JP2014134029A - Building reinforcement method and fiber-reinforced adhesive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To raise adhesiveness between a reinforced body and a fiber sheet, and a reinforcement effect of the reinforced body.SOLUTION: The present invention provides a building reinforcement method for reinforcing a building by sticking a fiber sheet to a reinforcement surface of a reinforced body via an adhesive compound. In this method, the adhesive compound contains urethane prepolymer containing an isocyanate group at a terminal to be obtained by making polyol react to polyisocyanate, the polyol contains polytetra methylene glycol and/or denatured polytetra methylene glycol, and two or more functions of polypropylene glycol, and the polyisocyanate contains diphenylmethane diisocyanate. It is preferable that the polyol further contains polyester polyol. It is preferable that the adhesive compound further contains external additive polyisocyanate, tertiary amine curing catalyst, and silica.

Description

  The present invention relates to a building reinforcing method and a fiber-reinforced adhesive sheet.

  In recent years, a fiber sheet bonding method has been spreading as a method for reinforcing buildings. In this construction method, a carbon fiber sheet is impregnated with a resin and adhered to the concrete surface, whereby bending reinforcement, shear reinforcement, and toughness reinforcement of the concrete are performed.

  Conventionally, as the resin for impregnation used in the carbon fiber sheet construction method, a two-pack type epoxy resin system is mainly used. However, in the two-pack type epoxy resin system, the measurement and mixing of the resin must be performed on site, which is not only inferior in workability but also has a problem that quality may vary. In addition, since the resins must be mixed at a constant mixing ratio, there is a problem that at least one of the resins is left and the raw materials are wasted. Further, considering the time (pot life) from mixing the two liquids to curing the mixed liquid, there is a problem that the two liquids must be mixed little by little. In addition, since the process of applying the mixed liquid to the concrete surface and then applying the fiber sheet is performed, there is also a problem that a difference in skill may occur for each worker in applying the mixed liquid and attaching the fiber sheet. In addition, after the work is finished, the container in which the two liquids are mixed must be washed, or the empty can that contains the two liquids must be discarded. There is also a problem of accompanying.

  In order to solve the above problems, a one-component epoxy resin composite material that has a reinforcing effect equivalent to that of a conventional two-component epoxy resin composite material, has good workability, and is excellent in terms of work environment and resource consumption. A building reinforcement method has been proposed (see, for example, Patent Document 1). According to this method, since the mixing operation of the main agent and the curing agent is eliminated, the workability is excellent as compared with the conventional method, and the material is not wasted, so that it is excellent in terms of resource consumption.

JP 11-131823 A

  However, in general, the object to be reinforced is a foundation or a column base of a building, and the material of the fiber sheet is glass fiber, carbon fiber, or the like. Thus, since the materials of the materials to be bonded are greatly different, it is required to further increase the adhesiveness, the reinforcing effect and the like for both.

  Then, an object of this invention is to improve the adhesiveness of a to-be-reinforced body and a fiber sheet, and the reinforcement effect of a to-be-reinforced body further.

  In order to solve the above problems, the present inventors have conducted extensive research on the composition of the adhesive composition. As a result, a urethane prepolymer containing an isocyanate group at the terminal, obtained by reacting a polyol with a polyisocyanate, is obtained. Using a one-component moisture-curing adhesive composition, and the polyol contains both polytetramethylene glycol and / or modified polytetramethylene glycol and bifunctional or higher-functional polypropylene glycol. The inventors have found that the adhesiveness between the reinforced body and the fiber sheet is further improved by including diphenylmethane diisocyanate in the isocyanate, and the present invention has been completed. Specifically, the present invention provides the following.

  (1) The present invention is a building reinforcing method for reinforcing a building by attaching a fiber sheet to a reinforcing surface of a reinforced body via an adhesive composition, the adhesive composition comprising a polyol and It contains a urethane prepolymer having an isocyanate group at the terminal, obtained by reacting with polyisocyanate, and the polyol contains polytetramethylene glycol and / or modified polytetramethylene glycol and bifunctional or higher-functional polypropylene glycol. The polyisocyanate is a method for reinforcing a building, which contains diphenylmethane diisocyanate.

  (2) Moreover, this invention is a building reinforcement method as described in (1) whose said polyol further contains polyester polyol.

  (3) Moreover, this invention is a building reinforcement method as described in (2) whose said polyester polyol is an adipic acid type polyester polyol.

  (4) Moreover, this invention is a building reinforcement method in any one of (1) to (3) in which the said polyol further contains the polyol which has bisphenol A frame | skeleton.

  (5) Further, in the present invention, in addition to the polyisocyanate as a starting material of the urethane prepolymer, the adhesive composition further contains a polyisocyanate that is the same as or different from the polyisocyanate as the starting material. The building reinforcing method according to any one of 1) to (4).

  (6) Moreover, this invention is a building reinforcement method as described in (5) the polyisocyanate same or different from the polyisocyanate as the said starting material contains carbodiimide modified diphenylmethane diisocyanate.

  (7) Moreover, this invention is the building reinforcement method in any one of (1) to (6) in which the said adhesive composition further contains a curing catalyst.

  (8) Moreover, this invention is a building reinforcement method in any one of (1) to (7) in which the said adhesive composition further contains a silica.

  (9) Moreover, the present invention provides one release sheet of a fiber reinforced adhesive sheet in which release sheets are laminated on both surfaces of a fiber reinforced adhesive layer obtained by impregnating or laminating the fiber sheet with the adhesive composition. The fiber reinforced adhesive layer that is exposed and attached is attached to the reinforcing surface of the reinforced body, pressed from the other release sheet, and the fiber reinforced adhesive layer is cured by moisture. (1) To the building reinforcement method according to any one of (8).

  (10) The present invention also provides a fiber reinforced adhesive sheet in which release sheets are laminated on both surfaces of a fiber reinforced adhesive layer obtained by impregnating or laminating a fiber sheet with an adhesive composition, the adhesive composition The product contains a urethane prepolymer having an isocyanate group at the terminal, which is obtained by reacting a polyol and a polyisocyanate, and the polyol contains a polytetramethylene glycol and / or a modified polytetramethylene glycol and a bifunctional or more functional group. It is a fiber-reinforced adhesive sheet that contains polypropylene glycol and the polyisocyanate contains diphenylmethane diisocyanate.

  ADVANTAGE OF THE INVENTION According to this invention, the adhesiveness of a to-be-reinforced body and a fiber sheet and the reinforcement effect of a to-be-reinforced body can be improved further.

It is sectional drawing which shows the fiber reinforced adhesive agent sheet which concerns on this embodiment. It is a figure which shows the reinforcement construction method of the building using the said fiber reinforced adhesive sheet in case a to-be-reinforced body is concrete. It is the schematic which shows the fiber reinforced adhesive sheet | seat package which concerns on this embodiment. It is a figure which shows that the said fiber reinforced adhesive sheet is an elongate winding body which has a predetermined width direction as one form of the said fiber reinforced adhesive sheet. It is a figure which shows the reinforcement construction method of the building using the said fiber reinforced adhesive sheet in case a to-be-reinforced body is wood. It is the schematic of the test body in the tension test of a column base junction part.

  Hereinafter, specific embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and may be implemented with appropriate modifications within the scope of the object of the present invention. be able to.

  The present invention is a building reinforcing method for reinforcing a building by sticking a fiber sheet to a reinforcing surface of a reinforced body through an adhesive composition.

<Adhesive composition>
The adhesive composition is a one-component moisture-curing type and contains (A) a urethane prepolymer. In addition, it is preferable that the adhesive composition further contains (B) polyisocyanate, (C) a curing catalyst and / or (D) silica.

[(A) Urethane prepolymer]
(A) The urethane prepolymer has an isocyanate group at the terminal. This urethane prepolymer is obtained by reacting (A1) polyol with (A2) polyisocyanate.

[(A1) polyol]
The (A1) polyol contains both (A11) polytetramethylene glycol and / or modified polytetramethylene glycol and (A12) a bifunctional or higher functional polypropylene glycol. The (A1) polyol preferably further comprises (A13) a polyester polyol and / or (A14) a polyol having a bisphenol skeleton. And it is more preferable that (A13) polyester polyol contains adipic acid-type polyester. Hereinafter, polytetramethylene glycol is also referred to as “PTG”, modified polytetramethylene glycol is also referred to as “PTXG”, and polypropylene glycol is also referred to as “PPG”.

((A11) PTG and / or PTXG)
As the PTG, known polymers of tetrahydrofuran can be widely used. Although the molecular weight of PTG is not particularly limited, it is preferable to use a number average molecular weight of 500 to 5000, more preferably 500 to 2000. Hereinafter, the number average molecular weight is also referred to as “Mn”. PTG may be used alone or in combination of two or more.

  PTXG is a copolymer of tetramethylene ether and alkylene ether, and the alkylene ether preferably has a side chain. Examples of PTXG include a copolymer of tetrahydrofuran and an alkyl-substituted tetrahydrofuran, a copolymer of tetrahydrofuran and an alkylene oxide, a copolymer of tetrahydrofuran and an alkylene ether having a side chain, and the like. As a copolymer of tetrahydrofuran and alkyl-substituted tetrahydrofuran, for example, a copolymer of tetrahydrofuran and 3-alkyltetrahydrofuran described in JP-A-63-235320 can be mentioned as a suitable example.

  The molecular weight of PTXG is not particularly limited, but it is preferable to use a number average molecular weight of 500 to 5000, more preferably 1000 to 3000. PTXG may be used alone or in combination of two or more.

  Only one type of PTG and / or PTXG may be used, or two or more types may be used in combination. The combination is not particularly limited, but PTXG is preferably used from the viewpoint of workability. When two or more polyols are used in combination, two or more polyols and polyisocyanate may be reacted to synthesize a urethane prepolymer, or two or more urethane prepolymers having different polyol components may be mixed and used. Good.

  The content of PTG and / or PTXG is preferably 20% by weight to 70% by weight and more preferably 30% by weight to 60% by weight with respect to the total polyol. If it is less than 20% by weight, the toughness of the cured product is lowered and there is a possibility that the reinforcement effect against bending of the column base and concrete may not be sufficiently exhibited. If it exceeds 70% by weight, workability may be lowered, which is not preferable.

((A12) Bifunctional or higher functional PPG)
The PPG is not particularly limited as long as it is bifunctional or higher, but as the bifunctional or higher PPG, for example, an addition polymer of propylene oxide (propylene oxide, starting with a low molecular weight polyol or an aromatic / aliphatic polyamine), And random and / or block copolymers with alkylene oxides such as ethylene oxide).

  The content of the bifunctional or higher functional PPG is preferably 1% by weight or more and 80% by weight or less, and more preferably 20% by weight or more and 70% by weight or less with respect to the total polyol. If it is less than 1% by weight, workability may be lowered, which is not preferable. If it exceeds 80% by weight, the toughness of the cured product is lowered, and there is a possibility that the reinforcement effect against bending of the column base and concrete may not be sufficiently exhibited.

((A13) Polyester polyol)
Although not essential, the (A1) polyol preferably further contains a polyester polyol.

  Examples of polyester polyols include polycondensates obtained by reacting low molecular weight polyols and polybasic acids under known conditions.

  The low molecular weight polyol is a compound having two or more hydroxyl groups and a number average molecular weight of less than 400, such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butylene glycol, 1,3-butylene. Glycol, 1,2-butylene glycol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 3,3-dimethylolheptane, alkane (C7- 20) Diol, 1,4-dihydroxy-2-butene, 2,6-dimethyl-1-octene-3,8-diol, diethylene glycol, triethylene glycol, dipropylene glycol, 1,3- or 1,4-cyclohexane Dimethanol and mixtures thereof, 1,3- or 1,4- Chrohexanediol and mixtures thereof, dihydric alcohols such as hydrogenated bisphenol A and bisphenol A, for example, trivalent alcohols such as glycerin and trimethylolpropane, for example, tetravalents such as tetramethylolmethane (pentaerythritol) and diglycerin Alcohol, for example, pentahydric alcohol such as xylitol, for example, sorbitol, mannitol, allitol, iditol, dulcitol, altritol, inositol, dipentaerythritol, etc. And octahydric alcohols.

  Examples of the polybasic acid include oxalic acid, malonic acid, succinic acid, methyl succinic acid, glutaric acid, adipic acid, 1,1-dimethyl-1,3-dicarboxypropane, and 3-methyl-3-ethylglutaric acid. , Azelaic acid, sebacic acid, other saturated aliphatic dicarboxylic acids (C11-13) such as maleic acid, fumaric acid, itaconic acid, other unsaturated aliphatic dicarboxylic acids such as orthophthalic acid, isophthalic acid, terephthalic acid , Toluene dicarboxylic acid, naphthalenedicarboxylic acid, other aromatic dicarboxylic acids such as hexahydrophthalic acid, other alicyclic dicarboxylic acids such as dimer acid, hydrogenated dimer acid, and other carboxylic acids such as het acid, And acid anhydrides derived from these carboxylic acids, such as oxalic anhydride, succinic anhydride, Hydromaleic acid, phthalic anhydride, 2-alkyl (C12-C18) succinic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, and acid halides derived from these carboxylic acids, such as oxalic acid dichloride , Adipic acid dichloride, sebacic acid dichloride, and the like.

  Among these, from the viewpoint of workability, the polyester polyol is preferably an adipic acid-based polyester. Examples of adipic acid-based polyesters include esterified products of adipic acid and 3-methyl-1,5-pentanediol.

  The polyester polyol is not an essential component, but when the polyol contains the polyester polyol, the content thereof is preferably 1% by weight or more and 60% by weight or less with respect to the total polyol, and is preferably 10% by weight or more and 60% by weight or less. More preferably, it is more preferably 20% by weight or more and 50% by weight or less. If it is less than 1% by weight, it is possible that the improvement of the adhesion to the reinforced body and the fiber sheet and the improvement of the reinforcement effect against the bending of the column base and concrete obtained by containing the adipic acid polyester may not be sufficiently exhibited. There is sex. When it exceeds 60% by weight, workability may be lowered, and therefore, it is not preferable.

((A14) polyol having bisphenol skeleton)
Although not essential, the (A1) polyol preferably further contains a polyol having a bisphenol skeleton.

  A polyol having a bisphenol skeleton has a structure represented by the following general formula (1).

（式中、Ｒ_１及びＲ_２は、直鎖または分岐構造を有する炭素数１〜８の炭化水素を表し、Ｒ_３及びＲ_４は、それぞれ独立に水素、メチル基又はエチル基を表す。ｍ及びｎは１以上の整数から選ばれる。） General formula (1)

(In the formula, R ₁ and R _{2 each} represent a linear or branched hydrocarbon having 1 to 8 carbon atoms, and R ₃ and R ₄ each independently represent hydrogen, a methyl group, or an ethyl group. And n is selected from integers of 1 or more.)

  A polyol having a bisphenol skeleton can be obtained by addition reaction of a bisphenol compound and an alkylene oxide having 1 to 8 carbon atoms. A catalyst may be used in the production, and examples of the catalyst used include amine-based catalysts such as primary amines, secondary amines, tertiary amines and salts thereof, quaternary ammonium salts, and acid catalysts.

Examples of the bisphenol compound include (a) bis (4-hydroxyphenyl) methane, 2,4′-methylenebisphenol, 2,2′-methylenebisphenol in which R ₃ and R ₄ are hydrogen, and (a) R ₃ and R ₄ is a methyl group, 2,2-bis (4-hydroxyphenyl) propane, 2- (o-hydroxyphenyl) -2- (p-hydroxyphenyl) propane, (U) R ₃ is hydrogen, R ₄ is a methyl group, 1,1-bis or (4-hydroxyphenyl) ethane, a (d) _{R 3} is a methyl group, _{R 4} is ethyl group, 2,2-bis (4-hydroxyphenyl) butane Etc.

  Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, pentylene oxide, hexylene oxide, heptylene oxide, and octylene oxide. From the viewpoint of compatibility with other components, ethylene oxide and / or Or it is preferable that it is a propylene oxide.

  As the polyol having a bisphenol skeleton, one represented by the following general formula (2) is preferable because it is easily available. Examples of commercially available products include, for example, Bisol series manufactured by Toho Chemical Industry Co., Ltd., Adeka Polyol BPX series manufactured by Adeka Co., Ltd., New Pole BP series, BPE series manufactured by Sanyo Chemical Industries, Ltd., and Nippon Emulsifier Co., Ltd. BA series etc. are mentioned. These may be used alone or in any combination of two or more.

一般式（２）において、Ｒ_１、Ｒ_２、ｍ及びｎは、一般式（１）と同じである。 General formula (2)

In the general formula (2), R ₁ , R ₂ , m and n are the same as those in the general formula (1).

  The polyol having a bisphenol skeleton is not an essential component, but when the polyol contains a polyol having a bisphenol skeleton, the content thereof is preferably 1% by weight or more and 40% by weight or less based on the total polyol. More preferably, it is at least 30% by weight. If it is less than 1% by weight, there is a possibility that the reinforcement effect for the bending of the column base and concrete obtained by containing a polyol having a bisphenol skeleton cannot be sufficiently exhibited. If it exceeds 40% by weight, the cured product may be hard and brittle, and workability may also be reduced.

(Other polyols)
The present invention does not exclude that (A1) polyol includes other polyols different from the above (A11) to (A14). The other polyol may be any active hydrogen-containing compound having two or more active hydrogen groups, and is not particularly limited. For example, other polyols such as trifunctional or higher polyhydric alcohols and diols may be used. Examples include polyether polyol, polyester polyol, polybutadiene polyol, polyisoprene polyol, polyolefin polyol, polymer polyol, polycaprolactone polyol, and polyacrylic ester polyol. These polyols may be used alone or in combination of two or more.

[(A2) polyisocyanate]
The (A) urethane prepolymer is obtained by reacting the above (A1) polyol and (A2) polyisocyanate.

  (A2) The polyisocyanate contains diphenylmethane diisocyanate (MDI). By including MDI, the adhesiveness with respect to both a to-be-reinforced body and a fiber sheet is excellent.

  By the way, polyisocyanate may contain other polyisocyanate in addition to MDI. Other polyisocyanates are not particularly limited, and known polyisocyanate compounds having two or more isocyanate groups can be used. For example, polymeric MDI (PMDI), tolylene diisocyanate (TDI), xylene diisocyanate ( XDI), aromatic polyisocyanates such as naphthalene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate (HDI), lysine methyl ester diisocyanate, hydrogenated diphenylmethane diisocyanate, isophorone diisocyanate (IPDI), norbornane diisocyanate, hydrogenated Alicyclic polyisocyanates such as tolylene diisocyanate, carbodiimide-modified isocyanate, isocyanurate modification of the above isocyanate It can be used and the like.

  (A1) The method of making a polyol component and (A2) polyisocyanate react is not specifically limited, A well-known method can be used. Specifically, the polyol component having two or more hydroxyl groups (OH) and the polyisocyanate having two or more isocyanate groups (NCO) are used so that the isocyanate groups become excessive, that is, the NCO / OH equivalent ratio is more than 1. By making it react so that it may become large, the urethane prepolymer which has an isocyanate group at the terminal is obtained.

  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.

[(B) a polyisocyanate which is the same as or different from the polyisocyanate as the starting material, added in addition to the polyisocyanate as the starting material of the urethane prepolymer]
Although not essential, it is preferable that the adhesive composition of the present invention further contains (B) polyisocyanate in addition to (A2) polyisocyanate as a starting material for (A) urethane prepolymer.

  (B) The kind of polyisocyanate is not specifically limited, The same thing as what was demonstrated by (A2) polyisocyanate can be used. Among them, carbodiimide-modified MDI is preferably used as the polyisocyanate as the component (B), that is, as the polyisocyanate used for the post-addition, since foaming is small and the curing speed is high.

  (B) Polyisocyanate as component, that is, it is not essential to add polyisocyanate to component (A), but the adhesive composition contains polyisocyanate as component (B) The content thereof is preferably 40% by weight or less, more preferably 30% by weight or less based on 100 parts by weight of the (A) urethane prepolymer. If it exceeds 40% by weight, the cured product may be hard and brittle, which is not preferable.

[(C) Curing catalyst]
Although not essential, it is preferable that the adhesive composition of the present invention further contains (C) a curing catalyst in addition to (A) the urethane prepolymer.

  The kind of curing catalyst is not particularly limited, and examples thereof include a tertiary amine catalyst and a tin catalyst. As the tertiary amine catalyst, known tertiary amines can be widely used. For example, triethylamine, tripropylamine, triisopropylamine, tributylamine, triisobutylamine, tritertiary butylamine, triamylamine, trihexylamine. , Monoamines such as trioctylamine, tri-2-ethylhexylamine, methyldi-2-ethylhexylamine, dibutyl-2-ethylhexylamine, trihexadecylamine, tribenzylamine; tetramethyl 1,2-diaminoethane, tetramethyl 1,3 -Polyamines such as diaminopropane, tetramethylhexamethylenediamine, pentamethyldiethylenetriamine; triethylenediamine; N-ethylmorpholine, bis (morpholinoethyl) ether, 2,2'- Morpholino diethyl ether, bis (2,6-dimethylmorpholinoethyl) ether, bis (3,5-dimethylmorpholinoethyl) ether, bis (3,6-dimethylmorpholinoethyl) ether, 4- (3,5-dimethylmorpholino) And morpholine compounds such as -4 ′-(3,6-dimethylmorpholino) diethyl ether.

  As the tin catalyst, known organic tin compounds can be widely used. For example, divalent organic tin compounds such as tin octylate and tin naphthenate; dibutyltin dioctoate, dibutyltin dilaurate, dibutyltin diacetate, dibutyltin Tetravalent compounds such as dimaleate, dibutyltin distearate, dioctyltin dineodecanoate, dioctyltin dilaurate, dioctyltin diversate, dibutyltin oxide, dibutyltin bis (triethoxysilicate), reaction product of dibutyltin oxide and phthalate Organic tin compounds; and tin-based chelate compounds such as dibutyltin bis (acetylacetonate).

  (C) Although the blending ratio of the curing catalyst is not particularly limited, it is preferable to blend 0.01 to 10 parts by weight with respect to 100 parts by weight of (A) urethane prepolymer, and 0.01 to 2 parts by weight is blended. Is more preferable. One type of curing catalyst may be used alone, or two or more types may be used in combination.

[(D) Silica]
Although not essential, it is preferable that the adhesive composition of the present invention further contains (D) silica in addition to (A) the urethane prepolymer. By containing silica, thixotropy can be imparted and dripping can be prevented.

  Examples of silica (D) include fumed silica, calcined silica, precipitated silica, pulverized silica, fused silica, and the like, and it is preferable to use fine powder silica.

  The blending ratio of silica is not particularly limited, but it is preferable to blend 0.5 to 30.0 parts by weight with respect to 100 parts by weight of (A) urethane prepolymer, and to blend 3.0 to 15.0 parts by weight. Is more preferable. One type of silica may be used alone, or two or more types of silica may be used in combination.

[(E) Other ingredients]
In addition to the above (A) to (D), the adhesive composition comprises (E1) solvent, (E2) plasticizer, (E3) dehydrating agent (storage stability improving agent), and (E4) as necessary. In addition to coupling agents and (E5) fillers, colorants, anti-discoloring agents, adhesion-imparting agents, physical property modifiers, mold release agents, lubricants, tackifiers, anti-sagging agents, UV absorbers, antioxidants, water You may mix | blend various additives, such as a decomposition stabilizer, a flame retardant, and a radical polymerization initiator.

((E1) solvent)
The type of the solvent is not particularly limited, and examples thereof include alcohol solvents other than methanol such as ethanol and isopropyl alcohol, butyl glycidyl ether, allyl glycidyl ether, phenyl glycidyl ether, pentane, hexane, paraffin, and isoparaffin.

((E2) Plasticizer)
Examples of the plasticizer include dioctyl phthalate (DOP), dibutyl phthalate (DBP), dilauryl phthalate (DLP), butyl benzyl phthalate (BBP), dioctyl adipate, diisononyl phthalate (DINP), diisodecyl adipate, diisodecyl phthalate, trioctyl. Examples include phosphate, tris (chloroethyl) phosphate, tris (dichloropropyl) phosphate, propylene glycol adipate polyester, butylene glycol adipate polyester, alkyl alkyl stearate, and epoxidized soybean oil. can do.

((E3) dehydrating agent (storage stability improving agent))
The kind of dehydrating agent is not particularly limited, and is a low-molecular crosslinkable silyl group-containing compound such as vinyltrimethoxysilane, calcium oxide, p-toluenesulfonyl isocyanate (PTSI), which reacts with moisture present in the composition. ) And the like.

((E4) coupling agent)
Coupling agents include silane coupling agents such as chloropropyltrimethoxysilane, vinyltrichlorosilane, and 3-glycidoxypropyltrimethoxysilane, and titanium-based coupling agents such as isopropyltriisostearoyl titanate and isopropyltrilauryl myristyl titanate. Is mentioned.

((E5) filler)
Examples of the filler include organic or inorganic materials of various shapes, such as calcium carbonate, magnesium carbonate, zinc carbonate; carbon black; clay; talc; kaolin; diatomaceous earth; zeolite; titanium oxide, quicklime, iron oxide, Zinc oxide, barium oxide, magnesium oxide; aluminum sulfate; aluminum hydroxide; vinyl chloride paste resin; glass balloon, shirasu balloon, saran balloon, phenol balloon, vinylidene chloride resin balloon and other inorganic balloons, organic balloons, etc .; or these fatty acids And fatty acid ester-treated products, etc., and can be used alone or in combination. Moreover, you may use inorganic hollow fillers, such as a glass balloon and a silica balloon, and organic hollow fillers, such as a polyvinylidene fluoride and a polyvinylidene fluoride copolymer.

  Examples of the colorant include titanium oxide, chromium oxide, and zinc oxide.

  Examples of the ultraviolet absorber include benzotriazole-based ultraviolet absorbers such as 2- (3,5-di-tert-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, and 2- (4,6-diphenyl- 1,3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol and other triazine-based UV absorbers, benzophenone-based UV absorbers such as octabenzophene, 2,4-di-tert- Examples thereof include benzoate ultraviolet absorbers such as butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate.

  Examples of the antioxidant include hindered phenol compounds and triazole compounds. Examples of the hindered phenol antioxidant include pentaerythritol-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert). -Butyl-4-hydroxyphenyl) propionate], N, N'-hexane-1,6-diylbis [3- (3,5-di-tert-butyl-4-hydroxyphenylpropioamide], benzenepropanoic acid 3, Examples include 5-bis (1,1-dimethylethyl) -4-hydroxy C7-C9 side chain alkyl ester, 2,4-dimethyl-6- (1-methylpentadecyl) phenol, and the like.

  Examples of the hydrolysis stabilizer include aromatic carbodiimides, and carbodiimide monomers having a melting point of about 40 ° C., carbodiimide low-molecular polymers having a melting point of 60 to 90 ° C., and carbodiimide polymers having a melting point of 100 to 120 ° C. are particularly preferable. The hydrolysis stabilizer is preferably added in an amount of 0.01 to 3.0 parts by weight, more preferably 0.1 to 2.0 parts by weight, based on 100 parts by weight of the urethane prepolymer (A). .

  As the flame retardant, an organic halogen compound, a phosphorus compound, a nitrogen-containing compound such as a (iso) cyanuric acid derivative compound, an inorganic compound, or the like can be blended. In addition, it is preferable to mix | blend the flame retardant which does not contain a halogen from an environmental viewpoint.

[viscosity]
The viscosity of the adhesive composition is preferably about 5 to 500 Pa · s (23 ° C.) from the viewpoints of applicability, fluidity, and impregnation into a fiber sheet.

<Reinforcement of buildings>
The reinforcement of the building may be anything as long as the fiber sheet is attached to the reinforcing surface of the reinforced body through the adhesive composition. For example, the mixed liquid may be applied to the reinforcing surface of the reinforced body, and then the fiber sheet may be attached. Further, the fiber reinforced adhesive sheet 1 shown in FIG. 1 is used, and this fiber reinforced adhesive sheet 1 is attached to the reinforcing surface (for example, the surface of the foundation concrete 10) of the reinforced body by the method shown in FIG. Also good.

[Fiber-reinforced adhesive sheet 1]
FIG. 1 is a schematic cross-sectional view of a fiber-reinforced adhesive sheet 1. The fiber reinforced adhesive sheet 1 includes a first release sheet 2, a fiber sheet 3, a fiber reinforced adhesive layer 4 in which the fiber sheet 3 is impregnated or laminated, and a second release. Sheets 5 are sequentially laminated.

  The fiber sheet 3 may be any material as long as it is used as a material used in the fiber sheet bonding method. For example, a carbon fiber sheet, an aramid fiber sheet, a glass fiber sheet, and the like are known. . The thickness of the fiber sheet 3 is preferably 10 μm or more. When the thickness is less than 10 μm, it is not preferable in that the reinforced body may not be effectively reinforced even if the fiber reinforced adhesive sheet 1 is attached to the reinforcing surface of the reinforced body.

  The thickness of the fiber reinforced adhesive layer 4 is preferably 10 μm or more. If the thickness is less than 10 μm, it is not preferable because there is a possibility that the fiber-reinforced adhesive sheet 1 may not be effectively bonded even if it is attached to the reinforcing surface of the reinforced body.

[Accommodating form of fiber-reinforced adhesive sheet 1]
Since the adhesive composition is cured by moisture in the air, when the fiber reinforced adhesive sheet 1 is used, it is required to take measures to prevent the adhesive composition from curing when not used. Any countermeasure may be used. For example, it is conceivable that the release sheets 2 and 5 are packaged with a package having moisture barrier properties in addition to taking moisture countermeasures.

  In the former case, the release sheets 2 and 5 may be made of a polyvinylidene chloride film, a polyvinyl alcohol film, a polyacrylonitrile film, an ethylene-vinyl alcohol copolymer film, an aluminum foil, a nylon multilayer film, a transparent vapor deposition film, or the like. Conceivable. In this case, it is preferable that the thickness of the release sheets 2 and 5 is 5 μm or more. When the thickness is less than 5 μm, it is not preferable in that the moisture or ultraviolet blocking property may not function effectively.

  In the latter case, it is conceivable to use a package 20 as shown in FIG. It is sufficient if the package 20 has a moisture barrier property, but from the viewpoint of handling and disposal, as shown in FIG. 3, the package 20 can be sealed by heat sealing or adhesion, including an aluminum foil or an aluminum deposited film. A bag is preferred.

  The state of the fiber reinforced adhesive sheet 1 accommodated in the package 20 may be any state. For example, a plurality of fiber reinforced adhesive sheets 1 may be accommodated in the package 20 in a state where they are stacked, or as shown in FIG. 4, a fiber reinforced adhesive sheet as a long winding body. A plurality of 1 may be accommodated in the package 20. Above all, it can be processed freely according to the shape of the reinforcing surface of the body to be reinforced, and since it is excellent in carrying, a plurality of fiber reinforced adhesive sheets as long winding bodies are accommodated in the package 20. Is preferred. When the fiber reinforced adhesive sheet 1 is used to reinforce a pillar of a house such as a timber, the width direction of the fiber reinforced adhesive sheet 1 considering that the width of the pillar of the house is about 150 mm. The length is preferably about 100 to 200 mm. Further, when the fiber reinforced adhesive sheet 1 is used for reinforcing a basic concrete such as a house, the to-be-reinforced body may be about 200 mm to 500 mm.

[Reinforcing procedure of building when fiber reinforced adhesive sheet 1 is used]

  Returning to FIG. 2, FIG. 2 is a diagram showing a procedure for reinforcing a building using the fiber-reinforced adhesive sheet 1 when the object to be reinforced is the basic concrete 10 of a house. First, the worker peels off the second release sheet 5 of the fiber-reinforced adhesive sheet 1 (FIG. 2 (a)). At this time, the fiber sheet 3 is disposed on the second release sheet 5 because the fiber sheet 3 is a separate layer from the fiber reinforced adhesive layer 4. Thereby, the fiber sheet 3 serves as a release layer, and the second release sheet 5 can be easily peeled off. Subsequently, the operator attaches the fiber reinforced adhesive layer 4 exposed by peeling the second release sheet 5 to the reinforcing surface of the foundation concrete 10, and uses the roller 11 to remove the first release sheet 2. Clamping is performed from the surface (FIG. 2B). At this time, the first release sheet 2 is preferably a transparent film in order to facilitate the pressing operation from the outside. Then, the fiber reinforced adhesive layer 4 is impregnated into the fiber sheet 3 by this pressing operation. Subsequently, the worker peels off the first release sheet 2 (FIG. 2 (c)) and cures the fiber reinforced adhesive layer 4 with moisture or ultraviolet rays (FIG. 2 (d)). In addition, the 1st peeling sheet 2 can be easily peeled by this hardening.

  By adopting this method, the fiber sheet can be affixed to the reinforced body without any steps of applying the adhesive composition to the reinforced surface of the reinforced body, so that the fiber reinforced adhesive sheet can be applied to the reinforced body very easily. In addition, the difference in quality that can occur depending on the skill of the operator can be suppressed.

  Moreover, although FIG. 2 demonstrates the case where a to-be-reinforced body is the basic concrete 10 of a house, it is not restricted to this, Even if the to-be-reinforced body is the pillar 12 or the base 13 made from wood, The fiber sheet 3 can be freely attached to the reinforcing surface (FIG. 5). Moreover, although illustration is abbreviate | omitted, a to-be-reinforced body is not restricted to a house, It can use for wide uses, such as a utility pole and a bridge pier.

  Moreover, although 1st Embodiment demonstrated impregnating the fiber reinforced adhesive layer 4 in the fiber sheet 3, and peeling the 1st peeling sheet 2 and hardening the fiber reinforced adhesive layer 4, fiber The first release sheet 2 may be peeled off after the reinforced adhesive layer 4 is cured. This is because the adhesive composition is cured by this moisture because the adherent concrete and wood have sufficient moisture. There is an advantage that the adhesive composition can be prevented from being transferred to the release sheet when the first release sheet 2 is peeled off by removing the first release sheet 2 after curing the fiber reinforced adhesive layer 4. can get.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention does not receive a restriction | limiting at all in these description.

<Synthesis of urethane prepolymer>

The components listed in Table 1 are as follows. In addition, a mixing | blending is a weight part of solid content.
(A1) Polyol (A11) PTG and / or PTXG
PTG (trade name: PTG-1000SN, number average molecular weight: 1000, manufactured by Hodogaya Chemical Co., Ltd.)
PTXG (trade name: PTXG-1800, number average molecular weight: 1800, manufactured by Asahi Kasei Fibers)
(A12) PPG
Bifunctional PPG (trade name: Actol D-3000, number average molecular weight: 3000, manufactured by Mitsui Chemicals)
Trifunctional PPG (trade name: Actol T-5000, number average molecular weight: 5000, manufactured by Mitsui Chemicals, Inc.)
(A13) Polyester polyol Adipic acid-based polyester (trade name: Kuraray polyol P-2010, esterified product of adipic acid and 3-methyl-1,5-pentanediol, bifunctional, number average molecular weight: 2000, manufactured by Kuraray Co., Ltd.)
(A14) Polyol having a bisphenol skeleton 2,2-bis (4-polyoxypropyleneoxyphenyl) propane (trade name: Adekapolyol BPX-11, functional, number average molecular weight: 360, manufactured by ADEKA)
(A2) MDI-containing polyisocyanate (trade name: Cosmonate PH, 4,4-diphenylmethane diisocyanate, manufactured by Mitsui Chemicals)
(A2 ′) Polyisocyanate TDI other than MDI (trade name: Cosmonate T-80, molecular weight: 174, manufactured by Mitsui Chemicals)
IPDI (trade name: VESTANAT IPDI, molecular weight: 222, manufactured by Degussa Japan)

  (A1) Polyol was added to a stirrer equipped with a thermometer in the amount shown in Table 1, and after dehydration treatment, (A2) isocyanate was added in the amount shown in Table 1, and 70 to 90 ° C under a nitrogen atmosphere. It was made to react for 5 hours and the urethane prepolymer which concerns on synthesis example ah was obtained. Table 1 also shows R values defined by the ratio of NCO to OH (NCO / OH) in these urethane prepolymers.

<Preparation of adhesive composition 1>

The components described in Tables 2 to 4 are as follows. In addition, a mixing | blending is a weight part of solid content.
(A) Urethane prepolymer Urethane prepolymer according to Synthesis Examples a to h synthesized in “Synthesis of urethane prepolymer” (B) Externally added polyisocyanate carbodiimide-modified MDI (trade name: Cosmonate LK, manufactured by Mitsui Chemicals)
(C) Curing catalyst Tertiary amine catalyst (trade name: U-CAT660M, 2,2′-dimorpholinodiethyl ether, manufactured by San Apro)
Tin catalyst (trade name: Neostan U-830, dioctyltin dineodecanoate, manufactured by Nitto Kasei)
(D) Silica (trade name: Aerosil RY200S, hydrophobic silica treated with dimethyl silicone oil, manufactured by Nippon Aerosil Co., Ltd.)
(E) Other components (E1) Solvent (trade name: IP Clean LX, isoparaffinic solvent based on isododecane, manufactured by Idemitsu Kosan Co., Ltd.)
(E2) Plasticizer: Diisononyl phthalate (DINP)
(E3) Dehydrating agent (storage stability improver, p-toluenesulfonyl isocyanate (PTSI))
(E4) Coupling agent (trade name: KBM403, 3-glycidoxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.)
(E5) Filler Aluminum hydroxide (trade name: Hygielite H32, Showa Denko)
Calcium carbonate (Brand name: Whiteon SB, manufactured by Shiraishi Calcium)

  In the formulations shown in Tables 2 to 4, the materials excluding the curing catalyst were stirred and mixed at room temperature under a nitrogen stream, and then the curing catalyst was added and stirred and mixed at room temperature under a nitrogen stream. An adhesive composition according to a comparative example was obtained.

<Evaluation of adhesiveness>
Evaluation of adhesiveness was performed according to JIS K6850. As the adherend, 5 × 25 × 100 mm rice bran (water content: 10%) was used. The adhesive composition was applied to a thickness of about 200 μm, and after bonding for an open time of 5 minutes, it was bonded. Then, what was aged at 23 degreeC50% RH for 1 week was made into the adhesive test body. The results are shown in Tables 5-7.

<Tension test of column base joint>
Tensile tests for column base joints are as follows: "Testing and evaluation of wooden members, etc. 4" Testing and evaluation methods for joints and joints "(June 2011 issue, Building Materials Testing Center) The following method was used with reference to the description.

1. Preparation of test body First, the test body shown in FIG. 6 was prepared. Both the pillar and the base were cedars having a cross-sectional dimension of 105 mm × 105 mm (water content: 10%), and the ends of the pillars were joined to the center of the base. The length of the base is 1000 mm, and the length of the pillar is 600 mm. Using a fixing bolt M12 and a square washer W4.5 × 45 at a position 400 mm outside from the column core, the torque value was fixed to about 30 N · m. Then, the adhesive composition according to the example and the comparative example is brushed in an inverted T shape so that the thickness is about 1 mm in the region that becomes the joint portion between the pillar and the base, and the brush-coated region A 100 mm wide glass fiber sheet (warp yarn 2310 tex, weft yarn 33.7 tex, thickness of about 0.87 mm) (trade name: glass tape, manufactured by Sakai Sangyo Co., Ltd.) was attached. Then, the adhesive composition was moisture-cured by allowing to stand for 7 days under conditions of 23 ° C. and 50% RH. The number of test specimens was one preliminary specimen and six specimens.

2. Test method (1) Force device TCLP-100kNB (made by Tokyo Sokki Co., Ltd.) was used as a force device. (2) Measuring device Electric displacement meter THS-1100 (capacity: 50 mm and 100 mm, non-linearity: 0.1% RO, sensitivity: 100 × 10 ⁻⁶ / mm and 200 × 10 ⁻⁶ , manufactured by Tokyo Keiki Co., Ltd. ) And load and displacement data were recorded continuously by computer control.
(2) Force application method The tensile load was applied to the column top part via the force jig with respect to the test body prepared by said "1. Preparation of test body". The force was applied according to the following procedure.
A) One preliminary test with monotonic force was performed, and the yield displacement (δy) was determined from the result.
(B) This test with repeated unidirectional force was performed on 6 or more bodies. The repetition history is repeated once in the order of 1/2, 1, 2, 4, 6, 8, 12, 16 times the yield displacement (δy) obtained in the preliminary test. In the preliminary test, when the yield displacement cannot be obtained, 1/10, 1/5, 3/10, 2/5, 2/1, 3/5, 7/10 of the displacement at the maximum load (δmax). , Repeated in the order of 1 times.
C. The applied force was applied after reaching the maximum load until the load decreased to 80% of the maximum load or the function of the joint was lost (displacement where the short tenon slips out: 30 mm or more).
(3) Measuring method The relative displacement of the pillar and soil and the absolute displacement of the pillar were measured. Displacement measurement includes material cracking due to testing, displacement due to penetration, and the like, and measurement was performed at two or more locations on the front and back of the member using the electric displacement meter.

3. Evaluation Method Using the load-displacement curve obtained in the test, a load-displacement envelope was created, and the maximum load was measured from this envelope, thereby confirming the reinforcement effect of the column base joint. The results are shown in Tables 5-7. Regarding the maximum load, the case where the maximum load is 45 kN or more is ““ ”, the case where it is 35 kN or more and less than 45 kN is“ ◯ ”, the case where it is 25 kN or more and less than 35 kN is“ △ ”, and it is less than 25 kN. The case was set to “x”.

<Concrete bending test>
A concrete bending test was conducted assuming unreinforced concrete foundation reinforcement. Conducted in the area occupying up to 400 mm from the top in the height direction on the front and back of concrete (width: 3400 mm, height: 600 mm, depth: 120 mm (however, the distance between the fulcrum in the width direction is 3000 mm)) The adhesive compositions according to Examples and Comparative Examples are brush-coated to a thickness of about 2 mm, and a glass fiber sheet having a width of 100 mm (warp yarn 2310 tex, weft yarn 33.7 tex, thickness about 0.87 mm) (trade name: glass) Tape, manufactured by Sakai Sangyo Co., Ltd. was attached. And after leaving still for 7 days under the conditions of 23 ° C. and 50% RH, a four-point bending test was performed with the applied point set at a position 500 mm from the center of the concrete. The force applying device was UH-200A (manufactured by SHIMADSU), and the measuring device for obtaining a load-displacement curve was the above displacement meter THS-1100 (manufactured by Tokyo Keiki Co., Ltd.). A load-displacement envelope was created using the load-displacement curve obtained in the test, and the reinforcing effect of the unreinforced concrete foundation was confirmed by measuring the maximum load and the displacement at that time from this envelope. The results are shown in Tables 5-7. As for the maximum load, the case where the maximum load is 60 kN or more is “” ”, the case where it is 55 kN or more and less than 60 kN is“ ◯ ”, the case where it is 50 kN or more and less than 55 kN is“ △ ”, and it is less than 50 kN. The case was set to “x”.

<Evaluation of workability>
Workability was evaluated assuming unreinforced concrete foundation reinforcement. In the front surface of concrete (width: 3400 mm, height: 600 mm, depth: 120 mm), the adhesive composition according to the example and the comparative example has a thickness of about 2 mm in a region occupying up to 400 mm in the height direction. It applied so that it may become. The results are shown in Tables 5-7. Can be applied smoothly without resistance, “C” when combs are visible and fiber sheets can be affixed, and can be applied smoothly to the extent that there is little resistance but no effect on workability. When the comb is standing and the fiber sheet can be affixed, “△” indicates that there is resistance during application, there is a problem in workability, the comb is not visible, or the fiber sheet is turned over. The case corresponding to any one or more of cases where pasting is not possible is defined as “x”.

  It contains a urethane prepolymer containing an isocyanate group at the terminal, obtained by reacting a polyol and a polyisocyanate, and the polyol contains polytetramethylene glycol and / or modified polytetramethylene glycol and bifunctional or higher-functional polypropylene glycol And the above polyisocyanate contains diphenylmethane diisocyanate, and when the fiber sheet is attached to the reinforcing surface of the reinforced body through the adhesive composition, the adhesion to the reinforced body and the fiber sheet, and workability It was confirmed that it was excellent in both, and could be effectively reinforced against both the column base and the bending of concrete (Examples 1 to 15).

  In particular, by comparing Examples 3, 5 and 6 with Example 1, when the polyol further contains a polyester polyol, the adhesion to the reinforced body and the fiber sheet and the reinforcing effect against bending of the concrete are enhanced. It was confirmed that it was suitable.

  Further, by comparing Example 9 and Example 15, it was confirmed that when the polyol further contains a polyol having a bisphenol A skeleton, it is preferable in terms of enhancing the reinforcing effect against bending of concrete.

  Further, by comparing Examples 9 to 12, the adhesive composition further contains a polyisocyanate that is the same as or different from the polyisocyanate as the starting material, in addition to the polyisocyanate as the starting material of the urethane prepolymer. In addition, it was confirmed that it is preferable in that the reduction in workability that can be caused by adding a filler made of aluminum hydroxide for the purpose of improving the adhesion performance of the column base joint portion can be effectively suppressed. In order to effectively suppress the decrease in workability, it may be possible to add a solvent or a diluent to the adhesive composition. In this case, however, the toughness of the cured product is reduced, and the column base and the concrete are bent. In some cases, a sufficient reinforcing effect cannot be obtained. By externally adding polyisocyanate to the adhesive composition, it is possible to effectively suppress a decrease in workability without reducing the toughness of the cured product.

  Moreover, by comparing Example 1 and Example 2, and Example 7 and Example 8, respectively, when the adhesive composition contains silica (Examples 1 and 7), the adhesive composition contains silica. It was confirmed that the workability was excellent as compared with the case where it was not contained (Examples 2 and 8).

  On the other hand, when the case (Examples 1-6 and Comparative Examples 1-4) which does not contain the filler which consists of aluminum hydroxide is examined, when a polyol does not contain polytetramethylene glycol and / or modified polytetramethylene glycol, It was confirmed that it is not preferable in that there is a possibility that a sufficient reinforcing effect against bending of the column base and concrete may not be obtained (Comparative Example 1).

  In addition, when the polyol does not contain a bifunctional or higher-functional polypropylene glycol, there is a possibility that sufficient adhesion to both the object to be reinforced and the fiber sheet may not be obtained, and a sufficient reinforcing effect for the column base is obtained. It was confirmed that there was a possibility that there was no possibility and there was a possibility that sufficient workability could not be obtained (Comparative Example 2).

  Further, when the polyisocyanate does not contain diphenylmethane diisocyanate, there is a possibility that sufficient adhesion to both the object to be reinforced and the fiber sheet may not be obtained, and a sufficient reinforcement effect for the column base cannot be obtained. It was confirmed that there was a possibility (Comparative Examples 3 and 4) that it was not preferable.

  Moreover, when considering the case (Examples 7-15 and Comparative Examples 5-8) which contains the filler which consists of aluminum hydroxide, when a polyol does not contain polytetramethylene glycol and / or modified polytetramethylene glycol, It was confirmed that it is not preferable because there is a possibility that a sufficient reinforcing effect against bending of concrete may not be obtained (Comparative Example 5).

  Further, it was confirmed that when the polyol does not contain bifunctional or higher-functional polypropylene glycol, it is not preferable because sufficient workability may not be obtained (Comparative Example 6).

  Moreover, when polyisocyanate did not contain diphenylmethane diisocyanate, it was confirmed that it is not preferable in the point that sufficient reinforcement effect with respect to the column base may not be obtained (Comparative Examples 7 and 8).

DESCRIPTION OF SYMBOLS 1 Fiber reinforced adhesive sheet 2 1st peeling sheet 3 Fiber sheet 4 Fiber reinforced adhesive layer 5 2nd peeling sheet 20 Fiber reinforced adhesive sheet package

Claims (10)

A building reinforcement method for reinforcing a building by sticking a fiber sheet to a reinforcing surface of an object to be reinforced via an adhesive composition,
The adhesive composition contains a urethane prepolymer having an isocyanate group at a terminal, obtained by reacting a polyol and a polyisocyanate,
The polyol contains polytetramethylene glycol and / or modified polytetramethylene glycol and bifunctional or higher-functional polypropylene glycol.
The method for reinforcing a building, wherein the polyisocyanate contains diphenylmethane diisocyanate.   The building reinforcing method according to claim 1, wherein the polyol further comprises a polyester polyol.   The building reinforcement method according to claim 2, wherein the polyester polyol is an adipic acid-based polyester polyol.   The building reinforcing method according to claim 1, wherein the polyol further contains a polyol having a bisphenol A skeleton.   5. The adhesive composition according to claim 1, further comprising a polyisocyanate that is the same as or different from the polyisocyanate as the starting material, in addition to the polyisocyanate as the starting material of the urethane prepolymer. Building reinforcement method.   The building reinforcing method according to claim 5, wherein the polyisocyanate which is the same as or different from the polyisocyanate as the starting material contains carbodiimide-modified diphenylmethane diisocyanate.   The building reinforcing method according to claim 1, wherein the adhesive composition further contains a curing catalyst.   The building reinforcing method according to claim 1, wherein the adhesive composition further contains silica. Peel off one of the release sheets of a fiber reinforced adhesive sheet in which release sheets are laminated on both sides of a fiber reinforced adhesive layer impregnated or laminated on the fiber sheet with the adhesive composition,
The exposed fiber reinforced adhesive layer is affixed to the reinforcing surface of the reinforced body, and is pressed from the other release sheet,
The building reinforcing method according to any one of claims 1 to 8, wherein the fiber-reinforced adhesive layer is cured by moisture. A fiber reinforced adhesive sheet in which release sheets are laminated on both sides of a fiber reinforced adhesive layer obtained by impregnating or laminating a fiber sheet with an adhesive composition,
The adhesive composition contains a urethane prepolymer having an isocyanate group at a terminal, obtained by reacting a polyol and a polyisocyanate,
The polyol contains polytetramethylene glycol and / or modified polytetramethylene glycol and bifunctional or higher-functional polypropylene glycol.
The fiber-reinforced adhesive sheet, wherein the polyisocyanate contains diphenylmethane diisocyanate.

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