JP4898212B2 - Hollow structure board - Google Patents

Description

  The present invention provides a hollow structure in which a face material is bonded to a surface of a hollow structure plate having a hollow portion partitioned by a large number of bosses or ribs between a pair of parallel thermoplastic resin liner plates by heat fusion. In particular, the present invention relates to a hollow structure plate for improving rigidity, heat resistance, and surface smoothness and eliminating warping.

  In recent years, as a hollow structural plate having a hollow portion partitioned by a large number of bosses or ribs between a pair of parallel thermoplastic resin liner plates, for example, a plastic hollow structural plate having a cylindrical independent air chamber, There is a hollow structure plate (trade name “Twin Cone” manufactured by Ube Nitto Kasei Co., Ltd.) formed by abutting or meshing embossed tip portions formed on a single embossed sheet (see, for example, Patent Document 1). In addition, as a related invention, there is a vehicle roof lining using a honeycomb structure plate (see, for example, Patent Document 2). These hollow structural plates are all lightweight and excellent in various physical properties such as water resistance, heat insulation, and chemical resistance, and are used in various applications such as curing sheets, pallet underlays, and partitioning.

Furthermore, on the surface of these hollow structural plates, for example, a face material such as a composite resin sheet reinforced with glass fiber is bonded by heat fusion, and improvement of mechanical properties and designability, etc. Functions according to the purpose are given.
International Publication No. 03/080326 Pamphlet JP 2000-326430 A

  However, the conventional hollow structure plate described above has the following problems (1) to (4). That is, the conventional hollow structure board is comprised with the liner board and face material made from a thermoplastic resin, and this thermoplastic resin generally has low rigidity and heat resistance. Therefore, in the conventional hollow structure board, (1) the rigidity is low and (2) the heat resistance is low. Therefore, for applications that require high rigidity and high heat resistance such as automobile interior materials. Cannot sufficiently satisfy the required performance.

  Further, the conventional hollow structure plate is obtained by bonding a face material on the surface of a hollow structure plate having a hollow portion partitioned by a large number of bosses or ribs between liner plates made of thermoplastic resin by heat fusion. However, at that time, since the hollow structure plate is formed with hollow portions partitioned by a large number of bosses or ribs, the thermoplastic resin cools and shrinks to cause sink marks, and dents are formed on the surface. Therefore, (3) surface smoothness will deteriorate in the conventional hollow structure board. In addition, when face materials are bonded to both surfaces of the hollow structure plate, a difference in cooling shrinkage occurs between the front surface side and the back surface side, and (4) warpage occurs.

  Then, this invention aims at providing the hollow structure board which can improve (1) rigidity, (2) heat resistance, (3) surface smoothness, and can eliminate (4) curvature.

In order to solve the above-described problems, the present invention provides an intermediate body formed by abutting and welding a plurality of frustoconical hollow protrusions protruding from each of a pair of parallel polypropylene resin liner plates. A hollow structure board in which a polypropylene base material is bonded to the surface by heat fusion and a paperboard is bonded to the face material, and the total weight of the hollow structure board is 2500 to 3500 g / m. ² and the ratio of the total basis weight to the basis weight of the paperboard is 4.17: 1 to 5.83: 1 .

  According to such a configuration, the hollow structure board made of thermoplastic resin has its surface protected not only by the face material but also by paperboard, and has rigidity and heat resistance as compared with the case where the intermediate body is protected only by the face material. improves. Moreover, since the dent produced on the surface of the hollow structure board is in a state of being blocked by the paperboard pasted thereon, the surface smoothness is improved. Moreover, since the shrinkage | contraction of the thermoplastic resin at the time of cooling is suppressed by sticking a paperboard on a face material, the curvature of a hollow structure board is eliminated.

Moreover, in this invention, it is preferable that ratio of the fabric weight of the said intermediate body and the fabric weight of the said paperboard is 1.92: 1-3.17: 1 .

  According to the present invention, in the hollow structural plate, (1) rigidity, (2) heat resistance, (3) surface smoothness can be improved, and (4) warpage can be eliminated.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a schematic cross-sectional view showing a hollow structure plate according to an embodiment of the present invention. The hollow structure board 10 shown in the figure is obtained by bonding a face material 2 on the surface of the intermediate body 1 by heat fusion and further bonding a paperboard 3 on the face material 2. In addition, although not shown in figure, it can be used for a spare tire lid, a deck board, a cargo lid member, a flooring floor member, etc. by bonding the skin material, such as a nonwoven fabric or a sheet material, on the paperboard 3.

<Intermediate>
The intermediate body 1 has a hollow portion partitioned by a large number of bosses between a pair of parallel thermoplastic resin liner plates. Specifically, a plurality of hollow protrusions 11a and 21a are formed so as to protrude from the pair of thermoplastic resin sheets 11 and 21, respectively, and these hollow protrusions 11a and 21a are butted together. A hollow portion 31 is formed in a space formed by welding and between the welded hollow projections and between the thermoplastic resin sheets 11 and 21. Although not shown in the drawings, the intermediate body 1 may have a hollow portion partitioned by ribs, and further, the hollow protrusions 11a and 21a are engaged with each other and welded. May be.

Examples of the thermoplastic resin used as a raw material for the intermediate 1 include olefinic resins such as low density polyethylene, high density polyethylene, linear low density polyethylene, homopolypropylene, random polypropylene, and block polypropylene, and their comonomers or comonomers and others. The copolymer with the monomer of these, etc. are mentioned, These may be used independently or may be used together. In addition, for the purpose of improving the rigidity of the intermediate 1, fillers such as talc, mica, calcium carbonate, and chopped strands such as glass fiber, aramid fiber, and carbon fiber may be added, and combustibility, conductivity, and weather resistance may be added. Various modifiers may be added for the purpose of modifying the resin such as properties.

 By the way, the hollow protrusions 11a and 21a formed in the intermediate body 1 have a truncated cone shape, and the rising angle of the side surface of the truncated cone shape is 45 to 80 °, preferably 50 to 70 °. When the rising angle is less than 45 °, the upper base area of the hollow protrusions 11a and 21a becomes small. Therefore, when a load is applied to the obtained hollow structure plate (intermediate body 1), they are welded to each other. The hollow protrusions 11a and 21a are easily peeled off and sufficient strength cannot be obtained (note that the diameter of the upper bottom portion of the hollow protrusions 11a and 21a is preferably 2 to 4 mm). On the other hand, when the rising angle exceeds 80 °, the frustum-shaped side surface portion becomes a film when vacuum forming is performed, and sufficient strength cannot be obtained. Moreover, the space | interval of the lower bottom part of adjacent hollow projection body 11a, 21a shall be 1-5 mm. If the distance between the lower bottom portions is less than 1 mm, the formability is deteriorated, and if it exceeds 5 mm, the number of protrusions per unit area decreases, and sufficient plane compression strength cannot be obtained.

 The hollow protrusions 11a and 21a are produced by performing vacuum forming using an embossing roll installed in a decompression chamber. The embossing roll has metal protrusions regularly arranged on the outer periphery, and the configuration of the metal protrusions is designed within the above range.

 In addition, the intermediate body 1 can be manufactured as follows. That is, a pair of upper and lower embosses in which two thermoplastic resin sheets supplied in parallel with each other are introduced into a decompression chamber, and are rotatably disposed in the decompression chamber and projecting pins regularly on the outer periphery. Each of the thermoplastic resin sheets 11 and 21 is adsorbed on the peripheral surface of the roller, and a number of hollow protrusions 11a and 21a are formed on the thermoplastic resin sheets 11 and 21 in accordance with the pin shape protruding from both embossing rollers. Form. Further, a heating means for heat fusion is provided in contact between these thermoplastic resin sheets 11 and 21 to heat the hollow protrusions 11a and 21a, and the hollow protrusions 11a and 21a are heated at the tangential positions of both embossing rollers. The end faces are heat-sealed. In this state, the integrated intermediate 1 is obtained by being taken up by the take-up roller.

<Face material>
The face material 2 is preferably a thermoplastic resin that is the same as or compatible with the intermediate body 1.

<Paperboard and its bonding method>
The method of attaching the paperboard 3 on the face material 2 is not particularly limited. For example, a thermoplastic resin film (compatible with the face material 2 on the paperboard 3 side (surface to be brought into contact with the intermediate) in advance) (Not shown) is laminated, heated at a temperature at which the thermoplastic resin melts, and pressure-bonded. Further, a hot melt film having good adhesiveness may be interposed between the face material 2 and the paperboard 3, and an adhesive may be used in some cases. Moreover, by laminating a thermoplastic resin film on both surfaces of the paperboard 3 in advance, it is possible to perform heat welding such as a decorative film or a nonwoven fabric on the surface layer side, and design properties can be imparted. Basis weight of the paperboard 3 is about 100 to 1000 g / ^{m 2} is preferred. If the basis weight is too small, it becomes difficult to obtain surface smoothness, and if the basis weight is large, the weight increases.

(Weight of hollow structure plate)
The basis weight of the hollow structure plate 10 obtained by the above method is preferably about 500 to 5000 g / m ² . If the basis weight is too small, the side surface of the frustoconical shape becomes a film, and sufficient strength, rigidity, etc. cannot be obtained. Further, when the two embossed products are heat-sealed, the thickness of the hollow protrusions 11a and 21a is reduced, so that the adhesive force is reduced. Further, if the basis weight is too large, the weight is naturally increased, and cooling after molding becomes insufficient, so that the mold cannot be removed successfully.

  According to the above configuration, the intermediate body 1 made of a thermoplastic resin has its surface protected not only by the face material 2 but also by the paperboard 3, and thereby has a hollow structure as compared with the case where it is protected only by the face material 2. The (1) rigidity and (2) heat resistance of the plate are improved. Moreover, since the dent which arose on the surface of the hollow structure board will be in the state blocked | closed by the paperboard 3 stuck on it, (3) surface smoothness will improve. Furthermore, since the shrinkage of the thermoplastic resin during cooling is suppressed by sticking the paperboard 3 to the face material 2, (4) warpage of the hollow structure board is eliminated.

Next, examples , reference examples and comparative examples of the present invention will be described. In addition, the total fabric weight and thickness were substantially the same as each reference example and Example, and the board | substrate 3 which was not bonded together was made into the comparative example.

< Reference Example 1>
As raw materials for intermediate 1 and face material 2, thermoplastic resin; E601 (Mitsui Horipro, block copolypropylene, MI = 0.8), filler; MAX2070T (Takehara Chemical Industries, talc masterbatch, talc content 70 wt% ) Was used. The other implementation conditions are as follows: the tip diameter of the metal protrusion is 2 mm, the root is 6 mm, the distance between the protrusions is 2 mm, and the height is 6 mm, and the weight of the intermediate body is 1000 g / m 2, and the surface material weight is 150 g / m 2. Paper weight per unit area (20 μm double-sided polyethylene film laminate, manufactured by Nippon Daishowa Paperboard); 600 g / m 2, molding speed: 0.6 m / min.

And it dry-blended in the ratio of said thermoplastic resin 90wt% and filler 10wt%, and was used as the raw material of the intermediate body 1. This raw material was melted and kneaded by two uniaxial extruders, and the thermoplastic resin sheets 11 and 21 in a molten state were extruded by two T dies arranged in parallel. Thereafter, vacuum is formed by a thermoplastic resin sheet vacuum-formed by a temperature-controllable forming roller on which metal protrusions are regularly arranged, and by a forming roller in which the metal protrusions of this forming roller are installed facing each other. A molded thermoplastic resin sheet was produced. And the heating means for heat fusion arrange | positioned in the contact state between this thermoplastic resin sheet | seats 11 and 21 is provided, the mutual hollow protrusions 11a and 21a are heated, and the hollow protrusion 11a in the tangent position of both embossing rollers , 21a are heat-sealed and integrated to obtain an intermediate 1. Further, a polypropylene resin sheet (face material 2) having the same composition as described above is bonded to the front and back of the intermediate body 1 by heat-sealing. When this hollow plate was allowed to cool to room temperature, the plate thickness was 13.3 mm, the total basis weight was 2500 g / m ² (intermediate basis weight = 1000 g / m ² , polypropylene resin face material sheet 150 × 2 = 300 g / m ² , A hollow structure board 10 of paperboard 600 × 2 = 1200 g / m ² ) was obtained.

  The hollow structural plate 10 was cut in the MD direction and the TD direction at a product size of 50 mm in width and 150 mm in length, and subjected to a bending test at a room temperature and 80 ° C. with a span of 100 mm. The resulting load-deflection curve The load at the time of bending 1 cm from the straight portion was obtained, the bending elastic gradient was calculated, and (1) rigidity and (2) heat resistance were measured. Moreover, (3) surface smoothness was measured in the product size of width 500mm and length 500mm. In the same table, by tracing the surface of the plate-shaped product with human hands, it is marked as ◎ if no irregularities on the surface of the plate material are detected by tactile sensation. If it was, Δ was given, and those that were clearly detected by visual sensation were marked with ×. Further, (4) the amount of warpage was measured as follows. That is, when the hollow structure plate 10 having the product size of 500 × 500 mm described above is installed on a smooth surface plate and the three corners of the four corners are brought into contact with a flat surface, the amount of lift of the remaining corners is increased. It was measured. When this amount of warpage was 2 mm or less, it was evaluated as ◯, and when it exceeded 2 mm, it was rated as x. The test results are shown in the following table. In addition, all the test results regarding the thickness, bending elastic gradient, and strength retention shown in the same table describe the average values in the MD direction and the TD direction.

< Reference Example 2>
In Reference Example 2, a hollow structure having a plate thickness of 14.3 mm, a total basis weight of 3200 g / m 2 (intermediate basis weight = 1000 g / m 2, polypropylene resin face sheet 500 × 2 = 1000 g / m 2, paperboard 600 × 2 = 1200 g / m 2) I got a plate. Otherwise, the same evaluation as in Reference Example 1 was performed.

<Comparative Example 1>
In Comparative Example 1, a hollow structure plate having a plate thickness of 13.3 mm, a total basis weight of 2500 g / m 2 (intermediate basis weight = 1000 g / m 2, polypropylene resin face material sheet 750 × 2 = 1500 g / m 2) was obtained. Otherwise, the same evaluation as in Reference Example 1 was performed.

<Comparative example 2>
In Comparative Example 2, a hollow structure plate having a plate thickness of 14.2 mm, a total basis weight of 3200 g / m 2 (intermediate basis weight = 1000 g / m 2, polypropylene resin face material sheet 750 × 2 = 1500 g / m 2) was obtained. Otherwise, the same evaluation as in Reference Example 1 was performed.

<Example 3>
In Example 3, a hollow structure having a plate thickness of 13.3 mm, a total basis weight of 3000 g / m 2 (intermediate basis weight = 1400 g / m 2, polypropylene resin face sheet 500 × 2 = 1000 g / m 2, paperboard 300 × 2 = 600 g / m 2) I got a plate. Otherwise, the same evaluation as in Reference Example 1 was performed.

<Example 4>
In Example 4, a hollow structure with a plate thickness of 13.6 mm, a total basis weight of 2750 g / m 2 (intermediate basis weight = 1150 g / m 2, polypropylene resin face material sheet 500 × 2 = 1000 g / m 2, paperboard 300 × 2 = 600 g / m 2) I got a plate. Otherwise, the same evaluation as in Reference Example 1 was performed.

<Example 5>
In Example 5, a hollow structure having a plate thickness of 13.5 mm, a total basis weight of 2500 g / m 2 (intermediate basis weight = 1000 g / m 2, polypropylene resin face sheet 500 × 2 = 1000 g / m 2, paperboard 300 × 2 = 600 g / m 2) I got a plate. Otherwise, the same evaluation as in Reference Example 1 was performed.

<Comparative Example 3>
In Comparative Example 3, a hollow structure plate having a plate thickness of 13.4 mm, a total basis weight of 3000 g / m 2 (intermediate basis weight = 1500 g / m 2, polypropylene resin face material sheet 750 × 2 = 1500 g / m 2) was obtained. Otherwise, the same evaluation as in Reference Example 1 was performed.

<Comparative example 4>
In Comparative Example 4, a hollow structure plate having a plate thickness of 13.3 mm, a total basis weight of 2750 g / m 2 (intermediate basis weight = 1250 g / m 2, polypropylene resin face material sheet 750 × 2 = 1500 g / m 2) was obtained. Otherwise, the same evaluation as in Reference Example 1 was performed.

<Comparative Example 5>
In Comparative Example 5, a hollow structure plate having a plate thickness of 13.3 mm, a total basis weight of 2500 g / m 2 (intermediate basis weight = 1000 g / m 2, polypropylene resin face sheet 750 × 2 = 1500 g / m 2) was obtained. Otherwise, the same evaluation as in Reference Example 1 was performed.

<Example 6>
In Example 6, a hollow structure with a plate thickness of 10.4 mm, a total basis weight of 3500 g / m 2 (intermediate basis weight = 1000 g / m 2, polypropylene resin face sheet 500 × 2 = 1000 g / m 2, paperboard 300 × 2 = 600 g / m 2) I got a plate. Otherwise, the same evaluation as in Reference Example 1 was performed.

<Example 7>
In Example 7, a hollow structure having a plate thickness of 9.9 mm, a total basis weight of 2500 g / m 2 (intermediate basis weight = 1000 g / m 2, polypropylene resin face sheet 200 × 2 = 400 g / m 2, paperboard 300 × 2 = 600 g / m 2) I got a plate. Otherwise, the same evaluation as in Reference Example 1 was performed.

< Reference Example 8>
In Reference Example 8, a hollow structure having a plate thickness of 11.5 mm, a total basis weight of 2500 g / m 2 (intermediate basis weight = 1000 g / m 2, polypropylene resin face sheet 200 × 2 = 400 g / m 2, paperboard 300 × 2 = 600 g / m 2) I got a plate. Otherwise, the same evaluation as in Reference Example 1 was performed.

<Comparative Example 6>
In Comparative Example 6, a hollow structure plate having a plate thickness of 10.5 mm, a total basis weight of 3500 g / m 2 (intermediate basis weight = 2000 g / m 2, polypropylene resin face material sheet 750 × 2 = 1500 g / m 2) was obtained. Otherwise, the same evaluation as in Reference Example 1 was performed.

<Comparative Example 7>
In Comparative Example 7, a hollow structure plate having a plate thickness of 9.8 mm, a total basis weight of 2500 g / m 2 (intermediate basis weight = 2000 g / m 2, polypropylene resin face material sheet 250 × 2 = 500 g / m 2) was obtained. Otherwise, the same evaluation as in Reference Example 1 was performed.

<Comparative Example 8>
In Comparative Example 8, a hollow structure plate having a plate thickness of 11.4 mm, a total basis weight of 4000 g / m 2 (intermediate basis weight = 2000 g / m 2, polypropylene resin face material sheet 1000 × 2 = 2000 g / m 2) was obtained. Otherwise, the same evaluation as in Reference Example 1 was performed.

As shown in Tables 1 to 13, each of the reference examples or Examples 1 to 8 shows a larger bending elastic gradient than Comparative Examples 1 to 8, and (1) is excellent in rigidity. In addition, the reference examples or Examples 1 to 8 show a large value as to the strength retention, that is, the elastic gradient (%) when the temperature is increased from room temperature to 80 ° C., as compared with Comparative Examples 1 to 8. (2) Excellent heat resistance. Furthermore, Examples 1-5 were excellent also in (3) surface smoothness compared with Comparative Examples 1-5, and (4) the point of elimination of curvature.

It is a section schematic diagram showing a hollow structure board in an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Intermediate body 2 Face material 3 Paperboard 10 Hollow structure board

Claims (2)

On the surface of the intermediate body formed by welding butt hollow protrusions each other of the plurality of frustoconical projecting from the respective pair of parallel polypropylene resin liner plate, made of a polypropylene resin by thermal fusion bonding bonded together to face material, a hollow structure plate formed by bonding a board on the surface material,
The total weight of the hollow structural plate is 2500 to 3500 g / m ² ;
A hollow structure board having a ratio of the total basis weight to the basis weight of the paperboard of 4.17: 1 to 5.83: 1 . In the hollow structure board according to claim 1,
The hollow structure board characterized by the ratio of the basis weight of the intermediate body and the basis weight of the paperboard being 1.92: 1 to 3.17: 1 .

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