KR20000039832A - Ph buffer reaction composition for aerosol product using metal container as packing materials - Google Patents

Abstract

PURPOSE: A pH buffer reaction composition for aerosol product using metal container as packing materials is provided which keeps stability of the content for a long time as minimizing the alteration of pH thereof and reduces corrosion caused by the alteration of pH. CONSTITUTION: A buffer reaction composition for aerosol product containing more than 20 wt.% of water comprises also 0.001-2.0 wt.% of weak acid and conjugate acid thereof, or weak base and conjugate base thereof simultaneously, based on the total weight of the composition. The weak acid or weak base can be citric acid, sodium citrate, benzoic acid, sodium benzoate, acetic acid, sodium acetate, boric acid, sodium borate, phosphoric acid, sodium phosphate tribasic, lactic acid, sodium lactate, sodium phosphate dibasic, sodium phosphate monobasic.

Description

Composition having pH buffering effect of aerosol product using metallic container as packaging material

The present invention relates to a composition having a pH buffering effect of an aerosol product using a metallic container as a packaging material. More specifically, the present invention substitutes pure water, which is the main solvent used in the formulation of aerosol products using a metallic container as a packaging material, simultaneously contains an appropriate amount of a weak salt of citric acid and weak acid, a weak base, and a base thereof, and a pair thereof. By using a buffer solution having a buffering action, it relates to an aerosol product composition which maintains the pH stability of the formulation and significantly reduces corrosion of the aerosol container due to pH changes.

In general, aerosol products are valves for discharging a target material sealed in a container by a pressure of liquefied gas or compressed gas filled with a stock solution in a metal, glass, or plastic container or sprayed, foamed, or battered. This product has a spray device such as hair setting and trimming products, hair treatment products, shaving creams, perfumes, fragrances, deodorants, indoor deodorants, antifog agents, household waxes, laundry pools, cleaners, etc. It is applied to various kinds of household goods.

In the case of aerosol products, metal containers of aluminum or tin plate that can withstand high pressures are generally widely used. Metal containers of aerosol products are generally used to prevent corrosion. In order to coat the inner surface with phenol resin, vinyl resin, epoxy-phenol resin and the like. However, in the long-term use or storage of the product, when corrosion occurs inside the container due to the generation of ions due to raw material decomposition or dissolution of the container coating material, change of pH, swelling or peeling of the container coating material. There is.

When comparing the relationship between corrosion and pH in the general state of water for aluminum containers and tin-plated containers, which are the most widely used aerosol metallic packaging materials, both metal materials form an oxide film such as aluminum oxide near pH neutral. It prevents the metal container from corroding effectively by preventing contact between the metal container and the metal container.However, the aluminum oxide film melts when it is acidic and basic (increase or decrease in pH), and the basic (pH increase) in the tin plated container oxide film. In the) state, it does not melt, but in acidity (pH reduction), it melts, making it an environment in which metal containers and contents can come into contact. Eventually, corrosion may occur through the following process.

Corrosion is inherently an electrochemical process. Corrosion in general aerosol vessels is caused by the liquid contents acting as an electrolyte and the anode and cathode located on the wall of the metallic vessel. Corrosion occurs and the electrons formed by this reaction move to the cathode through the metal vessel, resulting in a reduction reaction.

The reaction at the anode of aluminum and tin-plated containers, which are currently used as aerosol metal containers, can be expressed as

Sn → Sn ⁺⁺ + 2e (electron) and Al → Al ⁺⁺⁺ + 3e (electron)

The reaction at the cathode can be expressed as follows.

2H ⁺ + 2e → 2H → H ₂

Thus, for full, but for most of the corrosion reaction taking place is the release of hydrogen ions (H ^+), and thus the pH in the corrosion action in a very moderate one element of the solution represented by the concentration of hydrogen ions (H ^+). Factors that greatly affect corrosion besides pH include oxygen concentration in the vessel and the concentration of corrosive ions such as chlorine or sulfate in the stock solution.

Raw materials used in the present invention, such as forming an oxide film on the anode, such as phosphate and silicate, or forming a barrier between the stock solution and the container metal, such as amine, to prevent corrosion caused by these factors. Compared with the use of various corrosion inhibitors (corrosion inhibitor) which is relatively expensive, or by reducing the oxygen concentration inside the vessel by using nitrogen substitution or vacuum packaging, and preparing the stock solution using ion-exchanged water. It reduces the concentration of corrosive ions, and adjusts the pH of the stock solution by using a pH adjuster such as citric acid alone, but it has a function of simple pH control and generally does not have a pH buffering effect on the stock solution. Product contents when performing long-term stability storage tests performed on the product The pH of S.A. ranges from as low as 0.5 to as high as 3, with severe variations.

Therefore, the present invention is to improve the above-mentioned problems of the prior art, by using the basic properties of the buffer solution to minimize the pH change of the contents of the contents packaged in the metallic container to maintain the stability of the stock solution longer, the container according to the pH change It provides an aerosol product composition that can significantly reduce the corrosion of the product to maintain a constant product quality.

The present invention relates to an aerosol product packaged in a metal container while containing at least 20% by weight of water, wherein both a weak acid and a counter salt of the weak acid or a weak base and a counter acid of the weak base are simultaneously contained in an amount of 0.001 to 2.0% by weight based on the total weight of the composition. It relates to an aerosol prescription composition, characterized in that.

A buffer solution is generally a solution containing a significant amount of both weak acids and their bases or weak bases and their bases in the same concentration, or diluted to a small amount of acid or base, and the pH remains almost constant. A solution that exhibits a buffer action. For example, when a drop of concentrated acid is added to 1 liter of pure water, [H ⁺ ] is increased by about 5000 times, but 0.2 g of formula phosphoric acid (H ₃ PO ₄ ) is dissolved in 1 liter of water, and 0.3 g of formula is of hydroxide. When added to a buffer solution made by adding sodium (NaOH), [H ⁺ ] increases only less than 1%.

In general, the action of such a buffer solution is to describe the weak acid as HA and its salt as BA.

HA ⇔ H ^{+ +} A ^-

⇔ B ⁺ A + BA ^-

It becomes However, even though HA has a small degree of ionization originally, the ionization becomes weaker because a strong electrolyte BA with a common ion exists. In this state, if sensan is applied from the outside

H ₊ (sensan) + A ^- (salt) → HA

As a result, a weak acid HA that does not ionize is generated, so that [H ⁺ ] of the solution does not increase, and thus the pH of the stock solution does not decrease. If a base is added from the outside

_{^{OH - + HA → H 2 O}} + A -

Also does not change pH. In this way, so-called buffering action is shown for both acid and base from the outside.

According to the present invention, one of the stability factors of the product by minimizing the pH change in the undiluted solution using a weak acid and its salt, or a weak base and its conjugate acid for a product using water as the main solvent of the prescription and a metal aerosol container as a packaging material. It is to minimize the corrosion of the aerosol metal container which may be caused by the stabilization of the phosphorus stock pH and the pH change of the stock solution, and to maintain the proper pH of the stock solution suitable for the characteristics of each product to improve the quality of the aerosol product.

According to the present invention, in the case of other compositions used in aerosol prescription, products for hair setting or trimming, products for hair treatment, shaving creams, perfumes, fragrances, deodorants, indoor deodorants, antifog agents, household waxes, laundry pools General raw materials suitable for the use of products such as, cleaners, etc. may be used, but citric acid, sodium citrate, benzoic acid and sodium benzoate, Actic acid and sodium acetate, boric acid and sodium borate, phsphoric acid and sodium phosphate (tribasic), lactic acid and sodium lactate (weak lactate), sodium diphosphate (sodium phosphate, monobasic), sodium monophosphate (sodium phosphate, dibasic), etc. By having the buffering action against pH change that may occur in any combination, the packaging process of the temporal condition, or the contents of the product.

The weak or weak base used in the present invention is ammonium bicarbonate, ammonium carbonate, ammonium phosphate, ascorbic acid, benzoic acid, sodium benzoate, citric acid, sodium citrate, formic acid, fumaric acid, maleic acid, potassium bicarbonate, sodium carbonate, benzoic acid, benzoic acid Sodium, acetate, sodium acetate, boric acid, sodium borate, phosphoric acid, monosodium phosphate, sodium dihydrogen phosphate, sodium trihydrogen phosphate, lactic acid or sodium lactate.

In the present invention, a weak acid, a buffering agent, used as a buffering agent in the present invention, a counter salt of the weak acid, or a counter salt of the weak base and the weak base, is 0.001% to 2% by weight of each component to be combined with respect to the total weight of the composition. Each component is used in the same amount or in an amount so that the pH can be suited to the product characteristics within the range of. In this case, when used at a concentration of 2% by weight or more relative to the total weight of the contents affects the quality characteristics of the product, when used at a concentration of 0.001% by weight or less, the pH buffering effect of the stock solution is lowered to obtain the desired effect.

In addition, when the content ratio of water in the formulation content is lower than 20% by weight, there are very few aqueous solution components that may exhibit a buffering effect, so that the expected effects of pH stabilization and metal corrosion prevention cannot be obtained.

The metal material of the product packaging in the aerosol product composition according to the present invention uses an aluminum or tin plated container.

Hereinafter, the present invention will be described in detail with reference to Examples, but the technical scope of the present invention is not limited to these Examples.

Comparative Example 1 and Examples 1 to 3

Using the components of the general hair mousse product shown in Table 1 below to prepare Comparative Example 1 without the buffering capacity and to measure the pH immediately after the preparation, pH stability during long-term storage of the same stock solution and corrosion evaluation of the metal In the formulation of Comparative Example 1, citric acid and sodium citrate were applied by 0.1 wt%, respectively, and sodium dihydrogen phosphate in the formulation of Example 1 and Comparative Example 1, which is a citric acid buffer solution having a buffering action in the vicinity of pH 4-5. 0.1 wt% of sodium monohydrogen phosphate and 0.1 wt% of phosphate buffer solution having a buffering action at a pH of 5 to 7, respectively, and 0.1 wt% of boric acid and sodium borate were applied to the formulation of Comparative Example 1, respectively. Example 3, which is a boric acid buffer solution having a buffering action at a pH of 7 to 9, was prepared, and the pH of each sample was measured immediately after preparation under the same conditions as in Comparative Example 1, and then The stability of the stock solution according to the long-term aging of the Examples 1, 2, and 3 in which the buffering effect was applied by comparing the pH stability of the long-term storage and the corrosion evaluation of the metal to the results of Comparative Example 1 which did not exhibit the buffering effect. The inhibitory effect on the corrosion of metals was confirmed.

Unit: weight% Ingredient Name Comparative Example 1 Example 1 Example 2 Example 3 Distilled water 85.3 85.1 85.1 85.1 Citric acid --- 0.1 --- --- Sodium citrate --- 0.1 --- --- Sodium Dihydrogen Phosphate --- --- 0.1 --- Sodium hydrogen phosphate --- --- 0.1 --- Boric acid --- --- --- 0.1 borax --- --- --- 0.1 Polyquaternium-11 4 4 4 4 Polyoxyethylene lauryl ether 0.5 0.5 0.5 0.5 incense 0.2 0.2 0.2 0.2 ethanol 10 10 10 10 Total solution 100 100 100 100 -------------------------------------------------- ----- Stock solution (wt%) 95 95 95 95 LPG spray agent (wt%) 5 5 5 5 Finished product total 100 100 100 100

Manufacture and test method:

In Comparative Example 1, polyquaternium-11 was dissolved in purified water, and polyoxyethylurelauryl ether, ethanol, and then sequentially added while checking the dissolution state to prepare contents and measured pH.

In Examples 1, 2, and 3, a suitable amount of the buffer components shown in Examples 1, 2, and 3 in Table 1 was added to purified water to form a buffer solution, and polyquaternium-11 was dissolved in the buffer solution. Uril ether, ethanol, scent in order to check the dissolved state in order to prepare the contents and measure the pH of the stock solution immediately after preparation.

For the corrosive test of the contents of Comparative Example 1 and Examples 1, 2 and 3 respectively, the tin-plated container, which is a metal material commonly used in aerosol products, was cut into 0.5 cm horizontally and vertically to promote corrosion. In order to remove the designed coating of the outer surface using sandpaper, put each into a pressure-resistant glass container that can observe the internal change separately, and fill the contents of Comparative Example 1 and Examples 1, 2 and 3, respectively, and then insert the valve. And seal. After a suitable amount of LPG was injected into the sealed pressure-resistant glass container to mimic the state of the finished product, the corrosion state of the metal container material specimen contained in the 100-mL pressure-resistant glass container was visually observed while standing at room temperature.

In order to investigate the change in pH during long-term storage for Comparative Examples 1 and 1, 2 and 3, the contents of Comparative Example 1 and Examples 1, 2 and 3 were filled in a 100 ml pressure-resistant glass container, and the valve was Insert and seal. After imposing a proper amount of LPG into the sealed pressure-resistant glass container to mimic the state of the finished product, after 3 months storage at 50 ℃ high temperature for long-term stability test of aerosol products commonly used in cosmetic testing, remove the valve and the injection liquid The pH of was measured.

Comparative Example 2 and Examples 4 to 6

As shown in Table 2, Comparative Example 2 having no buffering effect was prepared by adjusting the pH of citric acid alone using components used in general mousse products for general hair, and measuring the pH immediately after preparation. Evaluation of pH stability and metal corrosion during storage was performed, and citric acid buffer solution having a buffering action in the vicinity of pH 4 to 5 by applying 1.5% by weight of citric acid and sodium citrate, respectively, to the formulation of Comparative Example 1 And sodium phosphate dihydrogen phosphate and sodium dihydrogen phosphate in the formulation of Comparative Example 1 and 1.5 wt%, respectively, which is a phosphate buffer solution having a buffering action in the vicinity of pH 5-7, and boric acid in the formulation of Comparative Example 1 Example 6, which is a boric acid buffer solution having a buffering action at a pH of 7 to 9 by applying 1.5 wt% of sodium and borate, respectively, and Comparative Examples 1 and 2 for each example After measuring the pH immediately after preparation under the same conditions as in the above, the pH stability during long-term storage of the same stock solution and the corrosion evaluation of the metal were performed to compare the results of Comparative Examples 1 and 2, which showed no buffering effect. For Examples 4, 5 and 6 to which this was applied, the stability of the stock solution over time and the inhibitory effect on metal corrosion were confirmed.

Unit: weight% Ingredient Name Comparative Example 2 Example 4 Example 5 Example 6 Distilled water 85.2 82.3 82.3 82.3 Citric acid 0.1 1.5 --- --- Sodium citrate --- 1.5 --- --- Sodium Dihydrogen Phosphate --- --- 1.5 --- Sodium hydrogen phosphate --- --- 1.5 --- Boric acid --- --- --- 1.5 borax --- --- --- 1.5 Polyquaternium-11 4 4 4 4 Polyoxyethylene lauryl ether 0.5 0.5 0.5 0.5 incense 0.2 0.2 0.2 0.2 ethanol 10 10 10 10 Total solution 100 100 100 100 -------------------------------------------------- ----- Stock solution (wt%) 95 95 95 95 LPG spray agent (wt%) 5 5 5 5 Finished product total 100 100 100 100

Manufacture and test method:

In Comparative Example 2, after dissolving citric acid in purified water and then dissolving polyquaternium-11, polyoxyethylene lauryl ether, ethanol, and fragrance were sequentially added while preparing the contents, and the pH was adjusted. Measure

For Examples 4, 5, and 6, a suitable amount of the buffer components shown in Examples 4, 5, and 6 in Table 2 was added to purified water to make a buffer solution, and polyquaternium-11 was dissolved in the buffer solution, and polyoxyethylene lauryl Etel, ethanol, fragrance in order to check the dissolved state in order to prepare the contents and measure the pH of the stock solution immediately after preparation.

For the corrosiveness test of the contents of Comparative Example 2 and Examples 4, 5 and 6, the tin plating vessel, which is a metal material generally used in aerosol products, was cut into 0.5 cm horizontally and vertically to promote corrosion. In order to remove the designed coating on the outer surface using sandpaper, put each of them into a pressure-resistant glass container to observe the internal changes separately, and fill the contents of Comparative Example 2 and Examples 4, 5 and 6, respectively, and then Insert and seal. After a suitable amount of LPG was injected into the sealed pressure-resistant glass container to mimic the state of the finished product, the corrosion state of the metal container material specimen contained in the 100-mL pressure-resistant glass container was visually observed while standing at room temperature.

In order to investigate the change of pH during long-term storage for Comparative Examples 2 and 4, 5 and 6, the contents of Comparative Examples 2 and 4, 5 and 6 were filled in a suitable amount in a 100 ml pressure-resistant glass container, and the valve was Insert and seal. After imposing a proper amount of LPG into the sealed pressure-resistant glass container to mimic the state of the finished product, after 3 months storage at 50 ℃ high temperature for long-term stability test of aerosol products commonly used in cosmetic testing, remove the valve and the injection liquid The pH of was measured.

Test result

3 months of 50 ° C. high temperature long-term aging, which is a method generally applied in pH and cosmetic tests immediately after preparation for the contents prepared in Comparative Examples 1 and 2 having no buffering effect and the contents of Examples 1 to 6 having a buffering effect. After the pH change was confirmed. The results are shown in Table 3.

pH stability and tin-plated container corrosion test results pH Tin Plated Metal Corrosion Date of Origin Early 3 months later pH difference Comparative Example 1 8.7 7.4 1.3 5 days later Comparative Example 2 7.6 6.4 1.2 3 days later Example 1 4.6 4.8 0.2 60 days later Example 2 6.8 6.9 0.1 85 days later Example 3 8.9 8.7 0.2 After 67 days Example 4 4.8 5.0 0.2 50 days later Example 5 7.0 7.3 0.3 After 78 days Example 6 8.9 8.5 0.4 63 days later

As shown in Table 3, in the case of Comparative Examples 1 and 2 without applying the solution showed a very large change in pH, Examples 1 to 6 having a buffering effect shows a very small change in pH to the pH stability of the contents It was confirmed to be effective. In addition, even in the results of visually confirming the corrosion inhibitory effect of the metal container material for Comparative Examples 1 and 2 and Examples 1 to 6, Examples 1 to 6 having a buffering effect compared to Comparative Examples 1 and 2 having no buffering effect were corroded. This much longer time was observed to be very effective in preventing corrosion of metallic aerosol containers such as tin-plated containers.

In addition, it was confirmed that the product quality according to the buffer solution application, that is, in the case of mousse as an example prescription, product quality such as setting force, bubble state, white powder generation amount, and stickiness, was not affected even when the buffer solution was applied.

The aerosol product composition according to the present invention maintains the stability of the stock solution for a longer time by minimizing the pH change of the stock solution packaged in the metallic container using the basic properties of the buffer solution, and significantly reduces the corrosion of the container according to the pH change. It can keep the quality of constant.

Claims (3)

All aerosol products packaged in metal containers with 20% by weight or more of water, wherein both the weak acid and its weak acid, or the weak base and its weak base, simultaneously contain 0.001 to 2.0% by weight of the total weight of the composition. An aerosol product composition. The method according to claim 1, wherein the weak acid or weak base is ammonium bicarbonate, ammonium carbonate, ammonium phosphate, ascorbic acid, benzoic acid, sodium benzoate, citric acid, sodium citrate, formic acid, fumaric acid, maleic acid, potassium bicarbonate, sodium carbonate, benzoic acid, benzoic acid Sodium, acetic acid, sodium acetate, boric acid, sodium borate, phosphoric acid, monosodium phosphate, sodium dihydrogen phosphate, sodium trihydrogen phosphate, lactic acid or sodium lactate are used, and the base and counter acid are commonly contained in the same prescription for buffering An aerosol product composition that produces an effect. The aerosol product composition according to claim 1, wherein the alumina or tin plated container is used as a metal material of the product packaging.