Compositions and methods are disclosed for treating a hair-bearing surface of a warm-blooded animal, including humans, dogs and cats infested with an ectoparasitic insect, such as lice and/or fleas. Compositions and methods are also disclosed for preventing the infestation or re-infestation of an ectoparasitic insect, such as lice and/or fleas on a hair-bearing surface of a warm-blooded animal, including humans, dogs and cats. The compositions include either a water-soluble polyalkylene glycol or a water-soluble polyalkylene oxide mixed with a polymer or copolymer comprising polyalkylene oxide having carboxylic acid-containing residues. Methods of the invention include topical application to a hair-bearing surface of an effective amount of a composition of this invention, and maintaining the same on the surface for a sufficient period of time to treat the surface. Further optional steps include washing or rinsing the composition from the surface, as well as combing the hair associated with the treated surface.

This invention relates generally to compositions and methods for topically treating a hair-bearing surface of a warm-blooded animal infested with an ectoparasitic insect.
Lice and fleas (collectively referred to herein as xe2x80x9cectoparasitesxe2x80x9d) infest a wide range of warm-blooded animals, including humans. A louse is a small, flat-bodied, wingless, biting or sucking insect present as an external parasite on hair-bearing surfaces of various animals. The human lice genera include pubic lice (Pthirus pubis, or Phthirus pubis), body lice (Pediculus humanus var. corporis), and head lice (Pediculus humanus var. capitis).
Pubic lice generally are confined to the hairs of the genital region, while body lice may be found on the hair of the axilla, eyebrows, eyelashes, beards, and hairy body surfaces. Both pubic lice and body lice may be acquired from direct contact with another infested person, from wearing contaminated clothing, from contaminated toilet seats and from contaminated bed linen. Body lice typically occur as the result of crowding in unhygienic conditions, while pubic lice are transmitted sexually.
Head lice are small hard-shelled ectoparasites that cling to hairs of the scalp while feeding, mating and laying eggs. The adult female head louse has a lifespan of about one month, and is ready to mate and reproduce within about a week after hatching. Under ideal conditions, a female head louse may produce up to 100 eggs in her lifetime, most commonly on the hair above the ears and the back of the head of human beings, and near the base of hair shafts. The eggs are cemented to the hair with a tenacious proteinaceous substance. Head lice eggs (commonly referred to as xe2x80x9cnitsxe2x80x9d) are protected by a chitinous sheath which surrounds the eggs and are attached to the hair. These eggs hatch in about seven to nine days and become mature in another week. As with pubic and body lice, head lice are also transmitted by personal contact, as well as by common use of brushes, combs or headgear. Poor hygienic and grooming habits are known to contribute significantly to the spread of head lice. Thus, head lice infestations are most serious in areas where the inhabitants have both substandard hygienic facilities and practices.
Lice have plagued mankind for many centuries, and lice infestation can be found throughout documented history. For example, lice have been responsible for the spread of typhus, causing decimation of many armies and navies from the 15th through the 18th centuries. Even today, lice are still considered as disease vectors and present serious health problems throughout the world. In particular, lice are vectors for staphylococcal skin infections, such as impetigo and furunculosis, and are also the principle method of transmission for typhus, trench fever and relapsing fever.
Head lice, pubic lice and body lice are all capable of infesting humans (referred to as pediculosis), the characteristics of which differ markedly within the species. Head lice infestation is characterized by itching and dermatitis. In long standing or neglected cases, scratching may result in marked inflammation, secondary infection by bacteria may occur, resulting in the formation of pustules, crusts and suppuration, and the hair may become matted and give rise to a disgusting odor. Today, head lice is an epidemic in roughly 2-3% of grade school children in the United States and England. Body lice infestation is characterized by intense itching and, in cases of heavy infestation, by red skin eruptions, mild fever, tiredness, irritability and possibly weakness. Pubic lice infestation is characterized by itching, especially in the genital or crural regions.
In addition to spreading diseases, lice carry a wide variety of bacteria on their exterior surfaces, and their fecal matter transmits disease when it enters the puncture wounds inflicted during feeding. As the lice feed on human skin, they inject their digestive juices into the skin. These materials, as well as the puncture wound itself, cause pruritus, which is painful to the animal host. Therapy that simply kills the louse leaves subcutaneous or intradermal residues that continue to itch for a significant time after the infestation is extinguished. Furthermore, scratching during and after the episode frequently leads to painful excoriation.
Previous methods for treating animals infested with lice have not been entirely satisfactory. In the past, chemical agents, including toxic pesticides or insecticides (termed pediculicides) have been used. Unfortunately, these compounds include potent neurotoxins, as well as carcinogens such as DDT, carbaryl, piperonyl butoxide, the synthetic pyrethrin analog permethrin or cholinesterase inhibitors such as neostigmine or prostigmine. Such pediculicides range from mildly toxic (pyrethrins) to toxic (lindane and malathion). All current methods involve the exposure of the scalp and hair to these agents in shampoos or creams, which are then washed off relatively quickly. Because of increased concern about the overall safety of such chemical agents, the search for new and effective pediculicides has intensified.
In addition to safety concerns regarding the current pediculicides, other problems also exist. One drawback is that chemical agents may not achieve the desired efficacy. For instance, lice have developed a significant degree of resistance to all of the topical pesticides. Natural pyrethrins and synthetic pyrethroids are routinely chosen for use in the treatment of warm-blooded animals infested with lice. Natural pyrethrins have their limitations as poor environmental stability, which is a severe drawback in the treatment of lice. Additionally, natural pyrethrins have low residual action due to this instability. The practical effect is that the use of natural pyrethrins necessitates frequent follow-up treatments. Synthetic pyrethroids are cheaper, more available and more stable than natural pyrethrins, and generally more effective against lice than natural pediculicides.
Not only are current treatments generally losing their ability to kill the adult lice and eggs, the dead nits remain firmly attached to the hairs after treatment. This is unsettling to the patient, as well a significant cosmetic problem. The only current means of removing dead nits is with a fine toothed comb, fingers or forceps. These methods are time consuming and less than certain. Furthermore, if the patient is a child, the child must be nit-free to return to school.
Other forms of treatment are physical in nature and include removal of the hair-infested areas in question, followed by washing with strong soap and optionally one of the pediculicides listed above. Clothing or instruments in contact with the affected body parts should also be decontaminated. These forms of treatment, however, are less than satisfactory.
In addition to lice, fleas constitute another ectoparasite that infests a wide range of animals. More specifically, the flea is an insect of the order Siphonaptera, marked by lateral compression, sucking mouth parts, extraordinary jumping powers, and ectoparasitic adult life in the hair and feathers of warm-blooded animals, including birds and mammals. The flea genera include the human flea (pulex irritans), the cat flea (ctenocephalides felis) and the dog flea (ctenocephalides canis). Using a suctorial proboscis on its head and armed with piercing mandibles, the flea inflicts an irritating and often painful bite to obtain the blood upon which it feeds.
In the case of dogs and cats, for example, male and female fleas mate while still in the animal""s coat. When the female flea lays her eggs, the eggs do not adhere to the fur, but fall off and are distributed to the animal""s environment. By this mechanism, the total environment of the animal is infested with flea eggs and infestation is greatest in locations where the animal spends most of its time.
Fleas require a blood meal in order to become sexually mature. Once sexually mature, the fleas are able to reproduce. After their first blood meal, fleas undergo a shift in metabolism such that they cannot survive for any time off the host. The blood must come from the correct host and the female flea""s appetite requires that she consume as much as 5 times her body weight of blood each day.
Flea eggs hatch to larvae in about two days There are three larval stages, each lasting about three days. In the last stage, the larva spins a cocoon and transforms into a pupa. Under optimum conditions (e.g., 33xc2x0 C. and 65% relative humidity), eggs develop through larvae to pupae in about 8-10 days. After a further period of approximately 8 days, the pupae develop into young adult fleas in the cocoon, still dispersed in the pet""s environment.
The young adult fleas wait until they sense the presence of an acceptable host animal, emerge from their cocoon and attempt to jump onto the host. The pre-emerged adult fleas sense, by carbon dioxide tension and/or vibrations, the presence of an animal host, and then emerge explosively and jump into the air and onto the passing host.
Under suitable environmental conditions of temperature and humidity, unfed fleas that fail to find a host can survive for some time in the environment, waiting for a suitable host. It takes at least three weeks for eggs to develop to pre-emerged adults, at which time the fleas are able to reinfest a host animal. However, the pre-emerged adults can remain viable in the cocoon for months, and as long as one year. In addition, under sub-optimal temperature conditions, it can take 4-5 months for eggs to develop into pupae containing pre-emerged adults.
As with lice, mankind has been waging a war against fleas for a very long time. In fact, fleas have been found embalmed along with King Tut""s cat. Flea infestation of animals is a health problem and economic concern because fleas are known to cause and/or transmit a variety of diseases. In addition to various diseases, bacteria are also carried by the flea and transmitted in the course of the bite. Fleas cause and/or carry infectious agents that cause, for example, flea allergy dermatitis, anemia, murine typhus, plague and tapeworm.
In addition to the transmittance of disease, infestation of dogs and cats with fleas has several undesirable effects for the animals. Such undesirable effects include local irritation and annoying itching which leads to scratching. Such scratching may even be to the point that open wounds or sores result, leading to secondary bacterial infections. In addition, a high proportion of pet animals, particularly dogs, become allergic to flea saliva, resulting in the chronic condition known as flea bite allergy (or flea allergy). This condition causes the animal to bite and scratch, leading to excoriation of the skin, secondary pyrogenic infection, hair loss, and chronic severe inflammatory skin changes. Allergic pets may suffer severe skin reactions to the bite of even a few fleas. These infested animals create a nervous impression and become more and more unattractive and irritable. Furthermore, most dogs and cats that are infested with fleas also become infected with Dipylidium caninum, the tapeworm transmitted by fleas.
Newly emerged fleas may attack any mammal, including humans, although they are not capable of full reproductive potential if human blood is their sole source of nutrition. Thus, the human owner of an infested dog or cat may be bitten by fleas. Some humans may suffer allergic skin disease as a result of such bites and/or from their excreta. It has, therefore, been desirable to find an effective method of controlling fleas that infest dogs and cats.
The medical and veterinary importance of flea infestation has prompted the development of reagents capable of controlling flea infestation. Early remedies included fumigation, and sulfur was used as early as 1,000 B.C. as a fumigant. Marco Polo used a sulfur-based oil as a mange treatment in 1300 A.D. Currently, a number of methods for the control of fleas are known, but all have various drawbacks.
Commonly encountered methods to control flea infestation are generally focused on use of insecticides in formulations such as sprays, shampoos, dusts, dips, or foams, or in pet collars. A large number of insecticidal active compounds have been disclosed for combating fleas, typical of these chemicals are propoxur, d-Limonene, cyano(3-pheoxypheny)methyl 4-chroroalpha (i-methylethyl)beneneacetate, pyrethrin, piperonyl butoxide and N-octyl bicycloheptane dicarboximide. Insect development inhibitors, such as fipronil, methoprene, or cyromazine, can also be added.
Unfortunately, many of the above insecticides and development inhibitors are often not successful in completely reducing flea populations on the pet. Like most insects, fleas can adapt to survive exposure to normal toxic agents. Additionally, the tolerance of dogs and cats to chemical agents varies Thus, if an insecticidal agent is employed, it is desirable to have a multiplicity of agents and methods available for controlling fleas.
A second problem associated with the use of insecticidal agents to control fleas is that many of the agents have been banned from most countries because of environmental persistence of residues and their effect on certain wildlife. Many of these chemicals are not rapidly biodegradable and constitute an environmental hazard if misused.
Aside from the environmental risks, many of the effective toxic agents have been banned because of long-term health risks, including risks of cancer to the pets and chronically exposed humans. In the United States, even some currently approved and available toxic agents that are effective against fleas are under scrutiny because of concerns for long-term health hazards to pets and to their owners. Additionally, many of these chemicals cannot be applied to the fur of animals, such as cats, that self-groom by licking the skin and fur. Even persons applying these flea killing chemicals to animals must often be very careful to avoid excessive contact with them. Those grooming animals must often wear rubber gloves to avoid continuous contact with the chemicals, must exercise care in keeping the chemicals out of the eyes and away from the mucus membranes, and avoid breathing vapor from the chemicals over long periods.
Flea removal vacuum systems have also been tried, such as the system disclosed in U.S. Pat. No. 4,279,095 which employs the use of a rather coarse brush of flexible, hollow rubber or plastic tubes to agitate the pet""s coat and draw the disturbed fleas and eggs by vacuum through a plenum chamber to a trapping filter. However, application of sufficient vacuum, by itself, to remove a meaningful percentage of the flea population hiding in, and clinging to, the coat of a particular pet has proven difficult in practice because the vacuum effect of a household vacuum cleaner alone does not effectively collect a significant percentage of the live fleas on a pet.
Another approach is flea combs. However, they require the pet owner to comb the animal intensively and frequently. Depending on the size of the animal, this may take from several minutes to an hour. Not every animal will always patiently put up with being combed, nor is every owner prepared to sacrifice time for this operation. Like the vacuum system, the comb alone does not effectively remove a significant percentage of the live fleas on a pet.
The use of anti-flea shampoos in many cases is impossible since most cats and a large number of dogs simply refuse to be given a bath. Furthermore, the effect of such bathing does not last for more than about a week and the laborious procedure then must be repeated Similar problems are encountered when using dips or rinses. Even the use of dusting powders is not tolerated by many animals without resistance since it takes several minutes to treat the entire surface of the coat uniformly and some dust is bound to get into the mouth, nose, and eyes of the animal. Even in the case of careful application, it is impossible to prevent the powder from being inhaled by the animal or its owner, and there is virtually no way for the owner to avoid an intensive contact with the active ingredient.
Several anti-flea organophosphorus compounds are available in the form of spot-on formulations. These are applied to a limited spot on the coat. In general, they exhibit good short-term activity against adult fleas, but when applied often the compositions have problematic toxicity. Some organophosphorus compounds are administered orally but have narrow safety limits and must never be applied simultaneously with other organophosphorus compounds.
More recently, the use of pet collars, in which an insecticide gas generating composition is included, have been widely adopted. Flea collars are very effective temporarily. A particular weakness of this method of treatment, however, is that it is normally effective in a very limited region of the animal""s body. In general, 100% kill is achieved in the region of the neck and thorax; however, more remote parts of the body are hardly affected. Medallions are also available which can be attached to the collar. However, their effectiveness is also unsatisfactory since they do not come into sufficient contact with the animal""s coat.
The collar and medallion also suffer from certain disadvantages. For instance, pet collars containing the insecticide dimethyl, 2,2-dichlorovinyl phosphate, (DDVP), have been widely used for the purpose of controlling fleas on dogs and cats. DDVP has been reported in the literature to have an objectionable depressing effect on the plasma and red cell cholinesterase. This is particularly acute at high concentrations which are produced during the first few days after a collar has been applied to the neck of the animal. Additionally, local skin irritation has occurred at the site of the collar especially when the collar is first placed on the animal.
Further, many of the known techniques disclosed above are principally directed to the control of adult fleas in the coat of the host animal, and do not take into account the different juvenile stages of the fleas existing in the animals""coats as well as on or in the floor, carpets, bedding, chairs and other places the infested animal usually comes into contact. The long life cycle, and especially the extended period of pre-emergence dormancy, has made flea control particularly difficult.
Accordingly, while advances have been made in the field of removing ectoparasitic insects, such as lice and fleas, further improvements are still needed. For example, compositions and methods are needed to effectively immobilize such ectoparasites and, in the case of lice, unlock the bond between the lice egg and the hair to ease removal of the eggs. Additionally, treatment is needed to which ectoparasites cannot evolve a resistance. The present invention fulfills these needs and provides further related advantages.
In brief, the present invention discloses compositions and methods for treating a hair-bearing surface of a warm-blooded animal, including humans, infested with an ectoparasitic insect. Additionally, the present invention discloses compositions and methods for preventing the re-infestation of an ectoparasitic insect on a hair-bearing surface of a warm-blooded animal. This is accomplished by topically applying to a hair-bearing surface of a warm-blooded animal in need of such treatment or prevention, an effective amount of a composition of this invention, and maintaining the composition on the surface for a sufficient period of time to treat the surface or to prevent re-infestation thereof by the ectoparasitic insect. Methods of this invention further include washing or rinsing the treated surface to remove lice or flea eggs, as well as the removal of the same by means of a comb or vacuum. Frequent prophylactic applications followed by combing or vacuuming can prevent infestations, and is especially appropriate in epidemic situations.
Compositions of this invention include, in one embodiment, a water-soluble polyalkylene glycol, such as polyethylene glycol, with a molecular weight ranging from 100,000 to 8,000,000. The compositions of this invention may also include further optional compounds, such as an antioxidant or a pediculicide.
These and other aspects of this invention will become evident upon reference to the following detailed description.
As mentioned above, this invention provides methods and compositions for treating a hair-bearing surface of a warm-blooded animal, including humans, infested with an ectoparasitic insect, as well as methods and compositions for preventing re-infestation of an ectoparasitic insect on a hair-bearing surface. More specifically, this invention provides methods for the topical application of an effective amount of a composition to the surface of a warm-blooded animal, for a sufficient period of time to treat the surface and/or prevent the re-infestation thereof
As used herein, the following terms have the meanings set forth below:
xe2x80x9cEctoparasitic insectxe2x80x9d means any of the numerous, usually small, invertebrae animals of the class Hexapoda, having an adult stage characterized by three pairs of legs, a segmented body and being parasitic on hair-bearing surfaces of the host. Ectoparasitic insects of the present invention include, but are not limited to, fleas and lice.
xe2x80x9cLicexe2x80x9d means any of various small, flat-bodied, wingless, biting or sucking insects of the order Anoplura present as an external parasite on hair-bearing surfaces of various animals. The louse may be either the adult louse or the lice egg (e.g., nit). The human lice genera include pubic lice (Pthirus pubis, or Phthirus pubis), body lice (Pediculus Humanus var. corporis), and head lice (Pediculus humanus var. capitis).
xe2x80x9cFleaxe2x80x9d means any of the various small, wingless, bloodsucking insects of the order Siphonaptera, that have legs adapted for jumping, and are parasitic on hair-bearing surfaces of warm-blooded animals. The flea may be either the adult flea or the flea egg (e.g., nit). The flea genera include the human flea (Pulex irritans), the cat flea (Ctenocephalides felis) and the dog flea (Ctenocephalides canis).
xe2x80x9cNitxe2x80x9d means the egg of an ectoparasitic insect, and includes the eggs of both lice and fleas.
xe2x80x9cTreatingxe2x80x9d means immobilizing and/or removing ectoparasitic insects from the surface. Removal of the immobilized lice or fleas from the treated surface may be accomplished by a subsequent step, which may take a variety of forms as discussed in greater detail below. An important aspect of this invention is that treating facilitates the subsequent removal of the immobilized lice or fleas. With respect to the louse eggs or nits, treating effects the nit cement that holds the eggs to the hair, thus facilitating their subsequent removal.
xe2x80x9cPreventionxe2x80x9d means to avoid the ectoparasitic infestation on a hair-bearing surface of a warm-blooded animal from occurring, or to hinder or impede, in advance, such infestation.
xe2x80x9cEffective amountxe2x80x9d means an amount sufficient to attain the desired result. The effective amount may include an amount in excess necessary to attain the desired result.
xe2x80x9cWater-solublexe2x80x9d means capable of being dissolved in water without the aid of a detergent or similar agent.
Compositions of this invention contain a water-soluble polyalkylene glycol. In one embodiment, the polyalkylene glycol is polyethylene glycol. Alternatively, compositions of this invention contain a mixture of a water-soluble polyalkylene oxide and a polymer or copolymer of polyalkylene oxide having carboxylic acid-containing residues.
A water-soluble polyalkylene glycol is represented by the formula HOxe2x80x94(Rxe2x80x94O)nxe2x80x94H. Thus, the polyalkylene glycol contains two terminal hydroxyl groups (xe2x80x94OH), with a mid-section composed of repeating alkyleneoxide groups (xe2x80x94ROxe2x80x94). The letter xe2x80x9cnxe2x80x9d in the formula represents the number of repeating alkyleneoxide units. This number may range from about 5 to several thousand. As the number of repeating units increases, the molecular weight of the polyalkylene glycol will also increase. In one embodiment, the molecular weight of the polyalkylene glycol, in terms of number average molecular weight, ranges from about 100,000 to about 8,000,000.
In one embodiment, the polyalkylene glycol constitutes from about 0.01 to about 45 weight percent by weight of the composition (based on the total weight of the composition). Thus, the ratio of the weight of polyalkylene glycol to the weight of the entire composition will be between about 0.01 to 45 percent. The composition may be prepared in a concentrated form, with little or no water. In such a composition, polyalkylene glycol will comprise about 45 weight percent by weight of the composition. Alternately, the composition may be prepared, with water present up to 90 percent by weight of the composition. In such a composition, polyalkylene glycol will comprise about 0.1 to about 1 percent by weight of the composition. Additionally, the composition may be prepared in a diluted form, with water present in an excess of 90 percent by weight of the composition. In such a composition, polyalkylene glycol will comprise about 0.01 to 0.1 percent by weight of the composition.
In one embodiment, the alkylene group, R, of the polyalkylene glycol is C1-C10alkylene, C3-C9alkylenecycloalkyl or C7-C20alkylenearyl. As used herein, alkylene group includes both straight chained and branched groups and include, but are not limited to, methylene (xe2x80x94CH2xe2x80x94), ethylene (xe2x80x94CH2CH2xe2x80x94), propylene (xe2x80x94CH2CH2CH2xe2x80x94), and pentylene (xe2x80x94CH2(CH2)3CH2xe2x80x94).
A C3-C9alkylenecycloalkyl includes both straight chained and branched alkylene groups with the number of carbon atoms independently ranging from three to nine for the alkylene group and from three to nine for the cycloalkyl group. Thus, the number of carbon atoms in the alkylene and the number of carbon atoms in the cycloalkyl may each independently range from three to nine. The cycloalkyl is covalently bonded to the alkylene. As used herein, a cycloalkyl is any cyclic moiety containing carbon and hydrogen, wherein carbon atoms are bonded in a sequential pattern forming a non-aromatic ring system. Representative examples of C3-C9alkylenecycloalkyl include, but are not limited to, cyclopentylethylene, 1-cyclohexyl-3-methyl-octylene, and 1-cyclopentyl-3-tert-butyl-heptylene.
A C7-C20alkylenearyl includes both straight chained and branched alkylene groups with the number of carbon atoms independently ranging from seven to twenty for the alkylene group and from seven to twenty for the aryl group. Thus, the number of carbon atoms in the alkylene and the number of carbon atoms in the aryl may each independently range from three to nine. The aryl is covalently bonded to the alkylene. As used herein, an aryl group is any cyclic aromatic moiety containing carbon and hydrogen wherein carbon atoms are bonded in a sequential pattern forming an aromatic ring system. Representative examples of C7-C20alkylenearyl include, but are not limited to, benzylethylene, 1-phenylheptylene, 2-phenylpropylene and 2-phenyl-3-methyl-octylene.
In one embodiment of the present invention, the polyalkylene glycol is in the form of a gel. As used herein a gel means a gelatinous, jelly-like colloid in which the dispersed phase has combined with the continuous phase to produce a semisolid material.
In another embodiment of the present invention, the polyalkylene glycol is polyethylene glycol. As used herein, polyethylene glycol is represented by the formula Hxe2x80x94(Oxe2x80x94CH2xe2x80x94CH2)nxe2x80x94OH, where n is greater than or equal to 4.
A polymer or copolymer of polyalkylene oxide having carboxylic acid-containing residues is represented by the formula R5Oxe2x80x94(R6(COOH)O)nxe2x80x94H. The letter xe2x80x9cnxe2x80x9d in the formula represents the number of repeating alkylene carboxylic acid units, and may range from about five to several thousand. Thus, the polymer or copolymer contains a terminal alkoxy group (R5O), with a mid-section composed of repeating alkylene oxide groups with carboxylic acid-containing residues (R6(COOH)O), and a terminal hydroxy group (OH). R5 of the alkoxy group is a straight chained or branched C1-C10 alkyl group. The repeating monomer, (R6(COOH)O), can be either acrylic acid or methacrylic acid, wherein R6(COOH) is CH2xe2x95x90CH(COOH) when the monomer is acrylic acid, and wherein R6(COOH) is CH2xe2x95x90C(CH3)(COOH) when the monomer is methacrylic acid.
Thus, in another embodiment of this invention, the composition contains polyalkylene oxide and a polymer or copolymer of polyalkylene oxide having carboxylic acid-containing residues. In one embodiment, the combination of polyalkylene oxide and the polymer or copolymer together constitutes from about 0.1 to about 99 percent by weight of the composition, based on the total weight of the composition. Thus, the ratio of the combined weight of polyalkylene oxide and the polymer or copolymer to the weight of the entire composition will be between about 0.1 to 99 percent. The composition may be prepared in a concentrated form, with little or no water. In such a composition, polyalkylene oxide and the polymer or copolymer together will comprise up to about 99 percent by weight of the composition. Alternately, the composition may be prepared with water present in an excess of 90 percent by weight of the composition. In such a composition, polyalkylene oxide and the polymer or copolymer together will comprise up to about 0.15 percent by weight of the composition. Additionally, the composition may be prepared in a diluted form, with water present in excess of 99 percent by weight of the composition. In such a composition, polyalkylene oxide and the polymer or copolymer together will comprise about 0.1 percent by weight of the composition.
In one embodiment, the compositions of this invention further comprise an antioxidant. As used herein, an antioxidant refers to an agent that inhibits or slows down or prevents the deterioration of materials, present in the composition, through oxidative processes. The specific antioxidant employed will depend on the desired composition. In one embodiment, the antioxidant is methylparaben. As used herein, methylparaben is 4-Hydroxybenzoic acid methyl ester.
Alternatively, suitable compositions are commercially available, although not recognized for use in the practice of the present invention. For example, Wallace-O""Farrell Inc. (Puyallup, Wash.) sells a composition under the trademark SLIPPERY STUFF(copyright) gel. SLIPPERY STUFF(copyright) gel is sold as a glycerin-free, hygienic, water-based, water-soluble, pharmaceutical lubricant. SLIPPERY STUFF(copyright) is an aqueous gel comprising polyethylene oxide as the preferred polyalkylene oxide; methylparaben as the antioxidant and sodium carboxypolymethylene as the preferred polymer or copolymer of polyalkylene oxide having carboxylic acid-containing residues resulting from the polymerization of a monomer selected from acrylic acid, methacrylic acid and salts thereof.
The methods of the present invention provide for topically contacting a composition as described above with a hair-bearing surface of a warm-blooded animal. The surface may be infested with lice, infested with nits, infested with fleas, infested with any combination thereof. If the composition is applied to a surface that is infested with lice, the composition may be applied in order to immobilize and remove the lice. If the composition is applied to a surface that is infested with nits, the composition may be applied in order to ease the subsequent removal of nits from the surface, whether dead, immobilized, or alive. If the composition is applied to a surface that is infested with fleas, the composition may be applied in order to immobilize and remove the fleas.
In one embodiment, the surface to which the composition is to be applied is a human body. Ectoparasites are found, on humans, most commonly, where hair is found on the body. Such areas include the scalp and hair on the scalp, the hairs of the genital region, the hair of the axilla, eyebrows, eyelashes, beards, and the body surface. In one embodiment, the surface is the head and hair on the head. In another embodiment, the surface is hair-bearing surface on the body of a human. In a further embodiment, the surface is the genital region of a human.
The treatment methods of the invention are achieved by topically applying a composition as described above. The composition may be topically applied to the surface by, for example, pouring the composition on the surface, or rubbing the composition over the surface When the composition is topically applied as described above, the composition should thoroughly saturate the surface. In order to thoroughly saturate the surface with the composition, a sufficient or adequate amount of composition should be employed.
The composition completely immobilizes lice and fleas within a few seconds after application, and the lice or fleas begin to suffocate. After extended continuous exposure, the lice or fleas would eventually die.
In a further embodiment, the method of this invention comprises the further step of removing the immobilized ectoparasite from the treated surface, including for example, removal of immobilized lice, fleas or nits from the treated surface. This may be accomplished by combing the hair with a fine-toothed, lice removal comb after the composition has been topically applied, thereby lifting the lice, fleas, or nits from the treated hair with the comb. In another embodiment, the surface may be washed or rinsed or washed and rinsed after the composition has been topically applied.
In this context, washing means applying soap, a detergent, a bleaching agent or a surfactant to the surface, preferably in the presence of water or another liquid, by immersing, dipping, rubbing or scrubbing, thereby cleansing the surface. xe2x80x9cRinsexe2x80x9d means to pass water or another liquid over the surface thereby cleansing the surface. xe2x80x9cCombingxe2x80x9d means to dress, arrange, sort, smooth, fasten or organize hair utilizing a comb or any thin, toothed strip of plastic, metal, bone, rubber, or other material. In another embodiment, the surface is vacuumed after the composition has been topically applied. xe2x80x9cVacuumingxe2x80x9d means the application of an apparatus on or close to the surface to remove debris from the surface by drawing the debris from the surface to the apparatus with the use of suction or a partial vacuum. Such a vacuuming apparatus may even include a combing device as mentioned supra.
The compositions and methods employed in the present invention overcome all the problems associated with the prior art methods and compositions. The compositions and methods employed in the present invention are non-toxic and environmentally safe. The compositions pose no known health risk to humans, dogs or cats. These compositions and methods are also inexpensive, yet effective (i.e., the ectoparasite cannot develop a resistance to the compositions, the compositions effectively suffocate the ectoparasite and the compositions break the bond between the lice nit and hair shaft). Additionally, dogs and cats who refuse to be given a bath or who do not tolerate being exposed to a dusting powder or spray do not react aggressively to the compositions and methods of the present invention.
The present invention is illustrated by the following examples, which are to be regarded as illustrative rather than restrictive. Unless otherwise noted, all parts and percentages in the examples, as well as the specification and claims, are by weight.

Compositions and methods for treating surfaces infected with ectoparasitic insects


A dye-based ink includes a dye and a solvent. The dye-based ink has a high print quality on plain paper. The dye-based ink may have a print quality similar to pigment-based inks. This may be particularly relevant for black inks.

Ink jet printing is generally a non-impact method for producing images by the deposition of ink droplets in a pixel-by-pixel manner to an image-recording element in response to digital signals.
The inks used in the various ink jet printers can be classified as either dye-based or pigment-based. A dye is a colorant, which is dissolved in the carrier medium. A pigment is a colorant that is insoluble in the carrier medium, but tends to be dispersed/suspended in the form of small particles, often stabilized against flocculation and settling by the use of dispersing agents. Pigment-based inks are generally considered to be less stable than dye-based inks. The carrier medium can be a liquid or a solid at room temperature in both cases. Commonly used carrier media include water, mixtures of water and organic co-solvents and high boiling organic solvents, such as hydrocarbons, esters, ketones, etc.
Plain paper is generally used to refer to paper that has not been specially coated or designed for specialty uses. Plain paper is generally composed of cellulose fibers and fillers. In many cases, fillers tend to be anistropic to the flow of ink and generally have little effect on wicking. However, when ink travels along and through cellulose fibers the flow tends to be directional, and, if a dye is deposited along the way, either through bonding at active sites or evaporation of the solvents, it is seen as wicking. Dye-based inks where the dye tends to penetrate into the paper and/or wick, tend to result in low optical density and/or ragged edges.
Pigment-based inks tend not to have the same problems as dye-base inks when printed on plain paper. Pigment-based inks have been formed which can create a high print quality (PQ) on plain paper. Due to the fact that pigment-based inks have been found to provide higher print quality than traditional dye-based inks, traditional wisdom has been that inks requiring a high print quality (typically black inks) should be pigment-based inks. One such high print quality pigment-based ink is sold by Hewlett Packard under the trade-name HP 56 black ink jet print cartridge for the Deskjet 5550, product # C6656AN.

Hewlett-Packard Development Company, L.P.


A method for stabilizing arsenic in a waste matrix includes the steps of combining with the waste matrix an agent for controlling the oxidation-reduction potential of the matrix, an agent for controlling the pH of the matrix and an agent for adsorbing or coprecipitating the arsenic in the matrix.

Not-applicable.
The present invention relates to methods for treating an arsenic-contaminated waste matrix to stabilize the arsenic and reduce arsenic leaching to contaminant acceptable levels. Arsenic, which is carcinogenic in its inorganic form, is identified in the Resource Conservation Recovery Act (RCRA) as a hazardous metal and is reportedly the third most common regulated inorganic contaminant found at Superfund sites.
Specific sources of hazardous waste containing arsenic include:
pesticides and herbicides [MSMA (monosodium methane arsonate), cacodylic acid (dimethyl arsinic acid), sodium arsenite, lead arsenate)],
ammonia still lime sludge from coking operations,
veterinary pharmaceuticals [(RCRA waste listing K084) wastewater treatment sludge, (K101) distillation tar residue from distillation of aniline-based compounds, (K102) residue from use of activated carbon for decolorization],
arsenic sulfide (D004) generated from phosphoric acid purification, and
wood preservative manufacturing wastes.
Other anthropogenic sources of arsenic include:
coal-burning fly ash from energy production
copper, lead and zinc smelter operations
gold mining operations, and
glass manufacturing and cotton gin processing.
While arsenic, like other metals, exhibits a positive valence state, in aqueous materials it usually exists not as a solitary cationic species but as an oxy-anion, typically in a mixture of a trivalent (+3), reduced form (arsenite, AsO33xe2x88x92) and/or a pentavalent (+5) oxidized form (arsenate, AsO43xe2x88x92). As a result, technologies that effectively treat other cationic metals are typically not effective for stabilizing arsenic.
The ability of arsenic to change oxidation state under certain environmental conditions poses a challenge to treatment methods because the different oxidation states have different mobilities in the environment. Arsenite is usually more mobile than arsenate. Also, arsenic is amenable to numerous chemical and biological transformations in the environment, which can result in increased mobility. The mobility of arsenic can be controlled by redox conditions, pH, biological activity and adsorption/desorption reactions.
Arsenic stabilization chemistry is complex and is influenced significantly by the chemical speciation of arsenic (valence state, inorganic vs. organic, etc.), the oxidation-reduction potential and acidity/alkalinity of the waste matrix, and the presence of other metals, counter ions, and complexing ligands. Arsenic is often present in waste with lead or chromium. Typical techniques for stabilizing these metals (e.g., treating with phosphate to stabilize lead, or treating with reducing agents to stabilize chromium) can undesirably increase arsenic leachability from wastes. When arsenic and chromium are found in together in the same waste matrix, the contaminants are typically present as chromated copper arsenate (CCA).
According to the U.S. Environmental Protection Agency, slag vitrification at 1,100 to 1,400xc2x0 C. is the Best Demonstrated Available Treatment (BDAT) for arsenic. In a vitrification process, all forms of arsenic are converted to arsenic oxide, which reacts with other glass-forming constituents and becomes immobilized in the glass formed. In most arsenic stabilization situations, vitrification is impractical, however, because of the high energy costs and a secondary problem of volatilizing arsenic to cause air pollution.
Other known detoxification technologies include chemistries that involve solidification or chemical stabilization. xe2x80x9cSolidificationxe2x80x9d is defined by US EPA as a technique that encapsulates the waste in a monolithic solid of high structural integrity. The encapsulation may be effected by fine waste particles (microencapsulation) or by a large block or container of wastes (macroencapsulation). Solidification does not necessarily involve a chemical interaction between the wastes and the solidifying reagents, but may mechanically bind the waste into the monolith. Contaminant migration is restricted by decreasing the surface area exposed to leaching and/or by isolating the wastes within an impervious capsule. xe2x80x9cStabilizationxe2x80x9d refers to those techniques that reduce the hazard potential of a waste by converting the contaminants into their least soluble, mobile, or toxic form. The physical nature and handling characteristics of the waste are not necessarily changed by stabilization. These definitions appear on page 2 of Conner, J. R., Chemical Fixation and Solidification of Hazardous Wastes, Van Nostrand Reinhold, New York (1990), which is incorporated herein by reference in its entirety.
U.S. Pat. No. 5,037,479 (Stanforth) discloses a method for treating solid hazardous waste containing unacceptable levels of leachable metals such as lead, cadmium and zinc, which includes the steps of mixing the solid waste with at least two additives, a pH buffering agent and an additional agent which is a salt or acid containing an anion that forms insoluble or non-leachable forms of the leachable metal, each agent being selected from a specified group of agents.
U.S. Pat. No. 5,202,033 (Stanforth et al.) discloses a method for treating solid hazardous waste containing unacceptable levels of leachable metals such as lead, cadmium, arsenic, zinc, copper and chromium, which includes the steps of mixing the solid waste in situ with a phosphate source or a carbonate source or ferrous sulfate. An additional pH controlling agent is optionally added under conditions which support reaction between the additive and pH controlling agent and the metals, to convert the metals to a relatively stable non-leachable form.
U.S. Pat. No. 5,430,235 (Hooykaas et al.) discloses a process for solidifying an arsenic-contaminated matrix as a rock-hard product using high dosages of a clay material, an iron salt, a manganese salt, an oxidizer, and a hydraulic binder such as Portland cement. The process disclosed in U.S. Pat. No. 5,430,235 has several disadvantages. Because of the requirement for a hydraulic binder, the process includes a curing period of 7 days or longer. The process also results in significant bulking (volume increase) of the treated waste materials. If dosage levels are lower than those identified as preferred, it is difficult to achieve solidification.
U.S. Pat. No. 5,347,077 (Hooykaas et al.) discloses a process for solidifying contaminated soil, sediment or sludge that may contain arsenic by adding iron, manganese, aluminum salts and Portland cement at dosages of 20 percent by weight and higher. Again, the process requires a curing period and has the additional disadvantage of high bulking after treatment. Hooykaas et al. use an oxidizing agent to oxidize organic matter, since it is difficult to solidify the waste matrix in the presence of organic matter.
U.S. Pat. No. 5,252,003 (McGahan) discloses a process for controlling arsenic leaching from waste materials by adding iron (III) ions and magnesium (II) ions, preferably in the form of iron (III) sulfate and magnesium oxide.
U.S. Pat. No. 4,723,992 (Hager) discloses a process for fixing pentavalent arsenic in soil by adding metal salts or iron, aluminum, or chromium and a weak organic acid.
U.S. Pat. No. 5,130,051 (Falk) discloses a process for encapsulating waste that contains toxic metals, including arsenic, by adding a mixture of alkaline silicate and magnesium oxide, and, optionally, borax, a concentrated acid, a reducing agent, and fly ash at high dosage rates.
The iron (ferric) sulfate treatment process is ineffective against reduced forms of arsenic and does not provide long-term stability of treated wastes because, under certain natural conditions, the ferric ions may be reduced to ferrous form, thereby remobilizing the arsenic. The solidification processes require very high additive dosages with resultant high bulking of the treated waste.
None of the known technologies discloses a process for cost-effectively and permanently stabilizing arsenic in contaminated soil, sediment, or sludge where the arsenic can be present in trivalent and pentavalent states, and in both organic and inorganic forms.
The patents mentioned in the Background of the Invention are specifically incorporated herein by reference in their entirety.
The present invention provides a method for stabilizing an arsenic-contaminated waste matrix and reducing the leaching of arsenic to acceptable levels. A major objective of the invention is to provide a method for treating an arsenic-contaminated waste matrix that contains arsenic in both the reduced (arsenite) and/or the oxidized (arsenate) form. Other objectives of the invention include efficiently treating both organic and inorganic arsenic compounds, providing long-term, permanent treatment of arsenic, providing treatment with low bulking potential, and providing a treatment method that is cost-effective and easy to conduct.
In the method of the present invention, an agent for controlling oxidation-reduction (redox) potential (ORP), an agent for controlling pH, and an agent for adsorption and coprecipitation of the arsenic are mixed with the arsenic-contaminated material.
The sum of the amounts of added ORP control agent, pH control agent and adsorption-coprecipitation agent are insufficient to cause the waste matrix to solidify without adding a binding agent of the type identified by Hooykaas. The ORP control agent and the pH control agent are added in amounts that will vary with the amount of contaminants present, but in any event, in amounts sufficient to bring most (at least about 50%) of the contaminating arsenic into its higher oxidized state. The arsenite/arsenate transition is controlled by adjusting the redox potential and pH in a coordinated manner. For example, see Vance, D. B., xe2x80x9cArsenic: Chemical Behavior and Treatment,xe2x80x9d National Environmental Journal 60-64 (May/June 1995), incorporated by reference herein in its entirety, which includes charts that depict the speciation of arsenic under various conditions. Agents for adsorbing and coprecipitating arsenic, such as ferric iron, are also known. Id. Although the chemicals used in the stabilization process can have a higher unit cost, the package cost is lower than that of solidification methods because the chemicals are used in small amounts. The ORP control agent, pH control agent and adsorption-coprecipitation agent can each be added to between 0.01 and 10 percent of the waste matrix, by weight.
The invention will be more fully understood upon consideration of the following detailed description.
Not applicable.
The invention describes a cost-effective, low-bulking, permanent method for stabilizing an arsenic-contaminated waste matrix wherein the method comprises the steps of incorporating an ORP control agent, a pH control agent, and an adsorption-coprecipitation agent. The types and additive rates of these component chemistries will depend on arsenic speciation and concentration, the waste matrix, and on the overall treatment objectives. A goal achieved by the method of the present invention is to bring the level of leachable arsenic to no higher than the maximum acceptable Toxicity Characteristic Leaching Procedure (TCLP) toxicity level of 5 mg/L dictated by RCRA. The same level would be set as the criterion for TCLP-arsenic in the proposed Universal Treatment Standard (UTS). The leachable arsenic as measured by the TCLP test can be reduced to a level below the maximum acceptable toxicity level of 5.0 mg/L, e.g., 0.5 mg/L, and perhaps lower.
The arsenic-contaminated materials can include, but are not limited to, sediment, soil, sludge and industrial wastes. The method is a low-bulking method, by which it is intended that after practicing the method the waste matrix volume is preferably no more than 10% greater, and more preferably no more than 5% greater, than before stabilization.
In a first embodiment of the method, each of the three agents is a separate class of chemical compound. In a second embodiment, a single chemical additive can act as two components in the treatment. An alternative would be that the chemical species added initially as one component of the chemistry may react with a waste matrix to produce a second component of the chemistry. In another embodiment, under suitable conditions, one chemical compound added to a specific waste matrix can serve the function of all three components in the disclosed arsenic stabilization method.
The ORP control agent can increase or decrease the redox potential of the waste matrix depending upon the arsenic speciation and presence of other metal contaminants. It is desirable to reduce the mobility by providing conditions where most (at least about 50%, preferably 60 to 95%, more preferably 80 to 95%) of the arsenic compounds are present in the higher oxidized (arsenate) state. For example, if a substantial fraction of arsenic is present in the arsenite form and no other major heavy metal oxy-anions are present in the waste, an oxidizing ORP agent is selected to increase the redox potential of the waste matrix.
This can be complicated by the presence of other heavy metal oxy-anions, such as hexavalent chromium, in the waste matrix. If the waste contains arsenic and another such heavy metal compound, the leaching potential of both the arsenic and the other heavy metal is decreased by lowering the redox potential of the waste matrix using a reducing ORP control agent. In this situation the ORP is reduced enough to convert chromium from its hexavalent state to less mobile trivalent state while the ORP would still be in the range for arsenic to be present most in its less mobile pentavalent state.
The oxidizing ORP control agent can be any compound that increases the redox potential of the waste matrix, although the compound is preferably one that has insignificant environmental impact upon the matrix. Suitable oxidizing ORP control agents include potassium permanganate, sodium chlorate, sodium perchlorate, calcium chlorite or another chlorinated oxidizing agent, sodium percarbonate, sodium persulfate, sodium perborate, potassium persulfate, hydrogen peroxide, magnesium peroxide, or another peroxide compound, compounds of multivalent elements at their higher oxidation state (e.g., ferric sulfate), gaseous oxygen, and ozone.
The reducing ORP control agents can be any compound that decreases the redox potential of the waste matrix, although the compound is preferably one that has insignificant environmental impact upon the matrix. Suitable reducing ORP control agents include ferrous sulfate, sulfur dioxide, sodium bisulfite, sodium metabisulfite, or the like.
In the presence of the adsorption-coprecipitation agent, the pH of the waste matrix controls the leaching potential of arsenic in conjunction with the redox potential of the waste. The pH control agent is selected to raise or lower the pH of the waste matrix depending on the original acidity/alkalinity of the waste and the treatment objectives, in accordance with the diagrams shown in Vance, supra. The pH control agents for raising pH can be any compound that raises the pH, without significant environmental impact, and can include magnesium oxide or hydroxide, calcium oxide or hydroxide, barium oxide or hydroxide, reactive calcium carbonate, sodium hydroxide, dolomitic lime, limestone (high calcium or dolomite), and the like.
The pH control agents for lowering pH can be any compound that lowers the pH, without significant environmental impact, and can include sulfuric acid, phosphoric acid, another mineral acid, or ferric sulfate, ferric chloride, aluminum sulfate, aluminum chloride, and like acidic compounds.
A suitable adsorption-coprecipitation agent can react with arsenic to form an insoluble arsenic compound or can immobilize arsenic on its surface by chemical adsorption. The adsorption-coprecipitation agent can be, but is not limited to, ferric sulfate, aluminum sulfate, activated alumina, or manganese dioxide.
The chemical additives, which can be in a solid state, aqueous slurry, or in solution, are thoroughly mixed with the waste matrix to be stabilized. The stabilization method can be performed in situ using conventional earth-moving equipment such as a back hoe, tiller, or drag line, or ex situ by blending the additives with the waste matrix in a mechanical device, such as a pugmill or a cement mixer. In a typical practice of the method for stabilizing arsenic and reducing arsenic leachability, the ORP control agent is mixed first with the waste matrix, followed by the adsorption-coprecipitation agent and then the pH control agent. Alternatively, all three components can be added simultaneously to, and mixed with, the waste matrix. The additive dosage requirements typically total less than 10-15 percent of the weight of the waste matrix. This is a major advantage over solidification methods, which require 20-30 percent or higher dosages of additives, including cement-like materials.
If the additives are mixed uniformly with the waste, no curing step is required. This is another significant advantage over solidification systems which typically requiring curing periods of one week or more.
The present invention will be more fully understood upon consideration of the following Examples which are intended to be exemplary and not limiting.

Stabilization of arsenic-contaminated materials


An improvement is described in microemulsion composition which has superior cling to a vertical surface and is especially effective in the removal of oily and greasy soil and are mild to the skin, containing an anionic detergent, a thickener, a hydrocarbon ingredient, a cosurfactant and water, wherein the composition has a pH of at least 12.5.

The present invention relates to a microemulsion composition containing a cosurfactant, perfume, anionic surfactant, a polymeric thickener and water and having a pH of at least 12.5, wherein the composition exhibits mildness while having excellent grease cutting capacity as well as superior cling to a vertical surface.
This invention relates to an improved thickened liquid microemulsion composition which has superior cling to a vertical surface and is designed in particular for cleaning dishware, pots and pans and hard surfaces and which is effective in removing burnt-on greasy soils leaving surfaces clean.
In recent years liquid detergents have become widely accepted for cleaning hard surfaces, e.g., painted woodwork and panels, tiled walls, wash bowls, bathtubs, linoleum or tile floors, washable wall paper, dishes, pots and pan etc. Such detergent liquids comprise clear and opaque aqueous mixtures of water-soluble synthetic organic detergents and water-soluble detergent builder salts. In order to achieve comparable cleaning efficiency with granular or powdered detergent cleaning compositions, use of water-soluble inorganic phosphate builder salts was favored in the prior art detergent liquids. These salts both complex hardness ions and provide alkalinity. These properties are well know to enhance soil removal. For example, such early phosphate-containing compositions are described in U.S. Pat. Nos. 2,560,839; 3,234,138; 3,350,319; and British Patent No. 1,223,739.
In view of the environmentalist""s efforts to reduce phosphate levels in ground water, improved detergent liquids containing reduced concentrations of inorganic phosphate builder salts or non-phosphate builder salts have appeared. A particularly useful self-opacified liquid of the latter type is described in U.S. Pat. No. 4,244,840.
However, these prior art liquid detergents containing detergent builder salts or other equivalent tend to leave films, spots or streaks on cleaned unrinsed surfaces, particularly shiny surfaces. Thus, such liquids require thorough rinsing of the cleaned surfaces which is a time-consuming chore for the user. Simply removing builder salts will generate less effective compositions.
In order to overcome the foregoing disadvantage of the prior art detergent liquid, U.S. Pat. No. 4,017,409 teaches that a mixture of paraffin sulfonate and a reduced concentration of inorganic phosphate builder salt should be employed. However, such compositions are not completely acceptable from an environmental point of view based upon the phosphate content. On the other hand, another alternative to achieving phosphate-free detergent liquids has been to use a major proportion of a mixture of anionic and nonionic detergents with minor amounts of glycol ether solvent and organic amine as shown in U.S. Pat. No. 3,935,130. Again, this approach has not been completely satisfactory and the high levels of organic detergents necessary to achieve cleaning cause foaming which, in turn, leads to the need for thorough rinsing which has been found to be undesirable to today""s consumers.
Another approach to formulating hard surfaced or liquid detergent compositions where product homogeneity and clarity are important considerations involves the formation of oil-in-water (o/w) microemulsions which contain one or more surface-active detergent compounds, a water-immiscible solvent (typically a hydrocarbon solvent), water and a xe2x80x9ccosurfactantxe2x80x9d compound which provides product stability. By definition, an o/w microemulsion is a spontaneously forming colloidal dispersion of xe2x80x9coilxe2x80x9d phase particles having a particle size in the range of 25 to 800 xc3x85 in a continuous aqueous phase.
In view of the extremely fine particle size of the dispersed oil phase particles, microemulsions are transparent to light and are clear and usually highly stable against phase separation.
Patent disclosures relating to use of grease-removal solvents in o/w microemulsions include, for example, European Patent Applications EP 0137615 and EP 0137616xe2x80x94Herbots et al; European Patent Application EP 0160762xe2x80x94Johnston et al; and U.S. Pat. No. 4,561,991xe2x80x94Herbots et al. Each of these patent disclosures also teaches using at least 5% by weight of grease-removal solvent.
It also is known from British Patent Application GB 2144763A to Herbots et al, published Mar. 13, 1985, that magnesium salts enhance grease-removal performance of organic grease-removal solvents, such as the terpenes, in o/w microemulsion liquid detergent compositions. The compositions of this invention described by Herbots et al. require at least 5% of the mixture of grease-removal solvent and magnesium salt and preferably at least 5% of solvent (which may be a mixture of water-immiscible non-polar solvent with a sparingly soluble slightly polar solvent) and at least 0.1% magnesium salt.
However, since the amount of water immiscible and sparingly soluble components which can be present in an o/w microemulsion, with low total active ingredients without impairing the stability of the microemulsion is rather limited (for example, up to 18% by weight of the aqueous phase), the presence of such high quantities of grease-removal solvent tend to reduce the total amount of greasy or oily soils which can be taken up by and into the microemulsion without causing phase separation.
The following representative prior art patents also relate to liquid detergent cleaning compositions in the form of o/w microemulsions: U.S. Pat. No. 4,472,291xe2x80x94Rosario; U.S. Pat. No. 4,540,448xe2x80x94Gauteer et al; U.S. Pat. No. 3,723,330xe2x80x94Sheflin; etc.
Liquid detergent compositions which include terpenes, such as d-limonene, or other grease-removal solvent, although not disclosed to be in the form of o/w microemulsions, are the subject matter of the following representative patent documents: European Patent Application 0080749; British Patent Specification 1,603,047; and U.S. Pat. Nos. 4,414,128 and 4,540,505. For example, U.S. Pat. No. 4,414,128 broadly discloses an aqueous liquid detergent composition characterized by, by weight:
(a) from 1% to 20% of a synthetic anionic, nonionic, amphoteric or zwitterionic surfactant or mixture thereof;
(b) from 0.5% to 10% of a mono- or sesquiterpene or mixture thereof, at a weight ratio of (a):(b) being in the range of 5:1 to 1:3; and
(c) from 0.5% 10% of a polar solvent having a solubility in water at 15xc2x0 C. in the range of from 0.2% to 10%. Other ingredients present in the formulations disclosed in this patent include from 0.05% to 2% by weight of an alkali metal, ammonium or alkanolammonium soap of a C13-C24 fatty acid; a calcium sequestrant from 0.5% to 13% by weight; non-aqueous solvent, e.g., alcohols and glycol ethers, up to 10% by weight; and hydrotropes, e.g., urea, ethanolamines, salts of lower alkylaryl sulfonates, up to 10% by weight. All of the formulations shown in the Examples of this patent include relatively large amounts of detergent builder salts which are detrimental to surface shine.
Furthermore, the present inventors have observed that in formulations containing grease-removal assisting magnesium compounds, the addition of minor amounts of builder salts, such as alkali metal polyphosphates, alkali metal carbonates, nitrilotriacetic acid salts, and so on, tends to make it more difficult to form stable microemulsion systems.
U.S. Pat. No. 5,082,584 discloses a microemulsion composition having an anionic surfactant, a cosurfactant, nonionic surfactant, perfume and water; however, these compositions do not possess the ecotoxicity and the improved interfacial tension properties as exhibited by the compositions of the instant invention.
This invention relates to cleaning compositions in the form of liquids, sprays and gels, which remove dried-on and cooked-on food and other difficult-to-remove soils from kitchen utensils, flatware, dishes, glassware, cookware, bakeware, cooking surfaces and surrounding areas in a convenient, easy, timely and mild manner.
Of the difficult-to-remove soils, the most severe is the baked and/or burned-on (especially when reheated and/or allowed to build up over time). Soil categories include grease, meat (including skin), dairy, fruit pie filling, carbohydrate and starch. Soiled substrate categories include aluminum, iron, stainless steel, enamel, Corningware, Pyrex and other glass cookware.
U.S. Pat. No. 6,228,832 teaches a microemulsion cleaning containing an anionic surfactant, triethanol amine, cosurfactant, alkali metal hydroxide, perfume and water and having a pH of at least 12.5.
The present invention provides an improved, clear, liquid cleaning composition having improved interfacial tension which improves cleaning hard surfaces in the form of a microemulsion which is suitable for removing grease from dishware and hard surfaces such as plastic, vitreous and metal surfaces having a shiny finish, oil stained floors, automotive engines and other engines, wherein the compositions are mild to the skin. More particularly, the improved cleaning compositions exhibit superior cling to a vertical surface and have good grease soil removal properties due to thexe2x80x94and addition of a mild amount of alkalinity.
Surprisingly, these desirable results are accomplished even in the absence of polyphosphate or other inorganic or organic detergent builder salts.
In one aspect, the invention generally provides a stable, optically clear microemulsion, cleaning composition especially effective in the removal of oily and greasy oil. The dilute microemulsion composition includes, on a weight basis:
0.1% to 10% of an anionic surfactant;
0.05% to 3% of a thickener;
0.1% to 2%, more preferably 0.25% to 1.5% of triethanol amine;
3% to 20% of at least one water-mixable cosurfactant;
0.1% to 2.0% of an alkali metal hydroxide such as potassium hydroxide and/or sodium hydroxide;
0.2 to 10.0% of a perfume, essential oil, or water insoluble hydrocarbon having 6 to 18 carbon atoms; and
the balance being water, wherein the composition has a pH of at least 12.5 and preferably at least about 13 and the composition does not contain an amine oxide surfactant, an alkyl polyglucoside surfactant, an ethoxylated nonionic surfactant, a zwitterionic surfactant, a fatty acid alkanol amide or an organic compound containing both ethoxylate groups and an ester group. The following thickeners are excluded from the instant composition because they fail to provide the proper rheological profile. These excluded thickeners are carrageenan, cellulose gum (KMO), hydroxyethyl cellulose (HEC), methyl cellulose, hydropropyl methyl cellulose, alumina, polygenic silicas, anionic polymers such as polyacrylic acid and polymethacrylic acid and nonionic synthetic polymers such as polyethylene glycol.
An object of the instant invention is to provide a composition which is effective in the removal of dirt especially on a vertical surface which has hardened on the surface or is baked on the surface such as the inside of an oven while providing a composition which has a low level of skin and eye irritation thereby permitting use of the product without having to use rubber protective gloves or eye protection.
The present invention relates to a stable microemulsion composition comprising approximately by weight: 0.1% to 10% of an anionic surfactant, 0.01% to 3% of a thickener, 3% to 20% of at least one cosurfactant, 0.1 to 2%, more preferably 0.25% to 1.5% of triethanol amine, 0.4% to 1.2% of an alkali metal hydroxide auch as sodium hydroxide and/or potassium hydroxide, 0.05% to 10% of a water insoluble hydrocarbon, essential oil or a perfume and the balance being water, said composition has a pH of at least 12.5 and preferably at least about 13.0 and the composition does not contain an amine oxide surfactant, an alkyl polyglucoside surfactant, an ethoxylated nonionic surfactant, a zwitterionic surfactant, a fatty acid alkanol amide or an organic compound containing both ethoxylate groups and an ester group. The following thickeners are excluded from the instant composition because they fail to provide the proper rheological profile. These excluded thickeners are carrageenan, cellulose gum (KMO), hydroxyethyl cellulose (HEC), methyl cellulose, hydropropyl methyl cellulose, polyacrylamides, polyvinyl alcohol, alumina, polygenic silicas, anionic polymers such as polyacrylic acid and polymethacrylic acid and nonionic synthetic polymers such as polyethylene glycol.
As used herein and in the appended claims the term xe2x80x9cperfumexe2x80x9d is used in its ordinary sense to refer to and include any non-water soluble fragrant substance or mixture of substances including natural (i.e., obtained by extraction of flower, herb, blossom or plant), artificial (i.e., mixture of natural oils or oil constituents) and synthetically produced substance) odoriferous substances. Typically, perfumes are complex mixtures of blends of various organic compounds such as alcohols, aldehydes, ethers, aromatic compounds and varying amounts of essential oils (e.g., terpenes) such as from 0% to 80%, usually from 10% to 70% by weight, the essential oils themselves being volatile odoriferous compounds and also serving to dissolve the other components of the perfume.
In the present invention the precise composition of the perfume is of no particular consequence to cleaning performance so long as it meets the criteria of water immiscibility and having a pleasing odor. Naturally, of course, especially for cleaning compositions intended for use in the home, the perfume, as well as all other ingredients, should be cosmetically acceptable, i.e., non-toxic, hypoallergenic, etc. The instant compositions show a marked improvement in ecotoxocity as compared to existing commercial products.
The hydrocarbon such as a perfume is present in the dilute o/w microemulsion in an amount of from 0.1% to 10% by weight, preferably from 0.4% to 3.0% by weight, especially preferably from 0.5% to 2.0% by weight.
Furthermore, although superior grease removal performance will be achieved for perfume compositions not containing any terpene solvents, it is apparently difficult for perfumers to formulate sufficiently inexpensive perfume compositions for products of this type (i.e., very cost sensitive consumer-type products) which includes less than 20%, usually less than 30%, of such terpene solvents.
Thus, merely as a practical matter, based on economic consideration, the dilute microemulsion detergent cleaning compositions of the present invention may often include as much as 0.2% to 7% by weight, based on the total composition, of terpene solvents introduced thereunto via the perfume component. However, even when the amount of terpene solvent in the cleaning formulation is less than 1.5% by weight, such as up to 0.6% by weight or 0.4% by weight or less, satisfactory grease removal and oil removal capacity is provided by the inventive diluted o/w microemulsions.
Thus, for a typical formulation of a diluted microemulsion according to this invention a 20 milliliter sample of microemulsion containing 1% by weight of perfume will be able to solubilize, for example, up to 2 to 3 ml of greasy and/or oily soil, while retaining its form as a microemulsion, regardless of whether the perfume contains 0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7% or 0.8% by weight of terpene solvent.
In place of the perfume in the microemulsion composition at the same previously defined concentrations that the perfume was used in the microemulsion composition one can employ an essential oil or a water insoluble hydrocarbon having 6 to 18 carbon such as a paraffin or isoparaffin.
Suitable essential oils are selected from the group consisting of: Anethole 20/21 natural, Aniseed oil china star, Aniseed oil globe brand, Balsam (Peru), Basil oil (India), Black pepper oil, Black pepper oleoresin 40/20, Bois de Rose (Brazil) FOB, Borneol Flakes (China), Camphor oil, White, Camphor powder synthetic technical, Cananga oil (Java), Cardamom oil, Cassia oil (China), Cedarwood oil (China) BP, Cinnamon bark oil, Cinnamon leaf oil, Citronella oil, Clove bud oil, Clove leaf, Coriander (Russia), Coumarin 69xc2x0 C. (China), Cyclamen Aldehyde, Diphenyl oxide, Ethyl vanilin, Eucalyptol, Eucalyptus oil, Eucalyptus citriodora, Fennel oil, Geranium oil, Ginger oil, Ginger oleoresin (India), White grapefruit oil, Guaiacwood oil, Gurjun balsam, Heliotropin, Isobornyl acetate, Isolongifolene, Juniper berry oil, L-methyl acetate, Lavender oil, Lemon oil, Lemongrass oil, Lime oil distilled, Litsea Cubeba oil, Longifolene, Menthol crystals, Methyl cedryl ketone, Methyl chavicol, Methyl salicylate, Musk ambrefte, Musk ketone, Musk xylol, Nutmeg oil, Orange oil, Patchouli oil, Peppermint oil, Phenyl ethyl alcohol, Pimento berry oil, Pimento leaf oil, Rosalin, Sandalwood oil, Sandenol, Sage oil, Clary sage, Sassafras oil, Spearmint oil, Spike lavender, Tagetes, Tea tree oil, Vanilin, Vetyver oil (Java), Wintergreen
Regarding the anionic surfactant present in the microemulsions any of the conventionally used water-soluble anionic surfactants or mixtures of said anionic surfactants can be used in this invention. As used herein the term xe2x80x9canionic surfactantxe2x80x9d is intended to refer to the class of anionic and mixed anionic-nonionic detergents providing detersive action.
Suitable water-soluble non-soap, anionic surfactants include those surface-active or detergent compounds which contain an organic hydrophobic group containing generally 8 to 26 carbon atoms and preferably 10 to 18 carbon atoms in their molecular structure and at least one water-solubilizing group selected from the group of sulfonate, sulfate and carboxylate so as to form a water-soluble detergent. Usually, the hydrophobic group will include or comprise a C8-C22 alkyl, alkyl or acyl group. Such surfactants are employed in the form of water-soluble salts and the salt-forming cation usually is selected from the group consisting of sodium, potassium, ammonium, magnesium and mono-, di- or tri-C2-C3 alkanolammonium, with the sodium, magnesium and ammonium cations again being preferred.
Examples of suitable sulfonated anionic surfactants are the well known higher alkyl mononuclear aromatic sulfonates such as the higher alkyl benzene sulfonates containing from 10 to 16 carbon atoms in the higher alkyl group in a straight or branched chain, C8-C15 alkyl toluene sulfonates and C8-C15 alkyl phenol sulfonates.
A preferred sulfonate is linear alkyl benzene sulfonate having a high content of 3-(or higher) phenyl isomers and a correspondingly low content (well below 50%) of 2-(or lower) phenyl isomers, that is, wherein the benzene ring is preferably attached in large part at the 3 or higher (for example, 4, 5, 6 or 7) position of the alkyl group and the content of the isomers in which the benzene ring is attached in the 2 or 1 position is correspondingly low. Particularly preferred materials are set forth in U.S. Pat. No. 3,320,174.
Other suitable anionic surfactants are the olefin sulfonates, including long-chain alkene sulfonates, long-chain hydroxyalkane sulfonates or mixtures of alkene sulfonates and hydroxyalkane sulfonates. These olefin sulfonate detergents may be prepared in a known manner by the reaction of sulfur trioxide (SO3) with long-chain olefins containing 8 to 25, preferably 12 to 21 carbon atoms and having the formula RCHxe2x95x90CHR1 where R is a higher alkyl group of 6 to 23 carbons and R1 is an alkyl group of 1 to 17 carbons or hydrogen to form a mixture of sultones and alkene sulfonic acids which is then treated to convert the sultones to sulfonates. Preferred olefin sulfonates contain from 14 to 16 carbon atoms in the R alkyl group and are obtained by sulfonating an a-olefin.
Other examples of suitable anionic sulfonate surfactants are the paraffin sulfonates containing 10 to 20, preferably 13 to 17, carbon atoms. Primary paraffin sulfonates are made by reacting long-chain alpha olefins and bisulfites and paraffin sulfonates having the sulfonate group distributed along the paraffin chain are shown in U.S. Pat. Nos. 2,503,280; 2,507,088; 3,260,744; 3,372,188; and German Patent 735,096.
Examples of satisfactory anionic sulfate surfactants are the C8-C18 alkyl sulfate salts and the C8-C18 alkyl sulfate salts and the C8-C18 alkyl ether polyethenoxy sulfate salts having the formula R(OC2H4)n OSO3M wherein n is 1 to 12, preferably 1 to 5, and M is a solubilizing cation selected from the group consisting of sodium, potassium, ammonium, and mono-, di- and triethanol ammonium ions. The alkyl sulfates may be obtained by sulfating the alcohols obtained by reducing glycerides of coconut oil or tallow or mixtures thereof and neutralizing the resultant product.
On the other hand, the alkyl ether polyethenoxy sulfates are obtained by sulfating the condensation product of ethylene oxide with a C8-C18 alkanol and neutralizing the resultant product. The alkyl sulfates may be obtained by sulfating the alcohols obtained by reducing glycerides of coconut oil or tallow or mixtures thereof and neutralizing the resultant product. On the other hand, the alkyl ether polyethenoxy sulfates are obtained by sulfating the condensation product of ethylene oxide with a C8-C18 alkanol and neutralizing the resultant product. The alkyl ether polyethenoxy sulfates differ from one another in the number of moles of ethylene oxide reacted with one mole of alkanol. Preferred alkyl sulfates and preferred alkyl ether polyethenoxy sulfates contain 10 to 16 carbon atoms in the alkyl group.
The C8-C12 alkylphenyl ether polyethenoxy sulfates containing from 2 to 6 moles of ethylene oxide in the molecule also are suitable for use in the inventive compositions. These surfactants can be prepared by reacting an alkyl phenol with 2 to 6 moles of ethylene oxide and sulfating and neutralizing the resultant ethoxylated alkylphenol.
Other suitable anionic detergents are the C9-C15 alkyl ether polyethenoxyl carboxylates having the structural formula R(OC2H4)nOX COOH wherein n is a number from 4 to 12, preferably 5 to 10 and X is selected from the group consisting of CH2, C(O)R1 and
wherein R1 is a C1-C3 alkylene group. Preferred compounds include C9-C11 alkyl ether polyethenoxy (7-9) C(O) CH2CH2COOH, C13-C15 alkyl ether polyethenoxy (7-9)
and C10-C12 alkyl ether polyethenoxy (5-7) CH2COOH. These compounds may be prepared by condensing ethylene oxide with appropriate alkanol and reacting this reaction product with chloracetic acid to make the ether carboxylic acids as shown in U.S. Pat. No. 3,741,911 or with succinic anhydride or phtalic anhydride.
Obviously, these anionic detergents will be present either in acid form or salt form depending upon the pH of the final composition, with the salt forming cation being the same as for the other anionic detergents.
Of the foregoing non-soap anionic surfactants, the preferred surfactants are the C9-C5 linear alkylbenzene sulfonates and the C13-C17 paraffin or alkane sulfonates. Particularly, preferred compounds are sodium C10-C13 alkylbenzene sulfonate and sodium C13-C17 alkane sulfonate.
Generally, the proportion of the nonsoap-anionic surfactant will be in the range of 0.1% to 5%, preferably from 0.4% to 3%, by weight of the dilute o/w microemulsion composition or the all purpose hard surface cleaning composition.
Suitable cosurfactants for the microemulsion over temperature ranges extending from 5xc2x0 C. to 43xc2x0 C. for instance are glycerol, ethylene glycol, water-soluble polyethylene glycols having a molecular weight of 300 to 1000, polypropylene glycol of the formula HO(CH3CHCH2O)nH wherein n is a number from 2 to 18, mixtures of polyethylene glycol and polypropyl glycol (Synalox) and mono C1-C6 alkyl ethers of ethylene glycol and propylene glycol having the structural formula R(X)nOH wherein R is C1-C6 alkyl group, X is (OCH2CH2) or (OCH2(CH3)CH) and n is a number from 1 to 4, diethylene glycol, triethylene glycol, 1methoxy-2-propanol, 1methoxy-3-propanol, and 1methoxy 2-3- or 4-butanol, and triethyl phosphate. Additionally, mixtures of two or more of the three classes of cosurfactant compounds may be employed where specific pH""s are desired.
Representative members of the polypropylene glycol include dipropylene glycol and polypropylene glycol having a molecular weight of 200 to 1000, e.g., polypropylene glycol 400. Other satisfactory glycol ethers are ethylene glycol monobutyl ether (butyl cellosolve), diethylene glycol monobutyl ether (butyl carbitol), triethylene glycol monobutyl ether, mono, di, tri propylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, mono, di, tripropylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monohexyl ether, diethylene glycol monohexyl ether, propylene glycol tertiary butyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monopropyl ether, ethylene glycol monopentyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monopentyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monopentyl ether, triethylene glycol monohexyl ether, mono, di, tripropylene glycol monoethyl ether, mono, di tripropylene glycol monopropyl ether, mono, di, tripropylene glycol monopentyl ether, mono, di, tripropylene glycol monohexyl ether, mono, di, tributylene glycol mono methyl ether, mono, di, tributylene glycol monoethyl ether, mono, di, tributylene glycol monopropyl ether, mono, di, tributylene glycol monobutyl ether, mono, di, tributylene glycol monopentyl ether and mono, di, tributylene glycol monohexyl ether, ethylene glycol phenyl ether and 1-phenoxy-2-propanol, ethylene glycol monoacetate and dipropylene glycol propionate.
The thickener which is used in the instant microemulsion is selected from the group consisting of hydrophobically modified polymers like Carbopol 614 manufactured by B. F. Goodrich Co. and Polygel K200, xanthan gum and Laponite caly manufactured by Southern Clay. One of the preferred thickeners, a xanthan gum called Keltrol T and sold by Merck and Co. The xanthan gum is an exocellular hetropolysaccharide having a molecular weight of about 1,000,000 to 10,000,000 and is used in a concentration of weight percent to about 1.0 weight percent, more preferably about 0.1 to about 0.7 weight percent, and most preferably 0.2 to 0.6 weight percent. When used at these concentration levels, the composition retains its microemulsion characteristics in that the essential micellar aggregates are maintained. The composition is still sprayable and will nicely cling to a vertical wall. Additionally, the compositions having the xanthan gum incorporates therein are shear thinning which means that the composition can be easily removed from the surface being cleaned without much mechanical action.
The final essential ingredient in the inventive microemulsion compositions having improved interfacial tension properties is water. The proportion of water in the microemulsion cleaning composition compositions generally is in the range of 20% to 99%, preferably 70% to 98% by weight.
As believed to have been made clear from the foregoing description, the dilute o/w microemulsion liquid detergent cleaning compositions of this invention are especially effective when used as is, that is, without further dilution in water, since the properties of the composition as an o/w microemulsion are best manifested in the neat (undiluted) form. However, at the same time it should be understood that depending on the levels of surfactants, cosurfactants, perfume and other ingredients, some degree of dilution without disrupting the microemulsion, per se, is possible. For example, at the preferred low levels of active surfactant compounds (i.e., primary anionic and nonionic detergents) dilutions up to 50% will generally be well tolerated without causing phase separation, that is, the microemulsion state will be maintained.
On the other hand, it is also within the scope of this invention to formulate highly concentrated microemulsions which will be diluted with additional water before use.
The cleaning composition of this invention may, if desired, also contain other components either to provide additional effect or to make the product more attractive to the consumer. The following are mentioned by way of example: Colors or dyes in amounts up to 0.5% by weight; bactericides in amounts up to 1% by weight; preservatives or antioxidizing agents, such as formalin, 5-bromo-5-nitro-dioxan-1,3; 5-chloro-2-methyl4-isothaliazolin-3-one, 2,6-di-tert.butyl-p-cresol, etc., in amounts up to 2% by weight; and pH adjusting agents, such as sulfuric acid or sodium hydroxide, as needed. Furthermore, if opaque compositions are desired, up to 4% by weight of an opacifier may be added. In final form, the clear microemulsions exhibit stability at reduced and increased temperatures. More specifically, such compositions remain clear and stable in the range of 5xc2x0 C. to 50xc2x0 C., especially 10xc2x0 C. to 43xc2x0 C. Such compositions exhibit a pH of at least 12.5 and preferably at least about 13.0. The liquids are readily pourable.
Because the compositions as prepared are aqueous liquid formulations and since no particular mixing is required to form the microemulsion, the compositions are easily prepared simply by combining all the ingredients in a suitable vessel or container. The order of mixing the ingredients is not particularly important and generally the various ingredients can be added sequentially or all at once or in the form of aqueous solutions of each or all of the primary surfactants and cosurfactants can be separately prepared and combined with each other and with the perfume. It is not necessary to use elevated temperatures in the formation step and room temperature is sufficient.
The instant microemulsion formulas explicitly exclude alkali metal silicates and alkali metal builders such as alkali metal polyphosphates, alkali metal carbonates, alkali metal phosphonates and alkali metal citrates.

Thickened microemulsion cleaning compositions comprising Xanthum gum


The continuous batch seed coating system of this invention includes a coating unit, liquid and dry treatment metering systems, a seed metering system, and a PLC controller. The coating unit includes a substantially unitary bowl, which is rotated to cyclically rotate seed being treated. The bowl is rotated within an enclosure, then evacuated after being treated. A peristaltic pump and a hopper-auger unit provide liquid and dry seed treatment formulations to the coating unit. The automated seed metering system pre-weighs seed to be conveyed into the coating unit. The PLC controller controls the retention time in the coating unit, the amounts and timing of seed treatment formulations, conveys seed to the coating unit, and optionally sounds alarms when one of the treatment formulations is not available or when seed is not present in the seed metering system.

1. Field of the Invention
This invention relates to seed treaters and, in particular, this invention relates to an automated and programmable seed treater for relatively small amounts of seed.
2. Background of the Invention
The benefits of treating planting seed are well-known. Among these benefits are reduced, or substantially eliminated, incidences of stand loss due to diseases and insects. With the advent of the newer fungicides and insecticides, extremely small amounts of active ingredients are coated on the seed surfaces. Therefore, in order to uniformly coat the seeds, treaters must administer ever decreasing amounts of formulations.
Both continuous and batch seed treaters are known to the art. However, most of these reduced treaters are designed to efficiently treat relatively large seed lots. Smaller seed lots have traditionally been treated by efficient batch systems. These small seed lots are often extremely valuable. Examples of these small seed lots include parent seeds (e.g., breeders, foundation, registered), hand-produced hybrid seeds, and vegetable seeds. These small seed lots must be treated uniformly with fungicides and insecticides to eliminate losses from diseases and insects. Also due to their high value, carryover between the seed lots must be eliminated. Heretofore, the seed lots were treated using inefficient protocols and equipment to eliminate the possibility of carryover. These protocols and equipment often resulted in seed lots, which were not treated uniformly.
To this end, a seed treating device is disclosed in German Patent DE 4411058, issued Apr. 3, 1997, and hereby incorporated by reference. This device has a mixing bowl connected to a high revolution, multi-turn actuator and a mechanism to feed seed into the mixing bowl. The bowl rotates to rotate seed been treated therein. The seed treating formulation is sprayed in the bowl while the seed is being rotated to uniformly coat the seed with the formulation. While effective, this device has two major limitations. The first limitation is that there is no mechanism for horizontally adjusting the position of the mixing bowl during assembly or after repair. Therefore, positioning the bowl requires excessive amounts of time and extensive trial and error. The second limitation relates to the method of forming the mixing bowl. The mixing bowl is formed from several metallic sheets. These sheets are bonded together, then formed into a bowl by being pressed and often hand beaten until the desired bowl shape has been attained. These bowls are not uniform and either size or shape. Therefore, other components must be especially made to fit these bowls. Consequently, repairing and replacing bowls of this treater usually involves replacing other parts as well.
There is then a need for a seed treater, which will efficiently treat small seed lots and which has bowls which are easily adjusted and uniform in size.
This invention substantially meets the aforementioned needs of the industry by providing a continuous batch seed coating system. The present continuous batch seed coating system efficiently treats small seed lots and eliminates carryover between seed lots. The present continuous batch seed coating system includes a coating unit. In a preferred embodiment, the present coating unit has a generally cylindrical lower member, a spin formed rotating bowl-shaped member, and a lid-shaped upper member. The bowl-shaped member is rotatably disposed in the lower member. The lower member, bowl-shaped member, and upper member cooperate to define a seed treating area. Also in a preferred embodiment, an adjustment assembly (mechanism) horizontally adjusts the position of the bowl-shaped member within the cylindrical lower member. The bowl-shaped member may be formed from a single metallic sheet and thus be unitary.
The present continuous batch coating system may further include liquid and dry treatment metering systems for conveying seed treatment formulations to the coating unit. The liquid metering system may include a peristaltic pump. The peristaltic pump conveys liquid seed treatment formulations through a house to the coating unit. The dry treatment metering system may convey dry seed treatment formulations from a hopper to the coating unit via an auger.
A seed metering system may be included within the present batch seed coating system. The seed metering system may include a holding bin with a clamshell gate, a weigh hopper and a load cell. The clamshell gate is closed upon sensing a predetermined seed weight in the weigh hopper. When the coating unit is ready to treat a batch of seed, the weigh hopper dumps seed their within into the coating unit.
The present continuous batch seed coating system may also include a PLC controller. In a preferred embodiment, the PLC controller controls seed retention time within the coating unit, causes liquid and/or dry seed treatment formulations to be dispensed to the coating unit, and actuates the seed metering system to deliver a predetermined amount of seed to the coating unit.
It is therefore an object of this invention, to provide a coating unit with a rotatable bowl formed from a single, metallic workpiece.
A yet further object of the present invention is to provide an upper (lid) coating unit member formed from a single, metallic workpiece.
A still further object of the present invention is to provide a coating unit upper (lid) member and a coating unit bowl member with uniform sizes and shapes.
Another object of the present invention is to provide interchangeable coating unit upper (lid) members and coating unit bowl members.