JP2007000720A - Urethane waterproof structure and environment-responsive type topcoat material using therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an urethane waterproof structure, which enables to execute works using a solvent a few in poison and also low in odor, and therefor is environment-friendly, and to provide a topcoat material used therefor. <P>SOLUTION: The urethane water-proof structure has a topcoat layer which is formed by an urethane based coat water-proof layer and an environment-responsive type topcoat material coated on the surface of the water-proof layer, wherein a main agent of the environment-responsive type topcoat material has the main component of its reaction components consisting of a polyfunctional isocianate compound, while a curing agent has the main component of its reaction components consisting of an acrylic polyol with the molecular weight of 1,500-20,000, and any each of the main agent and the curing agent can secure the solubility by the solvent a few in poison and also low in odor, the determined film-forming performance necessary as a topcoat and the elongation rate of a cured coat of 30-200%, and the topcoat material used for the urethane water-proof structure is provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a urethane waterproof structure on a building roof, a veranda, a balcony, an open corridor, etc., and an acrylic urethane paint forming a top coat layer of the waterproof structure, and more specifically, an environmentally friendly urethane that realizes low toxicity and low odor. It relates to waterproof technology.
The

In recent years, construction of large-scale apartment houses has been actively conducted in Japan, and the waterproofing of apartment verandas and balconies is indefinitely shaped for each building and has a small area. The demand for urethane waterproofing materials that can be easily installed on the site is increasing regardless of whether it is new or renovated. After applying a primer for imparting adhesiveness to the base mortar, etc. on such a small area, apply urethane waterproofing material 1kg to 3kg / square meter, and finally apply a top coat for imparting weather resistance. Adhesion methods that apply the paint to be formed are widespread.

Also, for waterproofing rooftops with relatively large areas such as schools, hospitals, office buildings, etc., apply a waterproof foam 2-5kg / sqm after installing a ventilation cushioning sheet, and finally apply a paint that forms a top coat. The buffer method is increasingly used especially for renovation work.
In any method, since the weather resistance is poor only with the urethane waterproof material, it is an indispensable process to form a top coat layer with good weather resistance on the upper layer.

As described above, urethane waterproof materials are often installed in areas that are relatively close to the living space, but conventional materials used for urethane waterproof materials and topcoat materials are highly harmful solvents such as toluene and xylene. Is generally blended. This is because toluene / xylene is an inexpensive solvent, and at the same time has excellent solubility (strong solvent), and also has excellent drying and volatility, and high construction efficiency can be obtained.

Currently, the urethane waterproof material generally used is based on an isocyanate group-terminated prepolymer synthesized from tolylene diisocyanate and polyoxyalkylene polyol, and is a 4,4 ′ · methylenebis (reactive with isocyanate group). It is a two-component reactive urethane waterproofing material composed of a curing agent in which a polyol such as 2-chloroaniline) (commonly referred to as MOCA) and a polyoxyalkylene polyol is used as a crosslinking agent, and a plasticizer, a filler, a pigment, and the like. , Commonly called MOCA cross-linked waterproof material. In this case, the tolylene diisocyanate used as the main agent is 80/20 (by weight) of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate due to industrial availability and balance of physical properties. Ratio) Mixed products are common.

In such waterproof materials, solvents such as toluene and xylene of several weight percent are blended in the main agent and curing agent to adjust the viscosity of the waterproof material. Currently, it is constructed with several weight percent of such diluents.

In the MOCA cross-linked waterproof material, the main agent contains about 1 to 3% by weight of free tolylene diisocyanate, and the curing agent contains about several% by weight of MOCA as a cross-linking agent. It is common. Both substances fall under the so-called designated chemical substances and specified chemical substances related to laws and regulations, and each content is 1% by weight or more. Become.

On the other hand, recently, a DETDA cross-linked waterproof material having good low-temperature curability using an isocyanate group-terminated prepolymer as a main component and diethyl toluenediamine (DETDA) as a main component as a cross-linking agent for a curing agent has been developed. This type of waterproofing material often uses 100% 2,4-tolylene diisocyanate as the isocyanate component of the main component in order to secure the pot life, and the NCO content is relatively low. Therefore, it is easy to make the free tolylene diisocyanate content 1% or less, and diethyltoluenediamine (DETDA) used for the curing agent is not a designated chemical substance or a specific chemical substance, and the conventional MOCA crosslinking type Since the waterproof material does not require the use of an organic lead catalyst such as lead octylate blended as an essential component in the curing agent, both the main agent and the curing agent can be said to be more environmentally friendly waterproof materials. In addition, since the blending amount of the plasticizer having a lower viscosity than that of the general-purpose waterproofing material can be blended relatively, it is easy to reduce the viscosity of the waterproofing material, and there is an advantage that the amount of solvent used during construction can be reduced.

However, the DETDA cross-linked waterproof material may need to use more plasticizer than the general-purpose waterproof material in order to secure the usable time, and it adheres to the general two-component reactive acrylic urethane topcoat material. It is difficult to maintain the property, and the plasticizer in the waterproof material is likely to be transferred to the top coat material.

On the other hand, recently, a one-component urethane waterproofing material in which a plasticizer, a solvent, a filler, a pigment, a latent curing agent and the like are blended with an isocyanate-terminated prepolymer is also used. Furthermore, water is added at the construction site to a one-component component containing an isocyanate-terminated prepolymer imparted with water-solubility, an alkaline earth metal oxide such as magnesium oxide, a plasticizer, a solvent (other than xylene and toluene), and a filler. Urethane waterproofing materials that add and react to solidify are being developed as environmentally friendly waterproofing materials, but there are problems in securing the usable time in summer and finishing, and adhesion of water-based topcoat materials used in the system There is also a problem with durability.

On the other hand, for the topcoat material forming the topcoat layer applied on the waterproof material, the non-yellowing polyfunctional isocyanate compound is prepared by a thinner mainly composed of toluene, xylene and butyl acetate having excellent solubility. , A main polymer diluted to have a solid content (prepolymer content) of about 10 to 50%, and a vinyl polymer resin (acrylic polyol) containing a hydroxyl group reactive with an isocyanate group, again with toluene, xylene and A two-component reactive acrylic urethane coating consisting of a curing agent (enamel) dissolved in thinner with butyl acetate as the main component and blended with additives such as pigments, fillers and defoaming to make the solid content around 50%. It is generally used, and the solvent amount in a state where the main agent and the curing agent are mixed is generally 50 to 70% by weight.

The acrylic polyol used in the curing agent generally has a molecular weight of 50,000 to 120,000 based on the balance of weather resistance, coating film strength, film forming property, cost, and the like. The thinner to be dissolved must be a strong solvent and also has good drying properties such as toluene, xylene solvent and fatty acid ester solvent with strong odor such as ethyl acetate and vinegar buttery, and has environmental problems. .

For this reason, as a countermeasure against toluene removal and xylene, a waterproof system using a water-based topcoat has been proposed in recent years. However, there are still problems such as deterioration in water resistance and finish, water adhesion resistance, coating strength and abrasion resistance, and weather resistance.
Further, in cold district construction, the water-based primer material and the water-based topcoat material, etc., are frozen during storage and construction, so that there is also a problem that construction in winter cannot be performed.

Patent documents related to the present invention include the following.
JP 08-143816 JP2002-364128 JP 2003-313538 A

In a waterproof structure consisting of a urethane waterproof layer and a top coat layer formed on this surface, it is relatively easy to replace a solvent that is blended in several percent of the urethane waterproof material with a solvent other than toluene or xylene. In addition, it is relatively easy to use a diluent other than toluene and xylene for the diluent used during construction. Construction with a solvent outside of the organic solvent poisoning prevention regulations with low toxicity and low odor is relatively easy (see Japanese Patent Application No. 2004-112882).

However, for the topcoat layer, in reality, it is necessary to take a technique such as forming by applying a two-component reactive acrylic urethane paint containing a considerable amount of odorous solvents such as toluene, xylene, ethyl acetate, and butyl acetate. Yes, there are few environmental measures.
The reason for this is that the two-component reactive acrylic urethane paint has excellent adhesion to urethane waterproofing materials, and has good film properties such as weather resistance, durability, drying properties, extensibility, and wear resistance. Is relatively economical. Furthermore, in order to balance the various performances, it is necessary to use a high molecular weight acrylic polyol of about 5 to 120,000 as a reaction component in the curing agent. The use of strong solvents (highly soluble) and solvents with strong odor and high solubility such as ethyl acetate and butyl acetate is inevitable.

In addition, in order to dissolve and apply the high molecular weight acrylic polyol as described above, there is a problem that a large amount of solvent of 50% to 70% is required in the coating mixture.
However, toluene and xylene are substances subject to the Poisonous and Deleterious Substances Control Law (Ministry of Health, Labor and Welfare) and the Odor Control Law (Ministry of the Environment). In addition, the Ministry of Education, Culture, Sports, Science and Technology is expected to become more strict in the future, with concentration measurements being obligated when handing over new and renovated schools from FY2002. On the other hand, discussions are ongoing regarding the regulation of the total amount of volatile organic solvents (VOC), and the need to reduce the amount of solvent used in the future is inevitable.

Furthermore, organic solvent poisoning prevention type 2 solvents such as ethyl acetate and butyl acetate are also very odorous and cause complaints from residents during construction.
Today, workability and performance are not inferior to conventional products, and the development of topcoat materials that use low-odor and low-toxic solvents as well as the absence of toluene and xylene is an urgent issue.

On the other hand, as for urethane waterproof materials, the currently widely used MOCA cross-linkable type has special chemicals and specified chemical substances such as free tolylene diisocyanate as the main agent and 4,4 ′ · methylenebis (2-chloroaniline) as the curing agent. Containing 1% by weight or more, there is room for improvement in the environment. On the other hand, for the less toxic DETDA cross-linked waterproof material that can be blended with 1% by weight or less of specialized substances and designated chemical substances, it is necessary to use a large amount of plasticizer in order to secure the pot life. There is a tendency for adhesiveness with the topcoat material to decrease, the tackiness of the topcoat layer to increase, the coating strength of the topcoat layer to decrease due to the transition to the topcoat layer, etc. Therefore, it is extremely difficult to design a topcoat material that does not contain toluene / xylene.

An object of the present invention is an environment-friendly urethane waterproofing that can be used for both a close contact method and a ventilation buffer method, and does not contain toluene / xylene, and can be constructed with a solvent that has as little toxicity and low odor as possible. The object is to provide a structure and a topcoat material used therefor.

The present invention is a urethane waterproof structure comprising a urethane-based coating film waterproof layer and a top coat layer formed by an environment-compatible top coat material applied to the surface of the waterproof layer, and the main component of the environment-responsive top coat material is While the main component of the reaction component is composed of a polyfunctional isocyanate compound, the curing agent is composed of an acrylic polyol having a molecular weight of 1500 to 20000 as the main component of the reaction component. Let's solve the above-mentioned conventional problems by realizing a urethane waterproof structure that can ensure the solubility by odorous solvent and the required film-forming property required for top coat and 30% to 200% cured film elongation. It is what.

In the urethane waterproof structure described above, the acrylic polyol having a molecular weight of 1500 to 20000 in the curing agent of the environment-friendly top coat material may be formed by a continuous bulk polymerization method.

Furthermore, in any of the above urethane waterproof structures, the solvent for the environmentally friendly top coat material may be composed of a solvent that is not regulated by the organic solvent poisoning prevention regulations.

  Furthermore, in any of the above urethane waterproof structures, the amount of the solvent contained in the environment-friendly top coat material may be 40% by weight or less and 15% by weight or more.

Moreover, in the urethane waterproof structure according to any one of the above, the waterproof material is a two-component reactive waterproof material, and the main component of the reaction component of the main agent is composed of an isocyanate group-terminated prepolymer, while the main component of the reaction component of the curing agent May be configured with DETDA.

The present invention is also an environmentally friendly topcoat material for forming a topcoat layer by applying it to a urethane-based waterproofing layer, and the main component of the environmentally friendly topcoat material is the main component of the reaction component. While it is composed of a polyfunctional isocyanate compound, the curing agent is composed of an acrylic polyol having a molecular weight of 1500 to 20000 as the main component of the reaction component, and both the main agent and the curing agent are soluble in a solvent having low toxicity and low odor. And providing an environmentally friendly top coat material capable of ensuring a predetermined film forming property required for a top coat and a cured coating film elongation rate of 30% to 200%. is there.

Furthermore, in the above-mentioned environment-friendly topcoat material, the acrylic polyol having a molecular weight of 1500 to 20000 in the curing agent may be composed of a product produced by a continuous bulk polymerization method.

Furthermore, in any one of the above environmentally friendly topcoat materials, the solvent contained is a solvent that is not regulated by the organic solvent poisoning prevention regulations.

In any of the above environmentally friendly topcoat materials, the amount of the solvent contained may be 40% by weight or less and 15% by weight or more.

In the present invention, the construction described above can be applied to both the close contact method and the ventilation buffer method, and the required construction is possible with a solvent that does not contain toluene / xylene, which is both toxic and odorous to the solvent. Therefore, it is possible to realize a urethane waterproof structure suitable for human health and a top coat material used therefor by being environmentally friendly.

In the present invention, the urethane waterproof layer is mainly composed of an isocyanate group-terminated urethane prepolymer produced by the reaction of tolylene diisocyanate and polyols, MOCA and polyols are blended as reaction components in the curing agent, and a plasticizer , A general-purpose MOCA cross-linked urethane waterproof material containing additives such as fillers, pigments, catalysts and antifoaming agents, and
DETDA cross-linked type that contains DETDA as the main component of the reaction component in the curing agent, and further contains additives such as plasticizers, fillers, pigments, catalysts, antifoaming agents, etc. A waterproof material is mentioned.

As mentioned above, this DETDA cross-linkable waterproof material can easily make the TDI content of specified chemical substances and specified chemical substances contained in the prepolymer of the main agent 1% by weight or less, and also specifies a curing agent. Since it can be designed without including chemical substances, specific chemical substances, and organometallic catalysts, it is preferable as the environmentally-friendly waterproof material of the present invention. Further, although DETDA is the main component of the cross-linking agent, a waterproof material using other polyamine or polyol as a cross-linking agent is also preferable.

In the present invention, the solvent blended in the waterproof material is preferably less than 1% of toluene / xylene, and more preferably a solvent outside the organic solvent poisoning prevention regulations.
The diluent added at the construction site also preferably has a toluene / xylene content of 1% or less, more preferably an organic solvent poisoning prevention rule-free solvent, specifically an aniline point of 40-80. Petroleum hydrocarbon solvents, alicyclic hydrocarbon solvents having 7 to 10 carbon atoms, and mixtures thereof.
Further, the present invention can be applied not only to the waterproof material but also to the one-component moisture-curable urethane waterproof material or the water-curable urethane waterproof material described above. The present invention can also be applied to a urethane waterproof material having methylthiotoluenediamine (Ethacure 300, manufactured by Albemarle Japan Co., Ltd.) as a main component of a crosslinking agent.

Next, although it is a two-component reactive acrylic urethane coating used for the top coat layer, a low molecular weight acrylic polyol having a molecular weight of 1500 to 20,000, which is a main component of the reaction component of the curing agent, is a normal urethane waterproof acrylic urethane top. The same raw materials as in the coat, polymerizable unsaturated monomer, hydroxyl group-containing polymerizable unsaturated monomer, and the like can be used.
As the polymerizable unsaturated monomer, for example, a vinyl-based monomer can be used, and specifically,
Aromatic vinyl monomers such as styrene, α-methylstyrene, p-tert-butylstyrene, vinyltoluene;
Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, iso-propyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, iso-butyl (meth) Acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, phenyl (meth) acrylate, dibromopropyl (meth) acrylate, tribromophenyl (Meth) acrylates such as (meth) acrylate or alkoxyalkyl (meth) acrylate;
Diesters of unsaturated dicarboxylic acids such as maleic acid, fumaric acid or itaconic acid and monohydric alcohols;
Vinyl esters such as vinyl acetate, vinyl benzoate, vinyl propionate, vinyl laurate, vinyl acid versatate;
(Per) fluoroalkyl group-containing vinyl esters such as perfluorocyclohexyl (meth) acrylate, di-perfluoroacrylic cyclohexyl fumarate or Ni-propyl perfluorooctanesulfoamidoethyl (meth) acrylate;
Vinyl ethers;

Or fluorine-containing compounds such as unsaturated carboxylic acid esters;
Or vinyl monomers having no functional group such as olefins such as (meth) acrylonitrile, vinyl chloride, vinylidene chloride, vinyl fluoride or vinylidene fluoride;
Silicon monomers such as vinylethoxysilane and γ-methacryloxypropyltrimethoxysilane;
(Meth) acrylamide, dimethyl (meth) acrylamide, N-methylol (meth) acrylamide 2- (meth) acryloyloxyethyl acid phosphate, dibutyl (2- (meth) acryloyloxydiethyl) phosphate, Nt-butyl ( Amide group-containing vinyl monomers such as (meth) acrylamide,
Etc. can be used.

As the hydroxyl group-containing polymerizable unsaturated monomer, specifically,
2-hydroxyethyl (meth) acrylate, 3-hydroxyethyl (meth) acrylate, caprolactone-modified hydroxy (meth) acrylate (ε-caprolactone addition monomer manufactured by Daicel Chemical Industries), N-methylol (meth) acrylamide, hydroxyethyl vinyl ether A polymerizable unsaturated monomer having a primary hydroxyl group such as a hydroxyl group-containing vinyl monomer;
Unsaturated monomers having secondary hydroxyl groups such as 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate,
Etc. can be used.

In order to improve curability, some carboxyl group-containing polymerizable unsaturated monomers can also be used. Specifically,
(Meth) acrylic acid, acrylic acid dimer, crotonic acid, maleic acid, fumaric acid, itaconic acid and other carboxyl group-containing vinyl monomers,
Etc.

Low molecular weight acrylic polyols are intended to ensure solubility in petroleum hydrocarbon solvents with relatively low odor and low toxicity, alicyclic hydrocarbon solvents having 7 to 10 carbon atoms, and to improve low-temperature properties. In order to obtain a low Tg, it is preferable to contain 5% by weight or more of a soft monomer such as butyl acrylate or 2-ethylhexyl acrylate. Further, at the least 40 wt% aromatic monomers such as styrene, elongation of low-temperature properties, the coating, weather resistance is insufficient, undesirably.

The weight average molecular weight needs to be 1,500 to 20,000, synthesis is difficult at 1,500 or less, film-forming property is reduced, and solubility at 20,000 or more is limited at 20,000 or more. It is not preferable as a component. Furthermore, in order to produce the effect of reducing the amount of solvent, it is preferably 10,000 or less.

The OH value is preferably 30 to 150 mg KOH / g based on the solid content of the polymer, and if it is 30 or less, the crosslinking density becomes too low and the adhesive strength and coating film strength are lowered. It becomes difficult to melt | dissolve and the elongation rate of a coating film will fall.
In addition, a non-water-dispersible acrylic resin (NAD resin), an acrylic polyol having a molecular weight of 20,000 or more, and an acrylic polymer containing no OH group can also be used.

As for the synthesis method, it can also be obtained by a conventionally known method of radical polymerization in a solution and a method of radical copolymerization in a solution using a reaction vessel that can raise the polymerization temperature to a higher level than usual and can seal the reaction system. It is done. It can also be produced by conventionally known bulk polymerization.

Further, it can be obtained by a method of performing continuous bulk polymerization at high temperature and high pressure as described in US Pat. No. 4,414,370, US Pat. No. 4,529,787, US Pat. No. 4,546,160, US Pat. No. 5,508,366, JP-A-60-215007 and the like. The resulting acrylic polyol has a relatively narrow molecular weight distribution and a narrow composition distribution, does not contain or contains a small amount of solvent, and does not contain or require a very small amount of necessary polymerization initiator. In addition, since the chain transfer agent can be eliminated, it has low odor, little yellowing with time and low weather resistance, and excellent adhesion to waterproofing material and tack resistance, especially DETDA It is excellent in adhesion to a cross-linked waterproof material, and is more preferable.

The main agent is a non-yellowing polyfunctional isocyanate compound, which is the main component, dissolved in a solvent. As the non-yellowing polyfunctional isocyanate compound, specifically,
1,6-hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, norbornane diisocyanate, dicyclohexylmethane diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated tolylene diisocyanate, dimeryl diisocyanate, trimethylene diisocyanate, tetramethylene xylylene diisocyanate, etc. Biuret bodies, isocyanurate bodies, adduct bodies, dimer bodies, prepolymers and modified bodies thereof of non-yellowing polyfunctional isocyanate compounds, modified bodies for imparting solubility in nonpolar solvents, and the like can be used.

The low molecular weight acrylic polyol used in the present invention is superior in solubility in solvents other than toluene and xylene, especially in solvents with low odor and toxicity, compared to ordinary acrylic polyols. Can be provided.
As solvents other than toluene / xylene, aliphatic esters having a boiling point of 85 ° C. to 230 ° C. are excellent in solubility and can be used. Specifically, propyl acetate, butyl acetate, pentyl acetate, methyl octenoate, ethyl-3-ethoxypropionate, 3-methoxy-butyl acetate, 3-methoxy-3-methyl-butyl acetate (Solfit AC), propylene Monocarboxylic acid esters such as glycol monomethyl ether acetate (PGMAC), propylene glycol monoethyl ether acetate (PGEAC), dipropylene glycol monomethyl ether acetate, dicarboxylic acid esters such as propylene glycol diacetate, dimethyl adipate, dimethyl glutamate, and dimethyl succinate Ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether acetate, ethylene glycol and Although esters synthesized from ethylene glycol can be used, propyl acetate, butyl acetate, methyl octenoate, ethyl-3-ethoxypropionate, 3- Methoxy-butyl acetate, propylene glycol monomethyl acetate, propylene glycol monoethyl acetate, and 3-methoxy-3methyl-butyl acetate are preferred.

However, propyl acetate and butyl acetate have strong odors and fall under the category 2 organic solvent poisoning prevention rules, and the other fatty acid ester solvents mentioned above do not fall under the organic solvent poisoning prevention rules and the odor is relatively mild. Therefore, the solvent used in the present invention is more preferable.

In addition, alicyclic hydrocarbon solvents having 7 to 10 carbon atoms (outside the poisoning prevention regulations) have relatively good solubility in low-molecular acrylic polyols, and have high volatile properties and low odor, and are addicted to organic solvents. It is a solvent outside the preventive regulations and is preferred. Specific examples include methylcyclohexane, ethylcyclohexane, dimethylcyclohexane, Ricasolve 900 (C9 aromatic hydrogenated product), and Ricasolve 1000 (C10 aromatic hydrogenated product).

Low boiling aromatic naphtha and aromatic petroleum-containing hydrocarbon solvents are classified as Type 2 or Type 3 in the organic solvent poisoning prevention regulations, have a slightly aromatic odor, but have relatively good solubility and are used. be able to. Specific examples include Shellsol A, HAWS, LAWS (Shell Chemicals Japan Co., Ltd.), Swazol 1000 (Maruzen Petrochemical Co., Ltd.), A Solvent (Shin Nippon Oil Co., Ltd.), and the like.

Aliphatic and alicyclic petroleum hydrocarbon solvents have low odor and are often outside the organic solvent poisoning prevention regulations, but can be used supplementarily because their solubility decreases.
Specifically, Shellsol D40, Shellsol S (Shell Chemicals Japan Co., Ltd.), Exor D30, Exor D40 (manufactured by ExxonMobil)
An IP solvent (made by Idemitsu Petrochemical Co., Ltd.) can be mentioned.

In addition, the second type solvent (organic solvent poisoning prevention regulations) having a relatively strong odor such as cyclohexanone, methylcyclohexanone, methyl ethyl ketone, and methyl isobutyl ketone can be partially used.

On the other hand, as with the curing agent, an aliphatic ester solvent having a boiling point of 85 ° C. to 230 ° C. is preferable for the solvent that dissolves the polyfunctional isocyanate compound that is the main agent, and is preferably methyl octenoate, ethyl- More preferred are solvents outside the organic solvent poisoning prevention regulations such as 3-ethoxypropionate, 3-methoxy-butyl acetate, propylene glycol monomethyl acetate, propylene glycol monoethyl acetate, 3-methoxy-3methyl-butyl acetate. Moreover, a C7-10 alicyclic hydrocarbon-type solvent, a low boiling point aromatic naphtha, and an aromatic containing petroleum-type hydrocarbon solvent can be used.
Aliphatic and alicyclic petroleum hydrocarbon solvents are limited in use because of their reduced solubility.

In the present invention, the above-mentioned solvent can be blended, but the content of toluene and xylene must be 1% or less for both the main agent and the curing agent, and aliphatic esters that do not fall under the organic solvent poisoning prevention regulations and It is preferable to use an alicyclic hydrocarbon solvent having 7 to 10 carbon atoms as a main component.

Further, in the conventional top coat for urethane waterproof material, the solvent amount in the mixture of the main agent and the curing agent (in the curing agent) is generally 50% to 60% by weight, but the low molecular acrylic polyol of the present invention is used. When used, the viscosity can be considerably reduced compared to conventional methods, so even if the amount of solvent in the mixture is reduced to 40% to 15%, construction with rollers, brushes, etc. is possible, resulting in high solids (low solvent Can be realized. In that case, the molecular weight of the acrylic polyol used as the main component is preferably 1500 to 10,000.

The environment-friendly topcoat material of the present invention includes pigments, curing catalysts, and additives usually added to the topcoat material, such as pigment wetting / dispersing agents, leveling agents, antifoaming agents, repellency inhibitors, thickeners. In addition, other components such as an antioxidant and an ultraviolet ray inhibitor can be blended.

Further, an anti-slip material, a matting agent, an inorganic filler, and the like can be blended.

Furthermore, in this invention, it is preferable that the elongation rate (JISA6909, dumbbell No. 2, 20 mm between marked lines) of the cured coating film of the two-component acrylic urethane coating used for the top coat is 30% to 200%. This is a very soft material for the urethane waterproof layer, which is the foundation, and is designed to have an elongation of 450% or more so that it can follow the cracks in the concrete, and the top coat applied on it is not flexible. This is because there is a risk of cracking without being able to follow the change in the ground.
In addition, in the topcoat using the low molecular weight acrylic polyol of the present invention, when the elongation is 30% or less, cracking is likely to occur on the urethane waterproof layer, and when it is 200% or more, the adhesiveness to the urethane waterproof material is increased. The film strength also decreases.

Properties of low molecular weight acrylic polyol and solubility in solvent The following Table 1 shows the low molecular weight acrylic polyol used as the main component of the curing agent of the two-component reactive acrylic urethane coating used in the topcoat layer and its solubility in the solvent. It was shown to. The solubility in Table 1 indicates that the solvent other than toluene and xylene is mixed and stirred so as to be a low molecular weight acrylic polyol / solvent = 1/1 (weight ratio). X was evaluated. Among the low molecular weight acrylic polyols, Joncryl 911 and Joncryl 934 contained butyl acetate as a solvent in the product, and therefore, the solubility test was performed after concentrating to 99% by weight or more of solid content with an evaporator.

Description of solvents in Table 1 above:
MBA: Metoacese, manufactured by Daicel Chemical Industries, Ltd., 3-methoxybutyl acetate shell sol S: aliphatic petroleum hydrocarbon, Shell Chemicals Japan Co., Ltd. MCH: methylcyclohexane, Maruzen Petroleum Co., Ltd., Swazol 1000: aromatic content Petroleum hydrocarbon solvent (containing less than 1% xylene), manufactured by Maruzen Petroleum Corporation

Preparation of Topcoat Curing Agent The topcoat curing agent was blended according to the topcoat curing agent formulation shown in Table 2 below, and dispersed by a sand mill to obtain curing agents 1-5. It should be noted that Joncryl 911 blended with curing agent 1 and Joncryl 934 blended with curing agent 2 contained butyl acetate as a solvent in the product, and therefore, those concentrated to 99% by weight or more of solid content using an evaporator were used. . The curing agent 6 is a curing agent for the top coat (Altack Coat Q, manufactured by Tajima Roofing Co., Ltd.) currently used.

Description of raw materials in Table 2 above:
MBA: Metoace, manufactured by Daicel Chemical Industries, Ltd., 3-methoxybutyl acetate MCH: methylcyclohexane, titanium oxide manufactured by Maruzen Petroleum Co., Ltd., R-32, additives manufactured by Sakai Chemical Industry Co., Ltd. : TN-12, manufactured by Sakai Chemical Industry Co., Ltd., dibutyltin laurate

Preparation of main agent of top coat According to the main agent composition of top coat shown in Table 3 below, main agents 1 and 2 were obtained. Main agent 3 is the main agent of the currently used top coat (Altack Coat Q, manufactured by Tajima Roofing Co., Ltd.).

Description of raw materials in Table 3 above:
Duranate 24A-100: Hexamethylene diisocyanate non-yellowing polyisocyanate (biuret), manufactured by Asahi Kasei Chemicals Corporation, solid content 100% by weight, NCO content: 23.5% by weight
Duranate THA-100: Hexamethylene diisocyanate non-yellowing polyisocyanate (isocyanurate), manufactured by Asahi Kasei Chemicals Co., Ltd., solid content: 100% by weight, NCO content: 21.2% by weight
MBA: Metoace, manufactured by Daicel Chemical Industries, Ltd., 3-methoxybutyl acetate

Preparation of main component of waterproofing material A 2-liter four-necked flask was charged with a polyol and a solvent, and then with a diisocyanate according to the formulation shown in Table 4 below. Thereafter, the mixture was reacted at 90 to 100 ° C. with stirring in a nitrogen stream for 7 hours, and then cooled to room temperature and collected in a can to obtain a MOCA crosslinked waterproofing agent main agent and a DETDA crosslinked waterproofing agent main agent. The NCO content of the MOCA cross-linked waterproofing agent main ingredient after collecting the cans was 3.48% by weight, and the NCO content of the DETDA cross-linked waterproofing agent main ingredient was 2.99% by weight.

Description of raw materials in Table 4 above:
PP-2000: Sanniks diol PP-2000, manufactured by Sanyo Chemical Industries, Ltd., polyoxypropylene diol, OH value 56.1 mgKOH / g
GP-3000: Sannixdiol GP-3000, manufactured by Sanyo Chemical Industries, Ltd., polyoxypropylated glycerin, OH value 56.1 mgKOH / g
G-600: Polyoxypropylated glycerin, manufactured by Daiichi Pharmaceutical Industries, Ltd., OH value 280.5 mgKOH / g
TDI-80: Coronate T-80, manufactured by Nippon Polyurethane Industry Co., Ltd., 2,4-tolylene diisocyanate 80% -containing product, NCO content 48.3% by weight
TDI-100: Coronate T-100, manufactured by Nippon Polyurethane Industry Co., Ltd., 2,4-tolylene diisocyanate 100% -containing product, NCO content 48.3% by weight

Preparation of curing agent for waterproof material In a 2 liter metal container, MOCA dissolved in predetermined T-500 is blended according to the blending of the following Table 5, and DINP, lead octylate, additive, shell sol S liquid The product was charged at low speed with a stirrer (diameter 50 mm) and homogenized, and then mixed with calcium carbonate and toner and mixed at 1500 rpm for 15 minutes to obtain a MOCA crosslinked waterproofing material curing agent. The DETDA crosslinked waterproofing agent curing agent was charged with DETDA, DINP and additive liquids according to the formulation shown in Table 5, mixed at a low speed with a stirrer (diameter 50 mm), and then mixed with calcium carbonate and toner. Obtained by mixing for minutes.

Description of raw materials in Table 5 above:
MOCA: Iharacuamine MT, manufactured by Ihara Chemical Industry Co., Ltd., 4,4′-diamino-3,3′-dichlorodiphenylmethane DETDA: diethyltoluenediamine, manufactured by Lonza Japan Co., Ltd.
T-500: Polyhardener T-500, manufactured by Daiichi Pharmaceutical Industry Co., Ltd., polyoxypropylated glycerin, OH value 33.7 mgKOH / g
DINP: Sansosizer DINP, manufactured by Shin Nippon Rika Co., Ltd., lead diisononyl phthalate octylate: Minicor P-20S, manufactured by Harima Chemicals Co., Ltd., 2-ethylhexylate, 20% as Pb Additives: manufactured by Enomoto Kasei Co., Ltd. Calcium carbonate: NS # 100, manufactured by Nitto Flour Industry Co., Ltd.
Toner: Made by Mikuni Color Co., Ltd.

Preparation of Waterproof Material As shown in Table 6 below, the MOCA crosslinked waterproofing agent main component and the MOCA crosslinked waterproofing material curing agent were blended at a weight ratio of 100/200 to obtain a MOCA crosslinked waterproofing material. Moreover, the DETDA crosslinked waterproofing material main ingredient and the DETDA crosslinked waterproofing material hardening | curing agent were mix | blended by 100/200, and the DETDA crosslinked waterproofing material was obtained.

Preparation of High Solid Curing Agents Topcoat Curing Agents were blended according to the topcoat curing agent composition shown in Table 7 below, and dispersed with a sand mill to obtain curing agents 3, 7-9.

Description of raw materials in Table 7 above:
Arufon UH-2041: Acrylic polyol, manufactured by Toa Gosei Co., Ltd., solid content 100% by weight, glass transition point-50 degrees Celsius, OH value 120 mg KOH / g, molecular weight 2500
MBA: Metoace, manufactured by Daicel Chemical Industries, Ltd., 3-methoxybutyl acetate MCH: methylcyclohexane, titanium oxide manufactured by Maruzen Petroleum Co., Ltd .: R-32, additives manufactured by Sakai Chemical Industry Co., Ltd .: DBTDL manufactured by Enomoto Kasei Co., Ltd. : TN-12, manufactured by Sakai Chemical Industry Co., Ltd., dibutyltin laurate

Preparation of High Solid Topcoat Main Agent According to the topcoat main agent formulation shown in Table 8 below, main agents 4 to 7 were obtained.

Description of raw materials in Table 8 above:
Duranate 24A-100: Non-yellowing polyisocyanate (biuret), manufactured by Asahi Kasei Chemicals Corporation, solid content: 100% by weight, NCO content: 23.5% by weight
MBA: Metoace, manufactured by Daicel Chemical Industries, Ltd., 3-methoxybutyl acetate MCH: Methylcyclohexane, manufactured by Maruzen Petroleum Corporation

In the following, according to the following Table 9, Examples 1 to 7 of the top coat and their performance will be described.

Example 1
Evaluation was performed on the main agent 1 using duranate 24A-100 which is a buret body of hexamethylene diisocyanate as the main agent and the curing agent 1 using Joncryl 911 which is an acrylic polyol having a molecular weight of 4000.
First, regarding the environmental compatibility (curing agent) of the solvent, it was evaluated as “Good” because it was sufficiently dissolved in the MBA / MCH mixed solvent, and the odor was mild. Further, both the MOCA cross-linked waterproof material and the DETDA cross-linked waterproof material have good adhesion, and excellent elongation and tackiness.
Note 1: Environmental compatibility of solvents (curing agent)
A solvent that can be dissolved in a 1/1 (weight ratio) mixed solvent of MBA that is a slightly high boiling aliphatic ester solvent and MCH that is a relatively low boiling alicyclic solvent is evaluated as ◎. Those that did not dissolve but only dissolved in MBA alone were evaluated as “good”, and those using toluene / xylene were evaluated as “poor”.
2. Adhesion test MOCA crosslinkable waterproofing material (1/2) and DETDA crosslinkable waterproofing material were each applied at 2 kg / square meter, and then one specimen was cured in a thermostatic chamber at 23 ° C./50% humidity for 3 days. Later, a top coat was applied (0.15 kg / square meter), and another specimen was cured for 3 days in a thermostatic chamber at 23 ° C./50% humidity and then exposed for 3 days on an outdoor exposure table (temperature 15 ° C. to 28 ° C.). The top coat was applied after (° C / no rain).
Each specimen was subjected to an adhesion test on the seventh day after the top coat was applied.
In the adhesion test, a rubbing test was performed to observe the peeling of the top coat after rubbing the same place on the surface of the top coat 10 times (moving at a width of 5 cm) at the corner of the rubber spatula cut to a thickness of 5 mm.
Evaluation ○: When not peeled at all, evaluation Δ: Partially peeled (30% or less), evaluation ×: When peeled 30% or more Note 3, elongation rate (JISA 6909, dumbbell No. 2, 20 mm between marked lines)
Evaluation ○: Elongation rate is 30% to 200% (23 ° C)
Evaluation x: The elongation rate Note 4 other than that, and the top coat surface on the day after the tackiness application is checked with a finger.
Evaluation ○: Evaluation with no tack (stickiness) Δ: Feels slightly tacky, but a person can walk.
Evaluation x: There is tack and it is difficult for people to walk.

Examples 2 and 3
For the same main agent as in Example 1, Joncryl934 (Example 2), which is an acrylic polyol having a molecular weight of 6000, and Arufon, which is an acrylic polyol having a molecular weight of 2500.
Curing agents 2 and 3 using UH-2041 (Example 3) were evaluated.
In any case, the environmental compatibility of the solvent was good, and the adhesiveness to the waterproof material, elongation rate, and tackiness were also good.

Example 4
Curing agent 4 in which Arufon UH-2041 having a molecular weight of 2500 and Joncryl 587 having a molecular weight of 16,500 were blended at 1/1 (weight ratio) with respect to the same main agent as in Example 1 was evaluated.
Regarding the environmental compatibility of the solvent, it was soluble in MBA single solvent, but was not soluble in MBA / MCH = 1/1, and the evaluation was Δ. However, the adhesion to the waterproof material was good, and the tackiness was very good. Although the elongation was slightly reduced, it was within the practical range.

Example 5
The curing agent 5 using Actflow UME-2005, which is an acrylic polyol having a molecular weight of 3000, was evaluated with respect to the same main agent as in Example 1.
The environmental compatibility of the solvent is good, and there is no problem with the MOCA cross-linked waterproof material base, but the acrylic produced by the continuous bulk polymerization method whose adhesion and tackiness to DETDA cross-linked waterproof material have been evaluated up to Example 4 Lower than polyol.

Examples 6 and 7
Main agent 2 using duranate THA-100 which is an isocyanurate of hexamethylene diisocyanate as the main agent, and Joncryl 911 and Arufon which are the acrylic polyols used in Examples 1 and 3.
Examples 6 and 7 were performed using UH-2041.
Even the main component of the isocyanurate body was good with no significant differences in adhesion to the waterproof material, elongation rate, and tackiness.

Comparative Example 1
As a comparative example, an evaluation was performed on Altac Coat Q (manufactured by Tajima Roofing Co., Ltd.), which is a general two-component acrylic urethane paint used conventionally.
Since the molecular weight of acrylic polyol is about 100,000, toluene / xylene and butyl acetate are the main components of the solvent, so the environmental compatibility of the solvent is x.
There is no problem with adhesion to general-purpose MOCA cross-linkable waterproof materials, but adhesion to DETDA cross-linkable waterproof materials is △ to ×, and tackiness is also △ to practical use. Has a problem.

Next, examples of making the top coat highly solid will be described as Examples 8, 9, and 10 together with Comparative Example 2 with reference to Table 10 below.

Examples 8, 9, 10
Using Arufon UH2041 having a low viscosity as an acrylic polyol (2,500 mPa · s), adjusting the solvent amount of the main agent and the curing agent, the solid content of the top coat during mixing was 53% (Example 8), 65% (Example 8) Example 9) was adjusted to 75% (Example 10).
Each material was constructed with a medium hair roller for 1 square meter (1 m × 1 m), and the roller workability (the weight of the roller at the time of construction) and the finish were evaluated.
In Example 8, the roller workability is very light and can be applied (evaluation ○), and uniform application is easy (evaluation ○).

* 5 Roller workability A 1m2 (1m x 1m) top coat is applied with a brush on a DETDA cross-linked waterproof material, and the workability at that time is evaluated.
Evaluation ○: Roller workability is light and the material can be stretched thinly.
Evaluation x: The roller workability is heavy and the material cannot be stretched thinly.

Note 6 Finished finish Check the finished finish when DETDA type cross-linked waterproofing material is coated with top coat.
Evaluation (circle): When it can apply | coat uniformly without coating unevenness.
Evaluation ×: When uneven coating occurs or uniform application is not possible

In Example 9, the roller workability is good (evaluation ○). Moreover, it could apply | coat uniformly (evaluation (circle)).
In Example 10, the roller workability was also good (evaluation ○), and the construction was uniform (evaluation ○).

As Comparative Example 2, the same resin composition as that of the example was prepared so that the solid content was 90%.
Roller workability was heavy and it was difficult to extend the material thinly (Evaluation ×). Moreover, it was difficult to apply uniformly (evaluation x).

Claims (9)

A urethane waterproof structure comprising a urethane coat waterproofing layer and a topcoat layer formed by an environmentally friendly topcoat material applied to the surface of the waterproof layer, wherein the main component of the environmentally friendly topcoat material is the reaction component While the main component is composed of a polyfunctional isocyanate compound, the curing agent is composed of an acrylic polyol having a molecular weight of 1500 to 20000 as the main component of the reaction component, and both the main agent and the curing agent are low toxic and low odor solvents. A urethane waterproof structure characterized in that the predetermined film-forming property required as a top coat and a stretch ratio of a cured coating film of 30% to 200% can be secured. 2. The urethane waterproof structure according to claim 1, wherein the acrylic polyol having a molecular weight of 1500 to 20000 in the curing agent of the environmentally friendly topcoat material is produced by a continuous bulk polymerization method. 3. The urethane waterproof structure according to claim 1, wherein the solvent for the environmentally friendly top coat material is a solvent that is not regulated by the organic solvent poisoning prevention regulations. The urethane waterproof structure according to any one of claims 1 to 3, wherein the amount of solvent contained in the environmentally friendly topcoat material is 40% by weight or less and 15% by weight or more. 5. The urethane waterproof structure according to claim 1, wherein the waterproof material is a two-component reactive waterproof material, and the main component of the reaction component of the main agent is composed of an isocyanate group-terminated prepolymer, while the reaction component of the curing agent is Urethane waterproof structure characterized by comprising DETDA as the main component An environmentally friendly topcoat material for forming a topcoat layer by applying it to a urethane-based waterproofing layer. The main component of this environmentally friendly topcoat material is a polyfunctional isocyanate compound whose main component is a reactive component. On the other hand, the curing agent is composed of an acrylic polyol having a molecular weight of 1500 to 20000 as the main component of the reaction component, and both the main agent and the curing agent are required for solubility in a low-toxicity, low-odor solvent and as a top coat. An environmentally friendly top coat material characterized by ensuring a predetermined film-forming property and a cured coating film elongation rate of 30% to 200%. The environmentally friendly topcoat material according to claim 6, wherein the acrylic polyol having a molecular weight of 1500 to 20000 in the curing agent is produced by a continuous bulk polymerization method. The environmentally friendly topcoat material according to claim 6 or 7, wherein the solvent contained is a solvent that is not regulated by the organic solvent poisoning prevention regulations. The environmentally friendly topcoat material according to any one of claims 6 to 8, wherein the amount of solvent contained is 40% by weight or less and 15% by weight or more.