US3318817A - Process for preparing detergent tablets - Google Patents

Description

United States Patent 3,313,817 PROCESS FOR PREPARING DETERGENT TABLETS George Cunningham Smith, Jr., Montgomery, Ohio, as-

signor to The Procter 8: Gamble Company, Cincinnati,

Ohio, a corporation of Ohio N0 Drawing. Filed July 16, I965, Ser. No. 472,674 1 Claim. (Cl. 252137) This application is a continuation-in-part of copending application Ser. No. 205,219, filed June 26, 1962, and now abandoned.

This invention relates to detergent compositions in the form of a tablet and a process for making them. More particularly, it relates to a detergent tablet, formed by compressing particles such as powder, granules, or flakes, which Will be strong and resistant to abrasion yet will dissolve in a reason-able time.

Detergent tablets have many advantages over detergent granules, flakes, and liquids, both for laundry and dish washing purposes. In the first place, tablets contain a premeasured amount of detergent. This eliminates pos sible errors in measurement and equipment and spillage problems. In the second place, tablets can be handled readily. Therefore, tablets are ideal for automatic dispensers. Thirdly, tablets take up less space than granules or liquids, because they are compressed. These advantages of convenience, economy, and adaptability are lost to a great extent, however, if the tablet is not suificiently strong and resistant to abrasion to permit ordinary handling. Also, unless the tablet dissolves quickly in water, a housewife will not want it.

Tablets can be formed in many ways, but the tablets that provide rapid disintegration are those that are formed by compressing particulate detergent matter. In order to produce a strong tablet by compression of particulate matter, the use of high pressures has been recommended. However, high pressure creates a tablet which does not dissolve easily. It is possible to add tablet disintegrating agents such as effervescent materials or materials that swell in water to aid disintegration, but these do not completely solve the problem of slow disintegration when high pressures are used to form the tablet. Low-pressure tablet formation has not generally proven satisfactory since the tablets often will not remain intact during handlin-g.

Accordingly, it is an object of this invention to provide a detergent tablet which is strong, resistant to abrasion, and quick-dissolving.

Another object of this invention is to provide a process for making such a detergent tablet.

A further object of this invention is to provide a detergent tablet in which the organic suds builder also acts to bind the detergent particles together.

The tablets of this invention are conventional detergent tablets formed by the compression of particulate detergent ingredients which have been strengthened by the dispersion of from about 1% to about by weight of the tablet of a substantially non-hygroscopic, normally waxy amide having a melting point of from about 100 F. to about 300 F. between the particles of said tablet, at least a portion of said amide being fused to more than one adjacent particle.

The amides of this invention contain an acyl radical having from about 7 to about 22' carbon atoms and melt at not less than about 100 F. and not more than about 300 F. The melting point is important from a practical standpoint. Amides melting at less than 100 F. cannot be used since storage temperatures could reasonably be expected to exceed this temperature and would result in undesirable bleeding of the amide. A melting point of more than 300 F., on the other hand, would lead to difliculties in applying the amide and would necessitate too high a temperature for fusing the amide. Tablet performance, e.g., dissolving time, is adversely affected by the use of high melting amides. Within this essential range of melting points, selection of the particular amides can be based upon tablet performance characteristics if desired. The more Water soluble or dispersible amides are preferred for a quick-dissolving tablet. (For example, lauroyl and myristoyl glycerol and ethanol amides.) Also, when sudsing is desirable, those amides which act as detergency and suds builders (e.g., lauroyl and myristoyl glycerol amides, ethanol amides, isopropanol amides, ammonia amides, and N-methyl amides) are preferred. Since the typical dish washing detergent is a high-sudsing detergent, the tablets of this invention are highly desirable for dish washing since the amide can serve the dual functions of a suds builder and tablet strength improver.

Examples of suitable fatty amides include: saturated amides having an acyl group with from 7 to about 22 car bon atoms; N-methyl amides having an acyl group of from about 10 to about 22 carbon atoms; N-isopropanol amides having an acyl group of from about 10 to about 22 carbon atoms; N-isobutyl amides having an acyl group of from about 10 to about 18 carbon atoms; N-ethanol amides having an acyl group of from about 7 to about 22 carbon atoms; N-diethanol amides having an acyl chain of from about 10 to about 22 carbon atoms; un saturated amides such as oleamide and erucamide; amides of the above types derived from natural oils such as coconut oil, palm oil, tallow, etc.; saturated and unsaturated monoand di-carboxylic acid amides with alkyl and aryl groups substituted on the nitrogen, so long as the melting point is between F. and 300 F; and mixtures thereof. Further examples of such amides and their use in detergent compositions can be found in US. Patents 2,383,737, 2,388,738, 2,383,739, 2,383,740.

The tablets of this invention are especially characterized by the interparticulate bonding action of the aforementioned amide constituent. In order to achieve this bonding action, the amide should first be dispersed between a substantial portion of the particulate constituents of the tablet. There are several methods of dispersal which achieve the desired bonding. If the amide is available in the form of particles, simple mechanical mixing of the amide with the other detergent materials, which will hereinafter be more fully described, prior to compressing the tablet will provide the necessary dispersion of the amide. The amide can also be liquefied, e.g., melted, and applied to, e.g., sprayed on, the particles of the other detergent constituents prior to compressing the tablet, which provides an adequate dispersion. A third method involves applying, e.-g., spraying, the molten amide on the surface of the finished tablet. A fourth method involves applying an amide dust to the surface of the tablet and then melting the dust. These last two methods disperse the amide only between particles at or near the surface of the tablet, but nevertheless provide effective bonding characteristics for the tablet.

Once the amide is dispersed between the particles of the other constituents in the completed tablet by either mechanical mixing or by applying, e.g., spraying, the amide on the particulate tablet constituents prior to compression, heat is applied to the tablet, thereby melting the amide. When the tablet is subsequently cooled below the melting point of the amide, the fusion. of the amide to the adjacent particles cements them together, thereby forming a strong, abrasion-resistant, fast-dissolving tablet.

The method of dispersing the amide, the amount of heating of the tablet, and the type of amide present determine the specific increase in tablet strength that will be derived from the fused amide. Less than 5% amide by Weight of the tablet will not provide sufiicient intimate contact for fusion and more than 15% amide by weight of the tablet will produce a sticky, slow dissolving tablet when the amide is dispersed throughout the tablet. However, when sprayed on the surface, from 1% to amide by weight of the tablet is suflicient to provide a strongabrasion resistant, quick-dissolving tablet.

For the same amount of amide, spraying the amide on the surface will provide a stronger tablet, but care must be taken that the amide does not seal too large a percentage of the interparticulate voids since the water must attack the tablet through these voids, in order to dissolve the tablet quickly. More than 5% amide will tend to close too many interparticulate voids on the surface of the tablet. However, this method does provide exceptional abrasion resistance.

If the amide is applied in powdered form with the particulate detergent constituents prior to tableting, the amide particle size is important. Particles of amide larger than about 28 mesh will not permit .suflicient dispersion of the amide among the particulate detergent ingredients and particles of amide smaller than about 200 mesh are fines which fill interparticulate voids in the finished tablet and thereby inhibit dissolving. The preferred method to apply the amide is as a spray on the particles of other detergent constituents prior to forming the tablet. This spray causes agglomerating of the other constituents and partially coats the particles, thereby aid.- ing the formation of the tablet and promoting more interparticulate bonding during the subsequent melting and cooling steps.

The amount of tablet heating desired will depend to a great extent upon the performance desired. The heat should be sufficient to melt at least part of the amide in order to provide an increase in strength and abrasion resistance. Heating the amide-containing tablet sufficiently to melt that portion of the amide which is near the surface of the tablet is the preferred procedure. This latter procedure, which is somewhat analogous to case hardening of metals, permits a substantial increase in strength and abrasion resistance without a concomitant increase in dissolving time. If the entire tablet is heated to a point where all of the amide melts, there is a substantial increase in strength, but an increase in dissolving time is also often effected.

The detergent tablets can contain, in addition to the amide constituent, from about 5% to about 50% by weight of said tablet of a normally particulate detergent surfactant (i.e., a surfactant which can be made in normally particulate form prior to forming said tablet) with a particle size of from about to about 100 mesh and a moisture content of less than about 10% by weight of said detergent surfactant; and from about 35% to about 94% by weight of said tablet of a normally particulate material selected from the group consisting of the sodium, potassium, and ammonium salts of ethylenediaminetetraacetic acid and nitrilotriacetic acid, sodium and potassium tripolyphosphates, sodium and potassium acid pyrophosphates, sodium and potassium pyrophosphates, trisodium and tripotassium phosphates, and sodium and potassium phytates, inert inorganic salts (e.g., Na SO NaCl, KCl, K 50 and (NH SO and mixtures thereof, said material having a particle size of from about 35 to about 200 mesh. The detergent surfactant particles, and any other particles, can contain organic suds builders which can be used in reduced amounts because of the presence of the amide binding agent. The tablet can also contain, if desired, a tablet disintegrating agent which has a particle size of from about 35 to about 200 mesh; about 10% by weight of said tablet of such minor ingredients .as soil suspending agents (e.g., carbo-xy methylcellulose), brighteners, corrosion and tarnish inhibitors (e.g., sodium or potassium silicate and benzotriazole) and dyes.

The detergent surfactant of the tablets of this invention can be any detergent surfactant which can be made in normally particulate form by drying or cooling, for example, either alone or in combination with any of the other tablet constituents. The detergent surfactants can be soap, anionic non-soap, nonionic or zwitterionic. At least 5% by weight of the tablet should be detergent surfactant in order to provide a tablet of suitable size having a suitable concentration of detergent surfactant for washing purposes.

More than 50% by weight of detergent surfactant in the tablet will lead to an excessively sticky tablet and this in turn will lead to a deficiency of interparticulate voids thereby preventing the water from diffusing through the tablet to dissolve said tablet.

The particle size of the detergent surfactant should be not more than about 10 mesh and not less than about mesh. This size range is equivalent to particles, which when screened on Tyler screens, will be on 100 mesh and through 14 mesh. Particles larger than 14 mesh make it difficult to mix in uniformly other constituents because of the diameter ratios and particles smaller than 100 mesh will promote segregation of the detergent surfactant particles from other particles and slow dissolving rate by blocking interparticulate voids which serve as penetration routes for the Water.

The particulate form is not critical. Granules, beads, flakes, needles, and powders can be used. Non-particulate forms, e.g., pastes, liquids or plastic forms, are not acceptable since they will rearrange in the tablet causing stickiness and slow dissolving rates.

The detergent surfactant should not contain more than about 10% by weight of the detergent surfactant of water. Too much water will cause stickiness which will prevent the particles from being free-flowing during compression and thereby prevent the formation of a satisfactory tablet. Tablets formed with an excess of water would have a deficiency of interparticulate voids and would, therefore, have a slow dissolving rate.

Examples of suitable detergents include:

(1) Ordinary alkali metal soaps such as the sodium and potassium salts of the higher fatty acids of naturally occurring plant or animal esters (e.g., palm oil, coconut oil, babassu oil, soybean oil, castor oil, tallow, whale and fish oils, grease and lard, and mixtures thereof) or of synthetically produced fatty acids (e.g., by the oxidation of petroleum, or by hydrogenation of carbon monoxide by the FischenTropsch process), and of resin acid (e.g., rosin and those resin acids in tall oil) and/or of napthenic acids. Sodium and potassium soaps can be made by direct saponification of the fats and oils or by the neutralization of the free fatty acids which are prepared in a separate manufacturing process.

(2) Synthetic organic detergents characterized by their high solubility in water, their resistance to precipitation by the constituents of hard water and their surface active and effective detergent properties, including:

(a) Anionic synthetic detergents (excluding true soaps): This class of synthetic detergents can be broadly described as the Water-soluble salts, particularly the alkali metal salts, of organic sulfuric reaction product having in the molecular structure an alkyl radical containing from about 8 to about 22 carbon atoms and a radical selected from the group consisting of sulfonic acid and sulfuric acid ester radicals. Important examples of the synthetic detergents which form a part of the preferred compositions of the present invention are the sodium or potassium alkyl sulfates, especially those obtained by sulfating the higher alcohols produced by reducing the glycerides of tallow or coconut oil; sodium or potassium alkyl benzene sulfonates, in which the alkyl group contains from about 9 to about 15 carbon atoms, especially those of the types described in United States Letters Patent Nos. 2,220,099 and 2,477,383; sodium alkyl glyceryl ether sulfonates, especially those ethers of the higher alcohols derived from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulfates and sulfonates; sodium or potassium salts of sulfuric acid esters of the reaction product of one mole of a higher fatty alcohol (e.g., tallow or coconut oil alcohols) and about three moles of ethylene oxide; sodium or potassium salts of alkyl phenol ethylene oxide ether sulfate with about four units of ethylene oxide per molecule and in which the alkyl radicals contain about 9 carbon atoms; the reaction product of fatty acids esterified with isethionic acid and neutralized with sodium hydroxide where, for example, the fatty acids are derived from coconut oil; sodium or potassium salts of fatty acid amide of a methyl taurine in which the fatty acids, for example, are derived from coconut oil; and others known in the art, a number being specifically set forth in United States Letters Patent Nos. 2,486,921, 2,486,922 and 2,396,278.

(b) Nonionic synthetic detergents: This class of synthetic detergents may 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. The length of the hydrophilic or polyoxyalkylene radical which is condensed with any particular hydrophobic group can be readily adjusted to yield a watersoluble compound having the desired degree of balance between hydrophilic and hydrophobic elements.

For examples, a well known class of nonionic synthetic detergents-is made available on the market under the trade name of Pluronic. These compounds are formed by condensing ethylene oxide with an hydrophobic base formed by the condensation of propylene oxide with propylene glycol. The hydrophobic portion of the molecule which, of course, exhibits water insolubility has a molecular weight of from about 1500 to 1800. The addition of polyoxyethylene radicals to this hydrophobic portion tends to increase the Water solubility of the molecule as a whole and the liquid character of the products is retained up to the point where polyoxyethylene content is about 50% of the total weight of the condensation product.

Other suitable nonionic synthetic detergents include:

(i) The polyethylene oxide condensates of alkyl phenols, e.g., the condensation products of alkyl phenols having an alkyl groupcontaining 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 to 25 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.

(ii) Those derived from the condensation of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylene diamineproducts which may be varied in composition depending upon the balance between the hydrophobic and hydrophilic elements which is desired. For examples, compounds containing from about 40% to about 80% polyoxyethylene by weight and having a molecular weight of from about 5000 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 2500* to 3000, are satisfactory.

(iii) 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.

(iiii) Trialkyl amine oxides and trialkyl phosphine oxides wherein one alkyl group ranges from 10 to 18 carbon atoms and two alkyl groups range from 1 to 3 carbon atoms; the alkyl groups can contain hydroxy substituents; specific examples are dodecyl diethanol amine oxide and tetra decyl dimethyl phosphine oxide.

wherein R is an alkyl radical containing from about 8 to about 22 carbon atoms, R and R contain from 1 to about 3 carbon atoms, R is an alkylene chain containing from 1 to about 3 carbon atoms, X is selected from the group consisting of hydrogen and a hydroxyl radical, Y is selected from the group consisting; of carboxyl and sulfonyl radicals and wherein the sum of the R R and R radicals is from about 14 to about 24 carbon atoms.

(d) Amphoteric and ampholytic detergents which can be either cationic or anionic depending upon the pH of the system and which are represented by detergents such as dodecyl-beta-alanine, N-alkyltaurines such as the one prepared by reacting dodecylamine with sodium isethionate according to the teaching of US. 2,658,072, N-higher alkylaspartic acids such as those produced according to the teaching of US. 2,438,091, and the products sold under the trade name Miranol and described in US. 2,528,378.

In addition to the detergent surfactant of the tablets of this invention, other constituents can be used as hereinbefore mentioned. Detergency builders are a highly desirable constituent. Not only do they aid detergency, but in the case of the inorganic builders they promote the formation of particles when the detergent surfactant itself does not readily form particles. The builder can make up the balance of the tablet (up to 94% by weight of the tablet); however, when the inorganic builders are used, high levels may tend to cause brittleness of the tablet, thereby decreasing the tablets strength.

The builder can be added separately in particulate form or formed into particles with the detergent surfactant and/or the other constituents as hereinafter described. It added separately, the particle size should not be larger than about 35 mesh or smaller than about 200 mesh. Particles larger than 35 mesh are not very soluble and particles smaller than 200 mesh tend to separate from particles of other constituents and block interparticulate voids.

Examples of desirable particulate detergency builders include ethylenediaminetetraacetic acid; sodium and potassium tripolyphosphates, acid pyrophosphates, pyrophosphates, and phosphates; and sodium and potassium phytates.

The tablets can also contain particulate inorganic salts which are inert to the formula to act as fillers. As for the inorganic detergency builders, and for the same reasons, these inorganic salts cannot be present in amounts more than about 94% by weight of the tablet, but preferably are present in lesser amounts. The particle size of such salts should range from about 35 to about 200 mesh if they are added separately to the tablet mix rather than being formed into particles with other tablet constituents, e.g., detergent surfactant, as hereinafter described.

The tablet can also contain a tablet disintegrating agent to promote break-up of the tablet. Such an agent is not necessary, however. These agents are of three distinct kinds. One kind evolves gas upon contact with water thereby promoting break-up of the tablet. Examples include a mixture of sodium bicarbonate or sodium sesquicarbonate together with citric acid or other acidifying agents such as sodium acid pyrophosphate. The second kind absorbs Water and swells, thereby breaking the tablet. An example of this kind is starch. The third kind dissolves readily and allows water to pass into the tablet to aid dissolution. An example of this kind is lactose. Combinations of these agents can also be used.

The disintegrating agent can make up the balance of the tablet (up to 94% by Weight of the tablet) but is normally a much smaller percentage (e.g., up to 40% by weight of the tablet). The disintegrating agent has a particle size of from about 35 mesh to about 200 mesh for the same reasons as hereinbefore mentioned for the builders and fillers.

Other minor ingredients can also be added to the tablets of this invention (to the particulate mixture prior to compression). Soil suspending agents, such as carboxymethylcellulose, optical brighteners, sodium and potassium silicates, dye, and benzotriazole can be added in amounts up to about 10% by weight of the tablet. Normally they are formed into particles with the detergent surfactant.

As hereinbefore mentioned, the tablets of this invention are especially characterized by the interparticulate bonding action of the amide. The first step in the process of preparing the tablets of this invention involves forming particles of the detergent constituents, unless the constituents are already in the form of particles. This can be done by forming a paste from as many of the dry ingredients as is desired and water and then drying said paste on a roll to form flakes or by forming a slurry and then spray-drying the slurry to form granules. Other processes of forming particulate detergent matter preparatory to tablet compression can be used for this invention and the process of forming the particles is not critical. The particle size should be from about 14 mesh and to about 65 mesh. A mean particle size of 35 mesh is desired.

Particles of detergent constituents are mixed together to form a tablet mix. At this point, as hereinbefore described, the liquified (e.g., molten) amides used in this invention can be applied (e.g., sprayed on) to the mix prior to forming the tablet or the amides can be blended with the other constituents if they are in particulate form. Preferably the mix is then passed through a 10 mesh screen to break up large agglomerates. The tablet is then formed using a pressure preferably of from about 20 to about 600 pounds per square inch gauge. The exact pressure desired for a specific formulation is not critical and will be a compromise between strength and abrasion resistance, and dissolving rate in water. There is a relationship between the pressure used in tablet formation and dissolving rate such that high pressures ordinarily increase the dissolving time. Therefore, low pressures within the aforementioned range are preferred if very fast dissolving tablets are desired.

It the amide is not applied to (e.g., sprayed on) the tablet mix or blended with the tablet mix as particulate matter, it can be applied to the surface of the tablet. It is essential, as hereinbefore mentioned, to leave a substantial percentage of the interparticulate voids in the surface of the tablet uncovered by the amide application to permit the Water to penetarte the tablet. A coarse spray is the preferred form of amide application to achieve this object. The next step in the process of preparing the tablets of this invention is to heat the tablets to a temperature above the melting point of the amide used and below both the decomposition points of the tablet constituents and the temperatures where the constituents will react. The tablet is held at this temperature for a sufficient period of time to melt the amide. This temperature is generally in the range of 100 F. to 400 F. If the amide is in the tablet mix, this heating step can be carried out in the tablet formation step by means of heated dies. In any event the heating step can be carried out with either radiant heat, a heated gaseous medium, or any other means of heating or combination thereof. If the tablet contains materials which will be adversely affected by a particular 6 means of heating, such means would not be chosen. For example, if the tablet contains materials which effervesce upon contact with water, steam would not be a desirable choice as a heating medium.

The next step is a cooling step which can be accomplished by means of natural cooling, refrigeration, or any other means or combination thereof. Again, care should be taken that any cooling medium used does not affect or react with the tablet constituents.

The process and the tablets of this invention have many advantages over prior knowledge involving treating the tablet surface with water to form interparticulate crystalline bonds. Such a treatment only strengthens the surface and requires hydratable salts whereas treatment in depth is possible with the process of this invention which does not make such salts an essential tablet improvement. Also, the process of this invention can be used when the tablet contains materials that effervesce upon contact with water.

The following examples are illustrative of the process of this invention and the tablets prepared by said process.

EXAMPLE I An aqueous crutcher paste was formed from sodium alkyl (dodecyl) benzene sulfonate, sodium sulfate (Na SO the sodium salt of the sulfated version of the reaction product between one mole of coconut alcohol (2%--C10, 66%C 23%-C14, and 9%C16) and three moles of ethylene oxide, sodium chloride (NaCl), and sodium tripolyphosphate. The components were mixed together in a crutcher paste and then roll-dried to form flakes having a particle size range of from 14 to 65 mesh and a moisture content of about These flakes were then dry mixed with granular sodium acid pyrophosphate and sodium sesquicarbonate having a particle size range of from 35' mesh and 200 mesh. After a pre-mixing of about one half to one minute in a rotating inclined cylinder with baflles, the monoethanol amide of coconut oil fatty acids, color, and a German silver tarnish inhibitor (benzotriazole) were mixed and heated to 230 F. The mixture was sprayed on the composition while mixing was continued. Next water and perfume were sprayed on. The total mixing time was about fifteen minutes. The amounts of the ingredients added gave a total mix of forty-five pounds and the percentages by weight were as follows:

Sodium tetrapropylene benzene sulfonate 18.45 Sodium coconut ethylene oxide sulfate 6.15 Na2SO4 NaCl 2.90 Sodium tripolyphosphate 23.80 Sodium sesquicarbonate 27.90 Sodium acid pyrophosphate 8.50 Coconut oil fatty acid monoethanol amide 7.50 H O 0.75 Extras (perfume, color, inhibitors) 0.126

The finished mix, which had a size range from about 14 mesh to about 200 mesh, was screened through a mesh Tyler standard screen and tableted in dies at a pressure of about p.s.i. Each tablet contained approximately 8.5 g. of material, was about 1% inches in diameter, and was approximately 1.00 cm. high. The tablets were heated with a blast of hot air and radiant heat to create an average environment temperature of 750 F. for an average time of 2 seconds, thereby fusing the amide and binding together adjacent particulate tablet ingredients. The resulting tablets were hard and resistant to impact or abrasion yet dissolved easily in mildly agitated water in about seconds with eflervescence. They were satisfactory in all ways for washing dishes, sudsing and cleaning.

When in the above example the following detergents are substituted either wholly or in part for the sodium tetrapropylene benzene sulfate and/ or the sodium coconut alkylene oxide sulfonate detergents substantially equivalent results are obtained in that the detergent tablet is stronger, more abrasion resistant and quicker dissolving than similar detergent tablets prepared without the amide component fused to the adjacent particles.

Sodium, potassium and/ or ammonium- (a) Coconut soap;

(b) Tallow soap;

(c) Alkyl sulfate wherein the alkyl is derived from coconut oil;

(d) Alkyl sulfate wherein the alkyl radical is derived from tallow;

(e) Alkyl sulfonates prepared by sulfonating alpha olefins containing an average of about 12 carbon atoms;

(f) Alkyl benzene sulfonates containing straight alkyl chains containing an average of about 12 carbon atoms;

g) Alkyl glyceryl ether sulfonates wherein the alkyl group is derived from coconut oil;

(h) Coconut oil fatty acid monoglyceride sulfates wherein the fatty acid group is derived from coconut oil;

(i) Fatty acid monoglyceryl sulfonates wherein the fatty acid group is derived from coconut oil;

(j) Alkyl ethylene oxide sulfates wherein the alkyl radical is derived from tallow, and Where there are about 3 moles of ethylene oxide per mole of fatty alcohol;

(k) Alkyl phenol ethylene oxide sulfates containing about 4 units of ethylene oxide per molecule in which the alkyl radical contains about 9 carbon atoms;

(1) Fatty acyl isethionates wherein the fatty acyl groups are derived from coconut oil;

(111) The condensation product of ethylene oxide with a condensation product of propylene oxide and propylene glycol, the ethylene oxide constituting 50% of the total weight of the condensation product and the total molecular weight of the condensation product being about 3600;

(n) Alkyl phenol ethylene oxides wherein the alkyl group contains about 12 carbon atoms and there are approximately 10 moles of ethylene oxid per mole of alkyl phenol, the condensation product of alcohols derived from coconut oil and about 10 moles of ethylene oxide per mole of coconut alcohol;

() Dodecyl dimethyl amine oxide;

(p) Tetradecyl dimethyl phosphine oxide;

(q) 3 (N,N dimethyl N hexadecylammonio)-propane-l-sulfonate;

(r) 3 (N,N dimethyl N coconutalkylammonio)-2- hydroxy-propane-l-sulfonate;

(s) 3 (N,N diethyl-N-hexadecylammonio)-propanel-carboxylate;

(t) Dodecyl-beta-alanine;

(u) N-dodecyltaurine;

(v) N-dodecylaspartate; and

(w) Mixtures thereof, eg 1:1 mixtures of coconut soap and alkyl sulfonates; alkyl sulfates and alkyl benzene sulfonates; conconut oil fatty acid monoglyceride sulfates and fatty acyl isethionates; and alkyl phenol ethylene oxide and dodecyl dimethyl amine oxide. I

Also when in the above example the following detergency builders are substituted either wholly or in part for the sodium tripolyphosphate substantially equivalent results are obtained in that the detergent tablet is stronger, more abrasion-resistant and quicker-dissolving than similar detergent tablets prepared without the amide component fused to the adjacent particles.

Sodium, potassium and/ or ammonium (a) Tripolyphosphates;

(b) Ethylenediaminetetraacetates;

(c) Pyrophosphates;

(d) Phosphates; and

(e) Mixtures thereof, e.g. in 1:1 ratios.

Also, when in the above example, the following inorganic salts are substituted either wholly or in part for the sodium sulfate and/ or sodium chloride, substantially equivalent results are obtained in that the detergent tablet is stronger, more abrasion-resistant and quicker-dissolving than similar detergent tablets prepared without the amide component fused to the adjacent particles.

Sodium, potassium and/ or ammonium (a) Sulfates;

(b) Chlorides; and

(c) Mixtures thereof, eg in 1:1 ratios.

Further, when in the above example, the following disintegrating agents are substituted either wholly or in part for the mixture of sodium sesquicarbonate and sodium acid pyrophosphate, substantially equivalent results are obtained in that the detergent tablet is stronger, more abrasion-resistant and quiclrer-dissolving than similar detergent tablets prepared without the amide component fused to the adjacent particles:

(a) A mixture of (1) sodium, potassium and/or ammonium bicarbonates and/or sesquicarbonates and (2) citric acid and/or ammonium, sodium and/ or potassium acid pyrophosphates;

(b) Starch;

(c) Lactose; and

(d) Mixtures thereof, e.g. in 1:1 ratios.

Myristic ethanolamide (M.P. 99-l00 C.); lauric ethanolamide; lauric glycerolamide (M.P. 9498 O); myristic glycerolamide (M.P. 101-102 0.); palmitic glycerolamide (M.P. 100 C.); coconut oil glycerolamide (M.P. 90 C.); lauric amide (M.P. 102 (3.); myristic amide (M.P. 102 C.); caproamide (M.P. -101" C.); caprylamide (M.P. 105-110 C.); N-ethyl lauramide; N-methyl myristamide; N-butyl lauramide; palmitic diethanola mide; coconut ammonia amide; tallow ammonia amide and diethanolamide; N-isopropyl coconut amide; and N-isobutyl coconut amide can be substituted for the coconut oil fatty acid monoethanolamide of this example with substantially equivalent results in that the tablets prepared With these amides, wherein the amides are fused to adjacent particles in the tablets, are stronger tablets for the same dissolving time and the tablets are more abrasion resistant than tablets prepared without said amides fused to said adjacent particles.

A tablet was prepared with the following formula:

EXAMPLE 11 Percent Sodium tetrapropylene benzene sulfonate (14 mesh to 65 mesh, 85% active, 13% Na S0 and 2% This mix having a particle size range of from 14 mesh to 200 mesh was dried to 95% of its original weight. When this mix is tableted at a pressure of about 35 p.s.i. and the tablets are sprayed with about 4% by weight of the tablet of molten lauric ethanolamide heated to a temperature of about 200 F., and the tablets are then cooled, a strong, abrasion-resistant tablet is formed. Similarly, when about 2% by weight of the tablet of a dust of lauric ethanolamide is applied to the surface of the tablet, melted, and then cooled, a strong abrasionresistant tablet results. Another suitable tablet is a strong, abrasion-resistant, quick-dissolving detergent tablet consisting essentially of:

(1) 38% by weight of sodium tetrapropylene benzene sul-fonate flakes having an active content of about 85% by weight, and the balance being sodium sulfate, about 2% by weight water;

(2) 32.6% by weight sodium sesquicarbonate;

(3) 10.9% by weight sodium tripolyphosphate;

(4) 8.7% by weight sodium acid pyrophosphate; and

(5) 7.6% by weight of lauric monoethanolamide having a melting point of about 180 F.; the particulate mixture containing about 2.2% by weight additional free water.

The amide in said tablet was dispersed between the carbon atoms and each of the other two jparticulate ingredients prior to compression, the amide alkyl groups contains from 1 to about 3 being fused, at least in part, to adjacent particles. carbon atoms, said alkyl groups containing What is claimed is: from to about 2 hydroxy substituents;

The process of preparing a strong, abrasion resistant, (q) trialkyl phosphine oxides wherein one (quick-dissolving detergent tablet comprising the steps of: alkyl group contains from about 10 to (A) Preparing tablet from: about 18 carbon atoms and each of the .(1) from about to about 50% by weight of other two alkyl groups contains from about said tablet of a water soluble detergent capable of being formed into particles prior to forming said tablet with a particle size of about 14 to about 100 mesh and a moisture content of less than about by weight of said detergent, said detergent being selected from the group 1 to about 3 carbon atoms, said alkyl groups containing from 0 to about 2 hydroxy substituents;

(r) zwitterionic detergent compounds having the formula consisting of: 15 R2 (a) alkali metal soaps containing from about 1 ';B 4 9 8 to about 18 carbon atoms; 3

(b) alkali metal alkyl sulfates containing R X from about 8 to about 22 carbon atoms;

(0) alkali metal alkyl sulfonates containing 20 wherein R is an alkyl radical containing from about 8 to about 22 carbon atoms; from about 8 to about 22 carbon atoms,

(d) alkali metal alkyl benzene sulfonates in R and R contain from 1 to about 3 carbon which the alkyl groups contain from about atoms, R is an alkylene chain containing 9 to about 15 carbon atoms; from 1 to about 3 carbon atoms, X is se- (e) alkali metal alkyl glyceryl ether sulfo- 25 lected from the group consisting of hydronates in which the alky lgroups contain gen and a hydroxyl radical, Y is selected from about 8 to about 22 carbon atoms; from the group consisting of carboxyl and (f) alkali metal fatty acid monoglyceride sulsulfonyl radicals and wherein the sum of fates wherein the fatty acid contains from the R R and R radicals is from about about 8 to about 22 carbon atoms; 0 14 to about 24 carbon atoms;

(g) alkali metal fatty acid monoglyceride (s) alkyl-beta-alanine wherein the alkyl radisulfonates wherein the fatty acid contains cal contains from about 8 to about 22 carfrom about 8 to about 22 carbon atoms; bon atoms;

(h) alkali metal salts of sulfuric acid esters (t) N-alkyl taurines wherein the alkyl radical of the reaction products between fatty alcocontains from about 8 to about 22 carbon hols containing from about 8 to about 22 atoms; carbon atoms and about 3 moles of ethylene (u) N-alkyl aspartic acids wherein the alkyl oxide; groups contain from about 8 to about 22 (i) alkali metal alkyl phenol ethylene oxide carbon atoms; and

ether sulfates containing about 4 units of (v) mixtures thereof; ethylene oxide per molecule and in which (2) from 0% to about 94% by weight of said the alkyl radicals contain about 9 carbon tablet of a detergency builder selected from the atoms; group consisting of ethylenediaminetetraacetates,

(j) alkali metal fatty acyl isethionates wheretripolyphosphates, acid pyrophosphates, alkaline in the fatty acyl groups contain from about pyrophosphates, orthophosphates, phytates, and 8 to about 22 carbon atoms; mixtures thereof, wherein the cation portion of (k) alkali metal salts of fatty acid amides of said detergency builder is selected from the methyl taurine in which the fatty acids congroup consisting of sodium, potassium and amtain from about 8 to about 22 carbon atoms; monium cations; said detergency builder having (1) the condensation product formed by cona particle size of from about 35 to about 200 densing ethylene oxide on a base prepared mesh; by condensing propylene oxide with pro- (3) from about 0% to about 94% by weight of pylene glycol, said base having a molecular said tablet of an inorganic salt which is inert to weight of from about 1500 to 1800 and the the formula and is selected from the group conamount of polyoxyethylene being at least sisting of sodium sulfate, sodium chloride, poabout 50% by weight of the condensation tassium sulfate, potassium chloride, ammonium product; sulfate, ammonium chloride, and mixtures there- (m) alkyl phenol ethylene oxide condensates of, said inorganic salt having a particle size of wherein said alkyl group contains from from 35 to 200 mesh; and about 6 to about 12 carbon atoms and (4) from about 0% to about 94% by weight of wherein there are about 10 to 25 moles of said tablet of a tablet disintegrating agent seethylene oxide per mole of alkyl phenol; lected from the group consisting of:

(n) condensation products of ethylene oxide (a) mixtures of a carbonate selected from with a base prepared by condensing prothe group consisting of sodium bicarbonate, pylene oxide with ethylene diamine, the potassium bicarbonate, ammonium bicarbase having a molecular weight of from bonate, sodium sesquicarbonate, potassium about 2500 to 3000, the amount of ethylene sesquicarbonate, ammonium sesquicarbonoxide being from about 40% to about ate, and mixtures thereof, and an acidify- Y Weight of the 11101601116; ing agent selected from the group consisting (o) the condensation product of aliphatic al- 7 of citric acid, acid pyrophosphates containcohols containing from about 8 to 18 caring a cation selected from the group conbon atoms with from about 10 to 30 moles sisting of sodium, potassium and ammoniof ethylene oxide per mole of alcohol; um, and mixtures thereof;

(p) trialkyl amine oxides wherein one alkyl (b) starch;

group contains from about 10 to about 18 5 (c) lactose; and

13% (d) mixtures thereof, said disintegrating agent having a particle size of from about 35 to about 200 mesh; by forming the said ingredients into a tablet at a pressure of from about 20 to 600 pounds per square inch;

(B) Spraying from about 1% to 5% by Weight of said tablet of a molten, substantially non-hygroscopic, normally Waxy fatty amide having a melting point of from about 100 F. to about 300 F., and selected from the group consisting of:

(a) ammonia amides containing from about 7 to about 22 carbon atoms;

(b) N-methyl amides containing an acyl group containing from about 10 to about 22 carbon atoms;

(c) N-isopropyl amides containing an acyl group containing from about 10 to about 22 carbon atoms;

(d) N-isobutyl amides containing an acyl group containing from about 10 to about 18 carbon atoms;

(e) N-ethanol amides containing an acyl group containing from about 7 to about 22 carbon atoms;

() N-diethanol amides containing an acyl group containing from about 10 to about 22 carbon atoms; and

(g) mixtures thereof;

onto the surface of the tablet in such a way that at least a port-ion of the amide becomes interparticu- 14 lately fused to more than one adjacent particle, and thereafter (C) Cooling said tablet below the melting point of said amide.

References Cited by the Examiner UNITED STATES PATENTS 1,450,865 4/1923 Pelc 252-157 2,129,264 9/1938 Downing et 131- 2,528,378 10/ 1950 Mannheimer. 2,560,097 7/1951 Emerson et al 252-174 X 2,653,913 9/1953 Van Dijck et al. 252-161 2,746,931 5/1956 Vitale et al 252-137 3,081,267 3/1963 Laskey 252-174 X 3,159,581 12/1964 Diehl 252-137 X 3,172,859 3/1965 Percival et a1. 252-137 FOREIGN PATENTS 1,059,351 3/1954 France.

741,637 12/1955 Great Britain.

OTHER REFERENCES Reinisch et al., Jour. Society of Cosmetic Chemists, November 1954, vol. 5, No. 3, pp. 169-178.

LEON D. ROSD OL, Primary Examiner.

ALBERT T. MEYERS, SAMUEL H. BLECH,

Examiners.

I. GLUCK, Assistant Examiner.