JPH035299B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for underwater jointing of waterproof sheets, and more specifically, a rubber adhesive is applied in advance to one sheet that will become the joint part of the waterproof sheets in the air, and the other sheet is It relates to a method of jointing the joint in water after pasting a sulfur-type adhesive tape. (Prior Art) Conventionally, waterproof sheets such as vulcanized rubber sheets or resin sheets have been widely used in the field of civil engineering and construction, but these waterproof sheets have dimensional restrictions depending on manufacturing equipment, and the length Even though it is possible to extend up to 200 to 300 meters, the width is at most 2 to 10 meters. Therefore, these waterproof sheets are either joined at the factory or transported to the construction site.
The reality is that the tarpaulin sheets are joined together on site. However, in the case of offshore reclamation, the method of laying joined sheets on the seabed as described above requires joining a wide area of sheets on land, transporting them by ship, and sinking them to the seabed. However, it is extremely troublesome and time-consuming work.
Therefore, underwater jointing of waterproof sheets is the most rational method for construction work in which the above-mentioned wide-area sheets are laid on the seabed or underground. Conventionally, physical fixing methods have generally been used to create underwater joints, such as the riveting method in which adhesive is sandwiched between sheet wraps and metal plates are placed on both sides of the sheet and fixed with rivets; The fastener construction method, in which the pipe is joined with a fastener, and the concrete-in-pipe method, in which the end of the sheet is inserted into the pipe and filled with concrete, have been proposed. (Problems to be solved by the invention) However, the riveting method and the pipe-in-pipe concrete method require extremely time-consuming underwater work, and the reality is that the fastner method has only been put into practical use at present, with only the equivalent of a diving suit. However, if this was applied to an underwater joint, it would be expensive, and if kept underwater for a long period of time, there would be problems with durability. The present invention deals with this situation and employs chemical fixing means instead of the physical fixing means described above, which allows for easy jointing in water and without the use of special jigs. This provides an underwater joint method that greatly improves workability. (Means for Solving the Problems) That is, the present invention is characterized in that ethylene-propylene terpolymer, butyl rubber, or a blend thereof, which has low water absorption, is attached to the end of one waterproof sheet in the air. After applying a rubber-based adhesive made of rubber and pasting a self-vulcanizing adhesive tape to the end of the other waterproof sheet, submerge the waterproof sheet in water, and remove the end of the waterproof sheet under water. The point is that the lap parts are joined by rolling pressure while overlapping them in a sandwiched state. The method of the present invention is that the rubber adhesive and adhesive tape are hardly affected by moisture, that is, the adhesive strength between the waterproof sheets does not decrease in water, but rather the adhesive strength increases as the rubber adhesive and adhesive tape harden. It was created by discovering the fact that it improves adhesiveness, and it can be said that it is distinctive in that it has shifted from the previous emphasis on adhesion only in the air to adhesion in an underwater environment. The figure is a longitudinal cross-sectional view of an underwater seat joint structure in which the underwater joint method of the present invention is implemented.
First, attach adhesive tape 3 to the edge of the sheet in the air.
One tarpaulin sheet 4 to which is attached and the other tarpaulin sheet 6 to which rubber adhesive is applied to the edge of the sheet,
Normally submerged in water 1 on the other side 2 within a water pressure of 10 atmospheres. Next, the ends of the waterproof sheet 4 and the waterproof sheet 6 are overlapped, but at this time, after removing the release paper adhering to the surface of the adhesive tape 3, the waterproof sheets 4 and 6 are rolled by rolling with a rolling pressure roller. Join 6 comrades. Each of these tasks will be performed by divers. In the present invention, the rubber adhesive 5 may be applied to the ends of the waterproof sheets 4 and 6 at a rate of 0.1 to 1.0 kg/m ² . The waterproof sheet used in the present invention is, for example, a vulcanized rubber sheet made of ethylene propylene terpolymer (EPT), butyl rubber (IIR), or a blend thereof, or a resin sheet such as EVA or PVC. In addition, adhesive tapes are naturally vulcanized and have low water absorption, such as EPT, IIR, or other adhesive tapes.
A blend of EPT and IIR is preferred, and in addition to a vulcanizing agent, vulcanization accelerator, adhesive, and softening agent, stearic acid, carbon black, inorganic filler, ZnO, etc. may be mixed as needed. It is blended. Among these, the above-mentioned vulcanizing agents include sulfur, morpholine, disulfide, phosphorus-containing polysulfide, sulfur-containing compounds such as sulfur chloride, P-quinonedioxime, P-P'-dibenzoyl quinonedioxime, etc. oxime type, or peroxide type such as α-cumyl hydroperoxide, methyl ethyl ketone peroxide, hydrogen peroxide, acetylacetone peroxide, t-butyl hydroperoxide, t-butyl peroxybenzoate, etc. The amount of vulcanizing agent used is usually 1 part by weight per 100 parts by weight of the rubbery polymer.
~6 parts by weight. In addition, vulcanization accelerators include thiazoles such as 2-mercabutobenzothiazole and dibenzothiazole disulfide, tetramethylthiuram monosulfide, tetramerthiuram disulfide, and dipentamethylenethiuram hexasulfide. Examples include thiuram type, dithiocarbamate type such as Zn-di-n-butylthiocarbamate, PbO ₂ , trimene base, etc. The amount of these vulcanization accelerators used is usually
The amount is 1 to 10 parts by weight per 100 parts by weight of the rubbery polymer. Further, as the adhesive to be mixed, aromatic hydrocarbon resins such as Petrozine (manufactured by Mitsui Petrochemicals), which is a petroleum-based hydrocarbon resin, and aliphatic cyclic hydrocarbons such as Hiretsu (manufactured by Mitsui Petrochemicals) are used. , unsaturated hydrocarbon polymers such as Escorets (manufactured by Etsu Chemical Co., Ltd.), hydrocarbon-based tackifying resins such as Taku Ace (manufactured by Mitsui Petrochemicals Co., Ltd.), and phenol resins such as phenol formaldehyde resins. The amount of these adhesives used is 30 to 100 parts by weight per 100 parts by weight of the rubbery polymer.
Also, known softeners are used with these adhesives, typical examples of which include preprocessed oil, polybutene, liquid paraffin, pine tar, and other petroleum-based high-boiling compounds. The amount of these softeners used is 30 to 150 parts by weight per 100 parts by weight of the rubbery polymer. In addition, as a compound for a self-vulcanizing adhesive tape with a relatively fast vulcanization rate, an oxime type vulcanizer such as p-quinone dioxime or P-P'-dibenzoyl quinone oxime is added to 100 parts by weight of the rubbery polymer. It is sufficient to add 1 to 2 parts by weight of a sulfurizing agent, 3 to 4 parts by weight of a vulcanization accelerator such as PbO ₂ , 30 to 100 parts by weight of an adhesive, and 30 to 150 parts by weight of a softening agent such as process oil. On the other hand, for a relatively slow natural vulcanization type adhesive tape formulation, sulfur-based vulcanization selected from sulfur, morpholine disulfide, phosphorus-containing polysulfide, sulfur chloride, etc. is used for 100 parts by weight of rubbery polymer. 1 to 3 parts by weight of an agent, 2 to 6 parts by weight of a vulcanization accelerator selected from thiazole, thiuram, or dithiocarbamate, 30 to 100 parts by weight of an adhesive,
30 to 150 parts by weight of a softening agent such as process oil may be added. This adhesive tape has an initial strength of the joint part of the waterproof sheet, that is, a self-adhesion strength of 1 to 3 kgf/25 cm.
Without this self-adhesive strength, if the joined waterproof sheets are pulled during construction of an underwater joint, the waterproof sheets will shift and change at the joint. Therefore, in order to satisfy this self-adhesive strength, 30 to 100 parts by weight of an adhesive is added to 100 parts by weight of the rubbery polymer to provide surface tack, and 30 to 150 parts by weight of a softener is added to the adhesive tape. Mooney viscosity (ML ₁ + ₅ 100℃) from 4 to
Must be in the range of 25. The thickness of this adhesive tape should be 0.5 to 2 mm; if it is more than 2 mm, a step will be created between the waterproof sheets at the joint, making them easy to peel off at the initial stage of joining, which is not preferable. On the other hand, rubber adhesives are EPT, which has low water absorption,
IIR, chlorinated butyl rubber, etc. is blended with the same vulcanizing agent, vulcanization accelerator, etc. as in the above-mentioned adhesive tape, and the composition can be naturally vulcanized by dissolving it in a normal solvent such as toluene. Liquid adhesive, 30000CPS depending on ease of application, preferably 10~
30000 CPS is good, and the solid content is preferably 8% or more, preferably 8 to 25%, from the standpoint of waterproofing effect (adhesive) in water. The coating amount of the above rubber adhesive is 0.1 to 1.0
It is about Kg/ ^m2 . In the present invention, adhesive tape is attached to the joints of one waterproof sheet, release paper is pasted thereon, and a rubber adhesive is applied to the joints of the other waterproof sheet, and then these waterproof sheets are exposed to fresh water or seawater. Submerge in water, etc. After that, the diver overlaps the joined ends of the waterproof sheets, and at the same time peels off the release paper and rolls the lap part with a rolling pressure roller. For example, it is desirable to improve the adhesive strength between the waterproof sheets and to remove moisture existing between the waterproof sheets. Moreover, as time passes, the adhesive tape and the rubber adhesive adjacent thereto vulcanize, so that the waterproof tapes adhere to each other even more firmly, making underwater joint construction extremely safe. (Example) The thickness of the rubber compound shown in Table 1 in the factory
A naturally vulcanized adhesive tape of 1.0 to 1.5 mm, width 100 mm, and Mooney viscosity 5 was formed, and after being stored at 25° C. for 2 days, it was brought to the bonding site. This adhesive tape was attached to the edge (200 mm) of a vulcanized rubber sheet made of a blend of EPT and IIR.
Release paper was attached. On the other hand, Neo Bond #110JS (manufactured by Mitsuboshi Belting Co., Ltd.) butyl rubber adhesive was applied to the edge (200 mm) of a vulcanized rubber sheet having the same formulation as above. Next, heat the above two waterproof sheets at 15-17℃ for 40℃.
The waterproof sheets were submerged in water to a depth of ~50 cm, and the ends of the waterproof sheets were overlapped and simultaneously the release paper was removed and rolled using a rolling pressure roller (0.5 kg/cm). After joining,
It was taken out of the water and subjected to a peel test. The peel test test piece was made by punching out the bonded waterproof tape to a size of 1 x 6 inches.
A T-peel test was performed at ~25°C and a speed of 50 mm/min. The results are shown in Table 2.

【table】

[Table] Each is a cohesive failure of adhesive tape or adhesive. (Effects of the Invention) As described above, according to the underwater joint construction method of the present invention, a naturally vulcanizable adhesive tape is attached to the end of one waterproof sheet, and the adhesive tape is attached to the end of the other waterproof sheet. A rubber-based adhesive is applied and the waterproof sheets are joined in an underwater environment,
As the adhesive tape and adhesive harden over time, the adhesive strength between the waterproof sheets increases, so there is no need to use physical fixing means.
In addition, the combination of adhesive tape and rubber adhesive provides sufficient initial strength immediately after joining the waterproof sheet, and even when the ends of the sheet are rolled under water, the moisture contained in the joined ends can be released to the outside. This has the effect of increasing the adhesive strength of the joint and making it easier to joint underwater.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an underwater waterproof sheet joint structure in which the underwater joint construction method of the present invention is implemented. 3... Adhesive tape, 4, 6... Waterproof sheet, 5
...Rubber adhesive.

Claims (1)

[Claims] 1. A rubbery polymer consisting of butyl rubber, ethylene-propylene terpolymer, or a blend thereof, which has low water absorption in the air, is coated with a vulcanizing agent at the end of one waterproof sheet in the air.
A rubber adhesive containing a vulcanization accelerator is applied, and a rubber adhesive made of ethylene-propylene terpolymer, butyl rubber, or a blend thereof, which has low water absorption in the air, is applied to the other end of the waterproof sheet. After attaching a self-adhesive self-vulcanizing adhesive tape containing a vulcanizing agent and a vulcanization accelerator to the polymer, both of the above waterproof sheets are submerged in water, and the ends of the above waterproof sheets are overlapped in the water. 1. An underwater jointing method for a waterproof sheet, characterized in that the lap portions are joined by rolling pressure.