JP7804438B2 - Performance evaluation method for stationary air fresheners - Google Patents

Description

The present invention relates to a method for evaluating the performance of fragrance ingredients in stationary air fresheners when attached to interior materials.

In recent years, due to factors such as airtight housing and a more Westernized (meat-eating) diet, various unpleasant odors, such as body odor, have become more prevalent in indoor spaces. To eliminate the unpleasant odors and create a more comfortable indoor space, air fresheners containing fragrance ingredients are widely used.

Traditionally, air fresheners are known in various types, including stationary, spray, and aerosol types. Among these, stationary types are widely accepted by consumers because they can be installed to continuously release the air freshener, creating and maintaining a comfortable space.

On the other hand, air fresheners not only have the ability to scent a space with the volatilized fragrance, but also have deodorizing properties that mask unpleasant odors with their fragrance, depending on the type of fragrance used. Therefore, when developing air fresheners, it is necessary to properly evaluate their air freshener and deodorizing properties. In particular, with stationary air fresheners, the volatilized fragrance components not only float around the space, but also adhere to interior materials such as wallpaper, floors, curtains, and sofa fabric, thereby exerting their air freshener and deodorizing properties. Therefore, it is desirable to properly evaluate the air freshener and deodorizing properties exerted by the fragrance components of stationary air fresheners when they are attached to interior materials.

Various methods for evaluating the efficacy of volatile agents such as air fresheners, deodorizers, and deodorants have been reported. For example, the Association of Air Fresheners, Deodorizers, and Deodorants has created "Voluntary Standards for Air Fresheners, Deodorizers, and Deodorants for General Consumers," which stipulate methods for evaluating the efficacy of air fresheners and other such agents. Furthermore, Patent Document 1 proposes a method for evaluating the deodorizing performance of a deodorant that is placed in a bag containing an odor-emitting substance.

However, no evaluation method has been reported to date that can accurately determine the fragrance and deodorizing performance exhibited when fragrance ingredients emitted from stationary air fresheners adhere to interior materials.

Japanese Patent Application Laid-Open No. 2019-205631

The object of the present invention is to provide an evaluation method that can determine the performance of fragrance ingredients in stationary air fresheners when attached to interior materials such as wallpaper, floors, curtains, and sofa fabric.

The inventors conducted extensive research to solve the above-mentioned problems and discovered that the performance of a stationary air freshener's fragrance components when attached to interior materials can be determined by first placing a test piece in an atmosphere in which the fragrance components of a stationary air freshener have been vaporized for a predetermined period of time, thereby creating a test piece with the vaporized fragrance components attached to it, and then placing the test piece with the fragrance components attached to it in an atmosphere filled with a malodor for a predetermined period of time and then evaluating the smell of the test piece. The present invention was completed based on this finding and through further research.

That is, the present invention provides the following aspects.
Item 1. A method for evaluating the performance of a fragrance component of a stationary air freshener when attached to an interior material, comprising:
A first step is to place a test piece in an atmosphere in which a fragrance component of a stationary air freshener has been evaporated, thereby preparing a test piece to which the fragrance component has been attached;
The evaluation method includes a second step of placing the test piece with the fragrance component attached thereto prepared in the first step in an atmosphere filled with a malodor, and a third step of evaluating the odor of the test piece after the second step.
Item 2. The evaluation method according to Item 1, wherein the test piece is a sheet cut from wallpaper.
Item 3. The evaluation method according to Item 1 or 2, wherein the first step is carried out while ventilating the space.
Item 4. The first step is performed in a box-shaped space surrounded by a floor, sides, and a ceiling,
Item 4. The evaluation method according to any one of Items 1 to 3, wherein in the first step, a test piece is placed on at least one of the floor surface, the side surface, and the ceiling surface.
Item 5. The evaluation method according to Item 4, wherein in the first step, test pieces are placed on at least one location on the side surface, at least one location on the bottom surface, and at least one location on the ceiling surface.
Item 6. The first step is carried out in a box-shaped space surrounded by a floor, sides, and a ceiling, and the ceiling is provided with a ventilation device;
The air in the box-shaped space is discharged from the ceiling surface by the ventilation device,
Item 3. The evaluation method according to Item 1 or 2, wherein in the first step, test pieces are placed only on at least one location on the side surface and at least one location on the bottom surface.
Item 7. The evaluation method according to any one of Items 1 to 6, wherein in the third step, a sensory evaluation of the odor is performed on the test piece after the second step.
Item 8. The evaluation method according to Item 7, wherein the odor prevention performance and fragrance performance are determined by evaluating the malodor intensity and pleasantness of the odor in the sensory evaluation.

The evaluation method of the present invention makes it possible to determine the deodorizing and fragrance properties exhibited when fragrance components volatilized from a stationary air freshener adhere to interior materials such as wallpaper. Therefore, the evaluation method of the present invention can be used to easily select air fresheners that combine excellent deodorizing and fragrance properties.

FIG. 1 is a schematic diagram of a box-shaped space used in Test Example 2.

The evaluation method of the present invention is a method for evaluating the performance of fragrance components of a stationary air freshener when attached to an interior material, and is characterized by including a first step of placing a test piece in an atmosphere in which the fragrance components of the stationary air freshener have been vaporized to create a test piece with the fragrance components attached; a second step of placing the test piece with the fragrance components attached created in the first step in an atmosphere filled with a malodor; and a third step of evaluating the odor of the test piece after the second step. The evaluation method of the present invention is described in detail below.

[Evaluation target]
The evaluation method of the present invention is a method for evaluating the performance exhibited when the fragrance component of a stationary air freshener volatilizes and adheres to an interior material.

In the present invention, a "stationary air freshener" refers to an air freshener that is left in a space such as a toilet, room, car, shoe cabinet, or closet and is allowed to evaporate. The stationary air freshener to be evaluated in the present invention may be an air freshener that contains a deodorizing component in addition to a fragrance component. Furthermore, the form of the stationary air freshener to be evaluated in the present invention is not particularly limited, and it may be in any form, such as liquid or gel. Furthermore, in the evaluation method of the present invention, the stationary air freshener to be evaluated may be a known product, or it may be a previously unknown product that is a candidate for development.

The evaluation method of the present invention can evaluate the fragrance performance (ability to impart fragrance) and/or deodorizing performance (ability to mask unpleasant odors) when a stationary air freshener volatilizes and the fragrance components adhere to interior materials. In the present invention, interior materials refer to interior materials used in spaces where stationary air fresheners are installed, and examples include wallpaper, flooring, curtain fabric, sofa fabric, etc.

[Test piece]
In the present invention, a test piece is an object to which the volatilized fragrance component of a stationary air freshener is attached. In the evaluation method of the present invention, the test piece is used as a simulation of an interior material, and the performance of the fragrance component volatilized from the stationary air freshener when attached to the test piece is evaluated.

The test specimen may be any specimen that mimics an interior material, such as a cut sheet of interior material; or a sheet made of the same material as the interior material, such as a textile product, resin sheet, leather sheet, or wooden sheet. If the test specimen is a cut sheet of wallpaper or a sheet made of the same material as wallpaper, the evaluation method of the present invention makes it possible to evaluate the performance of the evaporated fragrance components when they adhere to the wallpaper.

The size of the test piece may be within a range that allows for odor evaluation in the third step described below, and may be, for example, from 10 ^cm to 50 ^cm , preferably from 20 cm ^to 40 ^cm , and more preferably from ²⁵ cm to ³⁶ cm.

[First step]
In the first step, a test piece is placed in a space where the fragrance component of the stationary air freshener has evaporated, to prepare a test piece to which the fragrance component evaporated from the stationary air freshener has adhered.

In the first step, the space used may be any space capable of forming a space in which a test specimen can be placed, and examples thereof include a sealed bag, a container with a lid, a box-shaped space, etc. A box-shaped space is a space surrounded by a floor, sides, and a ceiling. The volume of the space in which the fragrance components of a stationary air freshener are evaporated is not particularly limited, but may be, for example, 5 L or more, preferably 5 L to 5000 L. Specifically, when a sealed bag, a container with a lid, etc. is used to simply form a space in which a test specimen can be placed, the volume of the space is preferably, for example, 6 L to 10 L. In addition, in the case of a box-shaped space, the volume of the space may be, for example, 5 L to 5000 L.

Furthermore, if a box-shaped space is used as the space for volatilizing the fragrance components of a stationary air freshener, and the volume and shape of the box-shaped space are made to be similar to those of the space in which the stationary air freshener to be evaluated is installed, it becomes possible to evaluate the performance of the stationary air freshener under conditions close to those of actual use. For example, when a stationary air freshener to be used in a home toilet is to be evaluated, a box-shaped space having a volume of about 1000 L to 5000 L, preferably about 2000 L to 4000 L, and more preferably about 2500 L to 3000 L, and a bottom area of about 1.0 m ² to 3.0 m ² , preferably about 1.0 m ² to 2.0 m ² , and more preferably about 1.0 m ² to 1.5 m ² may be used.

The space in which the fragrance components of a stationary air freshener are dispersed may also be a space in which a stationary air freshener is actually installed, such as a toilet, living room, closet, shoe cabinet, or car interior.

There are no particular restrictions on where the test specimen is placed within the space, and it can be set appropriately depending on the type of space being used. For example, in the case of a box-shaped space, the performance of the stationary air freshener can be evaluated for each location where the test specimen is placed, so the location of the test specimen can be set depending on the location within the space where the performance of the stationary air freshener is to be evaluated.

In the case of a box-shaped space, the test specimen may be placed in at least one location on the bottom, side, and ceiling, preferably at least one location on the side, more preferably at least one location on the side and at least one location on the bottom and ceiling, and even more preferably at least one location on the side, at least one location on the bottom, and at least one location on the ceiling. For example, in a relatively small living space such as a toilet, odors adhering to the wall surface are easily detected, so by placing the test specimen on at least one location on the side of the box-shaped space, it becomes possible to more appropriately evaluate the performance that will be perceived during actual use in that living space.

To place the test specimen in the space, simply use adhesive or tape to secure it in place. Alternatively, if you are placing the test specimen on the bottom surface, you can simply place the specimen on top.

To place the test specimen in a space where the fragrance components of a stationary air freshener have evaporated, simply place the stationary air freshener in the space where the test specimen is placed, allowing the fragrance components to evaporate. Alternatively, if it is not possible to place a stationary air freshener in the space, you can prepare air in advance from which the fragrance components have evaporated from the stationary air freshener, and then introduce that air into the space where the test specimen is placed.

In the first step, the time for which the test piece is left in the space where the fragrance components of the stationary air freshener have evaporated should be long enough for the evaporated fragrance components to adhere to the test piece, and can be set appropriately depending on the volume of the space used, etc., but examples include a time of approximately 10 hours to 100 hours, preferably approximately 12 hours to 80 hours, and more preferably approximately 12 hours to 72 hours.

The first step may also be carried out while ventilating the space. Living spaces such as toilets and rooms are typically ventilated, so by bringing the test piece into contact with the fragrance components emitted from the stationary air freshener while ventilating the space in the first step, it is possible to evaluate the performance of the stationary air freshener in an environment that more closely resembles an actual usage environment. In the case of a box-shaped space, it is preferable to install a ventilation device on the ceiling surface so that the air in the box-shaped space is exhausted from the ceiling surface by the ventilation device. When the first step is carried out while ventilating the space, the number of ventilations per hour can be, for example, 5 to 20 times, preferably 7.5 to 15 times, and more preferably 8 to 12 times. Here, the number of ventilations per hour refers to the number of times per hour that all of the air in the space is replaced with outside air.

The test specimens thus prepared with the fragrance ingredients attached are then subjected to the second step below.

[Second step]
In the second step, the test piece to which the perfume component prepared in the first step is attached is placed in a space filled with a malodor.

The space in which the first step was performed may be used as the space in which the second step was performed, but it is preferable to remove the test piece from the space used for the first step and perform the second step in a different space from the first step.

The space used in the second step may be any space large enough to accommodate a test piece, such as a sealed bag or a container with a lid, which has a sealed interior. There are no particular restrictions on the volume of the space used in the second step, but examples include a volume of approximately 5 L or more, preferably 5 L to 15 L, and more preferably 7.5 L to 12 L.

To place the test specimen in the space, the test specimen may be placed in the space, or it may be fixed in the space using adhesive or adhesive tape, etc.

To place a test piece in a space filled with a malodorous substance, the malodorous component is introduced into the space where the test piece is placed. The type of malodorous component introduced is preferably one that may be present in the space where the performance of a stationary air freshener is being evaluated. Specific examples include trimethylamine, triethylamine, methyl mercaptan, hydrogen sulfide, methyl sulfide, acetaldehyde, butyric acid, isovaleric acid, and acetic acid. The amount of malodorous component introduced into the space may be set so that the malodorous component concentration in the space is approximately 0.001 ppm to 100 ppm, preferably approximately 0.1 ppm to 100 ppm, and more preferably approximately 1 ppm to 10 ppm. Before introducing the malodorous component into the space where the test piece is placed, it is desirable to replace the air in the space with odorless air.

In the second step, the time for which the test specimen is placed in the space filled with the malodor can be set appropriately taking into consideration the type and amount of malodor components being introduced, but can be, for example, from 1 hour to 12 hours, preferably from 1 hour to 6 hours, and more preferably from 1 hour to 3 hours.

The test strips thus contacted with the malodor are then subjected to the third step below.

[Third step]
In the third step, the test piece after the second step is removed and its odor is evaluated.

Odor evaluation may be performed by measuring the level of malodor on the test piece using a measuring device such as an odor sensor, but it is preferable to conduct a sensory evaluation of the odor of the test piece to analyze in detail the actual odor perceived.

For example, the sensory evaluation may use at least one of malodor intensity and scent pleasantness as evaluation items. Malodor intensity may be evaluated by assessing the level of malodor perceived from the test piece, and the deodorizing performance of the stationary air freshener being evaluated can be determined based on the evaluation results. Scent pleasantness may be evaluated by assessing the overall scent pleasantness perceived from the test piece, and the scent performance of the stationary air freshener being evaluated can be determined based on the evaluation results. Sensory evaluation is preferably conducted by multiple people trained in scent testing, and the evaluation results are preferably scored for each evaluation item. For example, malodor intensity can be scored according to the Odor Intensity Rating Method, and scent pleasantness can be scored according to the Pleasant/Unpleasant Rating Method.

Furthermore, it is preferable to prepare a test piece that has undergone only the second step as a control and compare the odor evaluation in the third step with this control.

Based on the results of the odor evaluation in the third step, the performance of the fragrance components emitted from the stationary air freshener when they adhere to interior materials can be determined. For example, the higher the degree to which the test piece suppresses the malodor, the more excellent the stationary air freshener being evaluated is judged to be able to exhibit odor-preventing performance, and the more pleasant the odor of the test piece, the more excellent the fragrance performance of the stationary air freshener being evaluated is judged to be.

The present invention will be explained below using examples, but the present invention is not limited to these examples.

Test Example 1
Four types of liquid stationary air fresheners A to D with different ingredients were prepared, and the performance of the air fresheners attached to wallpaper was evaluated using the following method. Stationary air fresheners A and C have the same scent. Stationary air freshener A contains more fragrance components to enhance deodorizing performance than stationary air freshener C. Stationary air fresheners B and D have the same scent. Stationary air freshener B contains more fragrance components to enhance deodorizing performance than stationary air freshener D.

Wallpaper (stick-on wallpaper <br/remoisturizing type> option: pattern: SW-34 Frisch, manufactured by Asahipen Co., Ltd.) was cut into a 5cm x 5cm square to serve as the test specimen. The test specimen was attached with masking tape to the inside of a 6L bag, with the wallpaper surface facing outward. Each stationary air freshener was placed in a 10L airbag with a tap (manufactured by GL Sciences) in a state that allowed it to evaporate, and the bag was sealed and evacuated. Next, 5L of odorless air that had been filtered through activated carbon was filled into the 10L airbag with a tap and left to stand for one hour to prepare air in which the fragrance components of the stationary air freshener had volatilized. Next, the entire amount of air from which the fragrance components of the stationary air freshener had volatilized was introduced into the bag with the test specimen attached inside, and the bag was sealed and left to stand for one hour to create a test specimen with the fragrance components attached.

Next, the test piece with the fragrance attached was removed from the bag and attached with masking tape to the inside of a new 10L airbag with a tap, with the wallpaper facing outwards. The 10L airbag with a tap was then sealed and evacuated, after which 5L of odorless air that had been filtered through activated carbon was filled in. Triethylamine was then introduced into the airbag to bring the triethylamine concentration inside to 1000 ppm, and the airbag was left to stand in a sealed state for 1 hour. As a control, a test piece with no fragrance attached was also left to stand in the triethylamine space under the same conditions.

The test specimens were then removed from the airbags and subjected to a sensory evaluation of the odor intensity and the pleasantness/unpleasantness of the odor using a six-level odor intensity rating system and a pleasantness/unpleasantness rating system ranging from -2.0 to +2.0. The sensory evaluation was performed by eight trained panelists, and the average score was calculated for each evaluation item. The evaluation criteria for the six-level odor intensity rating system and pleasantness/unpleasantness rating system are shown below.
<6-level odor intensity rating method (bad odor intensity evaluation criteria)>
0: Odorless 1: Barely detectable odor (detection threshold)
2: A weak smell that can be identified (recognition threshold)
3: Easily detectable odor 4: Strong odor 5: Intense odor <Pleasure/Discomfort Degree Indication Method (Evaluation Criteria for Pleasure/Discomfort)>
+2: Comfortable +1: Slightly comfortable 0: Neither comfortable nor uncomfortable -1: Slightly uncomfortable -2: Uncomfortable

The results are shown in Table 1. Comparing the results of stationary air freshener A and stationary air freshener C, which have the same scent, the score improvement value of stationary air freshener A was greater. Comparing the results of stationary air freshener B and stationary air freshener D, which have the same scent, the score improvement value of stationary air freshener B was greater. These results confirm that the evaluation method of the present invention can be used to evaluate the deodorizing performance of the fragrance components of a stationary air freshener when attached to wallpaper.

The score improvement is the difference between the control score and the score for each stationary fragrance.

Test Example 2
The liquid stationary air fresheners A to D used in Test Example 1 were prepared, and the performance of the air fresheners attached to wallpaper was evaluated by the following method.

Wallpaper (sticker-type wallpaper <br/remoisturizing type> option: pattern: SW-34 Frisch, manufactured by Asahipen Co., Ltd.) was cut into a 5 cm x 5 cm square to serve as the test piece.

A box-shaped space (bottom: 90 cm x 130 cm square, height: 220 cm) with a bottom, sides, and ceiling was prepared. A schematic diagram of the box-shaped space is shown in Figure 1. Although not shown in Figure 1, the box-shaped space has a door on the front side and a ventilation system installed on the ceiling. The door is a single-leaf door. The door's support (hinge) is on the right side when viewed from the outside of the box-shaped space. Outside air flows into the box-shaped space through the gap in the door and is exhausted from the ceiling by the ventilation system. Test specimens were attached with masking tape to five locations within the box-shaped space: one location on the bottom, three locations on the sides, and one location on the ceiling, with the wallpaper facing outward. Details of the locations where the test specimens were attached are shown in Table 2.

Ventilation conditions within the box-shaped space were adjusted to a wind speed of 0.36 m/s (ventilation rate 9 times/hour), and the temperature and humidity within the box-shaped space were maintained at 22.5°C and 40% RH, respectively. Each stationary air freshener was left overnight on a shelf within the box-shaped space in a state where it could volatilize, creating test specimens with the fragrance components of the stationary air fresheners adhered to them. Note that the door to the box-shaped space was kept closed when the stationary air fresheners were left overnight.

Next, the test piece with the fragrance component attached was removed from the box-shaped space and attached with masking tape to the inside of a 10L airbag with a tap, with the wallpaper surface facing outwards. The 10L airbag with a tap was then sealed and evacuated, after which 5L of odorless air that had been filtered through activated carbon was filled in. Triethylamine was then introduced into the airbag to bring the triethylamine concentration inside to 1000 ppm, and the airbag was left to stand in a sealed state for 1 hour. As a control, a test piece with no fragrance component attached was also left in the triethylamine space under the same conditions. The control was a test piece to which triethylamine had been attached without undergoing the process of attaching fragrance components from a stationary air freshener in the box-shaped space.

The test specimens were then removed from the airbags and subjected to a sensory evaluation of the odor intensity and the pleasantness/unpleasantness of the odor using a six-level odor intensity rating system and a pleasantness/unpleasantness rating system ranging from -2.0 to +2.0. The sensory evaluation was performed by eight trained individuals, and an average score was calculated for each evaluation item. The evaluation criteria for the six-level odor intensity rating system and pleasantness/unpleasantness rating system were the same as those in Test Example 1.

The results are shown in Table 3. Comparing the results of stationary air freshener A and stationary air freshener C, both of which have the same fragrance, the improvement in the score for stationary air freshener A was greater. Comparing the results of stationary air freshener B and stationary air freshener D, both of which have the same fragrance, the improvement in the score for stationary air freshener B was greater. These results also confirm that the evaluation method of the present invention can be used to evaluate the deodorizing performance of the fragrance components of a stationary air freshener when attached to wallpaper. In particular, these results confirm that by using a box-shaped space similar in shape to a household toilet and attaching the fragrance components of a stationary air freshener to wallpaper, it is possible to evaluate the deodorizing and fragrance performance of the fragrance components attached to each location in the box-shaped space. As shown in Table 2, by placing test specimens on multiple surfaces within the box-shaped space, it was confirmed that the fragrance components of the stationary air freshener were evenly attached to each surface of the ventilated space. For this reason, it is desirable to place test specimens in at least one location on the side, at least one location on the bottom, and at least one location on the ceiling. Furthermore, the results shown in Table 3 show that the improvement in scores for the bottom and side surfaces tends to be lower than the improvement in scores for the top surface. As long as test pieces are placed on at least the bottom and side surfaces, it is possible to evaluate the deodorizing performance of the fragrance ingredients in a stationary air freshener. Therefore, by placing test pieces in at least one location on the side surface and at least one location on the bottom surface, the evaluation test can be completed in a shorter time without reducing evaluation accuracy.

The score improvement is the difference between the control score and the score for each stationary fragrance.

Claims (8)

A method for evaluating the performance of a fragrance component of a stationary air freshener when attached to an interior material, comprising:
A first step is to place a test piece in an atmosphere in which a fragrance component of a stationary air freshener has been evaporated, thereby preparing a test piece to which the fragrance component has been attached;
The evaluation method includes a second step of placing the test piece with the fragrance component attached thereto prepared in the first step in an atmosphere filled with a malodor, and a third step of evaluating the odor of the test piece after the second step. The evaluation method described in claim 1, wherein the test piece is a cut sheet of wallpaper. The evaluation method described in claim 1 or 2, wherein the first step is performed while ventilating the space. The first step is carried out in a box-shaped space surrounded by a bottom surface , a side surface, and a ceiling surface,
4. The evaluation method according to claim 1, wherein in the first step, a test piece is placed on at least one of the bottom surface , the side surface, and the ceiling surface. The evaluation method described in claim 4, wherein in the first step, test pieces are placed on at least one location on the side surface, at least one location on the bottom surface, and at least one location on the ceiling surface. the first step is carried out in a box-shaped space surrounded by a bottom surface , a side surface, and a ceiling surface, and the ceiling surface is provided with a ventilation device;
The air in the box-shaped space is discharged from the ceiling surface by the ventilation device,
The evaluation method according to claim 1 or 2, wherein in the first step, test pieces are placed only on at least one location on the side surface and at least one location on the bottom surface. The evaluation method described in any one of claims 1 to 6, wherein in the third step, a sensory evaluation of the odor of the test piece after the second step is performed. The evaluation method according to claim 7, wherein the odor prevention performance and the fragrance performance are determined by evaluating the malodor intensity and the pleasantness of the smell in the sensory evaluation.