NO161981B - Particle-shaped, synthetic, organic detergent blend with dirt-releasing properties. - Google Patents

Description

The invention relates to detergents which are useful for

washing of synthetic, organic, polymer fiber-containing materials, such as polyesters, and which means that such a washed material acquires dirt-releasing properties. The invention relates more specifically to such detergents in particulate form which contain as the soil-releasing agent a copolymer of polyethylene terephthalate and polyoxyethylene terephthalate, a non-ionic surfactant, an alkaline builder which can reduce the soil-releasing effect of the soil-releasing material when it is in contact with such a material during storage,

and a stabilizing portion of polyvinylpyrrolidone (PVP) to help maintain the soil release properties of the soil release polymer despite the presence of the alkaline builder.

In US Patent Applications 396,637 and 396,761, structured, nonionic, synthetic, organic detergents are described which contain a preferred type of soil release copolymer of polyethylene terephthalate and polyoxyethylene terephthalate. When polyester fabrics or fabrics made of a mixture of polyester and cotton and articles made from such fabrics have been washed in the described products, these fabrics will acquire dirt-releasing properties, so that when they are later soiled with a lipophilic material, such as used motor oil, such an oil could be more easily removed during washing of the textile, regardless of whether this washing is carried out with the invented detergent or with a normal laundry detergent product. In US patent application 396762, it is stated that the aforementioned type of dirt-releasing polymer of polyethylene terephthalate and polyoxyethylene terephthalate can be dissolved in molten, non-ionic surfactant and that the solution can then be sprayed onto absorbent spray-dried beads of building material. The described mixtures and the method for producing them are applicable, but in some cases, such as when the builder is alkaline, the presence of this can adversely affect the soil-releasing ability of the soil-releasing polymer in the aforementioned detergents after storage at room temperature, and especially after storage at

high temperature. This appears to be due to the sensitivity of the dirt-releasing polymer to hydrolysis. It has now been shown that

if PVP of a certain type (molecular weight range)

is present in the detergent in intimate contact with the soil-releasing polymer, and can occasionally stain this, the soil-releasing ability of the detergent containing such a polymer is significantly improved after storage compared to a similar product in which no PVP is present.

The invention thus relates to a particulate, built-up, non-ionic, synthetic, organic detergent mixture for washing synthetic, organic, polymeric, fiber-containing materials and to help these acquire dirt-releasing properties, containing 15-22% by weight of a non-ionic, synthetic, organic surfactant, 30-80% by weight of a water-soluble, alkaline builder and 2-5% by weight of a dirt-releasing polymer of polyethylene terephthalate and polyoxyethylene terephthalate, which detergent mixture is characterized by the fact that it contains 0.3-2% by weight polyvinylpyrrolidone (PVP) with molecular weight 10,000-50,000 to stabilize the dirt-releasing polymer in the presence of the alkaline builder.

The water-soluble alkaline building salt is preferably sodium tripolyphosphate (normally pentasodium tripolyphosphate) which may be accompanied by sodium silicate, a certain polymer type of polyethylene terephthalate and polyoxyethylene terephthalate will be used, the nonionic surfactant will be a condensation product of higher fatty alcohol and ethylene oxide, and the PVP used will be water soluble and has a molecular weight within the specified range. Limited amounts of moisture and auxiliary additives may also be present in the present detergents.

Although various nonionic surfactants with satisfactory physical properties can be used, including condensation products of ethylene oxide and propylene oxide with each other and with hydroxyl-containing bases, such as nonylphenol or alcohols of the oxo type, it is strongly preferred to obtain the best results that the nonionic surfactant consists of a condensation ion product of ethylene oxide and higher fatty alcohol. In such products, the higher fatty alcohol has 10-20, preferably 12-15, carbon atoms, and the nonionic surfactant contains 3-20 or 30, preferably 6-11, ethylene oxide groups per mol. The nonionic surfactant is most preferably a surfactant in which the higher fatty alcohol has 12-15 carbon atoms and which contains

6-11 moles of ethylene oxide. Among such surfactants

mention may be made of Alfonic® 1214-60C and "Neodol" 23-6.5 and 25-7.

Among their particularly appealing properties, in addition to good washing power in terms of oily and greasy dirt deposits on goods to be washed, and an excellent compatibility with the available polymeric release agents,

is a relatively low melting point that is still significantly higher than the temperature of ice, so that they can be sprayed on base beads in the form of a liquid that quickly solidifies after it has penetrated the beads (the melting point is usually within the range of 40-55°C).

Various builders and combinations thereof that effectively complement the washing action of the nonionic, synthetic, organic surfactant or surfactants and enhance this action include water-soluble

builders. Among the water-soluble builders which are preferably used in the present detergents, and preferably in mixture with each other, both inorganic and organic builders can be used. Among the preferred inorganic water-soluble builders, the best include: various phosphates, preferably polyphosphates, such as the tripolyphosphates or pyrophosphates, more particularly the sodium tripolyphosphates or sodium pyrophosphates, e.g. pentasodium tripolyphosphate, tetrasodium pyrophosphate, sodium carbonate, preferably in the form of crystal soda, sodium silicate or mixtures thereof. The sodium silicate normally has a ratio Na20:SiO2 within the range 1:1.6-1:3, preferably 1:2-1:2.8, e.g. 1:2,4.

Among the water-soluble, inorganic building salts, the phosphates will usually be used in a larger proportion together with a smaller proportion of sodium silicate. The carbonate can be used together with bicarbonate and often with a smaller proportion of sodium silicate, and the silicate will rarely be used alone. Instead of using separate polyphosphates, it will occasionally be preferred to use mixtures of sodium pyrophosphate and sodium tripolyphosphate in the ratio within the range 1:10-10:1, preferably 1:5-5:1. It is of course recognized that changes in the phosphate's chemical structure can occur during kneading and spray drying so that the end product can be somewhat different from the components introduced into the kneading apparatus.

It will appear that the aforementioned water-soluble builders

are alkaline materials, and as a rule the alkalinity obtained will be such that a 1% aqueous solution of the detergent will have a pH within the range 8.5-12, e.g. 10. This alkalinity contributes to the fact that the detergent will be able to remove different types of dirt from clothes and keep them suspended, but it also has a negative effect as it tends to cause the breakdown of the dirt-releasing polymer used and thus adversely affect the ability of such a polymer to give the washed materials dirt-releasing properties.

Because polyesters used alone or in mixtures with cotton are lipophilic, they tend to attract and retain lipophilic dirt which may therefore still be present on the laundry after washing, rinsing and drying. Especially when it comes to polyester fibres, it is therefore important that the fibers in the materials being washed have dirt-releasing properties so that the washing of these will be effective. Especially because a number of cloth goods and other washable household goods have been made from polyesters or polyester blends in recent years, it is therefore important that maximum dirt-releasing properties are transferred to such a material. Any tendency for the dirt-releasing polymer used to break down should therefore be counteracted. The recognition that a certain material (PVP) stabilizes the dirt-releasing polymer used in the detergents according to the invention is thus an important recognition.

The polymer which promotes dirt release and which forms an essential component in the detergents according to the invention,

is a polymer of polyethylene terephthalate and polyoxyethylene terephthalate which is dispersible in water and which from washing water containing non-ionic surfactant and a builder for the non-

ionic surfactants, can be deposited on synthetic, organic, polymeric, fibrous materials, especially polyesters or polyester blends, so that these acquire dirt-releasing properties, while at the same time they will remain comfortable for a person wearing clothes made from such materials without hindering or to significantly inhibit the penetration of steam through such clothing. Such polyesters have also been shown to have antigen re-deposition properties and often help to remove stains from the substrate. They tend to keep dirt, especially oily or greasy dirt, dispersed in the wash water during washing and rinsing, so that the dirt is not redeposited on the laundry. Such useful products are copolymers of ethylene glycol or another suitable starting material for the ethylene oxide group, polyoxyethylene glycol and terephthalic acid or a suitable starting material for the terephthalic group. The copolymers can also be considered to be condensation products of polyethylene terephthalate, which can sometimes be referred to as an ethylene terephthalate polymer, and polyoxyethylene terephthalate. Although the terephthal group is preferred as the only dibasic acid group in the polymer,

according to the invention, the aim is also to use relatively small proportions of isophthalic acid and/or orthophthalic acid

(and occasionally also other dibasic acids) to modify the properties of the polymer. The proportions of such acids or starting materials for such supplementary groups added to the reaction mixture, and the corresponding proportions in the final polymer will, however, normally be less than 10% of each calculated on the total phthalic groups present,

and they will preferably be less than 5% of these.

The molecular weight of the polymer will lie within the range 15,000-50,000, preferably 19,000-25,000, e.g. about. 22000. Such molecular weights are weight average molecular weights in contrast to number average molecular weights, which for the polymers used here are often lower. In the polymers used, the polyoxyethylene will have a molecular weight of 1000-10000, preferably 3000-4000, e.g. about. 3400. In such polymers, the molar ratio between polyethylene terephthalate and polyoxyethylene terephthalate units (since

considered as such, units) lie innex? the range 2:1-6:1, preferably within the range 3:1.-4 vi, e.g. approximately, 3:1. The ratio between ethylene oxide and ffchaldel in the polymer

will be at least 10:1, preferably within about 20:1-30:1, and more preferably approx. 22:1. It thus appears that the polymer can be considered essentially to consist of a modified ethylene oxide polymer in which the phthalic group only constitutes a minor component, regardless of whether the calculation is made on a mole basis or a weight basis. It is considered surprising that with such a small proportion of ethylene terephthalate or polyethylene terephthalate in the polymer, the polymer is sufficiently similar to the polymer of the polyester fiber substrate (or other polymers to which it adheres, such as polyamides) that it is held firmly to this during washing, rinsing and drying. However, it appears from comparison tests and from various washing tests in which the dirt release is measured, that the described polymer in the present detergents will be effectively deposited on washed, synthetic goods, especially polyesters, so that these are better able to be washed free of oily dirt with a built , non-ionic detergent or another detergent product. It is believed that the polymer's increased hydrophilicity, which can be attributed to the large proportion of hydrophilic ethylene oxide groups in it, may be responsible for the excellent dirt-releasing properties that the polymer causes. the material on which the polymer is deposited will get, and this can also help it to cooperate with the built, nonionic surfactant.

Various articles in the literature, textbooks and patent documents describe production methods for the polymers used in the present detergents, and among these can be mentioned Journal of Polymer Science, Vol. 3 p, 609-6 30,

(1948), Journal of Polymer Science, Vol. 8, pp. 1-22 (1951), Fibers From Synthetic Polymers, by Hill, published by

Elsevier Publishing Company, New York, New York (1953) ,

pp. 320-322, British Patents 1,088,984 and 1,119,367 and US Patents 3,557,039, 3,893,929 and 3,959,230. Although

suitable methods for producing the polymers used here are described in these publications, it is considered that none of these describe the special polymers used in the detergents according to the invention (but such are described in the previously mentioned three patent applications, and some are commercially available) , and in none of these publications are the available detergents described. Such polymers can be considered to be arbitrarily built up of polyethylene terephthalate-

and polyoxyethylene terephthalate groups, such as those obtainable by reacting polyethylene terephthalate (e.g. spinning grade)

and polyoxyethylene terephthalate or by reacting ethylene glycol, polyoxyethylene glycol and acid starting materials (or methyl ester) thereof. However, in the existing

end detergents also use more ordered copolymers, such as e.g. such as are prepared by reacting components with predetermined or known chain lengths or molecular weights, to produce what may be termed block copolymers or non-random copolymers. Graft polymers can also be used.

The described materials are available from different suppliers, and the products of one of these will be described in more detail here. Useful copolymers for the preparation of the detergents according to the invention are sold by Alkaril Chemicals, Inc., and marketed products from this company which include

have been used with good results to produce satisfactory soil release promoting detergents, such as are sold under the trademarks "Alkaril QCJ" and "Alkaril QCF", formerly "Quaker QCJ" and "Quaker QCF". Products sold by this supplier in limited quantities and with the quality designations 2056-34B and 2056-41 have also been found to be acceptable. The QCJ product, which is normally supplied in the form of an aqueous dispersion, can also be obtained in the form of an essentially dry solid

material (QCF). When it is anhydrous or has a low moisture content (preferably below 2% moisture), it looks like a light brown wax, and the molar ratio between ethylene oxide and phthalic groups in this is approx. 22:1, The viscosity of a 16% dispersion in water at 100°C is approx. 96 cSt. /.05b-4i-poly, the veneer is not a hard one. light brown wax, and in danne is hydrophilic :hydtofobforhoiuit 15:1,. and we^kosita cen is approx. 265 cSt. 2056-34B poly>Kiren has out.S'.j«tidetav a hard, brown wax place t-t hydrof in 1- hydrophobfoxhold ^a. 10.3 : l .■

and its viscosity «3 r under the -name be tin gel i is >om mentioned above, approx. 255 cSt. The higher the molecular weight of the polymer, the lower its hydrophilic:hydrophobic molar ratio can be while still achieving a satisfactory dirt-releasing effect from the available detergents. QCJ-

and the QCF polymers have melting points (as determined by thermal differential analysis) of 50-60°C, but minor proportions of such products will remain solid at temperatures up to 100°C), a carboxyl analysis of 5-30 equivalents/10^ grams and a pH of 6-8 in distilled water at a concentration of 5%. The molecular weights (weight average) lie within the range 20,000-25,000, and the molar ratio between the ethylene terephthalate:poly-oxyethylene terephthalate units is approx. 74:26. All three mentioned marketed products are water-soluble or essentially water-soluble in lukewarm or warm water (at 40-70°C) or they are at least easily dispersible and can be characterized by having a high molecular weight above 15,000, generally within the range 19000-43000, and often preferably 19000-25000, e.g. about. 22000. In the present detergents, any specified amounts of the soil-releasing polymer will be on the basis of the polymer, including any insoluble materials therein (which may be less active as soil-releasing agents). Ideally, the release polymer used will be 100% water soluble.

For "solution" supply to materials or for solution addition to a detergent in washing water, the copciiners according to the invention can normally be used in the form of an aqueous dispersion. In such dispersions, a surfactant may be present to facilitate the maintenance of a uniform dispersion. Only small amounts of any such surfactant used will be present. The concentration of the polymer in the aqueous medium will normally be 5-25, preferably 10-20, e.g. 16.% on the basis of the detergent, and this is a concentration at which the aforementioned marketed products are normally supplied when a liquid form is desired. When the polymer is incorporated into a particulate detergent, it is preferable that it is present in a solid state, preferably in the form of an anhydrous, particulate, solid material with a particle size equal to the particle size of the other detergent components. It can alternatively be finely divided and in the form of a powder be applied to spray-dried beads of the other components. According to more preferred methods of incorporating the polymer into a detergent, the polymer can be dissolved in a non-ionic surfactant and sprayed onto base beads or it can be pelletized with carriers and mixed with the base beads. It has been found that the polymer should not be added to an aqueous kneaded slurry containing an anionic surfactant and/or a builder's salt, and it should not be contacted with a water-soluble builder's salt in the presence of moisture, especially at elevated temperature. In order to produce a free-flowing, particulate product, the polymer will therefore normally be essentially dry or have a very low moisture content. The use of such a product also makes it possible to produce basic beads with a normal moisture content without the moisture content being unduly increased by subsequent spraying of an aqueous dispersion of the polymer onto the beads.

The PVP used has proven to be effective where applicable

to stabilize the described dirt-releasing polymers in the presence of alkaline builders, and it is particularly effective in the presence of sodium tripolyphosphate which may be accompanied by

sodium silicate. Such a PVP has a molecular weight in the range of 10,000-50,000. A preferred PVP is sold under the names K-15 (molecular weight = 10,000) and K-30 (molecular

weight = 40000). The described products are water-soluble and are also soluble in molten, non-ionic surfactant of the type that is preferably used in the detergents according to the invention (a condensation product of a higher fatty alcohol with ethylene oxide).

Various suitable auxiliary additives can be present in the present detergents, such as e.g. enzyme powder that helps break down stains and other dirt so that it becomes easier to remove them, whereby the enzyme cooperates with the dirt-releasing polymer, perfumes, fluorescent whiteners, dyes (dyes and water-dispersible pigments, such as ultramarine blue), bactericides, fungicides or flow-promoting agents. Some of these materials can be added to the kneading machine so that they will form part of the basic beads, and some of these will be added afterwards. Inorganic fillers, such as sodium sul-

barrels or sodium chloride, can be used, but the amounts of these will preferably be limited, and one reason for this is that it has been shown that sodium sulphate is prone to reacting unfavorably with the polymers present. Among the enzymes can be both proteolytic and amylolytic enzymes

are used, such as those sold under the brand names Alcalase^ and "Maxazyme" which are both alkaline proteases (subtilisin).

In the present detergents, the amount of synthetic, organic, non-ionic surfactant is 15-22, e.g. about. 20 or 21, %. The total amount of water-soluble, alkaline builder is 30-80, preferably 45-70, %. When the builders are sodium tripolyphosphate and sodium silicate, which is preferred,

the amounts of these are preferably 40-65% and 5-13%, e.g.

54% and 10%. The amount of the dirt release polymer is 2-5, e.g. 3.%. The product's moisture

content will usually be 1-20, preferably 5-12, e.g. 9.%. The individual auxiliary additives preferably do not make up more than 10% of the detergent, and they are more preferably limited to 5% and often to 2 or 3%,

with the total quantity of auxiliary additives preferably not exceeding 25% and preferably limited to 15%, and more preferably to 5% or 10%, of the detergent. Of course, mixtures of the individual components in the present detergents and of auxiliary additives for these can often be used with advantage, and these are meant to be included when a single type of component is mentioned. Any enzyme powder present will usually be present in a concentration of 0.5-3, preferably 1-2,%. Such an enzyme powder is commercially available in the form of a mixture of active enzyme and carrier material, e.g. such as "Maxazyme" 37 5 .

Regardless of whether they have been prepared in advance and stored before use or whether they have been prepared immediately before use, the detergents can be used in diluted aqueous solution (or dispersion) in wash water to wash fully synthetic materials, including polyesters, cotton-synthetic fiber blends , including cotton, polyester blends, nylon or blends of such materials. The dry weight of the materials being washed will normally be 2-15 or 20% of the weight of the aqueous washing medium, preferably 5-10% of this. The washing will be carried out with agitation for a time of from 5 minutes to 0.5 hour or 1 hour, often from 10 to

20 minutes, and after washing the materials will be rinsed,

usually in several rinsing steps, and dried, e.g. in an automatic clothes dryer. The washing water will usually have a temperature of 10-95, preferably 15-60 or 20-50, and more preferably 40-50, °C, and the concentration of the detergent will be 0.05-1, preferably 0.05-0, 15, e.g. 0.06 or 0.13, %. The detergents have a bulk density of 0.2 or 0.4-0.9, preferably 0.6-0.9, e.g. 0.65, g/cm , and such detergents with preferred room density are normally used in a concentration of approx. 1/4 cup (or approx. 40 g) per washing, as the washing cylinder usually contains approx. 64 liters of water for top laying machines and 26-30 liters for front laying machines. When a washing machine of the "European" type is used in which higher concentrations of detergent are used together with smaller amounts of water and where the machines are generally operated at higher washing temperatures, it may be preferable to lower the washing temperature in order to achieve the best deposition of the polymer on the washed materials .

The upper part of the wide range of detergent concentrations given above can be considered suitable for European washing conditions, while the corresponding middle and lower parts apply to front-loading machines and top-loading machines and "American" type washing conditions, and the concentration for the front-loading machines is often lower than the concentration for the top-loading machines.

The proportions of the individual active components in the available detergents in the wash water will normally be 0.001-0.14% non-ionic surfactant, 0.006-0.40% builder, 0.0001-0.10% dirt-releasing agent and 0.00002 -0.50% PVP. These shares will preferably be respectively 0.003-0.02%, 0.02-0.05%, 0.0003-0.01% and 0.00006-0.006%. When sodium tripolyphosphate and sodium silicate are present in the wash water, the normal percentage amounts of the essential components of the present detergents that will be present in the wash water will be 0.0006-0.04% nonionic surfactant, 0.017-0.12% sodium tripolyphosphate, 0.002-0.023% sodium silicate, 0.0008-0.009% dirt-releasing polymer and 0.00013-0.004% PVP, the more preferred ranges being respectively 0.009-0.013%, 0.024-0.039%, 0.003-0.008%, 0.001-0.003%

and 0.0002-0.0012%.

The basic beads that can be used for the production of the detergents according to the invention are preferably spray-dried from an aqueous kneader slurry which will normally contain 40-70 or 75, preferably 50-65, % of the basic beads, the rest being water, preferably deionized water as described above (but tap water can also be used. The kneading machine slurry is preferably prepared by sequentially adding the various components to

such a way which will lead to the formation of the most possible mixable, easily pumpable and non-depositing slurry for spray drying. The order of addition of the materials can be varied depending on the circumstances, but it is most desirable when "depositable" kneading machine mixtures are used that a possible silicate solution is added last, and if this is not added last, it must at least be added after the addition of a possible gelling agent or "set"-inhibiting combination of materials or processing aids, such as citric acid or magnesium sulfate.

It is normally preferred that the whole or almost the whole amount

of the water is first added to the kneading apparatus, preferably approximately at the process temperature, after which the processing aids, if present, and other stable components in quantities, including any pigment or fluorescent whitening agent, are added, followed by most of the builder or builders, including phosphate

builder and silicate builder. As a rule, in such additions, each component will be carefully mixed in before the next component is added, but the addition methods can be varied depending on the circumstances so that simultaneous additions can be made if this is practical. Sometimes the component additions can be made in two or more portions,

and occasionally various components may be premixed prior to addition to speed up the mixing process. Normally, the mixing speed and effect will be increased as the materials are added.

The temperature of the aqueous medium in the kneader will

as a rule, be approximately room temperature or elevated temperature, and the temperature will normally lie within the range 20-80, preferably 30-75 or 80, and more preferably 40-70 or 80, °C. If the medium in the kneading apparatus is heated, this can promote the dissolution of the water-soluble salts

ter in the mixture and thereby increase miscibility, but up-

heating, if carried out in the kneader, can reduce the production capacity. Higher temperatures than 80°C, and occasionally temperatures above 70°C, will often be avoided due to the possibility of decomposition of one or more possible components in the kneader mixture, e.g. sodium bicarbonate. If the temperatures in the kneader are lower, these will also in some cases increase the upper limits for the solids content in the kneader mixture, presumably because normally gel-forming or bottom-depositing components are rendered insoluble. Such problems do not usually arise if the main builder present is a polyphosphate.

Mixing times in the kneader to achieve good slurries can vary greatly from as little as 5 minutes for small kneaders and for slurries with a higher moisture content to as long as 4 hours. The necessary mixing times to bring all components of the kneader mixture together in a substantially homogeneous manner in a medium can be as short as 10 minutes, but in some cases this can take up to 1 hour although 30 minutes is a preferred upper limit. Including such possible original mixing times, the mixing periods in the kneader will normally be from 15 minutes to 2 hours, e.g. from 20 minutes to 1 hour, but the mixture in the kneader should be such that it remains mobile and is not exposed to gel formation or solidification for at least 1 hour, preferably 2 hours, and more preferably 4 hours or for a longer time, after the preparation of mixing has been completed. The present mixtures are stable for at least 4 hours. They do not solidify during this time when polyphosphate is the main builder, and when carbonate-silicate mixtures are used, an anti-solidification agent, such as citric acid plus magnesium sulfate, will be present

to delay solidification.

The kneaded slurry is, together with the builder's salt or builder's salts and other components dissolved in the slurry or in particle form and evenly distributed in the slurry, transferred in the usual way to a spray drying tower which is normally placed near the kneader. The slurry is dropped from the bottom of the kneader to a positive displacement pump which forces the slurry at high pressure through nozzle pieces at the top of a conventional spray tower (counter-current or co-current), into which the small slurry droplets fall through a hot drying gas usually made up of the combustion products of fuel oil or a natural gas, in which the small droplets are dried to the desired pearl shape. During drying, absorbent beads are obtained which are particularly favorable for absorbing a heated non-ionic surfactant in liquid form which can be subsequently sprayed onto the beads.

After drying, the product is sifted to the desired size, e.g. corresponding to 2-0.25 or 0.15 mm,

and the product is then ready for application of a shower of non-ionic surfactant to the product.

Although the above description relates to the production of spray-dried foundation beads of inorganic building salt and these are preferred for the various reasons mentioned above, such as the desired spatial density, uniformity, flowability, strength and adsorption properties, according to the invention it is intended to use other equivalent or nearly equivalent base beads, such as those made up of agglomerates, mixtures, granules, milled products, pearls or chopped filaments. The non-ionic surfactant will usually have too high a temperature, such as 40-90, preferably 50-80, e.g. 55-°C, to ensure that this will be liquid. On cooling to room temperature, however, it will become solid in the desired way and often resemble a wax-like solid material. Although the non-ionic surfactant is slightly sticky at room temperature, this property will not necessarily make the final product have poor flowability because the surfactant will penetrate below the surface of the beads (into the beads). However, wax-like surfactants are preferred. The non-ionic surfactant is applied to the base beads which are kept in motion or tumbled in a known manner, in the form of a shower or in the form of small drops. The enzyme preparation (referred to here as enzyme although it is recognized that it also includes a carrier material), the dirt-releasing polymer, PVP and any other powdered auxiliary additives can be dusted on or mixed with the building base particles, and perfume and any other liquids to be subsequently added can be sprayed on the particles at a suitable time before or after the addition or additions of the powder or powders.

The non-ionic surfactant can be sprayed onto the absorbent building base beads, and the dirt-releasing polymer and PVP

can be added afterwards, as the dirt-releasing polymer is stabilized by PVP against the degrading effect of the alkaline building base pearls. Such a stabilizing effect exerted by PVP is obtained when the dirt-releasing polymer and PVP are in contact, preferably when contact between the dirt-releasing polymer and the alkaline build is also prevented or reduced. However, two particular ways of incorporating the nonionic surfactant, the soil release polymer and PVP into the product are highly effective and are preferred. The more preferred method is to spray dry an aqueous kneader slurry of the alkaline builder salt to form dried absorbent particles, dissolve the recipe amount of soil release polymer and PVP in nonionic surfactant in liquid form and spray or otherwise effectively distribute the non- ionic surfactant dissolution of the release polymer and PVP on

the surfaces of the alkaline building beads. When such a method is carried out, it is highly desirable that the nonionic surfactant be substantially or almost completely anhydrous and that it normally contains below 1, preferably below 0.5 and more preferably below 0.2,% moisture. It is preferred that the non-ionic surfactant has a temperature of 40-90, more preferably 50-80, °C, and at this temperature the normally solid and wax-like surfactant will be melted and the dirt-releasing polymer and PVP will normally dissolve in this (in recipe-

the quantities). Moreover, the base beads will preferably be heated and kept in motion, e.g. in a suitable mixing apparatus. as a rotating long drum or pipe with a slight slope, e.g. 5-10° in relation to the horizontal plane. The small sprayed droplets will preferably have a size that is obtained by using a typical spray gun, and they will generally have a diameter of 0.1-1 mm. Said spraying and mixing can be carried out in as little time as 1 or ?. minutes, but normally 5-10 minutes would be desirable. It is surprising that although the spraying of the surfaced non-ionic surfactant onto the base beads brings the soil-release polymer into close contact with such beads and the alkaline building salts of which the beads are composed, the soil-release-promoting polymer will remain stable upon storage, even at somewhat elevated temperatures, which is apparently due to the presence of PVP. Comparisons made with other dirt-releasing detergents with similar recipes, but without PVP, show that the experimental recipes are greatly superior in terms of long-term dirt-releasing properties.

Another preferred method for producing a detergent according to the invention includes dissolving PVP in a liquid medium, such as water, preferably alcohol, e.g. methanol, or a suitable volatile, chlorinated, organic solvent, such as methylene chloride. Desirable concentrations of PVP in the solvent will normally be within the range of 5-25%, with higher concentrations being preferred when removal of the solvent represents a problem, such as when water is used. The solvent solution of PVP is then applied to particulate soil release promoting polymer, the application amount being such that the desired prescription amount of PVP is applied to the soil release agent. When it is thus e.g. is it desirable that the leaching agent should contain 3% dirt-releasing polymer and 0.5% PVP, sufficient PVP solution will be sprayed or otherwise transferred onto the surfaces of the <p>articles by the dirt-releasing polymer to produce an intermediate product containing approx. 86% dirt-releasing polymer and approx. 14% RRP. The particle sizes for the dirt-releasing polymer will preferably lie within the same range as the desired sizes of the non-ionic surfactant builder particles in the final detergent, but other particle sizes can also be used, although these will not be as advantageous and may lead to the particles being separated in to a certain extent from the surfactant-builder<p>articles. Such surfactant builder particles will be prepared by spraying the recipe amount of molten nonionic surfactant onto the absorbent builder salt base beads in a similar manner as described above. The two particle types are then mixed together, and the product is ready for use. The detergent obtained is a detergent in which the polymer which promotes dirt release is protected by PVP against the degrading effect of the alkaline building salt. Moreover, the presence of the non-ionic surfactant on the building salt will be such that the surfactant covers significant parts of the building salt's surfaces and further helps to prevent harmful effects.

By applying PVP to the base beads (with non-ionic surfactant and soil-release polymer) and to the soil-release polymer particles, the PVP protects the soil-release polymer from the alkaline build-up and also improves the product in other ways. PVP exhibits useful antigen redeposition properties and has been observed to promote stain removal from fabrics. In the present detergents, it helps to release soil, especially at or near room temperature, to a greater extent than can be attributed to the stabilization of the soil release promoting polymer. A coating of PVP helps to protect the detergents against the effects of atmospheric moisture. However, PVP is easily soluble in the washing water, which leads to rapid dissolution and dispersion of the detergent components. Although a number of other products have been investigated, none of these have been shown to produce the highly desirable effects of PVP, even other water-soluble polymeric amides.

The invention is described in more detail using the examples below. Unless otherwise stated, all parts are based on weight and all temperatures are in °C.

A particulate, structured, non-ionic, synthetic, organic detergent according to the above recipe which is useful for washing synthetic, organic;?, polymer.-fibrous materials, such as polyester or polyester-cotton blend materials, and which this s-.it? gets smuHs-releasing properties, is produced using the following method: First, base beads of the tripolyphosphate and silicate are produced by dispersing the tripolyphosphate in the form of a finely divided powder in water and adding the recipe amount (9.58%) of anhydrous silicate in the form of a solution with 47.5% solids, the solids concentration in the prepared kneader mixture being approx. 55%. The water used is deionized, but occasionally tap water will be used provided its hardness is below 300 ppm, calculated as calcium carbonate. Preferably, the fluorescent whitening agent and any coloring agents, such as the blue dyes, which are sufficiently stable in the kneading apparatus, are also added to the kneading apparatus. The mixture in the kneader is kept at a temperature of 60-70°C, and the mixture is continuous. The mixture, including addition and grinding as

both are carried out while the mixing is taking place, normally taking from 20 minutes to 1 hour, but can be carried out for a longer time of up to 4 hours or longer because the phosphate-silicate-dye-white-agent dispersion solution does not show a tendency to solidify in the kneader.

After sufficient mixing to achieve an essentially uniform slurry in which the fluorescent whitening agent and dyes would normally preferably be present and where some moisture may be lost by evaporation during the mixing time and can be replaced if desired, the mixture is discharged from the kneader to a pump which pumps the mixture at a pressure of approx. 21 kg/cm 2 into the top of a counterflow spray tower in which the initial drying temperature is approx. 430°C and the final air temperature is approx. 105°C.

The base pearls obtained have a space density of approx. 0.5 g/cm<3 >when cooled after manufacture, and a particle size in the range from 2 to 0.15 mm. They can be aimed at such an area or at a particulate product with fewer smaller particles, e.g. to particles with a size from 2 to 0.25 mm. The moisture content of the product is approx. 12.1%. The base beads are free-flowing (typically 80% fluidity), non-sticky, sufficiently porous but solid on the surfaces, and able to readily absorb significant amounts of liquid non-ionic surfactant (and dissolved QCF and PVP) without becomes undesirably sticky.

After cooling the spray-dried base beads, these are sieved so that essentially all beads (over 95% and often over 80%) have a size corresponding to the area

from 2 to 0.15 mm, and they are sprayed with a

dissolution of QCF and PVP in anhydrous, nonionic surfactant in the recipe amounts for the final product. Thus becomes 0.5

part PVP and 3 parts QCF dissolved in 20.7 parts "Neodol 23-6.5" which is essentially anhydrous and has a temperature of approx. 71°C and sprayed on surfaces of foundation beads that are tumbled, preferably while the beads are mixed in a tumble drum which can be a long drum or a long tube with an inclination in relation to the horizontal plane of approx. 8°. The small sprayed droplets mainly have a particle size in the range from 0.1 to 1 mm, and the spraying is carried out so that there is a flow time in the spray mixing apparatus of 10-20 minutes, as enzyme and perfume are added to the mixture after the non-ionic surfactant containing PVP and QCF.

After cooling, the resulting detergent particles have a room density of approx. 0.65 g/cm 3. The product has an attractive and uniform appearance and is free-flowing and dust-free.

The detergents described above are excellent full detergents for clothes and are particularly suitable for washing household laundry in automatic washing machines and at the same time give the laundry dirt-releasing properties. When they are used at a temperature of 45-50°C and in a concentration of 0.05-0.15, e.g. 0.06, % in a washing machine with a capacity of 64 liters when washing normal loads of 100% polyester and 65% polyester - 3 5% cotton in domestic washing machines or commercial washing machines, regardless of whether these are of the type with top loading or front loading, or at higher temperatures and concentrations in washing machines of the European type, the available detergents give satisfactory results, which was to be expected from a knowledge of the components in these or normal washing performance properties, but in addition they contribute significantly to dirt is released from such materials. The present detergents are also satisfactory for washing nylon, acetate or mixed fibrous materials, and they also promote soil release from such materials although not to the same extent as is the case with the polyesters. When testing the washing and dirt-releasing effect of the present detergents, a washing machine with top loading or a test washing machine of the Terg-O-Tometer type is used, and the water temperature is approx. 45°C and the water contains a total of approx. 200 ppm hardness, calculated as CaCO^, due to mixed calcium and magnesium ions. The washing test times are all 10-15 minutes and the weight ratio cloth:water approx. 1:20. The items are rinsed twice automatically and are then dried in an automatic clothes dryer or other suitable drying device.

The presence of PVP together with the polymer which promotes soil release stabilizes the release polymer to a significant extent so that it is clear from observation with the naked eye and from reflectometer readings that better soil release during washing is obtained when a detergent comprising the release polymer and PVP is stored for 2 - 4 weeks at an elevated temperature and then used to wash polyesters and polyester-cotton blends, compared to the same product, but from which the PVP has been looped (not incorporated into the non-ionic surfactant with QCF), but which was stored and used in the same way. In order to achieve better stabilization of the polymer which promotes the release of dirt from the polyester material, the ratio between PVP and dirt release agent should be within the range of 1:15-1:2 or 1:1, preferably 1:10-1:3, f .ex. 1:5 or 1:6. The dirt release-promoting effect is more significant with repeated washings of clothes, usually up to 5 washings of the materials, using the present detergents (or with corresponding washing water solutions).

In addition to the fact that users of the present products will note that an improved soil release is obtained when washing normal amounts of cloth-containing items that have been soiled with oil or grease, comparative studies where used motor oil is applied to cloths made of polyester and polyester-cotton blend materials after that such cloths have been washed in the available detergents or with control detergents (which are the same as the detergents according to the invention, but without PVP), improved dirt release transport when using the products according to the invention when both these and the control detergents have been stored at elevated temperature, e.g. e.g. for 4 weeks at 45°C, before being used to wash the cloths. In such experiments, trained observers will note the improvement in soil removal when washing is carried out with a detergent according to the invention or with a control detergent, after first being treated with these detergents and then being soiled with oil, and these conclusions are confirmed by reflectometer control of the washed materials . Similar results are obtained when the polyester test materials are washed with the detergents of the invention and control detergents, the materials are soiled with used motor oil, and the materials are then washed with a commercially available detergent, such as a FAB-type phosphate-based anionic detergent.

When the above recipes are varied by varying the amounts of dirt-releasing polymer and PVP by plus or minus 20% and plus or minus 50%, similar results are obtained, but when using the larger amounts of PVP (and release polymer) the dirt-releasing effect becomes better after storage due to improved stability of QCF. In a similar way, when such changes are made to the building component,

the non-ionic surfactant (for "Neodol 25-7" and "Neodol 23-3")

and the enzyme component, as the recipes are kept within the previously indicated ranges, useful products are obtained with improved soil release properties despite storage, provided that PVP is present. Furthermore, when PVP is changed to "K-30", an excellent stabilization of QCF is obtained, but when "K-90" (mol. weight 360,000) is used, the stability is worse. The described results can also be achieved when other polyethylene terephthalate-polyoxyethylene terephthalate copolymers are used, provided that the molecular weights and ratios lie within the ranges indicated in the present description.

Example 2

When the detergents according to example 1 are produced by

to spray-dry the base beads, by allowing them to absorb a shower of heated, non-ionic surfactant (at 55°C)t by

coating QCF particles with a particle size in the range of 2 to 0.15 mm with PVP ("K-15")

for the production of particles which are still within the aforementioned area, and by mixing the two particulate intermediates in the correct proportional amounts, a stabilized detergent is obtained which promotes the release of dirt. The PVP solution used has a concentration of approx. 15% in methanol, water or methylene chloride and applied so that the recipe amount of PVP is deposited on the QCF used. Instead of using an inclined mixing drum, a fluidized bed dryer is used to coat the QCF particles with PVP and to evaporate the solvent.

Although the described coating method is applicable

and the products thereby obtained have a bulk density, washing power and ability to promote dirt release of lipophilic dirt that are comparable to the same properties for the products according to example 1, and furthermore have other good physical properties similar to those described in example 1, it is preferred to use the absorption method described in Example 1 because this does not require any additional equipment or additional processing steps except for a mixing tank to dissolve the QCF and PVP in the nonionic surfactant. Moreover, a device for recycling the solvent is not necessary, and evaporation of water does not need to be carried out.

It is surprising that the present detergents are so effective and have an acceptable and practical stability despite elevated temperature storage, because PVP is exceptionally highly soluble in water and it was not expected that it would "insulate" the soil release agent against atmospheric moisture which in the presence of water-soluble alkaline salt could be expected to cause degradation of the release agent. Furthermore, when a non-ionic surfactant containing dissolved release agent is deposited on the grounds of alkaline building salt, it was to be expected that when the alkaline material and QCF (or QCJ) are brought into intimate contact with each other, this would cause degradation of the f rig jøringsm tdle t or in the presence of PVP. However, this does not occur - which has been stated above. Because of the solubility of the nonionic surfactant in water and the fact that it is hydrophilic, it probably wasn't. to expect that it would limit the contact between the alkaline building salt and the agent which promotes dirt release. In short, the present invention, according to which PVP stabilizes materials that promote soil release from polyesters against alkaline hydrolysis and degradation, is surprising and represents an important advance in detergent technology.

Claims (2)

1. Particulate, built-up, non-ionic, synthetic, organic detergent composition for washing synthetic, organic, polymeric, fibrous materials and to impart soil release properties thereto, containing 15-22% by weight of a non-ionic, synthetic, organic surfactant, 30 -80% by weight of a water-soluble, alkaline builder and 2-5% by weight of a dirt-releasing polymer of polyethylene terephthalate and polyoxyethylene terephthalate, characterized in that the mixture contains 0.3-2% by weight of polyvinylpyrrolidone (PVP) with a molecular weight of 10,000-50,000 to stabilize the dirt-releasing polymer in the presence of the alkaline builder. 2. Detergent mixture according to claim 1, characterized in that the non-ionic surfactant is a condensation product of a higher fatty alcohol with 12-15 carbon atoms and 6-11 mol of ethylene oxide per mol higher fatty alcohol, the dirt-releasing polymer has a molecular weight of 19,000-25,000, the polyoxyethylene in the polyoxyethylene terephthalate has a molecular weight of 3,000-4,000, the molar ratio between ethylene terephthalate and polyoxyethylene terephthalate units in the polymer is 3:1-4:1, and the molar ratio between ethylene oxide and phthal part in this is 20:1-30:1, with sodium silicate with a ratio Na20:SiO2 of 1:2.0-1:2.8 being present as a builder, and The content of non-ionic surfactant, phosphate, silicate, dirt-releasing polymer, PVP and moisture is within the range of 15-22%, 40-65%, 5-13%, 2-5%, 0.3-2% and 5-12%.