EP3523413B1

EP3523413B1 - Bleaching composition

Info

Publication number: EP3523413B1
Application number: EP16810082.4A
Authority: EP
Inventors: Matteo LEGA; Stefano Resta; Luca Sarcinelli
Original assignee: Fater SpA
Current assignee: Fater SpA
Priority date: 2016-10-05
Filing date: 2016-10-05
Publication date: 2021-05-12
Anticipated expiration: 2036-10-05
Also published as: EP3523413A1; PT3523413T; WO2018066006A1

Description

The present invention relates to bleaching compositions, in particular to hypochlorite bleaching compositions, suitable for use in hard surface cleaning and laundry applications such as hand and machine laundry methods.

Background of the invention

Bleaching compositions are well-known in the art. Amongst the different bleaching compositions available, those relying on bleaching by hypohalite bleaches such as hypochlorite are often preferred, mainly for performance reasons, especially at lower temperature.
However a problem encountered with the use of hypochlorite based-compositions is the resulting damage and/or yellowing of the fabrics being bleached.
Several documents, such as EP0188145 , EP0867502 , J53081789 or J03137278disclose compositions containing phosphate compounds that are known to improve fabric whiteness and safety.
In particular, EP0867502 discloses a bleaching composition comprising sodium tripolyphosphate (STPP).
Bleaching compositions comprising hybrid polymers are disclosed in US2013165572 , US5185096 and WO2013064647 .
However, there is the need of further improved compositions.
It is therefore an object of the invention to provide a hypohalite-containing composition, suitable for use in laundry applications, which, maintaining the performances related to fabric whiteness, allows a better safety of fabrics treated therewith, in particular in terms of reduction of tensile strength loss.
It is another object of the invention to provide a hypohalite-containing composition, suitable for use in hard surface cleaning applications, which provides improved shine to surfaces treated therewith.

Summary of the invention

The applicant has now surprisingly found that the problem of fabric safety and shine of hard surface treated with a hypochlorite based-composition can be further solved with the use of a bleaching composition containing a hybrid polymer. Surprisingly, the use of a hybrid polymer results in a sensible reduction of tensile strength loss.
In particular, it has now been found that this objective can be met by compositions according to claim 1, a process according to claim 8 and a use according to claim 9.
According to a first aspect of the invention, there is provided a liquid bleaching composition.
The present invention also encompasses a process of treating fabrics where said fabrics are immersed in a bleaching solution formed by diluting said bleaching composition in water.
The present invention further encompasses the use, in a hypohalite bleaching composition, of a hybrid polymer, for providing improved fabric safety to the fabrics treated therewith while maintaining fabric whiteness comparable to that obtained with product that are free from the hybrid polymer.
The present invention further encompasses the use, in a hypohalite bleaching composition, of an hybrid polymer, for providing improved shine properties to hard surfaces treated therewith.
The present invention further encompasses the use, in a hypohalite bleaching composition with a surfactants system, of a hybrid polymer, for providing improved stability in terms of gas evolution from hypoalite degradation.

Detailed description of the invention

Hypohalite bleach

An essential component of the invention is a hypohalite bleach. Hypohalite bleaches may be provided by a variety of sources, including bleaches that are oxidative bleaches and subsequently lead to the formation of positive halide ions as well as bleaches that are organic based sources of halides such as chloroisocyanurates.
Suitable hypohalite bleaches for use herein include alkali metal and alkaline earth metal hypochlorites, hypo-bromites, hypoiodites, chlorinated trisodium phosphate dodecahydrates, potassium and sodium dichloroisocyanurates, potassium and sodium trichlorocyanurates, N-chloroimides, N-chloroamides, N-chloroamines and chlorohydantoins.
For liquid compositions, the preferred hypohalite bleaches among the above described are the alkali metal and/or alkaline earth metal hypochlorites, more preferably selected from the group consisting of sodium, potassium, magnesium, lithium and calcium hypochlorites, and mixtures thereof, even more preferably the sodium hypochlorite.
Preferably, the liquid compositions according to the present invention comprise said hypohalite bleach such that the content of active halide in the composition is of from 0.1% to 20% by weight, more preferably from 2% to 8% by weight, most preferably from 2.5% to 5% by weight of the composition.

Source of alkalinity

A source of alkalinity is another essential component for the compositions of the invention. The source of alkalinity ensures that the pH of the composition as it is, is typically from 12 to 14 measured at 25°C. Moreover, the composition of the invention is buffered to a pH value ranging from 7.5 to 13, preferably from 8 to 12, more preferably from 8.5 to 11.5 after the composition has been diluted into 1 to 500 times its weight of water. It is in this alkaline range that the optimum stability and performance of the hypohalite as well as fabric whiteness and safety are obtained. The pH range is suitably provided by the source of alkalinity and the hypohalite bleach mentioned hereinbefore, which are alkalis. Suitable sources of alkalinity for use herein are selected from the group consisting of pH buffering agents, strong bases or mixtures thereof.
Preferred pH buffering agents are selected from the group consisting of alkali metal salts of carbonates, polycarbonates, sesquicarbonates, silicates, polysilicates, borates, metaborates, phosphates, stannates, alluminates and mixtures thereof, and preferably are selected from the group consisting of sodium carbonate, sodium silicate, sodium borate, and mixtures thereof.
Preferred strong bases are selected from the group consisting of caustic alkalis such as sodium hydroxide, potassium hydroxide and/or lithium hydroxide, and/or the alkali metal oxides such as sodium and/or potassium oxide and mixtures thereof, and preferably are selected from the group consisting of sodium hydroxide and potassium hydroxide.
Preferably the source of alkalinity is a mixture of sodium carbonate and sodium hydroxide.
The amount of the source of alkalinity in the composition is from 0.05% to 10% by weight of the total composition, preferably from 0.5% to 5% and more preferably from 1.0 to 4.0.
Typical levels of such strong bases, when present, are of from 0.01% to 3.5% by weight, preferably from 0.1% to 3.0%, preferably from 0.5% to 2.8% even more preferably from 0.8 to 2.5% by weight of the composition.
Liquid bleaching compositions herein will contain an amount of pH buffering agent of from 0.05% to 5% by weight, preferably from 0.5% to 5% by weight, and more preferably in an amount of from 0.6% to 3% by weight of the composition.

Hybrid polymer

A hybrid polymer component is another essential component for the compositions of the invention.
The hybrid copolymers useful in the composition of the invention are all those disclosed in EP1746109B1 .
In particular, they derive from synthetic monomers chain terminated with a hydroxyl containing natural material. By using a hydroxyl containing natural material as the chain transfer agent, the molecular weight of the resultant polymer can be controlled, especially if the chain transfer agent is low in molecular weight. Further, no special initiation system is required, unlike graft copolymers. Indeed, graft copolymers typically require special redox initiating systems containing metallic ions. In contrast, hybrid copolymers according to the present invention use conventional free radical initiating systems.
The materials are also structurally different than graft copolymers disclosed in the art. Graft copolymers are defined as a backbone of one monomer or polymer and one or more side chains derived from another monomer(s) attached on to the backbone (Odian, George, PRINCIPLES OF POLYMERIZATION, 2nd ed., Wiley-Interscience, New York, p. 424 (1981)). Graft copolymers (such as those described in U.S. Patent Nos. 5,854,191 , 5,223,171 , 5, 227, 446 and 5,296,470 ) typically have a natural polymer backbone and short side chains derived from synthetic monomers. In contrast, the hybrid copolymers of the present invention have long chains of synthetic monomers that incorporate a moiety derived from natural material at the end of the chain. From Mark, Herman F., ENCYCLOPEDIA OF POLYMER SCIENCE AND TECHNOLOGY, 3rd ed., Vol. 11, Wiley-Interscience, New York, p. 380 (2004), fragments of a chain transfer agent are incorporated into polymer chains as end groups. A transfer reaction can therefore be used to introduce specific end groups into the polymeric material.
The hybrid polymers of the composition of the present invention comprise a hydroxyl containing naturally derived chain transfer agent selected from the group consisting of gluconic acid, glucoheptonic acid and naturally derived mono-, di-, oligo- or polysaccharides, as the chain terminating portion of the polymer.
Examples of naturally derived mono-, di-, oligo- or polysaccharides include sucrose, fructose, maltose, glucose, and saccharose, as well as reaction products of saccharides such as mannitol, sorbitol and so forth. The chain transfer agents include oxidatively, hydrolytically or enzymatically degraded monosaccharides, oligosaccharides and polysaccharides, as well as chemically modified monosaccharides, oligosaccharides and polysaccharides. Such chemically modified derivatives include carboxylates, sulfonates, phosphates, phosphonates, aldehydes, silanes, alkyl glycosides, alkyl-hydroxyalkyls, carboxy-alkyl ethers and other derivatives.
Polysaccharides useful in the present invention can be derived from plant, animal and microbial sources. Examples of such polysaccharides include starch, cellulose, gums (e.g., gum arabic, guar and xanthan), alginates, pectin and gellan. Starches include those derived from maize and conventional hybrids of maize, such as waxy maize and high amylose (greater than 40% amylose) maize, as well as other starches such as potato, tapioca, wheat, rice, pea, sago, oat, barley, rye, and amaranth, including conventional hybrids or genetically engineered materials.
Also included are hemicellulose or plant cell wall polysaccharides such as D-xylans. Examples of plant cell wall polysaccharides include arabino-xylans such as corn fiber gum, a component of corn fiber. An important feature of these polysaccharides is the abundance of hydroxyl groups. These hydroxyl groups provide sites for chain transfer during the polymerization process. The higher the number of secondary and tertiary hydroxyl groups in the molecule the more effective it will be as chain transfer agent.
Other polysaccharides useful as chain transfer agents include maltodextrins, which are polymers having D-glucose units linked primarily by α-1,4 bonds and have a dextrose equivalent ('DE') of less than about 20. Maltodextrins are available as a white powder or concentrated solution and are prepared by the partial hydrolysis of starch with acid and/or enzymes. In one aspect the chain transfer agents are maltodextrins and/or low molecular weight oxidized starches. Useful chain transfer agents according to the present invention have molecular weights of less than about 20,000. In another aspect, the chain transfer agents have molecular weights of less than about 2000. In even another aspect, chain transfer agents according to the present invention have molecular weights of less than 1000.
Polysaccharides can be modified or derivatized by etherification (e.g., via treatment with propylene oxide, ethylene oxide, 2,3-epoxypropyltrimethylarmnonium chloride), esterification (e.g., via reaction with acetic anhydride, octenyl succinic anhydride ('OSA')), acid hydrolysis, dextrinization, oxidation or enzyme treatment (e.g., starch modified with α-amylase, β-amylase, pullanase, isoamylase or glucoamylase), or various combinations of these treatments.
The hydroxyl-contairiing naturally derived chain transfer agents can be used from about 0.1 to about 75% by weight based on total weight of the polymer. In one aspect, the range is from about 1 to about 50% by weight of chain transfer agents based on total weight of the polymer.
In one embodiment, the hybrid copolymers are prepared from at least one hydrophilic acid monomer as the synthetic constituent. Examples of such hydrophilic acid monomers include but are not limited to acrylic acid, methacrylic acid, ethacrylic acid, α-chloro-acrylic acid, α-cyano acrylic acid, β-methyl-acrylic acid (crotonic acid), α-phenyl acrylic acid, β-acryloxy propionic acid, sorbic acid, α-chloro sorbic acid, angelic acid, cinnamic acid, p-chloro cinnamic acid, β-styryl acrylic acid (1-carboxy-4-phenyl butadiene-1,3), itaconic acid, maleic acid, citraconic acid, mesaconic acid, glutaconic acid, aconitic acid, fumaric acid, tricarboxy ethylene, 2-acryloxypropionic acid, 2-acrylamido-2-methyl propane sulfonic acid, vinyl sulfonic acid, sodium methallyl sulfonate, sulfonated styrene, allyloxybenzene sulfonic acid and maleic acid.
Moieties such as maleic anhydride or acrylamide that can be derivatized to an acid containing group can be used. Combinations of acid-containing hydrophilic monomers can also be used.
In one aspect the acid-containing hydrophilic monomer is acrylic acid, maleic acid, methacrylic acid, 2-acrylamido-2-methyl propane sulfonic acid or mixtures thereof.
In addition to the hydrophilic monomers described above, hydrophobic monomers can also be used as the synthetic constituent. These hydrophobic monomers include, for example, ethylenically unsaturated monomers with saturated or unsaturated alkyl, hydroxyalkyl, alkylalkoxy groups, arylalkoxy, alkarylalkoxy, aryl and aryl-alkyl groups, alkyl sulfonate, aryl sulfonate, siloxane and combinations thereof.
Examples of hydrophobic monomers include styrene, α-methyl styrene, methyl methacrylate, methyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, lauryl acrylate, stearyl acrylate, behenyl acrylate, 2-ethylhexyl methacrylate, octyl methacrylate, lauryl methacrylate, stearyl methacrylate, behenyl methacrylate, 2-ethylhexyl acrylamide, octyl acrylamide, lauryl acrylamide, stearyl acrylamide, behenyl acrylamide, propyl acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, 1-vinyl naphthalene, 2-vinyl naphthalene, 3-methyl styrene, 4-propyl styrene, t-butyl styrene, 4-cyclohexyl styrene, 4-dodecyl styrene, 2-ethyl-4-benzyl styrene, and 4-(phenyl butyl) styrene. Combinations of hydrophobic monomers can also be used.
The hybrid polymers have thus the performance properties of synthetic polymers but use lower cost, readily available and environmentally friendly materials derived from renewable sources.
In one aspect, the number average molecular weight of the hybrid copolymer is between about 1000 and about 100, 000. In another aspect, the number average molecular weight of the polymer is between about 2000 and about 25,000.
In the bleaching composition of the invention the hybrid polymer is present in an amount of about 0.02% to about 2% by weight of the total composition, preferably from 0.03% to 1% by weight of the total composition.
The polymerization process can be a solution or suspension process. The process involves polymerization using free radical initiators with one or more of the above hydrophilic and/or hydrophobic monomers, and the hydroxyl containing natural products used as chain transfer agents or chain stoppers. These chain transfer agents can be added either at the beginning of the reaction or during reaction as the monomer(s) is (are) added.
One advantage of this system is that it makes use of typical free radical initiators. Unlike grafting systems, special redox systems such as Ce(IV) salts are not required. Instead, easy-to-use thermally activated initiators such as sodium persulfate can be used. One skilled in the art will recognize that most initiating systems are applicable here.
A high degree of chain transfer can lead to crosslinking and formation of an insoluble gel. In one embodiment, this can be avoided by ensuring that monomer and initiator are fed over the same approximate period of time. If initiator feed lasts much longer than monomer feed, a crosslinked gel can form, particularly when oligopolysaccharides and polysaccharides (those having a molecular weight greater than about 1000) are used as the chain transfer agent.
As noted above, in some cases the reaction product forms a hybrid gel during manufacture of these hybrid copolymers. This is especially true if the synthetic monomer used is extremely reactive (e.g., acrylic acid reacted at low pH (protonated form)) or if the natural chain transfer agent has a molecular weight of greater than about 1000. A crosslinked gel starts to form after the monomer feed has ended and while the rest of the initiator is being fed in. This is undesirable in most cases, since the gel product cannot be diluted in water.
If an undesirable gel starts to form during the process due to a reactive monomer, it can be eliminated in a number of ways. This includes reducing monomer reactivity by neutralizing the monomer. Alternatively, additional chain transfer agents like thiols, sodium hypophosphite and alcohols can also be used. Thiols and alcohols are particularly useful in controlling molecular weight and preventing the formation of crosslinked gels. Finally, these gels can be eliminated by shortening the initiator feeds so that the initiator and monomer feeds are pumped over the same period of time.
Examples of the preparation of hybrid polymers encompassed in the scope of the present invention are illustrated in examples 1 to 6 of EP1746109 . A preferred hybrid polymer to be used in the bleaching composition of the present invention is Alcoguard H5941 from Akzo Nobel, a hybrid polymer as above described of amylose-polyacrylate having a molar ratio between the polyacrylate and the amylose of from 1:1 to 1:100, preferably from 1:1 to 1:10, more preferably from 1:2 to 1:5, even more preferably 1:3, a molecular weight of the polyacrylate between 140 and 2500 and a molecular weight of the amylose between 342 and 3400.

Surfactants

The composition according to the invention may also comprise one surfactant or a mixture of surfactants, added in a quantity sufficient to give the desired cleaning effectiveness.
The term "surfactant", as used herein refers to a substance which is able to lower the surface tension of the water. Preferably, the total level of surfactants varies from 0.001 to 20% w/w of the total quantity of aqueous solution, more preferably from 0.01 to 10%, even more preferably from 0.01 to 7%, even mere preferably from 0.0125 to 5%.
The surfactant or the mixture of surfactants contained in the liquid composition of the present invention are preferably anionic, nonionic, cationic, zwitterionic, amphoteric, ampholytic surfactants or mixtures thereof.
Below, a brief and non-comprehensive description of the various classes of surfactants that can be used in the present invention is provided, merely by way at example.

Anionic surfactants

Non-exhaustive examples of anionic surfactants suited to the present invention comprise conventional anionic surfactants. For example a sulfate surfactant, such as alkoxylate and/or non-alkoxylate alkyl sulfates, and/or sulfonated surfactants, for example, alkyl benzene sulfonates, and their hydrosoluble salts.
Examples of alkoxylate alkyl sulfates comprise ethoxylated, propoxylated, ethoxylated/propoxylated and butoxylated alkylsulfate surfactants. Preferably the alkyl group contains approximately 7 to approximately 20 atoms of carbon.
Other anionic surfactants that can be used for the present invention are the water soluble salts of paraffin sulfonates and secondary alkane sulfonates containing approximately 7 to approximately 20 atoms of carbon; alkyl glyceryl ether sulfonates, especially alcohol ethers from C7 to C20. Alternatively it is possible to use mixtures of alkyl benzene sulfonates with the paraffin sulfonates described above, secondary alkane sulfonates and alkyl glycerin ether sulfonates.
Another anionic surfactants useful for the present invention are the water soluble salts of carboxylic acid, for example lauroyl sarcosinate or myristoyl sarcosinate.
The anionic surfactants are preferably hydrosoluble salts of alkali metals, ammonium salts and alkylammonium salts.

Nonionic surfactants

Non-exhaustive examples of nonionic surfactants suited to the present invention comprise fatty alcohol alkoxylates and alkyl amine oxides.
The fatty alcohol alkoxylates can be chosen from alcohol alkoxylates and alkylphenol alkoxylates with formula RO-(E)_e-(P)_p-H, in which

R is chosen from the group consisting of linear or branched aliphatic hydrocarbon radicals containing approximately 8 to approximately 20 carbon atoms and linear or branched alkyl phenyl radicals in which the alkyl groups contain approximately 8 to approximately 20 carbon atoms ,
E is ethylene oxide and P is propylene oxide,
e and p, respectively, represent the mean degree of ethoxylation and propoxylation and are between 0 and 24 (with the sum of e + p equal at least to 1).

The alkyl amine oxides preferably have the formula R₁R₂R₃NO, in which each R₁, R₂ and R₃ groups are independently a C1-C30 alkyl group, more preferably a C1-C20 alkyl group, more preferably a C1-C18 hydrocarbon chain, even more preferably R₁ and R₂ are methyl groups, and R₃ is a C8-C18 hydrocarbon chain.

Cationic surfactants

Non-exhaustive examples of cationic surfactants suitable for the present invention, comprise quaternary ammonium surfactants, which can have up to 26 carbon atoms , alkoxylated surfactants of quaternary ammonium, such as hydroxyethyl dimethyl quaternary ammonium, hydroxyethyl lauryl dimethyl ammonium chloride.

Zwitterionic surfactants

Non-exhaustive examples of zwitterionic surfactants suitable for the present invention comprise derivatives of secondary and tertiary amines, derivatives of heterocyclic secondary and tertiary amines, or derivatives of quaternary ammonium quaternary phosphonium or compounds of tertiary sulphonium salts.

Ampholytic and/or amphoteric surfactants

Non-exhaustive examples of ampholytic and/or amphoteric surfactants suitable for the present invention include derivatives of secondary or tertiary aliphatic amines, or heterocyclic aliphatic derivatives of secondary and tertiary amines in which the aliphatic radical can be linear or branched. One of the aliphatic substituents can contain at least 8 atoms of carbon, for example 8 to 18 atoms of carbon, and at least one contains an anionic water solubilising group, for example carbonyl, sulfonate or sulfate.
The presence of at least one surfactant chosen from the group consisting of soluble salts of alkyl sulfates (primary or secondary}, soluble salts of alkyl sulfonates (primary or secondary}, paraffin sulfonates and secondary alkane sulfonates, linear or branched ethoxylated alcohols, amine alkyl oxides or quaternary ammonium surfactants is particularly preferred.

Optional ingredient

The composition according to the invention may also comprise further optional components such as perfumes, bleach-stable surfactants, organic or inorganic alkalis, pigments, dyes, optical brighteners, solvents, chelating agents, radical scavengers and mixtures thereof.
Preferably, the bleaching compositions of the invention are used in diluted form in laundry applications. The expression "used in diluted form" herein includes dilution by the user, which occurs for instance in handwash laundry applications, as well as dilution by other means, such as in a washing machine. Preferably, the bleaching composition is diluted into 5 to 500 times its weight of water for hand laundry application and 10 to 500 times its weight of water in a washing machine.
Thus, in another aspect of the invention, there is provided a process for bleaching fabrics with a bleaching composition as disclosed herein, where said fabrics are immersed in a bleaching solution formed by diluting said composition in water.
In yet another aspect of the invention, there is provided the use, in a hypohalite bleaching composition, of an hybrid polymer for providing improved safety to the fabrics treated therewith while maintaining whiteness properties comparable to those of bleaching compositions that do not comprise the hybrid polymer. By "improved safety", it is meant that hypohalite bleaching compositions, with the hybrid polymer, provide better safety, i.e. less tensile strength loss, compared to hypohalite bleaching compositions which do not comprise said hybrid polymer ingredient.
The invention is illustrated in the following nonlimiting examples, in which all percentages are on a weight basis unless otherwise stated.

Examples

Example 1: stability test

As a preliminary test, stability of Alcoguard H5941 was assessed in hypochlorite products.
The formulations of table 1 were prepared (the percentages are on a weight basis on the total composition).

Example 5, as well as examples 1, 2, 6, and 13 are not within the scope of current invention and they are therefore reference examples.

Table 1

sample	%AvCl	%NaOH	%Na₂CO₃	%STPP	%Alcoguard H5941	%water
1	3.00	1.00	1.75	---	---	Complement to 100%
2	3.00	1.00	1.75	0.049	---	Complement to 100%
3	3.00	1.00	1.75	---	0.049	Complement to 100%
4	5.00	1.00	1.75	---	0.200	Complement to 100%
5 (not within the invention)	2.00	1.00	1.75	---	0.01	Complement to 100%
6	3.00	1.20	1.20	0.049	---	complement to 100%
7	3.00	1.20	1.20	---	0.049	Complement to 100%
8	3.00	1.20	1.20	---	0.10	Complement to 100%
9	3.00	1.20	1.20	0.049	0.049	Complement to 100%
10	3.00	4.00	4.00	---	0.049	Complement to 100%
11	3.00	0.15	0.15	---	0.049	Complement to 100%
12	3.00	0.15	4.00	---	0.049	Complement to 100%
13	4.25	1	1.75	0.049	---	Complement to 100%
14	4.25	1	1.75	---	0.049	Complement to 100%
15	4.25	1	1.2	---	0.049	Complement to 100%

STPP: sodium tripolyphosphate

The stability of these formulations was assessed by Rapid Aging Test (RAT) performed storing 100 mL of sample at 50°C (±0.5°C) into a ventilated oven for 10 days. The bottles used for the test were 100 mL square bottle with plug cap in polyethylene.
As an example, some results are listed in table 2. Table 2

sample %AvCl after RAT

1 2.58

2 2.58

3 2.46

13 3.20

14 3.14

15 3.19
For all formulas, not relevant issues on stability were evidenced by the RAT. Slightly higher loss in AvCl% for Alcoguard formulation (sample 2 vs 3 and 13 vs 14) may be addressed to partial oxidation of the sugar backbone which, in principle, do not affect its beneficial effect in terms of fabric safety.

Example 2: performances in terms of whiteness and mechanical properties in laundry applications - knitted cotton

The performances, in terms of whiteness and mechanical proprieties, were assessed by the following procedure simulating hand-wash condition. For illustrative purpose, results will be reported for samples 2 and 3 of table 1.
7.5 g of each formulation was diluted in 500 mL of tap water (dilution 7.5/500; pH TW>10), having a Fe content of 61.3 ppb, a Mn content of 2.6 ppb and a total hardness of 26°f (260 mg/L) .
For every tested formulation, 5 fabrics (standard knitted cotton provided by equest, 20x20 cm, in total ≈ 70 g) were added to the solution. After 20 minutes, fabrics were rinsed 3 times and dried by tumble dryer. The wash cycle was repeated for 30 times.
The results have been compared to that obtained with those obtained on fabrics treated with a commercial bleaching formulation comprising 3.00% AvCl, 0.10% NaOH and 0.04% Na₂CO₃ (sample 16) and those of untreated fabrics.
The fabrics were analyzed by spectrophotometer in order to assess whiteness (WI Ganz).
The results are listed in Table 3. Table 3

Sample WI Ganz

2 (0.049 STPP) 132

3 (0.049 ALC) 127

16 (COM) 69

untreated fabric (knitted cotton) 227
No relevant differences between the formulations comprising Alcoguard (sample 3) and STPP (sample 2) were observed.
Mechanical properties of the samples have been measured using the burst test (UNI EN ISO 13938-2:2001).
Results of mechanical proprieties of fabrics treated with samples 2 and 3 are illustrated in table 4. These results were further compared to those obtained on sample 16 and those of untreated fabric. Table 4

sample Pressure at breakage (KPa)

2 (0.049 STPP) 377

3 (0.049 ALC) 408

16 (COM) 340

untreated fabric (knitted cotton) 441
From table 4, it is evident that the fabrics treated with sample 3 formulation containing Alcoguard H5941 show a tensile strength loss (calculated as pressure at breakage (untreated) - pressure at breakage (ALC)/ pressure at breakage (untreated)- pressure at breakage (COM)) of about 50% compared to the fabrics treated with a composition comprising STPP (sample 2) and of about 33% compared to the fabrics treated with a commercial composition (sample 16).

Example 3: performances in terms of whiteness and mechanical properties in laundry applications-woven cotton

In order to confirm the beneficial effect of Alcoguard H5941, the test was repeated changing the key experimental conditions, namely: type of cotton, simulated wash condition and product formula. In particular, the type of cotton used determines the type of resistance test performed on fabric: burst test (UNI EN ISO 13938-2:2001) for knitted cotton or tear test (UNI EN ISO 13934-1:2000) for woven cotton.
For illustrative purpose, formulations 6 and 7 were tested. The following procedure was used: 1.0 g of formulations 6 and 7 was diluted in 200 mL of tap water (dilution 2.5/500; pH TW>10). For every formulation, 5 fabrics (standard woven cotton provided by equest, 20x20 cm, in total ≈ 40 g) were added to the solution. After 20 minutes, fabrics were rinsed 3 times and dried by tumble dryer.
The wash cycle was repeated for 20 times.
The fabrics were analyzed by spectrophotometer in order to assess whiteness (WI Ganz).
The results are illustrated in table 5. Table 5

Sample WI Ganz

6 (0.049 STPP) 228

7 (0.049 ALC) 222

untreated fabric (woven cotton) 263
No relevant differences between the formulations comprising Alcoguard and STPP were observed.
Results on mechanical proprieties (tear test) on fabrics treated with sample formulations 6 and 7 are reported in table 6. These results were further compared to those obtained on woven cotton treated with sample formulation 16 and to untreated fabrics as references. Table 6

sample Pressure at breakage (KPa)

16 (COM) 265

6 (0.049 STPP) 285

7 (0.049 ALC) 310

untreated fabric (woven cotton) 328
Results for sample 7 clearly show a recovery in tensile strength loss about 50% compared with sample 6, confirming the beneficial effect.

Example 4: performances in terms of whiteness and mechanical properties in laundry applications-woven cotton

In order to deepen the understanding of the benefit deriving from the use of Alcoguard H5941, performances of formulation 6, 7, 8, 9, 16 were compared in the following test.
1.0 g of each formulation was diluted in 200 mL of tap water (dilution 2.5/500; pH TW>10). For every formulation, 5 fabrics (standard woven cotton provided by equest, 20x20 cm, in total ≈ 40 g) were added to the solution. After 20 minutes, fabrics were rinsed 3 times and dried by tumble dryer. The wash cycle was repeated for 20 times.
The fabrics were analyzed by spectrophotometer in order to assess whiteness (WI Ganz), and not relevant differences between Alcoguard and STPP were observed.
Results on mechanical proprieties (tear test) of fabrics are reported in table 7, together with the results on untreated fabrics as reference. Table 7

sample Force at breakage (N)

6 (0.049 STPP) 285

7 (0.049 ALC) 310

8 (0.10 ALC) 318

9 (0.049 STPP+0.049 ALC) 283

16 (COM) 265

untreated fabrics (woven cotton) 328
It can be noted that the presence of both Alcoguard and STPP (sample 9) in the formulation does not reach the reduction of tensile strength loss.
This phenomenon can be explained on the basis of the following model. The sugar backbone of Alcoguard is probably oxidized by the hypochlorite in the product; even in its oxidized form, it is supposed to have high affinity for the fibers, due to the structural analogy, and in particular for the oxidized (i.e. damaged) sites of the cellulose. Once deposed on the damaged sites of cellulose, Alcoguard could control the deposition of calcium carbonate, repairing the site and strengthening the fabric.
Accordingly, the presence of STPP (an excellent scale inhibitor) together with Alcoguard does not allow the deposition of calcium carbonate, inhibiting the reparation of the cellulose of the fabric.

Example 5: performances in terms of whiteness and mechanical properties in laundry applications-woven cotton

In order to verify the activity on mechanical properties of the composition of the invention, compositions 6 (0.049 STPP) and 7 (0.049 Alcoguard) have been tested after an aging of 1 week at 50°C. This allow to confirm the beneficial effect of the invention in aged product.
Multicycle test (20 cycle) were performed in washing machine (Ariston Hotpoint ARXF 109) at 30°C. The test procedure was the following:

Conditioning of the washing machine: before running a new test, run the washing program for resistant white cotton fabrics, 90°C, water only to strip out laundry products residues from the washing machine.
Load the washing machine with the testing tracers (standard woven cotton provided by equest, 20x20 cm, in total ≈ 40 g), weight and load the ballasts (3 Kg), load the soil strips (4).
Set the wash cycle for cotton (n°3 for the washing machine reported), as appropriate.
Weight 100.0 g of bleach and pour it into the bleach compartment. Close the lid and press the start button. Allow the machine to complete the rinse cycle and spin out.

The fabrics were analyzed by spectrophotometer in order to assess whiteness (WI Ganz), and the results are illustrated in table 8. No relevant differences between Alcoguard and STPP were observed. Table 8

Sample WI Ganz

6 (0.049 STPP aged) 242

7 (0.049 ALC aged) 247

untreated fabric (woven cotton) 263
Results on mechanical proprieties (tear test) of fabrics are reported in table 9, together with the results on untreated fabrics as reference. Table 9

sample Force at breakage (N)

6 (0.049 STPP - fresh) 391

7 (0.049 ALC - fresh) 423

6 (0.049 STPP - aged) 401

7 (0.049 ALC - aged) 437

untreated fabrics (woven cotton) 425
It can be observed that even after aging, the composition of the invention still allows a reduction of the loss in tensile strength of the treated fabrics.

Example 6: performances in terms of whiteness and mechanical properties in laundry applications- ISO cotton

In order to verify the activity on mechanical properties of the composition of the invention, compositions 6 (0.049 STPP) and 7 (0.049 Alcoguard) have been tested in standard condition, according to 5A EN26330:1996 in a Electrolux wascator.

Multicycle test (50 cycle) were performed at 40°C

The fabrics (ISO cotton F02) were analyzed by spectrophotometer in order to assess whiteness (WI Ganz). The results are illustrated in table 10. Alcoguard samples results in increased whiteness on these kind of cotton. Table 10

Sample WI Ganz

6 (0.049 STPP) 6

7 (0.049 ALC) 22

16 (COM) -5

untreated fabric (ISO cotton) 0
Results on mechanical proprieties (tear test) of fabrics are reported in table 11, together with the results on untreated fabrics as reference. Table 11

sample Force at breakage (N)

6 (0.049 STPP - fresh) 334

7 (0.049 ALC - fresh) 379

16 (COM) 289

untreated fabrics (woven cotton) 425
It can be observed that the composition of the invention allows a reduction of the loss in tensile strength of the fabrics treated according to standard procedures.

Example 7: performances on shine in hard surface cleaning applications

The following shine tests were performed, using water at 26°F (15GPG) and at two different temperatures (22 and 35°C).
The procedure was the following:
15 mL of products were diluted in 500 mL of water. A soft, previously conditioned, sponge was soaked in the solution, then wringed up to a water uptake of 2 g.
The sponge was rubbed uniformly on the surface of a black, conditioned ceramic tile. The operation was repeated 3 times in different directions. The tail was left to dry for 10 minutes before evaluation of 4 trained graders.
The following compositions were tested (Table 12). Composition 10 has been taken as reference.
Examples 17 and 18 are not in accordance to the current invention and they are therefore reference examples. Table 12

Sample %AvCl %NaOH %Na2CO3 %STPP %Alcoguard %water

17 3.00 1.2 1.2 0.049 --- Complement to 100

18 3.00 1.1 1.1 0.049 --- Complement to 100

19 3.00 1.1 1.1 --- 0.049 Complement to 100
The results are illustrated in table 13 wherein shine is measured in PSU units (defined on a scale ranging from 0= no difference to 4= very large difference): Table 13

Samples

Water Temperature (°C) 17 18 19

22 Reference + 1.0 + 2.4

35 Reference + 1.4 + 2.8
Alcoguard delivers a benefit in surface care in terms of shine and residues. A reasonable mechanism is the improved dispersion ability towards salt residues on the surface, which allows less visible strokes.

Example 8: stability test of thick formulations

In order to assess the feasibility of Alcoguard technology in all hypochlorite-based product, stability of Alcoguard H5941 was assessed in hypochlorite thick products.
The formulations of table 14 were prepared (the percentages are on a weight basis on the total composition).

Examples 20, 21, and 24-27 are not in accordance to the current invention and they are therefore reference examples.

Table 14

Compositions	20	21	22	23	24	25	26	27	28	29	30	31	32	33	34	35	36
Sodium hypochlorite	3	3	3	3	4.5	4.5	4.5	4.5	4.5	4.5	4.5	4.5	0.7	1	1.5	3	3
Sodium hydroxide	1.2	1.2	1.2	1.2	1	1	1	1	1	1	1	1	2	4.5	0.5	3	1.1
Sodium carbonate	1.2	1.2	1.2	1.2	-	-	-	-	-	-	-	-	2	-	0.5	3	1.1
sodium tripolyphosphate	0.049	0.049	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-
Alcoguard H5941	-	-	0.049	0.049	-	-	-	-	0.05	0.05	0.05	0.05	0.1	0.3	0.5	1	0.05
Periodic acid	-	-	-	-	0.005	0.005	0.005	0.005	0.005	0.005	0.005	0.005	-	-	-	-	-
trimethoxybenzoic acid	0.1	0.1	0.1	0.1	-	-	-	-	-	-	-	-	-	-	-	-	-
C12/C14 amine-oxide	-	-	-	-	2	2	-	-	2	2	-	-	1.1	-	0.1	1	-
C12/C18 amine-oxide	-	-	-	-	-	-	2	2	-	-	2	2	-	-	-	-	-
Na C8/C10 alkyl sulfate	-	-	-	-	0.45	0.45	0.3	0.3	0.45	0.45	0.3	0.3	-	0.15	-	-	-
C12/C18 alkyl EO3 sulfate	1.064	1.064	1.064	1.064	1	1	0.8	0.8	1	1	0.8	0.8	-	0.15	2	-	0.014
Cocobetaine	-	-	-	-	0.3	0.6	0.3	0.6	0.3	0.6	0.3	0.6	0.3	-	-	0.8	-
C12/C14 Carboxylate 2EO	-	-	-	-	0.5	-	-	-	0.5	-	-	-	0.3	-	-	0.2	-
C12/C14 Carboxylate 5EO	-	-	-	-	-	0.5	-	-	-	0.5	-	-	-	-	-	-	-
C12/C14 Carboxylate 7EO	-	-	-	-	-	-	0.5	-	-	-	0.5	-	-	-	-	-	-
Sodium Lauryl sarcosinate	-	-	-	-	-	-	-	-	-	-	-	-	0.5	-	-	0.3	-
C12/C14 benzalkonium chloride	-	-	-	-	-	-	-	-	-	-	-	-	-	-	0.2	-	-
C10 alcohol 3/5EO	-	-	-	-	-	-	-	0.5	-	-	-	0.5	0.5	0.1	-	-	-
Sodium 2-ethyl hexyl sulfate	-	-	-	-	1	0.5	1	0.5	-	0.5	1	0.5	-	0.2	-	0.2	-
Fatty acid	0.078	0.078	0.078	0.078	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.3	-	0.05	0.3	-	-
perfume	0.085	0.085	0.085	0.085	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.2	0.06 5	0.0 5	-	0.02
Iron (III)(in ppb)	-	400	-	400	-	-	-	-	-	-	-	-	-	-	-	-	-
Copper (II) (in ppb)	-	200	-	200	-	-	-	-	-	-	-	-	-	-	-	-	-
Blue copper phtalocyanine	0.0015	0.0015	0.0015	0.0015	-	-	-	-	-	-	-	-	-	-	-	-	-
Sodium silicate	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.05	0.05	0.1	-	-
minors and water	balanced up to 100%

The stability of these formulations was assessed by Gas Evolution Rate (GER), in order to further verify the suitability of Alcoguard H5941 as substitute of STPP.
As a matter of fact, hypochlorite-containing formulations develops molecular oxygen as main degradation product of the oxidant. This reaction is catalytically enhanced by metal impurities which are usually present in water, such as copper and iron. This phenomenon is very relevant for bleach products, because large values of gas evolution rate may cause bulging of bottles, which would cause drawbacks in terms of aesthetics and safety of the packaging. For this reason, GER is a key parameter for the assessment of the robustness of new formulations.
The Gas Evolution Rate test has been performed measuring the pressure increase in a close bottle containing a known volume of product at 50°C (±0.5°C). The pressure increase and the gas evolution rate were related on the basis of the following equation:

where: V_S = volume of the solution (L);
V_hs = volume of the headspace (cc);
ΔP/ Δt = rate of pressure increase in the head space (bar);
T= temperature (K);
R= Universal gas constant [8.31 (J/mol K)]

The equation takes into account:

1) The amount of product in the bottle, through the term: The pressure increase in the bottle increases considerably if the fill level is increased, for 2 reasons: (a) the amount of gas evolved is proportional to the volume of solution; (b) the pressure increase for each mole of gas evolved is inversely proportional to the headspace volume.
2) The distribution of the O₂ evolved between the gas and liquid phase, through the term: This term is a function of temperature and fill level and takes into account the fact that increasing the partial pressure of O2 leads to an increase of O₂ dissolved (Henry's law).

In order to test the product under a worst case scenario, composition from 13 to 16 were tested also with a contamination of iron (400 ppb) and copper (200 ppb), which was added on top of the product. Typically the product already contains about 200 ppb of iron and 200 ppb of copper coming from raw materials.
For a non-comprehensive illustrative purpose, the results of the test (GER) are illustrated for compositions from 20 to 23 of Table 14. Table 15

GER ((mLO₂/(500mL*day)) Day 0 Day 4 Day 10 Day 14

Composition 20 1.5 0.5 0.9 0.7

Composition 21 5.3 3.2 3.5 3.6

Composition 22 1.3 0.4 0.8 0.5

Composition 23 2.7 2.2 2.3 2.4
The results of the GER test indicate exceptional stability of the composition containing Alcoguard H5941 in presence of metals contaminations.

Example 9: performances in terms of whiteness and mechanical properties in laundry applications for woven and ISO cotton

In order to verify the activity on mechanical properties of the composition of the invention, compositions 13, 14 and 15 have been tested in a laundry test.
Multicycle test (20 cycle) were performed in washing machine (Ariston Hotpoint ARXF 109) at 30°C. The test procedure was the following:

Conditioning of the washing machine: before running a new test, run the washing program for resistant white cotton fabrics, 90°C, water only to strip out laundry products residues from the washing machine.
Load the washing machine with the testing tracers (for whiteness, standard woven cotton provided by equest, 20x20 cm, in total ≈ 40 g; for mechanical proprieties, ISO cotton 1mX1m), weight and load the ballasts (3 Kg), load the soil strips (4).
Set the wash cycle for cotton (n°3 for the washing machine reported), as appropriate.
Weight 100.0 g of bleach and pour it into the bleach compartment. Close the lid and press the start button. Allow the machine to complete the rinse cycle and spin out.

The fabrics were analyzed by spectrophotometer in order to assess whiteness (WI Ganz), and the results are illustrated in table 21. Not relevant differences between Alcoguard and STPP were observed. Table 21

Sample WI Ganz

17 206

18 185

19 180

Untreated fabric 260
Results on mechanical proprieties (tear test) of fabrics are reported in table 22, together with the results on untreated fabrics as reference. Table 22

sample Force at breakage (N)

17 391

18 423

19 414

untreated fabrics (ISO woven cotton) 425
It can be observed that even with high %AvCl, the composition of the invention still allows a reduction of the loss in tensile strength of the treated fabrics.

Claims

Liquid bleaching composition comprising:
- a hypohalite bleach in an amount of 2.5 to 5 % by weight of the total composition,

- a source of alkalinity in an amount of 0.05% to 10% by weight of the total composition, wherein the source of alkalinity is a mixture of sodium carbonate and sodium hydroxide, and

- an hybrid polymer in an amount of 0,02% to 2% by weight of the total composition, the hybrid polymer comprising:
a synthetic polymer as the backbone of the hybrid polymer, and

a chain transfer agent selected from the group consisting of gluconic acid, glucoheptonic acid and naturally derived mono-, di-, oligo- or polysaccharides, as the chain terminating portion of the polymer.
Liquid bleaching composition according to claim 1, wherein said hypohalite bleach is an alkali metal or an alkaline earth metal hypochlorite.
Liquid bleaching composition according to any of claims 1 or 2, wherein said hypohalite, based on active halide, is present in an amount of from 0.1% to 20% by weight.
Liquid bleaching composition according to claim 1, wherein the amount of said hybrid polymer is 0.02% to about 2% by weight of the total composition.
Liquid bleaching composition according to claim 1, wherein said hybrid polymer comprises polyacrylate as the synthetic polymer and amylose as chain transfer agent.
Liquid bleaching composition according to claim 5, wherein the molar ratio between the amount of polyacrylate and the amount of amylose from 1:1 to 1:100, preferably from 1:1 to 1:10, more preferably from 1:2 to 1:5, even more preferably 1:3, the molecular weight of the polyacrylate is of 1600 and the molecular weight of the amylose between 342 and 3400.
Liquid bleaching composition according to any of the preceding claims, wherein one or more surfactants are present and are comprised between 0.01% and 10% by weight of the total composition.
A process for bleaching fabrics with a bleaching composition according to any of claims 1 to 7, where said fabrics are immersed in a bleaching solution formed by diluting said bleaching composition in water.
Use, in a hypohalite bleaching composition as defined in claims 1 to 7, of an hybrid polymer in an amount of 0,02% to 2% by weight of the total composition, the hybrid polymer comprising:
- a synthetic polymer as the backbone of the hybrid polymer, and

- a chain transfer agent selected from the group consisting of gluconic acid, glucoheptonic acid and naturally derived mono-, di-, oligo- or polysaccharides, as the chain terminating portion of the polymer
for providing improved safety to the fabrics treated therewith or improved shine to the hard surface treated therewith.