A process for producing (2R,3S)-3-amino-4-phenylbutane-1,2-epoxide compounds which comprises treating a (2S,3S)-3-amino-1-halo-2-hydroxy-4-phenylbutane compound or a (2S,3S)-3-amino-4-phenylbutane-1,2-epoxide with a carboxylic acid quaternary ammonium salt or a carboxylic acid metal salt a quaternary ammonium salt and a quaternary ammonium salt, to give a (2S,3S)-1-acyloxy-3-amino-2-hydroxy-4-phenylbutane compound, further treating the same with a sulfonic acid halide in the presence of an organic base to give a (2S,3S)-1-acyloxy-3-amino-2-sulfonyloxy-4-phenylbutane compound, furthermore treating said compound with an inorganic base.

The processes so far known for producing said (2R,3S)-3-amino-1,2-oxirane comprise starting with L-phenylalanine, reducing the carboxyl group thereof to an alcohol function, reoxidizing the same to an aldehyde function, and thereafter 1) directly causing formation of the epoxide using a dimethylsulfonium methylide (J. Org. Chem., 1985, 50, 4615; J. Med. Chem., 1992, 35, 2525), 2) converting the aldehyde to the corresponding olefin by the Wittig reaction and epoxidizing the olef in using m-chloroperbenzoic acid (J. Org. Chem., 1987, 52, 1487; J. Med. Chem. 1992, 35, 1685), 3) reacting the aldehyde with trimethylsilylmethylmagnesium chloride, converting the resulting trimethylsilylalcohol to the corresponding olefin by treatment with trifluoroboron and, as in the method 2) mentioned above, conducting epoxidation using m-chloroperbenzoic acid (EP 0532-466 A2, U.S. Pat. No. 5,514,814) or 4) converting L-phenylalanine to the diazoketone form, degradating the same with hydrochloric acid, reducing the resulting .alpha.-ketone with NaBH.sub.4 and treating the resulting chlorohydrin with a base to give the epoxide (J. Med. Chem., 1994, 37, 1758), among others.
Meanwhile, there is no precedent technology for producing (2R,3S)-3-amino-1,2-oxirane compounds represented by the general formula (8) starting with a (2S,3S)-3-amino-1-chloro-2-hydroxy-4-phenylbutane compound or a (2S,3S)-3-amino-1,2-oxirane compound as in the process of the present invention.
Referring to the above known processes, the process 1) is disadvantageous in that it is necessary to use the sulfur compound in large amounts in the step of epoxide formation, the methods 2) and 3) are disadvantageous in that it is necessary to use the peroxide, which is explosive, in large amounts, and the method 4) is disadvantageous in that it is necessary to handle the diazo compound, which is also explosive, and, in addition, the selectivity toward the desired (2R,3S)-chlorohydrin in NaBH.sub.4 reduction is low. Thus, every process comprises a step undesirable from the viewpoint of commercial scale practicing.

Process for the preparation of (2r,3s)-3-amino-1,2-oxirane


A solid-form dishwasher detergent that contains a builder combination of conventional phosphates and crystalline layer silicates. Despite its phosphate content, the detergent provides improved protection to sensitive tableware, more particularly glasses and decorated tableware, and improved cleaning performance.

This invention relates to a dishwasher detergent in solid form containing a builder combination of conventional phosphates and crystalline layer silicates. Despite its phosphate content, the detergent according to the invention offers improved protection to sensitive tableware, more particularly glasses and decorated tableware, and develops high cleaning performance and, in some cases, further improved cleaning performance compared with conventional phosphate-containing dishwasher detergents.
Now that domestic dishwashing machines are used on a relatively wide scale, it is known that highly alkaline phosphate/metasilicate-based dishwasher detergents, although developing high cleaning performance, show unfavorable behavior in regard to corrosion of decorated tableware, i.e. colored on-glaze and in-glaze decorations applied to china, decorated glasses and gold decorations gradually lose color intensity and brilliance.
The citrate- or phosphate-based low-alkali dishwasher detergents introduced onto the market in recent years also have the above-mentioned effect, although to a lesser extent.
These disadvantages can largely be eliminated by adding relatively large quantities of water-soluble amorphous silicates, more particularly amorphous disilicates. At the same time, however, glasses undergo irreversible damage after only a few dishwashing programs with disilicate-containing detergents, as reflected in clouding and iridescence (iridescent colors).
European patent application EP-A-0 504 091 (Viking) describes phosphate-free dishwasher detergents which develop high cleaning performance against tea stains. These known detergents contain about 5 to 15% by weight of crystalline layer silicates and, in addition, 10 to 15% by weight of citric acid and also (co)polymeric polycarboxylates. Unfortunately, the overall cleaning performance of these low-alkali dishwasher detergents against problem soils apart from tea is unsatisfactory. Although their performance in removing tea stains is very good, it could still be improved.
The dishwasher detergents described in International patent application WO-A-94/16047 (Procter and Gamble) show improvements in the protection of silverware through the use of builders, bleaching agents released at a certain time and paraffin oil in quantities of 0.05 to 2.5% by weight. Citrate-containing formulations are clearly preferred. Other suitable builders are alumosilicates, phosphates and even crystalline layer silicates. Combinations of phosphate and crystalline layer silicates are not mentioned or even suggested, nor is there any reference to advantages arising out of the use of such builder combinations.
Finally, International patent application WO-A-96/12783 (Henkel) describes phosphate-free or low-phosphate dishwasher detergents based on citrate-containing formulations incorporating crystalline layer silicates which combine improved protection of decoration and glassware with high cleaning performance against tea stains. Unfortunately, the overall cleaning performance is again in need of improvement.
European patent application EP-A-0 416 366 (Hoeschst) describes a dishwasher detergent which contains 30% by weight of sodium tripolyphosphate, 30% by weight of crystalline sodium layer silicate, preferablyxe2x80x94as a proton donorxe2x80x94mineral acid and/or polycarboxylic acid and/or hydroxypolycarboxylic acids and/or phosphonic acids and/or acidic salts or esters thereof and which, overall, has a relatively low pH value. This known dishwasher detergent is characterized by its high cleaning performance.
However, detergents containing crystalline layer silicates as a builder raw material are also attended by the disadvantage that lime deposits can be formed on glass and crockery on account of the slow dissolving rate of the crystalline layer silicate. In addition, the raw material consists of very fine particles and contains large amounts of dust which can lead to production problems both in the manufacture of powders and granules and in the manufacture of dishwasher tablets.
Hitherto, there has been no satisfactory solution to the problem of ensuring decorationxe2x80x94and glass-protecting cleaning in combination with high cleaning performance as demanded by the consumer against such problem soils as tea, milk/milk products, egg/protein products, etc. coupled with safe manufacture free from production problems.
Accordingly, the problem addressed by the present invention was to provide a dishwasher detergent which would not have the disadvantages mentioned above, i.e. which would not cause any damage to glass, even after repeated use, but at the same time would develop high cleaning performance against tea stains and an excellent overall cleaning performance and which could be produced without any production problems both in the manufacture of powders and granules and in the manufacture of tablets.
It has surprisingly been found that this problem can be solved by phosphate-containing dishwasher detergents providing they contain crystalline layer silicates in a certain compounded form in addition to phosphates.
Accordingly, the present invention relates to a solid dishwasher detergent containing conventional phosphates and other typical ingredients, characterized in that, in addition to the phosphates, the detergent contains as an additional builder a powder-form or granular additive containing a crystalline layer silicate corresponding to general formula (I):
NaMSixO2x+1xc2x7y H2Oxe2x80x83xe2x80x83(I)
in which M is sodium or hydrogen, x is a number of 1.9 to 22 and preferably 1.9 to 4 and y is a number of 0 to 33, and (co)polymeric polycarboxylic acid as key constituents.
Conventional phosphates suitable for use as builders in dishwasher detergents include in particular alkali metal phosphates and polymeric alkali metal phosphates which may be present in the form of their alkaline, neutral or acidic sodium or potassium salts. Examples of such phosphates are trisodium phosphate, tetrasodium diphosphate, disodium dihydrogen diphosphate, pentasodium tripolyphosphate, so-called sodium hexametaphosphate, oligomeric trisodium phosphate with degrees of oligomerization of 5 to 1000 and more particularly 5 to 50 and the corresponding potassium salts or mixtures of sodium hexametaphosphate and the corresponding potassium salts or mixtures of sodium and potassium salts. The salts of the tripolyphosphate are particularly preferred. They are used in quantities of more than 30% by weight to 65% by weight and, more particularly, from 35 to 60% by weight, expressed as water-free active substance and based on the formulation as a whole.
Crystalline layer silicates corresponding to formula (I) are marketed by Clariant GmbH (Germany) under the trade name Na-SKS, including for example Na-SKS-1 (Na2Si22O45xH2O, kenyaite) Na-SKS-2 (Na2Si14O29xH2O, magadiite), Na-SKS-3 (Na2Si8O17xH2O), Na-SKS-4 (Na2Si4O9xH2O, makatite).
Compositions particularly suitable for the purposes of the invention are those containing crystalline layer silicates corresponding to formula (I) in which x is 2. Of these, Na-SKS-5 (xcex1-Na2Si2O5), Na-SKS-7 (xcex2-Na2Si2O5 natrosilite), Na-SKS-9 (NaHSi2O5.H2O), Na-SKS-10 (NaHSi2O5.3H2O, kanemite), Na-SKS-11 (xcfx84-Na2Si2O5) and Na-SKS-13 (NaHSi2O5), but especially Na-SKS-6 (xcex4-Na2Si2O5), are particularly suitable. An overview of crystalline layer silicates can be found, for example, in the articles published in xe2x80x9cHoechst High Chem Magazine 14/1993xe2x80x9d, pages 33-38 and in xe2x80x9cSeifen-xc3x96le-Fette-Wachsexe2x80x9d, Vol. 116, No. 20/1990xe2x80x9d, pages 805-808. According to the invention, the crystalline layer silicates corresponding to formula (I) are at least partly introduced into the dishwasher detergents according to the invention through the builder additive used in accordance with the invention. In one preferred embodiment of the invention, the crystalline layer silicates corresponding to formula (I) are introduced into the dishwasher detergents according to the invention solely through the builder additive used in accordance with the invention. The dishwasher detergents advantageously contain the crystalline layer-form silicate corresponding to formula (I) introduced through the builder additive in quantities of 2 to at most 30% by weight, preferably in quantities of 3 to 25% by weight and more preferably in quantities of 4 to 20% by weight.
In the context of the present invention, a (co)polymeric polycarboxylic acid is understood to be a non-neutralized or only partly neutralized homopolymer or copolymer. These include the homopolymers of acrylic or methacrylic acid and copolymers thereof with other ethylenically unsaturated monomers such as, for example, acrolein, dimethyl acrylic acid, ethyl acrylic acid, vinyl acetic acid, ally acetic acid, maleic acid, fumaric acid, itaconic acid, meth(allylsulfonic acid), vinyl sulfonic acid, styrene sulfonic acid, acrylamidomethyl propane sulfonic acid and monomers containing phosphorus groups such as, for example, vinyl phosphonic acid, allyl phosphoric acid and acrylamidomethyl propane phosphonic acid and salts thereof, and hydroxyethyl (meth)acrylate sulfates, allyl alcohol sulfates and allyl alcohol phosphates. Polymers such as these are described, for example, in German patent applications DE-A-23 57 036, DE-A-44 39 978 and in European patent applications EP-A-0 075 820 and EP-A-0 451 508.
Preferred (co)polymers have an average molecular weight of 1000 to 100,000 g/mole, preferably in the range from 2000 to 75,000 g/mole and more preferably in the range from 2000 to 35,000 g/mole. The degree of neutralization of the acid groups is advantageously between 0 and 90%, preferably between 10 and 80% and more preferably between 30 and 70%.
Other suitable polymers are, above all, homopolymers of acrylic acid and copolymers of (meth)acrylic acid with maleic acid or maleic anhydride.
Other suitable copolymers are derived from terpolymers which can be obtained by polymerization of 10 to 70% by weight of monoethylenically unsaturated dicarboxylic acids containing 4 to 8 carbon atoms or salts thereof, 20 to 85% by weight of monoethylenically unsaturated monocarboxylic acids containing 3 to 10 carbon atoms or salts thereof, 1 to 50% by weight of monounsaturated monomers, which release hydroxyl groups on the polymer chain after saponification, and 0 to 10% by weight of other radical-copolymerizable monomers. For the purposes of the use according to the invention, saponification of the monounsaturated monomers, which release a hydroxyl group on the polymer chain after saponification, is preferably carried out in a acidic medium. Products of the type mentioned above are described in German patent applications DE-A-43 00 772 and DE-A-195 16 957 and in WO-A-94/15978.
Graft polymers of monosaccharides, oligosaccharides, polysaccharides and modified polysaccharides, as described in German patent applications DE-A-40 03 172 and DE-A-44 15 623, are also suitable, as are the graft polymers with proteins of animal or vegetable origin disclosed in the European patent application, more particularly with modified proteins.
From the group of graft copolymers, copolymers of sugar and other polyhydroxy compounds and a monomer mixture with the following composition are preferably used: 45 to 96% by weight of monoethylenically unsaturated C3-10 monocarboxylic acid or mixtures of C3-10 monocarboxylic acids and/or salts thereof with monovalent cations, 4 to 55% by weight of monomers containing monoethylenically unsaturated monosulfonic acid groups, monoethylenically unsaturated sulfuric acid esters, vinyl phosphonic acid and/or the salts of these acids with polyvalent cations and 0 to 30% by weight of water-soluble monoethylenically unsaturated compounds modified with 2 to 50 moles of alkylene oxide per mole of monoethylenically unsaturated compound. Such compounds are described in DE-A-42 21 381 and in DE-A-43 43 993.
Other suitable polymers are polyaspartic acids and derivatives thereof in non-neutralized or only partly neutralized form. The polyaspartic acids normally accumulate in the form of their alkali metal or ammonium salts. The non-neutralized or only partly neutralized products may be obtained therefrom by adding appropriate quantities of organic or inorganic acids and optionally removing the salts formed.
Products of the type in question may also be obtained by the thermal reaction of maleic acid and ammonia or by the condensation of aspartic acid and subsequent hydrolysis of the polysuccinimide formed. The production of products such as these is described, for example, in DE-A-36 26 672, DE-A-43 07 114, DE-A-44 27 287, EP-A-0 612 784, EP-A-0 644 257 and WO-A-92/14753.
Graft polymers of acrylic acid, methacrylic acid, maleic acid and other ethylenically unsaturated monomers with the salts of polyaspartic acid normally accumulating in the above-described hydrolysis of the polysuccinimide are also particularly suitable. In their case, there is no need for the otherwise necessary addition of acid for the production of the only partly neutralized form of polyaspartic acid. The quantity of polyaspartate is normally selected so that the degree of neutralization of all the carboxyl groups incorporated in the polymer does not exceed 80%, preferably 60%. Products of the type mentioned are described in detail in International patent application WO-A-94/01486.
The quantities in which the non-neutralized or only partly neutralized (co)polymeric polycarboxylates are present in the compositions according to the invention are determined by the content of builder additives used in accordance with the invention and by their content of these polymers.
The builder additive used in accordance with the invention contains the crystalline layer silicate corresponding to formula (I) and the (co)polymeric polycarboxylic acid in a ratio by weight of preferably (40 to 1):1 and more preferably (20 to 2):1, ratios, of 7:1 to about 3:1, based on the water-free active substances, being particularly advantageous. The water content of the builder additives used in accordance with the invention is preferably 4 to 20% by weight, the upper appropriate limit to the water content being made dependent on the fact that the builder additive should still be stable and free-flowing and should not form any lumps, even after storage at elevated temperatures of, for example, 40xc2x0 C. It has been found that the lower limit to the water content influences the dissolving behavior of the builder additive. Accordingly, in the interests of a higher dissolving rate of the builder additive, additives containing 5 to 15% by weight of water are preferred, those containing 7 to 12% by weight of water being particularly preferred. The water content is determined over a period of 4 hours at a temperature of 140xc2x0 C.
The builder additives used in accordance with the invention may be produced simply by contacting the crystalline layer silicate corresponding to formula (I) with an aqueous solution, preferably a concentrated aqueous solution, of the (co)polymeric polycarboxylic acid, optionally followed by drying to the requisite water content. Conventional mixers and granulators, such as the Lxc3x6dige plowshare mixer or a Schugi mixer or an Eirich mixer or a Lxc3x6dige CB 30 Recycler and other machines known to the expert, which above all enable a liquid to be sprayed onto a solid, are as suitable as fluidized bed mixers/granulators. The polymer solution acts as an agglomeration aid. It is assumed that, in the reaction of the crystalline layer silicate corresponding to formula (I) with the acidic polymer, particularly where the polymer solution used has a pH value below 4, the sodium ions of the silicate are partly replaced by protons. However, the silicate skeleton with its layer structure and the majority of the sodium ions remain unchanged. The effect of this is that the builder additives used in accordance with the invention have only a slightly reduced starting alkalinity, but a far lower residual alkalinity than the pure crystalline layer silicate corresponding to formula (I). The residual alkalinity may be adjusted through the polymer acid content of the additives. Accordingly, the builder additive may be used as a buffer in the dishwasher detergents.
The builder additives may contain large quantities of (co)polymeric polycarboxylic acid, preferably quantities of 2 to 40% by weight, more preferably quantities of 5 to 30% by weight and most preferably quantities of 10 to 25% by weight. The content of crystalline layer silicates of formula (I) in the builder additives is preferably 50 to 90% by weight, more preferably 60 to 90% by weight and most preferably 65 to 85% by weight. The additives preferably have a calcium binding capacity above 185 mg CaCO3/g. The pH value of a 0.1% by weight aqueous solution at 20xc2x0 C. is preferably above 10, but below 12. The bulk density of the additives used in accordance with the invention varies according to the method used for their production and is normally above 400 to about 700 g/l. Whereas pure crystalline layer silicate corresponding to formula (I), such as SKS 6(copyright), normally accumulates in very fine-particle form and also contains large amounts of dust, the builder additive used in accordance with the invention is a relatively coarse-particle powder or an agglomerate or granules which are finer when produced in a fluidized bed and coarser when produced, for example, in a high-speed mixer. Relatively coarse-particle additives have a mean particle size (d50) of, for example, about 450 to 900 xcexcm whereas relatively free-particle additives have a mean particle size (d50) of about 280 to 330 xcexcm. Even in the fine-particle additives, however, the percentage of dust is far lower than in the commercially available pure crystalline layer silicates corresponding to formula (I), more particularly SKS 6(copyright).
The content of these builder additives in the dishwasher detergents according to the invention is variable within wide limits and depends both upon the content of crystalline layer silicates (I) in the dishwasher detergent formulation and upon the content of this crystalline layer silicate in the selected builder additive. Normal contents of these builder additives in the phosphate-containing dishwasher detergents are from about 2 to 40% by weight, contents of 5 to 35% by weight being preferred and contents of up to 30% by weight being particularly preferred.
Besides the ingredients used in accordance with the invention, the dishwasher detergents according to the invention, which may be present as granules, powders or tablets or other solid shaped bodies, may in principle contain any known ingredients typically present in dishwasher detergents. More particularly, the detergents according to the invention may contain other builders, surfactants, bleaching agents based on organic and/or more particularly inorganic peroxygen compounds, bleach activators, enzymes, sequestering agents, electrolytes, pH regulators and/or other auxiliaries such as, for example, silver corrosion inhibitors, foam regulators and dyes and perfumes. Tablets or other shaped bodies may also contain conventional disintegrators in the usual quantities.
In addition to the phosphates and the builder additives, the dishwasher detergents according to the invention ay also contain one or more other builders from the group of carbonates, hydrogen carbonates, amorphous silicates, crystalline layer-form silicates, which have not been introduced via the additive, and polybasic carboxylic acids or salts thereof, more particularly citric acid or citrate. In one preferred embodiment of the invention, however, the detergents do not contain any crystalline silicates of formula (I) which have not been introduced into the formulation through the builder additive. The detergents may also contain other (co)polymeric polycarboxylates of the usual type which are also soluble in water and which may serve as co-builders, particularly under hard water conditions. Other (co)polymeric polycarboxylates which may be used in accordance with the invention are, for example, polyacrylic acids and copolymers of maleic anhydride and acrylic acid and the sodium salts of these polymeric acids. Commercially available products are, for example, Sokalan(copyright) CP 5, CP 10 and PA 30 (BASF). Other commercially available and suitable polymers are, for example, POC QUAL AS 2057(copyright) (Degussa), Norasols(copyright), such as Norasol LMW 45N(copyright), Norasol SP 02N(copyright) and Norasol 470 N(copyright) (Rohm and Haas) or Alcosperse 175 N(copyright) (Alco). Polymers of native origin suitable as co-builders include, for example, oxidized starch, as known for example from International patent application WO 94/05762, as polyamino acids, such as polyglutamic acid and polyaspartic acid. Other possible builder components are naturally occurring hydroxycarboxylic acids such as, for example, monohydroxy and dihydroxy succinic acid, xcex1-hydroxypropionic acid and gluconic acid. Preferred organic builder components include the salts of citric acid, more particularly sodium citrate. The sodium citrate may be used as anhydrous trisodium citrate, but is preferably used in the form of trisodium citrate dihyrate. Trisodium citrate dihydrate may be used in the form of a fine or coarse crystalline powder. The acids corresponding to the co-builder salts mentioned may also be present, depending upon the pH value ultimately established in the detergents according to the invention. In a preferred embodiment, the dishwasher detergents according to the invention contain no more than 2% by weight of these additional (co)polymeric polycarboxylates which are not introduced via the builder additive. In one particular embodiment, the detergents are even free from these additional (co)polymeric polycarboxylates which have not been introduced via the builder additive.
Carbonates and hydrogen carbonates are among the alkalinity sources typically used. The detergents according to the invention may contain their sodium and/or potassium salts, for example in a quantity of 10 to 40% by weight and preferably 15 to 30% by weight, based on the detergent as a whole.
In view of the above-mentioned possible adverse effects of amorphous silicates and, above all, amorphous sodium silicates with a ratio by weight of Na2O to SiO2 of 1:1.8 to 1:3.3 and more particularly up to 1:2.5, these alkalinity sources are preferably present in the dishwasher detergents in quantities of less than 4% by weight and, more particularly, less than 2% by weight. Particularly preferred detergents are advantageously free from amorphous silicates and also from metasilicates.
Peroxygen compounds suitable for use in detergents according to the invention include, in particular, organic per acids or peracidic salts of organic acids, such as phthalimidopercaprioc acid, perbenzoic acid or salts of diperdodecanedioic acid, hydrogen peroxide and inorganic salts which release hydrogen peroxide under the washing/cleaning conditions, including perborates, percarbonates and/or persilicates. Hydrogen peroxide may also be produced by an enzymatic system, i.e. an oxidase and its substrate. If solid peroxygen compounds are to be used, they may be used in the form of powders or granules which may also be coated in known manner. A particularly preferred embodiment is characterized by the use of alkali metal percarbonate, alkali metal perborate monohydrate, alkali metal perborate tetrahydrate or hydrogen peroxide in the form of aqueous solutions containing 3% by weight to 10% by weight of hydrogen peroxide. If a detergent according to the invention contains peroxygen compounds, they are present in quantities of preferably up to 50% by weight and more preferably from 5% by weight to 30% by weight. The addition of small quantities of known bleach stabilizers, for example phosphonates, borates or metaborates and metasilicates, and magnesium salts, such as magnesium sulfate, can be useful.
However, other typical oxygen bleaching agents are the organic per acids. Preferred organic per acids include above all the highly effective phthalmidoperoxycaproic acid, although any other known per acids may be used in principle.
Compounds which form aliphatic peroxocarboxylic acids containing preferably 1 to 10 carbon atoms and more preferably 2 to 4 carbon atoms and/or optionally substituted perbenzoic acid under perhydrolysis conditions may be used as bleach activators. Substances bearing O- and/or N-acyl groups with the number of carbon atoms mentioned and/or optionally substituted benzoyl groups are suitable. Preferred bleach activators are polyacylated alkylenediamines, more particularly tetraacetyl ethylenediamine (TAED), acylated triazine derivatives, more particularly 1,5-diacetyl-2,4-dioxohexahydro-1,3,5-triazine (DADHT), acylated glycolurils, more particularly tetraacetyl glycoluril (TAGU), N-acylimides, more particularly N-nonanoyl succinimide (NOSI), acylated phenol sulfonates, more preferably n-nonanoyl- or isononanoyl-oxygenzenesulfonate (n- or iso-NOBS), carboxylic anhydrides, more particularly phthalic anhydride, acylated polyhydric alcohols, more particularly triacetin, ethylene glycol diacetate, 2,5-diacetoxy-2,5-dihydrofuran and the enol esters known from German patent applications DE 196 16 693 and DE 196 16 767, acetylated sorbitol and mannitol and the mixtures thereof (SORMAN) described in European patent application EP 0 525 239, acylated sugar derivatives, more particularly pentaacetyl glucose (PAG), pentaacetyl fructose, tetraacetyl xylose and octaacetyl lactose, and acetylated, optionally N-alkylated glucamine and gluconolactone, and/or N-acylated lactams, for example N-benzoyl caprolactam, which are known from International patent applications WO 94/27970, WO 94/28102, WO 94/28103, WO 95/00626, WO 95/14759 and WO 95/17498. The substituted hydrophilic acyl acetals known from German patent application DE 196 16 769 and the acyl lactams described in German patent application DE 196 16 770 and in International patent application WO 95/14075 are also preferably used. The combinations of conventional bleach activators known from German patent application DE 44 43 177 may also be used. Bleach activators such as these are present in the usual quantities, preferably in quantities of 1% by weight to 10% by weight and more preferably in quantities of 2% by weight to 8% by weight, based on the detergent as a whole.
In addition to or instead of the conventional bleach activators mentioned above, the sulfonimines known from European patents EP 0 446 982 and EP 0 453 003 and/or bleach-boosting transition metal salts or transition metal complexes may also be present as so-called bleach catalysts. Suitable transition metal compounds include, in particular, the manganese-, iron-, cobalt-, ruthenium- or molybdenum-salen complexes known from German patent application DE 195 29 905 and the N-analog compounds thereof known from German patent application DE 196 20 267, the manganese-, iron-, cobalt-, ruthenium- or molybdenum-carbonyl complexes known from German patent application DE 195 36 082, the manganese, iron, cobalt, ruthenium, molybdenum, titanium, vanadium and copper complexes with nitrogen-containing tripod ligands described in German patent application DE 196 05 688, the cobalt-, iron-, copper- and ruthenium-ammine complexes known from German patent application DE 196 20 411, the manganese, copper and cobalt complexes described in German patent application DE 44 16 438, the cobalt complexes described in European patent application EP 0 272 030, the manganese complexes known from European patent application EP 0 693 550, the manganese, iron, cobalt and copper complexes known from European patent EP 0 392 592, the cobalt complexes known from International patent applications WO 96/23859, WO 96/23860 and 96/23861 and/or the manganese complexes described in European patent EP 0 443 651 or in European patent application EP 0 458 397, EP 0 458 398, EP 0 549 271, EP 0 549 272, EP 0 544 490 and EP 0 544 519. Combinations of bleach activators and transition metal bleach catalysts are known, for example, from German patent applications DE 196 13 103 and from international patent application WO 95/27775. Bleach-boosting transition metal complexes, more particularly with the central atoms Mn, Fe, Co. Cu, Mo. V, Ti and/or Ru, are used in typical quantities, preferably in a quantity of up to 1% by weight, more preferably in a quantity of 0.0025% by weight to 0.25% by weight and most preferably in a quantity of 0.01% by weight to 0.1% by weight, based on the detergent as a whole. A bleach-boosting combination prepared by thoroughly mixing a water-soluble salt of a divalent transition metal selected from cobalt, iron, copper and ruthenium and mixtures thereof, a water-soluble ammonium salt and optionally a peroxygen-based oxidizing agent and also inert carrier materials is described, for example, in earlier German patent application P 197 09 284.5.
Although, in principle, chlorine-containing bleaching agents may be present in the detergents according to the invention and the invention also encompasses chlorine-containing formulations, chlorine-free bleaching agents only are preferably used.
Dishwasher detergents according to the invention may contain corrosion inhibitors as an ingredient for protecting the tableware or the machine itself, silver protectors being particularly important for dishwashing machines. Known corrosion inhibitors, for example those described in DE 43 25 922, DE 41 28 672 and DE 43 38 724, may be used. Above all, silver protectors selected from the group of triazoles, benzotriazoles, bisbenzotriazoles, aminotriazoles, alkylaminotriazoles and the transistion metal salts or complexes may generally be used. Benzotriazole and/or alkylaminotriazole is/are particularly preferred. In addition, dishwashing formulations often contain corrosion inhibitors containing active chlorine which are capable of distinctly reducing the corrosion of silver surfaces. According to the above documents, chlorine-free dishwashing detergents contain in particular oxygen- and nitrogen-containing organic redox-active compounds, such as dihydric and trihydric phenols, for example hydroquinone, pyrocatechol, hydroxyhydroquinone, gallic acid, phloroglucinol, pyrogallol and derivatives of these compounds. Salt-like and complex-like inorganic compounds, such as salts of the metals Mn, Ti, Zr, Hf, V, Co and Ce are also frequently used. Of these, the transition metal salts selected from the group of manganese and/or cobalt salts and/or complexes are preferred, cobalt(ammine) complexes, cobalt(acetate) complexes, cobalt(carbonyl) complexes, chlorides of cobalt or manganese and manganese sulfate being particularly preferred. Zinc compounds may also be used to prevent corrosion of tableware. These silver protectors may normally be present in quantities of up to about 5% by weight.
Enzymes suitable for use in the detergents are enzymes from the class of proteases, lipases, cutinases, amylases, pullunases, oxidases and peroxidases, glucanases and mixtures thereof, for example, such as BLAP(copyright), Optimase(copyright), Opticlean(copyright), Maxacal(copyright), Maxapem(copyright), Alcalase(copyright), Esperase(copyright), Savinase(copyright), Durazym(copyright) and or Purafect(copyright) OxP; amylases, such as Termamyl(copyright), Amylase-LT(copyright), Maxamyl(copyright), Duramyl(copyright) and/or Purafect(copyright) OxAm; lipases, such as Lipolase(copyright), Lipomax(copyright), Lumafast(copyright) and/or Lipozym(copyright). Enzymes obtained from fungi or bacteria, such as Bacillus subtilis, Bacillus Licheniformis, Streptomyces griseus, Humicola lanuginosa, Humicola insolens, Pseudomonas pseudoalcaligenes and Pseudomonas cepacia are particularly suitable. These enzymes optionally used as an additional ingredient may be absorbed onto supports and/or encapsulated in membrane materials to protect them against premature inactivation, as described for example in European patent EP 0 564 476 and in International patent application WO 94/23005. They are present in the dishwasher detergents according to the invention in quantities of preferably up to 10% by weight and more preferably from 0.05% by weight to 5% by weight, enzymes stabilized against oxidative degradation, as known for example from International patent applications WO 94/02597, WO 94/02618, WO 94/18314, WO 94/23053 or WO 95/07350, being particularly preferred. The proteases preferably used in detergents according to the invention include the enzymes known from International patent applications WO 91/02792, WO 92/21760 and WO 95/23221.
Surfactants, more particularly low-foaming nonionic surfactants, optionally in admixture with anionic and/or switterionic surfactants, may also be added as optional ingredients to the detergents according to the invention. Such surfactants promote the removal of fatty soils, serve as wetting agents and optionally act as granulation aids in the production of the detergents. They may be used in quantities of up to 10% by weight, preferably up to 5% by weight and more preferably in the range from 0.5% by weight to 3% by weight. Extremely low-foaming compounds are normally used, especially in detergents intended for use in dishwashing machines. Preferred compounds of this type are C12-18 alkyl polyethylene glycol polypropylene glycol ethers containing up to 8 moles ethylene oxide and 8 moles propylene oxide units in the molecule. However, other known low-foaming nonionic surfactants may also be used, including for example C12-18 alkyl polyethylene glycol polybutylene glycol ethers containing up to 8 moles ethylene oxide units and 8 moles butylene oxide units in the molecule, end-capped alkyl polyalkylene glycol mixed ethers and the foaming, but ecologically attractive C8-14 alkyl polyglucosides with a degree of polymerization of about 1 to 4 (for example APG(copyright) 225 and APG(copyright) 500 of Henkel KGaA) and/or C12-14 alkyl polyethylene glycols containing 3 to 8 ethylene oxide units in the molecule. Surfactants from the glucamide family such as, for example, alkyl-N-methyl glucamides in which the alkyl moiety preferably emanates from a C6-14 fatty alcohol, are also suitable. It is of advantage in some cases to use the described surfactants in the form of mixtures, for example alkyl polyglycoside in admixture with fatty alcohol alkoxylates or glucamide in admixture with alkyl polyglycosides. The hydroxyl-containing alkoxylated alcohols described in EP-A-0 300 305 are also particularly preferred. It has been found that these hydroxy mixed ether surfactants have an excellent clear rinse effect. This applies in particular to mixtures with other nonionic surfactants, such as fatty alcohol alkoxylates, for example Dehypon LS 54(copyright), in admixture with Dehydol LS 4(copyright), to mixtures of hydroxy mixed ethers and APG(copyright) and to mixtures of fatty alcohol, ethoxylates, hydroxy mixed ethers and alkyl polyglycoside. Besides the clear-rinse effect, these surfactant mixtures also contribute towards significantly reducing stress cracking in plastics.
Suitable anionic surfactants are, in particular, soaps and those which contain sulfate or sulfonate groups withxe2x80x94preferablyxe2x80x94alkali metal ions as cations. Preferred soaps are the alkali metal salts of saturated and unsaturated C12-18 fatty acids. Fatty acids such as these may also be used without complete neutralization. Suitable surfactants of the sulfate type include the salts of sulfuric acid semiesters of C12-18 fatty alcohols and the sulfation products of the above-mentioned nonionic surfactants with a low degree of ethoxylation. Suitable surfactants of the sulfonate type include linear alkyl benzenesulfonates containing 9 to 14 carbon atoms in the alkyl moiety, alkane sulfates containing 12 to 18 carbon atoms and olefin sulfonates containing 12 to 18 carbon atoms, which are formed in the reaction of corresponding monoolefines with sulfur trioxide, and xcex1-sulfofatty acid esters which are formed in the sulfonation of fatty acid methyl or ethyl esters.
If the detergents foam too vigorously in use, for example where anionic surfactants are present, up to 6% by weight and preferably from about 0.5% by weight to 4% by weight of a foam-suppressing compound, preferably from the group of silicon oils, mixture of silicon oil and hydrophobicized silica, paraffins, paraffin/alcohol combinations, hydrophobicized silica, bis-fatty acid amides and other known commercially available defoamers, may be added to them. Other optional ingredients in the detergents according to the invention are, for example, perfume oils.
The dishwasher detergents according to the invention are present in solid form. They may be made up as powders or granules or even as shaped bodies, more particularly tablets. They may be conventionally produced, for example by mixing, granulation, compacting, such as roller compacting, tabletting and/or by spray drying. In some cases, the ingredients may even be used in precompounded form for the production of the dishwasher detergents according to the invention.
The tablets may be single-phase or multiphase, single-color or multicolored tablets and, more particularly, may consist of one layer or of several layers, more particularly two layersxe2x80x94a form in which tablets are already commercially available. In multilayer tablets, the builder additive may be present either in one layer only or may be distributed over several layers or all the layers.
To produce detergents according to the invention in the form of tablets, all the ingredientsxe2x80x94optionally for each layerxe2x80x94may be mixed together in a mixer and the resulting mixture tabletted in conventional tablet presses, for example eccentric presses or rotary presses, under pressures of about 50 to 100 kN and preferably under pressures of 60 to 70 kN. In the case of multilayer tablets in particular, it can be of advantage if at least one layer is compressed in advance, preferably under pressure of 5 to 20 kN and more particularly 10 to 15 kN. Fracture-resistant tablets which still dissolve sufficiently quickly under in-use conditions are readily obtained in this way; they have fracture and flexural strengths of normally 100 to 200 N and preferably above 150 N. A tablet produced in this way preferably has a weight of 15 g to 40 g and, more particularly, 20 g to 30 g. The tablets may be of any shape, including round, oval or angular and variations thereof. Corners and edges are advantageously rounded off. Round tablets preferably have a diameter of 30 mm to 40 mm. The size of rectangular or square tablets in particular, which are mainly introduced from dispensing compartments, for example of dishwashers, is dependent on the geometry and the size of the dispensing compartment. For example, preferred embodiments have a base area of (20 to 30 mm)xc3x97(34 to 40 mm) and, more particularly, 26xc3x9736 mm or 24xc3x9738 mm.
Dishwasher detergents according to the invention in the form of dust-free, storage-stable and free-flowing powders and/or granules with high bulk densities of 750 to 1200 g/l can be produced by mixing the builder components with at least part of the liquid components in a first stage in which the bulk density of the resulting premix is also increased and then combining the other components of the dishwasher detergent with the premix thus obtained, if desired after drying.
The detergents according to the invention are added by hand or, as indicated above, by suitable dispensers. The concentrations in which they are used in the main wash cycle, whether or not a prerinse cycle has taken place, are preferably from about 2 to 8 g/l and more preferably from 2 to 5 g/l.
The dishwashing program is generally augmented and terminated by a few rinse cycles with clear water after the main wash cycle and a final rinse cycle with a conventional rinse aid. After drying, completely clean and hygienically satisfactory tableware free from tea and other stains is obtained. Even after numerous wash cycles, the advantages afforded by using the detergents according to the invention, such as improved glass protection and decoration protection, are clearly in evidence.
However, the dishwasher detergents according to the invention not only develop very high cleaning performance against tea stains, they also produce significant improvements in the removal of protein-containing soils and soils produced by milk products in relation to dishwasher detergents of comparable composition which also contain phosphate and crystalline layer silicates corresponding to formula (I), butxe2x80x94in the case of the latterxe2x80x94in powder form and not in the form of the builder additive used in accordance with the invention. In contrast to formulations containing fine-particle crystalline layer silicate, the production of the powders, granules or tablets according to the invention is problem-free.

Solid machine dishwashing detergent with phosphate and crystalline lamellar silicates


A drum pillow for use in a bass drum is disclosed herein. The drum pillow can be permanently or removably inserted into the interior of the bass drum shell. The preferred embodiment of the drum pillow is used to xe2x80x9cdeadenxe2x80x9d or modify the sound, esp. overtones, of the bass drum during live performances, particularly when the drum is being struck by a typical foot-operated bass beater. An alternate embodiment is designed for use in studio recording sessions, where the situation calls for an even xe2x80x9cdeaderxe2x80x9d sound. Also disclosed herein is a method for using the drum pillow for the purposes described.

This invention relates generally to musical instrument accessories and more particularly to an insert for a bass drum that is used to xe2x80x9cdeadenxe2x80x9d or modify the sound from the drum.
Many percussion instruments, particularly bass drums, have striking surfaces, i.e. drumheads, that vibrate to such an extent when struck that the sound produced thereby echoes and reverberates more than is desirable. Such overtones seriously reduce the quality of the sound from the drum. Consequently, in most situations, drummers would like to deaden, or dampen, the reverberation of the drumhead to produce a crisper, cleaner sound.
For years, drummers have been using various spontaneous methods to deaden the sound produced by the drums. One of these methods has been to toss loose rags or pillows inside the drum to absorb some of the sound overtones. Another method has been for the drummer to use his or her hand to directly dampen the vibrations of the drumhead. These methods have been used particularly with bass drums, which are large enough so that the inside of the drum can be easily accessed.
A bass drum is generally constructed of a cylindrical drum shell with two open ends, and at least one drumskin stretched across an open end forming a xe2x80x9cdrumhead.xe2x80x9d The circular edge of the drumhead therefore coincides with the circular edge of the drum shell. The drum is usually positioned on the floor so that the drumhead is generally orthogonal to the floor. A foot-operated xe2x80x9cbass beaterxe2x80x9d strikes the drumhead at a strike point somewhat higher than the exact geometric center of the drumhead.
There have been some patented devices directed toward such xe2x80x9csound-deadeningxe2x80x9d in bass drums. The Montano U.S. Pat. No. 5,233,898 discloses and claims a drum damper comprising cushioning means and fastening means similar to the present invention. However, Montano""s fastening means is a very specific arrangement of two straps using anchors fixedly attached to the interior of the drum shell designed for holding the cushion in compression against both the drum shell and the drumhead. In contrast, the present invention does not use straps at all because the presence of any straps or other non-absorbing material over the drum pillow serves to detract from the acoustic functionality of the drum pillow. Furthermore, Montano""s device has a contact surface that specifically covers 25% or less of the drumhead area generally below the strike point and including only a small part of the edge of the drumhead. Because the majority of the higher sound harmonics are generated at the edge of the drumhead, it would be desirable to have pillow contact, and therefore damping action, all along the edge of the drumhead.
Crago et al., in U.S. Pat. No. 5,088,376, discloses an hourglass-shaped drum pillow that is compressed between the two drumheads of a bass drum. The Crago device is specifically designed to be used only in a drum with two drumheads, and again, the pillow surface covers only a drumhead area generally below the strike point and including only a small part of the edge of the drumhead.
Arnold, Payson, and Beals et al., respectively in U.S. Pat. Nos. 6,043,420, 4,338,850, and 5,107,741, disclose quite complicated dampening devices that are hinged or otherwise swing so as to make and break contact with the drumhead and thereby selectively deaden the vibrations from the drumhead at various times during play (similar to use of the drummer""s hand). These devices are difficult for the drummer to control, because they require so much attention and manipulation, and therefore are inconsistent, ineffective and less than optimal.
Because of the dual nature of the uses of bass drums, the present invention has been developed in two specific embodiments, one for live performances and one for studio recording sessions. The embodiment for live performances has been chosen as the preferred embodiment. It is believed that the qualities and characteristics of the invention will be best understood in the context of this preferred embodiment.
The preferred embodiment of the present invention comprises two identical foam pieces that have been acoustically shaped and designed to provide optimal sound quality when properly positioned within the drum shell of a bass drum so as to contact the entire circular edge of the drumhead. The four sides will be referred to as the contact surface (positioned against the drumhead), the outer surface (positioned against the drum shell), the inner surface (directed toward the interior of the drum), and the free surface (directed away from the drumhead).
Because most drummers prefer a dampened sound resulting from drumhead coverage (drum pillow contact) of approximately 25 percent of the total area, the preferred embodiment of the present invention covers approximately 25 percent of the entire drumhead area. However, because the majority of the higher sound harmonics are generated at the edge of the drumhead (where the drumhead vibrations encounter the drum shell and bounce back), the preferred embodiment of the present invention of the permanent drum pillow has been designed to provide pillow contact, and therefore damping action, all along the circular edge of the drumhead. (Previous drum pillow designs have covered only a small part of the drumhead edge.) Furthermore, the preferred embodiment is provided in two pieces, an upper portion and a lower portion, so that any particular drummer can remove the upper portion if he or she prefers a more xe2x80x9clivelyxe2x80x9d sound from the drum.
The contact surface of each piece is generally planar and is intended to impinge against the inside of the drumhead so as to contact approximately 12 percent of the drumhead area. The outer curve of the contact surface simply follows the curve of the bass drum shell. The inner curve of the contact surface has been chosen so as to provide the requisite contact surface area. Experiments have shown that a bevel around the outer edge of the contact surface improves the fit of the drum pillow within the drum shell, particularly for drum shells with edge lips; however, it is important to keep the bevel relatively small so as not to interfere with the sound absorption characteristics of the drum pillow.
In the preferred embodiment, one or more Velcro(trademark) strips hold the pieces of the drum pillow in place inside the drum shell. Obviously, different types of hook-and-loop fasteners or even different types of fasteners, such as snaps, could be used to secure the drum pillow in place. However, it has been found that the Velcro(trademark) strips are effective while having the benefit of being easy to install while maintaining the structural and acoustic integrity of the drum shell, e.g., without drilling holes or making permanent indentations in the drum shell. In the preferred embodiment, one portion of the Velcro(trademark) fastener is applied to the interior of the drum shell and one portion is applied to the drum pillow. The drum pillow can therefore be made a temporary or a permanent installation, according to the particular drummer and situation.
Each of the two pieces of the preferred embodiment of the drum pillow is made of a single piece of dense foam to absorb higher harmonics, and each is covered with a rayon (or preferably silk) slipcover to further clean up and sharpen the sound, as well as to improve and customize the drum pillow""s appearance. Other devices, such as many of the patented devices above-mentioned, are constructed of two or more pieces, only one of which is sound-absorbing. However, it has been found that having the entire drum pillow made of dense foam shaped into the desired form, while being simple to manufacture and manipulate, provides optimal sound-absorption properties.
During sound recording sessions, in contrast to live performances, drummers and producers typically prefer a much xe2x80x9cdeaderxe2x80x9d sound from bass drums. Therefore, it is desirable that significantly more than 25 percent of the drumhead area be dampened. A first alternate embodiment of the present invention comprises a single, three-sided foam piece that has been acoustically shaped and designed to provide optimal sound quality for sound recording purposes. The geometric parameters of the sides have been carefully chosen after much acoustic experimentation focusing on sound quality and simplicity of design. The three sides will be referred to as the contact surface (positioned against the drumhead), the bottom surface (positioned against the drum shell), and the top surface.
The contact surface is generally planar and is intended to impinge against the inside of the drumhead so as to contact approximately 50% of the drumhead area. Instead of covering the drumhead edge, this first alternate embodiment covers an area of the drumhead generally below the strike point of the bass-beater. It has been shown that for optimal acoustics, the upper point of the contact surface of the drum pillow must impinge the drumhead at approximately the strike point of the bass beater. The lower curve of the contact surface simply follows the curve of the bass drum shell. Experiments have shown that a bevel around the lower edge of the contact surface improves the fit of the drum pillow; however, it is important to keep the bevel relatively small so as not to interfere with the sound absorption characteristics of the drum pillow.
The bottom surface of this first alternate embodiment of the present invention of the drum pillow is designed to mate with and fit into the curve of the drum shell. The top surface and the bottom surface are both designed to smoothly taper the drum pillow from the contact surface at the drumhead which is being stricken to the far point at the opposite drumhead or the open end of the drum shell (depending on whether there is a second drum head on the particular bass drum).


A solid cleansing composition comprising

Antioxidants are known to be useful in combating various conditions of the body associated with the activity of free radicals. Antioxidants quench free radicals so they can not interact with the body""s systems.
Among the most well known antioxidants are the vitamins, particularly Vitamin E and its precursors. When used in topical compositions, particularly cleansing compositions, the Vitamin E and its precursors can have difficulty with deposition on skin.
We have now discovered a soap bar, which can deposit significant levels of Vitamin E precursor as well as other vitamins and their precursor(s).
In accordance with the invention, there is a solid cleansing composition comprising:
a. About 1 to about 90 wt. % soap,
b. About 0.01 to about 2.0 wt. % of a Vitamin E precursor or mixture thereof,
c. Vitamin E precursor deposition effective amount of a cationic deposition polymer or mixture thereof and,
d. From zero to the essential absence of Vitamin E.
Soap, the long chain alkyl carboxylate salt, can be present in the solid composition in quantities of from about 1 to about 90 wt. %, desirably about 5 to about 90 wt. %, with desirable minimum of at least about 10, 20, 30, 40, 50 or 60 wt. %. The higher quantities, about 60 to about 90 wt. % are found in the traditional soap bar. Intermediate quantities of soap such as about 40 to about 70 wt. % are generally found in a combination bar while lower quantities of soap, about 10 to about 40 wt. % are generally found in a syndet bar. Preferred salts are the soaps prepared from the alkali metals, such as sodium and potassium and ammonia such as ammonium or substituted ammonium.
Other surfactants can be present or omitted as well. Examples of these surfactants include but are not limited to alkyl sulfates, anionic acyl sarcosinates, methyl acyl taurates, N-acyl glutamates, acyl isethionates, alkyl sulfosuccinates, alkyl phosphate esters, ethoxylated alkyl phosphate esters, trideceth sulfates, protein condensates, mixture of ethoxylated alkyl sulfates and the like.
Alkyl chains for these surfactants are about C8-C22, preferably about C10-C18, more preferably about C12-C18.
Anionic non-soap surfactants can be exemplified by the alkali metal salts of organic sulfate having in their molecular structure an alkyl radical containing from about 8 to about 22 carbon atoms and a sulfonic acid or sulfuric acid ester radical (included in the term alkyl is the alkyl portion of higher acyl radicals). Preferred are the sodium, ammonium, potassium or triethanolamine alkyl sulfates, especially those obtained by sulfating the higher alcohols (C8-C18 carbon atoms), sodium coconut oil fatty acid monoglyceride sulfates and sulfonates; sodium or potassium salts of sulfuric acid esters of the reaction product of 1 mole of a higher fatty alcohol (i.e., tallow or coconut oil alcohols) and 1 to 2 moles of ethylene oxide; sodium or potassium salts of alkyl phenol ethylene oxide ether sulfate with 1 to 10 units of ethylene oxide per molecule and in which the alkyl radicals contain from 8 to 12 carbon atoms, sodium alkyl glyceryl ether sulfonates; the reaction product of fatty acids having from 10 to 22 carbon atoms esterified with isethionic acid and neutralized with sodium hydroxide; water soluble salts of condensation products of fatty acids with sarcosine; and others known in the art.
Zwitterionic surfactants can be exemplified by those which can be broadly described as derivatives of aliphatic quaternary ammonium, phosphonium, and sulfonium compounds, in which the aliphatic radicals can be straight chain or branched and wherein one of the aliphatic substituents contains from about 8 to 18 carbon atoms and one contains an anionic water-solubilizing group, e.g., carboxy, sulfonate, sulfate, phosphate, or phosphonate. A general formula for these compounds is:
Wherein R2contains an alkyl, alkenyl, or hydroxy alkyl radical of from about 8 to about 18 carbon atoms, from 0 to about 10 ethylene oxide moieties and from 0 to 1 glyceryl moiety; Y is selected from the group consisting of nitrogen, phosphorus, and sulfur atoms; R3 is an alkyl or monohydroxyalkyl group containing 1 to about 3 carbon atoms; X is 1 when Y is a sulfur atom and 2 when Y is a nitrogen or phosphorus atom, R4 is an alkylene or hydroxyalkylene of from 0 to about 4 carbon atoms and Z is a radical selected from the group consisting of carboxylate, sulfonate, sulfate, phosphonate, and phosphate groups.
Examples include: 4-[N,N-di(2-hydroxyethyl)-N-octadecylammonio]-butane-1-carboxylate; 5-[S-3-hydroxypropyl-S-hexadecylsulfonio]-3 hydroxypentane-1-sulfate; 3-[P,P-P-diethyl-P 3,6,9 trioxatetradecyl-phosphonio]-2-hydroxypropane-1-phosphate; 3-[N,N-dipropyl-N-3 dodecoxy-2-hydroxypropylammonio]-propane-1-phosphonate; 3-(N,N-dimethyl-N-hexadecylammonio)propane-1-sulfonate; 3-(N,N-dimethyl-N-hyxadecylammonio)-2-hydroxypropane-1-sulfonate; 4-N,N-di(2-hydroxyethyl)-N-(2 hydroxydodecyl)ammonio]-butane-1-carboxylate; 3-[S-ethyl-S-(3-dodecoxy-2-hydroxypropyl)sulfonio]-propane-1-phosphate; 3-(P,P-dimethyl-P-dodecylphosphonio)-propane-1-phosphonate; and 5-[N,N-di(3-hydroxypropyl)-N-hexadecylammonio]-2-hydroxy-pentane-1-sulfate.
Examples of amphoteric surfactants which can be used in the compositions of the present invention are those which can be broadly described as derivatives to aliphatic secondary and tertiary amines in which the aliphatic radical can be straight chain or branched and wherein one of the aliphatic substituents contains from about 8 to about 18 carbon atoms and one contains an anionic water solubilizing group, e.g., carboxy, sulfonate, sulfate, phosphate, or phosphonate. Examples of compounds falling within this definition are sodium dodecylaminoproprionate, sodium 3-dodecylaminopropane sulfonate, N-alkyltaurines, such as the one prepared by reacting dodecylamine with sodium isethionate according to the teaching of U.S. Pat. No. 2,658,072, N-higher alkyl aspartic acids, such as those produced according to the teaching of U.S. Pat. No. 2,438,091, and the products sold under the trade name xe2x80x9cMiranolxe2x80x9d and described in U.S. Pat. No. 2,528,378. Other amphoterics such as betaines are also useful in the present composition.
Examples of betaines useful herein include the high alkyl betaines such as coco dimethyl carboxymethyl betaine, lauryl dimethyl carboxy-methyl betaine, lauryl dimethyl alpha-carboxyethyl betaine, cetyl dimethyl carboxymethyl betaine, lauryl bis-(2-hydroxyethyl)carboxy methyl betaine, stearyl bis-(2-hydroxypropyl)carboxymethyl betaine, oleyl dimethyl gamma-carboxypropyl betaine, lauryl bis-(2-hydro-xypropyl)alpha-carboxyethyl betaine, etc. The sulfobetaines may be represented by coco dimethyl sulfopropyl betaine, stearyl dimethyl sulfopropyl betaine, amido betaines, amidosulfobetaines, and the like.
Many cationic surfactants are known to the art. By way of example, the following may be mentioned:
stearyldimenthylbenzyl ammonium chloride;
dodecyltrimethylammonium chloride;
nonylbenzylethyldimethyl ammonium nitrate;
tetradecylpyridinium bromide;
laurylpyridinium chloride;
cetylpyridinium chloride;
laurylpyridinium chloride;
laurylisoquinolium bromide;
ditallow(Hydrogenated)dimethyl ammonium chloride;
dilauryldimethyl ammonium chloride; and
stearalkonium chloride.
Additional cationic surfactants are disclosed in U.S. Pat. No. 4,303,543 see column 4, lines 58 and column 5, lines 1-42, incorporated herein by references. Also see CTFA Cosmetic Ingredient Dictionary 4th Edition 1991, pages 509-514 for various long chain alkyl cationic surfactants; incorporated herein by references.
Nonionic surfactants can be broadly defined as compounds produced by the condensation of alkylene oxide groups (hydrophilic in nature) with an organic hydrophobic compound, which may be aliphatic or alkyl aromatic in nature. Examples of preferred classes of nonionic surfactants are:
1. The polyethylene oxide condensates of alkyl phenols, e.g., the condensation products of alkyl phenols having an alkyl group containing from about 6 to 12 carbon atoms in either a straight chain or branched chain configuration, with ethylene oxide, the said ethylene oxide being present in amounts equal to 10 to 60 moles of ethylene oxide per mole of alkyl phenol. The alkyl substituent in such compounds may be derived from polymerized propylene, diisobutylene, octane, or nonane, for example.
2. Those derived from the condensation of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylene diamine products which may be varied in composition depending upon the balance between the hydrophobic and hydrophilic elements which is desired. For example, compounds containing from about 40% to about 80% polyoxyethylene by weight and having a molecular weight of from about 5,000 to about 11,000 resulting from the reaction of ethylene oxide groups with a hydrophobic base constituted of the reaction product of ethylene diamine and excess propylene oxide, said base having a molecular weight of the order of 2,500 to 3,000 are satisfactory.
3. The condensation product of aliphatic alcohols having from 8 to 18 carbon atoms, in either straight chain or branched chain configuration with ethylene oxide, e.g., a coconut alcohol ethylene oxide condensate having from 10 to 30 moles of ethylene oxide per mole of coconut alcohol, the coconut alcohol fraction having from 10 to 14 carbon atoms. Other ethylene oxide condensation products are ethoxylated fatty acid esters of polyhydric alcohols (e.g., Tween 20-polyoxyethylene (20) sorbitan monolaurate).
4. Long chain tertiary amine oxide corresponding to the following general formula:
R1R2R3Nxe2x86x920
wherein R1 contains an alkyl, alkenyl or monohdroxy alkyl radical of from about 8 to about 18 carbon atoms, from 0 to about 10 ethylene oxide moieties, and from 0 to 1 glyceryl moiety, and R2 and R3 contain from 1 to about 3 carbon atoms and from 0 to about 1 hydroxy group, e.g., methyl, ethyl, propyl, hydroxy ethyl, or hydroxypropyl radicals. The arrow in the formula is a conventional representation of a semipolar bond. Examples of amine oxides suitable for use in this invention include:
Dimethyldodecylamine oxide, oleyl-di(2-hydroxyethyl)amine oxide, dimethyloctylamine oxide, dimethyldecylamine oxide, dimethyltetradecylamine oxide, 3,6,9 trioxaheptadecyldiethylamine oxide, di(2-hydroxyethyl)-tetradecylamine oxide, 2-dodecoxyethyldimethylamine oxide, 3-dodecoxy-2-hydroxypropyldi(3-hydroxypropyl)amine oxide, dimethylhexadecylamine oxide.
5. Long chain tertiary phosphine oxides corresponding to the following general formula:
RRxe2x80x2Rxe2x80x3Pxe2x86x920
wherein R contains an alkyl, alkenyl or monohydroxyalkyl radical ranging from 8 to 20 carbon atoms in chain length, from 0 to about 10 ethylene oxide moieties and from 0 to 1 glyceryl moiety and Rxe2x80x2 and Rxe2x80x3 are each alkyl or monohydroxyalkyl groups containing from 1 to 3 carbon atoms. The arrow in the formula is a conventional representation of a semipolar bond. Examples of suitable phosphine oxides are: Dodecyldimethylphosphine oxide, tetradecylmethylethylphosphine oxide, 3,6,9-trioxaoctadecyidimethylphosphine oxide, cetyldimethylphosphine oxide, 3-dodecoxy-w-hydroxypropyldi(2-hydroxyethyl)phosphine oxide stearyldimethylphosphine oxide, cetylethyl propylphosphine oxide, oleyldiethylphosphine oxide, dodecyldiethylphosphine oxide, tetradecyldiethylphosphine oxide, dodecyldipropylphosphine oxide, dodecyldi(hydroxymethyl)phosphine oxide, dodecyldi(2-hydroxyethyl)phosphine oxide, tetradecylmethyl-2-hydroxypropylphosphine oxide, oleyldimethylphosphine oxide, 2-hydroxydodecyldimethylphosphine oxide.
6. Long chain dialkyl sulfoxides containing one short chain alkyl or hydroxy alkyl radical of 1 to about 3 carbon atoms (usually methyl) and one long hydrophobic chain which contain alky, alkenyl, hydroxy alkyl, or keto alkyl radicals containing from about 8 to about 20 carbon atoms, from 0 to about 10 ethylene oxide moieties and from 0 to 1 glyceryl moiety. Examples include: octadecyl methyl sulfoxide, 2-ketotridecylmethyl sulfoxide, 3,6,9-trioxaoctadecyl 2-hydroxyethyl sulfoxide, dodecyl methyl sulfoxide, oleyl 3-hydroxypropyl sulfoxide, tetradecyl methyl sulfoxide; 3 methoxytridecylmethyl sulfoxide, 3-hydroxytridecyl methyl sulfoxide, 3-hydroxy-4-dodecoxybutyl methyl sulfoxide.
7. Alkylated polyglycosides wherein the alkyl group is from abut 8 to about 20 carbon atoms, preferably about 10 to about 18 carbon atoms and the degree of polymerization of the glycoside is from about 1 to about 3, preferably about 1.3 to abut 2.0.
Quantities of these surfactants can vary but which can be generally included in the solid formulation are at least about 1, 2, 5, 10, 20 or about 30 wt. % up to about 60 wt. % as a maximum.
Water is present in the solid formulation, preferably a bar in quantities of from about 5 to about 30 wt. % of the solid. Desirable quantities are from about 7 to about 30 wt. %, and about 9 to about 25 wt. %.
Examples of Vitamin E precursor or mixture thereof include esters of vitamin wherein the acid has from 2 to about 20 carbon atoms, including Vitamin E acetate, proprionate, hexanoate, cocoate, palmitate, stearate, and the like. Other vitamin antioxidant(s) and or their precursors such as Vitamin A and Vitamin C and mixtures thereof of each or both can also be present in the formulation. Precursor of Vitamin A include esters having about 2 to about 20 carbon atoms including the myristate and palmitate. Vitamin C precursors include the cholesteryl and the sodium ascorbyl phosphate salt.
Quantities of Vitamin E precursor can be at a minimum of about 0.01, 0.02 or about 0.05 wt. % of the formulation, desirably at least about 0.1 or 0.2 wt. %. Maximum quantities of Vitamin E precursor are dependent upon the level of skin toxicity but are primarily dependent upon the plateau level of observed activity for the Vitamin E effect. Generally, no more than about 2 or about 1.5 wt. % should be employed.
With respect to Vitamin C and A and their precursors, minimum quantities are from about 0.01 or 0.02 or 0.05 wt. % of the formulation. Maximum quantities are generally no more than about 2 or about 1.5 wt. %.
An important part of the solid formulation are Vitamin E precursor deposition effective amounts of cationic polymer. Examples of such a deposition polymer include but are not limited to the following groups:
(I) cationic polysaccharides;
(II) cationic copolymers of saccharides and synthetic cationic monomers, and
(III) synthetic polymers selected from the group consisting of:
(a) cationic polyalkylene imines
(b) cationic ethoxy polyalkylene imines
(c) cationic poly[N-[3-(dimethylammonio)propyl]-Nxe2x80x2[3-(ethyleneoxyethylene dimethylammonio)propyl]urea dichloride]
(d) in general a polymer having a quaternary ammonium or substituted ammonium ion.
The cationic polysaccharide class encompasses those polymers based on a 5 or 6 carbon sugars and derivatives, which have been made cationic by engrafting of cationic moieties onto the polysaccharide backbone. They may be composed of one type of sugar or of more than one type, i.e. copolymers of the above derivatives and cationic materials. The monomers may be in straight chain or branched chain geometric arrangements. Cationic polysaccharide polymers include the following: Cationic celluloses and hydroxyethyl celluloses; cationic starches and hydroxyalkyl starches; cationic polymers based on arabinose monomers such as those which could be derived from arabinose vegetable gums; cationic polymers derived from xylose polymers found in materials such as wood, straw, cottonseed hulls, and corn cobs; cationic polymers derived from fucose polymers found as a component of cell walls in seaweed; cationic polymers derived from fructose polymers such as Inulin found in certain plants; cationic polymers based on acid-containing sugars such as galacturonic acid and glucuronic acid; cationic polymers based on amine sugars such as galactosamine and glucosamine; cationic polymers based on 5 and 6 membered ring polyalcohols; cationic polymers based on galactose monomers which occur in plant gums and mucilages; cationic polymers based on mannose monomers such as those found in plants, yeasts, and red algae; cationic polymers based on galactomannan copolymer known as guar gum obtained from the endosperm of the guar bean.
Specific examples of members of the cationic polysaccharide class include the cationic hydroxyethyl cellulose JR 400 made by Union Carbide Corporation; the cationic starches Stalok(copyright) 100, 200, 300, and 400 made by Staley, Inc.; the cationic galactomannans based on guar gum of the Galactasol 800 series by Henkel, Inc. and the Jaguar Series by Celanese Corporation.
The cationic copolymers of saccharides and synthetic cationic monomers useful in the present invention encompass those containing the following saccharides: Glucose, galactose, mannose, arabinose, xylose, fucose, fructose, glucosamine, galactosamine, glucuronic acid, galacturonic acid, and 5 or 6 membered rinse polyalcohols. Also included are hydroxymethyl, hydroxyethyl and hydroxypropyl derivatives of the above sugars. When saccharides are bonded to each other in the copolymers, they may be bonded via any of several arrangements, such as 1,4-xcex1; 1,4-xcex2; 1,3-xcex1; 1,3-xcex2 and 1,6 linkages. The synthetic cationic monomers for use in these copolymers can include dimethyldiallylammonium chloride, dimethylaminoethylmethyacrylate, diethyldiallyl ammonium chloride, N,N-diallyl,N-N-dialklyl ammonium halides, and the like. A preferred cationic polymer is Polyquaternium 7 prepared with dimethyldiallylammonium chloride and acrylamide monomers.
Examples of members of the class of copolymers of saccharides and synthetic cationic monomers include those composed of cellulose derivatives (e.g. hydroxyethyl cellulose) and N,N-diallyl,N-N-dialkyl ammonium chloride available from National Starch Corporation under the tradename Celquat.
Further cationic synthetic polymers useful in the present invention are cationic polyalkylene imines, ethoxypolyalkelene imines, and poly {N-[3-(dimethylammonio)-propyl]-Nxe2x80x2-[3-(ethyleneoxyethylene dimethylammoniumo)propyl]urea dichloride] the latter of which is available from Miranol Chemical Company, Inc. under the trademark of Miranol A-15, CAS Reg. No. 68555-336-2. Preferred cationic polymeric skin conditioning agents of the present invention are those cationic polysaccharides of the cationic guar gum class with molecular weights of 1,000 to 3,000,000. More preferred molecular weights are from 2,500 to 350,000. These polymers have a polysaccharide backbone comprised of galactomannan units and a degree of cationic substitution ranging from about 0.04 per anydroglucose unit to about 0.80 per anydroglucose unit with the substituent cationic group being the adduct of 2,3-epoxypropyl-trimethyl ammonium chloride to the natural polysaccharide backbone. Examples are JAGUAR C-4-S, C-15 and C-27 sold by Celanese Corporation, which trade literature reports have 1% viscosities of from 125 cps to about 3500xc2x1500 cps.
Still further examples of cationic polymers include the polymerized materials such as certain quaternary ammonium salts, copolymers of various materials such as hydroxyethyl cellulose and dialkyldimethyl ammonium chloride, acrylamide and beta methacryloxyethyl trimethyl ammonium methosulfate, the quaternary ammonium salt of methyl and stearyl dimethylaminoethyl methacrylate quaternized with dimethyl sulfate, quaternary ammonium polymer formed by the reaction of diethyl sulfate, a copolymer of vinylpyrrolidone and dimethyl aminoethylmethacrylate, quaternized quars and guar gums and the like. Exemplary of cationic polymers which can be used to make the complexes of this invention include, as disclosed in the CTFA International Cosmetic Ingredient Dictionary (fourth Edition, 1991, pages 461-464); Polyquaternium -1, -2, -4 (a copolymer of hydroxyethylcellulose and diallyldimethyl ammonium chloride), -5 (the copolymer of acrylamide and beta-methacrylyloxyethyl trimethyl ammonium methosulfate), -6 (a polymer of dimethyl diallyl ammonium chloride), -7 (the polymeric quaternary ammonium salt of acrylamide and dimethyl diallyl ammonium chloride monomers), -8 (the polymeric quaternary ammonium salt of methyl and stearyl dimethylaminoethyl methacrylate quaternized with dimethyl sulfate), -9 (the polymeric quaternary ammonium salt of polydimethylaminoethyl methacrylate quaternized with methyl bromide), -10 (a polymeric quaternary ammonium salt of hydroxyethyl cellulose reacted with a trimethyl ammonium substituted epoxide), -11 (a quaternary ammonium polymer formed by the reaction of diethyl sulfate and a copolymer of vinyl pyrrolidone and dimethyl aminoethyl methacrylate), -12 (a polymeric quaternary ammonium salt prepared by the reaction of ethyl methacrylate/aietyl methacrylate/diethylaminoethyl methacrylate copolymer with dimethyl sulfate), -13 (apolymeric quaternary ammonium salt prepared by the reaction of ethyl methacrylate/oleyl methacrylateldiethylaminoethyl methacrylate copolymer with dimethyl sulfate), -14, -15 (the copolymer of acrylamide and betamethacrylyloxyethyl trimethyl ammonium chloride), -16 (a polymeric quaternary ammonium salt formed from methylvinylimidazolium chloride and vinyl pyrrolidone), -17, -18, -19 (polymeric quaternary ammonium salt prepared by the reaction of polyvinyl alcohol with 2,3-epoxy-propylamine), -20 (the polymeric quaternary ammonium salt prepared by the reaction of polyvinyl octadecyl ether with 2,3-epoxypropylamine), -22, -24 a polymeric quaternary ammonium salt of hydroxyethyl cellulose reacted with a lauryl dimethyl ammonium substituted epoxide), -27 (the block copolymer formed by the reaction of Polyquaternium-2 (q.v.) with Polyquaternium-17 (q.v.)), -28, -29 (is Chitosan (q.v.) that has been reacted with propylene oxide and quaternized with epichlorohydrin), and -30.
Quantities of such a cationic polymer are generally a minimum of about 0.01, 0.02 or 0.05 wt. % of the formulation. Generally, the maximum quantity is no more than about 1.0 or about 0.8 wt. % of the formulation.
As stated previously, there is an absence or an essential absence of Vitamin E present in the formulation. No more than about 0.05 or about 0.04 wt. % of the formulation should be present as Vitamin E, desirably 0 wt. %.
The cationic polymer brings about substantially increased deposition of the Vitamin E precursor onto the skin during the skin cleansing process utilizing the solid rinse off formulation, usually in the general physical form of a bar. Such increased deposition allows the effects of the vitamins, particularly Vitamin E, to assert itself since it is present on the skin in significant quantities for a longer period of time. Protection of the skin particularly in the area of quenching or neutralizing free radicals can occur because of the deposition. Replenishment of and addition to Vitamin E skin levels can also occur even after reduction of Vitamin E skin level following exposure to sun.
The following components can also be present in the solid formulation, for example: Antibacterials, triclosan and triclocarbanilide, preservatives, fragrances, colorants, striation producing materials, emollients, structurants, UV protectants and the like. Of particular significance are certain materials such as mineral oil, petrolatum, silicone and the like.
Below are examples of the invention together with comparison examples to show the substantially enhanced benefits of this new solid formulation.
The formulations are prepared by standard addition techniques.

Solid composition comprising vitamin E acetate

Abstract: a. About 1 to about 90 wt. % soap,

Abstract: b. About 0.02 to about 2.0 wt. % of a Vitamin E precursor or mixture thereof,

Abstract: c. A Vitamin E precursor deposition effective amount of a cationic deposition polymer or mixture thereof, and


The disclosure relates to a femoral prosthesis consisting of a metal rod having a male frustoconical end portion and a femoral head, or ceramic ball, having a frustoconical blind recess, assembled by means of a conical sleeve fitment. The ceramic ball is formed of material having an improved flexion breakage modulus and an improved elasticity modulus.

The invention relates to a femoral prosthesis consisting of a metal rod and a femoral head or ceramic ball, preferably of zirconia, assembled by a conical sleeve fixing. The said femoral head is generally associated with a high density polyethylene (PE) acetabular cup.
When a total hip prosthesis is implanted, femoral heads are used which have a diameter of usually between 22.22 and 32 mm according to the surgical procedures employed. The materials used for producing the femoral heads are preferably metals such as stainless steel, the alloys Cr-Co-Mo, titanium, etc., or ceramics such as dense sintered alumina. Such a ceramic material offers demonstrated advantages of biocompatibility and a better friction coefficient vis-a-vis the high density PE than the metals. But taking into account its mechanical properties which are indeed high but insufficient its use is confined to large diameter femoral heads greater than or equal to 28 mm and to limited geometrical configurations (essentially a maximum neck gap of 4 mm for femoral heads of 28 mm diameter and of 8 mm for a diameter of 32 mm), in the event of its being desired to implant femoral prostheses consisting of a metal rod which, by a conical sleeve mounting, is attached to an alumina ball.
At the present time, if it is desired to implant prostheses having small diameter femoral heads fixed by a conical sleeve mounting on the femoral rod, then only metals are used with the disadvantages which they offer, particularly of less satisfactory friction properties vis-a-vis the high density PE cup.
Attempts have been made to use dense alumina femoral heads in order to take advantage of its better friction coefficient but taking into account their inadequate mechanical characteristics, such femoral heads cannot be used with a diameter which is smaller than 28 mm and which are assembled by a conical sleeve fitment on the femoral head without running the risk of the said head splitting.
Thus, various arrangements or modifications of the conical sleeve fitment have been proposed to overcome this problem. These arrangements generally consist in introducing a xe2x80x9cstress deadenerxe2x80x9d into the conical sleeve fitment, between the metallic rod and the ceramic head.
It is possible, for example, to quote:
FR 2580170 (Flegeau) the use of an intermediate metal sleeve which by various means (particularly metallisation, brazing . . . ) is rendered rigid with a ceramic cup forming the femoral head, the said sleeve being engaged onto the frustoconical part of the femoral head;
FR 2610514 (Cuilleron) the pouring of a metal into a ceramic cup, providing in this solidified mass a recess in which the end of the femoral head is housed;
FR 2391711 (Sulzer) the use of a plastics sleeve inserted between the ceramic material and the metal.
All these solutions may provide answers to the problem of the mechanical strength of dense alumina femur heads but they are often difficult to use at the time when it is necessary to position the prosthesis and they do not generally satisfy the surgeon.
That is why the applicants have sought to perfect a femoral prosthesis comprising an assembly by direct conical sleeve fitment between a femoral head of ceramic material and of small diameter of not more than 26 mm and a metal femoral rod without the help of intermediate members and/or other associated fixing means such as gluing, brazing, tenon, etc.
Thus, such a prosthesis is not subject to bursting when subjected to intense mechanical stresses, while it is at the same time simple to use and to place in position.
The invention is a femoral prosthesis consisting of a metal rod comprising at one of its ends a male frustoconical portion and a ceramic femoral head comprising at least one frustoconical blind recess, assembled by means of a conical sleeve fitment, characterized by the combination of the following means: the said head is of ceramic material, preferably dense stabilised zirconia, it has a diameter of not more than 26 mm, the total angle at the apex of the frustoconical blind recess used for the conical sleeve fitment is generally greater than 4xc2x0, the inlet diameter of the said truncated cone serving for conical sleeve fitment measured at the periphery of the femoral head is comprised between 8 and 14 mm and preferably between 10 and 11 mm.
The zirconia ceramic is obtained by sintering from a mixture of powdered zirconia and a stabilising agent known by a man skilled in the art, such as Y2O3, MgO, CaO, rare earth oxides . . . or their mixtures, the final content of ZrO2 being generally greater than 95% (by weight). Either natural sintering is carried out after shaping and pressing cold, or a sintering under load of better still a sintering under isostatic load (HIP=Hot Isostatic Pressing) possibly including a presintering stage without a load.
Thus, a stabilised zirconia ceramic is obtained in the quadratic phase which can be used in accordance with the invention. The quadratic phase is also known in the art as the tetragonal phase. It is preferably that it should have at least the following physical properties:
a specific mass in excess of 6 g/cu.cm or 98% of the theoretical density
mean grain size (measured by electron scanning microscope using the method NF A 04102, which corresponds to ASTM E 112/82) less than or equal to 1 micron
flexion breakage modulus 3 points better than 920 MPa (draft French Standards B41G Doc 12, now NF B 41-104, August 1989)
elasticity modulus (ASTM C 674 method) better than 220 GPa
A sintered ceramic of another type, for example oxide, carbide, nitride, may likewise be used according to the invention so long as it has at least the mechanical characteristics of resistance to flexion, Young""s modulus,  and grain size previously indicated for zirconium and obviously so long as it satisfies the biocompatibility conditions required for the present application.
Advantageously, stabilised zirconia parts can be used which are obtained by HIP; for example, they have at least the following characteristics:
specific mass greater than 6 g/cu.cm
mean grain size less than 1 micron
resistance to flexion greater than 1600 MPa
Young""s modulus in excess of 220 GPa .
Similarly, other ceramics may be used which have at least the characteristics of one or other of the two aforementioned series.
The femoral head is generally spherical and has a diameter of at most 26 mm; the invention is particularly interesting for spheres with a diameter of 22.22 mm. The said head comprises at least one frustoconical blind recess the axis of which is preferably radial and the applicants have found that it was preferably necessary to use a total angle at the apex of at least 6xc2x0 in order to obtain femoral prosthesis with a small diameter head (of at most 26 mm), of sufficiently high strength to be implanted with the minimum risk of breakage. It is generally considered that the femoral head has to be able to withstand a minimum loading of about 30 to 35 kN without damage or breakage. This rupture loading is measured according to the draft French Standards PR.S 90443 of Feb. 10, 1988, now NF S 90-443 of Sep. 28, 1988 in which an increasing force is applied to the femoral head mounted on the metal rod according to the axis of the assembly. A notable increase in solidity is obtained preferably by using an angle of about 10xc2x0.
Likewise, it is essential that simultaneously the inlet diameter of the cone should be as defined hereinabove, values in excess of 14 mm being in particular likely to increase significantly the risk of breakage of the femoral head.
The frustoconical blind recess has lateral walls which serve to ensure a self-locking assembly by conical sleeve fitment, being in contact with the walls of a corresponding metal male cone of preferably the same conicity, the said male cone situated at one end of a femoral rod of which the other end is implanted into the femur, is fitted with force and is therefore locked directly in the frustoconical recess.
The said blind frustoconical recess serving for a sleeve-like fitment opens out onto the surface of the said head either directly or through another slightly more open truncated cone, as will be seen hereinafter.
The metal femoral rod may be of an alloy of Ti, stainless steel, Cr-Co-Mo or any other metals or alloys used for making orthopaedic implants.
It is possible to optimise the mounting of the femoral head on the metal rod by any known means and particularly by the apparatus described in U.S. Pat. No. 4,964,869, issued Oct. 23, 1990, which matured from application Ser. No. 07/372,753, filed Jun. 28, 1989 claiming priority based upon French Patent Application No. Jun. 28, 1989 claiming priority based upon French Patent Application No. 88-09042 filed Jun. 28, 1988 in which the contact between the male cone of the said rod and the female cone of the said head, ensuring assembly by a self-locking conical sleeve mounting, occurs only in a deep frustoconical zone of the blind recess in the ceramic head. In the Examples of U.S. Pat. No. 4,964,869 (xe2x80x9cthe Auclair patentxe2x80x9d), Examples 1,2,3, correspond to practical tests of ceramic balls with a diameter of 28 mm and a recess of a depth of 16.5 mm (i.e. the depth of the recess extends about 58.8% of the diameter of the balls), and examples 4 and 5 correspond to tests made on balls of sintered zirconium oxide of 28 mm diameter with a recess having a depth of 20 mm (i.e. the depth of the recess extends about 71.4% of the diameter of the balls).
FIG. 1 shows a femoral prosthesis according to the invention. In it, reference numeral 1 denotes the femur
2 denotes the metal femoral rod, of which the end 3 is implanted into the femur and of which the frustoconical end 4 serves to assemble, by conical sleeve fitment, itself on the ceramic femoral head 5 of small diameter,
at 6, the side wall of the frustoconical recess provided in the femoral head 5 which is in contact over its entire height with the lateral wall 7 of the male cone 4, and
at 8 a space between the apex of the male truncated cone 4 and the bottom of the truncated recess provided in the head 5.
In this case, the blind recess consists of a single truncated cone which opens out directly onto the surface of the femoral head 5.
FIGS. 2 and 3 illustrate ways to optimise the conical sleeve fitment according to the invention, carried out according to the apparatus disclosed by French Application No. 88-09042 according to which the contact between the male and female cones takes place in a xe2x80x9cdeepxe2x80x9d zone of the blind recess in the ceramic femoral head 5. According to the Auclair patent, the depth of the bearing surface on which there is contact between the lateral surface of the recess and the corresponding surface of the peg in general comprises between 15% and 80%, preferably between 25 and 70%, of the total depth of the recess. Examples 2, 3 and 5 of the Auclair patent describe out of contact portions which extend into the head about 19.6%, 37.5% and 26.8% of the total head diameter, respectively.
FIG. 2 shows that the zone of contact by self-locking conical sleeve fitting between the ceramic femoral head 5 and the metal femoral rod 4 occurs at 9 in the xe2x80x9cdeepxe2x80x9d zone of the blind recess. The total angle at the apex according to the invention is that of this frustoconical contact zone. The non-contact zone 11 is situated towards the outside of the blind recess and is obtained in this case by a more flared machining of the femoral head 5. The entrance diameter 10 of the frustoconical blind recess where contact occurs is measured on the circle obtained by the intersection of the outer surface of the femoral head 5 and the extension of the truncated contact cone 9.
In FIG. 3, the contact zone 9 is still situated in the deep zone of the blind recess. The non-contact zone 11 is obtained in this case by a relief machining of the corresponding part of the male cone 4 on the metal femoral rod. The diameter at the entrance 10 to the frustoconical blind contact recess is likewise measured on the circle obtained by intersection of the said frustoconical recess with the outer surface of the femoral head.

Femoral prosthesis employing a small ceramic ball