 to 1.8 wt %.
The salt can for example be selected from potassium salts, sodium salts, choline salts, ammonium salts, calcium salts and combinations thereof. Examples are potassium chloride, sodium chloride, choline choride, and combinations thereof.
The products comprise 40 to 90 wt % of a fat phase. Preferably the total amount of fat phase in products according to the invention is from 50 to 90 wt %, more preferred 55 to 90 wt %, most preferred 65 to 85 wt %.
Besides a fat blend, the fat phase comprises optionally fat soluble ingredients like colourants, vitamins and flavours.
Most known fat blends that are suitable for liquid frying products were found to be suitable for products according to the invention.
The known liquid/squeezable frying products fat blend usually consists of a mixture of an oil, a fat which at ambient temperature is fully liquid, and a fat which is solid at ambient temperature, the so-called hardstock. The ratio of liquid and solid fat is chosen such that after proper processing together with an aqueous phase a product with a suitable squeezable or pourable consistency is obtained.
The presence of hardstock fat in liquid frying products aims to contribute to stabilisation of the emulsion. As explained above unstable liquid frying products show phase separation in the form of oil separation.
The solid fat crystals which are needed for the stability of the emulsion, on the other hand may adversely affect its pourability. Liquid frying products manufacture therefore requires a hardstock fat with properties which are delicately balanced. Any suitable hardstock may be used.
A liquid frying product having a pourability rating (Bostwick value) of less than 7 is too thick and lacks acceptable pourability and squeezability.
Fully hydrogenated high erucic rapeseed oil (shortly denoted as fully hardened rapeseed oil or RPh70) is a well known hardstock fat which complies with the above specification. It is suited for the manufacture of satisfactory liquid or squeezable frying products which combine good stability with good pourability. However also other hardstocks may be used such as sunflower seed oil with a melting point of about 69xc2x0 C., soy bean oil with a melting point of about 65xc2x0 C., palm oil with a melting point of about 58xc2x0 C., arachidic oil with a melting point of about 60xc2x0 C. and cotton seed oil with a melting point of about 62xc2x0 C. Combinations of one or more of these hardstock fats or interesterified blends of these fats may also be suitably applied.
Presently, from all above mentioned fats mainly fully hardened rapeseed oil is employed for the commercial preparation of high quality liquid frying products. Its use is described e.g. in U.S. Pat. No. 5,756,142.
Most liquid or squeezable frying products are prepared with 1.5-5 wt. % hardstock fat on total product.
In addition to the hardstock the fat blend comprises a relatively low melting fat.
As the low melting fat an oil rich in triglycerides comprising (poly) unsaturated fatty acid residues is highly preferred.
Therefore the low melting fat is preferably selected from the group comprising sunflower oil, soybean oil, rapeseed oil, cottonseed oil, olive oil, corn oil, groundnut oil, or low melting butterfat fractions and/or combinations thereof. These fats may be partially hydrogenated.
The composition of the fat blend is preferably such that the fat blend shows a solid content of 1 to 3, more preferred 2.5 to 3.0% at 5xc2x0 C. and 1.5 to 3, more preferred 2.0 to 2.5% at 15xc2x0 C. and 2 to 3, more preferred 1.5 to 2.0 at 35xc2x0 C.
In addition to the above mentioned ingredients, food products according to the invention may optionally contain further ingredients suitable for use in these products. Examples of these materials are sweetener materials, EDTA, spices, bulking agents, egg yolk, stabilising agents, flavouring materials, colouring materials, acids, preserving agents, vegetable particles etc.
However the amount of these ingredients should be such that the desired characteristics are not severely drawn back by the presence of these ingredients. Therefore for example the presence of low amounts of flavour components, colouring agents is tolerated. However the presence of sugars or stabilising agents, which are known to cause browning is often less preferred.
Moreover it will be appreciated that all these ingredients when added will be mentioned on the ingredient list, which in many cases may reduce the perceived naturalness of the products.
Advantageously the products according to the invention comprise gas such as nitrogen, carbon dioxide or another, preferably inert gas. It has been found that such gas if present can suitably further stabilise a water in oil emulsion. Preferably however the stability of the product without gas is already acceptable e.g. having an oil separation of below 5 vol % after storage for 4 weeks at 25xc2x0 C. and fulfilling the other desires indicated above. Optional gas may then be added for further stabilisation.
Generally the balance of compositions according to the invention will be water.
Products according to the invention can be prepared by general methods as known to the person skilled in the art. For example a premix comprising all ingredients is prepared, followed by blending and mixing in order to establish a suitable emulsion. If desired the crystallisation of solid fat if present can either be performed a priory or as a processing step in which the premix is cooled by one or more scraped surface heat exchangers. In such a step also the process of emulsification could take place. Emulsification could on the other hand as well be envisaged by other kinds of techniques as, e.g. membrane emulsification and alike.
If a small amount of hardened fat such as hardened rapeseed oil is present in the final product, a preferred process comprises the steps of melting triglyceride oil in shear mixer such as an A unit, cooling to below the alpha crystallisation temperature and subsequent, or prior to cooling, mixing the triglyceride oil with the aqueous phase.
The resulting product is preferably stored at a temperature from 0 to 15xc2x0 C.
All concentrations in this specification are weight concentrations unless indicated otherwise.