US3328305A - Process for preparing detergent compositions - Google Patents

Description

United States Patent 3,328,305 PROCESS FOR PREPARING DETERGENT COMPOSITIONS Vincent Lamherti, Upper Saddle River, NJ., assignor to Lever Brothers Company, New Yorlt, N.Y., a corporation of Maine No Drawing. Filed Feb. 16, 1966, Ser. No. 527,727 15 Claims. (Cl. 25289) The present invention relates to an improvement in the preparation of detergent compositions.

This application is a continuation-in-part of application, Ser. No. 757,202, filed Aug. 26, 1958, now abandoned, and application Ser. No. 175,812 filed Feb. 26, 1962, now abandoned.

Cellulose ethers are frequently employed in both dry and liquid detergent compositions as soil suspending agents. The incorporation of cellulose ethers in liquid detergent compositions presents a considerable problem in that these compounds are not readily soluble or dispersible in water. Thus, when a cellulose ether is added to water at room temperature to effect hydration thereof, lumps of cellulosic gel are formed which are extremely difficult to dissolve or disperse in water.

Heretofore, the formation of aqueous dispersions of cellulose ethers has been affected by one of several methods. For example the cellulosic compounds may be dispersed by first mixing them thoroughly with a minor amount of hot water and allowing them to wet out for a short time. A major amount of water is then added either as cold water or ice and the aqueous slurry stirred until a smooth uniform dispersion of the cellulosics is obtained. This so-called hot water method, the principal method used heretofore for dispersing cellulose ethers, is costly and time consuming because of the necessity for heating and cooling the water.

Another method which has been employed heretofore involves the use of wetting agents which are miscible with water, such as methyl alcohol, ethyl alcohol, and glycerol. In this process, the cellulosic compounds are wetted with one of these water-miscible wetting agents to yield a slurry which is subsequently added to a major portion of cold water. Stirring of the alcoholic aqueous slurry produces a uniform dispersion of the cellulosic compounds.

It is an object of this invention to overcome the difficulties heretofore encountered in the hydration of water imbibing materials such as cellulose ethers.

It is another object of this invention to provide a rapid and convenient method for effectively hydrating a cellulosic material.

It is a further object of the invention to provide a method for preparing cellulosic slurries which can be easily admixed with substantial amounts of water which may contain various other ingredients to provide a uniform lump-free dispersion of the cellulosic material.

These and other related objects are achieved by a process for hydrating a cellulose ether which comprises wetting the cellulose ether with an effective amount of a soap-forming fatty acid or mixture of fatty acids which is immiscible with water and which is liquid at about room temperature to form a cellulosic slurry which can be added directly to water or to an aqueous formulation containing other conventional detergent components. The resulting aqueous admixture is then agitated to form a uniform, smooth, stable, lump-free, aqueous dispersion. The step of wetting the cellulosic material with a suitable fatty acid prior to mixing with water can be conveniently described as prewetting the cellulosic with the fatty acid.

The term effective amount refers to an amount of wetting agent which is sufficient to wet the cellulose ether to such a degree that it can be easily and completely hydrated to provide a smooth, lump-free dispersion.

By hydrating cellulose ethers in accordance with the process of the present invention, the costly and time consuming heating and cooling cycles of the hot water method are not necessary. Moreover, in the process of the present invention wetting agents are employed which are not miscible with water as has been true of the previously employed wetting agents, such as methyl alcohol, ethyl alcohol, and glycerol. This is indeed quite unusual, since one would ordinarily expect that in order to disperse the cellulose ethers in water by a prewetting technique, the wetting agent should be miscible with or dispersible in water.

In general, the present process is applicable to the production of any aqueous composition, e.g., a detergent composition, containing a cellulose ether in the formulation. While it is preferred, for best results, to add the wetted cellulosic material to water alone thereby forming a uniform slurry prior to the addition of any other ingredients such as detergent components, the order of addition of the ingredients is not critical. Thus, for example, the cellulose other which has been wetted with a soapforming fatty acid which is pourable at room temperature can be added to an aqueous composition containing at least some of the detergent components and this composition agitated to produce a uniform, smooth formulation to which any of the balance of the ingredients of the complete detergent formulation may be added, thus producing a smooth uniform lump-free dispersion. Accordingly, the term aqueous formulation, as used herein, is intended to include compositions comprising water and some or all of the other ingredients of the final formulation, as well as water alone. Alternatively, some or all of the ingredients of the detergent formulation can be admixed with the wetted cellulosic material and this mixture can then be mixed with water to form the final formulation. Regardless of the order in which the various additives are mixed with the fatty acid-wetted cellulosic material, the final product is a smooth, uniform, stable, lumpfree, aqueous detergent composition.

The term detergent formulation components as used herein is intended to include any and all of the usual ingredients commonly found in detergent formulations. Such components include the well known organic detergents of the anionic, cationic, nonionic and ampholytic classes, e.g., alkyl sulfonates, sulfated alcohols, fatty acid salts, alkylbenzene sulfonates, quaternary ammonium compounds, polyethylene oxide condensates of fatty acids, aliphatic alcohols, aromatic alcohols, and the like.

The wetting of the cellulose ether with the fatty acid can be accomplished at about room temperature (about 'F.) or if desired at the elevated temperatures usually encountered in manufacturing plants e.g., up to about F. In general, the amounts of the reagents employed are about one part of cellulose ether to at least about 0.70 part and preferably about one part, of fatty acid and about sixteen to about eighty parts and preferably about thirty parts of water. The agitation period is about five minutes at relatively high stirrer speeds.

The fatty acids suitable for use in the practice of this invention include any aliphatic monocarboxylic acid or mixtures thereof which is immiscible and nondispersible in water and which can be saponified to yield a watersoluble soap. The fatty acids which may be straight or Patented June 27, 1967- branched chain can be derived from natural sources or may be prepared synthetically, e.g., from alpha olefins. The term liquid at room temperature refers to material having the ability to wet a solid at that temperature. This characteristic is generally recognized by the existence of a pourablc liquid phase. Generally, the preferred fatty acids having the ability to wet cellulose ethers at room temperature are those acids containing from to 22 carbon atoms which are immiscible and nondispersible in water. Suitable acids include oleic acid, coconut oil fatty acids, palmitoleic acid, linoleic acid, linolenic acid, ricinoleic acid, and the like as well as mixtures of fatty acids which individually may be solid at room temperature but in combination have a liquid phase capable of wetting the cellulosic material. Illustrative mixtures of fatty acids which are liquid at room temperature, include mixtures of capric acid and lauric acid (e.g., 80% capric, lauric), mixtures of capric acid and myristic acid (e.g., 80% capric, 20% myristic), mixtures of capric acid and oleic acid (e.g., a 1:1 mixture), mixtures of palmitic acid and capric acid (e.g., 10% palmitic and 90% capric), and certain mixtures of oleic acid with stearic acid or palmitic acid. The above percentages are by weight. Additional suitable fatty acids are the mixed acids obtained from naturally occurring oils such as cod liver oil, shark oil, seal oil, perilla oil, linseed oil, candlenut oil, hempseed oil, walnut oil, poppyseed oil, sunflowerseed oil, maize oil, rapeseed oil, mustardseed oil, apricot kernel oil, almond oil, castor oil and olive oil. Accordingly the term fatty acid as used herein, is intended to include both single fatty acids and mixtures of fatty acids, as described herein.

A particularly important advantage obtained by using soap-forming fatty acids as wetting agents for the cellulosic material is that these agents can be saponified and converted to water-solublesoaps by treatment with an alkali. Thus, the wetting agent of the invention can be converted to a material which becomes a useful and integral part of the detergent composition unlike other known wetting agents which tend to separate out from the detergent composition thus rendering it unsightly to the user. Such incompatible wetting agents act as diluents to decrease the cost of the formulation and also decrease its effectiveness.

In addition to the detergents themselves, the formulations may contain other substances whichare adjuvants and additives such as builders, e.g., tripolyphosphates, pyrophosphates, sodium hexametaphosphate, sodium trimetaphosphate, alkali metals (e.g., sodium and potassium) carbonates, borates, silicates, persulfates, perborates percarbonates, and the like, bleaching agents of the oxygen-releasing and chlorine-releasing types e.g., the hypochlorites, and potassium and sodium dichlorocyanurate, trichlorocyanuric acid, chlorinated trisodium phosphate, dichloro-dimethylhydantoin, n-chlorosuccinimide, chloroamine-T, and the like, and germicides such as hexachlorophene, and the halogenated salicylani lides, e.g., 3,S-dibromosalicylanilide, 3,4,S-tribromosalicylanilide and the like.

The compositions may also contain optical brighteners, dyes, fillers, e.g., sodium chloride, sodium sulfate, and the like, emollients, skin conditioners and other suitable adjuvants.

The cellulose ether may be used alone or mixed with another cellulose ether. Typical examples thereof are a methylcellulose, e.g., one having 27.532% methoxyl groups per cellulose molecule; an ethylcellulose, e.g., one having 0.65 mole of ethoxyl groups per anhydroglucose unit; a sodium carboxymethylcellulose, e.g., one having 0.7 mole of carboxymethyl groups per anhydroglucose unit; a sodium carboxymethylmethylcellulose, e.g., one having 0.150.2 mole of carboxymethyl groups per anhydroglucose unit and 14-22% of methoxyl groups per cellulose molecule; a sodium carboxymethylethylcellulose, e.g., one having 0.1 mole of carboxymethyl groups and 1.0 mole of ethoxyl groups per anhydroglucose unit;

and a sodium carboxymethylhydroxyethylcellulose, e.g., one having 0.34 mole of carboxymethyl groups and 0.76 mole of hydroxyethyl groups per anhydroglucose unit.

Example 1 A mixture of 1.25 grams of sodium carboxymethylcellulose having 0.7 mole of carboxymethyl groups per anhydroglucose unit (120 high% active) and 3.4 grams of methylcellulose (viscosity 25 centipoises as measured in a 2% aqueous dispersion) having 27.5-32% methoxyl groups per cellulose molecule was prewetted with 5 grams of coconut oil fatty acids at room temperature (75 F.). The resulting cellulosic slurry was then added to 144.5 grams of water at room temperature under rapid mechanical stirring. After 5 minutes the stirring was stopped and the dispersion observed for undissolved flecks of cellulosic gel. The dispersion was again observed after 2.5 hours and 24 hours of further standing with no additional stirring. The observations are set forth below.

Flecks of undispersed gel remaining after:

5 minutes few 2.5 hours practically none 24 hours none Example 2 Five gram samples of (a) methyl cellulose of 4000 centipoise viscosity (in 2% aqueous dispersion) having from 27.5 to 32% methoxyl groups per cellulose molecule (Methocel NF 4000 cps.) and of (b) sodium carboxymethylmethylcellulose (of low viscosity measured in a 2% aqueous dispersion) having 0.2 mole of carboxymethyl groups and 1.0 mole of methoxyl groups per anhydroglucose unit were wetted with 5 gram portions of coconut oil fatty acids, and the resulting slurry added to water as described in Example 1, above. The aqueous dispersion was then examined as in Example 1 for undispersed cellulosic material. The results are set forth below.

Flecks of undispersed gel remaining after:

5 minutes Considerable 2.5 hours none 24 hours none Example 3 Various fatty acid wetting agents were used to prewet cellulosic materials described below, following the procedure outlined in Example 1, above. The amount of each wetting agent, the composition of the cellulosic materials and the results obtained are set forth in Table I, below.

TABLE I Flecks of Undispersed Cellulose Ether After- 5 minutes 2.5 hours 24 hours (:1) Coconut Oil Fatty Acids (5.0 None None"... None.

g.)As wetting agent for: 5.0 g. CMtZ (b) ()leic Acid (5.0 g.)As wetdo .do D0.

ting agent for: 5.0 g. CMC. (c) ()leic Acid (5.0 g.)As wet ting agent for mixture of:

1.25 g. CMIIEC 2 v s A "do (l0 D0. 3.40 g. Methocel t do d0 Do. 1) lcic Acid (5.0 g.)-As Wetting agent for:

1.25 g. CMEC 3 Practically do Do.

none. 3.40 g. Methocel 4 1 CMCsodium cnrboxymethylcellulose (technical grade) having 0.7 mole of carboxymethyl groups per anhydroglucose unit.

2 C M HE (7-s0dium carboxymethylhydroxyethylcellulose.

l CNlEC smlium carboxymethylethylcellulose having 0.1 mole of carboxymethyl groups and 1.0 mole of ethyl groups per anhydroglucose Ulll 4 \lcthylcclluloseMethocel containing 27% methoxyl groups per ccllulosc molecule.

Example 4 The fatty acid wetting process was effectively applied to the following detergent compositions.

Percent Carboxymethylcellulose technical grade, 0.7

degree of substitution 0.25 Methylcellulose (Methoceh 0.68 Coconut oil fatty acids 1.00 Sodium xylenesulfonate 2.17 Dodecylbenzene sulfonic acid 2.04 Sodium tallow methyltaurate 3.61

The condensation product of one mole of lauric monoethanol'amide with one mole of ethylene oxide 1.00 Triethanolamine 1.00 Tetrapotassium pyrophosphate 25.00 Sodium silicate (2.5 ratio) 3.10 Water, potassium hydroxide (to pH 11.8) and miscellaneous impurities 60.15

1 SiOeZ N320.

TABLE II Detergent composition prepared by acid ing cellulosic-fatty acid to following Brookfield viscosity (cps) Spindle N0. 2,

components at room temperature: 6 r.p.n1. 75 F.

(1) Water 520 (2) Water, potassium hydroxide 320 (3) Water, potassium hydroxide dodecylbenzene sulfonic acid (4) Water, potassium hydroxide dodecylbenzene sulfonic acid, sodium xylenesulfonate (5) Control (cellulosics hydrated by hot-watermethod) (6) Water, potassium hydroxide, dodecylbenzene sulfonic acid, sodium xylenesulfonate added to cellulosics wetted with coconut oil fatty acids (reverse of No. 4) 288 In general, the higher the viscosity of the dispersion, the more complete is the hydration of the cellulosic and the more stable is the detergent formulation. Since the maximum viscosity and the most stable formulations are obtained by adding the cellulosic slurry to the water component alone, this is the preferred method. In each case, however, the dispersion prepared by the process of the instant invention had a higher viscosity than that obtained by hydration via the hot-water method.

Example 5 The following anionic and nonionic liquid detergent formulations were prepared by the method of this invention in which the cellulosic material was wetted with the fatty acid wetting agent at room temperature to form a slurry which was then admixed with water to form a dispersion into which the balance of the ingredients were incorporated to provide a smooth uniform lumpfree dispersion.

I. ANIONIC DETERGENT ACTIVES Percent active basis Carboxymethylcellulose CT, 70 low 0.218 Methocel (R) 0.511 Oleic acid 0.753 Water 15.00 Sodium xylene/toluene sulfonate 7.930 Dodecylbenzene sulfonic acid 8.660 Potassium hydroxide 3.100 Laurie isopropanolamide 3.110 Tetrapotassium pyrophosphate 18.580 Sodium silicate (2.5 ratio) 2.520

Water, miscellaneous impurities, potassium hydroxide to pH 12.1 36.948

1 SiOz: M120. 1()() Percent active basis Carboxymethylcellulose CT, 70 low 0.153 Methocel 0.567 Coconut oil fatty acids 1.200 Water 15.000 Sodium xylenesulfonate 8.150 T riethanolamine 1.500 Laurie diethanolamide 4.000 Sodium laurylsulfa-te 8.000 Tetrapotassium pyrophosphate 15.000 Sodium silicate (2.5 ratio) 7.000 Water, miscellaneous impurities, potassium hydroxide to pH 12.0 39.430

1 S102 NaaO. 10 0.000

II. NONIONIC DETERGENT ACTIVES Percent active basis Carboxymethylhydroxyethylcellulose 0.50 Rapeseed fatty acids 1.00 Water 39.68 Sodium alginate (P'rotanol SF, 100 mesh) 1.07 T-riethanolamine 1.00 Dimethyl dodecylamine oxide 10.00 Tetrapotassium pyrophosphate 18.00 Sodium silicate (2.5 ratio) 6.00 Water, miscellaneous impurities 22.75

Potassium hydroxide to pH 10.7 100.00

A liquid detergent composition may be prepared as shown in Example 5(a), above substituting a 1:1 mixture of capric acid and oleic acid for the oleic acid shown therein.

Example 6 A liquid detergent composition is prepared by wetting one part by weight of sodium carboxymethyl cellulose with 0.7 part by weight of ricinoleic acid at a temperature of 70 F. The resulting slurry is then added to 25 parts by weight of water containing 5 parts by weight of the condensate of 1 mole of the ammonium salt of a mixture of sulfated fatty alcohols (myristyl and lauryl in a ratio of 2:1) with 3 moles of ethylene oxide. The product is a smooth uniform lump-free dispersion.

Example 7 Four grams of sodium carboxymethylcellulose were pre-wetted with 4 grams of linoleic acid at room temperature. The resulting slurry was added to grams of water and stirred to provide a homogeneous emulsion which was free of flecks of undispersed gel.

It will be appreciated that various modifications and variations may be made in the process of the present invention without departing from the spirit thereof; accordingly, the process of this invention is to be limited only by the scope of the appended claims.

What is claimed is:

1. In a process for preparing organic detergent formulations containing water and a cellulose ether, the improvement which comprises forming a cellulosic slurry by prewetting the cellulose ethe-r with an effective amount of at least one soap-forming aliphatic monocarboxylic fatty acid having from to 22 carbon atoms, said fatty acid being liquid at room temperature and immiscible and nondispersible in water.

2. A process as described in claim 1 for preparing aqueous detergent compositions wherein the effective amount of the fatty acid is at least about 0.70 part by weight per part of cellulose ether.

3. A process as described in claim 2 wherein the cellulose ether is prewetted with at least about 0.70 part by weight of fatty acid per part of cellulose ether to form a cellulosic slurry, admixing the slurry with from about 16 to about 80 parts of water to form a smooth stable lump-free dispersion.

4. A process as defined in claim 1 wherein the fatty acid is oleic acid.

5. A process as defined in claim 1 wherein the fatty acid is ricinoleic acid.

6. A process as defined in claim 1 wherein the fatty acid is palmitoleic acid.

7. A process as defined in claim 1 wherein the fatty acid is a mixture of fatty acids, said mixture being liquid at about room temperature.

8. A process as defined in claim 7 wherein the mixture of fatty acids consists essentially of capric acid and lauric acid.

9. A process as defined in claim 7 wherein the mixture of fatty acids consists essentially of palmitic acid and myristic acid.

10. A process as defined in claim 7 wherein the mixture of fatty acids consists essentially of capric acid and oleic acid.

11. A process as defined in claim 7 wherein the fatty acid is coconut oil fatty acids.

12. A process as defined in claim 7 wherein the fatty acid is rapeseed fatty acids.

13. A process as defined in claim 7 wherein the fatty acid is a mixture consisting essentially of percent by weight capric acid and 20 percent by weight lauric acid.

14. A process as defined in claim 7 wherein the fatty acid is a mixture consisting essentially of about 80 weight percent capric acid and about 20 weight percent myristic acid.

15. A process as defined in claim 7 wherein the fatty acid is a mixture consisting essentially of about weight percent palmitic acid and about 10 weight percent capric acid.

No references cited.

LEON D. ROSDOL, Primary Examiner.

ALBERT T. MEYERS, Examiner.

W. E. SCHULZ, Assistant Examiner.

Claims (1)

1. IN A PROCESS FOR PREPARING ORGANIC DETERGENT FORMULATIONS CONTAINING WATER AND A CELLULOSE ETHER, THE IMPROVEMENT WHICH COMPRISES FORMING A CELLULOSIC SLURRY BY PREWETTING THE CELLULOSE ETHER WITH AN EFFECTIVE AMOUNT OF AT LEAST ONE SOAP-FORMING ALIPHATIC MONOCARBOXYLIC FATTY ACID HAVING FROM 10 TO 22 CARBON ATOMS, SAID FATTY ACID BEING LIQUID AT ROOM TEMPERATURE AND IMMISCIBLE AND NONDISPERSIBLE IN WATER.