US3265582A

US3265582A - Permanent waving of hair

Info

Publication number: US3265582A
Application number: US374947A
Authority: US
Inventors: Kalopissis Gregoire
Original assignee: LOreal SA
Current assignee: LOreal SA
Priority date: 1960-04-15
Filing date: 1964-06-15
Publication date: 1966-08-09
Anticipated expiration: 1983-08-09
Also published as: DE1160984B; CH394496A; FR1309816A; GB913149A; NL120222C; BE599297A; NL287799A; NL259654A

Description

Aug. 9, 1966 G. KALOPISSIS 3,265,532

PERMANENT WAVING OF HAIR Filed June 15, 1964 I00 f, I

I ///x/ xx/ l 1 0 5 IO IS F I G l I l l pH=7.5 pH=8.5 PH=9.5

Fl G- 2 INVENTOR Gregoire Kalopissis ATTOR NEYS United States Patent 3,265,582 PERMANENT WAVING OF HAIR Gregoire Kalopissis, Paris, France, assignor to Societe Anonyme dite:L0real Filed June 15, 1964, Ser. No. 374,947 Claims priority, application France, Apr. 15, 1960, 824,620, Patent 1,309,816; Jan. 15, 1962, 884,897.

Austria, Oct. 12, 1960, 6A 767, Patent 219,770

7 Claims. (Cl. 167-87.1)

This application is a continuation-in-part of my prior application Serial No. 90,916, filed February 23, 1961, now forfeited, and application Serial No. 250,842, filed January 11, 1963, now abandoned.

This invention relates to the so-called permanent waving of hair and more particularly to the methods and materials for use in the setting of such permanent waves.

The permanent waving of hair is normally carried out in two separate phases, namely a first phase in which the fiber is softened with the aid of a chemical reducing agent to break the bonds of the keratin and is brought to a desired configuration, and a second phase commonly known as neutralization setting or oxidation, which has the object of reconstituting the --SS-- bonds broken in the first phase, so as to render permanent the modification made in the configuration of the hair during the first phase.

The present invention concerns only the second, socalled neutralization phase, and is applicable to all types of permanent waving processes regardless of the nature of the reducing agent employed to carry out the first phase of the treatment.

The first phase, which was at one time carried out at elevated temperature or in the cold with the aid of sulphi-tes, is now generally carried out in the cold, using various mercaptans, such as for example mercaptocarboxylic acids and their derivatives.

The second phase is commonly carried out in practice with the aid of an oxidizing agent and may be diagrammatically represented by the reaction:

2keratin GI-LOH2SH O 0 0 o o keratin Ol-LcHaSsflHrO keratin H2O NH \NH The oxidizing agents employed for the aforesaid purpose are, for example, hydrogen peroxide, alkali metal bromates and iodates, alkali perborates, urea peroxide, or chlorites.

However, all these products, which are now known for carrying out the neutralization phase, have disadvantages which are either specific to their chemical constitution or arise directly out of the fact that they are oxidizing agents.

These disadvantages include:

(a) The formation, apart from the keratin disulphides which it is desired to reform, of other oxidation products, such as for example cysteine residues, in accordance with the reactiont C 0 /C3 keratin CH.OH.SH keratin CH. CHQS 0 H N NH with the result that the original cysteine content of the hair is reduced andits mechanical strength is lowered.

Further, secondary chemical reactions may also take place which may lead inter alia to a more or less extensive oxidation even of the keratin disulphide formed, with the production, for example, of sulphoxides.

See

It is mainly by reason of these secondary reactions that the neutralization phase of permanent waving is a delicate operation which it is necessary to carry out with great care.

(b) The majority of the substances employed as neutralization agents in permanent waving have unsatisfactory storage properties and are likely to decompose, even with violence, which renders their handling and storage difiicult and sometimes dangerous.

Some of these products are also likely to ignite, with consequent danger.

(c) Owing to the fact that they are oxidizing substances, the neutralization products are likely to react with other organic compounds which may be desired to be used to treat the hair during the second phase of the waving, such as lacquers, fatty alcohols and brilliantines.

(d) Like all oxidizing agents, the products hitherto employed for the neutralization phase may produce a more or less pronounced decolorization of the hair, depending upon their concentration and the period for which they are applied.

It is an object of the present invention to provide a new neutralizing process for permanent waving, by means of which it is possible to obviate or minimize the disadvantages referred to above, and to provide compositions for use in said process.

It is a further object of the present invention to provide a new article of manufacture which consists of a solution having a polythionate base for neutralizing hair, which is being permanently waved, said solution being essentially characterized by the fact that it contains a buffering agent capable of maintaining the solution at a pH value of slightly acid to a pH of approximately 9.5.

It is still another object of the present invention to provide a new process for fixing hair when it is being permanently waved which is essentially characterized by the fact that it utilizes an aqueous solution containing polythionate ions maintained by a bufiering agent at a pH of slightly acid of approximately 9.5.

According to the present invention, in the permanent waving of hair by a process in which in a first phase the hair is treated with an agent which serves to break the SS- bonds of the keratin, and the hair is constrained to a desired configuration, there is provided a process of written as follows in the case of potassium tetrathionate.

2 eratin OH.GH2.SH KzSrOo keratin H.CH1.S.S.OH2.CH keratin KzSzO H2820;

NH H

It appears from the considerable research which has been carried out that this inter-exchange takes place very rapidly and in the cold in the case of keratin previously formation of oxidation products such as result from the use of the previously known oxidizing agents such as hydrogen peroxide, bromates, and the like, referred to above.

' It appears that the action of the polythionate results solely in the reconstitution of the SS- bonds of the keratin which were broken during the first phase of the treatment, i.e. the neutralizing solution according to the invention has a specific and selective action for the reformation of the -SS bonds of the hair.

In addition to the advantages of the process of the invention which have already been mentioned, it is emphasized that the performance of the second, so-called neutralizing phase of permanent waving operations is by this invention rendered extremely simple by reason of the fact that it is sufiicient to apply to hair which has already undergone the first reducing phase a solution of polythionates and to leave this solution in contact with the hair for several minutes and then to Wash the hair with water and to dry it. This operation takes place without any necessity to use a precise quantity of solution and without any necessity to observe a strict period of application.

Among the other advantages of the process of the invention, there .may be mentioned:

(a) the stability of potassium tetrathionate and of sodium tetrathionate in the solid state;

(b) the elimination of all the danger of ignition and decomposition which has been attendant upon the substances hitherto employed as neutralizing agents;

(c) the possibility of applying as neutralizing products the polythionates according to the invention mixed with a large number of organic products which are conventionally employed for the care of the hair;

((1) the reconstitution of the cysteine bridges by the polythionates, accompanied by a lowering of the pH value of the reaction, whereby the residual alkalinity of the reducing solutions is destroyed. Any danger of an attack on and hydrolysis in situ of the keratin of the hair is thus eliminated during the neutralizing period.

The concentration of the neutralizing solutions according to the invention is obviously a function of the number of S'-S bridges which have been reduced and which must be reconstituted. In other words, this concentration depends upon the concentration of the reducing agent applied in carrying out the first phase of the permanent waving, and upon the effectiveness of this product.

However, experience has shown that about g. of potassium tetrathionate or an equimolecular quantity of sodium tetrathionate is suflicient to carry out the second phase of a permanent wave on hair of a weight of the order of 60 g.

But generally speaking the concentration of the polythionate ions in the solution can reach one gram molecule per liter.

In accordance with the invention the buffering agents that may be used may be of any type provided they are capable of keeping the pH within the desired range and are compatible with the use of the solution for the neutralizing purpose and are harmless to the hair and skin. When it is desired to operate within the pH range of 7 to 9.5, the percentage of the buffer to the polythionates may be between and 35%.

Suitable buffering agents included by way of example are borax, sodium glycolate, ammonium carbonate, etc.

From among these buffering agents it is preferable to choose those available in the form of a powder, because they may be easily added to the polythionate powders used.

By utilizing a concentration of buffering agent equal to about 30% of the quantity of polythionate, it is possible tocarry out the neutralization within a reasonable time (say about 10-15 minutes) while keeping the pH substantially constant.

This pH value is, for example, 10.2 when a mixture of sodium carbonate and sodium bicarbonate is used, 9.3 when sodium glycolate is used, 9.2 when borax is used, 9 when disodium phosphate is used, 8.5 when ammonium carbonate or a mixture of boric acid and borax is used, and 7-8 with a mixture of citric acid and disodium phosphate.

The advantage obtained by keeping the pH of the polythionate solution above 7 and preferably between 7 and 9.5 by means of a buffering agent has been demonstrated by mechano-chemical methods which are based on the energy required to stretch the fiber in water for a certain percentage of its initial length, first before the treatment and then after the treatment. This method has been described in detail by Speakman and C011, in

the Journal of the Textile Institute, volume '58, page In order to compare the results secured by the addition of a buffering agent to the neutralizing solution the hair was softened for 10 minutes with 8% ammoniacal solution of ammonium thioglycolate having a pH of 9.2. The hair was then fixed for 15 minutes with a 15% solution of potassiumtetrathionate having an initial pH of 4.5.

Other hair was then treated with the same product under the same conditions, excepting only that the tetrathionate solution also contained 5% sodium glycolate which maintained the pH of the solution at about 9.3.

The results of the above-mentioned mechano-chemical measurements are shown on the accompanying single sheet of drawing. On this drawing, FIGURE 1 is a graph the abscissa of which shows in minutes the duration of the neutralizing treatment utilizing a potassium tetrathionate solution at a 15 concentration and the ordinate indicates in conventional units the supplementary energy which is necessary to obtain, after treatment with potassium tetrathionate, the same given elongation of a hair as before treatment.

Curve I shows the mechano-chemical evolution of hair treated with the above-described potassium tetrathionate solution which is not buffered, while curve II shows the mechano-chemical evolution of like hair treated with the also above-described potassium tetrathionate solution.

Examination of the graph shows that the use of a buffered tetrathionate solution results within 5 minutes in the same reconstitution of the keratin which is obtained by a 15 minutes treatment with an unbnffered tetrathionate solution.

In order to show more clearly the improvement which results from the utilization of the polythionates in the neutralizing step, the results of the same mechanochemical measurements are shown on FIGURE 2 which is a graph in which the ordinate indicates, still in the same conventional units, the same supplementary energy as in graph 1, while the abscissa shows the different pH-values at which the measurements have been carried out, the origin of the abscissa corresponding to a non-buffered 15% potassium tetrathionate solution; the points which correspond to the pH values 7.5-8.5 and 9.5 relate to buffered 15 potassium tetrathionate solution. This second graph relates to tests which have been effected during a contact time of 10 minutes.

This graph shows that the increasing of the supplementary energy (indicated by the ordinate) reach respectively rates of about 40, 45 and 60%, when the nonbufiered solutions are replaced by buffered solutions of pH values of 7.5-8.5 and 9.5.

In other words, maintenance 'of the tetrathionate solution at a pH greater than 7 and preferably between 7 and 9.5 not only reduces the time required for neutralization, but also resultsin a more complete reconstitution of the keratin.

A number of tests were made using other polythionate ions, and in particular potassium trithionates and pen tathionates. These tests have in all cases yielded results analogous to those which have just been described.

In order that the invention may be clearly understood, several examples of its use will now be described, purely by way of illustration:

Example 1 The hair is softened in a conventional manner with an 8% solution of ammonium thioglycolate, brought to a pH of 9.3 by adding ammonia, said solution being left on the hair for ten minutes.

After this the neutralization step is carriedout using a solution having the following composition which is prepared just before use:

Potassium tetrathionate g Borax 5 Water, q.s.p cc 150 The pH of this solution is 9.2.

After the solution has been left in contact with the hair for 15 minutes, the hair is rinsed and dried, and a very beautiful permanent wave is secured which is highly resistant to humidity.

Example 2 After having completed the reducing step in the manner described in Example 1, the neutralizing step is carried out using a solution having the following composition:

Potassium trithionate g 15 Ammonium carbonate g 4 Water, q.s.p. cc 150 The pH of this solution is 8.5.

The result obtained after a contact time of about 15 minutes is the same as in Example 1.

Example 3 After having completed the resuding step in the manner indicated in Example 1, a solution having the following composition is prepared immediately 'before use:

Potassium tetrathionate g 7 Potassium pentathionate g 8 Borax g 5 Water, q.s.p. cc 150 The pH of the solution is 9.2.

After having let this solution act for ten minutes, a beautiful permanent Wave of high quality is obtained.

Example 4 After having completed the reducing step in the manner described in Example 1, a solution having the following composition, prepared immediately before use, is employed as the neutralizer:

Potassium tetrathionate g Ammonium carbonate g 4 Water, q.s.p. cc 150 The pH of this solution is 8.5.

After a contact time of about 20 minutes the hair is rinsed and dried, and has acquired a permanent Wave of very good quality.

Example 5 After having completed the reducing step in the manner described in Example 1, a neutralizing solution is prepared just before it is to be used, by dissolving in 150 cc. of water 18 grams of a mixture of powders having the following composition:

Potassium tetrathionate g Sodium glycolate g 15 Silica gel g 1 A wetting agent having an alkyl aryl sodium sulfonate 'base commercially known as Neckal A g 4 The solution thus obtained has a pH of 9.3.

After permitting this solution to act on the hair for ten minutes, a permanent wave of very good quality is obtained.

The neutralizing solutions according to this invention may be used after having reduced the hair during the first permanent waving step with an ordinary reducing agent.

In particular, the following solutions may be used for the first (reducing) step:

Example 10 The hair is softened in a conventional manner with an 8% solution of ammonium thioglycolate, brought to a pH of 9.3 by adding ammonia, said solution being left on the hair for ten minutes.

After this, the neutralization step is carried out using a solution having the following composition which is prepared just before use:

Sodium tetrathionate g 13.5 Borax g 5 Water, q.s.p cc

The pH of this solution is 9.2.

After the solution has been left in contact with the hair for 15 minutes, the hair is rinsed and dried and a very beautiful permanent Wave is secured which is highly resistant to humidity.

Example 11 After having completed the reducing step in the manner described in Example 10, the neutralizing step is carried out using a solution having the following com-position:

Sodium trithiomate g 13.3 Ammonium carbonate g 4 Water, q.s.p cc 150 The pH of this solution is 8.5. The result obtained after a contact time of about 15 minutes is the same as in Example 10.

Example 12 After having completed the reducing step in the manner indicated in Example 10, a solution having the following composition is prepared immediately before use:

Sodium tetrathionate g 6.3 Sodium pentathionate g 7.10 Borax g 5 Water, q.s.p. cc 150 The pH of the solution is 9.2.

As indicated above the polythionate solution employed for neutralizing may contain adjuvants for special effects.

It is of particular value to include in the solution a surfaceactive agent, e.g. a non-ionic, cationic or anionic surface active agent or an agent having a softening or other desirable efiect on the hair, e.g. lanolin, or cholesterol. According to a further feature of the present invention therefore there are provided neutralizing compositions for use in the permanent wavingof hair which comprise an aqueous solution of a polythionate containing a surface-active agent, cholesterol or lanolin.

The invention further provides a permanent Waving kit which comprises, separately packaged within a single covering package, a first solution of a reducing agent which will, on application to hair, break the -S-S bonds of the keratin, and a second solution containing polythionate ions.

The following examples will serve to illustrate this form of the invention:

Example 13 A permanent wave treatment is carried out by first treating hair previously Wound on curlers with an ammonium thioglycolate solution containing 8% of thioglycolic acid and brought to a pH of 9.3 with ammonia. The hair is then rinsed with water and then saturated with an aqueous 10% potassium tetrathionate solution having an initial pH of 4.5. This solution is allowed to act on the hair for 15 minutes and the hair is then washed and dried. In this way, a permanent wave of very attractive appearance is obtained, which is maintained for a long period and which resists humidity.

Example -1 4 When the hair has been treated in a first phase with the solution employed for this purpose. in Example 13, the second neutnalizing phase is carried out, using an aqueous potassium tetrat'hionate solution having an initial pH of 5 which is prepared at the time of use by dissolving 8 g. of this compound in powder form in 100 cc. of water, and which is applied in the manner indicated in the foregoing example.

Example 15 A permanent wave treatment is carried out by treating the hair in a first phase with 8% oc-rnercapto-acetamide solution at a pH of 7, obtained with the aid of ammonia, and then carrying out the second, setting phase with an aqueous 4% potassium tetsnat-hionate solution having an initial pH of 6. There is thus obtained an excellent permanent wave on the hair.

Example 16 A permanent wave treatment is carried out by first treating the hair with an aqueous 6% thioglycolic acid solution in the form of its ammonium salt and having a pH of 8.2 obtained by the addition of ammonia and ammonium canbonate. The hair, without rinsing, is then saturated with an aqueous 12% sodium tetrathionate solution having an initial pH of 4.8. This solution is allowed to act for minutes, and the hair is then washed and dried. There is thus obtained a permanent wave of very attractive appearance and of good dunability.

Example 17 The first phase of a permanent wave treatment is carried out by any of the methods and products usually employed for this purpose. The hair, with or without rinsing, is then treated with the following neutralizing solution having an initial pH of 5.5

Potassium tetrathionate g 10 Cetyl 'trimethylammonium bromide g l Tween 80 (wetting agent) g 1 Water, q.s.p. cc 100 After a period of action of 10 minutes, the hair is washed and dried. This slightly teaming neutralizing so- =lultion imparts a gloss to the hair and makes it remarkably easy to comb.

Example 18 The first phase of a permanent waving operation is carried out in the usual way with the aid of an ammonium thioglycolate solution having a concentration of 0.066 gram mol. per cc. of water, adjusted to a pH of 9.7 by the addition of ammonia. This solution is allowed to act for 10 minutes on the hair, which is thereafter copiously rinsed.' There is then applied a neutralizing solution having an initial pH of 6 and corresponding to the following composition:

Potassium trithionate (K S O g 20 Sodium lauryl sulphate g 0.2 Water, q.s.p cc 150 This solution is allowed to act for about 10 minutes and the usual washing, rinsing and drying operations are then carried out. In this way, a curl having a very good, lasting stability is obtained.

Example 19 The first phase of a permanent wave treatment is carried out in the usual way with the aid of the following solution:

Thioglycolic acid g 8 Monoethanolamine g 7 Ammonia q.s. for pH 9.4.

Water, q.s.p. for 100 cc.

A neutralizing solution having the following composition is then applied:

Potassium pentathionate (2K S O -3H O) g 12 Cetyl-trimethyl ammonium bromide g 1.2 Sodium lauryl sulphate g 0.3 Water, q.s.p cc.. 120

This solution having an initial pH of 5.5 is allowed to act for about 10 minutes and the usual washing, rinsing and drying operations are then performed. There is thus obtained a very springy curl which has very good stability.

Example 20 The first phase of a permanent hair waving treatment is carried out as indicated in Example 19. There is then applied to the hair a neutralizing solution having the following composition, with an initial pH of 5.5:

Potassium tetrathionate g 7.5 Potassium pentathionate g 7.5 Lauryl-trimethylammonium bromide g 4 Water, q.s.p. cc 100 After a period of application of about 10 minutes, the usual washing, rinsing and drying are performed. There is thus obtained a springy curl of good quality.

Example 21 The first phase of a permanent hair waving treatment is carried out With a reducing solution having the following composition:

Ammonium sulphite g 13 Triethanolamine g 6 Water, q.s.p cc 100 This operation is performed by winding the hair in locks on 35 to 40 curlers and applying the solution in the usual manner, for about 5 minutes, to each lock protected by a rubber sleeve slip heated at a temperature of about 100 to C. The locks are thereafter unwound and allowed to cool, and the neutralizing solution having an initial pH of 6 and the following composition is applied:

Potassium tetrathionate g 20 Sodium lauryl sulphate g 1 Water, q.s.p cc 90 When this solution has been allowed to act for 10 minutes, the hair is washed, rinsed and dried. In this way, a permanent wave of good quality is obtained.

Example 22 The first phase of a permanent wave treatment is completed as indicated in Example 21, and when the wound locks have cooled sulficiently they are rinsed and a neutralizing solution having the following formula with an initial pH of 6 is applied for 10 minutes:

Sodium tetrathionate g 10 Sodium lauryl sulphate g 1 Cholesterol g 0.1 Water, q.s.p. cc 90 The locks are then unwound and this same neutralizing solution is applied for a second time, also for about 10 minutes.

An attractive wave is thus obtained.

Example 23 In the first phase of a permanent hair wave treatment, the hair is abundantly impregnated with the following reducing solution:

Sodium bisulphate g 5.5 Ammonium sulphite g 5.5 Urea g 14 Ethyl alcohol -cc 28 Ammonia q.s. pH 7.2 Water, q.s.p. cc 100 The hair is wound in locks on about 45 to 50 curlers and left in contact with the reducing solution for about 25 minutes under a hood. It is then well rinsed and a neutralizing solution having the following composition with an initial pH of 5.8 is applied:

Potassium tetrathionate g 15 Polyglycollic ester of lauric acid g 2 Lanolin g 0.5 Water, q.s.p. cc 100 The locks are then unwound and the hair is washed, rinsed and dried. A permanent wave of good appearance is obtained.

It will be noted that, in contrast to what is generally done with the conventional neutralizing agents, is it unnecessary, When polythionates are employed as neutralizing agents, to apply an intermediate rinse between the first hair softening phase and the second neutralizing phase.

What is claimed is:

1. The method of neutralizing hair which has been softened by breaking the SS-- bonds of the keratin therein and constrained to a desired configuration, which method comprises the step of treating said hair with a 5% to 20% by weight of an aqueous solution of the soluble alkali metal salt of tetrathionic acid, said solution being slightly acid to a pH of 9.5.

2. The method of neutralizing hair which has been softened by breaking the SS bonds of the keratin therein and constrained to a desired configuration, which method comprises the step of treating said hair with a 5% to 20% by Weight of a buffered aqueous solution of the soluble alkali metal salt of tetrathionic acid, said solution being slightly acid to a pH to 9.5 in which the amount of the buffering agent is between 15% and 35% of the amount of the tetrathionate.

3. A neutralizing aqueous solution for use in the permanent waving of hair, containing 5% to 20% by Weight of a soluble alkali metal salt of tetrathionic acid, said solution being slightly acid to a pH of 9.5.

4. A neutralizing aqueous solution for use in the permanent waving of hair, containing 5% to 20% by weight of a soluble alkali metal salt of tetrathionic acid, said solution being slightly acid to a pH of 9.5, and an amount of a bulfering agent between 15 and 35% of the amount of the tetrathionate.

5. A mixture of powders adapted to be dissolved in water together to form a solution for neutralizing hair which is being permanently waved, said mixture comprising the soluble alkali metal salts of tetrathionic acid and a suitable soluble buffering agent in the ratio of 3 parts of tetrathionate to about one part of buffering agent, said buffering agent being sufi'icient to maintain the pH value of the neutralizing solution made from said powders from slightly acid to a pH of 9.5.

'6. The method of neutralizing hair which has been softened by breaking the SS bonds of the keratin therein and constrained to a desired configuration, which method comprises the step of treating said hair with a 5% to 20% by Weight of an aqueous solution of the soluble potassium salt of tetrathionic acid, said solution being slightly acid to a pH of 9.5. v

7. The method of neutralizing hair which has been softened by breaking the --SS bonds of the keratin therein and constrained to a desired configuration, which method comprises the step of treating said hair with a 5% to 20% by weight of an aqueous solution of the soluble sodium salt of tetrathionic acid, said solution being slightly acid to a pH of 9.5.

References Cited by the Examiner UNITED STATES PATENTS Re. 23,771 9/1953 Neesby 16758 Re. 24,763 1/ 196-2 Neesby 16758 X 2,439,720 4/1948 Crosley et al 23115 2,768,875 10/1956 Neesby 16722 2,774,355 12/1956 Bell 16787.1 X 2,780,579 2/1957 SChWarZ et al. 16787. 1 2,901,399 8/1959 Clarey 167--87 2,906,273 9/ 1959 Beauregard 16787. 1

FOREIGN PATENTS 1,309,816 10/1962 France.

259,930 9/ 1927 Great Britain.

OTHER REFERENCES Gilman et al.: American Journal of Physiology, vol. 147, No. 1, pages -126, September 1946.

Goehring et al.: Chemical Abstracts, vol. 43, col. 2886 1949 Journal of the American Pharmaceutical Association, Pract. Pharmacy Ed, April 1947, page 226.

Sagarin Cosmetics: Science and Technology, published by Interscience Publishers, Inc., New York, 1957, pages 559-600.

LEWIS GOTTS, Primary Examiner.

RICHARD L. HUFF, Assistant Examiner.

Claims

3. A NEUTRALIZING AQUEOUS SOLUTION FOR USE IN THE PERMANENT WAVING OF HAIR, CONTAINING 5% TO 20% BY WEIGHT OF A SOLUBLE ALKALI METAL SALT OF TETRATHIONIC ACID, SAID SOLUTION BEING SLIGHTLY ACID TO A PH OF 9.5