JP5075964B2 - Non-slip tape and pallet forming member - Google Patents

Description

  The present invention relates to a non-slip tape that is attached to a pallet forming member made of polypropylene resin by thermal welding to suppress slippage of the load, and a pallet forming member to which the anti-slip tape is thermally welded.

  Conventionally, as described in Patent Document 1, a non-slip tape made of a synthetic resin containing a metallocene catalyst-based polyethylene as a main component and blended with other polymers and various additives has been known. Further, as described in Patent Document 2, an anti-slip tape that suppresses the load from slipping on the loading surface and a synthetic resin pallet to which the anti-slip tape is attached are known. The anti-slip tape described in Patent Document 2 is made of a synthetic resin in which a polypropylene resin and a compatibilizer are blended with a metallocene catalyst-based ethylene / α-olefin copolymer. The above-mentioned anti-slip tape is thermally welded to the loading surface of the synthetic resin pallet made of polyolefin resin.

JP 11-35747 A JP 2001-315778 A

  By the way, when a synthetic resin pallet is used, a drum can or the like having a non-rounded edge may be placed on the above-described anti-slip tape. At this time, the load of the load placed on the anti-slip tape is locally concentrated on a portion of the anti-slip tape on which the edge is placed. When the load slides or rolls on the non-slip tape from this state, a force that causes the portion of the anti-slip tape to follow the movement of the load, in other words, from the synthetic resin pallet. A force that peels off the non-slip tape acts on the part. As a result, the anti-slipping tape peels off in the above-mentioned part of the heat-welded portion between the anti-slip tape and the synthetic resin pallet so as to swell over the entire width of the anti-slip tape. And the peeling of the non-slip tape locally generated in this way gradually expands in the longitudinal direction of the anti-slip tape as the load slides. Therefore, there is a possibility that the entire anti-slip tape may be completely separated from the synthetic resin pallet in the end. Such a problem is conspicuously recognized in a configuration in which a non-slip tape is thermally welded to a polypropylene resin pallet.

  The present invention has been made in view of such circumstances, and an anti-slip tape capable of suppressing separation from the loading surface while suppressing the loading of the loaded load placed on the loading surface from slipping on the loading surface, and An object of the present invention is to provide a pallet forming member provided with a non-slip tape.

  The non-slip tape according to the present invention is a non-slip tape made of a blend polymer that is attached to a loading surface of a pallet forming member made of polypropylene resin by heat welding. The blend polymer is made of 30 thermoplastic elastomer made of polypropylene. It contains ˜50 mass%, contains 25 to 45 mass% of metallocene catalyst-based polyethylene, contains metallocene catalyst-based polypropylene, and has a weight average molecular weight of 150,000 or more.

  As a result of earnest study of the anti-slip tape made of the blend polymer, the present inventors have found that the blend polymer contains 30 to 50% by mass of a thermoplastic elastomer made of polypropylene, and 25 to 45% by mass of a metallocene catalyst-based polyethylene, The metallocene catalyst-based polypropylene is included, and by making the blend polymer have a weight average molecular weight of 150,000 or more, slippage of the load on the loading surface and peeling of the anti-slip tape from the loading surface can be suppressed. I found it. The anti-slip tape of the present invention is a blend polymer comprising a thermoplastic elastomer comprising 30 to 50% by mass of polypropylene and 25 to 45% by mass of a metallocene-catalyzed polyethylene, and the weight average molecular weight thereof is 150,000. The gist is that the metallocene catalyst-based polypropylene is blended so as to have the above values.

  In the present invention, the non-slip tape is formed of a blend polymer containing a metallocene catalyst-based polypropylene, among polypropylenes generally having a high thermal welding force with a polypropylene resin as a material of a synthetic resin pallet. As a result, compared with a structure in which a non-slip tape made of a blend polymer not containing a metallocene catalyst-based polypropylene is heat-welded, the heat-welding force between the structure (pallet forming member) made of polypropylene resin and the anti-slip tape is increased. be able to.

  Therefore, when such an anti-slip tape is thermally welded to the loading surface of the pallet forming member made of polypropylene resin, the anti-slip tape is hardly peeled off from the loading surface. For example, even if the weight of the load having an edge shape at the bottom part acts locally at the contact portion between the edge shape and the non-slip tape, and the load slides on the load surface, the non-slip tape at the contact portion. Peeling over the entire width, that is, the possibility of peeling off the full width can be reduced.

  Further, it is possible to suppress local full width peeling at the contact portion from gradually expanding in the longitudinal direction of the anti-slip tape due to sliding or rolling of the load. As a result, the possibility that the non-slip tape is completely separated from the pallet forming member can be further reduced, and in addition, the anti-slip performance to the loaded load, which is an important function in the pallet forming member, can be maintained for a long period of time. .

  By the way, it is possible to increase the thermal welding power between the loading surface of the pallet forming member made of polypropylene resin and the non-slip tape by blending the thermoplastic elastomer made of polypropylene and the metallocene catalyst type polypropylene into the blend polymer as described above. It is. However, the non-slip tape made of only a polypropylene-based material does not sufficiently exhibit the anti-slip performance. In this regard, in the present invention, the metallocene catalyst-based polyethylene is contained in the blend polymer in an amount of 25 to 45% by mass so that the anti-slip performance is exhibited in the anti-slip tape. Thereby, even if it is a non-slip tape made of a blend polymer having a high blending ratio of a polypropylene-based material, it is possible to suppress the anti-slipping tape from peeling from the loading surface while suppressing the load from slipping on the loading surface. .

The blend polymer in the present invention preferably contains a foaming agent and is foamed so that the foaming ratio of the foaming agent is 1.05 to 1.30 times.
As a result of further diligent research, the present inventors have found that by expanding the anti-slip tape, even if full width peeling occurs in the heat welded portion as described above, expansion of the full width peeling is suppressed. . And in this invention, the foaming agent of the quantity from which an expansion ratio becomes 1.05-1.30 time is contained in the blend polymer. When the anti-slip tape expands due to the foaming effect of the foaming agent, the anti-slip tape softens due to the effect, and thus its rigidity decreases.

By the way, when a strong force acts to peel off the anti-slip tape from the loading surface at the contact portion between the edge shape at the bottom of the load and the anti-slip tape as described above, The full width peeling is easily expanded, or the full width peeling is easily broken. In this respect, in the present invention, since the anti-slip tape is softened by the foaming effect of the foaming agent, even if local full width peeling occurs in the non-slip tape, the anti-skid tape is easily broken at the full width peeling portion. It becomes possible to prevent the full width peeling from expanding little by little over the entire tape. As a result, it is possible to prevent the anti-slip tape from being completely peeled off from the pallet forming member.

  In addition, since the anti-slip tape is softened by the foaming action as described above, the edge shape at the bottom of the load becomes easy to bite by the anti-slip tape. Therefore, the slip resistance of the non-slip tape itself can be improved.

In this invention, it is preferable that the said foaming agent is azodicarbonamide and the said foaming agent contains the said blend polymer 0.05-0.2 mass%.
As a result of further intensive studies, the present inventors have found that the foaming agent is azodicarbonamide, and the foaming agent is contained in the blend polymer in an amount of 0.05 to 0.2% by mass. I found out that In the present invention, the foaming agent is azodicarbonamide, and the foaming agent is contained in the blend polymer in an amount of 0.05 to 0.2% by mass.

  In the present invention, the expansion ratio can be realized by specifically defining the amount of azodicarbonamide, which is a foaming agent, contained in the blend polymer. Therefore, it is possible to prevent the spread of local full width peeling as described above, and to enhance the anti-slip performance to the load that expresses the anti-slip tape.

  In this invention, it is a pallet forming member made of polypropylene resin, and an anti-slip tape is thermally welded to the mounting surface of the pallet forming member, and the anti-slip tape is an anti-slip tape as described above. preferable.

  According to this invention, since the non-slip tape is a molded product of a blend polymer containing a metallocene catalyst-based polypropylene, it is possible to improve the thermal weldability between the pallet forming member made of polypropylene resin and the non-slip tape. In addition, since the anti-slip tape is also a molded product of a blend polymer containing a metallocene catalyst-based polyethylene, the anti-slip performance on the load can be maintained. Therefore, it is possible to provide a pallet forming member that satisfies the slip resistance required for the pallet forming member, and can suppress the full width peeling due to the local action of the weight of the load and the expansion of the full width peeling. Will be able to.

  According to the present invention, an anti-slip tape capable of suppressing a load placed on the loading surface from slipping on the loading surface while suppressing the separation from the loading surface, and a pallet forming member including the anti-slip tape are provided. Can be provided.

The perspective view which shows the isometric view structure which looked at the synthetic resin pallet formed with the pallet formation member from one loading surface side about one Embodiment of the pallet formation member which concerns on this invention. The perspective view which shows the perspective structure which looked at the synthetic resin pallets formed with the pallet formation member from the ground surface side. The schematic diagram which shows the aspect of the rolling test in the drum can edge part in a test example.

Hereinafter, an embodiment in which an anti-slip tape and a pallet forming member according to the present invention are embodied will be described with reference to the drawings.
First, the whole structure of the synthetic resin pallet 1 which is a four-way synthetic resin pallet will be described with reference to FIGS. As shown in FIGS. 1 and 2, the synthetic resin pallet 1 is formed in a rectangular parallelepiped shape in which an upper pallet forming member 2 and a lower pallet forming member 3 facing each other are welded. The upper pallet forming member 2 has a rectangular plate-like deck board 20 and a cylindrical upper girder 21 extending from the deck board 20 toward the lower pallet forming member 3. On the other hand, the lower pallet forming member 3 includes a rectangular plate-shaped grounding board 30 and a cylindrical lower girder 31 extending from the grounding board 30 toward the upper pallet forming member 2. The protruding end of the upper girder 21 and the protruding end of the lower girder 31 facing each other are welded to form the synthetic resin pallet 1. The upper pallet forming member 2 and the lower pallet forming member 3 are formed by a gas assist molding method using polypropylene resin.

  The deck board 20 of the upper pallet forming member 2 has a plurality of fitting holes 20H penetrating from the loading surface 20T, which is the outer surface of the deck board 20, to the loading side inner surface 20S of the deck board 20. . In each of the plurality of fitting holes 20H, rubber grommets are fitted in order to prevent the synthetic resin pallet 1 from slipping with respect to the fork of the forklift or the like. A plurality of anti-slip tapes 20L are laid on the loading surface 20T of the deck board 20 constituting the pallet body in order to prevent an article placed on the loading surface 20T from sliding with respect to the loading surface 20T. Yes.

  These anti-slip tapes 20L are thermally welded to the loading surface 20T of the deck board 20. As a method of thermally welding the anti-slip tape 20L to the loading surface 20T, for example, there is a method in which the loading surface 20T and the affixing surface of the anti-slip tape 20L are pressed against each other while being melted by hot air.

  The non-slip tape 20L contains 30 to 50% by mass of a thermoplastic elastomer made of polypropylene, contains 25 to 45% by mass of a metallocene catalyst-based polyethylene, contains the main component metallocene catalyst-based polypropylene, and has a weight average molecular weight. It is a tape made of a blend polymer of 150,000 or more.

  When the thermoplastic elastomer made of polypropylene is less than 30% by mass, it is necessary to increase the amount of the metallocene catalyst-based polyethylene in order to maintain the anti-slip performance. However, when a metallocene catalyst-based polyethylene is blended in place of the thermoplastic elastomer made of polypropylene, the weight average molecular weight of the material of the non-slip tape is lowered. Therefore, it becomes difficult to suppress the degree of blocking that can be suppressed by increasing the weight average molecular weight of the material of the non-slip tape as described later. On the other hand, when the compounding amount of the metallocene catalyst-based polypropylene is increased without changing the compounding amount of the metallocene catalyst-based polyethylene, the deviation of the molecular weight is relatively smaller in the metallocene catalyst-based polyethylene than in the thermoplastic elastomer, so that the non-slip tape The temperature at which the material melts becomes higher than when the blending amount of the metallocene catalyst-based polypropylene is small. As a result, in the process of manufacturing the non-slip tape, a part of the metallocene catalyst-based polyethylene is more easily decomposed as described later. Therefore, it becomes easy to produce | generate ethylene, and the mixture which has this ethylene as a main component adheres frequently as what is called spear in the discharge part of an extrusion die. Therefore, it becomes difficult to manufacture the non-slip tape.

  Moreover, when the thermoplastic elastomer which consists of polypropylenes is higher than 50 mass%, there exists a problem in the point that manufacturing cost becomes high because the compounding quantity of the said thermoplastic elastomer which is an expensive raw material increases.

On the other hand, when the metallocene catalyst-based polyethylene is less than 25% by mass, the non-slip tape 2
There is a problem in that 0L does not sufficiently exhibit the above-described anti-slip performance to the loaded load, which is an important function in the pallet forming member. Further, when the metallocene catalyst-based polyethylene is higher than 45% by mass, there is a problem in that the adhesion strength between the polypropylene resin pallet forming member and the anti-slip tape 20L cannot be sufficiently obtained.

  Such a non-slip tape 20L is formed by extrusion molding of the melted blend polymer so as to have a predetermined width and thickness. At this time, in order to completely melt the blend polymer, the melting temperature at the time of extrusion molding is set to be the melting temperature of the thermoplastic elastomer or metallocene catalyst polypropylene having a higher melting point than the metallocene catalyst polyethylene. Since the metallocene catalyst-based polyethylene is melted at a high melting temperature as described above, a part of the metallocene catalyst-based polyethylene having a relatively small molecular weight deviation is decomposed. As a result, ethylene is produced.

  Experience has shown that such ethylene formation becomes significant when the weight average molecular weight of the blend polymer is less than 150,000. More specifically, when the weight average molecular weight of the blend polymer of the raw material composition shown in Examples 1 and 2 is less than 150,000, the mixture containing ethylene as a main component of the decomposition product described above is discharged in the discharge portion of the extrusion die. It becomes easy to adhere as so-called spear. Thus, if it becomes easy to adhere to the discharge part of an extrusion die, since the operation | work which removes frequently will be needed, the stable continuous shaping | molding of the non-slip | skid tape 20L will be prevented significantly.

  On the other hand, since the weight average molecular weight of the blend polymer in this embodiment is 150,000 or more, generation | occurrence | production of the spear at the time of extrusion molding as mentioned above is suppressed. Even at the high extrusion temperature as described above, the continuous molding of the anti-slip tape 20L is not significantly hindered. On the other hand, if the weight average molecular weight of the blend polymer is continuously increased in order to suppress the occurrence of creep during extrusion molding, the anti-slip tape 20L becomes gradually rigid. And since the flexibility is lost from the surface of the anti-slip tape 20L as the stiffening progresses in this way, it becomes difficult to maintain the anti-slip performance of the anti-slip tape 20L gradually. Incidentally, the weight average molecular weight of the blend polymer is a value obtained by measurement by a conventional method using a high temperature GPC (gel permeation chromatograph) measurement device under a temperature condition of 135 ° C.

Next, the configuration of the anti-slip tape and the pallet forming member according to the present invention will be described more specifically with reference to examples.
Table 1 shows the composition of the blend polymer in the anti-slip tape 20L of Example 1 and the blending ratio thereof. In addition, Table 2 shows the composition of blend polymers and the blending ratio thereof in the anti-slip tape 20L of Example 2. Further, Table 3 shows the composition of blend polymers and the blending ratio thereof in the anti-slip tape 20L of the comparative example. In addition, in each of Tables 1 to 3, in addition to the composition and blending ratio of the blend polymer, the width and thickness of the anti-slip tape 20L are also shown.

  Incidentally, the blend polymer in the non-slip tape 20L of Example 1 is 39.2% by mass of a thermoplastic propylene elastomer, 34.3% by mass of a metallocene catalyst-based polyethylene, and 24.5% by mass of a metallocene catalyst-based polypropylene. And 2.0% by mass of a colorant.

The blend polymer in the anti-slip tape 20L of Example 2 is a blend polymer in which azodicarbonamide as a foaming agent is blended with the blend polymer of Example 1.
Unlike the examples 1 and 2, the blend polymer in the anti-slip tape 20L of the comparative example is a blend polymer in which the metallocene catalyst-based polypropylene is not blended.

  In addition, when the weight average molecular weight in the anti-slip tape 20L of Examples 1 and 2 was measured by a conventional method under a temperature condition of 135 ° C. using a high temperature GPC measurement apparatus, the weight average molecular weight was 176,600. It was a thousand.

これらの実施例１，２及び比較例に示される原料組成のブレンドポリマーからなる滑り止めテープ２０Ｌを、ポリプロピレン製のパレット形成部材における載荷面に上述の如く熱風を用いて熱溶着させ、これらのパレット形成部材を構成部材とする合成樹脂製パレットを用いて以下の剥離試験を実施した。

The anti-slip tape 20L made of the blend polymer of the raw material composition shown in Examples 1 and 2 and Comparative Example is thermally welded to the loading surface of the pallet forming member made of polypropylene using hot air as described above, and these pallets The following peel test was performed using a synthetic resin pallet having the forming member as a constituent member.

  As shown in FIG. 3, in the peel test, a local load is applied to the non-slip tape 20L by the edge of the drum, and the drum can be rolled in a place where the load is applied (to cross the anti-slip tape 20L). To roll). Then, the degree to which the non-slip tape 20L was peeled in the width direction and whether or not the anti-slip tape 20L was broken by rolling of the drum can were evaluated.

  In this test, the load weight of the pallet was set to 200 kg by using a drum can D containing 200 L of hydraulic oil as a load. The test temperature was 23 ± 2 ° C., and the drum part D was rolled so that the edge part at the edge part DE of the drum D reciprocated up to 1250 times in the tape width direction on the non-slip tape 20L. Each time the drum D was reciprocated 250 times, the drum was allowed to stand at room temperature for 24 hours or more under the above temperature, and then the degree of peeling of the non-slip tape 20L and whether or not the anti-slip tape 20L was broken was evaluated.

表４の試験結果に示すように、合成樹脂製パレット１の載荷面２０Ｔに熱溶着された滑り止めテープ２０Ｌを横切るようにドラム缶Ｄの縁部ＤＥを２５０回往復させる（転動させる）と、実施例１，２の滑り止めテープ２０Ｌを用いた試験では全幅剥離に至っていない。これに対し、比較例の滑り止めテープ２０Ｌを用いた試験では全幅剥離に至っている。また千切れはいずれも発生していない。これにより、メタロセン触媒系ポリプロピレンを含有させることによりポリプロピレン樹脂との熱溶着力が高められたことが確認された。なお、滑り止めテープ２０Ｌを横切るようにドラム缶Ｄの縁部ＤＥを５００回及び７５０回往復させたときも、２５０回往復させたときの試験結果と同じ結果であった。

As shown in the test results of Table 4, when the edge DE of the drum can D is reciprocated 250 times so as to cross the anti-slip tape 20L thermally welded to the loading surface 20T of the synthetic resin pallet 1, In the test using the non-slip tape 20L of Examples 1 and 2, full width peeling was not achieved. On the other hand, in the test using the anti-slip tape 20L of the comparative example, full width peeling was reached. Neither shreds have occurred. Thereby, it was confirmed that the heat welding power with the polypropylene resin was enhanced by containing the metallocene catalyst-type polypropylene. In addition, when the edge DE of the drum D was reciprocated 500 times and 750 times so as to cross the anti-slip tape 20L, the result was the same as the test result when the edge DE was reciprocated 250 times.

  When the edge DE of the drum D was reciprocated 1000 times so as to cross the anti-slip tape 20L, the anti-slip tape 20L of Example 2 and the comparative example reached full width separation, and the anti-slip tape 20L of Example 1 was reached. Only did not result in full width peeling. As a result, it was confirmed that the heat welding power with the polypropylene resin was increased by containing the metallocene catalyst-based polypropylene, but the heat welding power was lowered due to the foaming effect of the foaming agent in the anti-slip tape 20L of Example 2. . However, in the non-slip tape 20L of Example 2, although full width peeling was observed, it was torn off at the place where the full width peeled, in other words, full width peeling expanded in the longitudinal direction of the anti-slip tape 20L. It was confirmed that they did not.

  Therefore, even if full width peeling occurs when the non-slip tape 20L includes a foaming agent, it is possible to suppress the local full width peeling from being gradually transmitted and expanded in the longitudinal direction of the non-slip tape 20L. Is possible. As a result, it is possible to suppress separation of all of the non-slip tape 20L from the synthetic resin pallet 1 (upper pallet forming member 2). This is because the anti-slip tape 20L is softened by the foaming effect, in other words, the rigidity of the anti-slip tape 20L is reduced.

  When the edge DE of the drum D was reciprocated 1250 times so as to cross the anti-slip tape 20L, the anti-slip tape 20L of Examples 1 and 2 and the comparative example reached full width peeling. At this time, in the anti-slip tape 20L of Example 1, it was confirmed that tearing occurred at the part where the full width was peeled off, that is, the full width peeling was not expanded in the longitudinal direction of the anti-slip tape 20L. It was. Therefore, with the anti-slip tape 20L of Example 1, it is possible to suppress the occurrence of full width peeling and the expansion of the full width peeling in the longitudinal direction of the non-slip tape 20L. As a result, it is possible to prevent the anti-slip tape 20L from being separated from the synthetic resin pallet 1 (upper pallet forming member 2).

  Incidentally, in the anti-slip tape 20L of the comparative example, even when the edge DE of the drum can D was reciprocated 250 times so as to cross the anti-slip tape 20L as described above, full width peeling occurred. Even when the edge of the drum was reciprocated 1250 times across the anti-slip tape 20L, no tearing occurred. Then, as the number of times the edge DE of the drum D is reciprocated across the anti-slip tape 20L increases, it is confirmed that the full width peeling gradually increases in the longitudinal direction of the anti-slip tape 20L. It was.

  Therefore, according to the above-described test example, it was confirmed that the anti-slip tape 20L includes the metallocene catalyst-based polypropylene, so that the heat welding force between the anti-slip tape 20L and the pallet forming member made of polypropylene resin can be increased. . However, it was also recognized that the anti-slip tape 20L was torn at the part where the full width was peeled off. Therefore, although the thermal welding force between the anti-slip tape 20L and the pallet forming member is reduced, it is possible to suppress the expansion of the full width peeling region.

  Further, even if the anti-slip tape 20L containing the metallocene catalyst-based polypropylene is used, if the load applied to the anti-slip tape 20L accumulates, it will result in full width peeling. It was recognized that it was torn. Therefore, it is possible to increase the thermal welding force in the anti-slip tape 20L and to suppress the expansion of the full width peeling region.

  Next, as another test, a load test based on JIS Z 0602 1988, that is, a test for evaluating the anti-slip performance of the anti-slip tape was performed. The results are shown in Table 5. By the way, the test conditions were such that one crate containing a large beer bottle (with contents) was used as a load, the loaded weight was 27 kg, and the slip direction of the load was the direction of application of the non-slip tape. Moreover, the speed which inclines the loading surface 20T was made into 45 degrees / min.

  At this time, polypropylene crate and polyethylene crate were used, both of which were tested under the condition of DRY only. Incidentally, the DRY condition means that the synthetic resin pallet 1 and the anti-slip tape 20L are in a dry state and the crate is also in a dry state.

  Further, as a criterion for judging that the non-slip tape 20L satisfies the anti-slip performance, it is necessary that the inclination of the pallet on which the crate slides is 30 ° or more for polypropylene crate and 23 ° or more for polyethylene crate. It was. The test temperature was 23 ± 2 ° C., and this test was conducted after leaving the test at this temperature for 24 hours or more.

表５に示すように、メタロセン触媒系ポリエチレンを７０％以上含有するブレンドポリマーからなる比較例の滑り止めテープ２０Ｌを用いた試験では、ポリプロピレン製のクレートが滑落した角度は３９．２°であった。またポリエチレン製のクレートが滑落した角度は２８．２°であった。

As shown in Table 5, in a test using the anti-slip tape 20L of a comparative example made of a blend polymer containing 70% or more of a metallocene catalyst-based polyethylene, the angle at which the polypropylene crate slipped was 39.2 °. . The angle at which the polyethylene crate slipped was 28.2 °.

On the other hand, in the non-slip tape 20L of Example 1 made of a blend polymer containing no foaming agent, the angle at which the polypropylene crate slipped was 33.6 °. The angle at which the polyethylene crate slipped was 25.1 °. Further, in the anti-slip tape 20L of Example 2 made of a blend polymer containing a foaming agent, the angle at which the polypropylene crate slipped was 35.2 °. The angle at which the polyethylene crate slipped was 27.2 °.

  Thereby, in any case, it was confirmed that the above-described anti-slip tape 20L satisfies the criteria for determining that the anti-slip performance is satisfied. Moreover, it was recognized that when the blending ratio of the metallocene catalyst-based polyethylene decreases, the anti-slip performance of the anti-slip tape 20L decreases. Further, it was confirmed that the anti-slip tape 20L containing the foaming agent had higher anti-slip performance than the anti-slip tape 20L containing no foaming agent. This is considered to be due to the fact that the anti-slip tape 20L is softened by the foaming action and the bottom portion of the crate is easily bited into the anti-slip tape 20L. Moreover, it was confirmed that even if the blending ratio of the metallocene catalyst-based polyethylene was lowered to 34.3 mass%, anti-slip performance satisfying practicality was exhibited regardless of the presence or absence of the foaming effect.

  In addition, the present inventors verified whether or not the anti-slip performance of the anti-slip tape 20L was maintained while increasing the weight average molecular weight of the blend polymer as a product material. Here again, as a criterion for judging that the anti-slip tape 20L satisfies the anti-slip performance, the inclination of the pallet on which the crate slides is required to be 30 ° or more for polypropylene crate and 23 ° or more for polyethylene crate. It was supposed to be. As a result, when the weight average molecular weight of the blend polymer in Examples 1 and 2 was 250,000 or less, it was confirmed that the anti-slip tape 20L satisfied the anti-slip performance.

  Further, the anti-slip tape 20L obtained by extruding the blend polymer having the raw material composition shown in Examples 1 and 2 is said to contain 24.5% by weight of the metallocene catalyst polypropylene, but this is only an example. . When the thermoplastic polypropylene elastomer is 30-50% by mass and the metallocene-catalyzed polyethylene is 25-45% by mass, the blend polymer contains the metallocene-catalyzed polypropylene so that it is not slippery from the pallet forming member. It was possible to suppress peeling of the tape 20L.

  When the thermoplastic polypropylene elastomer is 30 to 50% by mass and the metallocene catalyst-based polyethylene is 25 to 45% by mass, the lower the blending ratio of the remaining metallocene catalyst-based polypropylene, the lower the pallet forming member. The tendency for the non-slip tape 20L to be easily peeled off was observed. Further, it was confirmed that the same results as in Example 2 could be obtained if the blending ratio of the remaining metallocene catalyst-based polypropylene was 15% by mass or more.

  Therefore, in order to more reliably suppress the anti-slip tape 20L from peeling from the pallet forming member, the blending ratio of the thermoplastic polypropylene elastomer and the metallocene catalyst-based polyethylene is 85% by mass or less, and the metallocene catalyst-based polypropylene. Is preferably 15% by mass or more.

  Further, when the thermoplastic polypropylene elastomer is 30 to 50% by mass and the metallocene catalyst-based polyethylene is 25 to 45% by mass, the higher the compounding ratio of the metallocene catalyst-based polypropylene, the more slip-proof performance to the load is lost. It was recognized that Further, it was confirmed that the same result as in Example 2 could be obtained if the blending ratio of the remaining metallocene catalyst-based polypropylene was 35% by mass or less.

Therefore, in order to suppress a decrease in the anti-slip performance in the pallet forming member, the blending ratio of the thermoplastic polypropylene elastomer and the metallocene catalyst polyethylene is 65% by mass or more, and the metallocene catalyst polypropylene is 35% by mass or less. It is preferable that

  Moreover, when the blend polymer of a raw material composition as shown in Example 2 is extrusion-molded, the rigidity of the anti-slip tape 20L can be reduced as a foaming effect by the blended foaming agent. That is, since the non-slip tape 20L is softened, the bottom portion of the load is easily bited by the non-slip tape 20L. As a result, it is possible to improve the slip resistance of the antiskid tape 20L itself.

  However, if the foaming ratio of the blend polymer with the foaming agent is less than 1.05, the extruded anti-slip tape 20L is not sufficiently softened, so it is difficult to improve the anti-slip performance of the anti-slip tape 20L. It was recognized that On the other hand, when the expansion ratio was greater than 1.30, it was recognized that the anti-slip tape 20L was too soft. In other words, if the expansion ratio is greater than 1.30, a large amount of scrap is generated from the anti-slip tape 20L when the load and the surface of the anti-slip tape 20L rub against each other due to vibration during transportation. There is concern. This is not preferable because it is difficult to ensure the durability of the anti-slip tape 20L, and the shavings need to be frequently cleaned. Therefore, when the blend polymer contains a foaming agent, the foam ratio of the blend polymer is desirably 1.05 to 1.30.

  Further, the anti-slip tape 20L obtained by extruding the blend polymer of the raw material composition shown in Example 2 contains 0.12% by mass of azodicarbonamide, which is a foaming agent, but this value is only an example. is there. From the viewpoint of production, the blending ratio may be such that the foaming agent can be stably blended with the blend polymer. When azodicarbonamide is included, it is preferably 0.05% by mass or more. On the other hand, from the viewpoint of production, in order to make the foaming ratio of the blend polymer within the range of 1.05 to 1.30 times as described above, the blending ratio of azodicarbonamide is set to the total mass of the blend polymer. At most 0.2% by mass or less is required. That is, the blend polymer preferably contains 0.05 to 0.2% by mass of azodicarbonamide.

  Next, the degree of blocking in Examples 1 and 2 and the comparative example is shown below. Incidentally, blocking refers to a phenomenon that occurs when a new empty pallet with a non-slip tape 20L thermally welded to both the loading surface 20T and the ground surface is stacked and stored. Specifically, it refers to a phenomenon in which the loading surface 20T and the ground contact surface of the pallet are not separated due to sticking of the non-slip tape 20L. Such blocking is a phenomenon caused by bleed-out of low molecular weight components such as oligomers and monomers generated from the anti-slip tape 20L when the synthetic resin pallet 1 is loaded and stored. The degree of the bleed-out greatly varies depending on the temperature, time, and load weight of the synthetic resin pallet 1 loaded and stored.

  In evaluating the degree of blocking, a plurality of new polypropylene synthetic resin pallets 1 each having a non-slip tape 20L thermally welded to the loading surface 20T and the ground surface were laminated. Next, in this state, a 1 t load was continuously applied for 4 weeks at a room temperature of 40 ° C. Then, the degree of blocking was evaluated by measuring the time required for the synthetic resin pallets 1 to separate from each other by their own weight, that is, until they fall freely.

As a result, the time required for the separation of the synthetic resin pallet 1 using the anti-slip tape of Example 2 containing the foaming agent as well as the anti-slip tape of Example 1 used the anti-slip tape of the comparative example. The time required for the separation of the synthetic resin pallet 1 was shorter. Thereby, it was confirmed that the degree of blocking was suppressed.

  Incidentally, in order to suppress the degree of blocking, it is effective to suppress the occurrence of bleedout as the main cause as described above. In addition, bleed-out is suppressed as the weight average molecular weight of the material increases. Therefore, if the weight average molecular weight of the material of the non-slip tape 20L is increased, the degree of blocking is also suppressed. Therefore, it is desirable that the weight average molecular weight is practically 150,000 or more in order to suppress such blocking in addition to suppressing the generation of decomposition products in the production described above.

As described above, according to the anti-slip tape and the pallet forming member according to this embodiment, the effects listed below can be obtained.
(1) Among the polypropylenes having a high heat-welding force with the polypropylene resin that is a material of the pallet forming member, the non-slip tape 20L is particularly formed of a blend polymer containing a metallocene catalyst polypropylene.

  If such a non-slip tape 20L is heat-welded to the loading surface 20T of the pallet forming member, it is possible to prevent the anti-slipping tape 20L from being peeled off from the loading surface 20T. More specifically, even if the weight of the load having an edge shape at the bottom portion acts locally at the contact portion between the edge shape and the anti-slip tape 20L, the load portion slides on the load surface 20T. It is possible to reduce the possibility that the non-slip tape 20L will peel off at the full width.

  In addition, it is possible to suppress the local full width peeling at the contact portion from gradually expanding in the longitudinal direction of the anti-slip tape 20L due to sliding or rolling of the load. This further reduces the possibility that the anti-slip tape 20L completely separates from the pallet forming member, and thus maintains the anti-slip performance on the loaded load, which is an important function in the synthetic resin pallet 1, over a long period of time. Is possible.

  Further, since 25 to 45 mass% of the metallocene catalyst-based polypropylene is contained in the blend polymer, it is possible to maintain the thermal welding force at a practically necessary level and to maintain the antislip performance.

  (2) The anti-slip tape 20L is formed from a blend polymer containing 15 to 35% by mass of a metallocene catalyst-based polypropylene. Thereby, it is possible to more surely maintain the anti-slip performance provided by the metallocene catalyst-based polyethylene while preventing the anti-slip tape 20L from peeling off from the pallet forming member.

  (3) The anti-slip tape 20L is formed of a blend polymer containing a foaming agent that makes the expansion ratio 1.05-1.30. According to this configuration, since the anti-slip tape 20L is softened by the foaming effect of the foaming agent, the rigidity of the anti-slip tape 20L is reduced.

  For this reason, when a strong force acts to peel off the anti-slip tape 20L from the loading surface 20T at the contact portion between the edge shape at the bottom of the load and the anti-slip tape 20L as described above, the anti-slip tape 20L is formed at the contact portion. As the entire width peels, it becomes easy to break.

Therefore, even if local full width peeling occurs in the non-slip tape 20L, the anti-skid tape 20L is torn before the full width peeling gradually propagates and expands the entire anti-slip tape 20L. Become. As a result, the anti-slip tape 20 is increased by expanding the full width peeling.
It becomes possible to avoid that L completely separates from the upper pallet forming member 2.

  (4) Since the blend polymer contains 0.05 to 0.2% by mass of azodicarbonamide as a foaming agent, it is possible to prevent the expansion of full width peeling as described above, and the anti-slip tape 20L. This makes it possible to enhance the anti-slip performance on the load that is developed by the machine.

  (5) Since the non-slip tape 20L is a molded product of a blend polymer containing a metallocene catalyst-based polypropylene, it is possible to improve the thermal weldability with the synthetic resin pallet 1 made of polypropylene resin. Further, since the anti-slip tape 20L is also a molded product of a blend polymer containing a metallocene catalyst-based polyethylene, it is possible to maintain the anti-slip performance on the load.

  Therefore, while satisfying the anti-slip property required for the pallet 1 made of synthetic resin, it is possible to suppress the full width separation due to the local action of the weight of the load, and the transmission and expansion of the full width separation. And it becomes possible to provide the synthetic resin pallet 1 which maintains the anti-slip performance to the loaded luggage for a long period of time.

In addition, the said embodiment can also be implemented with the following aspects.
The non-slip tape 20L may be heat-welded to a polypropylene resin skid pallet. Thereby, the heat welding force of the skid pallet and the anti-slip tape 20L can be improved.

  In the above embodiment, azodicarbonamide is used as the thermal decomposition type foaming agent. However, the present invention is not limited to this. For example, dinitrosopentamethylenetetramine, which is also a thermal decomposition type foaming agent, may be used. . Even if it does in this way, the effect according to said (3)-(5) can be acquired.

  The amount of the foaming agent contained in the blend polymer may be less than 0.05% by mass or higher than 0.2% by mass. Even if it is such a blending amount, the effect according to the above (3) and (5) can be obtained as long as the foaming action occurs.

  The amount of the metallocene catalyst-based polypropylene contained in the blend polymer may be less than 15% by mass or higher than 35% by mass. Even if it is such a compounding quantity, the effect according to said (1) can be acquired as long as the heat welding power with the synthetic resin pallet 1 which consists of polyolefin resin by a metallocene catalyst type polypropylene is strengthened.

  -A blend polymer containing 30-50% by mass of a polypropylene-based thermoplastic elastomer, 25-45% by mass of a metallocene-catalyzed polyethylene and a metallocene-catalyzed polypropylene has an affinity for polypropylene as the remainder of these. You may mix | blend a compatibilizing agent in order to raise. As the compatibilizer, it is desirable to use a hydrogenated polybutadiene resin. Even if it does in this way, the effect according to said (1)-(5) can be acquired.

  In the above embodiment, the metallocene catalyst-based polyethylene is used as the main blending agent of the blend polymer. However, the present invention is not limited to this. For example, a metallocene catalyst-based ethylene / α-olefin copolymer may be used. Even if it does in this way, the effect according to said (1)-(5) can be acquired.

  The synthetic resin pallet 1 may be a two-way pallet or a four-way pallet. Further, the anti-slip tape 20L may be thermally welded to a portion other than the loading surface 20T of the synthetic resin pallet 1, for example, a ground surface.

  -These residues may exist in the blend polymer containing the thermoplastic elastomer which consists of 30-50 mass% polypropylene, 25-45 mass% metallocene catalyst-type polyethylene, and metallocene catalyst-type polypropylene. For example, the total of these blending ratios does not reach 100% by mass, as in the case of 30% by mass of thermoplastic elastomer made of polypropylene, 25% by mass of metallocene catalyst-based polyethylene, and 15% by mass of metallocene catalyst-based polypropylene. Is the time. At this time, for example, a block copolymer-polypropylene, an ethylene-vinyl acetate copolymer, a low density polyethylene, a styrene butadiene rubber, a colorant, a foaming agent, a compatibilized product, and the like are appropriately blended as the above residue, so that the sum of the blending ratios May be 100% by mass. However, it is needless to say that it is a precondition that the practically necessary characteristics as the anti-slip tape, that is, the object of the present invention is satisfied.

  It is possible to provide a non-slip tape capable of suppressing separation from a load surface while suppressing a load loaded on the load surface from slipping on the load surface, and a pallet forming member including the anti-slip tape.

  DESCRIPTION OF SYMBOLS 1 ... Synthetic resin pallet, 2 ... Upper pallet formation member, 3 ... Lower pallet formation member, 20 ... Deck board, 21 ... Upper girder, 20H ... Fitting hole, 20L ... Anti-slip tape, 20S ... Loading side inner surface, 20T ... Loading surface, 30 ... Grounding board, 31 ... Lower girder.

Claims (5)

A non-slip tape made of a blended polymer that is attached to the loading surface of a pallet forming member made of polypropylene resin by thermal welding,
The blend polymer is
Containing 30 to 50% by mass of a thermoplastic elastomer made of polypropylene,
Containing 25 to 45% by weight of a metallocene catalyst-based polyethylene,
Including metallocene catalyst polypropylene,
A non-slip tape characterized by having a weight average molecular weight of 150,000 or more. The blend polymer is
The blending ratio of the thermoplastic elastomer made of polypropylene and the metallocene catalyst-based polyethylene is 65 to 85% by mass,
The anti-slip tape according to claim 1, comprising 15 to 35% by mass of the metallocene catalyst-based polypropylene. The blend polymer includes a blowing agent;
The anti-slip tape according to claim 1 or 2, wherein the foaming ratio of the blend polymer is 1.05 to 1.30. The blowing agent is azodicarbonamide;
The blend polymer is
The anti-slip tape according to claim 3, comprising 0.05 to 0.2% by mass of the foaming agent. A pallet forming member made of polypropylene resin,
A non-slip tape is thermally welded to the loading surface of the pallet forming member,
The said antiskid tape is an antiskid tape as described in any one of Claims 1-4. The pallet formation member characterized by the above-mentioned.

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