JPH0222110B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure-sensitive adhesive sealing material useful as a sealing material for civil engineering and construction. More specifically, the present invention applies pressure to the sealing materials or to the primer-treated surface by applying or pasting a non-adhesive pressure-sensitive adhesive on the surface of the compression recovery elastic body and the water-swellable rubber alone or in combination. The present invention relates to a sealing material that exhibits strong adhesive properties only when it is exposed to water.

The composition of sealing materials for civil engineering and construction can be roughly divided into those made by laminating unvulcanized rubber onto a compression-resilient elastic body (Japanese Patent Publication No. 52-1223), and water-swellable rubber (Japanese Patent Publication No. 57-1989).
158279, 55-3424, 58-18256), combination of water-swellable rubber and unvulcanized rubber (JP-A-57-57773, 57-
61077), etc. However, when unvulcanized rubber is used as an adhesive, due to its tackiness, for example, when used as an adhesive for a sealant of a segment of the shield construction method, it may cause damage to the segment to which the sealant is attached. During assembly, the sealing materials come into contact with each other and adhere to each other before the segments are assembled at predetermined positions, and the sealing materials come off from the seal grooves, causing water leakage, because they stick together at the predetermined positions.

In addition, when water-swellable rubber is used alone as a sealing material, the water-stopping effect is only due to the expansion pressure, and therefore, when water pressure is applied, sagging, slippage, etc. occur, and a complete water-stopping effect cannot be expected.

In general, pressure-sensitive adhesives require an appropriate viscosity in order to fully adhere to the adhered surface even with weak pressure such as finger pressure, and to increase the true contact surface based on microscopic observation (edited by Japan Adhesive Association, Adhesive Handbook)
However, the non-adhesive pressure-sensitive adhesive used in the present invention has no tackiness and does not exhibit adhesive properties with weak pressure such as finger pressure, and is not compatible with civil engineering and construction materials such as steel and cement concrete. It does not exhibit adhesive properties unless it is primed, and even if the adhesive surface, that is, the primer treated surface or the sealing material surface, is wet with water, it exhibits strong adhesive force by applying pressure.

Pressure-sensitive adhesives, which have viscosity and can be applied to the surface to be adhered to even with weak pressure, exhibiting adhesive strength on a wide range of adherends, are effectively used in duct tape, cellophane tape, etc.; When used as an adhesive for sealing materials in buildings, etc., there are various disadvantages.

Sealing materials for civil engineering and construction cannot exhibit their performance as water-stopping materials unless they are present at predetermined locations, such as in seal grooves of segments in shield construction methods or joints of humid pipes used in sewer pipes. When a pressure-sensitive adhesive with tackiness is used as an adhesive for a sealing material for civil engineering and construction, due to its tackiness, when it comes into contact with segments, fume pipes, etc., before the sealing material is installed in the designated position, the adhesiveness may decrease. In actual work sites, there are many cases where the sealant is installed in a position other than its intended position, causing water leakage.

The non-tacky pressure sensitive adhesive used in the present invention is
Softening point 60 of one or more selected from polyvinyl butyral and ethylene vinyl acetate copolymer
To 100 parts by weight of thermoplastic resin at ~120°C, 10 to 500 parts by weight, preferably 10 to 500 parts by weight of one or more terpenes, preferably hydrogenated terpene resins and coumaron indene resins, are added as an adhesion imparting agent. 20～
200 parts by weight, and 5 to 500 parts by weight, preferably 10 to 300 parts by weight, of a plasticizer are added and kneaded.
Thermoplastic resins, tackifiers that impart tackiness when pressure is applied, and plasticizers can be used singly or in multiple combinations, but when used in multiple combinations, the total amount must be within the above range. Don't go out of range. Further, an appropriate amount of an inorganic filler such as cement, talc, clay, calcium carbonate, etc. may be added and used.

The above plasticizers include phosphoric acid esters such as tricresyl phosphate and octyl-diphenyl phosphate; adipic acid esters such as dioctyl adipate and didecyl adipate; dibutyl sebacate and dioctyl sebacate. Typical sebacic acid esters; azelaic acid esters represented by dioctyl azelate and dihexyl azelate; citric acid esters represented by triethyl citrate and acetyl tributyl citrate; methyl phthalyl ethyl glycol and butylphthalyl butyl glycolate Glycolic acid esters represented by; aliphatic carboxylic acid esters represented by methyl acetyl ricinolate and butyl stearate; polyesters represented by polypropylene adipate and polypropylene sebacate; epoxidized soybean oil and epoxy butyl stearate Epoxy plasticizers such as chlorinated paraffins and chlorinated fatty acid esters; Alkylene glycol plasticizers such as butyl cellosolve and ethyl carbitol; Polyhydric plasticizers such as polyethylene glycol and polypropylene glycol Alcohol-based plasticizers; petroleum-based plasticizers represented by liquid paraffin and dodecylbenzene; polybutenes represented by polybutene and hydrogenated polybutene; sulfonamide-based plasticizers represented by toluenesulfonamide and N-methylbenzenesulfonamide Examples include phthalate ester plasticizers represented by dioctyl phthalate and dibutyl phthalate.

The pressure-sensitive adhesive sealing material of the present invention can be produced by applying or laminating a kneaded product of the above composition or a sheet-like product of the kneaded product onto the surface (usually both sides) of a core material. . As the core material, a compression-resilient elastic body, water-swellable rubber, or a composite thereof is preferably used.

Compression resilient elastic bodies include, for example, synthetic rubbers such as natural rubber, chloroprene rubber, and urethane rubber, elastomers such as soft vinyl chloride, and ethylene-vinyl acetate copolymers, and foams thereof.
Tensile strength according to JISK6301 (vulcanized rubber testing method) is 1
Kg/cm ² or more, or those with a hardness of 1 Kg/cm ² to 10 Kg/cm ² when compressed at 50% according to JIS A9514 (hard urethane foam insulation material compression test method) can be used.

Examples of water-swellable rubber include butyl rubber, natural rubber, styrene-butadiene rubber, polyisoprene rubber, polybutadiene rubber, chloroprene rubber,
Urethane rubber, ethylene-vinyl acetate copolymer,
Elastomers such as anhydrous silicic acid, hydrated silicic acid,
Powders such as calcium silicate, bentonite, polyvinyl alcohol, crosslinked sodium, potassium, and ammonium salts of isobutylene-maleic anhydride copolymer, crosslinked sodium polyacrylate, and as necessary carbon black, calcium carbonate, clay, etc. It is a composition obtained by kneading general rubber additives such as inorganic fillers, oil, stearic acid, and anti-aging agents, and those having a water expansion ratio of about 1.2 to 10 times are preferably used.

The attached drawings are cross-sectional views illustrating the structure of the pressure-sensitive adhesive sealing material of the present invention, in which FIG. 1 shows a compression-resilient elastic body 2 coated with a non-adhesive pressure-sensitive adhesive 1 on both sides, and FIG. Figure 3 shows a non-adhesive pressure-sensitive adhesive 1 applied to both sides of a water-swellable rubber 3, and a non-adhesive pressure-sensitive adhesive 1 applied to both sides of a composite (laminate) of a compression resilient elastic body 2 and a water-swellable rubber 3. A pressure-sensitive adhesive 1 was applied.

When applying the pressure-sensitive adhesive sealing material of the present invention, it is necessary to apply a primer in advance to the object, ie, the portion to which the sealing material for civil engineering and construction is applied, such as a humid pipe or segment. Primer is a rubber adhesive and generally has the following composition.

Elastomer 30-50 Resin 30-50 Filler 10-40 Plasticizer 1-6 Anti-aging agent 0.2-0.4 Vulcanizing agent 2-10 Vulcanization accelerator 0.5-2 Organic solvent 65-80 Examples of the elastomer include natural rubber, Synthetic isoprene rubber, recycled rubber, SBR, polyisobutylene, CR, NBR, etc., and resins such as rosin, its derivatives, petroleum resins, thermosetting and thermoplastic phenolic resins, t-butylphenol resin, terpene-modified phenolic resin, etc. However, examples of fillers include carbon black, silicates,
Calcium carbonate, clay-based, etc. are used as plasticizers, such as polybutenes, phthalic acid-based, and petroleum-based process oils, etc. As anti-aging agents, such as aromatic amines, phenol derivatives, quinones, etc. are used as vulcanizing agents. For example, sulfur, metal oxides, phenolic resins, etc. are used as vulcanization accelerators, polysulfur compounds such as dithiocarbomates are used as vulcanization accelerators, and aromatic solvents such as toluene and xylene are used as organic solvents. Examples include petroleum-based substances such as n-hexane, unleaded gasoline, mineral spirits, etc., ester-based substances such as ethyl acetate, and ketone-based substances such as acetone, MEK, MIBK, etc.

The non-adhesive pressure-sensitive adhesive of the present invention exhibits adhesive properties only when high pressure is applied, so it is a thermoplastic material with higher intermolecular attraction than elastomers, which are the main components of general pressure-sensitive adhesives. It uses resin. Therefore, the adhesive strength is high, and when used as an adhesive for segment sealing material, it can completely prevent the core material from shifting due to water pressure, which is the case when unvulcanized rubber is used as an adhesive. .

If the mixing ratio of the thermoplastic resin and the adhesion promoter is less than 10 parts by weight to 100 parts by weight of the thermoplastic resin, the adhesion will decrease, and if it exceeds 500 parts by weight, viscosity will occur and the adhesion will deteriorate. This is not preferable because it also reduces performance.

In addition, the type and amount of plasticizer used differs depending on the type of resin used, but thermoplastic resin
If the amount is less than 5 parts by weight per 100 parts by weight, the non-adhesive pressure-sensitive adhesive will not undergo deformation or minute flow even when high pressure is applied, and will not cause wetting with the adherend, resulting in poor adhesion. If more than 500 parts by weight is added, it is not preferable because it becomes sticky and at the same time weakens the intermolecular attraction and reduces the adhesive force.

Since the pressure-sensitive adhesive sealing material of the present invention uses a pressure-sensitive adhesive that does not have viscosity as its adhesive layer, for example, when it is used as a sealing material for a segment of a shield method, the sealing material cannot be used. Even if the sealants come into contact with each other during assembly of pasted segments, they will not adhere, and strong adhesion will only occur once the pressure from bolt tightening or propulsion jack pressure has subsided after the segments have been assembled in place. It is something that shows strength. In addition, this adhesive strength does not decrease even if the adhesive or primer surface is wet with water, making it easy to manage the segments at the assembly site. It is also possible to use water as a lubricant. Further, as the lubricant, inorganic powder such as cement, talc, clay, etc. may be used.

Next, the present invention will be specifically explained with reference to Examples.

The primer used in each example has the following composition (parts by weight).

Polychloroprene rubber 100 Calcined magnesia 4 Zinc white 5 Anti-aging agent 2 Acetone 300 Example 1 [Compression resilient elastic body] Urethane rubber foam Tensile strength 8Kg/cm ² Hardness at 50% compression 5Kg/cm ² [ Non-adhesive adhesive] Polyvinyl butyral 100 parts by weight Hydrogenated terpene resin 30 parts by weight Tricresyl phosphate 20 parts by weight Use a chloroprene rubber adhesive on both sides of the above 8 mm x 20 mm x 920 mm urethane rubber foam to make a 1 mm adhesive.
A sealing material having the structure shown in FIG. 1 was prepared by pasting the above-mentioned non-adhesive adhesive in the form of a tape measuring 20 mm x 920 mm. The sealing material groove 4 of the flange type pressure tester shown in Figs. 4 and 5 is coated with a primer in advance, dried, and filled with water. The sealing material A is bonded to both flanges by overlapping 10 mm of both ends and pressing. Stack them and tighten bolt 5 until the distance between both flanges is 0mm. Next, water pressure is applied from the water inlet 6 to expel the air inside from the air vent 7, and while applying water pressure of 3 kg/cm ² , loosen the bolts 5 until the distance between both flanges becomes 5 mm, and after 3 hours have passed, turn off the water pressure. After removing it and tightening it until the distance between both flanges was 0 mm, I immediately loosened the bolts while applying water pressure of 3 kg/cm ² so that the distance between the flanges was 5 mm.

Although the flange was opened and closed 10 times in this manner, no water leakage was observed.

In order to confirm whether the sealing material exerts sufficient adhesion even if the surface of the test piece coated with brimer is leaking with water, a non-stick pressure-sensitive adhesive (0.5 mm x 25 mm x 12.5 mm) was submerged in water. ) between the test pieces.
After applying a pressure of 10Kg/ ^cm2 for 5 minutes, JIS K6850
(Tensile shear adhesive strength test of adhesives) The tensile shear adhesive strength was measured according to the method. The result is 12
It was Kg/ ^cm2 .

Note that no adhesion occurred when the adhesion conditions were 0.5 Kg/cm ² for 5 minutes.

Example 2 [Compression resilient elastic body] Chloroprene rubber foam Tensile strength 10 Kg/cm ² Hardness at 50% compression 8 Kg/cm ² [Non-adhesive adhesive] Ethylene-vinyl acetate 100 parts by weight Coumaron indene resin 30 parts by weight Dioctyl phthalate 10 parts by weight Calcium carbonate 80 parts By weight Similarly to Example 1, a 1 mm x 20 mm x 920 mm tape-like material was formed using a chloroprene adhesive on both sides of the above 6 mm x 20 mm x 920 mm chloroprene rubber foam. A sealing material having the structure shown in FIG. 1 was created by pasting the above-mentioned non-adhesive.

A pressure test similar to that in Example 1 was conducted on this sealing material, but no water leakage was observed.

The result of the adhesion test was 11Kg/cm ² .

When the bonding conditions are 0.5Kg/cm ² for 5 minutes,
No adhesion occurred.

Example 3 [Compression resilient elastic body] Chloroprene rubber foam Tensile strength 10Kg/cm ² Hardness at 50% compression 8Kg/cm ² [Non-adhesive adhesive] Polyvinyl butyral resin 100 parts by weight Hydrogenated terpene resin 30 〃 Tricresyl phosphate 80 〃 Triflumal butyl phosphate 8 〃 Portland cement 130 〃 [Water-swellable rubber] Aquatite (manufactured by CI Kasei Co., Ltd.) The above chloroprene rubber foam of 2 mm x 20 mm x 920 mm and 1 mm x 20 mm x 920 mm By pasting the above water-swellable rubber using a chloroprene adhesive, and pasting the above non-adhesive adhesive in the form of a 1 mm x 20 mm x 920 mm tape on both sides using a chloroprene adhesive, A sealing material having the structure shown in FIG. 3 was prepared.

When the same pressure test as in Example 1 was conducted,
Water leakage was observed when the flange spacing was 3mm. However, 24 hours later, the water leak had stopped. Therefore, I opened the flanges to 5 mm, but
No water leakage was observed. Although the opening and closing operations were repeated 10 times while applying water pressure, no water leakage was observed.

The result of the adhesion test was 14Kg/cm ² .

When the bonding conditions are 0.5Kg/cm ² for 5 minutes,
No adhesion occurred.

Example 4 The sealing material of Example 3 was cut to a width of 12.5 mm and a length of 25 mm, and a primer was applied to the adhesive part of the test piece according to JIS K6850. After drying, the adhesive side of the sealing material was applied to the primer-treated surface with 10 kg of / ^cm2 pressure for 5 minutes, and then press the two pieces together so that the adhesive side bonded to the test piece and the opposite adhesive side face each other with a 1mm gap between them.
Fixed in water. After being left in water for 24 hours, the water-swellable rubber of the sealant expanded and the adhesive surfaces came into contact, and the tensile shear adhesive strength was measured.

As a result, the adhesive strength was 5 Kg/cm ² , and the fractured surface was a water-swellable rubber layer.

Comparative example Natural rubber 100 parts by weight Polyterpene resin 80 〃 Benzophenone 3 〃 The above mixture was applied to a test piece in an amount of 25 mm x 12.5 mm x 0.2 mm, and the test pieces were overlapped to give a weight of 0.5 Kg/cm ²
JISK9850 for the pressure applied for 5 minutes.
A tensile shear adhesion test was conducted in accordance with . The result was 3Kg/cm ² .

[Brief explanation of drawings]

1, 2 and 3 are sectional views showing embodiments of the sealing material of the present invention, respectively. 4 and 5 show a pressure tester, in which FIG. 4 is a side view thereof, and FIG. 5 is a plan view of the back surface of its top cover. In the figure, 1 is a non-adhesive pressure-sensitive adhesive, 2 is a compression resilient elastic body, 3 is a water-expandable rubber, 4 is a seal groove, 5 is a bolt, 6 is a water inlet, 7 is an air vent,
A is a sealing material test piece.

Claims (1)

[Scope of Claims] 1 (1) 100 parts by weight of one or more thermoplastic resins with a softening point of 60 to 120°C selected from polyvinyl butyral and ethylene vinyl acetate copolymers, (2) terpenes and 10 to 500 parts by weight of one or more adhesion promoters selected from malonindene resins and
(3) Non-adhesive, consisting of a mixture of 5 to 500 parts by weight of plasticizer, which does not exhibit adhesion with weak pressure such as finger pressure, and does not exhibit adhesion to the adherend unless treated with a primer, and the adhesive surface is A pressure-sensitive adhesive sealing material characterized in that a pressure-sensitive adhesive that exhibits adhesive properties even when wet with water is applied to the surface of a core material. 2. The non-adhesive pressure-sensitive adhesive sealing material according to claim 1, wherein the core material is a compression resilient elastic body. 3 The core material has a water expansion ratio of 1.2 to 10 in linear expansion ratio.
The non-adhesive pressure-sensitive adhesive sealing material according to claim 1, which is double water-swellable rubber. 4. The non-adhesive pressure-sensitive adhesive sealing material according to claim 1, wherein the core material is a composite of a compression-resilient elastic body and water-swellable rubber.