Patent Description:
Conventionally, a laminated body has been known which is formed by bonding, to a surface of an expansion-molded article, another member such as a sheet or a film. As such a laminated body, a laminated body has been known which is formed by (i) melting an expansion-molded article or another member by heat and (ii) bonding the expansion-molded article and the another member together by heat fusion.

As an example of the laminated body, Patent Literature <NUM> discloses an expanded article composite. The expanded article composite is formed by heat-fusing resin film with an expanded article substrate having asperities on a surface thereof. Further, as an example of the laminated body formed by heat fusion, Patent Literature <NUM> discloses a member for a sanitary equipment room. Moreover, as an example of the expansion-molded article, Patent Literature <NUM> discloses an expanded container which has, on a surface thereof, projections that are core-vent marks.

<CIT> relates to a rigid foam bolster which is secured to a plastic panel through linear welding by being vibrated sufficiently to heat the interface between the foam and panel. The surface of the panel softens and becomes partially molten. The foam is urged into the panel and molten plastic material flows into the foam. Energy directors may be provided on either the foam or panel surfaces. The finished articles are used as energy absorbing panels for installation in motor vehicle interiors.

<CIT> relates to heat insulating sheets having uncounted numbers of fine cells formed therein and having depressions and projections formed thereon. The sheets are superposed on each other with their uneven surface internally facing. Further, a low moisture permeable sheet is superposed on one side or on both sides of the superposed heat insulating sheets, to thereby form a heat insulating composite sheet for a building finish member. Thus, the composite sheet is made strong against compression, and its heat insulating performance does not lower with the lapse off time, to thereby exhibit good heat insulation performance.

<CIT> relates to a core plate made of a polyethylene foam which has two types of protrusions attached thereto.

The invention for which protection is sought is defined by the independent claims.

However, the expanded article composite disclosed in Patent Literature <NUM> has a problem that adhesion between the expansion-molded article and the another member is poor or a degree of the adhesion between the expansion-molded article and the another member is biased.

Moreover, the expanded article composite disclosed in Patent Literature <NUM> also has a problem that an air pocket is likely to be generated between the expansion-molded article and the another member and, consequently, the adhesion between the expansion-molded article and the another member becomes poor or ununiform adhesion is caused.

An object of an aspect of the present invention is to realize an expansion-molded article capable of being firmly heat-fused with another member.

In order to attain the above object, an expansion-molded article in accordance with an aspect of the present invention is an expansion-molded article which is to be heat-fused with another member, including at least one protrusion which is formed on at least one surface of the expansion-molded article which at least one surface is to be heat-fused with the another member, the at least one protrusion having at least two surfaces as viewed from above (in a planar view), as a boundary line between the at least two surfaces, at least one boundary line being present which intersects a direction from an outside of the at least one protrusion toward a center of an apex of the at least one protrusion.

According to an aspect of the present invention, it is possible to realize an expansion-molded article capable of being firmly heat-fused with another member.

In <FIG>, a boundary line between two surfaces of a protrusion is shown by a line. However, the boundary line is not limited to one that can be shown by a line. For example, as illustrated in <FIG>, in a case where a contour of a cross section of the protrusion can be approximated to a high-order curve, the boundary line between the two surfaces corresponds to an inflection point of the contour. In a case where there is no inflection point, the boundary line between the two surfaces corresponds to a center point of a planar part of the protrusion which planar part is located between the two surfaces. Further, there can be a case where the boundary line between the two surfaces is not clearly recognized as viewed from above (in a planar view). In such a case, the boundary line between the two surfaces of the protrusion also includes a boundary line corresponding to the inflection point as described above and a boundary line corresponding to the center point as described above. The boundary line corresponding to the inflection point and the boundary line corresponding to the center point are each shown by a dash-dot line as illustrated in <FIG>.

(a) and (c) through (i) of <FIG> are each a drawing illustrating an example of a shape of a protrusion of an expansion-molded article. (b) of <FIG> is a cross-sectional view illustrating a cross section of a laminated body <NUM>.

(c) of <FIG> is a drawing of a protrusion <NUM>, as viewed from above. (a) of <FIG> is a cross-sectional view of an expansion-molded article <NUM>, taken from a dotted line x1-x2 illustrated in (c) of <FIG>. As illustrated in (a) of <FIG>, another member <NUM> is heat-fused with a side of the expansion-molded article <NUM> on which side the protrusion <NUM> is formed. In short, the expansion-molded article <NUM> and the another member <NUM> are fused together by heat.

The expansion-molded article <NUM> can be a publicly known expansion-molded article such as a foam sheet, a foam board, an in-mold expansion-molded article obtained from expanded particles, or an injection expansion-molded article. The expansion-molded article <NUM> is made of a thermoplastic resin. Thus, it is possible to melt the thermoplastic resin and heat-fuse the expansion-molded article <NUM> and the another member <NUM> together. The thermoplastic resin is not limited to any particular one. Examples of the thermoplastic resin include polyolefin-based resins, polystyrene-based resins, styrene-modified polyolefin-based resins, polyester-based resins, polyphenylene ether-based resins, and polycarbonate-based resins. An expansion ratio of the expansion-molded article <NUM> is not limited to any particular one. In a case where a polyolefin-based resin is used as the thermoplastic resin, the expansion ratio can be, for example, <NUM> times, <NUM> times, <NUM> times, <NUM> times, <NUM> times, <NUM> times, <NUM> times, or <NUM> times.

Since the expansion-molded article <NUM> is composed of expanded particles, it is possible to melt the expansion-molded article <NUM> and heat-fuse the expansion-molded article <NUM> and the another member <NUM> together. In a case where the expansion-molded article <NUM> is composed of the expanded particles, it is possible to easily form the protrusion <NUM> by in-mold expansion molding.

Note that the expansion-molded article <NUM> is preferably made of an olefin-based resin because the olefin-based resin allows an effect of an aspect of the present invention to be remarkable, allows the expansion-molded article <NUM> to be excellent in shock absorbing property, chemical resistance, heat resistance, and deformation recovery ratio after compression, and allows the expansion-molded article <NUM> to be easily recycled. Furthermore, from these viewpoints, the expansion-molded article <NUM> is preferably one that is formed by subjecting, to in-mold expansion-molding, the expanded particles each of which is made of a polyolefin-based resin.

The another member <NUM> is not limited to any particular one, provided that the another member <NUM> can be heat-fused with the expansion-molded article <NUM>. Examples of the another member <NUM> includes sheets, films, and non-woven fabrics each of which sheets, films, and non-woven fabrics is made of a thermoplastic resin or a thermosetting resin. Examples of the thermoplastic resin and the thermosetting resin include homopolymers, random copolymers, block copolymers, and mixtures thereof. Furthermore, the thermoplastic resin can include thermoplastic resins each of which is reinforced by a fiber, a filler, or a rubber component. Similarly, the thermosetting resin can include thermosetting resins each of which is reinforced by a fiber, a filler, or a rubber component. Out of these materials listed, the another member <NUM> is preferably a sheet or a film each of which is made of the thermoplastic resin, from the viewpoint of adhesion.

As illustrated in (a) of <FIG>, at least one surface of the expansion-molded article <NUM>, which at least one surface is to be heat-fused with the another member <NUM>, is constituted by a base surface <NUM> and at least one protrusion <NUM> formed on the base surface <NUM>. For example, in a case where the expansion-molded article <NUM> has a shape of a plate-like rectangular parallelepiped, merely one surface of the expansion-molded article <NUM>, which one surface is to be heat-fused with the another member <NUM>, may be constituted by the base surface <NUM> and the protrusion <NUM>. Alternatively, merely one surface of the expansion-molded article <NUM>, which one surface is to be heat-fused with the another member <NUM>, and a surface of the expansion-molded article <NUM>, which surface is opposite to the one surface and is to be heat-fused with the another member <NUM>, may be each constituted by the base surface <NUM> and the protrusion <NUM>. Alternatively, all surfaces of the rectangular parallelepiped, which all surfaces are to be heat-fused with the another member <NUM>, may be each constituted by the base surface <NUM> and the protrusion <NUM>. Around the protrusion <NUM>, the base surface <NUM> is exposed outside. Note that the base surface <NUM> does not need to be exposed outside. In a case where the base surface <NUM> is not exposed outside, merely the protrusion <NUM> is exposed outside. Note that, in regard to exposure of the base surface <NUM>, the same applies to protrusions later described.

In a case where the expansion-molded article <NUM> and the another member <NUM> are heat-fused together, an apex of the protrusion <NUM>, which apex has a low heat capacity and is accordingly easily melted, first starts to be melted. Thus, since the apex of the protrusion <NUM> is definitely melted, it is possible to heat-fuse the expansion-molded article <NUM> and the another member <NUM> together uniformly in a surface direction. It is therefore possible to firmly heat-fuse the expansion-molded article <NUM> and the another member <NUM> together.

In a case where the expansion-molded article <NUM> and the another member <NUM> are heat-fused together as illustrated in (b) of <FIG>, the protrusion <NUM> is melted, so that the protrusion <NUM> spreads. This prevents heat from excessively reaching the base surface <NUM>. Since the protrusion <NUM> is melted on a priority basis, it is possible to reduce a deterioration of the base surface <NUM> which deterioration is caused by heat. Therefore, it is possible to prevent a reduction in adhesion which reduction is caused by the deterioration of the base surface <NUM> which deterioration is caused by heat, and possible to prevent a change in shape of the expansion-molded article <NUM> (particularly, a shape of the base surface <NUM>). In a case where (i) the expansion-molded article <NUM> and the another member <NUM> are heat-fused together and (ii) a distance between protrusions <NUM> is short, the protrusions <NUM> are melted, and accordingly the expansion-molded article <NUM> and the another member <NUM> are heat-fused together, that is, laminated. As a result, the laminated body <NUM> is formed. In a case where the distance between the protrusions <NUM> is long, the protrusions <NUM> are melted on a priority basis, then the base surface <NUM> is melted, and accordingly the expansion-molded article <NUM> and the another member <NUM> are heat-fused together. As a result, the laminated body <NUM> is formed.

In this manner, it is possible to form the laminated body <NUM> in which the expansion-molded article <NUM> and the another member <NUM> are firmly heat-fused together. Moreover, it is possible to produce the laminated body <NUM> which has a reduced possibility that the expansion-molded article <NUM> has a shape which is different from a required shape. Applications of the laminated body <NUM> include various applications, e.g., automotive and railroad applications such as interior panels for vehicles, deck boards for vehicles, and tibia pads; residential applications such as dressing tables, floor materials, heat-insulating core materials for walls, heat-insulating floor materials for bathrooms, and bathtub lids; transportation applications such as returnable cases and pallets; building materials such as frameworks and base materials; floats such as buoy; and storing containers such as tool boxes.

In a case where the expansion-molded article <NUM> and the another member <NUM> are heat-fused together, the protrusion <NUM> is first melted when the expansion-molded article <NUM> is heat-fused with the another member <NUM>. Since the protrusion <NUM> is first melted, it is possible to firmly heat-fuse the expansion-molded article <NUM> and the another member <NUM> together. Furthermore, since the protrusion <NUM> is melted on a priority basis, it is possible to reduce a deterioration of the base surface <NUM> which deterioration is caused by heat.

In a case where the expansion-molded article <NUM> and the another member <NUM> are heat-fused together, a stress is first exerted on the protrusion <NUM> when the expansion-molded article <NUM> is heat-fused with the another member <NUM>. Since the stress is first exerted on the protrusion <NUM>, the protrusion <NUM> is first melted. Moreover, as described above, since the protrusion <NUM> is melted on a priority basis, it is possible to reduce a deterioration of the base surface <NUM> which deterioration is caused by heat.

As illustrated in (a) of <FIG>, the protrusion <NUM> has a depression <NUM> in the apex thereof. As illustrated in (c) of <FIG>, the depression <NUM> has a structure such that the depression <NUM> has a depression bottom surface <NUM> having a rectangular shape and, as viewed from the above, has inclined surfaces <NUM> around the depression bottom surface <NUM>. Each of the inclined surfaces <NUM> is inclined so as to go down in a direction from an outside of the protrusion <NUM> toward the depression bottom surface <NUM>, as viewed from the above. Each of the inclined surfaces <NUM> has a trapezoidal shape. A bottom surface of the protrusion <NUM> (i.e., a boundary surface between the base surface <NUM> and the protrusion <NUM>) has a rectangular shape.

The protrusion <NUM> has five surfaces as viewed from the above. As a boundary line between two surfaces out of the five surfaces, at least one boundary line is present which intersects a direction from the outside of the protrusion <NUM> toward a center of the apex of the protrusion <NUM>. In a case where, as the direction from the outside of the protrusion <NUM> toward the center of the apex of the protrusion <NUM>, a direction d1 is, for example, considered, a boundary line b1 between a corresponding one of the inclined surfaces <NUM> and the depression bottom surface <NUM> intersects the direction d1.

According to a configuration of the protrusion <NUM>, part of the protrusion <NUM> which part is located around the depression <NUM> has a shape such that the part has a ridge line on an another member <NUM> side. The ridge line is constituted by boundary lines between the inclined surfaces <NUM> and outside surfaces of the protrusion <NUM>. The part of the protrusion <NUM> which part is located around the depression <NUM> has a tapered shape such that the part has the ridge line on a top thereof, and is easily melted. Therefore, in a case where the expansion-molded article <NUM> and the another member <NUM> are heat-fused together, it is possible to more definitely melt the protrusion <NUM>. Accordingly, it is possible to more firmly heat-fuse the expansion-molded article <NUM> and the another member <NUM> together.

(e) of <FIG> is a drawing of a protrusion 120a, as viewed from above. (f) of <FIG> is a drawing of a protrusion 120a_1, as viewed from above. (d) of <FIG> is a cross-sectional view of an expansion-molded article 10a, taken from a dotted line x1-x2 illustrated in each of (e) and (f) of <FIG>. As illustrated in each of (d) and (e) of <FIG>, instead of the expansion-molded article <NUM>, the expansion-molded article 10a may be used which has the protrusion 120a on a base surface <NUM> thereof. The protrusion 120a has a structure such that the protrusion 120a has a hemispherical shape and has a depression 121a on an apex thereof. The depression 121a has a curved surface and, as viewed from the above, has a circular shape. As illustrated in (e) of <FIG>, the protrusion 120a has the depression 121a in a center thereof, as viewed from the above. A bottom surface of the protrusion 120a (i.e., a boundary surface between the base surface <NUM> and the protrusion 120a) has a circular shape. In a case where, as a direction from an outside of the protrusion 120a toward a center of the apex of the protrusion 120a, a direction d2 is, for example, considered, a boundary line b2 between two surfaces intersects the direction d2.

Note that, as illustrated in (f) of <FIG>, the protrusion 120a_1 may be formed on the base surface <NUM>. In this case, a depression 121a_1 formed in an apex of the protrusion 120a_1 has a curved surface and, as viewed from the above, has an elliptical shape. Both ends of the depression 121a_1 coincide with a boundary line between the base surface <NUM> and the protrusion 120a_1, as viewed from the above. A bottom surface of the protrusion 120a_1 (i.e., a boundary surface between the base surface <NUM> and the protrusion 120a_1) has a circular shape. In a case where, as a direction from an outside of the protrusion 120a_1 toward a center of the apex of the protrusion 120a_1, a direction d3 is, for example, considered, a boundary line b3 between two surfaces intersects the direction d3.

According to respective configurations of the protrusion 120a and the protrusion 120a_1, the bottom surface of the protrusion 120a has a circular shape, and also the bottom surface of the protrusion 120a_1 has a circular shape. With these configurations, in a case where the expansion-molded article 10a and the another member <NUM> are heat-fused together, the protrusion 120a is melted and then spreads in a circular shape, whereas the protrusion 120a_1 is melted and then spreads in a circular shape. Therefore, it is possible to more firmly heat-fuse the expansion-molded article 10a and the another member <NUM> together.

(i) of <FIG> is a drawing of a protrusion 120b, as viewed from above. (g) of <FIG> is a cross-sectional view of an expansion-molded article 10b, taken from a dotted line y1-y2 illustrated in (i) of <FIG> of <FIG> is a cross-sectional view of the expansion-molded article 10b, taken from a dotted line x1-x2 illustrated in (i) of <FIG>. As illustrated in (g) of <FIG>, instead of the expansion-molded article <NUM>, the expansion-molded article 10b may be used which has the protrusion 120b on a base surface <NUM> thereof.

The protrusion 120b has a structure such that the protrusion 120b has a hemispherical shape and has a depression 121b in an apex thereof. The depression 121b has a curved surface and, as viewed from the above, has an elliptical shape. As illustrated in (i) of <FIG>, the protrusion 120b has the depression 121a in a center thereof, as viewed from the above. In a case where, as a direction from an outside of the protrusion 120b toward a center of the apex of the protrusion 120b, a direction d4 is, for example, considered, a boundary line b4 between two surfaces intersects the direction d4. A bottom surface of the protrusion 120b (i.e., a boundary surface between the base surface <NUM> and the protrusion 120b) has an elliptical shape.

(b) of <FIG> is a drawing of a protrusion 120c, as viewed from above. (c) of <FIG> is a drawing of a protrusion 120c_1, as viewed from above. (a) of <FIG> is a cross-sectional view of an expansion-molded article 10c, taken from a dotted line x1-x2 illustrated in each of (b) and (c) of <FIG>. As illustrated in each of (a) and (b) of <FIG>, instead of the expansion-molded article <NUM>, the expansion-molded article 10c may be used which has the protrusion 120c on a base surface <NUM> thereof.

The protrusion 120c includes a first protrusion <NUM> and a second protrusion <NUM>. The second protrusion <NUM> is formed on an upper surface of the first protrusion <NUM>. Each of the first protrusion <NUM> and the second protrusion <NUM> has a shape of a rectangular parallelepiped. As illustrated in (b) of <FIG>, the second protrusion <NUM> is formed in a center of the first protrusion <NUM>. A bottom surface of the protrusion 120c (i.e., a boundary surface between the base surface <NUM> and the protrusion 120c) has a rectangular shape. In a case where, as a direction from an outside of the protrusion 120c toward a center of an apex of the protrusion 120c, a direction d5 is, for example, considered, a boundary line b5 between two surfaces intersects the direction d5.

Note that, as illustrated in (c) of <FIG>, the protrusion 120c_1 may be formed on the base surface <NUM>. In this case, second protrusions <NUM> and <NUM> are formed on an upper surface of a first protrusion <NUM>. The second protrusion <NUM> may have a shape identical to or different from that of the second protrusion <NUM>. Moreover, three or more second protrusions may be formed on the upper surface of the first protrusion <NUM>. A bottom surface of the protrusion 120c_1 (i.e., a boundary surface between the base surface <NUM> and the protrusion 120c_1) has a rectangular shape. In a case where, as a direction from an outside of the protrusion 120c_1 toward a center of an apex of the second protrusion <NUM>, a direction d6 is, for example, considered, a boundary line b6 between two surfaces intersects the direction d6. Further, in a case where, as a direction from the outside of the protrusion 120c_1 toward a center of an apex of the second protrusion <NUM>, a direction d7 is, for example, considered, a boundary line b7 between two surfaces intersects the direction d7.

According to a configuration of the protrusion 120c, the second protrusion <NUM> has a low heat capacity and is accordingly easily melted. Thus, in a case where the second protrusion <NUM> is melted by heat, the second protrusion <NUM> easily spreads on a surface of the first protrusion <NUM>. Moreover, the first protrusion <NUM> which is to be melted also has a low heat capacity. Therefore, in a case where the expansion-molded article 10c and another member <NUM> are heat-fused together, it is possible to more definitely melt the protrusion 120c. Accordingly, it is possible to more firmly heat-fuse the expansion-molded article 10c and the another member <NUM> together. Note that the second protrusion <NUM> is preferably formed in a vicinity of an apex of the first protrusion <NUM>. This makes it possible to definitely melt a vicinity of the apex of the second protrusion <NUM>.

(e) of <FIG> is a drawing of a protrusion 120d, as viewed from above. (d) of <FIG> is a cross-sectional view of an expansion-molded article 10d, taken from a dotted line x1-x2 illustrated in (e) of <FIG>. As illustrated in each of (d) and (e) of <FIG>, instead of the expansion-molded article <NUM>, the expansion-molded article 10d may be used which has the protrusion 120d on a base surface <NUM> thereof.

The protrusion 120d includes a first protrusion 124a and a second protrusion 125a. The second protrusion 125a is formed on an apex of the first protrusion 124a. Each of the first protrusion 124a and the second protrusion 125a has a curved surface. As illustrated in (e) of <FIG>, the second protrusion 125a is formed in a center of the first protrusion 124a. A bottom surface of the protrusion 120d (i.e., a boundary surface between the base surface <NUM> and the protrusion 120d) has a circular shape. In a case where, as a direction from an outside of the protrusion 120d toward a center of an apex of the protrusion 120d, a direction d8 is, for example, considered, a boundary line b8 between two surfaces intersects the direction d8.

Note that, as illustrated in each of (f) and (g) of <FIG>, a protrusion 120d_1 may be formed on a base surface <NUM>. In this case, the protrusion 120d_1 includes a first protrusion 124a and second protrusions 125a and 126a. The second protrusions 125a and 126a are formed on the first protrusion 124a. The second protrusion 126a may have a shape identical to or different from that of the second protrusion 125a. Moreover, three or more second protrusions may be formed on an upper surface of the first protrusion 124a. A bottom surface of the protrusion 120d_1 (i.e., a boundary surface between the base surface <NUM> and the protrusion 120d_1) has a circular shape.

In a case where, as a direction from an outside of the protrusion 120d_1 toward a center of an apex of the second protrusion 125a, a direction d9 is, for example, considered, a boundary line b9 between two surfaces intersects the direction d9. In a case where, as a direction from the outside of the protrusion 120d_1 toward a center of an apex of the second protrusion 126a, a direction d10 is, for example, considered, a boundary line b10 between two surfaces intersects the direction d10. Note that (g) of <FIG> is a drawing of the protrusion 120d_1, as viewed from above. (f) of <FIG> is a cross-sectional view of an expansion-molded article 10d_1, taken from a dotted line x1-x2 illustrated in (g) of <FIG>.

(c) of <FIG> is a drawing of a protrusion 120e, as viewed from above. (a) of <FIG> is a cross-sectional view of an expansion-molded article 10e, taken from a dotted line y1-y2 illustrated in (c) of <FIG> of <FIG> is a cross-sectional view of the expansion-molded article 10e, taken from a dotted line x1-x2 illustrated in (c) of <FIG>. As illustrated in (a) of <FIG>, instead of the expansion-molded article <NUM>, the expansion-molded article 10e may be used which has the protrusion 120e on a base surface <NUM> thereof.

As illustrated in (c) of <FIG>, the protrusion 120e has two inclined surfaces <NUM>, each having a trapezoidal shape, and two inclined surfaces <NUM>, each having a triangular shape. Respective upper sides of the two inclined surfaces <NUM> coincide with each other, and each of the two inclined surfaces <NUM> is inclined such that respective lower sides of the inclined surfaces <NUM> go away from each other.

On both sides of the two inclined surfaces <NUM>, the two inclined surfaces <NUM> are respectively formed, and each of the two inclined surfaces <NUM> is also inclined. Each of the inclined surfaces <NUM> and <NUM> is inclined so as to go up in a direction from an outside of the protrusion 120e toward a center of the protrusion 120e, as viewed from the above. A bottom surface of the protrusion 120e (i.e., a boundary surface between the base surface <NUM> and the protrusion 120e) has a rectangular shape. In a case where, as a direction from the outside of the protrusion 120e toward a center of an apex of the protrusion 120e, a direction d11 is, for example, considered, a boundary line b11 between the two inclined surfaces <NUM> intersects the direction d11.

(e) of <FIG> is a drawing of a protrusion 120f, as viewed from above. (d) of <FIG> is a cross-sectional view of an expansion-molded article 10f, taken from a dotted line x1-x2 illustrated in each of (e) and (f) of <FIG>. As illustrated in (d) of <FIG>, instead of the expansion-molded article <NUM>, the expansion-molded article 10f may be used which has the protrusion 120f on a base surface <NUM> thereof. As illustrated in (e) of <FIG>, the protrusion 120f has four inclined surfaces <NUM>, each having a trapezoidal shape, and an upper surface <NUM>, having a rectangular shape. Four sides of the upper surface <NUM> respectively coincide with respective upper sides of the four inclined surfaces <NUM>. Each of the four inclined surfaces <NUM> is inclined. Each of the inclined surfaces <NUM> is inclined so as to go up in a direction from an outside of the protrusion 120f toward a center of the protrusion 120f, as viewed from the above. A bottom surface of the protrusion 120f (i.e., a boundary surface between the base surface <NUM> and the protrusion 120f) has a rectangular shape. In a case where, as a direction from the outside of the protrusion 120f toward a center of an apex of the protrusion 120f, a direction d12 is, for example, considered, a boundary line b12 between a corresponding one of the inclined surfaces <NUM> and the upper surface <NUM> intersects the direction d12.

Note that, as illustrated in (f) of <FIG>, a protrusion 120f_1 may be formed on the base surface <NUM>. The protrusion 120f_1 has three inclined surfaces <NUM>, each having a trapezoidal shape, and an upper surface <NUM>, having a triangular shape. Three sides of the upper surface <NUM> respectively coincide with respective upper sides of the three inclined surfaces <NUM>. Each of the three inclined surfaces <NUM> is inclined. Each of the inclined surfaces <NUM> is inclined so as to go up in a direction from an outside of the protrusion 120f_1 toward a center of the protrusion 120f_1, as viewed from the above. A bottom surface of the protrusion 120f_1 (i.e., a boundary surface between the base surface <NUM> and the protrusion 120f_1) has a triangular shape. In a case where, as a direction from the outside of the protrusion 120f_1 toward a center of an apex of the protrusion 120f_1, a direction d13 is, for example, considered, a boundary line b13 between a corresponding one of the inclined surfaces <NUM> and the upper surface <NUM> intersects the direction d13.

(h) of <FIG> is a drawing of a protrusion <NUM>, as viewed from above. (g) of <FIG> is a cross-sectional view of an expansion-molded article <NUM>, taken from a dotted line x1-x2 illustrated in (h) of <FIG>. As illustrated in (g) of <FIG>, instead of the expansion-molded article <NUM>, the expansion-molded article <NUM> may be used which has the protrusion <NUM> on a base surface <NUM> thereof. As illustrated in (h) of <FIG>, the protrusion <NUM> has eight inclined surfaces <NUM>, each having a trapezoidal shape, and an upper surface <NUM> and a bottom surface <NUM>, each having a rectangular shape. The eight inclined surfaces <NUM> may have an identical shape or different shapes. The upper surface <NUM> may have a shape identical to or different from that of the bottom surface <NUM>. The protrusion <NUM> has a shape such that, from an octahedron, two corners of the octahedron are cut out. Parts obtained by cutting out the two corners from the octahedron respectively correspond to the upper surface <NUM> and the bottom surface <NUM>. In a case where, as a direction from an outside of the protrusion <NUM> toward a center of an apex of the protrusion <NUM>, a direction d14 is, for example, considered, a boundary line b14 between a corresponding one of the inclined surfaces <NUM> and the upper surface <NUM> intersects the direction d14.

Four sides of the upper surface <NUM> respectively coincide with respective upper sides of four of the inclined surfaces <NUM> which four are located on an upper side of the protrusion <NUM>. Four side of the bottom surface <NUM> respectively coincide with respective lower sides of four of the inclined surfaces <NUM> which four are located on a lower side of the protrusion <NUM>. Respective lower sides of the four of the inclined surfaces <NUM> which four are located on the upper side of the protrusion <NUM> coincide with respective upper sides of the four of the inclined surfaces <NUM> which four are located on the lower side of the protrusion <NUM>. Each of the eight inclined surfaces <NUM> is inclined. The bottom surface <NUM> of the protrusion <NUM> (i.e., a boundary surface between the base surface <NUM> and the protrusion <NUM>) has a rectangular shape.

(b) of <FIG> is a drawing of a protrusion <NUM>, as viewed from above. (a) of <FIG> is a cross-sectional view of an expansion-molded article <NUM>, taken from a dotted line x1-x2 illustrated in (b) of <FIG>. As illustrated in (a) of <FIG>, instead of the expansion-molded article <NUM>, the expansion-molded article <NUM> may be used which has the protrusion <NUM> on a base surface <NUM> thereof.

As illustrated in (b) of <FIG>, the protrusion <NUM> has curved surfaces <NUM>, <NUM>, and <NUM>. As illustrated in (a) of <FIG>, a contour of a cross section of the protrusion <NUM> can be approximated to a high-order curve, and a boundary line b15 between the curved surfaces <NUM> and <NUM> corresponds to an inflection point v1 of the contour. A boundary line b18 between the curved surfaces <NUM> and <NUM> corresponds to an inflection point v2 of the contour. A bottom surface of the protrusion <NUM> (i.e., a boundary surface between the base surface <NUM> and the protrusion <NUM>) has a circular shape. In a case where, as a direction from an outside of the protrusion <NUM> toward a center of an apex of the protrusion <NUM>, a direction d15 is, for example, considered, the boundary line b15 between the curved surfaces <NUM> and <NUM> intersects the direction d15. The boundary line b18 between the curved surfaces <NUM> and <NUM> intersects the direction d15.

(e) of <FIG> is a drawing of a protrusion 120i, as viewed from above. (c) of <FIG> is a cross-sectional view of an expansion-molded article 10i, taken from a dotted line x1-x2 illustrated in (e) of <FIG> of <FIG> is a cross-sectional view of the expansion-molded article 10i, taken from a dotted line x3-x4 illustrated in (e) of <FIG>. As illustrated in (c) of <FIG>, instead of the expansion-molded article <NUM>, the expansion-molded article 10i may be used which has the protrusion 120i on a base surface <NUM> thereof. As illustrated in (e) of <FIG>, the protrusion 120i has curved surfaces <NUM> and <NUM>. The curved surface <NUM> has a substantially triangular shape, as viewed from above, and has a depressed shape. Note that the curved surface <NUM> may have a substantially quadrangular shape, as viewed from above.

As illustrated in (c) of <FIG>, a contour of a cross section of the protrusion 120i can be approximated to a high-order curve, and a boundary line b16 between the curved surfaces <NUM> and <NUM> corresponds to a center point c1 of the contour. The center point c1 is, in the cross section of the protrusion 120i, a center point of a planar part of the protrusion 120i which planar part is located between the curved surfaces <NUM> and <NUM>. A bottom surface of the protrusion 120i (i.e., a boundary surface between the base surface <NUM> and the protrusion 120i) has a circular shape. In a case where, as a direction from an outside of the protrusion 120i toward a center of an apex of the protrusion 120i, a direction d16 is, for example, considered, the boundary line b16 between the curved surfaces <NUM> and <NUM> intersects the direction d16.

(g) of <FIG> is a drawing of a protrusion 120j, as viewed from above. (f) of <FIG> is a cross-sectional view of an expansion-molded article 10j, taken from a dotted line x1-x2 illustrated in (g) of <FIG>. As illustrated in (f) of <FIG>, instead of the expansion-molded article <NUM>, the expansion-molded article 10j may be used which has the protrusion 120j on a base surface <NUM> thereof. As illustrated in (g) of <FIG>, the protrusion 120j has curved surfaces <NUM> and <NUM>.

As illustrated in (f) of <FIG>, a contour of a cross section of the protrusion 120j can be approximated to a high-order curve, and a boundary line b17 between the curved surfaces <NUM> and <NUM> corresponds to a center point c2 of the contour. The center point c2 is, in the cross section of the protrusion 120j, a center point of a planar part of the protrusion 120j which planar part is located between the curved surfaces <NUM> and <NUM>. A bottom surface of the protrusion 120j (i.e., a boundary surface between the base surface <NUM> and the protrusion 120j) has a circular shape. In a case where, as a direction from an outside of the protrusion 120j toward a center of an apex of the protrusion 120j, a direction d17 is, for example, considered, the boundary line b17 between the curved surfaces <NUM> and <NUM> intersects the direction d17.

Note that the shape of the protrusion is not limited to any particular one. The protrusion may merely have a shape of a hemisphere, a quadrangular pyramid, a circular cone, a rectangular parallelepiped, or the like, unlike the protrusions illustrated in <FIG>. Note also that the protrusion as described above may be formed on a base surface <NUM> (on a surface) at a density of not less than <NUM> per square centimeter and not more than <NUM> per square centimeter, and may be formed throughout a region of at least not less than <NUM>% of the base surface <NUM>. By forming the protrusion as described above on the base surface <NUM> at a density of not less than <NUM> per square centimeter and forming the protrusion throughout the region of at least not less than <NUM>% of the base surface <NUM>, it is possible to firmly heat-fuse the expansion-molded article and the another member <NUM> together. Moreover, it is possible to reduce a possibility that the expansion-molded article is separated from the another member <NUM>. Note also that the expansion-molded article which has the base surface <NUM> on which various kinds of protrusions as described above are provided may be formed.

Furthermore, by forming the protrusion as described above on the base surface <NUM> at a density of not more than <NUM> per square centimeter, it is possible to reduce a production cost because more protrusions, as described above, than needed are not formed on the base surface <NUM>.

According to the configuration of each of the protrusions illustrated in <FIG>, the each of the protrusions has at least two surfaces and, as a boundary line between the two surfaces, at least one boundary line which intersects the direction from the outside of the each of the protrusions toward the center of the apex of the each of the protrusions, as viewed from the above. With this configuration, as viewed from the above, the each of the protrusions has, not a shape such that the each of the protrusions has identical regularity in the direction from the outside of the each of the protrusions toward the apex of the each of the protrusions, but a shape such that the each of the protrusions has a tapered part obtained by a shape changing to different regularity along the way in the direction from the outside of the each of the protrusions toward the apex of the each of the protrusions. The each of the protrusions may have, for example, a shape such that, on the cross section of the each of the protrusions, an angle formed by the bottom surface and the contour of the each of the protrusions changes along the way or a shape such that, on the cross section of the each of the protrusions, a curvature changes along the way (the contour has an inflection point). Alternatively, the each of the protrusions may have a multi-stepped shape or a shape such that the each of the protrusions has a ridge line on the apex thereof.

The each of the protrusions has a boundary line, and has a tapered part. Therefore, in a case where the expansion-molded article and the another member <NUM> are heat-fused together, the each of the protrusions is easily melted. Accordingly, it is possible to firmly heat-fuse the expansion-molded article and the another member <NUM> together. Moreover, since the each of the protrusions is melted on a priority basis, it is possible to reduce a deterioration of the base surface <NUM> which deterioration is caused by heat. Therefore, it is possible to prevent a change in shape of the expansion-molded article (particularly, a shape of the base surface <NUM>).

Furthermore, the protrusion may have a multi-stepped shape, like the protrusion <NUM> illustrated in (a) through (c) of <FIG>, the protrusion 120a illustrated in (d) and (e) of <FIG>, the protrusion 120a_1 illustrated in (f) of <FIG>, the protrusion 120b illustrated in (g) through (i) of <FIG>, the protrusion 120c illustrated in (a) and (b) of <FIG>, and the protrusion 120d illustrated in (d) and (e) of <FIG>. With this configuration, since an uppermost part of the protrusion in a height direction of the multi-stepped shape is easily melted, it is possible to more definitely melt the protrusion in a case where the expansion-molded article and the another member <NUM> are heat-fused together.

The protrusion may have a shape such that, as viewed from the above, the protrusion is tapered in a direction from an outside of the protrusion to an apex of the protrusion and the protrusion has a ridge line on the apex of the protrusion, like the protrusion 120e illustrated in (a) through (c) of <FIG>, the protrusion 120f illustrated in (d) through (f) of <FIG>, and the protrusion <NUM> illustrated in (g) and (h) of <FIG>. With this configuration, part of the protrusion which part corresponds to the ridge line on the apex of the protrusion is easily melted. Therefore, in a case where the expansion-molded article and the another member <NUM> are heat-fused together, it is possible to more definitely melt the protrusion.

The protrusion may have a shape such that the protrusion has a plurality of protrusions (second protrusions) on the apex of the protrusion, like the protrusion 120c_1 illustrated in (c) of <FIG> and the protrusion 120d_1 illustrated in (f) and (g) of <FIG>. With this configuration, since the plurality of protrusions (second protrusions) of the protrusion are easily melted, it is possible to more definitely melt the protrusion in a case where the expansion-molded article and the another member <NUM> are heat-fused together.

In short, the shape of the protrusion is at least one selected from the group consisting of (<NUM>) the multi-stepped shape, (<NUM>) the shape such that, as viewed from the above, the protrusion is tapered in the direction from the outside of the protrusion toward the apex of the protrusion and the protrusion has the ridge line on the apex of the protrusion, and (<NUM>) the shape such that the protrusion has the plurality of protrusions on the apex of the protrusion.

A size of the protrusion as has been described is not limited to any particular one. For example, an area of a bottom surface of the protrusion (a boundary surface between the base surface <NUM> and the protrusion) is not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, not less than <NUM><NUM>, or the like, and not more than <NUM><NUM>, not more than <NUM><NUM>, not more than <NUM><NUM>, not more than <NUM><NUM>, not more than <NUM><NUM>, not more than <NUM><NUM>, not more than <NUM><NUM>, not more than <NUM><NUM>, not more than <NUM><NUM>, not more than <NUM><NUM>, not more than <NUM><NUM>, not more than <NUM><NUM>, not more than <NUM><NUM>, not more than <NUM><NUM>, not more than <NUM><NUM>, not more than <NUM><NUM>, not more than <NUM><NUM>, not more than <NUM><NUM>, not more than <NUM><NUM>, or the like.

Further, a height of the protrusion is not less than <NUM>, not less than <NUM>, not less than <NUM>, not less than <NUM>, not less than <NUM>, not less than <NUM>, not less than <NUM>, not less than <NUM>, not less than <NUM>, not less than <NUM>, not less than <NUM>, not less than <NUM>, not less than <NUM>, not less than <NUM>, not less than <NUM>, not less than <NUM>, not less than <NUM>, not less than <NUM>, not less than <NUM>, not less than <NUM>, not less than <NUM>, or the like, and not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, or the like. In such cases, the expansion-molded article and the another member <NUM> are likely to have good adhesion therebetween.

In a case where a first protrusion and a second protrusion are formed, the first protrusion has a size described in the immediately previous paragraph, and the second protrusion preferably has a size smaller than that of the first protrusion. Note that, in a case where the first protrusion and the second protrusion are formed, a total height of the protrusion preferably falls within a range of the height of the protrusion which range has been described in the immediately previous paragraph.

There is a case where, around the protrusion as has been described, the base surface <NUM> is exposed outside. In a case where protrusions are arranged on the base surface <NUM> at substantially regular intervals, it looks as if the base surface <NUM> has a groove in a grid pattern. This allows the base surface <NUM> to have a function of a groove through which air is discharged, in a case where the expansion-molded article and the another member <NUM> are laminated. Thus, it is possible to prevent an air pocket from being generated between the expansion-molded article and the another member <NUM>. As a result, it is possible to firmly heat-fuse the expansion-molded article and the another member <NUM> together, and also possible to prevent ununiform adhesion from occurring.

Note that, in a case where the protrusions are disposed so as to cover the base surface such that, around the protrusions, the base surface is not exposed outside, it looks as if peripheries of the protrusions form a groove in a grid pattern, because respective upper parts of the protrusions are separated from each other. This allows the peripheries of the protrusions to have a function of a groove (gap) through which air is discharged, in a case where the expansion-molded article and the another member <NUM> are laminated. Thus, it is possible to prevent an air pocket from being generated between the expansion-molded article and the another member <NUM>. As a result, it is possible to firmly heat-fuse the expansion-molded article and the another member <NUM> together, and also possible to prevent ununiform adhesion from occurring. Note, however, that, around the protrusions, the base surface is preferably exposed outside, from the viewpoint of a function of discharging air.

Next, a method of producing the expansion-molded article will be described. The expansion-molded article is produced with use of a fixed mold and a mobile mold which form a molding chamber in which the expansion-molded article is formed. First, the fixed mold and the mobile mold are closed so that the molding chamber is formed, and the molding chamber is filled with expanded particles. Next, the expanded particles are heated by causing steam to pass through the molding chamber. This causes the expanded particles to be fused with each other. Note that, in order to cause the steam to pass through the molding chamber, it is only necessary to provide a publicly known vent hole (core vent) or a publicly known drilled hole in each of the fixed mold and the mobile mold. Subsequently, the fixed mold and the mobile mold are showered with cooling water or the like so that the molding chamber is cooled. The fixed mold and the mobile mold are then opened, and an expansion-molded article is taken out. In this manner, it is possible to produce the expansion-molded article. Such a method is referred to as in-mold expansion molding. The method described here is merely an example.

Note that, in a case where the protrusions in accordance with an aspect of the present invention are formed, it is preferable to, instead of providing the publicly known vent hole or the publicly known drilled hole as it is in each of the fixed mold and the mobile mold, adjust a size, a position, and a shape of the vent hole or the drilled hole as appropriate, in order to cause the object of an aspect of the present invention to be attained and to cause the effect of an aspect of the present invention to be brought about. In other words, the conventionally publicly known vent hole and the conventionally publicly known drilled hole are each insufficient from the viewpoint of the object and the effect of an aspect of the present invention.

At least one of the fixed mold and the mobile mold has a mold surface on at least part of which recesses are formed so that the protrusions as described above are formed on the base surface <NUM>. That is, the protrusions as described above are formed on the base surface <NUM> by the recesses. Note that the mold surface is a surface of a mold which surface constitutes a molding chamber. Each of the recesses has a shape which fits with a corresponding one of the protrusions as described above. In a case where the protrusions are thus formed by the recesses, it is possible to, with a high degree of freedom and high accuracy, form the shape and dimensions (size) of each of the protrusions, each of which includes a depression, a second protrusion, and/or the like as described above, by adjusting the shape and dimensions (size) of a corresponding one of the recesses.

Note, however, that the shape of each of the recesses does not need to accurately fit with a corresponding one of the protrusions. For example, a case is considered where (i) each of the recesses has a hemispherical shape and (ii) the expanded particles each of which has a substantially spherical shape and each of which has a diameter slightly greater than that of the hemispherical shape of each of the recesses are subjected to in-mold expansion molding. In this case, a situation can arise where a plurality of expanded particles incompletely enter a single recess, that is, a situation can arise where part of a plurality of expanded particles enters a single recess without the single recess being completely filled with a single expanded particle. As a result, each of the protrusions on an in-mold expansion-molded article to be obtained tends to have a shape such that an apex of a hemispherical shape is depressed. This is because the expanded particles with which the molding chamber is filled are less likely to completely fit in the recesses and, accordingly, for example, the expanded particles are less likely to receive heat from the molds during in-mold expansion molding, so that the expanded particles are poorly fused with each other. Thus, an interface between the expanded particles is likely to be depressed. In such a case, the protrusions each of which has an apex in which a depression is formed are likely to be formed.

Further, for example, a case is considered where (i) each of the recesses has a hemispherical shape and (ii) the expanded particles each of which has a substantially spherical shape and each of which has a diameter sufficiently smaller than that of the hemispherical shape of each of the recesses are subjected to in-mold expansion molding. In this case, the expanded particles with which the molding chamber is filled are likely to completely fit in the recesses. Therefore, each of the recesses tends to have a shape which accurately fits with a corresponding one of the protrusions. In other words, each of the protrusions is likely to have a shape which conforms to the shape of a corresponding one of the recesses, that is, each of the protrusions is likely to have a hemispherical shape such that a depression is not formed in an apex.

In contrary, a case is considered where the expanded particles each of which has a substantially spherical shape and each of which has a diameter sufficiently greater than that of the hemispherical shape of each of the recesses are subjected to in-mold expansion molding. In this case, the expanded particles with which the molding chamber is filled are less likely to fit in the recesses, and a possibility that a plurality of expanded particles fit in a single recess is low. Therefore, each of the protrusions tends to have a hemispherical shape such that a depression is not formed in an apex. Although the expanded particles with which the molding chamber is filled are less likely to fit in the recesses, steam during molding causes the expanded particles to be softened and expanded, thereby making it likely for the expanded particles to fit in the recesses. Consequently, each of the protrusions is likely to have a shape which conforms to the shape of a corresponding one of the recesses.

Note, however, that, in a case where the shape of each of the protrusions is adjusted by adjusting the diameter of the hemispherical shape of a corresponding one of the recesses and the diameter of each of the expanded particles as described above, it is not possible to adjust all of the protrusions so as to have an intended shape, and the expansion-molded article is likely to have the protrusions which have various shapes. In order to adjust each of the protrusions so as to have an intended shape, it is preferable to employ a method of adjusting the shape and the dimensions (size) of a corresponding one of the recesses.

As a method of forming the protrusions, holes each passing through at least one of the molds may be formed in the at least one of the molds, instead of the recesses. The holes cause the molding chamber to be communicated with an outside of the molds. Each of the holes has a diameter smaller than that of each of the expanded particles. With this configuration, in a case where the molding chamber is filled with the expanded particles, each of the expanded particles does not enter any of the holes. Therefore, the expanded particles do not leak from the molding chamber through the holes. The expanded particles are softened and expanded in a case where the expanded particles are heated by steam. In so doing, part of the expanded particles enters the holes, so that the protrusions are formed on the base surface <NUM>.

In a case where, instead of the recesses, the holes each passing through at least one of the molds are formed in the at least one of the molds, it is possible to easily create the at least one of the molds, as compared with a case where the recesses are formed in at least one of the molds. Furthermore, even after a mold having no hole is created, it is possible to easily form the holes in the mold, and possible to increase a degree of freedom of forming the protrusions. For example, in a case where (i) the expansion-molded article and the another member <NUM> are heat-fused together and (ii) part of the expansion-molded article is poor in adhesion, it is possible to increase adhesion between the expansion-molded article and the another member <NUM> by forming the holes in the mold surface of any of the molds that corresponds to the part of the expansion-molded article which part is poor in adhesion. The recesses and the holes may be used in combination, and the recesses and the holes may be formed in the mold surface of at least one of the molds.

Note that at least one of the recesses may have a hole which passes through the at least one of the molds. The hole causes the molding chamber to be communicated with the outside of the molds. In a case where the molds are filled with the expanded particles, air in the molding chamber is discharged to the outside of the molds. This makes it likely for the recesses to be filled with the expanded particles. As a result, the protrusions are easily formed. Moreover, in a case where the expanded particles are heated by steam during molding, the expanded particles with which the recesses are filled are softened and expanded. This makes it more likely for the recesses to be filled with the expanded particles. That is, this makes it likely for each of the protrusions to have a shape which conforms to the shape of a corresponding one of the recesses. Furthermore, in a case where part of the expanded particles enters the hole, the part of the expanded particles can be a second protrusion. That is, the second protrusion 125a of the protrusion 120d illustrated in (d) and (e) of <FIG> may be formed by the expanded particles slightly entering the hole.

The depression 121a of the protrusion 120a illustrated in (d) and (e) of <FIG> may be formed by adjusting a pressure of the steam and/or heating time when the expanded particles with which the molding chamber is filled are heated. Specifically, a gap is produced between the expanded particles by adjusting the pressure of the steam and/or the heating time. Producing the gap between the expanded particles causes the shape of each of the recesses, formed in at least one of the molds, not to be completely transferred to the expanded particles. As a result, it is possible to form the depression 121a of the protrusion 120a.

More specifically, the pressure of the steam by which the expanded particles are heated is gradually varied, and adjusted to a pressure lower than a pressure at which the gap between the expanded particles in the recesses, formed in at least one of the molds, is filled and the shape of each of the recesses is completely transferred to the expanded particles. This causes expansion of the expanded particles by the steam to be small.

In this manner, by adjusting the pressure of the steam and/or the heating time when the expanded particles with which the molding chamber is filled are heated, it is possible to find out a condition under which the depression 121a of the protrusion 120a can be formed. Note, however, that a method of forming the depression 121a of the protrusion 120a is not limited to a method of adjusting the pressure of the steam and/or the heating time. The depression 121a of the protrusion 120a may be formed by adjusting various molding conditions.

Alternatively, without use of the fixed mold and the mobile mold, the protrusions as described above may be formed on the base surface <NUM> by directly cutting the expansion-molded article with use of a tool or the like. Alternatively, the protrusions as described above may be formed on the base surface <NUM> by (i) heating a mold having a shape which fits with each of the protrusions as described above and (ii) pressing the mold against the expansion-molded article. The other examples of the method of forming the protrusions on the expansion-molded article include the following examples, That is, the other examples of the method include a method of making a transfer by carrying out hot-pressing with use of a mold having asperities, a method of making a transfer with use of a roller having asperities, and a method of forming the protrusions by cutting, each of which methods is carried out when a publicly known thermoplastic foam board, a publicly known thermoplastic foam sheet, or a publicly known injection expansion-molded article is produced. By employing any of these methods, it is possible to form the expansion-molded article which is to be heat-fused with the another member <NUM>.

In a case where the another member <NUM> is heat-fused with the expansion-molded article, the another member <NUM> which is softened in advance without being heated or which is softened in advance by being heated may be laminated on the expansion-molded article having at least one protrusion as described above on the base surface <NUM>. By laminating the another member <NUM> on the expansion-molded article, the laminated body is formed. By softening the another member <NUM> in advance, it is possible to increase adhesion between the expansion-molded article and the another member <NUM>. In a case where a melting point of the another member <NUM> is lower than that of the expansion-molded article, the another member <NUM> is softened earlier than the expansion-molded article. Therefore, since an excessive pressure is not needed when the another member <NUM> is laminated on the expansion-molded article, the shape of the expansion-molded article is not changed. Furthermore, it is possible to laminate the another member <NUM> on the expansion-molded article while preventing a deterioration of a resin of the expansion-molded article.

In a case where the melting point of the another member <NUM> is higher than that of the expansion-molded article, the protrusion of the expansion-molded article is more easily melted when the another member <NUM> is laminated on the expansion-molded article. Therefore, an excessive pressure is not needed when the another member <NUM> is laminated on the expansion-molded article. Accordingly, the shape of the expansion-molded article is not changed. Furthermore, it is possible to laminate the another member <NUM> on the expansion-molded article while preventing a deterioration of the resin of the expansion-molded article.

Examples of a method of producing the laminated body as described above, specifically, a method of producing the laminated body by laminating and heat-fusing the expansion-molded article and the another member <NUM> include a method including (i) a laminating step of laminating the another member <NUM> on a laminating surface of the expansion-molded article on which laminating surface the protrusion is formed and (ii) a pressing step of pressing the expansion-molded article and the another member <NUM> which are laminated. The method of producing the laminated body preferably further includes a decompressing step. The method of producing the laminated body will be described below for each of these steps.

The laminating step is a step of laminating the another member <NUM> on the laminating surface (on which the another member <NUM> is to be laminated) of the expansion-molded article. Specifically, the laminating step is a step of laminating, on the expansion-molded article having at least one protrusion as described above on the base surface <NUM>, the another member <NUM> which is softened in advance without being heated or which is softened in advance by being heated. The expansion-molded article used in the laminating step is an expansion-molded article produced by the above-described production method.

The pressing step is a step of pressing the expansion-molded article and the another member <NUM> which are laminated in the laminating step. A pressure at which the expansion-molded article and the another member <NUM> are pressed is not limited to any particular one, provided that the pressure does not cause a change in shape of the expansion-molded article. Moreover, pressing time is also not limited to any particular one.

According to the expansion-molded article, the base surface <NUM> is exposed outside around the protrusion. In a case where the protrusions are arranged on the base surface <NUM> at substantially regular intervals, it looks as if the base surface <NUM> has a groove in a grid pattern. This allows the base surface <NUM> to have a function of a groove through which air is discharged, in a case where the expansion-molded article and the another member <NUM> are laminated. Thus, it is possible to prevent an air pocket from being generated between the expansion-molded article and the another member <NUM>. As a result, it is possible to firmly heat-fuse the expansion-molded article and the another member <NUM> together, and also possible to prevent ununiform adhesion from occurring.

The heat-fusing step is a step of heat-fusing the expansion-molded article and the another member <NUM> together. The heat-fusing step may be carried out simultaneously with the pressing step or may be alternatively carried out after the pressing step. A temperature at which heat fusion is carried out and time for which heat fusion is carried out are each not limited to any particular one, and may be each set depending on the melting point of each of the expansion-molded article and the another member <NUM>.

A method of carrying out the pressing step and the heat-fusing step specifically includes the following three molding methods:.

After the expansion-molded article and the another member <NUM> are laminated, the expansion-molded article and the another member <NUM> are subjected to the pressing step in which, for example, the thermocompression (press) molding, the pressure roller molding, the integral blow molding, or the like is carried out. This promotes discharge of air trapped between the expansion-molded article and the another member <NUM>. It is therefore possible to prevent an air pocket from being generated between the expansion-molded article and the another member <NUM>.

The decompressing step which is carried out as necessary may be carried out simultaneously with at least one of the laminating step, the pressing step, and the heat-fusing step, may be alternatively carried out before the laminating step or between any of these steps, or may be alternatively carried out throughout all of these steps including before the laminating step and between any of these steps. The decompressing step is preferably carried out simultaneously with the pressing step. A degree of decompression only needs to be a degree which does not cause a change in shape of the expansion-molded article. Specifically, the degree of decompression can be adjusted, as appropriate, in consideration of an amount of air trapped between the expansion-molded article and the another member <NUM>, a surface property of the laminated body to be produced, and the like.

By carrying out the decompressing step, air trapped between the expansion-molded article and the another member <NUM> is more efficiently discharged along the base surface <NUM>, which has a function of a groove. It is therefore possible to further prevent an air pocket from being generated between the expansion-molded article and the another member <NUM>.

Examples of a method of carrying out decompression include: a method of decompressing the whole of space surrounding the expansion-molded article and the another member <NUM>; a method of decompressing the whole or part of space surrounding a boundary between the expansion-molded article and the another member <NUM>; and a method of decompressing part of the boundary between the expansion-molded article and the another member <NUM> (directly remove air trapped between the expansion-molded article and the another member <NUM>). In a case where the protrusions are arranged on the base surface <NUM> at substantially regular intervals, it looks as if the base surface <NUM> has a groove in a grid pattern. Therefore, it is possible to discharge air trapped between the expansion-molded article and the another member <NUM> even by the method of decompressing part of the space surrounding the boundary between the expansion-molded article and the another member <NUM> or the method of decompressing part of the boundary between the expansion-molded article and the another member <NUM>.

Note that examples of a method of further carrying out the above-described decompressing step in addition to the pressing step and the heat-fusing step include vacuum molding and air-pressure molding. In a case where the decompressing step is carried out, the pressing step can be carried out with use of a difference in air pressure. Specific examples of the vacuum molding and the air-pressure molding include molding which is carried out with use of a TOM molding machine (three-dimensional surface decoration molding machine) available from Fu-se Vacuum Forming Ltd.

Note, however, that the method of producing the laminated body is not limited to the method including the above-described steps.

(a) and (b) of <FIG> are each a cross-sectional view illustrating a cross section of the expansion-molded article in a case where the base surface of the expansion-molded article is not a planar surface. As illustrated in (a) of <FIG>, a base surface <NUM> of an expansion-molded article <NUM> is constituted by horizontal surfaces 111a, a vertical surface 111b, and an inclined planar surface 111c.

The vertical surface 111b is a surface perpendicular to the horizontal surfaces 111a. The inclined planar surface 111c is a surface located between two of the horizontal surfaces 111a, and is a surface inclined from a higher one of the two of the horizontal surfaces 111a toward a lower one of the two of the horizontal surfaces 111a. Protrusions 120d are formed on each of the horizontal surfaces 111a, the vertical surface 111b, and the inclined planar surface 111c. Note that protrusions each of which has any other shape as described above may be formed on each of the horizontal surfaces 111a, the vertical surface 111b, and the inclined planar surface 111c. Note also that the base surface which has any other shape may be formed by combining, as appropriate, the horizontal surfaces 111a, the vertical surface 111b, and the inclined planar surface 111c.

As illustrated in (b) of <FIG>, a base surface <NUM> of an expansion-molded article <NUM> is a curved surface. Protrusions 120d are formed on the base surface <NUM>. Note that protrusions each of which has any other shape as described above may be formed on the base surface <NUM>. The base surface of the expansion-molded article may be a base surface which has any other shape that is not horizontal, other than a shape of the base surface as illustrated in each of (a) and (b) of <FIG>. In this manner, the base surface of the expansion-molded article does not need to be a horizontal surface. It is also possible to heat-fuse the another member <NUM> with the expansion-molded article which has the base surface that is not a horizontal surface.

(a) of <FIG> is a drawing illustrating a conventional expansion-molded article <NUM>. (b) of <FIG> is a drawing illustrating an expansion-molded article <NUM> which has protrusions each having a hemispherical shape. (c) of <FIG> is a drawing illustrating an expansion-molded article <NUM> which has protrusions each having a hemispherical shape and protrusions 120d.

As illustrated in (a) of <FIG>, a protrusion is not formed on a base surface of the conventional expansion-molded article <NUM>. Note, however, that a surface of the expansion-molded article <NUM> is not completely planar, and the expansion-molded article <NUM> has fine asperities. As illustrated in (b) of <FIG>, the protrusions each having a hemispherical shape are formed on a base surface of the expansion-molded article <NUM>. As illustrated in (c) of <FIG>, the protrusions, each having a hemispherical shape, and the above-described protrusions 120d are formed in combination on a base surface of the expansion-molded article <NUM>.

(a) through (c) of <FIG> are each a drawing illustrating a state of the another member <NUM> which has been peeled from the expansion-molded article after the another member <NUM> has been heat-fused with the expansion-molded article. (d) through (f) of <FIG> are each a drawing illustrating a state of the expansion-molded article from which the another member <NUM> has been peeled after the another member <NUM> has been heat-fused with the expansion-molded article. (g) through (i) of <FIG> are each a drawing illustrating a state in a case where the another member <NUM> is heat-fused with the expansion-molded article. In <FIG>, the another member <NUM> is a film.

(a), (d), and (g) of <FIG> are each a drawing concerning the conventional expansion-molded article <NUM>. (b), (e), and (h) of <FIG> are each a drawing concerning the expansion-molded article <NUM>. (c), (f), and (i) of <FIG> are each a drawing concerning the expansion-molded article <NUM>.

As illustrated in each of (a) through (c) of <FIG>, part of the expansion-molded article adheres to the another member <NUM> which has been peeled from the expansion-molded article after the another member <NUM> has been heat-fused with the expansion-molded article. Here, that the expansion-molded article which adheres to the another member <NUM> is larger in amount means that the expansion-molded article and the another member <NUM> are more firmly fused together.

Note that a laminated body illustrated in each of (g) through (i) of <FIG> can be produced as follows. Each of the expansion-molded articles <NUM>, <NUM>, and <NUM> is obtained by subjecting expanded polypropylene-based resin particles to in-mold expansion molding. The expanded polypropylene-based resin particles can be, for example, EPERAN available from Kaneka Corporation. The expansion-molded article <NUM> is formed with use of the expanded polypropylene-based resin particles each of which has a diameter of approximately <NUM>, and is a conventional expansion-molded article obtained by in-mold expansion molding without forming a recess and a hole in a mold surface of any of molds. In short, any protrusion in accordance with an aspect of the present invention is not formed on a surface of the expansion-molded article <NUM> which surface is to be heat-fused with the another member <NUM>.

The expansion-molded article <NUM> is formed with use of the expanded polypropylene-based resin particles each of which has a diameter of approximately <NUM>, and is the expansion-molded article in accordance with an aspect of the present invention which expansion-molded article is obtained by in-mold expansion molding with use of molds at least one of which has a mold surface on which recesses are formed. In this case, on the mold surface of the at least one of the molds, the recesses each of which has a substantially hemispherical shape and each of which has a diameter of <NUM> and a depth of <NUM> are formed at regular intervals at a density of <NUM> per square centimeter. Thus, the protrusions each of which has a substantially hemispherical shape and each of which has a diameter of <NUM> (an area of a bottom surface is <NUM><NUM>) and a height of <NUM> are formed on a surface of the expansion-molded article <NUM> which surface is to be heat-fused with the another member <NUM>.

The expansion-molded article <NUM> is formed with use of the expanded polypropylene-based resin particles each of which has a diameter of approximately <NUM>, and is the expansion-molded article in accordance with an aspect of the present invention which expansion-molded article is obtained by in-mold expansion molding with use of molds at least one of which has a mold surface on which recesses are formed. Some of the recesses each have, in its bottom, a hole which has a diameter of <NUM> and which passes through the at least one of the molds. In this case, in the mold surface of the at least one of the molds, the recesses each of which has a substantially hemispherical shape and each of which has a diameter of <NUM> and a depth of <NUM> are formed at regular intervals at a density of <NUM> per square centimeter. Further, the hole which has a diameter of <NUM> is formed in the bottom of, for example, every third recess. That is, the protrusions 120d are formed on the base surface <NUM> of the expansion-molded article by the every third recess. Each of the protrusions 120d is constituted by (i) a first protrusion which has a substantially hemispherical shape and which has a diameter of <NUM> (an area of a bottom surface is <NUM><NUM>) and a height of <NUM> and (ii) a second protrusion which is formed on an apex of the first protrusion and which has a diameter of <NUM> and a height of <NUM>.

Next, a polypropylene-based resin film which is commercially available and which has a thickness of <NUM> is placed on the surface of each of the expansion-molded articles <NUM>, <NUM>, and <NUM>. An obtained object is pressed from a polypropylene-based resin film side for <NUM> minute and <NUM> seconds at a pressure of <NUM> gf/cm<NUM> with use of a hot plate which is adjusted to a temperature of <NUM>. The laminated body illustrated in each of (g) through (i) of <FIG> can be thus produced. Note that the above-described method of producing the laminated body is an example.

Each of (a) through (c) of <FIG> illustrates the amount of the expansion-molded article which adheres to the another member <NUM>. Out of these amounts, the amount of the expansion-molded article <NUM> which adheres to the another member <NUM> ((a) of <FIG>) is the smallest, and the amount of the expansion-molded article <NUM> which adheres to the another member <NUM> ((c) of <FIG>) is the largest. That is, out of (a) through (c) of <FIG>, adhesion between the expansion-molded article <NUM> and the another member <NUM> is the poorest, and adhesion between the expansion-molded article <NUM> and the another member <NUM> is the strongest. Furthermore, the another member <NUM> illustrated in (c) of <FIG> is partially torn. As such, the adhesion between the expansion-molded article <NUM> and the another member <NUM> is particularly strong.

Therefore, by forming the protrusions, each of which has a hemispherical shape, on the base surface of the expansion-molded article <NUM>, it is possible to increase adhesion between the expansion-molded article <NUM> and the another member <NUM> in a case where the expansion-molded article <NUM> and the another member <NUM> are heat-fused together. Furthermore, by forming the protrusions 120d on the base surface of the expansion-molded article <NUM>, it is possible to further increase the adhesion between the expansion-molded article <NUM> and the another member <NUM> in a case where the expansion-molded article <NUM> and the another member <NUM> are heat-fused together.

In particular, the protrusions, each having a hemispherical shape, and the above-described protrusions 120d are formed in combination on the base surface of the expansion-molded article <NUM>. Although two protrusions each having a hemispherical shape are provided between the protrusions 120d, it is possible to increase the adhesion throughout the whole of a bonded surface.

Note that Patent Literature <NUM> discloses, in <FIG>, a configuration in which asperities are formed on a lower side of a foam layer. The asperities are asperities caused by cells generated during expansion (preliminary expansion) for forming the foam layer such as polystyrene foam, that is, asperities formed between expanded particles or on an interface between the expanded particles. As such, the asperities are different from the protrusion in accordance with an aspect of the present invention. It is explained, with use of the above-described expansion-molded article <NUM>, that adhesion of the foam layer with another member is poor.

Moreover, Patent Literature <NUM> discloses that, according to the invention of Patent Literature <NUM>, the foam layer is caused to adhere to a surface of a base material by residual heat of the base material. Thus, Patent Literature <NUM> suggests that, according to the invention of Patent Literature <NUM>, heat is transferred to the whole of the base material. In contrast, according to an aspect of the present invention, a mold or the another member <NUM>, each of which heats up, is brought into contact with the protrusion of the expansion-molded article so that heat is transferred to the protrusion and the protrusion is melted on a priority basis.

The present invention is not limited to the embodiments, but can be altered by a skilled person in the art within the scope of the claims. The present invention also encompasses, in its technical scope, any embodiment derived by combining technical means disclosed in differing embodiments.

Aspects of the present invention can also be expressed as follows:
An expansion-molded article in accordance with an aspect of the present invention is an expansion-molded article which is to be heat-fused with another member, including at least one protrusion which is formed on at least one surface of the expansion-molded article which at least one surface is to be heat-fused with the another member, the at least one protrusion having at least two surfaces as viewed from above (in a planar view), as a boundary line between the at least two surfaces, at least one boundary line being present which intersects a direction from an outside of the at least one protrusion toward a center of an apex of the at least one protrusion.

According to the above configuration, as viewed from the above, the at least one protrusion has, as the boundary line between the two surfaces, the at least one boundary line which intersects the direction from the outside of the at least one protrusion toward the center of the apex of the at least one protrusion. Therefore, as viewed from the above, the at least one protrusion has, not a shape such that the at least one protrusion has identical regularity in the direction from the outside of the at least one protrusion toward the apex of the at least one protrusion, but a shape such that the at least one protrusion has a tapered part obtained by a shape changing to different regularity along the way in the direction from the outside of the at least one protrusion toward the apex of the at least one protrusion. The at least one protrusion may have, for example, a shape such that, on a cross section of the at least one protrusion, an angle formed by a bottom surface and a contour of the at least one protrusion changes along the way or a shape such that, on the cross section of the at least one protrusion, a curvature changes along the way (the contour has an inflection point). Alternatively, the at least one protrusion may have a multi-stepped shape or a shape such that the at least one protrusion has a ridge line on the apex of the at least one protrusion.

Furthermore, the at least one protrusion has the boundary line, and has the tapered part. Therefore, in a case where the expansion-molded article and the another member are heat-fused together, the at least one protrusion is easily melted. Accordingly, it is possible to firmly heat-fuse the expansion-molded article and the another member together.

The expansion-molded article in accordance with another aspect of the present invention is preferably arranged such that a shape of the at least one protrusion is at least one selected from the group consisting of (<NUM>) a multi-stepped shape, (<NUM>) a shape such that, as viewed from the above, the at least one protrusion is tapered in a direction from the outside of the at least one protrusion toward the apex of the at least one protrusion and has a ridge line on the apex of the at least one protrusion, and (<NUM>) a shape such that the at least one protrusion has a plurality of protrusions on the apex of the at least one protrusion.

According to the above configuration, in a case where the at least one protrusion has the multi-stepped shape, an uppermost part of the at least one protrusion in a height direction of the multi-stepped shape is easily melted. Therefore, it is possible to more definitely melt the at least one protrusion in a case where the expansion-molded article and the another member are heat-fused together.

Furthermore, in a case where the at least one protrusion has the shape such that, as viewed from the above, the at least one protrusion is tapered in the direction from the outside of the at least one protrusion toward the apex of the at least one protrusion and the at least one protrusion has a ridge line on the apex of the at least one protrusion, part of the at least one protrusion which part corresponds to the ridge line on the apex of the at least one protrusion is easily melted. Therefore, in a case where the expansion-molded article and the another member are heat-fused together, it is possible to more definitely melt the at least one protrusion.

Moreover, in a case where the at least one protrusion has the shape such that the at least one protrusion has the plurality of protrusions on the apex of the at least one protrusion, the plurality of protrusions of the at least one protrusion are easily melted. Therefore, it is possible to more definitely melt the at least one protrusion in a case where the expansion-molded article and the another member are heat-fused together. Accordingly, it is possible to more firmly heat-fuse the expansion-molded article and the another member together.

The expansion-molded article in accordance with another aspect of the present invention is preferably arranged such that the at least one protrusion includes a first protrusion and a second protrusion; and the second protrusion is formed on the first protrusion.

According to the above configuration, the at least one protrusion may include the first protrusion and the second protrusion, and the second protrusion may be formed on the first protrusion. The second protrusion has a low heat capacity and is accordingly easily melted. Thus, in a case where the second protrusion is melted by heat, the second protrusion easily spreads on a surface of the first protrusion. Moreover, the first protrusion which is to be melted also has a low heat capacity. Therefore, in a case where the expansion-molded article and the another member are heat-fused together, it is possible to more definitely melt the at least one protrusion. Accordingly, it is possible to more firmly heat-fuse the expansion-molded article and the another member together. Note that the second protrusion is preferably formed in a vicinity of an apex of the first protrusion. Note also that a plurality of second protrusions may be formed.

The expansion-molded article in accordance with another aspect of the present invention is preferably arranged such that the at least one protrusion has a depression in the apex of the at least one protrusion.

According to the above configuration, the at least one protrusion has the depression which is formed in the apex of the at least one protrusion. Part of the at least one protrusion which part is located around the depression has a shape such that the part has a ridge line, and is accordingly easily melted. Therefore, it is possible to more definitely melt the at least one protrusion in a case where the expansion-molded article and the another member are heat-fused together. Accordingly, it is possible to more firmly heat-fuse the expansion-molded article and the another member together.

The expansion-molded article in accordance with another aspect of the present invention is preferably arranged such that a bottom surface of the at least one protrusion has a circular shape or an elliptical shape.

According to the above configuration, the bottom surface of the at least one protrusion has the circular shape or the elliptical shape. Therefore, in a case where the expansion-molded article and the another member are heat-fused together, the at least one protrusion is melted and then spreads in the circular shape or in the elliptical shape. Therefore, it is possible to more firmly heat-fuse the expansion-molded article and the another member together.

The expansion-molded article in accordance with another aspect of the present invention is preferably arranged such that the expansion-molded article is composed of expanded particles.

According to the above configuration, the expansion-molded article is composed of the expanded particles. Therefore, it is possible to melt the expansion-molded article and thereby heat-fuse the expansion-molded article and the another member together. Furthermore, in a case where the expansion-molded article is composed of the expanded particles, it is possible to easily form the at least one protrusion by in-mold expansion molding.

The present invention relates expansion-molded article in accordance with another aspect of the present invention is preferably arranged such that the at least one protrusion is formed on the at least one surface of the expansion-molded article, which at least one surface is to be heat-fused with the another member, at a density of not less than <NUM> per square centimeter and not more than <NUM> per square centimeter, and is formed throughout a region of at least not less than <NUM>% of the at least one surface of the expansion-molded article, which at least one surface is to be heat-fused with the another member.

According to the above configuration, the at least one protrusion is formed on the at least one surface of the expansion-molded article, which at least one surface is to be heat-fused with the another member, at a density of not less than <NUM> per square centimeter, and is formed throughout a region of at least not less than <NUM>% of the at least one surface of the expansion-molded article, which at least one surface is to be heat-fused with the another member. Therefore, it is possible to firmly heat-fuse the expansion-molded article and the another member together. Moreover, it is possible to reduce a possibility that the expansion-molded article is separated from the another member.

Furthermore, the at least one protrusion is formed on the at least one surface of the expansion-molded article, which at least one surface is to be heat-fused with the another member, at a density of not more than <NUM> per square centimeter. Therefore, it is possible to reduce a production cost without forming an extra protrusion on the at least one surface of the expansion-molded article, which at least one surface is to be heat-fused with the another member.

The expansion-molded article in accordance with another aspect of the present invention is preferably arranged such that the at least one surface of the expansion-molded article, which at least one surface is to be heat-fused with the another member, is constituted by a base surface and the at least one protrusion which is formed on the base surface; and around the at least one protrusion, the base surface is exposed outside.

According to the above configuration, the at least one surface of the expansion-molded article, which at least one surface is to be heat-fused with the another member, is constituted by the base surface and the at least one protrusion which is formed on the base surface, and around the at least one protrusion, the base surface is exposed outside. This causes the at least one protrusion to be melted on a priority basis in a case where the expansion-molded article and the another member are heat-fused together. Therefore, it is possible to prevent the base surface from being melted. Accordingly, it is possible to prevent a change in shape of the base surface. It is therefore possible to prevent a change in shape of the expansion-molded article.

Moreover, since around the at least one protrusion, the base surface is exposed outside, it is possible to prevent an air pocket from being generated between the expansion-molded article and the another member. As a result, it is possible to firmly heat-fuse the expansion-molded article and the another member together, and also possible to prevent ununiform adhesion from occurring.

A laminated body in accordance with an aspect of the present invention is a laminated body including: the expansion-molded article; and another member which is laminated on the expansion-molded article.

According to the above configuration, it is possible to form a laminated body in which the expansion-molded article and the another member are firmly heat-fused together.

A method of producing a laminated body in accordance with an aspect of the present invention is a method of producing a laminated body by laminating and heat-fusing the expansion-molded article and the another member, the method including: a laminating step of laminating the another member on a laminating surface of the expansion-molded article on which laminating surface at least one protrusion is formed; and a pressing step of pressing the expansion-molded article and the another member which are laminated.

According to the above configuration, it is possible to produce a laminated body in which the expansion-molded article and the another member are firmly heat-fused together. Moreover, it is possible to produce a laminated body which has a reduced possibility that the expansion-molded article has a shape which is different from a required shape.

Furthermore, in a case where, around the at least one protrusion, the base surface is exposed outside, it is possible to prevent an air pocket from being generated between the expansion-molded article and the another member. As a result, it is possible to produce a laminated body in which the expansion-molded article and the another member are firmly heat-fused together and ununiform adhesion is prevented from occurring.

The method in accordance with another aspect of the present invention is preferably arranged so as to include a decompressing step.

Claim 1:
An expansion-molded article (<NUM>, 10a, 10b, 10c, 10d, 10d_1, 10e, 10f, <NUM>, <NUM>, 10i, 10j, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) which is to be heat-fused with another member (<NUM>), comprising
at least one protrusion (<NUM>, 120a, 120a_1, 120b, 120c, 120c_1, 120d, 120d_1, 120e, 120f, 120f_1, <NUM>, <NUM>, 120i, 120j) which is formed on at least one surface (<NUM>) of the expansion-molded article which at least one surface (<NUM>, <NUM>, <NUM>) is to be heat-fused with the another member (<NUM>),
the at least one protrusion having at least two surfaces (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) as viewed in a planar view from above,
as a boundary line (b1 to b18) between the at least two surfaces, at least one boundary line being present which intersects, in the planar view, a direction (d1 to d17) from an outside of the at least one protrusion toward a center of an apex of the at least one protrusion,
the expansion-molded article being characterised in that it is composed of expanded particles.