JP3311712B2 - Protective layer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protective material suitably used as an architectural curing material for an opening frame, a pillar, a handrail or the like.

[0002]

2. Description of the Related Art Tubular thermoplastic resin foams having continuous cracks in the longitudinal direction are used as architectural curing materials such as open frames, columns, and handrails, cushioning materials for preventing injuries, protective materials for water pipes, and cushioning packaging materials. It is widely used in various fields as a member. As one of the uses, as shown in FIG. 9, for the purpose of protecting the surfaces of the pillars 1, the gates 2, and the like in the construction, the side edges 5 a, An example is a tubular resin foam architectural curing material 5 for holding and holding 5a. As a conventional technique relating to such a protective material, for example, there is one disclosed in Japanese Utility Model Publication No. 3045483. The purpose of this technology is to provide a safety indicator that can be easily attached and detached, does not stain or damage the scaffold, can be reused, and has an excellent shock absorbing function. . This safety display body is provided with a slit portion which is cylindrical and extends in the longitudinal direction, is colored in a stripe pattern such that yellow and black alternately on the side surface, and is made of plastic containing air bubbles.

[0003]

However, the above-mentioned safety display body is a cylindrical foam having a uniform thickness, and is bulky when packed and shipped. There was a problem that a large storage space was required.

[0004] It is an object of the present invention to solve the above-mentioned problems without increasing the bulk, thereby reducing the logistics cost and storage space, and furthermore, the grip when the material to be protected such as a pillar is covered and held. The object is to provide a high protection material.

[0005]

That is, the protective material according to claim 1 of the present invention has a continuous crack in the longitudinal direction, and both side edges forming the crack overlap each other and are perpendicular to the longitudinal direction. The cross-sectional shape is flat,
A tubular thermoplastic resin foam having a central portion thicker than the thickness of both side edges forming the crack, wherein the overlapping length is 5 to 4 of the length from one side edge to the other side edge.
At 0%, the length of the maximum outer diameter passing through the center of the cross section is 1.3 to 5.0 times the length of the minimum outer diameter passing through the center of the cross section. According to the protective material of the present invention, the tubular thermoplastic resin foam having the continuous cracks in the longitudinal direction has a flat cross section perpendicular to the longitudinal direction, so that it can be stably placed on the work site. It is possible to reduce logistics costs and storage space because it is not bulky, and when it is attached to a protected material such as a pillar, the protective material does not protrude much into the work space, which is advantageous in work. The grip force on the material to be protected is also increased. Further, according to the protective material of the present invention, since the cross-sectional shape is flat and the thickness of both overlapping side edges is thin, distribution cost and storage space can be reduced without being bulky.
In addition, according to this protective material, the cross-sectional shape is flat, and the side edges overlap each other, and the thickness of the central portion is formed thick, so that the side edges overlapping each other are expanded. , Reaction force (restoring force) on both side edges
Becomes larger. Therefore, to cover the protective material with pillars,
In addition, when a wall or the like that is continuous with the pillar or the like is sandwiched between both side edges thereof, the wall or the like is firmly clamped by the reaction force (grip force).

[0006] A protective material according to claim 2 of the present invention is:
Claim 1 is characterized in that the open cell ratio of the foam is 40% or less. According to the present invention, the grip force can be further increased, and the cushioning property is excellent.

Further, a protective material according to claim 3 of the present invention is characterized in that in claim 1 or 2, the foam has an average cell diameter of 200 to 800 μm. According to the present invention, the gripping force can be further increased because of the high toughness.

In the protective material of the present invention, both side edges of the tubular foam are expanded so that the hollow portion inside the tubular foam is expanded, and the tubular foam is sandwiched between the columns and the like so as to cover the columns and the like.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION As the base resin for the protective material in the present invention, for example, polyvinyl chloride resin such as polyvinyl chloride, polystyrene resin containing a rubber component, polyolefin such as polyethylene resin and polypropylene resin, etc. Resins, acrylic resins such as polymethyl methacrylate, and polycarbonate resins. Among the above, polyolefin resins such as polyethylene resins and polypropylene resins and polystyrene resins containing a rubber component are most suitable for imparting flexibility, compressive strain recovery and flexibility to the protective material of the present invention. Resin. The polyolefin-based resin is a resin containing an olefin component in an amount of 50 mol% or more. For example, branched low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, linear ultra-low-density polyethylene, ethylene −
Propylene block copolymer, ethylene-propylene random copolymer, ethylene-butene block copolymer, ethylene-butene random copolymer, ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ethylene-methacrylic acid copolymer Ethylene-based ionomer resin in which the polymer molecules are cross-linked with metal ions, propylene homopolymer, propylene-ethylene random copolymer, propylene-butene random copolymer, polybutene, polypentene, propylene-ethylene-butene ternary copolymer Examples include a polymer, a propylene-acrylic acid copolymer, a propylene-maleic anhydride copolymer, and the like. Further, in the present invention, a graft-modified polyolefin-based resin obtained by impregnating the above polyolefin-based resin with a vinyl monomer such as styrene and performing graft polymerization can also be used.

The above-mentioned polyolefin resin may be used after being cross-linked by peroxide or radiation or may be used without cross-linking. However, a non-cross-linked resin which has a simple production process and is recyclable is preferable.

As the polystyrene resin containing a rubber component, a resin obtained by blending or copolymerizing a base resin with a rubber component is used. Examples of the polystyrene resin containing a rubber component include a random copolymer, a block copolymer, and a graft copolymer comprising a styrene component such as styrene, α-methylstyrene, and P-methylstyrene, and a butadiene or isoprene-based diene component. Coalescing or
A mixture of these copolymers or a mixture of these copolymers and a polystyrene resin other than these copolymers may be used. The content of the rubber component is preferably from 1 to 45% by weight. If the rubber component is less than 1% by weight, the protective material may not be sufficiently imparted with flexibility and elasticity. On the other hand, if the rubber component is more than 45% by weight, the formation of a cell membrane at the time of extrusion foaming becomes incomplete, and the closed cell ratio is undesirably reduced. From these viewpoints, the content of the rubber component (diene component) in the styrene resin is 3 to
35% by weight is more preferred. In the present invention, additives used for ordinary extrusion foaming include a crystal nucleating agent, an ultraviolet absorber, an antioxidant, an antistatic agent, a coloring agent, a bubble regulator, an anti-shrinkage agent, and a conductivity imparting agent. For example, examples of the crystal nucleating agent include an aluminum salt of an aromatic carboxylic acid, dibenzylidene sorbitol, and sodium 2,2-methylenebis (4,6-di-tert-butylphenyl) phosphate. Examples of the foam control agent include talc,
Examples include inorganic powders such as silicon oxide and silica, metal salts of higher fatty acids such as zinc stearate and calcium stearate, and chemical foaming agents such as citric acid and sodium hydrogen carbonate which decompose by heating to generate gas. In addition, coloring can be performed by adding a coloring pigment or dye such as black, gray, brown, yellow, red, pink, green, and blue, depending on the purpose and application. When the above additives are added, it is usually preferable to adopt a master batch method in consideration of their dispersibility. The addition amount of each of the bubble regulator, the coloring pigment, and the dye is usually 0.001 to 100 parts by weight of the resin.
5 parts by weight. In addition, it is no different from the conventional art that a necessary amount of a known additive may be added.

In the present invention, as a foaming agent at the time of extrusion, for example, a thermally decomposable solid compound, a volatile liquid or gas, an inert gas or the like is used alone or in combination. As the thermal decomposition type solid compound, azodicarbonamide, dinitrosopentamethylenetetramine and the like can be used, and as the volatile liquid or gas, propane, normal butane, isobutane, normal pentane,
Saturated aliphatic hydrocarbons such as isopentane and neopentane, saturated alicyclic hydrocarbons such as cyclopentane and cyclohexane, 1-chloro-1,1-dichloroethane, 1,1,1,2-tetrafluoroethane, Halogenated hydrocarbons such as 1,1-chloroethane, ethers such as dimethyl ether, ketones such as acetone, and alcohols such as methanol and ethanol can be used. Carbon dioxide, nitrogen and the like can be used as the inert gas. In addition, water can be used as a blowing agent. Also, a mixed foaming agent with isobutane, normal butane, and 1,1,1,2-tetrachloroethane can be preferably used.

FIG. 1 shows an embodiment of the protective member according to the present invention, FIG. 2 shows a lip 20 of a die for extruding the protective member 10, and FIG. 3 shows the shape of FIG. FIG. 5 is an enlarged view of a main part showing a device immediately after extrusion for forming the protective material 10 of FIG.

The protective member 10 shown in FIG.
12 are formed in a cylindrical shape so as to overlap each other, and have a substantially elliptical cross section perpendicular to the longitudinal direction. As a method of forming the protective material 10,
For example, a tandem extruder of a type in which two extruders are connected in series as an extruder is used, and the thermoplastic resin and the cell regulator are supplied to the first extruder. A foaming agent is injected into a foamable melt, which is cooled in a second extruder to an appropriate temperature for foaming, and extruded under a low pressure from a lip 20 of a die attached to a tip of the extruder to form a foam (protection). Material 10) is obtained. At that time, die 2
Immediately after extrusion from 0, the mandrel 7 as shown in FIG.
It is preferable to isolate the side edges 11 and 12 by means such as 0 so that the side edges 11 and 12 do not fuse with each other. In addition, the mandrel 70
It is more preferable that a water channel or the like is formed inside, and cooling water is flowed through the channel, whereby cooling is performed. Both edges 11,1
For example, a protective material 10 having a shape in which the two are overlapped with each other is formed by using a chestnut-shaped lip 20 as shown in FIG. The central part 1 of the foam is separated by a vacuum conveyor 71 while being isolated from each other so as not to be fused and cooled.
4 in the extrusion direction (arrow MD in FIG. 3).
The foam can be easily manufactured by strongly cooling the outer surface of the foam with cold air while transferring the foam to the outer side, and cooling the outer part more than the inner part of the foam.
This utilizes the phenomenon that the higher the surface temperature of the foam immediately after extrusion, the faster the foaming agent escapes from that portion and the foam shrinks accordingly. If the degree of shrinkage of the inner portion of the foam is increased in this manner, the foam separated from the mandrel 70 gradually shrinks to the inside of the foam as the temperature decreases, and has a shape as shown in FIG. Curled up. If the length is appropriately cut after or during the contraction, the protective material 10 having the shape shown in FIG. 1 is obtained. In addition, the protective material 10 obtained by increasing the degree of shrinkage of the inner part of the extruded foam as described above has a larger gripping force on the material to be protected than the one formed into the same shape without utilizing the difference in the shrinkage. It is preferable because it becomes large.

In the present invention, in a cross section perpendicular to the longitudinal direction, the thickness of the central portion 14 and the side edges 11, 12
It is preferable that the thickness of the central portion 14 of the protective material 10 is larger than the thickness of the side edges 11 and 12. The reason for this is to reduce the level difference when the side edges 11 and 12 overlap each other in a state where they are attached to a bar-shaped object such as a handrail. The protective material 10 having the side edges 11 and 12 thinner than the central portion 14 can be easily obtained by using a die lip 20 having the shape shown in FIG. In the lip 20 of the shape of FIG. 2, the end 21 of the lip is also at the center 22 of the lip.
The size of the gap is also substantially the same,
1 has a lower extrusion rate of the foamable melt and a smaller amount of extrusion than the central portion 22 of the lip, and as a result, the foams having thinner side edges 11, 12 than the central portion 14 have. A body (ie, protective material 10) is obtained.

In the present invention, when the protective material 10 is formed by extrusion, as the take-up speed increases with respect to the extrusion speed, the surface irregularities tend to decrease and the surface condition tends to improve. However, as the take-up speed increases, the total cross-sectional area of the foam portion of the protective material 10 decreases, so the take-up speed is set in consideration of these points.

In the present invention, the cross-sectional shape of the protective member 10 perpendicular to the longitudinal direction is preferably a flat shape (substantially elliptical shape) as shown in FIG. Since the flattened material is not bulky, for example, the number of the protective materials 10 housed in a certain volume such as a cardboard box packing is greatly increased, and the distribution cost and storage space per one can be reduced. When the cross-sectional shape is flat, the maximum outer diameter (long axis) of the outer diameter passing through the center of the protective material 10 in a cross section perpendicular to the longitudinal direction
Is preferably 1.3 to 5.0 times the minimum outer diameter (short axis) of the outer diameter passing through the center of the protective material 10.
When the ratio of the major axis / minor axis is smaller than 1.3, the effect of reducing the distribution cost is small. On the other hand, if the ratio of the major axis to the minor axis is larger than 5.0, the workability is deteriorated when the material to be protected is covered and fixed, and the protective material 10 may fall off depending on the shape of the protective material 10. There is. In addition, the code | symbol 13 in FIG.
This is a crack formed in the protective material 10.

In the present invention, in the section perpendicular to the longitudinal direction, the length that the side edges 11 and 12 of the protection member 10 overlap with each other is set such that one side edge 11 of the protection member 10 extends from one end of the other side edge 12. The length to the end, that is, 5 to 40% of the entire width is preferable. If the overlapping length is less than 5%, the effect of reducing storage space and distribution costs is small. On the other hand, if it exceeds 40%, the workability may be deteriorated when the protective material 10 is spread and fixed on the material to be protected.

FIG. 4 shows an embodiment of a protective member according to the present invention, and FIG. 5 shows a lip 40 of a die for extruding the protective member 30. The protection member 30 shown in FIG. 4 is formed in a cylindrical shape so that both side edges 31 and 32 are opposed to each other, and they have a substantially elliptical cross section perpendicular to the longitudinal direction. I have. The protective member 30 shown in FIG. 4 has a flat shape and is not bulky as compared with a perfect circular member, which contributes to a reduction in distribution cost per one. The degree of the flattening is such that the length of the maximum outer diameter (long axis) of the outer diameter passing through the center of the protective material 30 is the length of the minimum outer diameter (shorter axis) of the outer diameter passing through the center of the protective material 30. 3-5.
It is preferably 0 times. The long axis / short axis ratio is 1.3.
If it is smaller, the effect of reducing distribution costs is small. on the other hand,
If the ratio of the major axis / minor axis is larger than 5.0, it is too flat and may hinder the covering and fixing of the material to be protected. In addition, the code | symbol 33 in FIG. 4 is a crack formed in the protective material.

The protective member 30 shown in FIG. 4 is formed by using a die lip 40 as shown in FIG. 5 and by the same method as the protective member 10 of the above-described embodiment. . Note that the side edges of the lip 40 shown in FIG. 5 are separated from the lip 20 in order to prevent the ends 31, 32 of the protective material 30 from overlapping after contraction. However, the protective material shown in FIG. 1 having a flat shape and overlapping side edges is the most compact, and greatly contributes to a reduction in distribution costs. Also, the gripping force of the protected material is the strongest.

FIG. 6 shows a reference example of a protective material having a continuous crack in the longitudinal direction, and FIG. 7 shows a lip 60 of a die for extruding the protective material 50. FIG. 8 shows a state in which the protective member 50 is attached to a column 80 formed of an H-shaped steel. The protection member 50 shown in FIG. 6 has locking portions 51 and 52 having bulges on both side edges. The cross-sectional shape of the locking portions 51 and 52 perpendicular to the longitudinal direction of the protective member 50 includes a triangular, square, elliptical shape and the like in addition to the substantially circular shape shown in FIG. The locking portions 51 and 52 are formed in a cylindrical shape so as to mesh with each other, and have a substantially elliptical cross section perpendicular to the longitudinal direction. Further, the locking portions 51 and 52 shown in FIG. 6 are formed continuously in the longitudinal direction of the protection member 50, but may be formed intermittently. The protective material 50 shown in FIG. 6 has a flat shape and is not bulky as compared with a perfect circular shape, which contributes to a reduction in distribution cost per one. The degree of the flattening is such that the length of the maximum outer diameter (long axis) of the outer diameter passing through the center of the protective material 50 is equal to the length of the minimum outer diameter (short axis) of the outer diameter passing through the center of the protective material 50, which is 1. 3-5.
It is preferably 0 times. The long axis / short axis ratio is 1.3.
If it is smaller, the effect of reducing distribution costs is small. on the other hand,
If the ratio of the major axis / minor axis is larger than 5.0, it is too flat and may hinder the covering and fixing of the material to be protected. In addition, the code | symbol 53 in FIG. 6 is a crack formed in the protective material 50. FIG.

As shown in FIG. 7, the protective material 50 shown in FIG. 6 uses a die lip 60 having substantially circular enlarged portions 61, 61 having a larger diameter at the end than the other portions. Since it is formed by the same method as the protection member 10 of the above embodiment, the description is omitted.

The protective member 50 thus formed is
As shown in FIG. 8, when attached to the H-section steel column 80, the locking portions 52, 51 are engaged with the H-section steel flanges 81, 81.
And the protection member 50 is securely held on the pillar 80.

In the protective members 10 and 30 according to the present invention or the protective member 50 of the reference example, in a cross section perpendicular to the longitudinal direction, a portion parallel to the direction of the maximum outer diameter passing through the center of the cross section (for example, the center) The parts 14, 34, 54) are preferably flat. The reason for this is that distribution costs and storage space can be further reduced due to the presence of flat portions. In addition, since it is difficult to roll, handling at the work site is further improved. Further, the flat portion such as a pillar is easily brought into surface contact with the material to be protected. Each protective material 10, 3 obtained through the lip 20 of FIG. 2, the lip 40 of FIG. 5, and the lip 60 of FIG.
0, 50 (side edges 11, 12 or 31.32 or 51, 52)
Are not formed by cutting after extrusion foaming, and do not have open cells due to the cutting (a skin at the time of extrusion foaming is formed at both ends). Such open cells may damage the surface when in contact with the material to be protected. Therefore, if such a protective material having no open air bubbles is used, even a protected material whose surface is easily damaged can be prevented from being damaged, and can be used with confidence. In the present invention “or reference example”, the continuous cracks include both side edges 11, 1 of the protective material 10 in FIG.
2, a crack 1 formed by both side edges 31, 32 of the protection member 30 in FIG. 4 and both side edges 51, 52 of the protection member 50 in FIG.
The workability is better when the 3, 33, and 53 are linear when attaching and detaching.

The length of the protective material 10, 30 of the present invention or the protective material 50 of the reference example is preferably 5.0 m or less, more preferably 0.5 to 3.0 m. If it is too long, it is difficult to handle it during transportation and storage, and if it is too short, a plurality of pieces must be attached to the material to be protected, which slightly deteriorates workability.
Also, the central portions 14, 34, 54 of the protective materials 10, 30, 50
Is preferably 3 mm or more, more preferably 5 mm or more. The thickness of the other portions (excluding the portion extending up to 10 mm from both ends in the direction perpendicular to the longitudinal direction of the protective material) is preferably 2 mm or more, more preferably 4 mm or more. In any case, when the thickness is small, there is a possibility that the grip strength when fixing to the material to be protected is inferior.

In the present invention or the reference example, the state in which the protective material is fixed to the material to be protected includes, for example, a point contact, a line contact, and a surface contact, and a line contact or a surface contact is preferable.

In the present invention or the reference example, in the section perpendicular to the longitudinal direction, in the direction of the maximum outer diameter of the outer diameter passing through the center of the protective material 10, 30, 50, the protective material 10 shown in FIGS. , 30, 50 are preferably provided. Without the round portions 15, 35, 55, there is a possibility that the grip force may be weakened when fixing to the material to be protected.

In the present invention or the reference example, the protective material 1
The density of the foams constituting 0, 30, 50 differs depending on the base resin. For example, for a polystyrene resin containing a rubber component, 0.013 to 0.10 g / cm ³ is preferable, and for a polypropylene resin, 0.015-0.
15 g / cm ³ , 0.02-
0.20 g / cm ³ is preferred. The protective material density was measured according to JIS A6767.
If the density of each foam constituting the protective material exceeds the upper limit of each density range, the gripping force will be too large when fixing to the protected material, the mounting workability will be inferior, and the cushioning will also be reduced. I do. On the other hand, when the density is below the lower limit of each density range, the gripping strength when fixing to the protected material is inferior, and there is a possibility that sufficient fixing cannot be performed.

In the present invention or Reference Example, the open cell ratio of the foam constituting the protective material is preferably 40% or less, more preferably 25% or less. When the open cell ratio is increased, the gripping force when fixing to the material to be protected is inferior, and there is a possibility that sufficient fixation cannot be performed, and the buffering property also deteriorates. The open cell ratio is defined as the maximum size that can be accommodated in a sample cup of a measuring device without deformation, while the foam is cut into a length of 25 mm ± 1 mm, the thickness is kept as it is (the sample accommodated in the sample cup). Is at least 625
It must be 0 mm ³ , and if one sample is less than this volume, a plurality of sheets are used so as to exceed the volume at the same time), and this sample is subjected to ASTM D-2856-7.
0 (Procedure C), the ratio of the true volume of the foam in the measurement sample was determined with an air-comparison hydrometer, and the open cell ratio was calculated. The apparent volume is an apparent volume obtained from the outer dimensions of the sample: Va (cm ³ ). The true volume of the foam to be measured: Vx (cm ³ ) is the sum of the volume of the resin constituting the foam and the total volume of the closed cells in the foam. Therefore, the volume of the interconnected bubbles (open cell ratio) can be determined by the following equation. Here, the weight of the foam to be measured: W (g), and the density of the base resin of the foam to be measured: ρ (g / cm ³ ). Open cell ratio (%) = (Va−Vx) × 100 / (Va−W / ρ)

In the present invention or the reference example, the average cell diameter of the foam constituting the protective material is 200 to 800 μm.
Is preferable, and 400 to 600 μm is more preferable. In order to reduce the average cell diameter to less than 200 μm, it is usually necessary to add a large amount of a cell adjusting agent, resulting in an increase in cost. If the average cell diameter is larger than 800 μm, the surface of the foam will have large irregularities or will have poor toughness.
As a method of measuring the average cell diameter, the number of cells in the thickness direction at the central portions 14, 34, 54 in an arbitrary cross section perpendicular to the extrusion direction of the foam is: N
(Pieces) and the thickness L (μm) at the center thereof were measured, and the average bubble diameter was calculated by the following equation. Average bubble diameter (μm) = (L / N)

The protective materials 10 and 30 of the present invention and the protective material 50 of the reference example are used in addition to protective materials such as opening frames, pillars, handrails, and the like. It is used as a material, cushioning packaging material and the like.

Hereinafter, the present invention will be described in more detail with reference to Examples.

EXAMPLE 1 In order to obtain the cross-sectional shape of the protective material 10 shown in FIG. 1, a screw made of a branched low-density polyethylene resin (melting point 107 ° C., MI = 4.7 g / 10 min) having a barrel inner diameter of 90 mm was used. Into the feeding section of the mold extruder at a rate of 50 kg per hour, and simultaneously, a cell regulator (talc) at a rate of 1.7 parts by weight per 100 parts by weight of the resin,
Further, an anti-shrinkage agent (stearic acid monoglyceride) was supplied at a ratio of 1.4 parts by weight. Then, a foaming agent (isobutane) was injected into the mixing section of the extruder at a ratio of 6.5 parts by weight to 100 parts by weight of the resin, and the resin and the foaming agent were mixed, as shown in FIG. Extrusion was performed after cooling the resin temperature between the extruder tip and the die to 106 ° C. using a die lip 20. Immediately after the extrusion, the extruded foam is isolated by a mandrel 70 also serving as a cooling device shown in FIG. The surface is strongly cooled by cold air, and then cut to a predetermined length by a cutting machine while being pressed by a roll (not shown). Then, at room temperature 23 ° C., after 72 hours, the protective material 1 having the shape shown in FIG.
0 is obtained. The density of the obtained protective material 10 is 0.04
6 g / cm ³ , the maximum outer diameter (long axis) of the outer diameter passing through the center of the protective material 10 and the minimum outer diameter (short) of the outer diameter passing through the center of the protective material 10 in a cross section perpendicular to the longitudinal direction. Axis) and the ratio of the long axis to the short axis is 1.8, and the length of the short axis is 50.
mm. The thickness of the central portion 14 of the protective material 10 is 10 mm, the thickness of the round portion is 9 mm, and 15 mm from the side edge.
The thickness at each position was 6 mm.

[0033]

Reference Example 1 In order to obtain the cross-sectional shape of the protective material 30 shown in FIG. 4, the same conditions as in Example 1 were used except that a die lip 40 as shown in FIG. 5 was used. 4
Was obtained. The density of the obtained protective material 30 is 0.046 g / cm ³ , the maximum outer diameter (long axis) of the outer diameter passing through the center of the protective material 30 in a cross section perpendicular to the longitudinal direction, and the length of the protective material 30. The ratio of the major axis / minor axis to the minimum external diameter (minor axis) of the outer diameter passing through the center was 2.1, and the minor axis length was 57 mm. The thickness of the central portion 34 of the protective material 30 was 9 mm, the thickness of the round portion was 7 mm, and the thickness at a position 15 mm from the side edge was 6 mm.

[0034]

REFERENCE EXAMPLE 2 Protective material 50 having a sectional shape as shown in FIG.
In order to obtain the above, a die lip 60 as shown in FIG. 7 was used. In order to obtain this protective material 50, similarly to the first embodiment, a branched low-density polyethylene resin, a cell regulator,
The anti-shrinkage agent was fed to a screw extruder. Then
The butane foaming agent was injected into the mixing section provided in the extruder, the resin and the foaming agent were mixed, and the resin was extruded after cooling and controlling the resin temperature between the extruder tip and the die. The extruded foam (protective material 50) is isolated and cooled by a mandrel similar to that shown in FIG. 3 so that the both ends are not fused, and the outer side of the foam is strongly cooled by cold air while being conveyed by a vacuum conveyor. Then, it was cut to a predetermined length to obtain a protective material 50. The density of the obtained protective material 50 is 0.046 g / cm.
³ , the protective material 5 in a cross section perpendicular to the longitudinal direction.
The ratio of the long axis / short axis of the maximum outer diameter (long axis) of the outer diameter passing through the center of 0 and the minimum outer diameter (short axis) of the outer diameter passing through the center of the protective material 50 is 1.6. The length of the short axis was 52 mm. The thickness of the central portion 34 of the protective material 50 is 9 mm,
The thickness of the round portion was 7 mm, and the thickness at a position 20 mm from the side edge (the neck portion at the locking portions 52 and 53) was 7 mm.

[0035]

As described above, the protective material according to the first aspect has a continuous crack in the longitudinal direction, the two side edges forming the crack overlap each other, and the cross section perpendicular to the longitudinal direction has a cross-sectional shape. It is a flat, tubular thermoplastic resin foam having a thicker central portion than the thickness of both side edges forming the split, and the overlapping length is from one side edge to the other side edge. 5 to 40% of the length, wherein the maximum outer diameter of the outer diameter passing through the center of the cross section is 1.3 to 5.0 times the length of the minimum outer diameter passing through the center of the cross section. Features. ADVANTAGE OF THE INVENTION According to the protective material of this invention, since the thickness of both side edges is thin, distribution cost and storage space can be reduced without becoming bulky, the required grip force is ensured because the thickness of the central part is large, and mutual protection is possible. When the overlapping side edges are expanded, the reaction force (restoring force) of the side edges increases, so that the protective material is covered by the pillars and the like, and the walls etc. which are continuous with the pillars are sandwiched by the both side edges. When it is mounted so that it is mounted, the wall or the like is firmly held by the reaction force (grip force). According to the protective material of the present invention, since the cross-sectional shape perpendicular to the longitudinal direction of the tubular thermoplastic resin foam having cracks continuous in the longitudinal direction is flat,
Since it can be stably placed on the work site and does not become bulky,
Distribution costs and storage space can be reduced, and when mounted on a protected material such as a pillar, the protective material does not protrude too much into the work space, which is advantageous in work and increases the gripping force on the protected material. . The protective material according to claim 2 is the protective material according to claim 1, wherein the open cell ratio is 4%.
0% or less. According to the present invention, the grip force can be further increased, and the cushioning property is excellent. The protective material according to claim 3 is the protective material according to claim 1 or 2, wherein the foam has an average cell diameter of 200 to 8%.
It is characterized in that it is 00 μm. According to the present invention, since the toughness is high, the grip force can be further increased, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view of a protective member according to an embodiment of the present invention, in which both side edges overlap each other.

FIG. 2 is a front view showing a lip shape of a die for forming the protective material of FIG. 1;

FIG. 3 is an enlarged perspective view of a main part showing a part of a device immediately after extrusion for forming the protective material of FIG. 1;

FIG. 4 is a perspective view showing a reference example of a protective material, in which both side edges face each other.

FIG. 5 is a front view showing a lip shape of a die for forming the protective material of FIG. 4;

FIG. 6 is a perspective view showing a reference example of a protective material, which is provided with locking portions on both side edges.

FIG. 7 is a front view showing a lip shape of a die for forming the protective material of FIG. 6;

8 is a cross-sectional view showing a state in which the protection member of FIG. 6 is attached to a protected member.

FIG. 9 is a perspective view showing an example of usage of a conventionally used building protection material.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Protective material 11, 12 Side edge 13 Split 14 Central part 15 Round part 20 Lip 30 Protective material 31, 32 Side edge 33 Split 34 Central part 35 Round part 40 Lip 50 Protective material 51, 52 Engagement part 53 Split 54 Central part 55 Round part 60 Lip 61 Enlarged part 70 Mandrel 71 Vacuum conveyor 80 H-section steel 81 Flange

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) E04G 21/30

Claims (3)

(57) [Claims] 1. A crack having a continuous crack in a longitudinal direction, both side edges forming the crack overlap each other, a cross section perpendicular to the longitudinal direction has a flat shape, and both edges forming the crack are provided. a central portion thickness is thicker cylindrical thermoplastic resin foam than the thickness, the overlapping
The length is 5 to 40 of the length from one side edge to the other side edge
%, The maximum outer diameter of the outer diameter passing through the center of the cross section is
1.3 to 5.0 times the length of the minimum outer diameter passing through the center of the cross section
Protective material, characterized in that. 2. The protective material according to claim 1, wherein an open cell ratio of the foam is 40% or less. 3. The foam has an average cell diameter of 200 to 800 μm.
3. The protective material according to claim 1, wherein m is m.