JP2007009672A - Crack repairing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive composition excellent in adhesion properties, releasability and low-temperature hardenability, and a crack repairing method which uses the adhesive composition and which has excellent workability. <P>SOLUTION: In this crack repairing method, a surface of the crack is sealed with a sealant; a repairing-agent injecting implement is fixed by means of an adhesive; and a repairing agent is injected into the crack. A one-component moisture-curing urethane adhesive composition containing a urethane prepolymer is used as the sealant and the adhesive. Preferably, the one-component moisture-curing urethane adhesive composition has transparency. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a crack repair method and an adhesive composition, and more specifically, seals the surface of a crack generated on a wall surface of a structure such as concrete, tile, stone, ceramic, metal, etc. and injects a repair resin. The present invention relates to a crack repairing method for fixing a tool for use and injecting a repairing resin, and an adhesive composition for crack repairing used in the method.

  Conventionally, the repair of cracks such as cracks and voids generated on the wall surface of a building or the like has been performed by injecting a repair resin. As a crack repair method, a repair resin injection device or a washer for fixing the device is fixed to the wall surface with an adhesive, and the surface of the crack is sealed with a sealant (sealing agent), and then the repair resin is placed in the crack. After the repair resin is cured, a repair resin injection device and a sealing agent are removed (see, for example, Patent Documents 1 to 3).

  Patent Document 1 discloses a two-component polyurethane resin composition, an epoxy resin, and an unsaturated polyester resin as an adhesive for fixing a resin injection device and a sealing agent for sealing the surface of a crack. Yes. However, the two-component resin needs to weigh and mix the components of the two components at the time of construction, which is likely to cause problems due to temperature changes and operational mistakes during mixing and stirring, and there is a problem in workability. It was.

On the other hand, Patent Documents 2 and 3 disclose a method for improving releasability using a modified silicone resin. However, the modified silicone resin is easy to break when it is peeled off, and is hardened at low temperatures such as in winter. There was a problem. It is usually opaque from the viewpoint of workability and cost, and does not have transparency.
Japanese Patent Laid-Open No. 62-146364 JP 9-189134 A JP 2002-249761 A

  An object of this invention is to provide the adhesive composition excellent in adhesiveness, peelability, and low-temperature curability, and the crack repair method excellent in workability | operativity using this adhesive composition.

  In order to solve the above-mentioned problems, the crack repair method of the present invention is a crack repair in which the surface of a crack is sealed with a sealant and a repairing agent injection tool is fixed with an adhesive, and the repairing agent is injected into the crack. It is a method, Comprising: 1 liquid moisture hardening type urethane-adhesive composition containing a urethane prepolymer as said sealing agent and adhesive agent is used, It is characterized by the above-mentioned.

It is preferable that the one-component moisture-curing urethane adhesive composition has transparency.
It is preferable that the one-component moisture-curable urethane adhesive composition contains a latent curing agent. More preferably, the latent curing agent is polyaldimine. The one-component moisture-curable urethane adhesive composition preferably further contains a hydrolyzable ester compound. In addition, it is preferable that the one-component moisture-curable urethane adhesive composition further contains p-toluenesulfonyl isocyanate.

The adhesive composition for repairing cracks of the present invention comprises a one-component moisture-curable adhesive composition containing a urethane prepolymer, and is used in the crack repairing method of the present invention.
It is preferable that the crack repair adhesive composition has transparency.
It is preferable that the one-component moisture-curable urethane adhesive composition contains a latent curing agent. More preferably, the latent curing agent is polyaldimine. The one-component moisture-curable urethane adhesive composition preferably further contains a hydrolyzable ester compound. In addition, it is preferable that the one-component moisture-curable urethane adhesive composition further contains p-toluenesulfonyl isocyanate.

  ADVANTAGE OF THE INVENTION According to this invention, the crack repairing method excellent in the adhesive composition for crack repair excellent in adhesiveness, peelability, and low-temperature curability, and workability | operativity can be provided. In addition, by using a composition having transparency as the adhesive composition for repairing cracks of the present invention, it is easy to construct because the position of cracks can be seen during construction, and the amount of adhesive used can be reduced. And economy can be improved.

  Embodiments of the present invention will be described below, but these are exemplarily shown, and it goes without saying that various modifications are possible without departing from the technical idea of the present invention.

  FIG. 1 is a schematic top view showing an example of repairing a crack, (a) is a top view showing a crack surface before repairing, and (b) is fixing the repairing agent injecting device by sealing the crack surface. A top view and (c) are top views showing a crack surface after repair. FIG. 2 is a schematic cross-sectional view showing an example of repairing a crack, (a) is a cross-sectional view showing a crack before repair, and (b) is a cross-section in which the surface of the crack is sealed and a repair agent injection device is fixed. FIG. 4C is a cross-sectional view showing a crack after repair.

  The crack repairing method of the present invention seals the surface of a crack with a sealant, and fixes a repairing agent injecting device with an adhesive, and then injects the repairing agent into the crack from the repairing agent injecting device. In the method, as the sealing agent and the adhesive, a one-component moisture-curable urethane adhesive composition containing a urethane prepolymer that is an adhesive composition for repairing cracks of the present invention is used.

  The one-component moisture-curable urethane adhesive composition is not particularly limited as long as it is a one-component moisture-curable composition containing a urethane prepolymer. As the urethane prepolymer, a urethane prepolymer having an active isocyanate group is used. Specifically, the urethane prepolymer includes a polyol having two or more hydroxyl groups (OH) and a polyisocyanate compound having two or more isocyanate groups (NCO) so that the isocyanate groups are excessive, that is, NCO / OH. It is obtained by reacting such that the equivalent ratio is greater than 1.

  The reaction conditions are not particularly limited. For example, the NCO / OH equivalent ratio is 1.3 to 10.0, more preferably 1.5 to 5.0, in a nitrogen or dry air stream. It is produced by reacting at ~ 100 ° C for several hours. When the NCO / OH equivalent ratio is less than 1.3, the viscosity of the prepolymer becomes high, causing a problem in workability, and when it exceeds 10, a problem may occur due to foaming.

  The polyol is not particularly limited as long as it is an active hydrogen-containing compound having two or more active hydrogen groups. Generally, a polyether polyol or a polyester polyol is preferably used, and a polyether polyol is particularly preferable. is there.

  More specifically, for example, as the polyether polyol, one or two kinds of diols such as ethylene glycol, propylene glycol and butylene glycol, triols such as glycerin and trimethylolpropane, and amines such as ammonia and ethylenediamine are used. Examples include polyether polyols such as random or block copolymers obtained by ring-opening polymerization of propylene oxide and / or ethylene oxide in the presence of the above. Examples of polyester polyols include polyester polyols such as copolymers obtained by polycondensation of adipic acid, sebacic acid, terephthalic acid, etc. in the presence of ethylene glycol, propylene glycol, 1,4 butanediol, neopentyl glycol, etc. In addition, low molecular active hydrogen compounds having two or more active hydrogen groups such as bisphenol A and ramester of castor oil can be mentioned. As the above compound, those having a molecular weight of usually 100 to 7000 and 2 to 4 OH groups in one molecule can be preferably used.

  Specific examples of the polyisocyanate compound include aromatic polyisocyanates such as diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), naphthalene diisocyanate, xylylene diisocyanate (XDI), and hexamethylene diisocyanate (HDI). ), Aliphatic polyisocyanates such as lysine methyl ester diisocyanate, alicyclic polyisocyanates such as hydrogenated diphenylmethane diisocyanate, isophorone diisocyanate, norbornane diisocyanate, hydrogenated tolylene diisocyanate, among these, toxicity and reaction The use of MDI is preferable from the viewpoints of performance and price.

It is preferable to mix a curing catalyst with the one-component moisture-curable urethane adhesive composition. The curing catalyst is a catalyst for accelerating curing of the urethane prepolymer, and examples thereof include organometallic compounds and amines.
Examples of the organometallic compound include divalent organic tin compounds such as tin octylate and tin naphthenate; dibutyltin dioctate, dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dimaleate, dibutyltin distearate, dioctyltin dilaurate, Tetravalent organic tin compounds such as dioctyltin diversate, dibutyltin oxide, dibutyltin bis (triethoxysilicate), a reaction product of dibutyltin oxide and phthalate; organic acid lead salts such as lead octylate and lead naphthenate Titanates such as tetra-n-butyl titanate and tetrapropyl titanate; organic bismuth compounds such as bismuth octylate, bismuth neodecanoate and bismuth rosinate; organic zirconium compounds such as zirconium octylate; Organic cobalt compounds; organic zinc compounds; organic manganese compounds; organic iron compounds; tin-based chelate compounds such as dibutyltin bis (acetylacetonate), zirconium tetrakis (acetylacetonate), titanium tetrakis (acetylacetonate), Examples thereof include chelate compounds of various metals such as aluminum tris (acetylacetonate), aluminum tris (ethylacetoacetate), acetylacetone cobalt, acetylacetone iron, acetylacetone copper, acetylacetone magnesium, acetylacetone bismuth, acetylacetone nickel, acetylacetone zinc, and acetylacetone manganese. Of these, organic tin compounds and metal chelate compounds are preferred, and tin-based chelate compounds are more preferred because of their high reaction rate and relatively low toxicity and volatility.

  Examples of the amines include primary amines such as butylamine and octylamine, secondary amines such as dibutylamine and dioctylamine, alkanolamines such as monoethanolamine, diethanolamine and triethanolamine, diethylenetriamine, Examples include primary amines such as triethylenetetramine, tertiary amines such as triethylamine, tributylamine, triethylenediamine, and N-ethylmorpholine, or salts of these amines and carboxylic acids. .

  The blending ratio of the curing catalyst is not particularly limited, but is preferably 0.01 to 10 parts by mass, more preferably 0.01 to 2 parts by mass with respect to 100 parts by mass of the urethane prepolymer.

  Moreover, it is preferable to mix | blend latent hardeners, such as a compound which produces | generates an amine by hydrolysis, to the said 1 liquid moisture hardening type urethane adhesive composition. Preferred examples of the compound that generates an amine by hydrolysis include dehydration reaction products of amines such as ketimine compounds, enamine compounds, and aldimine compounds and carbonyl compounds, and the like are reaction products of polyamines and aldehydes. Some polyaldimines are more preferred. By using the latent curing agent, the low-temperature curability can be improved and the workability in winter can be further enhanced. Furthermore, the use of a latent curing agent also has an effect of suppressing foaming.

  As the polyaldimine, conventionally known polyaldimines that generate amines by hydrolysis can be widely used, but polyaldimines derived from aromatic aldehydes are preferred, and polyaldimines represented by the following general formula (1) are preferred. Further preferred. These polyaldimines may be used alone or in combination of two or more.

式（１）中、Ｒ¹は炭素数６〜１５のアリール基であり、フェニル基及び１以上の置換基で置換された置換フェニル基が挙げられる。置換基としては炭素数が１〜９のアルキル基、炭素数が１〜９のアルコキシ基等が好ましい。上記アリール基の置換基数としては１〜３のものが好ましい。Ｒ¹としては、具体的には、フェニル基、メチルフェニル基、エチルフェニル基、プロピルフェニル基、ブチルフェニル基、ジメチルフェニル基、メトキシフェニル基、エトキシフェニル基、プロポキシフェニル基等が好適な例として挙げられる。Ｒ¹は１分子中で同一であっても異なっていても良い。
式（１）中、Ｒ²は、炭素数２〜１５で２価又は３価の炭化水素基、分子量が７０〜６，０００で２価又は３価のポリオキシアルキレン基、イソホロンジアミンのアミノ残基、又は下記一般式（２）で示されるアミンのアミノ残基である。なお、式（１）及び（２）中、ｎは２又は３を示す。

但し、式（２）中、Ｒ³は炭素数６〜１３で、かつ２価又は３価のビシクロ環、またはトリシクロ環からなる炭化水素基であり、ビシクロ環、トリシクロ環のシクロ環の炭素数は５〜１２のものが好ましい。更にシクロ環は置換基を有するものでも良い。置換基としては、メチル基、エチル基、プロピル基等のアルキル基等が好ましい。

In Formula (1), R ¹ is an aryl group having 6 to 15 carbon atoms, and examples thereof include a phenyl group and a substituted phenyl group substituted with one or more substituents. As a substituent, a C1-C9 alkyl group, a C1-C9 alkoxy group, etc. are preferable. The number of substituents of the aryl group is preferably 1 to 3. Specific examples of R ¹ include a phenyl group, a methylphenyl group, an ethylphenyl group, a propylphenyl group, a butylphenyl group, a dimethylphenyl group, a methoxyphenyl group, an ethoxyphenyl group, and a propoxyphenyl group. Can be mentioned. R ¹ may be the same or different in one molecule.
In the formula (1), R ² is a divalent or trivalent hydrocarbon group having 2 to 15 carbon atoms, a divalent or trivalent polyoxyalkylene group having a molecular weight of 70 to 6,000, and an amino residue of isophoronediamine. Or an amino residue of an amine represented by the following general formula (2). In formulas (1) and (2), n represents 2 or 3.

In the formula (2), R ³ is a hydrocarbon group having 6 to 13 carbon atoms and consisting of a bivalent or trivalent bicyclo ring or a tricyclo ring, and the carbon number of the bicyclo ring or the tricyclo ring. Is preferably 5-12. Furthermore, the cyclo ring may have a substituent. As the substituent, an alkyl group such as a methyl group, an ethyl group, or a propyl group is preferable.

  The method for producing the polyaldimine is not particularly limited, and can be easily produced by a known method such as reacting a polyamine and an aldehyde. For example, polyamine and aldehyde are heated in an acid catalyst in a solvent such as toluene, xylene, butyl acetate, or methylcyclohexane to perform an azeotropic dehydration reaction, and the distillation of water stops in the water droplet separator. The polyaldimine is obtained by continuing the reaction until. The mixing ratio of polyamine and aldehyde is suitably 1 to 2 equivalents of aldehyde with respect to 1 equivalent of amine. The reaction is usually complete in a few hours. After completion of the reaction, polyaldimine can be obtained by distilling off the aldehyde, the solvent and the like by reducing the reaction mixture under reduced pressure.

Examples of the polyamine include (a) aliphatic diamines such as ethylenediamine, 1,3-diaminopropane, tetramethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, decamethylenediamine, and 4,4′-diamino. Dicyclohexylmethane, isophoronediamine, bisaminomethylcyclohexane, 2,5- or 2,6-diaminomethylbicyclo [2.2.1] heptane, diaminocyclohexane, 3 (4), 8 (9) -bis (aminomethyl) -Alicyclic diamines such as tricyclo [5.2.1.0 ^2.6 ] decane, diaminodiphenylmethane, diaminodiphenyl ether, xylylenediamine, phenylenediamine, 3,5-diethyltoluene-2,4- or 2,6-diamine Aromatic diamine etc. Diamines such as polyoxyalkylene diamines obtained by converting the hydroxyl groups of polyoxyalkylene glycols obtained by addition polymerization of propylene oxide and / or ethylene oxide to water, ethylene glycol, propylene glycol and the like, and ( b) Addition polymerization of propylene oxide and / or ethylene oxide to triamine such as 1,3,5-tris (aminomethyl) benzene, 1,3,5-tris (aminomethyl) cyclohexane, glycerin, trimethylolpropane, etc. Triamines such as polyoxyalkylene triamine obtained by converting the hydroxyl group of the obtained polyoxyalkylene triols to amino groups are exemplified, and a low melting point polyamine having a melting point of 50 ° C. or lower is particularly preferable.

  Examples of the aldehyde include benzaldehyde, o-tolualdehyde, m-tolualdehyde, p-tolualdehyde, 4-ethylbenzaldehyde, 4-propylbenzaldehyde, 4-butylbenzaldehyde, 2,4-dimethylbenzaldehyde, 2,4, 5-Trimethylbenzaldehyde, p-anisaldehyde, p-ethoxybenzaldehyde and the like can be mentioned.

  The blending ratio of the latent curing agent is not particularly limited, but when using a compound such as polyaldimine that hydrolyzes to produce amines, it is included in the number of amino groups of amines produced by hydrolysis and the urethane prepolymer. It is desirable that the ratio of the number of isocyanate groups to be produced is 0.1 to 1.0, more preferably 0.2 to 0.6.

  When a latent curing agent such as polyaldimine is blended in the one-component moisture curable urethane adhesive composition, it is preferable to further blend a compound that promotes hydrolysis of the latent curing agent. As a compound which accelerates | stimulates this hydrolysis, a hydrolysable SL compound, p-toluenesulfonyl isocyanate, etc. are mentioned, for example. These compounds can be used alone or in combination of two or more. When two or more types are used in combination, the combination is not particularly limited, and for example, a hydrolyzable ester compound and p-toluenesulfonyl isocyanate may be used in combination.

The hydrolyzable ester compound is hydrolyzed with water to produce a free acid, and promotes hydrolysis of aldimine. For example, esters such as methyl formate, orthoformate such as methyl orthoformate and ethyl orthoformate Acetals such as esters and cyclohexanone dimethyl acetal are preferred in terms of storage stability. p-Toluenesulfonyl isocyanate is a compound represented by the following formula (3), and can be obtained by a known isocyanate synthesis method using phosgene or Hoffman decomposition, but is commercially available such as Additive TI manufactured by Sumitomo Bayer Urethane Co., Ltd. Goods can be used. Moreover, derivatives of p-toluenesulfonyl isocyanate may be used, and these derivatives are also included in the present invention.

  The compounding ratio of the compound that promotes the hydrolysis of the latent curing agent is not particularly limited, but it is preferably 0.1 to 20 parts by mass, particularly 0.1 to 6 parts by mass with respect to 100 parts by mass of the urethane prepolymer. .

  In the one-component moisture-curable urethane adhesive composition of the present invention, a filler, a plasticizer, an adhesion-imparting agent, a physical property modifier, a release agent, a lubricant, a thixotropic agent, a dehydrating agent (storage stability) Property improvers), tackifiers, sagging inhibitors, ultraviolet absorbers, antioxidants, flame retardants, colorants, radical polymerization initiators, and various solvents such as toluene and alcohol. .

  Examples of the filler include organic or inorganic materials of various shapes, such as calcium carbonate, magnesium carbonate, and zinc carbonate; carbon black; clay; talc; fumed silica, calcined silica, precipitated silica, ground silica, and fused silica; Kaolin; diatomaceous earth; zeolite; titanium oxide, quicklime, iron oxide, zinc oxide, barium oxide, magnesium oxide; aluminum sulfate; vinyl chloride paste resin; glass balloon, shirasu balloon, saran balloon, phenol balloon, vinylidene chloride resin balloon, etc. Inorganic balloons, organic balloons, and the like; or these fatty acid and fatty acid ester-treated products can be used, and these can be used alone or in combination. As the filler, it is preferable to use fine powder silica in order to increase transparency. Examples of the fine powdered silica include hydrophobic silica fine powder such as Aerosil RY-200S [trade name manufactured by Nippon Aerosil Co., Ltd.] and Aerosil R972 [trade name manufactured by Nippon Aerosil Co., Ltd.], and Fulex® E2. Examples include hydrophilic silica fine powders such as [trade name, manufactured by Tatsumori Co., Ltd.].

  Examples of the plasticizer include dioctyl phthalate (DOP), dibutyl phthalate (DBP), dilauryl phthalate (DLP), butyl benzyl phthalate (BBP), dioctyl adipate, diisononyl phthalate, diisodecyl adipate, diisodecyl phthalate, trioctyl phosphate, Tris (chloroethyl) phosphate, tris (dichloropropyl) phosphate, propylene glycol adipate polyester, butylene glycol adipate polyester, alkyl epoxy stearate, epoxidized soybean oil, and the like can be used alone or in combination it can.

  It is preferable that the one-component moisture-curing urethane adhesive composition has transparency. In the present invention, having transparency is sufficient if cracks are visible during construction. By using a transparent one-component moisture-curing urethane adhesive composition, workability during construction can be remarkably improved, and the amount of the adhesive composition used can be suppressed. Although it does not specifically limit as method to provide transparency to this adhesive composition, For example, the adhesive composition which has transparency can be obtained by adjusting the filler to add.

  FIG.1 and FIG.2 is schematic explanatory drawing which shows an example of the crack repair method of this invention. As shown in FIG. 1 and FIG. 2, the one-part moisture-curing urethane adhesive composition (adhesive composition for repairing cracks) is applied to the surface of the crack 10 to be repaired [FIG. 1 (a) and FIG. 2 (a)]. 1) After applying the material 12 by coating or the like to seal the surface of the crack 10 and fixing the repairing agent injection device 20 with the adhesive composition 12 [FIGS. 1 (b) and 2 (b)], The repair agent 14 is injected into the crack 10 from the injection port 30 of the injection device 20, and the adhesive composition 12 is peeled and removed after the repair agent 14 is cured [FIG. 1 (c) and FIG. 2 (c)]. The fixing of the repair agent injection device to the crack surface may be performed by directly fixing the repair agent injection device to the crack surface with an adhesive composition, and also the washer for fixing the injection device with an adhesive composition. The injection device may be fixed to the crack surface through a washer (not shown).

  The said repair agent is not specifically limited, What is necessary is just to use the well-known repair agent used for repair of a crack, for example, an epoxy resin. Also, the repair injection device is not particularly limited, and a known device can be used. For example, after fixing an injection metal fitting to the crack surface with the adhesive composition, a repair agent can be injected and filled from an injection port using an injection gun to repair the crack.

  The present invention will be described more specifically with reference to the following examples. However, it is needless to say that these examples are shown by way of illustration and should not be construed in a limited manner.

(Examples 1-5)
(Synthesis Example 1)
In a stirrer equipped with a thermometer, 88.4 parts by mass of polypropylene glycol having a molecular weight of 6000 (trade name Actol FC-280, manufactured by Mitsui Takeda Chemical Co., Ltd.) was dehydrated, and then 4,4′-diphenylmethane diisocyanate ( MDI) 11.6 parts by mass was added and reacted at 70 to 90 ° C. for 5 hours under a nitrogen atmosphere to obtain urethane prepolymer A having a terminal isocyanate content of 2.0%.

(Synthesis Example 2)
In a stirrer equipped with a thermometer, 84 parts by mass of a polypropylene glycol having a molecular weight of 5000 (manufactured by Mitsui Takeda Chemical Co., Ltd., trade name: Actol 87-34) was dehydrated, and then 4,4′-diphenylmethane diisocyanate (MDI). 16 parts by mass were added and reacted at 70 to 90 ° C. for 5 hours under a nitrogen atmosphere to obtain urethane prepolymer B having a terminal isocyanate content of 3.0%.

  As shown in Table 1, each component was blended and stirred and mixed at 90 ° C. under a nitrogen stream to obtain a one-component moisture-curable urethane adhesive composition. The following test was done with respect to the obtained adhesive composition. The results are shown in Table 2.

The compounding ratio of each compounding substance in Table 1 is shown in parts by mass, and 1) to 8) are as follows.
1) Urethane prepolymer A obtained in Synthesis Example 1
2) Urethane prepolymer B obtained in Synthesis Example 2
3) Aerosil RY-200S (fumed silica): manufactured by Nippon Aerosil Co., Ltd. 4) Whiten SB (heavy calcium carbonate): manufactured by Bihoku Powder Chemical Co., Ltd. 5) Sealet 200 (surface treated calcium carbonate): Maruo 6) STANN BL (dibutyltin laurate): Sansha Kisei Co., Ltd. 7) Normal paraffin SL: Shin Nippon Petrochemical Co., Ltd. 8) Diisononyl phthalate

(Test method)
(1) Peel test and tensile property test The obtained adhesive composition was applied on a slate to a width of 30 mm and a thickness of 3 mm and left at room temperature for 7 days. The thickness was measured and it was confirmed whether or not the trace of the adhesive remained on the slate. Further, the strength at break and the elongation at break were measured according to JIS K6251.

(2) Normal temperature and low temperature curability test In addition, after applying the obtained adhesive composition to a width of 30 mm and a thickness of 1 mm on a slate and leaving it to stand at room temperature for 1 day, a cured product of the adhesive composition by hand. Was peeled off and evaluated for curability and peelability at room temperature. The evaluation criteria are as follows.
○: There is no cut of the cured product and it can be peeled off without leaving a trace.
X: Hardened | cured material cuts or a trace remains.

Furthermore, after applying the obtained adhesive composition to a width of 30 mm and a thickness of 1 mm on the slate and leaving it at 5 degrees for 16 hours and 24 hours, the cured product of the adhesive composition was peeled off by hand, The curability and peelability of the film were evaluated. The evaluation criteria are as follows.
○: After 16 hours from application, the cured product is not cut and can be removed without leaving any trace.
(Triangle | delta): It can peel without a cut of hardened | cured material remaining in 24 hours after application | coating, and no trace remains.
X: Hardened | cured material cuts or a trace remains.

(3) Transparency test Moreover, about transparency, the said obtained adhesive composition is apply | coated by the application | coating thickness 1-2mm of normal application | coating on a concrete crack, and a crack can be confirmed immediately after application | coating of an adhesive composition. It was evaluated visually. The evaluation criteria are as follows.
○: The crack can be easily confirmed.
Δ: It is difficult to confirm cracks.
X: No cracks can be confirmed.

(Examples 6 to 10)
After stirring and mixing the urethane prepolymer, filler, curing catalyst and diluent at 90 ° C. in a nitrogen stream with the formulation shown in Table 3, polyaldimine, hydrolyzable ester compound and p-toluene with the formulation shown in Table 3 Sulfonyl isocyanate was added and stirred and mixed at room temperature under a nitrogen stream to obtain an adhesive composition. The obtained adhesive composition was tested in the same manner as in Example 1. The results are shown in Table 4.

The compounding ratio of each compounding substance in Table 3 is shown in parts by mass, 1), 3), 6) and 7) are the same as in Table 1, and 9) to 12) are as follows.
9) ALD-1 (dialdimine, amine value 337 mg KOH / g): Mitsui Takeda Chemical Co., Ltd. 10) Methyl orthoformate: Niho Chemical Co., Ltd. 11) Cyclohexanone dimethyl acetal 12) p-Toluenesulfonyl isocyanate

(Comparative Examples 1 and 2)
As shown in Table 5, after modifying silicone, a filler, and a plasticizer were mixed and heated and melted, dibutyltin diacetylacetonate was added as a curing catalyst to obtain an adhesive composition containing the modified silicone as a main component. The obtained adhesive composition was tested in the same manner as in Example 1. The results are shown in Table 6.

The blending ratio of each compounding substance in Table 5 is shown in parts by mass, 3), 4) and 8) are the same as in Table 1, and 13) and 14) are as follows.
13) MS polymer S203: manufactured by Kaneka Corporation 14) Neostan U-220: manufactured by Nitto Kasei Kogyo Co., Ltd.

(Comparative Example 3)
In a stirrer equipped with a thermometer, 90 parts by mass of polypropylene glycol having a molecular weight of 5000 (manufactured by Mitsui Takeda Chemical Co., Ltd., trade name: Actol 87-34) was dehydrated, and then 2, 4/2, 6 (80 / 20) 10 parts by mass of toluene diisocyanate was added and reacted at 70 to 90 ° C. for 5 hours under a nitrogen atmosphere to prepare urethane prepolymer C having a terminal isocyanate content of 2.5% and used as a curing agent.

  70 parts by mass of polypropylene glycol (manufactured by Mitsui Takeda Chemical Co., Ltd., trade name: Actol 79-56), 30 parts by mass of polypropylene glycol (manufactured by Mitsui Takeda Chemical Co., Ltd., trade name: Diol-3000), and dibutyltin 0.4 parts by mass of laurate (manufactured by Sansha Co., Ltd., trade name: STANN BL) was mixed and stirred to prepare a main agent.

  The obtained main agent and curing agent were mixed so that the mixing ratio was main agent: curing agent = 1: 0.5 (mass ratio) to obtain a two-pack type urethane adhesive composition. The obtained adhesive composition was tested in the same manner as in Example 1. The results are shown in Table 6.

  As shown in Table 2 and Table 4, the adhesive compositions of Examples 1 to 10 are easily peelable by hand, the adhesive does not remain as a trace, and the adhesive can be peeled off without being cut off. It had excellent strength and elongation, was extremely excellent in workability, and had good low-temperature curability. In particular, the adhesive compositions of Examples 1, 4, and 6 to 10 are transparent at the time of application, can be easily applied because the position of cracks can be seen at the time of construction, and the amount of adhesive used can be reduced. And the economy was excellent. The adhesive compositions of Examples 6 to 10 showed extremely good low-temperature curability.

  On the other hand, as shown in Table 6, the modified silicone-based compositions of Comparative Examples 1 and 2 left traces of the adhesive on the slate, and the adhesive was cut off when peeled off, which was difficult to remove. The curability and peelability were poor, and the two-component urethane composition of Comparative Example 3 had traces of adhesive remaining on the slate and poor low-temperature curability.

It is a schematic top view showing an example when repairing a crack, (a) is a top view showing a crack surface before repair, (b) is a top view in which the crack surface is sealed and a repair agent injection device is fixed, (C) is a top view showing a crack surface after repair. BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic explanatory drawing which shows an example at the time of repairing a crack, (a) is sectional drawing which shows the crack before repair, (b) is sectional drawing which sealed the crack surface and fixed the apparatus for repairing agent injection | pouring, ( c) is a cross-sectional view showing a crack after repair.

Explanation of symbols

10: crack, 12: 1 liquid moisture curable urethane adhesive composition (adhesive composition for repairing crack), 14: repair agent, 20: appliance for injecting repair agent, 30: injection port.

Claims (12)

  A crack repairing method for sealing a surface of a crack with a sealant and fixing a repairing agent injection device with an adhesive and injecting the repair agent into the crack, wherein the urethane prepolymer is used as the sealant and the adhesive. A method for repairing a crack, comprising using a one-component moisture-curable urethane adhesive composition containing   The crack repairing method according to claim 1, wherein the one-component moisture-curing urethane adhesive composition has transparency.   The repair method according to claim 1 or 2, wherein the one-component moisture-curable urethane adhesive composition contains a latent curing agent.   The repair method according to claim 3, wherein the latent curing agent is polyaldimine.   The repair method according to claim 3 or 4, wherein the one-component moisture-curable urethane adhesive composition contains a hydrolyzable ester compound.   The repair method according to any one of claims 3 to 5, wherein the one-component moisture-curable urethane adhesive composition contains p-toluenesulfonyl isocyanate.   An adhesive composition for repairing cracks comprising a one-component moisture-curable adhesive composition containing a urethane prepolymer.   The adhesive composition for repairing cracks according to claim 7, which has transparency.   The crack repairing adhesive composition according to claim 7 or 8, wherein the one-component moisture-curing urethane adhesive composition contains a latent curing agent.   The crack repairing adhesive composition according to claim 9, wherein the latent curing agent is polyaldimine.   The adhesive composition for repairing a crack according to claim 9 or 10, wherein the one-component moisture-curable urethane adhesive composition contains a hydrolyzable ester compound. The adhesive composition for repairing a crack according to any one of claims 9 to 11, wherein the one-component moisture-curable urethane adhesive composition contains p-toluenesulfonyl isocyanate.

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