CN1031286C - Improved Soap Bar - Google Patents

Abstract

The present invention relates to soap bars containing polyhydroxy fatty acid amides which exhibit good "staining" characteristics, desired firmness and good lather performance, which bars also have a reduced tendency to crack. Soap bars are provided containing soap and materials such as _C12 - _C18 N-methylglucamide.

Description

Improved Soap Bar

The present invention relates to soap bars, especially personal hygiene and/or cosmetic soap bars, comprising polyhydroxy fatty acid amides.

Formulations for personal washing soap bars (ie "toilet bars") have been in use for many years. However, despite historical usage, there are still some problems associated with soap bars. It is well known that formulators and users do not want soap bars to form a soap/water type gel, especially when stored in environments where they will come into contact with water during use, such as in soap trays, and the like, typical of household washdowns The formation of this glue is even more undesirable when used in the chamber. In this case the bar will become limp and soiled which, in addition to being unsightly, also loses soap during use. One way to reduce bar staining is to reduce the amount of water in the bar. However, with the reduction of the water content of the bar, it will be accompanied by cracking when stored. Additionally, for personal hygiene bars, good lathering properties are desirable. Otherwise, improperly adjusting the water volume of standard soap bars to minimize losses may adversely affect lather performance. Another way to reduce the loss of soap bars is to use higher saturated fatty acids (ie low iodine value) as raw materials for soap. However, low iodine value soaps have poor sudsing properties, and soaps that crack during storage have an unpleasant gritty feel. Therefore, the search is continuing to find ways to minimize the loss of soap bars so that the consumer does not have the impression that the use of the soap bars is uneconomical and that the lather, cleansing performance and other desired Performance is not adversely affected.

It is an object of the present invention to provide a soap bar which has low staining, suitable bar firmness in relation to reduced losses, suitable (even improved) sudsing properties and which is less prone to cracking during storage.

The present invention uses the method described below to combine polyhydroxy fatty acid amides with water-soluble fatty acid soaps to achieve the above-mentioned purpose.

The polyhydroxy fatty acid amides are added to reduce the tendency of the bar to gel, resulting in a bar with less staining and longer life. In addition, the polyhydroxy fatty acid amides facilitate lather and reduce bar cracking. These and other objects are accomplished by the present invention, as will be seen from the following disclosure.

USP 3,312,627, issued April 4, 1967 to DTHooker, addresses the problems of too much loss, too much solubility, or too soft a toilet bar when the bar is soaked in water. Hooker provides bars (column 8, line 20) containing certain fatty acid lithium soaps which he considers to be excellent for the practice of his invention, and he also describes the various types more broadly in column 4, lines 11-28. and may include nonionic surfactants of the formula RC(O)NR ¹ (R ² ) (wherein RC(O) contains from about 10 to about 14 carbon atoms and R ₁ and R ₂ are each H or C ₁ -C ₆ alkyl, said alkyl contains a total of 2 to about 7 carbon atoms, the total number of substituent hydroxyl groups is 2 to about 6) polyhydroxy amides. Among its foaming ingredients, Hooker describes stearoyl N-methylglucamide and lauroyl N-methylglucamide, see US Patent 3,312,626 also issued April 4,1967 to DT Hooker.

The following references will assist the formulator in the synthesis of polyhydroxy fatty acid amide surfactants useful in the present invention: U.S.P. 2,016,962, 1,985,424, 2,703,798, 2,993,887, EP-A 285,768; Kelkenberg, Tenside Surfactant Detergents 25 (1988) 8-13 and Biochem J. 1982. Vol. 207, PP 363-366.

In the art, various polyhydroxy fatty acid amides have been described. For example, J.W.Goodby, M.A.Marcus, E.Chin and P.L.Finn in Liquid Crystals (1988.Vol.3 No.11, PP1569-1581) entitled "Thermotropic Liquid Crystal Properties of Certain Straight-Chain Carbohydrate Amphiphiles" And A.Muller-Fahrnow, V.Zabel, M.Steifa and R.Hilgenfeld are entitled " nonionic detergent nonanoyl N-acyl, N-methylglucamides are disclosed in "Molecular and Crystal Structure of N-Methyl Glucamide". In recent years, there has been particular biochemical interest in the use of N-alkyl polyhydroxyamide surfactants, for example, for the dissolution of biofilms. See, for example, "N-D-glucose-N-methyl-alkylamide compounds, a new class of membrane biochemistry" published by J.E.K.Hildreth in Biochem.J. (1982, Vol.207.PP363-366). non-ionic detergent".

The use of N-alkyl glucamides in detergent compositions has also been discussed. U.S.P. 2,965,576 issued December 20, 1960 to E.R. Wilson and G.B. 809060 issued February 18, 1959 assigned to Thomas Hedley & Co., Ltd. also relate to anionic surfactants and may include N-methyl Certain amide surfactants of Glucamide (as low temperature suds booster 1) in detergent compositions. These compounds include N-acyl groups of higher linear fatty acids having 10-14 carbon atoms. These compositions may also contain auxiliary substances such as alkali metal phosphates, alkali metal silicates, sulfates and carbonates. It is also generally indicated that other ingredients such as fluorescent dyes, bleaching agents, perfumes and the like may also be present in said compositions to impart desired properties to the composition.

U.S. Patent 2,703,798, issued March 8, 1955 to A.M. Schwartz, relates to aqueous detergent compositions containing the condensation reaction product of N-alkylglucamines and fatty esters of fatty acids. It is believed that the reaction product can be used without further purification in aqueous detergent compositions. The preparation of sulfate esters of acylated glucosamines is also known as disclosed in U.S. Patent 2,717,894, issued September 13, 1955 to A.M. Schwartz.

PCT International Application WO 83/04412, published December 22, 1983, to J. Hildreth relates to amphiphilic compounds containing polyhydroxy aliphatic groups which are considered suitable for a variety of purposes, including cosmetic, pharmaceutical, Used as a surfactant in shampoos, lotions and eye ointments, as an emulsifier and dispersant for drugs, for biochemical solubilization of membranes, whole cells or other tissue samples and for the preparation of liposomes . Compounds disclosed therein include compounds having the formulas R'CON(R) _CH2R " and R"CON(R)R' (wherein R is H or an organic group and R' is an aliphatic hydrocarbon group having at least 3 carbon atoms) , and R″ is an aldosyl) compound.

EPO 285768, H. Kelkenberg et al., published October 12, 1988, relates to the use of N-polyhydroxyalkyl fatty acid amides as thickeners in aqueous detergent systems. Including the formula R ₁ C(O)N(X)R ₂ (wherein R ₁ is an alkyl group of C ₁ -C ₁₇ (preferably C ₇ -C ₁₇ ), R ₂ is H, C ₁ -C ₁₈ ( Preference is given to C ₁ -C ₆ ) alkyl or alkylene oxide, and X is an amide of polyhydroxyalkyl having 4 to 7 carbon atoms, such as N-methyl, coconut fatty acid glucamide). Although the aqueous surfactant system may contain other anionic surfactants. Such as alkyl aryl sulfonate, olefin sulfonate, sulfosuccinic acid half ester salt and fatty alcohol ether sulfonate and such as fatty alcohol polyglycol ether, alkylphenol polyglycol ether, fatty acid polyethylene glycol esters, polypropylene oxide-polyethylene oxide hybrid polymers, etc., but also showed that the thickening properties of amides are particularly useful in liquid surfactant systems containing paraffin sulfonates. Paraffin sulfonate/N-methyl coconut fatty acid glucamide/nonionic surfactant shampoo formulations are examples. In addition to thickening properties, the N-polyhydroxyalkyl fatty acid amides are believed to have excellent skin tolerance properties.

U.S.P. 2,982,737 issued May 2, 1961 to Boettner et al. relates to anionic surfactants containing urea, sodium lauryl sulfate and selected from the group consisting of N-methyl, N-sorbyl lauramide and N-methyl, N-sorbyl Nonionic surfactant of N-alkyl glucamide based myristamide.

Other glucamide surfactants are disclosed, for example, in DT 2,226,872 issued December 20, 1973 to HWEckert et al., which relates to surfactants containing one or more surfactants selected from the group consisting of polymeric phosphates, polyphosphates, A detergent composition of a builder salt of a valence chelating agent and a detergent base by adding a formula of R ₁ C(O)N(R _a )CH ₂ (CHOH) _n CH ₂ OH (wherein, R ₁ is C ₁ -C ₃ alkyl R ₂ is C ₁₀ -C ₂₂ alkyl, and n is 3 or 4) N-acyl polyhydroxyl alkylamine to be improved. The added N-acyl polyhydroxyalkylamines are used as soil suspending agents.

USP 3,654,166, issued April 4, 1972 to HWEckert et al., relates to detergent compositions containing at least one surfactant selected from anionic, zwitterionic and nonionic surfactants and containing as a fabric The formula of softening agent is R ₁ N (Z) C (O) R ₂ [wherein R ₁ is C ₁₀ -C ₁₂ alkyl, R ₂ is C ₇ -C ₂₁ alkyl, the total number of carbon atoms of R ₁ and R ₂ is 23 to 39, and Z may be an N-acyl, N-alkyl polyhydroxyalkyl compound of the formula —CH ₂ (CHOH) _m CH ₂ OH (m is 3 or 4) polyhydroxyalkyl].

USP 4,021,539, issued May 3, 1977 to H.M_ller et al., relates to cosmetic compositions for the treatment of skin comprising formula R ₁ N(R)CH(CHOH) _m R ₂ (wherein R ₁ is H, lower alkyl, hydroxy lower alkyl or aminoalkyl and heterocyclic aminoalkyl, R and R ₁ are the same, but they cannot both be H, R ₂ is CH ₂ OH or COOH) N-multiple of compounds Hydroxyalkylamines.

French patent 1,360,018 issued April 26, 1963 to the company Commercial Solvents relates to the addition of compounds of the formula RC(O)N(R ₁ )G (wherein R is a carboxylic acid functional group having at least 7 carbon atoms and R ₁ is H or lower alkyl, and G is a polymeric stable formaldehyde solution of an alditol having at least 5 carbon atoms) amides.

German Patent 1,261,861 issued February 29, 1968 to A. Heins relates to sugars of the formula N(R)(R ₁ )(R ₂ ) (where R is glucosamine) for use as wetting and dispersing agents group, R ₁ is C ₁₀ -C ₂₀ alkyl, R ₂ is C ₁ -C ₅ acyl) glucosamine derivatives.

The GB745,036 patent issued to Atlas Powder Company on February 15, 1956 relates to heterocyclic amides and their carboxylic acids that are considered to be used as chemical intermediates, emulsifiers, wetting agents, dispersants, detergents, fabric softeners, etc. esters. The compound is represented by the formula N(R)(R ₁ )C(O)R ₂ (wherein, R is dehydrated hexanepentaol or its carboxylate, R ₁ is a monovalent hydrocarbon group, and —C(O)R ₂ is an acyl group of a carboxylic acid having 2 to 25 carbon atoms).

The present invention relates to bar soap compositions comprising:

(a) from about 75% to about 85% by weight of a substantially water-soluble lithium-free fatty acid soap;

(b) about 1% by weight of a polyhydroxy fatty acid amide surfactant; and

(c) The remainder of the soap is typically water and optional minor ingredients such as perfume, preservatives and the like.

The bars of the present invention generally contain from about 75% to about 85% by weight of _C12 - _C18 soap in the form of sodium, potassium, ammonium or alkanolammonium salts; Hydroxy fatty acid amide surfactant; from about 8% to about 12% by weight water. Preferred polyhydroxy fatty acid amide surfactants are C ₁₂ -C ₁₈ alkyl N-methyl glucamides, and preferred fatty acid soaps contain mixed sodium salts of C ₁₂ -C ₁₈ fatty acids. Preferred soap bars of the present invention are characterized by a hardness value of less than about 3, more preferably less than about 2, as measured by the "dry" (ie, "as is") penetrometer test.

The most preferred soap bars of the present invention include:

(a) about 75% to about 85% sodium soap having an iodine value of about 25 to about 35;

(b) about 3% C ₁₂ -C ₁₈ N-methyl glucamide surfactant;

(c) from about 0.3% to about 0.5% NaCl; and

(d) about 10% water with the balance comprising conventional soap bar minor ingredients. The bars are characterized by a hardness value of from about 2 to about 2.5.

The present invention also includes a method for improving the firmness quality of soap bars containing substantially water-soluble lithium-free fatty acid soaps, wherein said soap bars contain from about 8% to about 12% (by weight) of water, but have no effect on lather performance. Having substantially no deleterious effect, or tendency for said bar of soap to crack during storage or use, said bar of soap being formulated so as to include:

(a) from about 8% to about 12% water;

(b) from about 75% to about 85% by weight of a substantially water-soluble lithium-free fatty acid-derived soap, said soap preferably having an iodine value in the range of from about 25 to about 35;

(c) from about 1% to about 10% by weight of a polyhydroxy fatty acid amide surfactant;

(d) from about 0.2 to about 0.6% by weight electrolyte; and

(e) forming said raw material into bars by conventional processing techniques.

The bars of the present invention may also optionally include synthetic ("synthetic") non-soap, non-polyhydroxy fatty acid amide detergents, generally at a level of from about 0% to about 30% of the bar, depending on the formulator. requirements.

In the present invention, all percentages, ratios and proportions are by weight unless otherwise stated. The patents and literature cited herein are incorporated by reference.

The bars of the present invention are prepared using processes and equipment well known and standard in the industry, and the manufacturing operations to form the bars form no part of the invention. However, to assist the formulator in practicing the invention, the following descriptions are made by way of example, and are not intended to be limiting of the method of operation of making soap bars used in the present invention.

189 lbs (85.6 kg) of tallow fatty acid, 27 lbs (12.2 kg) of stearic acid, and 54 lbs (24.4 kg) of coconut fatty acid were blended in a "crusher" at a temperature of about 120°F (49°C), The blender is equipped with a standard turbo agitator and recirculation ring for further improved mixing. The blend of fatty acids was then neutralized with NaOH solution. About 84 lbs (38 kg) of 50% solution is required to completely neutralize it. To the hydroxide solution was added 2.1 pounds (0.95 kg) of salt (NaCl) prior to addition of the hydroxide. During neutralization, the temperature rises to 180-190°F (82-88°C).

After neutralization is complete, add 9.78 lbs (4.4 kg) of tallow alkyl N-methylglucamide to the neutralized material in powder form while maintaining vigorous stirring to produce a good mixing effect and keep the temperature at about 180 °F (82°C). After adding the tallow alkyl N-methyl glucamide, agitation for about 15 minutes was sufficient to achieve good mixing.

The resulting mixture contained about 30% moisture and was then dried to 10.5% moisture in a vacuum flash dryer under the operating conditions described below.

Temperature before heat exchanger = 180°F (82°C)

Temperature after heat exchanger = 220°F (104°C)

Temperature of dry product fine bar = 120°F (49°C)

Vacuum chamber pressure = 40mmHg

The dried product fine bars are then processed into soap bars using standard processing equipment: pre-mills, mixers, grinders, plodders and printers. Soap bars made in this way can have a hardness rating ("dry") of about 2 as determined by the Penetrometer of Test 1 described below.

The following methods can be used to determine the physical parameters of the soap bars of the present invention.

Hardness Test Method: The hardness of the soap bars prepared by the present invention can be determined by the following method. In general, soap bars having hardness values ranging below about 3, preferably below about 2, give good consumption values, acceptable staining, etc. in the first test listed (Test 1). The first test listed involves the "needle" penetration, India, of the "dry" soap bar, which is in contact with no additional moisture other than about 10% of the moisture in its bar. In another test (Test 2, also shown below), the bar was wetted first. In the second test method, "spherical" penetration is used, and, in this type of test, a desired penetration score is less than about 1.25, more preferably less than about 1.0.

test 1

Bar Penetrometer Test

equipment:

——Precision Penetrometer 1/10mm Scale Tester (Type 1—Meter

538 Fisher Scientific)

——Cone penetrometer (12.79g)

——230.6g weight

- Kodak timer

method:

- place the bar of soap under the penetrometer cone while the bar is resting on the board,

  Cover the soap bar with thin wax paper.

- Lower the metal penetration cone gauge until the tip of the cone touches the surface of the wax paper (put

The paper is placed between the bar and the cone, and the cone is lowered to the point where the wax paper can be removed without

where the wax paper was torn).

-Remove the wax paper.

——The weight of the cone at the top of the cone rod is 230.66g.

- Compress the release lever of the cone for 10 seconds; relax; raise the cone arm; move to

A new location on the bar surface; repeat the procedure.

- Repeat the operation three times, using three penetration points to form a triangle on the bar.

- Press the knob of the top rod down to obtain the length accuracy for the penetrometer =

1/10 mm scale reading.

- The reading will be the cumulative sum of the three penetrations.

- Divide 3 by the cumulative sum to obtain the average penetrometer reading, then divide by 10 to obtain

Get the reading expressed in millimeters and record the hardness value (expressed in millimeters).

test 2

Ball Penetrometer Test/100ML Stain

equipment:

——Precision Penetrometer 1/10mm Scale Tester (Type 1—Meter

538 Fisher Scientific).

- spherical penetrometer (11.40 g).

——300.6g weight

-Petri dish, inner diameter 90mm, depth 22mm.

- Standard plastic rack (soap dish type; bars barely come into contact with water).

- Graduated cylinders or batching bottles.

method:

- Place the bar of soap in the center of a plastic rack in a Petri dish.

-Take the soap bar and put it in a room with 80/80 (80°F/80% relative humidity)

Inside, and add 100ml of distilled water, put in 80/80 room overnight.

— put the bar back in the laboratory the next morning and slowly remove it from the petri dish

Remove the soap bar and place it wet side up under the penetrometer ball.

- Lower the metal penetration ball just enough to touch the surface of the bar.

- The ball weighs 300.6g in the upper part of the shaft.

- For curved soap bars, ensure that the bar can be clamped when performing the measurement.

- Squeeze the release lever for 10 seconds; relax; raise the ball arm to wipe off the ball

For remaining gel, move the ball to a new location on the bar surface; repeat

method.

- Repeat the operation three times. For curved soap bars, make three points pass through the arc of the bar,

For brick bars, form a triangle.

- Press the knob of the top rod down to obtain the length accuracy for the penetrometer =

1/10 mm scale reading.

- The reading will be the cumulative sum of the penetrations.

- Divide 3 by the cumulative sum to obtain the average penetrometer reading, then divide by 10 to obtain

Get the reading expressed in millimeters and record the hardness value (expressed in millimeters).

The ingredients used in the practice of the invention are known materials and the ingredients themselves and the various methods of preparing them form no part of the invention. Rather, it is the combination of these ingredients to provide the compositions disclosed herein that the desired results are achieved which result in the present invention. However, to assist the formulator, the ingredients are described below.

Soap: The soap ingredients of the present invention are commercially known preparations comprising substantially water-soluble fatty acid salts, typically _C12 - _C18 fatty acid salts. Such salts include alkali metal, ammonium, alkanolammonium, and the like. Sodium salt, potassium salt, triethanolammonium, ammonium salt, etc. are mentioned as examples, but not limited thereto. (Neither water-insoluble soaps, especially lithium soaps, nor insoluble calcium and magnesium soaps are used as "soap" ingredients of the bars of the present invention). Fatty acids can be obtained synthetically or, more typically, by alkaline hydrolysis of fats and oils such as lard, palm oil, tallow, coconut oil, and the like. Coconut fatty acid, tallow fatty acid and palm fatty acid are mentioned as examples, but for soap in general the sources are not limited to these fatty acids and mixtures of fatty acids derived from various sources can be used. In a preferred method, the soaps used in the present invention have a lower degree of unsaturation, ie, a lower iodine number, preferably in the range of about 25 to about 35 iodine numbers. As is known in the art, low iodine value soaps can be prepared by hydrogenating fatty soap stock, or by mixing fatty soap stock with saturated fatty acids to lower the total iodine value of the stock. For example, soap bars prepared from the blended tallow/stearin/coconut fatty acids mentioned below yield very desirable soap bars, however, this can vary according to the formulator's requirements, purpose, and source of raw materials.

Water: The bar of the present invention has a water content of at least about 8%, and generally ranges from about 8% to about 15%, preferably about 10% by weight for the finished soap. The water content used by the formulator will depend on the softness of the bar acceptable to the formulator and the user, the chain length of the fatty acid soap, the amount of polyhydroxy fatty acid amide used in the bar, etc. These can be adjusted as usual.

Electrolytes: The soap bars of the present invention will be optional, but preferably will contain electrolytes, which are generally added to the bars to make their soaps in what is commonly referred to as the "neat" phase. The choice of electrolytes used in a soap bar is a matter for the formulator to decide. In general, however, inexpensive, water-soluble, toxically acceptable electrolytes include various organic salts, or more typically various inorganic salts, such as alkali metal halides, sulfates, phosphates, and the like. Among such substances, such as, but not limited to, sodium chloride (preferred), potassium chloride, sodium sulfate, sodium phosphate, etc. are fully illustrated by way of illustration. Generally, the level of electrolyte will not be greater than about 2%, and more preferably from about 0.2% to about 0.6% by weight of the bar.

Optional Materials: The bars of the present invention may optionally contain a variety of additional ingredients of the type commonly used in toilet and cosmetic bars. Illustrative ingredients include, but are not limited to, fragrances, sunscreens, pearlescent agents, antimicrobials, dyes, fatliquors such as glycerin, abrasives such as pumice, and the like. Such ingredients may typically range from about 0.1% to about 15% by weight of the bar, depending on the formulator's objectives.

An additional type of optional ingredient for use in the soap bars of the present invention includes synthetic detergents such as sulfated and sulfonated _C12 - _C18 alcohols, alkylbenzenes, and the like. Nonionic synthetic detergents such as C ₁₂ —C ₁₈ polyethoxylates, C ₁₂ —C ₁₈ alkyl phosphates, zwitterionic, cationic, amine oxide and other synthetic detergents can be used. Syndets of this type are well known and can be found in McCutcheon's Index of Standard Tables or other textbooks. If used, suitable levels of such syndets are from about 2% to about 15% by weight of the bar.

Polyhydroxy fatty acid amide surfactants: These materials, as well as various methods of synthesizing them, are known in the literature (eg see references incorporated in the background above). However, to further assist the formulator, suitable examples of synthetic methods for such polyhydroxy fatty acid amide surfactants of the present invention are provided below, but are not limited thereto.

The reaction of the polyhydroxylamines used to prepare the polyhydroxy fatty acid amide surfactants used in the present invention is referred to as the "R-1" reaction and is exemplified by the formation of N-methylglucamine, where R ^is methyl.

The reactants, solvents and catalysts for the R-1 reaction are generally well known materials available from various commercial sources. The following are non-limiting examples of materials that may be used in the present invention.

Amine substance: the amine used in the R-1 reaction of the present invention is a primary amine, its formula is R ¹ NH ₂ , wherein R ¹ can be such as alkyl, especially C ₁ -C ₄ alkyl, or C ₁ - C ₄ hydroxyalkyl. Examples thereof include, for example, methyl, ethyl, propyl, hydroxyethyl and the like. Non-limiting examples of amines useful in the present invention include methylamine, ethylamine, propylamine, butylamine, 2-hydroxypropylamine, 2-hydroxyethylamine, preferably methylamine. All such amines are often collectively referred to as "N-alkylamines".

Polyhydroxy species: Preferred sources of polyhydroxy species for use in the R-1 reaction include reducing sugars or reducing sugar derivatives. More preferred reducing sugars for use in the present invention include glucose (preferred), maltose, fructose, maltotriose, xylose, galactose, lactose or mixtures thereof. Catalyst: Various hydrogenation catalysts are suitable for R-1 reaction. Included among such catalysts are nickel (preferred), platinum, palladium, iron, cobalt, tungsten, various hydrogenation alloys, and the like. The most preferred catalysts of the present invention include "Union Catalyst G49B", a particulate nickel catalyst on silica available from Union Catalyst Company, Louisville, Kentucky. Solvent: The formation of the adduct in the R-1 step is carried out with an excess of amine as solvent, which may also be used in the subsequent reaction with hydrogen. Alcohols such as methanol can optionally be substituted for amines for the hydrogen reaction. Examples of typical solvents for the formation of amine-sugar adducts in this invention include methylamine, ethylamine and hydroxyethylamine, with methylamine being preferred, and methylamine/water solvents can also be used.

The general condition of R-1 reaction: The reaction condition of R-1 reaction is as follows:

(a) Adduct formation: The reaction time for adduct formation is generally about 0.5-20 hours, but depends somewhat on the reaction temperature chosen. Generally speaking, if the reaction is carried out at a lower temperature range of 0°C to 80°C, a longer reaction time is required, and vice versa. Usually, a satisfactory adduct product can be obtained within 1-10 hours above the preferred reaction temperature by 30°C-60°C. Good adduct formation is generally achieved at amine:sugar molar ratios of about 4:1 to 30:1. Typical sugar reactant concentrations in the amine solvent are 10% to 60% by weight. The formation of the adduct can be carried out at atmospheric or superatmospheric pressure (preferred).

(b) Reaction with hydrogen: Generally speaking, the reaction with hydrogen is carried out under the following conditions: for example, the temperature is 40°C-120°C, the pressure is 50-1,000 psi (pounds per inch ² ), or, for example, the temperature is 50 ℃-90℃, pressure 100-500psi, time 0.1-35 hours, generally 0.5-8 hours, preferably 1-3 hours. The adduct/solvent solution used in the hydrogen reaction is typically 10% to 60% by weight of solute. (It will be appreciated that the choice of hydrogen reaction conditions depends to some extent on the type of pressure equipment available to the formulator, and thus the above reaction conditions may be varied without departing from the invention). For the batch process, the hydrogen reaction catalyst is typically used in an amount of 1% to 40%, preferably about 2% to about 30% by weight solids, calculated on a weight catalyst: weight reducing sugar substituent basis. Of course, continuous processes can be run at much higher catalyst levels. The product of step (b) can be dried by solvent/water stripping, or crystallization, trituration or with the aid of an effective drying agent.

Example I

A weighed amount of anhydrous glucose (36.00 g; Aldrich Chemical Co.) was placed in a glass thimble which was placed in a dry ice bath and methylamine gas (68.00 g; Matheson) was condensed into the glass thimble . Then, the sleeve was placed in a swinging autoclave (500 ml volume), the autoclave was heated to 50° C., and was shaken for 5 hours at 50° C. under 600 psig (gauge pressure, lbs/ ⁱⁿ² ) nitrogen , in order to form an adduct (N-methylglucosylamine). The reaction was then cooled in a dry ice bath and the autoclave was vent cooled. Raney Nickel (7.2 g of a 50% suspension in water, type W/2, Aldrich Chemical Co.) was added. Under 500-600 psig of hydrogen, the reaction was heated to 50°C and rocked for 16 hours. The reaction was cooled in a dry ice bath, vented and flushed with nitrogen. The reaction solution was subjected to pressure filtration through a 4-inch bed Zeofluor filter (polytetrafluoroethylene, 47 mm, 0.5 μm filter) using Celite 545 (Fisher Scientific). The filtrate was concentrated under a nitrogen stream, so as to obtain 8.9 g of a white solid. The Celite plug was washed with about 300ml of water and the water was stripped on a rotary evaporator to give 18.77g of a white solid. The two solids were combined and, as analyzed, were of similar composition ( ⁹⁰⁺ purity by gas chromatography). The product is N-methylglucamine.

Example II

The procedure of Example 1 was repeated in an agitated autoclave equipped with a porous outlet filter, three impeller stirrer, outlet and inlet pipes and baffles. The reactants and reaction conditions for the preparation of N-methylglucamine are as follows: In 160 ml of methanol, 15 g of 20% G49B catalyst (Ni/silica; United Catalysts) and 75 g of glucose powder (Aldrich, Lot07605LW) were made into a slurry , and pretreated with _H2 for 1 h (50 °C), then the mixture was cooled and methanol was removed under pressure.

The reactor was cooled to below 5°C and charged with 76 ml of liquid methylamine.

In 250 psi of hydrogen, the reaction mixture was slowly heated to 60°C over 46 minutes and a sample was taken. At 60°C, heating was continued for 20 minutes, and sample 2 was taken out and heated at 60°C for 46 minutes (sample 3). Heating was then continued at 60° C. for 17 minutes (Sample 4). The reaction mixture was heated to 70°C for an additional 33 minutes (Sample 5). The total reaction time was 2.7 hours. The dry product was 93.2% N-methylglucamine (analysis by gas chromatography).

The polyhydroxyamine product of the above R-1 reaction, preferably substantially free of water, is desired and may be further used in an amide-forming reaction, referred to herein as the "R-2" reaction. A typical R-2 amide forming reaction of this invention is illustrated by the formation of lauroyl N-methylglucamide as described below. R ² C(O)N(Me)CH ₂ (CHOH) ₄ CH ₂ OH + MeOH wherein R ² is C ₁₁ H ₂₃ alkyl.

Thus, all reactions required to prepare polyhydroxy fatty acid amide surfactants include:

(a) reacting a reducing sugar (preferably glucose) or a reducing sugar derivative with an amine reactant (preferably methylamine) in an amine solvent (preferably methylamine) to obtain an adduct;

(b) reacting said adduct from step (a) dissolved in said amine solvent with hydrogen in the presence of a metal catalyst;

(c) removing said catalyst and substantially removing water and excess amine solvent from the reaction mixture to provide a polyhydroxylamine reaction product; and, thereafter the R-2 reaction;

(d) reacting said substantially anhydrous polyhydroxylamine product from step (c) with a fatty acid ester in an organic hydroxylic solvent, preferably methanol or propylene glycol, in the presence of a basic catalyst to form polyhydroxyl Fatty acid amide surfactants (preferably at reaction temperatures below about 100°C); and

(e) optionally removing said solvent used in step (d) when reaction step (d) is substantially complete.

More specifically, combining the R-1 and R-2 reactions of the present invention provides all of the steps (R-1 + R-2) that can be used to produce polyhydroxy fatty acid amide surfaces for use in the present invention having the formula Active agent: Wherein: R ¹ is H, C ₁ -C ₄ hydrocarbon group, 2-hydroxyethyl, 2-hydroxypropyl or a mixture thereof, preferably C ₁ -C ₄ alkyl, more preferably C ₁ or C ₂ alkyl, Most preferably C ₁ alkyl (i.e. methyl); and R ² is C ₅ -C ₃₁ hydrocarbyl moiety, preferably straight chain C ₇ -C ₁₉ alkyl or alkenyl, more preferably straight chain C ₉ -C ₁₇ Alkyl or alkenyl, most preferably straight chain C ₁₁ -C ₁₇ alkyl or alkenyl, or mixtures thereof; and Z has a straight chain hydrocarbyl chain with at least 3 hydroxyl groups directly attached to the chain A polyhydroxyhydrocarbyl moiety, or an alkoxylated derivative thereof (preferably ethoxylated or propoxylated), preferably Z is derived from a reducing sugar in a reductive amination reaction, more preferably Z is an alditol part. Suitable reducing sugars include glucose, fructose, maltose, lactose, galactose, mannose and xylose. High dextrose corn syrup, high fructose corn syrup and high maltose corn syrup as well as the individual sugars listed above can be used as raw materials. These corn syrups can provide a mix of sugar ingredients for Z. Of course no other suitable substances are discharged as starting materials. Z will preferably be selected from the group consisting _{of -CH2-} (CHOH) _{n- CH2OH} , -CH( _CH2OH )-(CHOH) _{n-1- CH2OH} , -CH2-(CHOH) ₂ (CHOR') (CHOH)—CH ₂ OH is a class of groups, in the above groups, n is an integer from 3 to 5, and R' is H or cyclic mono- or polysaccharides and their alkoxylated derivatives, more Preferred are alditol radicals (where n is 4), especially —CH ₂ —(CHOH) ₄ —CH ₂ OH.

In formula (I), ^R can be, for example, N-methyl, N-ethyl, N-propyl, N-isopropyl, N-butyl, N-isobutyl, N-2-hydroxyethyl base or N-2-hydroxypropyl.

Examples thereof include cocamide, stearamide, oleamide, lauramide, myristamide, capramide, palmitamide, tallowamide, and the like.

Z can be 1-deoxyglucitol, 2-deoxyfructitol, 1-deoxymaltitol, 1-deoxylactitol, 1-deoxygalactitol, 1-deoxymannitol, 1-deoxy Maltotriitol, etc.

The following reactants, catalysts and solvents are suitable for use in the R-2 reaction of the present invention and are listed by way of example only, but not limitation. Such materials are well known and generally available from a variety of commercial sources.

Reactants: A variety of fatty acid esters can be used in the R-2 reaction, including mono-, di-, and tri-esters (ie, triglycerides). Methyl esters, ethyl esters, etc. are very suitable. _The polyhydroxylamine reactant includes the reactants obtained by _{the above} - _mentioned R-1 reaction, for _{example , N—} Alkyl and N-hydroxyalkyl polyhydroxylamines. [The polyhydroxylamine obtained by the R-1 reaction is preferably not contaminated by residual amounts of metal hydrogenation catalysts, although some parts per million (e.g., 1-20 ppm) may be present]. Mixtures of esters and mixtures of polyhydroxyamine reactants may also be used.

Catalyst: The catalyst used in the R-2 reaction is a basic substance, such as alkoxide (preferred), hydroxide (rarely selected, because hydrolysis reaction may occur), carbonate, etc. Preferred alkoxide catalysts include alkali metal C ₁ -C ₄ alkoxides such as sodium methoxide, potassium ethoxide and the like. The catalyst can be prepared separately from the reaction mixture, or can be generated in situ using an alkali metal such as sodium. For in situ generation, such as sodium metal in methanol solvent, it is preferred that no other reactants be present until the formation of the catalyst is complete. Typical catalyst levels are about 5 mole percent of the ester reactants. Mixtures of catalysts may also be used.

Solvent: The organic hydroxyl solvent used in the R-2 reaction includes, for example, methanol, ethanol, propanol, isopropanol, butanol, glycerol, 1,2-propylene glycol, 1,3-propylene glycol, etc., methanol is preferred alcohol solvent, and 1,2-propanediol is the preferred diol solvent. Mixtures of solvents may also be used.

General R-2 Reaction Conditions: It is preferred to produce the desired product while minimizing the formation of cyclization by-products, ester amides and color bodies. The reaction temperature used is lower than about 135°C, generally about 40°C to about 100°C, preferably 50°C to 80°C, in order to achieve this purpose, especially in a batch process, the reaction time is generally about 0.5-2 hours, Even up to 6 hours. In continuous processes, slightly higher temperatures are permissible and shorter residence times are possible.

The following examples illustrate, but are not limited to, the practice of the R-2 reaction using N-polyhydroxylamines prepared by the R-1 reaction disclosed above (with water substantially removed). It should be noted that the concentration ranges of the reactants and solvents in Example III provide what may be referred to as a "70% concentration" (to the reactants) of the reaction mixture which achieves a good This is because a high yield of the desired polyhydroxy fatty acid amide product is rapidly obtained. Indeed, there are various indications that the reaction is substantially complete within 1 hour or less. The concentration of the reaction mixture at 70% concentration allows for easy handling. However, better results were obtained even at concentrations of 80% and 90%, as the chromatographic data indicated that even at these higher concentrations less undesirable by-products were formed. At higher concentrations, the reaction system is somewhat more difficult to handle and requires more efficient agitation (due to their initial viscosity), etc., at least initially. Once the reaction has progressed to a certain extent, the viscosity of the reaction system will decrease, and the mixing will gradually become easier.

Example III

In a round-bottomed flask equipped with a condenser, a drying tube and an argon covering protection, the product of Example 1 (9.00g, 0.0461mol, N-methylglucamine) was mixed with 8.22g of anhydrous methanol, and The methanol and N-methylglucamine of the reaction were heated to reflux temperature, refluxed for 15 minutes, added sodium methoxide (0.1245g, 0.0023mol Aldrich chemical company) and methyl ester (10.18g, 0.0461mol, Procter & Gamble CE1270, including C ₁₂ ~ C ₁₈ fatty acid ester), and the reaction was continued to reflux for 3 hours. Methanol was then removed under reduced pressure to afford an essentially colorless white product. Yields were not recorded because samples were taken at 30 minutes, 1 hour, 2 hours and 3 hours before drying. The dried sample was washed with cold methanol, filtered and final drying was performed under vacuum to yield 10.99 g of polyhydroxy fatty acid amide surfactant.

Example IV

All steps for the synthesis of amides at 80% reactant concentration are as follows.

A reaction mixture consisting of 84.87 g of fatty acid methyl esters (source: Procter & Gamble methyl esters CE1270), 75 g of N-methylglucamine (from Example I above), 1.04 g of sodium methoxide and a total of 39.96 g of methanol [approx. 20% (weight)] of the reaction mixture. The reactor consisted of a standard reflux unit equipped with a drying tube, condenser, and mechanical stirring blades. The N-methylglucamine/methanol was heated with stirring under argon (reflux), and when the solution reached the desired temperature, the ester and sodium methoxide catalyst were added. The reaction mixture was maintained at reflux for 6 hours and the reaction was substantially complete within 1.5 hours. After removal of the methanol, the recovered product weighed 105.57 g. Chromatographic analysis showed only traces of the undesired by-product ester amide and no detectable cyclization by-product.

Example V

Under 90% reactant content, repeat the method of embodiment IV, to carry out the synthesis step of polyhydroxy fatty acid amide, the content of undesired by-product is very low, and reaction is substantially completed in 30 minutes. In another approach, the reaction is started at a concentration of 70% reactants, for example methanol can be stripped during the reaction and the reaction is run to completion.

Example VI

The procedure of Example III was repeated with ethanol (99%) and 1,2-propanediol (substantially anhydrous), respectively, and the obtained products were satisfactory. In another approach, a solvent such as 1,2-propylene glycol is used in the R-2 step to strip the methanol throughout the process. The resulting surfactant/glycol mixture can be used directly in detergent compositions.

While the reaction conditions are thus disclosed (including the amine solvent in the R-1 step of the method), it is further determined that the amine/water solvent mixture used in the R-1 reaction can also provide additional advantages in the R-1 reaction . In particular, the reaction products formed using amine/water solvents are essentially colorless and relatively fast to high product yields. In the reaction product, there is substantially no reducing sugar, which can continue to form color in the subsequent R-2 reaction. The R-1 reaction in a mixed amine/water solvent is as follows.

Example VII

Using a stirred autoclave and the method of Example H, 15 g of 649B catalyst, 75 g of dextrose powder (Aldrich) and 160 mL of methanol were slurried and treated with _H2 to remove oxides from the catalyst surface. Methanol was removed and 80 mL (52.8 g) of methylamine was added to the glucose/catalyst mixture below 5°C, followed by 22 mL of water at room temperature.

The reaction mixture was heated to 70°C over 34 minutes and maintained at this temperature for 40 minutes during the hydrogenation. The water/methylamine solution in the reaction product (to remove the catalyst) was blown from the reactor through a glass frit and dried to give the N-methylglucamine product.

When using mixed amine/water solvents, a weight ratio of amine (preferably methylamine) to water of about 10:1 to about 1:1 is generally used. The substantially anhydrous (preferably less than about 1%, more preferably less than about 0.3% by weight of water) R-1 reaction product can then be used in the R-2 reaction to produce polyhydroxy fatty acids, as described above amides.

Although the foregoing disclosures generally relate to the cosolvent method of using fatty methyl esters to prepare N-methyl polyhydroxylamines such as N-methylglucamine and fatty acid amide derivatives thereof. it goes without saying. Various changes are also possible. Therefore reducing sugars such as fructose, galactose, mannose, maltose and lactose as well as sources of sugars such as high dextrose corn syrup, high fructose corn syrup and high maltose corn syrup can be used to prepare the reacted polyhydroxylamine substance (i.e. instead of glucosamine). Likewise, a variety of fats and oils (triglycerides) may be used in the present invention in place of the fatty esters listed above. Examples include fats and oils such as soybean oil, cottonseed oil, sunflower oil, beef tallow, lard, safflower oil, corn oil, canola oil, peanut oil, fish oil, canola oil, etc., or their hardened (hydrogenated) forms Both oils and triglycerides can be used as a source of triglycerides for use in this method. Due to the milder reaction temperatures and reaction conditions of the present invention, the desired product can be obtained with minimal formation of by-products. Therefore, the method of the present invention is particularly suitable for the preparation of long chain (such as C ₁₈ ) and unsaturated fatty acid polyhydroxy amides. When triglycerides or long chain methyl esters are used as reactants, a preformed portion of the polyhydroxy fatty acid amide surfactant may be used to help initiate the amide-forming reaction of R-2. Furthermore, the use of propylene glycol or glycerol or their preformed monoesters also helps to initiate the R-2 reaction. The yield of surfactant in the R-2 step can be increased by simply storing the cured product, which contains small amounts of entrained solvent and reactants. For example, the operation is carried out at 50° C., removing it from the reactor for several hours. Storage in this manner apparently allows the last portion of unreacted starting material to continue to form the desired polyhydroxy fatty acid amide surfactant. Thus, the yield can be significantly increased, that is, the reaction reaches a high degree of completion, which is of great significance in large-scale industrial production.

The following examples illustrate, but are not limited to, the use of the surfactant products of all of the R-1 and R-2 steps described above to prepare soap bar compositions by the process of the present invention. This is because various surfactants, perfumes and other optional ingredients well known to soap bar formulators can optionally be used in such compositions in conventional amounts.

Example VIII

A typical soap bar consists of the following:

Composition % (weight)

Fatty acid soap ^* 83.75

Alkyl Glucamides ^** 3.00

NaCl 0.44

Minor ingredients (spices, etc.) 2.5

Water Balance Amount

pH 10.25

^* Sodium salt of tallow/stearin/coconut fatty acids blended in a 70/10/20 weight ratio.

^** The mixed tallow alkyl N-methyl glucamide prepared by the method of Example III, wherein the number of carbon atoms of the tallow alkyl is in the range of 12 to 18.

Example IX

The bar of Example VIII was modified by reducing the soap content to 76% and increasing the alkyl glucamide (prepared as in Example IV) to 10% to give a softer bar .

Example X

The soap bar of Example VIII was modified by increasing the soap level to 85% and reducing the alkyl glucamide surfactant level to 2% to obtain a harder bar .

Example XI

Soap/syndeter mix bars are as follows:

Composition % (weight)

Fatty acid soap ^* 78.0

Synthetic detergent ^** 6.0

Glucosamide ^*** 8.0

NaCl/kcl (1:1 weight) 0.38

Water Balance Amount

^* Na/K coconut soap mixed 1:1 by weight.

^** Mixed C _14-18 alkyl sulfates, sodium salts.

^*** Mixed C ₁₂ -C ₁₈ alkyl N-methyl glucamides (prepared as disclosed in Example V above).

Claims (9)

1. A soap bar composition comprising: (a) 75%-85% (by weight) of a substantially water-soluble _C12 - _C18 fatty acid soap; (b) 1%-10% (weight) polyhydroxy fatty acid amide shown in the following formula

In the formula, R ¹ is C ₁ -C ₄ alkyl, R ² is straight chain C ₇ -C ₁₉ alkyl or alkenyl, and Z is derived from a reducing sugar in a reductive amination reaction; and (c) 8%-12% by weight of water. 2. The soap bar according to claim 1, wherein said fatty acid soap is in the form of a sodium, potassium, ammonium or alkanolammonium salt. 3. The soap bar according to claim 1, wherein ^R in the compound of formula is methyl. 4. The soap bar according to claim 3, wherein said fatty acid soap comprises mixed sodium salts of _C12 - _C18 fatty acids. 5. Soap bar according to claim 1, characterized in that the hardness value is lower than 3. 6. Soap bar according to claim 5, characterized in that the hardness value is lower than 2. 7. A soap bar according to claim 2 comprising 75% to 85% by weight of sodium soap having an iodine value in the range of 25 to 35, said soap bar being characterized by a hardness value of 2 to 2.5. 8. The soap bar according to claim 1 additionally comprising up to 30% by weight of a synthetic non-soap, non-polyhydroxy fatty acid amide detergent. 9. A soap bar according to claim 7, further comprising 0.2% to 0.6% by weight of electrolyte.