JP7839720B2 - Two-component hand-applied urethane waterproofing material composition and method for applying urethane waterproof coating layer - Google Patents

Description

This invention relates to a two-component, hand-applied urethane waterproofing material composition and a method for applying a urethane waterproof coating layer for sports floors and parking lots.

Urethane waterproofing materials are suitable for application in irregularly shaped and confined areas, and have been widely used for waterproofing balconies and eaves of apartment buildings and other multi-unit dwellings, as well as for waterproofing rooftops with many fittings, and even for full-scale rooftop waterproofing using breathable buffer sheets. On the other hand, for areas subjected to heavy loads such as sports floors and rooftop parking lots, a high-hardness urethane coating waterproofing layer with excellent elasticity and rigidity is required as a finishing material.

Currently, polyurethane waterproofing materials are classified into two types according to JIS A 6021 "Waterproofing Materials for Buildings": high-elongation type and high-strength type. The high-elongation type is a general-purpose waterproofing material for hand application, and is specified to have an elongation rate at break (hereinafter referred to as "elongation rate") of 450% or more, a tensile strength of 2.3 N/ ^mm² or more, and a tensile volume of 280 N/mm² or more, and is mainly used for non-pedestrian or light-pedestrian areas. On the other hand, the high-strength type is specified to have an elongation rate of 200% or more, a tensile strength of 10 N/ ^mm² or more, and a tensile volume of 700 N/mm² or more, and is often used for special applications such as waterproof floors for parking lots, root-resistant waterproofing materials for rooftop greening, and waterproofing materials for metal roofs, and mainly consists of ultra-fast-curing polyurethane materials that are spray-applied using a dedicated spray device that impact-mixes two highly reactive components. However, spray application presents a major problem due to the scattering of mist generated during application. This necessitates not only strict protection of the surrounding area with film, but also careful attention to nearby houses and cars, making it unsuitable for application in densely populated residential areas. Furthermore, spray equipment is expensive, and specialized technicians are required, limiting the number of contractors capable of performing the work. While JIS A 6021 does not specify hardness, the JIS D hardness of a typical spray coating using ultrafast-curing urethane material is around 35 to 45.

Among two-component, hand-applied urethane waterproofing materials that have few application problems, a two-component, environmentally friendly, hand-applied urethane waterproofing material composition (Patent Documents 1 and 2) is known that has a relatively high hardness coating film. This composition contains isophorone diisocyanate (hereinafter referred to as IPDI) as the main component and diethyltoluenediamine (hereinafter referred to as DETDA) as the curing agent, corresponding to the JIS A 6021 high-strength urethane rubber type. However, the hardness of its cured coating film is at most about 85 on the JIS A hardness scale (equivalent to 33 on the JIS D hardness scale), which is insufficient for use as a urethane coating layer for sports floors or parking lots.

Two-component, hand-applied urethane waterproofing materials are applied by mixing two liquid components in a mixer and then applying them by hand using a trowel, spatula, roller, brush, etc. After mixing in the mixer, a usable time of at least 30 minutes (hereinafter referred to as the pot life) is required.
The above-mentioned two-component urethane waterproofing material for hand application generally comes in two formulations: a summer formulation suitable for application at around 30°C in summer and a winter formulation suitable for application at around 10°C in winter, as the ambient temperature differs significantly between winter and summer application. For example, the summer formulation is designed to have a pot life of 50 minutes or more at 23°C, while the winter formulation is designed to have a pot life of 30 minutes or more at 23°C. Generally, pot life is defined as the time it takes for the viscosity to reach 60,000 to 100,000 mPa·s after mixing the two components at 23°C.
Furthermore, it is desirable that the urethane waterproofing material be applied in the evening and hardened enough for light foot traffic by the following morning, and it is considered best if the hardening time can be adjusted to within 17 hours throughout the year.

Generally, two-component, hand-applied urethane waterproofing materials use plasticizers to ensure sufficient working time throughout the year, as well as high elasticity and hardness. It is relatively easy to increase the resin concentration and thus the hardness of the urethane coating by replacing some of the plasticizer with a solvent that ultimately volatilizes into the air. However, in this case, the reaction between the main component and the hardener is accelerated, making it difficult to ensure sufficient working time.

Japanese Patent Publication No. 2017-43740 Japanese Patent Application Publication No. 10-17819

Conventionally, spray-type ultra-fast-curing polyurethane waterproofing materials, primarily used as finishing materials for sports floors and parking lots, have problems such as mist dispersion during application and the need for specialized technicians. On the other hand, the formulation technology for two-component, hand-applied polyurethane waterproofing materials has limitations in ensuring sufficient hardness and other properties for practical use in sports floors and parking lots, while also guaranteeing adequate pot life for summer application. Therefore, there has been a demand for a two-component, hand-applied polyurethane waterproofing material composition that maintains sufficient pot life throughout the year while also being durable enough for sports floors and parking lots.

In light of these problems, the inventors diligently studied a two-component, hand-applied urethane waterproofing material composition that has sufficient pot life throughout the year, possesses sufficient hardness for use as a finishing material for sports floors and parking lots, and does not require measures to prevent scattering during application or special equipment and dedicated technicians.
In a two-component, hand-applied urethane waterproofing material composition comprising a main component containing an isocyanate-terminated prepolymer consisting of polyisocyanate and polyol, a curing agent containing an aromatic polyamine and an inorganic filler, a plasticizer, and a solvent, we have discovered that by using isophorone diisocyanate as the polyisocyanate in the main component, diethyltoluenediamine as the aromatic polyamine in the curing agent, adjusting the ratio of the total amount of plasticizer (g) to the amount of amino groups (milliequivalent) of the aromatic polyamine to a specific range, and further using an aprotic solvent having a specific range of solubility parameters (SP value) as the solvent, we can obtain a two-component, hand-applied urethane waterproofing material composition that has sufficient pot life throughout the year and also has sufficient hardness of a cured coating film for use as a finishing material for sports floors and parking lots, thus completing the present invention.

The present invention relates to a two-component, hand-applied urethane waterproofing material composition comprising a main component containing an isocyanate-terminated prepolymer consisting of a polyisocyanate and a polyol, and a curing agent containing an aromatic polyamine and an inorganic filler,
In the main component, more than 70 equivalents of the polyisocyanates constituting the isocyanate-terminated prepolymer are isophorone diisocyanates, and the NCO content of the main component is 3.0% to 6.0% by mass.
The curing agent contains 20% to 80% by mass of inorganic filler, and more than 80 equivalents of the total reactive components in the curing agent are aromatic polyamines, and more than 70 equivalents of the aromatic polyamines are diethyltoluenediamine.
A plasticizer is added in an amount of 3 to 25 parts by mass per 100 parts by mass of isocyanate-terminated prepolymer in the main component, either separately in the curing agent or in both the main component and the curing agent.
The urethane waterproofing material composition contains 10% to 40% by mass of solvent, either in the curing agent or separately in both the main component and the curing agent, and the solvent contains more than 30% by mass of aprotic solvent with a solubility parameter (SP value) of 8.0 to 14.0.
The material is characterized by having a ratio of the amount of amino groups (milli-equivalent) of aromatic polyamine to the amount of plasticizer (g) of which is 4.0 to 45.0.
The present invention II is a method for applying a urethane waterproof coating layer, which includes applying a primer layer to a substrate surface, or applying a primer layer and a urethane waterproofing layer, then mixing the two-component, hand-applied urethane waterproofing material composition of the present invention II with an inorganic aggregate and applying the mixture.

The present invention includes the following embodiments.
[1] A two-component urethane waterproofing material composition for hand application, comprising a main component containing an isocyanate-terminated prepolymer consisting of a polyisocyanate and a polyol, and a curing agent containing an aromatic polyamine and an inorganic filler,
In the main component, more than 70 equivalents of the polyisocyanates constituting the isocyanate-terminated prepolymer are isophorone diisocyanates, and the NCO content of the main component is 3.0% to 6.0% by mass.
The curing agent contains 20% to 80% by mass of inorganic filler, and more than 80 equivalents of the total reactive components in the curing agent are aromatic polyamines, and more than 70 equivalents of the aromatic polyamines are diethyltoluenediamine.
A plasticizer is added in an amount of 3 to 25 parts by mass per 100 parts by mass of isocyanate-terminated prepolymer in the main component, either separately in the curing agent or in both the main component and the curing agent.
The urethane waterproofing material composition contains 10% to 40% by mass of solvent, either in the curing agent or separately in both the main component and the curing agent, and the solvent contains more than 30% by mass of aprotic solvent with a solubility parameter (SP value) of 8.0 to 14.0.
A two-component, hand-applied urethane waterproofing material composition in which the ratio of the amount of amino groups (milli-equivalent) of aromatic polyamine to the amount (g) of plasticizer is 4.0 to 45.0.
[2] The two-component urethane waterproofing material composition for hand application according to [1], wherein the polyol constituting the isocyanate-terminated prepolymer in the main component contains a polyoxyalkylene polyol, and the polyol constituting the isocyanate-terminated prepolymer in the main component contains 10 to 97 equivalents of a diol with a molecular weight of 1500 or more and 3 to 90 equivalents of a diol with a molecular weight of less than 1500 and a polyol with 3 or more functional groups in total.
[3] The two-component urethane waterproofing material composition for hand application according to [1] or [2], wherein the equivalent ratio of the isocyanate group of the main component to the amino group of the aromatic polyamine, which is a reactive component in the curing agent, is 0.9 to 1.5.
[4] A two-component, hand-applied urethane waterproofing material composition according to any one of [1] to [3], wherein more than 50 equivalents of the polyol constituting the isocyanate group-terminated prepolymer in the main component is a polyoxyalkylene polyol.
[5] A two-component, hand-applied urethane waterproofing material composition according to any one of [1] to [4], wherein the hardened coating film of the urethane waterproofing material composition has a JIS D hardness of 35 to 60.
[6] A method for applying a urethane waterproof coating layer, comprising applying a primer layer to a substrate surface, or applying a primer layer and a urethane waterproofing material layer, then mixing the two-component hand-applied urethane waterproofing material composition described in [1] with an inorganic aggregate and applying it.

The two-component, hand-applied urethane waterproofing material composition of the present invention exhibits sufficient hardness for use as a finishing material for sports floors and parking lots, and ensures a sufficient pot life throughout the year.
Furthermore, the application method for urethane waterproof coating layers for sports floors and parking lots according to the present invention offers excellent practical workability and durability, and is also environmentally friendly as it does not use any materials subject to the Specified Chemical Substances Act.

This first invention relates to a two-component, hand-applied urethane waterproofing material composition. Here, "two-component" refers to a main component and a hardener. "Hand-applied" means it is applied by hand using a trowel, spatula, roller, brush, etc. To ensure sufficient performance as a waterproofing layer for sports floors and parking lots, the hardness of the cured coating of the two-component, hand-applied urethane waterproofing material composition of this invention is preferably in the range of 35 to 60, and more preferably 37 to 50, according to the JIS D hardness (Durometer hardness test type D) test method for vulcanized rubber and thermoplastic rubber as specified in JIS K 6253. If the JIS D hardness is less than 35, the anti-slip properties, aggregate retention properties, and abrasion resistance will be insufficient, and if it exceeds 60, delamination between the general-purpose urethane layer and the two-component, hand-applied urethane waterproofing material composition becomes more likely.

The two-component, hand-applied urethane waterproofing material composition of the present invention comprises a main component containing an isocyanate-terminated prepolymer composed of a polyisocyanate and a polyol, and a curing agent containing an aromatic polyamine and an inorganic filler.

(Polyisocyanate)
The present invention requires the inclusion of more than 70 equivalents of isophorone diisocyanate (IPDI) as the polyisocyanate, preferably 75 equivalents or more of IPDI, and more preferably 80 equivalents or more. On the other hand, derivatives of IPDI that do not have two functionalities, such as nurates and adducts, have been commercialized, but they tend to restrict the elongation rate and therefore cannot be used in large quantities. It is preferable to use derivatives that do not have two functionalities in an amount of 0 to 30 equivalents of the total polyisocyanate component.

In the present invention, polyisocyanates other than IPDI can also be used in combination. Preferred polyisocyanates that can be used in combination are mildly reactive aliphatic or alicyclic polyisocyanates, such as hexamethylene diisocyanate, norbornene diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and hydrogenated tetramethylxylylene diisocyanate.
In addition, aromatic polyisocyanates such as tolylene diisocyanate, xylylene diisocyanate, and tetramethyl xylylene diisocyanate can also be used in some cases, but tolylene diisocyanate is a specified chemical substance under the Industrial Safety and Health Act and is undesirable from an environmental standpoint.

(Main ingredient NCO content and NCO/OH equivalent ratio)
In this invention, the NCO content of the main component must be between 3.0% by mass and 6.0% by mass. Within the range of plasticizer amounts in this invention, high hardness cannot be achieved unless the NCO content is 3.0% by mass or higher. On the other hand, if the NCO content exceeds 6.0% by mass, the amount of DETDA, the main component of the reactive components, also increases, resulting in a shorter pot life and problems with workability. Furthermore, in order to achieve high hardness and ensure good workability, it is preferable that the NCO content of the main component be between 3.3% by mass and 5.5% by mass.
The NCO/OH equivalent ratio, which is the equivalent ratio of the NCO group of the polyisocyanate to the OH group of the polyol during the production of the main component, is preferably 1.5 to 2.5, and more preferably 1.6 to 2.3. If it is less than 1.5, the main component will thicken excessively, and if it is greater than 2.5, there will be a large amount of free polyisocyanate, which is likely to cause problems such as a decrease in elongation and a shortened pot life.

(Main component: polyol)
While conventionally used polyols such as polyoxyalkylene polyols, polyester polyols, and alkyl polyols can be used as the polyol component to react with the polyisocyanate, it is preferable to use polyoxyalkylene polyol as the main component, as this provides a low-viscosity prepolymer and ensures a long working time. It is preferable to include more than 50 equivalents of polyoxyalkylene polyol in the main component, and more preferably more than 70 equivalents. If the polyoxyalkylene polyol content is 50 equivalents or less, it becomes difficult to ensure low viscosity and elongation, which are desirable for workability.
Furthermore, short-chain polyols such as 1,4-butanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, propylene glycol, and dipropylene glycol can also be used.

(Molecular weight and number of functional groups of the main polyol component)
In this invention, elongation plays an important role in efficiently increasing hardness. By ensuring sufficient elongation, not only the tensile product but also the tensile strength can be efficiently increased. Conversely, attempting to increase hardness without ensuring sufficient elongation results in a material unsuitable for urethane waterproofing.
Therefore, as the polyol used as the main component, it is preferable to use 10 to 97 equivalents of a diol with a molecular weight of 1500 or more, and more preferably 20 to 80 equivalents, in order to ensure elongation. If 100 equivalents of a diol with a molecular weight of 1500 or more are used, the separation points in the cured product disappear and the concentration of urethane bonds decreases, which leads to a decrease in hardness development and curability, and further to a decrease in final hardness.
To solve this problem, it is preferable to use a combined amount of 3 to 90 equivalents of a diol with a molecular weight of less than 1500 and a polyol with 3 or more functional groups, and more preferably 20 to 80 equivalents. It is not necessary to include both the diol with a molecular weight of less than 1500 and the polyol with 3 or more functional groups, but it is preferable to include at least one of them. It is preferable to use 0 to 90 equivalents of the diol with a molecular weight of less than 1500, and more preferably 20 to 80 equivalents. It is preferable to use 0 to 90 equivalents of the polyol with 3 or more functional groups, and more preferably 5 to 80 equivalents.
By using diols with a molecular weight of less than 1500, the concentration of urethane and urea bonds in the cured product increases, allowing for high hardness without significantly compromising elongation. Furthermore, by using polyols with three or more functional groups, branching points can be created in the cured product, improving hardness development and curability, thus facilitating high hardness.

As a diol with a molecular weight of 1500 or more, a general polyoxyalkylenediol can be used, and it is preferable to use polyoxypropylenediol and polyoxyethylenepropylenediol, which have low crystallinity and low viscosity, and it is not necessary to use a special diol.
As diols with a molecular weight of less than 1500, it is preferable to use polyoxyalkylenediols and short-chain polyols with molecular weights of 200 to 1200. As polyoxyalkylenediols, general polyoxypropylenediols and polyoxyethylenepropylenediols, which are low in crystallinity and viscosity, are more preferable, as they allow for a high NCO content without significantly increasing the viscosity of the main component, and enable high hardness without significantly impairing the elongation. Furthermore, short-chain diols with molecular weights of 200 or less, such as 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, ethylene glycol, diethylene glycol, dipropylene glycol, and tripropylene glycol, are preferable to use because they have high cohesive force and are effective in achieving high hardness.

Furthermore, polyether polyols with a molecular weight of 200 to 800, using bisphenol A as an initiator, can also be used because they have relatively high cohesive strength and are effective for increasing hardness. In addition, among polyester polyols, low-crystalline aromatic polyester polyols with a molecular weight of 300 to 800, using amorphous polyols such as 2-methyl-1,3-propanediol or 3-methyl-1,5-pentanediol, can be used because they have good alkali resistance and high cohesiveness.

As polyols with three or more functional groups, polyoxyalkylentriols with a molecular weight of 500 or more can be used, and general polyoxypropylene triols or polyoxyethylene propylene triols are preferred.
Furthermore, polyoxypropylene polyols or polyoxyethylene propylene polyols with four or more functional groups tend to restrict elongation, so they can be used in small quantities.
Polyoxyalkylentriols with a molecular weight of less than 500 can also be used, and polyoxypropylenetriols or polyoxyethylenepropylenetriols are preferred, but they tend to restrict the elongation rate, so they can only be used in small amounts.
Furthermore, trifunctional polyols such as trimethylolpropane and glycerin, and polyols with four or more functions such as pentaerythritol and sorbitol, tend to restrict elongation, so they can only be used in small amounts.

(Method of synthesizing the main ingredient)
In the synthesis method for isocyanate-terminated prepolymers, the reaction is not easily promoted by simply heating polyisocyanate and polyol, so it is preferable to use a catalyst. General urethane catalysts can be used, but organostincine catalysts such as DBTDL and DOTDL are preferred, as they can efficiently promote the reaction with the addition of small amounts such as 0.0001 to 0.1% by mass. The reaction temperature is preferably 60°C to 100°C, and the reaction can be completed in about 2 to 6 hours. After the reaction is complete, it is preferable to deactivate the catalyst with phosphoric acid or the like.

(Active hydrogen in the hardening agent)
As a curing agent, in order to achieve high hardness, it is necessary that more than 80 equivalents of the reactive components be aromatic polyamines, and more than 90 equivalents is preferable. Polyols as reactive components have some effect in ensuring elongation, but because they have lower cohesiveness than aromatic polyamines, they are not very effective in achieving high hardness.
Furthermore, it is necessary that more than 70 equivalents of the aromatic polyamine be diethyltoluenediamine (DETDA), preferably more than 80 equivalents, and more preferably more than 90 equivalents. If the amount of amorphous and highly reactive DETDA is 70 equivalents or less, it becomes difficult to ensure curability and high hardness through good reactivity with IPDI.

Regarding curing agents, examples of aromatic polyamines that can be used in combination include Curehard MED (4,4'-methylenebis(2-ethyl-6-methylaniline)) manufactured by Kumiai Chemical Industry Co., Ltd., which exhibit high reactivity similar to DETDA; Kayahard AA (4,4'-methylenebis(2-ethylaniline)) manufactured by Nippon Kayaku Co., Ltd.; Kayabond C-300 (4,4'-methylenebis(2,6-diethylaniline)) manufactured by Nippon Kayaku Co., Ltd.; and Kayabond C-400 (4,4'-methylenebis(2,6-diiso-propylaniline)) manufactured by Nippon Kayaku Co., Ltd. Furthermore, although they are less reactive aromatic polyamines, EtaCure 420 (4,4'-methylenebis(N-sec-butylaniline)) and EtaCure 300 (dimethylthiotoluenediamine) manufactured by Albemarle can also be used.

Polyols may be used as a reaction component as long as their concentration is 20 equivalents or less. Preferred polyols include those with a molecular weight of less than 1500, such as 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, short-chain polyols such as ethylene glycol, diethylene glycol, dipropylene glycol, tripropylene glycol, polyester polyols, and polycarbonate polyols, which are relatively highly cohesive. Among these, primary hydroxyl group polyols are more preferred because they are more reactive and less likely to remain unreacted, and among these, 1,3-propanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, and aromatic-containing polyester polyols with a molecular weight of 300 to 800 are even more preferred for achieving high hardness. Furthermore, as the aromatic polyester polyol, a liquid product using a low-crystallinity polyol, such as Kurapol (manufactured by Kuraray Co., Ltd.), is preferred.
Furthermore, polyols with a molecular weight of 1500 or more can also be used, including low-viscosity polyols such as polyoxypropylene polyols or polyoxyethylene propylene polyols, but these are undesirable from the standpoint of achieving high hardness due to their low cohesiveness.

(solvent)
In the present invention, the solvent must contain more than 30% by mass of an aprotic solvent with a solubility parameter (SP value) of 8.0 to 14.0, and the total solvent must be blended into the curing agent, or into both the main component and the curing agent, so that it accounts for 10% to 40% by mass relative to the urethane waterproofing material composition. Here, aprotic means that it does not contain active hydrogen (hydroxyl groups, amino groups, carboxylic acid groups, etc.) that reacts with the isocyanate group-terminated prepolymer contained in the main component.
In this invention, the solubility parameter (SP value) refers to the Hansen solubility parameter, which is an indicator that serves as a guideline for the solubility of a two-component solution.
The following formula (1) was used to calculate the SP value δ ((cal/ ^cm³ ) ^1/2 ) of each solvent.
δ=((δd ² + δp ² + δh ² )/4.2) ^1/2 ...(1)
Here, δd is called the London dispersion force term, δp is called the molecular polarization term, and δh is called the hydrogen bonding term.
Alternatively, the values (δd, δp, δh: unit (J/ ^cm³ ) ^1/2 ) listed in the Hansen Solubility Parameter Software (HSPiP ver. 4.1.x) or "HANSEN SOLBILITY PARAMETERS" A User's Handbook Second Edition can be used to calculate them.
Furthermore, when multiple solvents are used, the SP value was calculated as the weighted average of the SP values of each solvent using the following formula (2).
m=δ1φ1+δ2φ2...(2)
Here, δ1 and δ2 are the SP values of each solvent component, and φ1 and φ2 are the volume fractions of each solvent component.

In the present invention, the total amount of solvent must be 10% to 40% by mass relative to the urethane waterproofing material composition, preferably 15% to 30% by mass, and is blended either as a curing agent or separately as both the main component and the curing agent.
If the total amount of solvent is less than 10% by mass relative to the waterproofing material composition, it is difficult to ensure a sufficient pot life. On the other hand, if the total amount of solvent exceeds 40% by mass relative to the urethane waterproofing material composition, it is undesirable because there is a risk of shrinkage due to volatilization after application and it tends to cause inorganic fillers to settle easily.
In the present invention, more than 30% by mass of the total solvent must be an aprotic solvent with a solubility parameter (SP value) of 8.0 to 14.0, preferably 35% by mass or more, and more preferably 40% by mass or more. Alternatively, the entire solvent may be an aprotic solvent with a solubility parameter (SP value) of 8.0 to 14.0. If the aprotic solvent is 30% by mass or less of the total solvent, it is difficult to ensure a sufficient pot life. If the solubility parameter (SP value) of the aprotic solvent is less than 8.0, it is difficult to ensure a sufficient pot life, and if it is greater than 14.0, the hardness of the coating film will be insufficient, which is undesirable. On the other hand, if the aprotic solvent is 70% by mass or less of the total solvent, it may be used in combination with an aprotic solvent having a solubility parameter (SP value) of less than 8.0 or greater than 14.0. Nonpolar solvents with a solubility parameter (SP value) of less than 8.0 or greater than 14.0 that can be used in combination include aromatic petroleum hydrocarbon solvents, aliphatic and alicyclic petroleum hydrocarbon solvents, and alicyclic hydrocarbon solvents having 7 to 10 carbon atoms. Specifically, MC-2000 solvent (a mixture of normal paraffins and isoparaffins having 9 to 11 carbon atoms, manufactured by Sankyo Chemical Co., Ltd.) is preferably used.
In the present invention, it is preferable not to use protic solvents that may react with the isocyanate group of the isocyanate-terminated prepolymer contained in the main component.

In the present invention, aprotic solvents such as ethers, esters, ketones, nitriles, and aromatic hydrocarbons with a solubility parameter (SP value) of 8.0 to 14.0 can be used. Examples of ethers or esters include dialkyl glycol ethers such as ethylene glycol dimethyl ether (SP value = 8.6), diethylene glycol dimethyl ether (SP value = 8.8), diethylene glycol diethyl ether (SP value = 8.7), and diethylene glycol dibutyl ether (SP value = 8.3); cyclic ethers such as 1,4-dioxane (SP value = 10.0); aromatic ethers such as anisole (SP value = 9.4); ethylene glycol monomethyl ether acetate (SP value = 10.0), ethylene glycol monoethyl ether acetate (SP value = 9.6), ethylene glycol monobutyl ether acetate (SP value = 8.9); and diethylene glycol monoethyl ether Examples include glycol ether acetates such as acetate (SP value = 9.4), diethylene glycol monobutyl ether acetate (SP value = 9.0), propylene glycol monomethyl ether acetate (SP value = 8.7), propylene glycol monoethyl ether acetate (SP value = 9.0), dipropylene glycol monomethyl ether acetate (SP value = 9.2), and butylene glycol monomethyl ether acetate (SP value = 8.7); carbonate esters such as dimethyl carbonate (SP value = 9.9) and diethyl carbonate (SP value = 8.8); fatty acid esters such as ethyl acetate (SP value = 9.1) and γ-butyrolactone (SP value = 12.6); and benzoic acid esters such as methyl benzoate (SP value = 10.5). Other examples include ketones such as acetylacetone (SP value = 10.6) and acetophenone (SP value = 10.6), nitriles such as acetonitrile (SP value = 11.9) and benzonitrile (SP value = 8.4), amides such as N,N-dimethylformamide (SP value = 12.1) and N,N-dimethylformacetamide (SP value = 10.8), and aromatic hydrocarbons such as toluene (SP value = 8.9) and 1,2-dichlorobenzene (SP value = 10.0).
Among them, diethylene glycol dimethyl ether (SP value = 8.8), 1,4-dioxane (SP value = 10.0), anisole (SP value = 9.4), propylene glycol monomethyl ether acetate (SP value = 8.7), butylene glycol monomethyl ether acetate (SP value = 8.7), dimethyl carbonate (SP value = 9.9), diethyl carbonate (SP value = 8.8), ethyl acetate (SP value = 9.1), γ-butyrolactone (SP value = 12.6), methyl benzoate (SP value = 10.5), acetylacetone (SP value Preferably, the following are used: acetophenone (SP value = 10.6), acetonitrile (SP value = 11.9), benzonitrile (SP value = 8.4), N,N-dimethylformamide (SP value = 12.1), N,N-dimethylformacetamide (SP value = 10.8), toluene (SP value = 8.9), and 1,2-dichlorobenzene (SP value = 10.0), with propylene glycol monomethyl ether acetate (SP value = 8.7) and butylene glycol monomethyl ether acetate (SP value = 8.7) being the most preferred.

The boiling point of the solvent used in this invention is preferably in the range of 70 to 250°C, and more preferably in the range of 100 to 200°C. If the boiling point exceeds 250°C, the solvent tends to remain in the waterproof coating without volatilizing, leading to problems such as a decrease in hardness. On the other hand, if the boiling point is below 70°C, the solvent tends to volatilize easily from the curing agent, which is undesirable as it poses problems for the stability of the curing agent and the working environment.

(Inorganic fillers)
The hardening agent must contain 20% to 80% by mass of inorganic filler. Without the reinforcing effect of the inorganic filler, achieving high hardness becomes inefficient, and the waterproofing material will not be practical. If the amount of inorganic filler is less than 20% by mass, the reinforcing effect will be insufficient, and if it exceeds 80% by mass, the viscosity will increase, worsening the workability. The amount of inorganic filler to be added is preferably 30% to 75% by mass, and more preferably 40% to 70% by mass.

Calcium carbonate is preferred as an inorganic filler. Calcium carbonate is economically efficient, has good dispersibility during hardener production, exhibits low viscosity even when added in large quantities, easily reduces sedimentation during storage, and has minimal adverse effects on physical properties. Various types of calcium carbonate exist, including heavy calcium carbonate, light calcium carbonate, and surface-treated colloidal calcium carbonate. Any type of calcium carbonate can be used, and surface-treated colloidal calcium carbonate can be used as a vertical waterproofing material to impart thixotropy. Furthermore, inorganic fillers such as silica, kaolin, talc, bentonite, aluminum hydroxide, and barium hydroxide can be partially used. It is presumed that these inorganic fillers contain adhering water, resulting in a water content of approximately 1000 ppm to 3000 ppm in the hardener. This adhering water gradually reacts with excess isocyanate groups after the two-component mixture, contributing to improved physical properties.

(Plasticizer)
Next, in order to ensure a working time sufficient for construction throughout the year and to secure high elongation and high hardness, 3 to 25 parts by mass of plasticizer are required per 100 parts by mass of isocyanate-terminated prepolymer in the main component, preferably 7 to 20 parts by mass, and most preferably 8 to 15 parts by mass. If the amount of plasticizer is less than 3 parts by mass, it becomes difficult to secure the working time and elongation, and if it exceeds 25 parts by mass, it becomes difficult to achieve high hardness. In principle, the plasticizer is blended with the curing agent, but it is also possible to blend a portion of it with the main component.

As plasticizers, plasticizers that can be commonly blended into urethane resins can be used. Examples include phthalate esters such as diisononyl phthalate (DINP), dioctyl phthalate (DOP), and butyl benzyl phthalate (BBP), aliphatic dibasic acid esters, phosphate esters, trimellitic acid esters, sebacate acid esters, epoxy fatty acid esters, glycol esters, animal and vegetable oil-based fatty acid esters, petroleum and mineral oil-based plasticizers, and alkylene oxide polymerization-based plasticizers.
In particular, diisononyl phthalate (DINP) and dioctyl phthalate (DOP), which have a flash point of 200°C or higher, are preferable to use because they do not easily lose weight over the long term, are aromatic polyesters, and are resistant to hydrolysis.

(Amino group equivalent per unit of plasticizer)
When the main agent and the curing agent are mixed, the ratio of the amount of amino groups (milliequivalents) of aromatic polyamine to the amount of plasticizer (g), "amino groups (milliequivalents) / plasticizer (g)" (hereinafter also referred to as "amino group equivalents per plasticizer"), must be in the range of 4.0 to 45.0, preferably 4.5 to 40.0, and most preferably 5.0 to 35.0. If the "amino group equivalents per plasticizer" is less than 4.0, the concentration of aromatic polyamine becomes low, making it difficult to achieve high hardness, and if it exceeds 45.0, it becomes difficult to secure pot life and elongation. To achieve high hardness while securing elongation, the role of polyol as a reactive component is not very important, and the amount of plasticizer used and the "amino group equivalents per plasticizer" play important roles.

(Isocyanate group/aromatic amino group equivalent ratio)
It is preferable to set the equivalent ratio of the isocyanate group of the main component to the amino group of the aromatic polyamine, which is a reactive component in the curing agent (hereinafter referred to as the "isocyanate group/aromatic amino group equivalent ratio") in the range of 0.9 to 1.5, more preferably 0.92 to 1.40, and even more preferably 0.95 to 1.35. If the isocyanate group/aromatic amino group equivalent ratio exceeds 1.5, it becomes difficult to achieve high hardness, and if it is less than 0.9, there are many terminal amino groups during the curing process, resulting in poor physical properties.

(Curing accelerator)
In this invention, organosindic compounds, tertiary amines, metal carboxylate salts, etc., which are known to have a moisture-curing accelerating effect in reactions with isocyanate groups, can be used as reaction accelerators.
Examples of organosindic compounds include dibutyltin oxide, dioctyltin oxide, dibutyltin dilaurate, dibutyltin diacetate, dibutyltin di-2-ethylhexanoate, dioctyltin diacetate, dioctyltin dilaurate, dibutyltin dimercaptide, dibutyltin bisacetylacetonate, dibutyltin oxylaurate, dioctyltin dineodecanate, dibutyltin bisbutylmalate, and dioctyltin 2-ethylhexylmalate, with dibutyltin dilaurate and dioctyltin dilaurate being preferred. It is preferable to use the organosindic compound in the curing agent at a concentration of 0.001 to 0.1% by mass.

As tertiary amines, common tertiary amines such as triethylamine, tributylamine, triethylenediamine, N-ethylmorpholine, bis(2-morpholinoethyl) ether, and diazabicycloundecene can be used. However, imidazole compounds, which are special tertiary amines, are preferred in terms of foam suppression and high hardness development promotion effects. Examples of imidazole compounds that can be used include compounds with substituents at the 1st and 2nd positions, such as 1,2-dimethylimidazole, 1-isobutyl-2-methylimidazole, 1-benzyl-2-methylimidazole, and 1-benzyl-2-phenylimidazole, or compounds with a substituent at the 1st position, such as 1-methylimidazole and 1-allyliimidazole. Among these, imidazole compounds with substituents at the 1st and 2nd positions are more preferred due to their high hardness development promotion effect. It is preferable to use 0.01 to 2.0% by mass of the tertiary amine in the curing agent.

Furthermore, metal carboxylates, which are generally used as urethane catalysts, can also be used. While metal carboxylates have a weak moisture-curing acceleration effect, they strongly promote the reaction with aromatic polyamines, shortening the pot life and curing time. Therefore, they are preferable to use as winter catalysts than summer catalysts. Examples of metal carboxylates include 2-ethylhexanoic acid, neodecanoic acid, naphthenic acid, oleic acid, linoleic acid, linolenic acid, lead salts, zinc salts, bismuth salts, zirzirconium salts, tin salts, copper salts, magnesium salts, calcium salts, strontium salts, and barium salts of resin acids. Among these, calcium 2-ethylhexanoate and zinc 2-ethylhexanoate are preferred due to their high hardness-promoting effect. It is preferable to use 0.1 to 4.0% by mass of the metal carboxylate in the curing agent. On the other hand, lead carboxylate has a high effect in shortening pot life and curing time, but does not show much effect in promoting hardness, and its use is also undesirable from an environmental perspective.

As described above, compounds that are thought to promote moisture hardening can be used, but among them, organodin compounds and imidazole compounds can both promote high hardness without shortening the pot life and also have excellent foam suppression properties, and can be used particularly as catalysts in summer.
Furthermore, imidazole compounds are preferable because, unlike metal catalysts which tend to accelerate thermal degradation when added in large quantities, they hardly accelerate thermal degradation even when added in large amounts. While moisture-curing accelerators are generally added to the curing agent, a considerable amount can be added at the construction site during the two-component mixing process. On the other hand, while it is possible to add them to the main component, this is not highly preferable as it may impair storage stability.

On the other hand, carboxylic acids or acid anhydrides are effective in shortening the pot life and curing time because they promote the reaction between the IPDI prepolymer and the aromatic polyamine, and they hardly promote thermal degradation like carboxylic acid metal salts, so they can be preferably used as accelerators, especially for winter use. However, since they have almost no moisture curing effect, the effect of promoting high hardness development cannot be expected to be very high in formulations with a high isocyanate group/aromatic amino group equivalent ratio.
Examples of carboxylic acids include propionic acid, 2-methylpentanoic acid, octic acid, isononanoic acid, and naphthenic acid, with octic acid being preferred among them.
Examples of acid anhydrides include phthalic anhydride, hexahydrophthalic anhydride, methyl-hexahydrophthalic anhydride, methyl-tetrahydrophthalic anhydride, succinic anhydride, and maleic anhydride, with methyl-tetrahydrophthalic anhydride being preferred.
It is desirable to use 0.05 to 2.0% by mass of carboxylic acids and acid anhydrides in the curing agent, and some or all of them may be incorporated into the main component.

Furthermore, it is preferable to either pre-mix the acid anhydride catalyst into the main component or to mix the acid anhydride when mixing the main component and the hardener. However, adding the acid anhydride at the construction site each time is problematic due to storage and management issues with the acid anhydride, as well as the possibility of measurement errors due to the complexity at the construction site. Therefore, pre-mixing the acid anhydride into the main component is more preferable.

(Other additives)
In addition, the curing agent may contain additives such as wetting agents, defoaming agents, pigments, and weather-resistant agents as needed.

(Main component/Hardener mixing ratio)
The mixing ratio of the main component to the hardener is not particularly limited, but it is preferably in the range of 1/1 to 1/2 by mass ratio. However, generally, when the ratio is 1/2, the amount of plasticizer increases, which is unfavorable for achieving high hardness, so it is preferable that it be 1/1 to 1/1.75, and more preferably 1/1 to 1/1.5.

(Waterproofing methods for sports floors and parking lots)
The present invention relates to a method for applying urethane waterproof coatings for sports floors and parking lots.
The application method of the present invention cannot be used to directly apply the material to inorganic substrates such as concrete. In the case of inorganic substrates, the urethane waterproofing material will not adhere to them, so it is possible to apply the material after applying a primer that can block some of the moisture in the substrate and ensure adhesion. In addition, during renovations, it may be possible to apply the material on top of the existing urethane waterproofing layer by applying an intermediate primer. Furthermore, the material can be applied to inorganic substrates after fixing a breathable buffer sheet, a polymer sheet such as a PVC sheet, a rubber sheet, or a nonwoven fabric sheet with a primer, adhesive, mechanical fixing, or loose laying. Moreover, even in the case of metal substrates, adhesion cannot be ensured by directly applying the application method of the present invention for sports floors or parking lot urethane waterproofing coatings, so it is possible to apply the material after applying a dedicated primer.

The present invention provides a urethane waterproof coating layer for sports floors and parking lots that offers excellent practical workability and durability, and is environmentally friendly as it does not use any materials subject to the Specified Chemical Substances Act. This is achieved by applying a primer layer to the substrate surface, or by applying a primer layer and a general-purpose urethane waterproofing layer, followed by mixing the two-component, hand-applied urethane waterproofing composition of the first invention with inorganic aggregate and applying the mixture.

The primer layer of the present invention can be one that is normally used for urethane waterproofing layers, but generally a water-based primer is used. The water-based primer is not particularly limited, and epoxy resin-based, urethane resin-based, vinyl acetate resin-based, acrylic resin-based, styrene-butadiene rubber-based, chloroprene rubber-based emulsion-type water-based primers can be used.
Preferably, epoxy resin systems include those comprising two components: a main component consisting of an emulsion mainly composed of bisphenol A type, novolac type, brominated type, alicyclic type, or aliphatic type epoxy resin, and a curing agent consisting of an emulsion containing aliphatic polyamines, aromatic polyamines, alicyclic polyamines, polyamides, etc.
Furthermore, the urethane resin system consists of a main component comprising an emulsion primarily composed of polyol, and a curing agent comprising liquid MDI such as crude MDI or carbodiimide modified products.
In particular, a preferred primer is a one-component moisture-curing polyurethane resin. These primers may also contain fillers such as Portland cement to fill pinholes in the substrate. These primer materials are applied to the substrate using painting tools such as brushes, rollers, or rakes, but the amount used and the thickness of the coating film are not particularly limited, as long as it is an amount that can reliably bond the substrate and the polyurethane layer. Typically, the amount of primer layer applied is 0.15 to 0.20 kg/ ^m² , preferably about 0.20 kg/ ^m² .

In the construction method of the present invention, the general-purpose urethane waterproofing material used in the urethane waterproofing layer is not particularly limited, and commercially available general-purpose urethane waterproofing materials can be used. As a general-purpose urethane waterproofing material, those specified as high-elongation type according to JIS A 6021 "Waterproofing Coating Materials for Buildings" are preferred, and among these, those with relatively high strength and high hardness are preferred.

In the construction method of the present invention, the hardness of the hardened film of the high-hardness two-component hand-applied urethane waterproofing material composition used must be in the range of 35 to 60 on the JIS D hardness scale (Durometer hardness test type D) according to the hardness test method for vulcanized rubber and thermoplastic rubber specified in JIS K 6253, and more preferably 35 to 50. If the JIS D hardness is less than 35, the anti-slip properties, aggregate retention properties, and abrasion resistance will be insufficient, and if it exceeds 60, delamination will easily occur between the general-purpose urethane layer and the two-component hand-applied urethane waterproofing material composition. Furthermore, in this construction method, the hardened film of the two-component hand-applied urethane waterproofing material composition used is preferably tensile strength of 10 N/ ^mm² or more, preferably elongation of 300% or more, and preferably tensile volume of 700 N/mm or more. If the tensile strength is 10 N/mm² or ^less , the slip resistance, aggregate retention, and abrasion resistance will be insufficient. If the elongation is less than 300%, delamination will easily occur between the general-purpose urethane layer and the two-component hand-applied urethane waterproofing material composition. If the tensile strength is 700 N/mm² or less, crack-following ability will decrease, and problems such as peeling and blistering from the substrate will easily occur.
This invention is not intended for the repair of asphalt-based waterproofing layers, but rather for the waterproofing and protection of inorganic substrates such as concrete, metal substrates, polymer resin substrates, and rubber substrates. Furthermore, when using the two-component, hand-applied urethane waterproofing material composition of this invention in areas exposed to direct sunlight, it is generally recommended to apply a topcoat.

In the application method of the present invention, examples of inorganic aggregates to be mixed with the high-hardness two-component hand-applied urethane waterproofing material composition include silica sand, crushed porcelain aggregate, ceramic aggregate, ferroalloy lag, and hollow balloons. These aggregates are uniformly scattered immediately after or simultaneously with the application of the high-hardness two-component hand-applied urethane waterproofing material composition, and preferably have a particle size of 0.05 to 5.0 mm, and more preferably 0.1 to 3.0 mm. The inorganic aggregate is preferably contained in the high-hardness two-component hand-applied urethane waterproofing material composition at a concentration of 0.3 to 1.5 kg/ ^m² , and more preferably 0.3 to 1.0 kg/ ^m² .
As inorganic aggregates, for example, Inseragate® 1005, 2010 (manufactured by Nissei Sangyo Co., Ltd.), Powercron G (Fukushima sand, manufactured by Toto Kosan Co., Ltd.), AD aggregate (manufactured by AGC Polymer Building Materials Co., Ltd.), Sakurabashi S sand No. 4, No. 5 (manufactured by Cosmo Energy Solutions Co., Ltd.), silica sand No. 4, No. 5 (manufactured by Tohoku Silica Sand Co., Ltd.) are preferably used.

Raw materials The raw materials used in the following examples and comparative examples are as follows:
[Isocyanate]
IPDI: Isophorone diisocyanate, VESTANAT® IPDI (trade name), NCO content 37.8% by mass, NCO functional group count approximately 2.0, manufactured by Evonik Japan Co., Ltd. [Polyol]
PA-2000: Polyoxypropylene diol, Sannix® PA-2000, average molecular weight 2000 (product name), OH value 56.1 mg KOH/g, manufactured by Sanyo Chemical Industries, Ltd. GA-3000: Sannix® GA-3000 (product name), polyoxypropylene triol, average molecular weight 3000, OH value: 56.1 mg KOH/g, manufactured by Sanyo Chemical Industries, Ltd. GP-600: Polyoxypropylene triol, Sannix® GP-600 (product name), average molecular weight 600, OH value: 279 mg KOH/g, manufactured by Sanyo Chemical Industries, Ltd. P-2010: Aliphatic polyester diol, Kuraray polyol P-2010, average molecular weight 2000, OH value: 56.1 mg KOH/g, manufactured by Kuraray Co., Ltd. P-510: Aliphatic polyester diol, Kuraray Polyol P-510, average molecular weight 500, OH value: 224.4 mg KOH/g, manufactured by Kuraray Co., Ltd. F-1010: Aliphatic polyester triol, Kuraray Polyol F-1010, average molecular weight 10000, OH value: 167.4 mg KOH/g, manufactured by Kuraray Co., Ltd. BP-5P: Polyoxypropylene diol, Newpol (registered trademark) BP-5P, average molecular weight 500, OH value: 209 mg KOH/g, manufactured by Sanyo Chemical Industries, Ltd. 1,4-BD: 1,4-butanediol (trade name), manufactured by Mitsubishi Chemical Corporation [polyamine]
DETDA: Diethyltoluenediamine, EtaCure 100 (trade name), manufactured by Albemarle Japan Co., Ltd. [catalyst]
DOTDL: Dioctyl tin dilaurate, KS-1200A-1 (product name), manufactured by Kyodo Yakuhin Co., Ltd. NC-IM: 1-Isobutyl-2-methylimidazole, DABCO® NC-IM (product name), manufactured by Air Products Japan Co., Ltd. [solvent]
MC-2000: MC-2000 Solvent (trade name), a mixture of normal paraffins and isoparaffins with 9 to 11 carbon atoms, manufactured by Sankyo Chemical Co., Ltd. PMA: Propylene glycol monomethyl ether acetate, PMA (trade name), manufactured by Sankyo Chemical Co., Ltd. DMSO: Tetrahydrothiophene-1,1-dioxide, manufactured by Tokyo Chemical Industry Co., Ltd. PGME: Propylene glycol monomethyl ether, manufactured by Tokyo Chemical Industry Co., Ltd. DMC: Dimethyl carbonate, manufactured by Tokyo Chemical Industry Co., Ltd. Digrime: Diethylene glycol dimethyl ether, manufactured by Tokyo Chemical Industry Co., Ltd. Dioxane: 1,4-dioxane, manufactured by Tokyo Chemical Industry Co., Ltd. Acetylacetone: Acetylacetone, manufactured by Tokyo Chemical Industry Co., Ltd. Acetonitrile: Acetonitrile, manufactured by Tokyo Chemical Industry Co., Ltd. DMF: N,N-dimethylformamide, manufactured by Tokyo Chemical Industry Co., Ltd. DMAC: N,N-dimethylacetamide, manufactured by Tokyo Chemical Industry Co., Ltd. Toluene: Toluene, manufactured by Tokyo Chemical Industry Co., Ltd. Methoacetate: Methoxybutyl acetate, manufactured by Sankyo Chemical Co., Ltd. DEC: Diethyl carbonate, manufactured by Tokyo Chemical Industry Co., Ltd. Ethyl acetate: Ethyl acetate, manufactured by Tokyo Chemical Industry Co., Ltd. Anisole: Anisole, manufactured by Tokyo Chemical Industry Co., Ltd. O-DCB: 1,2-Dichlorobenzene, manufactured by Tokyo Chemical Industry Co., Ltd. Benzonitrile: Benzonitrile, manufactured by Tokyo Chemical Industry Co., Ltd. Methyl benzoate: Methyl benzoate, manufactured by Tokyo Chemical Industry Co., Ltd. Acetophenone: Acetophenone, manufactured by Tokyo Chemical Industry Co., Ltd. γ-Butyrolactone: γ-Butyrolactone, manufactured by Tokyo Chemical Industry Co., Ltd. [Plasticizer]
DINP: Diisononyl phthalate, Sansoizer® DINP (trade name), manufactured by Shin Nippon Rika Co., Ltd. [Inorganic filler]
NS#100: Calcium carbonate, NS#100 (product name), manufactured by Nitto Funka Kogyo Co., Ltd. Additives: Manufactured by Kusumoto Kasei Co., Ltd. [Commercial waterproofing material auxiliary materials]
Fast-curing OT Primer M Blue, OT Primer QQ, OT Coat QQ (manufactured by Tajima Roofing Co., Ltd.)
[Inorganic aggregate]
Inseragate (registered trademark) 1005 (manufactured by Nissei Sangyo Co., Ltd.)

Preparation of the main component: According to the formulations in Tables 1 to 9, the specified polyol, solvent, and dioctyl tin dilaurate were charged into a four-necked flask, followed by the specified polyisocyanate compound. The mixture was then reacted at 90-100°C for 1-2 hours with stirring to obtain each main component.

Preparation of the curing agent: According to the formulations in Tables 1 to 9, the specified liquids were placed in a metal container, mixed at low speed with a stirrer (dissolver blade) until homogenized, then a predetermined amount of calcium carbonate was added and mixed at 1500 rpm for 10 minutes to obtain each curing agent.

Example 1
In Example 1, the main component and hardener were obtained according to the formulation shown in Table 1. These main component and hardener were mixed in a mass ratio of 1:1 to obtain a urethane waterproofing material composition.
In Example 1, MC-2000, with a solubility parameter (SP value) of 7.2 to 7.8, was used as the solvent at a concentration of 20% by mass relative to the main component, and PMA, with a solubility parameter (SP value) of 8.7, was used as the hardener at a concentration of 15% by mass. The pot life of the hardened coating was 40 minutes, and the JIS D hardness of the cured coating was 41. This demonstrated good coating properties as a finishing material for two-component, hand-applied urethane waterproofing layers for sports floors and parking lots, while also ensuring a sufficient pot life for winter use.

Comparative Example 1
Comparative Example 1 was carried out in the same manner as Example 1, except that MC-2000, which has a solubility parameter (SP value) of 7.2 to 7.8, was used as the solvent for the curing agent instead of PMA. The pot life of Comparative Example 1, which did not use an aprotic solvent with a solubility parameter (SP value) of 8.0 to 14.0, was 28 minutes, which was shorter than that of Example 1. The JIS D hardness of the cured coating film was 41, and it showed good coating film properties as a two-component, hand-applied urethane waterproofing layer for sports floors and parking lots, but the pot life was insufficient even as a winter formulation.

Comparative Example 2
Comparative Example 2 was carried out in the same manner as Example 1, except that DMSO with a solubility parameter (SP value) of 14.5 was used as the solvent for the curing agent instead of PMA. The pot life of Comparative Example 2 was 84 minutes, and the JIS D hardness of the cured coating film was 25. The pot life was sufficient even for a summer formulation, but the coating film properties such as hardness were insufficient for a two-component, hand-applied urethane waterproofing layer for sports floors and parking lots.

Example 2
Example 2 was carried out in the same manner as Example 1, except that the NCO/OH equivalent ratio of the main component was adjusted to an NCO content of 3.64% by mass, and the amount of plasticizer used was 10.69 parts by mass per 100 parts by mass of prepolymer. The pot life of Example 2 was 66 minutes, and the JIS D hardness of the cured coating film was 35. It showed good coating film properties as a two-component, hand-applied urethane waterproofing layer for sports floors and parking lots, and also ensured a sufficient pot life for summer use.

Example 3
Example 3 was carried out in the same manner as Example 2, except that meteorite with a solubility parameter (SP value) of 8.7 was used as the solvent for the curing agent instead of PMA. The pot life of Example 3 was 62 minutes, and the JIS D hardness of the cured coating film was 35. It showed good coating film properties as a two-component, hand-applied urethane waterproofing layer for sports floors and parking lots, and also ensured a sufficient pot life for summer use.

Comparative Example 3
Comparative Example 3 was carried out in the same manner as Example 2, except that MC-2000 was used instead of PMA as the solvent for the curing agent. Comparative Example 3, which did not use an aprotic solvent with a solubility parameter (SP value) of 8.0 to 14.0, had a pot life of 43 minutes, which was shorter than that of Example 2. The JIS D hardness of the cured coating film was 35, and it showed good coating film properties as a two-component, hand-applied urethane waterproofing layer for sports floors and parking lots, but the pot life was insufficient for a summer formulation.

Comparative Example 4
Comparative Example 4 was carried out in the same manner as Example 2, except that PGME, a protic solvent with a solubility parameter (SP value) of 11.3, was used as the solvent for the curing agent instead of PMA, an aprotic solvent. The pot life of Comparative Example 4, which used PGME, a protic solvent with a solubility parameter (SP value) in the range of 8.0 to 14.0 that may react with the isocyanate group in the main component, was 21 minutes, which was shorter than that of Example 2. The JIS D hardness of the cured coating film was 35, and it showed good coating film properties as a two-component, hand-applied urethane waterproofing layer for sports floors and parking lots, but the pot life was insufficient even as a winter formulation.

Examples 4-7
Examples 4 to 7 were carried out in the same manner as Example 1, except that instead of PMA, DMC with a solubility parameter (SP value) of 9.9, diglyme with a solubility parameter of 8.8, dioxane with a solubility parameter of 10.0, and acetylacetone with a solubility parameter of 10.6 were used as solvents for the curing agent. The pot life of Examples 4 to 7 was 35 minutes, 41 minutes, 35 minutes, and 40 minutes, respectively, and the JIS D hardness of the cured coating film was 41 in all cases. These examples showed good coating film properties as a two-component, hand-applied urethane waterproofing layer for sports floors and parking lots, and ensured a sufficient pot life for winter use.

Examples 8-10
Examples 8 to 10 were carried out in the same manner as Example 1, except that acetonitrile with a solubility parameter (SP value) of 11.9, DMF with 12.1, and DMAC with 10.8 were used as solvents instead of PMA as the curing agent. The pot life of Examples 8 to 10 was 64 minutes, 80 minutes, and 98 minutes, respectively, and the JIS D hardness of the cured coating film was 37 in all cases. These examples showed good coating film properties as a two-component, hand-applied urethane waterproofing layer for sports floors and parking lots, and also ensured a sufficient pot life for summer use.

Example 11
Example 11 was carried out in the same manner as Example 1, except that the NCO/OH equivalent ratio of the main component was adjusted to an NCO content of 4.00% by mass, the amount of plasticizer used was 10.98 parts by mass per 100 parts by mass of prepolymer, and the isocyanate group/aromatic amino group equivalent ratio was 1.30. The pot life of Example 11 was 57 minutes, and the JIS D hardness of the cured coating film was 41. It showed good coating film properties as a two-component, hand-applied urethane waterproofing layer for sports floors and parking lots, and also ensured a sufficient pot life for summer use.

Example 12
Example 12 was carried out in the same manner as Example 11, except that PMA with a solubility parameter (SP value) of 8.7 was used as the solvent for the main component instead of MC-2000. The pot life of Example 12 was 93 minutes, and the JIS D hardness of the cured coating film was 43. It showed good coating film properties as a two-component, hand-applied urethane waterproofing layer for sports floors and parking lots, and also ensured a sufficient pot life for summer use.

Example 13
Example 13 was carried out in the same manner as Example 12, except that the isocyanate group/aromatic amino group equivalent ratio was 1.15. The pot life of Example 13 was 78 minutes, and the JIS D hardness of the cured coating film was 45. It showed good coating film properties as a two-component, hand-applied urethane waterproofing layer for sports floors and parking lots, and ensured a sufficient pot life for a summer formulation.

Example 14
Example 14 was carried out in the same manner as Example 12, except that the main agent/hardener mixing ratio was 1:1.5. The pot life of Example 14 was 113 minutes, and the JIS D hardness of the cured coating film was 41. It showed good coating film properties as a two-component, hand-applied urethane waterproofing layer for sports floors and parking lots, and ensured a sufficient pot life for summer use.

Example 15
Example 15 was carried out in the same manner as Example 13, except that the amount of PMA used as the curing agent was changed to 20.08% by mass, and the amount of plasticizer used was changed to 3.75 parts by mass per 100 parts by mass of prepolymer. The pot life of Example 15 was 73 minutes, and the JIS D hardness of the cured coating film was 48. It showed good coating film properties as a two-component, hand-applied urethane waterproofing layer for sports floors and parking lots, and also ensured a sufficient pot life for summer use.

Examples 16-18
Examples 16 to 18 were carried out in the same manner as Example 15, except that the NCO/OH equivalent ratio of the main component was adjusted to change the NCO content to 4.55% by mass, 5.04% by mass, and 5.55% by mass, respectively. The pot life of Examples 16 to 18 was 62 minutes, 47 minutes, and 35 minutes, respectively, and the JIS D hardness of the cured coating film was 50, 52, and 54. These coating films exhibited good properties as two-component, hand-applied urethane waterproofing layers for sports floors and parking lots, and sufficient pot life was ensured for Example 16 as a summer formulation and for Examples 17 and 18 as winter formulations.

Example 19
Example 19 was carried out in the same manner as Example 12, except that the polyol component of the main agent was polyester polyols instead of polyoxyalkylene polyols, and the amount of plasticizer used was 11.15 parts by mass per 100 parts by mass of prepolymer. The pot life of Example 19 was 72 minutes, and the JIS D hardness of the cured coating film was 38. It showed good coating film properties as a two-component, hand-applied urethane waterproofing layer for sports floors and parking lots, and also ensured a sufficient pot life for summer use.

Example 20
Example 20 was carried out in the same manner as Example 15, except that BP-5P was used instead of 1,4-BD as the main component diol with a molecular weight of less than 1500. The pot life of Example 20 was 75 minutes, and the JIS D hardness of the cured coating film was 42. It showed good coating film properties as a two-component, hand-applied urethane waterproofing layer for sports floors and parking lots, and also ensured a sufficient pot life for summer use.

Examples 21-28
Examples 21 to 28 were carried out in the same manner as Example 1, except that instead of PMA, the solvents used as curing agents were DEC with a solubility parameter (SP value) of 8.8, ethyl acetate with a solubility parameter (SP value) of 9.1, toluene with a solubility parameter (SP value) of 8.9, anisole with a solubility parameter (SP value) of 9.4, O-DCB with a solubility parameter of 10.0, benzonitrile with a solubility parameter (SP value) of 8.4, methyl benzoate with a solubility parameter (SP value) of 10.5, and acetophenone with a solubility parameter (SP value) of 10.6. The pot times for Examples 21 to 28 were 37 minutes, 39 minutes, 33 minutes, 34 minutes, 30 minutes, 43 minutes, 35 minutes, and 40 minutes, respectively, ensuring a sufficient pot time for winter formulations.

Example 29 (Example of a multi-layered structure for a parking lot)
On the surface of the concrete parking lot floor base, 0.15 kg/ ^m² of "Fast-Curing OT Primer M Blue" was applied uniformly with a roller as a penetrating primer, and 0.15 kg/ ^m² of "OT Primer QQ/Cement = 3/2 to 4/1" was applied as a film-thickening primer, and then allowed to dry.
Next, as a waterproofing layer, a high-strength, high-elongation waterproofing material conforming to JIS standards, with a hardness of 32D, a tensile strength of 13.3 N/ ^mm² , and an elongation rate of 492% at break, was applied at a rate of 2.0 kg/ ^m² using a trowel and dried. After drying, another layer was applied and dried in the same manner under the same conditions.
Next, the high-hardness two-component hand-applied urethane waterproofing material composition described in Example 13 was applied with a roller at a rate of 0.3 kg/ ^m² , and simultaneously or immediately after application, Inseragate® 1005 was sprayed at a rate of 0.6 kg/ ^m² . After curing, the high-hardness two-component hand-applied urethane waterproofing material composition described in Example 13 was further applied with a roller at a rate of 0.5 kg/ ^m² and dried.
Next, OT Coat QQ was applied twice as a topcoat using a roller at a rate of 0.2 kg/ ^m² , and then dried. The finished floor surface was a rough surface with a beautiful uneven texture.
<Impact Resistance Test>
The impact resistance test conducted according to the performance evaluation test method for membrane waterproofing (JASS8) showed that at 0°C and 20°C, all three units were rated as impact resistance level 4 (no holes were made in any of the three units when subjected to an impact from a height of 1.5m), and at 60°C, it was rated as impact resistance level 3 (at least one unit was punctured when subjected to an impact from a height of 1.5m).
<Durability Test>
Abrasion resistance and aggregate delamination resistance were evaluated using a rotary labeling tester. A swivel-type caster (thermoplastic polyurethane wheel, hardness D 46) was used, with a load of 16.2 kg per wheel, a wheel travel speed of 0.9 m/sec, and a turntable rotation speed of 59.4 revolutions/minute. The degree of aggregate detachment from the test specimen was examined at 20,000 rotations. As a result, almost no aggregate detachment was observed.

The measurement methods for each evaluation item in Tables 1 to 9 are as follows:

[NCO (mass%)]
Accurately weigh approximately 1 g of the main component into a 200 mL Erlenmeyer flask. Add 10 mL of 0.5 N di-n-butylamine (toluene solution), 10 mL of toluene, and an appropriate amount of bromophenol blue, then add approximately 100 mL of methanol and dissolve. Titrate this mixture with 0.25 N hydrochloric acid solution. The NCO (mass%) is calculated using the following formula.
NCO (mass%) = (blank titration value - 0.5N hydrochloric acid solution titration value) × 4.202 × factor of 0.25N hydrochloric acid solution × 0.25 ÷ sample weight

[Pot life (minutes)]
In an air-circulating environmental test chamber with a temperature of 23°C and a humidity of 50%, the time from the start of stirring and mixing the main agent and hardener in a predetermined ratio until the viscosity at 2 rpm reached 60,000 mPa·s was measured using a BH-type viscometer.

[Available construction time (hours)]
In an air-circulating environmental test chamber with a temperature of 23°C and humidity of 50%, a waterproofing material prepared by stirring and mixing the main agent and hardener in a predetermined ratio was applied at a rate of 2 kg/ ^m² . The time required for the material to become walkable with shoes on, even though it was not completely hardened, and for the next step of the work to begin was measured.

[Preparation of coatings for initial physical property measurements]
Based on JIS A 6021, a waterproofing material prepared by stirring and mixing the main agent and hardener in a predetermined ratio was applied at a rate of 2 kg/ ^m² in an air-circulating environmental test chamber at a temperature of 23°C and a humidity of 50%. After curing for 96 hours at a temperature of 23±2°C and a relative humidity of (50±10)%, the mold was removed, the coating film was turned over, and it was further cured for 240 hours at a temperature of 23±2°C and a relative humidity of (50±10)% to prepare a coating film for initial physical property measurement.

[Tensile strength (N/ ^mm² )]
Measurements were performed using a coating film intended for initial physical property measurement, in accordance with JIS A 6021.

[Elongation at break (%)]
Measurements were performed using a coating film intended for initial physical property measurement, in accordance with JIS A 6021.

[Tensile product (N/mm)]
Using the tensile strength and elongation at fracture described above, calculations were performed in accordance with JIS A 6021.

[JIS D hardness scale (Type D durometer)]
Measurements were performed using a coating film intended for initial physical property measurement, in accordance with JIS K 6253.

The composition and application method of the present invention can be suitably used as a two-component, hand-applied urethane waterproofing material for sports floors, parking lots, and the like.

Claims (6)

A two-component urethane waterproofing material composition for hand application, comprising a main component containing an isocyanate-terminated prepolymer consisting of a polyisocyanate and a polyol, and a curing agent containing an aromatic polyamine and an inorganic filler,
In the main component, more than 70 equivalents of the polyisocyanates constituting the isocyanate-terminated prepolymer (where equivalent percentage is based on the number of moles of isocyanate groups) are isophorone diisocyanates, and the NCO content of the main component is 3.0% to 6.0% by mass.
The curing agent contains 20% to 80% by mass of inorganic filler, and more than 80 equivalents of the total reactive components in the curing agent (where equivalent% is based on the number of moles of active hydrogen groups) is aromatic polyamine, and more than 70 equivalents of the aromatic polyamine (where equivalent% is based on the number of moles of amino groups) is diethyltoluenediamine.
A plasticizer is added in an amount of 3 to 25 parts by mass per 100 parts by mass of isocyanate-terminated prepolymer in the main component, either separately in the curing agent or in both the main component and the curing agent.
The urethane waterproofing material composition contains 10% to 40% by mass of solvent, either in the curing agent or separately in both the main component and the curing agent, and the solvent contains more than 30% by mass of aprotic solvent with a solubility parameter (SP value) of 8.0 to 14.0.
A two-component, hand-applied urethane waterproofing material composition in which the ratio of the amount of amino groups (milli-equivalent) of aromatic polyamine to the amount (g) of plasticizer is 4.0 to 45.0. The two-component, hand-applied urethane waterproofing material composition according to claim 1, wherein the polyol constituting the isocyanate-terminated prepolymer in the main component contains a polyoxyalkylene polyol, and the polyol constituting the isocyanate-terminated prepolymer in the main component contains 10 to 97 equivalents of a diol with a molecular weight of 1500 or more (wherein equivalent percentage is based on the number of moles of hydroxyl groups) and 3 to 90 equivalents of a diol with a molecular weight of less than 1500 and a polyol with 3 or more functional groups (wherein equivalent percentage is based on the number of moles of hydroxyl groups) . The two-component, hand-applied urethane waterproofing material composition according to claim 1, wherein the equivalent ratio of the isocyanate group of the main component to the amino group of the aromatic polyamine, which is a reactive component in the curing agent, is 0.9 to 1.5. The two-component, hand-applied urethane waterproofing material composition according to claim 1, wherein more than 50 equivalents (wherein equivalent percentage is based on the number of moles of hydroxyl groups) of the polyol constituting the isocyanate group-terminated prepolymer in the main component is polyoxyalkylene polyol. The two-component, hand-applied urethane waterproofing material composition according to claim 1, wherein the hardened coating of the urethane waterproofing material composition has a JIS D hardness of 35 to 60. A method for applying a urethane waterproof coating layer, comprising applying a primer layer to a substrate surface, or applying a primer layer and a urethane waterproofing material layer, then mixing the two-component, hand-applied urethane waterproofing material composition described in claim 1 with an inorganic aggregate and applying the mixture.