JP2019030597A - Vehicle seat member - Google Patents

Abstract

To provide a vehicle seat member that includes a core material comprising a foaming particle molded body being superior in the laminated adhesion with a polyurethane foam and productivity.SOLUTION: A vehicle seat member includes a core material comprising a thermoplastic resin foaming particle molded body, a polyurethane foam provided at a top side of the core material, and a seat cover for covering the polyurethane foam. The vehicle seat member is made as follows: the foaming particle molded body comprises a fusion body of the thermoplastic resin foaming particle having through-holes; the foaming particle molded body has cavities in communication with the outside; the porosity of the foaming particle molded body is 10 vol.% or more and less than 25 vol.%; a portion of the polyurethane foam is impregnated and solidified in the cavities of the foaming particle molded body; and an area ratio of the polyurethane foam portion in a cross section of the foaming particle molded body along the depth of 3 mm from the upper surface of the foaming particle molded body is 5-20%.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a vehicle seat member, and more particularly, to a vehicle seat member using a core material formed of a thermoplastic resin foam particle formed of thermoplastic resin foam particles having through holes.

  2. Description of the Related Art In recent years, a thermoplastic resin foam particle molded body (hereinafter, also simply referred to as “foamed particle molded body”) has been used as a core material for vehicle seat members such as automobiles. For example, in Patent Document 1, a cushion material that is elastically deformed when a load is applied, a frame member that reinforces the cushion material, and a foamed particle molded body are stacked as a raising member that secures the height of the cushion material. There is disclosed a vehicle seat characterized in that a surface cover that is disposed and formed so as to cover at least the cushion material is detachably attached to the cushion material. Further, in such a vehicle seat member, as shown in FIG. 7B of the same document, a stopper for fixing a seat cover such as a skin material is formed on the foamed particle molded body. It may be used by being inserted into a groove.

  On the other hand, Patent Document 2 provides a vehicle seat member that is excellent in bonding strength with polyurethane foam laminated on the upper side of the vehicle seat member and that is suppressed from deformation such as warpage caused by polyurethane foam lamination. An object of the present invention is to provide a foamed particle molded body in which foamed particles having no through-holes are fused to each other, and a base having substantially no voids and a foam having a through-hole formed above the base. Consisting of particles fused to each other and a communicating portion having a void communicating with the outside, the base and the communicating portion are fixed and integrated, and a portion of the polyurethane foam enters and solidifies into the void in the communicating portion. A vehicle seat member has been proposed.

JP 2011-16458 A JP 2017-35378 A

  However, when a core material made of a foamed particle molded body composed of expanded particles having through-holes as used in Patent Document 2 is used, the polyurethane foam laminate is excellent in laminate adhesiveness with polyurethane foam. There was a risk that it would be difficult to control the amount of urethane impregnation at the time.

  The present invention has been made in view of the above-described problems of the background art, and an object of the present invention is to provide a vehicle seat using a core material made of a foamed particle molded body composed of foamed particles having through holes. An object of the present invention is to provide a foamed particle molded body that is excellent in laminate adhesiveness and productivity between a thermoplastic resin foamed particle molded body and a polyurethane foam.

In order to achieve the above object, the present invention provides a vehicle seat member described in the following [1] to [10].
[1] A vehicle seat member comprising: a core material made of a thermoplastic resin foam particle molded body; a polyurethane foam provided on an upper surface side of the core material; and a seat cover that covers the polyurethane foam, The thermoplastic resin foamed particle molded body comprises a fused body of thermoplastic resin foamed particles having through-holes, and the thermoplastic resin foamed particle molded body has voids communicating with the outside, and the thermoplastic resin foamed particle molded body The porosity of the body is 10% by volume or more and less than 25% by volume, and the part of the polyurethane foam is impregnated and solidified in the voids of the thermoplastic resin foam particle molded body, and the thermoplastic resin foam particle molded body The area ratio of the polyurethane foam part in the cut surface obtained by cutting the thermoplastic resin foam molded body along a depth of 3 mm in a direction perpendicular to the upper surface from the upper surface Seat member, characterized in that 5 to 20%.
[2] The area per void in the cut surface obtained by cutting the thermoplastic resin foam particle molded body along the depth of 3 mm in a direction perpendicular to the upper surface from the upper surface of the thermoplastic resin foam particle molded body. The vehicle seat member according to [1], wherein the average value is 4 mm ² or less.
[3] The thermoplastic resin foamed particle molded article has a tensile strength of 0.2 MPa or more, and the thermoplastic resin foamed particle molded article has a compressive stress at 10% compression of 0.1 MPa or more. The vehicle seat member according to [1] or [2].
[4] The molded thermoplastic resin foamed particles are formed by melting tubular thermoplastic resin foamed particles having a compression load A of 10% or more in a direction perpendicular to the through-hole penetration direction of 0.5 N or more. The vehicle seat member according to any one of [1] to [3], wherein the vehicle seat member is attached.
[5] The foamed molded article of the thermoplastic resin has a compressive load B at the time of 10% compression in the penetrating direction of the through hole of 1 N or more, and a ratio B / A of the compressive load B to the compressive load A is 1 The vehicle seat member according to [4], which is formed by fusing cylindrical thermoplastic resin foamed particles that are ~ 3.
[6] The thermoplastic resin foamed particle molded body has an average hole diameter d of 1 to 3 mm and an average wall thickness t of 0.8 to 2 mm, and a ratio of the average wall thickness t to the average hole diameter d. The vehicular seat member according to any one of [1] to [5], which is formed by fusing cylindrical thermoplastic resin foam particles having a t / d of 0.4 to 1.
[7] The molded body density of the thermoplastic resin foamed particle molded body is 20 to 40 kg / m ³ , and the flexural modulus of the propylene-based resin constituting the thermoplastic resin foamed particle molded body is more than 1200 MPa. The vehicle seat member according to any one of [1] to [6].
[8] A stopper fixing groove is formed on the periphery of the bottom surface of the thermoplastic resin foamed particle molded body, and a stopper for fixing the seat cover is inserted into the stopper fixing groove. The vehicle seat member according to any one of 1] to [7].
[9] The vehicle seat member according to any one of [1] to [8], wherein an annular frame member is embedded in a peripheral portion of the thermoplastic resin foamed particle molded body by insert molding.
[10] The thermoplastic resin foam particles having the through holes are multilayer foam particles having a cylindrical polypropylene resin foam core layer and a polyolefin resin coating layer covering the foam core layer, and the coating layer The vehicle seat member according to any one of [1] to [9], wherein a melting point of the resin constituting the foam core is lower than a melting point of the resin constituting the foam core layer.

  According to the above-described vehicle seat member according to the present invention, the specific void ratio and the specific properties are satisfied even though the vehicle-formed seat member is constituted by the expanded particle molded body made of thermoplastic resin expanded particles having through holes. By using the molded body, the laminate adhesiveness and productivity of the thermoplastic resin foam particle molded body and the polyurethane foam are excellent.

  Further, by using a molded body composed of expanded particles satisfying specific properties, the fusion property and compression characteristics of the expanded particles located on the surface of the expanded particle molded body can be improved. When the stopper is inserted and fixed in the stopper fixing groove formed in the stopper, the stopper can be sufficiently fixed. Therefore, the fixing performance of the seat cover is also excellent.

It is the perspective view which showed one Embodiment of the vehicle seat member of this invention. It is sectional drawing which showed the fixing structure of the seat cover. (A) is the schematic diagram which illustrated the shape of the single layer thermoplastic resin expanded particle which has a through-hole of this invention, (b) is the multilayer thermoplastic which has the through-hole used in the Example of this invention. It is the schematic diagram which showed the shape of the resin foam particle. It is the schematic diagram which showed the shape of the thermoplastic resin expanded particle which has a through-hole used by the comparative example of this invention. It is a perspective view of the frame member used for the vehicle seat member shown in FIG. It is the perspective view which showed one Embodiment of the fastener used for this invention. (A) is a schematic diagram of a surface state of a thermoplastic resin foam particle molded body corresponding to an example of the present invention (a surface state in which only the outermost surface of the molded body is colored black and the direction of the expanded particle is emphasized); b) is a schematic diagram of a surface state of a thermoplastic resin foam particle molded body corresponding to a comparative example of the present invention (a surface state in which only the outermost surface of the molded body is black-colored and the direction of the expanded particles is emphasized). . (A) is an enlarged photograph of the cross section of a thermoplastic resin foam particle molded body cut along a depth of 3 mm from the upper surface of the thermoplastic resin foam particle molded body, and (b) is the thermoplastic resin foam particle molded body. It is a schematic diagram for demonstrating the cutting position.

Hereinafter, embodiments of a vehicle seat member according to the present invention will be described in detail with reference to the drawings.
In the following description, the preferred numerical range of the present invention may be shown as appropriate. In this case, the preferred range regarding the upper and lower limits of the numerical range, the more preferred range, and the particularly preferred range are all the upper and lower limits. Can be determined from the combination of Further, unless otherwise specified in the present specification, the front-rear direction, the left-right direction, and the up-down direction of the vehicle seat member are the front-rear direction, the left-right direction, and the up-down direction of the vehicle when installed in the vehicle. It is the same. In addition, in the present specification, the term “shrinkage” refers to molding shrinkage that occurs after molding of the thermoplastic resin foam particle molded body.

  As shown in FIG. 1, a vehicle seat member 100 according to the present invention includes a core material 10 formed of a thermoplastic resin foam particle molded body (hereinafter also simply referred to as “foamed particle molded body”), and the core material 10. A polyurethane foam 20 provided on the upper surface and a seat cover 30 provided on the outer surface side of the polyurethane foam 20 are provided.

  The core material 10 made of the foamed particle molded body is formed in a substantially rectangular parallelepiped shape, and as shown in FIG. 2, a stopper fixing groove 40 is formed at an appropriate position on the peripheral edge of the bottom surface. It is preferable that the stopper 50 of the seat cover 30 is inserted and the seat cover 30 is fixed to the core member 10.

  The core material 10 is preferably an integral molded product of the foamed particle molded body 11 and the frame member 12. The foamed particle molded body 11 will be described in detail later, and as shown in FIG. 3, the thermoplastic resin foam particles 60 (hereinafter also simply referred to as “foamed particles 60”) having through holes 61 are fused to each other. The foamed particle molded body 11 is molded and has voids. The foamed particle molded body 11 constituting the core material 10 is formed to satisfy properties such as a specific porosity and a specific tensile strength.

  In the present invention, the porosity of the foamed particle molded body 11 is 10% by volume or more and 25% by volume or less. If the porosity is too low, it becomes difficult to form a structure in which a part of the polyurethane foam 20 laminated above the voids of the foamed particle molded body 11 enters, and the foamed particle molded body 11 and the polyurethane foam 20 There is a possibility that the adhesiveness of the resin may be lowered. From this viewpoint, the lower limit of the predetermined range of the porosity is preferably 12% by volume or more, and more preferably 14% by volume or more. On the other hand, if the porosity is too high, the polyurethane foam may enter too much, resulting in poor productivity. Further, a stopper fixing groove is formed at the periphery of the bottom surface of the thermoplastic resin foam particle molded body, and when the stopper for fixing the seat cover is inserted into the stopper fixing groove, the seat cover 30 There is a possibility that the stopper 50 is easily detached from the stopper fixing groove 40 formed in the foamed particle molded body 11. From such a viewpoint, the upper limit of the predetermined range of the porosity is preferably 20% by volume or less, and more preferably 19% by volume or less.

Incidentally, the porosity of the foamed bead molded article 11 has a volume H obtained from the outside dimension of the foamed bead molded article (cm ^3), from the volume I except the gap portion of the foamed bead molded article (cm ^3), the following The volume ratio is calculated according to (Equation 1).

Porosity (volume%) = [(HI) / H] × 100 (Formula 1)

Specifically, it can be measured as follows.
Ten or more measurement target locations are randomly selected from the foamed particle molded body after the molding shrinkage is settled, and a rectangular parallelepiped having a volume of 50 cm ³ or more (for example, a rectangular parallelepiped having a size of 25 mm × 25 mm × 100 mm). ) Cut out a cut sample that does not have a shaped skin surface. For each of the cut sample, and calculates the volume H (cm ³⁾ from the cut sample external dimensions, measuring the volume excluding the void portion of the cut sample I (cm ^3). The volume I can be determined as a value for an increase in volume when the cut sample is submerged in alcohol. At this time, as alcohol, ethanol etc. can be used, for example. And based on the value of the volume H and the value of the volume I, the porosity is calculated as a volume ratio by the above (formula 1) (volume%). The porosity value calculated for each cut sample is arithmetically averaged and used as the porosity.

  A portion of the polyurethane foam has entered and solidified in the voids on the surface of the thermoplastic resin foam particle molded body, and the thermoplastic resin has a depth of 3 mm from the top surface of the thermoplastic resin foam particle molded body. The area ratio (hereinafter also referred to as impregnation ratio α) of the polyurethane foam portion in the cross section of the foamed particle molded body is preferably 5 to 20%. By satisfy | filling the said requirements, the sheet | seat core material for vehicles of this invention can maintain moderate adhesiveness of urethane, without being impregnated too much when laminating | stacking a polyurethane foam. From the above viewpoint, the upper limit of the impregnation ratio α is preferably 18% or less, more preferably 15% or less, and still more preferably 13% or less. The impregnation ratio is preferably a foamed particle molded body formed by in-mold molding using specific foamed particles described later.

  As shown in FIG. 8B, the measurement is performed using a cutter or the like in the depth direction perpendicular to the surface of the foamed particle molded body along the depth of 3 mm from the upper surface of the thermoplastic resin foamed particle molded body. It can be calculated by cutting and measuring the area of the portion where the polyurethane foam is present from a cross-sectional photograph (see FIG. 8A) in the cross section. In the measurement, it is preferable to measure a portion having a flat surface. If the measurement location is uneven, the projected area of the cut surface is measured.

It is preferable that the area ratio β per void in the cut surface along the depth of 3 mm from the upper surface of the thermoplastic resin expanded particle molded body is 0.4% or less. In addition, a space | gap means here the clearance gap part between the through-hole part of a foamed particle, and a foamed particle. Within the above range, since the area per void is small, the polyurethane foam is not excessively impregnated and has appropriate adhesiveness. From the above viewpoint, the area ratio β is preferably 0.3% or less, and more preferably 0.2% or less. The lower limit is approximately 0.05%. The foamed particle molded body that satisfies the above requirements is preferably a foamed particle molded body formed by in-mold molding using specific foamed particles described later.
The area γ (mm ² ) per void in the cross section along the depth of 3 mm from the upper surface of the thermoplastic resin expanded particle molded body is preferably 4 mm ² or less. Within the above range, since the area per void is small, the polyurethane foam is not excessively impregnated and has appropriate adhesiveness. From the above viewpoint, the area γ is preferably 3.5 mm ² or less, and more preferably 3.0 mm ² or less.

  In addition, the measurement of the area ratio β and the area γ per one void was measured in the same manner as when measuring the impregnation ratio α, a cross-sectional photograph of the thermoplastic resin foam particle molded body, The sum of the part impregnated with the polyurethane foam and the area of the void part not impregnated with the polyurethane foam is calculated. The through hole portion of the expanded particle and the gap portion between the expanded particles are added together. Then, the area γ and the area ratio β can be calculated as average values by dividing the sum by the number of voids in the photograph.

In the present invention, it is preferable that the compression stress (hereinafter also referred to as “10% compression stress S”) of the foamed particle molded body 11 at 10% compression is 0.1 MPa or more. When foamed particles are missing from the surface of the molded body, when the foamed particles on the surface of the molded body are locally compressed by a compressed material such as a stopper, the portion is recessed, and there is a stopper or the like between the surrounding foamed particles. It is considered that the foamed particles are easily caught from the surface of the molded body. Within the above range, even when the peripheral surface portion of the foamed particles located on the surface of the molded body is exposed on the surface, the foamed particles can withstand local compression and the foamed particles are missing from the surface of the molded body. Is prevented.
Further, when a stopper fixing groove is formed in the peripheral edge of the bottom surface of the thermoplastic resin foam particle molded body, and a stopper for fixing the seat cover is inserted into the stopper fixing groove, an external force is applied to the stopper 50. In this case, external force is locally applied to the wall surface of the stopper fixing groove 40 by the stopper 50, and the foam particles constituting the wall surface of the stopper fixing groove 40 may be crushed. If the compressive stress is within the above range, the through hole portion is prevented from being crushed extremely even if the wall surface is constituted by the foamed particles 60 having the through hole. Can be fixed. From such a viewpoint, the 10% compressive stress of the foamed particle molded body 11 is preferably 0.1 MPa or more and 0.3 MPa or less.

  Moreover, in this invention, it is preferable that the tensile strength T of the said foaming particle molded object 11 is 0.2 Mpa or more. If it is the said range, since it is excellent in the melt | fusion property of expanded particles, the expanded particle located in the molded object surface becomes difficult to chip. Furthermore, when a stopper fixing groove is formed in the periphery of the bottom surface of the thermoplastic resin foamed particle molded body, and a stopper for fixing the seat cover is inserted into the stopper fixing groove, an external force is applied to the stopper 50. In some cases, the foam 50 constituting the wall surface of the stopper fixing groove 40, which is the surface of the foamed particle molded body, is detached from the wall surface and chipped by the stopper 50. When the foamed particles constituting the wall surface are missing, it may be insufficient to fix the stopper 50. If the tensile strength is within the above range, the foamed particles are sufficiently fused with each other and chipping of the foamed particles is prevented, so that the stopper 50 can be sufficiently fixed in the groove 40. From this viewpoint, the tensile strength of the foamed particle molded body 11 is preferably 0.2 MPa or more and 4 MPa or less, and more preferably 0.25 MPa or more and 2 MPa or less.

  Moreover, it is preferable that the compression elastic modulus of the said foaming particle molded object 11 is 1.9 Mpa or more and 5 Mpa or less. This is because the stopper 50 moves when the stopper 50 of the seat cover 30 is inserted and fixed in the stopper fixing groove 40 formed on the peripheral edge of the bottom surface when the compression elastic modulus is in the numerical range. Even so, it can be sufficiently fixed. From this viewpoint, the compression elastic modulus of the foamed particle molded body 11 is more preferably 2 MPa or more and 4 MPa or less.

  In addition, the measured value can be employ | adopted for the tensile strength of the said foaming particle molded object 11 based on JISK6767 (1999). Specifically, a test piece of foamed particle compact having a dumbbell-like shape is attached to a tensile tester so that the distance between the clamps is 90 mm, and a load is applied at a tensile speed of about 500 mm per minute. The load at the time of fracture can be measured, and the tensile strength can be calculated from the obtained measured value. Further, 10% compression stress and compression modulus of the foamed particle molded body 11 were obtained by cutting out a test piece having a length of 50 mm, a width of 50 mm, and a thickness of 50 mm from the foamed particle molded body, and using the test piece, JIS K 6767 (1999). ) According to the compression test. In addition, when the sample thickness is 50 mm or less, a plurality of samples can be stacked and measured.

Furthermore, from the viewpoint of being excellent in strength and impact resistance and having appropriate elasticity, the molded body density of the foamed particle molded body 11 is preferably 20 kg / m ³ or more and 40 kg / m ³ or less. In particular, from the viewpoint of the fixability of the stopper 50, it is more preferably 25 kg / m ³ or more and 35 kg / m ³ or less. A plurality of expanded particle molded bodies having different molded body densities can be combined into a single expanded particle molded body 11. In this case, the density of each molded body of the expanded particle molded bodies 11 having different molded body densities may be within the above numerical range.

In addition, the measuring method of the molded object density of the said foaming particle molded object 11 can be measured as follows.
A cut sample of a predetermined size is cut out at five or more locations arbitrarily selected from the foamed particle molded body 11, the volume V (cm ³ ) of the cut sample is calculated from the outer diameter size, and the weight M ( g) is measured. Then, M / V is calculated by dividing the weight M (g) of the cut sample by the volume V (cm ³ ) of the cut sample. The value of M / V calculated for each cut sample can be arithmetically averaged to obtain the molded body density of the foamed particle molded body 11.

Next, in the present invention, the expanded particle 60 having a through hole used for forming the expanded particle molded body 11 will be described in detail.
Examples of the thermoplastic resin constituting the expanded particles 60 include polystyrene resins, polyolefin resins such as polyethylene and polypropylene, polybutylene succinate, polyethylene terephthalate, polyester resins such as polylactic acid, and polycarbonate resins. In addition, as the resin, a composite resin of a polystyrene resin and a polyolefin resin, a mixture of two or more of the above resins, and the like can also be used.

  As the thermoplastic resin constituting the expanded particles 60 (that is, the thermoplastic resin constituting the expanded particle molded body 11), a polyolefin resin or a composite resin of a polyolefin resin and a polystyrene resin is more preferable. The polyolefin resin is preferably a polyethylene resin or a polypropylene resin, and more preferably a polypropylene resin from the viewpoint of strength or impact resistance.

  Moreover, as a polypropylene resin, it is preferable that a bending elastic modulus is 800-1800 MPa, It is more preferable that it is 950-1600 MPa, It is still more preferable that it is 1100-1500 MPa. If it is in the said range, even if it is a foamed particle which has a through-hole, since it can endure local compression, the chip | tip of the foamed particle molded object surface can be suppressed. The bending elastic modulus of the resin can be obtained by preparing a test piece (test piece dimensions: length 80 mm, width 10 mm, thickness 4 mm) by injection molding based on JIS K 7171 (2008). In the case of the foamed particles having a multilayer structure, the resin constituting the core layer may satisfy the above range.

  The foamed particle molded body 11 composed of the foamed particles 60 containing a crystalline resin such as a polypropylene resin has a higher shrinkage rate than when an amorphous resin is used. In particular, when the foamed particle 60 having a through hole is used and the foamed particle molded body 11 and the frame member 12 having the above-described predetermined porosity are insert-molded, the dimensional error or warpage of the foamed particle molded body 11 is obtained. Is satisfactorily suppressed.

Further, the foamed particles 60 are formed with through holes 61 as shown in FIG. The illustrated expanded particle 60 has a through hole 61 having a circular cross section and is formed in a cylindrical shape. However, this does not limit the shape of the foamed particle 60. For example, the foamed particle 60 has at least a cylindrical hole penetrating in the vertical direction of a columnar foamed particle such as a cylinder, an elliptical column, or a prism. However, the present invention is not limited to this. The bulk density of the expanded beads is preferably 15~40kg / m ^3, and still more preferably from 20-30 kg / m ^3. For the bulk density, a 1 L graduated cylinder is prepared, and the composite thermoplastic resin foam particles are filled up to the 1 L mark of the graduated cylinder. The bulk density (kg / m ³ ) can be calculated by measuring the weight of the thermoplastic resin expanded particles per liter and converting the unit.

The average hole diameter d, which is the diameter of the through hole 61 of the expanded particle 60, is preferably 1 mm or more and 3 mm or less. When the average hole diameter d of the through holes 61 is within the above range, the voids of the foamed particle molded body 11 can be easily adjusted to a predetermined range. From this viewpoint, the average hole diameter d of the through holes 61 is more preferably in the range of 1.5 mm or more and 2.5 mm or less.
In addition, the average hole diameter d of the through-hole 61 measured the cross-sectional area of the through-hole 61 of the 50 or more foamed particle 60 observed in the cross-sectional photograph (cross-section orthogonal to a through-hole) of a foamed particle, and a cross-sectional area is circular. It can be calculated from these arithmetic averages in terms of the diameter of the area.

Moreover, it is preferable that the average thickness t of the foamed particle 60 is 0.8-2 mm. If the foamed particles used in the foamed particle molded body 11 of the present invention are within the above range, the foamed particles are not easily crushed by an external force because the foamed particles are thick, and the foamed particles located on the surface of the molded body It becomes difficult to chip. Further, when polyurethane foam is laminated, it has an appropriate impregnation property. Furthermore, when the average thickness of the foamed particles is thick, the secondary foaming force during molding tends to be high, and therefore the fusion property between the foamed particles constituting the surface of the resulting foamed particle molded body 11 is particularly high. Since it improves, the chip | tip of the molded object surface is prevented more. In addition, since the foamed particles constituting the wall surface of the stopper fixing groove 40 are difficult to be chipped, the fixing of the stopper 50 is further improved. From the above viewpoint, the average thickness t of the expanded particles 60 is more preferably 0.9 to 1.5 mm.
The average thickness t of the expanded particles 60 refers to the thickness from the surface of the expanded particles to the outer diameter of the through holes in FIG. 3. For example, in the cross-sectional photograph of the expanded particles (the cross section orthogonal to the through holes) A straight line is drawn from the particle surface toward the center of the through hole, and the length of the straight line from the surface of the expanded particle to the through hole wall portion of the expanded particle is measured. The thickness of the plurality of expanded particles observed as described above can be obtained as an arithmetic average of a total of 50 or more expanded particles evenly at 4 or more locations per expanded particle.

  Further, the ratio t / d of the average thickness t of the expanded particles 60 to the average pore diameter d of the through holes 61 of the expanded particles 60 is preferably 0.4 to 1, and preferably 0.6 to 0.9. It is more preferable. If the foamed particles used in the foamed particle molded body 11 of the present invention are within the above range, the difference between the two in the compression characteristics of the through direction of the through hole of the foamed particle and the direction perpendicular to the through hole is small. Further, the fixing of the stopper 50 is further improved.

The average outer diameter D of the expanded particles 60 is preferably 1.5 to 7 mm. If it is in the said range, a favorable molded object can be obtained. From the above viewpoint, the average outer diameter D of the expanded particles is more preferably 2 to 6 mm. The average outer diameter D of the expanded particles is a diameter when the cross-sectional area (including the hole portion of the expanded particles) in the cross section perpendicular to the through-hole of the expanded particles 60 is converted into a circle, and a total of 50 or more expanded particles It can be calculated as the arithmetic average of
The average length L of the expanded particles is preferably 2 to 7 mm. The average length L of the expanded particles refers to the length in the penetration direction of the through holes of the expanded particles, and can be obtained as an arithmetic average of a total of 50 or more expanded particles evenly at four or more locations per expanded particle.
In addition, the ratio L / D of the average length L to the average outer diameter D of the expanded particles 60 is preferably 0.5 to 2 and more preferably 1 to 1.5 from the viewpoint of moldability. .

  In addition, in the same manner as the measurement method of the expanded particles 60, the diameter d, the outer diameter D, the thickness t, etc. of the through holes of the expanded particle portion forming the molded body 11 can also be measured. In this case, it is possible to directly measure the through-hole portion of the foamed particle exposed on the surface of the molded body using a caliper or the like.

Moreover, it is preferable that the compression load A at the time of 10% compression to the direction perpendicular | vertical to the penetration direction of the through-hole of the foaming particle 60 per foaming particle is 0.5 N or more. Since the expanded particles 60 used in the present invention are excellent in compression characteristics in a direction perpendicular to the direction of penetration of the through holes, the peripheral surface portion 64 of the expanded particles is exposed on the surface of the expanded particle molded body (FIG. 7 ( Even a) see)) can withstand local compression, and chipping of the expanded particles located on the surface of the molded body is prevented. FIG. 7 is a diagram in which the outermost surface of the molded body is black-colored with ink or the like, and the direction of the expanded particles located on the surface of the molded body is emphasized. From FIG. 7, it can be seen that the foamed particles 60 located on the surface of the molded body 11 include those in which the through-hole cross-sectional portion 65 is exposed or those in which the peripheral surface portion 64 is exposed. Since only the outermost surface portion is colored black, the voids in the white portion are emphasized, but the adjacent foam particles 60 are fused to form the surface of the molded body.
In addition, if the foamed particles have excellent local compression characteristics, even the foamed particles having through holes are relatively thick. Therefore, in the impregnation of the polyurethane foam, the polyurethane foam is appropriately impregnated and the density of the polyurethane foam can be controlled. It becomes easy and has good adhesiveness. Further, even when the peripheral surface portion 64 of the foamed particles is exposed on the wall surface of the wall surface of the stopper fixing groove 40, it can withstand local compression even when the stopper 50 is displaced by an external force, and is sufficient. It is possible to hold the stopper 50. From the above viewpoint, the compression load A at the time of 10% compression in the direction perpendicular to the penetration direction of the through hole of the foamed particle 60 per foamed particle is preferably 0.6 N or more, more preferably 0.7 N or more. It is. The upper limit of the compression load A at 10% compression is approximately 2N.

  Further, the compression load B at the time of 10% compression in the penetration direction of the through hole of the foamed particle 60 per foamed particle is preferably 1 N or more, and more preferably 1.2 N or more. Thereby, the foamed particles 60 used in the present invention can more resist the movement of the stopper 50 even in the foamed particles on the groove wall surface forming the stopper fixing groove 40.

  In particular, the expanded particles 60 used in the present invention have a compressive load at the time of 10% compression in the through direction of the through holes with respect to a compressive load A at the time of 10% compression in the direction perpendicular to the through direction of the through holes of the expanded particles. The ratio B / A of B is preferably 1 to 3. In the foamed particle molded body having through holes, when the surface of the foamed particle molded body is formed, the local strength may vary greatly depending on the direction in which the foamed particles are arranged. That is, when the foamed particles are filled in the mold and molded in the mold, the through-hole portion 65 or the peripheral surface portion 64 appears on the surface of the foamed particle molded body (see FIG. 7). ). Which portion appears on the surface is considered to be randomly arranged, but when the peripheral surface portion 64 appears on the surface, it is considered that the local compression characteristics deteriorate. However, if it is within the above range, even if the arrangement direction of the expanded particles is different, the difference in compression characteristics due to the directionality of the expanded particles is small, so that the local compression properties are improved, Chipping of the expanded particles constituting the surface of the particle compact is prevented. In addition, if the compression ratio of the foamed particles is excellent, the through-holes of the foamed particles are not too large, can withstand the urethane impregnation pressure, and the polyurethane foam is appropriately impregnated, resulting in better adhesion. It will have. Further, when the stopper 50 is fixed, the stopper 50 is effectively prevented from being displaced in the stopper fixing groove 40. From the above viewpoint, the compression load ratio B / A of the expanded particles is more preferably 1.1 to 2.

  In addition, the compression load at the time of 10% compression of the expanded particles 60 per expanded particle is set to a test speed of 1 mm / min for one expanded particle as a test sample, and a compression test is performed according to JIS K 6767 (1999). Obtained by doing. In the measurement, each of the compression load A and the compression load B can be measured by changing the direction in which the expanded particles are placed on the flat plate, and the average value of 20 expanded particles is obtained.

  The expanded particle 60 may be composed of one layer from the outer surface to the inner surface, but is not limited to this and may have a multilayer structure. The resin constituting each layer of the multilayer expanded particle 60A having a multilayer structure may be the same type of resin or a different resin. For example, like a multilayer expanded particle 60A shown in FIG. 3 (b), it may be cylindrical and have a two-layer structure from the outer surface to the inner surface.

  As shown in FIG. 3B, the multilayer expanded particle 60 </ b> A having the through-hole 61 covers a cylindrical polypropylene resin foam core layer 62 (hereinafter also simply referred to as “core layer 62”) and the core layer 62. It preferably has a multilayer structure having a polyolefin-based resin coating layer 63 (hereinafter also simply referred to as “coating layer 63”). The illustrated multilayer expanded particle 60 </ b> A has a two-layer structure, but an arbitrary intermediate layer may be further provided between the core layer 62 and the covering layer 63.

  In the multilayer foamed particle 60A, the core layer 62 is a foamed layer made of a foamed resin, whereas the coating layer 63 may be a substantially non-foamed resin layer. Here, the term “substantially” means that there are no bubbles in the coating layer 63 (including those in which the bubbles once formed when the foamed particles are foamed are melted and destroyed and the bubbles disappear), In the range that does not affect the mechanical strength of the obtained foamed particle molded body 11, those having a very small number of fine bubbles are also included. The resin constituting the covering layer 63 is not particularly limited as long as it is a thermoplastic resin. For example, it may be a resin having the same physical properties, but is preferably a resin having a different melting point. In particular, the resin constituting the coating layer 63 of the multilayer expanded particle 60 </ b> A is preferably a resin having a lower melting point than the resin constituting the core layer 62. As the base resin of the covering layer 63, the same resin as the single-layer foamed particles 60 described above can be used. Among these, it is more preferable that the core layer 62 is a polypropylene resin and the coating layer 63 is a polypropylene resin or a polyethylene resin.

  Part or all of the expanded particles used in the expanded particle molded body 11 is a multilayer expanded particle 60A having a core layer 62 and a coating layer 63 covering the core layer 62, and the melting point of the resin constituting the coating layer 63 However, an embodiment in which the melting point of the resin constituting the core layer 62 is lower is one of the preferred embodiments of the present invention. According to this aspect, when the foamed particle molded body 11 is molded in the mold, the coating layer 63 is melted prior to the core layer 62 and the voids due to the through holes 61 are maintained, while the multilayer foam particles 60A (or the multilayer foaming) are maintained. The expanded particle molded body 11 can be molded by more reliably fusing the particles 60A and the expanded particles 60). Therefore, since the fusion property between the expanded particles on the surface of the molded body is improved, the expanded particles located on the surface of the expanded particles are hardly chipped. In particular, in the foam particles constituting the wall surface of the stopper fixing groove 40, even if the stopper moves, the foam particles constituting the wall surface are not easily chipped, and the stopper 50 is more difficult to come off from the stopper fixing groove 40.

  In the present invention, it is preferable to use foamed particles having a multilayer structure and a thick wall as the foamed particles having through holes. Due to the effect of improving the secondary foaming force by increasing the thickness of the foamed particles 60 having through-holes, the fusion property of the obtained foamed particle molded body 11 can be improved. In addition, since the thickness of the through-hole portion of the expanded particle is thick and the portion to be fused with the adjacent expanded particle is increased, the fusibility of the expanded particle existing on the surface of the expanded particle molded body is improved. Furthermore, the fusion property of the foamed particles themselves can be improved by using the multilayer foamed particles 60A. As a result, it is possible to prevent the foamed particles located on the surface of the foamed particle molded body from being chipped by external force. Furthermore, it becomes the expanded particle molded object 11 which satisfies the specific tensile strength and compression elastic modulus mentioned above, and can exhibit the durability which can fix the stopper 50.

The expanded particles 60 having through-holes used in the present invention can be manufactured, for example, as follows.
First, after melt-kneading a polypropylene resin as a base resin with an extruder, the resin particles are extruded into a strand shape and then cooled to an appropriate length after being cooled, or cut to an appropriate length and then cooled after being cooled. Manufacturing. At this time, to select a die having a slit similar to the cross-sectional shape of the desired cylindrical thermoplastic resin particles at the molten resin outlet of the extruder die, or to maintain the cylindrical shape, the inside of the slit By using a tube provided with a pressure adjusting hole for maintaining the pressure of the cylindrical strand hole at normal pressure or higher, expanded particles having a through hole can be produced.
Next, the resin particles are dispersed in a dispersion medium in the presence of a foaming agent in an airtight container, and heated to a temperature equal to or higher than the softening temperature of the resin particles to impregnate the resin particles with the foaming agent. After that, the container is opened, and the resin particles and the dispersion medium are simultaneously released into an atmosphere at a lower pressure than the inside of the container (usually under atmospheric pressure) while maintaining the pressure inside the container at a pressure higher than the vapor pressure of the foaming agent. Foamed particles 60 having through holes can be obtained by foaming the thermoplastic resin particles.

Further, the multilayer expanded particle 60A can be manufactured, for example, as follows.
Here, the foamed core layer 62 made of polypropylene resin and the polypropylene resin having a melting point Ts (° C.) lower than the melting point Tc (° C.) of the polypropylene resin constituting the core layer 62 are used. A method for manufacturing the multilayer expanded particle 60A including the non-expanded coating layer 63 will be described as an example.

First, multilayer resin particles including a non-foamed core layer and a non-foamed coating layer are produced as follows.
Two extruders, a core layer forming extruder and a coating layer forming extruder, are connected to a coextrusion die, and the core layer forming extruder includes a polypropylene resin for forming the core layer and, if necessary, The additive to be added is supplied and melt-kneaded. One extruder for forming a coating layer is supplied with a polypropylene resin for forming the coating layer and an additive that is added as necessary, and is melt-kneaded. Further, a sheath core type composite comprising a non-foamed cylindrical core layer and a non-foamed coating layer covering the outer surface of the core layer by joining the respective melt-kneaded materials in the coextrusion die. Form the body. Then, the composite layer is extruded from the pores of the die attached to the tip of the extruder, and is cut so as to have a predetermined weight. Multilayer resin particles having through-holes made of a coating layer made of can be obtained.

Next, the multilayer resin particles obtained as described above are dispersed in a dispersion medium in a closed container such as an autoclave, heated at a temperature equal to or higher than the softening temperature of the polypropylene resin that constitutes the core layer, and a foaming agent is pressed into the multilayer resin. The resin particles are impregnated with a foaming agent. Then, one end in the sealed container is opened while maintaining the pressure in the sealed container at a pressure equal to or higher than the vapor pressure of the foaming agent, and the multilayer resin particles and the dispersion medium are simultaneously released into an atmosphere at a lower pressure than in the container. At this time, the multilayer resin particles are foamed. By foaming, at least the core layer is in a foamed state to form a foamed core layer (core layer 62). In this way, the multilayer expanded particle 60A can be obtained. In the dispersion medium releasing foaming method, an aqueous medium is usually used as the dispersion medium.
In the dispersion medium releasing foaming method, it is preferable to add a dispersant to the dispersion medium so that the multilayer foam particles 60A heated in the container do not fuse with each other. The dispersant is preferably used in the range of 0.001 part by mass or more and 5 parts by mass or less per 100 parts by mass of the multilayer expanded particles 60A.

  Examples of the blowing agent include aliphatic hydrocarbons such as propane, butane, pentane, hexane, and heptane, cyclic aliphatic hydrocarbons such as cyclopentane and cyclohexane, chlorofluoromethane, trifluoromethane, 1, 2 and the like. -Organic physical foaming agents such as halogenated hydrocarbons such as difluoroethane, 1,2,2,2-tetrafluoroethane, methyl chloride, ethyl chloride, methylene chloride, and so-called nitrogen, oxygen, air, carbon dioxide, water An inorganic physical foaming agent is illustrated. An organic physical foaming agent and an inorganic physical foaming agent can also be used in combination. Among these various physical foaming agents, those mainly composed of one or more inorganic physical foaming agents selected from the group consisting of nitrogen, oxygen, air, carbon dioxide, and water are suitable. The filling amount of the foaming agent in the dispersion medium releasing foaming method is appropriately selected according to the type of foaming agent used, the foaming temperature, and the apparent density of the foamed particles to be obtained. Specifically, for example, when carbon dioxide is used as a foaming agent and water is used as a dispersion medium, the pressure in the sealed container in a stable state immediately before the start of foaming, that is, the pressure in the space in the sealed container (gauge pressure) ) Is preferably 0.6 MPa (G) or more and 6 MPa (G) or less.

  Next, the frame member 12 will be described. The frame member 12 is embedded in the foamed particle molded body 11 described above, reinforces the foamed particle molded body 11, and supports various stoppers. For example, as shown in FIG. 5, the frame member 12 includes an outer frame portion 12A and a center frame portion 12B, and a rear latch 12C and a front latch 12D are welded and supported at appropriate positions of the outer frame portion 12A. Has been.

  The frame member 12 is generally made of a metal member such as iron, aluminum, or copper, a resin member, or a member such as ceramics. Among these, from the viewpoints of durability, strength, and heat resistance to heat at the time of molding the foamed particle molded body 11, the frame member 12 preferably includes a metal member, and more preferably substantially includes a metal member. . The metal member is particularly preferably a steel material. The frame member 12 can be formed by welding or bending these members.

The frame member 12 is preferably composed of a long member having a diameter of 2 mm or more and 8 mm or less, more preferably 3 mm or more and 7 mm or less, and particularly preferably 3.5 mm or more and 6 mm or less. The tensile strength of the long member is preferably 200 N / mm ² or more. From the viewpoint of improving the strength of the core member 10, it is more preferable that the tensile strength is 250 N / mm ² or more 1300 N / mm ² or less. Further, the yield point of the long member is preferably 400 N / mm ² or more, and more preferably 440 N / mm ² or more. The long member having the above-described diameter and tensile strength can be easily formed into a predetermined shape, and the moderate strength and light weight of the core material 10 can be maintained.
In addition, the tensile strength of the said elongate member can be measured according to the measuring method shown by JISG3532 SWM-B.

  In order to dispose the frame member 12 inside the foamed particle molded body 11, insert molding is preferably employed, and the foamed particle molded body 11 and the frame member 12 are preferably integrally molded.

  In particular, in the production of a core material that is attached by embedding a part of the frame member in the foamed particle molded body, the foamed particles are molded in a state where the frame member is placed in a mold for molding the foamed particle molded body. According to the manufacturing method (hereinafter also referred to as “insert molding”) in which the foamed particle molded body and the frame member are integrated, the integrity of the foamed particle molded body and the frame member can be improved. Due to the difference in rate, the core material may be curved after molding, and dimensional errors and warpage may easily occur.

The core material 10 having the above-described structure is formed by using a foamed particle 60 having a through-hole (concept including the multilayer foamed particle 60A) without any loss of mechanical strength of the foamed particle molded body 11 over a predetermined range. Due to the presence of such voids, the bending of the core material 10 due to molding shrinkage of the foamed particle molded body 11 is suppressed, and the dimensional accuracy of the core material 10 is improved.
In addition, it is preferable that the said core material 10 has the annular frame member 12 from a viewpoint of the intensity | strength of the core material 10, and fixation to a vehicle body. The annular frame member 12 is preferably embedded along the outer edge of the expanded particle molded body 11 in plan view.

  Moreover, it is preferable that the foamed particle molded body 11 of the core material 10 is composed of the foamed particles 60 having through holes, and has slits (not shown) formed to alleviate unequal shrinkage due to molding shrinkage. Since the foamed particle molded body is a fused product of foamed particles having through-holes, the shrinkage force of the foamed particle molded body after molding is small, and the shrinkage force of the foamed particle molded body is divided by forming slits. The Therefore, warpage due to molding is prevented, and the dimensional accuracy is excellent. The slits are formed to alleviate unequal shrinkage at the time of molding shrinkage of the foamed particle molded body due to the frame member 12 being embedded in the foamed particle molded body 11. The shape and formation location of the slit are not limited as long as unreasonable shrinkage due to molding shrinkage can be mitigated, and can be formed in various forms.

  In addition, it is necessary to form the slit formed in the foamed particle molded body 11 as quickly as possible from the time when the foamed particle molded body formed by the molding apparatus is taken out of the mold and warped. Therefore, after taking out from a shaping | molding die, it can cut with a cutter, a heat ray, etc. in the preset place and depth. In addition to forming the slit, the slit may be formed in advance by forming a protrusion for forming the slit in the mold. Further, the width of the formed slit is preferably 0.1 to 20 mm, and more preferably 0.2 to 10 mm.

The core material 10 which is an integrally molded product of the foamed particle molded body 11 and the frame member 12 is manufactured as follows, for example.
First, the frame member 12 is arranged at a predetermined position in the core material molding die, and the foam particles 60 having through holes are filled in the die. Subsequently, heated foam is introduced into the mold, the foamed particles 60 having through holes are heated and subjected to secondary foaming, and the foamed particles 60 are fused together to embed the frame member 12. It is manufactured by molding. The core material 10 manufactured in this way is an integrally molded product of the foamed particle molded body 11 and the frame member 12, and is excellent in the integrity of both.

In the vehicle seat member 100 of the present invention, the polyurethane foam 20 that covers the upper surface of the core material 10 described above is partially solidified by entering the voids of the foamed particle molded body 11 constituting the core material 10. The polyurethane foam is preferably a flexible polyurethane foam that acts as a cushioning material.
As a means for realizing such a structure, a liquid polyurethane foam raw material is supplied onto the foamed particle molded body 11 constituting the core material 10 in a polyurethane foam lamination mold. At this time, when the raw material for polyurethane foam is supplied onto the foamed particle molded body 11, the raw material for polyurethane foam that has entered the voids foams, or the pressure of the polyurethane foam raw material is increased by the pressure at the time of foaming of the raw material for polyurethane foam. When a part is pushed into the gap, a part of the polyurethane foam enters and solidifies in the gap.
In addition, the said raw material for polyurethane foams can use a well-known material suitably, and can contain a polyurethane, various foaming agents, etc. Further, the amount of the liquid polyurethane foam raw material can be appropriately set according to the density of the desired polyurethane foam. Moreover, the conditions for foaming the raw material for polyurethane foam can also be set as appropriate.

  The vehicle seat member 100 has cushioning properties when the upper surface of the hard core material 10 is covered with the polyurethane foam 20 and has a lower core material 10 made of a lightweight material, so that the strength and rigidity are reduced. It will be excellent. Further, a part of the polyurethane foam 20 enters the voids of the foamed particle molded body 11 constituting the core material 10 and is solidified and integrated. Since the polyurethane foam 20 and the core material 10 are firmly joined, the both are separated. It will be suppressed.

  In the present invention, a stopper fixing groove 40 is formed at an appropriate position on the peripheral edge of the bottom surface of the core material 10 made of the above-mentioned foamed particle molded body, and the stopper 50 of the seat cover 30 is inserted into the stopper fixing groove 40, The cover 30 is fixed to the core member 10 so as to cover the outer surface side of the polyurethane foam 20.

  The seat cover 30 is not particularly limited, but may be a fiber structure such as a knitted fabric, a woven fabric, or a non-woven fabric, or may be a leather exterior structure such as an artificial leather, a synthetic leather, or a natural leather. Good. The stopper 50 can be made of, for example, a metal such as iron, aluminum, or copper, or a resin. Among them, a resin is preferably used because it is lightweight and easy to mold.

  As long as the stopper 50 is formed so that the seat cover 30 is fixed, the shape is not particularly limited. As shown in FIG. 6, an arrowhead 51 inserted into the stopper fixing groove 40, a seat cover, and the like. It is preferable to have a pressing portion 52 that presses 30, and at the tip of the arrowhead portion 51, when inserted into the stopper fixing groove 40, a plurality of grooves are formed so as to bite into the wall surface of the groove. It is preferable that the projection 53 is provided. The height H of the arrowhead 51 is preferably 10 to 50 mm, and more preferably 15 to 30 mm. Moreover, it is preferable that the width W of the press part 52 is 20-40 mm, and it is more preferable that it is 25-30 mm. The length L of the stopper 50 is preferably 20 to 500 mm, and more preferably 30 to 400 mm.

The stopper fixing groove 40 is formed on the peripheral edge of the bottom surface of the foamed particle molded body 11, and is formed according to the fixing location of the seat cover 30. The stopper fixing groove 40 has a groove depth and a groove width determined in accordance with the stopper 50 described above. From the viewpoint of removal force, a groove depth of 10 to 50 mm and a groove width of 3 to 10 mm are preferable. . Moreover, it is preferable to produce the place where the stopper fixing groove 40 is formed at a position of 10 to 100 mm from the peripheral edge of the bottom surface of the foamed particle molded body 11. Furthermore, in order to improve the removal force of the stopper 50, it is preferable that the stopper fixing groove 40 is formed in the foamed particle molded body 11 not by cutting but by in-mold molding.
In addition, it is preferable that the width | variety of the fastener fixing groove 40 is smaller than the full width of the arrowhead part 51 of the fastener 50, and it is preferable that it is 70 to 95% with respect to the full width of the arrowhead part 51 of the fastener 50, 80 More preferably, it is -90%.

  According to the vehicle seat member 100 according to the present invention, the properties such as the specific porosity and the specific tensile strength, although the foamed particle molded body 11 is composed of the expanded particles 60 having through holes. By using the foamed particle molded body 11 satisfying the above, chipping on the surface of the foamed particle molded body is prevented, and an appropriate impregnation property at the time of polyurethane foam lamination is obtained. Furthermore, when the stopper 50 is inserted into the stopper fixing groove 40 formed in the foamed particle molded body 11 and fixed, the stopper 50 can be sufficiently fixed. Therefore, the fixing performance of the seat cover 30 is excellent.

In addition, a vehicle seat member including a core material formed of a thermoplastic resin foam particle molded body, a polyurethane foam provided on an upper surface of the core material, and a seat cover that covers the polyurethane foam is a through hole as an example. And a foamed particle having a compression load A at 10% compression in a direction perpendicular to the direction of penetration of the through hole of 0.5 N or more, and the foamed particle is a propylene resin having a flexural modulus of 900 MPa or more The foamed particles are molded in-mold and the foamed particles are fused together to have voids communicating with the outside, the porosity is 10 volume% or more and less than 25 volume%, and the molded body density is 20 forming a ~40kg / m ³ thermoplastic resin PP bead molding is, after the polyurethane foam was laminated to a core material made of the thermoplastic resin foamed bead molded article, the polyurethane off Obtained by the method of covering the over arm in the seat cover.

  The Example and comparative example using the expanded particle which has a through-hole were implemented as follows.

The expanded particles used in the examples were prepared as follows.
Polyolefin resin (polypropylene) for forming a core layer by using an extruder having a 65 mm inner diameter core layer forming extruder and an outer cover layer forming extruder having an inner diameter of 30 mm provided with a multilayer strand forming die attached to the outlet side. Resin, melting point: 142 ° C., flexural modulus 1470 MPa), and polyolefin resin for forming a coating layer (polypropylene resin, melting point: 125 ° C.) are supplied to each extruder, melt-kneaded, and A melt-kneaded product was obtained. In addition, zinc borate was added to the resin constituting the core layer as a bubble adjusting agent, and a master batch was prepared using the resin constituting the core layer as a base resin and supplied to the extruder for forming the core layer. The content of zinc borate was adjusted to 1000 ppm by mass.
The two types of melt-kneaded materials obtained as described above were introduced into a die for forming a multi-layer strand, and merged in the die and extruded as a cylindrical strand from a small hole in a die attached to the tip of the die (non-foamed core) % By weight of layer:% by weight of coating layer = 95: 5). The extruded strand was cooled with water, cut with a pelletizer and dried to obtain cylindrical multilayer resin particles. The multilayer resin particle has a structure (sheath core shape) in which a coating layer and a non-foamed core layer are laminated, and has a through hole in the core layer.

800 g of multilayer resin particles prepared as described above and 3 L of water as a dispersion medium were charged into a closed container having a capacity of 5 L. At this time, with respect to 100 parts by mass of the multilayer resin particles, 0.3 parts by mass of kaolin as a dispersant, surfactant (trade name: Neogen (trademark), manufactured by Daiichi Kogyo Seiyaku Co., Ltd., sodium alkylbenzene sulfonate) 0.4 Part by weight (as an active ingredient) and 0.01 part by weight of aluminum sulfate were respectively added to the sealed container. Next, carbon dioxide (3.4 MPa) as a foaming agent is injected into the sealed container, and the contents in the sealed container are heated to a temperature lower by 5 ° C. than the foaming temperature of 146.5 ° C. while stirring the contents. Was maintained for 15 minutes to adjust the high temperature peak heat.
Thereafter, the temperature was further raised to the foaming temperature and held again for 15 minutes, and the equilibrium vapor pressure was adjusted to 3.6 MPa. Thereafter, the contents in the sealed container were discharged together with water under atmospheric pressure. At this time, the core layer was foamed to form a foam core layer, and the coating layer was a coating layer covering the peripheral surface of the foam core layer. In this way, multilayer expanded particles (see FIG. 3B) having through holes were obtained.
The obtained multilayer foamed particles had a bulk density of 30.0 kg / m ³ , an average particle weight of 1.5 mg, an average pore diameter of 1.4 mm, an average wall thickness of 1.1 mm, an average t / d = 0.8, an average L / D = 1.3.

[Example 1]
A frame member having the same configuration as that of the frame member 12 shown in FIG. 5 was produced from an iron rod-like body having a tensile strength (JIS G3532 SWM-B) of 500 N / mm ² . A steel rod-shaped body constituting the three front hanging latches on the front side was 5 mm in diameter, and a steel rod-shaped body in other locations was 4.5 mm in diameter. In addition, the cross | intersection location of the single piece iron rod-shaped body which comprises a frame member was joined by welding.

The frame member was placed in a core molding die (longitudinal direction 1330 mm, front-rear direction 600 mm, maximum thickness 225 mm). At this time, two rear latches are arranged on the rear side of the core material to be molded, and three front latches are arranged on the front side, and the front outer edge portion is from the bottom surface of the foamed particle molded body. The frame member was arranged so as to be embedded at a height of 20 mm, the mold was clamped, the multilayer foam particles obtained as described above were filled into the mold, and the core material was molded by steam heating. In addition, what provided the protrusion on the metal mold | die so that a slit might be formed in the peripheral part of a molded object was used. Heating with steam is performed by supplying steam into the mold for 4 seconds with the drain valves on both sides of the mold open and performing preheating (evacuation process), then heating with a forming steam pressure of 0.14 MPa (G). Then, one heating was performed in the opposite direction at a molding steam pressure of 0.20 MPa (G), and then main heating was performed from both sides with a molding steam pressure of 0.24 MPa (G). After heating, the pressure was released, water-cooled for 1 second, and air-cooled for 20 seconds to obtain a core material. After curing at 75 ° C. for 12 hours, the core material was slowly cooled for 6 hours. The stopper fixing groove is formed by forming a protrusion on the mold so that a groove having a depth of 20 mm and a width of 4 mm is formed in a part of the bottom peripheral edge of the foamed particle molded body, and the stopper is fixed by in-mold molding. A fixed groove was formed.
The properties of the used expanded particles having through-holes and the obtained expanded molded particles are shown in Table 1 as Example 1.

[Comparative Example 1]
As expanded particles, a bulk density of 25.3 kg / m ³ , an average particle weight of 1.5 mg, an average pore diameter of through holes of 2.8 mm, an average wall thickness of 0.7 mm, an average t / d = 0.3, and an average L / D = A core material in the same manner as in Example 1 except that a polypropylene resin foam particle having a through-hole of 0.9 (see FIG. 4) was used and part of the molding conditions was as follows. Was molded. The flexural modulus of the polypropylene resin is 980 MPa.
In Comparative Example 1, the forming steam pressure at the time of steam heating was set to one heating: 0.16 MPa (G), opposite one heating: 0.26 MPa (G), and main heating: 0.30 MPa (G). The water cooling time was 120 seconds and the air cooling time was 10 seconds. The properties of the used expanded particles having the through-holes and the obtained expanded molded particles are shown in Table 1 as Comparative Example 1.

For each of Example 1 and Comparative Example 1 (hereinafter also referred to as “measurement sample”) obtained as described above, after inserting the stopper 50 shown in FIG. 6 into the stopper fixing groove, the stopper 50 is inserted into the groove. The force applied when pulling out in the vertical direction was measured as the removal force (N). The extraction was performed twice for each measurement sample.
The measurement results are shown in Table 2 as Example 1 and Comparative Example 1.

For each of the measurement samples, a plurality of locations (specifically, measurement unit RH and measurement unit LH) indicated by ◯ in FIG. 1 were selected as measurement units. The difference in the distance between the measurement part in the measurement sample and the part corresponding to the measurement part in the measurement gauge was measured as a warp amount, and the case where the measurement part was warped was measured as a plus.
The measurement results are shown in Table 1 as Example 1 and Comparative Example 1.
In addition, in a polypropylene resin foamed particle molded body having no through-hole, when a molded body was produced by the same method, the amount of warpage was larger than that of the foamed particle molded body having a through-hole, which was RH 5.0 mm and LH 5.5 mm. Was a big one.

Further, in a molding die for laminating polyurethane foam, a liquid polyurethane foam raw material is supplied and laminated with respect to each of the measurement samples, and the liquid polyurethane foam raw material is foamed. A member in which polyurethane foam was laminated and integrated was produced. The foaming density was changed to 84 g / L and 93 g / L. In each of the obtained members, it was confirmed that the raw material for flexible polyurethane foam was appropriately impregnated in the foamed particle molded body, and the maximum impregnation depth from the surface of the foamed particle molded body was measured. For the measurement of the maximum impregnation depth, in the laminate of the foamed particle molded body and the polyurethane foam, the laminate was cut in the thickness direction so that the length of the laminated portion was 10 cm or more, and the maximum impregnation depth was measured in the cross section. . The above operation was performed at least in five places of the laminate, and the average value was obtained.
When the foam density of the polyurethane foam is 90 ± 5 g / L, the maximum impregnation depth is preferably 9 mm or less.
The measurement results are shown in Table 2 as Example 1 and Comparative Example 1.

Moreover, the sample which laminated | stacked the polyurethane foam of the foaming density 83g / L was cut out using the cutter etc. as a cross section of the foamed particle molded body along the depth of 3 mm from the upper surface of a thermoplastic resin foamed particle molded object, From the cross-sectional photograph (see FIG. 8A), the area of the portion where the polyurethane foam was present was measured. Similarly, the area of the void portion where no polyurethane foam was present was measured from the cross-sectional photograph. Each area and area ratio were calculated from the area of the photograph cross section. In addition, the number of voids was counted separately from cross-sectional photographs (excluding voids having a maximum diameter of less than 0.5 mm), and the area ratio β and area γ per void were calculated.
The measurement results are shown in Table 3 as Example 1 and Comparative Example 1.

  The vehicle seat member according to the present invention can be effectively used as a cushion material for various vehicles. Specifically, it can be used for various applications where cushioning is desired, such as seats for vehicles such as automobiles, motorcycles, airplanes, and trains, sofas, and chairs.

DESCRIPTION OF SYMBOLS 10 Core material 11 Foamed-particle molded object 12 Frame member 12A Outer frame part 12B Center frame part 12C Rear hook 12D Front hook 20 Polyurethane foam 30 Sheet cover 40 Stopper fixing groove 50 Stopper 51 Arrowhead 52 Pressing part 53 Projection 60 Expanded particle having through-hole 60A Multi-layer expanded particle having through-hole 61 Through-hole 62 Foam core layer 63 Cover layer 64 Peripheral surface portion 65 Through-hole portion 100: Vehicle seat member

Claims (10)

  A vehicle seat member comprising: a core material made of a thermoplastic resin foam particle molded body; a polyurethane foam provided on an upper surface side of the core material; and a seat cover covering the polyurethane foam, wherein the thermoplastic resin foam The particle molded body comprises a fused body of thermoplastic resin foam particles having through-holes, and the thermoplastic resin foam particle molded body has voids communicating with the outside, and the voids of the thermoplastic resin foam particle molded body The rate is 10% by volume or more and less than 25% by volume, and a part of the polyurethane foam is impregnated and solidified in the voids of the thermoplastic resin foamed particle molded body, from the top surface of the thermoplastic resin foamed particle molded body. The area ratio of the polyurethane foam portion in the cut surface obtained by cutting the thermoplastic resin foamed particle molded body along a depth of 3 mm in a direction perpendicular to the upper surface is 5 to 5. It characterized in that it is 0%, the sheet member for a vehicle. The average value of the area per void in the cut surface obtained by cutting the thermoplastic resin foam particle molded body along the depth of 3 mm from the upper surface to the upper surface of the thermoplastic resin foam particle molded body is 4 mm ^2. The vehicle seat member according to claim 1, wherein:   The thermoplastic resin foamed particle molded body has a tensile strength of 0.2 MPa or more, and the thermoplastic resin foamed particle molded body has a compressive stress at 10% compression of 0.1 MPa or more. Item 3. The vehicle seat member according to Item 1 or 2.   The above-mentioned thermoplastic resin expanded particle molded body is obtained by fusing cylindrical thermoplastic resin expanded particles having a compression load A at 10% compression in the direction perpendicular to the through-hole penetration direction of 0.5 N or more. The vehicle seat member according to claim 1, wherein the vehicle seat member is a vehicle seat member.   In the thermoplastic resin expanded particle molded body, the compression load B at the time of 10% compression in the penetration direction of the through hole is 1 N or more, and the ratio B / A of the compression load B to the compression load A is 1 to 3. The vehicle seat member according to claim 4, wherein the tubular thermoplastic resin foam particles are fused.   The thermoplastic resin expanded particle molded body has an average hole diameter d of 1 to 3 mm of through-holes, an average wall thickness t of 0.8 mm to 2 mm, and a ratio t / d of the average wall thickness t to the average hole diameter d. The vehicle seat member according to any one of claims 1 to 5, wherein the foamed cylindrical thermoplastic resin particles having a diameter of 0.4 to 1 are fused. The thermoplastic resin foam particle molded body has a molded body density of 20 to 40 kg / m ³ , and the propylene resin constituting the thermoplastic resin foam particle molded body has a flexural modulus of more than 1200 MPa. The vehicle seat member according to any one of claims 1 to 6.   A stopper fixing groove is formed in a peripheral edge of the bottom surface of the thermoplastic resin foam particle molded body, and a stopper for fixing the seat cover is inserted into the stopper fixing groove. The vehicle seat member according to claim 7.   The vehicle seat member according to any one of claims 1 to 8, wherein an annular frame member is embedded in a peripheral edge portion of the thermoplastic resin expanded particle molded body by insert molding.   The thermoplastic resin foam particles having the through-holes are multilayer foam particles having a cylindrical polypropylene resin foam core layer and a polyolefin resin coating layer covering the foam core layer, and constitute the coating layer. The vehicle seat member according to claim 1, wherein a melting point of the resin is lower than a melting point of the resin constituting the foam core layer.

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