CN1230978A - Detergent component or composition with protective coating - Google Patents

Abstract

The present invention relates to the application of certain coatings to particulate detergent components or compositions to improve free-flowing properties, improve dispensing and avoid powder formation. This is achieved by a two-step coating process wherein the first coating step comprises a process of mixing the detergent composition or component with a finely divided particulate material, preferably aluminosilicate, and the second coating step comprises a process of applying a coating agent. Suitable coating agents contain from 5% to 95% by weight of a cellulose polymer, from 5% to 95% by weight of a sugar and optionally from 0% to 30% by weight of a plasticizer.

Description

Detergent component or composition with protective coating

The present invention relates to the field of coated granular detergent ingredients or compositions.

It is known that the flow properties of granular detergents can be improved by "dusting" with finely divided particles, such as zeolites. US-A-3868336 discloses powdering detergent compositions with 0.5% to 15% by weight of water-insoluble flow promoters. However, pulverization with finely divided particles does not provide any effect on detergent dispersion, it also pulverizes the final detergent product and does not always provide sufficient improvement in flow properties.

Known film-coating agents used as liquids, melts or solutions are also known in the field of detergents, and GB-A-1395006 disclosed on May 21, 1975 discloses the use of film-coating agents for detergent components. Cellulose polymers, where sucrose and glucose are also disclosed as plasticizers together with dextrins. However, the use of cellulosic polymers and sugars in combination as film coating agents for detergent ingredients has not been disclosed so far.

The advantage of coating the detergent with the cellulosic polymer itself is that the film formed dries slowly and can form a tacky coating.

Mixtures of cellulosic polymers and sugars are known film coating agents in the pharmaceutical field. JP-51123815 published on October 29, 1976 and EP-A-0551700 published on July 21, 1993 all disclose the combination of cellulose polymer and sugar as a coating agent for pharmaceutical products, but do not suggest that these coatings Layers apply to detergent.

The object of the present invention relates to the application of certain coatings to granular detergent ingredients or compositions to improve free flow, improve dispersibility, avoid dust formation and improve stability of storage sensitive substances.

It is another object of the present invention to provide fast drying coatings which form a continuous film around detergent ingredients or composition particles.

Summary of the invention

The object of the present invention is achieved by a two-step coating process, wherein the first coating step comprises the process of mixing the detergent composition or components with finely divided particulate matter, preferably an aluminosilicate, and the second The coating step includes a process of applying a film coating agent. Suitable film coating agents contain 5%-95% by weight, preferably 10%-60% of cellulosic polymer; 5%-95% by weight, preferably 60%-90% of sugar and optionally 0-30% plasticizer.

Preferred detergent ingredients include nonionic surfactants, especially polyhydroxy fatty acid amides and bleach activators.

Detailed description of the invention

The term "cellulosic polymer" as used herein means a polymer composed of cellulose derivatives. Cellulose is a polysaccharide made from beta-D-glucose units linked together. In the derivatives one or more hydroxyl groups are substituted by other groups such as methyl, ethyl, propyl.

Preferred cellulosic polymers include methylcellulose, ethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, methylhydroxymethylcellulose, methylhydroxyethylcellulose , methyl hydroxypropyl cellulose and ethyl hydroxyethyl cellulose.

The term "sugar" as used herein is a generic term for the class of carbohydrates, which are generally crystalline and sweet, and which are water soluble. Sugars are derived from sucrose and fructose units which are sugars themselves. Preferred sugars include glucose, fructose, galactose, sucrose, maltose, lactose, sorbitol, mannitol, raffinose, trehalose.

The term "plasticizer" as used herein is a substance added to the original mass to soften the initial mass, and to make it more pliable. Preferred plasticizers include polyethylene glycol, polypropylene glycol, glycerin, triacetin with a molecular weight of 200-20,000.

The second film coating agent can be applied by any conventional coating device. Suitable apparatus include pan coaters, drum continuous coaters, spray fluidized granulators or spray fluidized continuous belts. In a specific embodiment of the present invention, the components of the second coating agent are dissolved or dispersed in a suitable solvent or carrier medium. The preferred solvent is water, and aqueous solutions generally containing 5% to 40% solids can be prepared.

The solution or dispersion can then be sprayed onto the detergent component or composition. The proportion of secondary film-coating agent required to provide a suitable coating depends on various parameters, such as the surface characteristics of the detergent component or composition, and can readily be determined experimentally. The second coating agent is preferably 0.1%-30% of the final product, more preferably 1%-5%, most preferably about 2%.

In the present invention, the detergent component or composition is coated with finely divided particulate material prior to coating with the second coating agent.

The detergent component or composition is coated with a first coat comprising up to 35%, preferably 1% to 20%, by weight of finely divided particulate material prior to application of the second coat. The first film coating agent has two purposes. First it separates the detergent particles (if they are sticky) so that they are fully coated with each other. Second, it is mixed into a second film coat to add additional structure to the coating.

Finely divided particles useful in the present invention include aluminosilicates having the following empirical formula:

M _z (zAlO ₂ )y]·xH ₂ O wherein z and y are integers of at least 6, the molar ratio of z to y is from 1.0 to about 0.5, and x is an integer from about 15 to about 264.

Useful aluminosilicate ion exchange materials are commercially available. These aluminosilicates may be crystalline or amorphous in structure and may be naturally occurring aluminosilicates or synthetically derived. A method of preparing aluminosilicate ion exchange materials is disclosed in US-A-3,985,669, Krummel et al., issued October 12,1976. Preferred synthetic crystalline aluminosilicate ion exchange materials for use in the present invention are available under the designations Zeolite A, Zeolite P(B), Zeolite MAP, Zeolite X and Zeolite Y. In an especially preferred embodiment, the crystalline aluminosilicate ion exchange material has the formula:

Na ₁₂ [(AlO ₂ ) ₁₂ (SiO ₂ ) ₁₂ ]·xH ₂ O wherein x is about 20 to about 30, especially about 27. This material is called Zeolite A. Dehydrated zeolites (x = 0-10) and "overdried" zeolites (x = 10-20) are also suitable for use in the present invention. "Overdry" zeolites are especially useful when a low moisture environment is desired, for example to improve the stability of detergent bleaches such as perborates and percarbonates. The aluminosilicate preferably has a particle size of about 0.1-10 microns in diameter. Preferred ion exchange materials have a particle size diameter of from about 0.2 microns to about 4 microns. The term "particle size diameter" in the present invention means the average particle size diameter by weight of a given ion exchange material, as determined by conventional analytical techniques such as microscopic determination using a scanning electron microscope. The crystalline zeolite A materials of the present invention are generally further characterized on a dry basis by having a calcium ion exchange capacity of at least about 200 meq calcium carbonate water hardness per gram of aluminosilicate, typically from about 300 meq/g to about 352 meq/g. The zeolite A materials of the present invention are further characterized by having a calcium ion exchange rate of at least about 2 grains Ca++/gallon/minute/gram/gallon (0.13 gCa++/liter/minute/gram/liter) silicon based on calcium ion hardness. Aluminate (dry basis), typically about 2 grains/gallon/minute/gram/gallon (0.13gCa++/liter/minute/gram/liter) to about 6 grains/gallon/minute/gram/gallon (0.39gCa++ /l/min/g/l). Optimum aluminosilicates for use in builders exhibit calcium ion exchange rates of at least about 4 grains/gallon/minute/gram/gallon (0.26 gCa++/liter/minute/gram/liter).

Other finely divided particulate materials include talc, silica and bentonite and other clays.

Granular detergent component or composition

Detergent ingredients or compositions are usually processed into granular form by one of a variety of methods. Spray drying is a method that has been widely used for decades. Dry neutralization, agglomeration, extrusion, granulation in a fluidized bed, flaking, encapsulation, granulation, pastilles and other methods have also become available in recent years.

Detergent compositions and components typically contain surfactants, builders, chelating agents, bleaches, bleach activators, enzymes, enzyme stabilizers, soil release agents, brighteners, suds suppressors, fabric softeners, anti Redeposition agents and mixtures thereof. The invention is especially suitable for use with nonionic or cationic surfactants, or with bleach activators.

Preferred nonionic surfactants for use in the present invention include two families of nonionic surfactants which have been found to be especially useful. These are nonionic surfactants based on alkoxylated (especially ethoxylated) alcohols and nonionic surfactants based on amidation products of fatty acid esters and N-alkylpolyhydroxylamines. The amidation products of esters and amines are generally referred to herein as polyhydroxy fatty acid amides. Particularly suitable for use herein are mixtures comprising two or more nonionic surfactants, at least one of which is selected from the group consisting of alkoxylated alcohols and polyhydroxy fatty acid amides.

Suitable nonionic surfactants include compounds prepared by condensation of alkylene oxide groups (hydrophilic) with organic hydrophobic compounds which are aliphatic or alkylaromatic in nature. The length of the polyoxyalkylene group condensed with any particular hydrophobic group can be readily adjusted to obtain a water-soluble compound having the desired balance of hydrophilic and hydrophobic moieties.

Especially preferred in the present invention are nonionic surfactants such as polyethylene oxide condensates of alkylphenols, such as alkylphenols having an alkyl group of about 6 to 16 carbon atoms in a linear or branched configuration Condensation product with about 4-25 moles of ethylene oxide per mole of alkylphenol.

Preferred nonionic surfactants are water-soluble condensation products of aliphatic alcohols containing from 8 to 22 carbon atoms in a linear or branched configuration with an average of up to 25 moles of ethylene oxide per mole of alcohol. Especially preferred are the condensation products of alcohols having alkyl groups containing about 9-15 carbon atoms with about 2-10 moles of ethylene oxide per mole of alcohol; and the condensation products of propylene glycol with ethylene oxide. Most preferred are the condensation products of alcohols having alkyl groups containing about 12-15 carbon atoms with an average of about 3 moles of ethylene oxide per mole of alcohol.

In an especially preferred embodiment of the present invention, the nonionic surfactant system further comprises a polyhydroxy fatty acid amide component.

Polyhydroxy fatty acid amides are prepared by reacting fatty acid esters with N-alkyl polyhydroxy amines. Preferred amines for use in the present invention are N-(R ₁ )CH ₂ (CH ₂ OH) ₄ -CH ₂ -OH, where R ₁ is typically an alkyl group such as methyl; preferred esters are C ₁₂ -C ₂₀ fatty acid methyl esters.

A process for the preparation of polyhydroxy fatty acid amides is described in WO926073, published April 16,1992. This application describes a process for the preparation of polyhydroxy fatty acid amides in the presence of solvents. In a highly preferred embodiment of the invention, N-methylglucamine is reacted with a C ₁₂ -C ₂₀ methyl ester.

Other nonionic surfactants useful as components of the surfactant system of the present invention include ethoxylated nonionic surfactants, glyceryl ethers, glucamides, glyceramides, glycerides, fatty acids, fatty acid esters, fatty acids amides, alkyl polyglucosides, alkyl polyglycol ethers, polyethylene glycols, ethoxylated alkylphenols and mixtures thereof.

The present invention is especially applicable to bleach activators. The inclusion of many bleach activators should be avoided for hygienic reasons and therefore dusty products should be avoided. The present invention provides a means of reducing or eliminating dust formation by providing an effective coating.

Particularly suitable ^bleach activators are hexanoyloxybenzenesulfonate, N,N, ^N1N1 tetraacetylated compounds, benzoyloxybenzenesulfonate, benzoylcaprolactam and mixtures thereof. The most suitable bleach activators are (6-octanoylamino-caproyl)oxybenzenesulfonate, (6-nonanoylamino-caproyl)oxybenzenesulfonate, (6-decanoylamino-caproyl)hydroxybenzenesulfonate, Besylate and their mixtures.

Example 1

% by weight

Polyhydroxy fatty acid amides 49

Nonionic Surfactant (AE5) 22

Hydrogenated Fatty Acids 17

The first coating agent - zeolite A 10

Second coating agent 2

A molten mixture of nonionic surfactant polyhydroxy fatty acid amide, ethoxylated alcohol and hydrogenated fatty acid is prepared. Micro-tablets of the molten mixture are then prepared by forming droplets of the molten material on a chilled steel belt and thereby solidifying. Equipment for carrying out the microtabletization process is commercially available from Sandvik.

The microtablets were then coated first with zeolite (10% by weight) and subsequently with a film-coating agent which was an aqueous solution with a solids content of 15% comprising hydroxypropylmethylcellulose (35 parts ), lactose (45 parts) and triacetin (20 parts).

The first application of the zeolite is done in the concrete mixer to ensure good distribution of the flow aid. The second film coating agent is applied by spraying the aqueous film coating agent in a spray fluidized bed granulator. The aqueous film coating agent is sprayed on the particles, and the excess water is dried with hot air. Example 2

% by weight

NACA-OBS 68

Citric acid 10

Anionic Surfactant (AE3S) 5

Maleic acid-acrylic acid copolymer 5

water 2

The first coating agent - zeolite A 5

The second coating agent 5NACA-OBS is (nonanoylamino-caproyl)oxybenzenesulfonate, which is a bleach activator. AE3S is an alkyl ether sulfate (contains 3EO groups per molecule).

A detergent component containing bleach activator, citric acid, anionic surfactant, copolymer and water is prepared by mixing dry matter and binder and passing the mixture through an extruder to form a bar. These strips were fed into a ball forming machine (Marumeriser(R), equipped with a rotating drum with friction plates) and formed into pellets of the desired size.

The pellets were then coated first with zeolite (5% by weight) and subsequently with a second coating agent which was a 15% solids aqueous solution comprising hydroxypropylmethylcellulose (35 Parts), lactose (45 parts) and triacetin (20 parts), the coating agent was applied in a spray fluidized bed granulator. Example 3

% by weight

Polyhydroxy fatty acid amides 6

Nonionic Surfactant (AE5) 18

Hydrogenated Fatty Acids 3

Glyceryl tristearate 1

Zeolite A 56

Carbonate 6

The first coating agent - zeolite A 5

Second coating agent 5

A melt mixture consisting of nonionic surfactant polyhydroxy fatty acid amide, ethoxylated alcohol, hydrogenated fatty acid, and glyceryl tristearate was prepared. The slurry was cooled and agglomerated with zeolite and carbonate in CBLoedige(R). The final agglomerates were dusted in a KM Loedige(R) with additional zeolite.

The agglomerates were then coated with a second film-coating agent, which was a 40% aqueous solution of solids consisting of hydroxypropylmethylcellulose (10 parts), lactose (45 parts) and sucrose (45 parts ).

The second film coating agent is added by spraying the aqueous film coating agent in a spray fluidized bed granulator. The aqueous film coating agent is sprayed on the particles, and the excess water is dried with hot air.

Claims (9)

1. A granular detergent composition or component, the detergent composition or component is applied by a two-step coating process, wherein the first coating step comprises mixing the detergent composition or component with finely divided particulate matter The process of mixing is characterized in that the second coating step comprises the process of applying film coating agent, and film coating agent contains: (i) 5% to 95% by weight of cellulosic polymer; (ii) 5%-95% by weight sugar. 2. A granular detergent composition or component according to claim 1, wherein the coating agent used in the second coating step comprises: (i) 10%-60% by weight cellulosic polymer; (ii) 60%-90% sugar by weight; and (iii) Optionally 0% to 30% by weight of plasticizer. 3. A granular detergent composition or component according to claim 1 wherein the finely divided particulate material is an aluminosilicate. 4. The detergent composition or component according to claim 1, wherein the coating agent contains a cellulosic polymer selected from the group consisting of methyl cellulose, ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, Hydroxypropylcellulose, methylhydroxymethylcellulose, methylhydroxyethylcellulose, methylhydroxypropylcellulose, ethylhydroxyethylcellulose, or mixtures thereof. 5. The detergent composition or component according to claim 1, wherein the coating agent contains sugar selected from the group consisting of sucrose, glucose, lactose, fructose, dextrin, cellulose, sorbitol, raffinose, trehalose or their mixture. 6. The detergent composition or component according to claim 1, wherein the coating agent contains at least 1% by weight of a plasticizer selected from polyethylene glycol, polypropylene glycol, glucose, Triacetin or a mixture thereof. 7. A detergent composition or component according to any one of claims 1-6, wherein the detergent component or composition comprises a nonionic surfactant. 8. A detergent composition or component according to claim 7, wherein the nonionic surfactant comprises a polyhydroxy fatty acid amide. 9. A detergent composition or component according to any one of claims 1-6, wherein the detergent component or composition contains a bleach activator selected from the group consisting of hexanoyloxybenzenesulfonate, N,N, ^N1 N ^1tetraacetyl compound, (6-octanoylamino-caproyl)oxybenzenesulfonate, (6-nonanoylamino-caproyl)oxybenzenesulfonate, (6-decanoylamino-caproyl)hydroxybenzenesulfonate Besylate, benzoyl caprolactam and mixtures thereof.