WO1995008617A1

WO1995008617A1 - Fabric conditioner

Info

Publication number: WO1995008617A1
Application number: PCT/EP1994/002889
Authority: WO
Inventors: Stuart Albert Emmons; Sigrun Eriksen; Katherine Jean Hartley Smith
Original assignee: Unilever Plc; Unilever N.V.
Priority date: 1993-09-22
Filing date: 1994-08-30
Publication date: 1995-03-30
Also published as: AU7692494A; GB9319567D0

Abstract

A solid rinse conditioner having excellent dispensing and dispersing properties. The rinse conditioner comprises particles making up granules. 90 wt% of the granules have a granule size from 250 νm to 100 νm and 90 wt% of the particles have a particle size from 5 νm to 90 νm.

Description

Fabric conditioner

This invention relates to Fabric Conditioners comprising a softening or anti-static component delivered to the wash from suspension in the wash liquor during a rinsing step. It particularly relates to fabric conditioners in powder form and most particularly to powders formulated from biodegradable and environmentally friendly components.

Fabric conditioning has been carried out either during the rinsing step of a fabric washing and rinsing process or during tumble drying of the fabric. In almost all commercial cases fabric conditioning during the rinse cycle is accomplished by adding a liquid dispersion of a fabric conditioning agent to the rinse water. The liquid dispersion was traditionally distributed and made available to consumers as a ready to use aqueous dispersion. More recently, concern for the environment and consumer convenience has led to the sale of concentrated aqueous dispersions.

In EP 234082 it has been proposed to supply fabric conditioner as a solid block. This approach requires the use of a special restraint for the block and may also require the modification of the washing machine to enable the block to be dissolved and dispensed by a spray system.

Various proposals have been made to supply fabric conditioner in granular or powdered form, particularly when the fabric conditioning is to be done in a so called ' softening in the wash" process which entails adding the conditioning agent at the same time as the washing powder and thus requires the use of conditioning agents that can be formulated in a granular form. EP 111074 is typical and uses a silica to carry the conditioning agent. A disadvantage of using a carrier such as silica is that it bulks up the product and serves no function beyond making the conditioning agent compatible with other ingredients that may be contained in a washing powder.

It has been suggested to add fabric conditioner in powdered form directly to the washing machine. If this is done via the normal dispensing compartment there is a considerable risk that the rinse conditioner will thicken or gel after contact with residual water from a previous wash. This would prevent or hinder dispensing of the proper dose of conditioner. A way round this problem is to add the powder directly to the wash at the appropriate time. EP 568 297 (Unilever) describes a product which is suitable for direct addition. However direct addition is extremely inconvenient when using front loading washing machines as it entails stopping the washing machine at the beginning of the final rinse cycle, opening it and trying to sprinkle powder over the washing before continuing with the rinse stage.

For these reasons, despite the obvious environmental and transport saving advantages of selling a water free powdered fabric conditioner, manufacturers have not done so.

In EP 569 184 (Unilever) there is described a method of delivering a fabric conditioner or fabric softener to a rinse liquor of a washing machine, comprising the steps of dispersing a powder containing the conditioner or softener by mixing the powder with domestic tap water to form a liquid dispersion of the powder outside the washing machine, then adding a dosed amount of the dispersion so formed to the rinse conditioner dispensing compartment of the washing machine in a conventional manner. Although this method of using a powder overcomes the problem of dispensing it from a dispensing compartment designed for a liquid fabric conditioner, consumers may prefer not to have to make up a liquid dispersion of the powder before using it. Solid fabric softening compositions for use in the rinse cycle are disclosed in WO 93/05139 (Procter and Gamble) . The particles of the composition have an average diameter of between 1 - 1000 μm, preferably between 5 and 250 μm.

WO 92/18593 (Procter and Gamble) discloses a granular fabric softener in which the particle size is between 50 and 1000 μm, preferably between 50 and 400 μm.

It is an object of the present invention to provide a powder fabric conditioner which has good dispensing and dispersion characteristics and can therefore be dispensed from the fabric conditioner compartment of a washing machine and quickly dispersed into the rinse liquor.

According to the present invention there is provided a dispensable and dispersible solid rinse conditioner comprising of particles and granules in which 90 wt% of the granules have a granule size from 250μm to lOOOμm and 90 wt% of the particles have a particle size from 5μm to 90μm.

Also according to the present invention there is provided a method of manufacturing a fabric conditioning composition comprising the steps of: a) selecting a solid conditioning material;

b) grinding the solid conditioning material to form particles;

c) sieving said particles;

d) mixing the other solid ingredients;

e) adding the liquid components, and mixing to form granules; f) sieving the granules to give the appropriate granule size.

We have found that mixing temperatures in excess of 30°C facilitate granulation and affect the particle size. It is further preferred if the mixing temperature is above 45°C.

This process makes particularly effective fabric conditioning powders if the conditioning material is a cationic material.

The invention further provides a process for softening fabrics comprising the steps of adding to the rinse liquor a granular rinse conditioner comprising of granules, said granules comprising of smaller particles.

In the context of this invention a granule may be defined as an agglomeration of bound particles.

It is preferred if the granules are formed by binding the particles together with a liquid. The preferred range for the granule size is from 250 to 500 μm. This is because such a granule size both dispenses and disperses. It is preferred if the particle size is from 10 μm to 50 μm, as particles of this size disperse quickly and so give good softening results. It is especially preferred if the mean particle size is from 20 to 30 μm.

The fabric conditioning agent may be formed from any material, however it is advantageous if it conforms to the required particle size.

Cationic and nonionic conditioning agents are the most suitable conditioning agents for the present invention. It is especially advantageous if cationic agents used. The most preferred cationic agents are the diester quaternary ammonium materials. Especially preferred are compounds in which the diester quaternary ammonium material is represented by the following formula:

OOCR²

(R _sN^*- (CH₂)_n CH X^"

CH₂OOCR

in which each R¹ group is independently selected from C_x-₄ alkyl, hydroxyalkyl or C₂-₄ alkenyl; and in which each R² group is independently selected from C₈-₂₈ alkyl or alkenyl groups, n is an integer from 0 to 5 and X^" is a compatible anion; it being especially preferred if X^" is a methyl sulphat-. anion.

The diester quaternary ammonium material may also be represented by the formula

in which R¹ is a C₁-C₄ alkyl groups, R² and R³ are the same or different C₁₂ - C₂₂ alkyl or alkenyl groups and T is -C-0 or -O-C- or -0-C-0 and X^" is a compatible anion.

II II II

O O O

The presence of an electrolyte greatly improves the fabric conditioners dispensing properties. The electrolyte is preferably an inorganic salt or a low molecular weight organic acid. It is preferred if the electrolyte has a high solubility . Examples of suitable electrolyte include sodium sulphate, sodium citrate and sodium chloride. It is particularly advantageous if the electrolyte is coated as an external layer onto the granule. It is further preferred if electrolyte is present at levels from 5wt% to 10wt%.

It is preferable if the composition contains a wetting aid. In the context of the present invention a wetting aid may be defined as any material which promotes the ingress of water into the softening material. Preferred wetting aids are nonionic materials such as sugar alcohols, alcohol ethoxylates, (poly)ethylene glycols and mixtures thereof. Of particular use with the present inventions are alcohol ethoxylates such as Dobanol 91-6EO (trademark ex Shell) and (poly) ethylene glycols, in particular (poly) ethylene glycols with molecular weights between 500 and 3,000 such as PEG 1500. It is also advantageous to use mixtures of wetting aids.

The presence of flow aids improves the dispensing of the granules and thus it is desirable if such flow aids are present within the fabric conditioning composition. It is advantageous if the flow aid is coated on the outside of the granules. Flow aids can be defined as materials that have high absorption capacities for the liquids present in the formulation. Examples of such flow aids include alumino silicate, amorphous silica and sodium carbonate. Amorphous silica is particularly advantageous as a flow aid.

The composition may also contain perfume, dye, antifoam, other dispersants such as low molecular weight cationics and other conventional fabric conditioner additives.

It is further preferred if during the manufacturing process a 90 μm sieve is used to sieve the particles, and 1,000 μm and 250 μm sieves are used to select the correct granule size. The invention will now be described with reference to the following non-limiting examples in which Examples of the present invention are illustrated by a number and comparative examples are illustrated by a letter:

EXAMPLES

STANDARD METHODS

Preparation of powders

The cationic material was ground and sieved to form particles with the desired particle size. The particles were sieved through an air swept sieve to remove any particles that were of the wrong size. The other solid ingredients, with the exception of the silica flow aid and if indicated the salt, were mixed in with the particles. The particles were then granulated by the addition of the liquid components, namely, wetting aid, dye, and perfume. The temperature of this granulation step was kept above 45°C to facilitate granulation. Silica flow aid or if indicated salt was then coated over the granular material by slow mixing with the granules. The granules were sieved to give the appropriate granular size.

Where necessary the cationic material was dried to remove excess solvent.

To measure the dispensing properties

1) Beaker method.

5.5g of powder was placed in a beaker and 20 ml of water added without disturbing the powder. The beaker was clamped at an angle of 45° in a rotary stirrer. The number of revolutions (38-40 rpm) were measured for the powder to become fully suspended in the water. To measure dispersion

1) (Black Cloth Test)

3.5 kg of fabric (black polycotton) was placed in the drum of a "Miele" (trademark) washing machine and rinsed for 3 minutes with 20dm³ of water (26°FH) at 5°C. The rinse water was pumped out . The fabric was lightly spun for 2 minutes. The drum of the machine was filled with water for 1 minute (13.3 dm³ of water) . The machine program was stopped and lOg of fabric conditioning powder was placed in the machines dispenser drawer together. The final rinse of the machine was started agai for a further minute (6.6 dm³ of water) . The rinse cycle was then agitated at 60 r.p.m. for 40 seconds. The final rinse liquor was pumped out. The clot^x s removed from the drum. This cycle experiment was repeated 3 times. Visual scoring of the residues indicated the dispensing properties of the powder. 0 indicates no residue, 5 indicates a heavy residue.

2) Filter Test

Filters of polymon mesh (150 μm mesh size) (trademark) (10cm) were weighed. Rinse conditioner powder, 5g (for lx) or 15g (for 3x concentrate) was weighed into a glass jar. Demineralised water (95g or 85g, at 20°) was added to the powder and the cap placed on the jar. The mixture was shaken for 2 seconds. All of the resulting dispersion was filtered through the Polymon mesh. The mesh was dried in the oven at 105°C for 2 hours, then weighed. The percentage of solid material retained by the mesh was calculated. EXAMPLES A, B AND 1

Examples 1, A and B were prepared according to the standard preparation of powders as described above. The formulation of all the 3 examples was as follows:

Table 1

Raw Material Chemical Name wt%

HT TMAPMS 1,2 dihardened tallowyloxy- 73.3 ex Hoechst 3-trimethyl ammonium propane methyl sulphate

PEG 1500 9.0

Perfume 4.9

Dye 0.4

Antifoam 1.0

Microsil* Alumino silicate 1.4

Salt Sodium Chloride 10.0

Tradename ex Crosfield

The powder were sieved such that Example A comprised of granules less than 250 um, Example B of granules less than 500 μm but also containing granules less than 250 μm and Example 1 of granules with a particle size between 250 μm and 500 μm. The dispensing properties were measured using the beaker method described above.

Table 2

Example Dispensing Score

A >30

B 25

1 6 It can be seen from Table 2 seen that if granules are less than 250 μm in size or have granules less than 250 um included in the fraction they do not dispense very well.

EXAMPLES 2 TO 8

A powder of the formulation in Table 3 was prepared according to the standard method above.

Table 3

wt/g

HT TMAPMS 72.85

Nonionic 10.51

Perfume 2.86

Dye (1% solution) 0.37

Clay 1.38

Antifoam 1.01

Microsil* 1.01

Sodium Chloride as in Table 4

The powder had a particle size range of 5 to 90 μm and a granular size between 250 and 710 um. Sodium chloride was added to the powders and the dispensing properties measured.

* Tradename

Nonionic = C₉-C_ι:. alcohol ethoxylated with 6 moles of ethylene oxide per mole of alcohol. Tabl-a 4

Example wt/g NaCL Dispensing Results (Beaker Method)

2 0 >3.0

3 2 4.0

4 4 3.3

5 5 2.5

6 6 2.2

7 8 2.0

8 10 1.0

It is thus demonstrated that the presence of an electrolyte aids the dispensing properties of the powder.

EXAMPLES 9 TO 12

Powders were prepared using the standard procedure. The powders had the following formulations:

Table 5

Example 9 Example 10 Example 11 Example 12 wt/g

HT TMAPMS 158 158 158 158

COCO 20 EO 11.4 11.4 11.4 11.4 (nonionic with 20 EO groups)

Perfume 6.2 6.2 6.2 6.2

Dye 1% 0.8 0.8 0.8 0.8 solution

Clay 3.0 3.0 3.0 3.0

Antifoam 2.2 2.2 2.2 2.2

Sodium 20.2 20.7 20.7 20.4 Chloride

Microsil* 0.0 4.4 4.4 2.2

Dosed Dosed Dosed outside inside outside granule granule granule

* Trademark

The powders fell within the particle size range 5 to 90 um and the granule size range 250 to 710 μm.

Table 6 demonstrates that the best dispensing measurements are obtained when flow aid is present and is coated on the outside of the granule. Table 6

Dispensing result (beaker method)

Example 9 22

Example 10 9

Example 11 17

Example 12 3

EXAMPLES C. D. E, 13. 14 and 15

Examples with the identical formulations shown in Table 7 were prepared according to the standard method. The particles were sieved to give the size distribution shown in Table 8, and the dispersion measured according to the standard test procedure.

Table 7

Weight/g

HT TMAPMS 105.56

Genopol C100* 3.92

Perfume 4.75

Microsil 5

* Tradename = coconut alcohol ethoxylated 10 moles of ethylene oxide per mole of alcohol (ex Hoechst) . Table 8

Example Particle Size μm % residue >150 μm

C <250 24

D <150 (includes less than 15.5 90 um)

E 90-125 19.7

13 <90 6.7

These results show the importance of how particle size effects the dispersion properties.

The test above was repeated to demonstrate the preference for a particle size greater than 10 μm.

Table 9

Example Particle Size % Residue >150 μm

14 <90 1.1

15 -8 5.2

EXAMPLES 16. 17. 18.19 AND 20

The following examples demonstrate the effect of wetting aids to aid the product to disperse and to dispense.

Table 10

Raw Example Example Example Example Example Material 16 17 18 19 20 wt (g)

HT TMAPMS 158.0 158.0 158.0 158.0 158.0

Nonionic 12.09 - - 19.4 -

50% - 18.82 - - - Sorbitol

PEG 1500 - 19.4 - -

PAS - - - 19.4

Perfume 10.53 10.53 10.53 10.53 10.53

Dye (1% 0.8 0.8 0.8 0.8 0.8 Solution)

Antifoam 2.2 2.2 2.2 2.2 2.2

Microsil* 3.0 3.0 3.0 3.0 3.0

Salt 20.74 21.48 21.55 21.55 21.55

Tradename

PAS = primary alcohol sulphate (chain length C₁₂)

Nonionic = C₉-C_π alcohol ethoxylated with 6 moles of ethylene oxide per mole of alcohol.

Table 11

Example Black Cloth Dispensing Softener Test Beaker Test

16 0 65% residue OK

17 0.33 5% residue OK

18 0 0.7% residue OK

19 0 - OK

20 3.0 - POOR EXAMPLES F AND 21

Examples F and 21 were of the composition stated in Table 12

Table 12

wt/g

HT TMAPMS 105.5

COCO 10 EO 3.9

Perfume 5.0

Microsil 4.8

The dispersibility was measured using the filter test procedure. The results are shown below:

Table 13

Example Granule Size μm % residue

F >1000 8.6

21 250-1000 0.6

EXAMPLES 22, 23 AND G

The Examples were made up following the standard method to the formulation listed in Table 14.

Table 14

wt %

HT TMAPS 84.95

Nonionic 20EO 6.13

Perfume 3.33

1% Dye Solution 0.43

Clay 1.61

Antifoam 1.18

Microsil 2.37

Nonionic 20EO = coconut alcohol ethoxylated with 20 moles of ethylene oxide per mole of alcohol.

Table 15

Example Granule Size μm % residue >150 μm

G 1000 - 1700 36.1

22 500 - 1000 19.3

23 250 - 500 11.1

Table 15 shows the % residue when the powders are subjected to the dispersion test known as the filter test. The results show the advantage of having granules less than 1,000 and preferably between 250 - 500 μm.

Claims

1) A solid rinse conditioner comprising of particles and

5 granules in which 90 wt% of the granules have a granule size from 250μm to lOOOμm and 90 wt% of the particles have a particle size from 5um to 90μm.

2) A solid rinse conditioner according to claim 1 in which 10 the particles are bound together by a liquid to form the granule.

3) A solid rinse conditioner according to claim 1 or claim 2 which comprises a cationic fabric softening material.

15

4) A solid rinse conditioner according to claim 3 in which the solid rinse conditioner comprises a diester quaternary ammonium material.

20 5) A solid rinse conditioner according to claim 4 in which the diester quaternary ammonium material is represented by the formula:

OOCR²

25

(R¹),^- (CH₂) CH X^"

30 CH₂OOCR²

in which each R. group is independently selected from C--₄ alkyl, hydroxyalkyl or C₂-₄ alkenyl; and in which each R₂ group is independently selected from C₈-₂₈ alkyl 35 or alkenyl groups; n is an integer from 0 to 5 and X^" is

• a compatible anion. 6) A solid rinse conditioner according to claim 4 in which the diester quaternary ammonium compound is represented by the formula:

in which R¹ is a C--C₄ alkyl groups or hydroxyalkyl, R² and R³ are the same or different C₁₂ - C₂₂ alkyl or alkenyl groups, X^" is a compatible anion and T is -C-0 or -O-C- or -O-C-O.

O

7) A solid rinse conditioner according to any preceding claim in which the granule size is from 250μm to 500μm and the particle size is from lOμ to 50μm.

8) A solid rinse conditioner according to any preceding claim which further comprises a wetting aid.

9) A solid rinse conditioner according to any preceding claim which further comprises an electrolyte.

10) A solid rinse conditioner according to claim 9 in which the electrolyte is coated on the exterior of the granule.

11) A solid rinse conditioner according to any preceding claim which further comprises a flow aid.

12) A process for softening fabrics comprising the steps of adding to the rinse liquor a granular rinse conditioner comprising of granules, said granules comprising of smaller particles.

13) A process for preparing a granular fabric conditioner comprising the following steps: a) selecting a solid conditioning material;

b) grinding the solid conditioning material to form particles;

c) sieving said particles;

d) mixing other solid ingredients;

e) adding liquid components to and mixing to form granules;

f) sieving the granules to give the appropriate granule size.