JPH07330854A - Production of cold-setting coating-waterproofing material - Google Patents

Abstract

PURPOSE:To produce the subject waterproofing material capable of stable cold application over the whole year and formation of an excellently finished cured coating film excellent in heat resistance and useful for a poured flooring material, etc., by using aromatic polyamines composed of a prescribed ratio of diethyltoluenediamine and a specified amine as the curing agent. CONSTITUTION:This waterproofing material is composed of (A) a main agent composed mainly of a prepolymer synthesized by reacting (i) toluylene diisocyanate with (ii) a polyol and having isocyanate terminals and (B) a curing agent composed mainly of an aromatic polyamine. The waterproofing material is produced by using a mixture of (iii) 30 to 90mol% diethyltoluenediamine and (iv) 10 to 70mol% aromatic secondary amine of the formula (R1 is a 1 to 4C alkyl) as the component (B), blending the main agent with the curing agent at a job site so that the equivalent ratio of the isocyanate groups in the main agent to the amino groups in the aromatic polyamine of the curing agent may be 0.8 to 2.0, applying and curing it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a room temperature curable polyurethane coating film waterproof material, a coated floor material and the like.

[0002]

2. Description of the Related Art Polyurethane-coated waterproof materials and floor covering materials are currently used in large quantities for waterproofing rooftops, balconies, and corridors of buildings, and elastic paving in sports facilities. This method uses polyols such as polypropylene ether polyols and tolylene diisocyanate (TDI).
An isocyanate-terminated prepolymer produced by a reaction with an aromatic diisocyanate as a main component, and a polyol and 4,4′-methylene-bis (2-chloroaniline) (MOCA) as an isocyanate reaction component (curing agent) 2 Room temperature curable polyurethane urea waterproof materials and floor coating materials, which are liquid-type hand-operated mixed coating methods, are the mainstream.

[0003]

The MOCA used as the main component of the curing agent in this method is solid at room temperature,
It requires a dissolution step to be incorporated into the hardener composition. However, MOCA has poor solubility in a solvent or a plasticizer and requires a large amount of a solvent or the like, but for the use in this field, use of these solvents beyond a certain limit must be avoided. Further, even if once dissolved in these, MOCA crystals often precipitate with the passage of time and the storage stability of the curing agent is lacking. Since MOCA has a certain degree of solubility in polyalkylene ether polyols, it is used almost in the form of a required amount dissolved therein at present.

However, since the reactivity of the main component with the isocyanate component is different between MOCA and polyol, a catalyst such as organometallic lead is indispensable for the smooth progress and completion of these reactions at room temperature. Even if the composition of the curing agent is assembled in this way, curing apparently proceeds in the winter (at low temperature), but in many cases tack remains on the coating surface forever. Then, the heat resistance of the cured coating film deteriorates. In the summer (at high temperature), the balance between pot life (the maximum time after mixing the main agent and curing agent and the time it can be applied without any problems, usually the time until the viscosity reaches 100,000 centipoise after mixing) and curability Is difficult to remove, and under high temperature and high humidity conditions, foaming often occurs due to the effect of moisture, resulting in poor surface finish and causing blisters. As described above, the related art has various difficulties that need improvement, and a formulation that enables stable construction throughout the year has been desired. Furthermore, MOCA is a specific chemical substance, and there are certain restrictions in its manufacture and use.

[0005]

The present inventors have arrived at the present invention as a result of repeated studies in order to solve the above-mentioned difficulties of the prior art. 1. A two-part type room temperature curable waterproof film comprising a base compound containing an isocyanate-terminated prepolymer as a main component obtained by a reaction of tolylene diisocyanate (TDI) and a polyol, and a curing agent containing an aromatic polyamine as a main component. In the production method, diethyltoluenediamine (hereinafter D) is used as an aromatic polyamine crosslinking agent which is the main component of the curing agent.
ETDA) and an aromatic secondary amine represented by the following general formula (1) are used,

[0006]

[Chemical 2]

(However, R ₁ = C ₁ -C ₄ alkyl group) 30 to 90 mol% of the aromatic polyamine is DETDA, and 10 to 70 mol% is aromatic 2 represented by the general formula (1). It is a primary amine, and the main agent and the curing agent are mixed and applied at the construction site so that the equivalent ratio of the isocyanate group of the main agent and the amino group of the aromatic polyamine of the curing agent becomes 0.8 to 2.0. A method for producing a room temperature-curable waterproof coating film characterized by being cured.

2. Polyol molecular weight 400-8000
2. The method for producing a room temperature curable waterproof film as described in 1, which is the polypropylene ether polyol or the polyethylene-propylene ether polyol. 3. Tolylene diisocyanate is a tolylene diisocyanate having a 2,4-isomer content of 80% by weight or more 1.
A method for producing the room-temperature-curable coating film waterproof material as described. 4. Tolylene diisocyanate is a tolylene diisocyanate having a 2,4-isomer content of 85% by weight or more. 3
A method for producing the room-temperature-curable coating film waterproof material as described. 5. 2. The method for producing a room temperature curable waterproof film as described in 1, wherein the NCO content of the isocyanate end prepolymer is 1.5 to 8% by weight. 6. 60-90 mol% of the aromatic polyamine in the curing agent is diethyltoluenediamine, and 10-40 mol% is the aromatic secondary amine represented by the general formula (1). Method of manufacturing waterproof material.

The isocyanate terminated prepolymer used as the main component of the base compound in the method of the present invention is TDI.
It is produced by the reaction of a polyol with a polyol. In this case, in order to reduce the amount of TDI remaining in a free state in the obtained prepolymer as much as possible, the charged TDI and the polyol are reacted in such a manner that the equivalent ratio of NCO / OH does not exceed 2.1. Is desirable. As the TDI used for producing the prepolymer according to the present application, commercially available 2,
Those having a 4-isomer content of 65 to 100% by weight can be used, but a prepolymer using TDI having a low 2,4-isomer content tends to shorten the work life, so the work life is shortened. In order to obtain it, it is preferable to use TDI having a 2,4-isomer content of 80% by weight or more, and most preferably 85% by weight or more. The waterproof material obtained by the present invention has a faster hardening property than conventional ones, and is suitable for repair or for construction of a small area. Therefore, the pot life is 1 at the construction temperature.
It is preferable to be able to hold for 5 minutes or more. Polyol, which is a raw material for the isocyanate-terminated prepolymer, can be any polyether polyol, polyester ester polyol, polycaprolactone polyol, etc. used for ordinary urethane prepolymers, but at room temperature for the waterproof film application of the present invention. Liquid, low viscosity molecular weight 400-8
000 polyalkylene ether polyols are preferred and the most preferred polyols are polypropylene ether polyols or polyethylene-propylene ether polyols. The isocyanate content of the isocyanate-terminated prepolymer is preferably in the range of 1.5 to 8% by weight. The coating film obtained when the content exceeds 8% by weight is
It becomes too hard and difficult to stretch, and if it is less than 1.5% by weight, the mechanical strength of the coating film becomes weak and the physical properties required for the use of the present invention cannot be maintained.

DETDA used as an essential component of the curing agent in the method of the present invention is 3,5-diethyltoluene-
A mixture of 2,4 and 2,6-diamine, which is liquid at room temperature and commercially available, for example, Etacure # 100 (manufactured by Ethyl Corporation).

The aromatic secondary amine represented by the above general formula [Chemical Formula 1] used together with DETDA includes N, N '.
-Di-secondary-butyl-para-phenylenediamine (trade name: Unilink # 4100, manufactured by UOP) is commercially available and is liquid at room temperature.

As described above, the aromatic polyamine used in the present invention, which is an essential component of the curing agent, is liquid at room temperature and freely compatible with diluents such as plasticizers.
The step of dissolving CA is unnecessary, and various difficulties derived from this are eliminated. When DETDA is used in an amount of 90 mol% or more of the aromatic polyamine in the curing agent, the reaction with the isocyanate component of the main component is fast, and it becomes difficult to obtain the desired pot life at high temperatures (summer).

When the aromatic secondary amine represented by the general formula (1) is used in an amount of 70 mol% or more of the aromatic polyamine in the curing agent, the reaction with the main agent becomes too slow and the curability at low temperature deteriorates. Also, the cured coating film has a low mechanical strength, which makes it unsuitable for use in the present invention. Therefore, in the method of the present invention,
DETDA in the curing agent and the aromatic secondary amine of the general formula (1) are used in combination within the above range. This makes it possible to assemble a formulation which has a good balance between pot life and curability not only at low temperatures (winter) but also at high temperatures (summer), that is, which enables stable construction throughout the year. Most preferred DETD because it gives a cured coating film that is fast-curing and has suitable mechanical properties for waterproofing and floor coating applications.
The amount of A used is 60% of the aromatic polyamine crosslinking agent in the curing agent.
~ 90 mol%.

By using DETDA in the curing agent, the influence of moisture caused in the curing agent or the construction environment is smaller than that in the case of using MOCA. Therefore, conventional techniques such as blistering due to foaming or poor finishability are required. You can prevent the difficulties that were involved. In addition, the cured coating film produced by the method of the present invention is less likely to be sticky on the surface of the coating film than that produced by the prior art, and has a good tacky finish in a short time. DETDA in the method of the invention
In addition, the aromatic secondary amine represented by the general formula (1) is registered as an existing chemical substance in Japan, and the conventional secondary amine
Unlike OCA, there are no restrictions on manufacturing or use.

Since the aromatic polyamine used as the main component of the curing agent in the method of the present invention is mainly liquid at room temperature as described above, it does not need to be dissolved in a diluent such as a plasticizer or a solvent. Is preferably diluted with a plasticizer in consideration of the quantitative balance with the main agent when assembling the composition of the curing agent, or in consideration of the reactivity with the main agent. As a plasticizer, dioctyl phthalate (DOP),
Usual plasticizers such as dioctyl adipate (DOA), tricresyl phosphate (TCP) and chlorinated paraffin can be used. The plasticizer is mainly added to the curing agent, but in some cases, it may be partially added to the main agent. The amount of the plasticizer used is preferably 130 parts or less with respect to 100 parts of the main polymer prepolymer. If it exceeds 130 parts, the plasticizer bleeds from the surface of the cured coating film and the mechanical strength of the coating film becomes weak, which is not suitable.

In the method of the present invention, DETDA in the curing agent is used.
That is, since a highly active aromatic amine is used as an essential component, the reaction rate (pot life and curability) can be adjusted by the amount used. Therefore, organometallic lead (2
The addition of a catalyst such as 0 wt%) is not essential, but in some cases a catalyst such as lead octoate can be added to the curing agent in an amount of 2 wt% or less. With this amount of use, the heat resistance of the coating film does not deteriorate.

The polyol used in the prior art as a solvent for dissolving MOCA in the curing agent and as an isocyanate reaction component is not an essential component in the present invention, but the polyol has much lower reactivity with isocyanate than DETDA. It can optionally be incorporated into the hardener as a plasticizer in order to bring about the same effect as the plasticizer. Examples of the polyol that can be used as a plasticizer include polypropylene ether polyol or polyethylene-propylene ether polyol having a molecular weight of 400 to 8000, and 3 per 100 parts of the prepolymer used.
It is preferably used in an amount of 5 parts or less. If it is blended in an amount more than this, the polyol tends to bleed on the surface of the cured coating film, and the mechanical strength of the coating film becomes low.

The curing agent of the present invention may optionally contain inorganic fillers such as calcium carbonate, talc, kaolin, zeolite, and silica, pigments such as chromium oxide, titanium oxide, red iron oxide, carbon black and iron oxide, or hindered amine-based agents. Stabilizers such as hindered phenols and benzothiazoles can be added.

To carry out the present invention, a base compound containing an isocyanate-terminated prepolymer as a main component, which is obtained by a reaction of TDI and a polyol, and DETDA and N,
At the construction site, a curing agent (including a plasticizer, a polyol, a filler, a catalyst, etc. in some cases) containing an aromatic secondary amine such as N′-di-secondary-butyl-para-phenylenediamine in a specific range is used. The isocyanate group of the main agent and the amino group of the aromatic polyamine of the curing agent are mixed in an equivalent ratio of 0.8 to 2.0, and the mixture is coated on the article to be coated and cured. If the equivalent ratio of the isocyanate group of the main agent to the amino group of the curing agent is less than 0.8, unreacted amine will bleed to the surface of the coating film and cause discoloration. If it exceeds 2.0, the curability will be slow. Since the mechanical strength is too low, neither of them can achieve the object of the present invention.

According to the method of the present invention, stable room-temperature construction can be carried out throughout the year, and in a short period of time, a waterproof coating material, a floor coating material, etc. having excellent heat resistance and weather resistance, which has a good finish without stickiness A cured coating film suitable for use can be obtained.
Although the method of the present invention is mainly used for manual mixing and coating, it can be used for machine construction using an automatic mixing device such as a static mixer or a dynamic mixer because the pot life and leveling possible time are long. Can be used.

[0021]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples. The symbols used in the examples have the following meanings. "←" in the table indicates that the value is the same as the value in the left column. [Main agent] D-2000: Polypropylene ether diol Molecular weight 2000 (manufactured by Takeda Pharmaceutical Company) D-3000: Polypropylene ether diol Molecular weight 3000 (manufactured by Takeda Pharmaceutical Company) D-400: Polypropylene ether diol Molecular weight 400 (manufactured by Takeda Pharmaceutical Company Limited) ) T-3000: Polypropylene ether triol molecular weight 3000 (manufactured by Takeda Pharmaceutical Company) T-5000: Polypropylene ether triol molecular weight 5000 (manufactured by Takeda Pharmaceutical Company)

[Curing agent] DETDA: Diethyltoluenediamine (Etacure 1
00, manufactured by Ethyl Corporation) Unilink 4100: N, N'-di-secondary-butyl-para-phenylenediamine (manufactured by UOP) MOCA: 4,4'-methylene-bis (2-chloroaniline) (Ihara Chemical DOP: Dioctyl phthalate (plasticizer, manufactured by Daihachi Chemical Industry Co., Ltd.) Polyol: Polypropylene ether diol D-2
000 Calcium carbonate: Inorganic filler (Maruo Calcium Co., Ltd.) Lead octoate: Catalyst, lead content 20% by weight, (Nippon Kagaku Sangyo Co., Ltd.) NCO / NH ₂ (NH) equivalent ratio: Prepolymer (main agent)
Equivalent ratio of the NCO groups of the above and the amino groups of the aromatic polyamine cross-linking agent of the curing agent (however, in Comparative Example 8 only NCO groups / (NH ₂ +
OH) group equivalent ratio)

[Working time and curability] Working time: the maximum time (minutes) after which the main agent and the curing agent are mixed and which can be applied without any trouble (time until the viscosity after mixing reaches 100,000 centipoise) ) Tack free time: Time (hours) until stickiness disappears on the surface of the coating (time until a person can ride on the coating after coating)

[Physical properties of cured coating] Basic physical properties: After coating, the coating is cured at 20 ° C. for 7 days, and then J
Results of coating film physical property test conducted according to ISA-6021 (JI
Breaking elongation is 450% or more and tensile strength is 25k according to S standard
gf / cm ² or more) Heat resistance: cured at 20 ° C. for 7 days, then in an oven at 80 ° C.
Result of coating film physical property test after heating for days Tensile strength retention ratio: Strength ratio (percentage) between tensile strength after heat resistance test and that of basic physical property (JIS standard 80 or more 1
50 or less)

Main agent (isocyanate-terminated prepolymer)
Preparation of 2 liters of glass Kolben according to the recipes of Table 1, Table 2 and Table 3 having a content ratio of 2,4-isomer to 2,6-isomer of 65:35, 80:20, respectively. 85/1
Charge TDI of 5 or 100: 0 and D under nitrogen flow.
-2000, D-3000, D-400, T-3000
Alternatively, polypropylene ether polyol of T-5000 is gradually added according to the equivalent ratio of each charged NCO group to OH group, and the mixture is heated and stirred at 80 to 105 ° C. for 4 to 8 hours to complete the reaction, and an isocyanate-terminated prepolymer (main component) is added. Prepared.

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

[Table 3]

Preparation of Curing Agent In a 2-liter cylindrical open container, DETDA, Unilink 4100, DO according to the recipes of Table 1, Table 2 and Table 3 were used.
P, optionally a polyol, calcium carbonate and optionally a lead octoate were charged and stirred at room temperature for 15 minutes using a dissolver to prepare each curing agent. However, only the curing agent of Comparative Example 8 was prepared by previously dissolving MOCA in a polyol (D-2000) by heating.

Example 1 2,4-isomer / 2,6 in 2 liters of glass Kolben
Charged 148.2 g of TDI with an isomer weight ratio of 65/35, 681.4 g of D-2000 and 170.4 g of TDI.
-3000 (D-2000 / T-3000 = 80/20
(Weight ratio) is gradually added, the temperature is raised to 90 to 100 ° C. with stirring under heating in a nitrogen stream at 80 ° C., the temperature is kept at this temperature for 5 hours to complete the reaction, and the prepolymer having an NCO content of 3.5% by weight is added. 1000 g was prepared. Separately from this, 49 g of DETDA and 15 g of Unilink 4100 (in an aromatic polyamine in the curing agent, in a 2 liter cylindrical open container,
80 mol% DETDA and 20 mol% Unilink
Included), 436 g of DOP and 500 g of calcium carbonate were charged and stirred at room temperature with a dissolver for 15 minutes to prepare 1000 g of a curing agent. After the main agent and the curing agent prepared above are left for 3 minutes in an atmosphere of 10 ° C (assuming winter), 20 ° C and 35 ° C (assuming summer) for 2 hours or more, the main agent and curing are performed in each atmosphere. Agent weight ratio 1/1
(NCO group of the main agent / NH ₂ and NH group equivalent ratio of the curing agent = 1.2) are mixed, and a slate plate primed while checking the pot life is coated with a trowel or spatula to a thickness of 1. It was applied so as to have a thickness of 5 to 2 mm. 20 ° C
Part of what was mixed in 1. on a glass plate with a thickness of 1.5-2 m
Then, it was cast at a temperature of 20 ° C. and used as a test piece for measuring coating film physical properties (basic physical properties and heat resistance).

[0031]

[Table 4]

As a result, as shown in Table 4, the pot life at 10 ° C., 20 ° C. and 35 ° C. was 40 minutes, 28 minutes and 1 respectively.
5 minutes, the desired pot life can be maintained even at high temperatures (summer), and the tack free time is 5 hours and 2.
The curability was good even at low temperatures of 5 hours and 1.5 hours, and there was no foaming and good finish was exhibited. 20 ° C 7
The basic physical properties and heat resistance of the coating film after the day are as shown in the table, and the performance of the coating film waterproofing material sufficiently satisfies the JIS standard.

Examples 2 to 5 In Examples 2 to 4, the weight ratio of 2,4-isomer / 2,6-isomer was 80/20, 85/15 as the raw material TDI of the main agent.
Alternatively, a prepolymer prepared by using 100/0 is used, and the weight ratio of the main agent to the curing agent is 1/1 (NCO of the main agent).
Tests were also carried out at 20 ° C. in Examples 2 and 3 and at 10 ° C. and 35 ° C. in Examples 2 and 3, mixed in a ratio of the ratio of NH ₂ and NH groups of the curing agent = 1.2). The results are shown in Table 4. That is, the higher the 2,4-isomer content, the longer the pot life and the easier it is to maintain the desired pot life, but the curability tends to be slightly slower. However, as seen in Example 4, even if the curing was slow, it became tack-free in 8 hours even at a low temperature (10 ° C.) and had a rapid curing property (in the conventional method of Comparative Example 8, this was 30 to 30%).
It was possible to maintain a pot life of 30 minutes even at high temperature (35 ° C.) for 40 hours, and there was no foaming, resulting in a coating film with good finish. Each of these cured coating films showed suitable physical properties as a waterproof material. In other words, it was shown that construction can be done without any problem throughout the year. Example 5 is an example in which a small amount of the catalyst was added to the curing agent with the composition of Example 4, but the curing rate was faster than that of Example 4, and a desired pot life was maintained with this amount of catalyst addition. However, it shows that the heat resistance does not deteriorate.

Examples 6 to 7 The same main polymer as in Example 4 was used as the prepolymer.
The use ratios of DETDA in the aromatic polyamine crosslinking agent of the curing agent and the aromatic secondary amine of Unilink 4100 are different from those in Examples 1 to 5, and in Examples 6 and 7, DETDA /
The same test as in Example 4 was carried out with Unilink 4100 = 65/35 or 40/60 mol%. The results show that, as can be seen from Table 4, as the proportion of the aromatic secondary amine used increased as compared with Example 4 (Examples 6 and 7), the pot life increased and the curability slowed down accordingly. The coating film tends to be slightly soft and the strength tends to decrease, but even if the tack free time at 20 ° C. is slightly delayed to 8 hours as in Example 7, it is still quick-curing as compared with the conventional method of Comparative Example 8. It was also shown that the physical properties of the cured coating film maintain the performance suitable as a waterproof material.

Example 8 As the prepolymer of the main component, the same prepolymer as in Examples 4 to 7 was used, and the mixing ratio of DETDA and the aromatic secondary amine (Unilink 4100) in the curing agent was 80/20 molar ratio. It is an example of the case of using the above-mentioned one and adding the polyol D-2000 to this as a plasticizer. The results show that, as shown in Table 4, the pot life and the curability are within the desired ranges, and the cured coating film also has physical properties suitable as a waterproof material. However, it was shown that the object of the present invention can be retained.

Example 9 The NCO content of the main polymer prepolymer was 2.4% by weight, which was lower than those of Examples 1 to 8 (NCO content 3.5% by weight), and was used in combination with DETDA in the curing agent. Link 410
In this example, the mixing ratio of 0 is 80/20 and the same ratio as in Examples 1 to 4 is used. As shown in Table 5, the pot life was 60 minutes (20 ° C) and 35 minutes (35
℃), tack free time 7 hours (20 ℃), 3-4
Although the curability is slightly slower than the time (35 ° C.) and that of Example 4, both are within the desired range and fast curability. Although the cured coating film became soft, it was shown to have suitable physical properties as a waterproof material.

[0037]

[Table 5]

Example 10 A prepolymer of the main agent having an NCO content of 7% by weight, which is higher than those of Examples 1 to 8 (NCO content 3.5% by weight), was used, and DETDA and Unilink in the curing agent were used. 4100
This is an example of the case where a mixture ratio of 65/35 molar ratio was used as in Example 6. As shown in Table 5, the pot life was 30 minutes (10 ° C.), 22 minutes (20 ° C.) or 15 minutes (35 ° C.), which was shorter than that of Example 4 or 6, but in any desired range. Accordingly, the tack free time was shortened and the curing time became faster than in Example 4 or 6, and the cured coating film became slightly hard, but it was shown that the physical properties are suitable as a waterproof material.

Examples 11 and 12 Using the same NCO content of 3.5% by weight as those of Examples 4 to 8 as the main agent, the amount of the aromatic polyamine cross-linking agent used in the curing agent was increased or decreased. NCO group / hardener NH ₂
And an NH group equivalent ratio of 0.9 or 1.8 and Example 6
It was increased or decreased compared to (NCO / NH ₂ + NH = 1.2). The mixing ratio of DETDA and Unilink 4100 in the curing agent was 65/35 and the same mixing ratio as in Example 6. As can be seen from Table 5, when the NCO group / NH ₂ and NH group equivalent ratio was 0.9 (Example 11), which was smaller than that in Example 6, the pot life was shortened to 32 minutes, while the tack free time was 3 Faster time and curability. When the NCO group / NH ₂ and NH group equivalent ratio is as large as 1.8 (Example 12), the pot life is extended to 65 minutes, while the tack free time is 8 hours and the curability is slightly slowed, but any desired Within the range of pot life and curability. The physical properties of the coating films all showed good performance that passed the JIS standards for waterproof materials.

Comparative Example 1 As a raw material TDI for the prepolymer of the main component, a 2,4-isomer / 2,6-isomer weight ratio of 80/20 (same as in Example 2) was used. DETDA and Aromatic 2
When the molar ratio of the secondary amine is 20/80 and the proportion of DETDA used is smaller and the proportion of the aromatic secondary amine used is larger than those of the examples (Examples 2, 4, 6 and 7). Was tested and the results are shown in Table 6.

[0041]

[Table 6]

As shown in Table 6, the pot life was extended to 70 minutes while the tack free time was delayed to 18 hours, and the curability was delayed to the extent that the next step such as coating the top coat could not be performed on the day of construction. . Further, it was shown that the cured coating film had weak mechanical strength and poor heat resistance, and generally did not satisfy the JIS standard for waterproof materials. That is, considering the results of Examples 1 to 7, in order to achieve the object of the present invention, DE which is an aromatic polyamine crosslinking agent in the curing agent is used.
There is a critical predetermined range for the mixing ratio of the aromatic secondary amine represented by TDA and Unilink 4100,
Comparative Example 1 shows that it is out of the limit.

Comparative Examples 2 and 3 The same prepolymer as in Examples 4 to 8, 11 and 12 was used as the main agent, Comparative Example 2 contained a large amount of plasticizer in the curing agent, and Comparative Example 3 contained in the curing agent. Each case was tested when the amount of the polyol used as a plasticizer was large. In each case, a curing agent having a mixing ratio of DETDA and aromatic secondary amine of 80/20 was used. Since Comparative Example 2 has a large amount of plasticizer, the weight mixing ratio of the main agent and the curing agent is 1 /
2.5 and Comparative Examples 2 and 3 are both NCO groups of the main agent /
The equivalent ratio of NH ₂ and NH groups of the curing agent was adjusted to 1.2. As shown in Table 6, as shown in Table 6, the plasticizer in Comparative Example 2 and the unreacted polyol in Comparative Example 3 bleed to the surface of the cured coating film, and thus neither of them can be used as the waterproof material intended by the present invention. Was shown.

Comparative Examples 4 and 5 In Comparative Examples 4 and 5, the NCO group of the main material / NH in the curing agent was used.
This is an example when the equivalence ratio of ₂ and NH groups is small and large. As shown in Table 6, when the equivalent ratio of NCO groups / NH ₂ and NH groups was reduced to 0.7 (Comparative Example 4), unreacted amine bleeds on the surface of the coating film, causing discoloration to be large and the equivalent ratio to 2 .4 (Comparative Example 5), the pot life becomes as long as 80 minutes and the curability slows down, and the coating film foams, making it impossible to obtain the waterproof material of the present invention in any case. That is, considering the results of Examples 4 to 7, 11 and 12, in order to achieve the object of the present invention,
The equivalence ratio of NCO groups in the base agent / NH ₂ and NH groups in the curing agent indicates that there is a critical predetermined range.

Comparative Examples 6 and 7 Comparative Examples 6 and 7 are the cases where the NCO content of the main agent is lower and higher than the examples, and the aromatic polyamine cross-linking agent DETDA and Unilink 4100 aromatic in the curing agent are used. The mixing ratio of the secondary amine is kept constant at a molar ratio of 80/20 to increase or decrease the amount of the secondary amine, and the NCO group of the main agent / NH _{2 of the} curing agent is added.
And the equivalent ratio of NH groups were adjusted to 1.2 in each case. As can be seen from Table 6, the result is N
When the CO content was reduced to 1.2% by weight (Comparative Example 6), the pot life was 75 minutes, which was sufficiently long, but the tack free time was 19 hours, which was slower than in Examples 4 and 9, and the curing The coating film has weak mechanical strength and poor heat resistance. When the NCO content of the main agent was as high as 9% by weight (Comparative Example 7), the tack-free time was 1 hour, which was fast curable, but the pot life was as short as 7 minutes, making hand coating difficult,
It was shown that the cured coating film was also stiff and brittle, lacked elasticity and was unsuitable as a waterproof material.

Comparative Example 8 Comparative Example 8 is an example using a conventional MOCA-polyol combination curing agent. 2,4-as the raw material TDI of the main agent
An isomer / 2,6-isomer weight ratio of 80/20 was used, and a curing agent and a catalyst of the MOCA-polyol combination system were used. As can be seen from Table 6, the pot life is sufficiently long, but the tack free time is as slow as 20 hours even at 20 ° C, which is 30 to 40 hours at a low temperature of 10 ° C. It was shown that the curing was slow enough so that it could not be transferred to coating.

[0047]

As can be seen from the above description, according to the present invention, a main component containing an isocyanate-terminated prepolymer as a main component, which is obtained by the reaction of TDI and a polyol,
A predetermined mixing ratio of aromatic polyamine of DETDA and aromatic secondary amine represented by Unilink 4100 and the like is used as a curing agent, and the equivalent ratio of the isocyanate group of the main agent and the amino group in the curing agent is within a predetermined range. By mixing at the construction site, hand-coating and curing, stable room-temperature construction can be performed throughout the year, it does not foam in a short time, does not leave surface tack, has good finish and heat resistance. It is possible to obtain a cured polyurethane coating film. Therefore, the method of the present invention can be effectively applied to waterproof membranes, floor coverings, etc. that are applied at room temperature.

Claims (6)

[Claims] 1. A two-part type room temperature curable waterproof coating film comprising a base material containing an isocyanate-terminated prepolymer as a main component obtained by a reaction of tolylene diisocyanate and a polyol, and a curing agent containing an aromatic polyamine as a main component. In the method for producing a material, a mixture of diethyltoluenediamine and an aromatic secondary amine represented by the general formula (1) is used as the aromatic polyamine which is the main component of the curing agent, and (However, R ₁ = C ₁ -C ₄ alkyl group) 30 to 90 mol% of the aromatic polyamine is diethyltoluenediamine, and 10 to 70 mol% of the general formula (1).
It is an aromatic secondary amine represented by the formula (1), and the equivalent ratio of the isocyanate group of the main agent to the amino group of the aromatic polyamine of the curing agent is 0.
A method for producing a room-temperature-curable waterproof film, comprising mixing, coating and curing so as to be 8 to 2.0. 2. The method for producing a room temperature curable waterproof film according to claim 1, wherein the polyol is polypropylene ether polyol having a molecular weight of 400 to 8000 or polyethylene-propylene ether polyol. 3. Tolylene diisocyanate having a 2,4-isomer content of tolylene diisocyanate of 80% by weight or more.
The method for producing a room temperature-curable waterproof coating film according to claim 1, which is 4. Tolylene diisocyanate having a 2,4-isomer content of tolylene diisocyanate of 85% by weight or more.
The method for producing a room temperature curable coating film waterproof material according to claim 3, wherein 5. NC of isocyanate terminated prepolymer
Claim 1 in which the O content is 1.5 to 8% by weight.
Item 7. A method for producing a room temperature-curable coating film waterproof material according to item. 6. The aromatic polyamine in the curing agent, 60 to 9
0 mol% is diethyltoluenediamine, 10-4
The method for producing a room temperature curable waterproof film according to claim 1, wherein 0 mol% is an aromatic secondary amine represented by (1).