PH26860A

PH26860A - Detergent composition

Info

Publication number: PH26860A
Application number: PH40239A
Authority: PH
Inventors: Peter James Powers
Original assignee: Unilever Nv
Priority date: 1989-03-22
Filing date: 1990-03-21
Publication date: 1992-11-16
Also published as: BR9001315A; GB2229448A; GB8906572D0; GB9006174D0; IN171534B

Description

C.A304 1 ; } » 2 -

DETERGENT COMPOSITION 2 68 ( 3 (

This invention relates to the manufacture of built non-soap detergent (NSD) bars. Such bars are composed of detergent active, detergent builder and usually fFiller(s) as the third main component. They are generally used for laundering fabrics and cleaning surfaces by direct application of the bar to the item being cleaned. 2 ) The physical properties of the bar, such as hardness and rate of wear in use, are very much affected by the mix of constituents in the bar. Some of the components, notably the detergent active, detergent builder and filler which are incorporated into a bar contribute greatly to the structural integrity of the bar. : Tetrasodium pyrophosphate is commonly used as a builder in detergent bars. For lather generation in the presence of calcium ions, it is the most effective phosphate builder for a given weight used. Surprisingly we have now found that even better building and lather generation can be achieved by using a binary mixture of phosphates as builder rather than the same weight of pyrophosphate.

This finding can be applied in bars with various detergent actives, but it is especially advantageous in bars where the detergent active includes primary alcohol sulphate.

This active is particularly sensitive to calcium ions and the removal of them is important for generation of lather by primary alcohol sulphate.

The use of mixed phosphates has a further advantage when the detergent active includes primary alcohol sulphate.

Detergent bars currently in production generally contain alkyl benzene sulphonate as the detergent active.

Endeavours to make bars incorporating primary alcohol sulphate (even in small proportions) as detergent active reveal that it is difficult to produce bars which are sufficiently hard and structurally strong and robust enough to be handled just after they have been extruded. ) 10 Insufficient strength and hardness shortly after extrusion is significant because it makes the freshly made bars difficult to handle.

We have now found that when bars are manufactured with primary alcohol sulphate as at least part of the detergent active, the hardness and strength of freshly manufactured bars can be improved without loss of building efficiency as compared with use of pyrophosphate alone as builder. This improvement is attainable by using a mixture of phosphate builders which includes orthophosphate or ) 20 tripolyphosphate, and incorporating that phosphate at an early stage in the procedure of mixing bar ingredients.

Especially, the orthophosphate or tripolyphosphate can be added during a step of neutralising anionic detergent active in its acid form. Since this improvement in hardness can be achieved without sacrifice of detergency building efficiency, it is a useful and very cost effective way of improving the hardness and structural strength of bars having primary alcohol sulphate as at least part of the detergent active.

According to the present invention there is provided a built detergent bar of composition comprising from 10% preferably 12.5% to 45% by weight of non-soap detergent active and from 12 to 60% by weight of detergency builder, in which bar: i) at least one third by weight of the detergent active present is primary alcohol sulphate; ii) the detergency builder comprises at least two alkali metal phosphates selected from ortho, pyro and ) 10 tripolyphosphates.

In such a system the weight ratio of the two phosphates employed preferably lies in the range from 5:1 to 1:5, preferably 3:1 to 1:3. All three phosphates may be employed together, in which case it is preferred that the weight ratio is such that no phosphate is present in an amount which is more than five times (better not more than three times) the total weight of the other two phosphates.

The phosphates will generally be sodium salts.

The detergent active may be primary alcohol ) 20 sulphate alone, or may be a mixture of this and other active (especially a mixture with alkyl benzene sulphonate) in a weight ratio lying between 2:1 and 1:20, preferably between 2:1 and 1:3. Suitable primary alcohol sulphate will generally have a primary alkyl group containing from 8 to 22 carbon atoms, especially 10 to 14 carbon atoms. Coconut alkyl chain lengths (i.e. C,,, C,, and mixtures thereof) are preferred.

Another detergent active which may be included is linear or branched chain alkyl benzene sulphonate with an alkyl chain length from 8 to 22 carbon atoms, especially 10 to 16 carbon atoms.

A further possible detergent active is C; to C,, fatty acyl C, to C, ester sulphonate, especially with C,, to

C,, fatty acyl esterified with methyl or ethyl, and mixtures of such ester sulphonates. All three of these detergent actives require a solubilising cation which will generally be an alkali metal, most commonly sodium. ' 10 Other detergent aclives, especially other anionic detergent actives may be included.

Detergent actives and builder components are well characterised in detergent bar technology. Such components are described in "Surface Active Agents" by Schwartz and

Perry (Interscience 1949) and Volume II by Schwartz, Perry and Berch (Interscience 1958). Specific examples of detergent actives usable in addition to those mentioned above include alkane sulphonates, secondary alcohol sulphates, alkyl ether sulphates, olefin sulphonates, ethoxylated : 20 alcohols and ethoxylated alcohol sulphates.

However, a notable possibility is to use primary alcohol sulphate alone, or with alkyl benzene sulphonate or fatty acyl ester sulphonate while any other active(s) do not constitute more than 20% by weight of the total detergent actives present.

It is preferred that the amount of detergent active present in the bar composition lies between 12.5 and 35% by weight of the composition.

As mentioned above the detergent builder must provide between 12 and 60% of the bar composition.

Preferably it provides between 12 and 45% of the bar composition. At least two phosphates must be present and may 5 constitute the whole of the detergency builder present.

However, other builder materials may also .be included.

Examples of other builders are: water soluble carbonates, e.g. sodium carbonate; organic builders, e.g. sodium nitrilotriacetate, sodium tartrate, sodium citrate, trisodium ; 10 carboxymethyl oxysuccinate, sodium oxydisuccinate, sodium sulphonated long-chain monocarboxylic acids, polymeric carboxylate builders such as polyacrylic acid and oxidised starch and cellulose; and aluminosilicate ion exchangers; e.g. zeolite 4A. Desirably the mixed phosphates provide at least 12% by weight of the bar composition. . Built NSD bars generally contain a proportion of filler which although chemically inert is significant in contributing to the properties of the bar. An appropriate range for such filler is 5 to 60% by weight of the composition. The filler may consist of water soluble salts such as sodium sulphate but possibly it includes water- insoluble filler. The filler present may even all be water insoluble and accordingly the possible amount of water insoluble filler is 5 to 60 wt%. Examples of water insoluble fillers are talc, kaolin, calcite, bentonite, aluminosilicate, dolomite, feldspar, calcium silicate and calcium sulphate.

Other ingredients may also be present in the bar composition. These include silicates, e.g. sodium alkaline and neutral silicates, sodium carboxymethyl cellulose and cellulose ethers, lather enhancing agents such as coconut alkanolamides (mono- and di- forms) and coconut alcohols, humectants such as glycerol, sorbitol and mono- and disaccharides, colouring materials, enzymes, fluorescers, opacifiers, germicides, perfumes and bleaching agents.

Alkanolamines may be included, as described in our

UK published patent application 2184452A. Aluminosilicate ) 10 may be formed in situ, as described in our UK published patent application 2099013A.

A built detergent bar in accordance with this invention will generally be substantially rigid, enabling it 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 its strength and become plastically deformable by hand pressure.

To prepare bars according to this invention it is suitable to begin with the detergent active, admix the orthophosphate and/or tripolyphosphate (the mixture of phosphates must include at least one of these) and then admix in succession any optional ingredients such as silicate, aluminium sulphate, the fillers, any remaining phosphate and finally minor ingredients such as perfume. Mixing can be carried out in a high shear mixer and be followed by conventional extrusion and bar stamping.

It is possible to commence with detergent active in acidic form, and admix a neutralising agent, the orthophosphate and/or tripolyphosphate.

The acidic detergent active which is neutralised could consist of the acid form of primary alcohol sulphate.

Alternatively it could be a mixture of primary alcohol sulphate with the acid form of alkyl benzene sulphonate.

Thus a mixing procedure could commence by mixing an aqueous slurry of sodium coconut alcohol sulphate with alkylbenzene sulphonic acid, and then adding sodium orthophosphate or tripolyphosphate with excess sodium carbonate to neutralise ; 10 the acid.

The invention will be explained further by the following examples and comparative examples. All percentages are by weight based on the whole composition unless the contrary is indicated.

Example 1

Bar compositions were prepared incorporating C,, alkyl benzene sulphonate (ABS) and coconut alcohol sulphate (PAS), both as sodium salts, as the detergent active. These compositions had the formulations set out in the following

Table I.

TABLE I

Percentages by Weight

Composition No: 1 2 3 4 5 6

Sodium tripolyphosphate 11.0 10.0 0 0 15.0 0

Sodium pyrophosphate 4.0 0 5.0 15.0 0 0

Sodium orthophosphate 0 5.0 10.0 0 0 15.0

PAS 16.8 16.8 16.8 16.8 16.8 16.8

ABS 11.2 11.2 11.2 11.2 11.2 11.2

Sodium carbonate 10.0 10.0 10.0 10.0 10.0 10.0

Sodium silicate (anhydrous) 2.9 2.9 2.9 2.9 2.9 2.9

Aluminium sulphate (anhydrous) 4.72 4.2 4.2 4.2 4.2 4.2

Calcite 25.5 25.5 25.5 25.5 25.5 25.5

Water 13.5 13.5 13.5 13.5 13.5 13.5

Minor ingredients ----- balance to 100% -----

The compositions given in Table I were tested for ability to generate and maintain lather in hard water. This is a test of the effectiveness of the detergency builder present. The procedure was as follows.

For each bar composition a stock solution (4g in 100ml) was made up by grating the bar into small fragments and by dissolving/dispersing the composition in demineralised water.

The solution (0.6ml) was pipetted into a measuring cylinder (100ml) together with demineralised water (47.4ml), hard water (1.0ml, 1000°FH) and sebum (0.5ml, 25g 1-1). Two measuring cylinders were then stoppered and, holding one in each hand, shaken 25 times. The cylinders were then exchanged, left into right hand and right into left hand, and shaken a further 25 times. Initial lather heights were measured in centimeters.

After 1 minute the lather heights were measured again. More of the stock solution (0.6ml1) was then added, the cylinders shaken again and the lather heights measured.

After 1 minute the process was repeated but with the addition of sebum (0.5ml, 25g 1-!'). A further three times, at one minute intervals, stock solution (0.6ml) was added, the cylinders shaken and the lather heights recorded.

This progressive addition results in a build-up of bar composition dosed into the solution as follows: 0.48g 1°! 0.95g 1°! 1.38g 1°} . 1.81g 1°! 2.25g 1°} 2.67g 171

The results are set out in the following Table II.

0 0 ad 1 1 [af [&) ad | df my = 0 al O 0 O 0 a

OQ . . - - . . ot oN ol on I~ an oN [®] OO od OO — . . . . . . oO ol od =+ tno nn nN oO oN oF 0 O

Oo . . . . . . —t nN od = 0 1 —t

AN Hoa On +1 . . > - . .

O £8) oN = \O OC = nn O on oO oO oO

OO . . * - - - — = =r ~~ oO ol 0 — 42

Oo — 4 _ >To 9 Tm o - o 1 out — oD on ot DO oO — 2 oA “ od inn 0 o nN in << o = [@) o . . . « . . " oN = Eg Ne 0 ol po ~—

J on on oN I~ oN oO i . . » « . . oN on In I~ 0 ol on oO =t nN I =F

OO . . . . . - ) oN LO nn 0 on ol i — r~ t= ~~ oN —{ . . . . . . =t on on nn I~ on

A

Oo nn 0 on nN in

OO » . - . - - .. mn wn 0 [ea on o +4

Zz < oO

Ea 22

Ba .. Pp — i — — — — w _—— Q oO Se ~~ a To Te ~~ 0 > wn jo SN] bo bp ho bo bo

Q, oo oT od [co] wn a0 I Ln I~ gH — ow = on © od 0 oO Q gs no . » . . . . 0 mn — nO oO oO i — ol ol

Ln oO ~~

Bars with the compositions 1 to 4 given in Table I were manufactured on a conventional plant for the manufacture of NSD bars. This plant consisted of a sigma mixer, mill and plodder. The bars were tested for bar hardness immediately after extrusion (while the bar was still hot) after one hour and after 24 hours. The test was carried out by means of a penetrometer.

The penetrometer used was a SUR type PNR 8 (Sommer und Runge of Berlin DBR). The needle had a point angle of 9 10' and was forced into a plane bar surface under a total load of 100g for 10 seconds. The results are set out in

Table III below.

TABLE III

Penetrometer Depths (mm)

Composition No: 1 2 3 4

Time after Temp extrusion

Zero 58°C 5.6 7.0 7.9 10.1 1 hour 26°C 1.2 1.3 2.1 2.1 24 hours 26°C 0.6 0.9 0.6 0.6

It can be seen from Table I that all six compositions contained a total of 15% of phosphate builder but compositions 1, 2 and 3 contained mixed phosphate builders whereas comparative compositions 4, 5 and 6 contained only one phosphate. Compositions 1, 2 and 3 gave lather heights which were generally equal to or greater than those achieved with any of compositions 4, 5 and 6.

Table III shows that compositions 1, 2 and 3 all gave greater hardness of freshly extruded bars, compared with composition 4.

Example 2

Bar compositions were prepared incorporating coconut alcohol sulphate (PAS) and coconut ethyl ester sulphonate (FAES) as detergent active. Both were in the form of sodium salts. These compositions were as set out in

Table IV below.

TABLE 1V

Percentages by Weight

Composition No: 7 8 9 10 11 12

Sodium tripolyphosphate 8.0 9.0 0 0 13.0 0

Sodium pyrophosphate 5.0 0 5.0 13.0 0 0

Sodium orthophosphate 0 4.0 8.0 0 0 13.0

PAS 18.6 18.6 18.6 18.6 18.6 18.6

FAES 12.4 12.4 12.4 12.4 12.4 12.4

Sodium carbonate 10.0 10.0 10.0 10.0 10.0 10.0 ! Calcite 30.0 30.0 30.0 30.0 30.0 30.0

Water and minor ingredients -------- balance to 100% ---------

The compositions given in Table IV were tested for ability to generate and maintain lather in hard water, using the same procedure as in Example 1. Results are set out in

Table V below.

on = =t wn OO ~~ «i . . « . . . — mn —t od =r 0 a\ —

Oo On QO on on on

Oo . . . . . . al t~ on =r 10 an oO \O nN a =t aN — . . . . . . in =r on nm Nel I~ — — tn on Oo Nn oO «A

OO . . - . . . oN \O 0 0 On od fou) \O = ~~ 0 MN oO — - . - . . . oN \O [a] = nn aK oO — ~~ —t on 0 Ln \O [@) . . . . . . oN an mn \O aN oN wn +

FS)

BE oO . . . . . .

QO

<Q i Nn a oO = . oO . . . . . . ! mn — Nn — ol on — — — — — \O =t Nn LO on i » . - . - . = ~ =t in \O I~ ~~ — an an oy on oN

Q . - » . . . .. [EQ aon 0 oJ oN mn

Oo — — a! = ©

Oo al

IE)

Ba) . » —t 1 —t — i — wn —_ Oo ~— ~w ~~ pa Te ~~. oO > 0 = bo bo bo ho to bo

Q, d Td oO tn oO i in ~~ 8 ~~ ow =r aN oN @ oN \O 0 oH G90 . . . . . . oO a ~~ no O oO — — al oN oO —

Bars with the compositions 7 to 10 given in Table

IV were made on a conventional NSD bar plant and tested for bar hardness immediately after extrusion (while the bar was still hot) and after 7 days. The test was carried out by means of a penetrometer as in Example 1. The results are set out in Table VI below.

TABLE VI

Penetrometer Depths (mm)

Composition No: 7 8 9 10

Time after Temp extrusion

Zero 60°C 5.1 5.4 5.7 9.7 7 days 25°C 0.6 0.7 0.6 0.6

All six compositions in Table IV contained a total of 13% of phosphate builder but compositions 7, 8 and 9 contained mixed phosphate builders whereas comparative compositions 10, 11 and 12 contained only one phosphate.

Compositions 7, 8 and 9 gave lather heights which were generally equal to or greater than those achieved with any of compositions 10, 11 and 12.

Table VI shows that compositions 7, 8 and 9 all gave greater hardness of freshly extruded bars, compared with composition 10.

Example 3

Bar compositions were prepared incorporating the sodium salt of coconut alcohol sulphate (PAS) as the sole detergent active. These compositions were as set out in

Table VII below.

TABLE VII

Percentages by Weight

Composition No: 13 14 ee ee ee ee ee en . ne

Sodium tripolyphosphate 14.0 0

Sodium pyrophosphate 0 21.0

Sodium orthophosphate 7.0 0

PAS 28.0 28.0

Sodium carbonate 10.0 10.0

Calcite 31.5 31.5

Water and minor ingredients ~----- balance to 100% —------

The compositions given in Table VII were tested for ability to generate and maintain lather in hard water, using the same procedure as in Example 1. Results are set out in Table VIII below.

TABLE VIII

Composition No: 13 11

Delay (mins): 0 1 0 1 ee ee

Product Lather Heights

Dosage _ 0.48g/1 1.9 0.9 2.1 0.9 0.95g/1 4.7 4.9 2.4 0.9 1.38g/1 5.0 5.2 2.9 1.4 1.81g/1 8.5 7.8 5.7 4.9 2.25g/1 13.0 12.2 9.5 7.3 2.67g/1 16.0 13.5 13.5 9.8

Once again the composition with mixed phosphate builder gave more lather than the single builder.

Claims

AE 26860

1. A built detergent bar of composition comprising from 10 to 45% by weight of non-soap detergent active and from 12 to 60% by weight of detergency builder, in which bar: i) at least one third by weight of the detergent active present is primary alcohol sulphate containing from 8 to 22 carbon atoms; ii) the detergency builder comprises at least two alkali metal phosphates selected from ortho, pyro and tripolyphosphates.

2. A bar according to claim 1 wherein the weight ratio of the phosphates is such that the weight of any one phbsphate is not more than 5 times the total weight of the other phosphate or phosphates present.

3. A bar according to claim 1 wherein at least 80% by weight of the detergent active is primary alcohol sulphate, or a mixture of primary alcohol sulphate and alkyl benzene sulphonate having a straight or branched alkyl group containing from 8 to 22 carbon atoms, or a mixture of primary alcohol sulphate and C;, to C,, fatty acyl C, to C, ester sulphonate.

4. A bar according to any one of the preceding claims which also contains 5 to 60% by weight of filler.

5. A bar according to any one of the preceding claims wherein the primary alcohol sulphate contains 10 to 14 carbon atoms.

6. A process for preparing a bar according to any one of the preceding claims which includes a step of mixing the said detergent active, while at least partially in an acid form, with the said tripolyphosphate and or orthophosphate and a neutralising agent.

C3304 ABSTRACT A built detergent bar of composition comprising from to 45% by weight of non-soap detergent active and from > 12 to 60% by weight of detergency builder, in which bar: (i) at least one third by weight of the detergent active present is primary alcohol sulphate containing from 8 to 22 carbon atoms; 10 (ii) the detergency builder comprises at least two alkali metal phosphates selected from ortho, pyro and tripolyphosphates.

15 . Use of a binary mixture of phosphates as buillder can give better building and lather generation that the best single phosphate builder. This is especially advantageous in bars where the detergent active includes primary alcohol sulphate.