JPH06246836A - Joint part of water barrier sheet - Google Patents

Abstract

PURPOSE:To join water barrier sheets by using a joining material which is never affected by meteorological or other execution conditions at the job-site and can be stored and managed with a high safety as a joining tape. CONSTITUTION:For a joining part of water barrier sheets 2, a vulcanized rubber sheet is used. In the production of the vulcanized rubber sheet, an adhesive tape 1 loaded with a vulcanizer is chemically reacted to a primer 3 loaded with a vulcanization accelerator and left to stand at room temperature to be vulcanized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint portion of a waterproof sheet and, more particularly, to a joint portion of a waterproof sheet for civil engineering.

[0002]

2. Description of the Related Art Conventionally, vulcanized rubber sheets have been widely used for water shielding in reservoirs, reservoirs, industrial waste treatment plants and the like. The reason for this is that the vulcanized rubber sheet has good weather resistance, unevenness of the base, flexibility to follow movement, and extensibility.

Construction of the water-impermeable sheet is generally carried by transporting the water-impermeable sheet (about 1.2 m × 10 m) to the site due to the restrictions on the size of the manufacturing equipment and the handling at the construction site. The method of further joint is taken. In the field, joints using adhesives or self-adhesive tapes are commonly used.

[0004]

However, the adhesive joint has a drawback that it is susceptible to local weather conditions. Specifically, the volatilization speed of the solvent in the adhesive changes depending on the temperature during construction, etc., so the adhesive open time (after applying the adhesive to the water-blocking sheet, the water-blocking sheet is bonded and then joined). Is difficult to set. Then, if the open time is set incorrectly, there is a risk of defective adhesion. In addition, there is a risk that the adhesive strength may decrease due to dew condensation under high temperature and high humidity. further,
It is also difficult to control the application amount of the adhesive, and setting the application amount based on an operator's mistake also contributes to defective adhesion.

As a method that is not so affected by local weather conditions, there is a method in which a self-adhesive tape is adhered (adhesive) to a water-blocking sheet and the water-blocking sheet is joined via this tape. However, the joint tape must be soft to some extent in order to adhere to the water-blocking sheet, but if it is too soft, it is difficult to secure sufficient adhesive strength between the water-blocking sheets. (In general, the adhesive strength increases as the strength (shear modulus) of the adhesive increases.) As a method to solve this problem, a vulcanizing agent or a vulcanization accelerator is mixed in the joint tape in advance, and A method of ensuring adhesive strength by gradually vulcanizing the tape has been considered. (Japanese Patent Publication No. 62-320
However, in this method, it is difficult to manage the tape from the manufacturing to the construction, and in some cases, there is a risk of joint construction using the vulcanized tape, which may result in defective adhesion.

An object of the present invention is to provide a joint method for a water-impervious sheet which is not affected by local construction conditions such as weather and has high safety in terms of storage management of the joint tape.

[0007]

In order to achieve the above object, the present invention provides (1) at the lap connecting portion of a water-impervious sheet, a primer containing a vulcanization accelerator is applied to the lap surface and the lap is applied. A vulcanized rubber sheet by narrowing an adhesive tape with a vulcanizing agent in between and chemically reacting with a primer with a vulcanization accelerator to vulcanize the adhesive tape while leaving it to stand. In particular, (2) the vulcanizing agent is a quinoid-based vulcanizing agent, and the vulcanization accelerator added to the primer is a metal oxide or an organic peroxide oxidant. It is characterized by being.

[0008]

The joint portion of the water-blocking sheet of the present invention is formed by chemically reacting the adhesive tape containing the vulcanizing agent with the primer containing the vulcanization accelerator, thereby allowing the adhesive tape to stand naturally. It can be vulcanized, has no influence of local construction conditions such as weather, and can be used as a joint for water-impervious sheets with a joint material that is highly safe in terms of storage management of joint tape.

[0009]

EXAMPLE A joint tape material having the composition shown in Table 1 was kneaded with a 10-inch test roll and extruded into a tape shape with a 50 mm extruder.

[0010]

[Table 1]

The tape had a thickness of 1 mm and a width of 100 mm. In the primer formulation table, butyl rubber, carbon black, and organic peroxide (Examples only) were kneaded with a 6-inch test roll, and this was dissolved in the solvent in the table to give a primer.

FIG. 1 is a sectional view for explaining a joint portion of a water-blocking sheet according to the present invention. In FIG. 1, 1 is a joint tape, 2 is a water-blocking sheet, and 3 is a primer. The above-mentioned primer is applied to the rubber-based waterproof sheet 2 (thickness 1
5 Adhesive) After being applied to the adhesive, the water-impervious sheets 2 were joined together by a method as shown in FIG. After the joint, the change in the shear adhesive force with time (curing time) and the shear adhesive force of the jointed sheet were measured after leaving the tape for a certain period of time. The standing temperature was 20 ± 1 ° C., and the adhesive strength was measured according to JIS K6854.

The relationship between the curing time and the adhesive strength is shown in FIG. The increase in the adhesive force of the example was remarkable as compared with the comparative example. This indicates that the butyl rubber is effectively vulcanized by the primer and the adhesive strength is increased.

The relationship between the standing period and the adhesive strength is shown in FIG. The time (curing time) from the bonding of the water shield sheet 2 to the measurement of the adhesive strength was 7 days in any standing period. In the comparative example, the adhesive strength decreased as the standing period increased from January. This is because vulcanization gradually progresses after the production of the joint tape 1 and the adhesiveness to the water-blocking sheet 2 is impaired. On the other hand, in the example, since the vulcanization occurs only when the primer and the tape come into contact with each other at the time of joint, there is no decrease in the adhesive force due to leaving the tape.

The vulcanization system of butyl rubber is a sulfur vulcanization system,
Quinoid vulcanization systems and resin vulcanization systems are generally known. Among these, a quinoid vulcanization system that can be vulcanized at room temperature is suitable for vulcanization while being left to stand. Examples of the quinoid vulcanizing agent include paraquinone dioxime, paraquinone dioxime benzoate, etc., which can be appropriately selected and used depending on the vulcanization rate under natural standing and required physical properties. In addition, other polymers, fillers, plasticizers, lubricants, antiaging agents, etc. may be added in order to make the tape material excellent in practicality. The joint tape can be processed by a calendar roll or an extruder. In addition, its dimensions can ensure sufficient adhesive force between the water-impervious sheets 2,
The size is not particularly limited as long as it is economical, but generally, the thickness is 0.5 to 1.5 mm and the width is 30 to 250.
mm is preferred.

The oxidizer to be mixed with the primer may be any one having an effect of activating the quinoid vulcanizing agent when left to stand naturally, but in general, oxidizers such as lead oxide and organic peroxide are preferable. The other structure of the primer is not particularly limited as long as it improves the adhesion between the joint tape 1 and the water-blocking sheet 2, but generally, butyl rubber or the like is dissolved in an organic solvent such as toluene, hexane, or xylene. Use the one. Jointing of the waterproof sheet 2 with the primer and the joint tape 1 is performed by a general method. That is, a primer is applied to the water-impervious sheet 2, and the water-impermeable sheet 2 is attached with the joint tape 1 interposed therebetween, and then the roller is pressed from above the water-impervious sheet 2 to complete the joint. After the joint, the vulcanizing agent is activated by the oxidizing agent, and the butyl rubber is vulcanized, so that the joint of the water-impervious sheet 2 becomes stronger.

By further adhering the joint tape 1 of this embodiment with a plasticizer, a resin or the like, the tape can be jointed even in water.

[0018]

EFFECTS OF THE INVENTION According to the present invention, it is possible to joint a water-impervious sheet with a joint material that is not affected by local construction conditions such as weather and is highly safe in terms of storage management of the joint tape.

[Brief description of drawings]

FIG. 1 is a cross-sectional view for explaining a joint portion of a waterproof sheet according to the present invention.

FIG. 2 is a characteristic diagram showing a relationship between curing time and adhesive strength.

FIG. 3 is a characteristic diagram showing a relationship between a leaving period and an adhesive force.

[Explanation of symbols]

 1 Tape for joint 2 Water barrier sheet 3 Primer

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display area B29L 7:00 4F

Claims (2)

[Claims] 1. A joint portion of a water-blocking sheet formed by wrapping adjacent end portions of vulcanized rubber sheets and vulcanizing and adhering the adhesive tape between the wraps. A joint portion of a water-impervious sheet, wherein a primer containing a vulcanization accelerator is applied to the lap surface, and a vulcanizing agent is added to the adhesive tape. 2. The joint portion of the water-blocking sheet according to claim 1, wherein the vulcanizing agent is a quinoid vulcanizing agent, and the vulcanization accelerator added to the primer is a metal oxide or an organic peroxide oxidant. .