A cyclic compound comprising m units of the formula Ia:

The present invention relates to condensates in particular cyclic calixarene compounds which are cyclic phenolic compounds. The compounds of the invention are particularly suitable as thermal stabilising additives in fuel and for use in lubricating oil compositions for medium or low speed diesel engines, especially four stroke engines. The invention also relates to fuel compositions and to lubricating oil compositions comprising said compounds, e.g. aviation fuel compositions.
In high speed aircraft, both civilian and military, the liquid fuel is combusted to produce power, but also is circulated in the aircraft as a heat exchange fluid to remove the excess heat generated at such speeds e.g. in lubricating oils. The fuel is thus maintained for long periods at high temperatures, which results in discoloration and decomposition to produce soluble coloured products and insoluble products such as gums, sediments and granular material; insoluble products can form deposits that reduce the heat exchange capacity and can block filters potentially causing loss of power. Soluble coloured by-products are unsightly and an indication of some decomposition. The cause of discoloration etc. may be from phenols, naphthenates and sulphur compounds and/or metals which are often present in the fuels.
In some oil fired devices, such as boilers and slow heating cookers, e.g. of the Aga type, kerosine oil fuel is passed down a narrow metal feed pipe to the combustion chamber where it is burnt. Parts of the pipe are sufficiently near the hot chamber for them to be heated to significant temperatures, resulting in the risk of thermal degradation of the fuel in the pipe, especially with slow feed rates and high residence times in the pipe. This degradation can form solid deposits which reduce the flow and ultimately stop it, causing the combustion to stop. To overcome this manufacturers of such devices have for many years recommended to their users that at least once each 6 months such pipe parts are cleaned of solid deposits of coke or other materials.
U.S. Pat. No. 5478367 describes the addition to diesel or jet fuel of a substituted unsaturated polyamine derivative dispersant to reduce particulate emissions on combustion and to reduce fouling i.e. deposition of insoluble deposits. The macrocyclic compounds preferably contain an Nxe2x95x90Cxe2x80x94Nxe2x80x94Cxe2x95x90O group and especially have fused rings, such as are made by reaction of a hydrocarbyl (e.g. fatty alkyl) succinic anhydride and a polyalkylene amine.
Canadian Patent Publ. 2067907 describes the addition to distillate jet fuels of hydroxylamines to stabilise them against degradation at elevated temperatures.
U.S. Pat. No. 5468262 describes addition to jet fuels of thermal stability additives which are prepared by reacting a polyamine, aldehyde and phenol to form a condensate which is then reacted with a succinic anhydride containing a polyolefin derived unsaturated group.
The additives are effective at 0.2% by weight.
EP-A-678568 describes addition to jet engine fuels of anti deposition agents which are derivatives of (thio)phosphonic acids.
Accordingly the present invention provides a cyclic compound comprising m units of the formula Ia.
and n units of the formula (Ib)
joined together to form a ring,
wherein Y and Y2 are divalent bridging groups which may be the same or different in each unit; R0 is H or (C1-C6) alkyl or is a metal or ammonium cation, (so the group CO2R0 is a carboxylic salt); R5 is H or (C1-C60) alkyl or OH group; and j is 1 or 2; R3 is hydrogen, a hydrocarbyl or a hetero-substituted hydrocarbyl group; each of R1, R2 and R4, which may be the same or different, is hydroxyl, hydrogen, hydrocarbyl or hetero-substituted hydrocarbyl, with the proviso that at least one of R1, R2, R4 is hydroxyl, and m+n is 4 to 20, m is 1-8 and n is at least 3 and preferably either R1 is hydroxyl and R2 and R4 are independently either hydrogen, hydrocarbyl or hetero-substituted hydrocarbyl, or R2 and R4 are hydroxyl and R1 is either hydrogen, hydrocarbyl or hetero-substituted hydrocarbyl; and m+n is from 4 to 20, m is from 1 to 8 and n is at least 3, with the proviso that in formula Ia at least one OH group is in the meta or para position to the COOR0 group and/or at least one R5 group is OH. Preferably in a second proviso, at least one of the following features (a) to (e) is met, namely the cyclic compound comprises at least one of (a) at least one formula (Ia) unit in the form of a carboxylate anion especially at least 2 carboxylate anions (b) at least one formula (Ia) unit in the form of an alkaline earth metal or alkali metal carboxylate salt, preferably a potassium or sodium salt, especially a potassium salt (c) at least 2 e.g. 3 or 4 units of formula (Ia) (d) an m+n value of 5-11, preferably 7-9 and especially 8 and (e) the cyclic compound is in the substantial absence of linear species comprising formula (Ia) and (Ib) units and/or or the substantial absence of unreacted formula (Ia) and (Ib) units, (e.g. of formula IIa and IIb hereafter).
Preferably the cyclic compound has at least 2 of (a) (b) (c) (d) and (e) preferably 3, most preferably 4 and especially all 5 in particular (a) and (c), or (b) and (c), and especially (d). In a preferred embodiment the invention provides a cyclic compound wherein m is 2, n is 6, and both the units of formula (Ia) are in the form of a potassium carboxylate salt, and the cyclic compound is in the substantial absence of linear species comprising formula (Ia) and (Ib) units and the substantial absence of unreacted formula (Ia) and (Ib) units.
When more than one xe2x80x94CO2R0 containing aromatic group unit is present in the ring (i.e. m greater than 1), the phenol units and the xe2x80x94CO2R0 containing aromatic groups may be distributed randomly, although this does not exclude the possibility that in some rings there may be several xe2x80x94CO2R0 containing aromatic groups joined together in a row. Thus the m and n units may be joined in block and/or randomly.
If desired, in addition to containing at least one unit of formula Ia, the cyclic compound may also contain at least one unit of formula
where R15 is H or C1-60 alkyl, and R16 and Y3 are as described above for R0 and Y2 respectively. Preferred groups for R15, R16 and Y3 are as described below for R5, R0 and Y/Y2 (apart from OH for R5). The preferred unit is derived from salicylic acid. The cyclic compound may contain 1-4 units of formula Ia and 1-4 units of formula Id, especially 1 or 2 of formula Ia and 1 or 2 of formula Id, in particular with a total of both of 2 or 3, preferably the cyclic compound consists essentially of units of formula 1a and 1b
In the formulae Ia/Ib Y, and Y2 may each independently be a hydrocarbyl bridging group or be a hetero-substituted hydrocarbyl group or up to 50% mole of the totality of Y, and Y2 group may be a hetero atom. The hydrocarbyl bridging group is preferably aliphatic and has a chain of 1-4 carbon atoms; preferably the group is of formula (CR7R8)d e.g. (CHR8)d where each of R7 and R8, which may be the same or different, represents hydrogen or hydrocarbyl e.g. of 1-20 carbons such as 1-6 carbons or 6-20 carbons, such as methyl or ethyl and d is an integer of 1-4 preferably 2 or especially 1; advantageously the group is of formula (CHR8)d where R8 is as defined above preferably methyl or especially hydrogen. Y, and/or Y2 may also represent a hetero-substituted hydrocarbyl group with a hetero atom, e.g. O, S or NH interrupting a chain of carbon atoms e.g. 2-4 carbon atoms, such as in CH2OCH2, CH2SCH2 or CH2NHCH2. Up to 50 mole % of the totality of Y and Y2 groups may be a hetero atom e.g. O or NH or especially 5, e.g. 1-50 mole % especially 8-20 mole % of said groups. Preferably Y and Y2 are hydrocarbyl groups, and the compound of formula I is sulphur free.
In the group of formula Ia, the group Y is usually ortho or para to an OH group and/or is usually meta to the CO2R0, but can be ortho to said CO2R0 group, especially when an HO group is meta to the CO2R0 group. The group Y is usually meta to the free valency in the ring but may be para thereto. In particular, group Y is para to an OH group and meta to a CO2R group so the group is of formula Ic.
where one R5 is OH and one R5 is hydrogen. In a special subclass the CO2R0 and OH groups in Ia are meta or para to one another unless there are two OH groups in the ring i.e. one of R5 is OH. When the group Ia contains two OH groups in the ring, they may be ortho or para to one another (as in 2,5, and 3,4, dihydroxy benzoic), but are preferably meta to one another, (as in 2,4, or 3,5 and 2,6 dihydroxy benzoic) especially when none, one or two OH groups is/are ortho to the CO2R0 group, in particular none or one, and advantageously one. When the group Ia contains two OH groups in the ring, one OH may be in the ortho position and the other be in the ortho, meta or para position relative to the CO2R0 group. When the group Ia contains only one OH group per ring, that OH group is meta or para but when there is more than one group Ia in the ring i.e. m is at least 2, the second or other group Ia may have the OH group ortho to the CO2R0 group, so the unit is a salicylic acid derivative.
Preferred units for formula Ia are from a mono hydroxy aromatic carboxylic acid, which is a meta or para hydroxy benzoic acid or a dihydroxycarboxylic acid, which is preferably 2,4, dihydroxy benzoic acid or 3,5,dihydroxy benzoic acid, but may be 2,5, or 2,6, or 3,4,dihydroxy benzoic acid.
When the second proviso in respect of the compounds of formula Ia/Ib applies, the units of formula Ia are preferably of formula Ic, especially when R5 is OH, in particular a resorcylic acid (or salt thereof).
Each of R1, R2 and R4 represents hydroxyl, hydrogen, hydrocarbyl or hetero-substituted hydrocarbyl with the proviso that at least one of R1, R2 and R4 represents hydroxyl. Thus all three may represent hydroxyl as in a phloroglucinol derivative, or two as in a resorcinol derivative (i.e. the compound of formula Ia/Ib contains a resorcinarene group), or one as in a phenol derivative. Preferably either R1 is hydroxyl and R2 and R4 are independently either hydrogen (which is preferred), hydrocarbyl or hetero-substituted hydrocarbyl, or R2 and R4 are hydroxyl and R1 is either hydrogen, hydrocarbyl or hetero-substituted hydrocarbyl.
Regarding R1 to R5 and R8, the term xe2x80x9chydrocarbylxe2x80x9d includes (C1-C60) alkyl such as t-butyl, t-amyl, s-butyl, isopropyl, octyl, nonyl, dodecyl and octadecyl. Alternatively the hydrocarbyl group may be derived from a polyolefin, for example polyethylene, polypropylene, polybutylene or a polyolefin copolymer, for example an ethylene/propylene copolymer, preferably derived from a polyisobutene. Alternatives include isoprene-butadiene, styrene-isoprene or styrene-butadiene block copolymers such as those disclosed in WO 96/40846, or ethylene-propylene and ethylene-butene-1 copolymers having molecular weights from 1500 to 2500 or 7500, as disclosed in U.S. Pat. No. 5,567,344 and U.S. Pat. No. 5,578,237. Mixtures of all the above may also be employed. Any hetero-substituted hydrocarbyl group has the heteroatom, preferably xe2x80x94Oxe2x80x94 or xe2x95x90NH, interrupting a chain of carbon atoms, such as an alkoxy-alkyl group of 2-20 carbons. Each of R1-R5 may otherwise be as described for R3 below.
The hydrocarbyl group for R1, R2 or R4 usually has 1-14 e.g. 1-6 carbons and is preferably saturated, especially an alkyl group e.g. methyl, ethyl, propyl, butyl or hexyl group. The hetero-substituted hydrocarbyl group has at least one e.g. 1-3 especially 1 hetero atom e.g. O S or NH interrupting a chain of carbon atoms e.g. 2-20, or 2-6 carbons as in an alkoxy alkylene group such as ethoxy ethyl.
R3 is hydrogen, hydrocarbyl or a hetero-substituted hydrocarbyl group. Preferably R3 is hydrocarbyl or a hetero-substituted hydrocarbyl in at least R3 group in the compound of formula I, especially with n such groups in the molecule. The hydrocarbyl group may be alkyl, alkenyl, cycloalkyl, aryl, aralkyl and contains at least 1 especially at least 4 or at least 8 carbon atoms e.g. 4-40 carbons in particular with 8-20 carbons in a chain. Preferred are linear or branched alkyl e.g. of 8-24 or 8-20 carbons, such as decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, lauryl, myristyl, stearyl, palmityl, propylene trimer or tetramer or alkenyl e.g. of 6-24 carbons such as oleyl, or cycloalkyl e.g. of 5-8 carbons such as cyclohexyl, aryl e.g. of 6-24 carbons such as phenyl, tolyl and alkylphenyl with 6-16 carbons in the alkyl e.g. dodecylphenyl and aralkyl e.g. of 7-26 carbons such as benzyl and alkyl substituted benzyl with 6-16 carbons in the alkyl e.g. dodecyl benzyl. R3 may also represent a polymeric hydrocarbyl group e.g. from a polyolefin group, especially from one or more olefins of 2-6 carbons such as ethylene, propylene, butene, isobutene; the polymeric groups may be from polyethylene, polypropylene, polybutene, an ethylene propylene copolymer or polyiso butene (which is preferred). Molecular weights of polymeric R3 groups may be 300-6000 e.g. 500-2000. In the compound of formula I, there may be different R3 groups in the same molecule.
In the compound of formula I, m is from 1 to 8 e.g. 1-4 especially 2 or in particular 1, while n is at least 3 e.g. 3-10, in particular 5-9 especially 6-8. The sum of m+n is 4 -20, preferably 5-10 in particular 7-9, e.g. 6 or 8, or a mixture of compounds with m+n having the value of 6 and 8. Preferably m is 1 or 2 and m+n is 5-10 e.g. 8.
In preferred calixarenes Y, or Y2 is CH2; R1 is hydroxyl; R2 and R4 are independently either hydrogen, hydrocarbyl or hetero-substituted hydrocarbyl; R3 is either hydrocarbyl or hetero-substituted hydrocarbyl; R0 is H or is substituted by an alkali metal ion, in particular a potassium ion; R5 is hydrogen or an alkyl group of 6 to 50 carbon atoms, preferably 4 to 40 carbon atoms, more preferably of 6 to 25 carbon atoms; j is 2 or preferably 1; and m+n has a value of at least 5, preferably at least 6, typically at least 8, where m is 1 or 2, preferably 1.
More preferably R2 and R4 are hydrogen; R3 is hydrocarbyl, preferably alkyl of greater than 4, preferably greater than 9 carbon atoms; R5 is hydrogen; and m+n is from 6 to 12 e.g. 8; m is 1 or 2.
In preferred compounds, R2 and R4 are hydrogen, m is 1 or 2, n is 5, 6 or 7, m+n is 6 and/or 8, R1 is hydroxyl, R3 is alkyl of 8-20 carbons e.g. dodecyl or octadecyl, or polyisobutenyl.
The metal in the salt form may be an alkali metal e.g. Li, Na, K, Rb or Cs, or an alkaline earth metal e.g. Mg or Ca, or the salt may be an ammonium or a quaternary ammonium salt e.g. of formula NR1R2R3R4 wherein R1-R4 are as defined above, especially with at least 3 and in particular 4 of them of less than 10 carbons.
For convenience the cyclic compounds may herein be referred to as xe2x80x9ccarboxy calixarenesxe2x80x9d.
For a review of calixarenes the reader is referred to xe2x80x98Monographs in Supramolecular Chemistryxe2x80x99 by C David Gutsche, Series Editor-J Fraser Stoddart, published by the Royal Society of Chemistry, 1989. Calixarenes having a substituent hydroxyl group or groups include homocalixarenes, oxacalixarenes, homooxacalixarenes and heterocalixarenes.
Calixarenes of the present invention may be made by reacting together appropriate amounts of the optionally substituted hydroxy benzoic acid e.g. (or carboxylic ester), an optionally substituted phenol, and a carbonyl compound which is preferably an aldehyde e.g. formaldehyde, or acetaldehyde, especially in the presence of a base and optionally a catalyst. The reaction may be performed in the presence of sulphur if the cyclic compound of formula Ia/Ib is to contain combined sulphur.
The calixarenes may be made by a process comprising reacting together, preferably in the presence of a basic catalyst, compounds of the formula (IIb) with one of formula IIa (especially IIc).
with an aldehyde of the formula Oxe2x95x90CR7R8 e.g. Oxe2x95x90CHR8, and optionally sulphur, or with a dihalide YX2 or Y2X2 where, R0 to R5, R7, R8 and j are as defined previously and X is chlorine, bromine or iodine.
Preferred basic catalysts are alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide. The process may also be performed in the substantial absence of a basic catalyst.
A proportion of the product may comprise linear molecules. Linear molecules are also composed of units having formulas (Ia) and (Ib) except that instead of the ends of the molecule being joined to form a ring, each end has a terminal group which is independently one of the following:
In the linear molecule the total number of units m+n is from 2 to 20, m is from 1 to 8 and n is at least 1. A further aspect of the invention provides the product (hereinafter called Product A) of reacting compounds of the formulas (IIb) above and IIa (preferably IIc) with an aldehyde of the formula Oxe2x95x90CHR8, and optionally sulphur; where R0 to R8 are as defined previously. The reaction product usually comprises at least 20% by weight of a cyclic compound comprising units of formulas (Ia) and (Ib) and no more than 80% of the linear version of said compound. Preferably the cyclic form comprises at least 40%, more preferably at least 60% and most preferably at least 80% by weight of the reaction product. Product A also can include but may exclude products isolated from said reaction product, but preferably include said isolated cyclic products containing the COOR0 group.
The process may be performed with an amount of base which is 0.01-0.2 equivalents per mole of the carboxylic salicylic acid, with the base being effectively in catalytic amount, or with 0.2-10 equivalents per mole of the carboxylic acid.
The process may be performed in a melt or in the presence of water or in a solution or suspension. The water may be added with the base e.g. aqueous sodium or potassium hydroxide solution, and/or a possible solvent for the formaldehyde (e.g. 10-30% formaldehyde solution), the amount of added water being usually 1-20% of the total weight of the reactants e.g. 5-15%. Advantageously the process is performed with the water present initially, and then once reaction has started, then any water present as well as water produced as by product is removed e.g. by evaporation or distillation, whether under reduced pressure, and/or heating at above 110xc2x0 C.
The process may also be performed in the presence of an inert organic liquid which may be a solvent for at least one of the reactants, e.g. the phenol and/or aromatic carboxylic acid and/or a solvent or non solvent for at least one of the phenolic products, especially a carboxy calixarene such as one of formula Ia/Ib and/or a linear phenolic species. The liquid is usually a hydrocarbon of atmospheric boiling point 100-160xc2x0 C., such as toluene or a xylene or methylbenzene. The amount of liquid may be 10-90% of the total weight of solvent and reactants, especially 50-90%. Preferably the liquid is immiscible with water and can entrain water in its distillation and/or reflux, e.g. a Dean and Stark apparatus.
The reaction is usually performed at 80-180xc2x0 C. e.g. 100-150xc2x0 C. and until substantially no more by product water is produced and separated at the end of the reaction, the solvent if any may be evaporated to leave a crude product, or the reaction product (optionally with solvent) treated or used as such.
The direct product of the process to make the carboxy calixarene may be used as such (i.e. without purification from other phenolic compounds) or may be converted from one salt form to another e.g. via ion exchange or by way of acidification to form the free acids, and then if desired formation of a salt by neutralisation. Preferably the direct product is purified to increase its content of cyclic and/or carboxylic species. The direct product may be distributed between a substantially water immiscible organic solvent e.g. an aliphatic liquid hydrocarbon, such as kerosene or hexane or an aromatic hydrocarbon such as toluene or xylene, and an aqueous medium. The medium may be basic e.g. with an alkali metal hydroxide or especially carbonate or bicarbonate, in which case the aqueous medium can extract the carboxylic species, while the non carboxylic species remains in the organic phase; the phases are then separated and then carboxylic salt recovered from the aqueous phase, or acidified to free carboxylic acid and recovered from an organic phase. The direct product may also be purified, when dissolved in organic solvent, by addition of a compound capable of producing a salt insoluble in the solvent e.g. addition of a barium salt (as such or in organic or aqueous solution) can cause precipitation of an insoluble barium carboxylate salt, which may be separated from the non carboxylic compounds. Acidification of the barium salt enables the free carboxylic acid to be recovered.
The direct product in organic solution is e.g. an aliphatic or aromatic hydrocarbon such as one described above, may be contacted with an anion exchange resin, so that the carboxylic compound(s) are bound to the resin, while the non carboxylic compounds are not. The treated resin may then be separated and treated with alkali metal hydroxide or alkoxide solution to regenerate the resin for reuse and to liberate the alkali metal salt of the carboxylic acid. The process may be batch wise or continuous (with a pair of resins in parallel, one for separation while the other is being regenerated). The resin is preferably a macroreticular one, and usually has quaternary ammonium cationic substituents; an example of such a resin is that sold under the Trade Mark Amberlyst 15.
The direct product may also be purified by shape selective separation by contact of the direct product (in acid or salt form) in organic solution with an inorganic porous solid, whose pores are insufficiently large to allow the carboxy calixarene to enter, but allow the linear products to enter. Preferred maximum diameter for pores are 100A, especially  less than 70 or  less than 50 A and especially above 20A. Examples of such porous solids are silica, alumina and silica/alumina as well as ceramic membranes, e.g. made of alumina or zirconia. The contact may be batch wise, e.g. passage of the direct product onto a bed of the solid and then elution of the cyclic compounds therefrom as the first eluted fraction; such beds may be in columns in parallel, one for separation of the cyclics while the other is being eluted of the other non cyclic materials. Preferably the separation is continuous e.g. in a cross flow made and/or with a tube of ceramic membrane, through the walls of which the non cyclics pass while the cyclics pass down the tube and are concentrated.
The direct product may also be purified by selective extraction e.g. trituration with a suitable organic solvent e.g. as described above especially an aromatic hydrocarbon such as toluene or xylene, and separation of insoluble material from a solution of soluble material, from which soluble material may be recovered by evaporation. Either of the materials may then be used as such in the fuel compositions of the invention or after further purification e.g. as described above.
Preferably to make the compounds of formula Ia/Ib in which at least some, and preferably substantially all, the carboxylic groups are in salt form, the amount of base is at least 0.2 equivalents per mole of the salicylic acid, in particular 0.2-10, such as 0.9-5 especially 2-5 or about 1. The base chosen is usually the one which provides the cations required in the product, e.g. sodium or potassium hydroxide or carbonate to provide sodium or potassium carboxy calixarene salt. If desired the base for the reaction may be different, and then the reaction product salt may be converted into the desired salt e.g. via ion exchange. Thus an alkali metal base can be used in the reaction and the salt converted to for example quaternary ammonium or calcium, salt form. In addition instead of adding the hydroxy aromatic carboxylic acid as free acid into the reaction process a preformed salt thereof may be used, e.g. sodium or potassium resorcinylate, in the form for example of a solid or in aqueous solution.
Preferably to make the compounds with at least 2 carboxylic acid groups per ring, whether those groups are in acid or salt form or both, the process preferably involves reaction of the hydroxy aromatic carboxylic acid e.g. resorcinylic acid and the phenol in a molar percentage of at least 20% carboxylic acid e.g. resorcinylic acid units based on the total of carboxylic e.g. resorcinylic acid and phenol e.g. 20-90%, such as 20-40%. Advantageously the amount of base present is 0.2-8 equivalents, based on the equivalents of carboxyl groups in the carboxylic acid e.g. resorcinylic acid e.g. 2-5 equivalents.
Preferably to make the carboxy calixarenes with a ring containing 5-11 aromatic rings (derived from the phenol and the carboxylic acid), especially with 7-9 such aromatic rings, and 1-3, in particular 2 or 3 carboxyl containing phenolic rings e.g. resorcinylic rings, the process usually involves the presence of a base with a cation of appropriate size, the larger the cation the larger the ring. Thus while a spread of carboxy calixarenes ring sizes is obtained, the average is usually lower for Li e.g. 5-7, than Na e.g. 6-8, than K 7-9 and Cs 9-11.
The fuel or lubricating composition e.g. jet fuel composition may also contain a non ring i.e. linear form of the compound of formula Ia/Ib i.e. with structural units as shown in the Formulae Ia/Ib but terminated usually by the phenol and/or hydroxy aromatic carboxylic acid e.g. resorcinylic acid units.
The present invention also provides the use of at least one of these carboxylic calixarenes of the invention i.e. of formula Ia/Ib or Product A to reduce the discoloration on heating of fuel compositions e.g. jet fuel and fuel compositions comprising kerosine.
The preferred additive is dodecyl-resorcinylic calix[8]arene, which is a resorcinylcalix[8]arene comprising 7 dodecyl substituted phenolic units and one resorcinylic acid unit joined by methylene bridges. Another preferred compound is the corresponding calixarene with 2 resorcinylic groups and 6 dodecylphenol units, preferably at least partially as an alkali metal salt e.g. potassium salt and especially in the form of the dipotassiumi salt.
The additive may be present in the composition in amount of at least 1, e.g. at least 5 ppm, such as 1-1000, 5-1000 e.g. 5-500 especially 5-200 or 10-100 ppm based on the weight of the composition e.g. the jet fuel composition. The additive may be mixed with the jet or other fuel composition in the form of a concentrate in solution, e.g. in an aliphatic aromatic hydrocarbon in 20-80% w/w solution, or it may be added as such to give a solution in the fuel. More than one of the carboxy calixarenes may be present e.g. 2-4, especially differing only in the values of at least one of m and n, especially n.
The composition can comprise jet fuel. The composition can comprise kerosine, in particular in jet fuel. The main component of the jet fuel itself is usually a middle boiling distillate boiling point in the range 150-250xc2x0 C. at atmospheric pressure and the fuel is usually kerosine which may be mixed with gasoline and optionally light petroleum distillate as in mixtures of gasoline and kerosene. The jet fuel may comprise mixtures of gasoline and light petroleum distillate, e.g. in weight amounts of 20-80:80-20 such as 50-75:50-25 which weight amounts may also be used for mixtures of gasoline and kerosene. The jet fuels for military use are designated JP4 to 8 e.g. JP4 as 65% gasoline/35% light petroleum distillate (according to US Mil. Spec. (MIL 5624G)), JP5, similar to JP4 but of higher flash point, JP7, a high flash point special kerosene for advanced supersonic aircraft and JP8, a kerosene similar to Jet Al (according to MJL 83 133C). Jet fuel for civilian use is usually a kerosene type fuel and designated Jet A or Jet Al. The jet fuel may have a boiling point of 66-343xc2x0 C. or 66-316xc2x0 C. (150-650xc2x0 F. e.g. 150-600xc2x0 F.), initial boiling point of 149-221xc2x0 C., e.g. 204xc2x0 C. (300-430xc2x0 F., e.g. 400xc2x0 F.), a 50% boiling point of 221-316xc2x0 C. (430-600xc2x0 F.) and a 90% boiling point of 260-343xc2x0 C. (500-650xc2x0 F.) and API Gravity of 30-40. Jet fuel for turbojet use may boil at 93-260xc2x0 C. (200-500xc2x0 F.) (ASTM D1655-59T). Further details on aviation fuels may be obtained from xe2x80x9cHandbook of Aviation Fuel Propertiesxe2x80x9d, Coordinating Research Council Inc., CRC Report No. 530 (Society of Automotive Engineers Inc., Warrendale, Pa., USA, 1983) and on US military 25 fuels, from xe2x80x9cMilitary Specification for Aviation Turbine Fuelsxe2x80x9d, MIL-T-5624P.
The jet fuel may be the straight run kerosene optionally with added gasoline, but preferably has been purified to reduce its content of components contributing to or encouraging formation of coloured products and/or precipitates. Among such components are aromatics and olefins and mercaptans. Thus the fuels may be purified to reduce their mercaptan content e.g. Merox fuels and copper sweetened fuels or to reduce their sulphur content e.g. hydrofined fuels or Merifined fuels. Merox fuels are made by oxidation of the mercaptans and have a low mercaptan S content (e.g. less than 0.005% wt S) such as 0.0001-0.005% but a higher disulphide S content (e.g. at most 0.4% or at most 0.3% wt S such as 0.05-0.25 e.g. 0.1-2%); their aromatic (e.g. phenolics) and olefins content are hardly changed. Hydrofined jet fuels are ones in which the original fuel has been hydrogenated to remove at least some of sulphur compounds e.g. thiols and under severe conditions to saturate the aromatics and olefins; hydrofined jet fuels have very low sulphur contents (e.g. less than 0.01% S by weight). Merifined fuels are fuels that have been extracted with an organic extractant to reduce or remove their contents of sulphur compounds and/or phenols. The jet fuel may also contain metals, either following contact with metal pipes or carried over from the crude oil; examples of such metals are copper, nickel, iron and chromium usually in amounts of less than 1 ppm e.g. each in 10-150 ppb amounts. Merox and hydrofined fuels are preferred and may be used in JP 4-8 jet fuels.
The fuel comprising kerosine may also be a fuel for combustion especially for non motive purposes, e.g. power generation, steam generation, and heating, especially for use 15 in buildings and for cooking, e.g. as described above. The fuel is particularly suitable for the devices e.g. boilers and slow cookers as described above in which there is localised preheating of the fuel before it is combusted. Such fuels are known as burning kerosine and may have the same physical properties as the kerosine based jet fuels described above, e.g. straight run kerosine, or kerosine modified to reduce its content of at least one of aromatics, olefins and sulphur compounds, as described above. The fuel may also contain metals as described above.
The fuel compositions of the invention contains the cyclic compound of formula Ia/Ib and may also contain at least one conventional additive e.g. for jet fuels or burning fuels such as an antioxidant, corrosion inhibitor, dispersant/detergent, (in particular in the case of hydroxy carboxylic acids (see below)), especially in amounts each of 1-1000 ppm, e.g. 20-200 ppm. The carboxy calixarenes i.e. additives of formula Ia/Ib may be present in the composition especially with a dispersant; the dispersant is in particular one for solids known for use in fuels e.g. automotive burning or aviation fuels. Such dispersants usually have a polymeric carbon backbone with pendant groups containing nitrogen, which may be primary, secondary or tertiary, in cyclic or acyclic systems, and especially in amine, amide or imide groupings, in particular cyclic imide groups. The dispersants may also contain 1-5 polymer chains which are bridged by the nitrogen containing groups. Examples of such dispersants are the reaction products of polyisobutene succinic anhydride (PIBSA) and polyamines. Such dispersants are known compounds for dispersing particles of in non aqueous systems e.g. hydrocarbon systems. The weight ratio of carboxy calixarene to dispersant may be 99:1 to 10:90, especially 30:70 to 70:30. The additives and the fuel composition are preferably substantially ashless. Burning kerosine is usually substantially free of the above additives apart from that of formula Ia/Ib.
The fuel compositions of the invention containing the compounds of formula Ia/Ib, have an improved thermal stability as shown by a reduced tendency to discolour and/or produce solids on heating compared to the fuel alone (in the isothermal corrosion and oxidation test (ICOT based on ASTM D487 1)). In some cases the combination of the compounds of formula Ia/Ib or Product A and certain other hydroxy carboxylic acid derivatives imparts to some fuels further improved stability still, better than either additive alone. This synergistic behaviour is found with combinations of the compound of formula Ia/Ib and the hydroxycarboxylic acid in Merox fuels.
Thus in a preferred embodiment the invention also provides a blend comprising at least one compound of formula Ia/Ib or Product A and at least one hydroxy carboxylic acid (different from said compound) with at least one chain of at least 8 carbon atoms. The invention also provides a fuel composition comprising said blend and a fuel comprising kerosine and/or a jet fuel which is a Merox fuel, especially one which has a mean deposit forming tendency in the ICOT test according to ASTM D4871 of 80-120mg deposit per liter of fuel, in particular 80-105mg/l.
In the blend of this invention the weight ratio of the compound (c) of formula Ia/Ib to hydroxycarboxylic acid is usually 10-90:90-1, in particular 30-85:70-15 and especially 35-65:65-35. The amount of the blend in the fuel is usually 10-1000 ppm e.g. 30-200 ppm.
The hydroxycarboxylic acid contains in total at least 1 hydroxyl group e.g. 1-4 such as 2 or 3 but preferably 1 hydroxyl group. It usually contains a hydroxyl group on a carbon atom alpha, beta or gamma to the carbon atom to which the carboxylic acid group is bonded and may optionally have 1 or more hydroxyl groups elsewhere in the molecule: preferably the only hydroxyl group in the molecule is in the alpha, beta or gamma especially the beta position. The hydroxy acid may be of formula,
wherein one of R11 and R13 represents hydrocarbyl and the other hydrogen or an organic group, each of R10, R12 and R14, which may be the same or different, represents hydrogen or an organic group, bonded via carbon or a heteroatom, which is O, N or S, with the proviso that at least one, and preferably only one of R10-R14 represents an organic group containing a carbon chain of at least 8 carbon atoms. Examples of the organic groups, bonded via carbon are alkyl, cycloalkyl, alkenyl, aralkyl or aryl, e.g. as described for R3 above, especially an alkyl group of 8-3 000 carbons, in particular 8-24 carbons especially dodecyl, octadecyl, and 50-3000 carbons e.g. polyolefinyl such as from polyisobutene. Examples of the organic group bonded via nitrogen are amino groups with long chain hydrocarbyl group e.g. 8-24 carbons, or amido or imido groups from long chain carboxylic acids with 8-3000 carbons, e.g. 8-24 carbons such as fatty acids e.g. stearic and palmitic acids, or 50-3000 carbons e.g. polyolefinyl such as from a carboxylic derivative from polyisobutene such as PIBSA. In particular R11 preferably represents hydroxyl/or hydrogen, R10 represents hydrogen or a long chain hydrocarbyl group of at least 8 carbons, especially 8-24 or 50-3000 carbons, R12 represents hydrogen or alkyl of 1-6 carbons e.g. methyl or ethyl, R13 represents hydroxyl or hydrogen and R14 represents hydrogen or a amino, amido or imido group with a long chain aliphatic group or long chain mono or di acyl group, in particular a long chain succiic imide e.g. PIBSA. Especially R10 or R14 contains a long chain aliphatic group but not both. Preferred examples of the hydroxy carboxylic acid are N(long chain acyl) derivatives of beta hydroxy amino acids e.g. serine and threonine and long chain hydrocarbyl alpha hydroxy acids e.g. 1-hydroxy dodecanoic, 1-hydroxypalmitic and 1-hydroxystearic acids, 1-hydroxyl polyiso butenyl-1-carboxylic acid (from PIB aldehyde).
The invention also provides a fuel composition comprising liquid hydrocarbons, at least a majority of which boil at atmospheric pressure at 251-350xc2x0 C. (according to ASTM D86). The hydrocarbon fuel may be diesel oil (e.g. as defined in European Standard EN590:1993, the disclosure of which is herein incorporated by reference), but is preferably gas oil (e.g. as defined in its European Standard the dislcosure of which is herein incorporated by reference), especially with a boiling range of 251-410xc2x0 C. The gas oil is a hydrocarbon fraction boiling between kerosine and light lubricating oil. The gas oil may be straight run gas oil, from direct distillation of crude oil under atmospheric pressure, cracked gas oil, which has the above boiling range and is made by distillation of the product of cracking high boiling or other oils either thermally or catalytically, or vacuum gas oil, with the above boiling range made by vacuum distillation of a residue, e.g. from a crude oil distillation or cracked oil distillation, or visbroken gas oil, made by treating one of the above gas oils to reduce its viscosity. The liquid hydrocarbon in the fuel composition may also be a product of hydrotreating or hydrofining a gas oil as described above; more information on these is provided below.
The fuel composition can thus contain at least a majority of a gas oil e.g. 51-100% (of the liquid hydrocarbons) e.g. at least 70% such as 70-90%, with usually up to 30% by weight (of total liquid hydrocarbons) of liquid hydrocarbons boiling above or below the gas oil, e.g. kerosine bp 150-250xc2x0 C. and heavy gas oils of Final Boiling Point 350-410xc2x0 C. Blends comprising a majority of gas oil with a minority of kerosene, or a majority of gas oil with a minority in total of kerosine and the heavy gas oil are preferred. The fuel composition may contain one or more of the types of gas oil discussed above, preferably with straight run gas oil and at least one other gas oil, especially with at least 50% or at least 70% of the straight run gas oil and up to 30% in total of one or more other gas oils e.g. cracked gas oil.
The fuel of the invention may comprise diesel fuel itself e.g. for use in diesel engines for motive use such as automobiles, trucks and buses, rather than the cruder gas oil, which contains diesel and a wide range of liquid hydrocarbons of boiling point above and below diesel. The gas oil is preferred for non motive uses. The fuel may also comprise biofuel from vegetable and/or animal sources, such as rapeseed oil esters e.g. the methyl ester, especially in weight ratios to liquid hydrocarbons of bp 251-350xc2x0 C. of 5-30:95-70.
The liquid hydrocarbons in the fuel of the invention may have at least one of and preferably all of the following distillation properties 220-250xc2x0 C. an initial bp (IBP) of 140-220xc2x0 C., a 10% distillation point of 190-250xc2x0 C., 50% distillation point of 220-250xc2x0 C., 90% distillation point of 280-380xc2x0 C. (e.g. 300-350xc2x0 C.) 95% distillation point of 320-380xc2x0 C. (e.g. 340-360xc2x0 C.) and a Final Boiling Point of 290-385xc2x0 C. (such as 330-360xc2x0 C.).
The hydrocarbons may have Conradson Carbon contents (by weight) of 0.01-1 e.g. 0.01-0.1 or 0.1-1. They may have aniline points of 40-80xc2x0 C. e.g. 60-75xc2x0 C. (as in gas oils) or 10-40 e.g. 15-30 (as in diesel oil). They may have a Specific Gravity of 0.80-0.90, e.g. 0.82-0.88 or 0.82-0.86, and a minimum Flash Point of at least 38xc2x0 C. (Closed, Abel.) or at least 55xc2x0 C. such as 75-95xc2x0 C. (Closed Pensky Martens). The cetane Number may be at least 40, 45, 49 or 51 such as 40-55, e.g. 45-48 or 49-54, but especially 40-49 or 45-49 as in gas oil. The sulphur chemical analysis may be less than 0.5% sulphur compounds (expressed as elemental S) such as 0.0001-0.5%, preferably less than 0.2% or 0.05% or 0.01%S, such as 0.05-0.2%S. The aromatic contents of the liquid hydrocarbons is usually less than 40% total aromatics e.g. 20-40% but especially less than 20% such as 5-15% total aromatics.
The liquid hydrocarbons e.g. gas oil or diesel preferably have been purified to reduce their content of components contributing to or encouraging formation of coloured products and/or precipitates or sulphur oxides on combustion. Among such components are aromatics and olefins and sulphur compounds. Thus the fuels may be purified to reduce their sulphur content e.g. in a corresponding manner to that described above for jet fuel e.g. hydrofined fuels or Merifined fuels. The fuel of the invention may also contain metals, either following contact with metal pipes or carried over from the crude oil; examples of such metals are copper, nickel, iron and chromium usually in amounts of less than 1 ppm e.g. each in 10-150 ppb amounts. Hydrofined fuels are preferred.
The fuel compositions of the invention include the cyclic compound of formula Ia/Ib or Product A and may also contain at least one conventional additive for automotive, heating or burner fuels e.g. an antioxidant, corrosion inhibitor, stabilisers, pour depressant, demulsiflers, antifoams, cetane improvers, lubricity additives, anti-static additives, dehazers, lubricity additives package compatibilisers and dispersant/detergent, (in particular in the case of hydroxy carboxylic acids (see below)), especially in amounts each of 1-1000 ppm, e.g. 20-200 ppm. The carboxy calixarene additives of formula I may be present in the composition especially with a dispersant; the dispersant is in particular one for solids known for use in fuels e.g. heating or burner fuels. Such dispersants usually have a polymeric carbon backbone with pendant groups containing nitrogen, which may be primary, secondary or tertiary, in cyclic or acyclic systems, and especially in amine, amide or imide groupings, in particular cyclic imide groups. The dispersants may also contain 1-5 polymer chains which are bridged by the nitrogen containing groups. Examples of such dispersants are the reaction products of polyisobutene succinic anhydride (PIBSA) and polyamines. Such dispersants are known compounds for dispersing particles of in non aqueous systems e.g. hydrocarbon systems. The weight ratio of carboxy calixarene to dispersant may be 99:1 to 10:90, especially 30:70 to 70:30. The additives and the fuel composition are preferably substantially ashless.
The fuel compositions of the invention containing the compounds of formula Ia/Ib or Product A, have an improved thermal stability as shown by a reduced tendency to discolour and/or produce solids on heating compared to the fuel alone. In some cases the combination of the compounds of formula Ia/Ib or Product A and certain other hydroxy carboxylic acid derivatives imparts to some fuels further improved stability still, better than either additive alone in particular with Merox fuels.
Thus the fuel composition may also include at least one hydroxy carboxylic acid 20 (different from said compound) with at least one chain of at least 8 carbon atoms. Examples of these other hydroxy carboxylic acids are given above in relation to the use in jet fuel or kerosene.
The fuels of the invention may be used in combustion apparatus for motive use or in particular for non motive use in which the fuel is subjected to heating to a temperature e.g. of 100-400xc2x0 C. such as 200-300xc2x0 C. before combustion e.g. by proximity to the combustion chamber or otherwise (which may be at 500-700xc2x0 C.). The feed pipes to the combustion chamber are usually made of metal e.g. copper or steel such as stainless steel, which may become corroded resulting in metal leaching into the oil encouraging degradation. The oil may be emitted into the chamber via a nozzle which becomes hot. The combustion may be in a vaporising burner in which metal in the burner chamber is heated by the flame and in turn vaporises the fuel; examples of such burners are vaporising and pot burners. The combustion is preferably in an atomising burner in which the fuel is atomised either directly, as in pressure jet burners (of low, medium or high pressure) (including simple and wide range burners) and blast burners, or indirectly as in rotary cup burners in which a sheet of fuel is made first and then atomised by contact with air. The atomising burners usually have a hot nozzle on and in which degradation deposits can form. The combustion apparatus may be used to produce heat directly as in industrial furnaces, e.g. for metals or ceramics, or industrial or domestic central heating or cooking as in slow cookers (e.g. of the Aga type) or for raising steam, e.g. process steam. Primarily the apparatus is used for raising power as in gas turbines for electrical power generation.
The invention also provides lubricating oil compositions suitable for xe2x80x98medium- or low-speed diesel engines, typically the four-stroke trunk-piston engine comprising said cyclic compound. Details of suitable lubricating oils and their other additives in addition to the cyclic compound are described in WO 9925677, the disclosure of which is hereby incorporated by reference, and the corresponding salts e.g. overbased calcium salts of the cyclic compound by analogy to those in WO 9925677 may be used in the lubricating oils of the invention.
In addition to the improved thermal stabilising effect imparted by the compounds of formula Ia/Ib to the fuels, the compounds have now been shown to have improved water tolerance properties. Fuels often pick up water during transport or as a contaminant, in particular in storage or processing. The presence of the water in the fuel is a problem if the fuel contains additives having surface active properties, because the latter stabilise emulsions of water and fuel, especially those made in high speed pumps e.g. in fuel transport lines. The stabilised emulsions increase the viscosity of the fuel. In addition when the fuel is gasoline, e.g. especially aviation fuel, such as jet fuel or aviation gasoline, the presence of water in the fuel is very disadvantageous, because in bulk form, the power developed on combustion is uneven and in bulk and droplet form it contributes to icing of the fuel on cooling, resulting in blocking of fuel jets causing loss of power, either temporarily or permanently. Thus many fuels especially aviation fuels are passed through coalescers en route from refinery to user to convert dispersed droplets of water to separable size droplets, which are then removed. The presence of any additives in the fuel with surface active properties causes the coalescers to fail and therefore the water not to be removed.
The compounds of formula Ia/Ib or Product A have a reduced tendency to stabilise emulsions of water, fuels and compound, compared to some known thermal stabilisers for aviation fuel, or detergents for formulated diesel or formulated gas oil (or for diesel base or gas base fuel (i.e. the hydrocarbon oil in the middle distillate boiling range)). By use of the compounds of formula Ib/Ib or Product A, the separation of water from the fuel is rendered more easy than with the other additives with less production of emulsions and intermediate phases between oil and water (according to the Institute of Petroleum IP 279/97 test), or faster breakage of dispersions (e.g. according to the ASTM D-1094 test). Thus the compounds are phase distinguishers helping to maintain a clear distinction between the water and oil phases, in contrast to the other additives which tend to reduce the distinction between or clarity of or sharpness of the interface between the oil and water.
The present invention provides a method of purifying a mixture of an oil Product which is a liquid fuel or lubricating oil composition, with at least one additive and water, at least part of the water being in the form of a dispersion of water in said Product, which method comprises providing said mixture in which said additive is an Additive (which herein means a compound of formula Ia/Ib or Product A hereinbefore), coalescing at least part of said water in said dispersion into separable droplets of water and separating said droplet water from an oil phase comprising the oil Product and Additive of reduced non-dissolved water content, especially one substantially free of non-dissolved water, e.g. water droplets or dispersion droplets. In the separation there are preferably produced water droplets and an oil phase, and no significant amount of interface material of oil and water. The method is preferably applicable when the oil Product is a hydrocarbon fuel, especially aviation fuel which may contain or may be substantially free of non-hydrocarbon performance additives (apart from the Additive) especially additives officially approved for aviation use.
The separation of water from fuels is performed at least once during the transport of the fuel from where it is made, in one part of a refinery, to the energy user, e.g. an engine of a means of transport on land, on or under sea, or in air, or an engine of a power ore heat generator e.g. an electricity generator or heating boiler. For diesel and gasoline, water may be separated once during the transport of fuel, e.g. in a refinery or blend terminal after it leaves storage, but because of the greater importance of use of substantially water free aviation fuels, water may be separated from aviation fuels more than once during the fuel transport e.g. 2-6 times, such as after any storage e.g. in a refinery, blend terminal or airport storage tank, especially just before the fuel is passed at the airport to refuel an aeroplane or helicopter or hovercraft.
The mixtures of water, fuel and Additive especially compound of formula Ia/Ib, e.g. dispersions, are usually substantially free of anti-icing additives, especially for aviation fuel e.g. jet fuel, as are the fuels ready for combustion (i.e. as passed to the energy user) which comprises the purified fuel composition comprising fuel and said compound.
The presence of water is also a problem in lubricants, both for land based vehicles, such as cars, trucks, buses and trains, and sea based transport e.g. ships, where marine lubricants need to function in the presence of sea water. The invention also provides the use of the compound of Additive especially formula Ia/Ib to restrict the formation of emulsions of water in a lubricant oil.
The oil Product to be purified in the method of the invention may be a blend of a first oil Product, especially a hydrocarbon fuel comprising said Additive, and a second oil Product, especially a hydrocarbon Fuel, which may be the same or different from the first oil Product and may contain, but preferably does not contain said Additive, each of the first and second oil Products being contaminated with water or susceptible of contamination with water.
Thus the present invention also provides a method of purifying an oil Product in which a first liquid oil Product comprising an additive is blended with a second liquid oil Product, at least one of said oil Products, and especially both, being contaminated with water or susceptible to subsequent contamination with water, water is mixed with one or both said oil Products if not already present therein, to produce a 2 phase mixture of said first and second oil Products, additive and water, at least some of the water being in a water in oil dispersion form, wherein said 2 phase mixture in which said additive is an Additive as herein before defined, is coalesced to produce water droplets, and the water is separated from an oil Product comprising said Additive of reduced water content. Preferably said oil Product is substantially free of undissolved water. Preferably the first oil Product is substantially free of non-dissolved water when it is blended with the second oil Product, which may or may not at that time contain undissolved water.
Thus the present invention also provides a blend of at least 2 liquid oil Products e.g. fuels, a first liquid oil Product comprising a first fuel or lubricant base, said Additive and dissolved water, and optionally undissolved water, and a second oil Product, e.g. fuel comprising a second fuel or lubricant base, which may be the same or different from the first base, and undissolved water. The fuel or lubricant bases may contain or may be substantially free of performance additives.
Instead of or as well as the first oil Product, e.g. fuel, comprising Additive being blended with said second oil Product, e.g. fuel, the invention is also beneficial when the second oil Product is passed separately through a line down which the first oil Product has passed, because in many cases the first passage of first oil Product leaves trace of said oil Product and Additive in this line, and/or the walls of the line have adherent or adsorbed Additive, removed from said first oil Product. By this means the second oil Product becomes contaminated with said Additive which in the case of other additives have adversely affected its water tolerance properties; this effect is greatly reduced with the Additives compared to the known thermal stabilisers.
Thus the present invention also provides a method of transporting at least 2 oil Products, e.g. fuels, separately along the same line, each oil Product e.g. fuel being contaminated with water or susceptible to contamination with water, wherein the earlier oil Product passing along the line comprises said Additive, and after passage down said line each oil Product containing water at least partly in dispersion form, is coalesced to produce droplets of water which are separated to leave an oil Product of reduced water content, especially substantially free of non-dissolved water, and preferably with substantially no interface e.g. less than 10% (based on the total value of separated water and interface).
In all the above methods of the invention, a benefit of the invention is that with some other thermally stabilising additives, there are substantial interface problems of the stage of separation of the drops e.g. with an amount of interface of at least 20% (of the value of separated water and interface).
The Additives have the effect of thermally stabilising the oil Products e.g. lubricant such as automative or marine lubricant and fuels e.g. aviation fuel, diesel, gas oil or gasoline, and also of not causing significant interfacial problems when water is separated from mixtures of the oil Product. This latter property is very important commercially for reasons as explained above.
Thus the present invention also provides the use (a) of the Additive to stabilise thermally a liquid oil Product e.g. fuel, especially a jet fuel, while at the same time rendering the stabilised oil Product substantially water immiscible or rendering it substantially non-emulsifiable to water. The use is thus of a combined heat stabiliser and phase separator.
The invention also provides the use (b) of the Additive to stabilise thermally a liquid oil Product, e.g. fuel, especially a jet fuel, without substantially affecting its interfacial tension (e.g. by less than 20% of the value of the oil Product e.g. fuel without the Additive). This use is thus of a combined heat stabiliser and interfacial tension maintainer. This technical effect is in contrast to other known thermal stabilisers, e.g. for jet fuel that have a significant surface active effect and severely reduce the interfacial tension of the fuel (e.g. by more than 30% of the value of fuel without the stabiliser).
The invention also provides the use (c) of the Additive to stabilise thermally a liquid oil Product e.g. fuel, while enabling it also to pass the single element test as defined as in the current edition of API 1581 (Specification and Clarification procedures for Aviation Jet Fuel Filter/Separators).
The Additive also can have a dispersant effect in diesel and/or gasoline, instead of or as well as a thermal stabiliser effect, so the above uses a-c can also be expressed in a similar manner with the two technical effects being the dispersant effect (rather than the thermal stabilising effect) and the non-emulsion stabilising effect e.g. phase separator or interfacial tension maintainer effect.
In addition known thermal stabilisers, e.g. for jet fuel, also adversely affect the active surfaces of coalescers, in which the fuel with dispersed water contacts the active surface effecting coalescing of the dispersed water droplets causing then to grow from a size of less than 1 micron to produce droplets of size at least 1 mm. The active surface of a successful coalescer is sufficiently hydrophilic to have the above effect, but in the presence of the known stabiliser the surface becomes more hydrophobic and tends to lose its coalescence power. Eventually the coalescer cannot fulful its function of coalescing water in the fuel and has to be replaced. The Additives have a much reduced effect on the active surface of the coalescer compared to the known stabiliser, thereby increasing the lifetime of the coalescer.
The present invention therefore also provides a method of increasing the lifetime of a coalescer, which is used to coalesce water present in a water dispersion in an oil Product, which comprises having in the oil Product an Additive. The dispersion of water oil Product and Additive is converted into droplets of water or a separate water phase, and an oil Product phase containing the Additive of reduced non-dissolved water content, and preferably substantially no interface of water and oil Product.
The coalescer usually comprises a fibre bed, often of different fibre diameters, pore size or density. The overall bed may be a random mixture of the above fibres, but preferably is in graded layers, to coalesce dispersions of wide range of water droplet sizes. The fibres usually have an affinity for water but are not completely hydrophilic; they may be polymeric with polar groups e.g. CONH, xe2x80x94COOxe2x80x94, but not alcoholic OH, as in cellulose, or cellulose ethers or esters; these fibres are of non-cellulosic polar polymers. Alternatively the fibres can be inorganic e.g. glass fibre especially glass treated with polar molecules such as glass treated with an organoxy-aminoalkyl silane or glass fibres bonded with phenolic resins e.g. phenol formaldehyde resins; these are hydrophobised inorganic fibres.
Coalescers and their structure and apparatus describing them are described in R. L. Brown and T. H. Wines, Hydrocarbon Processing December 1993 pp95-100 the disclosure of which is herein incorporated by reference.
The invention is illustrated in the following Examples.

Abstract: and n units of the formula (Ib):

Abstract: joined together to form a ring,

Abstract: R0 is H or (C1-C6) alkyl or is a metal or ammonium cation;

Abstract: R5 is H or (C1-C60) alkyl or OH group;

Abstract: j is 1 or 2;

Abstract: with the provisos that

Abstract: i) at least one of R1, R2, R4 is hydroxyl, and m+n is 4 to 20, m is 1-8 and n is at least 3, and

Abstract: ii) in formula Ia at least one OH group is in the meta or para position to the COOR0 group and/or at least one R5 group is OH.


In one example, a method including controlling milling of a component via a milling system, the milling system including a spindle, a tool holder coupled to the spindle, the tool holder configured to receive a milling tool; and the milling tool configured to remove at least a portion of the component via milling while the milling tool is rotated by the spindle and tool holder, wherein the milling system is configured to conduct an electrical signal between the milling tool and component during milling of the component when the milling tool is not broken; monitoring the electrical signal conducted between the milling tool and component; and determining whether the milling tool is broken based on the monitored electrical signal.

Various systems and techniques exist for milling components having complex shapes and surfaces that are susceptible to geometric variations, such as blades and vanes of gas turbine engines. Some existing systems and techniques have various shortcomings, drawbacks, and disadvantages relative to certain applications. Accordingly, there remains a need for further contributions in this area of technology.


According to an illustrative embodiment, an information processing apparatus includes an imaging unit; and an image generation unit to generate a display image based on a distance between the imaging unit and an object, wherein the distance is detected by using a plurality of images obtained by the imaging unit at respective focus distances.

The present disclosure relates to an information processing apparatus that projects an image or displays an image on a display, a program, and an information processing method.
In recent years, an input apparatus that projects an image of an input apparatus such as a keyboard on a plane of projection and receives, as an operation input, an operation of a user on the plane of projection is being developed. The input apparatus is configured to be able to determine an operation of a user, e.g., a motion of a hand by taking an image of a plane of projection with a camera.
For example, Japanese Patent Application Laid-open No. 2008-123316 discloses a data input method and data input apparatus, which take an image of a plane of projection of a keyboard image by using a plurality of imaging means, analyze the imaging data, specify a position of a user's finger that is in contact with the plane of projection, and receive a motion of the finger as an operation input. By taking an image of a plane of projection with a plurality of imaging means, it is considered possible to reduce an area under the shadow of a user's hand in a keyboard image.

Information processing apparatus, program, and information processing method


A process for preparing o-nitroaromatic acids by direct oxidation of the corresponding o-nitroalkylaromatic compounds, utilizing salts of certain catalytic metals in the presence of an oxygen-containing gas and an aliphatic aldehyde or ketone at elevated temperature and pressure, is provided. The process allows catalyst recovery and reuse.

Ortho-nitroaromatic acids are used in many applications, for example, as intermediates in dyes, pharmaceuticals and agrochemicals. Ortho-nitrobenzoic acid is used as a corrosion inhibitor. Anthranilic acid (2-aminobenzoic acid) can be prepared by hydrogenation of o-nitrobenzoic acid. Anthranilic acid is used as an intermediate in the manufacture of dyes, pharmaceuticals, pigments, perfumes and flavors and as an antioxidant.
It is well documented in the literature that ONAC show great resistance to direct oxidation compared with meta- or para- nitroalkylaromatic compounds. This was reported by Hasegawa et al, Bulletin Chem. Soc. Jap., 51 (5), 1490 (1978), based on a study of the liquid phase autoxidation of nitroalkybenzenes catalyzed by a transition metal and bromide ions in acetic acid. More recently Partenheimer, Catalysis of Organic Reactions, Pub. Marcel Dekker, Inc. 1995, p. 314 stated, "m- and p- nitrotoluene can be smoothly oxidized to the nitrobenzoic acids in high yield, while o-nitrotoluene is completely inert." In U.S. Pat. No. 4,906,771, Young et al. state that "It has been known while meta and para- nitrotoluene are readily oxidized, by means of molecular oxygen in the presence of bromine and a heavy metal oxidation catalyst, to the corresponding nitrobenzoic acid the ortho isomer, namely o-nitrotoluene, is unexpectedly resistant to oxidation by this process. Similarly, other o-nitroalkylaromatics, such as 2-nitro-paraxylene, are unexpectedly resistant to oxidation." Young et al. were able to obtain 50 to 90 mole % yields of ortho-nitrobenzoic acid by the direct oxidation of a mixture of ortho-nitrotoluene and an equivalent amount of a co-oxidizable compound, such as toluene or para-xylene at 120.degree. C. to 220.degree. C. and 150 psig and 400 psig. This process suffers from the disadvantages of requiring by-product separation steps, decreased reactor capacity for the production of the desired ortho-nitrobenzoic acids, permitting no catalyst recycle and requiring the use of corrosion resistant equipment made from expensive alloys.
Hull, U.S. Pat. No. 2,673,217. describes a process for the selective oxidation of alkylaromatic compounds using aldehyde-activated catalysts, by first preparing a catalyst solution which is "activated" by simultaneously adding an aliphatic aldehyde and an oxygen-containing gas, and thereafter feeding the alkylaromatic compounds, together with an excess of oxygen, into the catalyst solution while maintaining the catalyst in the solution in an active state by continuously adding aldehyde. The oxidation is conducted at low temperatures (between 50.degree. C. and 90.degree. C.) and pressures (usually atmospheric pressure). Only meta and para-nitroalkyl aromatic compounds are described as substrates and yields of the corresponding aromatic acids are low, between 20% and 37%; there is no disclosure of the oxidation of ortho-nitroalkylaromatic compounds.
There is a need for a safe, environmentally acceptable and economically attractive direct oxidation process for the production of ortho-nitroaromatic acids in high yield from orthonitroalkylaromatic compounds.

Process for producing ortho-nitro aromatic acids by oxidation of ortho-nitroalkylaromatic compounds


A touch device includes first and second electrodes intersecting each other, and a touch controller. The touch controller is configured to: apply a first driving signal to the first electrodes; selectively apply a second driving signal to the second electrodes; and detect self capacitances of at least one of the first electrodes and a first portion of the second electrodes intersecting the first electrodes. The at least one of the first electrodes is configured to receive the first driving signal, and the first portion of the second electrodes is configured to receive the second driving signal. The touch controller is further configured to detect mutual capacitances between the at least one of the first electrodes and a second portion of the second electrodes intersecting the first electrodes, in which the second portion of the second electrodes is configured not to receive the second driving signal.

Field
Exemplary embodiments of the present invention relate to a touch device and a driving method thereof.
Discussion of the Background
Display devices such as a liquid crystal display (LCD), an organic light emitting diode (OLED) display, and an electrophoretic display may include a field generating electrode and an electro-optical active layer. The OLED display may include an organic emission layer as the electro-optical active layer. The field generating electrode may be connected to a switching element such as a thin-film transistor to receive a data signal, and the electro-optical active layer may convert the data signal into an optical signal to display an image. A display device may include a touch sensing function which may interact with a user in addition to an image displaying function. The touch sensing function may determine contact information such as whether an object contacts or approaches a screen and a contact position thereof by sensing a change in pressure, charges, light, and the like, which are applied onto the screen in the display device, when the user writes a text or draws a figure by contacting or approaching the screen with a finger or a touch pen.
The display device may receive an image signal based on the contact information to display an image. The touch sensing function may be implemented by a touch sensor. The touch sensor may be classified according to various types, such as a resistive type, a capacitive type, an electro-magnetic (EM) type, and an optical type. The capacitive type touch sensor may include a sensing condenser including sensing electrodes that may transfer a sensing signal and identify whether a touch exists or a touch location by sensing a change in charged capacitance or a change in the amount of charged charges of the sensing condenser, which may occur when a conductor such as a finger approaches the touch sensor. A display device incorporating the touch sensor has been recently researched.
A capacitance method includes a self capacitance method and a mutual capacitance method. In the self capacitance method, a capacitance is detected by applying a voltage to each of touch sensor electrodes and measuring a resulting voltage change. In the mutual capacitance method, a capacitance is detected by applying a voltage in an x-axis direction and detecting a voltage induced in a y-axis direction intersecting the x-axis direction.
The self capacitance method may have high sensitivity, and thus may provide a hovering function. However, due to an unexpected touch phenomenon, i.e., a ghost point may occur during a multi-touch, which may render performing the touch sensing operation difficult.
The mutual capacitance method may have lower sensitivity than the self capacitance method, but a multi-touch operation may be possible. However, since the mutual capacitance method has low sensitivity, a sensitive function such as hovering may be limited.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concept, and, therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.

Touch device detecting mutual capacitance and self capacitance and driving method thereof


A digital subscriber line communicating system having a central office and a remote terminal connected through a telephone line, the transmitting side comprising a sliding window transmitting unit for transmitting DMT symbols according to the sliding window through the telephone line to the receiving side, and the receiving side comprising a sliding window receiving unit for receiving DMT symbols according to the sliding window from the transmitting side, the sliding window indicating the phase of cross-talk condition due to a TCM-ISDN transmission at the receiving side, whereby TCM cross-talk can be reduced without largely departing from the standard system.

1. Field of the Invention
The present invention relates to a digital subscriber line communicating system which utilizes an existing telephone line as a high speed data communication line. More particularly, it relates to an improvement of a modulation/demodulation system in a transmission apparatus used in the above-mentioned transmission system.
In recent years, multimedia services such as internet and so forth have expanded through the whole society including usual homes. Accompanied by such development, it has been strongly required to promptly provide an economical and reliable digital subscriber line communicating system for utilizing such services.
2. Description of the Related Art

Digital subscriber line communicating system


Present invention relates to a locking and emptying system of a refill cartridge containing nutrients or chemicals, said system comprising at least one replaceable refill cartridge, at least one receiving socket for the refill cartridge, in every receiving socket a locking mechanism of the refill cartridge, discharge means of the refill cartridge and control means of the locking system and for each refill cartridge a emptying container. The control means of the locking system are set to release the empty refill cartridge from the receiving socket only when the emptying container has enough free volume to receive the content of the next refill cartridge.

The automatic growing cabinets of plants comprises reservoirs for nutrients and other chemicals. Refilling of those reservoirs usually includes opening cap of those containers and adding corresponding nutrient or other chemical from a bottle or some other container.
This poses a risk to the user—during pouring liquid may be spilled, this may become in contact with clothes or skin, cause etching or cause skin irritation. In addition just breading in a vapours of those products can be irritating and/or dangerous.
Because this kind of growing cabinets (or other places of use of those refill cartridges) are both in professional and non-professional use (for example at home, in office), it must be insured that third parties (for example children) do not become contact with said nutrients or other chemicals.
From prior art are known different types of refill cartridges, which are used in many different fields. The ordinary consumer is most familiar for example with refill cartridges used in the inkjet printers. But similar cartridges are being used also in other fields.
In traditional systems said refill cartridges are usually removable from their receiving sockets at any moment when need for that occurs. Usually such refill cartridges are fixed into the receiving socket with manually releasable snap-in joint or other resilient retainer, which enables to keep refill cartridge in place and also to remove it.
Usually locking and emptying system of the refill cartridge comprises at leas one replaceable refill cartridge, at least one receiving socket for the refill cartridge and in every receiving socket a locking mechanism for the cartridge.
For example such a refill cartridge is known from the US patent US2012249691A1 (published on Apr. 10, 2014).

Locking and emptying system of refill cartridge containing nutrients or chemicals


The description is of a circuit which, according to one example embodiment, comprises the following: an input circuit node for receiving an RF oscillator signal; a test signal generator circuit, which comprises at least one modulator and which is embodied to generate an RF test signal by modulating the RF oscillator signal. Further, the circuit comprises at least one receive channel with a receiver circuit and a coupler, which is embodied to feed the RF test signal into the receiver circuit.

Radiofrequency (RF) transmitters and receivers are found in a multiplicity of applications, particularly in the field of wireless communication and in the field of radar sensors. In the automotive sector, there is an increasing demand for radar sensors which can be used, inter alia, in driver assistance systems (advanced driver assistance systems, ADAS) such as adaptive cruise control (ACC or radar cruise control) systems, for example. Such systems are able to automatically adapt the speed of an automobile in order thus to maintain a safe distance from other automobiles driving ahead (and from other objects and pedestrians). Further applications in the automotive sector are, for example, blind spot detection, lane change assist and the like.
Modern radar systems use highly integrated RF circuits which can unify all core functions of an RF front end of a radar transceiver in a single housing (single chip radio transceiver). Such highly integrated RF circuits are usually referred to as monolithic microwave integrated circuits (MMICs). An RF front end typically (but not necessarily) contains, inter alia, a phase-control-loop-switched voltage-controlled oscillator (VCO), power amplifiers (PAs), directional couplers, mixers and associated control circuit arrangements for controlling and monitoring the RF front end. An MMIC may also comprise circuits for analog signal processing in the baseband (or in an intermediate frequency band) and analog-to-digital converters (ADCs) in order to facilitate digital signal processing. Depending on application, digitally controlled oscillators (DCOs) may also be used instead of VCOs.
Testing one or more RF circuit components is often desired or necessary in sensor applications in order to facilitate a fault-free operation of the sensors and observance of the desired measurement accuracy. For this reason, RF circuits used in radar sensors may comprise components that facilitate one or more tests/self-tests in order to test and/or characterize certain RF circuit components.

Generation of an RF test signal for testing an RF receive circuit


Methods, systems, and apparatuses for providing layer-2 connectivity through a non-routed ground segment network, are described. A system includes a non-autonomous gateway in communication with a satellite configured to relay data packets. The non-autonomous gateway is configured to receive the data packets from the satellite at layer-1 (L1) of the OSI-model, generate a plurality of virtual tagging tuples within the layer-2 packet headers of the plurality of data packets. The non-autonomous gateway is further configured to transmit, at layer-2 (L2) of the OSI-model, the virtually tagged data packets. Each of the packets may include a virtual tagging tuple and an entity destination. The system further includes a L2 switch in communication with the non-autonomous gateway. The L2 switch may be configured to receive the data packets and transmit the data packets to the entity based on the virtual tuples associated with each of the data packets.

Satellite communications systems are becoming ubiquitous for communicating large amounts of data over large geographic regions. In typical satellite communications systems, end consumers interface with the systems through user terminals. The user terminals communicate, via one or more satellites, with one or more gateways. The gateways may then process and route the data to and from one or more networks according to various network protocols and tags processed at the network layer and above (e.g., layers 3 and above of the Open System Interconnection Reference Model (OSI) stack). While utilizing higher layers to route communications may provide certain features, such as enhanced interoperability, it may also limit certain capabilities of the network. For example, routing limits the types of tags that can persist across multiple sub-networks.
Presently, gateways in satellite networks are configured to support a number of services and perform a variety of network functions. For example, gateways perform IP Routing protocols, Layer-3 redundancy schemes, acceleration, AAA/Radius services (i.e., terminal registration on the network), DHCP/DNS, trivial file transfer protocol (TFTP), network time protocol (NTP), public key encryption (PKI), and the like. Such gateways are expensive to build and maintain. Furthermore, the services and functionality offered by these gateways are isolated to the customers for which the gateway specifically service. Many gateways providing the same or similar services and must be maintained in parallel in order to provide service to an entire customer base over a large geographical area.
Further, current implementations of satellite networks fail to provide the services and functionality at layer-2 (i.e., layer-2 of the OSI-model stack) communicating from one point on the network to another. Additionally, current implementations of satellite networks only provide redundancy within the gateway. For example, current satellite network implementations may provide redundant access to a points on the network (i.e., multiple fiber lines to a gateway such that if one line is compromised, service still continues over the second line); however, if, for example, the gateway itself is down (or a service of the gateway), there is currently no way for another gateway to continue to provide the service (or services) of a failed gateway.
Current gateway implementations typically communicate over layer-3 or "layer-2.5" (i.e., multi-protocol label switching (MPLS)). As such, networks using only layer-3 or layer-2.5 are limited in the services and network configurations that can be offered. For example, an MPLS network may be deployed using RFC-2547 which is MPLS that redistributes routes using border gateway protocol (BGP). Accordingly, such a deployment includes a layer-3 network over an MPLS underlying network, so each core node or gateway is routed (i.e., the MAC header of packets transmitted are altered), thus limiting the capabilities of the network.
Additionally, in current mobile IP implementations each mobile device is identified by its home address (i.e., at the mobile device's home agent) regardless of the mobile's device's current location. While the mobile device is away from its home network, the mobile device is assigned a care-of address. The care-of address identifies the mobile device's current location. The care-of address acts as a local endpoint of a tunnel back to the mobile device's home agent, and the home address. As such, mobile IP specifies how the mobile device registers with its home agent and how the home agent routes data to the mobile device through the tunnel (between the home argent and the care-of address).
Mobile IP has significant drawbacks. One drawback is that the when the mobile device moves out of its home location, the mobile device's care-of address is a virtual address. Hence, moving out of the home location requires a hand off, which changes the mobile device's IP address by adding a care-of-address. This is particularly problematic in IPv4 networks (e.g., connectivity is temporarily lost, browser session is lost, VPN session is lost, etc.). In many applications (e.g., VPN, VoIP), sudden changes in network connectivity and IP address causes significant problems. For example, an SSL tunnel for on-line banking will terminate. Furthermore, the tunnel between the home address and the care-of address is a layer-3 protocol, and as such, the as the mobile device moves out of its home location the mobile device is no longer connected to the same network (i.e., LAN, subnet, etc.). Additionally, traffic must be routed through the home agent location. For example, if the mobile device and the data the mobile device is accessing are at the same remote location, the data must travel all the way to the home agent location and then circle back to the remote location, thus greatly increasing latency. Accordingly, current mobile IP implementations fail to provide a persistent IP address and persistent connectivity and efficient data transfer over a large geographical area. For these and/or other reasons, it may be desirable to provide ground-segment networking with enhanced functionality.

Layer-2 connectivity from switch to access node/gateway


The present invention relates in general to a pressure discharge mechanism for closed vessels having an internal chamber designed to hold volatile and/or explosive substances in a sealed manner comprised of an at least one eutectic composition and a threaded joint designed to open or vent the closed vessel when the contents of the closed vessel reaches a predetermined temperature while maintaining full structural integrity during normal operation. In one aspect, the closed vessel is a munitions casing which functions as intended under normal operating environments, but then when exposed to extreme temperatures, reduces the munition's high order explosion capability, and is transformed into a safe, low order reaction with significantly less reactive potential. In one aspect, the closed vessel is a transport tanker which should not release substances contained therein. However, if the tanker catches fire, the pressure relief mechanism of the present invention reduces risk of explosion.

Hazardous materials, such as, for example, explosive materials, flammable materials, bio-hazardous materials, other types of materials that have a flash point, detonation or volatile ignition temperature that makes them hazardous, and in some cases, particularly chosen and developed for their hazardous properties, in for example, munitions applications, and the like, require safe storage, handling and disposal. Such materials are frequently stored and/or utilized in closed vessels. The closed vessels create challenges for the safe removal of the hazardous material, such as, for example, removing explosive material from munitions, and safe handling, such as, for transportation of munitions prior to desired deployment. The closed vessels also create challenges when the temperature of the closed vessel rises beyond the safe operating and handling temperature of the vessel.
Conventional pressure relief valves typically vent the contents of a closed vessel when the pressure in the vessel reaches a critical condition. However, conventional pressure relief valves do not provide a warning as to when a vessel is in a critical and an unsafe state.
Moreover, conventional pressure relief mechanisms may reduce the structural integrity of the closed vessel overall reducing the closed vessel capability to perform to its fullest potential under normal operating conditions.
In general, closed vessels have normal handling and operating temperatures between 60° F. to 160° F. In case of a fire, or other cause of extreme heat, the temperature of the closed vessel rises beyond a safe temperature of, for example, 160° F., the material contained inside the closed vessel expands and creates an increased internal pressure (hoop pressure). At a certain point, as the internal pressure increases, the closed vessel ruptures and creates a high order explosion. If this hoop pressure were to be relieved, the high order explosion can be reduced to a low order reaction. A low order reaction still has a flame and fire associated with it, but it does not explode. By eliminating the high order explosion, the hazardous material can be safely dealt with.
Safety is another important design aspect of transport and storage of volatile materials, as well as munitions, including, for example, artillery shells, bomblets, rockets, mortars, missiles, hand grenades and the like. For example, the propellants and explosives contained within munitions degrade over time, and thus their reliability decreases to an unacceptable level, resulting in munitions having a limited "shelf life". When the shelf life of a given munition is reached, it is withdrawn from stock and replaced with a new munition. This results in a problem in that these withdrawn, but still "live" munitions with dangerous high energy explosives ("energetics") and other hazardous materials, such as lead, must be "demilitarized," i.e. rendered to a state where they are no longer capable of being used as a munition or otherwise causing a safety threat. In order to accomplish this, the energetics must be removed from the munition and disposed of safely. Demilitarization procedures frequently involve the intentional burning of the munition.
Consequently, munitions need to be rendered "safe" instead of going high order when exposed to high temperatures, either from, for example, an intentional or accidental fire. Typically, however, munitions are not provided with a "safe" mode for exposure to high temperatures. As a result, the risk of a high order detonation is significant.
Heat exposure may be a rapid exposure to high temperatures (a fast cook off condition), or a slow, sustained exposure (a slow cook off event). Either exposure can result in a high order detonation.
A non-functional ("safe") mode is desirable so that firefighting efforts or demilitarizing procedures can be performed without the risk of a high order detonation from a single munition, or multiple munitions that may be packaged in a container such as in ammunition cans, pallets, and/or at an ammunition depot.
The design of munitions casings does not typically allow for the separation of the body after assembly. For example, the fragmentation body of a hand grenade is usually made of a cast iron member or a stamped metal with an embossed fragmentation pattern. The grenade body is made up of two pieces that are resistance welded, generally, along the diametric center of the body, thus creating a single piece body that functions as a pressure vessel for the energetics contained therein.
As a result of the detonation of the energetics, the munition is broken up and the fragments or the metal particles embedded in the body are scattered, causing damage to the surrounding environment. Such damage could be significant and in many cases unavoidable. For instance, if the munition were stored in a warehouse, a cook-off condition, whether slow or fast, would cause a chain reaction explosion or sympathetic detonation within the warehouse.
It is therefore an object of the present invention to provide a pressure discharge mechanism for closed vessels containing hazardous materials which automatically opens and/or vents said materials before the temperature and/or pressure in the vessel causes the vessel to rupture, and/or resulting in a high order detonation.
It is another object of the present invention to provide a pressure discharge mechanism that minimizes and/or eliminates high order detonations of closed vessels.
It is still another object of the present invention to provide a pressure discharge mechanism for closed vessels that provides a signal of an unsafe condition within the closed vessel to persons, such as, for example, fire fighters. It is yet another object of the present invention to provide a pressure discharge mechanism which will warn persons that the closed vessel has reached a critical condition, and that rupture and/or detonation thereof may be imminent. Prior to the advent of the present invention, the need for such a pressure discharge mechanism has heretofore remained unsatisfied.
It is yet another object of the present invention to provide a munition design that overcomes the afore mentioned problems associated with conventional munitions, and yet still functions normally under normal environmental conditions, with minimal manufacturing variances, in order to maintain the same user directions and training as for existing munitions, and to allow the use of conventional manufacturing procedures with minimal changes to the assembly lines. Prior to the advent of the present invention, the need for such a pressure discharge mechanism has heretofore remained unsatisfied.
For example, U.S. Pat. No. 6,752,085 provides an apparatus for releasably attaching a closure plate to an open end of a cylindrical casing, the apparatus having an inner member; a threaded outer ring biased in tension, disposed adjacent to the inner member, for releasably engaging an interior wall of the casing; and a eutectic spacer between the inner member and the outer ring. At temperatures below the melting point of the eutectic spacer, the outer ring is held in threaded engagement with the casing, and holds the closure plate in position in abutment with the casing. When the temperature of the eutectic spacer reaches its melting temperature, the eutectic spacer transitions to a liquid state, flows away from the apparatus, allowing the outer ring to retract into a groove in the inner member, and the closure to be released from the casing.
In another example, U.S. Pat. No. 5,398,498 provides a joint construction [that] is employed between a military rocket motor and a warhead adapted to be propelled be the motor. The motor includes a motor tube with a cylindrical front portion having an internal cylindrical surface therein. The warhead comprises an adapter ring having a cylindrical rear portion with an external cylindrical surface which is telescopically receivable within the internal cylindrical surface. The internal and external cylindrical surfaces are formed with respective confronting aligned internal and external helical screw thread grooves for receiving a fusible substantially helical joint member to form a secure connection between the rocket motor and the warhead. The helical joint member is made of a material having a low melting temperature, preferably a eutectic metal alloy, whereby the heat of a fire or the like will melt the joint member to disconnect the warhead from the rocket motor. The motor tube has a front wall with a vent operating therein, normally closed by a plug member. The adapter ring includes a means for retaining the plug member in the vent opening. The melting of the fusible joint member is effective to release the retaining action of the adapter ring, whereby any pressure in the motor tube expels the plug member and the adapter ring from the motor tube.


A method and apparatus for a monitoring technique for the rate of change of polarization state and of the polarization mode dispersion is proposed. This technique is used for performance monitoring and fault correlation as well as for the verification of commitments to customers with respect to the transmission system's tolerance to polarization mode dispersion.

Polarization mode dispersion (PMD) is an effect in fiber-optic systems which causes the transmission signals to spread in time, thereby causing signal degradation by intersymbol interference. The effect is essentially due to deviations from the ideal circular symmetry of the fiber, which may be caused by production imperfections or external influences. PMD may also be present in discreet optical components used in optical amplifiers. It is important to note that the state of polarization, as well as the instantaneous value of the PMD, can change with time. These changes may be very slow (e.g., if caused by changes of the fiber temperature) or fast (e.g., if caused by mechanical vibrations). PMD is a limiting factor for long-distance, high bit rate systems, such as long-haul wavelength division multiplexing (WDM) systems operating at bit rates of 10 Gb/s and above.
The PMD tolerance of a transmission system depends on its design parameters such as data rate, modulation format, forward error correction (FEC) and the available system margin. Also, PMD can be compensated for by the use of an optical PMD compensator (PMDC), which is placed in front of the receiver.
There are a number of problems associated with optical PMDCs. One of these is limited tracking speed (i.e., inefficient ability to follow a fast change in the polarization orientation and the PMD of the signal). The optical PMDC compensates PMD by adding to the signal the same amount of PMD but with the opposite sign as the transmission link resulting, ideally, in a zero PMD. A loss of tracking is likely to increase the PMD at the receiver over the value of PMD created on the transmission link.
If the optical receiver experiences high PMD, the bit error rate (BER) may increase beyond correcting capabilities of the forward error correction algorithms. Such events will therefore lead to bit errors which are seen by the user of the system. Because such errors often occur in bursts, they are difficult to monitor.

Polarization mode dispersion monitoring and fault correlation


A photoelectric conversion device has an insulator film disposed on a silicon layer having a photoelectric conversion region, the insulator film having a portion overlapped with the photoelectric conversion region, a silicon oxide film disposed on the insulator film, the silicon oxide film having a portion overlapped with the photoelectric conversion region, an electroconductive member disposed between the insulator film and the silicon oxide film, and a silicon oxide layer disposed between the electroconductive member and the silicon oxide film, in which the portion overlapped with the photoelectric conversion region of the silicon oxide film is in contact with the portion overlapped with the photoelectric conversion region of the insulator film and the hydrogen concentration of the silicon oxide film is greater than the hydrogen concentration of the silicon oxide layer.

Field of the Invention
The present technique relates to the structure around an electroconductive member in a photoelectric conversion device.
Description of the Related Art
In the photoelectric conversion device, while miniaturization of wiring has been demanded as in semiconductor devices, such as arithmetic operation devices and memory devices, a reduction in noise adversely affecting the photographed image quality has also been demanded.
In the miniaturization of wiring, Japanese Patent Laid-Open No. 2004-80045 describes patterning a metal film using a hard mask containing a PE-TEOS film.
Japanese Patent Laid-Open No. 2004-80045 does not examine insulator films, such as interlayer insulation films covering wiring. In general, silicon oxide films are used for the interlayer insulation film. However, when applied to the photoelectric conversion device, noises are likely to be generated depending on the characteristics of the interlayer insulation films.
Then, the present technique aims at providing a photoelectric conversion device with reduced noise.

Photoelectric conversion device, image pickup system, and method for manufacturing photoelectric conversion device