Aerosol product and method for producing aerosol product

Abstract

To provide an aerosol product in which a foaming agent as a content is hardly vaporized even when the pressure in a can is lowered by use, thereby hardly causing scattering at the time of discharge, and which can obtain a good foamy discharge material in which fine bubbles are dispersed, and to provide a method for producing the aerosol product.SOLUTION: An aerosol container comprising an outer container, an inner container accommodated in the outer container, and a valve attached to the outer container for switching between a communication state and a cutoff state between the inside of the inner container and the outside, a concentrate and a foaming agent filled in the inner container, and a pressurizing agent filled in a pressurizing space between the outer container and the inner container, wherein the inner container has a gas barrier property, and a dissolved amount (D) of the foaming agent in the concentrate at 25 °C is such that the concentrate and the foaming agent are not filled in the inner container, and less than the saturated dissolution amount (P0) of the foaming agent in the stock solution at the pressure (D0) when only the pressurizing agent is filled in the pressurizing space.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an aerosol product and a method for manufacturing the aerosol product. More specifically, the present invention relates to an aerosol product and a method for manufacturing the aerosol product, in which the foaming agent contained therein is unlikely to evaporate even when the pressure inside the can is reduced during use, thereby preventing scattering during discharge and enabling the production of a good foam-like discharge containing dispersed fine bubbles. [Background technology]

[0002] Conventionally, for example, a discharge product containing a concentrate and a foaming ingredient and dispensing a foamy food product has been known. Patent Document 1 discloses a pressure-accumulation type discharge product for a foamy food product, which includes an inner bag containing a liquid food product and a foaming ingredient, i.e., nitrous oxide and / or carbon dioxide, a can containing the inner bag, pressurized gas contained around the inner bag inside the can, and a discharge part for dispensing the contents of the inner bag. Because this pressure-accumulation type discharge product contains pressurized gas around the inner bag inside the can, it can discharge the functional food in foamy form even at the end of the can when the remaining amount is low. In particular, this pressure-accumulation type discharge product contains a mixed amount of foaming ingredient that is 2 to 8 times the saturated solubility of nitrous oxide and / or carbon dioxide in the liquid food at a temperature of 25°C and a pressure of 0.1 MPa. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2024-14798 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the pressure-accumulation type dispensing product described in Patent Document 1, as the fluid food and foaming ingredient in the inner bag are discharged with continued use, the pressure inside the can decreases. As a result, the foaming ingredient that was dissolved in the fluid food in the inner bag cannot completely dissolve in the fluid food and gasifies, forming a gas phase (gas accumulation). When the pressure-accumulation type dispensing product is used, such a gas phase is discharged simultaneously with the fluid food, causing the fluid food to splash or the foaming ingredient to degas, reducing foaming ability.

[0005] The present invention has been made in consideration of such conventional problems, and aims to provide an aerosol product and a method for manufacturing an aerosol product in which the foaming agent contained therein is less likely to evaporate even when the pressure inside the can drops during use, thereby making it less likely to splash when dispensed, and which can produce a good foam-like dispensed product with fine bubbles dispersed therein. [Means for solving the problem]

[0006] The present invention, which solves the above problems, mainly comprises the following configuration.

[0007] (1) An aerosol product comprising an outer container, an inner container housed in the outer container, and a valve attached to the outer container for switching between a communication state and a cut-off state between the inside and outside of the inner container; a concentrate and a foaming agent filled in the inner container; and a pressurizing agent filled in a pressurized space between the outer container and the inner container, wherein the inner container has gas barrier properties, and the amount of dissolution (D) of the foaming agent in the concentrate at 25°C is less than the saturated solubility (D0) of the foaming agent in the concentrate at a pressure (P0) when the inner container is not filled with the concentrate and the foaming agent and only the pressurizing agent is filled in the pressurized space.

[0008] According to this configuration, the aerosol product is adjusted so that the amount (D) of the foaming agent dissolved in the concentrate is less than the saturated amount (D0) of the foaming agent at the pressure (P0) when only the pressurizing agent is filled in the pressurized space. Therefore, even if the concentrate and foaming agent in the inner container decrease with use, increasing the volume of the pressurized space and decreasing the pressure in the pressurized space, the foaming agent dissolved in the concentrate remains dissolved at a dissolution amount (D) less than the saturated amount (D0) and is therefore less likely to vaporize within the inner container. As a result, even if the aerosol product is used until its contents are completely used up, a gas phase is less likely to be formed within the inner container due to the foaming agent. Therefore, when the concentrate is discharged, the aerosol product is less likely to discharge a gas phase, reducing the risk of splashing. The foaming agent is not wasted and can efficiently foam the concentrate. Therefore, the foaming agent does not need to be dissolved at a high concentration as in the past. Furthermore, the aerosol product can produce a good foamy discharged product with fine bubbles dispersed therein by vaporizing the discharged foaming agent.

[0009] (2) The aerosol product according to (1), wherein the foaming agent contains at least one of carbon dioxide gas, nitrous oxide gas, and nitrogen gas.

[0010] According to this configuration, these foaming agents dissolve in large amounts in the concentrate, and generally, a gas phase is likely to form upon use, but the aerosol product of the present invention, even when these foaming agents are used, is less likely to form a gas phase and is less likely to cause scattering of the discharged product. Furthermore, the aerosol product can produce a good foam-like discharged product with fine bubbles dispersed therein by vaporizing the discharged foaming agent.

[0011] (3) The aerosol product according to (1) or (2), wherein the pressure (P0) is 0.2 to 0.5 MPa.

[0012] With this configuration, the aerosol product can easily secure the required amount of foaming agent, disperse a large amount of fine bubbles in the discharged product, and easily produce a good foam state.

[0013] (4) A method for producing an aerosol product, using an aerosol container comprising an outer container, an inner container housed in the outer container and having gas barrier properties, and a valve attached to the outer container for switching between a communication state and a cut-off state between the inside of the inner container and the outside, the method comprising: a pressurizing agent filling step of filling a pressurizing agent into a pressurized space between the outer container and the inner container so that the pressure in the pressurized space at 25°C becomes pressure (P0); a contents filling step of filling a concentrate and a foaming agent into the inner container; and a dissolving step of dissolving the foaming agent in the concentrate, wherein in the dissolving step, the amount of the foaming agent dissolved in the concentrate (D) is less than the saturated amount of the foaming agent dissolved in the concentrate (D0) at the pressure (P0).

[0014] According to this configuration, the concentrate and foaming agent are filled into the inner container of an aerosol container having a pressure of P0. Therefore, when the concentrate is filled into the inner container during the content filling process, the pressure inside the aerosol container is higher than P0, and the concentrate in the inner container has a saturated solubility higher than D0. This allows the foaming agent filled into the inner container to dissolve in the concentrate without vaporizing. Furthermore, the resulting aerosol product is adjusted so that the dissolution amount (D) of the foaming agent in the concentrate is less than the saturated solubility (D0) of the foaming agent at the pressure (P0) when only the pressurizing agent is filled into the pressurized space. Therefore, even if the concentrate and foaming agent in the inner container decrease with use, increasing the volume of the pressurized space and decreasing the pressure of the pressurized space, the foaming agent dissolved in the concentrate is dissolved at a dissolution amount (D) less than the saturated solubility (D0) and is therefore less likely to vaporize within the inner container. As a result, even when the aerosol product is used until the contents are completely used, a gas phase is less likely to form within the inner container due to the foaming agent. Therefore, when the concentrate is discharged, the gas phase of the aerosol product is unlikely to be discharged at the same time, and the discharged product is unlikely to scatter. Furthermore, when the discharged foaming agent evaporates, the aerosol product can produce a good foam-like discharged product with fine bubbles dispersed therein.

[0015] (5) A method for producing an aerosol product, using an aerosol container comprising an outer container, an inner container housed in the outer container and having gas barrier properties, and a valve attached to the outer container for switching between a communication state and a cut-off state between the inside of the inner container and the outside, the method comprising: a pressurizing agent filling step of filling a pressurizing agent into a pressurized space between the outer container and the inner container so that the pressure in the pressurized space at 25°C becomes pressure (P0); a dissolving step of dissolving a foaming agent into a concentrate in a location separate from the inner container; and a content filling step of filling the inner container with the concentrate and the foaming agent prepared in the location separate from the inner container, wherein in the dissolving step, the foaming agent is dissolved in the concentrate so that the dissolution amount (D) of the foaming agent in the concentrate is less than the saturation dissolution amount (D0) of the foaming agent in the concentrate at the pressure (P0).

[0016] According to this configuration, the contents, in which a dissolution amount (D) of foaming agent is dissolved in a concentrate in a separate pressure-resistant container, pipeline, or other device, are filled into the inner container of an aerosol container having a pressure of P0. Therefore, when the contents are filled into the inner container during the contents filling process, the pressure inside the aerosol container is higher than P0, and the concentrate in the inner container has a saturated dissolution amount higher than D0. This allows the foaming agent to dissolve in the concentrate without vaporizing in the contents filled into the inner container. Furthermore, the resulting aerosol product is adjusted so that the dissolution amount (D) of the foaming agent in the concentrate is less than the saturated dissolution amount (D0) of the foaming agent at the pressure (P0) when only the pressurizing agent is filled into the pressurized space. Therefore, even if the concentrate and foaming agent in the inner container decrease with use, increasing the volume of the pressurized space and decreasing the pressure of the pressurized space, the foaming agent dissolved in the concentrate is less likely to vaporize in the inner container because it is dissolved at a dissolution amount (D) less than the saturated dissolution amount (D0). As a result, even if the aerosol product is used until the contents are completely used up, the foaming agent does not easily form a gas phase inside the inner container. Therefore, when the aerosol product is discharged, the gas phase is not easily discharged at the same time, and the discharged product is less likely to scatter. Furthermore, when the discharged foaming agent evaporates, the aerosol product can produce a good foam-like discharged product with fine bubbles dispersed therein. [Effects of the Invention]

[0017] According to the present invention, an aerosol product and a method for manufacturing an aerosol product can be provided in which the foaming agent contained therein is less likely to evaporate even when the pressure inside the can decreases during use, thereby making it less likely to splash when dispensed and enabling the production of a good foam-like dispensed product with fine bubbles dispersed therein. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic cross-sectional view of an aerosol product according to one embodiment of the present invention. [Figure 2]FIG. 2 is a schematic cross-sectional view illustrating the state of the aerosol product according to one embodiment of the present invention before the concentrate and the foaming agent are filled into the inner container. [Figure 3] FIG. 3 is a graph showing the relationship between the pressure (P0) and the pressure for each remaining amount of content in an aerosol product according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] <Aerosol products> FIG. 1 is a schematic cross-sectional view of an aerosol product 1 according to one embodiment of the present invention. The aerosol product 1 of this embodiment comprises an aerosol container comprising an outer container 2, an inner container 3 housed within the outer container 2, and a valve 4 attached to the outer container 2 for switching between a communication state and a blocked state between the interior and exterior of the inner container 3; a concentrate C and a foaming agent F (not shown) filled in the inner container 3; and a pressurizing agent G filled in the pressurized space S1 between the outer container 2 and the inner container 3. The inner container 3 has gas barrier properties. At 25°C, the dissolution amount (D) of the foaming agent F in the concentrate C is less than the saturated dissolution amount (D0) of the foaming agent F in the concentrate C at a pressure (P0) when the concentrate C and the foaming agent F are not filled in the inner container 3 and only the pressurizing agent G is filled in the pressurized space S1. Each of these components is described below.

[0020] (Outer container 2) The outer container 2 is not particularly limited. The outer container 2 is made of a metal such as tinplate or aluminum. The outer container 2 may also be made of a synthetic resin such as polyethylene terephthalate. The outer container 2 has a bottom 21, a substantially cylindrical body 22, a substantially tapered shoulder 23 whose diameter decreases upward from the upper end of the body 22, and a bead 24 formed in an annular shape at the upper end of the shoulder 23.

[0021] (Inner container 3) The inner container 3 is housed within the outer container 2 and has gas barrier properties. The inner container 3 comprises a joint part 31 connected to a housing 41 of a valve 4, which will be described later, and a pouch 32 welded to the joint part 31 and made by bonding the peripheries of multiple sheets together.

[0022] The joint part 31 has a through hole P1 formed therein that communicates with the inside of the housing 41. The joint part 31 has an attachment groove formed therein for attaching the dip tube 5 disposed in the inner container 3.

[0023] The dip tube 5 is a long cylindrical member. The concentrate C in the internal container 3 can be introduced into the housing 41 via the dip tube 5 and through the through-hole P1 of the joint part 31.

[0024] The sheet of pouch 32 has a gas barrier layer made of a metal foil such as aluminum foil or a synthetic resin such as EVAL or nylon, and chemical-resistant layers made of a synthetic resin such as polyethylene or polyethylene terephthalate are provided on both sides of the gas barrier layer. The gas barrier layer prevents the air-foaming agent filled in inner container 3 from permeating and migrating into pressurized space S1, and also prevents the pressurizing agent filled in pressurized space S1 from permeating and migrating into inner container 3.

[0025] (Valve 4) Valve 4 comprises a mounting cup 42 with a U-shaped cross-section covering portion that fits over bead portion 24 of outer container 2, a gasket placed on the inner surface of the covering portion, a cylindrical housing 41 with a bottom that is held by housing holding portion 42a at the center of mounting cup 42, a stem 43 that is housed within housing 41 so as to be able to move up and down, a stem rubber 44 that is sandwiched between housing 41 and mounting cup 42, and a spring 45 that urges stem 43 upward. A discharge member (not shown) is attached to the upper end of stem 43 to open and close valve 4 and discharge the contents.

[0026] The valve 4 is a component for switching between a communication state and a blocked state between the interior of the internal container 3 and the outside. Specifically, when a discharge member (not shown) attached to the upper end of the stem 43 is pressed down, the stem 43 of the valve 4 is pressed downward. This causes the stem rubber 44 to bend downward, opening the stem hole 46. As a result, the interior of the internal container 3 is connected to the outside (communication state), and the pressure of the pressurizing agent filled in the pressurized space S1 causes the contents (raw liquid C in which the foaming agent F is dissolved) in the internal container 3 to pass through the stem hole 46 and the stem passage 47 and be sent to the discharge member (not shown), where they are then discharged from the discharge hole of the discharge member. When the discharge member is released from being pressed down, the spring 45 urges the stem 43 upward, and the stem rubber 44 blocks the stem hole 46 again (blocking state). This stops the discharge of the contents.

[0027] (Stock solution C) The concentrate C is filled in the inner container 3. A specific amount of foaming agent is dissolved in the concentrate C within the inner container 3. When the concentrate C is discharged to the outside, the foaming agent vaporizes, and the concentrate C becomes a liquid, cream, or gel with fine bubbles dispersed in the discharged product, or foams into a foam.

[0028] There are no particular limitations on the concentrate C. Examples of concentrate C include foods such as whipped cream, margarine, edible oil, and dressing, and beverages such as water, tea, coffee drinks, dairy drinks, soft drinks, fruit juice drinks, nutritional drinks, and alcoholic drinks. Furthermore, concentrate C may also be skin care products such as skin lotions, emulsions, lotions, sunscreens, antiperspirants, and cleansers, and hair care products such as treatments, styling agents, and hair dyes.

[0029] The concentrate C may contain an emulsifier, a viscosity adjuster, a coloring agent, a fragrance, etc. as appropriate.

[0030] (Foaming Agent F) The foaming agent F is dissolved in the concentrate C in the inner container 3. When the foaming agent F is discharged to the outside, it vaporizes and causes the concentrate C to foam.

[0031] The foaming agent F is not particularly limited. Examples of foaming agents include carbon dioxide, nitrous oxide, nitrogen, compressed air, oxygen, helium, and mixtures thereof. Among these, the foaming agent F preferably contains at least one of carbon dioxide, nitrous oxide, and nitrogen. These foaming agents F dissolve in large amounts in the concentrate C and generally form a gas phase upon use. However, even when these foaming agents F are used, the aerosol product 1 of this embodiment is less likely to form a gas phase and cause the discharged product to splatter. Furthermore, since the foaming agent is not wasted and can efficiently foam the concentrate, it is not necessary to dissolve it at a high concentration as in conventional methods. Furthermore, the aerosol product 1 can produce a good foamed discharged product with fine bubbles dispersed as the discharged foaming agent evaporates.

[0032] In the aerosol product 1 of this embodiment, the amount of foaming agent F to be filled is an amount such that the amount of foaming agent F dissolved in the concentrate C (D) at 25°C is less than the saturated dissolution amount (D0) of the foaming agent F in the concentrate C at the pressure (P0) when the inner container 3 is not filled with the concentrate C or the foaming agent F and only the pressurizing agent G is filled in the pressurized space S1. FIG. 2 is a schematic cross-sectional view of the aerosol product of this embodiment, illustrating the state (P0) in which only the pressurizing agent G is filled in the pressurized space S1 and before the concentrate C and the foaming agent F are filled in the inner container 3. In the state shown in FIG. 2, the pouch 32 of the inner container 3 is not filled with the concentrate C or the foaming agent F. Therefore, the pouch 32 has a flat shape before it expands. The "pressure (P0) when the inner container is not filled with concentrate C and foaming agent F and only pressurizing agent G is filled in the pressurized space S1" can be measured after the pressurizing agent filling step, as will be described later in connection with the manufacturing method of an aerosol product. Even if the contents of the inner container 3 have been discharged to the end and only a small amount of the contents remains, the pressure (P0) can be estimated by measuring the pressure in the pressurized space S1.

[0033] As shown in FIG. 1, the aerosol product 1 of this embodiment is filled with the foaming agent F to the above-mentioned filling amount, and dissolved in the concentrate C. When the concentrate C in the inner container 3 is discharged from this state, the volume of the pouch 32 shrinks. As a result, the volume of the pressurized space S1 of the pressurized space increases, and the pressure in the pressurized space decreases. Even in such a case, the pressure in the inner container 3 can exceed the pressure (P0). Therefore, the aerosol product 1 can prevent the generation of a gas phase within the inner container 3 until the entire content of the inner container 3 is discharged. The saturated dissolution amount of the foaming agent is proportional to the pressure. Therefore, in other words, the filling amount of the foaming agent may be set to the saturated dissolution amount at a pressure lower than the pressure (P0).

[0034] (Pressure Agent G) The pressurizing agent G is filled in the pressurized space S1 between the outer container 2 and the inner container 3. The pressurizing agent G pressurizes the inner container 3 inward, thereby pressurizing the contents inside the inner container 3. Therefore, when the inside of the inner container 3 is connected to the outside during discharge, the contents inside the inner container 3 are pressurized according to the pressure difference between the pressure in the pressurized space S1 and the outside, and are discharged to the outside.

[0035] There is no particular limitation on the pressurizing agent G. For example, the pressurizing agent G may be the same as or different from the foaming agent F described above.

[0036] The pressurizing agent G can be filled into the pressurized space S1 between the outer container 2 and the inner container 3 by undercup filling when the valve 4 is attached to the outer container 2. The pressure (P0) inside the aerosol container when the pressurizing agent G is filled into the pressurized space S1 is preferably 0.2 MPa (25°C) or higher, more preferably 0.25 MPa (25°C) or higher. Furthermore, the pressure (P0) is preferably 0.5 MPa (25°C) or lower, more preferably 0.45 MPa (25°C) or lower. By keeping the pressure (P0) within the above range, the aerosol product 1 does not generate a gas phase within the inner container 3 until the contents within the inner container 3 are depleted. Furthermore, the aerosol product 1 can easily secure the amount of foaming agent G necessary to generate and disperse fine bubbles in the discharged product or to discharge the product in a good foam state.

[0037] As described above, according to the aerosol product 1 of this embodiment, the amount (D) of the foaming agent F dissolved in the concentrate C is adjusted to be less than the saturated dissolution amount (D0) of the foaming agent F at the pressure (P0) when only the pressurizing agent G is filled in the pressurized space S1. Therefore, even if the amount of concentrate C and the foaming agent F in the inner container 3 decreases with use, causing the volume of the pressurized space S1 to increase and the pressure in the pressurized space S1 to decrease, the foaming agent F dissolved in the concentrate C is dissolved at a dissolution amount (D) less than the saturated dissolution amount (D0), and is therefore less likely to vaporize within the inner container 3. As a result, even if the aerosol product 1 is used until the contents are completely used up, a gas phase is less likely to be formed within the inner container 3 due to the foaming agent F. Therefore, when the contents of the aerosol product 1 are discharged, a gas phase is less likely to be discharged simultaneously, and the discharged product is less likely to splash. Furthermore, the foaming agent is not wasted and can efficiently foam the concentrate, so it does not need to be dissolved at a high concentration as in the past. Furthermore, the aerosol product 1 can produce a good foam-like discharged product with fine bubbles dispersed therein by vaporizing the discharged foaming agent F.

[0038] <Aerosol product manufacturing method> One embodiment of the present invention relates to a method for manufacturing an aerosol product, which uses an aerosol container comprising an outer container, an inner container housed in the outer container and having gas barrier properties, and a valve attached to the outer container for switching between a communication state and a blocked state between the interior and exterior of the inner container. The method includes a pressurizing agent filling step in which a pressurizing agent is filled into the pressurized space between the outer container and the inner container so that the pressure in the pressurized space at 25°C is a pressure (P0); a contents filling step in which a concentrate and a foaming agent are filled into the inner container; and a dissolving step in which the foaming agent is dissolved in the concentrate. In the dissolving step, the amount of foaming agent dissolved in the concentrate (D) is less than the saturated amount of foaming agent dissolved in the concentrate (D0) at pressure (P0).

[0039] Furthermore, one embodiment of the present invention relates to a method for manufacturing an aerosol product, which uses an aerosol container comprising an outer container, an inner container housed in the outer container and having gas barrier properties, and a valve attached to the outer container for switching between a communication state and a blocked state between the interior and exterior of the inner container. The method for manufacturing an aerosol product includes a pressurizing agent filling step in which a pressurizing agent is filled into the pressurized space between the outer container and the inner container so that the pressure in the pressurized space at 25°C becomes pressure (P0); a dissolving step in which a foaming agent is dissolved in a concentrate in a location separate from the inner container; and a content filling step in which the concentrate and the foaming agent, prepared in a separate location, are filled into the inner container. In the dissolving step, the foaming agent is dissolved in the concentrate so that the amount of foaming agent dissolved in the concentrate (D) is less than the saturated amount of foaming agent dissolved in the concentrate at pressure (P0) (D0). Each of these steps is described below. In the following description, details similar to those described above in connection with the aerosol product embodiment will be omitted as appropriate.

[0040] (Pressure agent filling process) The pressurizing agent filling process is a process of filling the pressurized space between the outer container and the inner container with pressurizing agent so that the pressure in the pressurized space at 25°C becomes pressure (P0). Specifically, first, the inner container integrated with the valve is inserted through the opening of the outer container, and the valve is held in place so that a gap is formed between the bead portion and the cover portion. Alternatively, the bottom of the inner container may be attached to the bottom 21 of the outer container, leaving a gap between the bead portion and the cover portion. Next, using a pressurizing agent filling device, pressurizing agent is filled into the pressurized space in the outer container through the gap, and the mounting cup is crimped to seal it while pressing the valve against the bead portion.

[0041] The pressure (P0) when the pressurizing agent is filled into the pressurized space is preferably 0.2 MPa (25°C) or more, more preferably 0.25 MPa (25°C) or more. Furthermore, the pressure (P0) is preferably 0.5 MPa (25°C) or less, more preferably 0.45 MPa (25°C) or less. By keeping the pressure (P0) within the above range, the resulting aerosol product can easily secure the required amount of foaming agent, disperse a large amount of fine bubbles in the discharged product, and easily achieve a good foam state.

[0042] (Content filling process) The content filling process is a process of filling the concentrate and the foaming agent into the inner container. Specifically, in the content filling process, the concentrate and the foaming agent are filled into the inner container from the stem. The concentrate is filled by a concentrate filling machine while being pressurized to a pressure higher than pressure (P0). The filled concentrate causes the inner container to expand. This increases the pressure inside the aerosol container (P1). Next, the foaming agent is filled by a foam filling device at a pressure higher than pressure (P1).

[0043] (melting process) The dissolving process is a process in which the foaming agent is dissolved in the concentrate. In the content filling process described above, the concentrate filled in the inner container has a saturated dissolution amount at pressure (P1), so it easily dissolves the foaming agent. The foaming agent dissolved in the concentrate without vaporizing in the inner container reaches an equilibrium state (product pressure P2).

[0044] At equilibrium, the concentrate is dissolved in the foaming agent so that the amount of foaming agent dissolved in the concentrate (D) is less than the saturated amount of foaming agent dissolved in the concentrate (D) at pressure (P0). As a result, even when the concentrate and foaming agent in the inner container decrease with use, increasing the volume of the pressurized space and decreasing the pressure in the pressurized space, the foaming agent dissolved in the concentrate is dissolved at a dissolution amount (D) less than the saturated amount (D0), and therefore is less likely to evaporate within the inner container. As a result, the resulting aerosol product is less likely to form a gas phase due to the foaming agent within the inner container, even when used until the contents are completely used up. Therefore, when the concentrate is discharged, the aerosol product is less likely to discharge a gas phase, resulting in less scattering of the discharged product. Furthermore, when the discharged foaming agent evaporates, the aerosol product produces a well-formed discharge with finely dispersed bubbles.

[0045] The content filling step may be carried out in the same factory as the pressurizing agent filling step, or may be carried out in a different factory after the aerosol container filled with pressurizing agent is transported. Alternatively, the concentrate and foaming agent may be prepared by dissolving them in a location separate from the aerosol container (for example, in a pressure-resistant container such as a pressurized tank or in pressure-resistant piping such as a pipeline mixer), and then filling the inner container with the solution through the stem. This allows the content, in which the foaming agent is dissolved in the concentrate in an amount (D) in a pressure-resistant container or pipeline separate from the aerosol container, to be filled into the inner container of the aerosol container, which has a pressure of P0. This prevents evaporation of the foaming agent even during the content filling step.

[0046] As described above, according to the aerosol product manufacturing method of this embodiment, the resulting aerosol product is unlikely to form a gas phase due to the foaming agent in the inner container, even when the contents are used until they are completely consumed. Therefore, when the aerosol product is discharged, the gas phase is unlikely to be discharged at the same time, and the discharged product is unlikely to scatter. Furthermore, when the discharged foaming agent evaporates, the aerosol product can produce a good foam-like discharged product with fine bubbles dispersed therein. [Example]

[0047] The present invention will be described in more detail below with reference to examples. The present invention is not limited to these examples. Unless otherwise specified, "%" means "% by mass" and "parts" means "parts by mass."

[0048] 1. Setting the amount of foaming agent to be filled using water and carbon dioxide First, to define the characteristic of the aerosol product of the present invention, "the amount of dissolution of the foaming agent in the concentrate (D) at 25°C is less than the saturated dissolution amount of the foaming agent in the concentrate (D0) at a pressure (P0) when the inner container is free of the concentrate and the foaming agent, and only the pressurizing agent is filled in the pressurized space," an experiment was conducted to determine the saturated dissolution amount of the foaming agent. For clarity, purified water was used as the concentrate and carbon dioxide gas was used as the foaming agent. Figure 3 is a graph showing the relationship between pressure (P0) and the pressure for each remaining amount of content in the aerosol product of the present invention. An aluminum outer container (full capacity 330 mL) was filled with 150 g (150 mL) of purified water as the concentrate, and a valve was attached. Carbon dioxide gas was then filled through the stem, and the saturated dissolution amount was calculated when the equilibrium pressure in the aerosol container reached 0.30 MPa at 25°C. The saturated dissolution amount of carbon dioxide gas was found to be 0.75 g per 150 g of purified water.

[0049] Example 1 An inner container equipped with a gas barrier layer (aluminum foil) was placed inside an aluminum outer container (full capacity 330 mL), and nitrogen was filled into the pressurized space as a pressurizing agent, and a valve was attached. The pressure inside the aerosol container at this time (P0) was 0.37 MPa (pressurizing agent filling process). 150 g (150 mL) of purified water was filled into the inner container from the stem as the concentrate. The pressure inside the aerosol container at this time (P1) was 0.79 MPa. Furthermore, 0.75 g of carbon dioxide gas was filled into the inner container from the stem as a foaming agent (content filling process) and dissolved in the purified water (dissolving process). The pressure at this time (P2) was 0.80 MPa. The amount of foaming agent dissolved was 0.74 g.

[0050] (Comparative Example 1) An inner container equipped with a gas barrier layer (aluminum foil) was placed inside an aluminum outer container (full capacity 330 mL), and nitrogen was filled into the pressurized space as a pressurizing agent, and a valve was attached. The pressure inside the aerosol container at this time (P0) was 0.10 MPa. 150 g (150 mL) of purified water was filled into the inner container from the stem as the concentrate. The pressure inside the aerosol container at this time (P1) was 0.28 MPa. Furthermore, 0.75 g of carbon dioxide gas was filled into the inner container from the stem as a foaming agent, and dissolved in the purified water. The pressure at this time (P2) was 0.30 MPa. The amount of foaming agent dissolved was 0.71 g.

[0051] The aerosol products obtained in Example 1 and Comparative Example 1 were evaluated using the following methods to measure the initial discharge test, the pressure after initial discharge, the middle discharge test, the final discharge test, and the pressure after final discharge. The results are shown in Table 1.

[0052] Initial discharge test The obtained aerosol product was immersed in a thermostatic water bath adjusted to 25°C for 30 minutes, and the ejection state was evaluated until the push button attached to the stem was pressed and 50 g of the contents were ejected. (Evaluation criteria) ○: No bubbles were generated and the discharge was smooth. ×: Bubbles were generated and scattered during the process.

[0053] Pressure after initial discharge The pressure inside the aerosol container was measured after 50 g of the contents were discharged (67% of the contents remaining).

[0054] Mid-term discharge test After the initial ejection, the aerosol product was left to stand for one day, and the ejection state was evaluated until the push button was pressed and 50 g of the contents were ejected.

[0055] Final discharge test The aerosol product after mid-term ejection was left to stand for one day, and the ejection state was evaluated when the push button was pressed and the contents could no longer be ejected (0% of the contents remaining).

[0056] Pressure after final discharge The pressure inside the aerosol container after the entire content was discharged was measured.

[0057] FIG. 3 shows the pressure when the remaining amount of the contents was 100%, 67%, and 0% in Example 1 and Comparative Example 1.

[0058] [Table 1]

[0059] As shown in Figure 3 and Table 1, the aerosol product of Example 1 of the present invention had a foaming agent filling amount equal to the saturated dissolution amount at 0.30 MPa and P0 set to 0.37 MPa, so there were no bubbles until the entire content was discharged, resulting in a stable discharge state. On the other hand, the aerosol product of Comparative Example 1 had the same foaming agent filling amount as Example 1, but P0 set to 0.10 MPa, so after the initial discharge, the product was left standing for one day, and bubbles formed inside the internal container, causing splashing during discharge.

[0060] 2. Setting the amount of foam filling using whipped cream and nitrous oxide An aluminum outer container (full capacity 330 mL) was filled with 150 g (151.7 mL) of commercially available whipped cream (Megmilk Snow Brand Co., Ltd.) as the concentrate, and a valve was attached. Nitrous oxide was then poured into the container through the stem, and the saturated solution amount was calculated when the equilibrium pressure inside the aerosol container reached 0.30 MPa at 25°C. The saturated solution amount of nitrous oxide was found to be 1.35 g per 150 g of concentrate.

[0061] Example 2 An inner container equipped with a gas barrier layer (aluminum foil) was placed inside an aluminum outer container (full capacity 330 mL), and nitrogen was filled into the pressurized space as a pressurizing agent, and a valve was attached. The pressure inside the aerosol container at this time (P0) was 0.36 MPa (pressurizing agent filling process). 150 g (151.7 mL) of whipped cream was filled into the inner container from the stem as the concentrate. The pressure inside the aerosol container at this time (P1) was 0.75 MPa. Furthermore, 1.35 g of nitrous oxide was filled into the inner container from the stem as a foaming agent (content filling process) and dissolved in the concentrate (dissolving process). The pressure at this time (P2) was 0.75 MPa. The amount of foaming agent dissolved was 1.34 g.

[0062] (Comparative Example 2) An inner container equipped with a gas barrier layer (aluminum foil) was placed inside an aluminum outer container (full capacity 330 mL), and nitrogen was filled into the pressurized space as a pressurizing agent, and a valve was attached. The pressure inside the aerosol container at this time (P0) was 0.11 MPa. 150 g (151.7 mL) of whipped cream was filled into the inner container from the stem as the concentrate. The pressure inside the aerosol container at this time (P1) was 0.28 MPa. Furthermore, 1.35 g of nitrous oxide was filled into the inner container from the stem as a foaming agent, and dissolved in the concentrate. The pressure at this time (P2) was 0.30 MPa. The amount of foaming agent dissolved was 1.30 g.

[0063] The aerosol products obtained in Example 2 and Comparative Example 2 were evaluated using the same evaluation methods as above for the initial discharge test, the pressure after initial discharge, the middle discharge test, the final discharge test, and the pressure after final discharge. The results are shown in Table 2.

[0064] [Table 2]

[0065] As shown in Table 2, the aerosol product of Example 2 had a foaming agent filling amount equal to the saturated dissolution amount at 0.3 MPa and P0 set to 0.36 MPa, so there were no bubbles until the entire content was discharged, resulting in a stable discharge state. On the other hand, the aerosol product of Comparative Example 2 had the same foaming agent filling amount as Example 2, but P0 set to 0.11 MPa, so that after leaving it for one day after the initial discharge, air bubbles formed inside the internal container, causing splashing due to the bubbles during discharge. [Explanation of symbols]

[0066] 1. Aerosol products 2. Outer container 21 Bottom 22 Torso 23 Shoulder 24 Bead section 3. Inner container 31 Joint 32 pouches 4 valves 41 Housing 42 Mounting Cup 42a Housing holding part 43 Stem 44 Stem Rubber 45 Spring 46 Stem hole 47 Stem passage 5 Dip Tubes C stock solution G. Pressurizing agent P1 through hole S1 pressurized space

Claims

1. an aerosol container comprising an outer container, an inner container housed in the outer container, and a valve attached to the outer container for switching between a communication state and a cut-off state between the inside and outside of the inner container; A concentrate and a foaming agent to be filled in the inner container; a pressurizing agent filled in a pressurized space between the outer container and the inner container, The inner container has gas barrier properties, An aerosol product in which the amount of the foaming agent dissolved in the concentrate (D) at 25°C is less than the saturated amount of the foaming agent dissolved in the concentrate (D0) at a pressure (P0) when the concentrate and the foaming agent are not filled in the inner container and only the pressurizing agent is filled in the pressurized space.

2. 2. The aerosol product according to claim 1, wherein the foaming agent includes at least one of carbon dioxide gas, nitrous oxide gas, and nitrogen gas.

3. The aerosol product according to claim 1 or 2, wherein the pressure (P0) is 0.2 to 0.5 MPa.

4. An aerosol container is used, which comprises an outer container, an inner container housed in the outer container and having gas barrier properties, and a valve attached to the outer container for switching between a communication state and a cut-off state between the inside and outside of the inner container. a pressurizing agent filling step of filling a pressurizing agent into a pressurized space between the outer container and the inner container so that the pressure in the pressurized space at 25°C becomes a pressure (P0); a content filling step of filling the inner container with a concentrate and a foaming agent; a dissolving step of dissolving the foaming agent in the stock solution, In the dissolving step, the foaming agent is dissolved in the concentrate so that the amount of the foaming agent dissolved in the concentrate (D) is less than the saturated amount of the foaming agent dissolved in the concentrate (D0) at the pressure (P0).

5. An aerosol container is used, which comprises an outer container, an inner container housed in the outer container and having gas barrier properties, and a valve attached to the outer container for switching between a communication state and a cut-off state between the inside and outside of the inner container. a pressurizing agent filling step of filling a pressurizing agent into a pressurized space between the outer container and the inner container so that the pressure in the pressurized space at 25°C becomes a pressure (P0); a dissolving step of dissolving an air bubble agent in a concentrate in a location separate from the inner container; a content filling step of filling the inner container with the concentrate and the foaming agent prepared at the separate location, In the dissolving step, the foaming agent is dissolved in the concentrate so that the amount of the foaming agent dissolved in the concentrate (D) is less than the saturated amount of the foaming agent dissolved in the concentrate (D0) at the pressure (P0).

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