JPS61166873A - Adhesive for waterproofing sheet - Google Patents

Abstract

PURPOSE:The titled adhesive useful for bonding between a concrete material and a waterproofing sheet without requiring a solvent when it is used, consisting of a hydroxyl group-containing liquid diene polymer, a polyisocyanate compound and a bituminous substance. CONSTITUTION:The aimed adhesive consisting of (A) a hydroxyl group- containing liquid diene polymer [preferably 4-12C diene (co)polymer, such as polybutadiene, etc.], (B) a polyisocyanate compound (e.g., diphenylmethane diisocyanate, etc.), and (C) a bituminous substance (preferably straight asphalt). The ratio of the NCO group of the component B to the OH group of the component A is preferably 1.5-10.0.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an adhesive for a waterproof sheet, and more particularly to an adhesive for a waterproof sheet that does not require a solvent during use and has good adhesive properties.

[Technical background of the invention and its problems 1] In order to protect the outer surface of a concrete structure from erosion caused by rainwater, it is common to attach a waterproof sheet to this surface. In recent years, the structural forms of concrete structures have become extremely diverse, and there is therefore a demand for such waterproof sheets that are rich in diversity and can follow these various structural forms. Therefore, plastic sheets such as polyethylene, plastic foam sheets, asphalt sheets mixed with rubber, etc. are used. As the adhesive for attaching these waterproof sheets to the outer surface of concrete structures, chloroprene-based adhesive rubber glue is often used because of its compatibility with such sheet materials.

Such adhesives are solvent-based adhesives that harden by evaporation of the solvent, and when used, they must be dissolved in a solvent such as benzene or toluene to form a solution with a predetermined concentration.

However, these adhesives generally do not have very high adhesive strength, and the solvent does not evaporate quickly, especially in cold weather such as winter, so the adhesive does not harden sufficiently, resulting in an unsatisfactory result. There is a problem in that sufficient adhesive strength cannot be obtained.

OBJECTS OF THE INVENTION] An object of the present invention is to solve these conventional problems, to provide an adhesive for waterproof sheets that does not require a solvent during use, and has extremely high adhesive strength.

[Summary of the Invention] In the course of intensive research to achieve the above object, the present inventors discovered an adhesive that does not require a solvent when used, and that We focused on a composition containing a hydroxyl group-containing liquid diene polymer as a main component as a composition suitable for adhesion between a structure and a waterproof sheet as described above. The present invention was completed after confirming that when such a composition is used as an adhesive for waterproof sheets, the adhesive strength is significantly improved compared to conventional adhesives.

That is, the waterproof sheet adhesive of the present invention is characterized by comprising a hydroxyl group-containing liquid diene polymer, a polyisocyanate compound, and a bituminous substance.

There are no particular restrictions on the waterproof sheet to which the waterproof sheet adhesive of the present invention can be applied, but 1 usually polyethylene sheets,
Suitable examples include foamed polyethylene sheets, asphalt sheets, asphalt sheets compounded with rubber such as butyl rubber, ethylene-propylene rubber sheets compounded with butyl rubber, and soft polyvinyl chloride sheets.

The composition of the waterproof sheet adhesive of the present invention is known as a moisture-curable composition. That is, first, the hydroxyl group-containing liquid diene polymer, which is the first component, has a hydroxyl group at the molecular end, and usually has a number average molecular weight of 30.
It is a liquid diene polymer of 0 to 2500G, preferably 500 to too much.

These liquid diene polymers include diene polymers and diene copolymers having 4 to 12 carbon atoms, and copolymers of these diene monomers and α-olefinic addition polymerizable monomers having 2 to 22 carbon atoms. be. It also includes liquid diene polymers obtained by grafting polymerizable heptamers onto these liquid diene polymers, or liquid diene polymers modified by adding unsaturated carboxylic acids such as maleic anhydride or derivatives thereof. It is something to do. Specifically, butadiene homopolymer, imprene homopolymer, butadiene-styrene copolymer, butadiene-isoprene copolymer, butadiene-7crylonitrile copolymer,
Examples include butadiene-2-ethylhexyl acrylate copolymer and butadiene-n-octadecyl acrylate copolymer. These liquid diene polymers can be produced, for example, by subjecting a conjugated diene monomer to a heating reaction in the presence of hydrogen peroxide in a liquid reaction medium. The liquid diene polymer thus obtained has an average of 1.7 to 3 hydroxyl groups as functional groups.
．． It contains 0. The fine structure of these liquid diene polymers is not particularly limited, but when flexibility is desired, those having 50% or more of 1.4 bonds are used.Next, the second component, the polyisocyanate compound, is used. Examples include tolylene diisocyanate and diphenylmethane diisocyanate (MDI).

Crude MD1. Liquid modified product of diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, cyclohexane phenylene diisocyanate, chlorophenylene diisocyanate, naphthalene-1,5-diisocyanate, xylylene-2,2-
Diisocyanate, isopropylbenzene-2,4-diisocyanate, polymethylene polyphenylisocyanate, triphenylmethane triisocyanate, isophorone diisocyanate, polypropylene glycol or triol and tolylene diisocyanate addition reaction product,
Examples include an addition reaction product of 1 mol of trimethylolpropane and 3 mol of tolylene diisocyanate.

Further, the bituminous substance which is the third component is not particularly limited and known substances can be used, such as straight asphalt and semi-brown asphalt.

Examples include blown asphalt, tar, or a mixture thereof, and preferably straight asphalt or a combination of straight asphalt and other asphalt.

The blending ratio of these three components may be appropriately determined depending on the material of the waterproof sheet to be adhered. 6 Normally, the ratio of the hydroxyl group-containing liquid diene polymer to the polyisocyanate compound is hydroxyl group (OH) to isocyanate, !
(NGO) is preferably about 1.5 to 10 equivalents, more preferably about 1.5 to 6 equivalents. In addition, bituminous substances are liquid diene polymers containing hydroxyl groups.
It may be blended in a ratio of 30 to 1000 parts by weight, preferably 50 to 500 parts by weight, per 100 parts by weight.

In principle, the adhesive for waterproof sheets of the present invention has the above three components as essential components, but various additives may be added as necessary. Examples of additives include, for example, to improve physical properties. Glycerin, diglycerin, trimethylolpropane, 1,4-butanediol, ethylene glycol,
3 mole ethylene oxide adduct of bisphenol A,
N,N-bis(2-hydroxypropyl)aniline and the like can be added. Further, in preparing one composition, urethane catalysts such as di-n-butyltin dilaurate, stannath octoate, triethylenediamine, diethylenediamine, triethylamine, naphthenic acid metal salts, octylic acid metal salts, etc. can be used as catalysts for accelerating curing. . We also use process oils, phthalates, phosphates, etc. as plasticizers, and calcium carbonate as fillers.

Barium sulfate, carbon black, etc., petroleum resins, terpene resins, etc. can be added as tackifiers.

Various methods can be applied to prepare the waterproof sheet adhesive of the present invention from the above-mentioned components. For example, predetermined amounts of raw material components are blended.

Preferred methods include melt-kneading under heating.

[Embodiments of the Invention] Production Example (Production of Adhesive for Waterproof Sheet) Hydroxyl group-containing liquid polybutadiene (manufactured by Idemitsu Petrochemical Co., Ltd.) was placed in a separable flask with an internal volume of 1 fL.

Product name: Polybd R-45IT J': Hydroxyl group content i: 0.79 tae'q/g; Number average molecular weight: 2800) Straight asphalt heated and melted at 100g and 130°C (penetration 150/200)
452.6g was added and heated to 80°C under a reduced pressure of 1 mmHg.
The mixture was heated and dehydrated for 1 hour. Then, after cooling to 40°C, 31.4 g of 4,4°-diphenylmethane diisocyanate heated and melted at 60°C was added and vigorously stirred for 1 hour while maintaining the temperature at 80°C.

Thereafter, the temperature was raised to 180°C, and after stirring for 3 hours, 0.5 g of dibutyltin dilaurate was added as a curing accelerating catalyst, and after stirring for 15 minutes, the mixture was cooled to 40°C to obtain an adhesive for a waterproof sheet.

The tarpaulin adhesive thus obtained is black in color.
The viscosity at 25° C. was 1200 voids, and the content of isocyanate (NGO) groups was 0.9% by weight.

Example 1 Using the waterproof sheet adhesive obtained in the above production example,
After the concrete material and the various waterproof sheets shown were bonded together under the conditions shown below, a 180'' peel test was conducted.

Adhesive area: 2.5c+wX l0cm (25d
) Adhesive layer thickness: 2. Om ■ Curing adhesive conditions: 1 week curing at 25°C and 80% humidity 180° Peeling test: At 25°C, the waterproof sheet is peeled off in a direction 180° to the adhesive surface to the concrete surface, and the adhesive The adhesive strength (Kgf/in) at the time when cohesive rupture or interfacial wave cracking occurred was measured and the results are shown in the table.

Comparative Example 1 A peel test was conducted in the same manner as in Example 1 above, except that chloroprene rubber glue (adjusted to 20% by weight using a solvent and benzene) was used as the adhesive, and the results are shown below. It was shown to.

Example 2 Except that the temperature in the curing adhesive conditions was 5°C.
A peel test was conducted in the same manner as in Example 1, and the results are shown in the table.

Comparative Example 2 A peel test was carried out in the same manner as in Example 2, except that chloroprene rubber glue (adjusted to 20% by weight using benzene as a solvent) was used as the adhesive.
The results are shown in the table.

As is clear from the results shown, when the waterproof sheet adhesive of the present invention is used to bond a waterproof sheet to a concrete surface, peeling occurs due to cohesive failure of the adhesive, and the adhesive In contrast, when conventional adhesives are used, interfacial rupture occurs at the interface between the adhesive layer and the concrete surface with extremely small force, compared to the adhesive of the present invention. It was confirmed that the adhesive strength was extremely low.

Furthermore, while conventional adhesives significantly reduce adhesive strength when cured at low temperatures, the adhesive of the present invention maintains good adhesive strength even when cured at low temperatures, It is extremely effective for use.

[Effects of the Invention] As is clear from the explanation in Section 2 below, the adhesive for waterproof sheets of Mimaichi I does not need to be dissolved in a solvent when used, so it hardens at low temperatures as well as at room temperature. Furthermore, the adhesive strength is extremely useful for adhering conventional T materials and waterproof sheets.

Therefore, the waterproof sheet adhesive of the present invention has a wide range of applications in the civil engineering and construction fields, and its industrial value is high.

Claims (1)

[Scope of Claims] 1. An adhesive for waterproof sheets characterized by comprising a hydroxyl group-containing liquid diene polymer, a polyisocyanate compound, and a bituminous substance. 2. The ratio of the isocyanate groups of the polyisocyanate compound to the hydroxyl groups of the hydroxyl group-containing liquid diene polymer is 1.
．． The waterproof sheet adhesive according to claim 1, which has an equivalent weight of 5 to 10.0.