JP2009119358A - Construction method of covering material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a construction method of a covering material having excellent adhesion and following property to a concrete base to secure strength necessary for preventing the peel-off with less steps. <P>SOLUTION: The construction method of the covering material is carried out by applying a primer of one kind selected from a group of epoxy resin based primers and urethane resin based primers on the concrete base and after that, applying the covering material comprising an urethan resin composition containing following (A) and (B) on the primer applied surface, (A): an aliphatic and/or alicyclic isocyanate terminated urethan prepolymer and (B): a specific urethane oxazolidine compound and/or a polyaldimine compound. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for constructing a coating material.

  Conventionally, a glass cloth or a resin cloth is pasted with cement or epoxy resin to protect civil engineering concrete such as railway and road viaducts and bridges. This is because the strength in the punching test is excellent. However, while cement-based and epoxy-resin-based systems have the above-mentioned performance, these methods have many processes such as primer, cloth pasting, top-coating, and top-coating after applying primer, and the construction time is long. It was difficult to install after stopping the time and running of the vehicle.

  For example, when taking measures against concrete peeling on the outer walls of road viaducts, there are many methods of applying an acrylic urethane paint with high weather resistance after pasting a cloth made of polypropylene or vinylon using an epoxy resin. (For example, refer nonpatent literature 1). Although the coating film obtained by this construction method is high in strength, it is necessary to regulate the lane when passing through the road under the viaduct to secure a place where workers at high altitudes stop and work. When working at night with little vehicle traffic, the work time in one day is short and many processes are required for the construction, so the construction has to take several days.

In addition, a method of applying a urethane-based material is also performed, but this is a method of applying a primer, applying and curing a urethane-based material to obtain a cured product, and then applying a top coat. . Since the urethane material used in the method has low weather resistance, it was necessary to overcoat with a top coat having high weather resistance. A cured product obtained by applying and curing the urethane material is composed of a tolylene diisocyanate (hereinafter also referred to as TDI) urethane prepolymer and 4,4′-methylenebis (2-chlorobenzeneamine) (
Less than. This is a cured product obtained by combining a mixture of a polyol and a filler, and the mechanical strength of the cured product is relatively low. For this reason, unless a coating film thickness of 1.0 mm or more is applied, the punching load of 0.5 kN cannot be exceeded, and many materials must be used.
Japan Society of Civil Engineers "Surface protection method design guidelines (draft)" (2005)

  The present invention has been studied to solve the above-mentioned problems, and as a result, has excellent adhesion and followability with a concrete base, has high weather resistance, ensures strength for concrete protection, and has few steps. The purpose is to provide a construction method.

  As a result of intensive research to achieve the above-mentioned problems, the present inventors have used a coating material made of a specific urethane resin composition, so that even if it is a method for constructing a coating material with fewer steps than the conventional method, It has been found that it has weather resistance, is excellent in adhesion and followability with a concrete base, and can secure strength for concrete protection, and has completed the present invention.

That is, the successful method of the coating material of the present invention is:
After applying one kind of primer selected from the group consisting of an epoxy resin primer and a urethane resin primer on a concrete base, urethane containing at least the following (A) and (B) on the applied primer surface A coating material made of a resin composition is applied.
(A): Aliphatic and / or alicyclic isocyanate-terminated urethane prepolymer (B): (b1) and / or (b2) below
(B1): urethane oxazolidine compound obtained by reacting an aliphatic and / or alicyclic polyisocyanate with N-hydroxyalkyloxazolidine (b2): synthesized from a polyamine compound having two or more NH ₂ groups and an aldehyde compound The polyaldimine compound to be used The urethane resin composition preferably further contains a filler (C).

  The urethane resin composition is composed of a component (I) containing the components (A) and (B) and a component (II) containing the component (C) and water (D). It is preferable that it is a thing.

The component (I) is preferably a component containing the (A) and (b1).
Isocyanate group terminal obtained by reacting the component (I) with an aliphatic and / or alicyclic polyisocyanate and a polyoxyalkylene polyol having a number average molecular weight of 1000 or more and a low molecular polyol having a number average molecular weight of less than 1000 Urethane prepolymer (A-1) and aliphatic and / or cycloaliphatic polyisocyanate in an amount of 0.9 to 1.1 moles of N-hydroxyalkyloxazolidine in terms of hydroxyl group per mole of isocyanate group of the polyisocyanate The urethane polyoxazolidine compound (b1-1) obtained by reacting the urethane polyoxazolidine compound (b1-1) with 0.025 to 1 mol of the isocyanate group of the urethane prepolymer (A-1). The component is preferably contained at a ratio of 0.5 mol.

  The method for constructing a coating material according to the present invention has a small number of processes, and accordingly, the construction time is short. In addition, the construction method has high weather resistance, excellent adhesion to the concrete base and followability, and can secure strength for protecting the concrete.

Next, the present invention will be specifically described.
The method for applying the coating material of the present invention is as follows. After applying one kind of primer selected from the group consisting of an epoxy resin-based primer and a urethane resin-based primer to a concrete base, at least the following (A ) And (B), a coating material comprising a urethane resin composition is applied.

(A): Aliphatic and / or alicyclic isocyanate-terminated urethane prepolymer (B): (b1) and / or (b2) below
(B1): urethane oxazolidine compound obtained by reacting an aliphatic and / or alicyclic polyisocyanate with N-hydroxyalkyloxazolidine (b2): synthesized from a polyamine compound having two or more NH ₂ groups and an aldehyde compound The polyaldimine compound to be applied Since the coating method of the present invention has two essential steps, the step of applying the primer to the concrete base and the step of applying the coating material on the surface of the applied primer. The construction time can be shortened compared to the conventional method.

  The concrete substrate may be subjected to a substrate treatment in advance. Examples of the base treatment include a method of polishing and cleaning the surface of the base concrete dried to a moisture content of 5% or less. In addition, when there is a deficient portion in the foundation concrete, it is preferable to perform treatment so that the surface is smoothed by using an epoxy resin-based or acrylic resin-based foundation conditioning material as the foundation treatment.

  The method for constructing the coating material according to the present invention is superior in adhesion and followability with a concrete substrate, even if the number of steps is smaller than in the past, by using a specific primer and coating material described later. Strength can be secured. In addition, the coating | covering material used for this invention can be applied suitably, it hardens | cures with progress of time, and turns into hardened | cured material (coating film).

  Further, the coating material used in the present invention has high weather resistance by using (A) an aliphatic and / or alicyclic isocyanate-terminated urethane prepolymer, and it is necessary to further apply a top coat such as an acrylic urethane top coat. There is no.

  In the present invention, the fact that strength for protecting concrete can be secured means that a punch test has a punch test load of 0.5 kN or more. The push-out test method can be carried out according to the former Metropolitan Expressway Public Corporation Conservation Facility Department Conservation Technology Section “Examination of Applicability and Performance Evaluation Test Plan (draft) of new materials in concrete structures” B type.

〔Primer〕
As the primer, one kind of primer selected from the group consisting of an epoxy resin primer and a urethane resin primer can be used.

  As the epoxy resin-based primer, for example, Chemicrete E primer (manufactured by ABC Shokai), cleat bond CA primer (manufactured by ABC Shokai), or Protectreet S primer E (manufactured by ABC Shokai) can be used.

As the urethane resin-based primer, for example, Sun PC (manufactured by Mitsui Chemicals Polyurethane), Protectito S Primer U (manufactured by ABC Corporation) can be used.
In the case of many civil engineering concrete bases, the amount of water is large, and therefore an epoxy primer is preferable because sufficient adhesive strength can be secured stably.

The primer can be applied by using a spray, a brush, a trowel, a spatula, or a similar construction machine. The application amount of the primer is usually 0.05 to 0.3 kg / m ² , preferably 0.
. It applied in 1~0.2kg / m ^2.

(Coating material)
The coating material used for this invention consists of a urethane resin composition containing the following (A) and (B) at least.

(A): Aliphatic and / or alicyclic isocyanate-terminated urethane prepolymer (B): (b1) and / or (b2) below
(B1): urethane oxazolidine compound obtained by reacting an aliphatic and / or alicyclic polyisocyanate with N-hydroxyalkyloxazolidine (b2): synthesized from a polyamine compound having two or more NH ₂ groups and an aldehyde compound It is preferable from a viewpoint of the intensity | strength for concrete protection that the polyaldimine compound urethane resin composition further contains a filler (C).

Moreover, as a urethane resin composition, the 2 component type which consists of component (I) containing said (A) and (B), and component (II) containing said (C) and water (D). A urethane resin composition is preferred. The component (I) is preferably a component containing (A) and (b1), and the component (I) is a number average molecular weight in aliphatic and / or alicyclic polyisocyanate. Is an isocyanate group-terminated urethane prepolymer (A-1) obtained by reacting a polyoxyalkylene polyol having a molecular weight of 1000 or more and a low molecular polyol having a number average molecular weight of less than 1000, and an aliphatic and / or alicyclic polyisocyanate. Urethane polyoxazolidine compound (b1-1) obtained by reacting 0.9 to 1.1 mol of N-hydroxyalkyloxazolidine in terms of hydroxyl group with respect to 1 mol of isocyanate group of the polyisocyanate, the urethane prepolymer The urethane polyoxazolidine formation with respect to 1 mol of isocyanate group of (A-1) It is particularly preferred objects of (b1-1) is a component containing in a ratio of 0.025 to 0.5 mol.

  In addition, with the two-component urethane resin composition, the component (I) and the component (II) are stored separately, and the component (I) and the component (II) are mixed immediately before use as a coating material. The urethane resin composition to be used is shown. In addition, the one-component urethane resin composition refers to a urethane resin composition in which components constituting the urethane resin composition are stored together.

  Since the two-component urethane resin composition used in the present invention begins to harden when component (I) and component (II) are mixed, it must be stored separately until immediately before use as a coating material. On the other hand, when a one-component urethane resin composition is used, if water is contained as the urethane resin composition, curing proceeds during storage, so that it is preferable that water is not contained as much as possible.

  Even if it is a one-component urethane resin composition, (b1) and (b2) can be hydrolyzed by moisture in the air after being applied and the coating material can be cured. Use as a two-component urethane resin composition containing water (D) in (II) is preferable because sufficient curing can proceed even when the humidity is low, and the curing time can be shortened.

Dressing, depending on its composition, by using a metal trowel or the like, the coating amount is usually 0.5~3kg / m ^2, it is applied preferably 0.8~2kg / m ^2.
((A): aliphatic and / or alicyclic isocyanate-terminated urethane prepolymer)
The aliphatic and / or alicyclic isocyanate-terminated urethane prepolymer (A) used in the present invention is not particularly limited as long as it has an isocyanate group at the terminal. For example, aliphatic and / or alicyclic polypolymers A target isocyanate-terminated urethane prepolymer can be obtained by reacting an isocyanate with a polyol. Among them, polyoxyalkylene polyols having a number average molecular weight of 1000 or more in aliphatic and / or alicyclic polyisocyanates are easy to ensure the balance between the mechanical properties of the cured product and the workability of application to concrete structures. An isocyanate group-terminated urethane prepolymer (A-1) obtained by reacting a low molecular polyol having a number average molecular weight of less than 1000 is preferred.

  In the isocyanate group-terminated urethane prepolymer (A-1), examples of the aliphatic polyisocyanate include hexamethylene diisocyanate (HDI). Examples of the alicyclic polyisocyanate include isophorone diisocyanate (IPDI), norbornane diisocyanate (NBDI), dicyclohexylmethane-4,4′-diisocyanate (H12-MDI), 1,3-bis- (isocyanatomethyl) -cyclohexane ( H6-XDI). These polyisocyanates may be used alone or in combination of two or more. By using an aliphatic and / or alicyclic polyisocyanate as the polyisocyanate, it can be used as a coating material that does not turn yellow and has excellent weather resistance.

The number average molecular weight of the polyoxyalkylene polyol in the isocyanate group-terminated urethane prepolymer (A-1) is 1000 or more, and the number average molecular weight of the low molecular polyol is less than 1000, preferably 134 or less. The polyoxyalkylene polyol and the low molecular polyol are preferably monools or diols, and more preferably diols. Preferred polyoxyalkylene diols include polypropylene glycol, polyethylene glycol, and mixed polyols thereof. Preferred low molecular diols include diethylene glycol, dipropylene glycol, polytetramethylene ether glycol having a number average molecular weight of less than 1000, 1,4-butanediol and the like can be mentioned.

  When the isocyanate group-terminated urethane prepolymer (A-1) is prepared, the mixing ratio of the polyisocyanate, the polyoxyalkylene polyol, and the low molecular polyol is such that the ratio of the isocyanate group to the hydroxyl group is NCO / OH> 1.2 ( Molar ratio), preferably 1.2 <NCO / OH <2.5, more preferably 1.6 <NCO / OH <2.2. The mixing ratio of the polyoxyalkylene polyol and the low molecular polyol is preferably 0.2 to 2.0 mol, and more preferably 0.4 to 2.0 mol with respect to 1 mol of the polyoxyalkylene polyol. 1.5 mol, particularly preferably 0.6 to 1.2. Within the above range, the balance between the mechanical properties of the cured product and the workability of application to the concrete structure is good.

((B): (b1) and / or (b2))
Urethane oxazolidine compound (b1) obtained by reacting an aliphatic and / or alicyclic polyisocyanate with N-hydroxyalkyloxazolidine and / or a polyamine compound having two or more NH ₂ groups and an aldehyde compound used in the present invention As the polyaldimine compound (b2) synthesized from the following, the following can be used.

As (B), (b1) may be used alone, (b2) may be used alone, or (b1) and (b2) may be used in combination.
((B1): urethane oxazolidine compound obtained by reacting an aliphatic and / or alicyclic polyisocyanate with N-hydroxyalkyloxazolidine)
As the urethane oxazolidine compound (b1) obtained by reacting the aliphatic and / or alicyclic polyisocyanate with N-hydroxyalkyloxazolidine, for example, 2-isopropyl-3- (2-hydroxyethyl) -1,3 -Urethane oxazolidine compounds obtained by reacting oxazolidine with isophorone diisocyanate, among others, stable mechanical properties are obtained, and in terms of foaming suppression, aliphatic and / or alicyclic polyisocyanates The urethane polyoxazolidine compound (b1-1) obtained by reacting 0.9 to 1.1 mol of N-hydroxyalkyloxazolidine in terms of hydroxyl group with respect to 1 mol of the isocyanate group of the polyisocyanate is preferable.

In the urethane polyoxazolidine compound (b1-1), the reaction temperature when the aliphatic and / or alicyclic polyisocyanate and N-hydroxyalkyloxazolidine are reacted is preferably 80 to 100 ° C. The formation of the urethane polyoxazolidine compound (b1-1) can be confirmed by the disappearance of the peak at 2250 cm ⁻¹ as measured with an infrared spectrometer.

  Examples of the aliphatic polyisocyanate include the aliphatic polyisocyanates exemplified above, and examples of the alicyclic polyisocyanate include the alicyclic polyisocyanates exemplified above. Of these, IPDI, HDI, and H6-XDI are preferred. These polyisocyanates may be used alone or in combination of two or more. By using an aliphatic and / or alicyclic polyisocyanate as the polyisocyanate, it can be used as a coating material that does not turn yellow and has excellent weather resistance.

The N-hydroxyalkyloxazolidine used in the present invention is preferably one in which a substituent having a hydroxyl group at the terminal is bonded to the nitrogen atom of the oxazolidine ring represented by the following formula (1).

In Formula (1), R ¹ is a hydrogen atom or a monovalent organic group, preferably a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms. R ² is a divalent organic group, preferably an alkylene chain having 2 to 5 carbon atoms. Examples of the hydrocarbon group having 1 to 5 carbon atoms represented by R ¹ include a methyl group, an ethyl group, a propyl group, an isopropyl group, and the like, and an isopropyl group having 3 carbon atoms [—CH (CH ₃ ) ₂ ]. More preferable examples of the alkylene chain having 2 to 5 carbon atoms represented by R ² include an ethylene chain or a propylene chain, and an ethylene chain [—CH ₂ —CH ₂ —] having 2 carbon atoms is more preferable. . Further, a particularly preferable combination of R ¹ and R ^{2 includes} a combination in which R ¹ is an isopropyl group [—CH (CH ₃ ) ₂ ] and R ² is an ethylene chain [—CH ₂ —CH ₂ —]. Such an N-hydroxyalkyloxazolidine having R ¹ and R ² is preferable in terms of the reactivity after mixing the two components (I) and (II).

  The N-hydroxyalkyloxazolidine reacts a compound having two hydroxyl groups and one amino group in one molecule such as diethanolamine with aldehydes such as propionaldehyde, isobutyraldehyde, n-hexanal and benzaldehyde. Can be prepared. This reaction is usually carried out in an organic solvent such as benzene, toluene and xylene at a temperature in the range of 70 to 150 ° C. while removing water produced by the dehydration reaction from the reaction system. Of the above combinations, from the viewpoint of reactivity, it is preferable to react diethanolamine and isobutyraldehyde, and 2-isopropyl-3- (2-hydroxyethyl) -1,3-oxazolidine produced by this combination is preferable.

((B2): a polyaldimine compound synthesized from a polyamine compound having two or more NH ₂ groups and an aldehyde compound)
The polyaldimine compound (b2) used in the present invention is a polyaldimine compound synthesized from a polyamine compound having two or more NH ₂ groups and an aldehyde compound. For example, a polyaldimine compound obtained by subjecting a polyamine having two or more NH ₂ groups to a dehydration condensation reaction with an aldehyde compound, among others, the following general formula (α) is preferable in terms of balance between curability, storage stability, and mechanical properties. ) Is preferred, and a dialdimine compound obtained by subjecting diaminomethylbicyclo [2.2.1] heptane and benzaldehyde to a dehydration condensation reaction is most preferred.

(In the formula, X represents an aryl group having 6 to 15 carbon atoms. Y represents a divalent or trivalent hydrocarbon group having 2 to 15 carbon atoms, or a divalent or trivalent molecular weight of 70 to 6000. Represents a polyoxyalkylene group, and n represents 2 or 3.)
The polyaldimine represented by the general formula (α) is, for example, a polyamine and an aldehyde described in detail below, using a solvent such as toluene or xylene, and performing an azeotropic dehydration reaction under an acid catalyst, It is obtained by continuing the reaction until the distillation of water into the water droplet separator stops. The ratio of the above polyamine and aldehyde is preferably 1 to 2 equivalents of aldehyde with respect to 1 equivalent of amine.

As the polyamine used for the production of the polyaldimine represented by the general formula (α),
1) Aliphatic diamines such as ethylenediamine, 1,3-diaminopropane, tetramethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, decamethylenediamine, 4,4′-diaminodicyclohexylmethane, isophoronediamine, bis Alicyclic diamines such as aminomethylcyclohexane, 2,5- or 2,6-diaminomethylbicyclo [2.2.1] heptane, diaminocyclohexane, diaminodiphenylmethane, diaminodiphenyl ether, xylylenediamine, phenylenediamine, 3, Add propylene oxide and / or ethylene oxide to aromatic diamine such as 5-diethyltoluene-2,4- or 2,6-diamine, water, ethylene glycol, propylene glycol, etc. Diamines such as polyoxyalkylene diamines obtained by converting hydroxyl groups of polyoxyalkylene glycols obtained by polymerization to amino groups, 2) 1,3,5-tris (aminomethyl) benzene, 1,3, Obtained by converting the hydroxyl group of polyoxyalkylenetriols obtained by addition polymerization of propylene oxide and / or ethylene oxide to triamines such as 5-tris (aminomethyl) cyclohexane, glycerin, trimethylolpropane, etc. There are triamines such as polyoxyalkylene triamine.

  Examples of the aldehyde used for the production of polyaldimine include benzaldehyde, o-tolualdehyde, m-tolualdehyde, p-tolualdehyde, 4-ethylbenzaldehyde, 4-propylbenzaldehyde, 4-butylbenzaldehyde, 2, There are 4-dimethylbenzaldehyde, 2,4,5-trimethylbenzaldehyde, p-anisaldehyde, p-ethoxybenzaldehyde and the like.

((C): Filler)
The urethane resin composition of the present invention preferably further contains a filler.
The filler used in the present invention may be an organic filler or an inorganic filler, but an inorganic filler is preferable because it is inexpensive and easy to ensure workability. Examples of the filler include powders such as talc, alumina, clay, barium sulfate, titanium oxide, kaolin, calcium oxide, glass balloon, and organic balloon. In particular, the addition of calcium carbonate surface-treated with a resin acid or organic acid improves the affinity between the resin and the inorganic filler while the component (II) exhibits thixotropy, and further promotes the curing reaction by the surface treatment agent. Since the physical properties of the cured product are improved, it is preferable. The surface-treated calcium carbonate may be added alone, but is preferably used in combination with other fillers in order to ensure a balance between workability and physical properties. Examples of the surface-treated calcium carbonate include Sealet 500 (trade name, manufactured by Maruo Calcium Co., Ltd.) and Calfine 500 (trade name, manufactured by Maruo Calcium Co., Ltd.).

  The blending amount of the inorganic filler can be appropriately set in consideration of workability and physical properties. Moreover, the 2nd component can be made into a paste form by increasing the compounding quantity of an inorganic filler, and sedimentation of an inorganic filler can be prevented.

Moreover, by including an inorganic filler, the temperature dependence of the cured product properties of the cured coating material is reduced, and the concrete can be coated with a hardened cured product. Furthermore, since the composition containing an inorganic filler has thixotropy, no dripping occurs even when applied to a standing surface. In addition, when a two-component urethane resin composition is used as the urethane resin composition,
Since the component (II) contains an inorganic filler that may contain moisture, the storage stability of the two-component urethane resin composition is excellent.

((D): Water)
When the urethane resin composition of the present invention is a two-component urethane resin composition, the two-component urethane resin composition contains the components (I) and (A) containing the components (A) and (B). C) and component (II) containing water (D).

The water (D) contained in this component (II) is not particularly limited, but it is usually preferable to use purified water, for example, distilled water, ion-exchanged water or the like is preferably used.
In the case of using a one-component urethane resin composition as the urethane resin composition, if water is present, the presence of water is not preferable because curing starts during storage.
(Urethane resin composition)
The urethane resin composition used in the present invention contains at least the above (A) and (B), and preferably contains the above (C).

  The urethane resin composition may be a one-component urethane resin composition or a two-component urethane resin composition, but the component (I) containing the (A) and (B), A two-component urethane resin composition comprising the component (II) containing the (C) and water (D) is preferred.

  When using a one-component urethane resin composition, if it contains water, curing of the urethane resin composition proceeds during storage, which is not preferable, and it is preferable not to contain water except for water mixed in from the air or the like. When a coating material made of a one-component urethane resin composition is used, it is cured by moisture in the air after the coating material is applied.

  In the present invention, a two-component urethane resin composition having a short curing time is preferable. In this case, in order to avoid hardening of component (I) during storage, it is preferable to reduce the amount of water contained in component (I) as much as possible. In addition, curing begins by mixing component (I) and component (II) immediately before use, which is necessary for curing because the urethane resin composition itself contains water (D) as compared to the one-component type. Short time is preferred.

  In the urethane resin composition used in the present invention, the quantitative ratio of (A) and (B) is a ratio of 0.025 to 0.5 mol of (B) with respect to 1 mol of isocyanate group of (A). It is preferable that it is the quantity contained in.

  Moreover, it is preferable from a viewpoint of ensuring the intensity | strength for concrete peeling prevention that the urethane resin composition used for this invention contains a filler (C), and the sum total of (A) and (B) is 100 weight part. Then, it is usually contained in the range of 30 to 180 parts by weight, preferably 60 to 120 parts by weight.

Furthermore, the urethane resin composition of the present invention may further contain a liquid plasticizer, a curing catalyst, and other additives.
Examples of the liquid plasticizer include various esters and normal paraffins having no OH group, NH group and SH group. The blending amount of the plasticizer can be appropriately set in consideration of workability, physical properties, and the like. However, if the amount is too large, bleeding may occur and strength for preventing concrete peeling may be reduced.

Examples of the curing catalyst include a catalyst that promotes the ring opening of oxazolidine possessed by (b1) with water, and a reaction between an OH group, an NH group, and an isocyanate group that are generated when the oxazolidine ring reacts with water to open the ring. A promoting catalyst or the like can be used. These catalysts are preferably used in combination. Examples of the former include octylic acid, benzoyl chloride, and adipic acid. Examples of the latter include dibutyltin dilaurate (DBTDL), bismuth octylate, lead neodecanoate, stannous octoate, and the like. When the former and the latter are used in combination, the ratio of the former: the latter = 0.1: 1 to 1: 1 is preferable. Moreover, the catalyst which accelerates | stimulates the hydrolysis of the aldimine part which (b2) polyaldimine compound has, the catalyst which accelerates | stimulates reaction with OH group produced | generated by hydrolysis, and NH group, etc. can be used. The total addition amount of the curing catalyst can be appropriately set in consideration of workability and physical properties.

  Examples of other additives include various stabilizers such as antioxidants, ultraviolet absorbers, heat stabilizers, polymeric light stabilizers (HALS), pigments for coloring, and dyes. Moreover, various additives, such as an antifoamer, a leveling material, and a thixotropic agent, can also be blended.

  In addition, as the two-component urethane resin composition, the component (I) is preferably a component containing the above (A) and (b1), and the aliphatic and / or alicyclic polyisocyanate. An isocyanate group-terminated urethane prepolymer (A-1) obtained by reacting a polyoxyalkylene polyol having a number average molecular weight of 1000 or more and a low molecular polyol having a number average molecular weight of less than 1000, an aliphatic and / or alicyclic A urethane polyoxazolidine compound (b1-1) obtained by reacting 0.9 to 1.1 mol of N-hydroxyalkyloxazolidine in terms of hydroxyl group with respect to 1 mol of isocyanate group of the polyisocyanate to polyisocyanate, The urethane polymer per mole of isocyanate groups of the urethane prepolymer (A-1). Oxazolidine compound is particularly preferably a (b1-1) is a component containing in a ratio of 0.025 to 0.5 mole (hereinafter, referred to as component (I-1)).

  Component (I-1) used in the two-component urethane resin composition contains the isocyanate group-terminated urethane prepolymer (A-1) and the urethane polyoxazolidine compound (b-1). At this time, the urethane polyoxazolidine compound (b-1) is 0.025 to 0.5 mol, preferably 0.1 to 0.3 mol, based on 1 mol of the isocyanate group of the urethane prepolymer (A-1). Preferably it is contained in a proportion of 0.15 to 0.25 mol. When the ratio of the urethane prepolymer (A-1) and the urethane polyoxazolidine compound (b1-1) is in the above range, the coating material used in the present invention is excellent in curability, has no foaming, and has a good appearance. An object (coating film) can be obtained. When the ratio is less than 0.025 mol, many voids tend to be generated in the cured product. This is considered to be because there are few OH groups and NH groups generated by the opening of the oxazolidine ring, and the reaction between the NCO group and water proceeds to generate carbon dioxide and foam. On the other hand, when the ratio exceeds 0.5 mol, the physical properties of the obtained cured product tend to decrease. This is presumably because unreacted OH groups and NH groups remain to inhibit the polymerization reaction.

Component (II) used in the two-component urethane resin composition contains the filler (C) and water (D). The amount of water in the component (II) is preferably 0.5 to a total of 1 mol of the oxazolidine ring of (b1) in the component (I) and the aldimine part of (b2). 20 mol, more preferably 0.5 to 15 mol, particularly preferably 0.5 to 10 mol. Moreover, when the said component (I-1) is used as a component (I), Preferably it is 0.5-20 mol with respect to 1 mol of oxazolidine rings in a component (I-1), More preferably, it is 0. 0.5 to 15 mol, particularly preferably 0.5 to 10 mol. When the amount of water is in the above range, a completely cured time is short and a cured product having excellent mechanical strength can be obtained. The ratio of water contained in the component (II) is preferably 95 to 100 mol%, more preferably 96 to 100 mol%, based on all components capable of reacting with the isocyanate group contained in the component (II). Especially preferably, it is 97-100 mol%. Although water is a component capable of reacting with an isocyanate group, in the present invention, water first preferentially contributes to the ring-opening reaction of the oxazolidine ring, and the NH group or primary OH produced by the ring opening. It is believed that the group reacts with the isocyanate group more quickly than water. In this reaction, most of the isocyanate groups are consumed, and the slightly remaining isocyanate groups gradually react with the remaining water and moisture in the air without contributing to the ring-opening reaction of the oxazolidine ring. Therefore, it is considered that most of the water that is not consumed in the ring-opening reaction of the oxazolidine ring is gradually released out of the system.

The filler (C) contained in the component (II) is usually 30 to 180, preferably 60 to 120, when the weight of the component (I) is 100 parts by weight.
Examples of the component capable of reacting with an isocyanate group other than water optionally contained in the component (II) include amines. The amines are preferably amines having a molecular weight of 300 or less, such as monoamines such as methylamine, dimethylamine, butylamine and dibutylamine, and diamines such as ethylenediamine, isophoronediamine and norbornanediamine. When these amines are contained in the component (II), the amines are preferably less than 5 mol%, more preferably less than 4 mol%, based on all components capable of reacting with the isocyanate group in the component (II). Less than 3 mol% is particularly preferred. When the amines are contained in the above proportion, the reactivity of the OH group, NH group and isocyanate group generated when the oxazolidine ring is opened after mixing the component (I) and the component (II) is not affected. In addition, thixotropy can be imparted. Moreover, the reaction of OH group and NH group generated by the opening of the oxazolidine ring and the isocyanate group becomes the main reaction, and the component (I) and the component (II) are changed in a wide range of 100: 50 to 100: 300. However, the fluidity and thixotropy can be controlled by the blending ratio without affecting the pot life, complete curing time, and physical properties of the coated film after curing. In addition, since the component (II) acts as a curing agent for the component (I) when the component (II) contains a component capable of reacting with an isocyanate group other than water beyond the above range, the component (I) and the component The range of the blending ratio of (II) is narrowed, and it is not possible to sufficiently cope with changes in the work environment, and workability tends to be lowered.

  The component (II) may further contain a component that does not react with an isocyanate group, if necessary. Here, the “component that does not react with the isocyanate group” is a component that does not have an OH group, an NH group, and an SH group, and if it is such a component, the above-mentioned liquid plasticizer, curing catalyst, and other additions An agent may be included.

  In the two-component urethane resin composition comprising the component (I) and the component (II) that can be used in the present invention, all components that form a urethane resin skeleton are included in the component (I). ) And component (II) are mixed in an amount sufficient for reaction with an isocyanate group by (b1) opening the oxazolidine ring of the urethane oxazoline compound or hydrolyzing the aldimine part of the (b2) polyaldimine compound. It is not particularly limited as long as it can generate OH groups and NH groups, and can be changed in a wide range. For example, the amount of water in component (II) is preferably 0.5 to 20 mol relative to a total of 1 mol of the oxazolidine ring of (b1) in component (I) and the aldimine moiety of (b2). Preferably it is 0.5-15 mol, Most preferably, it is the range of 0.5-10 mol. When the ratio of water to be mixed is too large, the curing of the entire composition is slowed and foaming may occur slightly. When the ratio of water is too small, the curing inside the composition tends to be slower than the surface.

The specific mixing ratio (weight ratio) of component (I) and component (II) is, for example, 50 to 300 parts by weight, preferably 100 to 250 parts by weight of component (II) with respect to 100 parts by weight of component (I). Although it is a part by weight, it can be appropriately set depending on the composition of component (I) and component (II), and may be mixed beyond the above range. By adjusting the mixing ratio, the fluidity of the two-component urethane resin composition can be easily controlled. Furthermore, in order to adjust the viscosity and thixotropy of the composition in consideration of the environmental atmosphere and workability, this two-component composition is widely changed in the blending ratio of component (I) and component (II). However, it is possible to obtain a cured product having substantially constant physical properties, and is excellent in workability at a construction site where it cannot be accurately measured. For example, even if the component (II) is changed in the range of 50 to 300 parts by weight with respect to 100 parts by weight of the component (I), the strength for protecting the concrete can be ensured.

〔Example〕
EXAMPLES Next, although an Example is shown and this invention is demonstrated further in detail, this invention is not limited by these.

[Preparation of isocyanate group-terminated urethane prepolymer (A-1)]
Polyether polyol (Mitsui Chemicals Polyurethane Co., Ltd., trade name: Actol Diol2000, number average molecular weight = 2000) 71 parts by weight, 1,4-butanediol (Hiroshima Wako Co., Ltd., reagent grade, molecular weight = 90) 2.18 parts by weight and 27 parts by weight of isophorone diisocyanate (manufactured by Huls) were placed in a flask and heated and mixed at 95 ° C. for 1 hour in a nitrogen atmosphere. Next, 40 ppm of stannous octylate (manufactured by Hiroshima Wako Co., Ltd., reagent grade, trade name: Stanoct) was added to this mixture, and the mixture was heated and mixed at 85 ° C. for 3 hours. A prepolymer (A-1) was obtained. NCO% was measured with a potentiometric titrator, and the completion of the reaction was also confirmed.

[Preparation of N-hydroxyalkyloxazolidine]
Weigh 33 parts by weight of diethanolamine and 40 parts by weight of toluene as an azeotropic solvent in a Kolben equipped with a reflux separator, and add 27 parts by weight of isobutyraldehyde dropwise while stirring at 60 ° C. to raise the temperature to about 130 ° C. did. The temperature of the system was raised by an exothermic reaction caused by dropwise addition of isobutyraldehyde and a dehydration reaction was advanced with a reflux separator to remove 5 parts by weight of water. Then, excess isobutyraldehyde and toluene were removed under reduced pressure to obtain 2-isopropyl-3- (2-hydroxyethyl) -1,3-oxazolidine (hereinafter abbreviated as “OZ”).
[Preparation of Urethane Polyoxazolidine Compound (b1-1)]
A flask was charged with 40 parts by weight of isophorone diisocyanate (IPDI) and 60 parts by weight of the above OZ (isocyanate group: 1 mole of OZ: 1.05 mole), and these were reacted at 90 ° C. for 2 hours in a nitrogen atmosphere. A urethane polyoxazolidine compound (b1-1) was obtained. The production of the urethane polyoxazolidine compound (b1-1) was confirmed by the disappearance of the peak at 2250 cm ⁻¹ with an infrared spectrometer.

[Preparation of component (I)]
Isocyanate-terminated urethane prepolymer (A-1): 87 parts by weight and urethane polyoxazolidine compound (b1-1): 13 parts by weight were mixed to prepare component (I).

[Preparation of component (II)]
A 5-liter twin screw mixer was charged with 950 parts by weight of diisononyl ester adipic acid as a plasticizer, and then 163 parts by weight of gray toner (MC Industrial Co., Ltd.) and antifoaming agent Disparon P-450 (Enomoto Kasei Co. 15 parts by weight), 50 parts by weight of stabilizer B-75 (manufactured by Ciba Specialty Chemicals), and 20 parts by weight of dibutyltin dilaurate and 10 parts by weight of octylic acid were charged as a catalyst. Then, it stirred for 5 minutes so that the whole might become uniform. Next, 250 parts by weight of titanium oxide R-820 (Ishihara Sangyo Co., Ltd.) as an inorganic filler was charged with stirring, and further surface treated calcium carbonate / Calfine # 500 (manufactured by Maruo Calcium Co., Ltd.) 1400 parts by weight. After stirring for 30 minutes, 1400 parts by weight of heavy calcium carbonate NS-200 (manufactured by Nitto Flour Chemical Co., Ltd.) was charged and mixed and stirred at room temperature for 1.5 hours. Thereafter, 50 parts by weight of ion-exchanged water was added, and the mixture was stirred for 30 minutes, and defoamed for 5 minutes so that water did not fly to obtain component (II).

A concrete U-groove lid was used as a base, leaving a thickness of about 5 mm in advance, and removing the core and polishing the surface with a disk sander. At a temperature of 23 ° C. and a humidity of 50%, “Chemcrete E Primer” manufactured by ABC Shokai was applied as a primer at an application amount of 0.15 kg / m ² , and after 15 minutes, a coating material was applied at an application amount of 1.0 kg / m ² , A test specimen was prepared. It took about 1 hour from the start of applying the primer until the coating of the covering material was finished.

In addition, what mixed 100 weight part of said component (I) and 200 weight part of component (II) was used as a coating | covering material.

  The results are shown in Table 1.

A concrete U-groove lid was used as a base, leaving a thickness of about 5 mm in advance, and removing the core and polishing the surface with a disk sander. At a temperature of 23 ° C. and a humidity of 50%, “Sun PC” made by Mitsui Chemicals Polyurethane was applied as a primer at a coating amount of 0.15 kg / m ² .
Three hours later, the coating material was applied at an application amount of 1.0 kg / m ² to prepare a test specimen. It took about 4 hours from the start of applying the primer until the coating of the covering material was finished.

In addition, what mixed 100 weight part of said component (I) and 200 weight part of component (II) was used as a coating | covering material.

The results are shown in Table 1.
[Comparative Example 1]
A concrete U-groove lid was used as a base, leaving a thickness of about 5 mm in advance, and removing the core and polishing the surface with a disk sander. At a temperature of 23 ° C and humidity of 50%, an epoxy-based "Cleat Bond CA Primer" manufactured by ABC Corporation as a primer is applied in an amount of 0.15k.
It was applied at a rate of g / m ² , and the next day, “CLEATBOND AF” made by epoxy-based ABC Shokai was applied in an amount of 0.
3 kg / m ² is applied and immediately a propylene cloth (“Simtex Mesh SCM1810A” manufactured by Ube Nitto Kasei) is applied. Thereafter, “CLEATBOND AF” was applied at a coating amount of 0.4 kg / m ² . “Weather Guard A” made by ABC Shokai of acrylic urethane type the next day
U ”was applied at 0.2 kg / m ² to prepare a test specimen. It took about 3 days from the start of applying the primer until the application of the weather guard AU was completed.

The results are shown in Table 1.
[Comparative Example 2]
A concrete U-groove lid was used as a base, leaving a thickness of about 5 mm in advance, and removing the core and polishing the surface with a disk sander. At a temperature of 23 ° C. and a humidity of 50%, “Sun PC” made by Mitsui Chemicals Polyurethane was applied as a primer at a coating amount of 0.15 kg / m ² .
After 3 hours, apply “PROTECLITE S Putty” manufactured by ABC Shokai at an application rate of 1.3 kg / m ² .
The next day, “color top DL-SN” manufactured by ABC Shokai of acrylic urethane type is 0.2kg / m ²
The test specimen was prepared by coating with It took about 2 days from the start of applying the primer until the application of the color top DL-SN was completed.

The results are shown in Table 1.
"Workability"
In the above examples and comparative examples, the workability was evaluated as follows.

A primer is applied with a roller or a brush, and a member corresponding to a covering material is applied with a rubber spatula. A predetermined amount of material was applied to the wall surface, and workability was improved by not causing “sag”.
"Punch-out test method"
The specimens produced in the above examples and comparative examples were evaluated as follows.

  The push-out test method was carried out in accordance with the B type of the "Consultation on the applicability of the new material reinforcement and performance evaluation test plan (draft)" in the former Metropolitan Expressway Public Corporation Conservation Facility Department. That is, using a compression tester, the core part on the back surface on which the specimen was produced is pushed out once at a loading speed of 1 mm / min until the concrete is destroyed. Return to the state before loading after destruction and push out at a loading speed of 10 mm / min. The maximum load that can be extended to 10 mm or more was measured and used as a punch test load.

"Coating thickness"
A Teflon (registered trademark) sheet is applied to a glass plate so as not to be wrinkled, and an overcoating material similar to the amount used in the above Examples and Comparative Examples [“Coating Materials” (Examples 1 and 2), “ “Cleat Bond AF” (Comparative Example 1) and “Protectite S Putty” (Comparative Example 2)] are applied and cured for 1 week. The thickness of the cured coating after curing was measured using a thickness meter, and the thickness was determined as the thickness of each example and comparative example.

"Metal weather 300 hours"
At a temperature of 23 ° C. and a humidity of 50%, the coating material was applied to a 70 × 150 × 3 mm substrate with a coating amount of 1.0 kg / m ² and cured for 7 days. Next, one side of the specimen was irradiated with a metal halide weather resistance tester for 300 hours. The presence or absence of changes (chalking, blistering, cracking, peeling) on the surface coating material surface due to irradiation was visually observed.

"Crack tracking"
According to “Standard Specification for Concrete [Standard] Japan Society of Civil Engineers” JSCE-K 532-1999. At a temperature of 23 ° C. and a humidity of 50%, a “Chemicrete E primer” manufactured by ABC Shokai Co., Ltd. was applied to a substrate having dimensions of 40 × 120 × 10 mm at an application amount of 0.15 kg / m ² .
After 15 minutes, the coating material was applied at a coating amount of 1.0 kg / m ² and cured for 28 days to prepare a test specimen. The substrate was cut and pulled using a tensile testing machine at a tensile speed of 5.0 mm / min, and the amount of elongation was measured.

  As is clear from Table 1 below, the coating method of the present invention has fewer steps than the conventional method, and the time required for construction is short.

Claims (5)

After applying one kind of primer selected from the group consisting of an epoxy resin-based primer and a urethane resin-based primer on the concrete base,
A method for constructing a coating material, comprising: applying a coating material comprising a urethane resin composition containing at least the following (A) and (B) on the applied primer surface.
(A): Aliphatic and / or alicyclic isocyanate-terminated urethane prepolymer (B): (b1) and / or (b2) below
(B1): urethane oxazolidine compound obtained by reacting an aliphatic and / or alicyclic polyisocyanate with N-hydroxyalkyloxazolidine (b2): synthesized from a polyamine compound having two or more NH ₂ groups and an aldehyde compound Polyaldimine compounds   The said urethane resin composition contains a filler (C) further, The construction method of the coating | covering material of Claim 1 characterized by the above-mentioned.   The urethane resin composition comprises a component (I) containing the components (A) and (B) and a component (II) containing the component (C) and water (D). The method for constructing a coating material according to claim 2, wherein the method is a construction.   The said component (I) is a component containing said (A) and (b1), The construction method of the coating | covering material of Claim 3 characterized by the above-mentioned. The component (I) is
Isocyanate group-terminated urethane prepolymer (A-1) obtained by reacting an aliphatic and / or alicyclic polyisocyanate with a polyoxyalkylene polyol having a number average molecular weight of 1000 or more and a low molecular polyol having a number average molecular weight of less than 1000 )When,
Urethane polyoxazolidine compound obtained by reacting an aliphatic and / or cycloaliphatic polyisocyanate with 0.9 to 1.1 mol of N-hydroxyalkyloxazolidine in terms of hydroxyl group per 1 mol of isocyanate group of the polyisocyanate (B1-1) is a component containing 0.025 to 0.5 mol of the urethane polyoxazolidine compound (b1-1) with respect to 1 mol of the isocyanate group of the urethane prepolymer (A-1). The method for constructing a coating material according to claim 3 or 4, characterized in that