JP3359967B2 - Self-healing composite sheet for water barrier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a waste disposal site, an artificial reservoir, a river embankment, a roof of a reinforced concrete building,
Waterproof sheet for civil engineering construction laid to prevent water leakage in subway station buildings and underground buried objects, etc., which prevents the expansion of holes caused by contact with sharp objects during construction or use, and The present invention relates to a water-blocking self-healing composite sheet capable of automatically closing a hole.

[0002]

2. Description of the Related Art Water-blocking sheets for civil engineering construction to be installed on the roofs of the above-mentioned waste disposal sites and reinforced concrete buildings to prevent water leakage include polyvinyl chloride, polyethylene, and the like.
Sheets made of synthetic polymer materials such as synthetic rubber and asphalt are often used. The water-impervious sheets made of these synthetic polymer materials are all 100 to 600
% Of elongation, which makes it easier to fit the unevenness of the laying surface than metal-based impermeable sheets and can reduce the damage due to external force. When touched, tearing was likely to occur.

In order to prevent the tear, a composite sheet in which the above-mentioned synthetic polymer material sheet is reinforced with a fiber sheet such as a woven or non-woven fabric has been developed, but the composite sheet has a tensile elongation of 20% or less. Therefore, it is difficult to fit the unevenness of the laying surface as compared with the synthetic polymer material water-impervious sheet, and in particular, when the sheet hits an acute-angled object in a state where a tensile force is applied, tearing is likely to occur.

[0004] Therefore, composite sheets using a knitted fabric having a higher elongation than a woven or non-woven fabric have been developed. When it comes into contact with sharp objects, stress concentrates on the contact area and a hole is made, and contaminants in waste flow out from this hole together with water, causing groundwater and rivers to be polluted and having a serious adverse effect on the surrounding environment There was a problem.

[0005] In order to solve these problems, a water-insulating sheet made of a normal rubber or resin is provided on both front and back surfaces of a water-swellable sheet made of a water-swellable rubber or a water-swellable resin having a property of expanding when contacted with water. The outer sheet is laminated, and the obtained composite sheet is laid at a desired location. Under normal conditions where the composite sheet is not damaged, the outer sheet protects the water-expandable sheet to achieve the purpose of water shielding. In the case where a hole occurs in the composite sheet, the water-expandable sheet comes into contact with water intruding from the hole, thereby expanding the water-expandable sheet to close the hole and prevent water from entering. . However, in this case, since the water-swellable rubber or the water-swellable resin is used, there is a problem that the entire composite sheet becomes expensive.

[0006]

SUMMARY OF THE INVENTION The present invention is to improve a water-impervious sheet for civil engineering and construction made of the above-mentioned synthetic polymer material, and to remove holes formed during construction and use of the sheet by expensive water-absorbing material. Closes instantly without using a polymer, maintains its water-stopping effect, and maintains a good fit to the unevenness of the laying surface to enhance the reliability as a water-blocking sheet, and further reduces production costs. It makes it possible.

[0007]

The present invention has a water-crosslinking property in a slightly vulcanized state before immersion in water and a tensile strength of 10 kgf / cm ² or more after immersion in water at 70 ° C. for 24 hours. on both sides of the viscoelastic sheet shielding usually consists of a rubber or resin is a composite sheet obtained by laminating outer sheet of water, the
That the viscoelastic sheet of
A polymer based on contact with water
Slow-acting silane coupling agent that can be bridged, yes
Machine tin compound and carbon black, process oil
Manufactured by blending other additives , test for initial thickness t ₀
Thickness 10 minutes after applying 10kgf / cm ² load to the material
Is t, the equation “τ = (t ₀ −t) 100 / t ₀ ”
Is 15 to 45%, the breaking elongation of the composite sheet is 50% or more, and the tear strength is 10 kg.
It is a self-healing composite sheet for water shielding, characterized by having a f / cm or more. The composite sheet can be reinforced with a fiber sheet.

The viscoelastic sheet of the present invention is a polymer such as a rubber or a thermoplastic resin which has water crosslinkability and viscoelasticity and becomes an elastomer by water crosslinking, and has a tensile strength of 70 ° C. After 24 hours immersion in
It is at least 0 kgf / cm ² , preferably at least 20 kgf / cm ² . If the tensile strength is less than 10 kgf / cm ² , the hole sealing effect will not be maintained.

The polymer constituting the viscoelastic sheet may be a rubber or a thermoplastic resin which becomes an elastomer by water crosslinking, for example, a halogen-based polymer such as uncrosslinked halogenated IIR, halogenated EPDM, halogenated PE or CSM. A mercapto-based, vinyl-based or other slow-acting silane coupling agent and an organotin compound (eg, di-n-butyltin dilaurate) capable of crosslinking the polymer upon contact with water, and carbon black;
It is produced by blending process oil and other additives.

In this case, the preferred amount of the silane coupling agent is 1 to 2 times the halogen content in the halogen-based polymer. If the amount is less than 1, the appropriate water crosslinking can be obtained. On the other hand, if it exceeds twice, crosslinking proceeds in the processing step, and molding becomes difficult. The preferred amount of the organotin compound is 5 to 20% of the silane coupling agent. If the amount is less than 5%, the catalytic effect is insufficient, and if it exceeds 20%, the effect of increasing the amount is not obtained.
It is uneconomical.

In the present invention, the viscoelastic sheet made of the polymer is composited with the water-shielding outer sheet in a slightly vulcanized state before immersion in water. Has a viscoelasticity, and refers to a state in which the flowability or plasticity due to external force is slightly reduced compared to before the crosslinking, and 10 minutes after applying a load of 10 kgf / cm ² to the sample having the initial thickness t ₀ Assuming that the thickness is t, the plasticity coefficient τ defined by the equation τ = (t ₀ −t) 100 / t ₀ is 15 to 45, particularly 20 to
40 is preferred. If the plasticity coefficient τ is less than 15%,
When the sheet is perforated, the fluidity is low and self-sealing is not possible. On the other hand, if it exceeds 45%, the strength is insufficient. To move and become partially thin.

The slightly vulcanized viscoelastic sheet can be produced by substituting a part of the uncrosslinked halogen-based polymer with another partially crosslinked polymer (for example, a peroxide crosslinked product). In this case, a halogen-based polymer other than bromine, such as chlorinated I
It is preferred to use IR and to use a chlorinated polymer, for example a chlorinated IIR, as the partially crosslinked polymer. The amount of the partially crosslinked polymer is preferably 10 to 30%, more preferably 10% to the total weight of the polymer used (total amount of the uncrosslinked halogen-based polymer and the partially crosslinked polymer).
If it is less than 30%, the above-mentioned plasticity coefficient τ exceeds 45% and the strength is insufficient. Conversely, if it exceeds 30%, the plasticity coefficient τ becomes 15%.
% And the self-sealing function is reduced.

Further, the viscoelastic sheet in the slightly vulcanized state is
A part of the slow-acting silane coupling agent added to the unvulcanized halogen-based polymer (excluding the bromine-based polymer) may be partially replaced with a fast-acting silane coupling agent (for example, amino Silane coupling agent)
Can also be produced by substituting The preferable addition amount of the fast-acting silane coupling agent is 10 to 30% of the total addition amount of the silane coupling agent. When the addition amount is less than 10%, the plasticity coefficient τ is 45%.
%, The fluidity is insufficiently suppressed, and if it exceeds 30%, the effect of maintaining the self-sealing property cannot be obtained.

Further, the viscoelastic sheet in the slightly vulcanized state is
As the uncrosslinked halogen-based polymer, a halogen-based polymer having a relatively slow reaction, that is, a halogen-based polymer other than a bromine-based polymer, preferably a chlorinated IIR is used. It can also be produced by adding a small amount of a base polymer, preferably a brominated IIR. In this case, the preferable addition amount of the bromine-based polymer is 5 to 30% based on the total amount of the bromine-based polymer and the halogen-based polymer other than the bromine-based polymer. When the addition amount is less than 5%, the plasticity coefficient τ is 45%.
If it exceeds 30%, the fluidity is insufficiently suppressed, and if it exceeds 30%, the self-sealing function becomes insufficient and the effect of maintaining the sealing property cannot be obtained.

The outer sheet laminated on both the front and back surfaces of the viscoelastic sheet has a water barrier property and protects the viscoelastic sheet of the intermediate layer, and has an elastic modulus of 3 to 500 kgf /.
cm ² and a thickness of 0.5 to 20 mm are preferable. The outer sheet can be formed of PVC, high-density polyethylene, low-density polyethylene, cross-linked polyethylene, chlorinated polyethylene, EVA, or another olefin-based resin.

The above outer sheet is vulcanized independently,
Although it can be laminated on a viscoelastic sheet by adhesion, it can be formed into a sheet, then overlaid on the viscoelastic sheet in an unvulcanized state, and then vulcanized and integrated. And this invention composites by laminating the said viscoelastic sheet | seat and the outer surface sheet of the front and back, or reinforcing this laminated sheet with a fiber sheet, and making the elongation at break of the whole composite sheet 50% or more. , Tear strength 10kgf / cm
As described above, the fiber sheet may be a woven or knitted fabric, and its constituent fibers are natural fibers,
Any of a semi-synthetic fiber and a synthetic fiber may be used. The above-mentioned fiber sheet can be laminated on the surface of the outer sheet, can be provided in the outer sheet or embedded in the viscoelastic sheet, and can be interposed at the boundary surface between the outer sheet and the viscoelastic sheet. be able to.

[0017]

The self-healing composite sheet for water shielding according to the present invention has a water-crosslinking property and is formed by laminating a water-shielding outer sheet on both front and back surfaces of a viscoelastic sheet in a slightly vulcanized state. It is laid to prevent water leakage at the waste disposal site and other desired places as in the case of the conventional water-impervious sheet, and at that time, it is added appropriately with an adhesive or the like in the length direction and the width direction according to the width of the construction site. Area. In this case, since the elongation at break of the composite sheet is 50% or more and the tear strength is 10 kgf / cm or more, it is easy to fit the unevenness of the laying surface, and the breakage due to the operation at the time of construction is prevented, and the rock on the laying surface is prevented. When it comes into contact with sharp-angled objects such as stones and crushed stones, it is hard to break, and furthermore, expansion of the damaged portion is prevented.

However, since a water-blocking outer sheet made of a normal rubber or resin is laminated on both the front and back surfaces of the viscoelastic sheet, under normal conditions until the composite sheet is broken, The viscoelastic sheet is protected by the sheet, and the water-shielding of the entire composite sheet is maintained. If a hole is tentatively formed by the unevenness of the laying surface or a sharp object in the waste, the hole is momentarily closed by the viscoelasticity of the viscoelastic sheet in a slightly vulcanized state. When the viscoelastic sheet comes into contact with water that intrudes from, the crosslinking of the viscoelastic sheet progresses, and the tensile strength increases.Therefore, the expansion of the hole due to subsequent uneven settlement or other external force is prevented,
The water stopping effect is maintained.

However, the viscoelastic sheet was placed in water at 70 ° C. for 24 hours.
If the tensile strength after immersion for less than 10 kgf / cm ² , the hole sealing effect cannot be maintained. In addition, the degree of vulcanization of the viscoelastic sheet is lower than that in the slightly vulcanized state, and the plasticity coefficient τ is 45%.
When it exceeds, the strength is insufficient, and a part of the viscoelastic sheet moves in the front and back outer sheets due to pressurization during use, and becomes partially thin. On the other hand, when the degree of vulcanization is too advanced and the plasticity coefficient τ is less than 15%, the fluidity when a hole is formed in the sheet is so low that self-healing becomes impossible.

When the elongation at break of the composite sheet is less than 50%, the composite sheet is liable to be damaged due to unevenness of the laying surface, and at a waste disposal site due to unevenness of the waste. The tear strength is 10kg
If it is less than f / cm, the damaged part or hole will expand. And when the above composite sheet is reinforced with a fiber sheet,
The above elongation at break and tear strength are easily obtained. When the fiber sheet is interposed at the boundary between the viscoelastic sheet and the outer sheet, the number of steps is reduced, which is advantageous in terms of productivity.

[0021]

【Example】

Example 1 As shown in FIG. 1, the water-impermeable self-healing composite of Example 1 in which a water-impervious outer sheet 11, a viscoelastic sheet 12, a fiber sheet 13, and an outer sheet 11 similar to the above were laminated in order from the top. Sheet 10 was produced. Upper and lower outer sheets 11
Was formed into a sheet having a thickness of 0.7 mm by EPDM. The viscoelastic sheet 12 was prepared by kneading the following components with a Banbury mixer, cooling the mixture with air, and then using a sheet extruder to form a sheet having a thickness of 1.0 mm. In addition, the fiber sheet 13 is a circular knitted fabric (weight per unit area: 270 g / weight) of a jersey structure composed of crimped nylon yarn (140 denier).
m ² ) was used. Then, the unvulcanized outer sheet 1
1. An unvulcanized viscoelastic sheet 12, a fiber sheet 13 and an unvulcanized outer sheet 11 are superimposed, and the outer sheet 11 is vulcanized at 160 ° C. for 30 minutes by applying a surface pressure of 5 kgf / cm ² , At the same time, the viscoelastic sheet 12 and the fiber sheet 13 were integrated by bonding.

Table 1 Chlorinated butyl rubber 80 parts Partially cross-linked chlorinated butyl rubber 20 parts Polybutene 50 parts Carbon black HAF 80 parts Process oil 30 parts Polyethylene powder 5 parts Mercapto silane coupling agent 10 parts Organotin compound 1 part

Example 2 In Example 1, the compounding amount of the chlorinated butyl rubber was increased to 100 parts, the compounding of the partially cross-linked chlorinated butyl rubber was omitted, and 20% of the mercapto-based silane coupling agent was replaced with a quick-acting compound. A self-healing composite sheet 10 for water barrier of Example 2 was manufactured in the same manner as in Example 1 except that the amino-based silane coupling agent was substituted.

Example 3 The procedure of Example 1 was repeated, except that the chlorinated butyl rubber in Example 1 was increased to 90 parts and 10 parts of brominated butyl rubber was used instead of 20 parts of partially crosslinked chlorinated butyl rubber. The self-healing composite sheet 10 for waterproofing of No. 3 was manufactured.

Example 4 The self-repair for water barrier of Example 4 was carried out in the same manner as in Example 1 except that the fiber sheet 13 of Example 1 was omitted and a polyethylene sheet having a thickness of 1.0 mm was used as the outer sheet 11. The composite sheet 10 was produced.

Comparative Examples 1 and 2 A composite sheet of Comparative Example 1 was produced in the same manner as in Example 1 except that the silane coupling agent and the organotin compound of Example 1 were omitted. A composite sheet of Comparative Example 2 was produced in the same manner as in Example 1, except that the total amount of the chlorinated butyl rubber and the partially crosslinked chlorinated butyl rubber in Example 1 was replaced with unvulcanized brominated butyl rubber.

With respect to the composite sheets of Examples 1 to 4 and Comparative Examples 1 and 2, the plasticity coefficient of the viscoelastic sheet
The tensile strength before immersion in water, the tensile strength after immersion in water at 70 ° C. for 24 hours, the elongation at break and the tear strength of the composite sheet were measured. The plasticity coefficient τ was determined by applying a pressure of 10 kgf / cm ² to a sample having a diameter of 45 mm and an initial height of 12 mm using a hydraulic cylinder and measuring the height t after 10 minutes.
mm.

Further, a disk having a diameter of 260 mm is cut out from each of the composite sheets 10 of the above Examples and Comparative Examples to form a test piece, and six bolt holes (diameter of 18.2 mm) are formed along a 220 mm diameter circle inside the periphery. The test piece 10a was overlaid with a 14-mesh wire net 15 and fixed on a test stand 16 with a holding ring 17, a bolt 18 and a nut 19, as shown in FIG. Then, a water supply pipe 20 was connected to a hole provided at the center of the test table 16.

A nail (diameter 2.5 mm, length 14.4 mm) 21 is pierced into the test piece 10 a from above the wire mesh 15, and in this state, high-pressure water having a pressure of 5 kgf / cm ² is supplied from the water supply pipe 20. Then, the test piece was sent between the test piece 10a and the test table 16 and visually inspected for water leakage after 15 minutes. Further, high-pressure water having a pressure of 5 kgf / cm ² was supplied between the test piece 10a before the nail was pierced and the test table 16, and after 168 hours, the test piece 10a was nailed from above the wire mesh 15 to the test piece 10a. Was visually inspected for water leakage.

The test results are shown in Table 2 below. However, the tensile strength after immersion is the tensile strength after immersion in 70 ° C. water for 24 hours. In addition, the results of the water stoppage test were marked with 水 when no water leakage was observed with the naked eye, marked with じ when oozing was observed, and marked × when leakage was clearly observed.

Table 2 Example Comparative Example No. 1 2 3 4 1 2 Viscoelastic sheet Plasticity coefficient (%) 32 30 25 25 50 12 Tensile strength before immersion (kgf / cm ² ) 10 10 15 15 4 50 Tensile after immersion Strength (kgf / cm ² ) 28 23 22 22 4 50 Composite sheet Elongation at break (%) 120 120 120 400 130 100 Tear strength (kgf / cm) 36 35 33 32 30 34 Water stop test After 15 minutes 〇 〇 〇 〇 △ × After 168 hours 〇 〇 〇 〇 × ×

As shown in Table 2 above, Examples 1 to 4
Has a plasticity coefficient in the range of 15 to 45%,
Since the tensile strength after immersion is 10 kgf / cm ² or more, the result of the water stoppage test is good.
There was no water leakage after 68 hours. On the other hand, in Comparative Example 1, since the viscoelastic sheet was unvulcanized because it deviated from the slightly vulcanized state, its plasticity was excessive, and it did not have water crosslinkability. In any of the following cases, the results were insufficient, and Comparative Example 2 was out of the slightly vulcanized state and was in the vulcanized state. Therefore, the results of the water stoppage test were poor, and no self-sealing performance was observed.

[0033]

As described above, the invention described in claim 1 is in a slightly vulcanized state before immersion in water, and is in water at 70 ° C.
This is a composite sheet obtained by laminating a water-shielding outer sheet made of a normal rubber or resin on both front and back surfaces of a viscoelastic sheet having a water-crosslinking property having a tensile strength of 10 kgf / cm ² or more after immersion for a time. The elongation at break of the composite sheet is 50% or more,
Since it is a self-healing composite sheet for waterproofing, which has a tear strength of 10 kgf / cm or more, it can be used as a waterproofing sheet for civil engineering construction to prevent water leakage at waste disposal sites, It has good fit to the unevenness of the laying surface, and has excellent self-healing properties of holes generated during construction and use, and the viscoelastic sheet comes into contact with water leakage to promote crosslinking and increase tensile strength. In addition, the water stopping effect is maintained, the reliability as a water shielding sheet is improved, and the production cost can be reduced because an expensive water-absorbing polymer is not used.

In the second aspect of the present invention, the composite sheet of the first aspect is reinforced with a fiber sheet. The elongation at break and tear strength can be easily obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment.

FIG. 2 is a cross-sectional view of a water leak test apparatus.

[Explanation of symbols]

 10: Self-healing composite sheet for water shielding 10a: Test piece 11: Outer sheet 12: Viscoelastic sheet 13: Fiber sheet 15: Wire mesh 16: Test bench 17: Holding ring 20: Water supply pipe 21: Nail

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-6-286062 (JP, A) JP-A-6-255035 (JP, A) JP-A-6-2866063 (JP, A) JP-A-5-28 254062 (JP, A) JP-A-2-232245 (JP, A) JP-A-7-52292 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 1/00-35 / 00 E04B 3/12 B09B 1/00

Claims (2)

(57) [Claims] 1. A viscoelastic sheet which is in a slightly vulcanized state before immersion in water and has a water-crosslinking property having a tensile strength of 10 kgf / cm ² or more after immersion in water at 70 ° C. for 24 hours. a composite sheet of the outer sheet of water-blocking of rubber or resin formed by laminating the above-mentioned viscoelastic sheet due to water crosslinking
The halogen-based polymer which becomes an elastomer
Is a long-acting system that can be cross-linked by contact with water.
Run coupling agents, organotin compounds and carbon nanotubes
Manufactured by blending racks, process oils and other additives
And a load of 10 kgf / cm ² was applied to the sample having the initial thickness t _0.
When the thickness after 10 minutes is t, the expression “τ = (t
₀₋ t) 100 / t ₀ ”is 1
5 to 45%, and the elongation at break of the composite sheet is 50%
As described above, the self-healing composite sheet for waterproofing has a tear strength of 10 kgf / cm or more. 2. A viscoelastic sheet which is in a slightly vulcanized state before immersion in water and has a water-crosslinking property having a tensile strength of 10 kgf / cm ² or more after immersion in water at 70 ° C. for 24 hours. the shield made of rubber or resin by laminating outer sheet of water, and a composite sheet comprising a reinforced fiber sheet, said tacky
Halogenated elastic sheet becomes elastomer by water crosslinking
The polymer is cross-linked by contact with water.
Slow-acting silane coupling agents that can be
Compounds and carbon black, process oils
Manufactured by blending other additives, the sample with initial thickness t ₀
A thickness of 10 minutes after applying a load of 10 kgf / cm ² to t
Is defined by the equation “τ = (t ₀ −t) 100 / t ₀ ”.
Defined plasticity coefficient τ is 15 to 45%, the elongation at break of the composite sheet is 50% or more, and the tear strength is 10 kgf / cm.
A self-healing composite sheet for impermeable water characterized by the above.