Compositions and methods of rendering cellulosic materials flame resistant, and articles of manufacture including the materials, are disclosed. The compositions include one or more crosslinking agents, and, optionally, one or more phosphorus-based compounds. Dimethyloldihydroxyethylene urea, imidazole, imidazolidinones, dialdehydes, and dichlorotriazines are preferred crosslinking agents. The methods involve applying the composition to the material, and covalently linking the crosslinking agent to the material. An advantage of covalently linking the crosslinking agent to the cellulosic material is the lack of any potential toxicity associated with uncrosslinked fire retardants on the cellulosic material and the stability of the bonds between the material and the crosslinking agent to conventional steam cleaning and other carpet cleaning methods. In a preferred embodiment, the fire-retardant cotton-fiber composition is used to prepare cotton carpets, upholstery or raised surface apparel.

The present application relates to methods for reducing the flammability of cellulosic substrates, including cotton fiber carpets and raised surface apparel.
Cotton, like most textile fibers, is combustible. Whenever cotton is in the presence of oxygen and the temperature is high enough to initiate combustion (360-420xc2x0 C.), untreated cotton will either burn (flaming combustion) or smolder (smolder combustion). The degree of flammability depends on the fabric construction. Fabrics have different flammability requirements depending on the particular end use. Cotton fabrics, without the use of special flame-retardant finishes, meet practically all of these requirements for most existing end-uses. However, some new cotton product developments require special constructions or finishes to reduce their flammability. This is especially true in certain countries, such as the United States, which have strict regulations governing the flammability of these products.
Resistance to burning is one of the most useful properties that can be imparted to cotton fibers and textiles. Some end uses for cotton in textiles for apparel, home furnishings, and industry, can depend on its ability to be treated with chemical agents (flame-retardants) that confer flame resistance (FR). End uses requiring flame-retardant finishes include protective clothing (e.g., foundry workers apparel and fire fighters uniforms), children""s sleepwear, furnishing/upholstery, bedding, carpets, curtains/drapes, and tents.
Chemical agents for reducing the flammability of products containing cotton fiber and other cellulosic fibers are well known and generally grouped into two categories: durable and non-durable. The durable type tend not to be removed in conventional washes and the non-durable type are typically removed in conventional washes.
The variable manufacturing cost of a typical durable flame-retardant treatment is about $1-2 per yard, depending on fabric weight and other factors. This can be a major limitation. The flammability and flame resistance of cotton has been studied extensively and several comprehensive reviews of the subject are available.
Cotton is not currently the raw material of choice in the carpet industry. The carpet fiber business in the U.S. is roughly a 7,000,000 bale/year market, and cotton is less than one percent of this overall market. One reason that cotton has been almost excluded from this large market for fibers is the difficulty in complying with the Flammable Fabrics Act. This regulation requires that all carpets which are six feet by four feet or larger and are sold for residential use pass a flammability test. This test is commonly referred to as the xe2x80x9cPill Testxe2x80x9d. It calls for igniting a methenamine pill, which is placed in the center of a nine-inch by nine-inch carpet specimen. The specimen fails if the flame spreads to within one inch of a metal template containing an eight-inch diameter hole, which is placed on top of the carpet specimen prior to igniting the pill. The specimen passes if the flame does not spread to within one inch of the metal template.
For a residential carpet to be saleable, at least seven out of eight specimens must pass the test. Furthermore, if the carpet has been treated with a flame-retardant (with the exception of alumina trihydrate added to the back coating), then the carpet must be washed ten times as described in AATCC 124-1967 prior to testing.
There are numerous man-made fiber carpets which are currently available, many of which do not require any special treatments to pass federal flammability requirements because of the nature of the test. Many synthetic carpet fibers will melt away from the burning pill during the pill test, such that the pill eventually self extinguishes. The fuel load provided by these carpets in a fire, which is already burning, is not considered by the test method.
Other synthetic fiber carpets, such as polypropylene, require a flame-retardant such as alumina trihydrate. Alumina trihydrate is often added to a backcoating (or backing), as opposed to application directly to the carpet fibers. Synthetic thermoplastic fibers such as polypropylene melt quickly when exposed to a flame, for example, during the pill test. The burning pill then quickly falls, due to gravity, onto the backing. The backing typically includes three layers: a thermoplastic (usually polypropylene) primary backing layer, a latex adhesive layer (which may contain the flame-retardant) and a secondary thermoplastic (usually polypropylene) backing layer. Since the primary backing is also a low melting point thermoplastic, it quickly melts and allows the burning pill to come into direct contact with the latex. Since the latex often includes a flame-retardant, it can then suppress the spread of flames.
Certain other fibers, such as wool and modacrylic, are inherently flame resistant. These can be made into carpets which require no special treatments to pass the required pill test.
Cotton carpets can also be made which require no special treatments to pass the pill test. For example, a cut pile carpet can be made from a 3/2 Ne yarn composed of 90 percent cotton and 10 percent low melt thermoplastic fiber. The low melt fiber is allowed to melt, typically prior to tufting of the carpet. A carpet which includes 12 stitches per inch, {fraction (1/11)}-inch gauge, and xc2xc inch pile height can be constructed from this yarn. Such a carpet is generally dense enough, with a sufficiently low pile height, that it will pass the pill test without any additional treatment.
A disadvantage of relying on such low pile height constructions when manufacturing cotton carpets is that it is very limiting from a design and marketing standpoint. The consumer in the U.S. today has become accustomed to a wide variety of choices when selecting a carpet. Substantially limiting the choices of carpet construction is not a practical option for a successful marketing program.
Another disadvantage of attempting to reduce the flammability of a cotton (or cellulosic) carpet by construction alone is that achieving reduced flammability often means increasing the area density (oz./square yard) of the carpet. As the area density of the carpet increases, the cost also generally increases. This approach is therefore very restrictive and would limit the market to the small, upper price end.
Alumina trihydrate, which is effective on certain thermoplastic fiber carpets, is not typically effective on cotton-containing carpets. On cotton-containing carpets, the cotton yarn which is under and in the vicinity of the burning pill will tend to char but maintain sufficient integrity to support, insulate and separate the burning pill from the carpet backing. There is not a sufficient heat flux reaching the alumina trihydrate contained in the latex backing for the alumina trihydrate to be effective at suppressing the flame.
The use of flame-retardant low melt fibers in place of the typical non-flame-retardant low melt fiber used in the yarn has been attempted. The low melt fiber, in general, offers the advantages of improved resilience and tuft definition and minimizes shedding of loose fibers from the tufts. Testing has shown that flame retardant low melt fiber used in the yarn is not effective. Although various explanations have been offered, the mechanism is not understood.
Since federal law in the U.S. requires that any carpet which has a flame-retardant treatment (other than alumina trihydrate) be laundered ten times prior to flammability testing, any such flame-retardant which is applied for that purpose must remain effective after the ten home launderings. Because home launderings are rather effective at removing materials which are not chemically bonded to the fibers, durable flame retardants are generally the most effective.
There have been many techniques for imparting durable flame resistance properties to cellulosic substrates described in the literature. However, there are relatively few that are practiced today, due to commercial availability of the chemicals, safety concerns, process control issues or other reasons. Durable flame retardants are typically more complex, more expensive and more difficult to apply than non-durable treatments. The main flame retardant finishes used on cotton are phosphorus-based.
Two of the more common phosphorus-based systems which are used to provide durable flame resistance to cotton substrates are the xe2x80x9cpre-condensatexe2x80x9d/ammonia process and the reactive phosphorus process.
In the xe2x80x9cpre-condensatexe2x80x9d/NH3 process, the flame-retardant agent exists as a polymer in the fibrils of cotton fibers and is not combined chemically with OH groups in the cotton fiber. This process imparts durable flame resistance to 100% cotton fabrics when applied under proper application procedures. It produces fabrics with a good hand and strength retention. Proper application of pre-condensates to cotton fabrics requires adequate fabric preparation, proper padding/uniform application, proper phosphorus add-on relative to fabric properties, appropriate moisture control prior to ammoniation, control of the ammoniation step to ensure adequate polymer formation, and effective oxidation and washing of the treated fabric.
This process is very useful for specialty applications that can command a very high price, such as protective clothing for fire fighters and other workers who may be exposed to fire or excessive heat. It is generally not practical for cotton carpets or raised surface apparel that will be sold to the average consumer. The problems associated with this process include the high cost, the special equipment needed (ammoniation chamber) which is not generally available, and the two drying steps which are required.
Reactive phosphorus-based flame retardants are compounds (e.g., N-methylol dimethyl phosphonopropionamide (MDPPA)) that react with cellulose, the main constituent of cotton fiber. These compounds can be used both for cotton and for cotton blends with a low synthetic fiber content. The finish, usually applied to the fabric after the coloring stage, promotes char formation. The durability of the finish makes the resulting treated fabric suitable for curtains, upholstery, bed linen and protective clothing.
The reactive phosphorus-based flame retardants are typically applied using a pad/dry/cure method, in the presence of phosphoric acid catalyst. The finish is sometimes applied with a methylated melamine resin to increase the bonding/fixation of the agent to cellulose, which enhances the flame retardancy. Afterwashing is generally required, often with an alkali such as soda ash, followed by further rinsing and drying. The afterwashing helps to reduce loss of fabric strength. The reactive phosphorus-based process has the advantage of not requiring specialized equipment such as an ammonia cure unit, and has less affect on dyes than the pre-condensate process. However, this process can cause more strength loss than the pre-condensate process. Further, there can be a durability problem associated with some wash treatments if the instructions of the chemical supplier are not followed.
Reactive phosphorus-based flame retardants can be unsuitable for certain end uses, such as cotton or cotton blend carpets. This is especially true when the products contain formaldehyde, because of concerns about the human health effects of exposure to certain volatile organic compounds (VOC""s) which may have been released from carpeting or carpet backing in past years. Because of this, most carpet manufacturers generally consider even very low levels of formaldehyde to be unacceptable. Another issue is that these products are generally designed to be afterwashed as part of the application procedure. While the toxicity of such materials is generally low, there are significant concerns about the exposure of babies or small children to residual unfixed chemicals left on the carpet.
A non-phosphorus approach for rendering cotton fire retardant has been to incorporate a water-insoluble, solid particulate mixture of brominated organic compounds and metal oxides, optionally with a metal hydrate, into the carpet fiber (U.S. Pat. No. 4,600,606 to Mischutin). However, a limitation of the chemistry is that the metal oxide compounds may be rendered soluble when washed if the pH of the solution is on the acid side. Also, particles of brominated organic compounds may be irritating to people coming into contact with them, and may be harmful if ingested.
Another non-phosphorus approach has been to prepare a solution of boric acid, ammonium sulfate, borax, hydrogen peroxide, and optionally a surfactant and/or an alkyl phthalate ester, and apply this as a coating on cellulosic materials. A major limitation of this chemistry is the water-solubility of the components, which results in the composition being substantially removed during conventional washing.
There is a need for fire retardants for cotton fiber, especially when the fiber is used in a cotton carpet or in raised surface apparel, that survives a certain number of washings, including steam cleanings. The present invention provides such materials.
Compositions and methods for providing cellulosic substrates with reduced flammability, and articles of manufacture prepared from the resulting fire-resistant cellulosic substrates, are disclosed.
The compositions include one or more crosslinking agents and optionally include one or more phosphorus-based compounds, such as phosphorus oligomers. The methods involve applying to a cellulosic substrate a composition including a crosslinking agent, optionally in the presence of a phosphorus-based compound, and covalently linking the hydroxy groups on the cellulosic substrate to one or more of the groups on the crosslinking agent.
Cotton is a preferred cellulosic substrate. Other cellulosic substrates include flax, jute, hemp, ramie, lyocell and regenerated unsubstituted wood celluloses such as rayon.
The crosslinking agents are reactive molecules which include two or more reactive groups, which are capable of reacting with the hydroxy groups on cotton, or with derivatives formed from the hydroxy groups on cotton, for example, mesylate, triflate, and tosylate leaving groups. Suitable groups on the crosslinking agent for reacting with hydroxy groups on a cellulosic substrate include typical leaving groups in nucleophilic displacement chemistry and similar displacement chemistries. Suitable groups on the crosslinking agent for reacting with derivatives of the hydroxy groups on a cellulosic substrate such as mesylates and triflates include typical nucleophiles in nucleophilic displacement chemistry and similar displacement chemistries. Examples of suitable crosslinking agents include dichlorotriazines, ureas, imidazolidinones, imidazoles, dialdehydes, urethanes, carbonates, orthocarbonates, chloroformate, dihalides such as 1,2-dichloroethane, diesters such as dimethylsuccinate, diacid halides such as succinyl chloride, and the like.
The phosphoric acids and other reactive phosphorus-containing functional groups on the phosphorus-based compounds and the hydroxy groups on the cellulosic substrate can be linked via the crosslinking agents.
The resulting cellulosic fiber is fire resistant. When the crosslinking agent is crosslinked with the cellulosic substrate, the linkages between the reactive groups on the crosslinking agent and the hydroxy groups on the cellulosic fiber are stable to most conventional washings, including the ten home launderings specified in 16 C.F.R. 1630 and 1631 for carpets which have been treated with a flame retardant.
The treated fiber can be present alone or as blends of cotton and other commercially available fibers, including polyester. The fibers can be used to prepare suitable articles of manufacture, including carpets, raised surface apparel, other garments, upholstery, and other articles which have acceptable fire resistance based on required tests for that particular use. In a preferred embodiment, the fiber is cotton and the article of manufacture is a cotton-based carpet or raised surface apparel. The treated cotton carpets can have an area density between about 20 oz/yd2 and 120 oz/yd2, preferably between about 30 oz/yd2 and 80 oz/yd2.
The compositions can optionally include additional components, such as other fire retardants, dyes, wrinkle resist agents, foaming agents, buffers, pH stabilizers, fixing agents, stain repellants such as fluorocarbons, stain blocking agents, soil repellants, wetting agents, softeners, water repellants, stain release agents, optical brighteners, emulsifiers, and surfactants.
In those embodiments in which phosphorus based compounds are used, the resulting cellulosic substrate can be fire retardant enough for use in end uses requiring flame-retardant finishes. Examples of such end uses include protective clothing (e.g., foundry workers apparel and fire fighters uniforms), children""s sleepwear, furnishing/upholstery, bedding, carpets, curtains/drapes, and tents.
Compositions and methods for providing cellulosic substrates with reduced flammability, and articles of manufacture prepared from the resulting fire-resistant cellulosic substrates, are disclosed.
The compositions include one or more crosslinking agents, and optionally include one or more phosphorus-based compounds. The methods involve applying to a cellulosic fiber a composition including crosslinking agents, and optionally including one or more phosphorus-based compounds, and allowing the compounds to react with the substrate for an effective amount of time. When the compounds are applied in an aqueous solution, the temperature can be raised to a temperature suitable for driving off the water, and the reaction allowed to occur in the substantial absence of aqueous solvent.
Depending on the density of the cellulosic substrate, the substrate alone, such as a cotton carpet or raised surface apparel, can be nearly fire resistant enough to meet the U.S. requirements for flammability. A small increase in fire resistance can be sufficient to meet the U.S. guidelines. Accordingly, the use of conventional fire retardants such as organophosphorus compounds, halogenated aromatics, and metal carbonates, which impart fire resistance but which each have inherent problems associated with their use, can be avoided. Alternatively, when used, for example, in protective clothing, phosphorus based compounds can be used, to impart a higher level of fire retardancy to the resulting cellulosic substrate.
The following definitions are used herein:
The term xe2x80x9cpill testxe2x80x9d as used herein is a test used to determine whether a carpet is sufficiently fire resistant for use in the home. It calls for igniting a methenamine pill, which is placed in the center of a nine-inch by nine-inch carpet specimen. If the flame spreads to within one inch of a metal template containing an eight-inch diameter hole, which is placed on top of the carpet specimen prior to igniting the pill, the specimen fails. If the flame does not spread to within one inch of the metal template, then the specimen passes. For a residential carpet, as described above, to be saleable, at least seven out of eight specimens must pass the test. Furthermore, if the carpet has been treated with a flame-retardant (with the exception of alumina trihydrate added to the back coating), then the carpet must be washed ten times as described in AATCC 124-1967 prior to testing.
The term xe2x80x9c45 degree angle testxe2x80x9d as used herein refers to the flammability test for wearing apparel outlined in the Code of Federal Regulations Title 16, Part 1610. This test method determines the flammability of fabrics with raised surface fibers such as fleece. It calls for placing the specimen to be tested at a 45 degree angle and igniting it by exposing the surface to an open flame for one second. The flame must be one inch from the tip of the flame to the gas nozzle. The rate and intensity of the spread of the flame will categorize the flammability of the fabric.
The term xe2x80x9cacceptable handxe2x80x9d as used herein refers to the feel of the resulting substrate after it has been treated with the fire retardant composition.
The term xe2x80x9ccellulosic substratexe2x80x9d as used herein refers to substrates that include cellulosic fibers, such as cotton, jute, flax, hemp, ramie, lyocell, regenerated unsubstituted wood celluloses such as rayon, blends thereof, and blends with other fibrous materials in which at least about 25 percent, preferably at least about 40 percent of the fibers are cellulosic materials. The term xe2x80x9cfiberxe2x80x9d relates to fibers present in a substrate such as a carpet, raised surface apparel, upholstery, woven, knit, and nonwoven fabrics, and the like.
The term xe2x80x9cflame retardantxe2x80x9d as used herein refers to the chemical applied to the cellulosic substrate. The term xe2x80x9cflame resistantxe2x80x9d refers to the treated cellulosic substrate. The terms xe2x80x9cflame resistantxe2x80x9d and xe2x80x9creduced flammabilityxe2x80x9d as applied to substrates are not intended to imply that the materials are fireproof, or that they will not burn.
The term xe2x80x9ceffective fire retardant amountxe2x80x9drefers to an effective amount such that the treated substrate passes the required flammability test for that particular substrate.
The term xe2x80x9cdegree of substitutionxe2x80x9d refers to the number of hydroxy groups in the cellulosic substrate which are esterified, on average, per glucose moiety. For example, fire resistance can be obtained by esterifying a relatively low number of hydroxy groups on average on the cellulosic substrate. In one embodiment, the degree of substitution on the cellulosic substrate is between about 0.003 to 0.5. In another embodiment, the degree of substitution on the cellulosic substrate is between about 0.005 to 0.025.
The term xe2x80x9ccatalystxe2x80x9d is typically understood to mean a compound that facilitates a chemical reaction but which is regenerated, allowing further chemical reactions to take place. As used herein, the term xe2x80x9ccatalystxe2x80x9d also includes compounds which facilitate the coupling of carboxylic acid groups to hydroxy groups on a cellulosic substrate, even if the catalyst also eventually reacts with the substrate in some manner.
1. The Fire Retardant Composition
The fire-retardant composition includes a crosslinking agent, as well as various other optional components, along with a suitable solvent. The crosslinking agent is covalently linked to the cellulosic material.
A. Crosslinking Agents
As used herein, crosslinking agents are defined as any compound with two or more reactive groups which are capable of reacting with the hydroxy groups on cellulosic materials, or reacting with tosylate, mesylate, triflate or other leaving groups prepared from the hydroxy groups on cellulosic materials.
Reactive functional groups which participate in nucleophilic substitution reactions are typically nucleophiles, i.e., amine, hydroxy, and thiol groups, or leaving groups, i.e., chlorides, tosylates, mesylates, and the like. Using nucleophilic substitution chemistry, one typically cannot directly link two nucleophiles or two leaving groups. However, it is possible to link nucleophilic groups on two molecules by reacting them with a single molecule which has two leaving groups, or a functional group capable of reacting with both nucleophiles. This type of molecule is an example of a crosslinking agent. Crosslinking agents are well known to those of skill in the art.
Crosslinking agents can be used to covalently crosslink the hydroxy groups on the cellulosic material. Preferably, a sufficient quantity of crosslinking agents is present to covalently crosslink at least a sufficient amount of hydroxy groups on the cellulosic material to render it fire resistant enough for the intended use. For cotton carpets, a sufficient amount of crosslinking is typically between 0.12 and 2.0 percent of the hydroxy groups on the cotton.
Some crosslinking agents include one functional group which is capable of reacting with two or more nucleophilic groups under appropriate conditions. Examples of these include ureas, carbonates, orthocarbonates, chloroformates, urethanes, phosgene, diphosgene, triphosgene, thiophosgene, and the like, where the compound has two or more of these functional groups. Of these, ureas and other water-soluble crosslinking agents are preferred due to their relative ease of use and the avoidance of using organic solvents.
Preferred crosslinking agents are water-soluble, and react with the cellulosic substrate under relatively mild conditions (i.e., temperatures less than about 200xc2x0 C. (although with certain substrates, such as fleece, temperatures higher than 200xc2x0 C. are acceptable), pH between about 2 and 12, and do not contain appreciable amounts of formaldehyde or other materials known to be toxic to humans or animals on exposure. Preferred water-soluble crosslinking agents include ureas such as dimethyloldihydroxyethylene urea, imidazoles, imidazolidinones, dialdehydes, and dichlorotriazines.
Dichlorotriazinyl compounds are well known to those of skill in the art, and have been used for years as dyes for cellulosic substrates. Many of these compounds include carboxylic acid or sulfonic acid groups so that the compound is relatively water soluble at a certain pH range. An example of a suitable dichlorotriazinyl compounds is N,Nxe2x80x2-bis(dichloro-s-triazinyl)-4,4xe2x80x2-diaminostilbene-2,2xe2x80x2-disodiosulphonate (T-DAS), which is well known to bond to cotton and also to amino, thiol and hydroxyl groups (see, for example, Lewis and Lao, xe2x80x9cThe use of a crosslinking agent to achieve covalent fixation of hydroxyethylsulphone dyes on cottonxe2x80x9d, AATCC 1998 International Conference and Exhibition, Philadelphia Marriott, Philadelphia, Pa., pages 375-383, (Sep. 22-25, 1998), the contents of which are hereby incorporated by reference).
Dialdehydes are also well known to those of skill in the art, and have been used for years to crosslink various compounds to proteins and peptides. Examples include C2-6 dialdehydes, such as oxalaldehyde (Glyoxal), succindialdehyde and glutaraldehyde. They are typically sold as aqueous solutions, which are at least partially hydrated. Hydroxy groups are known to react with these compounds to form acetals and hemi-acetals. Amides, ureas and urethanes also react with dialdehydes to form various condensation products. Amines typically react with dialdehydes to form Schiff bases, which, if relatively unhindered, further react to form more complicated, uncharacterized products. The reaction with amide groups described above tends to proceed faster in alkaline media than in acidic media.
Imidazolidinones are commonly used in the textile industry. One example is dimethyloldihydroxy ethylene urea (DMDHEU). DMDHEU is commercially prepared from glyoxal, urea and formaldehyde, and often contains residual formaldehyde. The presence of residual formaldehyde is not advantageous when contact of the treated cellulosic materials with animals or humans is anticipated.
There are several commercially available imidazole derivatives commonly used as crosslinking agents in the textile industry. These include the Fixapret(trademark) family of crosslinking agents sold by BASF, including Fixapret NF(trademark), Which is commonly used with a catalyst system that include s a proprieta ry mixture of inorganic salts (Catalyst NB-202 from BASF). Examples of suitable water-soluble crosslinking agents include Fixapret(copyright) NF (BASF) and Freerez(copyright) NFR (Freedom Textile Chemicals, Co., Charlotte, N.C.).
B. Phosphorus-Based Compounds
The crosslinking agents which crosslink the cellulosic substrate can also crosslink the substrate with phosphorus-based compounds. As used herein, xe2x80x9cphosphorus-based compoundsxe2x80x9d are compounds which include a phosphorus atom and which are capable of being covalently linked to a crosslinking agent and/or a cellulosic substrate. Numerous phosphorus-based compounds are known for their fire retardant properties. Any phosphorus-based compound which is capable of being crosslinked with a cellulosic substrate via a crosslinkin agent as defined herein can be used.
Preferably, the phosphorus-based compounds include one or more reactive groups which can react with the crosslinking agent. Examples of suitable groups include halogen, hydroxy, carboxylic acid, aldehyde and amide groups. Suitable phosphorus-based acids include phosphorus acid, hypophosphorus acid, and polyphosphoric acid, and also include alkali metal mono and dihydrogen phosphates and hypophosphites. Examples of other suitable phosphorus-based compounds include (di) phosphonium halide, dialkyl 1-amino-1-deoxyglucityl phosphonates, phosphorus amides, amino polyhydroxyalkyl phosphonic acid, phosphonitrile chloride, phosphorimidic chloride, tris(haloalkyl) phosphates, haloalkyl phosphates, dihydroxyalkyl phosphite, dialkylphosphonoalkane amide, bis(haloalkyl) haloalkyl phosphonate, (mercapto)phosphonitrilate, N-hydroxyalkyl phosphonic esters, bis-(hydroxyalkyl)-phosphinic acid, tetrakis (xcex1-hydroxyalkyl) phosphonium halide, aryl haloalkyl phosphonate, hydroxyalkyl phosphonium salts, tris(polyhaloaryl) phosphate, halogenated phosphorthioates, phosphorus polyamides, phosphonitrilic halides, bis-(hydroxypolyalkoxyalkyl aminoethyl) phosphonates, where polyalkoxy is haloalkyl substituted, amino epoxy phosphonates and n-substituted derivative including polyphosphonates, N-hydroxymethyl-3-phosphonopropionamide, haloakyl or hydroxyalkyl-allyl-phosphonium halide, haloalkylphosphine oxide haloalkylphosphinic acids, tetrahydroxydiphosphorinane dioxide, tris(2-chloroethyl phosphate), tris(1-chloro-2-propyl) phosphate, tris (1,3-dichloro-2-propyl) phosphate, 2-bromoethyl-2-chloroethyl 3-bromopentyl phosphate, tetrakis (2-choroethyl)ethylene diphosphate, bis(2-chloroethyl) 2-chloroethyl phosphonate, oligomeric phosphonate-phosphate, oligomeric chlorethyl ethylene phosphate tris(3-hydroxypropyl) phosphine oxide, isobutylbis(3-hydroxypropyl) phosphine oxide, and bis(2-chloroethyl) vinyl phosphonate.
In a preferred embodiment, the phosphorus based compound is fixed onto the cellulosic substrate by reaction with maleic acid or another dicarboxylic or polycarboxylic acid and sodium phosphate, sodium hypophosphite.
As used herein, the term xe2x80x9calkylxe2x80x9d refers to monovalent straight, branched or cyclic alkyl groups preferably having from 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms (xe2x80x9clower alkylxe2x80x9d) and most preferably 1 to 6 carbon atoms. This term is exemplified by groups such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, n-hexyl, and the like In those cases where the minimum number of carbons are greater than one, e.g., alkenyl (minimum of two carbons) and cycloalkyl, (minimum of three carbons), it is to be understood that xe2x80x9clowerxe2x80x9d means at least the minimum number of carbons.
As used herein, the term xe2x80x9carylxe2x80x9d refers to an unsaturated aromatic carbocyclic group of from 6 to 14 carbon atoms having a single ring (e.g., phenyl) or multiple condensed (fused) rings (e.g., naphthyl or anthryl). Preferred aryls include phenyl, naphthyl and the like. Unless otherwise constrained by the definition for the aryl substituent, such aryl groups can optionally be substituted with from 1 to 5 substituents and preferably 1 to 3 substituents selected from the group consisting of hydroxy, acyl, alkyl, alkoxy, alkenyl, alkynyl, substituted alkyl, substituted alkoxy, substituted alkenyl, substituted alkynyl, amino, substituted amino, aminoacyl, acyloxy, acylamino, alkaryl, aryl, aryloxy, azido, carboxyl, carboxylalkyl, cyano, halo, nitro, heteroaryl, heteroaryloxy, heterocyclic, heterocyclooxy, aminoacyloxy, oxyacylamino, thioalkoxy, substituted thioalkoxy, thioaryloxy, thioheteroaryloxy, and trihalomethyl. Preferred substituents include alkyl, alkoxy, halo, cyano, nitro, and trihalomethyl.
As used herein, the terms xe2x80x9chaloxe2x80x9d or xe2x80x9chalogenxe2x80x9d refer to fluoro, chloro, bromo and iodo and preferably is either bromo or chloro. The terms haloalkyl and haloaryl refer to alkyl and aryl groups substituted with between 1 and 5, preferably between 1 and 3 halogen groups.
The phosphorus-based compounds are preferably linked to the crosslinking agent, which is in turn crosslinked with the cellulosic substrate. Means for linking the phosphorus-based compounds and crosslinking agents described herein are well known to those of skill in the art.
In one embodiment, the phosphorus-based compounds are coupled via a crosslinking agent to a cellulosic substrate by forming phosphate ester linkages with the phosphoric acid groups on the phosphorus-based compounds and a first reactive group on the crosslinking agent, and a second reactive group on the crosslinking agent is then reacted with the cellulosic substrate.
In those embodiments in which phosphorus based compounds are used, the resulting cellulosic substrate can be fire retardant enough for use in end uses requiring flame-retardant finishes. Examples of such end uses include protective clothing (e.g., foundry workers apparel and fire fighters uniforms), children""s sleepwear, funishing/upholstery, bedding, carpets, curtains/drapes, and tents.
For all of these fabric end uses, the chemicals can be applied, for example, by padding at 50-150 percent wet pickup, preferably between 70 and 100 percent wet pickup. However, other application techniques can also be used.
C. Suitable Solvents
Preferably, the crosslinking agents, along with any phosphorus-based compounds, are present in an aqueous solution, suspension or dispersion. However, other volatile solvents which are inert to the coupling chemistry and in which these materials are soluble or uniformly dispersible can be used.
D. Optional Components
Additional components can optionally be added to the fire-retardant composition. These include, but are not limited to, other fire retardants, dyes, wrinkle resist agents, foaming agents, buffers, pH stabilizers, fixing agents, stain repellants such as fluorocarbons, stain blocking agents, soil repellants, wetting agents, softeners, water repellants, stain release agents, optical brighteners, emulsifiers, and surfactants.
In one embodiment, the cellulosic substrate is a carpet. When other fire retardants are used in carpets, they can be present in the carpet fiber or the backing material. If a fire retardant is present in the backing layer, the fire retardant is preferably a material that activates at a temperature lower than alumina trihydrate. Preferably, no formaldehyde or other volatile organic compounds are released from the backing layer. Further, the fire retardants are preferably compatible with any latex formulation used in the carpet backing.
Suitable additional fire retardants include, but are not limited to, metal oxides, metal carbonates, halocarbons, phosphorus esters, phosphorus amines, phosphate salts, other phosphorus containing compounds, aluminum trihydrate, and nitrogen-containing compounds.
II. Cellulosic Substrates
Any cellulosic substrate which includes hydroxy groups can be treated with the above-compositions. Cotton is a preferred cellulosic fiber. Other cellulosic fibers include flax, jute, hemp, lyocell, ramie and regenerated unsubstituted wood celluloses such as rayon. The material can be a blend of fibers, such as a blend of cotton and a polyolefin such as polypropylene, a polyester or polytrimethyl terephthalate (PTT). The fiber composition is preferably at least 25, and, more preferably, at least 40 percent by weight cotton.
Any area density of carpet, raised surface apparel, or other woven, knit or nonwoven fabrics, can be constructed and used which is practical from a manufacturing standpoint. For carpet, an area density between 20 and 120 oz/yd2, preferably between 30 and 80 oz/yd2, is suitable.
III. Methods of Treating the Cellulosic Substrate
Methods for covalently linking a hydroxy group such as those on a cellulosic substrate and a reactive groups present on a crosslinking agent are well known to those of skill in the art. Preferably, the crosslinking agents do not contain formaldehyde or other toxic substances. Preferred methods are those which can be performed in aqueous solvents.
When the composition is applied to the cellulosic substrate by spray, foam or other low wet pickup methods commonly used for treating carpets with fluorochemicals, the percent by weight of the fire retardant solution which is applied to the cellulosic substrate is typically between about 5 and 100 percent by weight, preferably between about 10 and 50 percent by weight, and more preferably, between about 15 and 30 percent by weight of the fiber to be treated. The use of these methods and types of solutions helps to avoid adding excess water which will have to removed during drying.
The above ranges vary depending on the mode of application and the cellulosic substrate to be treated. For example, for raised surface apparel, larger amounts of the fire retardant solution may be required to achieve adequate fire resistance. The same general principal, of adjusting the solution concentration based on the total wet add-on, applies to other substrates as well, such as fiber fill, upholstery, children""s sleepwear, bedding, batting, protecting clothing and drapes.
After the composition is applied and excess water is removed, the material is heated at a sufficient temperature and for a sufficient time to drive off the solvent and/or react the crosslinking agent with the groups on the cellulosic substrate, and optionally with the phosphorus-based compound.
The composition can also be applied by other application techniques, including by exhaust application. In an exhaust application the liquor ratio may vary over a broad range of about 2 to 1 up to about 50 to 1. More preferably about 3 to 1 to about 20 to 1, meaning about 20 pounds of treating solution per pound of cellulosic containing substrate. In one preferred embodiment the liquor ratio is about 10 to 1 and the concentration of the crosslinking agent is adjusted accordingly down to a concentration ranging from 0.001 percent to about 5.0 percent and preferably from about 0.01 to 1.0 percent on the weight of the treating liquor which is equivalent to 0.1 percent to 10.0 percent on the weight of the cellulosic substrate. Wet crosslinking agents, which can also be applied by exhaust techniques from the same bath, can be applied with phosphorus-based compounds to provide covalent linkages which result in treatments which are durable to various cleaning techniques. One such wet crosslinking agent is known as T-DAS, a dichlorotriazine crosslinking agent.
As with the spray and foam application described above, the crosslinking reaction can occur in the dry state after the excess water has been removed or in the wet state, before the excess water is removed.
The material can then optionally be rinsed to remove residual, unreacted chemicals, and then dried. However, since the crosslinking agents used typically do not provide the carpet with odor or toxicity, subsequent rinsing may not be desired. Further, any unreacted functional groups on the crosslinking agents may be used to attach other types of molecules, for example, via the formation of ester or amide linkages. Examples of such molecules include fluoroalkyl compounds commonly used to impart stain-resist properties to carpets and other textile goods.
For protective clothing (e.g., foundry workers apparel and fire fighters uniforms), children""s sleepwear, furnishing/upholstery, bedding, carpets, curtains/drapes, and tents there are a variety of application techniques which can be used to apply the fire retardant solutions. These include immersion, dipping, dripping, cascading, liquor circulation throughout the substrate, padding, kiss rolls, and doctor blades. These techniques may be used alone or in conjunction with vacuum, squeeze rolls, centrifuge, air knives, gravity drainage or other techniques. The application can be done via a continuous or batch method.
The application(s) of the crosslinking agent(s) may be done to the fiber, yarn, fabric or carpet, either before, after, or in conjunction with other manufacturing or processing steps, such as dyeing, winding, finishing, cabling, heat setting, tufting or weaving.
For raised surface apparel, or any other apparel that may benefit from a reduction in flammability, the application may be done by any of the above mentioned techniques in fiber, yarn, fabric or garment form. Spraying, foaming, dipping or the xe2x80x9cMetered Addition Processxe2x80x9d are particularly suitable for garment application. The total amount of solution added to the substrate and the required concentration of crosslinking agent(s) in the solution will be dependent on many factors including the flammability test method, the weight and construction of the substrate, and blend levels of the many possible fibers in a blend.
The concentration of crosslinking agent(s) required to be effective, based on both the weight of the solution and on the weight of the substrate, will be dependent on the factors mentioned above for all substrates including raised surface apparel, carpets, upholstery, and any other substrate where it is desirable to reduce the flammability. Any of the application techniques which are mentioned above, or which are used to apply other chemical treatments to fibrous substrates, are considered suitable to be used herein for any cellulosic substrate where it is desired to reduce the flammability.
Where liquor ratios of the treating bath or solution are greater than 1:1 (i.e. greater than one pound of treating solution per pound of substrate), pre-treatment techniques, such as cationic pre-treatments can be used to encourage the treatment chemicals, for example, the crosslinking agents and/or phosphorus based compounds, to exhaust or move out of the solution and onto the cellulosic substrate.
Although the temperature required to effectively form the linkages would be expected to vary somewhat depending on the nature of the substrate to be treated and the crosslinking agent(s), a typical range of temperatures is between about 20 and 240xc2x0 C., more preferably between 40 and 200xc2x0 C. The temperature is preferably less than would otherwise be required to scorch or melt thermoplastic components of the substrate. Excessive heating can cause yellowing of the substrate fibers, so care should be taken to control the reaction temperatures. Crosslinking agents which will react with the cellulosic material, and, optionally, the phosphorus-based compound, in the wet state can be used to achieve fixation or reaction in the dyeing equipment used to dye cellulosic substrates.
Suitable reaction times are typically between approximately one minute and five hours. However, the reaction times relate in part to the pH of the fire retardant solution. At a pH less than 11 for hydroxy, thiol and amine groups, or greater than 4 for carboxylic acids, cure times are generally longer. However, there appears to be less of a change in the dye shade of dyed goods when a pH greater than 4 is used.
Carpets typically have a polypropylene backing layer, which tends to melt at temperatures above 300xc2x0 F. For this reason, it is preferable that this temperature not be exceeded when this type of carpet is treated. However, raised surface apparel, upholstery, drapes, bedding, protective clothing, batting, fabrics, fiber fill, and carpets with non-thermoplastic backings may not have this type of temperature limitation. When these types of substrates are treated, the reaction temperature may be elevated as required, consistent with the scorching and/or yellowing temperature of these materials. One of skill in the art can readily determine an appropriate set of temperatures for a particular substrate to be treated.
Those of skill in the art can readily determine an appropriate set of reaction conditions (amount of fire retardant solution to add and suitable temperatures and reaction times) to couple the crosslinking agent(s) to the cellulosic substrate.
IV. Methods of Evaluating the Fire Retardant Cellulosic Compositions
The suitability of the fire retardant composition for an intended use will depend on the ability of the treated cellulosic substrate to pass various standard flammability tests. The currently accepted test for carpets is the pill test. The currently accepted test for raised surface apparel is the 45 degree angle test. Other substrates or end uses such as protective clothing or children""s sleepwear may require a vertical flammability test or other flammability tests.
The testing protocol for these tests is well known to those of skill in the art. Using these tests, with a suitably prepared reduced flammability cellulosic fiber composition, one can readily determine the efficacy of the fire retardant composition for its intended use.
V. Articles of Manufacture Prepared from the Composition
The treated fiber compositions can be used for several purposes, including articles of clothing such as protective clothing (e.g., foundry workers apparel and fire fighters uniforms), raised surface apparel and children""s sleepwear, furnishing/upholstery, bedding, carpets, curtains/drapes, and tents. Cotton carpets and raised surface apparel are preferred articles of manufacture when the crosslinking agent alone, in the absence of a phosphorus based compound, is used. When used in carpets, the fiber preferably has an area density of between 20 oz/yd2 and 120 oz/yd2, more preferably between 30 oz/yd2 and 80 oz/yd2.

Methods for reducing the flammability of cellulosic substrates


The present invention provides compositions and methods for treating cancer in a subject by eliciting an immune response against an MIC alpha 3-domain polypeptide.

Recent advances in the field of cancer immunotherapy have demonstrated the ability of our immune system to eradicate even advanced cancers. These therapies are rapidly changing the face of cancer treatment. Unlike monoclonal antibody therapies which require repeated administration of antibodies to prevent tumor relapse, vaccines can induce endogenous immunological memory and thus have the potential to provide long-term protection.
The selection of antigens for vaccine therapy requires a comprehensive understanding of the biological role of the candidate antigens in tumor growth and their expression levels by tumor cells compared to normal tissues. MICA and the closely related MICB protein (abbreviated as MIC) are antigens that are absent or expressed at very low levels by normal cells, but are broadly upregulated by a variety of different cancers secondary to genomic damage. MIC is an important ligand for the NKG2D receptor on cytotoxic lymphocytes, specifically NK cells, CD8 T cells and gamma-delta T cells. Expression of MIC targets such cells for elimination by the immune system. However, many tumors are found to escape this important immune surveillance pathway by shedding MIC from the cell surface, a process in which the MIC alpha3 domain is unfolded by the disulfide isomerase ERp5 rendering it sensitive to cleavage by matrix metalloproteases such as ADAM 10 and ADAM 17. Shed MIC causes downregulation of the NKG2D receptor on NK cells and CD8 T cells. Proteolytic cleavage thus turns an immune-stimulatory protein into an immunosuppressive sub stance.
Thus a need exists for compounds to inhibit MICA shedding.

Vaccination with MICA/B alpha 3 domain for the treatment of cancer


A sump protector is a multi-tiered structure placed over a discharge sump at the bottom of a storage bin to enhance the flow of materials to the discharge sump while reducing discharge sump blockage. An upper segment includes a bracket for breaking apart clumped materials in the storage bin encountered by materials falling or flowing onto the sump protector from above. A lower segment situated below the upper segment is preferably securable to the floor of a storage bin. The sump protector includes several apertures that can limit the size of materials able to enter the sump protector (and reach the discharge sump). Even if some of the apertures become clogged, other apertures are available to allow materials to continue to flow to the discharge sump. A bottom panel of the lower segment may lack apertures so as to limit the forces exerted on a discharge sump control gate.

A discharge sump is a collection point for materials stored in a storage bin (such as grain stored in a grain bin). Materials are typically loaded into a storage bin from above, and unloaded through the discharge sump from below. A discharge sump typically includes a control gate for controlling the flow of materials so that the discharge sump is not overloaded.
Because granular materials in the storage bin can clump together (due to, for example, moisture accumulation or changes in temperature), the discharge sump can become blocked. If the discharge sump is fully or partly blocked, materials either cannot be unloaded from the storage bin or the unloading process requires more time because the flow of materials out of the bin slows. What is needed is a device that is able to resist sump blockage and maintain a steadier flow of materials out of the storage bin even if the stored materials clump together.
A sweep auger is a device used to draw (by "sweeping") materials in the storage bin to a centrally-located discharge sump so that the materials can be unloaded from the storage bin. The sweep auger is typically activated when the stored material no longer flows due to gravity but instead remains on the floor of the storage bin. What is needed is a device that is able to reduce sump blockage and is also capable of accommodating a sweep auger so that the sweep auger can remain mounted in the storage bin when the device is installed over the discharge sump.

Protector for a discharge sump of a storage bin


The present invention is directed to support members having surfaces that are rendered hydrophilic for use as a substrate for the immobilization of bioactive species thereon. The hydrophilic surfaces are chemically stable on the support member. The surfaces are also chemically variable to provide a variety of chemically functional groups for immobilization of bioactive species thereto. The surfaces comprise polymeric surfactants attached onto the surfaces of a support member and covalently cross-linked thereon to form a first layer. Hydrophilic polymers are then attached to the first layer on the support member to form a second layer thereon. The second layer is used to enhance the hydrophilicity of a support member, as well as, to provide a substrate for immobilizing bioactive species thereto. Methods for forming the first and second layers are also provided. In addition, methods for attaching bioactive substances to the hydrophilic polymers are provided.

In the fields of biotechnology, biomedicine, and bioremediation, for example, bioactive species are often immobilized onto a support member to more effectively utilize the bioactive species. The term "immobilize," and its derivatives, as used herein refers to the attachment of a bioactive species directly to a support member or to a support member through at least one intermediate component. As used herein, the term "attach" and its derivatives refer to adsorption, such as, physisorption or chemisorption, ligand/receptor interaction, covalent bonding, hydrogen bonding, or ionic bonding of a polymeric substance or a bioactive species to a support member. Bioactive species include enzymes, organic catalysts, ribozymes, organometallics, proteins, glycoproteins, peptides, polyamino acids, antibodies, nucleic acids, steroidal molecules, antibiotics, antimycotics, cytokines, carbohydrates, oleophobics, lipids, pharmaceuticals, and therapeutics, for example. Cells, such as, mammalian cells, reptilian cells, amphibian cells, avian cells, insect cells, planktonic cells, cells from non-mammalian marine vertebrates and invertebrates, plant cells, microbial cells, protists, genetically engineered cells, and organelles, such as mitochondria, are also bioactive species. In addition, non-cellular biological entities, such as viruses, virenos, and prions are considered bioactive species.
There are various materials suitable for use as a support member for immobilizing bioactive species. Examples of these materials include hydrocarbon polymers, fluorocarbon polymers, ceramics, and metals. Of these materials, polytetrafluoroethylene and porous polytetrafluoroethylene, are of particular interest as support members. Polytetrafluoroethylene (PTFE) is a hydrophobic fluorocarbon polymer well known to have exceptional resistance to solvent and chemical attack. Porous polytetrafluoroethylene can be made in a variety of ways. For example, coextrusion of a polytetrafluoroethylene extrudate with a readily vaporizable material, such as naptha, forms a material from which the readily vaporizable material is ultimately removed to render the material porous (See U.S. Pat. No. 3,281,511, which is incorporated herein by reference). Expanded polytetrafluoroethylene (ePTFE) or stretched polytetrafluoroethylene are porous fluorocarbon polymer materials characterized primarily by a multiplicity of interconnecting voids defined by nodes and fibrils of polytetrafluorethylene material. Expanded PTFE materials, including ePTFE membranes and films described hereinbelow, may be made according to the teachings of U.S. Pat. Nos. 3,953,566, 3,962,153, 4,096,227, 4,187,390, and 4,902,423, each of which is incorporated herein by reference. In general, porous PTFE materials are chemically stable and very biocompatible. The materials have easily controlled pore sizes with large surface area/volume ratios, good mechanical strength, and good resistance to fouling, among other properties. Accordingly, these materials are attractive as support members for the immobilization of bioactive species.
Several methods for immobilizing bioactive species onto fluorocarbon polymers, such as PTFE, porous PTFE, or hydrocarbon polymeric materials have been taught in the literature. These methods include, for example, chemical modifications of the polymeric material to form chemically reactive groups thereon for covalent bonding of a bioactive species to the material, adsorption of a bioactive species to the polymeric material, and modifying the polymeric material and/or a bioactive species with compatibilizers, surfactants, or wetting agents to alter their surface energies. As described below, there are difficulties with each of these methods.
Due to the extreme chemical inertness of the backbone of fluorocarbon polymers and many hydrocarbon polymers, only highly energetic classes of reactions can successfully alter the backbone of these materials to produce chemically reactive organic moieties thereon. When chemically reactive organic moieties are formed along the backbone of a fluorocarbon or hydrocarbon polymer, bioactive species can be attached to the moieties. For example, enzymes have been chemically attached onto ammonia plasma-treated fluoropolymer surfaces using ammonia plasma and glutaraldehyde (See M. Kawakami, H. Koya, and S. Gondo, "Immobilization of glucose oxidase on polymer membranes treated by low-temperature plasma," Biotech. Bioeng., 32: 369, (1988)), or aminosilane and glutaraldehyde (J. M. Taylor, M. Cheryan, T. Richardson, and N. F. Olson, "Pepsin immobilized on inorganic supports for the continuous coagulation of skim milk," Biotech. Bioeng., 19: 683 (1977), for example). Representative examples of these highly energetic reactions include, thermal decomposition (U.S. Pat. No. 5,296,510, issued to Shigeru et al.), irradiation with electrons, gamma rays, radio waves, microwaves (T. Kasemura, S. Ozawa, K. Hattori, "Surface Modification of Fluorinated Polymers by Microwave Plasmas," J. Adhesion, 33: 33 (1990); Commonwealth Scientific and Industrial Research Organisation in PCT/AU89/00220; Y. Ito, Y. Iguchi, T. Kashiwagi, Y. Imanisihi, "Synthesis and nonthrombogenicity of polyetherurethaneurea film grafted with poly(sodium vinyl sulfonate)," J. Biomed. Mater. Res., 25: 1347 (1991); and Y. Ito, M. Kajihara, Y. Imanishi, "Materials for enhancing cell adhesion by immobilization of cell adhesive peptide," J. Biomed. Mater. Res., 25: 1325 (1991)), or UV light (K. Allmer, A. E. Feiring, "Photochemical Modification of a Fluoropolymer Surface," Macromolecules, 24: 5487 (1991); A. B. Pointer, W. R. Jones Jr., R. H. Janse, "Surface energy changes produced by ultraviolet-ozone irradiation of poly(methyl methacrylate), polycarbonate, and polytetrafluoroethylene," Polym. Eng. Sci., 34: 1233 (1994)), glow discharge irradiation (R. Sipehia, G. Martucci, M. Barbarosie, C. Wu, "Enhanced Attachment of and Growth of Human Endothelial Cells Derived from Umbilical Veins on Ammonia Plasma Modified Surfaces of PTFE and ePTFE Synthetic Vascular Graft Biomaterials," Biomat. Art. Cells Immob. Biotech., 21:455 (1993)), and redox reactions with strong nucleophiles such as sodium or potassium aryloxides (C. A. Costello, T. J. McCarthy, "Surface-selective Introduction of Specific Functionalities onto Poly(tetrafluoroethylene)," Macromolecules, 20: 2819 (1987); A. J. Dias, T. J. McCarthy, "Introduction of carboxylic acid, aldehyde, and alcohol functional groups onto the surface of poly(chlorotrifluoroethylene)," Macromolecules, 20: 2068 (1987); G. E. Sweet, J. P. Bell, "Selective chemical etching of poly(ethylene terephthalate) using primary amines," J. Polym. Sci. Phys. Ed., 16: 1935 (1978); and H. B. Lin, S. L. Cooper, "Polyurethane copolymers containing covalently attached RGD-peptide," Mat. Res. Soc. Symp. Proc., 252: 185 (1992)), or ozone (R. L. Daubendiek, J. G. Calvert, "The Reaction of Ozone with Perfluorinated Polyolefins," Environ. Lett., 6: 253 (1974)).
These high-energy modifications can be highly destructive to polymeric materials, however. With PTFE and porous PTFE, for example, high-energy modifications of the fluorocarbon backbone often leads to uncontrolled surface erosion of the material, depolymerization of the perfluorocarbon backbone (A. B. Pointer, W. R. Jones Jr., R. H. Jansen, "Surface Energy Changes Produced by Ultraviolet-ozone Irradiation of Poly(methyl methacrylate), Polycarbonate, and Polytetrafluoroethylene," Polym. Eng. Sci., 34: 1233 (1994)), reduction in the strength of the polymer substrate (S. Kanazawa, T. Takiguchi, A. Nishimora, T. Morita, and A. Uno, "Development of a Hydrophilic PTFE porous membrane filter," Sumitomo Denki; 147:99 (Sept., 1995), and loss of defined fibrillar structure of porous expanded PTFE (U.S. Pat. No. 5,462,781, issued to Zukowski).
Furthermore, high energy modifications to hydrocarbon polymers and fluorocarbon polymers, such as PTFE or porous PTFE, often produce reactive compositions on the hydrocarbon or fluorocarbon backbone that have an undeterminable surface density, chemical identity, and chemical stability (X. Xie, T. R. Gengenbach, and H. J. Griesser, "Changes in wettability with time of plasma modified perfluorinated polymers," J. Adhesion Sci. Technol., 6:1411 (1992)). In addition, the modification of the hydrocarbon or perfluorocarbon backbone may be spatially uneven, with microscopic or macroscopic areas of the polymer remaining unmodified. At best, these surface compositions can only be empirically determined and so may be only partially known.
With a hydrophobic porous polymer, such as ePTFE or porous polyethylene, for example, modification of the backbone may be limited to the outer layers of the porous material, with the inner pore structures remaining mostly or completely unmodified. As a result, the unmodified regions of the polymer support member remain hydrophobic and so do not readily support wetting with high surface tension fluids. In the absence of such wetting, continuous passage of high surface tension fluids through the support member for mass transport of reactants or nutrients to and from an immobilized bioactive species cannot be established or maintained. Intermittent or incomplete passage of high surface tension fluid phases in a porous polymer support member can lead to channeling of the high surface tension fluid through only portions of the porous material, resulting in reduced efficiency. Moreover, these unmodified areas cannot be immobilized with bioactive species, resulting in inefficient use of the high surface area of the porous material.
Due to these limitations, modification of the backbone of a hydrocarbon or fluorocarbon polymer support member with a high energy reaction is most often an unsuitable method for immobilization of bioactive species.
As an alternative to these chemical modifications of polymeric surfaces, nonchemical methods have been employed to attach bioactive species to hydrocarbon and fluorocarbon support members. In the simplest method, a bioactive species is immobilized onto the surfaces of a fluorocarbon polymer via simple physicochemical adsorption. For example, M. Rucha, B. Turkiewicz, and J. S. Zuk, "Polymeric membranes for lipase immobilization," J. Am. Oil Chem. Soc., 67: 887 (1990) and Shults, M. et al., "Continuous In Vivo Glucose Analysis Based On Immobilized Enzyme Bound To Derivatized Teflon Membrane," Trans. ASAIO, 25: 66 (1979) each teach enzyme physisorption onto ePTFE. However, physisorption of bioactive species is often kinetically and thermodynamically unstable, highly reversible, and competitively displaced by solution phase reactants, products, or nutrients. In addition, physisorption may alter or damage the bioactive species. Thus, physisorption of bioactive species to hydrocarbon polymer or fluorocarbon polymer support members is not usually a suitable immobilization technique. Furthermore, the hydrophobic properties of a porous hydrocarbon polymer or porous fluorocarbon polymer support member, such as ePTFE, often prevent physisorption of a bioactive species in the inner pore structures of the support member.
In another non-chemical immobilization scheme, bioactive species such as cells have been immobilized to porous PTFE support members. For example, bacteria and yeast cells have been immobilized in PTFE fibril matrices using an emulsion of PTFE and surfactants (F. W. Hyde, G. R. Hunt, and L. A. Errede, "Immobilization of bacteria and Saccharomyces cerevisiae in poly(tetrafluoroethylene) membranes," Appl. Environ. Microbial., 57: 219 (1991)) The surfactant is necessary to ensure for the presence of a continuous water phase throughout the emulsion in order to allow diffusion of nutrients to cells immobilized within the porous regions of the material. This method for immobilization of cells in the porous matrices of a fluorocarbon polymer is quite harsh, however, as many surfactants are cytotoxic. As a result, this method is not generally applicable to all cell types because the reaction conditions are often toxic to cell types such as plant or mammalian cells. In addition, the surfactant may initially obstruct some or all of the void space of the pores in such a porous support member. Lastly, the surfactant may leach from the support member with time. This often presents a toxic environment to the immobilized cells or channelling of nutrients, resulting in a heterogeneous distribution of cells within the porous support member. Accordingly, this is often an unsuitable method for the immobilization of bioactive species.
In yet another non-chemical method, mammalian cells have been immobilized within ePTFE support members by forcing the cells into the pores of the material by hydrostatic pressure (University of Washington, PCT/US95/03735). However, cell viability is often low due to mechanical shearing forces produced during the process. In addition, the ePTFE remains hydrophobic and mass transport of liquid water across the thickness of the material may remain low, resulting in suboptimal transport of nutrients to the immobilized cells.
In an attempt to improve the immobilization of bioactive species adsorbed onto hydrocarbon or fluorocarbon polymer support members, the hydrophobicity of the surfaces of such polymer support members can be modified with hydrophilic surface active agents, or surfactants. Hydrophobic surfaces are low energy surfaces that are readily wetted by low surface tension fluids, such as low molecular weight hydrocarbons or alcohols, and most low molecular weight organic solvents, such as benzene, acetone, toluene, and dioxane, etc. Hydrophilic surfaces, on the other hand, are high energy surfaces that are readily wetted by high surface tension fluids. Examples of high surface tension fluids include, but are not limited to, liquid water, aqueous salt and protein solutions, dimethyl formamide, dimethyl sulfoxide, glycerol, hexamethyl phosphorictriamide, formamide, and glycol, for example. In these methods, surfactants were physisorbed onto the surfaces of a polymeric hydrocarbon or fluorocarbon support member. When a surfactant is applied to the surfaces of a hydrophobic polymeric support member, the surface energy of the support member is usually increased. The increased surface energy of the support member often facilitates attachment of a bioactive species to the support member. For example, U.S. Pat. Nos. 5,077,215, issued to McAuslan et al., 5,183,545, issued to Branca et al., and 5,203,997 issued to Koyama et al., teach the adsorption of anionic and nonionic fluorocarbon surfactants to the surface of fluorocarbon support members to modify their hydrophobicity. As a result, the normally hydrophobic surface of the polymer was rendered more hydrophilic. This was followed by physisorption of a bioactive species onto the surfactant-modified polymer surface.
In similar methods, the adsorption of surfactants onto polymeric support members is taught wherein bioactive species are subsequently bound to the adsorbed surfactants. For example, U.S. Pat. No. 5,263,992, issued to Guire et al., teaches adsorption of polymeric chains to a support member, to which biomolecules are attached through a photoactive agent. In this manner, bioactive species were more readily immobilized onto the support member than if directly immobilized onto the underlying hydrophobic polymer surface. Alternatively, the bioactive species may be covalently bonded directly to the surfactant rather than physisorbed thereto (See also, U.S. Pat. No. 4,619,897, issued to Hato et al., for example).
In these methods, the presence of a surfactant provided for a surface having a hydrophilicity that initially enhanced the immobilization of bioactive species. For porous support members, the surfactant also initially provided continuous water phases through the pores of the support member. As discussed in greater detail below, immobilization of bioactive species with surfactants is usually unstable over time, however.
The physicochemical stability of the immobilized bioactive species is another concern when bioactive species are immobilized with surfactants. The adsorption of surfactants to a polymeric support member can serve to enhance the strength of biospecies adsorption, but the biospecies may desorb from the surfactant-treated surface nevertheless. In order to improve the retention of the bioactive species on a support member, U.S. Pat. No. 4,885,250, issued to d'Eveleigh, teaches modifying biological ligands themselves with surfactants prior to physisorption of the surfactant onto the support member. However, modification of bioactive species with surfactants prior to physisorption onto hydrophobic polymer surfaces may dramatically impact the bioactivity of the bioactive species. For example, the enzyme lactate dehydrogenase was admixed with surfactants and physisorbed onto PTFE microparticles resulting in a drop in enzymatic activity of 96% (N. D. Danielson, and R. W. Siergiej, "Immobilization of enzymes on polytetrafluoroethylene particles packed in HPLC columns," Biotech. Bioeng., 23: 1913 (1981)). In another example, the enzyme urease was modified with perfluoroalkyl chains and then physisorbed onto ePTFE resulting in an initial drop in enzymatic activity of 10-18% and poor overall enzymatic stability (R. K. Kobos, J. W. Eveleigh, M. L. Stepler, B. J. Haley, S. L. Papa, "Fluorocarbon-Based Immobilization Method for Preparation of Enzyme Electrodes," Anal. Chem., 60: 1996 (1988)). Additionally, adsorbed surfactant-modified bioactive species may remain molecularly motile and may migrate and cluster on the surface of a hydrocarbon polymer or fluorocarbon polymer support member. This effect may be accelerated with the application of cosolvents, changes in pH, or elevated temperatures, such as autoclaving, often leading to significant reorganization of the bioactive species on the surface of the support member. This can cause a loss in wetting potential of the support member with high surface tension liquids and/or uneven spatial immobilization of a bioactive species (U.S. Pat. No. 5,352,511, issued to Abaysekara et al.). As a result of these limitations, modification of a bioactive species with a surfactant prior to immobilizing the bioactive species to a hydrophobic support member is most often an unsuitable method.
Surfactants, whether physisorbed onto a hydrophobic support member or attached to a bioactive species and then adsorbed to a hydrophobic support member, are subject to desorption. For example, R. I. Foster, et al. in "Analysis of Urokinase Immobilization on the polytetrafluoroethylene vascular prosthesis," Am. J. Surg., 156: 130 (1988) teach adsorption of the hydrocarbon surfactant tridodecylmethyl-ammonium chloride onto the surfaces of ePTFE followed by immobilization of the enzyme urokinase to the surfactant. The adsorption was unstable and the enzyme/surfactant construct was eventually displaced. An additional limitation with this immobilization method is the tendency for the surfactant to leach into the solute phase, often with undesired consequences, such as contamination or inactivation of desired products or the bioactive species. Accordingly, immobilization of bioactive species onto a hydrophobic support member with a surfactant is usually unstable, short-lived, and potentially harmful to the bioactive species.
The stability of surfactant adsorption on a hydrocarbon or fluorocarbon polymer surface can be enhanced by increasing the molecular weight of the surfactant (J. H. Lee, J. Kopecek, J. D. Andrade, "Protein-Resistant Surfaces Prepared by PEO-Containing Block Copolymer Surfactants," J. Biomed. Mater. Res., 23: 351 (1989)) or by lowering the molecular entropy of the surfactant (J. H. Lee, P. Kopeckova, J. Kopecek, J. D. Andrade, "Surface Properties of Alkyl Methacrylates with Methoxy (polyethylene oxide) Methacrylates and Their Application as Protein-resistant Coatings," Biomaterials, 11: 455 (1990)). Either of these approaches can be accomplished by producing surfactants with branched or comb-like hydrocarbon chains, rather than linear hydrocarbon chains, for example. However, the stability of the adsorbed surfactant may still be transient, albeit much stronger, and may desorb from the support surface nevertheless, rendering this technique potentially unfeasible for long term applications.
In another method to reduce surfactant desorption or surfactant motility, adsorbed surfactant chains may be covalently cross-linked to adjacent adsorbed surfactant chains, producing new surface-bound planar molecules. The resulting planar molecules are of very high molecular weight and have greatly reduced molecular entropy. This type of cross-linking dramatically reduces the incidence of desorption or surface migration of the surfactant. For example, U.S. Pat. Nos. 4,929,666, issued to Schmidt et al., and 5,006,624, issued to Schmidt et al. teach adsorbing copolymers of fluoroalkyl acrylates and carboxylic vinyls, respectively, onto fluorocarbon polymer surfaces, followed by surface cross-linking of adsorbed carboxylic moieties to produce a coating highly stable to surface reorganization or to desorption. In another example, a hydrophilic fluorocarbon polymer of tetrafluoroethylene-co-vinyl alcohol was adsorbed and chemically cross-linked to itself using a polyether bisoxirane cross-linker (U.S. Pat. No. 5,354,587, issued to Abaysekara). In another example, a hydrophilic hydrocarbon polymer of polyvinyl alcohol was adsorbed and cross-linked to itself using a dialdehyde cross-linker (U.S. Pat. Nos. 4,113,912 and 4,193,138, both issued to Okita). This resulted in the ePTFE surface being rendered wettable with liquid water and the adsorbed copolymer molecules being highly resistant to desorption or to surface migration. However, these hydrophilic surfaces have limited or greatly reduced numbers of chemically functional groups to which additional polymers or bioactive species can be attached. If the adsorbed copolymer layer is deficient in the desired number or identity of chemically functional groups it possesses, then the capacity of the adsorbed copolymer or surfactant layer to immobilize bioactive species will always remain suboptimal. Accordingly, this type of cross-linking of adsorbed surfactant or copolymer molecules on hydrocarbon or fluorocarbon polymer support members is often unsuitable for the subsequent immobilization of bioactive species.
A support member having chemically stable and chemically variable hydrophilic polymeric surfaces attached thereto as a substrate upon which bioactive species are stably and efficiently immobilized would be useful. Such a construction would enable a practitioner to increase the number and/or variety of immobilized bioactive species. A practitioner would also be able to select a conjugation scheme for immobilization of a bioactive species that is best suited for the particular bioactive species.

Materials and methods for the immobilization of bioactive species onto polymeric substrates


An X-ray analyzing apparatus is such that a diffraction pattern, in which the intensity of secondary X-rays (4) is associated with the angle of rotation of a sample (S), is stored; while the pattern is scanned by a line of the secondary X-rays (4) intensity in a direction of highness and lowness, points on the pattern having not higher intensity than the line are taken as candidate points; respective angles of rotation of the candidate points, when the maximum value of the difference in angle of rotation between the neighboring candidate points attains a predetermined angle, are stored; depending on coordinates of a point of measurement, the angle of rotation proximate to the coordinates is read out from the stored angles; and the sample (S) is set to the read out angle and the point of measurement is arranged within the field of view (V) of a detector (7).

1. Field of the Invention
The present invention relates to an X-ray analyzing apparatus and a method therefor for measuring an arbitrary point of measurement of a disc shaped sample such as, for example, a wafer.
2. Description of Related Art
Hitherto, the analysis of, for example, a wafer has been carried out by irradiating a sample surface with primary X-rays, detecting secondary X-rays emanating from the sample surface and then measuring the intensity of the secondary X-rays emitted by the sample surface. In the practice of this conventional X-ray analysis, it has been well recognized that a sample of a kind having a crystalline structure, such as, for example, a wafer, when irradiated with the primary X-rays, may emit the secondary X-rays containing not only fluorescent X-rays, but also diffracted X-rays. During the X-ray fluorescence analysis, these diffracted X-rays often constitute an obstruction to the measurement and the rotative direction of the sample in which the diffracted X-rays are generated changes depending on the cut plane of the sample which may be (110) or (111) plane in the crystalline structure.
Accordingly, the fluorescence analyzing method has been known in which, prior to the X-ray fluorescence analysis of the sample, while the sample is rotated an angle equal to or greater than 180° about a predetermined point of the sample, the primary X-rays are radiated towards the sample, secondary X-rays emanating from the sample and containing fluorescent X-rays and diffracted X-rays are detected, the sample is then rotated in such a direction that the intensity of the detected secondary X-rays may exhibit the minimum value, and in this condition the sample is thereafter transferred in XY directions, which are perpendicular to each other, in a plane parallel to the measuring surface to perform the analysis over the entire measuring surface of the sample. In this respect, see, for example, the patent document 1 listed below.
Also, as shown in FIG. 11 of the accompanying drawings, when with respect to a desired point of measurement (measuring site) positioned in the vicinity of an edge of a plate-like sample measurement is carried out by positioning the point of measurement so that the primary X-rays 2 are radiated from outside of a region above the sample S and the primary X-rays 2 so radiated may undergo a total reflection towards such region, a portion of the primary X-rays 2 are radiated towards a vertical end face of the sample S, accompanied by emission of strong scattered X-rays 9 in all directions. A portion of the scattered X-rays so emitted forms a large background to the fluorescent X-rays to be measured.
In view of the foregoing, a total reflection X-ray fluorescence spectrometer has been made available, in which with respect to an arbitrary point of measurement located in the vicinity of the edge of the sample, measurement is carried out by positioning the point of measurement so that the primary X-rays 2 are radiated from the region above the sample S and the primary X-rays 2 so radiated may undergo a total reflection towards outside of such region, to thereby suppress the scattered X-rays emitted from the end face of the sample. In this respect, see, for example, the patent document 2 listed below.


Disclosed is a semiconductor device having complementary metal insulator semiconductor field-effect transistors (MISFETs) in which a plurality of basic cells having N-channel MOSs and P-channel MOSs are disposed. In this semiconductor device, a sub MISFET is disposed adjacently to a stopper layer in a region adjacent to other basic cell. An element such as a transmission gate composed of a single element can be actualized by use of the sub-MISFET. In the semiconductor device of this invention, a working efficiency thereof is improved. A response velocity of the P-channel MOS can also be improved using the sub-MISFET. A numerical quantity of the basic cells constituting a circuit can be reduced, resulting in a reduction in parasitic capacity. An operating time of the circuit is thereby decreased.

Turning to FIG. 11, there is shown a semiconductor device based on complementary metal-oxide semiconductor (CMOS) field-effect transistors manufactured by a generally employed master slice method. The semiconductor device depicted in this Figure is formed by a gate array method on the basis of cells each consisting of two P-channel MOSs and two N-channel MOSs. A static RAM (SRAM) circuit is constructed by employing the semiconductor device described above.
FIG. 12 illustrates a cell 1 on which this semiconductor device is based. In this cell 1, a high concentration N-type diffused layer is formed by introducing an impurity, wherein a mask is a polysilicon gate 14 formed in a P-type well 10 on the semiconductor device. This high concentration N-type diffused layer 15 and the gate electrode 14 constitute two N-channel MOSs (N-MOSs) 11, 12. The gate electrodes 14 of these two N-MOSs 11, 12 are disposed in parallel and have the same orientation. The MOSs 11, 12 share the N-type diffused layer 15 with each other. This region is therefore used in common as a source or drain region. Further, a stopper layer 16, i.e., a high concentration P-type diffused layer, is formed in parallel with these MOSs 11, 12 in a region adjacent to a cell neighboring to the cell 1. This stopper layer 16 is a diffused layer assuming a substantially rectangular shape. The stopper layer is formed for separating the N-MOSs of the adjacent cells and preventing a channel formation when an inter-cell semiconductor surface is inverted. A power supply line is connected via this stopper layer 16 to a substrate, thereby reducing a difference between a substrate potential and a power supply potential. A latch-up of a parasitic transistor formed in the MOS is prevented.
On the other hand, the cell 1 is formed with two P-channel MOSs (P-MOSs) 21, 22 in symmetry with the N-MOSs 11, 12. In association with the P-MOSs 21, 22, as in the case of the N-MOSs 11, 12, a high concentration P-type diffused layer 25 is formed with a polysilicon gate electrode 24 serving as a mask. Owing to this diffused layer 25 and the gate electrode 24, the two P-MOSs 21, 22 are formed in parallel. As in the case of the N-MOSs 11, 12, the P-MOSs 21, 22 share a source or drain region with each other. In association with these P-MOSs 21, 22, for the same purpose as that of the stopper layer 16, a stopper layer 26 is formed of a high concentration N-type diffused layer.
As described above, one basic cell 1 comprises the two N-MOSs 11, 12, the two P-MOSs 21, 22 and stopper layers 16, 26. In the semiconductor device based on the master slice method, the basic cells are continuously formed at constant intervals. Those basic cells are connected with wires of A1 and the like, thus obtaining a desired circuit. The device depicted in FIG. 11 is one example of this arrangement. A SRAM is configured by the gate array method in which designing is effected in conformity with vertical/lateral fixed wiring rules. The following are problems inherent in the conventional complementary semiconductor device in which the P-MOSs and the N-MOSs are continuously formed. Even when a circuit module of a data switch of the above-described SRAM is constructed of unitary elements of N-MOSs, there is no alternative but to use one basic cell in terms of designing the circuit. Taking the wiring rules into consideration, it is difficult to largely change an area of the P-MOS and N-MOS, i.e., a channel width. For this reason, an operating time of the circuit is determined by the P-MOS whose response time is slow.
FIGS. 3 and 4 show a circuit of the SRAM in this embodiment. The SRAM in this embodiment is a 9-element-based logic circuit in which the N-MOS serves as a transmission gate. The transmission gates provided both on the reading side and on the writing side of this circuit are constructed of N-MOSs 41, 42. If the circuit in which the gates are composed of unitary elements of N-MOSs is configured by the conventional complementary semiconductor device given above, as illustrated in FIG. 11, three pieces of basic cells, viz., an area of 12 elements is required for the 9-element-based circuit.
On the other hand, the following relation about the operating time of the semiconductor device is established: EQU tr=4.times.C/(.beta..times.H.times.Vdd) (1)
where tr is the response time indicating a rise or decay time of the MOS, C is the load capacity indicating a capacity of the MOS itself and a capacity of wires parasitic to the MOS, H is the channel width, Vdd is the power supply potential, and .beta. is the current amplification rate per unit length of the MOS. The current amplification rate of the P-MOS is approximately a half or a third the current amplification rate of the N-MOS. Namely, if the channel widths H are substantially equal, the response time tr of the P-MOS is approximately twice or three times as large as that of the N-MOS. For instance, in the conventional complementary semiconductor device, an inverter is composed of the P-MOS and the N-MOS. In this case, because of the channel widths H being equal, a rise time of this inverter is required to be approximately twice or three times the decay time. Hence, in the circuit where a plurality of inverters are connected, the operating time of the device is conditioned by the response time of the P-MOSs.
In the light of such problems, the present invention aims at improving a working efficiency of a semiconductor device by ameliorating a layout of the semiconductor device based on a master slice method in which P-MOSs and N-MOSs are continuously formed and reducing an area occupied by a circuit. It is an object of the present invention to attain a semiconductor device capable of an operating time of a MOS logic circuit by restraining an increase in the area occupied by the circuit.


Communication between tasks within repeaters of a communication system can be improved in the following manner. Each repeater determines its repeater configuration which includes identifying any peripheral devices affiliated with the repeater. Next the repeaters establish which repeater will be the master repeater based on a predetermined protocol. A predetermined number of tasks is allocated among the repeaters based on which repeater is established as the master repeater and each repeater configuration. Finally, message routing tables are created based on the allocated trunking tasks, peripheral devices, and communication system configuration. The message routing tables are used in routing messages between tasks in the communication system.

Communication systems are known to comprise communication units, repeaters, peripheral devices and a central processor. Typically, the central processor performs all system wide tasks within the communication system, such as call processing, and establishes the control channel repeater.
Communication networks are known to comprise communication devices, such as repeaters, which are physically connected to a data link, such as a local area network (LAN). Communication networks allow communication devices to transmit messages to other communication devices and receive messages from other communication devices physically connected to the same data link. Since all communication devices physically connected to the data link receive all messages transmitted on the data link, each communication device has its own unique address. This allows a communication device the option of processing only those received messages addressed specifically to it. The unique address also allows a communication device to transmit messages addressed to a specific communication device.
As is known, the method of task communication between repeaters consists of messages sent via a pool of common buffers. All task processors within each repeater have access to the pool of buffers. Because the buffers are unformatted, when a task processor receives a message, it interprets the message according to its protocol. If a task processor were to receive a message in error, it would process the message according to its protocol as if it were a valid message. This may result in improper operation of the communication system. As is also known, this method requires each task processor to know the physical address of the task processors it needs to communicate with. This requires extra overhead to keep track of changes made to the communication system such as, if a repeater is added or removed from the system, or if a peripheral device is added, removed, or changed to another repeater in the communication system.
Therefore a need exists for a method for establishing transparent communication between a limited number of repeaters in a communication system that decouples tasks from hardware and system configurations, provides centralized buffer management, and requires less overhead.

Method for establishing communication between tasks of a limited number of repeaters in a communication system


A method and a system are provided for blending advertiser data with ad network data in order to serve finely targeted ads. In one example, the system receives campaign information from one or more advertisers. The campaign information includes at least one of a budget, criteria, and a creative. The system receives a notification from a user device about an available ad spot on a webpage for display at a browser running on the user device. The system receives data from an advertiser. The data from the advertiser pertains to managing an ad to be sent to the user device to fill the ad spot on the webpage. Then, the system combines the data from the advertiser with data from an ad network to obtain combined data. The ad network is configured for managing at least part of an ad campaign. The advertiser is also configured for managing at least part of the ad campaign.

An advertiser, such as Ford™ or McDonald's™, generally contracts a creative agency for ads to be placed in various media for the advertiser's products. Such media may include TV, radio, Internet ads (e.g., sponsored search ads, banner display ads, textual ads, streaming ads, mobile phone ads, etc.) or print medium ads (e.g., ads in newspapers, magazines, posters, etc.). The advertiser may engage one or more creative agencies that specialize in generating ads for one or more of the above media. A company wants to show the most relevant ads to end users in order to get the most value from their ad campaign.
It would be beneficial to use the data that the advertiser has in order to aim online ads at target consumers. Unfortunately, using data that advertisers have in targeted advertising involves complex ETL (extracting, transforming and loading), data sharing and tedious legal issues.

Blending advertiser data with ad network data in order to serve finely targeted ads


A method for routing data in a network includes receiving, by a first network node, data to be routed using a first layer protocol to a second network node where the first network node is intermittently connected to the second network node over a link spanning a portion of the network. The first network node determines that the link fails to meet a communications criteria and encapsulates the data using a second layer protocol to produce encapsulated data. The second layer protocol is transparent to the first layer protocol and the encapsulated data includes connectivity instructions to route the encapsulated data to the second network node via a third network node. The second network node and the third network node are in communication across the portion of the network and the first network node is able to transmit the encapsulated data to the third network node.

In the field of packet communications and networking, some network topologies are fixed while others may have a dynamically changing topology. An example of networks with a dynamically changing topology are non-terrestrial (satellite) networks used to provide global communications services where the satellite orbits may result in a satellite's adjacent neighbours frequently changing. Other terrestrial wireless networks may also exhibit similar characteristics.
Low Earth Orbit (LEO) satellite networks are proposed to provide coverage over a wide area with low latency. Compared to traditional satellite networks where satellites are positioned at higher altitudes, LEO satellite networks require more satellites to provide global coverage, mainly due to the smaller coverage provided by satellites positioned at low altitudes. For some LEO satellite networks, satellites are required to be uniformly distributed around the globe. This requires that multiple orbits be used, with multiple satellites placed in each orbit. The actual number is not germane to this discussion, as it will also vary with other requirements, such as the number of satellites that must be visible at any given time by a single user.
When a group of satellites is arranged in predefined orbits, the pattern of the orbits is referred to as a constellation. Once common constellation is known as a polar constellation where each orbit of satellites crosses the Earth's poles. Satellites are launched into separate orbital planes with all satellites in the orbit travelling in the same direction. Due to Earth's rotation, satellites that may be launched in a northward direction would later pass over the same point in a southward direction. At any point in time half the satellites will be travelling in one direction and half will be travelling in the other direction. At most places in the constellation, adjacent satellites in adjacent orbits will be travelling in the same direction. However, there are regions where satellites travelling in adjacent orbits will be travelling in opposite directions. These regions are given the term "orbital seam" or simply "seam." The orbital seam is of key concern when inter-satellite communication links are employed, due to the relative velocity of satellites in adjacent orbits on opposite sides of the seam. These communication links are only active for a short period of time as the satellites pass each other in travelling opposite directions and there the link may only be active for a short period of time.
Another type of satellite constellation is known as a Walker-Delta constellation. A Walker-Delta constellation is based on multiple, inclined orbits where the angle of inclination of a satellite is defined as the angle between the ground track of the satellite and the equator as the satellite passes from the southern-hemisphere to the northern hemisphere. When the angle of inclination is less than 90 degrees, polar region is not crossed. All satellites travel in the same direction and each satellite can form adjacencies over four links that are relatively stable until they cross at the extreme ends of the orbit where they change direction from a northward to a southward direction. In a Walker-Delta constellation, seam-like behaviour can exist as a satellite on a non-adjacent orbit begins to cross back over another orbit. In some cases, an extra fifth link may be needed to track and communicate between satellites in different orbits. The use of a fifth link is that a more complete mesh can be formed. Similar to the seam in a polar constellation, the rapid motion of the satellites relative to one another places constraints on topology flooding mechanisms that may be used at the IP layer.
The issue of the seam may be dealt with by avoiding routing traffic across the seam. Although the shortest path between a source and destination satellite may be across a seam, it is possible to route traffic to avoid unstable, sporadically active links at the seam crossing. However, this often leads to longer routes with a large number of satellite links which may lead to high latencies.
A network topology is the collection of network nodes (or simply "nodes") with links connecting the network nodes. In a satellite network, nodes are not stationary and have a position and velocity (absolute or relative). Links between nodes may be sporadic and will have a status and criteria. Examples of a link status are active, inactive, failed, etc. Examples of link communications criteria are bi-directional, uni-directional, transmission speed, error rate, intra-orbit (within the same orbit), inter-orbit (between orbits), inter-satellite link (ISL), ground to satellite link, etc. The communications criteria may also be evaluated by referring to a schedule or table, which may be either predetermined or dynamically determined based on the predictable motion of satellites in orbit. Satellites within the same orbit will have a fixed position with respect to each other. At most times, satellites adjacent to each other in adjacent orbits will have a relative position that changes slowly and predictably. Across the orbital seam the network may have a dynamically changing topology, however the topology will be changing in a predictable manner based on the position and velocity of each satellite.
Therefore, there is a need for a method and apparatus for communicating across portions of networks with dynamically changing topologies, such as at a seam, that obviates or mitigates one or more limitations of the prior art.
This background information is provided to reveal information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention.

Seam abstraction in communications networks