JPS632503Y2 - - Google Patents

Description

[Detailed description of the invention] In this invention, the edges of thick sheets of plastic are butted against each other, and a specific heat seal tape is bonded along the butting line (portion) of the thick sheets. The present invention relates to a thick sheet for waterproof construction in which the thick sheets are connected and the connected thick sheets can be bent linearly along the abutting portion.

Recently, attempts have been made to prevent water from seeping into the ground by covering irrigation rivers, reservoirs, agricultural or industrial water ponds, etc. with wide, thick plastic sheets. It's being done.

However, when using known thick sheets for waterproofing (generally having a thickness of about 1 mm or more) for irrigation rivers, reservoirs, etc.,
If you try to bend the thick sheet when constructing it at the corner of the bottom and side (slope) of a reservoir, etc., the rigidity of the thick sheet itself will prevent you from bending it into an angular shape. This may result in rounded corners or inability to form straight, well-defined creases, resulting in significant air gaps along the entire length of the corner, and thick sheets that require waterproofing. The material sometimes rose up from the surface and was not sufficient for waterproofing.

On the other hand, it is generally difficult to obtain thick plastic sheets of approximately 1 mm or more by directly molding a wide sheet from a molding machine, and the width of the thick sheet directly molded from a molding machine is approximately
The width was approximately 200 cm, so in order to manufacture thick plastic sheets with a wide width, the sheets were connected by overlapping the edges of multiple sheets and pasting them together. It is.

However, the method of bonding thick plastic sheets together is usually by heat-sealing the thick sheets, but this heat-sealing process is difficult because thick sheets have poor thermal conductivity. It is extremely difficult to do this, and in reality, it is only carried out in factories equipped with special equipment (even the wide sheets produced at these factories have a width limit of about 10 meters at most). It was not possible to easily connect long thick sheets at irrigation construction sites such as rivers and ponds.

Moreover, as mentioned above, the wide thick sheet described above cannot be bent at an angle so as not to have a radius.

Therefore, the above-mentioned attempts to waterproof irrigation systems using wide, thick plastic sheets have rarely been implemented.

The inventors were able to easily connect thick plastic sheets at the construction site, and
After studying a thick sheet that can be easily bent at an angle with straight creases to accommodate the corners of the construction site, we found that the edges of the thick plastic sheet were butted against each other. , the thick sheet to which the specific heat seal tape is bonded along the butt line (section) of the thick sheet can be bent linearly at an angle along the butt line (section), which is extremely suitable. He discovered something and completed this idea.

That is, in this invention, the linear edges of thick plastic sheets are butted against each other, and the crosslinked polyolefin layer and hot melt type adhesive are bonded so that the butt line of the thick sheets is approximately in the center. The thick sheet and the heat seal tape are joined together through the adhesive layer of the tape, and the thick sheets are attached to each other's edges. The present invention relates to a thick sheet for waterproof construction, characterized in that the connected thick sheets are connected along the abutting portions of the sheets, and the connected thick sheets can be bent linearly along the abutting lines.

In the thick sheet of this invention, the heat-sealing tape at the joint part (the part connecting the butt parts) of the thick sheets described above not only firmly connects the thick sheets, but also acts like a hinge. The above-mentioned thick sheet can be easily folded along the butt line, and a straight fold with an angle without a radius can be formed. Therefore,
The thick sheet of this invention can be used for irrigation rivers, reservoirs, etc.
Bottom and sides (slopes) of agricultural or industrial water ponds, etc.
By aligning the angled folds with the corners of the waterproof sheet, large gaps and voids will not be formed between the corners of rivers, reservoirs, etc. and the applied thick sheet. ,Also,
The thick sheet does not stand up too much from the surface near the corners where waterproofing is to be performed, and the entire surface of the thick sheet can be brought into close contact with the bottom and sides of rivers, reservoirs, etc., so that stored water, running water, etc. A thick sheet for waterproofing is an excellent way to prevent water from seeping into the interior.

This thick sheet is relatively simple to manufacture and can be manufactured without subjecting the plastic sheet to severe thermal history by using a specific heat-sealing tape, and can also be manufactured at the construction site. .

Below, we will discuss this idea with reference to the drawings.
I will explain in more detail.

FIG. 1 is a perspective view showing an example of the thick sheet of this invention.

FIG. 2 is a perspective view illustrating a folded state of the thick sheet of this invention.

Figure 3 shows that using the thick sheet of this invention,
FIG. 2 is a perspective view illustrating a situation in which an irrigation ditch is waterproofed.

As shown in Fig. 1, the thick sheet of this invention has straight edges (sides) of plastic thick sheets 1 and 1' butted against each other, and the butt line 6 of the thick sheets A heat-sealing tape 2, which will be described later, is overlaid on the abutted portion so that it is approximately in the center, and the thick sheets 1, 1' are attached via the adhesive layer 4 of the tape 2.
and heat seal tape 2 are joined together, and the thick sheets 1 and 1' are connected to each other along their edges, and the connected thick sheets are connected to the butt line 6 at the connection point. This is a thick sheet for waterproofing construction that can be bent straight along the line at an angle.

The heat seal tape used in this invention is
Any belt-shaped tape having at least a two-layer structure consisting of a crosslinked polyolefin layer 3 and a hot melt type adhesive layer 4 may be used.

The adhesive layer 4 comprises, for example, an adhesive component having a melting point in the range of about 50 to 110°C, in particular in the range of about 60 to 100°C, such as a tackifier, a polymeric component, It is preferable that the adhesive layer 3 is a hot melt type adhesive layer containing at least 10% by weight, particularly 20 to 100% by weight of other fillers.

The hot melt type adhesive layer 4 may be mainly formed of a heat-melting adhesive (hot melt type adhesive) containing an olefin (co)polymer and a tackifier. Preferably, the adhesion force to the surface of the thick sheet is preferably about 2.0 to 30 Kg/cm, especially about 4.0 to 25 Kg/cm in heat bonding performed by sufficiently heating to a high temperature of about 100 to 250°C.
It is preferable that the adhesive be made of a suitable adhesive.

Examples of olefin-based (co)polymers used in such adhesives include polyethylene,
Polypropylene, polyvinyl chloride, ethylene/vinyl acetate copolymer, ethylene/propylene copolymer, ethylene/ethyl acrylate copolymer, ethylene/methyl acrylate copolymer, ethylene/ethyl methacrylate copolymer, etc. (meth)acrylate copolymer, or ethylene/acrylic acid copolymer, ethylene/
Ethylene (meth) such as methacrylic acid copolymer
Acrylic acid copolymers, etc., and modified products of these polymers (e.g., maleated polyethylene,
maleated polypropylene, etc.), which may be used alone or as a mixture of two or more types.

Further, the tackifier used in the above adhesive can be arbitrarily selected from tackifiers commonly used in known hot melt type adhesives, and examples of the tackifier include:
Examples include rosin or rosin derivatives, pinene resins, coumaron resins, coumaron-indene resins, other aliphatic or alicyclic hydrocarbon resins, and aromatic hydrocarbon resins, among which melting points are about 110°C or less. , especially one with a temperature of about 60 to 100°C is optimal.

In addition to the above-mentioned adhesive components, the adhesive may also contain inorganic fillers such as talc, charcoal, silica, alumina, mica, and carbon black, or antioxidants, colorants, and softeners. The following additives may be included.

In this invention, as the adhesive, for example,
Polyolefin or modified polyolefin (especially ethylene polymer) about 50-95% by weight, especially 60-90%
weight% and melting point below about 110℃, especially about 60-100℃
A hot-melt type adhesive containing as a main component about 5 to 50% by weight, especially 10 to 40% by weight of a tackifier, is heated to a high temperature of about 100 to 250°C for thermal bonding. It is particularly suitable because the adhesive strength after adhesion is sufficiently high.

Note that the adhesive layer 4 of the heat seal tape
The polymer components are moderately cross-linked by irradiation with high-energy rays such as electron beams, This is particularly suitable for improving adhesive strength to thick plastic sheets, and the degree of crosslinking is approximately 5 to 50%, particularly 10 to 40%, as expressed by the gel fraction described below. It is best that the

The above gel fraction is calculated by putting the sample to be measured in xylene, dissolving it under reflux at a temperature of about 130°C for about 10 hours, and calculating the weight (Ag) of the sample that did not dissolve in the xylene. , is the value obtained by dividing the value obtained by dividing by the weight (Bg) of all the samples used, multiplied by 100.

Gel fraction=(A/B)×100 (%) The crosslinked polyolefin layer 3 of the heat seal tape 2 used in this invention may be formed by forming a polyolefin film or sheet (thickness: about 100-3000 μm, particularly 150-2500 μm) by extrusion molding or the like from a polyolefin resin composition containing an olefin polymer such as polyethylene, polypropylene, ethylene-propylene copolymer, or ethylene-vinyl acetate copolymer as the main component, and containing other polymers, plasticizers, antioxidants, flame retardants, fillers (calcium carbonate, silica, alumina, mica, carbon black, etc.), colorants, etc., and then crosslinking the polyolefin film or sheet with electron beams, X-rays, α-rays, β-rays, γ-rays, or the like to obtain a crosslinked polyolefin film or sheet. The degree of crosslinking of the crosslinked polyolefin film or sheet, as shown in the above-mentioned gel fraction, is about 20-90%, particularly 30-80%.
% is preferable.

The heat-sealing tape 2 can be produced, for example, by forming a polyolefin film or sheet by extrusion molding from the polyolefin resin composition described above, and coating the film or sheet by a lamination method in which an adhesive is extruded to form an adhesive layer. The laminate (sheet) can then be crosslinked from the adhesive layer side using an electron beam or the like to produce a tape consisting of a partially crosslinked adhesive layer and a crosslinked polyolefin layer. In addition, a crosslinked polyolefin film or sheet and an adhesive sheet are separately manufactured, and a laminate (sheet) is formed by bonding them together, and then the adhesive layer is irradiated with an electron beam or the like to form a laminate (sheet). It can also be produced by crosslinking.

In this invention, the thickness of the crosslinked polyolefin layer 3 and adhesive layer 4 in the heat seal tape 2 is not particularly limited, but for example, the thickness of the adhesive layer 4 is approximately 0.1 to 3.0. mm, especially 0.1
The thickness of the cross-linked polyolefin layer 3 is approximately 0.1-4.0 mm, particularly approximately 0.1-3.0 mm, and the ratio of the thickness of the adhesive layer 4 and the cross-linked polyolefin layer 3 is approximately 2.5 mm. , about 1:10 to 3:1, and the thickness of the entire heat seal tape is
It should be about 0.5 to 5 mm, especially about 1 to 4 mm.
It is preferred because it has flexibility for convenient handling or because it has sufficient mechanical strength after connection. The width of the heat seal tape 2 (the length in the direction perpendicular to the longitudinal direction of the tape 2) is approximately 5
~50cm, particularly preferably about 10~50cm.

In addition, in this invention, the heat seal tape 2 further includes a heat-resistant and/or flame-resistant reinforcing material layer (for example, a glass cloth layer, an aluminum foil layer, an asbestos layer, etc.) on the outside of the crosslinked polyolefin layer 3. may be provided.

The thick plastic sheet used in this invention has sufficient durability, weather resistance, and mechanical strength to be installed in irrigation rivers, reservoirs, etc.
Any type of plastic sheet may be used as long as it is waterproof, such as polyethylene, polypropylene, polyvinyl chloride, ethylene/vinyl acetate copolymer, ethylene/propylene copolymer, etc. It is molded from a resin composition whose main component is an olefin polymer, and has a thickness of about 0.5 to 5 mm, especially about 1 to 4 mm, and a width of about 50 mm.
A polyolefin sheet (especially a sheet of ethylene polymer such as polyethylene or ethylene/vinyl acetate copolymer) having a length of ~200 cm is suitable.

In this invention, it is preferable that the abutting portions 5 at the ends of the thick sheets 1 and 1' be so close that the edges of the thick sheets touch each other. As long as the distance between the edges of the sheets 1 and 1' is within about 5 mm, particularly within 3 mm, the edges of the thick sheets may be separated a little from each other.

The thick sheet of this invention can be manufactured by, for example, placing thick sheets made of plastic with their edges to be connected butted against each other, and heating the thick sheet with the above-mentioned crosslinked polyolefin layer 3 and adhesive layer 4. While overlapping the seal tape 2 along the butt line 6 of the edges of the thick sheets 1, 1' to be connected, apply the adhesive layer 4 of the heat seal tape 2 and/or the thick sheets 1, 1'. Preheat the surfaces of the edges to be connected, e.g. with the flame of a gas burner, to about 50-110°C, especially
Heat seal tape 2 at low temperature of 60~100℃
A method of temporarily bonding (and/or adhesion) the thick sheets 1, 1' and the heat seal tape 2 by heating them to a high temperature of about 100 to 250 degrees Celsius to heat-bond the thick sheets 1 and 1' and the heat seal tape 2, thereby connecting the thick sheets. is appropriate.

In the above-mentioned method, the supply of the heat-sealing tape 2 is carried out in the operation of overlapping the heat-sealing tape 2 along the abutting portions of the thick sheets 1 and 1' of the edges to be connected. It is preferable to do this under tension.

In addition, in the above-mentioned method, in the work of temporarily adhering the heat-sealing tape, for example, a pressing roll (for example, a metal roll, a rubber roll, a sponge roll, etc.) or a It is desirable to apply a pressing force by a combination of these rolls, because it allows the heat-sealing tape 2 to be temporarily bonded uniformly over the entire surface to the edge of the thick polyolefin sheet to be connected.

In the above manufacturing method, following the temporary adhesion of the heat seal tape 2 described above, the temporarily adhered heat seal tape 2 is heated from its outer surface to a temperature of approximately 100 to 250°C using, for example, the flame of a gas burner. Heat the thick plastic sheet to a high temperature, apply pressing force with the same pressing roll as described above (especially elastic roll, sponge roll, etc.),
1' edge and the heat seal tape 2 by approx.
It is preferable to carry out thermal bonding (fusion) at a high temperature of ~250°C, particularly 110~200°C.

In the above manufacturing method, the preheating and high-temperature heating are not only performed using the flame of the gas burner, but also using other known heating means, such as an electric heater, an infrared heater, another hot wire heater,
The pressing may be performed using a heating roll, an electric iron, spraying a heating medium, or the like, and other pressing means may also be used for the pressing roll.

The thick sheet of this invention can be manufactured by an extremely simple operation of connecting thick sheets of plastic using the heat-sealing tape described above.

Therefore, the thick sheet of this invention can be used at construction sites such as rivers and reservoirs for irrigation by connecting thick plastic sheets of 2 m or less in width one after another to form a long wide sheet and constructing the facility at the same time. I can do it.

As shown in FIG. 2, the thick sheet of this invention has a
Since the heat-sealing tapes 2 are overlapped and strongly bonded via the adhesive layer 4, this connecting portion has sufficient strength, and
Along the butt line, it can be folded at a crease 7 with no radius but with an angle, and for this purpose, as shown in FIG.
Corner parts 10a and 10b formed by a and 9b
Thick sheets of this invention (three thick plastic sheets 1a, 1b, 1c are attached to heat seal tape 2a,
2b) is a thick sheet for waterproofing construction that can be folded and attached tightly for construction purposes.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of the thick sheet of this invention. FIG. 2 is a perspective view illustrating a folded state of the thick sheet of this invention. Third
The figure is a perspective view illustrating a situation in which an irrigation ditch is waterproofed using the thick sheet of this invention. 1,1'; Thick plastic sheet,
2; Heat seal tape, 3; Crosslinked polyolefin layer, 4; Adhesive layer, 5; Butt portion, 6; Butt line, 7; Crease.

Claims (1)

[Scope of utility model registration request] The straight edges of thick sheets of plastic are butted against each other, and a heat treatment consisting of a cross-linked polyolefin layer and a hot-melt adhesive layer is applied so that the butt line of the thick sheets is approximately at the center. A sealing tape is overlapped at the abutting portion, and the thick sheet and the heat sealing tape are integrally joined via the adhesive layer of the tape, and the thick sheets are connected along the abutting portions of each other's edges. At the same time,
A thick sheet for waterproof construction, characterized in that the connected thick sheets can be bent linearly along the butt line.