JP5270990B2 - Foamed member and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a foamed member which can be fixed surely by a curing tape, and is suitable for protecting a corner of a member (a column, a wall etc.) to be protected. <P>SOLUTION: The foamed member 61 includes an apex 2 and two side walls 63A, 63B extending from the apex 2 to have an L-letter shape. These side walls 63A, 63B are formed in such a manner that they become thinner from their width-directional middle parts of the side walls 63A, 63B toward ends 63a, 63b, respectively. In this foamed member 61, curved recesses 63c, 63d are formed at inner walls of the side walls 63A, 63B, and a V-shaped recess 62a is formed at an outer wall of the apex 62. The depth of the recess 62a is extremely small relative to the thickness of the apex 62 (or the foamed member). <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a foam member suitable for protecting corners (for example, L-shaped corners) of a member to be protected (columns, walls, etc.), a manufacturing method thereof, and a member to be protected using the foam member. The present invention relates to a corner protecting method and a die for producing the foamed member.

  Corners such as pillars and walls are susceptible to damage, and may be damaged when transporting relatively large items such as furniture, for example. In addition, if the corners are exposed, people and surrounding objects may be damaged. In order to prevent such various damages and dangers, protective members (curing materials) for protecting the corners are used.

  As such a protective member, for example, a protective member formed of a thermoplastic resin foam is known. For example, in Japanese Utility Model Publication No. 51-37655 (Patent Document 1), a cutout portion is provided along the longitudinal direction of a synthetic resin cylindrical foam having elastic restoring force, and one of the cylindrical bodies in the cutout portion is provided. There is disclosed a shock absorbing material at the corner portion of the article, in which the end edge of the article is wound more inward than the other end edge.

  Japanese Patent No. 3182403 (Patent Document 2) discloses a cylindrical polyethylene-based resin foam or a cylindrical polypropylene-based resin foam which has a continuous crack in the longitudinal direction, and both side edges forming the crack overlap each other. The protective material for buildings comprised by this is disclosed. In addition, in this document, regarding the action of the protective material for a building, when attached to a protected material such as a column, both side edges that overlap each other are expanded, and the reaction force of the both end edges causes the column or the like to be covered. It is described that the protective material is firmly held.

  However, the protective members of these documents do not have a sufficient corner protection effect. In addition, because it has a structure in which the protected member is sandwiched or covered using elastic force (repulsive force), it can cover pipes with relatively small diameters or sides, etc. It becomes impossible to effectively protect the corners of members that are difficult to sandwich or cover. Moreover, even if such a protective member is fixed to a column or wall with a curing tape, which will be described later, it is easily peeled off due to its elastic force.

On the other hand, a protective member having an L shape is also known in order to protect the corner itself. Such an L-shaped protective member usually does not impair the design and workability of the member to be protected (for example, the peeling of a wall cloth, the protection of a wall, a pillar, etc.) in a state where the corner portion is covered. In order not to cause adhesion of the adhesive to the member, it is fixed to the member to be protected by a weak adhesive curing tape. As such a protective member, typically, in order to reduce the impact on the corner of the member to be protected, an L-shaped hard plastic member having a corner portion formed in a convex shape toward the outside is used. Are known. However, such a hard plastic protective member may not be able to sufficiently mitigate the impact acting on the corner. Moreover, such a protective member is easily broken by an impact and is not sufficient in terms of durability.
Japanese Utility Model Publication No. 51-37655 (page 2, right column, lines 2-6) Japanese Patent No. 3182403 (claims, paragraph number [0031])

  Therefore, the objective of this invention is providing the foaming member which can protect the corner | angular part of a to-be-protected member effectively, the manufacturing method of this foaming member, and the protection method of the to-be-protected member using the said foaming member.

  Another object of the present invention is to provide a foamed member that can be securely fixed to a protected member even with a temporary fixing material having a relatively weak adhesive force or fixing force, such as a curing tape, a method for producing the foamed member, and the foaming It is providing the protection method of the to-be-protected member using a member.

  Still another object of the present invention is to provide a foamed member capable of reliably protecting even a relatively large corner (such as an L-shaped corner of a wall), a method for producing the foamed member, and a protection using the foamed member It is in providing the protection method of a member.

  Another object of the present invention is to provide a die useful for producing a foamed member as described above.

  In order to achieve the above object, the present inventor has intensively studied an L-shaped foam member that can protect the corners of the member to be protected, and first, an L-shaped foam having a simple uniform overall thickness (or almost uniform). A member (a foamed member produced in Reference Example 1 shown later) was obtained. However, in such a foamed member, a gap is generated between the foamed member itself and the member to be protected (fixed part of the member to be protected). It was found that it could not be fixed with sufficient strength and was easily detached from the protected member.

  Therefore, in order to suppress the gap as described above as much as possible, an attempt was made to form both end portions of the side wall portion extending in an L shape from the top portion (corner portion) of the foamed member thinly. However, in such a foam member with thin end portions (a foam member manufactured in Reference Example 2 described later), although the gap due to the thickness of the foam member can be reduced, it is more longitudinal than a foam member having a uniform thickness. There was a problem that the warpage was likely to occur. Such warpage becomes more prominent as the length of the foamed member becomes longer, resulting in a large gap depending on the fixing portion with respect to the member to be protected, which hinders stable temporary fixing as described above.

  In order to solve the above-described problems, the present inventor has conducted further intensive studies, and as a result, the end portion of the side wall portion extending in an L shape from the top portion is formed thin, and at least one of the top portion and the side wall portion. In the foamed member formed with a crescent recess, warpage in the longitudinal direction is suppressed, and the corner of the protected member (wall, column, etc.) is securely fixed to the protected member even with a temporary fixing material such as a curing tape. The present invention has been completed by finding that it can be effectively protected.

  That is, the foam member of the present invention is an L-shaped foam member having two side wall portions extending in an L shape from the top portion, and is an end portion of each side wall portion (extended in detail). In the foam member, the end portion is formed thin, and a concave portion is formed in each side wall portion and / or the top portion along the longitudinal direction.

In the said foaming member, the side wall part may be formed thinly in the form from which the thickness becomes thin toward the edge part from the middle part of the width direction of a side wall part. By forming thin toward the end from the middle portion, it is possible to reduce the crab thickness Dara name towards the end, easily fixed to the protective member. Moreover, it can be set as sufficient thickness from a top part to the middle part, and the protection performance with respect to the corner | angular part of a to-be-protected member is not reduced. In the foamed member, a concave portion is formed along the longitudinal direction at a middle portion (for example, an inner wall or an outer wall of the middle portion) and / or a top portion (particularly, a middle portion and a top portion of the side wall portion in the width direction). May be. When a concave portion is formed in such a portion, warpage in the longitudinal direction can be more easily suppressed.

  The foamed member is usually formed of a thermoplastic resin, and may be formed of an olefin-based resin (particularly, polyethylene or the like), particularly from the viewpoint of flexibility, resilience, impact resistance, and the like.

  As described above, the foaming member of the present invention is prevented from warping in the longitudinal direction. For example, the foamed member formed to have a length of 1.7 m is made of an end portion of a side wall portion (specifically, each side wall portion). When mounted and measured so as to be in contact with the horizontal plane along the longitudinal direction, the height of warpage from the horizontal plane may be 20 mm or less. Such a foamed member of the present invention may be a foamed member for protecting a corner portion of a member to be protected (such as a wall).

  In the present invention, there is provided a method for producing the foamed member by extruding and molding a thermoplastic resin from a die, wherein the lip of the die extends in an L shape from an intersection (slit intersection). A lip having a slit having an L-shaped cross section composed of a slit portion, an end portion of each slit portion being formed with a narrow width, and a convex portion for narrowing the slit width at each slit portion and / or the intersection portion The manufacturing method of the foaming member which is is also included. In this method, the lip may be formed narrower from the middle part in the width direction of the slit part toward the end part. Moreover, in the said method, you may have a convex part in the intermediate part of the width direction of a slit part, and / or an intersection part (especially the intermediate part and intersection part of the width direction of a slit part).

  As described above, the foamed member of the present invention is useful as a member for protecting the corners of the protected member. Therefore, the present invention includes a method for protecting a corner portion of a member to be protected, the method for protecting the corner portion covering the corner portion with the foamed member. In this method, the corners may be covered with the foaming member fixed to the member to be protected by the curing tape. In this method, it is sufficient to cover at least the corners, and the corners of the member to be protected and the peripheral portions thereof may be covered. Since the foamed member of the present invention is formed with a thin end and warped in the longitudinal direction, the foamed member can be reliably fixed to the protected member with a curing tape.

  The present invention also provides a die for producing the foamed member by extrusion foaming, wherein the lip of the die has an L-shaped cross section composed of two slit portions extending in an L shape from the intersection. And a die having a narrowed end portion of each slit portion and a convex portion that narrows the slit width at each slit portion and / or the intersection point.

  Since the foamed member of the present invention has an L-shaped cross section and is formed of a foam, the corners of the protected member can be effectively protected. In particular, since the foamed member of the present invention has a thin end and a small warpage in the longitudinal direction, even a temporary fixing material having a relatively weak adhesive force or fixing force such as a curing tape is a protected member. Can be securely fixed. In addition, since the foamed member of the present invention has an L-shaped cross section and can be fixed with a temporary fixing material such as a curing tape, even a relatively large corner (such as an L-shaped corner of a wall). It can be reliably protected. Moreover, in this invention, die | dye useful in order to manufacture the above foaming members can be provided.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings as necessary.

  FIG. 1 is a schematic cross-sectional view showing an example of a foamed member of the present invention. In FIG. 1, a foam member 1 having an L-shaped cross section includes a top portion 2 and two side wall portions 3 </ b> A and 3 </ b> B extending from the top portion 2 in an L shape at an angle of approximately 90 degrees (for example, 80 to 100 degrees). The end portions 3a and 3b of the side wall portions 3A and 3B are formed thin (or thin). Specifically, the side wall portions 3A and 3B are formed in a form in which the thickness decreases from a middle portion in the width direction of the side wall portions 3A and 3B toward the end portions (extending end portions) 3a and 3b.

  And in this foaming member 1, recessed part 3c, 3d is formed in the inner wall of side wall part 3A, 3B, respectively. That is, of the side wall portions 3A and 3B, curved concave portions (saddle-shaped concave portions) 3c and 3d are formed on the inner wall (inner side) in the middle portion closer to the top than the central portion.

  The foamed member in FIG. 1 is a polyethylene foam having an expansion ratio of about 20 to 25 times, and is excellent in flexibility, impact resistance, and resilience. Moreover, although FIG. 1 is sectional drawing, the top part and side wall part of a foaming member are formed along the direction perpendicular | vertical to the longitudinal direction or cross section of a foaming member (it is the same also in the following figures). FIG. 2 shows a schematic perspective view of the foamed member of FIG. As can be seen from FIG. 2, the concave portions 3c and 3d form concave grooves along the longitudinal direction of the foamed member.

  In such a foamed member, the end portion of the side wall portion is formed to be thin (particularly, the thickness is reduced toward the end portion). Therefore, when fixing to the protected member, The step can be reduced. In addition, even if the end portion of the side wall portion is formed thin as described above, since the concave portion is formed in the side wall portion, the warpage in the longitudinal direction occurring in the foam molding is suppressed to be relatively small. Therefore, even a temporary fixing material having a weak adhesive force such as a curing tape can be reliably fixed to the protected member, and the protected member can be protected while exhibiting the excellent protection performance of the foamed member.

  And the foaming member of FIG. 1 and FIG. 2 can be manufactured using the die | dye shown below. FIG. 3 is a schematic cross-sectional view of a die for manufacturing the foamed member of FIG. In the example of FIG. 3, the lip 10 of the die has a slit 11 having an L-shaped cross section. The slit 11 is formed from an intersection portion (slit intersection portion) 12 corresponding to the top portion 2 and the intersection portion 12. The two slit portions 13A and 13B corresponding to the side wall portions 3A and 3B extending in an L shape at an angle of approximately 90 degrees. Then, the end portions 13a and 13b of the slit portions 13A and 13BC correspond to the thin end portions 3a and 3b, respectively, and have a width from the middle portion in the width direction of the slit portions 13A and 13B toward the end portions 13a and 13b. It is formed narrowly.

  The lip 10 has convex portions 13c and 13d that narrow the slit width corresponding to the curved concave portions 3c and 3d on the inner walls of the slit portions 13A and 13B. That is, of the slit portions 13A and 13B, U-shaped convex portions 13c and 13d are formed on the inner wall (or the inner side) near the middle portion, and the slit width is narrowed.

  When a thermoplastic resin is extruded and foam-molded from the lip having such a shape, a foamed member (foamed member in FIG. 2) having a cross-sectional shape corresponding to FIG. 1 and extending in the longitudinal direction can be obtained. In FIG. 3, the lip 10 has a square part, but when the foam 10 is extruded and foamed by passing through such a lip, the foam member has a rounded shape as a whole. Is formed. For example, curved extrusions 3c and 3d are formed by extrusion foaming after passing through the U-shaped projections 13c and 13c.

  FIG. 4 is a schematic sectional view showing another example of the foamed member of the present invention. In FIG. 4, the foam member 21 having an L-shaped cross section has the same structure as the foam member of FIG. 1 except that a flat portion 22 a is formed on the outer wall of the top portion 22. That is, the foam member 21 is formed of two side wall portions 23A and 23B that extend in an L shape from the top portion 22 and each end portion 23a and 23b is formed thin, and the inner walls of the side wall portions 23A and 23B are curved. Shaped recesses 23c and 23d are formed.

  In the foam member of FIG. 4, warping in the longitudinal direction can be further suppressed as compared with the foam member of FIG. 1 by providing the flat portion 22 </ b> A so as to flatten the top portion 22.

  FIG. 5 is a schematic cross-sectional view of a die for manufacturing the foamed member of FIG. In FIG. 5, the lip 30 has the same shape as the lip of FIG. 3 except that the outer wall of the intersection portion 32 has a flat portion (slit flat portion) 32 a that flattens and narrows the slit width. That is, the lip 30 has a slit 31 including an intersection portion 32 corresponding to the top portion 22 and slit portions 33A and 33B corresponding to the side wall portions 23A and 23B. The slit portions 33A and 33B include a thin end portion 23a. , 23b and narrow U-shaped convex portions 33c, 33d corresponding to the curved concave portions 23c, 23d are formed.

  FIG. 6 is a schematic cross-sectional view showing still another example of the foamed member of the present invention. In FIG. 6, the foam member 41 having an L-shaped cross section extends in an L shape from the top portion 42 in the same manner as in FIG. 1, and has two side wall portions 43 </ b> A and 43 </ b> B each having thin end portions 43 a and 43 b. It has.

  And in the example of FIG. 6, the recessed part 42a is formed in the inner wall (top part inner side) of the top part 42. FIG. That is, the recess 42 a forms a U-shaped (or needle-shaped) notch on the inner wall (inner side) of the top 42. The concave portion (notch portion) 42a is formed narrow (in a needle shape) so as not to deteriorate the impact resistance performance (protection performance) of the top portion. Similarly to the above, the recess 42a is formed along the longitudinal direction of the foamed member, and a concave groove is formed along the longitudinal direction of the foamed member.

  In the foamed member in this figure, unlike the foamed member in FIGS. 1 and 4, since the warpage in the longitudinal direction is suppressed by forming a recess at the top, similarly, the member to be protected is surely secured by the temporary fixing material. Can be fixed. Further, by forming the concave portion formed on the top portion narrowly, the protected member can be protected without impairing the excellent protective performance of the foamed member.

  FIG. 7 is a schematic cross-sectional view of a die for manufacturing the foamed member of FIG. In FIG. 7, the lip 50 extends in an L shape from the intersection 52, as in FIG. 3, and has a cross-section L composed of two slit portions 53A, 53B each having a narrow end 52b, 52c. A character-shaped slit 51 is provided.

  And the inner wall of the said intersection part 52 has the narrow U-shaped convex part 52a corresponding to the U-shaped recessed part 42a of FIG. 6, and narrows the slit width. In addition, this convex part 52a is formed to the middle part with respect to the thickness direction of the lip 50 (not shown). That is, the convex portion 52a is formed from the upper end portion of the lip to a predetermined middle portion with respect to the thickness direction or the extrusion direction (the direction of extruding the thermoplastic resin), and the convex portion is formed from the middle portion to the lower end portion of the lip. Not formed. If such a convex part is formed, the width | variety of the recessed part of the top part formed after foam molding can be made smaller compared with the case where the lip which formed the convex part over the whole thickness direction is used.

  FIG. 8 is a schematic cross-sectional view showing another example of the foamed member of the present invention. In FIG. 8, the foam member 61 having an L-shaped cross section extends in an L shape from the top portion 62 as in FIG. 1, the end portions 63a and 63b are formed thin, and the side wall portions 63A and 63B The inner wall is provided with side wall parts 63A and 63B formed with curved concave parts 63c and 63d, respectively.

  In the example of FIG. 8, a recess 62 a is further formed on the outer wall (top outer side) of the top 62. That is, the recess 62 a forms a notch having a mountain shape (inverted triangle shape) on the outer wall of the top portion 62. In addition, the depth of the recessed part 62a is slight with respect to the thickness of the top part 62 (or foaming member) (when the thickness of the top part 62 is set to 1, the depth is about 0.1 to 0.2).

  In the foamed member in FIG. 8, concave portions are formed on both the top portion and the side wall portion, and the effect of reducing the warpage in the longitudinal direction is very large. Moreover, since the depth of the recessed part of a top part is small, it can use suitably as a protection member, without impairing impact resistance performance.

  FIG. 9 is a schematic cross-sectional view of a die for manufacturing the foamed member of FIG. In FIG. 9, the lip 70 extends in an L shape from the intersection 72, as in FIG. 3, the end portions 72b and 72c are formed narrow, and the U-shaped convex portions 73c and 73d are formed on the inner wall. Has a slit 71 having an L-shaped cross section composed of two slit portions 73A and 73B.

  In the example of FIG. 9, a convex portion 72a having a mountain shape (triangular shape) corresponding to the concave portion 62a is further formed on the outer wall of the slit intersection portion 72A, and the slit width is narrowed in the convex portion 72a. Yes.

[Foamed material]
The foam member (protective member) of the present invention is an L-shaped foam member having two side wall portions extending in an L shape from the top portion, and each side wall portion and / or the top portion has a longitudinal direction. Concave portions are formed along the direction.

  The thickness of the foamed member of the present invention (thickness of the portion where the concave portion or the like is not formed, maximum thickness) can be selected in a range having sufficient protection performance according to the type of the protected member, for example, 3 mm to 5 cm, Preferably, it may be about 5 mm to 3 cm, more preferably about 7 mm to 2 cm (for example, 8 mm to 1.5 cm).

  The length in the width direction (extending direction) of the side wall portion of the foam member (or the length of one side in the cross section of the foam member) is, for example, 3 to 15 cm, preferably 3.5 to 10 cm, and more preferably 4 It may be about ˜8 cm. In addition, as long as it extends from the top part, the two side wall parts of a foam member may be symmetrical (or substantially symmetrical) shape with respect to the top part as shown in FIGS. It may be a simple shape. For example, in the foamed member, the length of one side wall portion may be different from the length of the other side wall portion.

  As described above, the foamed member of the present invention is a member in which the top portion and the side wall portion extend in the longitudinal direction. The length of the foamed member in the longitudinal direction depends on the length of the corner of the protected member, but is, for example, 30 cm to 4 m (for example, 50 cm to 3 m), preferably 1 to 2.5 m (for example, 1.2). ˜2 m), more preferably about 1.5 to 1.9 m.

  The cross-sectional shape of the foam member is L-shaped, but the L-shape does not mean only a shape having an angle of 90 degrees, for example, 50 to 130 degrees (for example, 60 to 120 degrees), The shape may preferably be about 70 to 110 degrees (for example, 80 to 100 degrees). In the present specification, for the sake of convenience, a term indicating a square shape such as a triangular shape is used. However, such a term used for a foam member does not usually mean a complete square shape, but a square shape. In many cases, it means a slightly rounded shape.

  And in the foaming member of this invention, while the edge part (each edge part of a side wall part) of each said side wall part is formed thinly, the recessed part is formed in the said side wall part and / or the said top part. By combining such a thin-walled end portion with the side wall portion and / or the concave portion at the top portion, it is possible to reduce the step difference from the fixed member and to obtain a foamed member in which warpage is remarkably suppressed.

  The end portion of the side wall portion (the end portion in the extending direction of the side wall portion) may be formed to be thin as long as the step with the member to be protected can be reduced and fixed. Therefore, it is sufficient that at least the end is formed thin, it may be formed thin from the top toward the end, and from the middle in the width direction of the side wall to the end as in the example of the above figure. It may be formed thinly in a form in which the thickness decreases along (towards the end), or only the end (or the vicinity thereof) may be formed thin. From the viewpoint of facilitating temporary fixing with the curing tape, a form in which the thickness decreases from the middle part in the width direction of the side wall part along the end part is more preferable.

  Of the recesses, the formation position of the recess formed in the side wall portion of the foamed member may be at least one surface of the side wall portion, and is not limited to the inner wall (inner wall surface) of the side wall portion. ), Or both the inner wall (inner wall surface) and the outer wall (outer wall surface). Moreover, the formation position of the recessed part formed in a side wall part is usually the middle part of the width direction of a side wall part (part except an edge part among side wall parts) in many cases, and in the width direction of a side wall part, for example, a center It may be between the center and the top, between the center and between the center and the end. Further, as in the example of the figure, the formation position of the two recesses formed on the side wall portion is not limited to a symmetric (substantially symmetric) position with respect to the top portion, and is an asymmetric position. Also good. For example, in the foam member, one concave portion may be formed in an intermediate portion in the width direction of the side wall portion, and the other concave portion may be formed between the intermediate portion in the width direction of the side wall portion and the end portion.

  The cross-sectional shape of the concave portion formed in the side wall portion is not limited to a curved shape (a bowl shape), and may be a mountain shape (an inverted triangle shape), a U shape, a V shape, or the like. Further, the maximum depth of the concave portion formed in the side wall portion (maximum depth of the depression) is, for example, 0.1 to 0.8, preferably 1 when the thickness of the side wall portion (or the maximum thickness of the foamed member) is 1. May be about 0.12 to 0.7, more preferably about 0.15 to 0.6. Specifically, the maximum depth of the recess formed in the side wall portion is within a range smaller than the thickness of the foamed member (or side wall portion), for example, 1 to 10 mm, preferably 1.5 to 7 mm, and more preferably 2 About 6 mm (for example, 2.5 to 5 mm) may be sufficient.

  Further, the maximum width of the recess formed in the side wall portion (maximum width of the dent) is, for example, 0.03 to 0.5, preferably 0.05 to 0 when the length in the width direction of the side wall portion is 1. .4, more preferably about 0.08 to 0.3. Specifically, the maximum width (maximum width of the dent) of the recess formed in the side wall portion may be, for example, about 2 mm to 3 cm, preferably about 3 mm to 2 cm (for example, 5 mm to 1.5 cm).

  When forming a recessed part in a top part, the shape is not specifically limited to the example of the said figure. For example, when forming a recessed part in a top inner wall (top inner side), the cross-sectional shape is not limited to U shape (needle shape), A mountain shape, V shape, etc. may be sufficient. Moreover, when forming a recessed part in a top outer wall (top outer side), the cross-sectional shape is not limited to an inverted triangular shape, and may be a U shape, a V shape, a curved shape, or the like. In any case, it is preferable to form the concave portion at the top so that the depth (the depth of the dent) does not become too large from the viewpoint of protecting the corner portion of the member to be protected. Therefore, the maximum depth of the concave portion formed at the top (maximum depth of the indentation) is, for example, 0.08 to 0.7, preferably 0.00 when the thickness of the top (or the thickness of the foamed member) is 1. It may be about 1 to 0.5, more preferably about 0.15 to 0.3. Moreover, the maximum width (maximum width of the dent) formed in the top portion may be, for example, about 0.5 to 7 mm, preferably about 0.7 to 5 mm (for example, 1 to 3 mm).

  Note that the depth of the concave portion at the top can also be adjusted by the site, shape, width, and the like to be formed. For example, as shown in the example of FIG. 3, when the concave portion is formed narrow, the side wall has a shape that can reinforce the protection performance of the top portion, so the concave portion is formed with a relatively large depth. In some cases, the protection performance can be maintained.

  In addition, the formation position of the recessed part formed in a top part is not limited to an outer wall or an inner wall, You may form in both an outer wall and an inner wall. Usually, from the viewpoint of protecting the member to be protected, the top is often formed on either the outer wall or the inner wall, particularly on the outer wall.

  The shape of the top portion may be L-shaped (square) or may be a different shape. For example, the top portion may be flattened or a bulging portion may be formed. If the top is formed in a different shape, the effect of reducing warpage may be further increased.

  When the concave portion is formed on the side wall portion and / or the top portion, a small concave portion (recess) having a shape corresponding to the concave portion is also formed at the position opposite to the position of the concave portion and the thickness direction along with extrusion foaming. There is a case. For example, when the concave portion is formed on the inner wall side of the side wall portion, the outer wall side located on the opposite side in the thickness direction may be slightly recessed. Formation of such a small recess is a phenomenon peculiar to foam molding. Therefore, the foamed member of the present invention may have a small recess generated by forming such a recess.

  In addition, what is necessary is just to form the recessed part formed along a longitudinal direction in at least any one among each side wall part and a top part as mentioned above, and may be especially formed in both each side wall part and a top part. If formed on both sides, the effect of reducing warpage is very large, and even if a foamed member is formed that is relatively long in the longitudinal direction (for example, the length in the longitudinal direction is 1 m or more (for example, 1 to 2.5 m)). Thus, it is possible to obtain a foam member having almost no warpage.

  In the foamed member of the present invention, warpage in the longitudinal direction is suppressed to be small. For example, when the foam member of the present invention is measured by placing a foam member formed to a length of 1.7 m so that the end of the side wall portion is in contact with the horizontal plane along the longitudinal direction, the warpage from the horizontal plane is measured. The height is 40 mm or less (for example, 0 to 35 mm), preferably 30 mm or less (for example, 0.5 to 25 mm), more preferably 20 mm or less (for example, 1 to 15 mm), particularly 10 mm or less (for example, 1.5 ~ About 7 mm). The “height of the warp” means the maximum distance between the end of the foam member and the horizontal plane. That is, when a 1.7 m foam member is placed without pressing against the horizontal plane so that the end of the side wall is in contact with the horizontal plane along the longitudinal direction (or the top is up), It means the distance at which the end portion is separated from the horizontal plane, and when the distance varies depending on the end portion, it means the maximum distance.

  As described above, the foam member of the present invention has a structure in which the top portion and the side wall portion extend in the longitudinal direction, and the end portion formed in the recessed portion or the thin wall also corresponds to the longitudinal direction. Is formed. Such recesses and thin-walled end portions are usually formed continuously along the longitudinal direction, but depending on the shape of the slit, etc., the foamed member is not formed with a recess in a very small portion in the longitudinal direction. It may not have a portion. For example, as shown in FIG. 3, when a narrow recess is formed, the surrounding thermoplastic resin closes the recess with foaming, and generates a portion where no recess is formed in a very small part in the longitudinal direction. There is.

  The foam member of the present invention may be an open cell or closed cell, but may be a closed cell in particular.

  The basis weight of the foamed member of the present invention may be, for example, about 10 to 100 g / m, preferably 15 to 70 g / m, and more preferably about 20 to 50 g / m (for example, 25 to 45 g / m). .

  The expansion ratio of the foamed member of the present invention is, for example, 2 to 80 times (for example, 10 to 70 times), preferably 12 to 60 times (for example, 15 to 55 times), and more preferably 18 to 50 times ( For example, it may be about 20 to 40 times.

[Method for producing foamed member]
The foam member of the present invention can be usually produced by extrusion foam molding of a thermoplastic resin from a die having a lip (die) having a shape corresponding to the foam member. That is, the lip has a slit having an L-shaped cross section composed of two slit portions extending in an L shape from the intersection portion, and an end of each slit portion is formed to be narrow, and each slit is formed. And / or a convex portion (slit convex portion) that narrows the slit width at the intersection.

  In the lip, the thickness (cross-sectional thickness) of the slit (or slit portion or intersection) can be selected according to the thickness of the foamed member, the foaming ratio, and the like, for example, 0.5 to 5 mm, preferably 0.8 to It may be about 4 mm, more preferably about 1 to 3 mm (for example, 1.2 to 2 mm). The width of the slit portion (or the length of one side of the cross section of the slit) may be, for example, 1 to 12 cm, preferably 1.5 to 8 cm, and more preferably about 2 to 5 cm.

  The maximum height of the protrusion at the intersection (for example, the protrusion on the outer wall of the intersection) is, for example, 0.1 to 0.95, preferably 0.1 when the thickness of the intersection (or slit) is 1. It may be about 2 to 0.9, more preferably about 0.3 to 0.85. In general, the width of the convex portion at the intersection is very small with respect to the slit portion. Therefore, even if the maximum height of the convex portion is relatively large as described above, the concave portion of the top portion formed in the foam member due to the expansion accompanying the foaming of the thermoplastic resin in the vicinity of the slit convex portion becomes the thickness of the top portion. On the other hand, it can be set to a very small range (the above range).

  Although the maximum width of the convex part of an intersection part is based also on the formation position, it may be 0.1-3 mm, for example, Preferably about 0.2-2 mm (for example, 0.3-1.5 mm). . In particular, when the convex portion is formed on the outer wall of the intersection portion, if the width is too large, warping is likely to be generated in the foamed member. Therefore, the maximum width of the convex portion of the intersection portion is, for example, 0.1 to 1. It is good also as 2 mm, Preferably about 0.2-1 mm (for example, 0.3-0.8 mm).

  Moreover, the maximum height of the convex part of a slit part is 0.05-0.8 when the thickness of a slit part (or slit) is 1, for example, Preferably it is 0.1-0.7, More preferably It may be about 0.2 to 0.6. Further, the maximum width of the convex portion of the slit portion may be, for example, about 0.1 mm to 2 cm, preferably about 0.5 mm to 1.5 cm (for example, 1 mm to 1 cm).

  In addition, the thickness of the extrusion direction of the slit may be, for example, about 3 mm to 10 cm, preferably about 5 mm to 7 cm, and more preferably about 1 to 5 cm. Moreover, in order to reduce the width | variety and depth of the recessed part formed in a foaming member, the slit convex part may be formed to the lip middle part with respect to the extrusion direction of a lip like the said example. When the slit concave portion is formed up to such a middle portion of the lip, the thickness in the extrusion direction of the slit convex portion (or the direction perpendicular to the cross section of the lip) is 0.1 to 1. It may be about 0.8, preferably about 0.2 to 0.7.

  Extrusion foaming can be performed using an extruder equipped with a die having a lip as described above. Examples of the extruder include a single screw extruder (for example, a vent type extruder), a twin screw extrusion, and the like. And a multi-stage extruder (such as a tandem extruder).

  The foamed member may usually be formed of a thermoplastic resin. Examples of the thermoplastic resin include olefin resins (eg, polyethylene resins, polypropylene resins, methylpentene resins, etc.), polystyrene resins [eg, polystyrene (GPPS), high impact polystyrene (HIPS), styrene-acrylonitrile. Copolymer (AS resin), styrene-acrylonitrile-butadiene copolymer (ABS resin), etc.], vinyl chloride resin (eg, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, etc.), vinyl acetate resin [ For example, polyvinyl acetate, vinyl acetate-ethylene copolymer (EVA resin), etc.], polyvinyl alcohol resin [eg, polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH resin), etc.], acrylic resin [For example, methyl methacrylate Resin (PMMA), methyl methacrylate-butadiene-styrene copolymer (MBS resin, etc.)], polyester resin [for example, polyalkylene arylate (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.)], polycarbonate resin, Examples thereof include polyamide-based resins (for example, polyamide 6, polyamide 6-6, etc.). The thermoplastic resin is, for example, a thermoplastic polyimide resin, a polyacetal resin, a (modified) polyphenylene ether resin (PPE), a polyphenylene sulfide resin (PPS), a polyether ether ketone (PEEK), or the like. Furthermore, a thermoplastic elastomer containing a constituent component of the thermoplastic resin is also included. These resins may be used alone or in combination of two or more.

  Of these resins, in order to impart excellent flexibility (flexibility), rebound resilience (restorability), impact resistance, etc. to the foamed member, usually a soft resin such as an olefin resin (particularly, a polyethylene resin) Resin) is often used.

The olefin resin includes an olefin monomer alone or a copolymer, and a copolymer of an olefin monomer and another copolymerizable monomer. The olefin monomer may be a chain olefin monomer or a cyclic olefin monomer, but is usually a chain olefin monomer (for example, ethylene, propylene, 1-butene, Α-C _2-20 chain olefins such as isobutene, 1-pentene, 4-methyl-1-pentene, especially α-C _2-4 chain olefins) are used. These olefinic monomers can be used alone or in combination of two or more.

More specifically, examples of the olefinic monomer alone or copolymer include α-C ₂₋ such as polyethylene (polyethylene such as high density polyethylene, low density polyethylene, linear low density polyethylene) and polypropylene. _20- chain olefin (especially α-C _2-4 chain olefin) homopolymer, α-C _2-20 chain olefin such as ethylene-propylene copolymer (especially α-C _2-4 chain olefin) ) A copolymer can be illustrated. Moreover, as a copolymer of an olefinic monomer and another copolymerizable monomer, for example, a copolymer of an α-C _2-20 chain olefin and another copolymerizable monomer [ For example, ethylene and other copolymerizable monomers such as ethylene-vinyl acetate copolymer (EVA resin), ethylene- (meth) acrylic acid ester copolymer, ethylene- (meth) acrylic acid copolymer, and metal salts thereof. And a copolymer of an α-C _2-4 chain olefin such as a copolymer with a monomer and another copolymerizable monomer].

  Among these olefin resins, ethylene such as polyethylene (polyethylene such as high density polyethylene, low density polyethylene, linear low density polyethylene), ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA resin), etc. Based resins are preferable, and polyethylene (polyethylene such as high density polyethylene, low density polyethylene, and linear low density polyethylene) is particularly preferable.

  These olefin resins may be used alone or in combination of two or more.

  The foaming agents that can be used for extrusion foaming are roughly classified into volatile foaming agents (physical foaming agents) and degradable foaming agents (chemical foaming agents). Examples of the volatile blowing agent include inorganic blowing agents such as nitrogen, carbon dioxide, oxygen, air, water, propane, butane (n-butane, isobutane), pentane (n-pentane, isopentane, etc.), hexane ( lower aliphatic hydrocarbons such as n-hexane), alicyclic hydrocarbons such as cyclopentane and cyclohexane, aromatic hydrocarbons such as toluene and benzene, chlorohydrocarbons such as methyl chloride and ethyl chloride, and fluorine such as chlorofluorocarbon. Organic foaming agents such as fluorinated hydrocarbons, alcohols such as methanol and 2-propanol, ethers such as dimethyl ether, methyl ethyl ether and petroleum ether, aldehydes such as formaldehyde, and ketones such as acetone and methyl ethyl ketone. Examples of the decomposable foaming agent include inorganic carbonates such as sodium bicarbonate and ammonium carbonate, organic acids such as citric acid, azo compounds such as 2,2′-azobisisobutyronitrile and azodicarbonamide, Examples thereof include sulfonyl hydrazide compounds such as benzenesulfonyl hydrazide and p-toluenesulfonyl hydrazide, nitroso compounds such as N, N′-dinitrosopentamethylenetetramine (DNPT), and azide compounds such as terephthalazide. These foaming agents may be used alone or in combination of two or more.

  The ratio of the foaming agent can be selected according to the type of foaming agent, the desired foaming ratio, and the like. For example, 0.01 to 30 parts by weight, preferably 0.1 to 25 parts by weight with respect to 100 parts by weight of the thermoplastic resin. It may be about 1 to 20 parts by weight, more preferably about 5 to 15 parts by weight.

  Furthermore, in extrusion foam molding, other additives may be added to the thermoplastic resin in order to form a foamed member. Other additives include, for example, foam nucleating agents (foaming aids), shrinkage inhibitors, bubble regulators, stabilizers (thermal stabilizers, UV absorbers, etc.), antiblocking agents, antifogging agents, and antioxidants. Agent, antistatic agent, colorant (dye, pigment, etc.), coupling agent, curing agent, flame retardant, lubricant, mold release agent, fragrance, plasticizer, biocide (bactericidal agent, bacteriostatic agent, antifungal agent) , Preservatives, insect repellents, etc.), viscosity modifiers, dispersants, fillers (calcium carbonate, carbon fibers, etc.). These additives may be used alone or in combination of two or more.

  Examples of the foam nucleating agent (foaming aid) include, for example, silicon compounds such as talc, silica and zeolite, inorganic acid metal salts such as metal carbonates or hydrogen carbonate metal salts (calcium carbonate, magnesium carbonate, sodium bicarbonate, etc.), Organic acid salts such as citric acid (fatty acids) and metal salts thereof (sodium citrate, calcium stearate, aluminum stearate, zinc stearate, etc.), metal oxides such as zinc oxide and aluminum oxide, aluminum hydroxide And metal hydroxides. These foam nucleating agents (foaming aids) may be used alone or in combination of two or more. The ratio of the foam nucleating agent (foaming aid) is, for example, 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight, more preferably 0.1 to 3 parts by weight with respect to 100 parts by weight of the thermoplastic resin. Part, especially about 0.2 to 2 parts by weight (for example, 0.1 to 1 part by weight). The ratio of the foam nucleating agent is, for example, 0.1 to 500 parts by weight, preferably 1 to 100 parts by weight, more preferably 5 to 50 parts by weight (for example, 10 to 30 parts by weight) with respect to 100 parts by weight of the foaming agent. Part by weight).

  Examples of the shrinkage preventing agent include esters of fatty acids and polyhydric alcohols, fatty acid amides, and the like. More specifically, esters of fatty acids (eg, lauric acid, myristic acid, palmitic acid, stearic acid, etc.) and polyhydric alcohols (eg, glycerin, xylitol, sorbitol, mannitol, etc.) include, Examples include triglycerides, monostearic acid triglycerides, and the like. Examples of the fatty acid amide include palmitic acid amide and stearic acid amide. These shrinkage inhibitors may be used alone or in combination of two or more. The proportion of the shrinkage inhibitor is, for example, 0.01 to 30 parts by weight, preferably 0.05 to 20 parts by weight, more preferably 0.1 to 15 parts by weight, and particularly preferably 0.1 to 30 parts by weight with respect to 100 parts by weight of the thermoplastic resin. About 5-10 weight part (for example, 1-5 weight part) may be sufficient. The ratio of the shrinkage inhibitor is, for example, 0.01 to 5 parts by weight, preferably 0.02 to 3 parts by weight, more preferably 0.05 to 2 parts by weight (for example, 100 parts by weight of the foaming agent). 0.1-1 part by weight).

  The foaming agent and other additives (for example, a foam nucleating agent, an anti-shrinkage agent, etc.) may be appropriately added or injected in the molding step as necessary. For example, the foaming agent and other additives may be mixed with the thermoplastic resin in advance and extruded and foamed, or injected into a thermoplastic resin melt-kneaded with an extruder.

  The foamed member of the present invention has an L shape and is useful as a foamed member (protective member) for protecting the corners of the protected member. In particular, the foamed member of the present invention has a thin end portion of the side wall portion and is suppressed from warping in the longitudinal direction, and therefore has a weak temporary tacking material such as a curing tape (adhesive force). Also, it can be securely fixed to the protected member without peeling off.

  Therefore, the present invention includes a method for protecting the corner portion of the member to be protected, and covering and protecting the corner portion with the foamed member. In this method, in particular, the foamed member may be covered with a curing tape fixed to the protected member. Examples of the protected member include members having corners (particularly L-shaped corners) such as pillars, walls, doors, partition materials, furniture, and equipment (such as electrical equipment).

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

  In the examples, the “height of warp” was measured by placing the foamed member formed to a length of 1.7 m on a horizontal plane as described above.

Example 1
The foam member (closed cell) of FIG. 1 was manufactured using the die of FIG. Using a tandem extruder (first stage 65 mm, second stage 90 mm), low density polyethylene (LDPE) (manufactured by Tosoh Corporation, Petrocene 173R, density = 0.924 g / cm ³ , MFR = 0.3) 100 parts by weight, 3.0 parts by weight of an anti-shrink agent (Boehringer Ingelheim Chemicals Co., Ltd., Activex 325), 1.0 part by weight of a nucleating agent (bicarbonate / citric acid, manufactured by Eiwa Kasei Co., Ltd., EE275) The mixture was melt-mixed, 9 parts by weight of foaming gas (n-butane) was injected from the center of the first-stage extruder, and extrusion foamed from a die.

  In the lip 10 of the die, the slit 11 having an L-shaped cross section has a thickness of 1.5 mm, the length of one side of the cross section of the slit is 15 mm, and the end portions 13a and 13b of the slit portion are formed with a radius of 0.4 mm. The maximum height of the convex portions 13c and 13d was 0.5 mm, the maximum width of the convex portions 13c and 13d was 3.2 mm, and the thickness of the die (lip 10) in the extrusion direction was 7.0 mm.

  In the obtained foamed member, the basis weight is 34.3 g / m, the expansion ratio is 23.2 times, the length of one side in the cross section is 58.7 mm, the maximum width of the recesses 3c and 3d is 1.8 mm, and the recesses 3c and 3d The maximum depth was 8 mm, the thickness was 10.4 mm, and the height of warpage was 15 mm (average value of N = 5).

(Example 2)
The foam member (closed cell body) shown in FIG. 4 was manufactured using the die shown in FIG. The materials used for foam molding and the extrusion foam molding conditions were all the same as in Example 1.

  In the lip 30 of the die, the thickness of the slit 31 having an L-shaped cross section is 1.5 mm, the length of one side of the cross section of the slit is 15 mm, and the end portions 33a and 33b of the slit portion are formed with a radius of 0.4 mm. The maximum height of the convex portions 33c and 33d is 0.5 mm, the maximum width of the convex portions 33c and 33d is 3.2 mm, the width of the flat portion 32a is 1.2 mm, and the die (lip 31) in the extrusion direction. The thickness was 7.0 mm.

  In the obtained foamed member, the basis weight is 33.0 g / m, the expansion ratio is 22.9 times, the length of one side in the cross section is 59.2 mm, the maximum width of the recesses 23c and 23d is 1.8 mm, and the recesses 23c and 23d The maximum depth was 8 mm, the thickness was 10.2 mm, and the height of warpage was 10 mm (average value of N = 5).

(Example 3)
The foam member (closed cell body) shown in FIG. 6 was manufactured using the die shown in FIG. The materials used for foam molding and the extrusion foam molding conditions were all the same as in Example 1.

  In the die lip 50, the slit 51 having an L-shaped cross section has a thickness of 1.5 mm, the length of one side of the cross section of the slit is 15 mm, and the end portions 53a and 53b of the slit portion are formed with a radius of 0.4 mm. The maximum width of the convex portion 52a is 0.6 mm, the maximum height of the convex portion 52a is 3 mm, the thickness of the die (lip 50) in the extrusion direction is 7.0 mm, and the thickness of the convex portion 52a in the extrusion direction is 3. 0.0 mm.

  In the obtained foamed member, the basis weight is 36.9 g / m, the expansion ratio is 23.5 times, the length of one side in the cross section is 56.7 mm, the maximum width of the recess 42 a is 9.2 mm, and the maximum depth of the recess 42 a Was 2.0 mm, the thickness was 11.4 mm, and the height of the warp was 5 mm (average value of N = 5).

Example 4
The foam member (closed cell body) shown in FIG. 8 was manufactured using the die shown in FIG. The materials used for foam molding and the extrusion foam molding conditions were all the same as in Example 1.

  In the die lip 70, the thickness of the slit 71 having an L-shaped cross section is 1.5 mm, the length of one side of the cross section of the slit is 15 mm, and the end of the slit portion is formed with a radius of 0.4 mm. , One side of the convex portion 72a is 0.56 mm, the maximum height of the convex portion 72a is 0.8 mm, the maximum height of the convex portions 73c and 73d is 0.5 mm, and the thickness of the die (lip 71) in the extrusion direction. Was 7.0 mm.

  In the obtained foamed member, the basis weight is 33.5 g / m, the expansion ratio is 22.4 times, the length of one side in the cross section is 57.2 mm, the maximum width of the recess 62a is 8.9 mm, and the maximum depth of the recess 62a Is 1.85 mm, the maximum width of the recesses 63 c and 63 d is 7.5 mm, the maximum depth of the recesses 63 c and 63 d is 1.6 mm, the thickness is 10.2 mm, and the height of the warp is 2.5 mm (N = 5) Average value).

(Reference Example 1)
In FIG. 3, the foamed member (closed cell body) was manufactured using a die in which the end portions 13a and 13b were not formed narrow and the convex portions 13c and 13d were not formed. The materials used for foam molding and the extrusion foam molding conditions were all the same as in Example 1.

  In the obtained foamed member, the basis weight was 37.0 g / m, the foaming ratio was 23.1 times, the length of one side in the cross section was 58.5 mm, the thickness was 8.8 mm, and the height of warpage was 10 mm (N = Average value of 5).

(Reference Example 2)
In FIG. 3, a foam member (closed cell body) was manufactured using a die in which the convex portions 13 c and 13 d were not formed. The materials used for foam molding and the extrusion foam molding conditions were all the same as in Example 1.

  In the obtained foamed member, the basis weight is 37.2 g / m, the foaming ratio is 24.5 times, the length of one side in the cross section is 58.5 mm, the thickness is 11.3 mm, and the height of warpage is 60.3 mm. Met.

(Evaluation of fixing strength of foamed members)
Using the foamed members obtained in Example 4, Reference Example 1 and Reference Example 2, the fixability to a protected member (wall) using a curing tape was evaluated as follows.

  A foamed member having a length of 1.7 m in the longitudinal direction covers the corners of the wall, and is fixed with a curing tape (manufactured by Koyo Chemical Co., Ltd., cut ace 25 mm width, adhesive strength 750 g / 25 mm), and the curing tape is peeled off. The time until was measured.

  In addition, four curing tapes that are cut to a length of 5 cm are prepared, and the lengths of the affixed portions of the side wall portion and the wall of the foam member are the same in the portions 5 cm from the upper end and the lower end of the foam member. (Ie, 2.5 cm).

  As a result of measurement under the above conditions, the foamed member obtained in Example 4 did not peel off the curing tape even after 48 hours. However, the foamed member of Reference Example 1 took 5 hours and the foamed member of Reference Example 2 Then, the curing tape peeled off in 2.5 hours.

FIG. 1 is a schematic sectional view showing an example of the foamed member of the present invention. FIG. 2 is a schematic perspective view of the foamed member of FIG. FIG. 3 is a schematic cross-sectional view of a die for manufacturing the foamed member of FIG. FIG. 4 is a schematic sectional view showing another example of the foamed member of the present invention. FIG. 5 is a schematic cross-sectional view of a die for producing the foamed member of FIG. FIG. 6 is a schematic sectional view showing still another example of the foamed member of the present invention. FIG. 7 is a schematic cross-sectional view of a die for manufacturing the foamed member of FIG. FIG. 8 is a schematic sectional view showing another example of the foamed member of the present invention. FIG. 9 is a schematic cross-sectional view of a die for manufacturing the foamed member of FIG.

Explanation of symbols

1, 2, 41, 61 ... Foam member 2, 22, 42, 62 ... Top 3A, 3B, 23A, 23B, 43A, 43B, 63A, 63B ... Side wall 3a, 3b, 23a, 23b, 43a, 43b, 63a , 63b: end portions of the side walls 3c, 3d, 23c, 23d, 63c, 63d ... concave portions of the side walls 22a ... flat portions 42a, 62a ... concave portions at the top 10, 30, 50, 70 ... lips 11, 31, 51, 71 ... Slit 12, 32, 52, 72 ... Intersection point 13A, 13B, 33A, 33B, 53A, 53B, 73A, 73B ... Slit part 13a, 13b, 33a, 33b, 53a, 53b, 73a, 73b ... of the slit part Ends 13c, 13d, 33c, 33d, 73c, 73d ... Slit convex part 32a ... Slit flat part 52a, 72a ... Intersection convex part

Claims (8)

A method for producing a foamed member having an L-shaped cross section having two side walls extending from a top to an L-shape by extrusion-molding a polyethylene-based resin from a die ,
In the foamed member, the end of each side wall is formed thin, and a recess is formed along the longitudinal direction in each side wall and / or the top , and the basis weight is 15 to 70 g / m. And is formed of closed cells with an expansion ratio of 2 to 80 times,
The lip of the die has an L-shaped slit composed of two slit portions extending in an L shape from the intersection portion, and an end of each slit portion is formed to be narrow, and each slit A method for producing a foamed member, which is a lip having a convex part that narrows a slit width at a part and / or the intersection part . In the foamed member, the side wall portion is formed thin in a form in which the thickness is reduced from the middle portion in the width direction of the side wall portion toward the end portion, and along the longitudinal direction in the middle portion and / or the top portion in the width direction of the side wall portion. The manufacturing method of Claim 1 in which the recessed part is formed. The manufacturing method of Claim 1 or 2 with which the recessed part is formed along the longitudinal direction in the middle part and top part of the width direction of a side wall part in a foaming member . The height of the warp from the horizontal plane is 20 mm or less when the foamed member formed to a length of 1.7 m is placed and measured so that the end of the side wall is in contact with the horizontal plane along the longitudinal direction. The manufacturing method in any one of 1-3 . Foam member, the manufacturing method according to any one of claims 1 to 4, which is a foam member for protecting the corners of the protective member. Lip, toward the end from the middle portion in the width direction of the slit portion formed in the narrow, to any one of claims 1 to 5 having a convex portion in the middle portion and / or the intersection portion in the width direction of the slit portion The manufacturing method as described. The manufacturing method in any one of Claims 1-6 in which a lip has a convex part in the middle part and the intersection part of the width direction of a slit part. A die for producing the foamed member obtained by the production method according to any one of claims 1 to 7 by extrusion foaming, wherein the lip of the die extends in an L shape from the intersection. A slit having an L-shaped cross section composed of two slit portions, each slit portion having a narrow end, and each slit portion and / or the intersection portion having a convex portion that narrows the slit width. Die.

Images