WO2023233025A1

WO2023233025A1 - Liquid detergent product

Info

Publication number: WO2023233025A1
Application number: PCT/EP2023/064882
Authority: WO
Inventors: Stephen Norman Batchelor; Neil Stephen Burnham
Original assignee: Unilever Ip Holdings B.V.; Unilever Global Ip Limited; Conopco, Inc., D/B/A Unilever
Priority date: 2022-06-03
Filing date: 2023-06-02
Publication date: 2023-12-07
Also published as: WO2023233026A1; WO2023233028A1

Abstract

An aqueous liquid detergent enclosed in a plastic container, wherein the detergent comprises: from 0.01 to 10 wt. % alkoxylated non-ionic surfactant; and from 0.0001 to 5 wt.% alkoxylated dye; and wherein the plastic of the container comprises low density polyethylene (LDPE), high density polyethylene (HDPE) or a combination thereof.

Description

LIQUID DETERGENT PRODUCT

Field of the invention

The present invention relates to a plastic container comprising an aqueous liquid detergent, wherein the plastic of the contains LDPE, HDPE or a combination thereof.

Background of the invention

Plastics, especially synthetic plastics, are ubiquitous in daily life due to their relatively low production costs and good balance of material properties. Synthetic plastics are used widely to make containers, such as bottles, for liquid laundry detergent products. Currently the overwhelming majority of synthetic plastics containers are based on virgin plastic. Virgin plastic is produced from increasingly scarce fossil sources, such as petroleum and natural gas. Additionally, the manufacturing of virgin plastics from fossil sources produces CO2 as a by-product. Plastics recycling, and in particular the use of post-consumer recycled plastic (PCR), has emerged as one solution to mitigate the issues associated with the wide-spread usage of virgin plastics.

PCR is preferably made from the mechanical recycling of plastic, typically packaging plastic and is described in Mechanical Recycling of Packaging Plastics: A Review, Z. O. G. Schyns,; M. P. Shaver Macromol. Rapid. Common. 2021, 42, 2000415.

We have found that when using PCR-based plastic containers the level of non-ionic surfactants during storage can change when compared to using virgin-based plastic containers, in case the plastic containers comprise low density polyethylene (LDPE) plastic, high density polyethylene (HDPE) plastic or a combination thereof. This represents problems when providing consistent detergent product quality, as the PCR and/or virgin content of the plastic container may not be fully controlled by the detergent manufacturer. The PCR/virgin content may depend on the region where the plastic containers are produced as well as in time, for example when PCR/virgin plastic demand outstrips supply. To provide consistent detergent product quality it is therefore desirable that the level of non-ionic surfactant is less affected by the PCR/virgin content of plastic container.

It is an object of the invention to provide an aqueous liquid detergent comprising alkoxylated non-ionic surfactant in a plastic container, where the plastic comprises low density polyethylene (LDPE), high density polyethylene (HDPE) or a combination; wherein the level of dissolved/dispersed alkoxylated non-ionic surfactant is less affected by the PCR and/or virgin content of the plastic container.

Summary of the invention

One or more of the above objects are achieved in a first aspect of the invention by an aqueous liquid detergent enclosed in a plastic container, wherein the detergent comprises:

• from 0.01 to 10 wt. % alkoxylated non-ionic surfactant; and

• from 0.0001 to 5 wt.% alkoxylated dye; and wherein the plastic of the container comprises low density polyethylene (LDPE), high density polyethylene (HDPE) or a combination thereof.

It was surprisingly observed that use of an alkoxylated dye reduced the observed changes of the alkoxylated non-ionic surfactant present in the liquid when exposed to PCR HDPE plastic versus virgin plastic HDPE.

This effect is highly beneficial for detergent manufacturers as it enables them to deliver consistent product quality even though the level of recycled plastic in HDPE/LDPE comprising containers can vary. In particular, the availability of PCR or virgin plastic can be affected by a mismatch between supply and demand in time or region.

Therefore, detergent formulations which are typically centrally developed but made in factories in different regions or time may result in the use of containers with different levels of PCR/virgin plastic. The ability to deliver detergents with improved product consistency, irrespective of the PCR/virgin plastic content of the container, is therefore highly beneficial.

In a second aspect the invention relates to a process for the manufacture of a detergent product according to the invention, wherein the process comprises the steps of: a) providing a plastic container

• wherein the plastic comprises low density polyethylene, high density polyethylene or a combination thereof; and

• wherein the plastic preferably comprises from 30 to 100 wt. % recycled plastic, based on the total weight of the plastic; b) providing an aqueous liquid detergent composition according to the invention; c) filling the container provided at step a) with the aqueous liquid detergent composition provided at step b) to provide the detergent product.

In a third aspect the invention relates to the use of an alkoxylated dye to improve product consistency of an aqueous liquid laundry detergent in a plastic container, preferably wherein the container comprises LDPE, HDPE or a combination thereof and more preferably wherein the container is transparent.

Detailed description of the invention

Definitions

Unless otherwise stated or is made clear from the context, with ‘the detergent” is meant the aqueous liquid detergent formulation as such, not including the container; with ‘the container’ is meant the plastic container as such, not including the aqueous liquid detergent composition; with ‘the product’ is meant the plastic container + the aqueous liquid detergent formulation contained therein. Weight percentage (wt. %) is based on the total weight of the aqueous liquid detergent, the container, or the product as indicated or as made clear from the context. It will be appreciated that the total weight amount of ingredients will not exceed 100 wt. %.

Whenever an amount or concentration of a component is quantified herein, unless indicated otherwise, the quantified amount or quantified concentration relates to said component per se, even though it may be common practice to add such a component in the form of a solution or of a blend with one or more other ingredients. It is furthermore to be understood that the verb "to comprise" and its conjugations is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. Finally, reference to an element by the indefinite article "a" or "an" does not exclude the possibility that more than one of the elements is present, unless the context clearly requires that there be one and only one of the elements. The indefinite article "a" or "an" thus usually means "at least one". Unless otherwise specified all measurements are taken at standard conditions. Whenever a parameter, such as a concentration or a ratio, is said to be less than a certain upper limit it should be understood that in the absence of a specified lower limit the lower limit for said parameter is 0. The plastic container used to contain the aqueous liquid detergent is preferably transparent. The term ‘transparent’ as used herein refers to the ability of light within the visible spectrum (400 to 700 nm) to pass through the container wall. The transparency can be quantified as the ratio between the light intensity measured after the light has passed through a material sample and the light intensity measured when the material sample has been removed. The ratio (i.e. x100) can be converted to a Transmittance ranging from 0% (no incoming light having passed through) to 100% (i.e. all incoming light having passed through). As used herein transparent refers to a Transmittance of at least 10% within the wavelength range of 400 to 700 nm, preferably of at least 20 %, 30 %, 40 %, 50 % and more preferably at least 60 %. The Transmittance refers to at least one wavelength of light within the visible spectrum, preferably to at least 40 %, more preferably at least 60%, even more preferably at least 80 % of the wavelengths within the visible spectrum, still even more preferably refers to the whole of the wavelength within the visible spectrum. Preferably at least 30 %, 50 %, 70 % and even more preferably at least 85 % of the total outer container surface area of the plastic container is transparent. Transmittance of the plastic container material can be suitably measured by using a LIV-VIS Spectrometer, preferably as based on a light path-length through the plastic of 1 mm. Suitable LIV-VIS spectrometers are available from a variety of suppliers, including Thermo Scientific, Perkin Elmer and Shimadzu.

With plastic containers are meant containers which are suitable for storing multiple doses of detergent and are preferably shape-stable when empty. With the term “plastic container” are meant containers which predominantly consist of plastic although they may comprise non-plastic additional materials. Preferably the plastic container comprises at least 60 wt.%, more preferably at least 80 wt.%, even more preferably at least 90 wt.% and still even more preferably at least 95 wt. % of plastic.

The aqueous liquid detergent of the invention preferably is a hand dishwash detergent, a machine dishwash detergent, a dishwash rinse aid, a laundry detergent, a fabric conditioner or a floor cleaner. Hand dishwash detergents and laundry detergents are the more preferred and laundry detergents are especially preferred.

The term “liquid” in the context of this invention denotes that a continuous phase or predominant part of the detergent is liquid and that the composition is flowable at 15 degrees Celsius or higher. Accordingly, the term “liquid” may encompass emulsions, suspensions, and compositions having flowable yet stiffer consistency, known as gels or pastes. The viscosity of the detergent is preferably from 200 to about 10,000 mPa.s at 25 degrees Celsius at a shear rate of 21 sec¹. This shear rate is the shear rate that is usually exerted on the liquid when poured from a bottle. Pourable liquid detergents preferably have a viscosity of from 200 to 1 ,500 mPa.s, preferably from 200 to 700 mPa.s.

The liquid detergent of the invention is aqueous, meaning it has an aqueous continuous phase. By “aqueous continuous phase” is meant a continuous phase which has water as its basis. Preferably, the detergent comprises at least 40 wt.%, more preferably 50 wt.%, even more preferably 60% wt. water and still more preferably at least 70% wt. water.

The term “laundry detergent” in the context of this invention denotes detergents intended for and capable of wetting and cleaning domestic laundry such as clothing, linens and other household textiles, preferably also when diluted in washing machine to form a wash liquor. Examples of liquid laundry detergents include heavy-duty liquid laundry detergents for use in the wash cycle of automatic washing machines, as well as liquid fine wash and liquid color care detergents such as those suitable for washing delicate garments (e.g. those made of silk or wool) either by hand or in the wash cycle of automatic washing machines.

Plastic container

The plastic container of the invention has a preferred internal volume of from 0.1 to 10L, more preferably from 0.2 to 5 L, even more preferably from 0.5 to 5 L and still even more preferably of from 0.5 to 2 L.

Advantageously the container has a pouring neck with a resealable screw top where the maximum dimension of the pouring neck of the container is at least 3 times smaller than the maximum dimension of the container. Preferably the container has a minimum width at it base, of 3 cm, more preferably 4 cm. The width is measured parallel to the flat surface on which the container stands in an upright position. On initial sale the container preferably is filled to greater than 95% of the container capacity by weight.

The plastic of the container may be coloured although it preferably is least in part transparent. This can be easily achieved by reducing the amount of colorant in the plastic as needed and/or by modifying the container wall thickness. Advantageously the plastic of the container contains essentially no added colorant (e.g. dyes or pigments) and has no perceivable colour (i.e. non-white, non-grey) to the untrained human eye.

The plastic of the container comprises low density polyethylene (LDPE), high density polyethylene (HDPE) or a combination thereof. The plastic may comprise further types of plastic. The plastic of the plastic container preferably comprises at least 20 wt.%, more preferably at least 50 wt.%, even more preferably at least 70 wt. % and still even more preferably at least 90 wt. % of LDPE, HDPE or a combination thereof, as based on the total weight of plastic in the plastic container. HDPE is the more preferred plastic-type to be comprised by the plastic container.

Preferably the plastic of the container comprises at least 30 wt. %, more preferably at least 50 wt. %, even more preferably at least 70 wt.%, still even more preferably at least 80 wt. % and still even more preferably at least 90 wt. % of recycled plastic, based on the total weight of the plastic of the container. These amounts advantageously refer to the amount of HDPE/LDPE recycled plastic content, based on the total HDPE/LDPE weight of the plastic container. The wt. % of recycled plastic can be determined by measuring the tensile strength of the plastic. Alternatively, recycled plastics can be distinguished from virgin plastic in various ways as recycled plastic often has polymers of reduced molecular weight and are characterized by the presence of impurities (see Rahimi et. al. “Chemical recycling of waste plastics for new materials production”, Nature Reviews Chemistry”, vol. 1 , Art. No. 0046, 2017).

Advantageously the plastic of the container contains from 0.01 to 6 wt. %, more preferably from 0.1 to 5 wt. % and even more preferably from 1 to 4.5 wt. % of a UV absorber, based on the total weight of the plastic container. The UV absorbers are present as additive in the plastic. Advantageous UV absorbers are one or more of benzophenones, salicylates, benzotriazoles, hindered amines and alkoxy (e.g. methoxy) cinnamates). More preferred UV absorbers are benzotriazole-based absorbers. Benzotriazole-based UV absorbers are described in Cantwell et. al. “Benzotriazoles: History, Environmental Distribution, and Potential Ecological Effects”, Chapter 16, Comprehensive Analytical Chemistry, Vol. 67, 2015, pages 513-545; and in Pospisil et. al. “Oxidation Inhibition in Organic Materials”, CRC Press, 1990. Benzotriazole-based UV absorbers are commercially available from e.g. BASF and Clariant.

A label carrying product information may be applied onto the outside of the container surface. The label is advantageously at least in part non-transparent to improve readability of any information thereon. Application of such labels is to communicate information about the product to the consumer, some of which information may be necessitated by law or regulation. The label can be applied as a heat-shrinkable sleeve, a suitable sticker, or in any other suitable manner. It is advantageous that the label, if present, is thin, meaning it has a thickness of from 0.01 to 2 mm and is itself made predominantly from a recyclable plastic and/or paper. Advantageously the label does not reduce the transparent surface area of the plastic container, in case it is transparent, by more than 50 %, preferably by no more than 30 % and even more preferably by no more than 20 %.

The plastic container of the invention is most advantageously in the shape of a bottle. Bottle shapes are predominantly devoid of sharp edges and corners, for example as opposed to cuboid boxes. As mentioned, the plastic container is preferably transparent.

Alkoxylated dyes

Alkoxylated dyes are dyes which contain at least one [alkoxy]_n containing group covalently bound to the chromophore, where n is the mole average value and is greater than or equal to 1.9, preferably greater than or equal to 2. The [alkoxy]_n containing group may be bound directly to an aromatic ring of the chromophore or more may be bound indirectly, such as via an N-atom of an amine or acid amide group. The [alkoxy]_n containing group may include a linker moiety and have the following structure:

-linker-[alkoxy]_nR

The alkoxy-monomers preferably have 2 to 4 carbon atoms and may form a mixed [alkoxy]_n containing group, such as a [alkoxy]_n groups containing mixtures of ethoxylate, propoxylate and butoxylate monomers. Dyes which have alkoxy monomers of the same type are preferred. [alkoxy]_n containing group(s) with ethoxy monomers are preferred. R is an organic group and preferably selected from alkyl, H, SO3H, CH2COOH, and quaternary amines, more preferably CH3, C2H5, and H, most preferably H.

As indicated, the at least one [alkoxy]_n containing group can suitably have a linker moiety between the [alkoxy]_n moiety and the remainder of the dye-structure. The linker is preferably an alkyl-group, which can be branched or linear, but preferably is linear. In general, overall linear structures for the poly-alkoxy containing groups are preferred. Also preferred are those which are end-capped with -OH (i.e. an hydroxy end-capping structure).

Considering the [alkoxy]_n moiety, n is advantageously from 2 to 20, more preferably from 2 to 15 and even more preferably from 2 to 8. In case more than one poly-alkoxy containing group is present, it is preferred that each has a mole average from 2 to 20, more preferably 2 to 15 and even more preferably 2 to 8 alkoxy units.

In the [alkoxy]_n moiety, ‘n’ generally refers to the mole average number of alkoxymonomers, in which ‘n’ thus can represent the average of a distribution. In this case beneficial are [alkoxy]_n moiety distributions in which the most prevalent molecular species has an alkoxy number which corresponds to that of the distribution average ‘n’. Further preferred are those distributions in which the molecular species with a degree of alkoxylation corresponding to the average number ‘n’ is present in a higher molar %. For example, if ‘n’ is 4, a molar distribution of 25% n=2, 50% n=4 and 25% n=6 is more preferred than a molar distribution of 30% n=2, 40% n=4 and 30% n=6. This beneficially applies to the average number of alkoxy-monomers in the alkoxylated dye as a whole and/or the average number of alkoxy-monomers in an individual [alkoxy]_n containing group.

The molar % of the molecular species with an ‘n’ closest to the average of the [alkoxy]_n distribution is preferably at least 2 molar %, more preferably at least 5 molar %, even more preferably at least 10 molar % and still even more preferably at least 15 molar % higher then than the molar % of the molecular species with an ‘n’ second-closest to the average of the [alkoxy]_n distribution. For example, where the average of the [alkoxy]_n is 4, the molecular species with [alkoxy^ is the species with ‘n’ closest to the average. Would the distribution contain also [alkoxy^, [alkoxyk and [alkoxy]s, both the [alkoxyk and [alkoxy]s are molecular species with a second closest value of ‘n’. In this case it is than preferred that the species [alkoxy^ is at least 2 molar % higher than the highest molar amount of [alkoxyk or [alkoxy]s (i.e. whichever one of these is present in the distribution with the higher molar %).

In case where the dye is a mixture of molecular species of different alkoxy chain length it is preferred if the mole fraction of molecular species with only a single alkoxy group in the chain is less than 5 mol%, preferably less than 2 mol%, more preferably less than 0.5 mol%, most preferably less than 0.1 mol%. An example of a single alkoxy group in a chain is N-CH2CH2OH..

The distribution of chain lengths is preferably measured using accurate mass spectroscopy in conjunction with chromatography, preferably with detection of the radical cations.

The alkoxylated dyes of the invention preferably have a maximum extinction coefficient of greater than 5000 L/mol/com in the range of 400 to 700 nm. Preferably the dyes are green, blue or violet in colour.

Preferably the alkoxylated dye of the invention is added to the aqueous liquid detergent in amount to provide an optical density of from 0.05 to 2 and preferably of from 0.1 to 0.5, as measured at the absorption maximum of the dye and using a path-length of 1 cm. The absorption maximum of dye should be within the range of from 400-700nm.

Preferably the amount of alkoxylated dye in the detergent of the invention is from 0.0001 to 0.4 wt. %, more preferably from 0.0005 to 0.1 wt. %, even more preferably from 0.001 to 0.05 wt. %, still even more preferably from 0.002 to 0.02 wt.% and still even more preferably from 0.005 to 0.01 wt.%

The dye chromophore is preferably selected from anthraquinone, mono-azo, bis-azo, and triphenylmethane, more preferably from anthraquinone. The alkoxylated dye of the invention may be a leuco dye, although non-leuco dyes are the more preferred.

More preferably the alkoxylated dye of the invention comprises or essentially is an alkoxylated anthraquinone dye of the following structure:

wherein the anthraquinone chromophore contains an amine group or an acid amide group in the 1 -position, the 4-position or both in the 1 -position and the 4-position; and wherein the chromophore contains at least one group containing an [alkoxy]_n moiety; wherein the at least one group containing an [alkoxy]_n moiety can be covalently bound at any of the numbered positions, directly or via the amine or acid amide group; and wherein n of the at least one group containing an [alkoxy]_n moiety is from 2 to 20. More preferred anthraquinone dyes of the invention have an amine group or acid amine group in both the 1- and 4-position.

Preferably the number of alkoxy monomers in an anthraquinone dye as a whole is from 2 to 40, preferably from 3 to 30 and more preferably from 4 to 20. The anthraquinone dye may have more than one [alkoxy]_n containing group. The number of [alkoxy]_n containing groups in an anthraquinone dye of the invention can suitably be from 1 to 8, but preferably is from 1 to 4, more preferably is 1 or 2 or 3 and even more preferably is 2.

Advantageously, the at least one [alkoxy]_n containing group is covalently attached at any one of the positions 1 to 4 of the anthraquinone dye of the invention, directly or via the N-atom of the amine or acid group.

Beneficial are anthraquinone dyes of the following structure:

X and Y contains a -[CH2CH2O]_nRi group, where

• n is from 2 to 20; and • Ri is an organic group or H, preferably Ri is CHsor H and more preferably Ri is H; and

• preferably X and Y represent the same group and more preferably are H; and

• preferably R2 and R3 are -CH2CH2CH2O(CH2CH2O)2RI and more preferably Ri is - H.

Preferred examples of dyes are 1-amino-2-polyethylenoxy-4-phenylamino- anthraquinone, 1-amino-2-methoxy-4-[-4-polyethleneoxy-anilyl]anthraquinone, 1- amino-2-polyethyleneoxy-4-(2,4,6-trimethylphenylamino) anthraquinone and N,N'- dialkyleneoxy-substituted 1 ,4-diaminoanthraquinones. More preferred are N,N'- dialkyleneoxy-substituted 1 ,4-diaminoanthraquinones.

(Further) beneficial alkoxylated anthraquinone dyes are the following:

It is preferred that an anthraquinone dye does not contain sulphate or sulphonate groups and more preferably contains no charged groups. In case of doubt the presence of charged groups is determined in water at a pH of 7.0 in otherwise standard conditions.

Further dyes

Besides the presence of alkoxylated dye, one or more further dyes may be present in the aqueous liquid detergent of the invention. Dyes are described in ‘Industrial Dyes’ edited by K. Hunger 2003 Wiley-VCH ISBN 3-527 -30426-6. Further dyes are preferably selected from cationic, anionic and non-ionic dyes and more preferably are selected from anionic and non-ionic dyes. Anionic dyes are negatively charged in an aqueous medium at pH 7. Examples of anionic dyes are found in the classes of acid and direct dyes in the Color Index (Society of Dyers and Colourists and American Association of Textile Chemists and Colorists). Anionic dyes preferably contain at least one sulphonate or carboxylate group. Non-ionic dyes are uncharged in an aqueous medium at pH 7, examples are found in the class of disperse dyes in the Color Index.

Further dye may be of any color but preferably is blue, violet, green or red and more preferably is blue or violet. Preferably the further dye is selected from acid dyes and disperse dyes. Most preferably the dye is a non-ionic dye. Preferably the dye is selected from those having an anthraquinone, mono-azo, bis-azo, xanthene, phthalocyanine or phenazine chromophore. More preferably the dye is selected from those having an anthraquinone or mono-azo chromophore.

Beneficially further dye is selected from: acid blue 80, acid blue 62, acid violet 43, acid green 25, direct blue 86, acid blue 59, acid blue 98, direct violet 9, direct violet 99, direct violet 35, direct violet 51 , acid violet 50, acid yellow 3, acid red 94, acid red 51 , acid red 95, acid red 92, acid red 98, acid red 87, acid yellow 73, acid red 50, 5 acid violet 9, acid red 52, food black 1 , food black 2, acid red 163, acid black 1 , acid orange 24, acid yellow 23, acid yellow 40, acid yellow 11 , acid red 180, acid red 155, acid red 1 , acid red 33, acid red 41, acid red 19, acid orange 10, acid red 27, acid red 26, acid orange 20, acid orange 6, sulphonated Al and Zn phthalocyanines, solvent violet 13, disperse violet 26, disperse violet 28, solvent 10 green 3, solvent blue 63, disperse blue 56, disperse violet 27, solvent yellow 33 and mixtures thereof. The alkoxylated dye of the invention and/or any further dye may be a shading dye. This is beneficial in particular when the liquid detergent is a laundry detergent. Leuco based shading dyes as described in WO2020/023812, most preferably a triphenyl methane leuco colourant are contemplated as well. Such leuco dyes are included by the term shading dyes, although preferably the shading dyes according to the invention are non- leuco shading dyes.

Shading dyes provide a shade to white fabric and preferably provide a blue or violet shade to white fabric. In this regard the shading dye gives a blue or violet color to a white cloth with a hue angle of 240 to 330, more preferably 260 to 320, most preferably 265 to 300. The white cloth used is bleached non-mercerised woven cotton sheeting. Preferably a 10 cm by 10 cm piece of white bleached non-mercerised woven cotton cloth is agitated in an aqueous solution (6° French Hard water, liquor 298K: cloth 30:1) 2g/L of a base detergent (10 wt.% linear alkyl benzene sulfonate, 5 wt.% primary alcohol ethoxylate (C12-15, with 7 moles of ethoxy groups), pH=8) for 30 minutes at room temperature. The cloths are removed, rinsed and tumble dried. The experiment is repeated with and without the addition of shading dye. The color of the cloth is measured using a reflectometer and expressed as the CIE L*a*b* values. The experiment was repeated with the addition of 0.001 wt.% of the dye to the formulation.

The total color added to the cloth was calculated as the AE value, such that AE = (AL²+ Aa²+ Ab²)⁰⁵ where AL = L(control)-L(dye); Aa = a(control)-a(dye); Ab = b(control)-b(dye)

The actual color of the cloth is calculated as the hue angle, which for the current range of colors is given by: Hue angle = 270+180/TT X atan(-Aa/Ab). A hue angle of 360/0 is red, 270 is blue and 180 is green.

A shading dye is able to deposit onto textile during domestic wash conditions in the presence of a wash liquor comprising surfactant. This may be assessed using the above test, where a shading dye will give a non-zero AE value.

The preferred total amount of shading dye in the detergent according to the invention is from 0.00001 to 0.1 wt. % more preferably from 0.0001 to 0.05 wt. %. More preferably further anionic dyes are not present, even more preferably further dyes are not present.

Alkoxylated non-ionic surfactant

Preferred nonionic surfactants of the invention include, advantageously, the reaction products of compounds having a hydrophobic group and a reactive hydrogen atom, for example, aliphatic alcohols, acids, amides with alkylene oxides, especially ethylene oxide either alone or with propylene oxide and methyl ester ethoxylates. Example nonionic surfactants are the condensation products of aliphatic Cs to C primary or secondary linear or branched alcohols with ethylene oxide>3EO generally 5 to 40 EO, preferably 7EO to 9EO mole average units.

Preferably the non-ionic surfactant comprises C12/14 alcohol ethoxylates with 7EO to 9EO mole average units; C16/18 alcohol ethoxylates with 7 to 13 EO mole average units; C16/18 Methyl ester ethoxylates with 7 to 13 EO mole average units or mixtures thereof and even more preferably essentially consists of such non-ionic surfactants or mixtures thereof.

For the non-ionic with C16/18 alcohol ethoxylates it is preferred that the predominant C18 moiety is 018:1 and more preferably 018:1 (A9). Preferably polyunsaturated chains are present at less than 11wt%.

The preferred amount of alkoxylated non-ionic surfactant of the invention is from 0.1 to 20 wt. %, more preferably from 1 to 12 wt. %, even more preferably from 3 to 8 wt.% and still even more preferably is from 4 to 6 wt.%.

Further surfactant

The aqueous liquid detergent of the invention preferably comprises from 5 to 60 wt. % of total surfactant, most preferably from 10 to 30 wt. %. Preferably the detergent of the invention comprises anionic surfactant in an amount of 2 to 50 wt.%, more preferably from 5 to 40 wt. % and even more preferably from 6 to 30 wt.%.

In general, the anionic surfactants and (further) nonionic surfactants of the surfactant system may be chosen from the surfactants described "Surface Active Agents" Vol. 1 , by Schwartz & Perry, Interscience 1949, Vol. 2 by Schwartz, Perry & Berch, Interscience 1958, in the current edition of "McCutcheon's Emulsifiers and Detergents" published by Manufacturing Confectioners Company or in "Tenside-Taschenbuch", H. Stache, 2nd Edn., Carl Hauser Verlag, 1981. Preferably the surfactants used are saturated.

Suitable anionic surfactants which may be used are usually water-soluble alkali metal salts of organic sulfates and sulphonates having alkyl radicals containing from about 8 to about 22 carbon atoms, the term alkyl being used to include the alkyl portion of higher acyl radicals. Examples of suitable synthetic anionic surfactants are sodium and potassium alkyl sulfates, especially those obtained by sulphating higher Cs to Cw alcohols, produced for example from tallow or coconut oil, sodium and potassium alkyl Cg to C20 benzene sulphonates, particularly sodium linear secondary alkyl C10 to Cw benzene sulphonates; and sodium alkyl glyceryl ether sulfates, especially those ethers of the higher alcohols derived from tallow or coconut oil and synthetic alcohols derived from petroleum. The preferred anionic surfactants are sodium C11 to Cw alkyl benzene sulphonates and sodium C12 to C alkyl sulfates. Highly preferred are anionic alkyl benzene sulfonates, which more advantageously are linear alkyl benzene sulphonates. Also applicable are surfactants such as those described in EP-A-328 177 (Unilever), which show resistance to salting-out, the alkyl polyglycoside surfactants described in EP-A-070 074, and alkyl monoglycosides.

Preferred surfactant systems are mixtures of anionic and nonionic surfactants, in particular the groups and examples of anionic and nonionic surfactants pointed out in EP-A-346 995 (Unilever). Especially preferred is surfactant system that is a mixture of an alkali metal salt of a Cw to Cw primary alcohol sulfate together with a C12 to C primary alcohol 3 to 7 EO ethoxylate. More preferably the surfactant systems are mixtures of anionic and nonionic surfactants exclusively.

The total nonionic surfactant is preferably present in amounts of less than 50 wt. %, most preferably of less than 20 wt. % based on the total weight of the surfactant system. Anionic surfactants can be present for example in amounts in the range from at least 50 wt. % based on the total weight of the surfactant system. A highly advantageous surfactant comprises 50 to 99 wt. % of linear alkyl benzene sulfonates, based on the total weight of surfactants. Beneficially, the weight ratio of anionic:nonionic surfactant is greater than 2 (i.e. more than twice the weight amount of anionic compared to the amount of nonionic).

Preferably, the weight ratio of total non-ionic surfactant to total alkyl ether sulphate surfactant (wt. non-ionic I wt alkyl ether sulphate surfactant) is from 0.5 to 2, preferably from 0.7 to 1.5, most preferably 0.9 to 1.1.

If linear alkyl benzene sulphonate is present, preferably the weight ratio of total non- ionic surfactant to linear alkyl benzene sulphonate (wt. non-ionic/ wt. linear alkyl benzene sulphonate) is from 0.1 to 2, preferably 0.3 to 1 , most preferably 0.45 to 0.85.

Cosurfactants

A detergent of the invention may contain one or more cosurfactants (such as amphoteric (zwitterionic) and/or cationic surfactants) in addition to the non-soap anionic and/or nonionic detersive surfactants described above. Specific cationic surfactants include C8 to C18 alkyl dimethyl ammonium halides and derivatives thereof in which one or two hydroxyethyl groups replace one or two of the methyl groups, and mixtures thereof. Cationic surfactant, when included, may be present in an amount ranging from 0.1 to 5 wt.%. Specific amphoteric (zwitterionic) surfactants include alkyl amine oxides, alkyl betaines, alkyl amidopropyl betaines, alkyl sulfobetaines (sultaines), alkyl glycinates, alkyl carboxyglycinates, alkyl amphoacetates, alkyl amphopropionates, alkylamphoglycinates, alkyl amidopropyl hydroxysultaines, acyl taurates and acyl glutamates, having alkyl radicals containing from about 8 to about 22 carbon atoms preferably selected from C12:0, C14:0, C16:0 ,C18:0 and C18: 1 , the term “alkyl” being used to include the alkyl portion of higher acyl radicals. Amphoteric (zwitterionic) surfactant, when included, may be present in an amount ranging from 0.1 to 5 wt.%. Mixtures of any of the above-described materials may also be used.

PH

The suitable pH of the aqueous liquid detergent depends on the type of detergent. Preferably the aqueous liquid detergent has a pH from 5 to 9, preferably from 6 to 8, as measured at 293K in case it is a laundry detergent. In case the aqueous liquid detergent is a machine dishwash liquid the preferred pH is from 7 to 10. Fluorescent Agent

The aqueous liquid detergent of the invention preferably comprises a fluorescent agent (also known as optical brightener), especially when it is a laundry detergent. Fluorescent agents are well-known, and many such fluorescent agents are available commercially. Usually these fluorescent agents are supplied and used in the form of their alkali metal salts, for example, the sodium salts. The total amount of the fluorescent agent or agents used in the detergent composition of the invention is generally from 0.005 to 2 wt. %, more preferably 0.01 to 0.1 wt. %. Preferred classes of fluorescer are: Di-styryl biphenyl compounds, e.g. Tinopal (Trade Mark) CBS-X, Diamine stilbene di-sulphonic acid compounds, e.g. Tinopal DMS pure Xtra and Blankophor (Trade Mark) HRH, and Pyrazoline compounds, e.g. Blankophor SN. Preferred fluorescers are: sodium 2 (4-styryl-3-sulfophenyl)-2H-napthol[1 ,2-d]triazole, disodium 4,4'-bis{[(4-anilino-6-(N methyl-N-2 hydroxyethyl) amino 1 ,3,5-triazin-2- yl)]amino}stilbene-2-2' disulfonate, disodium 4,4'-bis{[(4-anilino-6-morpholino-1 ,3,5- triazin-2-yl)]amino} stilbene-2-2' disulfonate, and disodium 4,4'-bis(2- sulfostyryl)biphenyl.

It is preferred that the aqueous liquid detergent according to the invention comprises a fluorescer. When the aqueous liquid detergent of the invention is used to make a diluted wash liquor in a domestic method of treating a textile, the fluorescer is preferably present in the range from 0.0001 g/l to 0.1 g/l, preferably 0.001 to 0.02 g/l in the diluted wash liquor.

Perfume

Preferably the aqueous liquid detergent comprises a perfume. The perfume is preferably in the range from 0.001 to 3 wt. %, most preferably 0.1 to 1 wt. %. Many suitable examples of perfumes are provided in the CTFA (Cosmetic, Toiletry and Fragrance Association) 1992 International Buyers Guide, published by CFTA Publications and OPD 1993 Chemicals Buyers Directory 80th Annual Edition, published by Schnell Publishing Co.

It is commonplace for a plurality of perfume components to be present in a detergent formulation. In the detergent of the present invention, it is envisaged that there will be four or more, preferably five or more, more preferably six or more or even seven or more different perfume components. In perfume mixtures preferably 15 to 25 wt. % are top notes. Top notes are defined by Poucher (Journal of the Society of Cosmetic Chemists 6(2):80 [1955]). Preferred top-notes are selected from citrus oils, linalool, linalyl acetate, lavender, dihydromyrcenol, rose oxide and cis-3-hexanol. Perfume and top note are advantageously used to cue the detergency benefit provided by the detergent of the invention.

Polymeric cleaning boosters

Anti-redeposition polymers stabilize the soil in the wash solution thus preventing redeposition of the soil. Suitable soil release polymers for use in the invention include alkoxylated polyamine, preferably alkoxylated polyethyleneimines. Polyethyleneimines are materials composed of ethylene imine units -CH2CH2NH- and, where branched, the hydrogen on the nitrogen is replaced by another chain of ethylene imine units. Preferred alkoxylated polyethyleneimines for use in the invention have a polyethyleneimine backbone of about 300 to about 10000 weight average molecular weight (M_w). The polyethyleneimine backbone may be linear or branched. It may be branched to the extent that it is a dendrimer. The alkoxylation may typically be ethoxylation or propoxylation, or a mixture of both. Where a nitrogen atom is alkoxylated, a preferred average degree of alkoxylation is from 10 to 30, preferably from 15 to 25 alkoxy groups per modification. A preferred material is ethoxylated polyethyleneimine, with an average degree of ethoxylation being from 10 to 30, preferably from 15 to 25 ethoxy groups per ethoxylated nitrogen atom in the polyethyleneimine backbone. Mixtures of any of the above-described materials may also be used.

A composition of the invention will preferably comprise from 0.025 to 8% wt. of one or more anti-redeposition polymers such as, for example, the alkoxylated polyethyleneimines which are described above. More preferably, the polyamine is an alkoxylated cationic or zwitterionic di or polyamine polymer, wherein the positive charge is provided by quaternisation of the nitrogen atoms of the amines, and the anionic groups (where present) by sulphation or sulphonation of the alkoxylated group. Preferably the alkoxylate is selected from propoxy and ethoxy, most preferably ethoxy.

Preferably greater than or equal to 50 mol% of nitrogen amines are quaternizsed, preferably with a methyl group. Preferably the polymer contains 2 to 10, more preferably 2 to 6, most preferably 3 to 5 quanternised nitrogen amines. Preferably the alkoxylate groups are selected from ethoxy and propoxy groups, most preferably ethoxy.

Preferably the polymer contains ester (COO) or acid amide (CONH) groups within the structure, preferably these groups are placed, so that when all the ester or acid amide groups are hydrolyzed, at least one, preferably all of the hydrolyzed fragments has a molecular weight of less than 4000, preferably less than 2000, most preferably less than 1000.

Preferably the polymer is of the form:

where Ri is a C3 to C8 alkyl group, X is an a (C2H4O)nY group where n is from 15 to 30, where m is from 2 to 10, preferably 2, 3, 4 or 5 and where Y is selected from OH and SOs' and preferably the number of SOs' groups is greater than the number of OH groups. Preferably there are from 0, 1 or 2 OH groups. X and Ri may contain ester groups within them. X may contain a carbonyl group, preferably an ester group. There is preferably 1 C2H4O unit separating the ester group from the N, such that the structural unit N- C2H4O-ester- (C2H4O)_n-iY is preferred.

Such polymers are described in WO2021239547 (Unilever), An example polymer is sulphated ethoxylated hexamethylene diamine and examples P1 , P2, P3, P4, P5 and P6 of WO2021239547. Acid amide and ester groups may be included using lactones or sodium chloroacetate respectively (Modified Williamson synthesis), addition to an OH or NH group, then subsequent ethoxylation.

An example reaction scheme for inclusion of an ester group is

Addition of lactones is discussed in WO2021/165468. Soil release polymers

Soil release polymers (SRP) help to improve the detachment of soils from the surface to be cleaned, such as a fabric or hard surface, by modifying the surface during washing. SRPs for use in the invention may include a variety of charged (e.g. anionic) as well as non-charged monomer units and structures may be linear, branched or starshaped. The SRP structure may also include capping groups to control molecular weight or to alter polymer properties such as surface activity. The weight average molecular weight (M_w) of the SRP may suitably range from about 1000 to about 20,000 and preferably ranges from about 1500 to about 10,000.

SRPs for use in the invention may suitably be selected from copolyesters of dicarboxylic acids (for example adipic acid, phthalic acid or terephthalic acid), diols (for example ethylene glycol or propylene glycol) and polydiols (for example polyethylene glycol or polypropylene glycol). The copolyester may also include monomeric units substituted with anionic groups, such as for example sulfonated isophthaloyl units.

Other types of SRP for use in the invention include cellulosic derivatives such as hydroxyether cellulosic polymers, C1-C4 alkylcelluloses and C4 hydroxyalkyl celluloses; polymers with poly(vinyl ester) hydrophobic segments such as graft copolymers of poly(vinyl ester), for example Ci-Ce vinyl esters (such as poly(vinyl acetate)) grafted onto polyalkylene oxide backbones; poly(vinyl caprolactam) and related co-polymers with monomers such as vinyl pyrrolidone and/or dimethylaminoethyl methacrylate; and polyester-polyamide polymers prepared by condensing adipic acid, caprolactam, and polyethylene glycol.

The overall level of SRP, when included, may range from 0.1 to 10%, depending on the level of polymer intended for use in the final diluted composition and which is desirably from 0.3 to 7%, more preferably from 0.5 to 5% (by weight based on the total weight of the diluted composition).

Suitable soil release polymers are described in greater detail in II. S. Patent Nos. 5,574,179; 4,956,447; 4,861 ,512; 4,702,857, WO 2007/079850 and W02016/005271 . If employed, soil release polymers will typically be incorporated into the liquid detergent in concentrations ranging from 0.01 to 10 wt.%, more preferably from 0.1 to 5 wt.%. Hydrotropes

A detergent of the invention may incorporate non-aqueous carriers such as hydrotropes, co-solvents and phase stabilizers. Such materials are typically low molecular weight, water-soluble or water-miscible organic liquids such as C1 to C5 monohydric alcohols (such as ethanol and n- or i-propanol); C2 to C6 diols (such as monopropylene glycol and dipropylene glycol); C3 to C9 triols (such as glycerol); polyethylene glycols having a weight average molecular weight (M_w) ranging from about 200 to 600; C1 to C3 alkanolamines such as mono-, di- and triethanolamines; and alkyl aryl sulfonates having up to 3 carbon atoms in the lower alkyl group (such as the sodium and potassium xylene, toluene, ethylbenzene and isopropyl benzene (cumene) sulfonates). Mixtures of any of the above-described materials may also be used. Non-aqueous carriers, when included, may be present in an amount ranging from 0.1 to 20 wt.%, preferably from 2 to 15 wt.%, and more preferably from 10 to 14 wt.%. The level of hydrotrope used is linked to the level of surfactant and it is desirable to use hydrotrope level to manage the viscosity in such detergents. The preferred hydrotropes are monopropylene glycol and glycerol. Preferably the detergent contains less than 2 wt.% ethanol, more preferably less than 0.5 wt.% ethanol, preferably it is essentially devoid of ethanol.

Builders and sequestrants

The detergent of the invention preferably contains organic detergent builder or sequestrant material. Examples include the alkali metal, citrates, succinates, malonates, carboxymethyl succinates, carboxylates, polycarboxylates and polyacetyl carboxylates. Specific examples include sodium, potassium and lithium salts of oxydisuccinic acid, mellitic acid, benzene polycarboxylic acids, and citric acid. Other examples are DEQUEST™, organic phosphonate type sequestering agents sold by Monsanto and alkanehydroxy phosphonates.

Other suitable organic builders include the higher molecular weight polymers and copolymers known to have builder properties. For example, such materials include appropriate polyacrylic acid, polymaleic acid, and polyacrylic/polymaleic acid copolymers and their salts, for example those sold by BASF under the name SOKALAN™. If utilized, the organic builder materials may comprise from about 0.5 to 20 wt. %, preferably from 1 to 10 wt. % percent, of the detergent. The preferred builder level is less than 10 wt. % and preferably less than 5 wt. % percent of the detergent. More preferably the liquid detergent is a non-phosphate built detergent formulation, i.e., contains less than 1 wt.% of phosphate. Most preferably the detergent formulation is not built meaning it contains less than 1 wt. % of builder. A preferred sequestrant is HEDP (1 -Hydroxyethylidene - 1 ,1,-diphosphonic acid), for example sold as Dequest 2010. Also suitable but less preferred, as it gives inferior cleaning results, is Dequest(R) 2066 (Diethylenetriamine penta(methylene phosphonic acid or Heptasodium DTPMP).

The following builders are especially preferred: 2 ,2',2"-nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), iminodisuccinic acid (IDS), ethylenediamine-N,N'-disuccinic acid (EDDS), methylglycine-N,N- diacetic acid (MGDA), glutamic acid-N,N-diacetic acid (GLDA), N- (2-hydroxyethyl)iminodiacetic acid (EDG), aspartic acid-N-monoacetic acid (ASMA), aspartic acid-N,N-diacetic acid (ASDA), aspartic acid-N-monopropionic acid (ASMP), iminodisuccinic acid (IDA), N-(sulfomethyl)aspartic acid (SMAS), N-(2-sulfoethyl)- aspartic acid (SEAS), N-(sulfomethylglutamic acid (SMGL), N-(2-sulfoethyl)-glutamic acid (SEGL), N-methyliminodiacetic acid (MID A), serine-N,N-diacetic acid (SEDA), isoserine-N,N-diacetic acid (ISDA), phenylalanine-N,N-diacetic acid (PHDA), anthranilic acid-N,N-diacetic acid (ANDA), sulfanilic acid-N,N-diacetic acid (SLDA) , taurine-N,N- diacetic acid (TLIDA) and N'-(2-hydroxyethyl)ethylenediamine-N,N,N'-triacetic acid (HEDTA), diethanolglycine (DEG). Although these builder’ species are mentioned using their acid form, it is to be understood that their partial or full salt forms are included in this denomination. The acid forms of the builder’ are preferred. These builders are preferably present in an amount of from 0.01 to 10 wt. %, more preferably from 0.2 to 5 wt. %.

Polymeric thickeners

A detergent of the invention may comprise one or more polymeric thickeners. Suitable polymeric thickeners for use in the invention include hydrophobically modified alkali swellable emulsion (HASE) copolymers. Exemplary HASE copolymers for use in the invention include linear or crosslinked copolymers that are prepared by the addition polymerization of a monomer mixture including at least one acidic vinyl monomer, such as (meth)acrylic acid (i.e. methacrylic acid and/or acrylic acid); and at least one associative monomer. The term “associative monomer” in the context of this invention denotes a monomer having an ethylenically unsaturated section (for addition polymerization with the other monomers in the mixture) and a hydrophobic section. A preferred type of associative monomer includes a polyoxyalkylene section between the ethylenically unsaturated section and the hydrophobic section. Preferred HASE copolymers for use in the invention include linear or crosslinked copolymers that are prepared by the addition polymerization of (meth)acrylic acid with (i) at least one associative monomer selected from linear or branched C8-C40 alkyl (preferably linear C12-C22 alkyl) polyethoxylated (meth)acrylates; and (ii) at least one further monomer selected from C1-C4 alkyl (meth) acrylates, polyacidic vinyl monomers (such as maleic acid, maleic anhydride and/or salts thereof) and mixtures thereof. The polyethoxylated portion of the associative monomer (i) generally comprises about 5 to about 100, preferably about 10 to about 80, and more preferably about 15 to about 60 oxyethylene repeating units. Mixtures of any of the above-described materials may also be used. When included, a detergent of the invention will preferably comprise from 0.01 to 5 wt. % but depending on the amount intended for use in the final diluted product and which is desirable, from 0.1 to 3 wt. % based on the total weight of the diluted composition.

Enzymes

One or more enzymes are preferably present in the aqueous liquid detergent of the invention. Preferably the level of each enzyme in the detergent is from 0.0001 wt. % to 0.1 wt. % protein.

Preferably, the composition may comprise an effective amount of one or more lipases, cellulases, proteases, amylases, hemicellulases, peroxidases, hemicellulases, xylanases, xantanase, lipases, phospholipases, esterases, cutinases, pectinases, carrageenases, pectate lyases, keratinases, reductases, oxidases, phenoloxidases, lipoxygenases, ligninases, pullulanases, tannases, pentosanases, malanases, - glucanases, arabinosidases, hyaluronidase, chondroitinase, laccase, tannases, nucleases (such as deoxyribonuclease and/or ribonuclease), phosphodiesterases, or mixtures thereof.

Examples of preferred enzymes are sold under the following trade names Purafect Prime®, Purafect®, Preferenz® (DuPont), Savinase®, Pectawash®, Mannaway®, Lipex ®, Lipoclean ®, Whitzyme ® Stainzyme®, Stainzyme Plus®, Natalase ®, Mannaway ®, Amplify ® Xpect ®, Pristine®, Celluclean ® (Novozymes), Biotouch (AB Enzymes), Lavergy ® (BASF). Detergent enzymes are discussed in W02020/186028(Procter and Gamble), W02020/200600 (Henkel), W02020/070249 (Novozymes), W02021/001244 (BASF) and WO2020/259949 (Unilever).

A nuclease enzyme is an enzyme capable of cleaving the phosphodiester bonds between the nucleotide sub-units of nucleic acids and is preferably a deoxyribonuclease or ribonuclease enzyme. Preferably the nuclease enzyme is a deoxyribonuclease, preferably selected from any of the classes E.C. 3.1.21.x, where x=l, 2, 3, 4, 5, 6, 7, 8 or 9, E.C. 3.1.22. y where y=l, 2, 4 or 5, E.C. 3.1.30. Z where z= 1 or 2, E.C. 3.1.31.1 and mixtures thereof.

Preservative

Food preservatives are discussed In Food Chemistry (Belitz H.-D., Grosch W., Schieberle), 4th edition Springer. Isothiazolone based preservative may also be used. The detergent preferably contains a preservative or a mixture of preservatives, selected from benzoic acid and salts thereof, alkylesters of p-hydroxybenzoic acid and salts thereof, sorbic acid, diethyl pyrocarbonate, dimethyl pyrocarbonate, preferably benzoic acid and salts thereof, most preferably sodium benzoate. The preservative is preferably present at 0.1 to 3 wt.%, preferably 0.3 wt.% to 1 .5 wt.%, where the weight is calculated for the protonated form of the preservative.

External Structurants

Detergents of the invention may have their rheology further modified by use of one or more external structurants which form a structuring network within the detergent. Examples of such materials include hydrogenated castor oil, microfibrous cellulose and citrus pulp fibre. The presence of an external structurant may provide shear thinning rheology and may also enable materials such as encapsulates and visual cues to be suspended stably in the liquid.

Further optional ingredients

The detergent of the invention may contain further optional ingredients to enhance performance and/or consumer acceptability. Examples of such ingredients include foam boosting agents, polyelectrolytes, anti-shrinking agents, anti-wrinkle agents, antioxidants, sunscreens, anti-corrosion agents, drape imparting agents, anti-static agents, ironing aids, further colorants such as pigments, pearlisers and/or opacifiers. Each of these ingredients will be present in an amount effective to accomplish its purpose. Generally, these optional ingredients are included individually at an amount of up to 5% (by weight based on the total weight of the diluted composition) and so adjusted depending on the dilution ratio with water.

Process

The process according to the invention relates to the manufacture of an aqueous liquid detergent according to the first aspect of the invention, wherein the process comprises the steps of: a) providing a plastic container

• wherein the plastic preferably comprises from 30 to 100 wt. %, preferably 50 to 100 wt. % recycled plastic, based on the total weight of the plastic; b) providing an aqueous liquid detergent composition according to the invention; c) filling the container provided at step a) with the aqueous liquid detergent composition provided at step b) to provide the detergent product.

It will be appreciated that steps a) and b) can be done in any order.

A particular benefit of the invention is that the detergent of the invention shows improved stability against change induced by the type of plastic present in the container. In particular, the presence of the alkoxylated dye maintains the level of the alkoxylated non-ionic surfactant during storage in the presence of PCR or virgin plastic. Hence advantageously the process of the invention includes a further step d) which is to store the detergent product for at least two weeks, preferably at least 4 weeks and more preferably for at least 6 weeks before first opening/use by the consumer. This storage time includes factory storage time as well as the in-store shelf-time of the product. The storage conditions may be any convenient conditions but preferably is at ambient temperature (i.e. between 15 and 25 degrees Celsius, preferably 20 degrees Celsius).

As indicated preferably the container contains at least some recycled plastic. The amount of recycled plastic comprised by the plastic container provided at step a) can be determined by the wt.% of recycled plastic feed material used to make the plastic container (i.e. as based on the total plastic used to make the container). Plastic containers comprising (or made essentially from) recycled plastic are nowadays also commercially available and the methods of their manufacture are well known in the art. Information of recycled plastics as well as their use to make detergent bottles is discussed in the literature, such as in Methods of Recycling, Properties and Applications of Recycled Thermoplastic Polymers. M.E. Grigore, Recycling 2017, 2, 24. Generally, to convert reclaimed post-use plastic into a useable feedstock to manufacture new plastic containers the plastic is washed, dried and suitably pelletized. The pelletized recycled plastic can then be optionally mixed with virgin pelletized plastic and subjected to processes to shape it into new plastic containers. Such shaping techniques include thermoforming, blow molding, injection-molding or injection stretch blow molding. A general description thereof can be found e.g. in Hans-Georg Elias “An introduction to plastics”, 1993. The UV absorber, if present, is preferably added to the plastic feed material while it is molten and mixed therewith prior to forming the container.

Preferably the plastic container is obtainable by a process wherein based on the total amount of plastic feedstock, at least 30 wt.%, preferably at least 50 wt.%, more preferably 70 wt.% and even more preferably at least 90 wt.% of the feedstock is recycled plastic, preferably post-consumer recycled plastic, where the remainder may be virgin plastic.

The provision of the aqueous liquid detergent at step b) can be done using conventional methods know in the art. Generally, the methods comprise the step of adding ingredients in any suitable order and mixing to obtain a desired homogeneity of the final aqueous liquid detergent.

Preferably the product of the invention is obtainable by the process of the invention.

It will be appreciated that the aqueous liquid detergent can be advantageously enclosed in the container in such a way as to be at least in part in direct contact with the plastic of the container. An added benefit of the invention is that the container of the invention reduces the need for any inner liner material which prevents or reduces contact of the detergent with the plastic of the container. Preferably the ratio of the plastic surface area in direct contact with the liquid detergent is from 400 to 6000 cm²/L, more preferably from 1000 to 5000 cm²/L and even more preferably from 2000 to 4500 cm²/L.

Unless otherwise indicated, preferred aspects in the context of one aspect of the invention (e.g. the plastic container comprising an aqueous liquid detergent composition) are also applicable as preferred aspects in the context of one of the other aspects, (e.g. the process to manufacture the plastic container comprising an aqueous liquid detergent composition) mutatis mutandis.

The invention is now illustrated by the following non-limiting examples.

Examples

Example 1

An ethoxylated blue anthraquinone dye was synthesized according to example 1 of US7632682. The blue dye had the following structure:

The dye contains 2 chains, each with 3 repeating CH2CH2O alkoxylate units as shown in the structure by the bold bonds, giving a total of 6 alkoxy units in the dye.

Analysis of the dye by accurate mass spectroscopy in conjunction with supercritical CO2 based chromatography (Waters UPC2, BEH column, SM - Methanol + 10mM Ammonium Acetate BSM - MethanokIPA 80:20 + 10mM Ammonium Acetate), showed it to contain a minor amount of dye with the same chromophore but a lower number of CH2CH2O alkoxylate units. The results are shown in the table below:

An aqueous liquid laundry detergent was formulated to contain 5 wt.% linear alkyl benzene sulfonate and 5 wt.% C12-14 alcohol ethoxylate with an average of 7 moles of ethoxylation at a pH=7. A sulfonate acid dye (Acid Violet 50, comparative) or the ethoxylated anthraquinone of the structure as indicated directly above (of the invention) were each separately dissolved in the detergent formulation to give an optical density of approx. 1 (1cm max visible absorption). The formulations were divided in portions of 2 g. To each aliquot was added 1 g of PCR HDPE or virgin HDPE pellets and the aliquots were stored for 1 month.

The relative concentration of the alcohol ethoxylate with exactly 7, 8, 9 and 10 ethoxylate units was measured by chromatography in combination with accurate mass spectrometry detection (UPC² Agilent, BEH Hillic column, positive ion). The results in Table 1 show the % difference in the amount of the non-ionic in a liquid sample of the detergent stored in the presence of virgin plastic pellets versus when stored in the presence of recylced plastic pellets (virgin/PCR). This when using either the ethoxylated anthraquinone dye (inventive) or the acid dye (comparison). The experiments were conducted twice.

Table 1 : % difference of the non-ionic in the liquid when using recycled or virgin plastic pellets.

The results show that use of alkoxylated anthraquinone dye according to the invention maintains the level of alkoxylated non-ionic surfactant when exposed to recycled and virgin plastic pellets whereas use of the acid dye does not. Example 2

An aqueous liquid laundry detergent was formulated to contain 5 wt.% linear alkyl benzene sulfonate and 5 wt.% C12-14 alcohol ethoxylate with an average of 7 moles of ethoxylation. A sulfonate anthraquinone acid dye (Acid Green 25, comparative) or the ethoxylated anthraquinone of the structure as used in Example 1 (of the invention) were each separately dissolved in the detergent formulation to give an optical density of approx. 1 (1cm max visible absorption). The formulations were divided in portions of 2 g. To each aliquot was added 1 g of PCR HDPE or 1g of virgin HDPE pellets or 1g of virgin PET (Polyethylene terephthalate) pellets and the aliquots were stored for 18 days.

The relative concentration of the alcohol ethoxylate with exactly 5, 6, 7, 8, 9 and 10 ethoxylate units was measured by chromatography in combination with accurate mass spectrometry detection (UPC² Agilent, 2-pic, positive ion). The results in Table 2 show the % difference in the amount of the non-ionic in a liquid sample of the detergent stored in the presence of the HDPE plastics in comparison to PET when using either the ethoxylated anthraquinone dye (inventive) or the acid dye (comparison). The values are calculated using the equation (HDPE/PET -1)*100, where HDPE is the integral for the HDPE and PET for the PET. The experiments were conducted twice with 2 chromatographic runs per repeat.

Table 2: % difference of the non-ionic in the liquid when using recycled or virgin plastic HDPE pellets in comparison to PET.

The results show that use of alkoxylated anthraquinone dye according to the invention maintains a more consistent level of alkoxylated non-ionic surfactant across when exposed to PET, recycled and virgin plastic HDPE pellets whereas use of the acid green 25 dye does not. In PCR HDPE a significant change in the alkoxylated non-ionic surfactant is seen when using Acid Green 25.

Claims

1. An aqueous liquid detergent enclosed in a plastic container, wherein the detergent comprises:

• from 0.01 to 10 wt. % alkoxylated non-ionic surfactant; and

2. An aqueous liquid detergent enclosed in a plastic container according to claim 1 , wherein the detergent is a laundry detergent further comprising from 2 to 50 wt. % anionic surfactant and having a pH of from 5 to 9 as measured at 293 Kelvin, where preferably the amount of anionic surfactant is from 5 to 40 wt. % and more preferably is from 6 to 30 wt. %.

3. An aqueous liquid detergent enclosed in a plastic container according to claim 1 or claim 2, wherein the plastic container is transparent to at least part of the light in the visible spectrum of 400 to 700nm.

4. An aqueous liquid detergent enclosed in a plastic container according to any preceding claim, wherein the plastic of the container comprises at least 20 wt.%, more preferably at least 50 wt.%, even more preferably at least 70 wt. % and still even more preferably at least 90 wt. % of LDPE, HDPE or a combination thereof, as based on the total weight of plastic in the plastic container.

5. An aqueous liquid detergent enclosed in a plastic container according to any preceding claim, wherein the alkoxylated dye is an alkoxylated anthraquinone dye of the following structure:

wherein the anthraquinone chromophore contains an amine group or an acid amide group in the 1 -position, the 4-position or both in the 1 -position and the 4- position; and wherein the chromophore contains at least one group containing an [alkoxy]_n moiety; wherein the at least one group containing an [alkoxy]_n moiety is covalently bound at any of the numbered positions, directly or via the amine or acid amide group; and wherein n of the at least one group containing an [alkoxy]_n moiety is from 2 to 20. An aqueous liquid detergent enclosed in a plastic container according to any preceding claim, wherein the at least one group containing an [alkoxy]_n moiety is attached at any one of the positions 1 to 4, directly or via the N-atom of the amine or acid amide group. An aqueous liquid detergent enclosed in a plastic container according to any preceding claim, wherein the anthraquinone dye has an amine group or acid amide group at both the 1- and 4 position. An aqueous liquid detergent enclosed in a plastic container according to any preceding claim, wherein the anthraquinone dye has the following general formula: structure:

where R2, R3, X and Y are H or an organic group and at least one of the groups R2, R3, X and Y contains a -[CH2CH2O]_nRi group, where

• n is from 2 to 20; and

• R1 is an organic group or H, preferably R1 is CHs or H and more preferably R1 is H; and

• preferably X and Y represent the same group and more preferably are H; and

• preferably R2 and R3 are -CH2CH2CH2O(CH2CH2O)2RI and more preferably R1 is -H. An aqueous liquid detergent enclosed in a plastic container according to any preceding claim, wherein the amount of the alkoxylated dye is from 0.0001 to 0.4 wt. %, preferably from 0.0005 to 0.1 wt. %, more preferably from 0.001 to 0.05 wt. %, even more preferably from 0.002 to 0.02 wt.% and still even more preferably from 0.005 to 0.01 wt.%. An aqueous liquid detergent enclosed in a plastic container according to any preceding claim, wherein the non-ionic surfactant is a condensation product of aliphatic Cs to C primary or secondary linear or branched alcohols with ethylene oxide and having from 5 to 40 EO and preferably the non-ionic surfactant comprises C12/14 alcohol ethoxylates with 7EO to 9EO mole average units; C16/18 alcohol ethoxylates with 7 to 13 EO mole average units; C16/18 Methyl ester ethoxylates with 7 to 13 EO mole average units or mixtures thereof. An aqueous liquid detergent enclosed in a plastic container according to any preceding claim, wherein the amount of non-ionic surfactant is from 0.1 to 20 wt. %, preferably from 1 to 12 wt. %, more preferably from 3 to 8 wt.% and even more preferably is from 4 to 6 wt.%. An aqueous liquid detergent enclosed in a plastic container according to any preceding claim, wherein the ratio of the total weight of non-ionic surfactant to the total weight of alkyl ether sulphate surfactant is from 0.5 to 2, preferably is from 0.7 to 1.5 and more preferably is from 0.9 to 1.1. An aqueous liquid detergent enclosed in a plastic container according to any preceding claim, wherein the plastic of the container comprises at least 30 wt.%, preferably at least 50 wt.%, more preferably 70 wt.% and even more preferably at least 90 wt.% of recycled plastic, based on the total weight of the plastic of the container. A process for the manufacture of a detergent product according to any preceding claim, wherein the process comprises the steps of: a) providing a plastic container

• wherein the plastic comprises low density polyethylene, high density polyethylene or a combination thereof; and • wherein the plastic preferably comprises from 30 to 100 wt. % recycled plastic, based on the total weight of the plastic; b) providing an aqueous liquid detergent composition according to the invention; c) filling the container provided at step a) with the aqueous liquid detergent composition provided at step b) to provide the detergent product; and d) preferably storing the detergent product for at least 2 weeks before first use of the detergent, more preferably at least 4 weeks and even more preferably at least 6 weeks. Use of an alkoxylated dye in an aqueous liquid laundry detergent according to any preceding claim to improve product stability of the aqueous liquid laundry detergent in a plastic container, and more preferably in a transparent plastic container, comprising at least 30 wt.% of recycled plastic based on the total plastic of the container, wherein the plastic of the container comprises low density polyethylene (LDPE), high density polyethylene (HDPE) or a combination thereof; and wherein the aqueous liquid laundry detergent further comprises alkoxylated non-ionic surfactant.