JP2003003153A - Structure crack sealing material and construction method using the same - Google Patents

Abstract

(57) [Problem] To provide a structural crack-sealing material which produces a uniform foam cured product, exhibits an excellent water stopping effect, and does not cause environmental pollution. SOLUTION: The urethane prepolymer-containing structure crack-sealing material comprises (A) a urethane prepolymer having an isocyanate group at a molecular terminal and (B) a trimellitate ester and a benzoate ester as a viscosity reducing agent. Characteristic structure crack sealing material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crack sealant suitable in the field of civil engineering and construction, particularly for sealing cracks generated in structures such as ceilings, floors and wall surfaces to prevent water penetration and intrusion. It is a thing.

[0002]

2. Description of the Related Art Conventionally, a structure is cracked immediately after construction due to various actions such as an earthquake and uneven settlement of the foundation ground, at every place such as a rooftop, floor slab, skeleton, pillar, and ceiling. Occurs, rainwater, groundwater, seawater, etc. permeate and leak water,
It often produces spring water.

Conventionally, for sealing cracks in these structures, (a) a method of pressing and setting and fixing quick-setting cement, (b) a method of injecting cement milk, and (c) injecting an epoxy resin. A method, (d) a method of caulking various sealing materials, and (e) a method of injecting a polyisocyanate compound are known.

However, (a) the method of pressing and setting and fixing the quick-setting cement fixes only the cracks on the surface portion, and the inside is not filled and sealed at all. (B) In the method of injecting cement milk, there are problems that it cannot be injected into the microcracks, that the injected cement milk flows out at the water leak portion, and that it takes time to cure.
(C) In the method of injecting an epoxy resin, if the crack depth is deep, it is necessary to completely fill it, and in the case of a crack in water leakage, defective adhesion to the crack portion or leakage of the injected material may occur. (D) In the method of caulking various sealing materials, it is necessary to treat cracks in a V-cut shape in advance at the time of pouring, and to dry and then caulk, and there is a problem that the cracks cannot be applied in a wet state. .

In addition, in the method of injecting the (e) polyisocyanate compound, when the polyisocyanate compound is injected into the cracks in the leaked water, the reaction with water causes the foaming and hardening to proceed to the filling and sealing to the deepest part, but there is a large void inside. If present, there is a problem in that the outer peripheral portion of the polyisocyanate compound injected into the portion reacts with water, and a state in which water cannot penetrate into the inside occurs, and an uncured portion is generated to impair the reinforcing action of the crack portion. In order to solve the problem, Japanese Patent Application Laid-Open No. 1-249883 has been disclosed. At that time, although it is proposed to add a viscosity reducing agent,
It was found that the reaction cured product lacks uniformity in the size and hardness of the foam after foaming, and it is liberated from the cured product depending on the viscosity reducing agent used, and it inhibits the environment.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a structure crack sealant which produces a uniform foam cured product, exhibits an excellent water blocking effect, and does not cause environmental pollution.

SUMMARY OF THE INVENTION The present invention provides a urethane prepolymer-containing structural crack sealant, wherein (A) a urethane prepolymer having isocyanate groups at both ends of the molecule and (B) a trimellitic acid as a viscosity reducing agent. The present invention relates to a structure crack sealing material containing an ester and a benzoic acid ester, and a construction method characterized by treating a structure crack with the sealing material.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The urethane prepolymer (A) in the present invention has an isocyanate group at the molecular end, and is usually one which is foamed and cured by water or water in the air. The urethane prepolymer is a terminal isocyanate group-containing prepolymer obtained by reacting (a) an active hydrogen compound and (b) a polyisocyanate compound under conditions of excess isocyanate groups, and the NCO / OH equivalent ratio is preferably 1 0.5 or more, more preferably 1.5 to
It is obtained by reacting at a ratio of 50.0, and preferably has an average number of isocyanate groups in one molecule of 1.5 or more, and it may be used alone or as a urethane prepolymer (A) and (b) poly It is preferably supplied as a mixture with an isocyanate compound and is liquid at room temperature.

Examples of the (a) active hydrogen compound used in obtaining the urethane prepolymer (A) in the present invention include polyester polyols, polyether polyols,
Polyester polyamide polyols, polycarbonate polyols, polycaprolactone polyester polyols, polybutadiene polyols, polypentadiene polyols, polyacrylic polyols, castor oil-based polyols, low molecular weight diols, trimethylolpropane, glycerin, sorbitol, mannitol,
It is selected from dulcitol and the like.

The above-mentioned low molecular weight diols have a molecular weight of 20.
0 or less, such as ethylene glycol, propylene glycol, butanediol, diethylene glycol, dipropylene glycol, 1,4 butanediol,
1,6 hexanediol, neopentyl glycol, bisphenol A, etc. are mentioned.

The above polyether polyols include
For example, the low molecular weight diol, glycerin, trimethylolpropane, hexanetriol, triethanolamine, pentaerythritol, ethylenediamine, tolylenediamine, diphenylmethanediamine, tetramethylolcyclohexane, methylglucoside, 2,2,6,2.
Starting from 6-tetrakis (hydroxylmethyl) cyclohexanol, ethylenediamine, diethylenetriamine, metaphenylenediamine, 4,4-methylenedianiline, diethylaminopropylamine, xylylenediamine, sorbitol, mannitol, sucrose and the like, alkylene oxides such as ethylene. Oxide, propylene oxide, butylene oxide, etc. are added.

Examples of polybutadiene polyols include trade names polybd R-45HT and R-45.
M, R-15HT (product of Idemitsu Petrochemical Industry Co., Ltd.), N
ISSO-PB G-1000, G-2000 (manufactured by Nippon Soda Co., Ltd.) and the like are available.

Examples of the polyisocyanate compound (b) used for obtaining the urethane prepolymer (A) in the present invention include, for example, 4,4'-diphenylmethane diisocyanate (abbreviated as MDI) and dianisidine diamine. Isocyanate
Aromatic diisocyanates such as tritene, tridene diisocyanate, metaxylylene diisocyanate, hexamethylene diisocyanate, phenylene diisocyanate, 1,5-naphthalene diisocyanate, polymethylene polyphenyl polyisocyanate, hydrogenated MDI, hydrogenated TDI, etc. Examples thereof include organic polyisocyanate compounds selected from the group consisting of alicyclic diisocyanates and mixtures thereof, but especially polymethylene polyphenyl polyisocyanate is safe during work, stability of curing reaction, and durability. In terms of

The viscosity reducing agent (B) used in the present invention is usually the above urethane prepolymer of 2000 mPa · sec (25 ° C.).
Since it has the above-mentioned high viscosity and is poor in workability, it is for reducing the viscosity of the prepolymer, and mainly contains trimellitic acid ester and benzoic acid ester. In addition to these compounds, other thinning agents can be used in combination as long as the effects of the present invention are not impaired.

The quantitative ratio of the trimellitic acid ester and the benzoic acid ester, which are the main components of the above-mentioned viscosity reducing agent (B), can be appropriately selected so long as the effects of the present invention are achieved, but the weight ratio is preferably trimellitic acid. Acid ester / benzoic acid ester = 10 to 90/10 to 90, more preferably 20 to 80
/ 20-80. Further, when other thickener is used in combination, trimellitic acid ester / benzoic acid ester / other thinning agent = 10 to 90/10 to 90/0 to 20 (wt%), more preferably 20 to 80 / 20-80 / 0-1
It is 5 (% by weight), and as the other thinning agents, those which are not the substances subject to the environmental pollution investigation can be suitably used.

Examples of the trimellitic acid ester include trimellitic acid mono-, such as methyl, ethyl, propyl, butyl, hexyl, 2-ethylhexyl and octyl.
Di- and tri-alkyl esters can be increased, but considering the characteristics of the foam after curing, trimellitic acid alkyl triesters having 1 to 4 carbon atoms are preferable.
Further, as the benzoic acid ester, methyl benzoate,
Alkyl esters such as ethyl, propyl, butyl, hexyl, 2-ethylhexyl and octyl, diethylene glycol dibenzoate ester, dipropylene glycol dibenzoate ester, polyoxyethylene glycol dibenzoate ester, polyoxypropylene glycol dibenzoate ester, etc. However, considering the characteristics of the foam after curing, a diester of benzoic acid dialkylene glycol is preferable.

Other thinning agents that can be used in the present invention include those selected from plasticizers, solvents, process oils and the like, which may be used alone or as a mixture.

Examples of such plasticizers include phthalic acid esters such as dioctyl phthalate, dibutyl phthalate, diethyl phthalate, dimethyl phthalate, diheptyl phthalate, diphenyl phthalate, diisodecyl phthalate, ditridecyl phthalate, diundecyl phthalate, benzyl phthalate and the like; Isophthalic acid derivative esters such as dimethyl isophthalate and di (2-ethylhexyl) isophthalate; Tetrahydrophthalic acid esters such as di-2-ethylhexyl) tetrahydrophthalate and dioctyl tetrahydrophthalate; dibutyl adipate, dioctyl adipate, diisodecyl adipate, diisononyl adipate, etc. Adipic acid ester;
Azelaic acid esters such as diisooctyl azelate and diisooctyl azelate; Sebacic acid esters such as dibutyl sebacate and dioctyl sebacate; Maleic acid esters such as dibutyl maleate, dimethyl maleate and dioctyl maleate; Dibutyl fumarate , Maleic acid ester such as dioctyl fumarate; trimellitic acid derivative ester such as tributyl trimellitate and trioctyl trimellitate: citric acid ester; itaconic acid ester; oleic acid derivative; ricinoleic acid derivative; stearic acid derivative; sulfonic acid Derivative esters, glycol esters, glycerin esters, phosphoric acid ester derivatives and the like can be mentioned, but it is better not to use those that cause problems of environmental pollution, and even if they are used, they can be stopped to the extent that they do not cause problems.

As solvents, for example, acetone, cellosolve acetate, xylene, methyl acetate, ethyl acetate, butyl acetate, cyclohexanone, 1,4-dioxane, tetrahydrofuran, toluene, normal hexane, methyl ethyl ketone, methyl isobutyl ketone, methyl butyketone, industrial gasoline , Solvent naphtha, petroleum ether, petroleum naphtha, petroleum benzine and the like.

Examples of process oils include natural turpentine oil, sulfate turpentine oil, heavy turpentine oil, α
-Pinene, alloocimene, alloocimene oxide, hydrogenated turpentine low polymer, tall oil, coumarone resin, indene resin, petroleum-based paraffin high-boiling fraction, petroleum naphthene high-boiling fraction, petroleum aroma high-boiling fraction Etc.

The amount of the (B) thinning agent used in the present invention is preferably 5 to 250 parts by weight, more preferably 10 to 1 part by weight based on 100 parts by weight of the urethane prepolymer (A).
It is 50 parts by weight.

In the crack sealing material of the present invention, as a catalyst usually used in the production of various urethane resins, a known catalyst for promoting the reaction between an isocyanate group and an active hydrogen atom and a known epoxy resin are used. The curing catalyst and the like can be used in combination.

Examples of the catalyst include tertiary amine compounds such as trimethylamine, triethylamine, tributylamine, N-dimethyllaurylamine, N-diethyllaurylamine, N, N'-methylpiperazine, N, N'-.
Dimethylbenzylamine, N-methylmorpholine, N-ethylmorpholine, triethylenediamine, N-pentamethylethylenetriamine, N, N, N ', N'-tetramethylpropylenediamine, N-polymethylpolyethylenepolyamine, etc., alone or as a mixture. Any of the above can be used.

As the catalyst, known organometallic compounds that accelerate the reaction between isocyanate groups and active hydrogen atoms, for example, cobalt naphthenate, barium naphthenate, bismuth naphthenate, lead naphthenate, zinc naphthenate, octyl. Cobaltate, cobalt octylate, barium octylate, bismuth octylate, lead octylate, zinc octylate, tin naphthenate, tin octylate, tetra-n-butyltin, tri-n-butyldusacetate, dimethylzuzuchloride, dibutyltin dilaurate Any one can be used as long as it is selected from the group consisting of single and mixtures thereof.

The amount of the catalyst used in the present invention is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the urethane prepolymer (A).

Further, in the crack sealant of the present invention, foam stabilizers usually used in the urethane foaming reaction, such as Silicon L-520 manufactured by Nippon Unica Co., Ltd., are used as long as the effects of the present invention are not impaired. , L-540, L-580, L-3600,
L-5340, SZ-1649, SZ-1671, SZ
-1651 and the like selected from the group consisting of a single substance and a mixture, ultraviolet absorbers, antioxidants, fillers such as cement, calcium carbide, talc, mica, slag, silica sand,
Any of wood flour and the like can be used as long as it is selected from the group consisting of a single substance and a mixture.

When the crack sealing material of the present invention is used, a crack sealing material of 30 to 1000 mPa · sec (25 ° C.), which is suitable for injection work, is used, and the crack sealing material is used for cracking a structure. For example, it is injected by an injector such as a grease pump, a chemical pump, a sprayer, or a caulking gun, reacted with water present in the crack, foamed and cured, and repaired. When there is no water in the crack, water is sprayed on the crack surface in advance.

Examples of the structure to be processed in the present invention include ceilings of structures such as houses, buildings, bridges and roads,
It is a floor surface, a wall surface, and a skeleton, and the materials thereof are concrete, mortar, metal, plywood, FRP board and the like.

[0028]

EXAMPLES The present invention will be described in detail with reference to Examples. The present invention is not limited to only these specific examples. Also, "part" and "%" in the text are based on weight unless otherwise specified.

Synthesis of Prepolymer 1 In a 1 L flask, 860 g of polymethylene polyphenyl isocyanate (trade name: Millionate MR-200 manufactured by Nippon Polyurethane Industry Co., Ltd.) and a polyether polyol having a molecular weight of 500 (manufactured by Dainippon Ink and Chemicals Co., Ltd.) 70 g of trade name Hyprox RQ500) was weighed and reacted at 80 ° C. for 4 hours, and the brown viscosity was 4000 mPa · se.
C (25 ° C.), a resin having a free isocyanate group content of 27% was obtained.

Synthesis of Prepolymer 2 In a 2 L flask, 956 g of polymethylene polyphenyl isocyanate (trade name: Millionate MR-200 manufactured by Nippon Polyurethane Industry Co., Ltd.) and a polyether polyol having a molecular weight of 1000 (manufactured by Dainippon Ink and Chemicals Co., Ltd.) 242 g of trade name Hyprox DP-1000) was weighed and reacted at 80 ° C. for 4 hours to give a brown viscosity of 120.
0mPa · sec (25 ℃), free isocyanate group content is 2
A resin showing 3% was obtained.

[0031]

[Foaming test] To 100 parts of the resin of each example, 0.5 part of NN'-dimethyllaurylamine and 0.3 part of silicon SZ-1649 were added and uniformly mixed, and 10 parts of water was added thereto with a spatula. The mixture was mixed for 10 seconds, and a foam hardening test was conducted.
It was investigated whether the shape of the cured foam was uniform or non-uniform.

[0032]

[Storage test] Resin of each example 200 g Glass bottle 250 m
L was weighed and allowed to stand for 3 weeks in a 50 ° C. thermostatic bath to test the stability of the system.

[0033]

[Sealing test] Width 50 x length 300 x width 300 (mm) Two wet concrete plates were overlaid and a crack model was created with the perimeter of the gap sealed with quick-setting cement, and foam hardening from the gap end The filling state was tested by injecting the adjustment liquid to which the water of the sex test was not added.

[0034]

[Water immersion test] The cured product of the foaming curing test was immersed in water for 24 hours to test whether or not free matter was generated on the water surface.

Example 1 100 parts of prepolymer 1 and tributyl trimellitate (trade name: Monosizer T, manufactured by Dainippon Ink and Chemicals, Inc.)
BTM and abbreviated as TBTM hereinafter) / diethylene glycol dibenzoate (manufactured by Dainippon Ink and Chemicals, Inc., trade name Monosizer PB-3 and abbreviated as PB-3) = 2/8
(Weight ratio) When 100 parts of the mixture was weighed and mixed, a brown resin having a viscosity of 460 mPa · sec (25 ° C.) and a free isocyanate group content of 13% was obtained.

Example 2 100 parts of Prepolymer 1 and TBTM / PB-3 = 8 /
When 100 parts of the 2 (weight ratio) mixture was weighed and mixed, a brown resin having a viscosity of 550 mPa · sec (25 ° C.) and a free isocyanate group content of 12.8% was obtained.

Example 3 100 parts of Prepolymer 1 and TBTM / PB-3 = 5 /
When 5 parts (100 parts by weight) of the mixture were weighed and mixed, a brown resin having a viscosity of 500 mPa · sec (25 ° C.) and a free isocyanate group content of 13.1% was obtained.

Example 4 60 parts of Prepolymer 2 and TBTM / PB-3 / 2,
2,4 Trimethyl-1,3 pentanediol diisobutyrate (Eastman Kodak Co., Ltd., trade name Kodaflex TXIB Plasticsizer, abbreviated as TXIB hereinafter)
= 68/17/15 (weight ratio) 140 parts of the mixture was weighed and mixed to obtain a resin having a brown viscosity of 60 mPa · sec (25 ° C) and a free isocyanate group content of 7.2%.

Example 5 60 parts of Prepolymer 2 and TBTM / PB-3 = 5/5
(Weight ratio) When 140 parts of the mixture was weighed and mixed, a brown resin having a viscosity of 150 mPa · sec (25 ° C.) and a free isocyanate group content of 6.9% was obtained.

Comparative Example 1 When 100 parts of Prepolymer 1 and 100 parts of DBP were weighed and mixed, a brown resin having a viscosity of 260 mPa · sec (25 ° C.) and a free isocyanate group content of 12.8% was obtained.

Comparative Example 2 100 parts of prepolymer 1 and 100 parts of DOP were weighed and mixed to obtain a resin having a brown viscosity of 580 mPa · sec (25 ° C.) and a free isocyanate group content of 13.0%.

Comparative Example 3 100 parts of Prepolymer 1 and 100 parts of palmitic acid methyl ester were weighed and mixed to obtain a brown viscosity of 60 mPa · se.
c (25 ° C), free isocyanate group content 13.0%
Was obtained.

Comparative Example 4 When 100 parts of Prepolymer 1 and 100 parts of TCP were weighed and mixed, a brown resin having a viscosity of 360 mPa · sec (25 ° C.) and a free isocyanate group content of 13.0% was obtained.

Comparative Example 5 When 60 parts of Prepolymer 2 and 140 parts of DBM were weighed and mixed, a brown resin having a viscosity of 55 mPa · sec (25 ° C.) and a free isocyanate group content of 6.9% was obtained.

Comparative Example 6 A mixture of 60 parts of prepolymer 2 and 140 parts of dioctyl sebacate (hereinafter abbreviated as DOS) was weighed and mixed, and the brown viscosity was 70 mPa · sec (25 ° C.) and the free isocyanate group content was 6.7%. Was obtained.

Comparative Example 7 A mixture of 60 parts of Prepolymer 2 and 140 parts of TBTM was weighed and mixed, and a brown resin having a viscosity of 145 mPa · sec (25 ° C.) and a free isocyanate group content of 6.8% was obtained.

Comparative Example 8 When 60 parts of Prepolymer 2 and 140 parts of PB-3 were weighed and mixed, a brown resin having a viscosity of 180 mPa · sec (25 ° C.) and a free isocyanate group content of 6.9% was obtained. It was

Comparative Example 9 Polymethylene polyphenyl isocyanate (trade name: Millionate MR-200 manufactured by Nippon Polyurethane Industry Co., Ltd.)
100 g of DOP (manufactured by Mitsubishi Chemical Industry Co., Ltd.) 100
When g was weighed and reacted at 40 ° C. for 2 hours, a brown resin having a viscosity of 100 mPa · sec (25 ° C.) and a free isocyanate group content of 16% was obtained. When this resin is subjected to a foaming test, a sealing test and a water immersion test, 0.5 part of NN'-dimethyllaurylamine, 0.3 part of silicon SZ-1964 and 0.2 part of sodium acetate are added to 100 parts of the resin. Was added and the others were performed in the same manner.

[0049]

[Table 1] Each test result

[0050]

[Table 2] (In the table) * 1: Large brittleness * 2: Large shrinkage

As shown in the above Examples 1 to 5, the structure crack sealing material of the present invention was compared with the test results of Comparative Examples 1 to 9 and was found to be foam curability, storage stability and crack sealing. It was confirmed that the product had excellent properties and stability in immersion in water, and was free of the generation of free substances.

[0052]

INDUSTRIAL APPLICABILITY The present invention increases the load on the environmental water area when the cracks generated in the conventional structure walls, floors, ceilings and the like below the groundwater level are leaked to the ground. Since the crack filling layer can be formed without causing such a crack, it is particularly useful in a place where environmental pollution is a concern, such as various existing fillers, and has a great feature that injection can be performed without enormous environmental pollution prevention measures.

Claims (5)

[Claims] 1. A urethane prepolymer-containing structural crack sealing material, comprising (A) a urethane prepolymer having an isocyanate group at a molecular end and (B) a trimellitic acid ester and a benzoic acid ester as a viscosity reducing agent. A structure crack sealing material characterized by: 2. The structure crack sealing material according to claim 1, wherein the urethane prepolymer (A) is obtained by using polymethylene polyphenyl polyisocyanate. 3. The structure crack sealing material according to claim 1, wherein the thinning agent (B) contains 20% by weight or less of a thinning agent other than the trimellitic acid ester and the benzoic acid ester. . 4. The trimellitic acid ester 1 is used as the viscosity reducing agent (B).
0 to 90% by weight and benzoic acid ester 10 to 90% by weight
The structure crack sealing material according to any one of claims 1 to 3, comprising: 5. A construction method comprising treating a structure crack with the structure crack sealing material according to any one of claims 1 to 4.