WO2017125727A1

WO2017125727A1 - Antifoam formulation

Info

Publication number: WO2017125727A1
Application number: PCT/GB2017/050108
Authority: WO
Inventors: Madeleine Eleanor ANDERSON; Paul Hugh Findlay; David Alan Pears; Lisa Elizabeth SCULLION
Original assignee: Revolymer (U.K.) Limited
Priority date: 2016-01-18
Filing date: 2017-01-18
Publication date: 2017-07-27
Also published as: GB201600914D0

Abstract

Antifoam formulations are disclosed, as well as their methods of manufacture and their uses in powder laundry detergents. The antifoam formulations may be readily incorporated into powder laundry detergent formulations, wherein they exhibit remarkable stability properties. In particular the antifoam formulations retain their remarkable defoaming properties throughout more than 2 months of storage within powder laundry detergent formulations.

Description

ANTIFOAM FORMULATION

INTRODUCTION

[0001 ] The present invention relates to antifoam formulations, processes for their preparation, and their uses, particularly in laundry detergents.

BACKGROUND OF THE INVENTION

[0002] In many aqueous systems foaming can be an issue, either due to the presence of surfactants or from the inclusion of particulates or the processing of the liquid system. This foaming can either make further processing or transportation of the liquid problematic such as in the food industry, dyeing, sewage treatment, agrochemical treatments or in ceramic production. The same is also true of many cleaning products, either industrially or in the home care markets, wherein foams decrease the physical forces required to provide efficient detergency or can produce large amounts of foaming which can spill-over in-use, such as in the case for industrial or domestic laundry systems. Many aqueous surfactant systems can give rise to excessive foaming during the washing process by the inclusion of air and the formation of stable air bubbles, foams, during the cleaning process. The persistence of the foams is due to the high elasticity of the air-liquid interface which is formed due to the action of the surfactant. To this end a number of efficient antifoam agents have been developed over the years to counteract this effect.

[0003] Antifoam agents act by reducing the lifetime of the air-water interface of the foams by further reducing the air water interfacial tension and essentially invading the space occupied by the surfactant and lowering the films elasticity; thereby bursting the bubbles that are formed. Many agents have been developed to achieve this and can be split into soluble and insoluble materials. Insoluble examples include small hydrophobic cross-linked particles such as silicas or aluminas which are too large to take part in the stabilisation of the bubble but can migrate to the interface and lead to their rupture. There are also numerous groups of soluble examples including metal soaps, fatty acids, hydrophobic oils or amphiphilic polymers.

[0004] When used in powder formulations, such as a powder laundry detergent, liquid antifoam agents are usually prepared in a solid format by incorporation or processing with other solid fillers and binders to give a solid particle which can be post-dosed into a powder formulation and can be uniformly dispersed prior to packaging. Typically, such solid particles are prepared in such a manner so as to possess similar particle sizes and bulk densities as the powder formulation, so as to aid uniform distribution throughout. [0005] However, antifoam agents typically suffer from a reduction in stability, that is to say a reduction of performance, upon storage in formulation, particularly where they are incorporated into a hostile formulation which may possess addition surfactants, have a high pH and contain residual water, such as a laundry powder formulation. This is also exacerbated when the formulation is stored for a long time period before use, especially at elevated temperatures or humidity. It is thought that the reduction in performance occurs due to migration of the antifoam active into the formulation due to free or active water in the formulation aided by surfactants. It is also assumed that the high pH of the formulation can also lead to destabilisation of either the antifoam containing particle or of the active itself. This so-called spreading gives much lower local concentrations of the active which results in a drop in performance. As mentioned previously, this occurs much faster at higher temperatures and humidity and as such is a major issue when storing or using powder detergents in, for example, tropical regions or where an open package is stored for a long period of time in a warm, humid environment, such as under a domestic sink. There is therefore a need for solid antifoam agents that can be readily incorporated into laundry powder formulations, and which demonstrate extended stability characteristics.

[0006] The present invention was devised with the foregoing in mind.

SUMMARY OF THE INVENTION

[0007] According to a first aspect of the present invention there is provided a solid antifoam formulation comprising:

5 - 25 wt.% of an antifoam agent;

0.1 - 7 wt.% of a water-soluble polymer;

10 - 55 wt.% of an absorbent

5 - 55 wt.% of a filler; and

5 - 60 wt.% of a non-strongly alkaline, water-soluble salt.

[0008] According to a second aspect of the present invention, there is provided a solid laundry detergent formulation comprising a solid antifoam formulation defined herein.

[0009] According to a third aspect of the present invention, there is provided a process for the preparation of a solid antifoam formulation as defined herein, said process comprising the steps of:

a) mixing the antifoam agent, water-soluble polymer, absorbent, filler, non-strongly alkaline, water-soluble salt, and water; and

b) drying the mixture resulting from step a). [0010] According to a fourth aspect of the present invention, there is provided a solid antifoam formulation obtained, obtainable or directly obtained by a process defined herein.

[0011 ] According to a fifth aspect of the present invention, there is provided a use of a solid antifoam formulation defined herein for reducing the formation of foam.

DETAILED DESCRIPTION OF THE INVENTION

Solid antifoam formulations

[0012] As described hereinbefore, the present invention provides a solid antifoam formulation comprising:

5 - 25 wt.% of an antifoam agent;

0.1 - 7 wt.% of a water-soluble polymer;

10 - 55 wt.% of an absorbent

5 - 55 wt.% of a filler; and

5 - 60 wt.% of a non-strongly alkaline, water-soluble salt.

[0013] When compared with currently-available formulations, the solid antifoam formulations of the present invention present a number of advantages. Perhaps most notably, the solid formulations may be readily incorporated into powder laundry detergents, wherein they exhibit remarkable stability properties. In particular, when compared with currently-available formulations, the antifoam formulations of the invention demonstrated no significant reduction in defoaming properties (i.e. the ability to collapse a quantity of foam) after ageing at 30 °C and 80% relative humidity for up to 84 days.

[0014] Noting that the antifoam formulations may be used in powder detergent formulations, it may be important that the antifoam formulation does not include any strongly alkaline components (e.g. carbonates, such as sodium carbonate).

[0015] The antifoam agent may be any component which has the capacity to reduce the formation of foam. Such agents include fatty acids, esters of fatty acids, soaps, organic liquids and silicones. Suitably, the antifoam agent comprises a silicon-based polymer. More suitably, the antifoam agent comprises a siloxane-based polymer.

[0016] Silicones, which may be employed as antifoam agents have the general structure shown below:

wherein R and R' are independently selected from a C1 to C12 straight chain or branched alkyl, a poly ether group, such as poly or oligo ethylene glycol, or a C1 to C12 straight chain or branched alkyl optionally substituted by one or more hydroxyl, amine or carboxy groups. Suitably, R and R' are independently selected from a C1 to C12 straight chain or branched alkyl. Most suitably, R and R' are methyl, ethyl, propyl or butyl, particularly methyl.

[0017] Typically, the silicone may be linear, branched or lightly cross-linked and have a molecular weight of 100 to 400,000 Da. The silicone may also be end-functionalised at one or all the chain ends, with, for example, a further alkyl group or an alkyl hydroxyl unit. In an embodiment the silicone is a polydimethylsiloxane (PDMS) based polymer.

[0018] In a particular embodiment, the antifoam agent comprises a polydialkylsiloxane-based polymer. Suitably, the antifoam agent comprises polydimethylsiloxane (i.e. silicone) or a polydimethylsiloxane-based polymer. In exemplary embodiments, the antifoam agent is a polydimethylsiloxane or a polydimethylsiloxane-based polymer.

[0019] The antifoam agents useful in the present formulations may have a viscosity at 25 °C of 1 ,500 - 50,000 mPa-s. Suitably, the antifoam agents useful in the present formulations may have a viscosity at 25 °C of 1 ,500 - 40,000 mPa-s. Suitably, the antifoam agents useful in the present formulations may have a viscosity at 25 °C of 1 ,500 - 35,000 mPa-s. More suitably, the antifoam agents useful in the present formulations may have a viscosity at 25 °C of 2,000 - 40,000 mPa-s.

[0020] In an embodiment, the antifoam agents useful in the present formulations may have a viscosity at 25 °C of 1 ,500 - 5,000 mPa-s. Suitably, the antifoam agents useful in the present formulations may have a viscosity at 25 °C of 1 ,500 - 4,000 mPa-s. More suitably, the antifoam agents useful in the present formulations may have a viscosity at 25 °C of 2,000 - 4,000 mPa-s.

[0021 ] In an embodiment, the antifoam agents useful in the present formulations may have a viscosity at 25 °C of 20,000 - 40,000 mPas. Suitably, the antifoam agent may have a viscosity at 25 °C of 25,000 - 35,000 mPas. [0022] The antifoam agent may have a density at 25 °C of 0.95 - 1 .1 gem ^~3. Suitably, the antifoam agent may have a density at 25 °C of 0.95 - 1 .05 gem ^~3.

[0023] In an embodiment, substantially all of the antifoam agent is the active ingredient(s) exhibiting the antifoam properties.

[0024] The antifoam agent may be anhydrous.

[0025] In an embodiment, the solid antifoam formulation comprises 5.0 - 20 wt.% of the antifoam agent. Suitably, the solid antifoam formulation comprises 5.5 - 20 wt.% of the antifoam agent. More suitably, the solid antifoam formulation comprises 7.0 - 17.5 wt.% of the antifoam agent. Even more suitably, the solid antifoam formulation comprises 7.5 - 16.0 wt.% of the antifoam agent. Most suitably, the solid antifoam formulation comprises 8.0 - 16.0 wt.% of the antifoam agent.

[0026] In an embodiment, the solid antifoam formulation comprises 10.0 - 17.0 wt.% of the antifoam agent. Suitably, the solid antifoam formulation comprises 12.0 - 17.0 wt.% of the antifoam agent. More suitably, the solid antifoam formulation comprises 14.0 - 16.0 wt.% of the antifoam agent.

[0027] The water-soluble polymer may have a solubility of at least 200 g/L water at 25 °C. This encompasses polymers that are entirely water-soluble or substantially water-soluble. The solubility of substantially water-soluble polymers may be increased by changes in temperature, pH, or an increase in dilution factor.

[0028] The water-soluble polymer may be a linear, branched or cross-linked homopolymer or copolymer, or a mixture thereof. Suitable polymers include one or more of poly(vinylpyrrolidone), functionalised polyvinyl alcohol)s, and linear, branched or cross-linked polymers or copolymers prepared from one or more of the following monomers: N- vinylpyrollidone, (meth)acrylic acid, acrylic acid, maleic acid, fumaric acid, itaconic acid, 2- acrylamido-2-methyl-1 -propanesulfonic acid, vinyl alcohol, vinyl acetate, poly (vinyl alcohol)s, (such as Mowiol® from Kuraray), functionalised poly (vinyl alcohol)s (including, for example, butyl acetals), polymers such as Kolloidon® or Luvicross® available from BASF, acrylic copolymers such as Carbopol® (homo- and copolymers of acrylic acid crosslinked with a polyalkenyl polyether) or Ultralez 10, 21 , 30 or Noveon®AA-1 range from Lubrizol (acrylic acid polymer crosslinked with divinyl glycol), and the Sokolan® range from BASF (PAA) such as CP5, CP10 and PA30.

[0029] In an embodiment, the water-soluble polymer is polyvinyl alcohol) (PVOH) or a polyvinyl alcohol)-based polymer. [0030] PVOH polymers are typically manufactured by the polymerisation of vinyl acetate to obtain polyvinyl acetate) (PVAc). Thereafter the PVAc is hydrolysed to polyvinyl alcohol), as shown in Scheme 1 below:

Polyvinyl alcohol) (PVOH) Polymers

Scheme 1 - preparation of polyvinyl alcohol) polymers from vinyl acetate

[0031 ] It will be appreciated that during hydrolysis of the PVAc, a number of the vinyl acetate groups present may remain un-hydrolysed in the resulting PVOH polymer. Such polymers, with a mixture of vinyl alcohol units and un-reacted vinyl acetate units, are commonly referred to by the name PVOH by those skilled in the art. The degree of hydrolysis of a PVOH is important in determining its properties.

[0032] Optionally, a second olefinic monomer, such as ethylene or propylene, may be copolymerised with the vinyl acetate and the resulting copolymers hydrolysed to create vinyl alcohol groups in the same manner. The olefinic monomer may be present in an amount from 1 to 50 mol% or 2 to 40 mol% or 5 to 20 mol% of the polymer backbone. The resulting polyvinyl alcohol) polymers typically have modified water solubility and other physical properties compared with those derived from homopolymers of vinyl acetate. Alternatively, the olefinic monomer may be a vinylic, acrylic or methacrylic monomer, including styrene, acrylonitrile, methacrylonitrile, crotononitrile, vinyl halides, vinylidene halides, (meth)acrylamide, N,N- dimethyl acrylamide, vinyl polyethers of ethylene or propylene oxide, vinyl esters such as vinyl formate, vinyl benzoate or vinyl ethers (such as VeoVa™ 10 available from Momentive™), vinyl ethers of heterocyclic vinyl compounds, alkyl esters of mono-olefinically unsaturated dicarboxylic acids and in particular esters of acrylic and methacrylic acid; vinyl monomers with hydroxyl functionality 2-hydroxy ethyl (meth)acrylate, 2-hydroxy propyl (meth)acrylate, glycerol mono(meth)acrylate, 4-hydroxy butyl (meth)acrylate, hydroxyl stearyl methacrylate, N-methylol (meth)acrylamide; vinyl monomers with additional functionality for crosslinking or adhesion promotion or post functionalization of the vinyl polymers, such as diacetone acrylamide, aceto acetoxy ethyl (meth)acrylate, glycidyl methacrylate, 2-acrylamido-2-methylpropane sulfonic acid, (meth)acrylic acid, beta carboxy ethyl (meth)acrylate, maleic anhydride, styrene sulfonic acid, sodium sulfo propyl methacrylate, itaconic acid; N, N'-dimethyl acrylamine, N-isopropyl acrylamide, Ν,Ν-dimethyl ethyl amino (meth)acrylate, Ν,Ν-diethyl ethyl amino (meth)acrylate, Ν,Ν-dimethyl propyl amino (meth)acrylate, Ν,Ν-diethyl propyl amino (meth)acrylate, 4- and 2- vinyl pyridine, amino methyl styrene, crotonic acid, esters of crotonic acid, crotononitrile, vinyl imidazole; and basic amine monomers can be polymerised as the free amine, protonated salts or as a quaternised amine salt. Where a monomer is indicated with a prefix in brackets (e.g. meth) it shall be understood that it be used in a form with or without the methyl substitution, or alternatively an alternative alkyl group may be present. For example, in the case of acrylic acid, methacrylic acid or another derivative such as ethacrylic acid may be used.

[0033] In addition it may be envisioned that a PVOH based polymer may conceivably contain 'PVOH' as a block within another polymer or copolymer or as grafts to, or from, another polymer or copolymer backbone or as a branched polymer containing short, oligomeric or polymeric cross-links within the polymeric or co-polymeric structure as a whole. A degree of cross-linking may be beneficial in order to maintain structural integrity of the coated layer as well as to increase the barrier properties of the layer. Cross-linking may be carried out by any suitable technique which are well known and may include the use of agents such as epoxides, formaldehyes, isocyanates, reactive siloxanes, anhydrides, amidoamines, boric acid and suitably reactive transition metals and derivatives thereof.

[0034] It will be appreciated that PVOH may also be prepared by the hydrolysis of other polyvinyl esters) such as polyvinyl formate), polyvinyl benzoate) or polyvinyl ethers). Similarly a copolymer of vinyl alcohol such as poly(ethylene-vinyl alcohol) may also be prepared by copolymerising the relevant monomer with a vinyl ester other than vinyl alcohol and hydrolysing the resulting polymer for instance. Such polymers are also within the scope of the present invention.

[0035] PVOH grades with varying degrees of polymerization and hydrolysis are available under the trade name Mowiol (Kuraray Chemicals) and include partly and fully saponified grades. Specific examples of fully saponified Mowiol include those known as 3-85, 4-88, 4-98, 6-98, 8- 88, 10-98, 13-88, 15-99, 20-98 and 30-98 (CAS Nos: 9002-89-5). Specific examples of partly saponified Mowiol include those known as 3-85 G4, 4-88 G2, 8-88 G2, 18-88 G2, 23-88 G2, 47-88 G2, 3-85, 4-88, 5-88, 8-88, 13-88, 18-88, 23-88, 26-88, 32-88, 40-88, 44-88, 47-88, 30- 92, 4-88 LA, 8-88 LA and 40-88 LA (CAS Nos: 23213-24-5). The first number in the nomenclature denotes the viscosity of the 4 % aqueous solution at 20 "C as a relative measure for the molar mass of the Mowiol; the second number denotes the degree of hydrolysis of the polyvinyl acetate from which the Mowiol grade is derived. Mowiol 3-85, 3-88, 4-88 and 4-98 and are particularly preferred, especially Mowiol 3-88 and 4-88. [0036] In an embodiment, the water-soluble polymer is a PVOH or PVOH-based polymer having degree of hydrolysis within the range 60-99%. Suitably, the water-soluble polymer is a PVOH or PVOH-based polymer having degree of hydrolysis within the range 85-99%. Such high degree of hydrolysis gives rise to favourable solubility characteristics.

[0037] In another embodiment, the water-soluble polymer is a PVOH or PVOH-based polymer having a molecular weight in the range of 1 ,000 to 300,000 Da. Aqueous solutions of such polymers having improved handling characteristics.

[0038] In a particular embodiment, the water-soluble polymer is a polyvinyl alcohol)-based polymer in which a portion of the hydroxyl groups have been modified by reaction with a (2- 22C)aldehyde. The use of such polymers may considerably improve the processing of the antifoam formulations with respect to the unmodified PVOH-based polymer. Suitably, the water- soluble polymer is a polyvinyl alcohol)-based polymer in which a portion of the hydroxyl groups have been modified by reaction with a (2-10C)aldehyde. The degree of modification of the PVOH based polymer may be from about 0.1 % to about 50 %, by this it is meant that the OH' portion of the PVOH has been replaced by the given percentage. The person skilled in the art will appreciate that, for example, in the case of the reaction of an aldehyde with 'PVOH' for each molar quantity of aldehyde two molar quantities of OH' are substituted via the acetalation reaction. Hence a 50 % modified PVOH will have been reacted with 25 % of a suitable aldehyde, and, of course the degree of hydrolysis of the PVOH will dictate the maximum level of substitution possible.

[0039] In another embodiment, the modified water-soluble polymer is a PVOH based polymer in which at least a portion of the H atoms of the -OH groups have been exchanged for 2-10C aldehyde groups (i.e. by an ester linkage). Suitably, between 0.1 and 50 % of the -OH groups have been exchanged for 2-10C aldehyde groups. More suitably, between 1 and 15 % of the - OH groups have been exchanged for 2-10C aldehyde groups. Even more suitably, between 2 and 12% of the -OH groups have been exchanged for 2-10C aldehyde groups.

[0040] In another embodiment, the modified water-soluble polymer has a structure that can be schematically represented by formula (I) shown below:

(I) wherein each R_x is (1 -9C)alkyl, (2-9C)alkenyl or (2-9C)alkynyl,

x denotes the proportion of modified PVOH monomeric moieties, y denotes the proportion of residual acetate monomeric moieties present in the polymer following hydrolysis to yield the PVOH, and

z denotes the proportion of unmodified PVOH monomeric moieties.

[0041 ] It will also be understood that formula (I) shows a schematic representation illustrating the structures of the various monomeric moieties that collectively constitute the modified PVOH. Hence, formula (I) does not necessarily imply that the water-soluble polymers are block copolymers or alternating copolymers. On the contrary, monomeric moieties x, y and z may be randomly distributed throughout polymers falling within the scope of formula (II). It will also be understood that PVOH-based polymers falling within the scope of formula (II) may comprise, in addition to monomeric moieties x, y and z, other monomeric moieties.

[0042] In another embodiment, the water-soluble polymer is the product formed by reacting a PVOH-based polymer with a 2-1 OC aldehyde, such that between 0.1 and 50 % of the -OH groups are exchanged for 2-1 OC aldehyde groups. Suitably, the water-soluble polymer is the product formed by reacting a PVOH-based polymer with a 2-1 OC aldehyde, such that between 1 and 15 % of the -OH groups are exchanged for 2-1 OC aldehyde groups. More suitably, the water-soluble polymer is the product formed by reacting a PVOH-based polymer with a 2-1 OC aldehyde, such that between 2 and 12 % of the -OH groups are exchanged for 2-1 OC aldehyde groups. Even more suitably, the water-soluble polymer is the product formed by reacting a PVOH-based polymer with a 2-1 OC aldehyde, such that between 2 and 10 % of the -OH groups are exchanged for 2-1 OC aldehyde groups. Most suitably, the water-soluble polymer is the product formed by reacting a PVOH-based polymer with a 2-1 OC aldehyde, such that between 4 and 9 % of the -OH groups are exchanged for 2-1 OC aldehyde groups.

[0043] In a particularly suitable embodiment, the water-soluble polymer is a PVOH polymer in which a portion of the available -OH groups have been modified by reaction with butyraldehyde. Such polymers have a structure according to formula (I) wherein R_x is butyl. Suitably, the degree of substitution of the OH groups for such polymers is from 0.1 to 50 %. More suitably, the degree of substitution of the OH groups for such polymers is from 1 to 20 %. Most suitably, the degree of substitution of the OH groups for such polymers is from 2 to 10 %

[0044] In an exemplary embodiment, the water-soluble polymer is a PVOH polymer having a degree of hydrolysis of 85-99 % that has modified by reaction of 5 % or 8 % of the available OH groups with butyraldehyde.

[0045] In an embodiment, the antifoam formulation comprises 0.5 - 4.5 wt.% of the water- soluble polymer. Suitably, the antifoam formulation comprises 0.8 - 3.8 wt.% of the water- soluble polymer. More suitably, the antifoam formulation comprises 1 - 3.5 wt.% of the water- soluble polymer. Even more suitably, the antifoam formulation comprises 1 .5 - 3.5 wt.% of the water-soluble polymer. Yet more suitably, the antifoam formulation comprises 1 .8 - 3.0 wt.% of the water-soluble polymer. Yet more suitably, the antifoam formulation comprises 1 .8 - 2.5 wt.% of the water-soluble polymer. Most suitably, the antifoam formulation comprises 1 .8 - 2.2 wt.% of the water-soluble polymer.

[0046] In an embodiment, the antifoam formulation comprises 3.5 - 4.5 wt.% of the water- soluble polymer.

[0047] The absorbent assists in the processing of the solid antifoam formulation, by acting as a reservoir for water that is used during manufacture. The absorbent also assists in binding together the solid formulation during the drying stage of manufacture. Any suitably absorbent may be used.

[0048] The absorbent is suitably a starch. Starches are glucose polymers in which glucopyranose units are bonded by a/pfta-linkages. Suitably, the absorbent is a starch selected from potato starch, maize starch, wheat starch, rice starch and partially pregellatinised starches from the aforementioned list. Alternatively, the absorbent may be a modified starch or a gum. Most suitably, the absorbent is maize starch or potato starch.

[0049] In an embodiment, the antifoam formulation comprises 10.5 - 50 wt.% of the absorbent. Suitably, the antifoam formulation comprises 12 - 50 wt.% of the absorbent. More suitably, the antifoam formulation comprises 15 - 50 wt.% of the absorbent. Yet more suitably, the antifoam formulation comprises 17.5 - 47.5 wt.% of the absorbent.

[0050] In an embodiment, the antifoam formulation comprises 34.0 - 50.0 wt.% of the absorbent. Suitably, the antifoam formulation comprises 35.0 - 47.0 wt.% of the absorbent. More suitably, the antifoam formulation comprises 36.0 - 45.0 wt.% of the absorbent. Yet more suitably, the antifoam formulation comprises 36.0 - 41 .0 wt.% of the absorbent. [0051 ] The filler comprises an organic filler, an inorganic filler, or a mixture thereof.

[0052] In an embodiment, the filler comprises one or more organic fillers. Organic fillers include saccharides, polysaccharides, and derivatives thereof. As used herein, the term "saccharide" refers to the group that includes sugars, starch and cellulose. The saccharides are divided into the following chemical groups: monosaccharides, disaccharides, oligosaccharides and polysaccharides.

[0053] As used herein, the term "monosaccharide" refers to the simple sugars that are the building blocks of carbohydrates. A monosaccharide cannot be further reduced by hydrolysis into another simple sugar. Examples of monosaccharides include glucose, dextrose, fructose and galactose.

[0054] As used herein, the term "disaccharide" refers to a carbohydrate formed when two monosaccharides undergo a condensation reaction which involves the elimination of a small molecule, such as water. Examples of disaccharides include sucrose, lactose, and maltose.

[0055] As used herein, the term "oligosaccharide" refers to a carbohydrate formed from a small number (typically three to nine) of monosaccharide units.

[0056] As used herein, the term "polysaccharide" refers to polymeric carbohydrate molecules composed of long chains of monosaccharide units bound together by glycosidic linkages, which on hydrolysis give the constituent monosaccharides or oligosaccharides. Polysaccharides range in structure from linear to highly branched. The term "polysaccharide" typically refers to molecules containing ten or more monosaccharide units, although it may also encompass molecules with fewer than ten monosaccharide units. When all the monosaccharides in a polysaccharide are the same type, the polysaccharide is called a homopolysaccharide or homoglycan, but when more than one type of monosaccharide is present they are called heteropolysaccharides or heteroglycans. Polysaccharides have the general formula of Cx(H₂0)_y where x is typically a number between 200 and 2,500. As the repeating units in the polymer backbone are often six-carbon monosaccharides, the general formula can also be represented as (C₆Hio0₅)n where 40≤n≤3,000. Examples of suitable polysaccharides include starch, cellulose, glycogen, chitin, callose or laminarin, chrysolaminarin, xylan, arabinoxylan, mannan, fucoidan and galactomannan.

[0057] As used herein, the term "derivative" refers to a chemically or physically modified saccharide or polysaccharide, for example, carboxy methyl cellulose.

[0058] In a particular embodiment, the filler is an organic filler that is a cellulosic material. The cellulosic material may be cellulose fibres (including microcrystalline cellulose), methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose or carboxy-functional celluloses such as carboxymethyl cellulose. Most suitably, the cellulosic material is microcrystalline cellulose.

[0059] In another embodiment, the filler is an inorganic filler. Inorganic fillers include talcs, micas, zeolites, silicates and clays. Suitably, the inorganic filler is talc or bentonite, most suitably talc.

[0060] In an embodiment, the filler is a cellulosic compound, optionally in combination with an inorganic filler selected from talcs, micas, zeolites, silicates and clays.

[0061 ] In an embodiment, the filler is a mixture of microcrystalline cellulose and/or talc.

[0062] In an embodiment, the antifoam formulation comprises 5 - 50 wt.% of the filler. Suitably, the antifoam formulation comprises 5 - 45 wt.% of the filler. More suitably, the antifoam formulation comprises 5 - 40 wt.% of the filler. Even more suitably, the antifoam formulation comprises 7.5 - 35 wt.% of the filler. Even more suitably, the antifoam formulation comprises 15 - 35 wt.% of the filler. Most suitably, the antifoam formulation comprises 20 - 35 wt.% of the filler.

[0063] In an embodiment, the antifoam formulation comprises 8.0 - 32.5 wt.% of the filler. Suitably, the antifoam formulation comprises 8.0 - 30.0 wt.% of the filler. More suitably, the antifoam formulation comprises 8.0 - 28.0 wt.% of the filler. Even more suitably, the antifoam formulation comprises 8.0 - 12.0 wt.% of the filler.

[0064] In an embodiment, the antifoam formulation comprises 23.0 - 28.0 wt.% of the filler.

[0065] The non-strongly alkaline, water-soluble salt is one which typically forms an aqueous solution having a pH of ≤9. In contrast to strongly alkaline salts such as carbonates, non- strongly alkaline salts do not have a detrimental effect on the washing process when they are used as part of a detergent formulation. Suitable salts include alkali metal, alkali earth metal or transition metal salts of halides, sulfates, phosphates, oxides, acetates, citrates, bicarbonates or nitrates.

[0066] In an embodiment, the antifoam formulation does not comprise a strongly alkaline water-soluble salt (e.g. a salt that forms an aqueous solution having a pH of >9, such as sodium carbonate).

[0067] In certain embodiment, the non-strongly alkaline, water-soluble salt is one which typically forms an aqueous solution (0.1 N) having a pH of ≤9 or≤8.5.

[0068] In an embodiment, the non-strongly alkaline, water-soluble salt comprises one or more selected from the group consisting of sodium sulfate, sodium chloride, sodium acetate, potassium sulfate, potassium chloride and sodium citrate. Suitably, the non-strongly alkaline, water-soluble salt comprises one or more selected from the group consisting of sodium sulfate and sodium citrate.

[0069] In an embodiment, the non-strongly alkaline, water-soluble salt comprises one or more selected from the group consisting of sodium bicarbonate, sodium sulfate, sodium chloride, sodium acetate, potassium sulfate, potassium chloride and sodium citrate. Suitably, the non- strongly alkaline, water-soluble salt comprises one or more selected from the group consisting of sodium bicarbonate, sodium sulfate and sodium citrate.

[0070] In an embodiment, the antifoam formulation comprises 5 - 55 wt.% of the non-strongly alkaline, water-soluble salt. Suitably, the antifoam formulation comprises 5 - 50 wt.% of the non-strongly alkaline, water-soluble salt. More suitably, the antifoam formulation comprises 5.5 - 50 wt.% of the non-strongly alkaline, water-soluble salt. More suitably, the antifoam formulation comprises 7.5 - 45 wt.% of the non-strongly alkaline, water-soluble salt. More suitably, the antifoam formulation comprises 7.5 - 35 wt.% of the non-strongly alkaline, water- soluble salt.

[0071 ] In an embodiment, the antifoam formulation comprises 16.0 - 40.0 wt.% of the non- strongly alkaline, water-soluble salt. Suitably, the antifoam formulation comprises 18.0 - 38.0 wt.% of the non-strongly alkaline, water-soluble salt. More suitably, the antifoam formulation comprises 18.0 - 25.0 wt.% of the non-strongly alkaline, water-soluble salt. More suitably, the antifoam formulation comprises 18.0 - 22.0 wt.% of the non-strongly alkaline, water-soluble salt.

[0072] In an embodiment, the antifoam formulation comprises 30.0 - 40.0 wt.% of the non- strongly alkaline, water-soluble salt.

[0073] In an embodiment, the antifoam formulation has a moisture content of 10 wt.% or less. Suitably, the antifoam formulation has a moisture content of 5 wt.% or less. More suitably, the antifoam formulation has a moisture content of 2 wt.% or less.

[0074] In an embodiment, the antifoam formulation is organic solvent-free. Owing to the fact that the formulations of the invention are processed using aqueous solvent, they may be devoid of any organic solvent.

[0075] The solid antifoam formulation is suitably provided in particulate or granular form. Suitably, the granules are uncoated matrix particles. Within such an uncoated matrix particle, all of the components of the granule may be substantially uniformly distributed throughout the entirety of the granule.

[0076] In an embodiment, the solid antifoam formulation has an average particle size of 10 to 10,000 μηι. The particles can be substantially spherical, or spheroidal, or cylindrical in shape. Where the particles are spherical, or spheroidal, suitable mean particle diameters are 10 to 3,000 μηι, more suitably 100 to 2,000 μηι. Where the particles are cylindrical in shape, they may have mean diameters of 100 to 2,000 μηι. Suitably, the cylinders are 0.5 to 5 cm in length.

[0077] Most suitably, the particles of the solid antifoam formulation have a mean particle size of 0.5 to 1 .5 mm. The particles may be of any form. Suitably they are in the form of granules.

[0078] The particles have bulk densities from 0.35 to 1 .0 gem ³. Suitably, the particles have bulk densities from 0.35 to 0.8 gem ³

[0079] Numbered paragraph (1 ) to (8) below outline particular embodiments of the solid antifoam formulation. It will be understood that the term "comprising" used therein, and throughout this specification as a whole, may be replaced with the term "consisting essentially of".

1 ) A solid antifoam formulation comprising:

7.5 - 20 wt.% of an antifoam agent;

0.5 - 4.5 wt.% of a water-soluble polymer;

15 - 50 wt.% of an absorbent

5 - 50 wt.% of a filler; and

5 - 55 wt.% of a non-strongly alkaline, water-soluble salt.

2) A solid antifoam formulation comprising:

10 - 17.5 wt.% of an antifoam agent;

0.8 - 3.8 wt.% of a water-soluble polymer;

17.5 - 47.5 wt.% of an absorbent

5 - 45 wt.% of a filler; and

5 - 55 wt.% of a non-strongly alkaline, water-soluble salt.

3) A solid antifoam formulation comprising:

10 - 17.5 wt.% of an antifoam agent;

0.8 - 3.8 wt.% of a water-soluble polymer;

17.5 - 47.5 wt.% of an absorbent

5 - 40 wt.% of a filler; and

7.5 - 55 wt.% of a non-strongly alkaline, water-soluble salt.

4) A solid antifoam formulation comprising:

10 - 16 wt.% of an antifoam agent;

0.8 - 3.8 wt.% of a water-soluble polymer;

17.5 - 47.5 wt.% of an absorbent

7.5 - 45 wt.% of a filler; and

7.5 - 55 wt.% of a non-strongly alkaline, water-soluble salt. ) A solid antifoam formulation comprising:

14 - 16 wt.% of an antifoam agent;

1 - 3 wt.% of a water-soluble polymer;

17.5 - 47.5 wt.% of an absorbent

7.5 - 35 wt.% of a filler; and

5 - 50 wt.% of a non-strongly alkaline, water-soluble salt.) A solid antifoam formulation comprising:

14 - 16 wt.% of an antifoam agent;

1 - 3 wt.% of a water-soluble polymer;

17.5 - 47.5 wt.% of an absorbent

15 - 35 wt.% of a filler; and

7.5 - 45 wt.% of a non-strongly alkaline, water-soluble salt.) A solid antifoam formulation comprising:

14 - 16 wt.% of an antifoam agent;

1 - 3 wt.% of a water-soluble polymer;

17.5 - 47.5 wt.% of an absorbent

20 - 35 wt.% of a filler; and

7.5 - 35 wt.% of a non-strongly alkaline, water-soluble salt.) A solid antifoam formulation comprising:

14 - 16 wt.% of an antifoam agent;

1 .5 - 3.5 wt.% of a water-soluble polymer;

17.5 - 47.5 wt.% of an absorbent

20 - 35 wt.% of a filler; and

7.0 - 17.0 wt.% of an antifoam agent;

1 .5 - 4.5 wt.% of a water-soluble polymer;

34.0 - 50.0 wt.% of an absorbent

8.0 - 32.5 wt.% of a filler; and

16.0 - 40.0 wt.% of a non-strongly alkaline, water-soluble salt.0) A solid antifoam formulation comprising:

10.0 - 17.0 wt.% of an antifoam agent;

1 .5 - 3.0 wt.% of a water-soluble polymer;

36.0 - 45.0 wt.% of an absorbent

8.0 - 28.0 wt.% of a filler; and

18.0 - 38.0 wt.% of a non-strongly alkaline, water-soluble salt. 1 ) A solid antifoam formulation comprising: 10.0 - 17.0 wt.% of an antifoam agent;

1 .5 - 2.5 wt.% of a water-soluble polymer;

36.0 - 45.0 wt.% of an absorbent

8.0 - 12.0 wt.% of a filler; and

18.0 - 38.0 wt.% of a non-strongly alkaline, water-soluble salt.) A solid antifoam formulation comprising:

14.0 - 16.0 wt.% of an antifoam agent;

1 .5 - 2.5 wt.% of a water-soluble polymer;

36.0 - 45.0 wt.% of an absorbent

8.0 - 28.0 wt.% of a filler; and

14.0 - 16.0 wt.% of an antifoam agent;

1 .5 - 2.5 wt.% of a water-soluble polymer;

36.0 - 45.0 wt.% of an absorbent

8.0 - 12.0 wt.% of a filler; and

18.0 - 25.0 wt.% of a non-strongly alkaline, water-soluble salt.) A solid antifoam formulation comprising:

14.0 - 16.0 wt.% of an antifoam agent;

1 .8 - 2.2 wt.% of a water-soluble polymer;

36.0 - 45.0 wt.% of an absorbent

8.0 - 12.0 wt.% of a filler; and

14.0 - 16.0 wt.% of an antifoam agent;

1 .8 - 2.2 wt.% of a water-soluble polymer;

36.0 - 40.0 wt.% of an absorbent

8.0 - 28.0 wt.% of a filler; and

10.0 - 14.0 wt.% of an antifoam agent;

1 .8 - 2.2 wt.% of a water-soluble polymer;

37.0 - 42.0 wt.% of an absorbent

8.0 - 28.0 wt.% of a filler; and

18.0 - 38.0 wt.% of a non-strongly alkaline, water-soluble salt. [0080] In any of numbered paragraphs (1 ) to (16) above, the antifoam agent, water-soluble polymer, absorbent, filler and non-strongly alkaline, water-soluble salt may have any of the definitions appearing hereinbefore.

[0081 ] In any of numbered paragraphs (1 ) to (16) above, the antifoam agent may comprise polydimethylsiloxane or a polydimethylsiloxane-based polymer.

[0082] In any of numbered paragraphs (1 ) to (16) above, the water-soluble polymer is a PVOH or a PVOH-based polymer. Suitably, the water-soluble polymer is a PVOH in which a portion of the available OH groups have been modified by reaction with butyraldehyde.

[0083] In any of numbered paragraphs (1 ) to (16) above, the absorbent is a starch. Suitably, the starch is potato starch or maize starch.

[0084] In any of numbered paragraphs (1 ) to (16) above, the filler is microcrystalline cellulose, or a mixture of microcrystalline cellulose and talc.

[0085] In any of numbered paragraphs (1 ) to (16) above, the non-strongly alkaline, water- soluble salt is sodium sulfate, sodium citrate, or a mixture thereof.

Preparation of solid antifoam formulations

[0086] As described hereinbefore, the present invention also provides a process for the preparation of a solid antifoam formulation as defined herein, said process comprising the steps of:

b) drying the mixture resulting from step a).

[0087] The solid antifoam formulations of the invention can be prepared by a number of different processing techniques, including granulation, extrusion and spheronisation, and spray agglomeration.

[0088] In an embodiment, the water-soluble polymer mixed in step a) is provided as an aqueous solution. Suitably, the water-soluble polymer mixed in step a) is provided as an aqueous solution comprising 1 -25 wt% of the water-soluble polymer.

[0089] In another embodiment, prior to mixing in step a), the antifoam agent is heated to a temperature of 50 to 100 °C. Suitably, prior to mixing in step a), the antifoam agent is heated to a temperature of 60 to 90 °C. More suitably, prior to mixing in step a), the antifoam agent is heated to a temperature of 70 to 85 °C. The antifoam agent may be so heated for between 5 and 200 minutes. Suitably, the antifoam is so heated for between 30 and 100 minutes. [0090] In another embodiment, step b) is performed on a fluid bed dryer.

[0091 ] In another embodiment, step b) comprises drying the mixture resulting from step a) at a temperature of 25 to 80 °C. Suitably, step b) comprises drying the mixture resulting from step a) at a temperature of 35 to 65 °C. More suitably, step b) comprises drying the mixture resulting from step a) at a temperature of 45 to 55 °C.

[0092] In a particular embodiment, the solid antifoam formulation may be produced by a granulation technique. In such embodiments, step a) comprises adding water to the antifoam agent, water-soluble polymer, absorbent, filler, non-strongly alkaline, water-soluble salt under mixing, wherein the quantity of water added is sufficient to form discrete granules of the mixture; and step b) comprises drying the discrete granules resulting from step a) (e.g. in a fluid bed dryer).

[0093] In another particular embodiment, the solid antifoam formulation may be produced by an extrusion technique. In such embodiments, step a) comprises mixing the antifoam agent, water-soluble polymer, absorbent, filler, non-strongly alkaline, water-soluble salt, and water, to form a mixed mass, which is then extruded as an extrudate; and step b) comprises drying the extrudate resulting from step a). Optionally, prior to drying step b), the extrudate may be treated so as to form discrete granules (e.g. spheronisation).

[0094] In another particular embodiment, the solid antifoam formulation may be produced by a spray agglomeration technique. In such embodiments, step a) comprises:

a1 ) mixing the antifoam agent, absorbent, filler, and non-strongly alkaline, water-soluble salt to form a dry mixture, and

a2) spraying onto the mixed dry mixture an aqueous solution of the water-soluble polymer;

and step b) comprises drying the mixture resulting from step a).

[0095] Suitably, no organic solvents are used in the processes of the invention.

[0096] As described hereinbefore, the present invention also provides a solid antifoam formulation obtained, directly obtained or obtainable by a process defined herein.

Applications

[0097] As described hereinbefore, the present invention also provides a solid laundry detergent formulation comprising a solid antifoam formulation defined herein. [0098] As described hereinbefore, the present invention also provides a use of a solid antifoam formulation defined herein for reducing the formation of foam.

[0099] The antifoam formulations of the invention can be readily incorporated into granular or powder detergent formulations, wherein they demonstrate excellent stability.

[00100] In an embodiment, the laundry detergent formulation comprises 5 - 25 wt.% of the solid antifoam formulation. Suitably, the laundry detergent formulation comprises 10 - 20 wt.% of the solid antifoam formulation.

EXAMPLES

Materials, Abbreviations and Suppliers

[00101] The materials used throughout the examples are as follows:

Arbocel UFC M8 Rettenmaier Corporation

Butyraldeyde Aldrich Chemical Company

Maize starch Roquette Corporation

Mowiol® Kuraray Co LTD

Potato starch Roquette Corporation

SC 1 132 silicone fluid Wacker AG

AF 1500 acc silicones

Xiameter^® ACP-3425 Dow Corning

Sodium hydrogen carbonate Aldrich Chemical Company

Sodium hydroxide Aldrich Chemical Company

Sodium Sulfate Aldrich Chemical Company

Sulfuric acid Aldrich Chemical Company

Maize Starch Roquette Corporation

MCC Sidley Industrial 10 Sidley Chemical Co., Ltd

Talc Aldrich Chemical Company

or Imerys

Trisodium citrate Mistral Chemical Company

ECE-2-modified containing no antifoam colour fastness test detergent, (phosphate-free) IS0105 C 08 88031 -modified obtained from WFK GmbH.

[00102] Moisture contents were measured on an Adam PMB 202 moisture balance. General methods

Butyration of polyvinyl alcohol)

[00103] The following procedure outlines the preparation of butyvated PVOH (PVB) solution. The same procedure was used for 4-98, 4-88 and 10-98 PVOH starting materials:

[00104] Mowiol^® 4-98 (ex Kuraray, 300 g) was added to deionised water (1 .2 L) with stirring at room temperature (in one aliquot) and heated to 90 °C, over the course of 1 hour, and stirred with heating for a further 2 hours after which an isotropic, straw coloured solution of pH ~5 - 6 was achieved. The solution was then cooled to 60 °C and 2 M H₂S0₄ (20.1 mL, 0.04 mols) was added giving pH ~2 - 3, butyraldehyde (19.27 g, 0.27 mols) was then added, the solution was stirred at 60 °C for a further 4 hours before cooling to room temperature and neutralising to pH 7 with 0.5 M NaOH solution (ca 160 mL). The solution was then referred to as "PVB" having a total solids content of ca 20 % w/w. This solution was further diluted, as required, by the addition of deionised water.

Preparation of Antifoam Granules

[00105] Small-scale granulations were performed on a food grade Kenwood FPP220 Multipro Compact mixer and subsequently dried on an Aeromatic Fielder Strea 1 fluid bed dryer. The general procedure is outlined below in reference to the preparation of G1 .

[00106] Maize starch (95 g), Arbocel M8 UFC (62.5 g) and sodium sulfate (50 g) were weighed directly into the blender and mixed together for 10 seconds on speed "2" for 10 seconds. SC1 132 (37.5 g), previously heated in an oven to 75° C for 90 minutes, was then added to the dry powder with mixing at speed "2" , uniformly over the course of ~ 1 minute. The previously prepared PVB solution (49.5 g, 5 % weight/weight solids 4-98 8% BA) was then added with high speed mixing at speed "2", uniformly over the course of 2 minutes. Demineralised water (55.8 g) was then added with blending until the mixture reached the point where discrete, non dusty, granules were visible. The particles were then dried in a fluid bed dryer for 40 mins with a 50 °C inlet temperature. The particles were sieved to between 250 and 1 ,000 μηι and a moisture content of 3.6 % weight/weight.

Extrusion and Spheronisation

[00107] Formation of the wet mass was performed on a food grade Kenwood FPP220 Multipro Compact mixer the extrusion was perfumed on a Caleva Variable Density Extruder with the 0.7 mm diameter hole die plate. The spheronisation was performed on a Caleva Multi Bowl Spheroniser 250 (MBS250). Drying of the particles was performed on an Aeromatic Fielder Strea 1 .

Extrusion

[00108] Potato starch (88 g), Arbocel M8 UFC (58 g) and sodium sulfate (20 g) were weighed directly into the blender and mixed together for 10 seconds on a speed setting "2". SC1 132 (30 g) was heated in an oven to 80 °C for 40 minutes and added to the dry powder, then blended together for 10 seconds. PVB solution (40 g - 10% weight/weight solids 4-98 8% BA) was slowly added whilst mixing on a speed setting "2". Demineralised water (54 g) was added with blending until the mixture reached the correct consistency, this was determined by taking a portion of the mixture and compressing by hand, when the material held a shape that required pressure to break it apart and gave a 'slide' texture between thumb and forefinger the material was ready. Extrusion was carried at 50 rpm and the resulting material dried in a STREA fluid bed dryer for 45 mins with a 50 °C inlet temperature.

Spheronisation

[00109] The general procedure is outlined below in reference to the preparation of S1 .

[00110] The formulation was made in the exact same way asE1 . Immediately after extrusion the material was placed into a Caleva 250 mm bowl benchtop spheroniser and spheronised for 1 minute at a speed of 1200 rpm. The resulting spheroids were then dried in the same manner as the extrudates in G1 although for only 25 minutes.

Spray agglomeration

[00111] Spray agglomeration was performed on a Glatt Mini Glatt 5 spray dryer fitted with a top spray configuration with a 0.5 mm nozzle attachment. The procedure is outlined below in relation to the preparation of SA 1 .

[00112] Maize starch (45.5 g), Arbocel M8 UFC (30 g) and sodium sulfate (24 g) were weighed directly into the blender and mixed together for 10 seconds on a high speed setting. SC1 132 (30 g), previously heated to 70 °C in an oven for 90 minutes, was then added to the dry powder with mixing at speed "2", evenly over the course of -40 seconds. The powder was then spray agglomerated in the mini Glatt with a 5 % PVB (prepared from Mowiol® 4-98) solution at an addition rate of 0.2 g/min and a fluid bed temperature of 30 °C. To give particles with a mean size distribution of between 250 and 1 ,000 μηι and a moisture content of 0.25 % w/w Antifoam formulations

[00113] Table 1 below outlines antifoam formulations of the invention.

Table 1 - Composition of antifoam formulations of the invention

G1 1 Maize starch Arbocel UFC Sodium PVB (10-98, SC1 132 15.0 37.7 M8 sulfate 8% BA) 62

25 20 2.3

G12 Maize starch Arbocel UFC Sodium PVB (4-98, SC1 132 15.0

37.7 M8 sulfate 8% BA) 2.3

33

25 20

G13 Maize starch Arbocel UFC Sodium PVB (4-98, SC1 132 15.0

37 M8 sulfate 8% BA) 37

24.5 20 3.5

G14 Maize starch Arbocel UFC Sodium PVB (4-98, SC1 132 15.0

36 M8 sulfate 8% BA)

12 24 2

Sodium 26

citrate

12

G15 Maize starch Arbocel UFC Sodium PVB (4-98, SC1 132 15.0

30 M8 sulfate 8% BA)

10 21 .5 2

23

Sodium

citrate21 .5

G16 Maize starch Arbocel UFC PVB (4-98, SC1 132 15.0

20 M8 Sodium 8% BA)

10 sulfate 30 2

Talc 28

(Aldrich)

23

G17 Maize starch MCC (Sidley Sodium PVB (4-98, SC1 132 15.0

20 industrial) sulfate 8% BA)

10 30 2

Talc 27

(Aldrich)

23

G18 Maize starch MCC Sidley Sodium PVB (4-88, SC1 132 1 1 .5

20 industrial sulfate 8% BA)

10 30 2

Talc

29

(Aldrich)

26.5

G19 Maize starch MCC Sidley Sodium PVB (4-88, SC1 132 15.0

20 industrial sulfate 25 8% BA)

10 2

Talc 31

(Aldrich)

28

G20 Maize starch MCC Sidley Sodium PVB (4-88, SC1 132 15.0

20 industrial sulfate 30 8% BA)

10 2

22

Talc (Imerys) G21 Maize starch Arbocel UFC Sodium PVB (4-98, SC1 132 15 28 M8 hydrogen 8% BA)

25 carbonate 2

10

39

Sodium

sulfate

20

G22 Maize starch Talc (Imerys) Sodium PVB (4-88 SC1 132 15.0

38 25 sulphate 8% Bu) 25

20 2

G23 Maize starch Talc (Imerys) Sodium PVB (4-88 SC1 132 12.5

39 25.5 sulphate 8% Bu) 25

21 2

G24 Maize starch Talc (Imerys) Sodium PVB (4-88 SC1 132 15.0

37.5 15 sulphate 8% Bu)

20.5 2

Sodium 21

Hydrogen

Carbonate

10

G25 Maize starch Talc (Imerys) Sodium PVB (4-88 SC1 132 15

38 5 sulphate 8% Bu)

20 2

Sodium

Hydrogen

17

Carbonate

15

Sodium

citrate

5

G26 Maize starch Talc (Imerys) Sodium PVB (4-88 SC1 132 15

38 5 sulphate 8% Bu)

20 2

Sodium

17

Hydrogen

Carbonate

20

G27 Maize starch MCC Sodium PVB (4-88 SC1 132 12.5

40.5 (Arbocel sulphate 8% Bu)

UFC M8) 17.5 2

21

10 Sodium

citrate

17.5

G28 Maize starch MCC Sodium PVB (4-88 SC1 132 7.8

44.4 (Arbocel sulphate 8% Bu)

UFC M8) 17.1 3.9

21

9.8 Sodium

citrate

17.0

G29 Maize starch MCC Sodium PVB (4-88 SC1 132 10.9

41 .1 (Arbocel sulphate 8% Bu)

UFC M8) 17.2 3.9

21

9.8 Sodium

citrate

17.1

G30 Maize starch MCC Sodium PVB (4-88 SC1 132 7.9

39 (Arbocel sulphate 8% Bu)

UFC M8) 18.9 3.9

22

1 1 .5 Sodium

citrate

18.8 G31 Maize starch MCC Sodium PVB (4-88 SC1 132 10.5

37.7 (Arbocel sulphate 8% Bu)

UFC M8) 18.3 3.8

21

1 1 .3 Sodium

citrate

18.4

G32 Maize starch MCC Sodium PVB (4-88, Xiameter® ACP

38 (Arbocel sulfate 8% BA) 3425 15.0

UFC M8) 17.5 2

20

10 Sodium

citrate 17.5

G33 Maize starch MCC Sodium PVB (4-88,

38 (Arbocel sulfate 8% BA) AF 1500 15.0

UFC M8) 17.5 2

17

10 Sodium

citrate 17.5

G34 Maize starch MCC (Sidley Sodium PVB (4-88, SC1 132 15.0

38 industrial) sulfate 8% BA)

10 17.5 2

18

Sodium

citrate 17.5

Spray agglomeration

SA1 Maize starch Arbocel UFC Sodium PVB (10- SC1 132 15.0

39 M8 sulfate 98 8% BA)

16

26 20 1

SA2 Maize starch Arbocel UFC Sodium PVB (10- SC1 132 15.0

38 M8 sulfate 98 8% BA)

25 20 2 35

The terms "wt.%" and "%w/w" are used synonymously herein.

Defoaminq properties of antifoam formulations

[00114] Deionised water (100 mL) was placed into a 250 mL measuring cylinder with 4.2 g of WFK powder was then added to the cylinder. 0.20 g antifoam containing composite was then added. The cylinder was closed with a lid and left for one minute. The cylinder was fully inverted 10 times. Immediately after shaking, the time measured until the foam had collapsed to a rest of 10% was recorded.

[00115] To test the stability of the formulations, samples containing 4.2 g of the standard WFK detergent with 0.2 g of antifoam composite were placed into polyethylene bags and sealed. The bags were placed into a climate controlled chamber at 30 °C and 80% relative humidities for 14, 28, 56 & 84 days. Each sample was tested using the method above and each sample was tested in duplicate [00116] The foam collapsing times were recorded, in seconds, from the end of shaking until a foam level of 10 mL was achieved; this was averaged from the data obtained from each sample. The results are presented in Table 2 below:

Table 2 - Comparison of defoaminq properties of antifoam formulations of the invention and commercially available antifoam products

Average Foam Collapsing time in

seconds

Days Stability 0 14 28 56 84

Sample Sample form

SP 150 Commercial 4.0 1 1 22 25 33

Product- Wacker (15%

active)

Xiameter Commercial 5.0 5.0 6.5 9.0 15.5 APW- product - Dow

4248 Corning

(12.5% active)

G-920 S Commercial 8.0 7.0 9.0 15.5 28.5

product - SIXIN - (10- 20% active)

G-20 T Commercial 2.5 4.0 4.0 14 24

product - SIXIN - (16- 18% active)

E1 Extrudate 6.0 7.0 8.5 12 8.5

S1 Spheroids 17 10 9.5 12.5 22

G1 Granule 1 .5 1 .5 1 .5 2.0 3.0

G2 Granule 1 .5 2.0 2.0 2.5 2.5

G3 Granule 2.0 1 .0 1 .5 3.0 2.5

G4 Granule 6.0 6.0 7.0 7.0 8.0

G5 Granule 3.5 n/d n/d 3.5 4.5

G6 Granule 1 .5 1 .0 2.0 3.0 3.0

G7 Granule 1 .5 1 .5^' 2.0 3.0 3.0 G8 Granule 3.0 2.0 2.0 2.5 7.5

G9 Granule 3.5 3.5 4.5 4.5 5.5

G10 Granule 4.5 2.0 4.5 6.5 6.0

G1 1 Granule 3.0 4.0 4.0 4.5 5.5

G12 Granule 3.5 1 .5 2.0 2.0 2.5

G13 Granule 4.5 1 .5 2.0 2.5 2.5

G14 Granule 3.0 2.5 2.5 3.0 5.0

G15 Granule 5.0 4.5 6.5 6.5 14.5

G16 Granule 4.0 5.0 7.0 13.5 16.5

G17 Granule 4.5 5.5 7.0 7.5 13.0

G18 Granule 8.0 7.0 8.0 1 1 .0 16.0

G19 Granule 6.0 6.0 6.5 8.0 13.5

G20 Granule 4.5 6.5 7.0 12.5 24.0

G21 Granule 3.5 5.5 5.0 4.5 4.5

G22 Granule 5.0 5.0 5.5 6.5 9.0

G23 Granule 8.5 5.5 5.0 7.5 10.5

G24 Granule 5.5 5.5 8.0 1 1 .0 17.0

G25 Granule 2.5 5.5 8.0 12.0 35.0

G26 Granule 3.5 5.5 10.0 21 .5 26.0

G27 Granule 3.5 3.0 3.0 3.0 3.0

G28 Granule 5.0 3.5 3.5 4.0 4.0

G29 Granule 4.5 3.5 3.0 3.5 3.5

G30 Granule 6.0 3.0 3.5 3.5 4.0

G31 Granule 5.0 3.5 3.5 4.0 4.0

G32 Granule 4.0 n/d n/d n/d n/d

G33 Granule 5.0 n/d n/d n/d n/d

G34 Granule 3 3 2 2 4

SA1 Spray 3.0 4.0 4.0 4.0 5.0

agglomerate

SA2 Spray 4.0 4.0 4.0 4.0 3.0

agglomerate

n/d - not determined

[00117] The results presented in Table 2 demonstrate that the antifoam formulations of the invention exhibit defoaming properties that are comparable or considerably better than commercially-available products when the fresh samples are compared. Moreover, the results demonstrate that the antifoam formulations of the invention have markedly improved stability when compared with commercially-available products, and show only negligible decrease in performance when stored for up to 84 days.

[00118] While specific embodiments of the invention have been described herein for the purpose of reference and illustration, various modifications will be apparent to a person skilled in the art without departing from the scope of the invention as defined by the appended claims.

Claims

1 . A solid antifoam formulation comprising:

5 - 25 wt.% of an antifoam agent;

0.1 - 7 wt.% of a water-soluble polymer;

10 - 55 wt.% of an absorbent

5 - 55 wt.% of a filler; and

5 - 60 wt.% of a non-strongly alkaline, water-soluble salt.

2. The solid antifoam formulation of claim 1 , wherein the water-soluble polymer is

polyvinyl alcohol) or a polyvinyl alcohol)-based polymer.

3. The solid antifoam formulation of claim 1 or 2, wherein the water-soluble polymer is a polyvinyl alcohol)-based polymer in which a portion of the hydroxyl groups have been modified by reaction with a (2-10C)aldehyde.

4. The solid antifoam formulation of any of claims 1 , 2 or 3, wherein the water-soluble polymer is a polyvinyl alcohol)-based polymer in which a portion of the hydroxyl groups have been modified by reaction with butyraldehyde.

5. The solid antifoam formulation of any preceding claim, wherein the antifoam formulation comprises 0.5 - 4.5 wt.% of the water-soluble polymer.

6. The solid antifoam formulation of any preceding claim, wherein the antifoam formulation comprises 1 .5 - 4.5 wt.% of the water-soluble polymer.

7. The solid antifoam formulation of any preceding claim, wherein the antifoam formulation comprises 1 .5 - 3.0 wt.% of the water-soluble polymer

8. The solid antifoam formulation of any preceding claim, wherein the antifoam formulation comprises 1 .5 - 2.5 wt.% of the water-soluble polymer

9. The solid antifoam formulation of any of claims 1 to 8, wherein the antifoam formulation comprises 0.8 - 3.8 wt.% of the water-soluble polymer.

10. The solid antifoam formulation of any preceding claim, wherein the antifoam agent comprises silicone.

1 1 . The solid antifoam formulation of any preceding claim, wherein the antifoam agent has a viscosity at 25°C of 20,000 - 40,000 mPas.

12. The solid antifoam formulation of any preceding claim, wherein the antifoam agent has a viscosity at 25°C of 25,000 - 35,000 mPas.

13. The solid antifoam formulation of any preceding claim, wherein the antifoam agent has a density at 25 °C of 0.95 - 1 .05 gem ³.

14. The solid antifoam formulation of any preceding claim, wherein the antifoam formulation comprises 7.0 - 20 wt.% of the antifoam agent.

15. The solid antifoam formulation of any preceding claim, wherein the antifoam formulation comprises 7.5 - 20 wt.% of the antifoam agent.

16. The solid antifoam formulation of any preceding claim, wherein the antifoam formulation comprises 10 - 17.5 wt.% of the antifoam agent.

17. The solid antifoam formulation of any preceding claim, wherein the antifoam formulation comprises 12.0 - 17.5 wt.% of the antifoam agent.

18. The solid antifoam formulation of any preceding claim, wherein the antifoam formulation comprises 14.0 - 16.0 wt.% of the antifoam agent.

19. The solid antifoam formulation of any preceding claim, wherein the filler comprises an organic filler, an inorganic filler, or a mixture thereof.

20. The solid antifoam formulation of claim 19, wherein the organic filler is a cellulosic

compound.

21 . The solid antifoam formulation of claim 20, wherein the cellulosic compound is

microcrystalline cellulose.

22. The solid antifoam formulation of claim 19, 20, or 21 , wherein the inorganic filler

comprises one or more selected from the group consisting of talc and bentonite.

23. The solid antifoam formulation of any preceding claim, wherein the antifoam formulation comprises 5 - 40 wt.% of the filler.

24. The solid antifoam formulation of any preceding claim, wherein the antifoam formulation comprises 7.5 - 35 wt.% of the filler.

25. The solid antifoam formulation of any preceding claim, wherein the antifoam formulation comprises 8.0 - 32 wt.% of the filler.

26. The solid antifoam formulation of any preceding claim, wherein the antifoam formulation comprises 8.0 - 28 wt.% of the filler.

27. The solid antifoam formulation of any preceding claim, wherein the antifoam formulation comprises 8.0 - 12 wt.% of the filler.

28. The solid antifoam formulation of any of claims 1 to 27, wherein the antifoam

formulation comprises 23.0 - 28 wt.% of the filler.

29. The solid antifoam formulation of any preceding claim, wherein the absorbent is a

starch.

30. The solid antifoam formulation of any preceding claim, wherein the absorbent is maize starch or potato starch.

31 . The solid antifoam formulation of any preceding claim, wherein the antifoam formulation comprises 15 - 50 wt.% of the absorbent.

32. The solid antifoam formulation of any preceding claim, wherein the antifoam formulation comprises 17.5 - 47.5 wt.% of the absorbent.

33. The solid antifoam formulation of any of claims 1 to 31 , wherein the antifoam

formulation comprises 34.0 - 50.0 wt.% of the absorbent.

34. The solid antifoam formulation of claim 33, wherein the antifoam formulation comprises 36.0 - 45.0 wt.% of the absorbent.

35. The solid antifoam formulation of any preceding claim, wherein the non-strongly

alkaline, water-soluble salt has a pH of ≤ 8.5.

36. The solid antifoam formulation of any preceding claim, wherein the non-strongly alkaline, water-soluble salt comprises one or more selected from the group consisting of sodium bicarbonate, sodium sulfate, sodium chloride, sodium acetate, potassium sulfate, potassium chloride and sodium citrate.

37. The solid antifoam formulation of any preceding claim, wherein the non-strongly

alkaline, water-soluble salt comprises one or more selected from the group consisting of sodium sulfate, sodium chloride, sodium acetate, potassium sulfate, potassium chloride and sodium citrate.

38. The solid antifoam formulation of any of claims 1 to 36, wherein the non-strongly

alkaline, water-soluble salt comprises one or more selected from the group consisting of sodium bicarbonate, sodium sulfate and sodium citrate.

39. The solid antifoam formulation of any preceding claim, wherein the non-strongly

alkaline, water-soluble salt comprises one or more selected from the group consisting of sodium sulfate and sodium citrate.

40. The solid antifoam formulation of any preceding claim, wherein the antifoam formulation comprises 5 - 50 wt.% of the non-strongly alkaline, water-soluble salt.

41 . The solid antifoam formulation of any preceding claim, wherein the antifoam formulation comprises 7.5 - 45 wt.% of the non-strongly alkaline, water-soluble salt.

42. The solid antifoam formulation of any preceding claim, wherein the antifoam formulation comprises 7.5 - 35 wt.% of the non-strongly alkaline, water-soluble salt.

43. The solid antifoam formulation of any of claims 1 to 41 , wherein the antifoam

formulation comprises 16.0 - 40.0 wt.% of the non-strongly alkaline, water-soluble salt.

44. The solid antifoam formulation of claim 43, wherein the antifoam formulation comprises 18.0 - 25.0 wt.% of the non-strongly alkaline, water-soluble salt.

45. The solid antifoam formulation of any preceding claim, wherein the antifoam formulation has a moisture content of 10 wt.% or less.

46. The solid antifoam formulation of any preceding claim, wherein the antifoam formulation has a moisture content of 2 wt.% or less.

47. A solid laundry detergent formulation comprising the antifoam formulation of any preceding claim.

48. The solid laundry detergent formulation of claim 45, wherein the laundry detergent formulation comprises 5 - 25 wt.% of the antifoam formulation of any preceding claim.

49. A process for the preparation of a solid antifoam formulation as claimed in any of claims 1 to 47, said process comprising the steps of:

b) drying the mixture resulting from step a).

50. The process of claim 49, wherein the quantity of water used in step a) is such that the mixture resulting from step a) is granular.

51 . The process of claim 49 or 50, wherein step b) comprises drying the mixture resulting from step a) in a fluid bed dryer.

52. The process of any of claims 49, 50 or 51 , wherein step b) comprises drying the mixture resulting from step a) at a temperature of 25 - 80 °C.

53. The process of any of claims 49 to 52, wherein prior to mixing in step a), the antifoam agent is heated to a temperature of 50 - 100 °C.

54. The process of any of claims 49 to 52, wherein the water-soluble polymer mixed in step a) is provided as an aqueous solution.