JP7067602B1 - Urethane coating waterproof top coat composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a topcoat composition for waterproofing a urethane coating film, which has excellent extensibility and gives a topcoat having reduced tackiness. SOLUTION: A polyisocyanate containing at least 30% by mass or more of a dimer body selected from the group consisting of an aliphatic isocyanate and an alicyclic isocyanate and containing two or more isocyanate groups in one molecule. , (A2) At least one polyol selected from the group consisting of polyether polyols, polyester polyols, polycaprolactone polyols and polycarbonate polyols having an average number of functional groups of 2.2 or more and a number average molecular weight of 300 to 3,500. A urethane containing the polyisocyanate resin (A) obtained by reacting with and having a reaction molar ratio ([NCO] / [OH]) of the polyisocyanate (A1) and the polyol (A2) of 3.0 or more. Top coat composition for coating film waterproofing. [Selection diagram] None

Description

The present invention relates to a top coat composition for waterproofing a urethane coating film.

Conventionally, a coating film waterproofing method has been widely used as a waterproofing method for rooftops, balconies, balconies, open corridors, etc. of buildings.
In this method, a primer layer is formed on the surface of a base material such as concrete or mortar, a urethane-based waterproof material layer is formed on the primer layer, and a top coat layer is further formed on the primer layer to form a multi-layer waterproof structure. Is common.

In this case, the top coat is applied for the purpose of protecting the urethane-based waterproof material layer and improving the aesthetic appearance, and acrylic urethane-based paints are widely used (see Patent Documents 1 to 3). In order to protect the waterproof material layer for a long period of time, the extensibility of the top coat is important from the viewpoint of following the behavior of the base and ensuring reliable waterproof performance. In addition, the waterproof layer is usually sticky (tack), and if the tack is too strong, it cannot walk smoothly on it, and it becomes difficult to clean it when dust adheres to it. Therefore, from the viewpoint of maintainability, it is necessary to reduce the tackiness of the top coat.

Japanese Unexamined Patent Publication No. 2002-309156 Japanese Unexamined Patent Publication No. 2004-263121 Japanese Unexamined Patent Publication No. 2007-720

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a urethane coating film waterproof topcoat composition which has excellent extensibility and gives a topcoat having reduced tackiness. ..

As a result of diligent studies to achieve the above object, the present inventors contain at least one dimer body selected from the group consisting of aliphatic isocyanates and alicyclic isocyanates in a predetermined ratio in one molecule. A polyisocyanate resin obtained by reacting a polyisocyanate containing two or more isocyanate groups with a predetermined polyol at a predetermined ratio is used as one component of a composition for a top coat to obtain a top coat. The present invention has been completed by finding that the extensibility can be remarkably improved and the tackiness thereof can be reduced.

That is, the present invention provides the following urethane coating film waterproof top coat composition.
1. 1. (A1) A polyisocyanate containing at least 30% by mass or more of a dimer body selected from the group consisting of an aliphatic isocyanate and an alicyclic isocyanate and containing two or more isocyanate groups in one molecule, and (A2). React with at least one polyol selected from the group consisting of polyether polyols, polyester polyols, polycaprolactone polyols and polycarbonate polyols having an average number of functional groups of 2.2 or more and a number average molecular weight of 300 to 3,500. For waterproofing urethane coating films containing the polyisocyanate resin (A) thus obtained and having a reaction molar ratio ([NCO] / [OH]) of the polyisocyanate (A1) and the polyol (A2) of 3.0 or more. Top coat composition.
2. 2. One urethane coating film in which the aliphatic isocyanate and the alicyclic isocyanate is at least one selected from the group consisting of hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and norbornane diisocyanate. Top coat composition for waterproofing.
3. 3. A top coat composition for waterproofing a urethane coating film having 1 or 2 in which the polyol (A2) has an average functional group number of 2.2 to 4 and a number average molecular weight of 400 to 3,000.
4. Top coat composition for urethane coating waterproofing according to any one of 1 to 3 in which the reaction molar ratio ([NCO] / [OH]) of the polyisocyanate (A1) and the polyol (A2) is 3.0 to 12.0. thing.
5. A top coat composition for waterproofing a urethane coating film according to any one of 1 to 4 which is a two-component type.
6. (A1) A polyisocyanate containing at least 30% by mass or more of a dimer body selected from the group consisting of an aliphatic isocyanate and an alicyclic isocyanate and containing two or more isocyanate groups in one molecule, and (A2). React with at least one polyol selected from the group consisting of polyether polyols, polyester polyols, polycaprolactone polyols and polycarbonate polyols having an average number of functional groups of 2.2 or more and a number average molecular weight of 300 to 3,500. For waterproofing urethane coating films containing the polyisocyanate resin (A) thus obtained and having a reaction molar ratio ([NCO] / [OH]) of the polyisocyanate (A1) and the polyol (A2) of 3.0 or more. Hardener for topcoat compositions.

The urethane coating waterproof topcoat composition of the present invention is obtained because a polyisocyanate resin obtained by reacting the above-mentioned specific polyisocyanate with a specific polyol at a predetermined ratio is used as one component. The extensibility of the top coat can be remarkably improved and the tackiness thereof can be reduced.

Hereinafter, the present invention will be described in more detail.
The top coat composition for waterproofing a urethane coating film according to the present invention contains at least 30% by mass or more of at least one dimer body selected from the group consisting of (A1) aliphatic isocyanates and alicyclic isocyanates in one molecule. Polyisocyanates containing two or more isocyanate groups and (A2) polyether polyols, polyester polyols, polycaprolactone polyols and polycarbonate polyols having an average number of functional groups of 2.2 or more and a number average molecular weight of 300 to 3,500. It contains a polyisocyanate resin (A) obtained by reacting with at least one polyol selected from the group consisting of the above, and the reaction molar ratio ([NCO] / [OH] of the polyisocyanate (A1) and the polyol (A2). ]) Is 3.0 or more.

As the aliphatic isocyanate and the alicyclic isocyanate in the dimer body, various conventionally known polyisocyanates can be appropriately selected and used.

Examples of the aliphatic isocyanate include hexamethylene diisocyanate, 1,4-tetramethylene diisocyanate, 2-methylpentane-1,5-diisocyanate, 3-methyl-pentane-1,5-diisocyanate, lysine diisocyanate, and trioxyethylene diisocyanate. Can be mentioned.

Examples of the alicyclic isocyanate include isophorone diisocyanate, norbornane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and hydrogenated tetramethylxylylene diisocyanate.

Among these, the dimer body preferably contains a dimer body of hexamethylene diisocyanate in consideration of reducing the tackiness of the obtained top coat.

The content of the dimer body is 30% by mass or more in the component (A1), but is preferably 35% by mass or more, more preferably in consideration of further improving the extensibility and tackiness of the obtained top coat. Is 45% by mass or more, more preferably 50% by mass or more. The upper limit thereof is not particularly limited, but is usually 70% by mass or less.

Further, the component (A1) may contain other isocyanates other than the above-mentioned aliphatic isocyanate and alicyclic isocyanate as the balance. Examples of such isocyanates include aromatic isocyanates and aromatic aliphatic diisocyanates. These isocyanates may be used alone or in combination of two or more. Further, those adduct bodies, allophanate bodies, trimmer bodies and the like may also be used.

As aromatic isocyanates, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4' -Diphenyl ether diisocyanate, 2-nitrodiphenyl-4,4'-diisocyanate, 2,2'-diphenylpropane-4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,4' -Diphenylpropane diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, naphthylene-1,4-diisocyanate, naphthylene-1,5-diisocyanate, 3,3'-dimethoxydiphenyl-4,4'-diisocyanate and the like can be mentioned.

Examples of the aromatic aliphatic diisocyanate include xylylene-1,4-diisocyanate and xylylene-1,3-diisocyanate.

In the present invention, the polyisocyanate (A1) contains two or more isocyanate groups in one molecule from the viewpoint of significantly improving the extensibility of the obtained topcoat and reducing its tackiness, but the polyol (A2). ), 2 to 4 are preferable, and 2 to 3 are more preferable, considering the suppression of gelation during the reaction with) and the improvement of handleability during use.
The viscosity of the polyisocyanate (A1) is not particularly limited, but is preferably 50 to 900 mPa · s at 25 ° C., more preferably 100 to 700 mPa · s, in consideration of handleability at the time of use.

As the polyisocyanate (A1), a commercially available product can also be used, and specific examples thereof include EXCELHARDENER X-19 (manufactured by Asia Industries Co., Ltd.), Coronate 2365 (manufactured by Tosoh Co., Ltd.), and Desumodor N 3400 (Sumitomo Chemical Co., Ltd.). (Manufactured by Cobestlor Urethane Co., Ltd.) and the like.

The polyol (A2) includes at least one polyol selected from the group consisting of a polyether polyol, a polyester polyol, a polycaprolactone polyol and a polycarbonate polyol. As these polyols, various conventionally known polyols can be used.

As the polyether polyol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol obtained by ring-opening polymerization of ethylene oxide, propylene oxide, tetrahydrofuran and the like using a low molecular weight polyol, a low molecular weight polyamine, and a low molecular weight amino alcohol as an initiator. Etc., and copolymers thereof and the like.

Examples of polyester polyols include succinic acid, adipic acid, sebacic acid, azelaic acid, terephthalic acid, isophthalic acid, orthophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, hexahydroorthophthalic acid, naphthalenedicarboxylic acid, 1,4-. One or more polycarboxylic acids such as cyclohexanedicarboxylic acid and trimetic acid, acid esters, or acid anhydrides, and ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1 , 3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanedi Examples thereof include polyols obtained by dehydration condensation with one or more of low molecular weight polyols such as methanol, trimethylolpropane, glycerin, and pentaerythritol.

Examples of the polycaprolactone polyol include a polyol obtained by ring-opening polymerization of a cyclic ester monomer such as ε-caprolactone and γ-valerolactone using a low molecular weight polyol, a low molecular weight polyamine, and a low molecular weight amino alcohol as an initiator.

Examples of the polycarbonate polyol include polyols obtained by reacting the above small molecule polyols with ethylene carbonate, diethyl carbonate, diphenyl carbonate and the like.

In the present invention, among these, a polyether polyol that can give a top coat having excellent extensibility is preferable, and a polyoxypropylene triol is particularly preferable from the viewpoint of further reducing the tackiness.

In the present invention, the average number of functional groups of the polyol (A2) is 2.2 or more from the viewpoint of significantly improving the extensibility of the obtained topcoat and reducing its tackiness, but with the polyisocyanate (A1). 2.2 to 4 is preferable, and 2.2 to 3 is more preferable, in consideration of suppressing gelation during the reaction of the above and improving compatibility with the main agent.

The number average molecular weight of the polyol (A2) is 300 to 3,500, preferably 400 to 3,000, from the viewpoint of significantly improving the extensibility of the obtained top coat and reducing its tackiness. be.
The number average molecular weight is a measured value (polystyrene conversion value) measured by gel permeation chromatography (hereinafter abbreviated as GPC) measured by a differential refractometer detection.

Commercially available products can be used as the polyol (A2), and specific examples thereof include Sanniks GP-400 (manufactured by Sanyo Kasei Co., Ltd.), Sanniks GP-1000 (manufactured by Sanyo Kasei Co., Ltd.), and Sanniks. GP-3000 (manufactured by Sanyo Chemical Industries, Ltd.), Kuraray polyol F-1010 (manufactured by Kuraray Co., Ltd.), Polylite OD-X-2588 (manufactured by DIC Co., Ltd.), PCP-100L (manufactured by Toso Co., Ltd.), etc. Can be mentioned.

The polyisocyanate resin (A) can be obtained by reacting the above-mentioned polyisocyanate (A1) with the polyol (A2) in the presence or absence of a solvent.
The reaction conditions between the polyisocyanate (A1) and the polyol (A2) are not particularly limited, and for example, an excess amount of the polyisocyanate (A1) at 20 to 150 ° C. in the presence of a urethanization catalyst, if necessary. And a method of reacting the polyol (A2).

At this time, the reaction molar ratio ([NCO] / [OH]) of the polyisocyanate (A1) [NCO] and the polyol (A2) [OH] significantly improves the extensibility of the obtained top coat. From the viewpoint of reducing the tackiness, it is 3.0 or more, but in consideration of handleability at the time of use, it is preferably 5.0 or more, more preferably 7.0 or more. The upper limit of the reaction molar ratio is not particularly limited, but is preferably 12.0 or less, more preferably 10.0 or less.

The urethanization catalyst can be appropriately selected from known catalysts. Specific examples thereof include dibutyl tin laurate and dioctyl tin laurate.

The reaction between the polyisocyanate (A1) and the polyol (A2) can be carried out in the absence of a solvent or in the presence of a solvent.
The solvent is not particularly limited as long as it does not adversely affect the reaction. Specific examples thereof include aliphatic or alicyclic hydrocarbons such as n-hexane, n-heptane, n-octane, cyclohexane and cyclopentane; toluene, xylene, ethylbenzene, low boiling aromatic naphtha, high boiling aromatic naphtha. Aromatic hydrocarbons such as ethyl acetate, n-butyl acetate, n-amyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether pro Esters such as pionate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 3-methoxybutyl acetate; methanol, ethanol, iso-propanol, n-butanol, iso-butanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether , Ethylene glycol mono n-butyl ether, propylene glycol monomethyl ether, propylene glycol mono n-propyl ether, diethylene glycol monobutyl ether and other alcohols; acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl n-amyl ketone, cyclohexanone and other ketones; dimethoxyethane , Ethers such as tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether; N-methylpyrrolidone, dimethylformamide, dimethylacetamide, ethylene carbonate and the like can be mentioned. These may be used alone or in combination of two or more.

The isocyanate content of the obtained polyisocyanate resin (A) is preferably 2.0 to 6.0% by mass from the viewpoint of reducing the tackiness of the obtained topcoat, and a topcoat having excellent extensibility can be provided. Considering the points, it is more preferably 2.2 to 5.0% by mass, and even more preferably 2.2 to 4.5% by mass.

The solid content concentration of the obtained polyisocyanate resin (A) is preferably 15 to 40% by mass, more preferably 20 to 30% by mass, from the viewpoint of storage stability.

The urethane coating waterproof top coat composition of the present invention contains the above-mentioned polyisocyanate resin (A) as one component, but since the polyisocyanate resin (A) is characteristic, it is reacted and cured with the polyisocyanate resin (A). The component (polyol resin (B)) of the above may be appropriately selected from those generally used for the present application. Specific examples thereof include acrylic polyols and fluorine-based polyols. Among these, acrylic polyols are preferable from the viewpoint of balance between weather resistance and cost.
Further, the above-mentioned polyisocyanate resin (A) is suitable as a curing agent for a urethane coating film waterproof top coat composition because it can give excellent extensibility to the obtained urethane resin and reduce tackiness. ..

As the acrylic polyol, various acrylic polyols obtained by radical copolymerization of an acrylic monomer having a hydroxyl group and another polymerizable monomer having an unsaturated double bond can be used.

Specific examples of the acrylic monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, and 4-hydroxy. Examples thereof include butyl (meth) acrylate, N-methylolated acrylamide, ε-caprolactone-modified hydroxy (meth) acrylate, carbonate-modified methacrylate (manufactured by Daicel Chemical Industry Co., Ltd., HEMAC) and the like. These may be used alone or in combination of two or more.

Specific examples of the polymerizable monomer having an unsaturated double bond include a carboxylic acid group-containing monomer such as (meth) acrylic acid, maleic acid, fumaric acid, and itaconic acid, and an epoxy group-containing monomer such as glycidyl (meth) acrylate. Amino group-containing monomers such as N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl. (Meta) acrylate, iso-butyl (meth) acrylate, t-butyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, pentyl (meth) ) C1-C24 alkyl (meth) acrylate monomers such as acrylates, hexyl (meth) acrylates, octyl (meth) acrylates, decanyl (meth) acrylates, undecanyl (meth) acrylates, lauryl (meth) acrylates, and stearyl (meth) acrylates. , Aromatic hydrocarbon monomers such as styrene, α-methylstyrene and vinyltoluene, vinyl ether monomers such as methylvinyl ether and ethylvinyl ether, vinyl acetate, vinyl propionate, (meth) acrylonitrile, N-vinylpyrrolidone and the like. .. These may be used alone or in combination of two or more. In particular, it is preferable to use an alkyl (meth) acrylate monomer as the polymerizable monomer having an unsaturated double bond.

The radical copolymerization is carried out using a polymerization initiator in the absence of a solvent or in the presence of a suitable organic solvent.
The organic solvent is not particularly limited as long as it does not adversely affect the reaction. Specific examples thereof include those exemplified by the reaction between the polyisocyanate (A1) and the polyol (A2).
The polymerization initiator can be appropriately selected from known radical polymerization initiators, for example, 2,2'-azobisisobutyronitrile, azobisisobutyronitrile, benzoyl peroxide, t-butyl peroxide, etc. Cumene hydroperoxide and the like can be mentioned. These may be used alone or in combination of two or more.
The reaction temperature is usually about 60 to 150 ° C. The reaction time is usually about 1 to 12 hours.

Further, as the acrylic polyol and the fluorine-based polyol, commercially available products can also be used.
Commercially available acrylic polyols include Excelol 290, Excelol 170 (above, manufactured by Asia Kogyo Co., Ltd.), Acrydic A-801-P, and Acrydic A-823 (above, Dainippon Ink and Chemicals Co., Ltd.). ) Made) and the like.
Examples of commercially available fluorine-based polyols include Lumiflon LF-100 and Lumiflon LF-200 (all manufactured by Asahi Glass Co., Ltd.).

In the urethane coating waterproof top coat composition of the present invention, the blending ratio of the polyisocyanate resin (A) and the polyol resin (B) is not particularly limited, but the cross-linking density is increased to increase the cross-linking density of the top coat coating. Considering that the performance is sufficiently exhibited, the molar ratio ([NCO] / [OH]) of the isocyanate group in the polyisocyanate component and the hydroxyl group in the polyol component is preferably 0.8 or more. In particular, considering the foaming due to the reaction between the excess isocyanate group and water, it is preferably 0.9 to 3.0, more preferably 1.0 to 2.5.

An organic solvent may be added to the urethane coating film waterproof top coat composition of the present invention, if necessary. As the organic solvent, various solvents conventionally used in the top coat composition can be used. Specific examples thereof include aromatic hydrocarbon solvents such as toluene and xylene; ester solvents such as ethyl acetate, n-butyl acetate and n-amyl acetate; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; cyclohexane, methyl cyclohexane and ethyl. Alicyclic hydrocarbon solvents such as cyclohexane; petroleum hydrocarbon solvents such as mineral spirits; ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether pro Examples thereof include pionates, diethylene glycol monoethyl ether acetates, diethylene glycol monobutyl ether acetates, glycol ether esters solvents and the like. These solvents may be used alone or in combination of two or more.

Further, the urethane coating film waterproof top coat composition of the present invention may contain a coloring pigment, an extender pigment, a surface conditioner, a defoaming agent, a thickener, a settling inhibitor, an ultraviolet absorber, and a light stabilizer, if necessary. Various additives such as agents and catalysts may be blended. In the case of a two-component composition, these solvents and various additives may be blended in either one of the polyisocyanate component and the polyol component, or may be blended in both.

The urethane coating film waterproof top coat composition of the present invention can be suitably used as a two-component room temperature curing type composition in which two components are mixed and coated on site.
In this case, the coating method is not particularly limited, and a known method such as brush coating or roller coating may be appropriately selected. Further, the coating amount, the thickness of the coating film, the drying time and the like may be appropriately set according to the type of the urethane waterproof material and the like.

Hereinafter, the present invention will be specifically described with reference to synthetic examples, comparative synthetic examples, examples and comparative examples, but the present invention is not limited to the following examples. In the following, "part" means "part by mass", and "%" means "% by mass".

The raw materials used are as follows.
EXCELHARDENER X-19: aliphatic dimer-modified polyisocyanate, Coronate manufactured by Asia Industries Co., Ltd. 2612: aliphatic adduct-modified polyisol, HDI manufactured by Toso Co., Ltd .: hexamethylene diisocyanate, coronate manufactured by Toso Co., Ltd. 2770: fat Group allophanate-modified polyisocyanate, Desumodor N 3200 manufactured by Toso Co., Ltd .: aliphatic biuret-modified polyisocyanate, Sanniks GP-1000 manufactured by Sumika Cobestrourethane Co., Ltd .: polyoxypropylene triol, number average molecular weight 1,000 , Sanyo Kasei Co., Ltd. Sanniks PP-1000: Polyoxypropylene glycol, Number average molecular weight 1,000, Functional groups 2.0, Sanyo Kasei Co., Ltd. Sanniks GP-400: Poly Oxypropylene triol, number average molecular weight 400, number of functional groups 3.0, Sankix GP-3000 manufactured by Sanyo Kasei Co., Ltd .: polyoxypropylene triol, number average molecular weight 3,000, number of functional groups 3.0, Sanyo Kasei Co., Ltd. Claret Polyol F-1010: Polyol polyol, number average molecular weight 1,000, number of functional groups 3.0, Polylite OD-X-2588 manufactured by Claret Co., Ltd .: Polycaprolactone polyol, number average molecular weight 1,250, number of functional groups 3. 0, PCP-100L manufactured by DIC Co., Ltd .: Polypolypolyol, number average molecular weight 1,000, number of functional groups 3.0, manufactured by Toso Co., Ltd.)
Sanniks GP-250: Polyoxypropylene triol, number average molecular weight 250, number of functional groups 3.0, Sanyo Chemical Industries, Ltd. Sanniks GP-4000: Polyoxypropylene triol, number average molecular weight 4,000, number of functional groups 3. 0, manufactured by Sanyo Chemical Industries, Ltd.

[1] Synthesis of polyisocyanate resin (Synthesis Example 1) Synthesis of polyisocyanate resin A-1 EXCELHARDENER X-19 (Asa Kogyo Co., Ltd.) was installed in a reactor equipped with a stirrer, thermometer, cooling tube and nitrogen gas introduction tube. ), Aliphatic dimer-containing polyisocyanate) 170.0 parts, Sanniks GP-1000 (manufactured by Sanyo Kasei Co., Ltd., polyoxypropylene triol: molecular weight = 1,000) 30.0 parts, xylene 800.0 parts Was charged and the temperature was raised to 80 ° C. 0.1 part of dibutyltin dilaurate was added and reacted at the same temperature for 10 hours to obtain a polyisocyanate resin A-1. The obtained polyisocyanate resin A-1 had an isocyanate content of 3.9% and a solid content concentration of 20.0%.

(Synthesis Examples 2-9)
Polyisocyanate resins A-2 to A-9 were obtained in the same manner as in Synthesis Example 1 except that the composition of each component was changed according to Table 1.

(Comparative Synthesis Example 1) Synthesis of polyisocyanate resin A-10 EXCELHARDENER X-19 126.5 parts, Sanniks GP-1000 73. 5 parts and 800.0 parts of toluene were charged, and the temperature was raised to 80 ° C. 0.1 part of dibutyltin dilaurate was added and reacted at the same temperature for 10 hours to obtain a polyisocyanate resin A-10. The obtained polyisocyanate resin A-10 had an isocyanate content of 1.7% and a solid content concentration of 20.0%.

(Comparative Synthesis Examples 2-9)
Polyisocyanate resins A-11 to A-18 were obtained in the same manner as in Comparative Synthesis Example 1 except that the composition of each component was changed according to Table 2.

[2] Preparation of top coat composition for urethane coating film waterproofing (Examples 1 to 9, Comparative Examples 1 to 9)
The main agent using the hydroxyl group-containing resin in which the above polyisocyanate resins A-1 to A-18 are combined as a curing agent was prepared as follows.

400.0 parts of xylene and 200.0 parts of butyl acetate were charged in a reactor equipped with a stirrer, a thermometer, a condenser and a dropping device, and the temperature was raised to 110 ° C. while stirring. There, 80.0 parts of 2-hydroxyethyl methacrylate, 100.0 parts of styrene, 320.0 parts of methyl methacrylate, 250.0 parts of n-butyl methacrylate, 247.0 parts of n-butyl acrylate, 3.0 parts of acrylic acid. , T-Butylperoxy-2-ethylhexanoate (18.0 parts) and toluene (100.0 parts) were added dropwise over 4 hours. After completion of the dropping, the reaction was carried out at the same temperature for 1 hour. Further, a mixture consisting of 2.0 parts of t-butylperoxy-2-ethylhexanoate and 100.0 parts of toluene was added dropwise over 1 hour. After completion of the dropping, the mixture was reacted at the same temperature for 3 hours, having a solid content concentration of 56.0%, a viscosity of 4000 mPa · s (25 ° C.), a hydroxyl value of 33.9 mgKOH / g (solid content), a number average molecular weight of 15,000, and an average sensory function. A transparent acrylic polyol resin solution having a radix of 9.1 was obtained.
Subsequently, 256 parts of this acrylic polyol resin solution, 88 parts of pigment CR-95 (manufactured by Ishihara Sangyo Co., Ltd.), 56 parts of xylene, and 400 parts of glass beads were mixed and dispersed with a paint shaker for 1 hour. After the dispersion was completed, the glass beads were removed to prepare a white paint having a solid content concentration of 57.8% and a hydroxyl value of 12.1 mgKOH / g, which was used as a main ingredient.
The main agent and the curing agent were mixed at a [NCO] / [OH] molar ratio of 1.1 and mixed well to obtain a topcoat composition.

The performance of each topcoat composition obtained in the above Examples and Comparative Examples was measured according to the following method. The results are shown in Table 3.
(1) Tackiness Two-component room temperature curing urethane coating film waterproof material (trade name: Saraseine K, manufactured by AGC Polymer Building Materials Co., Ltd.) is applied to the surface of a slate plate (30 cm x 30 cm) at a ratio of 2 kg / m ² . After that, curing was performed for 24 hours under the conditions of 23 ° C. and 50% relative humidity. The top coat composition prepared above was coated on this at a rate of 0.15 kg / m ² using a medium hair roller, and cured under the conditions of 23 ° C. and 50% RH for 24 hours for testing. The body was made. The surface condition of the test piece was confirmed by touching the finger, and those having no stickiness were evaluated as "○" as having excellent tackiness, and those having stickiness were evaluated as "x" as having inferior tackiness.

(2) A two-component room temperature curable urethane coating film waterproof material is applied to the surface of a release paper (30 cm x 30 cm) at a ratio of 2 kg / m ² , and then under conditions of 23 ° C. and 50% relative humidity. It was cured for 24 hours. On this, the top coat composition prepared above was coated at a ratio of 0.15 kg / m ² using a medium hair roller, and cured under the conditions of 23 ° C. and 50% RH for 24 hours. After curing, the coating film was peeled off from the release paper and punched out using a No. 2 dumbbell. The extensibility was evaluated using a tensile tester (Autograph AG-5000C manufactured by Shimadzu Corporation) at a tensile speed of 200 mm / min until a crack was formed in the top coat, and evaluated in the following three stages.
<Evaluation criteria>
◯: Elongation rate 100% or more Δ: Elongation rate 50% or more and less than 100% ×: Elongation rate less than 50%

As shown in Table 3, the coating film prepared from each top coat composition of Examples has better tackiness and extensibility than the coating film prepared from each top coat composition of Comparative Example. You can see that.

Claims (8)

(A1) Polyisocyanate containing at least one dimer body selected from the group consisting of aliphatic isocyanates and alicyclic isocyanates in an amount of 30% by mass or more and containing two or more isocyanate groups in one molecule, and (A2) average. By reacting with at least one polyol selected from the group consisting of polyether polyols, polyester polyols, polycaprolactone polyols and polycarbonate polyols having a number of functional groups of 2.2 or more and a number average molecular weight of 300 to 3,500. The obtained polyisocyanate resin (A) and
Containing with polyol resin (B)
A urethane coating waterproof top coat composition having a reaction molar ratio ([NCO] / [OH]) of the polyisocyanate (A1) and the polyol (A2) of 3.0 or more. The first aspect of claim 1, wherein the aliphatic isocyanate and the alicyclic isocyanate are at least one selected from the group consisting of hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and norbornane diisocyanate. Top coat composition for urethane coating waterproofing. The top coat composition for waterproofing a urethane coating film according to claim 1 or 2, wherein the polyol (A2) has an average number of functional groups of 2.2 to 4 and a number average molecular weight of 400 to 3,000. The urethane coating film according to any one of claims 1 to 3, wherein the reaction molar ratio ([NCO] / [OH]) of the polyisocyanate (A1) and the polyol (A2) is 3.0 to 12.0. Top coat composition for waterproofing. The top coat composition for waterproofing a urethane coating film according to any one of claims 1 to 4, wherein the polyol resin (B) is an acrylic polyol or a fluorine-based polyol. When the blending ratio of the polyisocyanate resin (A) and the polyol resin (B) [molar ratio of isocyanate groups in the polyisocyanate component and hydroxyl groups in the polyol component ([NCO] / [OH])] is 0.8 or more. The top coat composition for waterproofing a urethane coating film according to any one of claims 1 to 5. The top coat composition for waterproofing a urethane coating film according to any one of claims 1 to 6, further comprising an organic solvent. (A1) Polyisocyanate containing at least one dimer body selected from the group consisting of aliphatic isocyanates and alicyclic isocyanates in an amount of 30% by mass or more and containing two or more isocyanate groups in one molecule, and (A2) average. By reacting with at least one polyol selected from the group consisting of polyether polyols, polyester polyols, polycaprolactone polyols and polycarbonate polyols having a number of functional groups of 2.2 or more and a number average molecular weight of 300 to 3,500. Contains the obtained polyisocyanate resin (A),
A curing agent for a urethane coating waterproof topcoat composition having a reaction molar ratio ([NCO] / [OH]) of the polyisocyanate (A1) and the polyol (A2) of 3.0 or more.