EP0034194B1 - Process for the manufacture of easily dispensable granules for washing and cleaning purposes which contain non-ionic surface-active agents - Google Patents

Abstract

1. A process for the production of a pourable granular washing and cleaning agent containing non-ionic surfactants from the class of polyalkylene glycol ether derivatives by adding the non-ionic surfactant to a powder-form to granular constituent of the washing and cleaning agent and subsequently combining the premix thus obtained with the remaining constituents of the washing and cleaning agent, characterized in that the non-ionic surfactant used is a compound corresponding to the following general formula R-O-[C2 H3 (CH3 )-O]m -(C2 H4 O)n -H in which R is an aliphatic C8 -C20 -hydrocarbon radical, m is a number of from 0.5 to 8 and n is a number of from 2 to 20 with the proviso that n is equal to or greater than m.

Description

In the manufacture of detergents and cleaning agents containing nonionic surfactants, the procedure is often such that these surfactants are applied in liquid or molten form to a powdery component of the agent, e.g. Tripolyphosphate, perborate or a silicate with a large absorbent surface, sprayed on or mixed on. The prepowder thus applied is then combined with the other powder components. Such processes are described, for example, in US Pat. No. 3,769,222, DE-A 25 35 792 and DE-A 27 17 281. The procedure has the advantage over hot spray drying of non-ionic detergent-containing detergent slurries in that there are no evaporation losses of volatile nonionic surfactants and dust removal chambers or the exhaust air are not contaminated by the evaporated components.

Since the nonionic surfactants commonly used in detergents solidify at temperatures below 25-30 ° C, however, considerable difficulties can arise in the mixing and granulating process if the powder to be charged has a temperature of less than 20 ° C, for example from 0 to 10 ° C. This is usually the case in the cold season when the powder is taken from a usually unheated wagon or silo. The nonionic surfactant then solidifies into solid, fat-like agglomerates and can no longer be distributed homogeneously in the powder. However, since it is relatively cumbersome and expensive in the industrial area to heat larger amounts of powder uniformly, one is forced to use nonionic surfactants or surfactant mixtures which are still liquid or at least sufficiently pasty at the low temperatures so that they are still homogeneous distribute, cf. see DE-C 24 18 294. However, the choice of surfactants is considerably restricted, i.e. it can no longer be carried out from the point of view of optimal cleaning and dirt-carrying capacity. In particular, the highly washable, readily water-soluble, higher ethoxylated compounds can no longer be used in these cases. Rather, one relies on the use of low-melting coconut fatty alcohol ethoxylates with a low degree of ethoxylation, but which have a strong intrinsic odor, which is perceived by some consumers as unpleasant.

in der R einen aliphatischen Kohlenwasserstoffrest mit 8 bis 20 Kohlenstoffatomen, m eine Zahl von 0,5 bis 8 und n eine Zahl von 2 bis 20 bedeuten, mit der Maßgabe, daß n gleich oder größer als m ist.A method has now been found which avoids the disadvantages shown. The invention relates to a process for the production of a pourable, nonionic surfactant from the class of detergent and cleaning agent granules containing polyalkylene glycol ether derivatives by admixing the nonionic surfactant to a powdery to granular component of the detergent and cleaning agent and then combining the premix obtained in this way with the other constituents of the detergent and cleaning agent, characterized in that a compound of the general formula I is used as the nonionic surfactant

in which R is an aliphatic hydrocarbon radical having 8 to 20 carbon atoms, m is a number from 0.5 to 8 and n is a number from 2 to 20, with the proviso that n is equal to or greater than m.

Compounds of the formula (I) are preferably used in which R is a primary alkyl or alkenyl radical having 12 to 18 carbon atoms and in which m is a number from 1 to 5 and n is a number from 3 to 15 with the proviso that that n is 2 to 10 times m.

Nonionic surfactants of the formula (I) are known and are obtained, for example, according to US Pat. No. 2,174,761 by reacting alcohols with propylene oxide and then with ethylene oxide.

mit x = 0,9-13, y = 1,3-4 und z = 1-6. Geeignet sind weiterhin kieselsäurehaltige Mittel bzw. kolloidale Tone, wie oberflächenaktive Kieselsäure (Aeroslie), Magnesiumsilikat, Bentonite und Smektit-Tone, allerdings sind derartige Stoffe aus waschtechnischer Sicht weniger interessant, da sie im Gegensatz zu den Buildersalzen lediglich als Adsorptionsmittel wirken und keinen Beitrag zur Wasch- und Reinigungswirkung leisten. Auch Gemische verschiedener pulverförmiger oder körniger Materialien können für den genannten Zweck verwendet werden.The process can be carried out by powdering any mixture. shaped detergent ingredients, optionally after prior granulation or spray drying, mixed with the nonionic surfactants of the formula (I) and granulated at the same time, uniform mixing being facilitated by spraying the surfactant in the form of a fine spray. However, a certain powder constituent of the detergent is preferably treated in the manner according to the invention and this surfactant-containing premix is then combined with the other powder constituents. For this purpose, for example, the so-called builder salts are suitable, which include the condensed phosphates, alkali silicates, alkali carbonates, alkali borates and alkali sulfates. Also suitable are water-insoluble builder salts, in particular ion-exchanging sodium aluminum silicates of the formula

with x = 0.9-13, y = 1.3-4 and z = 1-6. Silica-containing agents or colloidal clays, such as surface-active silica (aerosil), magnesium silicate, bentonites and smectite clays, are also suitable, but such substances are less interesting from a washing point of view since, in contrast to the builder salts, they only act as adsorbents and make no contribution to Perform washing and cleaning effects. Mixtures of various powdery or granular materials can also be used for the purpose mentioned.

The use of powdered or granular sodium perborate tetrahydrate as the starting material for the premix has proven particularly expedient. This saves an additional mixing process because the perborate, due to its thermal sensitivity, is usually not spray-dried together with the other detergent components, but is only subsequently mixed into the spray product. The particular suitability of sodium perborate is surprising since conventional technical perborates are generally crystalline and not porous and therefore only have a relatively low absorption capacity for liquid or pasty substances.

In the mixing or granulation process, stable agglomerates are formed between the nonionic surfactant and the powder particles, or the surfactant forms a more or less closed coating on the particles. Assuming sodium perborate as the powder base, the amount of the nonionic agent should be 5 to 20 percent by weight, preferably 7 to 15 percent by weight of the premix. If builder salts are used as the base powder, the amount of the nonionic surfactant to be applied can be within the same limits. If the builder salts are in voluminous or spray-dried form, for example when using sodium aluminum silicates or voluminous tripolyphosphates as the base powder, the proportion of nonionic surfactant can be increased to 35 percent by weight, based on the premix containing surfactant.

The agglomerates or the coatings can be produced in such a way that the melted nonionic surfactant, heated to temperatures above 30 ° C., preferably 50 ° to 70 ° C., is intimately mixed with the base powder to be charged. The base powder to be used can have a temperature of 0 ° to 30 ° C. Additional heating of the powder before or during the mixing process is not necessary. Rather, even when using a relatively cold powder, a homogeneous distribution without dust formation is guaranteed.

Mixing can be carried out continuously or in batches using conventional mixing, granulating or spraying devices. Suitable are e.g. Drum, cascade, plow shovel or other mixers working according to the compulsory mixing method as well as arrangements in which the liquid melt is continuously sprayed onto a free-falling powder or a thin layer spread on a conveyor belt. After spraying, granulation may follow.

The grain size and liter weight of the base powder used can vary within wide limits. However, the proportion of coarse-grained particles with a grain size of more than 2 mm should expediently be less than 10 percent by weight and preferably less than 2 percent by weight. The fine fraction with a grain size of less than 0.1 mm is preferably less than 25% by weight and in particular less than 10% by weight. The average grain size is advantageously 0.1 to 0.8 mm.

The treatment with the liquid surfactant generally leads to an increase in grain size, the fine particles with a grain size of less than 0.2 mm being largely or completely cemented into larger particles. The proportion of particles with a grain size of 1 to 3 mm increases only slightly. If necessary, coarser particles can be sieved out, crushed and then reused. The average grain size of the perborate or builder salt treated with nonionic surfactant is 0.4 to 1.0 mm and is thus of the order of magnitude of a detergent and cleaning agent powder obtained by spray drying or granulation. This is a particular advantage, since it counteracts undesired segregation processes during the transport or storage of the detergents.

If necessary, further additives, such as dyes, pigments or fragrances, can be applied to the base powder together with the nonionic compound. The use of colored additives enables the powder mixture to be spotted in a visually appealing and marking manner.

The powder charged with the nonionic surfactant of the formula (I) is mixed with the other, preferably spray-dried powder components using customary mixing devices, the weight ratio of the powder applied to the other powder components being 1:10 to 1: 3 and the content of the composite washing and detergent on the surfactant of formula (I) is 1 and 10 percent by weight. In the case of textile detergents, this second component contains at least one anionic, nonionic or zwitterionic surfactant as well as at least one framework substance which has a complexing action or binds the lime hardness of the water and optionally further washing aids.

Suitable anionic surfactants are those of the sulfonate or sulfate type, in particular alkylbenzenesulfonates, olefin sulfonates, alkyl sulfonates and α-sulfofatty acid esters, primary alkyl sulfates and the sulfates of ethoxylated, 2 to 3 glycol ether groups having higher molecular weight alcohols. Also suitable are alkali soaps of fatty acids of natural or synthetic origin, for example the sodium soaps of coconut, Paimkern- or tallow fatty acids and, if foam suppression is desired, also those of hydrogenated rapeseed or fish oil fatty acids. Alkyl betaines and especially alkyl sulfobetaines are suitable as zwitterionic surfactants. The anionic surfactants are preferably in the form of the sodium salts. If the anionic and zwitterionic compounds mentioned have an aliphatic hydrocarbon radical, this should preferably be straight-chain and have 8 to 22, preferably 12 to 18, carbon atoms. In the compounds having an araliphatic hydrocarbon radical, the preferably unbranched alkyl chains contain 6 to 16, in particular 10 to 14, carbon atoms.

In a preferred embodiment, the spray-dried detergents contain at least one nonionic surfactant which differs from the compound of the formula I. These are ethoxylated alcohols, vicinal diols and alkylphenols of the structure indicated with an average of 3 to 20, preferably 5 to 15, glycol ether groups. Mixtures of ethoxylated, primary C ₁₄ -C ₁ g alcohols, such as tallow fatty alcohol or oleyl alcohol, of which a part thereof has 10 to 16 glycol ether groups and a second part has 3 to 7 glycol ether groups. The quantitative ratio of the two parts can preferably be 4: 1 to 1: 4.

If the surfactant of the formula applied to the perborate or builder salt does not contain more than 6-8 ethylene glycol ether groups at a content of 1 to 4 propylene glycol groups, water-soluble, higher ethoxyated C ₁₄ -C ₁₈ alcohols with 10 to 16 ethylene glycol ether groups are preferably used in the spray powder. In these cases, the weight ratio of the low-ethoxylated surfactants of the formula I applied to the perborate or builder salt to the higher-ethoxylated surfactants contained in the spray powder is advantageously 3: 1 to 1: 4, preferably 1: 1 to 1: 3.

Further suitable nonionic surfactants are those which are derived from the abovementioned compounds and have both ethylene glycol and propylene glycol ether groups, for example alcohols with 10 to 30 ethylene glycol ether groups and 3 to 30 propylene glycol ether groups; also ethoxylation products of mercaptans, fatty acid amides and fatty acids. The water-soluble polyethylene oxide adducts containing 20 to 250 ethylene glycol ether groups and 10 to 100 propylene glycol ether groups with polypropylene glycol, ethylene diaminopolypropylene glycol and alkyl polypropylene glycol with 1 to 10 carbon atoms in the alkyl chain can also be used. The compounds mentioned usually contain 1 to 5 ethylene glycol units per propylene glycol unit. Nonionic compounds of the amine oxide and sulfoxide type, which can optionally also be ethoxylated, can also be used.

Suitable builders are the polymer phosphates, carbonates and silicates of potassium and in particular sodium, the latter having a ratio of Si0 ₂ to Na ₂ 0 of 1: 1 to 3.5: 1. In particular, the pentasodium triphosphate is suitable as the polymer phosphate, which may be present in a mixture with its hydrolysis products, the mono- and diphosphates, and also more highly condensed phosphates, for example the tetraphosphates.

The polymer phosphates can also be completely or partially replaced by organic, complexing aminopolycarboxylic acids. These include in particular alkali salts of nitrilotriacetic acid and ethylenediaminotetraacetic acid. The salts of diethylenetriamineopentaacetic acid and the higher homologues of the aminopolycarboxylic acids mentioned are also suitable. These homologs can be prepared, for example, by polymerization of an ester, amide or nitrile of N-acetic acid aziridine and subsequent saponification to give carboxylic acid salts or by reacting polyethylenimine with chloroacetic acid or bromoacetic acid salts in an alkaline medium. Other suitable aminopolycarboxylic acids are poly (N-succinic acid) ethylene imine, poly (N-tricarballylic acid) ethylene imine and poly (N-butane-2,3,4-tricarboxylic acid) ethylene imine, which are obtainable analogously to the N-acetic acid derivatives .

Furthermore, complexing polyphosphonic acid salts may be present, e.g. the alkali salts of aminopolyphosphonic acids, in particular aminotri- (methylenephosphonic acid), 1-hydroxyethane-1,1-diphosphonic acid, methylenediphosphonic acid, ethylenediphosphonic acid and salts of the higher homologues of the polyphosphonic acids mentioned. Mixtures of the aforementioned complexing agents can also be used.

Of particular importance are the nitrogen-free and phosphorus-free polycarboxylic acids which form complex salts with calcium ions, including polymers containing carboxyl groups. Citric acid, tartaric acid, benzene hexacarboxylic acid and tetrahydrofuran tetracarboxylic acid are suitable. Polycarboxylic acids containing carboxymethyl ether groups can also be used, such as 2,2'-oxydisuccinic acid and polyhydric alcohols partially or completely etherified with glycolic acid or hydroxycarboxylic acids, for example triscarboxymethylglycerol, biscarboxymethylglyceric acid and carboxymethylated or oxidized polysaccharides. Also suitable are the polymeric carboxylic acids with a molecular weight of at least 350 in the form of the water-soluble sodium or potassium salts, such as polyacrylic acid, polymethacrylic acid, poly-a-hydroxyacrylic acid, polymaleic acid, polyitaconic acid, polymesaconic acid, polybutene tricarboxylic acid and the copolymers of the corresponding monomeric carboxylic acids with one another or with ethylene unsaturated compounds such as ethylene, propylene, isobutylene, vinyl methyl ether or furan.

Water-insoluble complexing agents can also be used. These include phosphorylated cellulose and graft polymers of acrylic acid or methacrylic acid on cellulose, which can be in the form of a woven fabric, non-woven fabric or powder. Furthermore, there are spatially crosslinked and thereby water-insoluble copolymers of acrylic, methacrylic, crotonic and maleic acids and others polymerizable polycarboxylic acids, if appropriate with other ethylenically unsaturated compounds in the form of the sodium or potassium salts, are suitable as sequestering agents. These insoluble copolymers can be in the form of nonwovens, sponges or in the form of finely ground, specifically light foams with an open-cell structure. Inorganic water-insoluble cation exchangers, for example zeolites and in particular water-containing aluminum silicates of the formula (Na20), can also be used. Al ₂ O ₃ . (SiO ₂ ) _y . (H ₂ O) _z with x = 0.9-13, y = 1.3-4.0 and z = 1 to 6.

Neutral salts, in particular sodium sulfate, and magnesium silicate, which acts as a stabilizer for per compounds, can be considered as further constituents. Further washing aids which may be present in the spray-dried powder component are graying inhibitors and optical brighteners and additives which improve the powder structure. e.g. Alkali salts of toluene, cumene or xylene sulfonic acid.

Suitable graying inhibitors are in particular carboxymethyl cellulose, methyl cellulose, furthermore water-soluble polyesters and polyamides from polyvalent carboxylic acids and glycols or diamines, which have free carboxyl groups, betain groups or sulfobetaine groups capable of salt formation, and polymers or copolymers of vinyl alcohol, vinyl amide pyrrolidones which are soluble in water in a colloidal manner and acrylonitrile.

Suitable optical brighteners are the alkali salts of 4,4-bis (-2 "-anilino-4" -morpholino-1,3,5-triazinyl-6 "-amino) -stilbene-2,2'-disulfonic acid or compounds of the same structure which carry a diethanolamino group, a methylamino group or a .beta.-methoxyethylamino group instead of the morpholino group. A ^2- pyrazoline and compounds of the same structure which carry a carboxymethyl or acetylamino group instead of the sulfonamido group It is also possible to use substituted aminocoumarins, for example 4-methyl-7-dimethylamino or 4-methyl-7-diethylaminocoumarin the compounds 1- (2-benzimidazolyl) -2- (1-hydroxyethyl-2-benzimidazolyl) ethylene and 1-ethyl-3-phenyl-7-diethylamino-carbostyril can be used. The brighteners for polyester and polyamide fibers are the compounds 2 , 5-di- (2-benzoxaz olyl) thiophene, 2- (2-benzoxazolyl) naphtho [2,3-b] thiophene and 1,2-di- (5-methyl-2-benzoxazolyl) ethylene are suitable. Brighteners of the substituted diphenylstyrile type may also be present. Mixtures of the aforementioned brighteners can also be used.

In addition to the two powder components, there may be other powder components that are not suitable for joint processing with the perborate and not for hot spray drying. These include bleach activators, especially tetraacetylglycoluril or tetraacetylethylenediamine. The powder particles consisting of the bleach activators can be coated with coating substances, in particular mixtures of water-soluble polymers and fatty acids or fatty alcohols, in order to avoid an interaction between the per compound and the activator during storage. Other additives that are added to the powder separately are enzymes from the class of proteases, lipases and amylases or mixtures thereof. Enzymes obtained from bacterial strains or fungi such as Bacillus subtilis, Bacillus licheniformis and Streptomyces griseus are particularly suitable. The enzymes can be embedded in coating substances or subsequently granulated onto the spray-dried powder component. Fragrances and certain fat-like foam suppressants, such as trialkyl melamines or paraffin hydrocarbons, are also preferably sprayed onto the spray-dried powder subsequently.

It is to be regarded as a particular advantage of the method according to the invention that a flawless mixing result is achieved with comparatively little expenditure of energy and time. The granules produced by the process according to the invention are free of dust and lumps, homogeneous and free-flowing and free-flowing, these advantageous properties also being achieved when the base powder used has temperatures of less than 10 ° C. due to appropriate storage conditions. In contrast to such granules, which are produced using low-melting coconut fatty alcohol ethoxylates with a low degree of ethoxylation, they are characterized by a substantial lack of odor, which is welcomed by the consumer. In addition, the nonionic surfactants to be used according to the invention tend to form little undesirable foam compared to low-ethoxylated coconut fatty alcohols, which is why the process products can advantageously be used in automatic washing machines and dishwashers. When used, they are characterized by a high cleaning and fat dissolving power.

example 1

The sieve analysis of the sodium perborate tetrahydrate to be charged showed the following distribution

90 kg of the perborate were in a drum mixer with fast rotating mixing elements (so-called LÖDIGE mixer). The temperature of the perborate taken from a silo was 10 ° C. 10 kg of a tallow fatty alcohol reacted first with 1.2 mol of propylene oxide and then with 6.3 mol of ethylene oxide were introduced into the rotating mixer. The temperature of the melted nonionic surfactant was 60 ° C. The mixing process was complete after 2.5 minutes and the granules obtained were tested for homogeneity, freedom from dust and free-flowing properties. Mixtures were made in the same manner for comparison, using other common nonionic surfactants. The results can be found in Table I. The abbreviations ÄO and PrO stand for ethylene oxide and propylene oxide, V for comparative experiment.

The dust test was carried out as follows. A round polyethylene film (diameter 45 cm) is spread out on a clean foam rubber mat (dimensions 50 x 50 cm, thickness approx. 1 cm). A cylindrical receptacle with a diameter of 18 cm and a height of 10 cm is placed in the middle of the film. A sheet metal cylinder of 40 cm in diameter and 70 cm in height which is closed on one side is placed with the opening facing downwards in such a way that the distance between the cylinder wall and the edge of the collecting vessel is the same everywhere. This cylinder has a round hole of approx.3.5 cm in diameter in the middle of the closed side, into which a funnel with a 19 cm long tube of 2.5 cm inside diameter is inserted. 100 g of the product to be examined is trickled into the funnel or the cylinder via a shaking channel. The product falls into the container on the bottom of the film. The dust content of the product, however, is released from the product flow in the free fall and is swirled in the air inside the large cylinder.

After the 100 g of product have been added, wait 1 minute. During this time, the dust is deposited on the film on the floor. The cylinder and the receptacle are then carefully removed and the film is carefully folded up and the amount of dust deposited on it is determined by weighing. According to this method, the laterally deposited, i.e. the amount of dust not remaining in the product is recorded. It corresponds approximately to the loss of dust.

Screening analyzes were also carried out on individual process products. The results are shown in Table 11.

The results show that the product produced in accordance with the invention is a narrow and therefore inexpensive. permanent grain spectrum and is free of coarse and fine particles as well as dust-like particles.

The granules were combined in a free-fall mixer with a hollow spherical powder obtained by hot spray drying to give detergents of the following composition (data in% by weight):

Detergent samples were filled into 200 g folding boxes and subjected to a shaking test for 2 hours. The detergent and perborate grains did not separate.

Example 2

As described in Example 1, 450 kg of sodium perborate, which had been taken from an unheated silo and had a temperature of 4 ° C., were mixed in the mixer with 50 kg of a nonionic surfactant heated to 70 ° C. and 5 kg of perfume oil. The nonionic surfactant was prepared by reacting a coconut tallow fatty alcohol mixture (chain length C ₁₂ ―C ₁₈ , average chain length C ₁₅ , ₅ ) with 1.5 moles of propylene oxide and 5 moles of ethylene oxide. The mixing process was finished after 3 minutes. The premix was mixed in a continuously operating free-fall mixer with a spray-dried hollow-sphere powder in a weight ratio of 1: 4. The two powder components were fed to the mixer via belt scales.

The mixed powder had the following composition (in percent by weight):

The powder mixture was homogeneous and had a liter weight of 460 g. The sieve numbers were

The powder was free-flowing and free-flowing, free of unpleasant smells and did not tend to separate.

Claims (6)

1. A process for the production of a pourable granular washing and cleaning agent containing non-ionic surfactants from the class of polyalkylene glycol ether derivatives by adding the non-ionic surfactant to a powder-form to granular constituent of the washing and cleaning agent and subsequently combining the premix thus obtained with the remaining constituents of the washing and cleaning agent, characterised in that the non-ionic surfactant used is a compound corresponding to the following general formula

in which R is an aliphatic C₈―C₂₀-hydrocarbon radical, m is a number of from 0.5 to 8 and n is a number of from 2 to 20 with the proviso that n is equal to or greater than m.

2. A process as claimed in Claim 1, characterised in that a non-ionic surfactant of formula I, in which R is a primary C₁₂―C₁₈ alkyl or alkenyl radical, is used.

3. A process as claimed in Claims 1 and 2, characterised in that a non-ionic surfactant of formula I, in which m is a number of from 1 to 5 and n is a number of from 3 to 15, n amounting to between 2 and 10 times m, is used.

4. A process as claimed in Claims 1 to 3, characterised in that the non-ionic surfactant of formula I is mixed with powder-form to granular sodium perborate tetrahydrate in such a quantity that the premix contains from 5 to 20% by weight of non-ionic surfactant, after which the premix is combined with the remaining constituents of the powder.

5. A process as claimed in Claims 1 to 4, characterised in that the non-ionic surfactant of formula I is mixed with powder-form to granular sodium perborate tetrahydrate in such a quantity that the premix contains from 7 to 15% by weight of non-ionic surfactant, after which the premix is combined with the remaining constituents of the powder.

6. A process as claimed in Claims 1 to 5, characterised in that the non-ionic surfactant of formula I is used in such a quantity that it makes up a total of from 1 to 10% by weight of the washing and cleaning agent.