PH26563A - Detergent composition - Google Patents

Description

DETERGENT COMPOSITION

Thie invention relates to the msrmfscture of built detergent lsundry bare. Such bare comprise detergent achive, tuilder snd optionally fillers, abraelves, perfumes and eilicabes.

The bare are manufactured by a preferred procese which requires the addition of water and customarily the bars contain alkaline ingredients so that the bar forms an alkaline solution when diesolved/dispersed in water. The preferred process of manufacture involves mixing under conditions of high temperature and shear followed by extrusion into billets.

To enhance the cleaning performance of such laundry bare it is desirable to incorporate bleaching compounds. Bleaches are liable to decompogition when placed in intimate contact with the other constituents of the bar. In the past the addition of bleach has been achieved by coating a bleach core with an sbradable wax to isolate it from the rest of the ingredients.

GB 1 438 647 (Unilever Ltd/POTTER) discloses a method of forming a detergent bar containing a hypochlorite bleach where the detergent active is in the form of particles which are lightly mixed with wax coated hypochlorite particles and pressed into bars.

The wax coating is abradable on contact with a fabric

: “ or domestic hard earface to relesge the bleach.

We have now found that iv is possible to incor- porate coabed bleach particles into lamandry bar compositions formed nsing the potentially damsging conditions of high temperature, shear snd extraeion and thet bare eo Tormed mitigate the problem of bleach decomposition during ehorage.

Accordingly the present invention provides ® 1emuandry bar cowprielng detergent, mctive nd builder 1D characterised in thet the bar ig formed from an extruded, shesr wixed dough snd additionally contains a chlorine blemch encepealated with = costing meterisl whieh ie ineoluble in water ah pH 7.

Suprieingly, =n effective encapenlating material can remain effective deeplle the stress of being mixed into the ber composition znd extruded with it.

It ie preferred that the bar composition hae = anter content, at the Lime of mermfeotnre, of nol more then 12%, preferzbly not more than 10% by weight of the 29 bar componition.

The detergent active employed in the bar le preferably preeent in an amount of 10 to 60% by welght of the bar composition, more preferably 12 to 45% by weight. The detergent active will normally be a 26 non-goap detergent active guch as alkyl benzene sulphonate having 8 to 22 carbon atoms in the alkyl group, Cq to Cia primary alcohol gulrhate, or Cq to Cia ’

fatty acid C4 to Cy ester sulphonate. Various other non-goap detergent actives may be used. It is algo . | feasible to use soap ag detergent active although it would be preferable to utilise an exceptionally dry 8O&P.

The detergent builder is desirably present in an amount from 5 to 60% by weight of the bar composition, more preferably 10 te 60%, yet more preferably 12 to 45% of the composition. The builder may include hydratable phosphate (which term embraces condensed phosphates such as pyrophosrhate or tripolyphosphate).

Other inorganic or organic buildere can be included also. Examples are water soluble carbonate, e.g. sodium carbonate; organic builders, e.g. sodium nitrilotriacetate, sodium tartrate, sodium citrate, trisodium carboxymethyl oxysuccinate, sodium oxydi- succinate, sodium sulphonated long-chain monocarboxylic acids, polyacrylates and oxldieed polysaccharides; and aluminosilicate ion exchangers; e.g. zeolite 4A. In particular, use of phosphate builders or polyphophate Te detergency builder may provide at least 3% by weight of the bar composition.

Chlorine bleach incorporated in accordance with thie invention can be selected from oxygen-chlorine bleaches such as hypochlorite conveniently in the form of lithium or calcium hypechlorite, or bleaching powder. Presently preferred are nitrogen-chlorine =4°7 . .

' bleaches such me sodium or potmssinm ealte of chloro- igoeymrmric melds or mn oxyden containing bleach gach se pohaesinm monoperenlphate. . The combing material with which the bleach le encapenlated ie insolnble in water at neutrality. It ig preferably insoluble under acid conditions alec, bal golnble or ewellsble in maueone alkaline solntion so that when the bar ie need euch me by rabbing on wet fabric, the encapeulsting coating swells or dieesolves, go releasing the bleach. However it would also be possible to rely on abrasion during wee Lo expos the blexch.

Possible coating materiale which are insoluble in neutral to acid aqueous solution are fatty acids. 16 Preferred are alkali-scluble or swellable polymers.

These may have monomer units selected from acrylic and methacrylic acide, styrenee and mixtures thereof.

Application of coating material to bleach particles is " preferably carried out in a fluidised bed.

United States Patent 4 758 968 and equivalente elsewhere describes in detail a technique fer encapsulation of particles, which may be bleach par- jeles, with polymer latex. The procedure disclosed therein is our preferred route for the preparation of coated bleach particlee.

We have found that bleach particles coated in accordance with that application have good storage gtability in lanndry bere, deeplte the presence of woater snd mlkaline material in = detergent bar composition. In addition te this gurprising finding, we have mleo found that costed bleach particles survive mixing into a detergent bar dough prior to extrusion even when mixing and siabeeguent extrusion are carried out nt temperatures well mbove the gluse transition temperatnre of the polymer need to encapeulate the bleach particles.

Built laundry bars generally contain a propor- tion of filler which although chemically inert le gignificant in contributing to the properties of the bar. Such filler may be incorporated in bars of this invention and an appropriate range for such filler is 5 to 60% by weigh of the bar composition. The filler may consist of water soluble salts such as sodium sulphate but poseible it includes water-ineoluble filler. The filler present may even all be water insoluble and accordingly the possible amount of water insoluble filler ig 5 to 60 wt%. Examples of water insoluble fillers are tale, kaolin, calcite, bentonite and aluminosilicate.

Other ingredients may aleo be present in the bar composition. These Include silicates, e.g. alkaline sodium silicate, sodium carboxymethyl cellulose, lather enhancing agents such as coconut alkanolamides (both mono—- and di- derivatives) as well as coconut alcohol,

Pa colouring materiale, enzymes, fluorescers, opacifiers, germicides and perfumes.

It will be appreciated that this invention is concerned with detergent bars which will generally be subetantially rigid, enabling such a bar to be rubbed against an item of laundry. Of course if a bar is soaked in water or stored under conditions of excessive humidity it may lose ite strength and become plasti- ally deformable by hand pressure.

The bars according to thie invention may be prepared by progressively mixing the ingredients, with water, ueing a high ehear mixer as 1s conventional and then extruding. It may be desirable to add the coated bleach particles last of all the constituente so that they are subjected to the least amount of shear. 1f the bar making procedure entails neutralisation of the acid form of detergent active, it is important to complete the neutralisation before adding the bleach which reacte with strong acid. 290 Embodiments of this invention will now be described with reference to the accompanying examples.

Example 1

Potassium dichloroisocyanuric acid (RDCCA) from

Monsanto chemicals and having a mean particle size of 560 um was coated with a latex polymer from National

Starch under deeignation NSC78-6312. This polymer contained the following monomer unite, by welght baeed on the polymer: 10% styrene 60% n-butyl mcrylate 30% methecrylic acid.

The polymer had a glass transition temperature Tg of approximately 40°C. Its particle size was very emall, 0.2 to 0.5u. It wae supplied as a latex, and used in thie form, when it contained 40% w/w polymer and had a pH of 2.9.

Coating wae carried out by the technique described in US 4 759 956, using a Glatt fluidized bed coating apparatus. The polymer latex was sprayed in by the

Wureter spray method. The bed temperature was main- tained at 42°C which was of course close tc the glaee transition temperature of the polymer of approximately 40°C. } The coated particles contained 75% by weight of the bleach as core particles and 25% by weight polymer coating.

Example Za

Ron-soap built doughe of the composition listed in

Table I in which all percentages are by weight of the dough formulation (alkyl benzene sulphonic acid neutralised).

Table I (% w/w in dough)

A B

ABS 30.5 30.5

Soda Ash 15.7 15.7

Caleite (CaCl,) 19.4 20.65

SCHMC 2.0 2.0

TSPFP 4.1 4.1

STP 7.1 7.1

Na,50, 5.1 65.1

Water 11.0 11.0

KDCCA (coated) 5.1 -

KDCCA (uncoated) - 3.85

ABS denotes alkyl benzene sulphonate

SCHC denotes sodium carboxymethyl cellulose

TSPP denotes tetrasodium pyrorhosphate

STP denotes scodiumtripclyrphosphate

KDCCA denotes potassium dichloroisocyanuric acid

The doughs were prepared in 500 gram batches in a heated 1 kg capacity Z-blade mixer ab 75°C. KDCCA particles from Example 1 were smdded to the dough at the finsl etege of mixing. The temperature wae maintained at 75°C for 50 minutes. Samplee were analysed for percentage KDCCA remaining after 5, 25 and 50 minutes.

For » 1st series of reeulte the KDCCA periiclee were into the dough for 2 mites mt T5 rpm and the dough wae left to stand in the heated mixer for the remainder of the 50 minnte period. Additions} mixing . 5 for 30 seconds wae carried out prior to sampling.

For = 2ud series of resulie the KDCCA particles Oo were mixed into the dongh for 50 minates ah 10 rEm.

For & 3rd series of reeulhs the KDCCA particles were mixed into the dough for 50 minates at T5 rpm. 10 Dough stability dats: KDCCA corien Eormlation Particle % residual DCCA ak 75°C mine 25 mine 50 mine 1 A conted 98 105 97 1 B nneonthed 104 97 103 2 A cornted 101 98 97 2 B nneonted 103 75 B87 3 A coated 96 68 48 3 B nneoated 100 43 29

The reenlte indicate that polymer coated KDCCA : 20 particles need in dough A show improved gtabilivy over the uncoated KDCCA particles need in dough B ander conditions of conhinaome mixing.

. }

The variations in sequentizl memsuremente sre thought to reflect small differences in the uniformity of particle distritution thoroughont the dough.

The comparative stability of conted KDCCA particles ie all the more eurprising when it is reslised thet the polymer costing hae a transition temperature of approx. anc i.e. the conting mppesnre Lo survive shesnr forces exerted at sn temperature 35°C in excess of ite glass Lransitlion temperature.

Exzmple 2b

Non-soap, built detergent laundry bare were made from the ingredients listed in Table II in which all percentages are by weight of the formulation used in the manufacture of the bars (prior to neutralisation of 1b the alkyl benzene sulphonic acid).

TABLE II

NSD formulations weed in the manufacture of bare % w/w in form lation

Ingredient c RD E ’ 5 Eescane F : 28.56 28.0 28.0

Sod= Ash 6.0 20.0 20.0

Water 5.0 6.0 6.0 : Calcite 16.0 23.0 24.25

SCHC - 2.0 2.0 . 10 Pyrophoephate 9.4 4.9 4.0

Sodinm Tripolyphoephate - 7.9 7.0

Na ,50, : 14.1 5.0 5.0

NaHCO, 8.0 - -

Borax 8.0 - -

Coated KDCCA (GK54) 5.0 5.0 -

Uncoated RDCCA - - 3.76 100.00 100,00 100.00 pH (2.5% Sol) 8.90 10.31 10.40

Eecane F is alkyl benzene sulphonic acid SCMC denotes sodiumcarboxymethyl cellulose

Formulations © snd D in Table II contalned corted

KDCCA produced =e in Example 1 above. Formmletlion E contained EDCCA which had not been coated, and wae need in en mmount to provide an egual quantity of EDCCA iteelf. i : Thig resulted in final bar compositione as given in Table III below, the alkyl benzene sulphonic acid having been neutralised to alkyl benzene sulphonate.

The bare were made using a Z-blade mizer and a small extruder. The sodium alkyl benzene sulphonate wae made “in situ’ by neutralising alkyl benzene enlphenic meid with excess soda seh ab 55°C, approximately half the water being ndded at thie stage. - Sodinm pyrophosphate and, where sppropriate sodium tripolyphosphate were sdded next followed by the reset of the ingrediente snd remaining water. After thorough mixing the reenlting dough wae cooled Lo 40-45°C and the blesch particles mixed in for 1-2 mlnates. The mixture wae then extruded into bare.

TABLE I11

NSD barcompositiont % w/u in formulation

Ingredient c b E

ABS 31.0 30.5 ag. 6

Soda Ash 1.4 15.75 15.75

Water 5.9 6.9 6.9

Calcite 16.2 23.4 24.7

SCHMC - 2.05 2.056

Pyrophosrhate 8.6 4.1 4.1

STP - 7.1 7.1

Na,50, 14.4 6.1 5.1

NaHCO, 8.2 - -

Borax 8.2 - -

Coated KDCCA 5.1 6.1 - : Uncoated RDCCA - - 3.8 100.00 100.00 100.00

Example 3

Some bars produced in Example Zb were wrapred in glassine paper alche, others were wrapped in glassine paper and then enclosed in a plastic bag. Bars wrapped in each way were stored for varying periods of time under various conditions of temperature and humidity and then analysed to determine the remaining KDCCA content. It was noted that there wae some uptake of

, moisture and a correction was made for thie eo the resulte could be expressed ae percentages of the amount of KDCCA originally present. Theege results are set out in the following three tables. They demonstrate that the coating wae very effective to increase the amount of KDCCA remaining after etorage.

Storage stability data: KDCCA % KDCCA Surviving after different periods of storage } under the stated conditions of temperature. humidity and method of bar wrapping

A. Storage Conditions - Laboratory (22°C/40% RH)

Wrapping Glassine paper or glassine paper plus plastic % KDCCA SurvivingX

Storage Time Glassine Glasgine paper (Days) Paper plug plaetic ec D E Cc D E 0 100 "100 100 100 100 100 7 89.2 110.4 70.7 95.0 108.6 72.1 20 ’- 96.8 - - 103.9 - 27 90.9 - 32.6 B9.7 - 35.3 50 105.8 - - 100.5 - - 111 - 92.2 7.6 - 93.7 6.7 118 90.0 - - 96.0 - - * Corrected for water wphake by the bar during shorage.

Results indicated thet conted EDECA used in bare © snd D ie enbetsnbially etable during storage wherehs uncoated EDCCA ae used in bar E in unstable.

Example 4

Storage stability data: KDCCA

B. Shorsme conditions - 28°C/70% BH

Wrapping Glassine paper or glagelne paper plus plastic % EDCCA Surviving

Storage Time Glagsine Glassine paper (Daye) Paper plug plastic

Cc D E o D E

C0 100 100 10D 100 100 100 7 © 80.7 104.7 37.8 87.5 105.6 38.9 - 98.2 - - 106.2 - 27 89.0 - 4.4 92.2 - 4.7 50 98.2 - - 105.5 - - 111 - 66.0 0.7 - 82.3 1.8 : 118 95.7 - - 92.0 - - 20 ¥ Corrected for water uphzke during eLorade.

Reenlte mgain show the comparatively high .

Co etabllity of costed KDCCA (me need in compositions © and D) compared with wncosted FKDCCA (me need in composition BE).

Example 5

C. Ghorase conditions - 37°C/70% EH

Wrapping Glassine paper or glassine paper plus plastic ¥ KDCCA Surviving#®

Storage Time Gleeaine Qlaceline paper (Daye) Eaper plus plastic

C Db E Cc D E 0 100 109 100 100 100 100 7 83.2 94.5 6.6 90.7 94.8 11.0 - 72.7 ~ - 83.6 - 27 87.5 - 2.2 91.7 - 2.5 50 85.7 , - 108.3 - - 111 - 16.8 1.2 - 33.1 1.5 16 118 56.1 - - BT7.5 - - ¥ Corrected for water uptake during storage.

Conted blesch is sgain mach more gtable than nncoated blesch. .

Coated bleach is less stable than at 28/70 or ambient. 20 Coated bleach is more stable in composition C than in :

D.

Coated bleach is more stable when plastic wrapped.

Example 6

Potassium dichloroisocyanuric acid (KDCCA) was conbed with wax of melting point 50°C according ho the method of Exsuple 1 except that the WAX WE rpplied me sn molten epray from = tLorroldal mixer/conter. The coated particles contained T6% by weight of the bleach ag core parbicles rnd 25% by weight wsx coating.

Example T

Non-goap, bullt detergent jaundry bars were made from the ingredients 1isted in Table iV in which all . percentages are by weight of the formulation need in the manufacture of the bars.

TABLE IY

Ingredient E E

Alkyl benzene sulphonic acid 28.0 27.6

Soda Ash 20.0 15.8

Hater 6.0 2.0

RB —

A1,(804) 5 14.5H,0 3.5

Alkaline ailicate (48% golids) - 2.0

SCMC 2.0 0.92 - R

Ti0, 0.5

Calelte 24.25 34.7

STF 7.0 2.4

Na, pyrophosphate 4.0 4.8

Sodium sulphate 5.0 3.0

Perfume - 0.3

Wax coated KDCCA - 2.5

Uncoated RDCCA 3.75 - 100.00 100.00 pH (2.5% solution) 10.4 10.3

Formulation E in Table IV contained KDCCA which hed not been combed. Formilation F in Table IV oconhained KDCCA produced recording Lo Example 6 shove.

The bare were made according to the method of - : Example 2.

Exsmple 8

The bars produced in Example 7 were wrapped in glaseine paper and then enclosed in a plastic bag. The bare were stored under various conditions of tempera- ture and humidity and then analysed to determine ‘the remaining KDCCA content. Corrections were made for moisture uptake and the results expressed Ag pPercen- tages of the amount of KDCCA originally present.

The results are get cut in the following table. They demonstrate that the coating was very effective in increasing the amount of KPCCA remaining after storage. , Storage stability data: RKDCCA

Storage % _KDCCA surviving*

Time (Davs) 22°C/40% RH 28°C /70% RH 37°Cc/70% RH

E F E E E E

0 100 - 100 - 100 - 1 - 82.8 - - - - 4 - 83.2 - - - | - 7 72.1 - 38.9 - 11.0 - 11 - 83.6 - "88.4 57.2 : 19 - 101.20 - 76.9 53.2 20 - - - - - oo 27 35.3 - 1.7 71.2 2.5 - 33 - 76.8 - - - 42.4 49 - 84.8 ~- 62.0 - 32.4 50 - - - - - ~ 60 - 84.0 - 69.6 - 17.6 83 - 80.8 82.4 6.4 96 ~ 76.4 - 54.8 - 5.2 104 - - - 686.4 - 5.2 111 6.7 ~ 1.8 - 1.5 - 118 - - - - - - * Corrected for water uptake during storage.

The results indicate that coated RDCCA in bars F is substantially more stable during storage than uncoated KDCCA in bars E.

Example 9

Potaselum monopersulphate (RMFP3) wae coated with the latex polymer of Example 1 according to the method of Example 1. The ccating was applied at a nominal level of 25% w/w of the total coated particle. The average size of the particles wae approximately 250 pm.

Example 10

Bon-soap doughg were prepared from the ingrediente iigted in Table V in which all percentages are by weight. The doughs were prepared in 500 gram batches in 8 hested lkg capaclhy Z-blrde mixer ah 15°C. KMES particles were mixed into the dough ah 5% w/w for 2 pinmtes st 75 rpm. The Lemperstnre WAG maintained at 75°C and the dough wag left to stand in the mixer for : 50 minutes. Samples were analysed for percentage bleach remaining after 5, 25 and 50 minutes.

Additional mixing for 30 geconde was carried out immediately before removal of a sample for analysis.

TABLE V

% w/w in formulation

Ingredient G H 1 J

Escane F 28.0 28.0 28.0 28.0

Soda Ash 20.0 20.0 20.0 20.0

Water 6.25 6.25 5.0 6.256 . Calcite 22.75 20.75 22.0 22.75

BCHMC 2.0 2.0 2.0 2.0

Na, Pyrophosphate | 4.0 4.0 4.0 4.0

STP 7.0 7.0 7.0 7.0

Na, S80, 5.0 5.0 5.0 5.0

Magilex 808 - 2.0 2.0 -

KMPS 6.0 5.0 - -

Coated KMPS - - 5.0 5.0

Escane F ig alkyl benzene sulphonic acid.

Magilex 808 is a bleach stabiliser mixture of magnesium eilicate/organic sequestrant ex Rhone Poulenc.

Dough stability data: EMPS % recidasnl EMES at 15°C formulation Bleach Level of 5 mine 25 mine S0mine : particle Coating b GQ uncoated - 4.1 2.9 2.5

H uncoated - 5.5 4.8 3.5 1 coated 20.356 - - 87.9

J coated 25.0 66.2 72.4 77.3

The results indicate that polymer coated KMPS uged in doughs I and J is substantially stable whereas uncoated KMPS ag used in doughe 1 and J is unstable. These results are all the more surprieing when 1t ig realized that the transition temperature of the combing ie sround 40°C snd the dengh Lemperature WAG maintained ath 75°C throughout the yest. A marginal improvement in stability ie seen for : compositions H and I which comprieee Mzgilex 808, = bleach stabiliser.

Example 11

Non-scap, built detergent laundry bars were made from the ingredients jigted in Table VI in which all percentages are by weight of the formulation used to prepare the final bar. The bare were made according to the method of

Example 2. oF = 23 =

TABLE VI

% w/w in formalation

Ingredient, KE L

Escmne F 28.5 28.5

YY) b Na, CO 6.0 6.90

H,0 5.0 5.0

Calcite 16.0 18.56

SCMC - -

Na, Pyrophosrhate 3.0 3.0 i0 Na, Pyrophosphate 6.4 6.4

STP - -

Na HCO, 8.¢ 8.0

Borax SH, 0 8.¢ 8.0

Na,50, 8.1 9.1

Coated RMPS 10,0 - oo

Uncoated KMPS - 7.5 100.00 100.00 pH (2.5% solution) B.9 8.9

Example 12

The bars produced in Example 11 were wrapped in glassine paper and then enclcoeed in a plastic bag. The bars were then stored in various conditions of temperature and humidity and then analysed to determine the remaining KMPS content. Corrections were made for moisture uptake.

! . ’ . .

Storage etability detn: EKMPS

Storage % RMPS surviving¥

Time

BE L RK L RK L

0 83.0 73.5 83.0 73.5 83.0 73.56 13 - 72.6 - 5.1 - 5.5 22 86.2 64.5 87.4 6.0 86.0 4.8 43 - 58.0 - 2.0 - 3.0 85 101.5 - 23.3 ~ 86.9 - , 84 - 54.0 - 1.6 - 1.4 111 - | 46.0 - 0.8 - 1.8 142 - - - - - - 148 95.5 - 69.6 - 41.8 - % corrected for water uptake during etorage.

The results indicate that coated KMPS in bare K is substantially more stable during storage than uncoated

KMPS in bars L.

Claims (10)

CLAIMS ' .

1. A laundry bar comprieing from 10% to 60% by weight of detergent active and from B to 60% by weight of builder characterieged in that the bar is formed from an extruded, shear mixed dough and additionally comprises chlorine and/or oxygen bleach encapsulated with a coating material which 1g insoluble in water ab = pH 7-

2. A bar according to claim 1 characterised in that the coating material ie soluble or swellable in aqueous alkaline solution.

3. A bar according to claim 1 characterised in that the bar comprises from 0.1% to 10% by weight of bleach. i5

4. A bar according to claim 1 characterised in that the weight ratio of bleach to coating material lies in the range from 10:1 to 1:4.

5. A bar according to claim 1 wherein the bleach : ig selected from the group of potassium dichloroiso- cyanuric acid salts thereof, and potassium monopeér- sulphate.

6. A bar according to claim 1 wherein the coating material ie a synthetic pelymer. 7 A bar according to claim 1 characterised in : 25 that the bar comprises from ¢.5% to 6% by weight of bleach.

* , J ,

8. A bar mccording to claim 1 characterised in that the weight ratio of blench Lo combing maherial liee in the range 5:1 Lo 1:1,

g. A lmundry bar as olximed in claim 7 charse- teriged in that the coating material is wax.

10. A process for prepering & bar according Lo claim 1 comprieinag the steps of: (1) encapsulating bleach particles by costing in un Tlnidieed bed; and (11) mixing detergent rotive snd bullder, gubeequent ly adding the encepenlated bleach particles, mixing nnd extrading ioho bare. WILLIAM JOHN ILEY ARTHUR GEORGE LEIGH Taventors