A process for washing articles in a mechanical washing machine including the steps of:

The present invention is in the field of machine dishwashing. More specifically, the invention encompasses automatic dishwashing detergents and rinse aids and a process for using them.
To wash articles in a commercially available dish washing machine entails using three product types. Salt is added to the salt compartment to soften the water, a dish washing formulation is used to clean the articles and a rinse aid is used to ensure that the articles are rinsed with no streaks or smears.
The salt in the machine does not have to be replaced every wash, however it is inconvenient for consumers replace the salt.
The present invention relates to a process of washing dishes that obviates/lessens the need for salt in a machine dish washing formulation.
Accordingly, the present invention provides a process for washing articles in a mechanical washing machine comprising the steps of:
i) treating the articles with a wash liquor comprising a dishwashing composition and; said composition when undiluted circulated comprising greater than 20 wt.% of a bicarbonate salt; followed by
ii) treating the articles with a rinsing solution comprising a rinse aid the rinse aid when undiluted comprising at least 20wt% of a water-soluble acid builder or salt thereof; wherein minimal rejuvenation of ion exchange material within the machine is needed.
The invention also discloses use of citric acid in a rinse aid composition for use in an automatic dishwashing machine so no salt is required for the rejuvenation of ion exchange material within the machine, use of bicarbonate salt in a dishwashing composition for use in an automatic dishwashing machine so no salt is required for the rejuvenation of ion exchange material within the machine and use of a chelating agent in a dish washing composition for use in an automatic dish washing machine so no salt is required for the rejuvenation of ion.
The invention further relates to a kit of parts for use in an automatic dishwashing machine comprising:
(i) a first container of rinse aid composition;
(ii) a second container of dishwashing composition and;
(iii) instructions that no salt is to be added to the machine.
European dish washers have within them ion exchanger materials which soften the water thus aiding the cleaning of utensils and lessening deposition of insoluble salts. The ion exchange material is regenerated by the use of salt(sodium chloride), put into the machine by the consumer. Most machines have a dial which the consumer sets to a pre-determined level depending on the hardness of the water supplied to the machine. Depending on the machine type the machine softens water in two ways:
On a hard water setting it either regenerates the ion exchange material frequently (e.g. every 2 washes) or it adds a high quantity of saturated sodium chloride solution to the ion exchange material (e.g. 75 ml). Correspondingly on a low water setting it either regenerates the ion-exchanger infrequently (every 5 washes) or it adds lower quantities of saturated sodium chloride solution to the ion exchange material each wash (e.g. 30 ml).
The present invention has found that the ion exchange material does not need to be as frequently rejuvenated if formulations according to the invention are used. Preferably the ion exchange material does not need to be rejuvenated; that is no salt needs to be added to the machine.
Thus a machine that frequently doses salt every 5 washes will when used with the formulation of the invention only need to dose e.g. every 2 washes, thus the dial can be set accordingly. Alternatively a machine that doses salt every wash at a dose of 25 g will only need to dose at less than 10 g
At very high water harness only 40 washes from a 1kg pack of salt can be achieved, but using formulations according to the invention greater than 100 washes can be achieved.
Thus, in the present invention minimal rejuvenation of ion exchange material means that the average level of salt that is needed per wash can be represented by the following formula:
degree of hardness of waterxe2x80x9430xc3x9725/40 g
When the degree of water hardness is 30 or less, no salt is added.
The detergency builder system is preferably water-soluble and more preferably comprises a bicarbonate salt, preferably sodium or potassium bicarbonate most especially sodium bicarbonate. Bicarbonate salts are particularly preferred as builders as they also have a buffering capacity. It is preferable if the bicarbonate is present at a level greater than 20 wt% of the total composition, more particularly at least 24-wt% of the total composition.
It is preferable if the builder further comprises a carboxylate or polycarboxylate builder containing from one to four carboxy groups, particularly selected from monomeric polycarboxylates or their acid forms, homo or copolymeric polycarboxylic acids or there salts in which the polycarboxylate comprises at least two carboxylic radicals selected from each other by not more than two carbon atoms. Preferred carboxylates include the polycarboxylate materials described in U.S. Pat. No. 2,264,103, including the water-soluble alkali metal salts of mellitic acid and citric acid, dipicolinic acid, oxydisuccinic acid and alkenyl succinates. The water-soluble salts of polycarboxylate polymers and copolymers, such as are described in U.S. Pat. No. 3,308,067 are also be suitable for use with the invention.
Of the builder materials listed in the above paragraph, the preferred polycarboxylates are hydroxycarboxylates containing up to three carboxy groups per molecule, especially citric acid or its salt, particularly sodium citrate. It is preferable if the carboxylate builder is present at a level of at least 20 wt% of the total formulation, more preferably at a level greater than 30 wt%.
It is preferred if the weight ratio of polycarboxylate builder to bicarbonate builder is at least 1:1, preferably greater than 3:2
Further soluble detergency builder salts which can be used with the present invention are poly-valent inorganic and poly-valent organic builders, or mixtures thereof. Non-limiting examples of suitable water-soluble, inorganic alkaline detergency builder salts include the alkali metal carbonates, borates, phosphates, polyphosphates, tripolyphosphates, phosphono carboxylates. Specific examples of such salts include the sodium and potassium tetraborates, carbonates, tripolyphosphates, orthophosphates and hexametaphosphates. However it is preferable if the detergent formulation is free or only has low levels (5% or less) of builder salts which precipitate during the wash in the presence of calcium, an example of such a salt is sodium tripolyphosphate.
In preferred builder systems the weight ratio of alkali metal bicarbonate to alkali metal carbonate is greater than 1:1, preferably greater than 2:1 in particularly preferred systems the builder does not comprises a alkali metal carbonate.
Other suitable detergency builders organic alkaline compounds such as water-soluble amino polyacetates, e.g. sodium and potassium ethylenediamine tetraacetates, nitrilotriacetates and N-(2-hydroxyethyl)nitrilodiacetates; water-soluble salts of phytic acid, e.g. sodium and potassium phytates; water-soluble polyphosphonates, including sodium, potassium and lithium salts of ethane-1-hydroxy-1, 1-diphosphonic acid; sodium, potassium and lithium salts of methylenediphosphonic acid and the like.
It is to be understood that, while the alkali metal salts of the foregoing inorganic and organic poly-valent anionic builder salts are preferred for use herein from an economic standpoint, the ammonium, alkanolammonium, e.g. triethanol-ammonium, diethanolammonium, and the like, water-soluble salts of any of the foregoing builder anions are useful herein.
Mixtures of organic and/or inorganic builder salts can be used herein.
While any of the poly-valent builder materials are useful herein, the compositions of the invention are preferably free of phosphate builders for environmental and ecological reasons.
Preferred builders for use in the invention are sodium citrate and sodium bicarbonate and mixtures thereof. Alternatively the potassium salts of these acids may be used.
Preferably, the total amount of builder in the composition is from about 30 to 80% by weight, more preferably from 40 to about 70% by weight, most preferably from 50 to 70%.
Suitable forms of silica include amorphous silica, such as precipitated silica, pyrogenic silica and silica gels, such as hydrogels, xerogels and aerogels, or the pure crystal forms quartz, tridymite or crystobalite, but the amorphous forms of silica are preferred. Suitable silicas may readily be obtained commercially. They are sold, for example under the Registered Trade Name Gasil 200 (ex Crosfield, UK).
Preferably, the silica is in the product in such a form that it can dissolve when added to the wash liquor. Therefore, addition of silica by way of addition anti-foam particles of silica and silicone oil is not preferred.
The particle size of the silica material of the present invention may be of importance, especially as it is believed that any silica material that remains undissolved during the washing process, may deposit on the glass at a later stage. Therefore, it is preferred that silica material are used that have a particle size (as determined with a Malvern Laser, i.e. xe2x80x9caggregatedxe2x80x9dparticles size) of at most 40 xcexcm, more preferably at most 30 xcexcm, most preferably at most 20 xcexcm provides better results in the wash. In view of incorporation in a cleaning composition, it is preferred that the particle size of the silica material is at least 1 xcexcm, more preferably at least 2 xcexcm, most preferably at least 5 xcexcm.
Preferably the primarily particle size of the silica is in general less than about 30 nm, in particular less than about 25 nm. Preferably, elementary particles size are less than 20 nm or even 10 nm. There is no critical lower limit of the elementary particle size; the lower limit is governed by other factors such as the manner of manufacture, etc. In general commercial available silicas have elementary particle sizes of 1 nm or more.
Preferably, the silica material is present in the wash liquor at a level of at least 2.5xc3x9710xe2x88x924%, more preferably at least 12.5xc3x9710xe2x88x924%, most preferably at least 2.5xc3x9710xe2x88x923% by weight of the wash liquor and preferably at most 1xc3x9710xe2x88x921, more preferably at most 8xc3x9710xe2x88x922%, most preferably at most 5xc3x9710xe2x88x922% by weight of the wash liquor.
Preferably, the level of dissolved silica material in the wash liquor is at least 80 ppm, more preferably at least 100 ppm, most preferably at least 120-ppm and preferably at most 1,000 ppm. It is noted that for the silica material to be effective, the lower level of dissolved silica material depends on the pH value, i.e. thus at pH 6.5, the level is preferably at least 100 ppm; at pH 7.0 preferably at least 110 ppm; at pH 7.5 preferably at least 120 ppm; at pH 9.5 preferably at least 200 ppm; at pH 10 preferably at least 300 ppm; at pH 10.5 preferably at least 400 ppm.
Preferably, the silica material is present in the cleaning composition at a level of at least 0.1%, more preferably at least 0.5%, most preferably at least 1% by weight of the cleaning composition and preferably at most 10%, more preferably at most 8%, most preferably at most 5% by weight of the cleaning composition.
The composition optionally comprises alkali metal silicates. The alkali metal may provide pH adjusting capability and protection against corrosion of metals and against attack on dishware, including fine china and glassware benefits. When silicates are present, the SiO2 level should be from 1% to 25%, preferably from 2% to 20%, more preferably from 3% to 10%, based on the weight of the ADD. The ratio of SiO2 to the alkali metal oxide (M2O, where M=alkali metal) is typically from 1 to 3.5, preferably from 1.6 to 3, more preferably from 2 to 2.8. Preferably, the alkali metal silicate is hydrous, having from 15% to 25% water, more preferably, from 17% to 20%.
The highly alkali metasilicates can in general be employed, although the less alkaline hydrous alkali metal silicates having a SiO2:M2O ratio of from 2.0 to 2.4 are, as noted, greatly preferred. Anhydrous forms of the alkali metal silicates with a SiO2:M2O ratio of 2.0 or more are also less preferred because they tend to be significantly less soluble than the hydrous alkali metal silicates having the same ratio.
Sodium and potassium, and especially sodium, silicates are preferred. A particularly preferred alkali metal silicate is a granular hydrous sodium silicate having a SiO2:Na2O ratio of from 2.0 to 2.4 available from PQ Corporation, named Britesil H20 and Britesil H24. Most preferred is a granular hydrous sodium silicate having a SiO2:Na2O ratio of 2.0. While typical forms, i.e. powder and granular, of hydrous silicate particles are suitable, preferred silicate particles having a mean particle size between 300 and 900 microns and less than 40% smaller than 150 microns and less than 5% larger than 1700 microns. Particularly preferred is a silicate particle with a mean particle size between 400 and 700 microns with less than 20% smaller than 150 microns and less than 1% larger then 1700 microns. Compositions of the present invention having a pH of 9 or less preferably will be substantially free of alkali metal silicate.
Enzymes may be present in the compositions of the invention.
Examples of enzymes suitable for use in the cleaning compositions of this invention include lipases, peptidases, amylases (amylolytic enzymes) and others which degrade, alter or facilitate the degradation or alteration of biochemical soils and stains encountered in cleansing situations so as to remove more easily the soil or stain from the object being washed to make the soil or stain more removable in a subsequent cleansing step.
Well-known and preferred examples of these enzymes are lipases, amylases and proteases. The enzymes most commonly used in machine dishwashing compositions are amylolytic enzymes. Preferably, the composition of the invention also contains a proteolytic enzyme. Enzymes may be present in a weight percentage amount of from 0.2 to 5% by weight. For amylolytic enzymes, the final composition will have amylolytic activity of from 102 to 106 Maltose units/kg. For proteolytic enzymes the final composition will have proteolytic enzyme activity of from 106 to 109 Glycine Units/kg.
Bleach material may optionally and preferably be incorporated in composition for use in processes according to the present invention. These materials may be incorporated in solid form or in the form of encapsulates and less preferably in dissolved form.
The bleach material may be a chlorine- or bromine-releasing agent or a peroxygen compound. Peroxygen based bleach materials are however preferred.
Organic peroxy acids or the precursors therefor are typically utilized as the bleach material. The peroxyacids usable in the present invention are solid and, preferably, substantially water-insoluble compounds. By xe2x80x9csubstantially water-insolublexe2x80x9d is meant herein a water-solubility of less than about 1% by weight at ambient temperature. In general, peroxyacids containing at least about 7 carbon atoms are sufficiently insoluble in water for use herein.
Inorganic peroxygen-generating compounds are also typically used as the bleaching material of the present invention. Examples of these materials are salts of monopersulphate, perborate monohydrate, perborate tetrahydrate, and percarbonate.
Monoperoxy acids useful herein include alkyl peroxy acids and aryl peroxyacids such as peroxybenzoic acid and ring-substituted peroxybenzoic acids (e.g. peroxy-alpha-naphthoic acid); aliphatic and substituted aliphatic monoperoxy acids (e.g. peroxylauric acid and peroxystearic acid); and phthaloyl amido peroxy caproic acid (PAP).
Typical diperoxy acids useful herein include alkyl diperoxy acids and aryldiperoxy acids, such as 1,12-di-peroxy-dodecanedioic acid (DPDA); 1,9-diperoxyazelaic acid, diperoxybrassylic acid, diperoxysebacic acid and diperoxy-isophthalic acid; and 2-decyldiperoxybutane-1,4-dioic acid.
Peroxyacid bleach precursors are well known in the art. As non-limiting examples can be named N,N,Nxe2x80x2,Nxe2x80x2-tetraacetyl ethylene diamine (TAED), sodium nonanoyloxybenzene sulphonate (SNOBS), sodium benzoyloxybenzene sulphonate (SBOBS) and the cationic peroxyacid precursor (SPCC) as described in U.S. Pat. No. 4,7S1,015.
If desirably a bleach catalyst, such as the manganese complex, e.g. Mn-Me TACN, as described in EP-A-0458397, or the sulphonimines of U.S. Pat. No. 5,041,232 and U.S. Pat. No. 5,047,163, is to be incorporated, this may be presented in the form of a second encapsulate separately from the bleach capsule or granule. Cobalt catalysts can also be used.
Among suitable reactive chlorine- or bromine-oxidizing materials are heterocyclic N-bromo and N-chloro imides such as trichloroisocyanuric, tribromoisocyanuric, dibromoisocyanuric and dichloroisocyanuric acids, and salts thereof with water-solubilizing cations such as potassium and sodium. Hydantoin compounds such as 1,3-dichloro-5,5-dimethyl-hydantoin are also quite suitable.
Particulate, water-soluble anhydrous inorganic salts are likewise suitable for use herein such as lithium, sodium or calcium hypochlorite and hypobromite. Chlorinated trisodium phosphate and chloroisocyanurates are also suitable bleaching materials.
Encapsulation techniques are known for both peroxygen and chlorine bleaches, e.g. as described in U.S. Pat. No. 4,126,573, U.S. Pat. No. 4,327,151, U.S. Pat. No. 3,983,254, U.S. Pat. No. 4,279,764, U.S. Pat. No. 3,036,013 and EP-A-0,436,971 and EP-A-0,510,761. However, encapsulation techniques are particularly useful when using halogen based bleaching systems.
Chlorine bleaches, the compositions of the invention may comprise from about 0.5% to about 3% avCl (available Chlorine). For peroxygen bleaching agents a suitable range are also from 0.5% to 3% avO (available Oxygen). Preferably, the amount of bleach material in the wash liquor is at least 12.5xc3x9710xe2x88x924% and at most 0.03% avO by weight of the liquor.
A surfactant system comprising a surfactant selected from nonionic, anionic, cationic, ampholytic and zwitterionic surfactants and mixtures thereof is preferably present in the composition.
Typically the surfactant is a low to non foaming nonionic surfactant, which includes any alkoxylated nonionic surface-active agent wherein the alkoxy moiety is selected from the group consisting of ethylene oxide, propylene oxide and mixtures thereof, is preferably used to improve the detergency without excessive foaming. However, an excessive proportion of nonionic surfactant should be avoided. Normally, an amount of 15% by weight or lower, preferably 10% by weight or lower, more preferably 7% by weight or lower, most preferably 5% by weight or lower and preferably 0.1% by weight or higher, more preferably 0.5% by weight or higher is quite sufficient, although higher level may be used.
Examples of suitable nonionic surfactants for use in the invention are the low- to non-foaming ethoxylated straight-chain alcohols of the Plurafac(copyright) RA series, supplied by the Eurane Company; of the Lutensol(copyright) LF series, supplied by the BasF Company and of the Triton(copyright) DF series, supplied by the Rohm and Haas Company.
Other surfactants such as anionic surfactant may be used but may require the additional presence of an antifoam to surpress foaming. If an anionic surfactant is used it is advantageously present at levels of 2 wt% or below.
A water-soluble polymeric polycarboxylic compound is advantageously present in the dish wash composition. Preferably these compounds are homo- or co-polymers of polycarboxylic compounds, especially co-polymeric compounds in which the acid monomer comprises two or more carboxyl groups separated by not more than two carbon atoms. Salts of these materials can also be used.
Particularly preferred polymeric polycarboxylates are co-polymers derived from monomers of acrylic acid and maleic acid. The average molecular weight of these polymers in the acid form preferably ranges from 4,000 to 70,000.
Another type of polymeric polycarboxylic compounds suitable for use in the composition of the invention are homo-polymeric polycarboxylic acid compounds with acrylic acid as the monomeric unit. The average weight of such homo-polymers in the acid form preferably ranges from 1,000 to 100,000 particularly from 3,000 to 10,000. Such polymers are present as anti-scalants.
Acrylic sulphonated polymers as described in EP 851 022 (Unilever) are also suitable.
Preferably, this polymeric material is present at a level of at least 0.1%, more preferably at levels from 1 wt% to 7 wt% of the total composition.
A chelating agent may be present in the composition. If present it is preferable if the level of chelating agent is from 0.5 to 3 wt% of the total composition.
Preferred chelating agents include organic phosphonates, amino carboxylates, polyfunctionally-substituted compounds, and mixtures thereof.
Particularly preferred chelating agents are organic phosphonates such as xcex1-hydroxy-2 phenyl ethyl diphosphonate, ethylene diphosphonate, hydroxy 1,1-hexylidene, vinylidene 1,1 diphosphonate, 1,2 dihydroxyethane 1,1 diphosphonate and hydroxy-ethylene 1,1 diphosphonate. Most preferred is hydroxy-ethylene 1,1 diphosphonate.
These chelating agents are present to mitigate the scaling of glasses.
Anti-tarnishing agents such as benzotriazole and those described in EP 723 577 (Unilever) may also be included.
Optional ingredients are, for example, buffering agents, reducing agents, e.g., borates, alkali metal hydroxide and the well-known enzyme stabilisers such as the polyalcohols, e.g. glycerol and borax; anti-scaling agents; crystal-growth inhibitors, threshold agents; thickening agents; perfumes and dyestuffs and the like.
Reducing agents may e.g. be used to prevent the appearance of an enzyme-deactivating concentration of oxidant bleach compound. Suitable agents include reducing sulphur-oxy acids and salts thereof. Most preferred for reasons of availability, low cost, and high performance are the alkali metal and ammonium salts of sulphuroxy acids including ammonium sulphite ((NH4)2SO3), sodium sulphite (Na2SO3), sodium bisulphite (NaHSO3), sodium metabisulphite (Na2S2O3), potassium metabisulphite (K2S2O5), lithium hydrosulphite (Li2S2O4)etc., sodium sulphite being particularly preferred. Another useful reducing agent, though not particularly preferred for reasons of cost, is ascorbic acid. The amount of reducing agents to be used may vary from case to case depending on the type of bleach and the form it is in, but normally a range of about 0.01% to about 1.0% by weight, preferably from about 0.02% to about 0.5% by weight, will be sufficient.
The invention relates to washing processes in mechanical dish washing machines wherein the wash liquor has a low pH. By xe2x80x9clow pHxe2x80x9d is meant here that the pH of the wash liquor is preferably higher than about 6.5, more preferably 7.5 or higher, most preferably 8.5 or higher. Preferably the pH is lower than about 10.5, more preferably lower than about 10, more preferably lower than about 9.5. The most advantageous pH range is from 8.5 to 10.
The present invention preferably relates to processes of mechanically washing soiled articles with a wash liquor at a temperature of at least 40xc2x0 C., more preferably at least 50xc2x0 C., most preferably at least 55xc2x0 C.
The rinse aid for use in the invention comprises a water soluble acid builder or salt, preferably organic acids including, for example, carboxylic acids, such as citric and succinic acids, polycarboxylic acids, such as polyacrylic acid, and also acetic acid, boric acid, malonic acid, adipic acid, fumaric acid, lactic acid, glycolic acid, tartaric acid, tartronic acid, maloic acid, their derivatives and any mixtures of the foregoing.
Suitable water-soluble monomeric or oligomeric carboxylate builders can be selected from a wide range of compounds but such compounds preferably have a first carboxyl logarithmic acidity/constant (pK1) of less than 9, preferably of between 2 and 8.5, more preferably of between 2.5 and 7.5.
The carboxylate or polycarboxylate builder can be monomeric or oligomeric in type although monomeric polycarboxylates are generally preferred for reasons of cost and performance. Monomeric and oligomeric builders can be selected from acyclic, alicyclic, heterocyclic and aromatic carboxylates.
Suitable carboxylates containing one carboxy group include the water-soluble salts of lactic acid, glycolic acid and ether derivatives thereof. Polycarboxylates containing two carboxy groups include the water-soluble salts of succinic acid, malonic acid, (ethylenedioxy) diacetic acid, maleic acid, diglycolic acid, tartaric acid, tartronic acid and fumaric acid, as well as the ether carboxylates and the sulfinyl carboxylates. Polycarboxylates containing three carboxy groups include, in particular, water-soluble citrates, aconitrates and citraconates as well as succinate derivatives such as the carboxymethyloxysuccinates, lactoxysuccinates, and aminosuccinates, and the oxypolycarboxylate materials such as 2-oxa-1,1,3-propane tricarboxylates. The carboxylate or polycarboxylate builder compounds described above can also have a dual function as pH controlling agents. Polycarboxylates containing four carboxy groups include oxydisuccinates, 1,1,2,2-ethane tetracarboxylates, 1,1,3,3-propane tetracarboxylates and 1,1,2,3-propane tetracar-boxylates. Polycarboxylates containing sulfo substituents include the sulfosuccinate derivatives, and the sulfonated pyrolysed citrates.
Alicyclic and heterocyclic polycarboxylates include cyclopentane-cis,cis,cis-tetracarboxylates, cyclopen-tadienide pentacarboxylates, 2,3,4,5-tetrahydroturan-cis, cis, cis-tetracarboxylates, 2,5-tetrahydrofuran-cis-dicarboxylates, 2,2,5,5-tetrahydrofuran-tetracarboxylates, 1,2,3,4,5,6-hexane-hexacarboxylates and carboxymethyl derivatives of polyhydric alcohols such as sorbitol, mannitol and xylitol. Aromatic polycarboxylates include mellitic acid, pyromellitic acid and the phthalic acid derivatives disclosed in British Patent No. 1,425,343.
Of the above, the preferred polycarboxylates are hydroxycarboxylates containing up to three carboxy groups per molecules, more particularly citrates or citric acid.
As an alternative to the above phosphonates may be used.
The parent acids of the monomeric or oligomeric polycarboxylate chelating agents or mixtures thereof with their salts, e.g. citric acid or citrate/citric acid mixtures are also contemplated as components of builder systems of rinse compositions in accordance with the present invention.
A surfactant system comprising a surfactant selected from nonionic, anionic, cationic, ampholytic and zwitterionic surfactants and mixtures thereof is preferably present in the composition.
The surfactant system most preferably comprises low foaming nonionic surfactant, selected for its wetting ability, preferably selected from ethoxylated and/or propoxylated nonionic surfactants, more preferably selected from nonionic ethoxylated/propoxylated fatty alcohol surfactants.
The surfactant system is typically present at a level of from 1% to 40% by weight, more preferably 1.5% to 30% by weight, most preferably from 5% to 20% by weight of the compositions. If an anionic surfactant is used it is advantageously present at levels of 1 wt% or below.
The compositions of the invention may contain organic solvents, particularly when formulated as liquids or gels. The compositions in accord with the invention preferably contain a solvent system present at levels of from 1% to 30% by weight, preferably from 3% to 25% by weight, more preferably form 5% to 20% by weight of the composition. The solvent system may be a mono or mixed solvent system. Preferably, at least the major component of the solvent system is of low volatility.
Suitable organic solvent for use herein has the general formula RO(CH2C(Me) HO)nH, wherein R is an alkyl, alkenyl, or alkyl aryl group having from 1 to 8 carbon atoms, and n is an integer from 1 to 4. Preferably, R is an alkyl group containing 1 to 4 carbon atoms, and n is 1 or 2. Especially preferred R groups are n-butyl or isobutyl. Preferred solvents of this type are 1 -n-butoxypropane-2-ol (n=1): and 1(2-n-butoxy-1 -methylethoxy)propane-2-ol (n=2), and mixtures thereof.
Other solvents useful herein include the water-soluble CARBITOL7 solvents or water-soluble CELLOSOLVE7 solvents. Water-soluble CARBITOL7 solvents are compounds of the 2-(2 alkoxyethoxy) ethanol class wherein the alkoxy group is derived from ethyl, propyl or butyl; a preferred water-soluble carbitol is 2(2-butoxyethoxy) ethanol also known as butyl carbitol. Water-soluble CELLOSOLVE7 solvents are com-pounds of the 2-alkoxyethoxy ethanol class, with 2-butoxyethoxyethanol being preferred.
Other suitable solvents are benzyl alcohol, and diols such as 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol.
Hydrotropes may be present and are typically present at levels of from 0.5% to 20%, preferably from 1% to 10%, by weight.
Useful hydrotropes include sodium, potassium, and ammonium xylene sulfonates, sodium, potassium, and ammonium toluene sulfonate, sodium potassium and ammonium cumene sulfonate, and mixtures thereof.
In a highly preferred aspect of the invention, the rinse aid compositions have a pH as a 1% solution in distilled water at 20xc2x0 C. of less than 7, preferably from 0.5 to 6.5, most preferably from 0.5 to 1.0.
The dish washing composition for use in the invention may be in any product form, however it is preferred if it granular. Granular in the context of the present invention includes both powdered material and tablets.
The rinse aid is preferably a liquid.
Dishwash compositions according to the present invention may be dosed in the wash liquor at levels of from 10 g/l to 2.5 g/l.
Rinse aid composition according to the present invention may be dosed in the final rinse liquor at levels 1 g/l or less.
The invention will now be illustrated by the following non-limiting Examples.
All percentages are on a weight basis.

Abstract: (i) treating the articles with a wash liquor including a dishwashing composition; said composition when undiluted including greater than 20 wt.% of a bicarbonate salt followed by (ii) treating the articles with a rinsing solution including rinse aid the rinse aid when undiluted comprising at least 20 wt. % of a water soluble acid builder or salt thereof; wherein minimal rejuvenation of ion exchange material within the machine is needed.

Unilever Home and Personal Care, USA, division of Conopco, Inc.


The invention describes a polymer with high transmission for UV rays, this transmission being preserved even after prolonged exposure to UV light (tanning lamps). The polymer is further characterized by a low residual monomer content (determined as methyl methacrylate).

The present invention relates to an improved material for covering the UV lamps in tanning beds.
From European Patent 0016870 there are already known plastics based on methyl methacrylate which have high transmission for UV A radiation (315 to 380 nm) and for UV B radiation (280 to 315 nm). Their high UV transmission is preserved even during prolonged exposure to radiation if the plastic contains a small concentration of a sterically hindered amine. Corresponding compounds trap radicals which are formed during radiation exposure and which would otherwise slowly destroy the plastic material. Such additives are described in Japanese Patent 03-47856, and are known as xe2x80x9chindered amine light stabilizersxe2x80x9d or HALS. Plastics which are based on polymethyl methacrylate (PMMA), which contain sterically hindered amines and which have high UV transmission are also described in German Unexamined Specification DE-OS 3421859.
Heretofore Plexiglas(copyright) GS 2458 (commercial product of Rohm GmbH) has been used to cover the UV lamps of tanning beds. The material is easy to care for and transmits a high percentage of tanning UV radiation. The thickness of the covers used has ranged between 3 and 8 mm.
Since both the radiant power of UV lamps on the whole and the UVB component of the radiation have increased in the course of technical development, a considerable reduction of transmission is suffered in standard materials with thicknesses of  greater than 4 mm after about 20 hours of exposure.
Exposure Results
In this case: standard formula (Plexiglas(copyright) 2458), 8 mm thick, tempered (30 minutes, 160xc2x0 C.). Lamp: light box, Ergoline ST Turbo Power lamps, 9 tubes:
A yellow discoloration known as yellow core develops in the interior of the plate. The UV light is absorbed, the customer no longer becomes tanned and the plate must be replaced relatively early.
Object
The object was therefore to provide a material which, even at the lamp intensities that are common today, yellows not at all or only slightly while also having high UV transmission. At the same time, it must be ensured that the additives which prevent development of the yellow core are physiologically safe. Only substances which are approved by the FDA and are in conformity with the European Union and German Health Agency directives may be added. It is intended that plates will be made available which do not exhibit yellow core even at the lamp powers which are standard today in combination with material thicknesses of more than 4 mm. The large thicknesses of more than 4 mm are necessary, since the cover of the UV lamps has cantilever structure and the plates are hot-formed at about 160xc2x0 C.
Achievement
Good UV transmission over a long period is a primary requirement for tanning bed material.
It has now been found that the object can be achieved by addition of alcohols, alcohol mixtures and even water and/or further compounds to the monomer mixture of the standard formula. The compound or the mixture respectively being used will be referred to hereinafter as active components. Examples of suitable alcohols are monohydric or polyhydric C1 to C10 alcohols, which may also be branched, such as methanol, ethanol, propanol, isopropanol or tert-butanol or pentanols. A further improvement can be achieved by the use of further compounds, such as vinyl compounds, butyl lactate and siloxanes as well as mixtures of the said compounds. Vinyl compounds can be understood as vinyl esters of aliphatic carboxylic acids, such as vinyl acetate. There can also be used vinyl esters of general formula I:
[see original for formula] (Formula I)
where:
R1, R2 and R3 are alkyl groups, wherein at least one group represents a methyl group. The total number of carbon atoms in groups R1 to R3 is 9, 10 or 11.
The compounds of formula I are available from Shell Chemicals under the names VeoVa9 (9 carbon atoms, R1 to R3), VeoVa10 (10 carbon atoms, R1 to R3) or VeoVa11 (11 carbon atoms, R1 to R3).
The alcohols, alcohol mixtures or further active components are mixed in with the monomer mixture in proportions of 0.1 to 10 wt %. Contents of 0.2 to 8 wt % of active components are preferred, and contents of 0.2 to 6 wt % of active components are especially preferred.
Methyl methacrylate comprises 85 to 95 wt % of the monomer mixture.
Composition of the standard formula:
As initiator there can be used the initiators that are standard in cast polymerization; see H. Rauch-Puntigam, Th. Vxc3x6lker in xe2x80x9cAcrylic and Methacrylic Compoundsxe2x80x9d, Springer-Verlag 1967; Houben-Weyl, 4th Edition, Volume XIV/1, Macromolecular Substances, Part 1, pp. 1010 to 1078, Georg Thieme Verlag, 1961).
As plasticizer there can be used acetyl tributyl citrate or triethyl citrate. In some cases it may also be possible to omit the plasticizer.


The present invention provides a new and improved color concentrate comprising from about 5% to about 20% by weight metal particles component, from about 1% to about 15% by weight colorant material and from about 60% to about 90% by weight thermoplastic polymer. The metal particles component comprises aluminum particles having an undefined configuration and an average particle size of from about 75 xcexcm to about 150 xcexcm. The concentrate can be utilized to color thermoplastic polymers and produce a high metallic effect.

The present invention concerns a color concentrate for use in coloring plastics. More particularly, the present invention concerns a metal containing thermoplastic color concentrate for use in imparting a metallic effect or appearance to the thermoplastic polymer that is being colored.
Thermoplastic polymers are often colored in the molten state by the addition of color concentrates. Color concentrates are concentrated dispersions of a colorant in a carrier polymer. The carrier polymer being either the same as or compatible with the polymer to be colored. Color concentrates are generally used to ensure good dispersibility and incorporation of pigments and other additives. Use of color concentrates can also create a much cleaner environment for an end user, for an end user does not have to involve oneself with dusty pigments and other hard to handle materials.
There are several methods for adding a color concentrate to a thermoplastic polymer that is to be colored. However, the most common method utilized today involves the controlled metering of the color concentrate into the throat of a polymer extruder using pellet feeders. In this application, the concentrate is supplied in a pellet form.
Color concentrates containing metal particles are known in the prior art. Such concentrates are utilized to impart a metallic look or effect to polymers. However, to date, the use of such concentrates has presented a variety of problems including poor incorporation or distribution of the metal within the polymer, low metal loading levels that fail to produce a meaningful metallic effect in the polymer being colored and the formation of knit lines, flow lines, diration lines and other molding marks upon use of the colored polymer. Moreover, such concentrates have commonly been made using a wax carrier, and waxes at higher concentrations are undesirable in many applications. The present invention affords a metal filled color concentrate that overcomes these deficiencies.
The present invention provides a new and improved metal containing color concentrate that affords a variety of advantages including a high metal content, good metal and pigment dispersibility and distribution, minimal adverse influence on the physical properties of the polymer being colored and good molding characteristics.
The color concentrate of the present invention comprises from about 5% to about 20% by weight metal particles component, from about 1% to about 15% by weight colorant material (pigment), and from about 60% to about 90% by weight thermoplastic polymer. The metal particles component comprises particles that exhibit an undefined configuration and an average particle size of from about 75 to about 150 xcexcm. The color concentrates of the present invention include less than about 5% by weight wax.
These and other aspects of the present invention will become clear to those skilled in the art upon the reading and understanding of the specification and the claims below.
Color concentrates made in accordance with the present invention yield various advantages. These advantages include: (i) the production of a concentrate that provides good dispersion and distribution when added to the thermoplastic polymer being colored; (ii) the production of colored thermoplastic polymer that displays a significant metallic look or effect that is noticeable in even low light conditions (e.g., in an office or within a house); and (iii) the absence of knit lines, flow lines and diration lines upon molding of the colored thermoplastic polymer. The formation of knit lines is avoided because the metal particles do not pile up into a vertical orientation during molding. Additionally, knit lines are avoided because there is no agglomeration of metal particles within the thermoplastic polymer.
Color concentrates made in accordance with the present invention may utilize a variety of different thermoplastic carrier polymers or mixtures of such polymers. Waxes are not used as the carrier in concentrates of the present invention. Thus, the color concentrates of the present invention comprise less than 5% by weight wax. The thermoplastic carrier polymer may comprise an amorphous or crystalline material selected from the group consisting of a styrenic polymer, a vinyl halide polymer, polyamides and an olefinic polymer. The styrenic polymers include, for example, polystyrene, high impact polystyrene (HIPS), styrene/acrylonitrile copolymers (SAN), copolymers of acrylonitrile/butadiene/styrene (ABS) and substituted styrenes such as xe2x88x9d-methyl styrene, methyl methacrylate, polysulphones and copolysulphones, polyphenylene oxides (PPO), polycarbonates, polymers and copolymers of acetals, and thermoplastic polyurethanes. Polyamide polymers include, for example, Nylon 6, Nylon 6,6 and Nylon 6,12. Vinyl halide polymers include, for example, poly(vinyl chloride) (PVC).
The olefinic polymers include, for example, polymers and copolymers of xe2x88x9d-olefins such as polyethylene, polypropylene, polybutene, poly-4-methyl pentene- 1, propylene/ethylene copolymers and copolymers of 4-methyl pentene-1 with linear xe2x88x9d-olefins containing 4 to 18 carbon atoms.
Preferably, whatever polymer system is utilized, it is best if a significant portion of the polymer is supplied in powder form to ensure proper mixing. Use of a blend of powder and pellets helps to prevent the settling of the metal particles during mixing. Preferably, the powder accounts for from about 30% to about 70% by weight of the thermoplastic carrier.
The metal particles component of the present invention comprises a distribution of aluminum particles in the range of 75 to about 150 xcexcm having an undefined configuration. The undefined configuration and the particle size distribution have been found to be critical relative to the formation of a product with a significant metal effect. Undefined configuration means aluminum particles that display neither a spherical nor a lenticular configuration. The undefined particles have a very irregular shape. Metal particles suitable for use in the present invention may be purchased from the A Obron Atlantic Corporation of Painesville, Ohio.
The colorant material may comprise any one or more of a number of commercially available colors or pigments so as to provide the described color effect in the concentrate and the thermoplastic polymer that is to be colored. As used in this specification and claims below xe2x80x9ccolorant materialxe2x80x9d means any conventional inorganic or organic pigment or organic dyestuff. Such materials are described, for example, in Kirk-Othmer Encyclopedia of Chemical Technology, Third Edition, Vol. 6, pp. 597-617, which is incorporated herein by reference. Examples of inorganic pigments include, for example, titanium dioxide, iron oxide, zinc chromate, cadmium sulfides, chromium oxides and sodium aluminum silicate complexes. Examples of organic type pigments include azo and diazo pigments, carbon black, phthalocyanines, quinacridone pigments, perylene pigments, isoindolinone, anthraquinones, thioindigo and solvent dyes.
Various types of additives may also be included in the process. Such additives may include, for example, stabilizers and/or process aids such as alkaline earth metal soaps and carboxylates such as calcium benzoate, calcium octoate and calcium naphthenate, Friedel-Crafts cation progenitor compounds such as zinc oxide, zinc hydroxide, zinc carbonate, zinc acetate, zinc laurate, zinc naphthenate, zinc stearate, zinc oleate, zinc 2-ethyl-hexoate, cadmium oxide, cadmium hydroxide, cadmium carbonate, cadmium acetate, cadmium laurate, cadmium naphtheneate, cadmium stearate, cadmium oleate, cadmium 2-ethyl-hexoate, calcium stearate, aluminum oxide, aluminum hydroxide, aluminum carbonate, aluminum acetate, aluminum chlorolaurate, antimony oxide, antimony hydroxide, antimony carbonate, antimony naphthenate, tin oxide, tin hydroxide, tin carbonate, tin naphthenate, and tin 2-ethyl-hexoate, aliphatic polyhydric compounds such as trimethylolethane, trimethylolpropane, tetramethylolcyclohexanol, pentaerythritol, dipentaerythritol, and tripentaerythritol and tri-(2-hydroxyethyl) iso-cyanurate (THEIC). Waxes may be included, but at levels of less than 5% by weight of the color concentrate so as not to detrimentally effect the properties and molding characteristics of the uncolored thermoplastic polymer. Examples of such waxes include paraffins, castor oil waxes and ethylene bis-stearamide.
Various types of fillers and/or reinforcers may also be included in the concentrate. Such fillers and/or reinforcers include, for example, CaCO3, barium sulfate, talc, glass, clay and mica.
The portions of polymeric resin, colorant material and metal particles component can vary quite a bit. Generally, when producing the concentrate, the mixture utilized comprises from about 60 to about 90 weight percent thermoplastic carrier polymer, from about 5 to about 20 weight percent metal particles component and from about 1 to about 15 weight percent colorant material. The mixture may comprise up to 8 weight percent additives. Preferably, the mixture comprises from about 65 to about 85 weight percent thermoplastic polymer, from about 7 to about 17 weight percent metal particles component, and from about 1 to about 10. weight percent colorant material.
The concentrate is formed in a two-step process. In both steps it is imperative that the mixing be low intensity and low shear in nature so as not to affect the particle size of the aluminum particles. The first step involves a premix of the various components in a mixer such as a Papenmeir mixer, a Waring blender or a Henschel mixer. A Henschel mixer is preferred. A low speed, of for example, 2-8 meters per second is preferred. Mineral oil may be added in minor amounts to the mix to help prevent dusting. The second step of the process involves the melt mixing of the premix in a melt mixer such as a single or twin screw extruder, or a Banbury mixer.
The above described color concentrate may be formulated in any desired physical form to be blended with uncolored (unformulated) thermoplastic polymers and processed into a molded or shaped article. It will be recognized by one skilled in the art, however, that for most molding and/or shaping processes, pellets of the concentrate are most advantageous for accommodating most molding and shaping apparatuses or processes, e.g., injection molding, extrusion molding or shaping, blow molding and the like.
The color concentrate will be blended with virgin (uncolored) thermoplastic polymer in an amount sufficient to give the desired high metallic effect, and other such properties desired for the article to be formed. Generally, this amount will range in a ratio by weight from about 50 to 1 to about 5 to 1 of virgin polymer to the color concentrate. This blend ratio results in an approximate metal particles component concentration in the blend of from about 0.15% to about 2% by weight of the total blend. In a more preferred embodiment of the invention, the blend ratio will vary from about 25 to 1 to about 10 to 1 of the virgin polymer resin to the color concentrate.
The blend compositions made in accordance with the present invention may then be utilized to prepare a variety of different molded or shaped articles by various molding and shaping processes. For example, such molded articles as bottles, closures, automotive parts, toys, furniture and cabinet parts and the like. These molded articles may be prepared by such processes as injection molding, rotational molding, injection blow molding, sheet extrusion, film extrusion, blow molding, thermoforming and the like. For example, closures, toys and furniture parts may be prepared by injection molding. Bottles are generally prepared by injection blown molding techniques and plastic bags are prepared from blow film.


The dyes have an average particle size within the range from 5 nm to 1 xcexcm and a variance of less than 50%. They are especially useful for ink-jet ink preparations.

The present invention relates to precipitated, water-insoluble dyes in colloidally disperse form, to a process for preparing them and to their use.
Pigments and disperse dyes are the most important representatives of the group of water-insoluble dyes. It is frequently necessary, in the case of disperse dyes even essential, to use them in colloidally disperse form. The colloidally disperse form is particularly important when the dyes are used in ink-jet printing, a widely used process, for the contactless printing of various print media, for example paper, film, photopaper and textiles. To obtain a colloidally disperse form, the dye crystals are generally mechanically comminuted, for example by grinding. A decisive disadvantage of grinding is that metallic attritus or attritus from the grinding media ends up in the dye powder and can lead to major problems in the use of the dye powder. For example, ink-jet printing nozzles may be damaged or blocked.
Pigments and disperse dyes in colloidally disperse form have to be stabilized against recrystallization, agglomeration and flocculation. U.S. Pat. No. 5,531,816 proposes a waterborne ink-jet ink composition comprising at least one deagglomerated pigment having a particle size within the range from 5 nm to 1 xcexcm, at least one water-insoluble organic compound and at least one amphiphilic compound. The amphiphile solubilizes the water-insoluble organic compound in the aqueous phase in the form of small droplets. The pigment is dispersed in the droplets of the water-insoluble organic compound and so maintained in the deagglomerated state.
DE 27 32 500 A describes a process for preparing water-dispersible, pulverulent disperse dyes by spray drying a solution of the dyes in formic acid, formamide, N-methylformamide, butyrolactone or ethylene glycol. The solution may further comprise dispersants, surfactants and protective colloids. The dye powder obtained consists of particles in the nanoparticle range.
Prior art dye particles all have a relatively broad particle size distribution, which is why the brilliance of the color leaves something to be desired. In addition, prior art dye particles are highly crystalline and have a nonuniform particle shape.
It is an object of the present invention to provide water-insoluble dyes in colloidally disperse form which have a narrow particle size distribution. In addition, the dye particles shall be substantially spherical and amorphous.
It has now been found that this object is achieved, surprisingly, by dye particles obtained by precipitation from a solution of the dye in a water-miscible organic solvent.
The present invention accordingly provides precipitated, water-insoluble or sparingly water-soluble dyes in colloidally disperse form having an average particle size within the range from 5 nm to 5 xcexcm and having a particle size distribution width (variance) of less than 50% (both measured by quasi-elastic light scattering and evaluation by the cumulant method; cf. Bruce J. Berne and Robert Pecora, xe2x80x9cDynamic Light Scatteringxe2x80x9d, John Wiley and Sons, Inc. 1976, p. 196f.).
The average particle size is preferably within the range from 5 nm to 1 xcexcm, especially within the range from 5 nm to 500 nm. The width of the particle size distribution is preferably less than 40%.
The dye particles of the invention possess only a small crystalline content by virtue of the process used for preparing them. The crystallinity is preferably not more than 30%, especially not more than 10%. Particularly preferably, the particles are present in completely amorphous form.
In addition, preferably not less than 80%, especially not less than 90%, of the dye is present in the form of spherical particles.
Because of their narrow particle size distribution, the dyes of the invention provide a cleaner color, and hence greater brilliance, in paper and photo printing in particular. In addition, they also provide higher color strength.
The dyes of the invention further exhibit advantageous viscosity characteristics and are simple to apply to fibers because of their high amorphous content.
Preference according to the invention is given to water-insoluble or sparingly water-soluble azo, anthraquinone, quinophthalone, methine and azamethine dyes.
The dye particles of the invention can be prepared by two different methods, by
A) precipitating it from a solution in a water-miscible organic solvent, or
B) preparing an oil-in-water emulsion from a solution of the dye in a water-immiscible organic solvent and precipitating the dye particles by stripping off the solvent.
Method A) (Water-miscible Solvent)
To produce the dye particles of the invention, the coarsely crystalline dye particles are initially dissolved in a suitable water-miscible organic solvent. Which solvent is used depends on the solubility properties of the dye. In principle, all water-miscible (which also includes those solvents which are miscible with water only to a proportion of not less than about 10% by weight) organic solvents are usable. In general, thermally stable solvents of this type are used. Suitable solvents are:
1. mono- and polyalcohols such as methanol, ethanol, n-propanol, isopropanol, glycol, glycerol, propylene glycol, polyethylene glycols, etc.;
2. ethers, such as tetrahydrofuran, dioxane, 1,2-propanediol 1-n-propyl ether, 1,2-butanediol 1-methyl ether, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, etc.;
3. esters, such as methyl acetate, monoesters of ethylene glycol or propylene glycols with acetic acid, butyrolactone, etc.;
4. ketones, such as acetone or methyl ethyl ketone;
5. amides, such as formamide, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and hexamethylphosphoramide;
6. sulfoxides and sulfones, such as dimethyl sulfoxide and sulfolane;
7. alkanecarboxylic acids, such as formic acid or acetic acid.
Preference is given to the solvents recited above under 1 to 5, especially methanol, ethanol, n-propanol, isopropanol, 1,2-butanediol 1-methyl ether, 1,2-propanediol 1-n-propyl ether, dimethylacetamide, N-methylpyrrolidone or acetone.
The amount of solvent depends on the dye to be dissolved. In general, it is desirable to keep the amount of solvent used to a minimum.
The coarsely crystalline dyes are generally dissolved at elevated temperature, since the solubility is too low at room temperature or below. The dissolving is preferably effected at from 50 to 300xc2x0 C., especially at from 100 to 300xc2x0 C. If the boiling point of the solvent is too low, the dissolving may also be effected under superatmospheric pressure, for example at a pressure of up to 50 bar.
The precipitating of the dye particles in colloidally disperse form is then effected by adding water to the solution of the dye in the water-miscible organic solvent. The temperature at which the precipitating step takes place is not critical. Advantageously, water of from 0 to 50xc2x0 C. is added to the hot solution of the dye.
The water preferably comprises at least one protective colloid in order that the reagglomeration of the colloidally disperse particles may be prevented. Protective colloids used include the natural or synthetic polymers customarily used for this purpose. Useful natural or semisynthetic protective colloids include for example gelatin, including fish gelatin, starch or starch derivatives, such as dextrins, pectin, gum arabic, casein, caseinate, alginates, cellulose and cellulose derivatives, such as methylcellulose, carboxymethylcellulose, hydroxypropylcellulose or hydroxypropylmethylcellulose.
Useful synthetic protective colloids are water-soluble homo- or copolymers, which can be neutral polymers, cationic polymers or anionic polymers. Similarly, complexes of polycationic and polyanionic polymers and also coacervates are contemplated.
The polymers are polymerized from monomers having hydrophilic groups and optionally comonomers having hydrophobic groups, the ratio between hydrophilic and hydrophobic groups being chosen in such a way that the copolymer is water-soluble.
Suitable hydrophilic monomers include for example N-vinyllactams, such as N-vinylpyrrolidone; acrylamide or methacrylamide and their N-C1-C4-mono- or N,N-di-C1-C4-alkyl derivatives; acrylic acid or methacrylic acid; monomers having a primary, secondary or tertiary basic nitrogen atom, such as amino-C2-C4-alkyl acrylates and methacrylates, e.g., dimethylaminoethyl (meth)acrylate, and the C1-C4-alkyl-quaternized derivatives thereof; ethylenically unsaturated sulfonic acids, such as vinylsulfonic acid; acrylamido-N-propanesulfonic acid and styrenesulfonic acid; hydroxy-C2-C4-alkyl acrylates and methacrylates; allyl alcohol and methallyl alcohol; olefinically unsaturated compounds having epoxy groups, such as glycidyl acrylate and glycidyl methacrylate; monoesters and diesters of ethylenically unsaturated C4-C8-dicarboxylic acids, such as maleic acid and itaconic acid, with amino alcohols, such as dimethylaminoethanol; and amides or imides of these carboxylic acids with diamines, such as dimethylaminopropylamine.
Suitable comonomers having hydrophobic groups include for example C2-C4-alkyl vinyl ethers, such as ethyl vinyl ether; vinyl esters of C2-C8-carboxylic acids, such as vinyl acetate and vinyl propionate; C1-C8-alkyl acrylates and methacrylates, such as methyl, ethyl, n-butyl and 2-ethylhexyl acrylates and methacrylates; aromatic vinyl compounds such as styrene; and 1-olefins having up to 20 carbon atoms, such as ethylene, propylene or isobutylene.
Polymers useful as protective colloid are thus in particular polyvinylpyrrolidone, polyacrylic acid or polymethacrylic acid and copolymers thereof with a dicarboxylic anhydride of an ethylenically unsaturated C4-C8-carboxylic acid, such as maleic anhydride or itaconic anhydride; polyvinyl alcohol and partially hydrolyzed polyvinyl acetate; polyacrylamide and polymethacrylamide and their partially hydrolyzed derivatives; polymers of monomers having a primary, secondary or tertiary amino group and the N-C1-C4-mono- and N,N-C1-C4-dialkyl derivatives and also the C1-C4-alkyl-quaternized derivatives thereof; polyethylene oxides and polypropylene oxides and also block copolymers thereof; polyamino acids such as polyaspartic acid and polylysine, and also condensates of phenylsulfonic acid with urea and formaldehyde and condensates of naphthalenesulfonic acid with formaldehyde.
The amount of protective colloid in the aqueous phase is generally within the range from 1 to 50% by weight, preferably within the range from 5 to 30% by weight, based on the total weight of the aqueous phase. The weight ratio of dye to protective colloid is generally within the range from 2:1 to 1:20. The amount of aqueous phase added depends on the dye, the concentration of the dye solution and the concentration of protective colloid in the aqueous phase. In general, the dye solution and the aqueous phase are used in a weight ratio within the range from 1:2 to 1:20.
The dye particles may be precipitated in the presence of additives customary in such cases, for example in the presence of one of the below-mentioned surfactants.
The mixing of dye solution and aqueous phase advantageously takes place as rapidly as possible. Suitable equipment for this purpose is known to the person skilled in the art. It is possible to use, for example, Y- or T-mixers or static mixers.
The novel process for producing the dye particles can be operated continuously or batchwise.
Method B) (Water-immiscible Solvent)
To prepare the dye particles of the invention by method B, the coarsely crystalline dye particles are initially dissolved in a suitable water-immiscible organic solvent. Which solvent is used depends on the solubility properties of the dye. In principle, all water-immiscible organic solvents are usable. In general, thermally stable solvents of this type are used.
Preferred solvents are chlorinated hydrocarbons, such as chloroform, dichloroethane or methylene chloride.
The dissolving of the dye is effected as described under A).
The solvent phase is vigorously stirred into the aqueous phase with the aid of a suitable apparatus, for example an Ultra-Turrax, to prepare an oil-in-water emulsion.
The water comprises at least one emulsifier to stabilize the emulsion droplets and prevent coalescence.
The emulsifiers used include the abovementioned natural, semisynthetic or synthetic protective colloids.
The amount of emulsifier in the aqueous phase is generally within the range from 1 to 50% by weight, preferably within the range from 5 to 30% by weight, based on the total weight of the aqueous phase. The weight ratio of dye to emulsifier is generally within the range from 2:1 to 1:20. The amount of aqueous phase added depends in particular on the emulsifying power of the emulsifier and on the desired emulsion droplet size. In general, the dye solution and the aqueous phase are used in a weight ratio within the range from 1:2 to 1:20.
The emulsifying may be carried out in the presence of additives customary in such cases, for example in the presence of one of the below-described surfactants.
As the next step of method B), the solvent is stripped out of the emulsion by reduced pressure and/or by heating the emulsion to convert the emulsion into a purely aqueous dispersion. In the process, the dye particles of the invention are formed by precipitation.
The novel process for producing the O/W emulsion and the removal of the solvent by stripping can be carried out continuously or batchwise.
The colloidal dye solution obtained using the process of the invention can be processed directly into the desired colorants. Alternatively, the dye solution can be concentrated by removing some of the volatiles in a conventional manner. The volatiles can also be removed completely, for example by spray drying. This provides the dyes of the invention in the form of a dry powder which can be reconverted into a colloidal solution in water.
The amount of dye in the colorant is generally within the range from 0.1 to 10% by weight, preferably within the range from 1 to 8% by weight.
The as-precipitated colloidal solution of the dye can be used directly as colorant. In general, however, additive and auxiliary substances customary for the formulating of a colorant will be added. Particular preference is given to processing the dyes, or colloidal dye solutions, into ink-jet ink preparations comprising at least one of the dyes of the invention in colloidally disperse form in an aqueous medium.
For most applications, it is necessary to add surfactants, which are selected according to the desired field of application. The customary anionic, cationic or nonionic surfactants may be used.
Suitable surfactants, especially for use in ink-jet preparations, are anionic, cationic and nonionic surfactants. Anionic surfactants include for example soaps, alkanesulfonates, olefinsulfonates, alkylarylsulfonates, alkylnaphthalenesulfonates, alkyl sulfates and alkyl ether sulfates, alkyl methyl ester sulfonates, acylglutamates, sarcosinates and taurates. Examples are sodium lauryl sulfate, sodium lauryl ether sulfate, oleylsulfonate, nonylbenzenesulfonate, sodium dodecylbenzensulfonate and butylnaphthalenesulfonate.
Catonic surfactants include for example alkyltrimethylammonium halides/alkyl sulfates, alkylpyridinium halides and dialkyldimethylammonium halides/alkyl sulfates.
Suitable nonionic surfactants include for example alkoxylated animal/vegetable fats and oils, e.g., maize oil ethoxylates, castor oil ethoxylates, tallow fat ethoxylates; glyceryl esters, for example glyceryl monostearate; fatty alcohol alkoxylates and oxo-alcohol alkoxylates; alkylphenol alkoxylates, for example isononylphenol ethoxylates; and sugar surfactants, for example sorbitan fatty acid esters (sorbitan monooleate, sorbitan tristearate), polyoxyethylene sorbitan fatty acid esters.
It is also possible to use zwitterionic surfactants, such as sulfobetaines, carboxybetaines, alkyldimethylamine oxides, for example tetradecyldimethylamine oxide, and polymeric surfactants, such as di-, tri- and multi-block polymers of the type (AB)x-, ABA and BAB, for example polyethylene oxide-block-polypropylene oxide, polystyrene-block-polyethylene oxide, and AB comb polymers, for example polymethacrylate-comb-polyethylene oxide.
The amount of surfactant, if present, is generally within the range from 0.5 to 25% by weight, especially within the range from 1 to 15% by weight, based on the total weight of the preparation.
The preparation may comprise further additives, such as viscosity control additives, for example water-soluble starch and cellulose derivatives as thickeners, additives for improving the drying characteristics, for example isopropanol, acetone, diethylene glycol, butyltriglycol; biocides and fungicides; sequestrants, such as ethylenediaminetetraacetic acid; and buffer solutions for pH control.
The dyes and colorants of the invention are useful for printing print media, especially paper, foil, film, papers for the reproduction of digital photographic images and graphics, and also for printing textiles, especially those composed of synthetic fibers. The preferred process for printing textiles is transfer printing.

Precipitated water-insoluble colorants in colloid disperse form


A beverage container opener which includes a housing having a holding surface and a first operational part is disclosed. The operational part includes a first gripping member for engaging at least a first portion of a circumference of a bottle cap and a second gripping member for engaging a different second circumferential portion of the bottle cap. A slider is actuable by the user from at least the holding surface to effect relative movement between the first and second gripping member towards each other to engage the circumference of the bottle cap therebetween. The rotation of the housing while the first and second gripping members engage the bottle cap, thereby facilitating rotation of the bottle cap by providing greater torque forces thereon.

In the past, various types of bottle openers and container openers have been proposed. However, the prior art devices have suffered from several disadvantages.
In several cases, difficulty has arisen in grasping the cap of a bottle. This is the case particularly if the cap to the bottle is relatively small, requiring the user to grasp the bottle cap tightly in a small area and to cause rotation of the cap about a very small circle. This has been difficult particularly for young children or older people who do not generally have the dexterity or strength in their hands and fingers to grasp the bottle cap and also rotate it quickly.
In other opener constructions with use with can lift tabs, it has been found that current can tab lifter devices in the prior art use two contact points to raise the tab and open the beverage can. This is shown, for instance, in FIG. 10 which shows contact points A and B of an opening tab used on a conventional beverage can. Contact point A is the weakest point of the lift tab and point B is formed as an engageable end which pivots about a fulcrum into bearing contact with a partially detachable portion of the can lid. In use, the user is required to apply a downward force on the lifter device at the same time as the force applied to open the can in order to avoid damaging the can tab. The tab on a beverage can has a strong area and a weaker area. If, however, the tab breaks or bends, it typically breaks or bends at mid-points C and D as shown in FIG. 12. This can cause substantial difficulties in thereafter opening the can, if it can be opened at all.


Soft, multi-fingered resilient robotic fingers for selectively assisting the ventricles, and in particular the left ventricle, of a weak heart to produce internal pressure and to pump blood from one or more sides, in synchrony with the natural systolic contraction of the ventricle, as well as providing arrhythmia control of a beating heart. The apparatus is microprocessor and electrically-controlled and completely implantable. The plurality of soft fingers monitor and gently squeeze the heart (systole) to enhance blood circulation and assist a weak heart. The soft fingers work in harmony, by means of a micro-processor controlled solenoid or other linear robotic actuators such as metal-hydride actuators or polymeric artificial muscles, and a resilient body or a spring, to close once the solenoid is powered electrically and quickly retract away from the heart when the solenoid is not powered. This quick opening action allows the heart to expand freely (diastole) once it is compressed to allow the blood to naturally and freely return to the heart ventricles and coronary veins. The soft fingers can be connected to each other by means of elastic membranes or skirts to provide a resilient compression cup. The structure is equipped with a flexible and undulating stem connecting the structure to the robotic actuation mechanism housed in the abdomen of the patient. Monitoring electrones can be affixed to the soft fingers. The power supply for the implanted device can be long lasting batteries that can be recharged transcutaneously.

1. Field of the Invention (Technical Field)
The present invention relates to heart compression and assist and arrhythmia control devices. More particularly the invention relates to a multi-soft fingered, resilient electrical heart compression apparatus which can be implanted external to the patient""s heart for compressing a heart ventricle robotically and intelligently, which contains control means such as bradycardic (pacing) and tachyarrhythmic (cardioverting/defibrillating) to facilitate the device operation in synchronism with left ventricular contraction. The apparatus is also preferably capable of transcutaneous recharging of the implanted batteries, or can be powered by a pair of transcutaneous conducting wires by an electronic battery pack system worn around a user""s waist.
2. Background Art
There presently exists no implantable heart compression device to help patients suffering from congestive heart failure (CHF), a progressive disease often precipitated by acute myocardial infarction. All artificial heart or left ventricular assist devices have either not worked in the past or are just temporary solutions for patients needing a donor heart for transplant. Existing devices generally feature blood flow pathways made from non-biological materials that often damage blood cells and blood proteins and produce clots, thereby presenting a generic risk thromboembolism in the circulatory system. In fact, blood clots cause most of the deaths reported after implantation of an artificial heart or assist device. The majority of these patients have a normal right ventricle; however, most have a left ventricle that has been damaged in specific regions. Therefore, there is a need for a heart compression device designed to assist the weak muscles of a failing heart that augments the heart""s pumping power. This device could also incorporate pacemaker and implantable cardioverter/defibrillator technology for treating patients who also suffer from such electrical dysfunctions as bradycardia or tachyarrhythmias. Current Left Ventricular Assist Device (LVAD) devices are heavy and generally have to be attached to a cart to be dragged around by the patient. In addition, they lack a satisfactory implantable energy source, requiring patients to be constantly tethered to an external power source. Previous attempts to provide ventricular assistance have ranged from artificial hearts (e.g., the Jarvik-7), to devices which directly pump the blood, via an artificial pathway inserted through the ventricular wall to devices which exert pressure on the outside of the heart. Historically, heart-compression devices involve some form of flexible bladder within a support structure such that expansion of the bladder presses on the ventricle and facilitates expulsion of blood. These types of devices are disclosed in U.S. Pat. No. 3,587,567 to Schiff; U.S. Pat. No. 3,371,662 to Heid et al.; U.S. Pat. No. 4,048,990 to Goetz; and U.S. Pat. No. 4,192,293 to Asrican. U.S. Pat. No. 4,506,658 to Casile discloses a truncated conical structure of sac-lined rigid panels separated by contractible and expandable sections. Another type of cardiac assist system is designed to compress all or part of the heart by alternately tightening and releasing a circumferential compression band. For example, U.S. Pat. No. 4,304,225 to Freeman teaches the use of a flexible strap which is fixed to a contoured plastic block and which would pass across the back of the heart. In response to electrical pulses, a motor assembly alternately reels in and releases the flexible strap, thereby forcing fluid from the organ. This prior art device is ineffective because a pressure of between 20 and 70 mm Hg in the volume under the strap pumps blood from the right ventricle but not the left, since 70 mm Hg or more is required for blood to exit the left ventricle into the aorta. Freeman also discloses the use of a tubular compression sleeve that substantially encircles the heart and which comprises a series of interconnected expandable elliptical chambers. In use, a liquid solution is pumped into the sleeve from a supply chamber, causing the elliptical chambers to expand radially inward to compress the heart in its systolic phase. The solution then is released from the sleeve back to a supply chamber, permitting the heart to expand in its diastolic phase. These bladder-type devices can lead to a buildup of blood in the lungs, producing pulmonary complications. U.S. Pat. No. 4,583,523 to Kleinke and Freeman illustrates another prior art heart assist mechanism. This device compresses the aorta, not the left ventricle, and it compresses during the diastolic phase of cardiac contraction instead of the systolic phase. There is no means to monitor the adequacy of left ventricular stroke volume.
U.S. Pat. No. 4,925,443 to Marlin S. Heilman and Steve A. Kolenik, discloses an implantable ventricular assist device which includes, (1) one or more movable compression assemblies for engaging a ventricle of the heart; (2) an operating mechanism for cyclically actuating the movable compression assemblies and thereby alternately ejecting blood from the ventricle and permitting the ventricle to refill; (3) a sensing means to detect adequacy of ventricular stroke volume and/or pressure; (4) a control mechanism to assure adequate ventricular stroke volume by regulating the compressive force of the compression assemblies, and also to control pacemaker, cardioverter/defibrillator, and recorder subsystems; and (5) an electrical power source.
To prevent the edges of the compression assembly pressure plates from creating pressure points which might cause possible damage to the heart, a related continuation-in-part patent, U.S. Pat. No. 5,098,369, to Marlin S. Heilman, et al., discloses replacing the contact pad of each compression assembly with a gel-filled contact pad of special construction that compresses the heart ventricle more uniformly without damaging the ventricle. Another related patent, U.S. Pat. No. 5,098,369, to Heilman, et. al., discusses a ventricular assist device for a heart which includes a compression band-stay-pad assembly for encircling substantially the entire heart perimeter and comprising an elongated band member or chain disposed in a sealed protective structure filled with a lubricating medium.
Yet another related patent, U.S. Pat. No. 5,558,617, to Heilman, et. al, discusses a ventricular assist device for a heart including a compression band-stay-pad assembly for encircling substantially the heart perimeter and comprising an elongated band member or chain disposed in a sealed protective structure filled with a lubricating medium. The band member is fixed at one end and wound upon, or unwound from, a rotatable spool by a drive motor through a speed reducer.
Other previous attempts to provide ventricular assistance have ranged from artificial hearts (e.g., the Jarvik-7), to devices which directly pump the blood via an artificial pathway inserted through the ventricular wall, to devices which exert pressure on the outside of the heart. Most frequently, these latter pressure-exerting devices involve some form of flexible bladder within a support structure such that expansion of the bladder presses on the ventricle and facilitates expulsion of blood. These types of devices are disclosed in U.S. Pat. No. 3,233,607 to Bolie; U.S. Pat. No. 3,279,464 to Kline; U.S. Pat. No. 3,587,567 to Schiff; U.S. Pat. No. 3,371,662 to Heid et al.; U.S. Pat. No. 4,048,990 to Goetz; U.S. Pat. No. 4,192,293 to Asrican; U.S. Pat. No. 3,455,298 to Anstadt; U.S. Pat. No. 4,690,134 to Snyder; U.S. Pat. No. 5,169,381 to Snyder; U.S. Pat. No. 5,256,132 to Snyder; U.S. Pat. No. 4,731,076 to Noon et al.; and U.S. Pat. No. 4,957,477 to Lundbxc3xa4ack. U.S. Pat. No. 4,506,658 to Casile discloses a truncated conical structure of sac-lined rigid panels separated by contractible and expandable sections. U.S. Pat. No. 4,621,617 to Sharma shows another similar device which is electromagnetically controlled and comprises a pair of hinged compression members. Further, U.S. Pat. No. 4,536,893 to Parravicini teaches using two segmented sacs, selectively fed by a pumping fluid to compress the right and left ventricles separately. In general, bladder systems have various shortcomings. These include the possibility of catastrophic bladder fluid leakage (as a result of the fluid pressures involved), a propensity for damaging the heart surface due to poor fixation and/or rubbing of the bladder against the heart""s surface, and the unnatural convex form presented to the heart""s surface during systolic bladder expansion. U.S. Pat. No. 4,583,523 to Kleinke and Freeman illustrates a heart assist mechanism that compresses the aorta, rather than a ventricle, and it compresses during the diastolic phase of cardiac contraction instead of the systolic phase.
Other prior art references of relevance to the present invention are:
U.S. Pat. No. 5,250,167 to Adolf, et al., and U.S. Pat. No. 5,389,222 to Shahinpoor in connection with electrically controllable polymeric actuators;
Y. Wakisaka, et al., xe2x80x9cApplication of Hydrogen Absorbing Alloys to Medical and Rehabilitation Equipmentxe2x80x9d, IEEE Trans. on Rehabilitation Engineering, Vol. 5, No. 2, pp. 148-157 (1997);
M. Shahinpoor, xe2x80x9cIonic Polymer Metal Composition as Biomimetic Sensors and Actuatorsxe2x80x9d, in Polymer Sensors and Actuators, edited by Y. Osada and D. DeRossii, Springer-Verlag Publishing, Springer (1999); and
M. Shahinpoor, Y. Bar-Cohen, J. O. Simpson, J. Smith, xe2x80x9cIonic Polymer Metal Composites (IPMC""s) as Biomimetic Sensors, Actuators and Artificial Musclesxe2x80x94a Reviewxe2x80x9d, J. Smart Mater Structures, Vol. 7, pp 15-30 (1998).
This invention comprises an implantable and entirely electrically-controlled external heart compression apparatus in the form of soft, multi-fingered resilient robotic hands for selectively assisting the ventricles, and in particular the left ventricle, of a weak heart to produce more internal pressure and to pump blood from one or more sides in synchrony with the natural systolic contraction of the ventricle. In addition, a number of methods for externally compressing a heart is included. The preferred apparatus also provides arrhythmia control of the beating heart and is powered by a robotic solenoid actuator or similar robotic actuation mechanism, including robotic metal hydride actuators as well as electroactive polymeric artificial muscles. Each of these apparatuses is for cyclically actuating the resilient compression soft fingers, thereby cyclically pumping blood from the ventricles and allowing the ventricles to refill. These apparatuses are completely implantable in the body of a patient external of the heart, thereby avoiding thrombogenesis and other complications that may arise from contact between the blood flow and artificial, nonbiological surfaces. The plurality of soft fingers comprise suitably located electrodes for heart monitoring purposes to determine the ventricular stroke volume and/or pressure. Specifically, the apparatus provides for an entirely electrically-controllable and micro-processor-controlled multi-fingered resilient sphinctering heart-compression that can be implanted inside the ribcage of a patient with a weak heart and gently squeeze the weak heart (systole) to enhance blood circulation and assist the weak heart. These apparatuses are comprised of a specially designed assembly of soft fingers that work in harmony, by means of a micro-processor controlled solenoid or other linear robotic actuators, and a resilient body or a spring, to close once the robotic solenoid is powered electrically. The apparatus is designed to be normally open (not compressing) when there is no power to the robotic solenoid or actuator. The assembly is spring loaded so that when power is removed, the fingers immediately spring open. This apparatus operates like the fingers of a hand to squeeze a weak heart (systole) but otherwise to quickly retract and stay open and away from the heart in an idle manner if the robotic actuation means is not powered. This quick opening action allows the heart to expand freely (diastole) once it is compressed to allow the blood to naturally and freely return to the heart ventricles and coronary veins. External pressure by the myocardium during ventricular systole compresses the heart muscle (myocardium) and decreases blood flow to the coronary veins that feed the heart even though the aortic pressure is increased. Thus, more than 70 percent of the coronary arterial flow occurs during diastole. The multi-fingered configuration may also have the soft fingers connected to each other by elastic membranes, bladders or skirts to provide a resilient, multi-fingered compression cup as well. In one embodiment of the invention the multi-fingered compression apparatus is equipped with a long slender and flexible and undulating stem connecting the multi-fingered compression structure to the robotic actuation mechanism housed in the abdomen of the patient. In another embodiment of the invention, an assembly of electroactive polymer fingers or patches are sutured to the myocardium and are directly electrically flexed to squeeze the heart. Yet in another embodiment of the invention, an assembly of bladder-like fingers is inflated by hydrogen gas from an electrically controlled metal-hydride actuator to create compression of the heart. The preferred embodiment of robotic actuator is a solenoid for its quick action and retraction. However, alternatively, linear motors or robotic actuators as well as robotic metal hydride actuators and polymeric artificial muscles can also be used. The power supply for the implanted apparatus can be long lasting batteries that can be recharged transcutaneously, and various other components of the apparatus can be noninvasively computer-programmed and interrogated by external circuits. The entire apparatus can be implanted endoscopically or through the abdomen of the patient rather than opening of the patient""s chest. The power and electronic control means may also be placed outside the body, around the waist of the person, and directly connected by means of conducting wires through sutured conduits to the implanted apparatus.
A primary object of the present invention is to provide a weak heart, a family of new heart assist devices that are robotically computer controllable and implantable in the patient""s body external to the heart, that are further, compact and light-weight.
A further object of the invention is to provide selective compression of different parts of the heart or thoracic aorta in synchrony and harmony with the natural systolic and diastolic motions of the heart.
Yet another object of the present invention is to provide an endoscopically implantable selective heart compression device equipped with built-in robotic metal hydride actuators that are electronically computer controllable.
Yet another object of the present invention is to provide an endoscopically implantable selective heart compression device equipped with robotic electroactive polymeric muscles that are electrically computer controllable.
A primary advantage of the present invention is to provide selective compression of different parts of the heart and thoracic aorta by means of specially contoured soft resilient fingers.
Yet another advantage of the present invention is to provide the heart with complete lateral and twist motions, while engaged in compression of the weak heart, by means of a flexible stem.
A further advantage of the present invention is to provide a patient with a weak heart an totally endoscopically implantable, multi-fingered compression device equipped with built-in metal hydride actuators for pneumatic computer-controlled compression of the heart.
Yet another advantage of the present invention is to provide a patient with a weak heart an endoscopically implantable, multi-fingered compression device equipped with electroactive polymeric artificial muscles which are robotically computer controllable.
Other objects, advantage and novel features, and further scope of applicability of the present invention will be set forth in part in the detailed description to follow, taken in conjunction with the accompanying drawings, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

Electrically-controllable multi-fingered resilient heart compression devices


A temperature control system includes a cabinet or system housing having a plurality of heating compartments for containing intravenous solution bags or other medical items. Each heating compartment is independently heat controlled via a controller, and includes a heating assembly including a heater, a U-shaped heating plate, a temperature sensor and a cut-out switch for disabling the heater when a threshold temperature is exceeded. The desired or set point temperature for each heating compartment may be independently entered to the controller via an input device. The heating plate has a generally U-shaped configuration with a thermally conductive bottom wall and thermally conductive side walls extending therefrom. The heater is typically affixed to the underside of the bottom wall, wherein, upon heating of the bottom wall, heat is conducted through the side walls to provide an even distribution of heat to medical items placed within the heating compartment. Each heating compartment may further include a collapsible rack structure allowing a user to selectively partition each heating compartment based upon the specific types of medical items to be heated.

1. Technical Field
The present invention pertains to systems for heating medical items. In particular, the present invention pertains to a system for heating and maintaining medical solution containers (e.g., bags or bottles containing saline or intravenous (IV) solutions, antibiotics or other drugs, blood, etc.) or other medical items (e.g., instruments, blankets, etc.) at desired temperatures by providing an even distribution of heat to the medical items placed within the system.
2. Discussion of Related Art
Generally, various items are required to be heated prior to utilization in a medical procedure to prevent thermal shock and injury to a patient. These items typically include intravenous solution, surgical instruments, bottles and blankets. In order to provide the necessary heated items for use in medical procedures, medical personnel may utilize several types of warming systems to heat items toward their operational temperatures. For example, ovens may be disposed within operating rooms to heat items to desired temperatures. Further, U.S. Pat. No. 4,419,568 (Van Overloop) discloses a wet dressings heater having a base with side walls defining a cavity, and an insert connected to the base and defining at least one recess in the cavity for receiving wet dressings. A heater has an electrical heating element in close proximity to the insert recess for heating the wet dressings, while the temperature of the heating element is controlled in a desired temperature range for those wet dressings.
U.S. Pat. No. 4,495,402 (Burdick et al) discloses a warmer for heating wet dressings and other articles disposed within a heating and storage compartment. The articles are arranged within the compartment in stacked relation and disposed on a plate that is supplied with thermal energy from a heater. The plate includes a center aperture whereby a first thermal sensor is disposed in the aperture in contact with a bottommost article. Control circuitry is disposed beneath the plate to control the heater to maintain temperature ofthe bottommost article at a desired level based on the temperatures sensed by the first thermal sensor and a second thermal sensor responsive to heater temperature.
U.S. Pat. No. 5,408,576 (Bishop) discloses an intravenous fluid warmer having a cabinet structure to accommodate a plurality of intravenous fluid bags. A temperature sensor and pad of heating filaments are disposed within the cabinet structure, whereby the temperature sensor enables automatic temperature regulation of the pad of heating filaments to heat the intravenous fluid bags. The heating filaments are covered by a rubber layer to prevent melting of the bags during heating. A temperature indicator disposed on the cabinet structure permits a user to ascertain when a desired temperature is attained, whereby an intravenous fluid bag is removed from the intravenous fluid warmer via an opening defined in a side of the cabinet structure.
U.S. Pat. No. 5,986,239 (Corrigan, III et al.) discloses a conductive warmer for flexible plastic bags. The warmer includes a heat-conducting member of thermally conductive material having a plurality of fins which are parallel and spaced apart to define a plurality of bag-receiving compartments. The fins are connected to a back portion of the heat-conducting member to which a heating element is attached in a heat-exchanging relationship. The heating element conducts heat through the back portion and fins of the heat-conducting member to the bags.
In addition, the related art provides warming systems for other types of items. For example, U.S. Pat. No. 4,605,840 (Koopman) discloses a horizontal holding cabinet for prepared food, wherein the cabinet has a plurality of drawer-containing modules arranged side-by-side to each other. Each module has a heating element and an integral water reservoir and is capable of being independently heated and humidified. The modules each further include a drawer receiving cavity having an open front adapted to receive a drawer frame. The cavity bottom wall is provided with one or more heating elements, whereby the module walls conduct heat to heat the cavity. A temperature thermostat is mounted on the undersurface of the cavity bottom wall to sense cavity temperature and is further connected to a thermostatic controller that controls the heating elements in accordance with a desired temperature.
The warming systems described above suffer from several disadvantages. In particular, ovens typically do not have a high degree of accuracy or control, thereby enabling use of items having temperatures incompatible with a medical procedure and possibly causing injury to a patient. Further, the Burdick et al and Bishop warmers employ heaters that generally contact a particular portion of an article being heated, thereby heating articles in an uneven manner and enabling formation of hot spots. Moreover, the Burdick et al, Bishop, Corrigan, III et al and Van Overloop warming systems heat items simultaneously to only a single desired temperature rendering them incompatible for applications requiring various items to be heated to different temperature ranges. These systems further employ a heating element covering a substantial portion of a conducting member, thereby increasing system costs and power usage. The above described systems typically have heating area dimensions specifically configured to accommodate particular items and, therefore, are limited with respect to the types of items that may be heated by those systems. The Koopman system employs heating elements disposed within a housing cavity and not in direct contact with the surface supporting an item. This typically requires the system to heat the cavity, thereby providing increased heating time for an item to attain a particular temperature. In addition, the above-described warming systems do not provide a selectively configurable structure for partitioning system compartments to facilitate a relatively even heat distribution for additional or varying items placed therein.
The present invention overcomes the aforementioned problems and provides several advantages. For example, the present invention warming system distributes heat evenly to one or more medical items of varying shapes and sizes, thereby ensuring relatively uniform heating of items with enhanced temperature control. Further, since medical items are supported within system compartments on a heating plate, the medical items are not in direct contact with a heater, thereby avoiding creation of xe2x80x9chot spotsxe2x80x9d. Moreover, the present invention reduces costs by utilizing a single common controller to simultaneously control each heater within system compartments, and provides versatility since each compartment heater may be individually controlled to enable the system to heat medical items contained within different compartments to the same or different desired temperatures. In addition, a warming system rack structure of the present invention provides even heat distribution and enhanced temperature regulation of individual medical items contained within the receptacles. Since most hospital personnel are unaware of the temperature of a particular medical item prior to use, the rack structure provides a fairly high degree of control of that temperature.
Accordingly, it is an object of the present invention to heat a medical item to a desired temperature by uniformly distributing heat about the medical item, thereby avoiding creation of xe2x80x9chot spotsxe2x80x9d and xe2x80x9ccold spotsxe2x80x9d.
It is another object of the present invention to simultaneously maintain various items at different desired temperatures for use in medical procedures.
Yet another object of the present invention is to simultaneously maintain various items at different desired temperatures for use in medical procedures via a temperature control system including heating compartments individually controlled by a common controller, wherein each heating compartment is maintained at a desired temperature.
Still another object of the present invention is to evenly distribute heat about a medical item within a heating compartment of the system by conducting heat through a heating plate that at least partially surrounds the medical item.
A further object of the present invention is to provide a collapsible rack structure within a system heating compartment to partition that compartment and facilitate a uniform distribution of heat to additional or varying items.
The aforesaid objects may be achieved individually and in combination, and it is not intended that the present invention be construed as requiring two or more of the objects to be combined unless expressly required by the claims attached hereto.
According to the present invention, a temperature control system includes a cabinet or system housing having an interior partitioned into individual heating compartments for containing medical items. Each compartment includes a heating assembly having a generally U-shaped heating plate with thermally conductive bottom and side walls, a heater, a temperature sensor and a temperature cut-out switch. The heater is typically disposed beneath the bottom wall of the heating plate and applies heat to the heating plate to heat medical items placed thereon. The U-shaped configuration of the heating plate ensures even distribution of heat applied to one or more medical items placed within the heating compartment. The system further includes a controller in communication with the heater and temperature sensor of each heating assembly, wherein the controller controls heating of each compartment based upon a user selected desired or set point temperature associated with that compartment. A collapsible rack structure may additionally be disposed within one or more compartments to form individual receptacles in those compartments for receiving and heating medical items placed therein.
The above and still further objects, features and advantages of the present invention will become apparent upon consideration of the following detailed description of specific embodiments thereof, particularly when taken in conjunction with the accompanying drawings, wherein like reference numerals in the various figures are utilized to designate like components.

Temperature controlled cabinet system and method for heating items to desired temperatures