JP2022040772A - Cushion material and vehicular sheet comprising the same - Google Patents

Abstract

To provide a cushion material that can reduce the vibration in the high frequency region (10 Hz or more) and can improve the riding comfort of an occupant.SOLUTION: The present invention discloses a cushion material 14 to be combined with a pad body 12 of a vehicular sheet. The cushion material 14 has a gas permeability of 2 cm3/cm2/s or more and 25 cm3/cm2/s or less, measured in accordance with the B method of JIS-K6400-7: 2012 and for a test piece of 150 mm long, 150 mm wide and 20 mm thick in size.SELECTED DRAWING: Figure 2

Description

The present invention relates to a cushion material and a vehicle seat provided with the cushion material. More specifically, the present invention relates to a cushion material integrated with a pad body of a vehicle seat and a vehicle seat provided with the cushion material.

Generally, a vehicle seat for an automobile or the like is configured by disposing a pad body and a cushion material integrated with the pad body on a metal seat frame constituting the skeleton. For example, Patent Document 1 describes that a soft cushion material (slab pad) manufactured by slab molding can be attached on a pad body to give a soft feel and improve the ride comfort of an occupant. There is.

Japanese Unexamined Patent Publication No. 11-221131

However, according to the study of the present inventor, the slab pad as described in Patent Document 1 generally has a large air permeability in order to realize a soft feel. Therefore, it is easy to collapse and lose its shape when the occupant is seated. As a result, it tends to be difficult to absorb the vibration in the high frequency region (10 Hz or more) among the engine vibration and the vibration from the road surface generated during idling and running of the vehicle. As a result, the vibration in the high frequency region is directly transmitted to the occupant, and there is a problem that an unpleasant sensation of buzzing is generated in the thigh of the occupant.

The present invention has been made in view of the above circumstances, and an object thereof is a cushion material capable of reducing vibration in a high frequency region (10 Hz or higher) and improving the ride quality of a occupant, and the cushion. The purpose is to provide vehicle seats equipped with materials.

The invention of claim 1 is a cushioning material used integrally with a pad body of a vehicle seat, to which the B method of JIS-K6400-7: 2012 is applied, and has a length of 150 mm, a width of 150 mm, and a thickness of 20 mm. It is characterized in that the air volume measured by a test piece of a size is 2 cm ³ / cm ² / s or more and 25 cm ³ / cm ² / s or less.

According to the first aspect of the present invention, since the ventilation amount of the cushion material is 25 cm ³ / cm ² / s or less, the cushion material is less likely to be crushed or lose its shape when the occupant is seated. As a result, the cushion material acts as a so-called damper, and the vibration in the high frequency region (10 Hz or higher) can be suitably absorbed by the cushion material. This makes it possible to reduce the unpleasant buzzing feeling that occurs in the thighs and the like of the occupant. In addition, since the amount of air permeability of the cushion material is 2 cm ³ / cm ² / s or more, appropriate air permeability is ensured for the cushion material, and the occupant is less likely to feel stuffy. Therefore, the ride quality of the occupant can be improved.

The invention of claim 2 is characterized in that, in the invention of claim 1, the aeration amount is 5 cm ³ / cm ² / s or more and 22 cm ³ / cm ² / s or less. According to the invention of claim 2, the effect of the invention of claim 1 can be exhibited at a higher level. For example, it is possible to realize at least one of improvement of vibration absorption in a high frequency region and reduction of stuffiness discomfort.

According to the invention of claim 3, in the invention of claim 1 or 2, a test piece having a size of 400 mm in length × 400 mm in width × 20 mm in thickness is compressed (compressed) to 75% of the initial thickness by a pressure plate having a diameter of 200 mm. (Speed: 50 mm / min), immediately remove the load, return the pressure plate to the initial position, leave it for 1 minute, repeat the same operation twice, perform precompression twice, and then leave the test piece for 1 minute. Then, the hysteresis loss rate measured by compressing the pressure plate to 75% of the initial thickness (compression rate: 50 mm / min) is 17% or more and 28% or less. Is. According to the invention of claim 3, in addition to the effect of the invention of claim 1 or 2, the resilience of the cushion material can be suppressed. As a result, it is possible to suppress the sitting collapse (disordered posture) at the time of sitting and improve the sitting property. In addition, it is possible to improve the holdability and posture stability during running. In addition, it is possible to suppress the compression residual strain at the time of sitting to a small value and improve the stability at the time of leaving.

The invention of claim 4 is characterized in that, in the invention of any one of claims 1 to 3, the thickness is 5 mm or more and 30 mm or less. According to the invention of claim 4, in addition to the effect of the invention of any one of claims 1 to 3, it is difficult for the occupant to bottom out when the occupant is seated, and the vibration absorption can be further improved. In addition, it is possible to suppress wobbling when sitting and improve sitting performance.

The invention of claim 5 is characterized in that, in the invention of any one of claims 1 to 4, the apparent density is 0.040 g / cm ³ or more and 0.095 g / cm ³ or less. .. According to the invention of claim 5, in addition to the effect of the invention of any one of claims 1 to 4, the voids (cells) inside the cushion material are less likely to be crushed, and the vibration absorption can be further improved. can. In addition, the weight of the cushion material can be suppressed to improve the fuel efficiency of the vehicle.

The invention of claim 6 is the invention of any one of claims 1 to 5, characterized in that it is a molded product including an inner layer and a skin layer having a higher apparent density than the inner layer. Is. According to the invention of claim 6, by providing a high-density skin layer, in addition to the effect of the invention of any one of claims 1 to 5, crushing and shape loss at the time of sitting are suppressed at a high level. , Vibration absorption can be further improved.

The invention of claim 7 is the invention of any one of claims 1 to 6, wherein a test piece having a size of 400 mm in length × 400 mm in width × 20 mm in thickness is loaded with 4.9 N by a pressure plate having a diameter of 200 mm. The position of the pressure plate at the time of addition is used as a reference position, the test piece is compressed to 75% of the initial thickness (compression rate: 50 mm / min), and then the pressure plate is pressed at a speed of 50 mm / min. After performing pre-compression to return to the position, the test piece is left for 1 minute, then compressed to 25% of the initial thickness by the pressure plate (compression rate: 50 mm / min), and held for 20 seconds. It is characterized in that (25% ILD hardness) is 30N / 314cm ² or more and 180N / 314cm ² or less. According to the invention of claim 7, in addition to the effect of the invention of any one of claims 1 to 6, the voids (cells) inside the cushion material are less likely to be crushed, and the vibration absorption can be further improved. can. In addition, it is possible to suppress the rigidity from becoming too large and further suppress the resilience.

The invention according to claim 8 is described in any one of claims 1 to 7, wherein the pad body is integrated with the pad body and is interposed between the pad body and at least a part of the occupant's body. It is a vehicle seat characterized by being provided with a cushion material. According to the invention of claim 8, it is possible to realize a vehicle seat in which vibration in a high frequency region is reduced and the ride quality is improved.

The invention of claim 9 is characterized in that, in the invention of claim 8, the cushion material is adhered to the pad body. According to the invention of claim 9, in addition to the effect of the invention of claim 8, the pad body and the cushion material can be firmly integrated for a long period of time. In addition, workability during manufacturing can be improved.

It is a front view of the vehicle seat which concerns on one Embodiment of this invention. FIG. 3 is a cross-sectional view taken along the line AA of FIG. It is a schematic diagram which shows the state of a vibration test. Vibration transmission coefficient characteristic curve (horizontal axis: frequency, vertical axis: vibration transmission rate).

Hereinafter, preferred embodiments of the present invention will be described. It should be noted that matters other than those specifically mentioned in the present specification and necessary for carrying out the present invention can be grasped as design matters of those skilled in the art based on the prior art. The present invention can be carried out based on the matters disclosed in the present specification and the drawings and the common general technical knowledge in the art. In addition, the notation of "A to B" indicating a range in this specification includes the meanings of "A or more and B or less", as well as "preferably larger than A" and "preferably smaller than B".

≪Vehicle seat≫
FIG. 1 is a front view of a vehicle seat 10 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line AA of FIG. The vehicle seat 10 is attached to a vehicle (not shown) and constitutes a seating portion for an occupant. The vehicle seat 10 supports the body of the occupant. The vehicle seat 10 is a seat back (backrest) to which the back of the occupant's upper body abuts and supports the occupant's upper body (for example, from the shoulder to the waist) from behind. However, the vehicle seat 10 may be a seat cushion or the like that supports the lower body of the occupant (for example, from the buttocks to the thighs) from below in the vertical direction. The vehicle seat 10 is typically covered with a cover body made of cloth, resin, leather, or the like, but the cover body is not shown in FIGS. 1 and 2.

Here, the vehicle seat 10 includes a seat back frame (not shown) forming a skeleton of the seat back, a pad body 12, and a cushion material 14. In the lateral direction, the cushion material 14 is arranged at the central portion 12c of the pad body 12. More specifically, the pad body 12 has a pair of groove portions 12b (see FIG. 2) having a substantially U-shaped cross section extending in the vertical direction, and the cushion material 14 is arranged between the pair of groove portions 12b. One cushion material 14 is arranged in each of the upper portion and the lower portion of the central portion 12c of the pad main body 12. Although the number of pad bodies 12 is one here, a plurality of two or more may be used. Further, although the number of cushion materials 14 is two here, it may be only one or three or more. Further, although the cushion material 14 is arranged only in the central portion 12c of the pad main body 12 here, the cushion material 14 may be arranged in the side portion 12s in addition to the central portion 12c or in place of the central portion 12c. good. Further, the shapes and arrangements of the pad body 12 and the cushion material 14 can be appropriately changed according to, for example, the shape of the vehicle seat 10.

The pad body 12 is assembled to a seat back frame (not shown). The pad body 12 may be the same as that conventionally used for this kind of application, and its material, properties, shape and the like are not particularly limited. The pad body 12 is preferably made of polyurethane foam (urethane foam). The pad body 12 can be manufactured by a conventionally known method, for example, molding (mold molding). The pad body 12 is foam-molded by injecting a polyurethane raw material containing, for example, a polyol component, a cross-linking agent, a foaming agent, a foam-regulating agent, a catalyst, a communicating agent, and a polyisocyanate component into a molding die. Can be manufactured by The polyol component of the pad body 12 may contain, for example, polypropylene glycol (PPG) and a polymer polyol (POP). The polyisocyanate component of the pad body 12 may contain toluene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI).

The cushion material 14 is arranged at a position (seating position) where the occupant of the vehicle seat 10 is seated. The cushion material 14 is arranged on the seating surface side of the pad body 12. The cushion material 14 constitutes an upper layer portion (for example, a surface layer portion) at the seating position. The cushion material 14 is interposed between the pad body 12 and at least a part of the occupant's body. The cushion material 14 is interposed here between the pad body 12 and the back of the occupant's upper body. The cushion material 14 may be covered with a cover body made of, for example, cloth, resin, or leather. The cushion material 14 is in the form of a sheet (plate) here. The cushion material 14 is integrated with the pad body 12.

In addition, in this specification, "integration" is a concept including attachment, adhesion, attachment, molding, insertion and the like. That is, for example, the cushion material 14 may be placed on the pad body 12 or may be non-detachably adhered to the pad body 12, such as a magic tape (registered trademark) on the pad body 12. It may be detachably attached with the pad body 12 and molded integrally with the pad body 12 (for example, insert molding in which the cushion material 14 is inserted into a molding die for molding the pad body 12 and then the pad body 12 is foam-molded). It may be inserted, or it may be inserted inside the pad body 12.

Here, the cushion material 14 is adhered to and fixed to the pad body 12. By adhesion, the pad body 12 and the cushion material 14 can be firmly integrated for a long period of time. In addition, in this specification, "adhesion" refers to a general state of being bonded by a chemical or physical force. For example, the cushion material 14 is integrated with the pad body 12 via an adhesive, double-sided tape, or the like. It means that it is.

The cushion material 14 is typically a resin foam. The cushion material 14 is preferably made of polyurethane foam (urethane foam). The cushion material 14 may be a soft or semi-rigid polyurethane foam. The cushion material 14 has a single-layer structure here. As will be described in detail later, the cushion material 14 can be manufactured, for example, by injecting a polyurethane raw material as described above into a molding die and foam molding. The cushion material 14 may be composed of, for example, a crosslinked product of PPG as a polyol component as a first component (a component having the highest mixing ratio in terms of mass ratio; the same shall apply hereinafter), or mainly a crosslinked product of PPG (the same shall apply hereinafter). It may be configured as a component that occupies 50% by mass or more of the entire cushion material 14).

The cushion material 14 needs to have an air flow rate (average air flow rate) of 2 to 25 cm ³ / cm ² / s. The cushion material 14 preferably has a ventilation amount of 5 cm ³ / cm ² / s or more, for example, 6 cm ³ / cm ² / s or more. By setting the amount of airflow to a predetermined value or more, appropriate air permeability is ensured in the cushion material 14, and the discomfort of stuffiness is less likely to occur when sitting. For example, even when the occupant is large and heavy, or when he / she sits for a long time in the hot summer, the ride quality can be improved and the passenger can spend comfortably.

The cushion material 14 preferably has a ventilation amount of 22 cm ³ / cm ² / s or less, for example, 15 cm ³ / cm ² / s or less, and 10 cm ³ / cm ² / s or less. By setting the air permeability to a predetermined value or less, the cushion material 14 acts as a so-called damper and absorbs vibrations during idling and running of the vehicle, especially vibrations in a high frequency region (so-called bluble vibrations). , Vibration absorption can be improved. As a result, for example, as compared with the case where only the pad body 12 is used without the cushion material 14 or the case where the slab pad as described in Patent Document 1 is used, an unpleasant buzzing feeling occurs in the thighs of the occupants and the like. Can be relatively reduced. The method of measuring the air volume will be described in a test example described later.

The cushion material 14 has a hysteresis loss rate of about 15% or more, preferably 17% or more, more preferably 20% or more, for example, 22% or more, and about 30% or less, preferably 28% or less, more preferably. It is preferably 26% or less, for example, 25% or less. By setting the hysteresis loss rate to a predetermined value or more, the resilience of the cushion material can be suppressed. As a result, it is possible to suppress the occupant from collapsing when sitting (disordered posture) and improve the sitting performance. In addition, it is possible to improve the holdability and posture stability during running. By setting the hysteresis loss rate to a predetermined value or less, the compression residual strain at the time of sitting can be suppressed to a small value, and the stability at the time of leaving the occupant can be improved. Thereby, the above-mentioned effect can be stably exhibited for a long period of time. The method for measuring the hysteresis loss rate will be described in a test example described later.

The cushion material 14 has an apparent density of approximately 0.03 g / cm ³ or more, preferably 0.04 g / cm ³ or more, more preferably 0.05 g / cm ³ or more, for example 0.06 g / cm ³ or more. , Approximately 0.1 g / cm ³ or less, preferably 0.095 g / cm ³ or less, more preferably 0.085 g / cm ³ or less, for example 0.08 g / cm ³ or less. By setting the apparent density to a predetermined value or more, the voids (cells) inside the cushion material 14 are less likely to be crushed when the occupant is seated. This makes it possible to improve the vibration absorption. By setting the apparent density to a predetermined value or less, the cushion material 14 can be made lighter, the weight can be suppressed, and the fuel efficiency of the vehicle can be improved.

The cushion material 14 preferably has a higher apparent density than the pad body 12. For example, 0.01 g / cm ³ or more, preferably 0.02 g / cm ³ or more, for example 0.025 g / cm ³ or more, and the apparent density may be high. The method for measuring the apparent density will be described in a test example described later.

The cushion material 14 has a 25% ILD hardness of approximately 20N / 314cm ² or more, preferably 30N / 314cm ² or more, more preferably 45N / 314cm ² or more, for example 50N / 314cm ² or more, and approximately 200N / 314cm. It is preferably ² or less, preferably 180N / 314cm ² or less, more preferably 120N / 314cm ² or less, for example, 100N / 314cm ² or less, 80N / 314cm ² or less. By setting the 25% ILD hardness to a predetermined value or more, the voids (cells) inside the cushion material 14 are less likely to be crushed when the occupant is seated. This makes it possible to improve the vibration absorption. By setting the 25% ILD hardness to a predetermined value or less, it is possible to prevent the rigidity from becoming too large (in other words, repulsion too much). The method for measuring the 25% ILD hardness will be described in a test example described later.

The cushion material 14 has a thickness t (average thickness, see FIG. 2) of about 3 mm or more, preferably 5 mm or more, for example, 10 mm or more, more preferably 15 mm or more, and about 50 mm or less, preferably 30 mm or less. It is preferably 25 mm or less. By setting the thickness t to a predetermined value or more, for example, even when the occupant's physique is large and the weight is heavy, it becomes difficult for the occupant to bottom out when sitting. This makes it possible to improve the vibration absorption. By setting the thickness t to a predetermined value or less, it is possible to suppress lateral wobbling when the occupant is seated and improve the seating property.

The cushion material 14 is preferably a molded product including an inner layer and a skin layer (surface layer) having a higher apparent density than the inner layer. The skin layer typically constitutes the surface of the inner layer and intervenes between the inner layer and the occupant's body. By providing a high-density skin layer, it is possible to suppress crushing and shape loss when the occupant is seated at a high level. In addition, vibration absorption can be improved.

≪Manufacturing method of cushion material≫
The cushion material 14 can be manufactured, for example, by a manufacturing method including the following preparation step and molding step. In the preparation step, first, a resin premix containing a polyol component and a polyisocyanate component are prepared as polyurethane raw materials. The resin premix contains, as essential components, a polyol component, a foaming agent, a defoaming agent, a catalyst, and may further contain other additives. Examples of the additive include a cross-linking agent, a communicating agent, a flame retardant, a filler, a colorant, a stabilizer, and the like.

Although not particularly limited, it is preferable that PPG is the first component of the polyol component, and it is preferable that the polyol component is substantially (95% by mass or more of the total polyol component) composed of PPG. It is preferable that the polyol component is substantially free of POP (for example, the POP is 10% by mass or less and 5% by mass or less of the total polyol component). The foaming agent, defoaming agent, catalyst, and additive (crosslinking agent, communicating agent, etc.) may be the same as those conventionally used for this type of application, and are not particularly limited. The cross-linking agent may be a polyhydric alcohol or amines. The catalyst may be an amine compound. The foaming agent may be water. The foam stabilizer may be silicone oil.

Further, although not particularly limited, the polyisocyanate component may have MDI as the first component, and it is preferable that the polyisocyanate component is substantially (95% by mass or more of the total polyisocyanate component) composed of MDI. It is preferable that the polyisocyanate component is substantially free of TDI (for example, TDI is 10% by mass or less and 5% by mass or less of the total polyisocyanate component).

Although not particularly limited, the mixing ratio of the cross-linking agent may be approximately 0.5 to 5 parts by mass when the polyol component is 100 parts by mass. The blending ratio of the foaming agent is preferably about 2 to 5 parts by mass when the polyol component is 100 parts by mass. The mixing ratio of the catalyst is preferably about 0.35 to 2.5 parts by mass when the polyol component is 100 parts by mass. The blending ratio of the defoaming agent is preferably about 0.2 to 2 parts by mass when the polyol component is 100 parts by mass. The communicating agent may be approximately 0.5 to 5 parts by mass when the polyol component is 100 parts by mass. The mixing ratio of the polyisocyanate component is preferably about 25 to 80 parts by mass when the resin premix is 100 parts by mass.

In the molding process, the polyurethane raw material is foam-molded. Specifically, the polyurethane raw material prepared above, that is, the resin premix and the polyisocyanate are mixed and injected into the molding mold main body (lower mold), and the lid (upper mold) is closed. As a result, the polyol component and the polyisocyanate component are chemically reacted, and the obtained polymer is foam-molded with the gas (carbon dioxide) generated at the same time as the reaction. The conditions for foam molding (molding temperature, etc.) may be the same as before. The molding temperature may be, for example, 40 to 90 ° C. From the above, the cushion material 14 made of polyurethane foam can be obtained.

The properties of the cushion material 14 (for example, the above-mentioned aeration amount, hysteresis loss rate, apparent density, 25% ILD hardness) are determined by, for example, the molding method and the composition of the polyurethane raw material (for example, the polyol component and / or the polyisocyanate component). It depends largely on the type) and the compounding ratio of each component. For example, according to the study of the present inventor, in the slab molding as described in Patent Document 1, the aeration amount of the molded product becomes larger than 25 cm ³ / cm ² / s, and the above-mentioned aeration amount range is realized. Difficult to do. Therefore, as the molding method, it is preferable to adopt a method other than slab molding, for example, molding. For example, by first preparing a polyurethane raw material in which each of the above-mentioned components is mixed in the above-mentioned blending ratio, and then obtaining a molded product by molding, the cushioning material 14 having the above-mentioned air permeability can be suitably realized.

As described above, according to the cushion material 14, it is possible to suitably absorb the vibration in the high frequency region (10 Hz or more) and reduce the unpleasant sensation of buzzing. In addition, the occupant is less likely to feel stuffy. Therefore, the ride quality of the vehicle can be improved. The cushion material 14 can be suitably used for various vehicles, for example, automobiles such as passenger cars and trucks.

Hereinafter, examples relating to the present invention will be described, but the present invention is not intended to be limited to those shown in such examples.

As Example 1, a cushion material was produced by molding a polyurethane raw material. Specifically, first, 0.5 parts by mass of a polyol component (PPG), a cross-linking agent (Actcol (registered trademark) KL-210 (manufactured by Mitsui Chemicals SKC Polyurethane Co., Ltd.)), and a foaming agent (water) are added. 3.3 parts by mass and a total of 1.35 parts by mass of catalysts (TD-33A (manufactured by Huntsman), ZF-22 (manufactured by Huntsman), TOYOCAT (registered trademark) -D60 (manufactured by Tosoh Corporation)) and foam conditioning 0.6 parts by mass of the agent (SZ1346E (manufactured by Dow Tosoh Co., Ltd.)) and 3.5 parts by mass of the communicating agent (Sannicks (registered trademark) FA-159 (manufactured by Sanyo Kasei Kogyo Co., Ltd.)). Was mixed to prepare a resin premix. The catalyst was 0.35 parts by mass for TD-33A, 0.1 parts by mass for ZF-22, and 0.9 parts by mass for D60. Each part by mass is a blending ratio with 100 parts by mass of the polyol component (PPG).

Next, the resin premix prepared above and MDI as a polyisocyanate component are mixed at a mass ratio of 100: 36.35 and molded to prepare a cushion material (Example 1) made of a molded product. did. Further, for comparison, a cushion material (Comparative Example 1) made of a slab molded product manufactured by slab molding was prepared.

Next, a commercially available base pad material (pad body) was prepared. This base pad material contains PPG and POP as a polyol component and uses a TDI / MDI blend as a polyisocyanate component. Then, the following measurements were performed on the prepared two types of cushion materials (Example 1 and Comparative Example 1) and the base pad material. The results are shown in Table 1.

(1) Measurement of airflow amount Using a Frazier type air permeability tester, apply the B method of JIS-K6400-7: 2012, and measure the airflow amount with a test piece measuring 150 mm in length × 150 mm in width × 20 mm in thickness. It was measured.

(2) Measurement of Hysteresis Loss Rate The measurement was performed with reference to the E method of JIS-K6400-2: 2012. That is, first, using Shimadzu Autograph AG-I type (manufactured by Shimadzu Corporation), a rectangular parallelepiped-shaped test piece measuring 400 mm in length × 400 mm in width × 20 mm in thickness was used with a pressure plate having a diameter of 200 mm to obtain the initial thickness. It was compressed to 75% (compression rate: 50 mm / min). Immediately after that, the load was removed and the pressure plate was returned to the initial position and left for 1 minute. Pre-compression, which repeats this compression and leaving, was performed twice in total. Next, the test piece was left for 1 minute and then compressed to 75% of the initial thickness with a pressure plate (compression rate: 50 mm / min) to draw a load-deflection curve. Then, the hysteresis loss rate was calculated from the load-deflection curve by the calculation method described in the E method of JIS-K6400-2: 2012.

(3) Measurement of apparent density The apparent density was calculated by measuring the outer shape and weight of the test piece. That is, the "apparent density" refers to the mass per unit volume including the voids in a substance having voids inside.

(4) Measurement of 25% ILD hardness The measurement was performed with reference to JIS-K6400-2: 2012. That is, first, using the Shimadzu Autograph AG-I type (manufactured by Shimadzu Corporation), a load of 4.9 N was applied to a rectangular parallelepiped test piece measuring 400 mm in length × 400 mm in width × 20 mm in thickness with a pressure plate having a diameter of 200 mm. The test piece was compressed to 75% of the initial thickness (compression rate: 50 mm / min) with the position of the pressure plate at the time of addition as the reference position. Next, the pressure plate was returned to the reference position at a speed of 50 mm / min. After performing this precompression, the test piece is left for 1 minute, compressed to 25% of the initial thickness with a pressure plate (compression rate: 50 mm / min), and held for 20 seconds, and then the force (25% ILD). Hardness) was measured.

Next, the vibration transmissibility was measured. That is, in order to reduce the vibration in the high frequency region (blur vibration) during idling or running of the vehicle, in the vibration curve (horizontal axis: frequency, vertical axis: vibration transmission rate) obtained in the vibration test, the high frequency region. It is said that it is effective to reduce the vibration transmission rate of the frequency (10 Hz or higher). Therefore, a vibration test was performed using a seat cushion vibration tester V-0545 (manufactured by Saginomiya Seisakusho Co., Ltd.), and the vibration transmissibility was measured.

FIG. 3 is a schematic diagram showing the state of the vibration test. Specifically, first, only the base pad material (length 400 mm × width 400 mm × thickness 40 mm) was installed on the vibration table, and the center of the base pad material was suppressed by a disk-shaped weight (iron laboratory, 20 kg). In this state, the vibration table was sweep-vibrated at a constant acceleration (0.2 G) to give a vibration G having a frequency of 1 to 25 Hz. Then, the vibration G'of the stylus when the vibration G was applied was measured, and the vibration transmissibility (G'/ G) of the base pad material was obtained. Further, as shown in FIG. 3, for the cushion material (Example 1, Comparative Example 1), a test piece (length 400 mm × width 400 mm × thickness 20 mm) is installed on the base pad material, and the vibration transmission rate is increased. (G'/ G) was calculated.

FIG. 4 is a vibration transmission coefficient characteristic curve showing the frequency on the horizontal axis and the vibration transmission coefficient on the vertical axis. The smaller the value of the vibration transmissibility, the better the vibration absorption. As shown in FIG. 4, when the cushion material of Example 1 is used, particularly in the high frequency region of 10 Hz or higher, it is relatively comparatively compared with the case of using only the base pad material or the case of using the cushion material of Comparative Example 1. The vibration transmission rate was kept low.

Further, the cushioning materials of Examples 2 to 4 were produced by molding the polyurethane raw material according to Example 1. In addition, Example 2 was the same as Example 1 except that the density was increased, Example 3 was the same as Example 1 except that the blending ratio of the foaming agent was reduced, and Example 4 was poly. Cushion materials were prepared in the same manner as in Example 1 except that the type of isocyanate component (MDI) was changed. Then, in Examples 2 to 4, the above-mentioned measurements (1) to (4) were carried out in the same manner as in Example 1. Although not shown, the cushioning materials of Examples 2 to 4 are relative to each other, as in the case of the cushioning material of Example 1, as compared with the case of using only the base pad material or the case of using the cushioning material of Comparative Example 1. The vibration transmission rate was kept low in the high frequency region of 10 Hz or higher.

Next, the cushioning materials (thickness 20 mm) of Examples 1 to 4 and Comparative Example 1 were subjected to sensory evaluation of the following items. In the sensory evaluation, the cushioning materials of Examples 1 to 4 and Comparative Example 1 were attached to the vehicle seat of an actual vehicle (specifically, the seat back and the pad body of the seat cushion), and the subject got on the vehicle and determined. The actual vehicle was driven at a running speed of 40 to 60 km / h. The results are shown in Table 2 with the following reference numerals.
-Blur feeling: While the vehicle is idling or running, (◎) the subject's upper body and lower body do not feel the buzzing feeling; (〇) rarely, the upper body and lower body feel the buzzing feeling, but it is not noticeable; ( ×) It is unpleasant to feel the sensation of buzzing in the upper and lower body. ・ Feeling stuffy: (◎) There is no discomfort of stuffiness even after running for a long time; There is, but it is not noticeable; (×) It is unpleasant because there is a clear stuffy feeling even when running for a short time ・ Holdability: (◎) There is little rolling or wobbling even on a sharp curve, and the cushion material adheres to the body It feels like you are idling; (○) You can feel a little rolling or wobbling on a sharp curve; (×) You can feel a lot of rolling or wobbling while driving, and your body is unstable.

As shown in the evaluation results in Table 2, by using the cushioning materials of Examples 1 to 4, it is possible to suppress the bluble vibration relatively as compared with the case of using the cushioning material of Comparative Example 1, from the sensory evaluation. It was backed up. Further, in the cushion materials of Examples 1 to 4, the discomfort of stuffiness was reduced by ensuring the air flow amount of 2 cm ³ / cm ² / s or more. In particular, by ensuring a ventilation amount of 5 cm ³ / cm ² / s or more, the air permeability was further enhanced, and it was possible to spend a comfortable time even when sitting for a long time. Further, in the cushion materials of Examples 1 to 4, by setting the hysteresis loss rate to 17% or more, for example, 20% or more, rolling and wobbling were suppressed, and the hold feeling was good.

Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of the claims. The techniques described in the claims include various modifications and modifications of the specific examples exemplified above.

10 Vehicle seat 12 Pad body 14 Cushion material

Claims (9)

A cushioning material that is used integrally with the pad body of the vehicle seat.
Applying the B method of JIS-K6400-7: 2012, the air volume measured with a test piece measuring 150 mm in length × 150 mm in width × 20 mm in thickness is 2 cm ³ / cm ² / s or more 25 cm ³ / cm ² Is less than / s,
Cushion material for vehicle seats, which is characterized by this. The air volume is 5 cm ³ / cm ² / s or more and 22 cm ³ / cm ² / s or less.
The cushioning material according to claim 1, wherein the cushioning material is characterized by the above. A test piece measuring 400 mm in length × 400 mm in width × 20 mm in thickness is compressed to 75% of the initial thickness with a pressure plate having a diameter of 200 mm (compression rate: 50 mm / min), and then the load is immediately removed to apply the above. The pressure plate is returned to the initial position, left for 1 minute, and then the same operation is repeated twice. After that, the test piece is left for 1 minute and then compressed to 75% of the initial thickness with the pressure plate. The hysteresis loss rate measured by (compression rate: 50 mm / min) is 17% or more and 28% or less.
The cushioning material according to claim 1 or 2, wherein the cushioning material is characterized by the above. The thickness is 5 mm or more and 30 mm or less.
The cushioning material according to any one of claims 1 to 3, wherein the cushioning material is characterized by the above. The apparent density is 0.040 g / cm ³ or more and 0.095 g / cm ³ or less.
The cushioning material according to any one of claims 1 to 4, wherein the cushioning material is characterized by the above. A molded product comprising an inner layer and a skin layer having a higher apparent density than the inner layer.
The cushioning material according to any one of claims 1 to 5, wherein the cushioning material is characterized by the above. The position of the pressure plate when a load of 4.9 N is applied with a pressure plate having a diameter of 200 mm to a test piece having a size of 400 mm in length × 400 mm in width × 20 mm in thickness is used as a reference position, and the test piece is used as the first test piece. After compressing to 75% of the thickness (compression rate: 50 mm / min), the pressure plate is precompressed to return to the reference position at a speed of 50 mm / min, and then the test piece is left for 1 minute and then the test piece is described. The force (25% ILD hardness) after compressing to 25% of the initial thickness with a pressure plate (compression rate: 50 mm / min) and holding for 20 seconds is 30 N / 314 cm ² or more and 180 N / 314 cm ² or less. ,
The cushioning material according to any one of claims 1 to 6, wherein the cushioning material is characterized by the above. With the pad body
The cushioning material according to any one of claims 1 to 7, which is integrated with the pad body and is interposed between the pad body and at least a part of the occupant's body.
To prepare
A vehicle seat that features this. The cushion material is adhered to the pad body.
The vehicle seat according to claim 8, characterized in that.

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