RECKITT BENCKISER UK LTD (GB)
DE DOMINICIS MATTIA (US)
| US6281187B1 | 2001-08-28 | |||
| US20050215457A1 | 2005-09-29 | |||
| GB2390097A | 2003-12-31 |
| Claims
1. A method of preparing solid coloured particles by dry mixing the particles with a dye in the absence of binding agent and / or solvent .
2. A method as in claim 1 where the solid particles are crystals such as sodium chloride, sugar, acrylic polymer or sesquicarbonate.
3. A method as claimed in claim 1 or 2 wherein the solid particles and the dye powder are in a ratio from 10 to 1 up to 10000 to 1.
4. A method as claimed in claim 3 wherein the solid particles and the dye powder are in a ratio from 100 to 1 up to 1000 to 1.
5. A method as claimed in any one of the proceeding claims wherein the method is performed with a mixing speed from 5 to 100 rpm, more preferably from 10 to 50 rpm.
6. A method as claimed in any one of the proceeding claims wherein the method is performed with a mixing time from 1 minute up to 5 hours, more preferably from 15 to 75 minutes.
7. A detergent product containing a particles produced in accordance with any one of the proceeding claims . |
METHOD OF COLOURING SOLID PARTICLES
The invention relates to a method of colouring particles.
Standard methods known to colour solid particles generally involve dissolution of a dye in a viscous liquid, such as a non ionic surfactant, and spraying of the coloured mix on top of solid particles under mixing. The viscous liquid helps to absorb the dye and acts as a binding agent to avoid the undesired premature release of the dye during product storage .
This method at least two disadvantages: lump formation due to particle stickiness and loss of brightness, par- ticularly in case the solid particles are crystals, due to viscous liquid opaque thin layer formation.
We have found a new method of colouring solid particles, especially crystals, which allows good absorption of the dye without premature release and which maintains crystal brightness . The bright coloured crystals obtained can then be mixed and used for preparing a solid powder composition without causing an issue of colour stability in the final solid composition. Other features of this dye- ing method are its simplicity and very economic way of execution.
According to the present invention there is provided a method of preparing solid coloured particles by dry mix- ing the particles with a dye in the absence ' of binding agent and / or solvent .
It has been found that in the method according to the present invention the colour is then not released from the coloured particles, e.g. to other solid raw materials. Also particles coloured in this way maintain good brightness after the colouring process.
The mixing can be done in rotary drum at a speed of at least 5 rpm, preferably above 10 rpm. The mixing speed should not be above 100 rpm, preferably above 50 rpm to avoid damaging particles, e.g. by breaking. The mixing time can vary depending on the quantity of powder dye added and colouration intensity requested. Mixing time can range between 1 minute and 5 hours . Preferred mixing time is between 15 and 75 minutes.
A further aspect of the invention is the addition of prepared coloured particles to cleaning powder compositions which have a different colour from the coloured particles. It has been found that coloured particles prepared in accordance with the present invention do not release their absorbed dye even in tough storage conditions of 4O 0 C and 75% RH.
A further advantage of the invention is good solubility of coloured particles when it is dissolved, e.g. in tap water for cleaning purpose.
Solid particles to be coloured are for example crystals. Examples of crystals include sodium chloride, sugars, sesquicarbonate, acrylic polymers crystals.
Examples of dyes useful for present invention include copper phthalocyanin complex, triphenyl methane, anthracene sulphonic acid sodium salts, triphenylcarbinol- anhydrid calcium salt, etc. These dyes can be added to the crystals in a percentage above 0.01, more preferably above 0.1%.
The dyed particles can then be added to a powder cleaning composition which can contain typical cleaning compo- nents .
Surfactants may be present in the composition in an amount of, for example, 0.001 to 30%wt, ideally 0.01 to 15%wt and preferably 0.1 to 5%wt. The surfactant is, for example, an anionic or nonionic surfactant or mixture thereof. The nonionic surfactant is preferably a surfactant having a formula RO(CH 2 CH 2 O) n H wherein R is a mixture of linear, even carbon-number hydrocarbon chains ranging from Ci 2 H 25 to C 16 H 33 and n represents the number of re- peating units and is a number of from about 1 to about 12. Examples of other non-ionic surfactants include higher aliphatic primary alcohol containing about twelve to about 16 carbon atoms which are condensed with about three to thirteen moles of ethylene oxide.
Other examples of nonionic surfactants include primary alcohol ethoxylates (available under the Neodol tradename from Shell Co.), such as Cu alkanol condensed with 9 moles of ethylene oxide (Neodol 1-9) , Ci 2 -1 3 alkanol con- densed with 6.5 moles ethylene oxide (Neodol 23-6.5), C 12 - 13 alkanol with 9 moles of ethylene oxide (Neodol 23- 9) , Ci 2 -I 5 alkanol condensed with 7 or 3 moles ethylene
oxide (Neodol 25-7 or Neodol 25-3) , C 14 - I5 alkanol condensed with 13 moles ethylene oxide (Neodol 45-13) , C 9 - 1X linear ethoxylated alcohol, averaging 2.5 moles of ethylene oxide per mole of alcohol (Neodol 91-2.5), and the like.
Other examples of nonionic surfactants suitable for use in the present invention include ethylene oxide condensate products of secondary aliphatic alcohols containing 11 to 18 carbon atoms in a straight or branched chain configuration condensed with 5 to 30 moles of ethylene oxide. Examples of commercially available non-ionic detergents of the foregoing type are C 11 - 1S secondary alkanol condensed with either 9 moles of ethylene oxide (Ter- gitol 15-S-9) or 12 moles of ethylene oxide (Tergitol 15- S-12) marketed by Union Carbide, a subsidiary of Dow Chemical .
Octylphenoxy polyethoxyethanol type nonionic surfactants, for example, Triton X-100, as well as amine oxides can also be used as a nonionic surfactant in the present invention.
Other examples of linear primary alcohol ethoxylates are available under the Tomadol tradename such as, for example, Tomadol 1-7, a C 11 linear primary alcohol ethoxylate with 7 moles EO; Tomadol 25-7, a C 12 -C 15 linear primary alcohol ethoxylate with 7 moles EO; Tomadol 45-7, a C 14 -C 15 linear primary alcohol ethoxylate with 7 moles EO; and Tomadol 91-6, a C 9 -C 11 linear alcohol ethoxylate with 6 moles EO .
Other nonionic surfactants are amine oxides, alkyl amide oxide surfactants.
Preferred anionic surfactants are frequently provided as alkali metal salts, ammonium salts, amine salts, aminoal- cohol salts or magnesium salts. Contemplated as useful are one or more sulfate or sulfonate compounds including: alkyl benzene sulfates, alkyl sulfates, alkyl ether sulfates, alkylamidoether sulfates, alkylaryl polyether sul- fates, monoglyceride sulfates, alkylsulfonates, alkyla- mide sulfonates, alkylarylsulfonates, olefinsulfonates, paraffin sulfonates, alkyl sulfosuccinates, alkyl ether sulfosuσcinates, alkylamide sulfosuccinates, alkyl sulfo- succinamate, alkyl sulfoacetates, alkyl phosphates, alkyl ether phosphates, acyl sarconsinates, acyl isethionates, and N-acyl taurates . Generally, the alkyl or acyl radical in these various compounds comprise a carbon chain containing 12 to 20 carbon atoms .
Other surfactants which may be used are alkyl naphthalene sulfonates and oleoyl sarcosinates and mixtures thereof.
Examples of suitable bleaches are oxygen bleaches. Suitable level of oxygen bleaches is in the range from 0.01 to 90%wt, preferred level is between 0.1 and 60%wt, ideally 10 to 50%wt. As used herein active oxygen concentration refers to the percentage concentration of elemental oxygen, with an oxidation number zero, that being reduced to water would be stoichiometrically equivalent to a given percentage concentration of a given peroxide compound, when the peroxide functionality of the peroxide compound is completely reduced to oxides . The active oxygen sources increase the ability of the compositions
to remove oxidisable stains, to destroy malodorous molecules and to kill germs.
The concentration of available oxygen can be determined by methods known in the art, such as the iodimetric method, the permanganometric method and the cerimetric method. Said methods and the criteria for the choice of the appropriate method are described for example in "Hydrogen Peroxide", W. C. Schumo, C. N. Satterfield and R. L. Wentworth, Reinhold Publishing Corporation, New York, 1955 and "Organic Peroxides", Daniel Swern, Editor Wiley Int. Science, 1970.
Suitable organic and inorganic peroxides for use in the compositions according to the present invention include diacyl and dialkyl peroxides such as dibenzoyl peroxide, dilauroyl peroxide, dicumyl peroxide, persulphuric acid and mixtures thereof .
Suitable preformed peroxyacids for use in the compositions according to the present invention include diper- oxydodecandioic acid DPDA, magnesium perphthalatic acid, perlauric acid, perbenzoic acid, diperoxyazelaic acid and mixtures thereof . Peroxygen bleaching actives useful for this invention are: percarbonates, perborates, peroxides, peroxyhydrates, persulfates. Preferred compound is sodium percarbonate and especially the coated grades that have better stability. The percarbonate can be coated with silicates, borates, waxes, sodium sulfate, sodium carbonate and surfactants solid at room temperature .
Optionally, the compositions may additionally comprise
from 0% to 30%, preferably from 2% to 20% of peracid precursors, i.e. compounds that upon reaction with hydrogen peroxide product peroxyacids . Examples of peracid precursors suitable for use in the present invention can be found among the classes of anhydrides, amides, imides and esters such as acetyl triethyl citrate (ATC) described for instance in EP 91 87 0207, tetra acetyl ethylene diamine (TAED) , succinic or maleic anhydrides .
The composition may, for example, comprise at least one builder or a combination of them, for example in an amount of from 0.01 to 50%wt, preferably from 0.1 to 20%wt.
Builders of present invention has the function of or chelating agents for metals, or anti-redeposition agents or alkali source or mixture of them.
Examples of builders are described below: - the parent acids of the monomeric or oligomeric poly- carboxylate chelating agents or mixtures therefore with their salts, e.g. citric acid or citrate/citric acid mixtures are also contemplated as useful builder components .
- borate builders, as well as builders containing borate- forming materials than can produce borate under detergent storage or wash conditions can also be used.
- iminosuccinic acid metal salts
- polyaspartic acid metal salts.
- ethylene diamino tetra acetic acid and salt forms. - water-soluble phosphonate and phosphate builders are useful for this invention. Examples of phosphate buiders are the alkali metal tripolyphosphates, sodium potassium and ammonium pyrophosphate, sodium and potassium and am-
monium pyrophosphate, sodium and potassium orthophosphate sodium polymeta/phosphate in which the degree of polymerisation ranges from 6 to 21, and salts of phytic acid. Specific examples of water-soluble phosphate builders are the alkali metal tripolyphosphates, sodium potassium and ammonium pyrophosphate, sodium and potassium and ammonium pyrophosphate, sodium and potassium orthophosphate, sodium polymeta/phosphate in which the degree of polymerization ranges from 6 to 21, and salts of phytic acid. Such polymers include the polycarboxylates containing two carboxy groups include the water-soluble salts of succinic acid, malonic acid, (ethylenedioxy) diacetic acid, maleic acid, diglycolic acid, tartaric acid, tartronic acid and fumaric acid, as well as the ether carboxylates and the sulfinyl carboxylates.
Polycarboxylates containing three carboxy groups include, in particular, water-soluble citrates, aconitrates and citraconates as well as succinate derivates such as the carboxymethloxysuccinates described in GB-A-I, 379, 241, lactoxysuccinates described in GB-A-I, 389, 732, and amino- succinates described in NL-A-7205873, and the oxypolycar- boxylate materials such as 2-oxa-l, 1, 3-propane tricar- boxylates described in GB-A-I, 387, 447.
Polycarboxylate containing four carboxy groups include oxydisuccinates disclosed in GB-A-I, 261, 829, 1,1,2,2- ethane tetracarboxylates, 1, 1, 3 , 3-propane tetracarboxy- lates and 1 , 1 , 2 , 3 -propane tetracarobyxlates . Polycar- boxylates contining sulfo substituents include the sulfo- succinate derivatives disclosed in GB-A-I, 398, 421, GB-A- 1,398,422 and US-A-3 , 936448 , and the sulfonated pyrolsed
σitrates described in GB-A-I, 439, 000.
Alicylic and heterocyclic polycarboxylates include cyclopentane-cis , cis , cis-1etracarboxylates , cyclopentadi- enide pentacarboxylates, 2,3,4,5, 6-hexane - hexacarboxy- lates and carboxymethyl derivates of polyhydric alcohols such as sorbitol, mannitol and xylitol. Aromatic polycarboxylates include mellitic acid, pyromellitic acid and the phthalic acid derivatives disclosed in GB-A- 1,425,343.
Of the above, the preferred polycarboxylates are hydroxy- carboxylates containing up to three carboxy groups per molecule, more particularly_-C-itjrat.es .
Suitable polymer water-soluble compounds include the water soluble monomeric polycarboxylates, or their acid forms, homo or copolymeric polycarboxylic acids or their salts in which the polycarboxylic acid comprises at least two caroxylic radicals separated from each other by not more than two carbon atoms, carbonates, bicarbonates, borates, phosphates, and mixtures of any of thereof.
The carboxylate or polycarboxylate builder can be mono- meric or oligomeric in type although monomeric polycarboxylates are generally preferred for reasons of cost and performance .
Suitable carboxylates containing one carboxy group in- elude the water soluble salts of lactic acid, glycolic acid and ether derivatives thereof. Polycarboxylates containing two carboxy groups include the water-soluble
salts of succinic acid, malonic acid, (ethylenedioxy) di- acetic acid, maleic acid, diglycolic acid, tartaric acid, tartronic acid and fumaric acid, as well as the ether carboxylates and the sulfinyl carboxylates . Polycarboxy- lates containing three carboxy groups include, in particular, water-soluble citrates, aconitrates and citra- conates as well as succinate derivates such as the car- boxymethloxysuccinates described in GB-A-I, 379, 241, lac- toxysuccinates described in GB-A-I, 389, 732, and aminosuc- cinates described in NL-A-7205873 , and the oxypolycar- boxylate materials such as 2-oxa-l, 1, 3-propane tricar- boxylates described in GB-A-I, 387, 447.
PoIycarboxylate containing four carboxy groups include oxydisuccinates disclosed in GB-A-I, 261, 829, 1,1,2,2- ethane tetracarboxylates , 1,1,3,3 -propane tetracarboxy- lates and 1 , 1 , 2 , 3 -propane tetracarobyxlates . Polycar- boxylates contining sulfo suibstituents include the sul- fosuccinate derivatives disclosed in GB-A-1, 398,421, GB- A-I, 398,422 and US-A-3 , 936448 , and the sulfonated pyrol- sed citrates described in GB-A-I, 439, 000.
Alicylic and heterocyclic polycarboxylates include cyclopentane-cis , cis , cis-tetracarboxylates , cyclopentadi- enide pentacarboxylates , 2 , 3 ,4, 5, 6-hexane - hexacarboxy- lates and carboxymethyl derivates of polyhydric alcohols such as sorbitol, mannitol and xylitol. Aromatic polycarboxylates include mellitic acid, pyromellitic acid and the phthalic acid derivatives disclosed in GB-A- 1,425,343.
Of the above, the preferred polycarboxylates are hydroxy-
carboxylates containing up to three carboxy groups per molecule, more particularly citrates.
More preferred polymers are homopolymers , copolymers and multiple polymers of acrylic, fluorinated acrylic, sulfonated styrene, maleic anhydride, metacrylic, iso- butylene, styrene and ester monomers.
Examples of these polymers are Acusol supplied from Rohm & Haas, Syntran supplied from Interpolymer and Versa and Alcosperse series supplied from Alco Chemical, a National Starch & Chemical Company.
The parent acids of the monomeric or oligomeric polycar- boxylate chelating agents or mixtures therefore with their salts, e.g. citric acid or citrate/citric acid mixtures are also contemplated as useful builder components.
In the context of the present application it will be ap- preciate that builders are compounds that sequester metal ions associated with the hardness of water, e.g. calcium and magnesium, whereas chelating agents are compounds that sequester transition metal ions capable of catalysing the degradation of oxygen bleach systems. However, certain compounds may have the ability to do perform both functions .
Suitable chelating agents to be used herein include chelating agents selected from the group of phosphonate che- lating agents, amino carboxylate chelating agents, poly- functionally-substituted aromatic chelating agents, and further chelating agents like glycine, salicylic acid,
aspartic acid, glutamic acid, malonic acid, or mixtures thereof. Chelating agents when used, are typically present herein in amounts ranging from 0.01% to 50%wt of the total composition and preferably from 0.05% to 10%wt.
Suitable phosphonate chelating agents to be used herein may include ethydronic acid as well as amino phosphonate compounds, including amino alkylene poly (alkylene phosphonate) , alkali metal ethane 1-hydroxy diphosphonates, nitrilo trimethylene phosphonates, ethylene diamine tetra methylene phosphonates, and diethylene triamine penta methylene phosphonates . The phosphonate compounds may be present either in their acid form or as salts of different cations on some or all of their acid functionalities. Preferred phosphonate chelating agents to be used herein are diethylene triamine penta methylene phosphonates . Such phosphonate chelating agents are commercially available from Monsanto under the trade name DEQUEST TM.
Polyfunctionally-substituted aromatic chelating agents may also be useful in the compositions herein (see U.S. patent 3,812,044, issued May 21, 1974, to Connor et al.). Preferred compounds of this type in acid form are dihy- droxydisulfobenzenes such as 1, 2-dihydroxy -3,5- disulfobenzene .
A preferred biodegradable chelating agent for use herein is ethylene diamine N,N' -disuccinic acid, or alkali metal, or alkaline earth, ammonium or substitutes ammo- nium salts thereof or mixtures thereof. Ethylenediamine N, N 1 -disuccinic acids, especially the (S, S) isomer have been extensively described in US patent 4, 704, 233, No-
vember 3, 1987, to Hartman and Perkins. Ethylenediamine N,N 1 -disuccinic acids is, for instance, commercially available under the tradename ssEDDS TM from Palmer Research Laboratories .
Suitable amino carboxylates to be used herein include ethylene diamine tetra acetates, diethylene triamine pen- taacetates, diethylene triamine pentaacetate (DTPA) ,N- hydroxyethylethylenediamine triacetates, nitrilotri- acetates, ethylenediamine tetrapropionates, triethylene- tetraaminehexa-acetates, ethanol-diglycines, propylene diamine tetracetic acid (PDTA) and methyl glycine diace- tic acid (MGDA) , both in their acid form, or in their alkali metal, ammonium, and substituted ammonium salt forms. Particularly suitable amino carboxylates to be used herein are diethylene triamine penta acetic acid, propylene diamine tetracetic acid (PDTA) which is, for instance, commercially available from BASF under the trade name Trilon FS TM and methyl glycine di-acetic acid (MGDA) .
Solvents can be used for present invention at levels of 0.01 to 30%wt, preferred level is between 0.1-3% wt . The solvent constituent may include one or more alcohol, gly- col, acetate, ether acetate, glycerol, polyethylene glycol with molecular weight ranging from 200 to 1000, silicones or glycol ethers. Exemplary alcohols useful in the compositions of the invention include C 2 -C 8 primary and secondary alcohols which may be straight chained or branched, preferably pentanol and hexanol .
Preferred solvents for the invention are glycol ethers and examples include those glycol ethers having the general structure. Preferred solvents for the invention are glycol ethers and examples include those glycol ethers having the general structure Ra-O- [CH 2 -CH (R) - (CH 2 ) -O] n -H, wherein Ra is Ci- 2 o alkyl or alkenyl, or a cyclic alkane group of at least 6 carbon atoms, which may be fully or partially unsaturated or aromatic; n is an integer from 1 to 10, preferably from 1 to 5; each R is selected from H or CH 3 ; and a is the integer 0 or 1. Specific and preferred solvents are selected from propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol n-propyl ether, ethylene glycol n-butyl ether, diethylene glycol n-butyl ether, diethylene glycol methyl ether, propylene glycol, ethylene glycol, isopropanol, ethanol, methanol, diethyl- ene glycol monoethyl ether acetate, and particularly useful are, propylene glycol phenyl ether, ethylene glycol hexyl ether and diethylene glycol hexyl ether.
The composition may, for example, comprise one enzyme or a combination of them, for example in an amount of from 0.01 to 10%wt, preferably from 0.1 to 2%wt. Example of granular enzymes are proteases, modified proteases stable in oxidisable conditions, amylases, cellulases and lipases.
Additional, optional, ingredients, selected from a list consisting fragrance, anticaking agent as sodium xylene sulfonate and magnesium sulfate, dye, are present at levels of up to 5%w/v, preferably less then l%w/v.
The present invention is described with reference to the following non-limiting examples.
Examples :
Crystals were coloured by a dry mixing process . The crystals used were sesquicarbonate crystals . The level of powder dyes added was in the range 0.1 - 0.3%. Examples of tested dyes are Bley Vitasyn V 8501 from Clariant and Blue Pigmasol 6900 from BASF. The time of mixing in the rotary drum set at about 30 rpm was in the range 20 - 40 minutes. At the end of the preparation, the coloured crystals were sieved through a 150μm sieve to remove fine crystals and non absorbed dyes.
The coloured crystals were evaluated in terms of brightness and in terms of colour stability in a laundry additive cleaning matrix to check the colour was not released during storage stability over time.
BRIGHTNESS ASSESSMENT:
Brightness assessment was done through visual evaluation by using as a reference of brightness the non coloured crystal (rating = 4) and as a reference of opacity the amorphous form (rating = 0) . The rating is assigned by visual evaluation of the samples under D65 lamp light, which is a simulation of sunlight.
The higher the rating number the better the brightness appearance .
STORAGE STABILITY TEST:
The dyed crystals were mixed with a laundry additive white powder product and any negative in terms of dye transfer to the white matrix or lumps formation have been assessed over time at T=40°C and 75%RH.
Also in this case two visual rating values have been as- signed for lumps formation and dye transfer.
In case of dye transfer and lumps formation the lower the rating the better. Ideally the rating should be zero for both.
EXAMPLE 1:
Crystals of sesquicarbonate were coloured by using the conventional method of dissolving the dye in a viscous surfactant mix and spraying it onto the crystals . The crystals were also coloured through the new process by dry mixing. Two dyes were used for this study: Bley Vi- tasyn V 8501 and Blue Pigmasol 6900.
Sesquicarbonate crystals were coloured using Bley Vitasyn V 8501 and Blue Pigmasol 6900 blue dyes. The conventional method for colouring solid water soluble particles was used. The method dissolves the dye in a mixture of surfactants, in this case Lialet 125-5 surfactant was used. The coloured viscous liquid was sprayed when warm
(T=40°C) onto the crystals, under mixing in a drum at 30 rpm speed. The rotary drum is left to mix for 5 minutes in order to allow absorption of the coloured liquid onto the crystals . The coloured crystals are left to sit for at least 30 minutes.
The coloured crystals were also prepared by using the new dry mixing method where the crystals are charged into the rotary drum and then the solid dye powder is added. The system is left to mix for about 30 min.
In both process at the end of the mixing the coloured crystals are filtered through a 150μm sieve to remove fine particles and non absorbed fine dyes.
RESULTS;
The previously described blue coloured crystals were assessed in terms of brightness and in terms of dye transfer and lump formation when added at a level of 5% in a
10 white laundry additive powder product. The laundry additive powder product was based on sodium percarbonate, so-
dium carbonate, surfactants, enzymes and other minor ingredients .
5 It is evident that as the dry mixing dyeing process is able to provide a colouration of the crystals preserving their brightness and avoiding or significantly reducing storage issues once the crystals are. added to a white matrix.
10
Next Patent: CHECK-IN SYSTEM