EP0138597A2

EP0138597A2 - Detergent bars

Info

Publication number: EP0138597A2
Application number: EP84307006A
Authority: EP
Inventors: Stephen Anderson; John Martin Behan; Terrence Allan Clarke
Original assignee: Unilever PLC
Current assignee: Unilever PLC
Priority date: 1983-10-14
Filing date: 1984-10-12
Publication date: 1985-04-24
Also published as: DE3479517D1; IN159933B; GB8327617D0; AU575347B2; CA1232818A; AU3417684A; EP0138597A3; ZA847992B; BR8405166A; EP0138597B1; ATE45765T1; JPS60104198A

Abstract

@ The effectiveness of the deodorant composition disclosed in UK 2016507 in soap formulations can be improved by incorporating the compositions in a transparent soap formulation containing rosin.

Description

BACKGROUND OF THE INVENTION: The presence of a transparent phase structure in a soap bar will usually provide the bar with transparent properties. The literature in the field of soap technology describes how soap bars can be provided with transparent properties by suitable selection of processing conditions and components. Quantitative measurements of transparency can be made using methods described in the literature, for example visual print size, voltage and graded lines, but there is a general acceptance of the term transparent to describe a class of soap bars.
The supply of a skin deodorancy effect from a detergency bar intended for personal washing has long been viewed as a desirable property. A number of deodorant materials have been described in the literature and include germicides and deodorant compositions which are perceivable by the olfactory sense and can be used as a perfume material or as a base for a perfume material. Examples of deodorant compositions of this latter class are disclosed in, for example UK patent specification 2016507 (Unilever).

GENERAL DESCRIPTION OF THE INVENTION:

It has been found that the deo-effectiveness of a deodorant material having a result of from 0.5 to 3.5 in a Deodorant Value Test described in UK 2016507 is increased when incorporated in a rosin containing transparent bar. The rosin will usually be present in the range from about 1% to about 30% by weight of the bar preferably above about 4% and the deodorant composition in the range from about 0.1% to about 10% by weight. The increase in the deodorant composition effectiveness derives from the matured transparent phase of the soap which-may, in some product compositions, not be appreciated in the form of a transparent bar. Thus the presence of an opaque filler, for example titanium dioxide or silica, would mask the total bar property of transparency but the existence of the transparent phase structure would provide an increase in the deo-effectiveness. The method of forming the transparent phase structure is not critical; the intense working and casting methods form bars which provide an environment in which the deodorant material has increased effectiveness.
The transparency will increase to a commercially useful level during maturation. This process will usually be allowed to proceed at ambient temperature ie, about 20°C but higher temperatures ie, up to about 30°C and up to about 40°C are usable for some compositions. The transparent phase will preferably satisfy the test requirements of US 2970116 (Kelly) and have a Translucency Voltage of 30 or less.

TEST METHODS USED:

The deo-effectiveness of deodorant compositions is measured as the Deodorant Value (DV) by the method described in UK patent specification 2016507. This specification also discloses the lipoxidase test, by which the lipoxidase inhibiting capacity is measured, and the morpholine test from which the Raoult variance ratio is derived.

INGREDIENTS OF THE SOAP FORMULATION:

i) Rosin, which is a wood derived material, contains about 90% of rosin acids which provide a detergent product on neutralisation. A general description of rosin and its properties will be found in 'Soap Manufacture' vol I by J Davidsohn et al (Interscience 1953).
ii) The water soluble salts of long-chain monocarboxylic acids will usually be the sodium and potassium salts with the former being preferred. Commercial transparent soaps may contain a proportion of potassium soap but this is not essential. The long-chain acids will be derived from triglycerides of animal or vegetable origin, for example tallow, coconut, palm and palm kernel. Synthetic acids, for example those obtained by the oxidation of paraffins, may also be used as components.
iii) The deodorant compositions are described generally and specifically in UK 2 016 507. These compositions will usually be prepared from ingredients selected from six defined classes of organic compounds.

Preferably the soap bar will include a deodorant composition consisting essentially of from about 45 to 100% by weight of at least five components and from 0 to about 55% by weight of other ingredients, each of the components being selected from components having a lipoxidase inhibiting capacity of at least 50% and components having a Raoult variance ratio of at least 1.1, the components and ingredients being so chosen that the deodorant value of the deodorant composition is within the range 0.50 to 3.5.
Each component should be allocated to one of six classes. These classes are:

Class 1 - Phenolic substances:
2 - Essentail oils, extracts, resins, "synthetic" oils (denoted by "AB"):
3 - Aldehydes and ketones:
4 - Polycyclic compounds:
5 - Esters:
6 - Alcohols.

In attributing a component to a class, the following rules are to be observed. Where the component could be assigned to more than one class, the component is allocated to the class occurring first in the order given above: for example clove oil, which is phenolic in character, is placed in Class 1 although it otherwise might have been allocated to Class 2. Similarly, 2-n-heptyl cyclopentanone which is a polycyclic ketone is attributed to Class 3 instead of Class 4.
Specific examples of the perfume components are:

Class 1 - (Phenolic Substances) iso-Amyl salicylate, Benzyle salicylate, Carvacrol, Clove leaf oil, Ethyl vanillin, iso-Eugenol, LRG 201, Mousse de chene Yugo, Pimento leaf oil and Thyme oil red.
Class 2 - (Essential oils, extracts, resins, "synthetic" oils, (denoted by "AB") Benzoin Siam resinoid, Bergamot AB 37, Bergamot AB 430, Geranium AB 76, Geranium oil, Opononax resinoid, Patchouli oil, Petitgrain oil and Pomeransol AB 314.
Class 3 - (Aldehydes and ketones) 6-Acetyl-1,1,3,4,4,6-hexamethyl-tetrahydronaphthalene, p-t-Amyl cyclohexanone, p-t-Butyl-alpha-methyl hydrocinnamic aldehyde, 2-n-heptylcyclopentanone, alpha-iso-Methyl ionone and beta-Methyl napthyl ketone.
Class - 4 - (Polycyclic Compounds) Coumarin, 1,3,4,6,7,8- Hexahydro-4,6,6,7,8,8-hexamethyl cyclopenta-alpha-2-benzopyran, 3a-Methyl-dodecahydro-6,6,9a-trimethylnaphtho(2,1-b)furan and beta-Naphthyl methyl ether.
Class 5 - (Esters) o-t-Butylcyclohexyl acetate, p-t-Butylcyclohexyl acetate, Diethyl phthalate, Nonanediol-1,3-diacetate, Nonanolide-1:4, i-Nonyl acetate and i-Nonyl formate.
Class 6 - (Alcohols) Dimyrcetol, Phenylether alcohol and Tetrahydromugoul.

The rules are applied only to those components of the deodorant composition present at a level of at least 0.5% by weight of the composition.
The deodorant compositions to which this application relates are minor but relatively expensive ingredients. Thus any route to reducing the problem of the economics of their commercial use must be of benefit.
iv) The soap bar may include non-soap detergents in amounts which would not interfere with the production of the transparent phase. Examples of these actives are alkane sulphonates, alcohol sulphates, alkyl benzene sulphonates, alkyl sulphates, acyl isethionates, olefin sulphonates and ethoxylated alcohols.
v) Transparent soaps may contain components to assist in the processing or provision of the desired properties, examples are potassium soaps, glycerol, sorbitol and castor derived soaps.

GENERAL & PREPARATIVE METHODS

There are two general process routes used to make transparent soaps. The traditional method involves casting the molten soap into frames; this process is known as the cast bar route. More recently transparent soaps have also been made by an energetic working route using mills, mixers, refiners or other suitable devices. These two routes will be discussed separately. Other routes, for example the use of specific additives or cooling steps, can also provide a transparent product; the present invention is not limited in the route by which transparency is obtained.

Cast Bar Route

There are three main methods used to make cast transparent bars.

i) Full Boiled Process

The oils and fats are saponified, washed and fitted as for a conventional milled soap. The soap is then dissolved in sufficient alcohol to form a (isotropic) solution. Some variations in technique occur in making the alcohol solution. Either the fitted liquid soap is directly dissolved in alcohol, or the soap is dired to a controlled total fatty matter (TFM) before being dissolved in alcohol or alcohol/water. Various grades of "denatured alcohol", industrial or methylated spirits have been used for this purpose, most containing 90-95% ethanol.

ii) Cold Process

The melted oils and fats are mixed with clarifier/filter and with alkali, poured into frames and allowed to react in situ without the external application of heat. In order to completely saponify the oils and fats under these conditions a rather large excess of caustic is required which remains in the final bar; free caustic levels of greater than 1% are common in the type of bar.

iii) Semi-boiled Process

This is the most common route for producing cast transparent soaps. The molten oils and fats, containing aids to transparency such as alcohol, are mixed with the caustic and after the spontaneous saponification has subsided the mix is heated to near boiling point to complete the saponification. The liquid soap together with added components is then cast in frames, cooled and matured.

Formulations of Cast Transparent Bars

Tallow (may be replaced partly or completely by hardened oils with a similar titre), bleached palm oil, coconut oil or palm kernel oil and castor oil are the most commonly used sources of fatty acids (Davidsohn, Soap Manufacture Vol I). For filling and aids to transparency, sugar, glycerol and alcohol are the main organic raw materials, and sodium carbonate, potassium carbonate and sodium silicate represent the main inorganic raw materials. A number of formulations for cast transparent soap bars are given in the literature.

Energetic Working Route

The oils and fats can be saponified, washed, fitted and dried using conventional soap-making procedures.
Colouring material and perfume can be incorporated by the standard methods used for conventional soap production. The transparency is generated during an energetic working stage.
Mechanical devices such as blade mixers, mills refiners and screw extruders can be used to work the soap base.
The plodding, stamping and wrapping stages can be carried out as for a conventional soap line. The transparency will normally increase during a maturation period.
Literature descriptions of this route are found in US 2 970 116 (Kelly).

Formulation of Energetically Worked Bars

Formulations are as for conventional, high tallow soaps. They may in addition contain for example potassium soaps, higher levels of glycerol or sorbitol.

EXAMPLES

The invention will be specifically described by reference to three examples.

Example I

The following bars were prepared and subjected to panel testing with the regime described in UK 2016507. The deodorant composition used was a perfume composition having a Deodorant Value of 1.0 when subjected to the test procedure described previously. The results are given in the Table quoting the difference in perceived odour score with respect to the control.

Bar A - Soap Bar

The appropriate blend of tallow and coconut fats and oils (80/20) were saponified, washed, fitted and vacuum dried to 12% moisture content using standard soap-making procedures. The dried soap chips, to which no perfume or colouring material were added, were subsequently milled and plodded in the conventional manner to provide an opaque bar.

Bar B - Soap Bar Containing Deodorant Composition

This bar was made using the same procedures described for Bar A with the addition of 1½% of the perfume having a deodorant value (DV) of 1.0 during the milling stage. The bars were stored for a period of six weeks at 20°C before testing.

Bar C - Transparent Soap (rosin-free) Containing Deodorant Composition

The standard pan-room procedures were modified so as to minimise the loss of the more soluble components (glycerol and potassium soap). The fats and oils were added to the nigre of the previous boil. The mix was saponified by using the appropriate blend of NaOH/KOH and fitted so the neat soap separated on top of nigre and a small amount of lye. The neat soap layer was removed and additional glycerol added (to take account of the small loss the lye) together with additional electroyte. When vacuum dried to 18% moisture content the composition of the neat soap was such that it contained:
The dried soap chips were placed in a sigma blade mixer and 1½% of the perfume used in bar B added. The soap was worked in a Sigma blade mixer at a temperature and water content in the ranges described in US 2970116 for a period sufficient to generate a transparent phase. Care was taken to minimise water loss by enclosing the mixer; the temperature was controlled by means of a thermostatic heat-jacket. The bars were subsequently plodded and stamped in the conventional manner. They were then stored at 20°C and matured for 6 weeks before testing.

Bar D - Transparent Soap (with rosin) containing Deodorant Composition

Bar D was made using the procedures for Bar C except for the pre-saponification stage where the rosin (5% by weight of the final bar) was incorporated into the formulation by adding it to the nigre of the previous boil. The fats and oils were then added to the rosin and nigre and the saponification and subsequent stages were carried out as described for Bar C.
The four soap bars were subjected to the odour test described; the difference in Odour Score compared to bar A are given in the Table.
These results demonstrate the use of a rosin containing transparent bar enhances the effectiveness of a deodorant composition. It is seen the transparent bar (rosin-free) has the same difference in Odour Score (allowing for experimental variation) as the standard bar B.

Example II

A deodorant composition was added to a rosin containing transparent bar at a level of 1.5%. The deodorant composition had a deodorant value (DV) of 0.78. The product bar, which had the same base formulation as bar D of Example I, had a difference in Odour Score of 1.36.

Example III

A deodorant composition with the formulation below was added to a rosin containing transparent bar at a level of 1.5%.
The deodorant composition had a deodorant value (DV) of 0.60. A comparison bar having the formulation of bar C of Example I had a difference in Odour Score of 0.76. The product bar, which had the same base formulation as bar D of Example I had a difference in Odour Score of 1.35.

Deodorant Composition Formulation

Ingredients

Claims

1. A detergent bar composition including a deodorant composition having a result of from 0.5 to 3.5 in the Deodorant Value Test characterised in that the composition includes a transparent phase and rosin.

2. A composition according to claim 1 wherein the deodorant composition present at level of at least about 0.1% by weight of the composition.

3. A composition according to claim 1 or 2 wherein the deodorant composition is present at a level up to about 10% by weight of the composition.

4. A composition according to any preceding claim wherein the rosin is present at a level above about 1% by weight.

5. A composition according to any preceding claim wherein the rosin is present at a level up to about 30% by weight.