KR920002116B1 - Soap compositions - Google Patents

Abstract

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Description

Soap composition

The present invention relates to a cosmetic soap composition, in particular a cosmetic soap composition in the form of a bar.

The bar soap composition generally consists of 85-92% by weight of soap and 8-15% by weight of water. Soaps are usually derived from mixtures of oils and / or fatty acids having a mixed oxo number of up to 60 and the incorporation of the fillers is limited.

There are several limitations when using such compositions. In particular, the high water content or high unsaturation presented by the higher oxo number results in a soft and sticky composition, making it impossible to process into bars. Such soft and sticky compositions cannot be handled by running at normal speed with conventional extrusion equipment. Increasing the water content of bar soaps tends to shrink during storage and has the incidental consequence of cracking due to stress.

The use of water soluble fillers, such as polyols, results in degradation of the perceived properties by the user, such as foaming, hardness of the bar, abrasion rate and degree of surface receding.

In summary, successful bar cosmetic soap compositions should be able to be processed with conventional extrusion equipment (and therefore the compositions should not be too soft or sticky), should provide satisfactory foaming properties and other user cognitive properties and should not crack. Another point that soap compositions should avoid is weathering (ie, crystals on the surface of bar soaps when processed, stored or used).

There have been many proposals to incorporate inorganic electrolytes in bar soaps in various amounts and for various reasons. See, eg, British Patent 1244346 (Colgate).

The inventors have found that by incorporating certain electrolytes it is possible to avoid the above limitations and at the same time provide satisfactory properties.

In contrast, it has been found that this is not possible with other electrolytes tested by the inventors.

According to the first aspect of the present invention, the bar-shaped cosmetic soap contains the following ingredients.

40-89% by weight soap (calculated as anhydride)

1-33% by weight of tetrasodium pyrophosphate (calculated as anhydride Na ₄ P ₂ O ₇ )

* (X + 4)-(X + 19)% by weight of water, where X% is the calculated amount of water required for complete hydration of pyrophosphate to decahydrate

Hydration of sodium pyrophosphate to methacrylate proceeds as follows.

Na ₄ P ₂ O ₇ +10 H ₂ O → Na ₄ P ₂ O ₇ 10 H ₂ O

The X value can be easily calculated from the amount of pyrophosphate. The molecular weight of anhydrous Na ₄ P ₂ O ₇ is 266. And the molecular weight of water is 18. Therefore, if the weight percentage of anhydrous pyrophosphate is y%, the% of water is given by

In other words, the amount of water is given by

(0.68y + 4)% ≤X% ≤ (0.68y + 19%)

In the transplant, x% is the total amount of water (weight) and y% is the amount of sodium pyrophosphate calculated as anhydride.

By incorporating sodium pyrophosphate, the present inventors can lower the amount of soap in the composition to 40-89% by weight (calculated as anhydride) to 4.68-41.44% by weight of water, and at the same time yield stress (ie hardness). It has been found that it can be maintained at acceptable levels and at other acceptable levels.

The amount of soap in the composition (calculated as anhydride) need not exceed 85% or even 80% by weight. The amount of sodium pyrophosphate is preferably 10-30% by weight. The actual proportion of the components selected in each case depends, among other things, on the desired properties of the final bar soap and the type of soap mixture selected for incorporation into the bar soap. For example, when the water content is low, a softened oil mixture is required rather than a hardened oil mixture (ie, oxo <60). For this purpose, the minimum total water content is preferably 9.68% by weight.

The hardness of bar soap can be quantified by measuring the yield stress of the bar.

The bar type cosmetic soap used in the present invention has a yield stress of 3.0 × 10 ⁵ Nm ⁻² or more at 20 ° C., and preferably a maximum yield stress value of 10 × 10 ⁵ Nm ⁻² or less (20 ° C.). For the measurement of yield stress, see Basic Rheology (G WScott Blair, Academic Press, London 1969) and Ammeter: Industrial Applications (Ed. K. Walters, Research Studies press John wiley &amp; sons). New York 1980).

Soap sources suitable for use in the compositions of the present invention are already source of conventional cosmetic soaps such as tallow, hydrogenated tallow, hydrogenated rice bran oil, hydrogenated linseed oil, palm oil, hydrogenated palm oil, coconut oil and babasse oil. Typical soap blending ratios are tallow, hydrogenated tallow, hydrogenated rice bran oil, hydrogenated linseed oil, palm oil, hydrogenated palm oil and mixtures 60-95% by weight, coconut oil, babasse oil, and mixtures 40 -5% by weight. However, the inventors have found that fatty acid moieties may be used in the compositions of the present invention in oil mixtures having a higher degree of olefinic unsaturation than is commonly used for bar cosmetic soaps. In particular, it has been found that soap compositions having an oxo number of 60 or more can be used in the composition of the present invention. Examples of oils having a high degree of olefin unsaturation that can be used include soybean oil, sunflower oil linseed oil, cottonseed oil and rice bran oil. Such oils may be present up to 100% by weight of the soap mixture and the proportion may be determined, for example, by the normal price of the locally available material. Thus bar soaps can be prepared from soap mixtures having an oxovalent value of up to 130. Preferably all soaps present are sodium soaps.

The composition may contain a filler that is water soluble more than is possible in the absence of sodium pyrophosphate. Examples of such water-soluble fillers include sugar, glycerol, sorbitol, sucrose and the like. Its content depends on the filler. Sucrose may be contained in the range of 0-10% by weight of the final weight of the bar soap within a range that does not adversely affect the characteristics of the bar soap.

The composition of the present invention contains an excess of fat such that free fatty acid is present in the bar soap by adding the desired free fatty acid itself to the soap mixture or by adding an acid such as citric acid or phosphoric acid to the soap mixture which releases the free fatty acid from the soap mixture. can do. It is desirable to have an excess of fat so that 5-10% by weight of free fatty acid of the soap mixture used is present.

In addition to sodium pyrophosphate, there are salts that take water as crystal water. However, all of these salts were found to be inadequate. Some have relatively low temperatures for loss of hydration water, below the atmospheric temperature in tropical climates. Weathering was also observed in all conventional hydrated salts except sodium pyrophosphate. While not wishing to be bound by any theory, it appears that the use of an electrolyte will determine whether weathering will occur in a composition containing soap and water according to the present composition. There is a lower limit for this solubility (otherwise, weathering is observed). Since only tetrasodium pyrophosphate is below this limit, it provides a bar soap without the problem of weathering.

The composition of the present invention may be prepared by mixing sodium pyrophosphate with a water-containing soap. Preferred method is as follows. That is, anhydrous sodium pyrophosphate is added to a so-called pure soap composed of about 70% soap and 30% water in molten state. Sodium pyrophosphate can be added as a dry powder, as a hot concentrated solution, or as a slurry containing a small amount of hot water. The soap mixture containing sodium pyrophosphate is then dried to the intended moisture content. At this time, optionally a reduced pressure flash dryer commonly used to dry the pure soap to a moisture content suitable for the conventional cosmetic soap. However, the degree of drying required in the composition is lower. Another manufacturing method is to process the process in a dryer while metering and supplying sodium pyrophosphate to the net soap.

Another method of preparation is to mix sodium soap pyrophosphate with soap soap formed from drying the soap, for example, soap noodles formed from a reduced pressure flash dryer. Such soap noodle and additive mixing is performed using a mixer that shears the mixture.

Sodium pyrophosphate incorporated into the composition by adding sodium pyrophosphate at a relatively early stage in the process of processing the soap into a bar form becomes hydrated form at an early stage so that subsequent processing of the composition can be carried out according to conventional processes. In general, this step is a step of mixing the minor components such as dyes, fragrances, antioxidants, preservatives, etc. using a chip mixer and pressing together in the form of a bar through milling, pulverizing, extrusion.

Thus, a second aspect of the invention is a method of making a soap composition according to the first aspect of the invention, comprising mixing 1-33% by weight of sodium pyrophosphate based on the water-containing soap and the final bar cosmetic soap. To provide.

Water-containing soaps have a water content of more than 20% by weight and the soap is preferably subjected to a drying step. Moisture-containing soap is convenient as a pure soap.

The composition thus obtained is usually pressed into bars in the form of milling and flotation. The present invention will now be described in more detail by the following examples in which all percentages are by weight.

Example 1

Various bar soaps were prepared by varying the amounts of soap, water and tetrasodium pyrophosphate.

Bar soaps were prepared in a test plant. That is, sodium tetrapyrophosphate in the form of slurry is added to the pure soap (water content of about 30% by weight), dried to a desired water content, and pressed into a bar form through milling and plunging. The pyrophosphate slurry was prepared immediately using the calculated amount of water to be 6% by weight of the final composition. Pure soap was a typical 80/20 tallow / coconut soap.

The yield stress of bar soap at 20 ° C. can be determined by observing the point at which bar soap is cut by a cheese wire weighing for a period of time. A balanced, horizontally fixed cheese wire (dcm) hanging on a freely rotatable arm is brought into contact with freshly prepared bar soap cooled to room temperature (20 ° C.). Place one edge of the soap under the wire, cutting it by stretching the wire to the point where the weight of the wg equals the resistance of the bar soap when the wg weight is placed on the arm directly above the cheese wire. ) Length Lcm is determined. At this point, the stress produced by the wire and the yield stress of the bar soap are the same. The distance to this point was about 30 seconds. In practice, one minute of standard cutting time was deducted in each case.

For bar soaps with orthogonal edges in the cross section, the yield stress is calculated by the following equation.

The user characteristics of the bar soap, in particular the rate of wear out, the phenomenon of receding and foaming during use were tested using the bar soap stored at room temperature at 20 ℃ for more than 4 weeks and the appearance was also examined.

Bar soaps were examined at regular intervals while stored under aging conditions. Storage was carried out for 1 week at 90 ° C and 20 ° C, 1% at 70 ° C and 37 ° C. The cycle was repeated for several months to examine the appearance of bar soap at each frequency.

Various compositions and their yield stress values are shown in Table 1 below. Here, `` free water '' (theoretical value) means the amount of calculated water remaining after the complete hydration of pyrophosphate. The control composition in the table means a conventional 80/20 tallow / coconut bar soap composition that does not contain sodium pyrophosphate.

TABLE 1

It was observed that all of the compositions of Table 1 according to the present invention had a yield stress greater than 3.0 × 10 ⁵ Nm ⁻² , which is the minimum hardness of the compositions that can be processed with cosmetic soap using conventional equipment.

In comparison, comparative compositions C, D, G, H, J whose theoretical free water content is higher than the levels allowed by the present invention do not have sufficient hardness. Composition I, which contains insufficient water for complete hydration of pyrophosphate, has a negative theoretical value. This composition is extremely hard and therefore has poor user properties. In other words, the wear rate is low and the foaming is poor. Weathering is also observed during storage. Composition L is a composition containing a level of soap that does not meet the conditions of the present invention. The hardness of this composition is satisfactory but its user properties are not good. The user properties of the composition that meet the conditions of the present invention provide satisfactory results in all cases.

The abrasion ratio of the control A1, A, F, K and L soaps, and the foaming bubble properties were measured and the results are shown in Table 2 below.

TABLE 2

The results in Table 2 suggest that the bar soaps of the present invention have properties comparable to the control soaps with high soap content and no sodium pyrophosphate.

Example 2

Various bar soaps were prepared in the same manner as in Example 1, except that other hydrated salts were used instead of tetrasodium pyrophosphate. Bar soap was stored under aging promoting conditions and the appearance of bar soap was examined at regular intervals. The composition and the results of the storage test are shown in Table 3 below. As can be seen from the table, all bar soaps had an undesirable appearance in which weathering was observed after some storage.

TABLE 3

Example 3

Various bar soaps were prepared in the same manner as in Example 1, except that sucrose having different amounts was mixed with tetrasodium pyrophosphate. The yield stress of these bar soaps was measured at 20 ° C. User characteristics were observed using bar soaps stored at 20 ° C. for at least 4 weeks. The retreat characteristic of the user was determined by a test that weighed the amount of debris produced from the bar soap left in the water at a constant depth for a period of time.

The composition and results are shown in Table 4.

TABLE 4

The first control soap in the table is a conventional 80/20 tallow / coconut makeup soap composition. The second control soap is hand soap, which is much harder and tends to recede. Comparative composition M does not contain sodium tetrapyrophosphate and only sucrose shows that the improvement in hardness is not sufficiently achieved and the amount of retreat is excessively large. Composition N together with tetrasodium pyrophosphate has a satisfactory hardness and a much lower amount of retreat. Compositions P containing higher amounts of sucrose with tetrasodium pyrophosphate have satisfactory hardness.

Example 4

Various bar soaps were prepared in the same manner as in Example 1 except that an oxo value of 60 or more was used as an oil mixture for soap base.

Two different oil mixtures were used. One (Q) was a mixture of tallow 32% by weight, soybean oil 48% by weight, and coconut oil 20% by weight, with a total oxo value of 83.

Another mixture (R) was a mixture of 80% by weight soybean oil and 20% by weight coconut oil with a total oxo number of 110. The component composition of bar soap and the yield stress values at 20 ° C. of each bar soap are shown in Table 5 below.

TABLE 5

In each case, the bar soap has a yield stress higher than 3 × 10 ⁵ Nm ⁻² to provide a cosmetic soap with an acceptable level of hardness. Comparative bar soaps that contain soap from the same oil mixture but no sodium tetraphosphate are so soft and sticky that it is not possible to process bar soaps using conventional extrusion equipment. Bar soap Q has the following user characteristics:

Worn-out rate: 17%, Rejected when using: 6, Bubble amount: 36mls

This property is comparable to that of the control bar soap used in Example 1.

Example 5

Various bar soaps were prepared in the same manner as in Example 1. However, this bar soap was made from a mixture of 60/40 tallow / coconut soaps that contained excess fat, ie, free fatty acids (FFA). The amount of free fatty acids present is expressed as a percentage of tallow / coconut soap mixture present. That is, 60/40, 5 mixture means that 60% by weight of tallow soap and 40% by weight of coconut oil soap, the presence of 5% by weight of free fatty acid of the total weight of the soap mixture.

Detailed compositions are shown in Table 6 below.

TABLE 6

The yield stress, abrasion ratio, receding properties and foaming properties at 20 ° C. of each bar soap were evaluated. The results are shown in Table 7 below.

TABLE 7

The results in Table 7 show that overweight bar soaps containing tetrasodium tetraphosphate have user and hardness characteristics comparable to overweight bar soaps containing no pyrophosphate, and therefore bar soaps with a higher soap / fat ratio. Suggests that.

Claims (11)

Bar-shaped equipment containing the following ingredients, 40-90% by weight soap (calculated as anhydride) Sodium pyrophosphate (calculated as anhydrous Na ₄ P ₂ O ₇ ) * (X + 4)-(X + 19)% by weight of water, where X% by weight is the amount of water calculated for the complete hydration of pyrophosphate to decahydrate The bar shaping equipment according to claim 1, wherein the soap content (calculated as anhydride) is 85 wt% or less. The bar shaping equipment according to claim 2, wherein the soap content (calculated as anhydride) is 80 wt% or less. The bar shaping equipment according to claim 1, wherein the total water content of the bar soap ranges from 4.68% to 41.44% by weight. The bar shaping equipment of claim 1 wherein the amount of tetrasodium pyrophosphate (calculated as anhydride) is in the range of 10-30% by weight of the final bar shaping equipment composition. The bar shaping equipment of claim 1 wherein the soap comprises a soap mixture wherein the fatty acid moiety has at least 60 oxo valences. The bar shaping equipment of claim 1, wherein the bar soap contains 5-10% by weight of the free fatty acid of the soap mixture used. The bar shaping equipment of claim 1, wherein the bar soap contains a water-soluble filler. The bar shaping equipment according to claim 1, wherein the yield stress at 20 ° C is in the range of 3.0 × 10 ⁵ Nm ⁻² to 10 × 10 ⁵ Nm ⁻² . 40-89% by weight soap (calculated as anhydride), 1-33% by weight sodium pyrophosphate, comprising mixing 1-33% sodium pyrophosphate pyrophosphate with a water-containing soap of the final bar soap (Calculated as anhydrous Na ₄ P ₂ O ₇ ), and (X + 4) (X + 19)% by weight of water, where X% is the amount of computational water required for complete hydration of pyrophosphate to decahydrate. Method for producing bar-shaped equipment silk containing. The manufacturing method according to claim 10, wherein the water-containing soap is pure soap.