A process for making bread snacks with fillings of high water content is disclosed and the snacks have shelf lives at chilled or ambient temperatures of more than six weeks. Baked bread is used as raw material.

Bread is a common food in many countries. In particular dark whole grain rye bread is becoming more and more popular.
Apart from this growth platform, snacking is also a growing consumer trend all over the world with emphasis on sweet and salty snacks. What is missing are convenient and premium quality savory snacks based on bread, in particular dark rye bread, with, e.g., cheese or sausage filling.
Longer shelf life, dough-based snacks with fillings are currently made by combining, e.g., fat-based creams in various flavor directions or fruit fillings with the raw dough prior to the baking process.
Existing wheat dough-based snacks with fillings or salty crackers filled with fat-based cream have in common that they are very dry and often not of good quality. To be shelf stable, it is necessary that the water content of these snacks is low. A synonym for dryness is the amount of free water in this food product measured as the so-called water activity (Aw value) where pure water represents the value 1. A dry cracker provides an Aw of about 0.2 and a soft yeast dough or a biscuit dough provide Aw values of about 0.80-0.89. At these levels, the risk of pathogenic bacteria growth is almost zero, however, good GMP (Good Manufacturing Practice) is required when processing in order also to reduce the risk of potential yeast and mold growth.
To prevent filled bread dough snacks getting soggy after baking in particular with aging, it is required that the filling has a water activity similar to or reduced with respect to that of the dough. This balanced water activity ensures that water is not transferred between the filling and the dough. Savory or sweet dairy-based creams can be formulated to match a similar water activity, but they then taste very dry and no longer fresh. When a fresh slice of bread is spread with butter and topped with, e.g., cream cheese, it is known that this is done for immediate consumption. It needs to be eaten within hours because of moisture transferring from the topping into the bread. Fresh dairy products such as fresh cheese or cream cheese have a water activity of about 0.98-0.99, process cheese spreads or sausage spreads have such about 0.96 due to their high salt contents.
Shelf stable or chilled storage stable snacks consisting of dough and filling are currently made by adding, e.g., an Aw-reduced, fat-based, sweet dairy cream to the raw yeast dough prior to baking or to the baked goods after baking and cooling. When making dough-enrobed snacks using sweet or savory fillings with Aw values greater than 0.85, it is recommended to bake the snack fully with the filling to achieve optimum GMP. As described earlier, longer shelf life dough-based snacks are made by adding the filling to the raw dough prior to baking. During baking, the filling gets exposed to the convecting heat. Depending on the baking time required for the individual type of dough, it could happen that the filling inside eventually starts to cook. Hand in hand with that, the pressure created steam leads to an expansion of the filling creating a pressure on the dough. When the dough is not flexible enough or does not expand in like manner, it is possible that the filling escapes explosively through cracks in the dough destroying the complete snack. The resulting postbaking product would not be acceptable for the consumer. Making conventional rye bread is based on very long baking processes. Because of this, it is extremely difficult to produce, e.g., cream cheese-filled rye bread snacks.
Making filled bread snacks in general involves a further issue, especially when using flexible raising doughs based on yeast or leavening agents. These doughs sustain the expansion of the filling during baking but it is often observed that a hollow space remains inside the snack on top of the filling after cooling. This is an obvious quality defect and reduces the consumer acceptance of the snack.
It was known that dark rye bread has a fairly long shelf life in comparison with other more wheat dough-based breads. This is mainly due to it being made from sour fermented rye dough which provides the rye bread with a low pH post baking of about 4.4-4.6. When this bread is additionally fully pasteurized in a closed container post baking, a shelf life of up to 6 months at ambient storage can be achieved. Different from other breads, rye bread is also fairly moist having a water activity of about 0.95-0.97 depending on the freshness and formulation of the bread.
Upon spreading cream cheese with an Aw value of about 0.99 on a slice of dark rye bread, e.g., pumpernickel, it does happen that the rye bread will become soggy after a while because the relative Aw difference still brings about a significant moisture transfer. The present invention relates to a process for making a rye bread snack with, e.g., a cream cheese type filling and which is stable for more than 6 or 12 weeks at chilled storage conditions without significant moisture transfer.
It is also known that the taste of bread or other baked goods is created especially during the baking process. The exposure to heat causes the caramelization of the sugar components or a Maillard reaction of the other dough components resulting in the typical baking aromas, flavors and colors. This is especially true for the rye bread baking process. Rye bread needs to be baked fairly long to get the typical dark color and strong flavor. As described above, it would be extremely difficult to make a filled rye bread snack exposed to such a baking process.
NL-A-8100325 describes a process for making a novel filled rye bread which needs long baking times and wherein the product is packed hot into foils.
DE-A-41 42 018 describes a process for making a shelf stable filled bread. This process has the disadvantage that the moisture transfer is not resolved, fillings are very limited and pasteurization takes place in two special plastic foils.
DE-A-39 25 055 teaches a process for making natural filled food (rye bread) which starts from raw sourdough and uses a full baking process. The shelf life of the products is short because the moisture transfer is not taken into consideration.
DE-U-296 09 924 illustrates a process for making a dough-enrobed sausage wherein prebaked rye dough is used for coating a special sausage which is for immediate consumption. An in-pack pasteurization process is not mentioned.
DE-A-25 15 224 describes a process for making a cuttable ready-to-eat dish which uses a special layering technique to make a baked meal preparation based on rye bread for immediate consumption.
All of those prior art references have in common that the aspects of shelf life and durability with regard to any quality defects because of moisture transfer or micro-biological constrains are not mentioned.
The problem underlying the present invention is to provide novel filled dough enrobed snacks which provide a more fresh tasting filling, a good authentic bread taste, an optimum filling volume distribution in the inside of the bread and a long shelf life under chilled and ambient conditions.
The invention provides a process for making bread snacks with fillings of high water content and shelf lives at chilled and ambient temperatures of more than six weeks and which is characterized in that baked bread is used as raw material.
The invention also provides the bread snacks which are obtainable by that process.
The process is especially useful for snacks on the basis of rye bread.
The process of the invention preferably includes the followings steps:
(i) the baked bread is ground
(ii) water is added to the ground bread to improve its extrudability and to adjust its water activity to about 0.95-0.98 or higher,
(iii) the bread/water mixture is kneaded to a bread dough,
(iv) the bread dough is coextruded with the filling and
(v) the snacks are formed, packed and pasteurized.
In a preferred embodiment, glycerine is added in step (ii) in an amount of up to about 5 weight-% to permit the adjustment of the target water activity and to improve the coextrusion capability of the bread.
In a further preferred embodiment of the invention, protein powder is added in step (ii) in an amount of up to about 5 weight-% to improve the sticking properties of the bread dough.
The water activity of the filling and that of the bread in the finished snacks are about the same and is in the range of about 0.95-0.98, preferably 0.96-0.97.
The process of the invention enables the manufacture of a range of novel multicomponent snack products. These snack products have a fresh tasting filling, a good authentic bread taste, an optimum filling volume distribution in the inside of the bread and a long shelf life under chilled and ambient conditions.
The process according to the invention is especially suitable for savory type snacks based on rye bread and containing cheese type fillings, like process cheeses, Aw-reduced cream cheese but also sweet compositions. The key difference from established technologies is that this invention uses already baked bread as raw material. The benefit of this is that a composed snack does not need to be baked further for developing the typical and liked bread flavors. The applied pasteurization of the complete snack in the pack delivers a safe product which can be stored for a long time either chilled or at ambient temperatures depending on the composition.
The process of this invention is now described in more detail.
A rye bread conventionally bulk baked in casings is ground after baking by a rotating knife cutter or high shear mixer, such as a Stephan cutter, into coarse crumbs. The moisture and consequently the water activity of this blend is adjusted by the addition of a defined amount of water and/or glycerine. When aiming for a snack with a more moist fresh filling such as, e.g., a cream cheese type filling, small amounts of water, e.g. about 10% water, are added to raise the initial Aw to about 0.95 to 0.98.
The water activity is defined as follows:       Aw    =          P      Po        ,
wherein
P=partial pressure of water in the food product at temperature T,
Po=saturated water pressure of pure water at the given temperature T.
The Aw adjustment can be counterbalanced somewhat by adding glycerine. This permits the further addition of water, which is sometimes required for improving the coextrusion capability of the created dough. Glycerine, on the other hand, was found very beneficial for improving the dough structure after pasteurization. Accordingly, recommended usage levels could be in the range between 0 and about 5 weight-%, preferably about 2 weight-%. To further improve the processability of the dough blend made from crumbs and water and glycerine, the addition of protein powder is recommended in a range of 0 to about 5 weight-%, most preferably about 2-3 weight-%. Any protein can be used which provides good sticking properties when moisturized and which coagulates upon being heat treated. This could be animal, microbial or vegetable protein powders. Cereal proteins such as gluten are preferable but albumen protein is most preferable. It helps to increase the dough sticking properties necessary for good formability in a coextrusion process but most important it provides the desired firmness of the rye dough after pasteurization when an increased amount of water has been added to raise the Aw value. Further ingredients investigated for supporting extrusion capabilities and dough firmness rebuild were starch or other hydrocolloids, especially when fully hydrated prior to the addition in a separate cooking step in the formula defined water content. Any starch or hydrocolloid is suitable to firm-up the dough but blends of native starches with maltodextrins, in particular a blend of a native waxy corn starch with dextrin, were found most appropriate with regard to simultaneously providing very good sticking properties.
The created sticky rye dough adjusted to an Aw value of about 0.97 can be put into one of the hoppers of a Rheon coextruder. This machine is capable of combining dough with fillings into a multicomponent snack. The filling could be, e.g., a standard process cheese spread known on the market in the UK under the brand name Dairylea. It is also possible to use nonmeltable shredded process cheese if a very hard filling is desired. Both fillings have Aw values round about 0.95-0.97 depending on their dry matter.
A filling derived from cream cheese would be most preferable for creating a fresh tasting snack. To reduce the water activity of cream cheese to the target value, it is recommended to intervene during the conventional cream cheese making process with the addition of specific ingredients. So-called humectants such as glycerine, sorbitol but also ordinary sugar or salt are most effective for Aw reduction. All have in common that they have a very negative effect on the taste of the cream cheese. Apart from using humectants, the addition of any approved food grade ingredients has an effect on the water activity due to the dry matter increase in the cream cheese. Proteins were found to have the most potent relative Aw reducing effect followed by non-sweet maltodextrins and fat.
Accordingly, a well-balanced mixture of milk protein, fat and carbohydrates is chosen for making a product of the invention. For example, 80% cream cheese (40% dry matter) is mixed with 10% skim milk powder, 6% low DE maltodextrin, 2% carboxymethylcellulose and 2% glycerine (all % are weight-%), homogenized and pasteurized at 75xc2x0 C. and filled into buckets. This cream cheese has a water activity of about 0.97 and also provides good heat stability when exposed to secondary heating in a snack. The filling is introduced into the second hopper of the Rheon extruder and coextruded into the rye dough forming a dough bar with cream cheese type filling. The filling is completely enclosed in the created dough snack. It is individually packed into a sealable plastic on, e.g., a form-fill-seal (FFS) packaging line. The snack pack is slightly vacuumized and exposed to a modified atmosphere (MAP) prior to sealing. The reduced pressure in the pack causes the dough to remain in a better shape when exposed to external heat. The snack packs then pass through a microwave heating tunnel with controlled electrical heat exposure ensuring that the snack reaches up to 75xc2x0 C. throughout for at least one minute. The snack pack could also be pasteurized in a moist heat (85xc2x0 C.) environment provided by a continuously or batch operated autoclave.
After cooling, the resulting snack is fully intact and provides excellent taste quality. It can be stored refrigerated or under ambient conditions depending on the type of dough, filling and variability of composition for more than 6 weeks.

Process for making a range of long shelf life, filled bread snacks


In connection with a window arrangement for a motor vehicle, a windup window shade has been pre-assembled on the inside of the window. The windup window shade is preassembled either completely or in its essential parts, so that assembly of the vehicle at the assembly line is considerably simplified.

Modern automobile body shapes are distinguished by relatively large window areas. Because of strong sunlight, the large window areas result in considerable heat generation in the interior of the vehicle and, in connection with vehicles with air conditioning, this extensive heat generation results in a not inconsiderable use of energy in order to counteract the heating effects on the vehicle.
For this reason, motor vehicles are increasingly equipped with windup window shades.
In this connection it is known to attach two guide rails laterally next to the window, in which the end of the traction rod of the window shade web is guided. The length of the traction rod is adjustable in order to be able to accommodate various window widths. Actuation takes place by means of the thrust members running in the guide rails.
The guide rails for such windup window shades are quite filigreed structures. They are made of a light alloy and are therefore very sensitive to damage. A small force is already sufficient to destroy them, as long as they are not fastened on a solid supporting element.
It is therefore difficult to assemble the guide rails accurately in the vehicle.
Moreover, it is necessary to assemble the guide rails in the correct position in respect to the windup shaft, or the windup shaft in the correct position in respect to the guide rails. The traction rod can only be threaded into the guide rails after the windup roller and the guide rails have been assembled.
Considerable difficulties in performing this filigreed work arise during assembly on the assembly line.
Based on the foregoing it is the object of the invention to considerably simplify the assembly of the windup window shade on the assembly line.
In accordance with a first aspect of the invention, this object generally is attained by a pre-assembled window arrangement for subsequent use as a window of a motor vehicle, with the arrangement comprising: a window with an interior face that will face the interior of the motor vehicle in the assembled state of the window arrangement in a vehicle and, a windup window shade that includes: windup shaft that is rotatably seated in bearing means, at least one window shade web that is fastened by one edge on the windup shaft, at least one pair of guide rails, each of which extends laterally beside the extended window shade web, and each of which contains at least one guide groove, a traction rod that is connected with an edge of the windup window shade remote from the windup shaft, and whose respective ends are each guided in the guide grooves of the respective guide rails, and a drive mechanism for moving the traction rod along the guide rails and for rotating the windup shaft; and, wherein the guide rails are fastened at least in sections on the interior face of the window.
The above object generally is achieved according to a second aspect of the invention by pre-assembled window arrangement for subsequent use as a window of a motor vehicle, with the window arrangement comprising: a window with an interior face that will face the interior of the motor vehicle in the assembled state of the window arrangement in a vehicle and, a windup window shade that includes: a windup shaft that is rotatably seated in bearing means, at least one window shade web that is fastened by one edge on the windup shaft, at least one pair of guide rails, each of which extends beside a lateral edge of the extended window shade web, and each of which contains at least one guide groove, a traction rod that is connected with an edge of the windup window shade remote from the windup shaft, and whose respective ends are guided in the guide grooves of the respective guide rails, and a drive mechanism for moving the traction rod along the guide rails and for rotating the windup shaft (32); and wherein the bearing means for the windup shaft are fastened on the interior face of the window.
The considerable simplification of the assembly is achieved when the guide rails are already glued together, at least partially, with the window by the manufacturer. The window is a very stable component, which lends a corresponding stability to the guide rails as long as they are glued together with the window at least in part.
A particularly rugged connection is achieved if the guide rails are glued together with the window over almost the entire length. The non-glued section then possibly forms an inlet section immediately bordering the windup shaft.
It is also possible to achieve a simplification if at least the windup shaft with all associated elements is already glued together with the respective window by the manufacturer of the windup window shade. At the assembly point on the assembly line it is then only necessary to glue in the window and to make the connection with the guide rails. This can be further simplified if short guide rail pieces have already been fastened on the window, into the end of which the traction rod has already previously been threaded. It is then possible without problems to connect these guide rail pieces with the finished guide rails on the assembly line.
Preferably the guide rails are connected with the respective window over the entire length by means of a connection incorporated in the material.
A bracket can be employed for seating the windup shaft, which is simultaneously used for maintaining the drive motor. If it is useful for reasons of stability and weight, or for other reasons, it is also possible to fasten the bearing means independently of the gear motor.
With strongly curved windows it is advantageous if a bracket, which forms a straight edge pointing away from the inside, is glued to the inside of the window. In the assembled state, the top of the bracket constitutes a section of the rear window shelf, while the edge of the bracket simultaneously represents an edge of the outlet slit of the blind.
The guide grooves in which the traction rod moves are preferably undercut grooves, so that they are capable of simultaneously serving as guide tubes for the thrust members. In the case of thrust members, they are able to maintain the thrust members secure against kinking.
The drive mechanism for the windup window shade of the window arrangement becomes very simple if a spring drive is provided, by means of which the windup shaft is biased in the direction of winding up the windup window shade. In this case it is possible to use an electric motor for driving the traction rod. The electric motor determines the departure position of the windup window shade, while the windup shaft follows correspondingly.
In the simplest case the thrust members are linearly-shaped thrust members, because these can be easily housed underneath the rear window shelf, so that it is not necessary to house any thrust members or thrust mechanisms at the other end of the windup window shade, which is remote from the windup shaft.
The window shade web consists of a woven material or a perforated foil, which is dyed more or less dark.
Further embodiments of the invention are inter alia subject of dependent claims. It is intended here that also those combinations of characteristics are considered to be claimed, for which there is no explicit exemplary embodiment.

Window with a windup window shade fastened thereon


A method and device that interrogates the availability of a called party before placing a communication from the calling party to the called party. A callback may be initiated so that both communications are completed simultaneously. The routing of communication may take place through any one of a number of different networks and at another time of the day, even if the caller does not otherwise have access to those networks.

1. Field of the Invention
The present invention relates to a system for providing transparent access to different types of communication networks that may be incompatible with each other and some of which may be incompatible; with the equipment used by the calling party or the called party, least cost routing in such a system, maintaining quality of communication in such a system, prioritizing the routing of such communications, evaluating different communication access locations to determine where to send a communication, synchronizing communications, blocking incoming communications while waiting for the synchronizing to be completed, and minimizing the cost of communications using such a system. This system also monitors and records the services used on each of the unrelated service providers. This information is then utilized for billing purposes and for paying the service providers.
2. Description of the Related Art
Presently when communication services are offered on a global basis, communications are established through the equipment of a plurality of service providers located in various countries. This communication is dominated by large carriers which have formed the global network through reciprocal agreements. Smaller competing carriers, who may offer the same service at lower prices, currently do not have reciprocal agreements between them.
The invention provides these smaller competing carriers with access to each other without the use of the large carriers. Such access provides the calling party (e.g., a subscriber of the smaller competing carrier) with the option of obtaining optimum service at lower prices while ensuring that the appropriate service providers get paid. The calling party can now have cheaper access to different types of telecommunication networks that the party may not have access to under the current large carrier system. It may be cheaper or preferred for the calling party to use smaller carriers to communicate with another location by routing the communication over a digital data network rather than an analog voice network, or by routing the communication over a paging network rather than a cellular network or a combination of networks.

This patent is subject to a terminal disclaimer.

Efficient communication through networks


Speckled detergent compositions with colored glassy phosphates and conventional detergent ingredients.

The present invention relates to speckled detergent compositions comprising colored glassy phosphates. The colored glassy phosphates impart improved aesthetic appeal as well as functionality to granular detergent compositions.
The commercial marketing of laundry detergent products often involves the use of distinctive product aesthetics to help consumers differentiate one given product from other commercially available products of the same general type. Colored, e.g., dyed or pigmented, speckles are sometimes used to create such distinctiveness. Colored speckles known in the art are generally opaque.
Various methods of making granular colored speckles are known in the art. For example, U.S. Pat. No. 4,097,418 issued Jun. 27, 1978, to The Procter and Gamble Co. describes an agglomeration process wherein an inorganic alkaline salt is agglomerated with an anionic surfactant paste which serves as an adhesive agent containing a coloring agent, to provide the speckled detergent composition. Another method is to merely mix two differently colored spray dried granular compositions in the desired proportions.
Accordingly the need remains for a colored speckle that is easily and inexpensively produced and provides for superior consumer recognition of the product in which it is included. Additionally, there is a need for a colored speckle that offers aesthetic appeal while also improving the cleaning power of the detergent composition in which it is included.
By the present invention it has now been discovered that glassy phosphates can be used to make transparent speckles with very distinct visual characteristics in comparison to traditional opaque speckles. Additionally, it has been discovered that the appearance of the speckles can be further enhanced by coating them with sparkled materials, resulting in more visible and distinct speckles. Speckles made from glassy phosphates also provide significantly improved builder capability than sodium carbonate builders. Sodium carbonate builders have the drawback of precipitating calcium carbonate which can build up on fabric. In contrast, glassy phosphate builders exert a powerful sequestering and suspending effect and tend to hydrolyze or revert in aqueous solution and heat to pyrophosphates and orthophosphates.
The present invention meets the aforementioned needs by providing a speckled detergent composition comprising from about 0.01% to about 8.0% by weight of the total composition, of colored glassy phosphate speckles, preferably from about 0.1% to about 5.0% by weight of the total composition, most preferably from about 0.5% to about 3.5% by weight of the total composition and from about 92.0% to about 99.99%, preferably from about 95.0% to about 99.9%, and most preferably from about 96.5% to about 99.50% of conventional laundry ingredients selected from the group consisting of surfactants, builders, chelants, brighteners, bleaching ingredients, photobleaches, enzymes, soil release polymers, dye transfer inhibitors, fabric integrity polymers, fillers, perfumes and mixtures thereof.
It has also been discovered that using functional dyes to color glassy phosphates provides a dual benefit. First an aesthetic benefit is achieved by providing translucent color to the speckles and second, a functional benefit is achieved by improving the cleaning performance of the detergent composition the particles are added to.
All percentages, ratios, and proportions herein are on a weight basis unless otherwise indicated. All documents cited are hereby incorporated by reference in their entirety.
The present invention provides speckled granular detergent compositions useful in hand and machine clothes washing operations which provide an especially desirable aesthetic appeal as well as delivering superior cleaning. Detergent compositions according to the present invention comprise from about 92.0% to about 99.99%, preferably from about 95.0% to about 99.9%, and most preferably from about 96.5% to about 99.50% of conventional laundry ingredients selected from the group consisting of surfactants, builders, chelants, brighteners, bleaching ingredients, photobleaches, enzymes, soil release polymers, dye transfer inhibitors, fillers, perfumes and mixtures thereof and from about 0.01% to about 8.0% by weight of the total composition, of colored glassy phosphate speckles, preferably from about 0.1% to about 5.0% by weight of the total composition, most preferably from about 0.5% to about 3.5% by weight of the total composition.
The present invention also provides the detergent formulator the option of either significantly reducing the amount of detergent builder added to the detergent composition, while maintaining the detergent""s performance or alternatively keeping the same level of builder while adding the glassy phosphate speckles and significantly improving the cleaning performance of the detergent.
Colored Speckles
The colored speckles described herein are comprised of glassy phosphates and a dye and/or pigment. Glassy phosphates useful in the present invention are represented by the formula M2O:P2O5, wherein M is an alkali metal, preferably sodium or potassium, and the molar ratio between both oxides is from about 0.7:1 to about 1.3:1. The preferred glassy phosphates are those having about 21 phosphorous atoms, in the molecule. However, also suitable are glassy phosphates of shorter chain lengths such as 6 and 13 phosphorous atoms. Also useful are larger glassy phosphates such as sodium acid metaphosphate. Sodium glassy phosphates of other alkali metals such as potassium can also be used to produce colored glassy speckles. Glassy phosphates provide speckles that are transparent rather than opaque like those previously known in the art. By transparent is meant that light travels through the speckles undisturbed. The glassy phosphates useful in the present invention are described in U.S. Pat. No. 2,568,110 to Irving Beiley et al, Sep. 18, 1951, (herein incorporated by reference) and in General and Inorganic Chemistry, J. R. Partington, 4th Ed., MacMillan, 1967, (herein incorporated by reference).
Glassy phosphates are commercially available as dry powders, fine granules, plates, and coarse granules. For example, Sodaphos, Hexaphos(copyright), Glass H(copyright) and Sodium Acid Metaphosphate(copyright) are brands of glassy phosphates manufactured by FMC Corporation, these phosphates respectively having an approximate chain length of 6, 13, 21 and greater than 21 phosphorus atoms. Glass H(copyright) is the preferred material in this range of glassy phosphates. Polyphosphates which have the empirical formulae Na16P14O43 and Na12P10O31 are sold by the Hooker Chemical Corporation, Niagara Falls, New York and are also suitable.
Due to the building and dispersing properties of glassy phosphates it is possible to reduce the level of phosphate builder in a product containing glassy phosphate speckles, without reducing the performance of the detergent. Alternatively, if the phosphate builder of a detergent composition is not reduced, the glassy phosphates provide additional building and dispersing capacity resulting in superior performance.
The speckles may also optionally contain a commercial sparkling material such as Timiron Dazzle MP-161 available from Rona EM Industrial Chemicals, to provide additional aesthetic benefits.
Generally speckles in detergent products should be in the range of from 200 to 3000 microns, preferably 300 to 1500 microns in size which is equal to or larger than the detergent base granule size. This ensures easy visibility of the speckles by the consumer.
Dyes
Glassy phosphates are colored with conventional dyes and/or pigments as well as functional dyes which provide a second function in addition to providing color to the speckle. Functional dyes suitable for use in the present invention include photo-bleaches such as metal phthalocyanines, and complexes of photo-bleaches such as zinc phtalocyanine and aluminum phtalocyanine. However, other types of dyes such as polymeric colorants (i.e. Liquitint, available commercially from Milliken Chemical) and other hydrophilic dyes are suitable for use in the present invention. Additionally, adsorption of pigments, such as titanium dioxide coated with mica, onto the particles will result in shiny speckles. The amount of dye or pigment adsorbed onto the glassy phosphate particles is from about 0.1% to about 2.0% by weight of the glassy phosphate content, preferably from about 0.05% to about 1.0% by weight of the glassy phosphate content, and most preferably from about 0.1% to about 0.5% by weight of the glassy phosphate content. The most preferable dyes for use in the present invention are the photobleaches such as metal phthalocyanines, and complexes of them, for example, zinc phtalocyanine and aluminum phtalocyanine. These types of dyes are activated by visible light providing bleaching performance on hydrophilic substrates, as well as a distinctive hue on white fabrics, in addition to providing a translucent colored speckle.
Process
The glassy phosphate particles are dyed by the adsorption of a hydrophilic dye (i.e. metal phthalocyanines or complex of them), polymeric colorants or/and pigments, onto the glassy phosphate surface. This process is more advantageous than conventional absorption or blending of the dyes/pigments with the glassy phosphates because it involves a less complicated process and provides a transparent rather than opaque speckle. Traditional blending methods reduce the transparency of the speckle due to hydrolysis of the phosphates into shorter species which form crystals in the speckle.
The adsorption process can be carried out several different ways. One such method uses a blend of water and a non-polar solvent as the carrier of the dye and/or pigment. The glassy phosphates are dried by evaporation of the non-polar solvent at a temperature between 25xc2x0 C.-100xc2x0 C., preferably between 40xc2x0 C.-80xc2x0 C. and most preferably between 50xc2x0 C.-60xc2x0 C.
The ratio of the water and non-polar solvent blend is from 99%:1% to 10%:1% by weight of the total blend, preferably from 50%:1% and more preferably from 40%:1% by weight of the total composition. The non-polar solvent must be miscible in water in these ratios.
Another method to carry out adsorption of the dyes and/or pigments is the atomization of the dyes and/or pigments onto the glassy phosphate particles. This process is carried out in a fluid bed where the inlet air is from about 90xc2x0 C. to about 110xc2x0 C., preferably from about 100xc2x0 C. to about 105xc2x0 C. The pressure and speed of atomization and the air volume must be adjusted according to the desired dye and/or pigment concentration on the particle. The drying time of the speckles should be minimized to avoid unnecessary overheating.
The colored glassy phosphate speckles described herein are incorporated into detergent compositions by various methods including but not limited to dry admixing.
Optional Detersive Ingredients
As a preferred embodiment, the conventional detergent ingredients are selected from typical detergent composition components such as detersive surfactants and detersive builders. Optionally, the detergent ingredients can include one or more other detersive adjuncts or other materials for assisting or enhancing cleaning performance, treatment of the substrate to be cleaned, or to modify the aesthetics of the detergent composition. Usual detersive adjuncts of detergent compositions include the ingredients set forth in U.S. Pat. No. 3,936,537, Baskerville et al. and in Great Britain Patent Application No. 9705617.0, Trinh et al., published Sep. 24, 1997. Such adjuncts are included in detergent compositions at their conventional art-established levels of use, generally from 0% to about 80% of the detergent ingredients, preferably from about 0.5% to about 20% and can include color speckles, suds boosters, suds suppressors, antitarnish and/or anticorrosion agents, soil-suspending agents, soil release agents, dyes, fillers, optical brighteners, germicides, alkalinity sources, hydrotropes, antioxidants, enzymes, enzyme stabilizing agents, solvents, solubilizing agents, chelating agents, clay soil removal/anti-redeposition agents, polymeric dispersing agents, processing aids, fabric softening components, static control agents, bleaching agents, bleaching activators, bleach stabilizers, etc.
Surfactants
The hand and/or machine washing detergent compositions of the present invention may optionally comprise a non mid-chain branched alkyl sulfate or non-mid chain branched aryl sulphonate surfactant. Depending upon the embodiment of the present invention one or more categories of surfactants may be chosen by the formulator. Preferred categories of surfactants are selected from the group consisting of anionic, cationic, nonionic, zwitterionic, ampholytic surfactants, and mixtures thereof. Within each category of surfactant, more than one type of surfactant of surfactant can be selected. For example, preferably the solid (i.e. granular) and viscous semi-solid (i.e. gelatinous, pastes, etc.) systems of the present invention, surfactant is preferably present to the extent of from about 0.1% to 60%, preferably to about 30% by weight of the composition.
Nonlimiting examples of surfactants useful herein include:
a) C11-C18 alkyl benzene sulfonates (LAS);
b) C10-C20 primary, branched-chain and random alkyl sulfates (AS);
c) C10-C18 secondary (2,3) alkyl sulfates having the formula:
xe2x80x83wherein x and (y+1) are integers of at least about 7, preferably at least about 9; said surfactants disclosed in U.S. Pat. No. 3,234,258 Morris, issued Feb. 8, 1966; U.S. Pat. No. 5,075,041 Lutz, issued Dec. 24, 1991; U.S. Pat. No. 5,349,101 Lutz et al., issued Sep. 20, 1994; and U.S. Pat. No. 5,389,277 Prieto, issued Feb. 14, 1995 each incorporated herein by reference;
d) C10-C18 alkyl alkoxy sulfates (AEXS) wherein preferably x is from 1-7;
e) C10-C18 alkyl alkoxy carboxylates preferably comprising 1-5 ethoxy units;
f) C12-C18 alkyl ethoxylates, C6-C12 alkyl phenol alkoxylates wherein the alkoxylate units are a mixture of ethyleneoxy and propyleneoxy units, C12-C18 alcohol and C6-C12 alkyl phenol condensates with ethylene oxide/propylene oxide block polymers inter alia Pluronic(copyright) ex BASF which are disclosed in U.S. Pat. No. 3,929,678 Laughlin et al., issued Dec. 30, 1975, incorporated herein by reference;
g) Alkylpolysaccharides as disclosed in U.S. Pat. No. 4,565,647 Llenado, issued Jan. 26, 1986, incorporated herein by reference;
h) Polyhydroxy fatty acid amides having the formula:
xe2x80x83wherein R7 is C5-C31 alkyl; R8 is selected from the group consisting of hydrogen, C1-C4 alkyl, C1-C4 hydroxyalkyl, Q is a polyhydroxyalkyl moiety having a linear alkyl chain with at least 3 hydroxyls directly connected to the chain, or an alkoxylated derivative thereof; preferred alkoxy is ethoxy or propoxy, and mixtures thereof; preferred Q is derived from a reducing sugar in a reductive amination reaction, more preferably Q is a glycityl moiety; Q is more preferably selected from the group consisting of xe2x80x94CH2(CHOH)nCH2OH, xe2x80x94CH(CH2OH)(CHOH)nxe2x88x921CH2OH, xe2x80x94CH2(CHOH)2xe2x80x94(CHORxe2x80x2)(CHOH)CH2OH, and alkoxylated derivatives thereof, wherein n is an integer from 3 to 5, inclusive, and Rxe2x80x2 is hydrogen or a cyclic or aliphatic monosaccharide, which are described in U.S. Pat. No. 5,489,393 Connor et al., issued Feb. 6, 1996; and U.S. Pat. No. 5,45,982 Murch et al., issued Oct. 3, 1995, both incorporated herein by reference.
Additionally, the surfactant may be a midchain branched alkyl sulfate, midchain branched alkyl alkoxylate, or midchain branched alkyl alkoxylate sulfate. These surfactants are further described in No. 60/061,971, Oct. 14, 1997, No. 60/061,975, Oct. 14, 1997, No. 60/062,086, Oct. 14, 1997, No. 60/061,916, Oct. 14, 1997, No. 60/061,970, Oct. 14, 1997, No. 60/062,407, Oct. 14, 1997. Other suitable mid-chain branched surfactants can be found in U.S. Patent applications Ser. Nos. 60/032,035, 60/031,845, 60/031,916, 60/031,917, 60/031,761, 60/031,762 and 60/031,844. Mixtures of these branched surfactants with conventional linear surfactants are also suitable for use in the present compositions.
Detergency Builders
The handwashing detergent composition may also include a detergent builder to assist in controlling mineral hardness and to enhance the removal of particulate soils. Inorganic or P-containing detergent builders include, but are not limited to, the alkali metal, ammonium and alkanolammonium salts of polyphosphates (exemplified by the tripolyphosphates, pyrophosphates, and glassy polymeric meta-phosphates), phosphonates, phytic acid, silicates, carbonates (including bicarbonates and sesquicarbonates), sulphates, and aluminosilicates. However, non-phosphate builders are required in some locations. Importantly, the compositions herein function surprisingly well even in the presence of the socalled xe2x80x9cweakxe2x80x9d builders (as compared with phosphates) such as citrate, or in the so-called xe2x80x9cunderbuiltxe2x80x9d situation that may occur with zeolite or layered silicate builders.
Examples of silicate builders are the alkali metal silicates, particularly those having a SiO2:Na2O ratio in the range 1.6:1 to 3.2:1 and layered silicates, such as the layered sodium silicates described in U.S. Pat. No. 4,664,839, issued May 12, 1987 to H. P. Rieck. NaSKS-6 is the trademark for a crystalline layered silicate marketed by Hoechst (commonly abbreviated herein as xe2x80x9cSKS-6xe2x80x9d). Unlike zeolite builders, the NaSKS-6 silicate builder does not contain aluminum. NaSKS-6 has the delta-Na2SiO5 morphology form of layered silicate. It can be prepared by methods such as those described in German DE-A-3,417,649 and DE-A-3,742,043. SKS-6 is a highly preferred layered silicate for use herein, but other such layered silicates, such as those having the general formula NaMSixO2x+1.yH2O wherein M is sodium or hydrogen, x is a number from 1.9 to 4, preferably 2, and y is a number from 0 to 20, preferably 0 can be used herein. Various other layered silicates from Hoechst include NaSKS-5, NaSKS-7 and NaSKS-11, as the alpha, beta and gamma forms. As noted above, the delta-Na2SiO5 (NaSKS-6 form) is most preferred for use herein. Other silicates may also be useful such as for example magnesium silicate, which can serve as a crisping agent in granular formulations, as a stabilizing agent for oxygen bleaches, and as a component of suds control systems.
Examples of carbonate builders are the alkaline earth and alkali metal carbonates as disclosed in German Patent Application No. 2,321,001 published on Nov. 15, 1973.
Aluminosilicate builders are useful in the present invention. Aluminosilicate builders are of great importance in most currently marketed heavy duty granular detergent compositions, and can also be a significant builder ingredient in liquid detergent formulations. Aluminosilicate builders include those having the empirical formula:
xe2x80x83Mz(zAlO2)y].xH2O
wherein z and y are integers of at least 6, the molar ratio of z to y is in the range from 1.0 to about 0.5, and x is an integer from about 15 to about 264.
Useful aluminosilicate ion exchange materials are commercially available. These aluminosilicates can be crystalline or amorphous in structure and can be naturally-occurring aluminosilicates or synthetically derived. A method for producing aluminosilicate ion exchange materials is disclosed in U.S. Pat. No. 3,985,669, Krummel, et al, issued Oct. 12, 1976. Preferred synthetic crystalline aluminosilicate ion exchange materials useful herein are available under the designations Zeolite A, Zeolite P (B), Zeolite MAP and Zeolite X. In an especially preferred embodiment, the crystalline aluminosilicate ion exchange material has the formula:
Na12[(AlO2)12(SiO2)12].xH2O
wherein x is from about 20 to about 30, especially about 27. This material is known as Zeolite A. Dehydrated zeolites (x=0-10) may also be used herein. Preferably, the aluminosilicate has a particle size of about 0.1-10 microns in diameter.
Organic detergent builders suitable for the purposes of the present invention include, but are not restricted to, a wide variety of polycarboxylate compounds. As used herein, xe2x80x9cpolycarboxylatexe2x80x9d refers to compounds having a plurality of carboxylate groups, apreferably at least 3 carboxylates. Polycarboxylate builder can generally be added to the composition in acid form, but can also be added in the form of a neutralized salt. When utilized in salt form, alkali metals, such as sodium, potassium, and lithium, or alkanolammonium salts are preferred.
Included among the polycarboxylate builders are a variety of categories of useful materials. One important category of polycarboxylate builders encompasses the ether polycarboxylates, including oxydisuccinate, as disclosed in Berg, U.S. Pat. No. 3,128,287, issued Apr. 7, 1964, and Lamberti et al, U.S. Pat. No. 3,635,830, issued Jan. 18, 1972. See also xe2x80x9cTMS/TDSxe2x80x9d builders of U.S. Pat. No. 4,663,071, issued to Bush et al, on May 5, 1987. Suitable ether polycarboxylates also include cyclic compounds, particularly alicyclic compounds, such as those described in U.S. Pat. Nos 3,923,679; 3,835,163; 4,158,635; 4,120,874 and 4,102,903.
Other useful detergency builders include the ether hydroxypolycarboxylates, copolymers of maleic anhydride with ethylene or vinyl methyl ether, 1,3,5-trihydroxy benzene-2,4,6-trisulphonic acid, and carboxymethyloxysuccinic acid, the various alkali metal, ammonium and substituted armionium salts of polyacetic acids such as ethylenediamine tetraacetic acid and nitrilotriacetic acid, as well as polycarboxylates such as mellitic acid, succinic acid, oxydisuccinic acid, polymaleic acid, benzene 1,3,5-tricarboxylic acid, carboxymethyloxysuccinic acid, and soluble salts thereof.
Citrate builders, e.g., citric acid and soluble salts thereof (particularly sodium salt), are polycarboxylate builders of particular importance for liquid detergent formulations due to their availability from renewable resources and their biodegradability. Citrates can also be used in granular compositions, especially in combination with zeolite and/or layered silicate builders. Oxydisuccinates are also especially useful in such compositions and combinations.
Also suitable in the detergent compositions of the present invention are the 3,3-dicarboxy-4-oxa-1,6-hexanedioates and the related compounds disclosed in U.S. Pat. No. 4,566,984, Bush, issued Jan. 28, 1986. Useful succinic acid builders include the C5-C20 alkyl and alkenyl succinic acids and salts thereof. A particularly preferred compound of this type is dodecenylsuccinic acid. Specific examples of succinate builders include: laurylsuccinate, myristylsuccinate, palmitylsuccinate, 2-dodecenylsuccinate (preferred), 2-pentadecenylsuccinate, and the like. Laurylsuccinates are the preferred builders of this group, and are described in European Patent Application 86200690.5/0,200,263, published Nov. 5, 1986.
Other suitable polycarboxylates are disclosed in U.S. Pat. No. 4,144,226, Crutchfield et al, issued Mar. 13, 1979 and in U.S. Pat. No. 3,308,067, Diehl, issued Mar. 7, 1967. See also Diehl U.S. Pat. No. 3,723,322.
Fatty acids, e.g., C12-C18 monocarboxylic acids, can also be incorporated into the compositions alone, or in combination with the aforesaid builders, especially citrate and/or the succinate builders, to provide additional builder activity. Such use of fatty acids will generally result in a diminution of sudsing, which should be taken into account by the formulator.
In situations where phosphorus-based builders can be used, the various alkali metal phosphates such as the well-known sodium tripolyphosphates, sodium pyrophosphate and sodium orthophosphate can be used. Phosphonate builders such as ethane-1-hydroxy-1,1-diphosphonate and other known phosphonates (see, for example, U.S. Pat. Nos. 3,159,581; 3,213,030; 3,422,021; 3,400,148 and 3,422,137) can also be used.
Adjunct Ingredients
The compositions herein can optionally include one or more other detergent adjunct materials or other materials for assisting or enhancing cleaning performance, treatment of the substrate to be cleaned, or to modify the aesthetics of the detergent composition (e.g., perfumes, colorants, dyes, etc.). The following are illustrative examples of such adjunct materials.
Enzymesxe2x80x94Enzymes can be included in the formulations herein for a wide variety of fabric laundering purposes, including removal of protein-based, carbohydrate-based, or triglyceride-based stains, for example, and for the prevention of refugee dye transfer, and for fabric restoration. The enzymes to be incorporated include proteases, amylases, lipases, cellulases, and peroxidases, as well as mixtures thereof. Other types of enzymes may also be included. They may be of any suitable origin, such as vegetable, animal, bacterial, fungal and yeast origin. However, their choice is governed by several factors such as pH-activity and/or stability optima, thermostability, stability versus active detergents, builders and so on. In this respect bacterial or fungal enzymes are preferred, such as bacterial amylases and proteases, and fungal cellulases.
Enzyme Stabilizersxe2x80x94The enzymes employed herein are stabilized by the presence of water-soluble sources of calcium and/or magnesium ions in the finished compositions which provide such ions to the enzymes. (Calcium ions are generally somewhat more effective than magnesium ions and are preferred herein if only one type of cation is being used.) Additional stability can be provided by the presence of various other art-disclosed stabilizers, especially borate species: see Severson, U.S. Pat. No. 4,537,706.
Bleaching Compoundsxe2x80x94Bleaching Agents and Bleach Activatorsxe2x80x94The detergent compositions herein may optionally contain bleaching agents or bleaching compositions containing a bleaching agent and one or more bleach activators. When present, bleaching agents will typically be at levels of from about 1% to about 30%, more typically from about 5% to about 20%, of the detergent composition, especially for fabric laundering. If present, the amount of bleach activators will typically be from about 0.1% to about 60%, more typically from about 0.5% to about 40% of the bleaching composition comprising the bleaching agent-plus-bleach activator. Mixtures of bleaching agents can also be used.
Polymeric Soil Release Agentxe2x80x94Any polymeric soil release agent known to those skilled in the art can optionally be employed in the compositions and processes of this invention. Polymeric soil release agents are characterized by having both hydrophilic segments, to hydrophilize the surface of hydrophobic fibers, such as polyester and nylon, and hydrophobic segments, to deposit upon hydrophobic fibers and remain adhered thereto through completion of washing and rinsing cycles and, thus, serve as an anchor for the hydrophilic segments. This can enable stains occurring subsequent to treatment with the soil release agent to be more easily cleaned in later washing procedures.
Chelating Agentsxe2x80x94The detergent compositions herein may also optionally contain one or more iron and/or manganese chelating agents. Such chelating agents can be selected from the group consisting of amino carboxylates, amino phosphonates, polyfunctionally-substituted aromatic chelating agents and mixtures therein, all as hereinafter defined. Without intending to be bound by theory, it is believed that the benefit of these materials is due in part to their exceptional ability to remove iron and manganese ions from washing solutions by formation of soluble chelates.
Clay Soil Removal/Anti-redeposition Agentsxe2x80x94The compositions of the present invention can also optionally contain water-soluble ethoxylated amines having clay soil removal and antiredeposition properties. Granular detergent compositions which contain these compounds typically contain from about 0.01% to about 10.0% by weight of the water-soluble ethoxylates amines; liquid detergent compositions typically contain about 0.01% to about 5%.
Polymeric Dispersing Agentsxe2x80x94Polymeric dispersing agents can advantageously be utilized at levels from about 0.1% to about 7%, by weight, in the compositions herein, especially in the presence of zeolite and/or layered silicate builders. Suitable polymeric dispersing agents include polymeric polycarboxylates and polyethylene glycols, although others known in the art can also be used. It is believed, though it is not intended to be limited by theory, that polymeric dispersing agents enhance overall detergent builder performance, when used in combination with other builders (including lower molecular weight polycarboxylates) by crystal growth inhibition, particulate soil release peptization, and anti-redeposition.
Brightenerxe2x80x94Any optical brighteners or other brightening or whitening agents known in the art can be incorporated at levels typically from about 0.05% to about 1.2%, by weight, into the detergent compositions herein. Commercial optical brighteners which may be useful in the present invention can be classified into subgroups, which include, but are not necessarily limited to, derivatives of stilbene, pyrazoline, coumarin, carboxylic acid, methinecyanines, dibenzothiophene-5,5-dioxide, azoles, 5- and 6-membered-ring heterocycles, and other miscellaneous agents. Examples of such brighteners are disclosed in xe2x80x9cThe Production and Application of Pluorescent Brightening Agentsxe2x80x9d, M. Zahradnik, Published by John Wiley and Sons, New York (1982).
Dye Transfer Inhibiting Agentsxe2x80x94The compositions of the present invention may also include one or more materials effective for inhibiting the transfer of dyes from one fabric to another during the cleaning process. Generally, such dye transfer inhibiting agents include polyvinyl pyrrolidone polymers, polyamine N-oxide polymers, copolymers of N-vinylpyrrolidone and N-vinylimidazole, manganese phthalocyanine, peroxidases, and mixtures thereof. If used, these agents typically comprise from about 0.01% to about 10% by weight of the composition, preferably from about 0.01% to about 5%, and more preferably from about 0.05% to about 2%.
Other Ingredientsxe2x80x94A wide variety of other ingredients useful in detergent compositions can be included in the compositions herein, including other active ingredients, carriers, hydrotropes, processing aids, dyes or pigments, solvents for liquid formulations, solid fillers for bar compositions, etc. If desired, soluble magnesium salts such as MgCl2, MgSO4, and the like, can be added at levels of, typically, 0.1%-2%, to provide additional suds and to enhance grease removal performance.
Various detersive ingredients employed in the present compositions optionally can be further stabilized by absorbing said ingredients onto a porous hydrophobic substrate, then coating said substrate with a hydrophobic coating. Preferably, the detersive ingredient is admixed with a surfactant before being absorbed into the porous substrate. In use, the detersive ingredient is released from the substrate into the aqueous washing liquor, where it performs its intended detersive function.
The colored speckles described herein are suitable for use in non-aqueous, liquid detergent compositions containing non-aqueous solvents as carriers. Low molecular weight primary or secondary alcohols exemplified by methanol, ethanol, propanol, and isopropanol are suitable. Monohydric alcohols are preferred for solubilizing surfactant, but polyols such as those containing from 2 to about 6 carbon atoms and from 2 to about 6 hydroxy groups (e.g., 1,3-propanediol, ethylene glycol, glycerine, and 1,2-propanediol) can also be used. The compositions may contain from 5% to 90%, typically 10% to 50% of such carriers.
The detergent compositions herein will preferably be formulated such that, during use in aqueous cleaning operations, the wash water will have a pH of from about 6.5 to about 11, preferably from about 8.5 to about 10.7. Techniques for controlling pH at recommended usage levels include the use of buffers, alkalis, acids, etc., and are well known to those skilled in the art.
Detergent Compositions


This invention relates to fuel oil, especially middle distillate fuel oil, compositions comprising middle distillate fuel oil and at least one fuel-soluble or fuel dispersible calcium and/or magnesium salt.

This invention relates to fuel oil, especially middle distillate fuel oil, compositions of improved combustion performance, particularly demonstrating reduced particulate matter emission and/or smoke. This invention is especially directed to hydrocarbon middle distillate fuel oil compositions.
Certain organometallic compounds are known to be effective combustion improvers for distillate fuels such as home heating oils. For example, U.S. Pat. No. 3,112,789 describes the use of cyclopentadienyl manganese tricarbonyls for this purpose.
EP-B-0 476 196 describes an additive composition for hydrocarbonaceous fuel comprising
(a) one or more fuel-soluble manganese carbonyl compounds;
(b) one or more fuel-soluble alkali or alkaline earth metal containing detergents; and
(c) one or more fuel-soluble ashless dispersants;
and its use for reducing the soot, smoke and/or carbonaceous products produced on combustion of the fuel and for reducing the acidity of the carbonaceous products.
U.S. Pat. No. 3,883,320 discloses jet engine fuels comprising an oil-soluble transition metal compound, an oil-soluble compound of a secondary metal selected from the alkaline earths and an oil-soluble ammonium salt for inhibiting the formation of visible smoke and minimising the deposition of ash on jet engine parts.
Canadian Patent No. 1,188,891 describes an additive comprising at least one oil-soluble and/or dispersible compound of a transition metal and/or alkaline earth metal as well as one of several inhibitors against polymerisation and oxidation of hydrocarbons which inhibits the formation of soot. Examples 1 and 2 disclose compositions containing overbased (carbonated) barium sulphonate.
EP-B-0 022 110 describes an emulsifier containing a mixture of a non-ionic surface active ethylene oxide adduct and calcium dodecylbenzene sulphonate and its use for the manufacture of an emulsion of water in mineral oil.
GB-A-2 091 291 discloses an additive for a diesel fuel oil, which comprises on oil soluble or dispersible calcium compound and an oil soluble or dispersible iron compound, for smoke suppression.
U.S. Pat. No. 3,539,312 discloses a hydrocarbon light distillate fuel oil composition containing minor amounts of calcium sulfonate and an overbasing component represented by the formula:
Ca[O(R1O)yR]z
in which R represents nil, hydrogen, or an alkyl radical having from 1 to 10 carbons atoms, R1 is an alkylene radical having from 2 to 4 carbon atoms, y has a value from 0 to 4, z has a value of 1 when R is nil, and z has a value of 2 when R is H or alkyl. Such fuel compositions are discussed in relation to reduction in smoke emissions.
There is, however, a continuing need for fuel oils which on combustion produce lower levels of particulate matter; this is especially important for the middle-distillate fuels, such as diesel fuels and heating oils.
Further, there is an on-going demand to minimise the cost of additives used, and reduce the amount and range of metals used in fuel oils, for example, in order to reduce the formation of ash deposits upon combustion, or in order to preserve metals for other uses.
The present invention meets this need by providing a hydrocarbon middle distillate fuel composition comprising middle distillate fuel oil and at least one fuel-soluble neutral calcium and/or magnesium salt. It has been surprisingly found that such fuel compositions produce a lower amount of particulate matter on combustion.
Accordingly, a first aspect of the present invention is a hydrocarbon middle distillate fuel composition free of transition metal compounds comprising middle distillate fuel oil and at least one fuel-soluble or fuel-dispersible neutral calcium and/or magnesium salt of sulphonic acid, phenol, sulphurised phenol, salicylic acid or carboxylic acid wherein the sulphonic acid contains at least 22 carbon atoms.
A second aspect of the present invention is the use of at least one fuel-soluble or fuel-dispersible neutral calcium and/or magnesium salt of sulphonic acid, phenol, sulphurised phenol, salicylic acid or carboxylic acid, in fuel oil, which is preferably free of transition metal compounds, to reduce particulate emissions during combustion of the fuel oil.
A third aspect of the present invention is a method for reducing particulate emissions during operation of a fuel oil combustion device comprising addition to the fuel oil, which is preferably free of transition metal compounds, used therein of at least one fuel-soluble or fuel-dispersible neutral calcium and/or magnesium salt of sulphonic acid, phenol, sulphurised phenol, salicylic acid or carboxylic acid.
Hydrocarbon Middle Distillate Fuel Oil
The term xe2x80x98hydrocarbon middle distillate fuel compositionxe2x80x99 as used herein refers to middle distillate fuel oils which are substantially free, and preferably free, of ethers and/or alcohols. As used herein the term xe2x80x98substantially freexe2x80x99 with reference to ethers and/or alcohols in fuel oil refers to an amount of up to 20 mass % based on the mass of the middle distillate fuel oil, preferably up to 10 mass %, more preferably up to 5 mass %.
The use of transition metal compounds can be avoided in the present invention and such metals may be preserved for other uses if desired. Examples of transition metal compounds are compounds of the metals manganese, iron, cobalt, nickel, copper, zinc and molybdenum. In particular, use of manganese and iron compounds may be avoided, especially manganese carbonyl compounds, ferrocene or iron naphthenate.
Middle distillate fuel oils generally boil within the range of about 100xc2x0 C. to about 500xc2x0 C., e.g. 150xc2x0 to about 400xc2x0 C., for example, those having a relatively high Final Boiling Point of above 360xc2x0 C. (ASTM D-86). Middle distillates contain a spread of hydrocarbons boiling over a temperature range, including n-alkanes which precipitate as wax as the fuel cools. They may be characterised by the temperatures at which various %""s of fuel have vaporised, e.g. 10% to 90%, being the interim temperatures at which a certain volume % of initial fuel has distilled. The difference between say 90% and 20% distillation temperature may be significant. They are also characterised by pour, cloud and CFPP points, as well as their initial boiling point (IBP) and final boiling point (FBP). The petroleum fuel oil can comprise atmospheric distillate or vacuum distillate, or cracked gas oil or a blend in any proportion of straight run and thermally and/or catalytically cracked distillates. The most common middle distillate fuels are jet fuels, diesel fuels and heating oils. The heating oil may be a straight atmospheric distillate, or it may contain minor amounts, e.g. up to 35 mass %, of vacuum gas oil or cracked gas oils or of both.
Heating oils may be made of a blend of virgin distillate, e.g. gas oil, naphtha, etc. and cracked distillates, e.g. catalytic cycle shock. A representative specification for a diesel fuel includes a minimum flash point of 38xc2x0 C. and a 90% distillation point between 282 and 380xc2x0 C. (see ASTM Designations D-396 and D-975).
The fuel oil may also be an animal or vegetable oil, or a mineral oil as described above in combination with an animal or vegetable oil. Fuels from animal or vegetable sources are known as biofuels and are believed to be less damaging to the environment on combustion, and are obtained from a renewable source. It has been reported that on combustion less carbon dioxide is formed than is formed by the equivalent quantity of petroleum distillate fuel, e.g. diesel fuel, and very little sulphur dioxide is formed. Certain derivatives of vegetable oil, for example rapeseed oil, e.g. those obtained by saponification and re-esterification with a monohydric alcohol, may be used as a substitute for diesel fuel. It has recently been reported that mixtures of a rapeseed ester, for example, rapeseed methyl ester (RME), with petroleum distillate fuels in ratios of, for example, 10:90 by volume are likely to be commercially available in the near future.
Thus, a biofuel is a vegetable or animal oil or both or a derivative thereof, particularly an oil comprising fatty acid and/or fatty acid esters.
Vegetable oils are mainly tricylcerides of monocarboxylic acids, e.g. acids containing 10-25 carbon atoms and listed below
where R is an aliphatic radical of 10-25 carbon atoms which may be saturated or unsaturated.
Generally, such oils contain glycerides of a number of acids, the number and kind varying with the source vegetable of the oil.
Examples of oils are rapeseed oil, coriander oil, soyabean oil, cottonseed oil, sunflower oil, castor oil, olive oil, peanut oil, maize oil, almond oil, palm kernel oil, coconut oil, mustard seed oil, beef tallow and fish oils. Rapeseed oil, which is a mixture of fatty acids partially esterified with glycerol, is preferred as it is available in large quantities and can be obtained in a simple way by pressing from rapeseed.
Examples of derivatives thereof are alkyl esters, such as methyl esters, of fatty acids of the vegetable or animal oils. Such esters can be made by transesterification.
As lower alkyl esters of fatty acids, consideration may be given to the following, for example as commercial mixtures: the ethyl, propyl, butyl and especially methyl esters of fatty acids with 12 to 22 carbon atoms, for example of lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, elaidic acid, petroselic acid, ricinoleic acid, elaecostearic acid, linoleic acid, linolenic acid, eicosanoic acid, gadoleic acid, docosanoic acid or erucic acid, which have an iodine number from 50 to 150, especially 90 to 125. Mixtures with particularly advantageous properties are those which contain mainly, i.e. to at least 50 mass % methyl esters of fatty acids with 16 to 22 carbon atoms and 1, 2 or 3 double bonds. The preferred lower alkyl esters of fatty acids are the methyl esters of oleic acid, linoleic acid, linolenic acid and erucic acid.
Commercial mixtures of the stated kind are obtained for example by cleavage and esterification of natural fats and oils by their transesterification with lower aliphatic alcohols. For production of lower alkyl esters of fatty acids it is advantageous to start from fats and oils with high iodine number, such as, for example, sunflower oil, rapeseed oil, coriander oil, castor oil, soyabean oil, cottonseed oil, peanut oil or beef tallow. Lower alkyl esters of fatty acids based on a new variety of rapeseed oil, the fatty acid component of which is derived to more than 80 mass % from unsaturated fatty acids with 18 carbon atoms, are preferred.
Preferably the biofuel is present in an amount of up to 50 mass % based on the mass of the middle distillate fuel oil, more preferably of up to 10 mass %, especially up to 5 mass %.
Also, the fuel oil preferably has a sulphur concentration of 0.2% by mass or less based on the mass of the fuel. Preferably, the sulphur concentration is 0.05% by mass or less, more preferably 0.03% by mass or less, especially 0.01% by mass or less. The art describes methods for reducing the sulphur concentration of hydrocarbon middle distillate fuels, such methods including solvent extraction, sulphuric acid treatment, and hydrodesulphurisation. Fuel oils having such low sulphur levels show good response to the neutral salts of the present invention despite the reduced tendency of such fuels to produce particulate emissions.
Preferably the hydrocarbon middle distillate fuel oil is diesel fuel or heating oil.
Fuel-Soluble or Fuel-Dispersible Neutral Calcium and/or Magnesium Salt
The term xe2x80x98neutralxe2x80x99 as used herein refers to metal salts that are predominantly neutral in character, that is most of the metal is associated with the surfactant anion. For a metal salt to be completely neutral, the total number of moles of the metal cation to the total number of moles of surfactant anion associated with the metal will be stoichiometric. For example, for every one mole of calcium cations there should be two moles of sulphonate anions.
The metal salts of the present invention include predominantly neutral salts where minor amounts of non-surfactant anions, such as carbonate and/or hydroxide, succinate may also be present provided their presence does not alter the predominantly neutral character of the metal salt.
Thus, metal salts of the present invention preferably have a metal ratio of less than 2, more preferably less than 1.95, especially less than 1.9, advantageously less than 1.8, more especially less than 1.6, for example less than 1.5, such as less than 1.4 or less than 1.35. The metal ratio is preferably at least about 1.0. The metal ratio, as used herein, is the ratio of total metal to the metal associated with the surfactant. So metal salts having a metal ratio of less than 2 have greater than 50% of the metal associated with the surfactant anion.
Any type of surfactant may be used in the present invention. Examples of suitable surfactants are sulphonic acids, phenol, sulphurised phenol, salicylic acid and carboxylic acid.
The metal ratio can be calculated by
a) measuring the total amount of metal in the neutral metal salt; and then
b) determining the amount of metal associated with the surfactant.
Suitable methods for measuring the total metal content are well known in the art and include X-ray fluorescence and atomic absorption spectrometry.
Suitable methods for determining the amount of metal associated with the surfactant include potentiometric acid titration of the metal salt to determine the relative proportions of the different basic constituents (for example, metal carbonate and metal surfactant); hydrolysis of a known amount of metal salt then the potentiometric base titration of the organic surfactant to determine the equivalent moles of surfactant; and determination of the non-surfactant anions, such as carbonate, by measuring the CO2 content.
In the case of a metal sulphonate, ASTM D3712 may be used to determine the metal associated with the sulphonate.
In the instance where a composition comprises neutral metal salt and one or more co-additives, then the neutral metal salt(s) may be separated from the co-additives, for example, by using dialysis techniques and then the neutral metal salt may be analysed as described above to determine the metal ratio. Background information on suitable dialysis techniques is given by Amos, R. and Albaugh, E. W. in xe2x80x9cChromatography in Petroleum Analysisxe2x80x9d) Altgelt, K. H. and Gouw, T. H., Eds., pages 417 to 421, Marcel Dekker Inc., New York and Basel, 1979.
The neutral salts of the present invention may be salts of one type of surfactant or salts of more than one type of surfactant. Preferably, they are salts of one type of surfactant.
Sulphonic acids used in accordance with this aspect of the invention are typically obtained by sulphonation of hydrocarbyl-substituted, especially alkyl-substituted, aromatic hydrocarbons, for example, those obtained from the fractionation of petroleum by distillation and/or extraction, or by the alkylation of aromatic hydrocarbons. Examples include those obtained by alkylating benzene, toluene, xylene, naphthalene, biphenyl or their halogen derivatives, for example, chlorobenzene, chlorotoluene or chloronaphthalene. Alkylation of aromatic hydrocarbons may be carried out in the presence of a catalyst with alkylating agents having from about 3 to more than 100 carbon atoms, such as, for example, haloparaffins, olefins that may be obtained by dehydrogenation of paraffms, and polyolefms, for example, polymers of ethylene, propylene, and/or butene. The alkylaryl sulphonic acids usually contain from about 22 to about 100 or more carbon atoms; preferably the alkylaryl sulphonic acids contain at least 26 carbon atoms, especially at least 28, such as at least 30, carbon atoms. The sulphonic acids may be substituted by more than one alkyl group on the aromatic moiety, for example they may be dialkylaryl sulphonic acids. The alkyl group preferably contains from about 16 to about 80 carbon atoms, with an average number of carbon atoms in the range of from 36-40, or an average carbon number of 24, depending on the source from which the alkyl group is obtained. Preferably the sulphonic acid has a number average molecular weight of 350 or greater, more preferably 400 or greater, especially 500 or greater, such as 600 or greater. Number average molecular weight may be determined by ASTM D3712.
When neutralising these alkylaryl sulphonic acids to provide sulphonates, hydrocarbon solvents and/or diluent oils may also be included in the reaction mixture, as well as promoters.
Another type of sulphonic acid which may be used in accordance with the invention comprises alkyl phenol sulphonic acids. Such sulphonic acids can be sulphurized. Preferred substituents in alkyl phenol sulphonic acids are substituents represented by R in the discussion of phenols below.
Sulphonic acids suitable for use in accordance with the invention also include alkyl sulphonic acids. In such compounds the sulphonic acid suitably contains 22 to 100 carbon atoms, advantageously 25 to 80 carbon atoms, especially 30 to 60 carbon atoms.
Preferably the sulphonic acid is hydrocarbyl-substituted aromatic sulphonic acid, more preferably alkyl aryl sulphonic acid.
Phenols used in accordance with the invention may be non-sulphurized or, preferably, sulphurized. Further, the term xe2x80x9cphenolxe2x80x9d as used herein includes phenols containing more than one hydroxyl group (for example, alkyl catechols) or fused aromatic rings (for example, alkyl naphthols) and phenols which have been modified by chemical reaction, for example, alkylene-bridged phenols and Mannich base-condensed phenols; and saligenin-type phenols (produced by the reaction of a phenol and an aldehyde under basic conditions).
Preferred phenols from which neutral calcium and/or magnesium salts in accordance with the invention may be derived are of the formula
where R represents a hydrocarbyl group and y represents 1 to 4. Where y is greater than 1, the hydrocarbyl groups may be the same or different.
The phenols are frequently used in sulphurized form. Sulphurized hydrocarbyl phenols may typically be represented by the formula:
where x, represents an integer from 1 to 4. In some cases, more than two phenol molecules may be linked by (S)x bridges, where S represents a sulphur atom.
In the above formulae, hydrocarbyl groups represented by R are advantageously alkyl groups, which advantageously contain 5 to 100 carbon atoms, preferably 5 to 40 carbon atoms, especially 9 to 12 carbon atoms, the average number of carbon atoms in all of the R groups being at least about 9 in order to ensure adequate solubility in oil. Preferred alkyl groups are nonyl (e.g. tripropylene) groups or dodecyl (e.g. tetrapropylene) groups.
In the following discussion, hydrocarbyl-substituted phenols will for convenience be referred to as alkyl phenols.
A sulphurizing agent for use in preparing a sulphurized phenol or phenate may be any compound or element which introduces xe2x80x94(S)xxe2x80x94 bridging groups between the alkyl phenol monomer groups, wherein x is generally from 1 to about 4. Thus, the reaction may be conducted with elemental sulphur or a halide thereof, for example, sulphur dichloride or, more preferably, sulphur monochloride. If elemental sulphur is used, the sulphurization reaction may be effected by heating the alkyl phenol compound at from 50 to 250xc2x0 C., and preferably at least 100xc2x0 C. The use of elemental sulphur will typically yield a mixture of bridging groups xe2x80x94(S)xxe2x80x94 as described above. If a sulphur halide is used, the sulphurization reaction may be effected by treating the alkyl phenol at from xe2x88x9210xc2x0 C. to 120xc2x0 C., preferably at least 60xc2x0 C. The reaction may be conducted in the presence of a suitable diluent. The diluent advantageously comprises a substantially inert organic diluent, for example mineral oil or an alkane. In any event, the reaction is conducted for a period of time sufficient to effect substantial reaction. It is generally preferred to employ from 0.1 to 5 moles of the alkyl phenol material per equivalent of sulphurizing agent.
Where elemental sulphur is used as the sulphurizing agent, it may be desirable to use a basic catalyst, for example, sodium hydroxide or an organic amine, preferably a heterocyclic amine (e.g., morpholine).
Details of sulphurization processes are well known to those skilled in the art, for example U.S. Pat. Nos. 4,228,022 and 4,309,293.
As indicated above, the term xe2x80x9cphenolxe2x80x9d as used herein includes phenols which have been modified by chemical reaction with, for example, an aldehyde, and Mannich base-condensed phenols.
Aldehydes with which phenols used in accordance with the invention may be modified include, for example, formaldehyde, propionaldehyde and butyraldehyde. The preferred aldehyde is formaldehyde. Aldehyde-modified phenols suitable for use in accordance with the present invention are described in, for example, U.S. Pat. No. 5,259,967.
Mannich base-condensed phenols are prepared by the reaction of a phenol, an aldehyde and an amine. Examples of suitable Mannich base-condensed phenols are described in GB-A-2 121 432.
In general, the phenols may include substituents other than those mentioned above. Examples of such substituents are methoxy groups and halogen atoms.
Salicylic acids used in accordance with the invention may be non-sulphurized or sulphurized, and may be chemically modified and/or contain additional substituents, for example, as discussed above for phenols. Processes similar to those for phenols may also be used for sulphurizing a hydrocarbyl-substituted salicylic acid, and are well known to those skilled in the art. Salicylic acids are typically prepared by the carboxylation, by the Kolbe-Schmitt process, of phenoxides, and in that case, will generally be obtained (normally in a diluent) in admixture with uncarboxylated phenol.
Preferred substituents in oil-soluble salicylic acids from which neutral calcium and/or magnesium salts in accordance with the invention may be derived are the substituents represented by R in the above discussion of phenols. In alkyl-substituted salicylic acids, the alkyl groups advantageously contain 5 to 100 carbon atoms, preferably 9 to 30 carbon atoms, especially 14 to 20 carbon atoms.
Carboxylic acids which may be used in accordance with the invention include mono- and dicarboxylic acids. Preferred monocarboxylic acids are those containing 8 to 30 carbon atoms, especially 8 to 24 carbon atoms. (Where this specification indicates the number of carbon atoms in a carboxylic acid, the carbon atom(s) in the carboxylic group(s) is/are included in that number.) Examples of monocarboxylic acids are iso-octanoic acid, stearic acid, oleic acid, palmitic acid and behenic acid. Iso-octanoic acid may, if desired, be used in the form of the mixture of C8 acid isomers sold by Exxon Chemical under the trade name xe2x80x9cCekanoicxe2x80x9d. Other suitable acids are those with tertiary substitution at the xcex1-carbon atom and dicarboxylic acids with 2 or more carbon atoms separating the carboxylic groups. Further, dicarboxylic acids with more than 35 carbon atoms, for example, 36 to 100 carbon atoms, are also suitable. Unsaturated carboxylic acids can be sulphurized.
In the instance where more than one type of surfactant is present in the metal salt, the proportion of any one type of surfactant to another is not critical provided the neutral character of the metal is not altered.
It will be appreciated by one skilled in the art that a single type of surfactant may contain a mixture of surfactants of the same type. For example, a sulphonic acid surfactant may contain a mixture of sulphonic acids of varying molecular weights. Such a surfactant composition is considered as one type of surfactant.
As used in this specification the term xe2x80x9chydrocarbylxe2x80x9d refers to a group having a carbon atom directly attached to the rest of the molecule and having a hydrocarbon or predominantly hydrocarbon character. Examples include hydrocarbon groups, including aliphatic (e.g. alkyl or alkenyl), alicyclic (e.g. cycloalkyl or cycloalkenyl), aromatic, and alicyclic-substituted aromatic, and aromatic-substituted aliphatic and alicyclic groups. Aliphatic groups are advantageously saturated. These groups may contain non-hydrocarbon substituents provided their presence does not alter the predominantly hydrocarbon character of the group. Examples include keto, halo, hydroxy, nitro, cyano, alkoxy and acyl. If the hydrocarbyl group is substituted, a single (mono) substituent is preferred.
Examples of substituted hydrocarbyl groups include 2-hydroxyethyl, 3-hydroxypropyl, 4-hydroxybutyl, 2-ketopropyl, ethoxyethyl, and propoxypropyl. The groups may also or alternatively contain atoms other than carbon in a chain or ring otherwise composed of carbon atoms. Suitable hetero atoms include, for example, nitrogen, sulphur, and, preferably, oxygen.
The calcium and/or magnesium salt of the present invention may be present in an amount of from 0.1 to 100 ppm by mass of metal based on the mass of the fuel oil composition, preferably from 0.1 to 50 ppm; more preferably from 0.1 to 25 ppm, especially from 0.1 to 10 ppm, such as from 1 to 5 ppm. Whilst the salt is preferably fuel soluble to allow even distribution throughout the fuel, dispersible salts are also usable.
The neutral calcium and/or magnesium salts of the present invention are xe2x80x9cfuel-solublexe2x80x9d or xe2x80x9cfuel-dispersiblexe2x80x9d in the fuel oil but these do not mean that they are soluble, dissolvable, miscible or capable of being suspended in the fuel oil in all proportions. They do mean, however, that the salts of the present invention are, for instance, soluble or stable dispersible in the fuel oil to an extent sufficient to exert their intended effect in the environment in which the fuel oil composition is employed. Moreover, the additional incorporation of other additives such as those described hereinafter may affect the fuel solubility or dispersibility of the salts of the invention.
Concentrates comprising the calcium and/or magnesium salt of the present invention in admixture with a carrier liquid (e.g. as a solution or a dispersion) are convenient as a means for incorporating the calcium and/or magnesium salt into bulk oil such as distillate fuel, which incorporation may be done by methods known in the art. The concentrates may also contain other additives as required and preferably contain from 3 to 75 mass %, more preferably 3 to 60 mass %, most preferably 10 to 50 mass % of the additives preferably in solution in oil. Examples of carrier liquid are organic solvents including hydrocarbon solvents, for example petroleum fractions such as naphtha, kerosene, lubricating oil, diesel and heater oil; aromatic hydrocarbons such as aromatic fractions, e.g. those sold under the xe2x80x98SOLVESSOxe2x80x99 tradename; and paraffinic hydrocarbons such as hexane and pentane and isoparaffins. The carrier liquid must, of course, be selected having regard to its compatibility with the additives and with the fuel.
Accordingly another aspect of the inventions is a fuel oil concentrate free of transition metal compounds comprising at least one neutral calcium and/or magnesium salt as defined in the first aspect of the invention.
The calcium and/or magnesium salt of the present invention may be incorporated into bulk oil by other methods such as those known in the art. If co-additives are required, they may be incorporated into the bulk oil at the same time as the calcium and/or magnesium salt of the present invention or at a different time.
The calcium and/or magnesium salt of the present invention may be used singly or as mixtures. They may also be used in combination with one or more co-additives such as known in the art, for example the following: detergents, dispersants, antioxidants, corrosion inhibitors, dehazers, demulsifiers, metal deactivators, antifoaming agents, cetane improvers, cosolvents, package compatibilisers, and lubricity additives and antistatic additives.
In the instance where both calcium metal salt and magnesium metal salt are present in the fuel oil, the mass to mass ratio based on active ingredient of calcium metal salt to magnesium metal salt is from 10:1 to 1:10, preferably from 5:1 to 1:5, more preferably from 2:1 to 1:2, such 1:1.
In the instance where each of the neutral calcium and magensium salts of the invention are used, it should be appreciated that interaction may take place between the neutral calcium and magnesium salts after they have been mixed in the fuel oil, in either the process of mixing or any subsequent condition to which the composition is exposed, including the use of the composition in its working environment. Interactions may also take place when further auxiliary additives are added to the compositions of the invention or with components of fuel oil. Such interaction may include interaction which alters the chemical constitution of the additive. Thus for example the compositions of the invention include compositions in which interaction between any of the additives has occurred, as well as compositions in which no interaction has occurred between the components mixed in the fuel oil.
An aspect of the present invention is a hydrocarbon middle distillate fuel composition free of transition metal compounds comprising middle distillate fuel oil and, in admixture therewith, at least one fuel-soluble or fuel-dispersible neutral calcium and/or magnesium salt as defined in the first aspect of the invention.
It has been found that neutral calcium and/or magnesium salt of the present invention are effective in fuel compositions free of transition metal compounds. In particular fuel oils which comprise at least one fuel-soluble neutral calcium salt are particularly well suited to reducing particulate matter emission. In one preferred aspect of the present invention, at least one of the neutral metal salts is a salt of sulphonic acid. Preferably the neutral metal salt is calcium sulphonate and preferably has a Total Base Number (TBN), as measured according to ASTM D2896, of at most 50, more preferably at most 30, such as at most 20.
An advantage of the present invention is that the use of expensive transition metal compounds in fuel oils can be avoided whilst achieving effective particulate matter reduction. The amount of metal used in fuel oils may also be reduced.
In a further aspect of the invention, the neutral salts have been found to give effective lubricity enhancement of a fuel oil. Concern about fuel oil lubricity is growing due to the step-wise introduction of legislation limiting fuel sulphur content, changes in fuel manufacturing processes necessary to meet these lower sulphur levels (as low as 0.05% sulphur by weight, per weight of fuel) leading to a decrease in inherent lubricity and an increased requirement for additives to boost lubricity levels, such that the fuel injection system (and particularly the fuel injection pump) remains effectively lubricated and not subject to excess wear.
Treatment with the neutral salts at levels of up to 1000 ppm or higher, such as 0.1 ppm to 1000 ppm (mass of additive per mass of the total fuel) have proved effective to improve fuel lubricity, as measured in tests such as the HFRR (High Frequency Reciprocating Rig) test.
Thus, the present invention also provides the use of the salt as defined in the second aspect of the invention, to improve the lubricity of fuel oil having a sulphur content of less than 0.2% mass, per mass of fuel (and preferably of less than 0.05% mass, per mass of fuel). The invention also provides a method for improving the lubricity of such fuel oil, comprising the addition thereto of the salt.