JPH09174775A - Waterproofing sheet for engineering works - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a sheet excellent in pliability, properties for execution of work, heat-sealing properties, etc. SOLUTION: Inner and outer layers are constituted of a copolymer of ethylene and alpha-olefin which is obtained by using a metallocene catalyst and of which the density is 0.88-0.92g/cm<3> , the melt index 0.5-5 and Mw/Mn 1.5-5. An intermediate layer is the copolymer of the ethylene and the α-olefin which is obtained by using the metallocene catalyst and of which the density is 0.86g/cm<3> or above and less than 0.88g/cm<3> , the melt index 0.5-5 and the Mw/Mn 1.5-5, or an ethylene-vinyl acetate copolymer of which the content of vinyl acetate is 8-25wt.%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water impervious sheet for civil engineering, which is made of a specific resin and is excellent in flexibility, mechanical strength, heat sealability and workability.

[0002]

2. Description of the Related Art An ornamental pond, a water hazard on a golf course, a landfill site for a waste treatment plant, etc., has a water-blocking construction to maintain the beauty of the facility and prevent environmental pollution. For these water shield constructions, for example, rubber water shield sheets, vinyl chloride water shield sheets, high density polyethylene water shield sheets, and other civil water shield sheets are used. However, in the case of rubber-based water-impervious sheets, it is necessary to process them with an adhesive because the heat-sealing properties (heat-sealing properties) between the sheets are poor, and poor workability is pointed out. The mechanical waterproofing sheet tends to have a decrease in mechanical strength due to the decrease of the plasticizer with time, and the high density polyethylene waterproofing sheet can cope with unevenness of the terrain probably because of insufficient flexibility. However, there was a problem that construction and handling were difficult.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a water impervious sheet for civil engineering which is excellent in flexibility, mechanical strength, heat sealability and workability.

[0004]

The gist of the present invention is to provide an inner layer,
A polyolefin-based water blocking sheet for civil engineering comprising three layers, an intermediate layer and an outer layer, wherein the inner layer and the outer layer are obtained by polymerizing using a metallocene catalyst (a) ethylene and 3 to 12 carbon atoms. Copolymer with α-olefin, wherein (b) density is 0.88 g / cm ³ or more, 0.92 g
/ Cm ³ or less, (c) melt index 0.5 to 5
g / min, and (d) ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (hereinafter referred to as "Mw / Mn") is 1.5 to 5, and the polyolefin-based copolymerization weight is (E) Ethylene and α having 3 to 12 carbon atoms, which is composed of a polymer and whose intermediate layer is obtained by polymerization using a metallocene catalyst.
A copolymer with an olefin and having a (f) density of 0.
86 g / cm ³ or more, less than 0.88 g / cm ³ (g)
Melt index is 0.5 to 5 g / min, and (h) M
A polyolefin-based copolymer having a w / Mn of 1.5 to 5, or an ethylene-vinyl acetate copolymer having a vinyl acetate content of 8 to 25% by weight. Another aspect of the present invention resides in the above-mentioned polyolefin-based waterproofing sheet for civil engineering, wherein the intermediate layer has a thickness of 50 to 95% of the total thickness of the polyolefinic waterproofing sheet for civil engineering. Exist.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
In the present invention, the metallocene catalyst (also referred to as single-site catalyst or Kaminsky catalyst) is described in JP-A-3-163.
No. 088, Japanese Patent Application Laid-Open No. 7-118431, Japanese Patent Application Laid-Open No. 7-148895, etc., a catalyst composed of a metallocene-based transition metal complex and an organic aluminum compound, which is used by being supported on an inorganic substance. It may be done.

Examples of the metallocene-based transition metal compound include a transition metal selected from Group IVB (titanium, zirconium, hafnium), a cyclopentadienyl group, a substituted cyclopentadienyl group, a dicyclopentadienyl group, and a substituted diene. A cyclopentadienyl group, an indenyl group, a substituted indenyl group, a tetrahydroindenyl group, a substituted tetrahydroindenyl group, a fluorenyl group or a substituted fluorenyl group is coordinated with 1 or 2 ligands, or among these Coordinating the two groups of the above are covalently bonded, and additionally having a ligand such as a hydrogen atom, an oxygen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, and an acetylacetonato group. Is mentioned.

As the organoaluminum compound,
Alkyl aluminum and chain or cyclic aluminoxane can be mentioned, and as alkyl aluminum, triethyl aluminum, triisobutyl aluminum, dimethyl aluminum chloride, diethyl aluminum chloride, methyl aluminum dichloride, ethyl aluminum dichloride, dimethyl aluminum chloride, diisobutyl aluminum hydride, diethyl can be used. Aluminum hydride, ethylaluminum sesquichloride, etc. can be exemplified, and the chain or cyclic aluminoxane can be produced by contacting the above alkylaluminum with water. Water is added, or water of crystallization of complex salts or water of adsorption of organic or inorganic compounds It can be obtained by reacting aluminum.

Examples of the carrier for supporting the metallocene catalyst include silica gel, zeolite, diatomaceous earth and the like. As the α-olefin copolymerized with ethylene, one having 3 to 12 carbon atoms is used. Examples of such a compound include propylene, 1-butene, 1-
Pentene, 1-hexene, 1-heptene, 1-octene, 4-methyl-1-pentene, 1-decene and the like can be mentioned, and one or a mixture of two or more thereof can be used. The ratio of α-olefin to ethylene is 5 to 40% by weight.
It is preferred that

A method for producing an ethylene-α-olefin copolymer by using a metallocene catalyst is described in JP-A-56.
-18607, JP-A-58-225106, JP-A-6-336539, JP-A-7-258.
The gas phase method, the slurry method, the solution method, the high pressure ionic polymerization method, etc. as disclosed in Japanese Patent No. 481 can be exemplified. Polymerized using the above metallocene catalyst, ethylene-α-olefin copolymer (polyolefin-based copolymer), Ziegler catalyst or, compared to a polyolefin-based copolymer polymerized using a solid catalyst, flexibility and Although it has excellent mechanical strength and heat sealability, in particular, in the present invention, the density is 0.88 g in the inner layer and outer layer of the waterproof sheet for civil engineering (hereinafter, referred to as “water blocking sheet”). / Cm ³ or more, 0.92 g / cm ³ or less, a melt index of 0.5 to 5 g / min, and an Mw / Mn of 1.5 to 5 are used.

Density of 0.88 g / cm ³ or more, 0.92
g / cm ³ or less, the water-impervious and more preferably 0.89 g / cm ³ or more, 0.91 g / cm ³ less to range well in terms of workability, density is less than 0.88 g / cm ³ If the sheet is sticky and exceeds 0.91 g / cm ³ , the ability to follow uneven terrain is poor. Further, the melt index is 0.
The range of 5 to 5 g / min, and more preferably 0.8 to 2 g / min is good in terms of moldability of the water-blocking sheet, and further, Mw / Mn determined by gel permeation chromatography (GPC). Is preferably 1.5 to 5, more preferably 2 to 4 in terms of mechanical properties and heat sealability.

Further, the intermediate layer has a density of 0.86 g / c.
m ³ or more, less than 0.88 g / cm ³ , a melt index of 0.5 to 5 g / min, and a Mw / Mn of 1.5 to 5, or a vinyl acetate content of 8 to 25% by weight of ethylene-vinyl acetate copolymer is used. The density of the polyolefin-based copolymer is 0.
86 g / cm ³ or more, good flexibility when in the range of less than 0.88 g / cm ^3, also the melt index is 0.
The range of 5 to 5 g / min, and more preferably 0.8 to 2 g / min is good in terms of moldability of the water-blocking sheet, and further, Mw / Mn determined by gel permeation chromatography (GPC). It is good in terms of mechanical properties that (weight average molecular weight / number average molecular weight) is in the range of 1.5 to 5, more preferably 2 to 4.

The vinyl acetate content of the ethylene-vinyl acetate copolymer is 8 to 25% by weight, more preferably 15% by weight.
When it is in the range of 20% by weight, the transparency, flexibility and durability of the water barrier sheet are good. When the density, melt index, Mw / Mn, or vinyl acetate content of each of the above resin layers is within a predetermined range, flexibility, mechanical strength, workability,
It is possible to obtain a water barrier sheet having the best balance of performances such as heat sill properties.

Each layer of the water-blocking sheet of the present invention has a high density polyethylene (HDP) within a range not impairing its performance.
E), linear low density polyethylene (LLDPE), high pressure polyethylene (LDPE) and polypropylene (PP)
Crystalline polyolefins such as, natural rubber, various synthetic rubbers, thermoplastic elastomers, or tackifiers, cross-linking agents and various fillers such as carbon black, calcium carbonate, silica, metal fibers, carbon fibers and antioxidants, UV absorption Agents, light stabilizers, flame retardants, colorants and the like may be added as necessary. The water-impermeable sheet of the present invention preferably contains 0.1 to 10% by weight, preferably 1 to 5% by weight of carbon black for the purpose of improving weather resistance.
The waterproof sheet of the present invention can be manufactured by a multilayer T-die extrusion method, an extrusion coating method, or the like. Alternatively, each layer may be separately manufactured by a T-die extrusion method or the like and then laminated.

The total thickness of the waterproof sheet is usually 0.5 to 3 m.
m, preferably 1-2 mm. Further, it is good in terms of workability that the thickness of the intermediate layer is 50 to 95%, preferably 60 to 90% of the whole. The water-impervious sheet produced in this manner is usually wound up and stored, but the sheets may stick to each other during storage to deteriorate workability during rewinding. In order to prevent this, it is preferable to mix an inorganic filler in each layer, the inner and outer layers, or one of the layers, or to emboss both sides or one side of the water shield sheet.

[0015]

EXAMPLES The present invention will be described below based on examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

<Evaluation of Polyolefin (Co) Polymer> (1) Density: According to ASTM D1505, the density was measured by a density gradient tube method using a mixed solution of methanol / benzyl alcohol. (2) Melt index (MI): ASTM D12
38 was measured. (3) Mw / Mn: G using trichlorobenzene as a solvent
Mw and Mn were measured from a calibration curve (using standard polystyrene) using the PC method, and calculated from this.

<Evaluation of Sheet> (1) Formability: Ease of forming was evaluated when the water-blocking sheet was produced by an extruder. The evaluation criteria are as follows. ◯: The sheet could be produced without problems and was wound up. B: The sheet could be produced, but the appearance was poor. X: The sheet could not be formed. (2) Tensile test: Measured according to JIS K6301. (3) Bending stiffness: Measured according to JIS K7106.

(4) Heat-sealing property: Two water-proof sheets having a thickness of 1.5 mm were pressure-bonded using a heat sealer, and the adhesiveness of the part was evaluated. The evaluation criteria are as follows. O: Completely fused. Δ: Partially fused, but peelable by hand. X: It can be peeled with almost no force. The heat sealing was performed under the following two conditions, and the conditions were shown as Condition 1 and Condition 2. Condition 1: Temperature 150 ° C., pressure 2 kg / cm ² , time 3 seconds Condition 2: Temperature 170 ° C., pressure 3 kg / cm ² , time 5 seconds

(5) Workability: With respect to the obtained water-impervious sheet, a dent having a depth of 50 cm, a width of 1 m and a length of 2 m was dug in a field, and a sheet was applied to this dent to evaluate it. The evaluation criteria are as follows.・ Following unevenness ○ ・ ・ ・ It was possible to cope with unevenness of the terrain. Δ: It was not possible to deal with fine irregularities, and a gap was partially formed with the ground. ×: Unable to deal with unevenness, and a large gap was created between the ground and the ground.・ Workability ○ ・ ・ ・ I was able to work without problems. Δ: Sticky and poor in workability. ×: The work was difficult because the stickiness was severe.

Example 1 PF1140 manufactured by Dow Chemical Co., which is a polyolefin copolymer manufactured by using a metallocene catalyst, is used as a resin for the inner and outer layers, and EG8150 manufactured by Dow Chemical Co. is used as a resin for the intermediate layer. 3 layer T die molding machine manufactured by Plastic Technology Laboratory (intermediate layer 40 mmφ, inner and outer layers 30 for each)
mmφ), molding temperature 190 ° C, take-up speed 2m /
A water impervious sheet was produced under the condition that the total sheet thickness was 1.5 mm. The above-mentioned evaluation was performed on the obtained water-permeable sheet. The results are shown in Table 1.

Example 2 PL1840 manufactured by Dow Chemical Co., which is a polyolefin-based copolymer produced using a metallocene catalyst, is used as a resin for the inner and outer layers, and EG8100 manufactured by Dow Chemical Co. is used as a resin for the intermediate layer. Then, a water barrier sheet was prepared in the same manner as in Example 1 and evaluated. The results are shown in Table 1. Example 3 Using the same resin as in Example 1, a waterproof sheet was prepared by the same method and evaluated. The results are shown in Table 1.

Example 4 The same resin as in Example 1 was used, except that LV420 manufactured by Mitsubishi Chemical Co., Ltd., which is an ethylene-vinyl acetate copolymer, was used as the resin for the intermediate layer. A waterproof sheet was prepared by the method and evaluated. Table 2 shows the results. Example 5 A resin was used in the same manner as in Example 1 except that LV540, an ethylene-vinyl acetate copolymer, manufactured by Mitsubishi Chemical Corporation, was used as the resin for the intermediate layer, and was shielded in the same manner as in Example 1. A water sheet was prepared and evaluated. Table 2 shows the results.

Comparative Example 1 DEFD-1210 manufactured by Nippon Unicar Co., Ltd., which is a polyolefin-based copolymer produced using a Ziegler catalyst.
(Ultra low density polyethylene) is used as the resin for the inner and outer layers, and EG8100 manufactured by Dow Chemical Co., which is a polyolefin-based copolymer produced using a metallocene catalyst, is used as the resin for the intermediate layer, and the same as in Example 1. A water-impermeable sheet was prepared by the method of 1. and evaluated. The results are shown in Table 1.

Comparative Example 2 Mitsubishi Heavy Industries' 65 mmφT was manufactured by using JS015R (high-density polyethylene) manufactured by Mitsubishi Chemical Co., Ltd., which is a polyolefin-based copolymer manufactured using a Ziegler catalyst, as a resin for the inner layer (single layer). Molding temperature 19 by die molding machine
An impermeable sheet was prepared under the conditions of 0 ° C., a take-up speed of 2 m / min, and a sheet thickness of 1.5 mm, and evaluated. The results are shown in Table 1. Comparative Example 3 EG8150 manufactured by Dow Chemical Co., which is a polyolefin-based copolymer manufactured using a metallocene catalyst, is used as a resin for the inner and outer layers, and LV780 manufactured by Mitsubishi Chemical Corporation, which is an ethylene-vinyl acetate copolymer, is used as an intermediate. Using the same as the resin for the layer, a waterproof sheet was prepared in the same manner as in Example 1 and evaluated. Table 2 shows the results.

Comparative Example 4 DEFD-1210 manufactured by Nippon Unicar Co., Ltd., which is a polyolefin-based copolymer produced using a Ziegler catalyst
(Ultra-low density polyethylene) is used as the resin for the inner and outer layers and is an ethylene-vinyl acetate copolymer L manufactured by Mitsubishi Chemical Corporation.
Using V420 as the resin for the intermediate layer, a waterproof sheet was prepared in the same manner as in Example 1 and evaluated. Table 2 shows the results. Comparative Example 5 JS015R (high-density polyethylene) manufactured by Mitsubishi Chemical Co., Ltd., which is a polyolefin polymer manufactured using a Ziegler catalyst, was used as a resin for the inner and outer layers, and an ethylene-vinyl acetate copolymer Mitsubishi Chemical (stock) was used. ) LV540 manufactured as a resin was used as a resin for the intermediate layer, and a waterproof sheet was prepared in the same manner as in Example 1 and evaluated. Table 2 shows the results.

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

EFFECTS OF THE INVENTION The water-impermeable sheet of the present invention has flexibility, can cope with uneven terrain, has a good heat-sealing property, and has a large strength, so that it is extremely useful as a water-impermeable sheet for civil engineering. .

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[Procedure amendment]

[Submission date] April 10, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0004

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[0004]

The gist of the present invention is to provide an inner layer,
A polyolefin-based water blocking sheet for civil engineering comprising three layers, an intermediate layer and an outer layer, wherein the inner layer and the outer layer are obtained by polymerizing using a metallocene catalyst (a) ethylene and 3 to 12 carbon atoms. Copolymer with α-olefin, wherein (b) density is 0.88 g / cm ³ or more, 0.92 g
/ Cm ³ or less, (c) melt index is 0.5 to
5, and (d) the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) (hereinafter referred to as “Mw / Mn”) is 1.
5 to 5, which is composed of a polyolefin-based copolymer, and whose intermediate layer is obtained by polymerizing using a metallocene catalyst, of (e) ethylene and an α-olefin having 3 to 12 carbon atoms. Copolymer and (f) density is 0.86
A polyolefin-based copolymer having g / cm ³ or more and less than 0.88 g / cm ³ , (g) melt index of 0.5 to 5, and (h) Mw / Mn of 1.5 to 5. Or an ethylene-vinyl acetate copolymer having a vinyl acetate content of 8 to 25% by weight, and another aspect of the present invention resides in a water-impermeable sheet for a civil engineering civilization. Is 50 to 95% of the total thickness of the polyolefin-based waterproof sheet for civil engineering, which is included in the above-mentioned polyolefin-based waterproof sheet for civil engineering.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

A method for producing an ethylene-α-olefin copolymer by using a metallocene catalyst is described in JP-A-56.
-18607, JP-A-58-225106, JP-A-6-336539, JP-A-7-258.
The gas phase method, the slurry method, the solution method, the high pressure ionic polymerization method, etc. as disclosed in Japanese Patent No. 481 can be exemplified. Polymerized using the above metallocene catalyst, ethylene-α-olefin copolymer (polyolefin-based copolymer), Ziegler catalyst or, compared to a polyolefin-based copolymer polymerized using a solid catalyst, flexibility and Although it has excellent mechanical strength and heat sealability, in particular, in the present invention, the density is 0.88 g in the inner layer and outer layer of the waterproof sheet for civil engineering (hereinafter, referred to as “water blocking sheet”). / cm ³ or more, 0.92 g / cm ³ or less, a melt index of 0.5 to 5, and Mw / Mn uses the polyolefin-based copolymer is 1.5 to 5.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

Density of 0.88 g / cm ³ or more, 0.92
g / cm ³ or less, the water-impervious and more preferably 0.89 g / cm ³ or more, 0.91 g / cm ³ less to range well in terms of workability, density is less than 0.88 g / cm ³ If the sheet is sticky and exceeds 0.91 g / cm ³ , the ability to follow uneven terrain is poor. Further, the melt index is 0.
The range of 5 to 5, more preferably 0.8 to 2 is good in terms of the formability of the water-impermeable sheet, and further determined by gel permeation chromatography (GPC).
When Mw / Mn is in the range of 1.5 to 5, more preferably 2 to 4, it is good in terms of mechanical properties and heat sealability.

[Procedure Amendment 5]

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Further, the intermediate layer has a density of 0.86 g / c.
m ³ or more, less than 0.88 g / cm ³ , a melt index of 0.5 to 5, and a Mw / Mn of 1.5 to 5, or a polyolefin acetate having a vinyl acetate content of 8 to 25% by weight. % Ethylene-vinyl acetate copolymer is used. The density of the polyolefin-based copolymer is 0.86g
/ Cm ³ or more and less than 0.88 g / cm ³ have good flexibility and a melt index of 0.5 to
5, more preferably in the range of 0.8 to 2 in terms of moldability of the water-blocking sheet, and further, Mw determined by gel permeation chromatography (GPC).
/ Mn (weight average molecular weight / number average molecular weight) is 1.5 to
5, more preferably in the range of 2 to 4 in terms of mechanical properties.

[Procedure correction 6]

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[Correction target item name] 0026

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[0026]

[Table 1]

[Procedure amendment 7]

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[0027]

[Table 2]

Claims (2)

[Claims] 1. A water blocking sheet for civil engineering civil engineering consisting of three layers, an inner layer, an intermediate layer and an outer layer, wherein the inner layer and the outer layer are obtained by polymerization using a metallocene catalyst,
(A) a copolymer of ethylene and an α-olefin having 3 to 12 carbon atoms, wherein (b) the density is 0.88 g / cm.
³ or more and 0.92 g / cm ³ or less, (c) melt index of 0.5 to 5 g / min, and (d) ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (hereinafter, “Mw
/ Mn ") is 1.5 to 5, and the intermediate layer is obtained by polymerizing using a metallocene catalyst. (E) Ethylene and the number of carbon atoms A copolymer with 3 to 12 α-olefins, wherein (f) the density is 0.86 g / cm ³ or more, 0.88 g
/ Cm ^3, less than (g) melt index 0.5 to 5
g / min, and (h) Mw / Mn of 1.5 to 5, or a polyolefin copolymer, or an ethylene-vinyl acetate copolymer having a vinyl acetate content of 8 to 25% by weight. A water barrier sheet for polyolefin civil engineering characterized by. 2. The polyolefin-based waterproof sheet for civil engineering according to claim 1, wherein the thickness of the intermediate layer is 50 to 95% of the total thickness of the polyolefin-based waterproof sheet for civil engineering.