JP2023003104A - Nursing-care tool including cushion - Google Patents

Abstract

To provide a nursing-care tool including a cushion that has a high level of softness but prevents its bottom from coming into contact with the floor due to excessive softness, also has proper repulsion to assist in a user's movements, and further has high chemical resistance.SOLUTION: The present invention provides a nursing-care tool including a cushion composed of a resin foam. The cushion has such a property that a compression load F10 (N) necessary for compressing by 10 mm a test piece of the cushion of 30 cm wide, 25 cm long and 20 mm thick at a temperature of 23°C, with a 30 mmφ columnar compressor and at a compression rate of 15 mm/sec is, preferably, 50 N or more and 250 N or less, and more preferably, 90 N or more and 150 N or less.SELECTED DRAWING: None

Description

The present invention relates to a nursing care tool with a cushion, which is particularly suitable for dispersing the user's load due to its high degree of flexibility, but does not bottom out due to being too soft, has an appropriate resilience and high chemical resistance. The present invention relates to nursing care equipment such as bathroom and bathtub chairs and bathtub handrails, which are equipped with cushions made of resin foam having high durability and weather resistance.

With the advent of the aging society, in order to assist the posture and movement of the elderly and physically handicapped, for example, Japanese Patent Application Laid-Open No. 2007-61509 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2018-15418 (Patent Document 2) ), a chair for a bathroom or a bathtub with cushions attached to the surface of the seat, backrest and / or armrests, and Japanese Patent Application Laid-Open No. 2019-180676 (Patent Document 3). Nursing care tools such as handrails for bathtubs are known, in which cushions are attached to the grips of the handrails so that the user feels like they are there. In addition, unlike the material of the body portion that forms the main frame of the chair or handrail, generally, the material of the cushion is a flexible and water-resistant foamed resin.

By the way, the purpose of attaching a cushion to a nursing care tool is to improve the comfort when the user sits on the nursing care tool, and the ease of gripping when holding the care tool with the palm to support one's own weight. For this reason, cushions used in nursing care devices are required to have high flexibility and low repulsive force in order to disperse the load such as body weight imposed by the user and support the user with low pressure, as with general cushions.

However, on the other hand, if the cushion used in nursing care equipment is too soft or has too low a repulsive force, the load such as the user's weight will reduce the hardness of the hard member placed underneath to support the cushion. It can sink and compress until you feel it, giving the user a feeling of bottoming out. In this case, the part of the body that feels the bottom is often locally high pressure, and the user of the care device may have thin muscles such as the buttocks and subcutaneous fat, so skin and bones may be affected. There is a problem that damage such as abrasions, internal bleeding, and bruises is given.

In addition, many people who use nursing care equipment have weakened muscles and weak legs. Another problem is that the repulsive force of the cushion cannot be used to assist the movement of the user.

On the other hand, it is conceivable to increase the thickness of the cushion in order to prevent the user from feeling the feeling of bottoming out. Therefore, it was required to be able to be folded and stored compactly so that it would not get in the way when not in use for a long period of time, and there was a constraint that the thickness of the cushion could not be too thick.

In addition, some nursing care equipment is used in environments of medium temperature and high humidity, such as in bathrooms and bathtubs. The cushions used in nursing care equipment are frequently disinfected with chemicals such as sodium chlorite and alcohol, and detergents such as soap, and are dried in the sun after washing, resulting in high chemical resistance and high durability. , and high weather resistance (light resistance) and high heat resistance were also required.

To address the above-mentioned problems, for example, Japanese Patent Application Laid-Open No. 2004-323603 (Patent Document 4) discloses a technique of using a gel-like low-resilience material for cushions and floor cushions, and Japanese Patent Application Laid-Open No. 2009-091541. A publication (Patent Document 5) discloses a technique of using a cushion made of a low-resilience material for a nursing care tool. Further, Japanese Patent Laying-Open No. 2012-10921 (Patent Document 6) discloses a cushion that alleviates the force of displacement of the user when seated by laminating at least two layers of cushions made of different foams.

However, all of the cushions described in Patent Documents 4, 5, and 6 are designed to disperse the load applied by the user under the design constraint that the thinner the thickness of the cushion, the better, as described above. While having sufficient flexibility to be used, it does not bottom out, has a high repulsive force that assists the user's movement when standing up, and has high chemical resistance. However, it did not solve the unique problem required for nursing care equipment. Moreover, the cushion described in Patent Document 6 has a problem that the manufacturing process is complicated and the cost is high because at least two layers of cushions made of different foams must be laminated.

Japanese Patent Application Laid-Open No. 2007-61509 JP 2018-15418 A JP 2019-180676 A Japanese Patent Application Laid-Open No. 2004-323603 JP 2009-091541 A JP 2012-10921 A

Therefore, the present invention is suitable for dispersing the load applied by the user due to its high degree of flexibility, but it does not bottom out due to being too soft and has an appropriate repulsive force to allow the user to move freely. To provide a nursing care tool equipped with a cushion capable of assisting and having high chemical resistance and high weather resistance.

The present inventors have conducted intensive research on the materials used for the cushions of nursing care equipment, the configuration of the cushions, and the characteristics of the cushions. The inventors have found that a cushion that satisfies predetermined conditions required by using a compressive load and/or a recovery load can solve the above problems, and have completed the present invention.

That is, according to the present invention, there is provided a nursing care tool having a cushion made of a resin foam, and the properties of the cushion are determined by measuring a test piece of the cushion with a width of 30 cm, a length of 25 cm, and a thickness of 20 mm at a temperature of 23°C and a diameter of 30 mm. The compression load F ₁₀ (N) required to compress 10 mm at a compression speed of 15 mm/sec using a cylindrical compressor is preferably 50 N or more and 250 N or less, more preferably 90 N or more and 150 N or less, most preferably 100 N or more and 140 N. A care device is provided which is:

In the nursing care tool of the present invention, the characteristics of the cushion are further improved by compressing the above-mentioned test piece by 10 mm at a compression rate of 15 mm / sec at a temperature of 23 ° C. using the above-mentioned compressor, and then immediately recovering at a recovery rate of 15 mm / sec. The hysteresis loss ratio in the compression-recovery cycle is preferably 40% or less, more preferably 30% or less.

Since the nursing care device of the present invention has the above-described characteristics of the compression load _F10 and hysteresis loss rate of the cushion, even when the cushion is composed of a single layer, it can disperse the load applied by the user such as body weight. It is possible to secure suitable flexibility, yet not make the user feel bottoming out due to being too soft, and it is possible to assist the user's movement by having an appropriate repulsive force.

In the nursing care tool of the present invention, the characteristics of the cushion were further evaluated by compressing a cushion test piece of width 30 cm × length 25 cm × thickness 20 mm before the accelerated deterioration test at a temperature of 23 ° C. using a cylindrical compressor of 30 mmφ. A pre-test compression cycle in which 10 mm is compressed at 15 mm / sec, and a post-test compression cycle in which the test piece after the following accelerated deterioration test is compressed at a temperature of 23 ° C. and 10 mm at a compression rate of 15 mm / sec using the compresser. The ratio (Fc/Fa) of the compression load Fa (N) before the test and the compression load Fc (N) after the test in the amount of deformation is preferably 0.9 or more and 1.4 or less, more preferably 0.9 or more and 1. It should be 1 or less.
[Deterioration acceleration test conditions]
Sodium hypochlorite-based detergent was applied to the entire surface of a cushion test piece of width 30 cm x length 25 cm x thickness 20 mm, wrapped in a resin sheet, and kept at constant temperature and humidity at 23°C and 50% RH for 7 hours. The step of leaving and the step of leaving the exposed test piece under constant temperature and humidity of 60° C. and humidity of 98% RH for 16 hours are repeated for 5 cycles. Next, after irradiating the test piece with ultraviolet light for 5 hours under the conditions of an illuminance of 70 mW, a temperature of 63° C. and a humidity of 50% RH, the test piece is left at a constant temperature and humidity of 23° C. and a humidity of 50% RH for 24 hours or more. to stabilize the temperature of the specimen.

In the nursing care device of the present invention, since the cushion has the compressive load _F10 and the hysteresis loss rate as described above, the ratio of the compressive load of the cushion before and after the accelerated deterioration test (compressive load after test / compressive load before test) Fa) also shows a value of 0.9 or more and 1.4 or less, and can have extremely high chemical resistance and weather resistance.

In addition, in the nursing care tool of the present invention, when requesting load dispersion due to higher flexibility, higher prevention of bottoming, assistance of user's movement due to higher repulsive force, and higher chemical resistance, The thickness of the cushion is preferably 5 mm or more and 100 mm or less, more preferably 7 mm or more and 50 mm or less, from the viewpoint of compact storage when not in use. Also, the resin material forming the foam is not particularly limited, but from the viewpoint of water resistance, chemical resistance, etc., it is particularly preferable to use an olefin resin.

According to the present invention, there is provided a nursing care tool comprising a cushion made of a resin foam, and the characteristics of the cushion are determined by measuring a test piece of the cushion with a width of 30 cm, a length of 25 cm, and a thickness of 20 mm at a temperature of 23°C and a cylindrical shape of 30 mmφ. The compression load F ₁₀ (N) required to compress 10 mm at a compression speed of 15 mm / sec using a compressor is preferably 50 N or more and 250 N or less, more preferably 90 N or more and 150 N or less, most preferably 100 N or more and 140 N or less. An assistive device is provided.

According to the nursing care tool of the present invention, the cushion has flexibility suitable for dispersing the load imposed by the user such as body weight. To improve the easiness of grasping and the like when supporting one's own weight by grasping with the palm.

In addition, according to the nursing care tool of the present invention, since the cushion is prevented from sticking to the bottom due to being too soft, it is suitable for elderly people, physically handicapped people, people requiring nursing care, etc. who have thin muscles such as buttocks and subcutaneous fat. Even the user does not apply high pressure to the bottomed body part to cause damage such as abrasion, internal bleeding, and bruises to the skin and bones. Furthermore, according to the nursing care tool of the present invention, since the cushion has an appropriate repulsive force, even a user with weakened legs due to weakened muscle strength can use it when moving from a sitting position to a standing position. , the repulsive force of the cushion can be used to assist the user's movement.

According to the nursing care tool of the present invention, the cushion has a compression load ratio (compression load Fc after test/compression load Fa before test) at the same compression amount before and after the accelerated deterioration test, which is close to 1.0. Almost no progress of deterioration is seen in accelerated tests, and it has extremely high chemical resistance, high durability, and high weather resistance against disinfection with chemicals such as sodium hypochlorite and alcohol, and washing with detergents such as soap. .

FIG. 4 is an explanatory diagram schematically showing hysteresis in the relationship between the amount of compression of a foam cushion and the load.

BEST MODE FOR CARRYING OUT THE INVENTION A nursing care tool according to an embodiment of the present invention will be described in detail below with reference to the drawings. The present invention is not limited to the embodiments shown below, and various modifications are possible without departing from the technical idea of the present invention.

The care tool of this embodiment includes a cushion made of resin foam. Nursing care equipment suitable for the present invention includes, for example, a chair for a bathroom and a bathtub shown in Patent Documents 1 and 2, a handrail for a bathtub shown in Patent Document 3, a bathtub stand, a bath board, a portable toilet, and a walking chair. Auxiliary vehicles and the like are included.

The environment in which the nursing care tool of the present embodiment is used is mainly for elderly people, people with physical disabilities, people who need nursing care, etc., who have thin muscles such as buttocks and subcutaneous fat, or those who have weakened muscles and legs. It is assumed that it will be used by weak people. In addition, it is assumed that nursing care equipment will be used not only in normal indoor/outdoor environments, but also in medium-temperature and high-humidity environments such as bathrooms and bathtubs. Furthermore, since nursing care equipment is usually not used for a long period of time, it is required that it be compact or that it can be made compact by folding. It is assumed that they will be disinfected immediately with chemicals such as sodium hypochlorite and alcohol, and detergents such as soap.

<Resin component of foam>
The cushion used for the care tool of this embodiment is formed from a resin foam. Resin materials for the foam that are preferably used in this embodiment include, for example, olefin resins, ethylene-α-olefin copolymers, ethylene-vinyl acetate copolymers, ethylene-acrylic acid ester copolymers, ethylene-acryl Polyethylene resins such as acid copolymers or ethylene-vinyl alcohol copolymers, polypropylene resins such as propylene-α-olefin copolymers, polyurethane resins other than olefin resins, polyester resins, polyvinyl chloride resins, Examples include polystyrene resins, silicone resins, acrylic resins, cellulose acetate resins, thermoplastic elastomer resins, rubber resins, and the like.

Among these resin materials, it is preferable to use an olefin resin from the viewpoint of water resistance, strength, sanitation, slip resistance, and the like. From the viewpoint of chemical resistance, it is possible to use polyethylene resins such as ethylene-α-olefin copolymers, ethylene-vinyl acetate copolymers, ethylene-acrylic acid ester copolymers, and ethylene-acrylic acid copolymers. preferable. From the viewpoint of weather resistance, it is preferable to use a polyethylene resin such as an ethylene-vinyl acetate copolymer, an ethylene-acrylic acid ester copolymer, or an ethylene-acrylic acid copolymer. From the viewpoint of flexibility, it is preferable to use a polyethylene resin such as an ethylene-vinyl acetate copolymer, an ethylene-acrylic acid ester copolymer, or an ethylene-acrylic acid copolymer. From the viewpoint of minimizing changes in hardness due to ambient temperature, it is preferable to use a polyethylene-based resin such as an ethylene-vinyl acetate copolymer. Moreover, the above-mentioned olefin-based resins and polyethylene-based resins may be used alone or in combination of two or more thereof.

The foamed resin material used for the cushion of this embodiment needs to have appropriate hardness and heat resistance to withstand hot water of 40 to 50° C. after forming the foamed body. For example, if the hardness of the resin material itself is too hard, the obtained resin foam will be so hard that it loses appropriate flexibility. On the other hand, if the hardness of the resin material itself is too soft and the heat resistance to hot water is too low, the resulting resin foam will shrink when used in a bathroom or bathtub. This is because there arises a problem that the hardness becomes hard.

Therefore, for example, when ethylene-vinyl acetate resin is used as the resin for foaming forming the cushion of the present embodiment, the content of vinyl acetate relative to the ethylene-vinyl acetate resin is 3 to 50 from the viewpoint of flexibility and heat resistance. % by mass, more preferably 5 to 40% by mass, even more preferably 7 to 35% by mass, and most preferably 10 to 30% by mass.

The ethylene-vinyl acetate resin changes its hardness and melting point (heat resistance) depending on the content of vinyl acetate. Specifically, the higher the vinyl acetate content in the ethylene-vinyl acetate resin, the higher the flexibility and the lower the melting point. The vinyl acetate content in the ethylene-vinyl acetate resin can be measured by a method according to JIS K7192:1999.

In addition, when ethylene-vinyl acetate resin is used as the foaming resin for forming the cushion, the melt flow rate, which is an index of the molecular weight of the ethylene-vinyl acetate resin, is 0.1 to 30 (g / 10 min), more preferably 0.5 to 20 (g / 10 min), more preferably 1 to 10 (g / 10 min), 1.5 to 5 ( g/10 min) is most preferred.

The melt flow rate indicates the fluidity (viscosity) of a resin heated and melted up to the molding temperature. Since the lower the melt flow rate value, the higher the viscosity, the ethylene-vinyl acetate resin with a low melt flow rate value is judged to be an ethylene-vinyl acetate resin with a high molecular weight.

In foam molding, if the melt flow rate is too high, that is, if the viscosity of the melted resin is too low, bubbles will escape during foaming, making it impossible to obtain a desired expansion ratio. On the other hand, if the melt flow rate is too low, that is, if the viscosity of the molten resin is too high, the growth of cells during foaming will be insufficient, and the desired expansion ratio cannot be obtained. For this reason, the use of ethylene-vinyl acetate resin adjusted to an appropriate melt flow rate range has a significant effect on the flexibility of the resulting resin foam, and is an important factor to consider in foam molding. . The melt flow rate of ethylene-vinyl acetate resin can be measured according to JIS K7210 under conditions of a temperature of 190° C. and a load of 21.18 N.

<Other Components of Foam Resin>
The resin material of the foam forming the cushion of the present embodiment may contain softening agents, fillers, antioxidants, release agents, weather resistance imparting agents, flame retardants, lubricants, antibacterial agents, and antifungal agents, if necessary. , an antiviral agent, a foaming accelerator, and the like can be blended. A cross-linking reaction may be used for molding the resin foam, and in that case, a cross-linking agent such as a peroxide-based cross-linking agent or a sulfur-based cross-linking agent may be blended.

<Method for producing foam>
There is no particular limitation on the molding method of the resin foam that constitutes the cushion of the present embodiment, and a bead foam molding method, a batch foam molding method, a press foam molding method, a normal pressure secondary foam molding method, an injection foam molding method, and an extrusion foam molding method. A widely known foam molding method such as a molding method and a foam blow molding method can be used.

<Structure of foam>
As the structure of the resin foam constituting the cushion of this embodiment, there is no particular limitation on the form of the cells of the resin foam, and any form such as closed cells, open cells, or mixed cells thereof may be adopted as necessary. be able to. However, since the cushion used in this embodiment needs to have a moderate repulsive force that can assist the user's movement while having high flexibility, the resin foam cells that constitute the cushion are mainly composed of closed cells. It is preferable that

Also, the cells in the resin foam may differ in cell size, cell shape, cell density, etc. depending on the thickness direction of the cushion, that is, the surface layer and the intermediate layer. Since the cushion used in this embodiment needs to have a moderate repulsive force while having high flexibility as described above, it is preferable that the size of the cells in the surface layer is smaller and denser than in the intermediate layer. .

The foaming ratio of the resin foam constituting the cushion of the present embodiment is _{a value (ρ 0 /} ρ ₁ ). The flexibility of the resin foam has a correlation with the expansion ratio, and the higher the expansion ratio, the softer the resin foam. Since the cushion used in this embodiment requires high flexibility and moderate resilience, the expansion ratio of the resin foam is preferably 5 times or more and 50 times or less, and 7 times or more and 30 times or less. more preferably 9 times or more and 25 times or less, and most preferably 10 times or more and 20 times or less.

<Cushion shape, etc.>
The cushion of the present embodiment, which is made of the resin foam as described above, is not particularly limited in shape, and can be in any shape, such as a flat plate shape or an uneven shape corresponding to the shape of the buttocks, depending on the care tool to which the cushion is attached. can be adopted. In addition, the surface portion of the cushion may be textured from the viewpoint of improving drainage and preventing slipping. In addition, the cushioning material using the resin foam may be covered with another cover material from the viewpoint of improving the design and sanitation. Furthermore, there is no particular limitation on the fixing method for attaching the cushioning material to the care tool, and a known fixing method such as a fixing method combining a convex portion and a concave portion that fits therewith can be used.

A. Influence of properties of each foam on sitting comfort, etc. 1. Formation of foam The resin composition for foaming of foams 1 to 8 constituting the cushion according to one embodiment of the present invention was produced using the following raw materials under the following conditions and with the formulation shown in Table 1 below. .
<Production of Foaming Resin Composition>
The foaming resin composition for forming foams 1 to 8 includes (a) a foaming resin, (b) a foaming agent, (c) a foaming aid, (d) a cross-linking agent, and (e) a stabilizer shown below. The agents were blended at the compounding ratio shown in Table 1, and kneaded at 85° C. for 15 minutes in a roll kneader to prepare a sheet-like foaming resin composition having a thickness of 2 mm.
(a) Foaming resin:
・ EVA-1: ethylene-vinyl acetate resin E (product name “Ultrasen 630”, manufactured by Tosoh Corporation, vinyl acetate content 15% by mass)
・ EVA-2: ethylene-vinyl acetate resin E (product name “Ultrasen 634”, manufactured by Tosoh Corporation, vinyl acetate content 26% by mass)
(b) Foaming agent: azodicarbonamide (product name “Uniform AZ”, manufactured by Otsuka Chemical Co., Ltd.)
(c) foaming aid: activated zinc white (product name "META-Z", manufactured by Inoue Lime Industry Co., Ltd.)
(d) Cross-linking agent: dicumyl peroxide (product name “Percumyl D”, manufactured by NOF Corporation)
(e) Stabilizer: Phenolic antioxidant (product name "Irganox 1010", manufactured by BASF Corporation)

<Molding of foam>
The sheet-like foaming resin composition obtained in the manufacturing process of the foaming resin composition described above is laminated by changing the number of layers depending on the thickness of each foam (see Table 1), and is heated by a press molding machine. Foaming sheets of foams 1 to 8 having sizes shown in Table 1 were prepared by heat-pressing at 85° C. for 10 minutes.
Next, each of the foam sheets of foams 1 to 8 was heated in an oven at a temperature of 140° C. for 40 minutes for pre-foaming. Place it in a mold of 2, 5, 10, 15, 20, 30, 50 mm and heat it in an oven at a temperature of 190 ° C. for 20 minutes to obtain the expansion ratio (times) and density shown in Table 2 (g/cm ³ ) of width 30 cm×length 25 cm×thickness 2, 5, 10, 15, 20, 30, 50 mm. The foams 1 to 8 thus obtained were used as the foams of Examples 1 to 4, Reference Example 5, and Comparative Examples 1 to 3, respectively, and the following evaluation tests were performed.
The density ρ ₁ of each foam was measured according to JIS K7222. In addition, the expansion ratio of each foam 1 to 8 is the value obtained by dividing the density ρ ₀ of the solid before foaming determined according to JIS K7112 by the density ρ ₁ of the foam determined according to JIS K7222 (ρ ₀ /ρ ₁ ). I asked as

2. Characteristic evaluation of foam <Compression load F ₁₀ , hysteresis loss rate, compression-recovery load ratio (Fb/Fa) of each foam>
Compressive load F ₁₀ (N) required to compress each 20 mm thick foam of Examples 1 to 4, Reference Example 5 and Comparative Examples 1 to 3 by 10 mm, compression-recovery cycle hysteresis loss rate (%), The ratio (Fb/Fa) of the recovery load Fb (N) to the compression load Fa (N) at the same amount of deformation is measured using a test apparatus equipped with the following compressors according to JIS K6400-2: 2012. It was measured by performing a compression-recovery cycle test on the foam.

[Compressor]
The shape of the compressing element was a stainless steel cylinder with a diameter of 30 mm and a length of 50 mm. This compressor was attached and fixed to the load cell of the tester described below.
[testing machine]
An autograph precision universal testing machine AG-50kND type manufactured by Shimadzu Corporation and a load cell capacity of 5kN were used.
As the test conditions, autograph software "TRAPEZIUM X" manufactured by Shimadzu Corporation was used, compression speed 15 mm / sec, recovery speed 15 mm / sec, retention time between compression and recovery 0 seconds, data acquisition frequency 100 times. /sec.
Maximum values and hysteresis loss ratios were obtained from the same software.
<Test environment>
After stabilizing the temperature of the test piece by leaving it for 24 hours or longer in a constant temperature and humidity chamber controlled at a temperature of 23° C. and a humidity of 50% RH, the test was conducted.

That is, each foam having a thickness of 20 mm of Examples 1 to 4, Reference Example 5 and Comparative Examples 1 to 3 was used as a test piece, and the test piece was subjected to a temperature of 23 ° C. and a diameter of 30 mm until the deformation amount decreased from 0 mm to 10 mm. A load-deformation curve of each foam as shown in FIG. 1 was measured by compressing at a compression speed of 15 mm/sec using a cylindrical compressor and immediately recovering at a recovery speed of 15 mm/sec. From the load-deformation curve of each foam, the compression load F ₁₀ (N) required to compress each foam by 10 mm is obtained, and is surrounded by the origin o-compression curve X-point a-point b-origin o Calculate the hysteresis loss rate (%) from the ratio (percentage) of the area surrounded by the origin o-compression curve X-point a-recovery curve Y-point c to the area, and compressive load Fa (N) at the same deformation amount A ratio (Fb/Fa) of the recovery load Fb (N) was determined.

For each foam of Examples 1 to 4, Reference Example 5 and Comparative Examples 1 to 3, the compression load Fa when the deformation amount of the foam in the compression cycle is 0, 2, 4, 5, 6, 8 (mm) (N), the compressive load F ₁₀ (N) when the deformation of the foam is 10 (mm), and the deformation of the foam in the recovery cycle is 8, 6, 5, 4, 2 (mm). Table 3 shows the measurement results of the recovery load Fb (N).

From the measurement results in Table 3, the ratio of the recovery load Fb (N) to the compression load Fa (N) at the same deformation amount ( Fb/Fa) and hysteresis loss rate (%) are shown in Table 4.

<Sensory evaluation of each foam>
The foams of Examples 1 to 4, Reference Example 5 and Comparative Examples 1 to 3 were evaluated by a sensory test by five monitors. Specifically, each foam having a thickness of 20 mm of Examples 1 to 4, Reference Example 5 and Comparative Examples 1 to 3 shown in Table 2 was used as a test piece, and Examples 1 to 4, Reference Example 5 and Comparative Example 1 were used. Each test piece of ~ 3 is spread on the surface of the seat body of a bathroom chair (product name "Rakuraku opening and closing shower bench S Fit", manufactured by Aronkasei Co., Ltd.), and when the monitor sits, the "softness" felt in the buttock and "feeling of bottoming out" (sitting comfort), and "feeling of support when standing up" (degree of load reduction when standing up) that you feel in your arms when you stand up with your hands on both armrests after sitting on the monitor. It was carried out by evaluating and calculating the average value.
[Evaluation criteria]
5 points: Very good, no feeling of bottoming out.
(When standing up, almost no force is required on the arm supported by the armrest.)
4 points: Excellent, no feeling of bottoming out.
(When standing up, the arm supported by the armrest requires some strength.)
3 points: normal
2 points: Inferior, feeling of bottoming out.
(When standing up, the arm supported by the armrest requires strong force.)
1 point: Very poor, strong feeling of bottoming out.
(When standing up, the arm supported by the armrest requires a very strong force.)

The overall evaluation of each foam of Examples 1 to 4, Reference Example 5, and Comparative Examples 1 to 3 was based on the above-mentioned three items of "softness", "feeling of bottoming out", and "feeling of help when standing up". All points are 3.5 or higher with "○", any one of the evaluation points of the three items is 3.0 or more and less than 3.5, and the evaluation points of the other items are all 3.5 or more. A certain case was evaluated as "Δ", and a case where any one of the evaluation points of the three items was less than 3.0 was evaluated as "×".

Table 5 shows the results of sensory evaluation of the foams of Examples 1-4, Reference Example 5 and Comparative Examples 1-3.

<Ratio of compression load before and after accelerated deterioration test (Fc/Fa) of each foam, hysteresis loss rate>
The compression load ratio at the same deformation amount of the foams of Examples 2 and 3 before and after the accelerated deterioration test and each foam of Reference Example 5 (compression load Fc after test/compression load Fa before test), hysteresis loss rate ( %) was calculated using the above-mentioned Autograph software by performing a compression cycle test on each foam using the above-mentioned Autograph precision universal testing machine according to JIS K6400-2:2012.

That is, the foams of Examples 2 and 3 and the foam of Reference Example 5 having a thickness of 20 mm were used as test pieces, and the test pieces before the accelerated deterioration test were heated to 23 ° C. and 30 mmφ until the deformation amount changed from 0 mm to 10 mm. The compression load Fa-deformation curve of each foam before the accelerated deterioration test was measured by compressing at a compression rate of 15 mm/sec using a cylindrical compressor.

On the other hand, the accelerated deterioration test was carried out according to the following procedure. That is, the foam of Examples 2 and 3 and the foam of Reference Example 5 having a thickness of 20 mm were used as test pieces, and a sodium hypochlorite-based detergent (trade name “Kabikiller”, manufactured by Johnson Co., Ltd.) was applied to the entire surface of the test piece. is applied, and the test piece wrapped in a resin sheet (trade name “Saran Wrap (registered trademark) 30 cm × 50 m”, manufactured by Asahi Kasei Home Products Co., Ltd.) so that the coating solution does not dry, temperature 23 ° C., humidity 50% RH It was left for 7 hours in a constant temperature and constant humidity room kept at .
Next, each test piece taken out from the resin sheet was washed with water, and after washing away the coating liquid, a constant temperature and humidity bath (trade name “Cosmopia EC-85MHHP” type, Hitachi Appliances) kept at a temperature of 60 ° C. and a humidity of 98% RH manufactured by Co., Ltd.) for 16 hours.
Then, a combination of a constant temperature and humidity test using the sodium hypochlorite-based detergent described above and a constant temperature and humidity test under an exposure environment with a temperature of 60 ° C. and a humidity of 98% RH is repeated 5 cycles as one cycle. , Using an ultraviolet irradiation device (device name “Isuper UV Tester SUV-W151” type, lamp name “Multi-metal lamp for UV tester ME06-L31WX / SUV” type, manufactured by Iwasaki Electric Co., Ltd.), illuminance 70 mW, temperature 63 Each test piece was irradiated for 5 hours under conditions of ℃ and humidity of 50% RH.

Next, each test piece is left in a constant temperature and humidity room at a temperature of 23 ° C. and a humidity of 50% RH for 24 hours or more to stabilize the temperature of each test piece, and after the accelerated deterioration test, each test piece is , By compressing at a compression speed of 15 mm / sec using a cylindrical compressor of 30 mmφ at a temperature of 23 ° C until the deformation amount changes from 0 mm to 10 mm, the compressive load Fc-deformation of each foam after the accelerated deterioration test A volume curve was measured.

From the load-deformation curve of each foam, the ratio of compressive load at the same deformation amount before and after the accelerated deterioration test (compressive load Fc after test/compressive load Fa before test) was obtained, and as shown in FIG. Origin o-compression curve before accelerated deterioration test X-point a-point b-for the area surrounded by origin o, compression curve before origin o-accelerated deterioration test X-point a-point d-recovery after accelerated deterioration test The hysteresis loss rate (%) was obtained from the ratio (percentage) of the area surrounded by the curve Z-origin o using the above-described autograph software (trade name "TRAPEZIUM X", manufactured by Shimadzu Corporation).

For the foams of Examples 2 and 3 after the accelerated deterioration test and the foam of Reference Example 5, the compressive load Fc ( N) is shown in Table 6.

From the measurement results in Tables 3 and 6, the compression load ratio at the same amount of deformation (post-test compression load Fc/ Table 7 shows the compression load (Fa) before the test and the hysteresis loss rate (%) after the accelerated deterioration test.

3. Discussion According to the evaluation results of the sensory test shown in Table 5, the cushions made of the foams of Examples 1 to 4 and Reference Example 5 provide excellent sitting comfort without bottoming out while having high flexibility. Furthermore, it was confirmed that the user's movement can be assisted by having an appropriate repulsive force. On the other hand, the cushions made of the foams of Comparative Examples 1 to 3 are lacking in any of the characteristics of flexibility, prevention of bottoming out, and/or feeling of support for standing up, and are not suitable as cushions for nursing care equipment. confirmed.

In order for the cushion made of foam used for nursing care equipment to have high flexibility, not to bottom out, and to have an appropriate repulsive force, the foams of Examples 1 to 4 and Reference Example 5 shown in Table 3 were used. From the properties of the foams of Comparative Examples 1 to 3, the compressive load F ₁₀ (N) required to compress the foam by 10 mm is preferably 50 N or more and 250 N or less, more preferably 90 N or more and 150 N or less. turned out to be favorable.

In addition, in order to obtain a cushion made of foam suitable for use in nursing care equipment as described above, the foams of Examples 1 to 4 and Reference Example 5 shown in Table 4 and the foams of Comparative Examples 1 to 3 It was found that the hysteresis loss rate (%) is preferably 40% or less, more preferably 30% or less, based on body characteristics. Similarly, the ratio (Fb/Fa) of the recovery load Fb (N) to the compression load Fa (N) at the same amount of deformation is preferably 0.4 or more and 1.0 or less, more preferably 0.6 or more and 1.0. It turned out that it is more preferable to be 0 or less.

Comparison of the compression load ratio (post-test compression load Fc/pre-test compression load Fa) at the same deformation amount before and after the accelerated deterioration test of the foams of Examples 2 and 3 and the foam of Reference Example 5 shown in Table 7 From this, the foams of Examples 2 and 3 have a compression load ratio (Fc/Fa) before and after the accelerated deterioration test that is close to 1.0. It was found to have extremely high chemical resistance and high durability against disinfection with chemicals such as sodium and alcohol and cleaning with detergents such as soap. On the other hand, the foam of Reference Example 5 is different only in that the amount of cross-linking agent is larger than that of the foam of Example 2, as shown in Table 1, although the cause of the progress of deterioration in the accelerated deterioration test is not clear. ing. From this, the foam of Reference Example 5 has a higher degree of cross-linking during foam molding than the foam of Example 2, and the residual strain after foam molding is higher. is presumed. For this reason, it is presumed that the foam of Reference Example 5 was released from the residual strain and the like by the accelerated deterioration test, causing some kind of state change, and the deterioration progressed by the accelerated deterioration test.

In addition, in order to have high chemical resistance and high durability as described above, the same It was found that the compression load ratio (Fc/Fa) in the amount of deformation is preferably 0.9 or more and 1.4 or less, and more preferably 0.9 or more and 1.1 or less. Similarly, it was found that the hysteresis loss rate (%) is preferably 26% or less, more preferably 24% or less.

B. Influence of foam shape (thickness) on sitting comfort, etc. 1. Production of Foam In order to investigate the influence of the shape (thickness) of the foam constituting the cushion according to one embodiment of the present invention on the comfort of sitting, a foam having the properties shown below was produced and an evaluation test was conducted. rice field.
That is, the foaming resin composition and the molded foam used for molding each foam were the same as in the above "A. Effect of properties of each foam on sitting comfort, etc.”. Foams 1-4 and 6-8 of width 30 cm x length 25 cm x thickness 2, 5, 10, 15, 20, 30, 50 mm were made with a weight of 100 g/cm ³ ). The foams 1 to 4 and 6 to 8 thus obtained were used as the foams of Examples 1 to 4 and Comparative Examples 1 to 3, respectively, and the following evaluation tests were performed.

2. Characteristic evaluation of foam <Compressive stress P at 25% strain, flexibility index Pt of each foam due to thickness difference>
The foams of Examples 1 to 4 and the foams of Comparative Examples 1 to 3 were tested for comfort (hardness) in accordance with JIS K6767: 1999, using the test equipment shown below. It was evaluated using the compressive stress P (kPa) at 25% strain.
[testing machine]
An autograph precision universal testing machine AG-50kND type manufactured by Shimadzu Corporation and a load cell capacity of 5kN were used.
As the test conditions, autograph software "TRAPEZIUM X" manufactured by Shimadzu Corporation was used, compression speed 15 mm / sec, recovery speed 15 mm / sec, retention time between compression and recovery 0 seconds, data acquisition frequency 100 times. /sec.
Compressive stress at 25% strain was obtained from the same software.
<Test environment>
After stabilizing the temperature of the test piece by leaving it for 24 hours or longer in a constant temperature and humidity chamber controlled at a temperature of 23° C. and a humidity of 50% RH, the test was conducted.

From the above test results, for the foams of Examples 1 to 4 and Comparative Examples 1 to 3, the compressive stress P (kPa) at 25% strain of each foam with a thickness of 20 mm, the thickness t (mm) and Table 8 shows the calculation results of the flexibility index Pt (kPa·mm) obtained by multiplying the compressive stress P (kPa) at 25% strain of the foam having a thickness of 20 mm.

<Evaluation of sitting comfort due to differences in thickness of each foam>
Seating comfort (flexibility, bottoming feeling) depending on the difference in thickness t (mm) of the foams of Examples 1 to 4 and the foams of Comparative Examples 1 to 3 was evaluated by a sensory test by five monitors.
Specifically, the foams of Examples 1 to 4 shown in Table 2 above and the foams having thicknesses shown in Table 9 below of Comparative Examples 1 to 3 were used as test pieces, and Examples 1 to 4 and Comparative Examples were used. Each test piece from 1 to 3 was laid on the surface of the seat body of a bathroom chair (product name “Rakuraku Open/Close Shower Bench S Fit”, manufactured by Aron Kasei Co., Ltd.), and the “softness” felt on the buttocks when the monitor sat down. "Feeling on the bottom" (feeling of sitting on the bottom) (sitting comfort) was evaluated according to the following criteria, and the average value was calculated.
[Evaluation criteria]
5 points: Excellent (no feeling of bottoming out)
4 points: excellent (no feeling of bottoming out)
3 points: Normal 2 points: Inferior (there is a feeling of bottoming out)
1 point: very poor (strong feeling of bottoming out)

The overall evaluation of the sitting comfort of the foams of Examples 1 to 4 and the foams of Comparative Examples 1 to 3 was 3.5 for each of the above two items of "softness" and "feeling on the bottom". "○" for those that are above, "△" for cases where any one of the evaluation points of the two items is 3.0 or more and less than 3.5 and the evaluation points of the other items are 3.0 or more, Any one of the evaluation points of the two items was evaluated as "x" if it was less than 3.0.

Table 9 shows the evaluation results of the comfort of sitting on the foams of Examples 1 to 4 and the foams of Comparative Examples 1 to 3 by a sensory test.

3. Consideration According to the evaluation results of the comfort of sitting due to the difference in the thickness of the foam in the sensory test shown in Table 9, the cushions made of the foams of Examples 1 to 4 preferably have a thickness of 5 mm or more and 100 mm or less, more preferably 7 mm or more. It was confirmed that, in the range of 50 mm or less, it is possible to provide excellent sitting comfort with moderate hardness while achieving both high flexibility and high degree of prevention of bottoming. On the other hand, the cushions made of the foams of Comparative Examples 1 and 2 can prevent bottoming in a wide range of 2 mm or more and 100 mm or less, but are too hard and lack flexibility, resulting in a low overall evaluation of sitting comfort. Although Example 3 is excellent in flexibility, it was not possible to prevent it from bottoming out, and it was confirmed that it is not suitable as a cushion for nursing care equipment.

In order for the cushion made of foam used for nursing care equipment to have both high flexibility and high degree of bottoming prevention and to have moderate hardness, the foams of Examples 1 to 4 shown in Table 8 and Comparative Example 1 From the properties of the foam of ~3, the compressive stress P (kPa) at 25% strain of the foam with a thickness of 20 mm is preferably 35 kPa mm or more and 250 kPa mm or less, and 40 kPa mm or more and 200 kPa mm or less. 40 kPa or more and 100 kPa or less is most preferable. Similarly, in order to prevent the cushion from bottoming out, the flexibility index Pt (kPa ·mm) is preferably 500 kPa·mm or more, more preferably 900 kPa·mm or more. However, the flexibility index Pt (kPa mm) increases as the thickness t of the foam cushion increases, improving sitting comfort. Therefore, the upper limit is preferably 10000 kPa·mm or less, more preferably 8000 kPa·mm or less. Furthermore, it is most preferably 7000 kPa·mm or less.

Claims (5)

A nursing care tool comprising a cushion made of resin foam,
The characteristics of the cushion are the compression required to compress a cushion test piece of width 30 cm x length 25 cm x thickness 20 mm to 10 mm at a compression speed of 15 mm / sec using a cylindrical compressor of 30 mm diameter at a temperature of 23 ° C. A nursing care tool characterized by having a load F ₁₀ (N) of 50N or more and 250N or less. The characteristics of the cushion are further evaluated by compressing the test piece by 10 mm at a compression rate of 15 mm/sec using the compresser at a temperature of 23 ° C. and then recovering at a recovery rate of 15 mm/sec. The nursing care tool according to claim 1, which is 40% or less. The characteristics of the cushion were further evaluated by compressing the test piece by 10 mm at a compression speed of 15 mm/sec at a temperature of 23° C. using the compression element before the accelerated deterioration test described below, and the compression cycle after the accelerated deterioration test described below. In the post-test compression cycle in which the test piece is compressed by 10 mm at a compression speed of 15 mm / sec using the compresser at a temperature of 23 ° C., the compression load Fa (N) before the test and the compression load Fc (after the test) at the same amount of deformation N) ratio (Fc/Fa) is 0.9 or more and 1.4 or less, the nursing care tool according to claim 1 or 2.
[Deterioration acceleration test conditions]
Sodium hypochlorite-based detergent was applied to the entire surface of a cushion test piece of width 30 cm x length 25 cm x thickness 20 mm, wrapped in a resin sheet, and kept at constant temperature and humidity at 23°C and 50% RH for 7 hours. The step of leaving and the step of leaving the exposed test piece under constant temperature and humidity of 60° C. and humidity of 98% RH for 16 hours are repeated for 5 cycles. Next, after irradiating the test piece with ultraviolet light for 5 hours under the conditions of an illuminance of 70 mW, a temperature of 63° C. and a humidity of 50% RH, the test piece is left at a constant temperature and humidity of 23° C. and a humidity of 50% RH for 24 hours or more. to stabilize the temperature of the specimen. The nursing care tool according to any one of claims 1 to 3, wherein the cushion has a thickness of 5 mm or more and 100 mm or less. The nursing care tool according to any one of claims 1 to 4, wherein the resin foam is an olefin resin foam.

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