JPS6232098B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for adhering waterproof sheets, and more particularly, to a method for adhering vulcanized synthetic rubber waterproof sheets together for use in water-blocking water reservoirs, reservoirs, treatment ponds, rivers, and the like. In the case of joining vulcanized rubber sheets, conventionally the vulcanized rubber sheets were molded to a certain width and thickness in a factory and transported to the construction site, where the vulcanized rubber sheets were joined together. The bonding material used was generally a solvent-based adhesive. However, when using this solvent-based adhesive, there are constraints such as a predetermined application amount, open time, and appropriate pressure bonding, but these conditions are largely influenced by the environmental conditions during work. For example, in strong winds, adhesion is inhibited by adhesion of sand and dust; in high temperatures, the open time is shortened, resulting in poor adhesion due to over-drying; and in low temperatures, the open time becomes longer, affecting construction efficiency. In times of high humidity, condensation water may adhere to the adhesive surface, resulting in poor adhesion, so it was necessary to fully understand the environmental conditions. In addition, there are many other causes of adhesion failure, such as variations in adhesive strength due to uneven coating and poor adhesion due to insufficient rolling pressure. These adhesion failures manifest themselves as phenomena directly caused by water leakage, such as lifting of joints at corners, curling of joint ends, and peeling. In order to improve these points, the applicant first interposed a naturally vulcanized type of unvulcanized rubber as an adhesive tape between the lap parts of the tarpaulin sheet, and naturally vulcanized the adhesive sheet. However, when using such adhesive tape, the joint structure of the waterproof sheet is limited to lap joints, making it difficult to obtain other joint structures. The range of use for adhesive tape is narrow, and the adhesive tape itself tends to stiffen and deform due to elongation, making it difficult to obtain the desired adhesive performance.Furthermore, in areas with large residual strain after installation, the shrinkage rate increases, making it difficult to bond. There were cases where it became a defective part, and there was still plenty of room for improvement. Thus, the present invention solves these drawbacks by improving the structure of the adhesive tape, making it possible to perform not only lap joining but also butt joining of waterproof sheets, and improving construction efficiency by preventing deformation of the adhesive tape. , and the purpose is to firmly bond the waterproof sheet and increase the water-blocking effect. That is, the feature of the present invention is that a rubbery polymer made of ethylene-propylene terpolymer, butyl rubber, or a blend thereof contains a vulcanizing agent, a vulcanization accelerator, etc., and has a Mooney viscosity (M L ₁₊₅ , 100°C).
An adhesive tape made by laminating and adhering a naturally vulcanized adhesive layer with a self-adhesive property of 5 to 20 and a base material of a vulcanized rubber sheet made of ethylene-propylene terpolymer, butyl rubber, or a blend thereof.
A method of bonding waterproof sheets by laminating waterproof sheets made of vulcanized synthetic rubber at the butt or lap portions and spanning both sheets, and vulcanizing the adhesive layer of the adhesive tape on site. be. Hereinafter, specific embodiments of the bonding method of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows an example of the present invention, in which both vulcanized rubber sheets (waterproof sheets) 1 and 1' to be adhered are brought into abutting state, and an adhesive layer 3 is preliminarily applied across both sheets 1 and 1'. An adhesive tape 2 in which a base material 4 of a vulcanized rubber sheet is laminated and bonded is placed, and the joint is rolled and bonded using a roller or the like. FIG. 2 shows another embodiment of the method of the present invention, in which waterproof sheets 1 and 1' are simply wrapped, and an adhesive tape 2 is formed by laminating an adhesive layer 3 and a base material 4 of a vulcanized rubber sheet. The case is shown in which the above-mentioned sheets 1 and 1' are bonded together so as to straddle them. Therefore, the base material 4 of the adhesive tape used in each of the above cases is a vulcanized rubber sheet made of ethylene-propylene terpolymer, butyl rubber, or a blend thereof, which has excellent weather resistance, and the adhesive layer 3 is made of ethylene-propylene terpolymer, butyl rubber, or a blend thereof. - A rubbery polymer consisting of propylene terpolymer (EPDM), butyl rubber (IIR) or a blend thereof, with a vulcanizing agent,
In addition to a vulcanization accelerator, adhesive, and softener, stearic acid, carbon black inorganic filler, ZnO, etc. are mixed and blended as needed. Among these, the above-mentioned vulcanizing agents include sulfur and morpholine. Sulfur-based compounds consisting of sulfur-containing compounds such as disulfide, phosphorus-containing polysulfide, sulfur chloride, P-quinone dioxime, P-P-dibenzoyl. Oxime type such as quinone dioxime, or peroxide type such as α-cumyl hydroperoxide, methylene ethyl ketone peroxide, hydrogen peroxide, acetylacetone peroxide, t-butyl hydroperoxide, t-butal peroxypenzoate, etc. When used, these vulcanizing agents should be used in an amount of 1 part by weight per 100 parts by weight of the rubbery polymer.
~6 parts by weight are used. Further, as the vulcanization accelerator, 2-mercaptobenzothiazole, dibenzothiazole. Thiazoles such as disulfide, tetramethylthiuram. Monosulfide, tetramethylthiuram. Disulfide, dipentamethylenethiuram. Thiuram series such as hexasulfide, or Zn-di-
There are dithiocarbates such as n-butyldithiocarbamate, PbO ₂ , trimene base, etc., and the amount of these vulcanization accelerators used is 2 to 10 parts by weight per 100 parts by weight of the rubbery polymer. Further, as adhesives to be mixed, aromatic hydrocarbon resins such as Petrozine (manufactured by Mitsui Petrochemicals), which are usually petroleum-based hydrocarbon resins, and aliphatic cyclic hydrocarbons such as Hiretsu (manufactured by Mitsui Petrochemicals) are used. , unsaturated hydrocarbon polymers such as Escorets (manufactured by Etsutsu Chemical Co., Ltd.), hydrocarbon-based adhesive resins such as Tatsuku Ace (manufactured by Mitsui Petrochemicals Co., Ltd.), and phenol resins such as phenol formaldehyde resin. The adhesive is suitably used in an amount of about 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 process 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. The adhesive layer 3 of the adhesive tape used here is a naturally vulcanized type made of the above-mentioned composition, and has a particularly high initial adhesion strength with the waterproof sheet 1, that is, self-adhesion strength after the joint is rolled with a roller or the like. 1.0
Approximately 3.0Kg/25cm should be generated, and without this self-adhesive force, when the joined waterproof sheets are wrapped or stretched during construction, the waterproof sheets will shift and deform at the joints. Therefore, in order to satisfy this self-adhesive strength, the adhesive must be made of a rubbery polymer.
Add 30 to 100 parts by weight to 100 parts by weight to give surface tack, and further add 30 to 150 parts of a softener to make the Mooney viscosity of the adhesive layer (M L ₁₊₅ 100℃) in the range of 5 to 20. That is essential. This is because with this Mooney viscosity, even if dirt, sand, etc. adhere to the joint surface of the waterproof sheet, the adhesive layer will surround these foreign substances, and the foreign substances will not penetrate into the adhesive layer. This is because the adhesive strength between the waterproof sheet and the adhesive tape is not affected much. The thickness of this adhesive tape 2 is 0.5 to 2.0 mm and 2 mm.
If this is the case, it is not preferable because a difference in level between the waterproof sheet and the waterproof sheet will be created at the joint, making it easy to peel off at the initial stage of joining. Among them, the thickness of adhesive layer 3 is 0.5~
2.0 mm, preferably 0.5 to 1.5 mm. The waterproof sheet 1 used in the method of the present invention is preferably made of a material having excellent weather resistance, such as ethylene-propylene terpolymer, butyl rubber, or a blend thereof. However, since the adhesive tape 2 used in the method of the present invention is made by laminating the base material 4 of a vulcanized sheet and the adhesive layer 3, it is less deformed and easier to handle than an adhesive tape with only an adhesive layer. Therefore, construction efficiency is good. Furthermore, this adhesive tape can be used not only for lap butt joint structures of waterproof sheets, and has the advantage of being extremely versatile. Example 1 The adhesive layer composition whose composition ratio is shown in Table 1 below (the composition of this example is in parentheses) was prepared with a thickness of 0.8 mm and a width of 0.8 mm.
120mm, Mooney viscosity (M L ₁₊₅ , 100℃) 9 tape molded into 1mm thick EPDM/IIR
The center of the adhesive tape laminated on a vulcanized synthetic rubber sheet (see Table 1) is EPDM/
An adherend consisting of an IIR synthetic rubber vulcanized sheet is
It was installed from the top so that it was in the area where the sheets met, and rolled with a roller at a linear pressure of 0.5 kg/cm.

[Table] To conduct a peel test on the above-obtained bonded waterproof sheet, a test piece was made by punching out a 1 x 6 inch piece, and this was tested using a tensile tester at a peel rate of 50.
mm/min and a measurement temperature of 20 to 25°C according to the T-peel test. As a result, the initial peel adhesion was 2.5Kg/25mm, and the adhesion over time under storage conditions of 80℃ gear oven and 70℃ warm water, as well as after exposure when the sample was mounted at 45 degrees south. The forces were as shown in Figures 3 and 4, respectively. Next, attach the waterproof sheets 1, 1' to the hook-shaped model 5 made of mortar as shown in Fig. 5, attach them to the joints with adhesive tape 2, and after exposing them, remove the raised parts of the joint corners. When the condition was investigated, the results shown in Table 3 were obtained.

[Table] Example 2 Next, a solvent-based naturally vulcanizing butyl adhesive was applied to the lap part (100 mm) of a waterproof sheet made of the same vulcanized rubber as in Example 1 to a thickness of 0.4 to 0.5 mm. ,
Roller compaction with 30 minutes open time (linear pressure 0.5Kg/
cm) (Comparative Example 1), the same adhesive tape as the adhesive layer composition shown in Example 1 was interposed on the lap of Comparative Example 1, and roller rolling pressure (linear pressure 0.5 kg /cm) (Comparative Example 2) and the method of Example 1 were used to carry out on-site construction, and the workability of each case was compared.
The results are shown in Table 4. The construction period was from September to October in Japan (maximum outdoor surface temperature 56-64°C).

[Table] As can be seen from the above examples, the bonding method of the present invention uses a shape-retaining adhesive tape consisting of a naturally vulcanized adhesive layer and a vulcanized rubber sheet, making it easier to handle during construction. In addition, construction efficiency is further improved by reducing mistakes during construction, and it is also possible to join waterproof sheets not only by lap joints but also by butt joints, especially with the butt joint method. Because the adhesive tape is simply pasted across both sheets, the construction time is much shorter than the method of interposing a solvent-based adhesive or adhesive tape in the lap area, and it is significantly superior to conventional methods for adhering waterproof sheets. No improvement,
This is a highly practical method.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of a waterproof sheet joint according to the bonding method of the present invention, FIG. 2 is a cross-sectional view of a waterproof sheet joint showing a modification of the present invention, and FIG. 3 is a cross-sectional view of a waterproof sheet joint according to the adhesive method of the present invention. Figure 4 shows the changes in peel adhesion strength of the waterproof sheet obtained in Example 1 when stored in a gear oven at 80°C and in hot water at 70°C. FIG. 5 is a graph showing changes in adhesive strength over time during exposure, and is a perspective view showing the state of adhesion of the waterproof sheet to the corner of the base in Example 1. 1, 1'... Waterproof sheet, 2... Adhesive tape, 3...
Adhesive layer, 4... base material.

Claims (1)

[Claims] 1 A rubbery polymer consisting of ethylene-propylene-terpolymer, butyl rubber, or a blend thereof, containing a vulcanizing agent, a vulcanization accelerator, etc., with a Mooney viscosity (M L ₁₊₅ , 100°C) of 5 to 20 and self-adhesion. A waterproof sheet made of vulcanized rubber is prepared by laminating and adhering a naturally vulcanized adhesive layer with a base material of a vulcanized rubber sheet made of ethylene-propylene terpolymer, butyl rubber, or a blend thereof. A method for adhering a waterproof sheet, characterized in that the waterproof sheets are bonded by laminating both sheets in a state where they are straddled at the abutting portion or lap portion, and naturally vulcanizing the adhesive layer of the adhesive tape.