JP2000007989A - Cold curable composition for forming waterproof coating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyurethane-based, cold curing, two-pack type composition which can be stably applied through the year without causing foaming or blistering even under high temperature and high humidity conditions in summer, and can give a waterproof coating film excellent in appearance and mechanical properties. SOLUTION: The objective composition comprises (A) a first liquid comprising an isocyanate group-terminated urethane prepolymer and (B) a second liquid containing aromatic polyamines comprising 75-95 mole % of 4,4'-methylenebis(2- chloroaniline) and 25-5 mole % of diethyltoluene diamine, a polyol and an organometal catalyst, the equivalent ratio of amino groups in the aromatic polyamines in the second liquid to hydroxyl groups in the polyol ranging from 1:1 to 9:1 and the equivalent ratio of isocyanate groups in the first liquid to the total of amino groups and hydroxyl groups in the second liquid ranging from 4:5 to 2:1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a room-temperature-curable two-pack type composition to be mixed and used on site during the work of applying a waterproof coating film. More specifically, the present invention relates to a room-temperature-curable two-part composition that gives a polyurethane-based waterproof coating film having a good finish and excellent coating characteristics without causing blistering due to foaming.

[0002]

2. Description of the Related Art Heretofore, polyurethane coating waterproofing materials and coated flooring materials have been used in large quantities for applications such as waterproofing of rooftops, verandas and corridors of buildings, and elastic pavement of sports facilities. As a construction material for the polyurethane coating waterproofing material and the coated flooring material, an isocyanate group-terminated prepolymer obtained by a reaction between a polyol such as polypropylene ether polyol and an aromatic diisocyanate such as tolylene diisocyanate has been used as a prepolymer component. A two-pack, room-temperature-curable urethane material for on-site construction using polyol and 4,4'-methylenebis (2-chloroaniline) (hereinafter abbreviated as MOCA) as a curing agent component of isocyanate is dominant.

[0003] In this two-pack type room-temperature-curable urethane material, MOCA used as a main component of the curing agent is solid at room temperature, has high crystallinity, has poor dissolution stability in a solvent such as a plasticizer, and is difficult to handle. Despite this, the reaction with the isocyanate is relatively slow, and the pot life required for on-site construction (after mixing the prepolymer component and the hardener component, the This is the time required for the viscosity to reach 60,000 centipoise after mixing, and it is easy to secure the cured coating film in accordance with the JIS standard (JIS A-6021) for polyurethane coating waterproofing material. Meets physical property standards. However, this is foaming due to moisture under hot and humid conditions in summer,
It has the disadvantage of causing a blistering phenomenon and significantly impairing the finished feeling of the coating film surface.

[0004] In order to improve such disadvantages, MOC
A, mixed with a modified MOCA obtained by reacting a mixture of o-chloroaniline and aniline with formalin has been used.
The use of a polymer has the disadvantage of deteriorating the mechanical properties of the formed urethane waterproof coating film. As described above, the conventional polyurethane-based room-temperature-curable two-part composition for forming a waterproof coating has some disadvantages, can be stably applied throughout the year, has a good appearance, and has excellent appearance. Nothing capable of providing a coating film having mechanical properties was known.

[0005]

Under such circumstances, the present invention can be used stably throughout the year without foaming or swelling even under high temperature and high humidity conditions in summer. An object of the present invention is to provide a polyurethane-based room temperature-curable two-part composition capable of providing a waterproof coating film having excellent appearance and mechanical properties.

[0006]

SUMMARY OF THE INVENTION The present inventor has conducted various studies on a room temperature-curable two-pack type composition to be mixed and used on site when performing a work of applying a waterproof coating film. As a result, in addition to the components of the second liquid, MOCA, the polyol and the organometallic catalyst, diethyltoluenediamine is further contained, and this is combined with the first liquid containing the isocyanate group-terminated urethane prepolymer, so that it can be exposed to high temperature and high humidity. Polyurethane cold-curable two-part composition that does not generate foaming or swelling, has a good finish feeling, and gives a coating film with excellent mechanical properties such as tensile strength, tear strength and elongation. The present invention was made based on this finding.

That is, the present invention provides (A) a first liquid containing an isocyanate group-terminated urethane prepolymer and (B) 4,4'-methylenebis (2-chloroaniline)
75-95 mol% and diethyltoluenediamine 25-5
A second liquid containing an aromatic polyamine consisting of mol%, a polyol and an organometallic catalyst, wherein the equivalent ratio of the amino group of the aromatic polyamine to the hydroxyl group of the polyol in the second liquid is 1: 1 to 9: 1. Wherein the equivalent ratio of the isocyanate groups in the first liquid to the total of amino groups and hydroxyl groups in the second liquid is in the range of 4: 5 to 2: 1. A composition for forming a coating film is provided.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the composition of the present invention, the prepolymer component of the first liquid (A) is mainly composed of an isocyanate group-terminated prepolymer obtained by reacting tolylene diisocyanate with a polyol. . There is no limitation on the type of tolylene diisocyanate, which is one raw material of the prepolymer, and various isomers may be used alone or in a mixture, but those mainly containing 2,4-isomer are particularly preferable. Those containing mainly the 2,4-isomer include, for example, those having a commercially available 2,4-isomer content of 65%.
１００100% by weight, but the prepolymers obtained using tolylene diisocyanate having a low 2,4-isomer content tend to have a shorter pot life and thus have a longer pot life. It is preferable that the content of the 2,4-isomer be 80% by weight or more.

The polyol to be reacted with the tolylene diisocyanate can be arbitrarily selected from polyether polyols, polyester polyols, polycaprolactone polyols and the like used for ordinary urethane prepolymers. However, a polyalkylene ether polyol having a molecular weight of 400 to 8000, which is a liquid at room temperature and has a low viscosity, is preferable, and in particular, a polypropylene ether polyol, a polyethylene-propylene ether polyol and a mixture thereof have an average hydroxyl group of 2 to 2.
Three are preferred.

The isocyanate group-terminated prepolymer obtained from the above-mentioned tolylene diisocyanate and polyol preferably has an isocyanate group content in the range of 1.5 to 7% by weight. When the content is less than 1.5% by weight, the mechanical strength of the obtained coating film is insufficient, and when it exceeds 7% by weight, the pot life becomes short, the work becomes difficult, and the coating film becomes hard. It becomes too hard to elongate. In the composition of the present invention, the isocyanate group-terminated prepolymer of the first liquid (A) may be used alone or in combination of two or more.

Next, the components constituting the second liquid (B) of the composition of the present invention are an aromatic polyamine, a polyol, and an organometallic catalyst.
A 75-95 mol% and diethyltoluenediamine 25-
It is necessary to use a mixed aromatic amine consisting of 5 mol%. If the amount of diethyltoluenediamine in this aromatic polyamine is more than 25 mol%, the reaction is too fast to obtain a desired pot life, and if it is less than 5 mol%, swelling due to foaming occurs at high temperature and high humidity in summer. Occurs
The feeling of finish deteriorates.

The polyol used in combination with the aromatic polyamine must be used in an equivalent ratio of the amino group of the aromatic polyamine to the hydroxyl group of the polyol in the range of 1: 1 to 9: 1. If the number of hydroxyl groups is less than this, the reaction will be faster and the desired pot life will not be obtained. If it is larger than this, the reaction will be too slow and the desired pot life will not be obtained, and the tack after gelation will not be satisfactory. It becomes sufficient, and the mechanical properties such as hardness and tensile strength of the obtained coating film decrease.

In the composition of the present invention, the diethyltoluenediamine used as the aromatic polyamine of the second liquid (B) includes 3,5-diethyltoluene-2,4-diamine and 3,5-diethyltoluene-2,3-diethyltoluene. Mention may be made of 6-diamines and mixtures thereof. This mixture is commercially available, for example, as ETACURE 100 (manufactured by Ethyl Corporation).

In the composition of the present invention, the polyol of the second liquid (B) is a polypropylene ether polyol or a polyethylene-propylene ether polyol having a molecular weight of 400 to 8000, and preferably has an average number of hydroxyl groups of 2 to 3. The organometallic catalyst used in the second liquid (B) of the composition of the present invention includes generally known organotin compounds and organolead compounds, and among them, lead octylate is preferred.

As described above, in the polyurethane cold-setting waterproofing material, the second liquid (B) comprising MOCA, polyol and organometallic catalyst is obtained by mixing diethyl toluenediamine as an aromatic polyamine component. Consisting of conventional MOCA, polyol and catalyst system, and modified MOC as aromatic polyamine
Compared with the case where A is mixed and used, the influence of the components in the second liquid (B) or moisture brought from the construction environment is reduced, foaming and swelling are less likely to occur, and a good finished feeling of the cured coating film is obtained. And a coating film having excellent mechanical properties can be formed.

In the composition of the present invention, when the first liquid (A) and the second liquid (B) are mixed at the time of use, the first liquid (A)
The isocyanate group of the isocyanate group-terminated urethane prepolymer in the above, the MOCA and diethyltoluenediamine in the second liquid (B) react with the polyol to extend the chain. However, in the absence of a catalyst, the reaction between the isocyanate group and MOCA and diethyltoluenediamine proceeds, but the reaction between the isocyanate group and the polyol hardly proceeds, and the polyol only acts as a plasticizer. . In contrast, when an organometallic catalyst such as an organic lead carboxylate is present, the reaction of the isocyanate group with MOCA, diethyltoluenediamine and polyol proceeds competitively, and random chain extension is performed by all these molecules, and the physical properties are increased. A well balanced polyurethane coating is formed. Therefore,
In the composition of the present invention, it is necessary to use an organometallic catalyst.

The composition of the present invention can contain a plasticizer if desired. As the plasticizer, for example, a general plasticizer such as dioctyl phthalate, dioctyl adipate, tricresyl phosphate, or chlorinated paraffin can be used. Further, the second liquid (B) may contain calcium carbonate, talc, kaolin, zeolite,
Inorganic fillers such as diatomaceous earth, pigments such as chromium oxide, titanium oxide, red iron oxide, carbon black, iron oxide,
A hindered amine-based, hindered phenol-based, benzothiazole-based stabilizer, or an antifoaming agent, an anti-separation agent, a dispersant, an anti-settling agent, a thickener, and the like can be added.

The composition of the present invention comprises a prepolymer component having an isocyanate group-terminated urethane prepolymer of the first liquid (A) as a main component, an aromatic polyamine of a second liquid (B) component as a main component, a polyol, At the construction site, the equivalent ratio of the isocyanate group in the prepolymer component and the active group (NH ₂ + OH) in the curing material component is combined with the organometallic catalyst and the curing material component containing the above-mentioned additive as required. 4:
By mixing and applying the mixture at a ratio of 5 to 2: 1 and applying the mixture on the object to be cured, a polyurethane coating waterproofing material can be formed. If the equivalent ratio of the isocyanate group to the active group (OH + NH ₂ ) is smaller than this, unreacted amine or polyol bleeds to the surface of the coating film to cause discoloration, and if it is larger than this, the curing speed is too slow. In addition, the mechanical strength of the resulting coating film also decreases.

[0019]

According to the composition of the present invention, as compared with the conventional curing material components, there are no phenomena such as foaming and swelling under high temperature and high humidity, and a good finish is obtained, and the mechanical properties of the cured coating film are improved. Excellent things can be obtained. Since the composition of the present invention has such excellent performance, it is suitably used for applications such as polyurethane coating waterproofing materials and coated flooring materials. When the composition of the present invention is applied, mixing and coating are mainly performed manually.However, since the working time and the leveling time can be increased, an automatic mixing device such as a sticky mixer or a dynamic mixer is used. The machine construction used is also possible.

[0020]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

The following were used as the prepolymer component and the curing material component. (1) First liquid (A) component P-2000: polypropylene ether diol [manufactured by Daiichi Kogyo Seiyaku Co., Ltd.], average molecular weight 2000, OH value 5
6.0 mgKOH / g T-5000: polypropylene ether triol
[Daiichi Kogyo Seiyaku Co., Ltd.], molecular weight 5000, OH value 33.3.
7 mgKOH / g TDI-80: Tolylene diisocyanate [manufactured by Nippon Polyurethane Industry Co., Ltd.], NCO content 48.3% by weight, 2,4-TDI / 2,6-TDI = 8/2 weight ratio TDI-100: Tolylene diisocyanate [manufactured by Nippon Polyurethane Industry Co., Ltd.], NCO content 48.3% by weight, 2,4-TDI 100% by weight 1,4-BD: 1,4-butanediol [manufactured by Nacalai Tesque, Inc.]

(2) Second liquid (B) component DETDA: diethyltoluenediamine (Ethacure 100, manufactured by Ethyl Corporation), amine value 6
29 mg KOH / g P-2000: The same as that used for the first liquid (A) component T-5000: The same as that used for the first liquid (A) component Pb-20: Catalyst: Lead Solution adjusted to 20% content [manufactured by Nippon Chemical Industry Co., Ltd.], solvent: mineral terpene, solvent concentration 47% by weight ML-520: modified MOCA solution [manufactured by Ihara Chemical Industry Co., Ltd.], modified MOCA / P- 2000 = 50/50
Weight ratio, amine value 210 mgKOH / g MOCA: 4,4'-methylene-bis (2-chloroaniline) [Cureamine-MT, manufactured by Ihara Chemical Industry Co., Ltd.], amine value 420.2 mgKOH / g DOP: dioctyl phthalate [ Plasticizer, manufactured by Dainippon Ink and Chemicals, Inc.] NS-100: Calcium carbonate [filler, manufactured by Nitto Powder Chemical Co., Ltd.] P-420: Antifoaming agent [manufactured by Kusumoto Chemicals]

Examples 1 to 7 and Comparative Examples 1 to 3 (1) Preparation of First Liquid (A) Tolylene diisocyanate (TDI) was charged into a 2-liter four-neck separable flask according to the composition shown in Table 1. Then the polyol was charged. Thereafter, the mixture was gradually heated to 80 ° C. while stirring under a nitrogen stream, reacted at that temperature for 7 hours, and then cooled to room temperature to prepare a prepolymer component. Isocyanate group content is JI
It was measured according to SK 1558. In addition, the charging amount was set to a 10-fold scale when the parts by weight in Table 1 were replaced with g.

(2) Preparation of Second Liquid (B) First, in a 1-liter polypropylene beaker, add DETD to a mixed liquid of DOP and MOCA according to the formulation shown in Table 1.
A or ML-520, T-5000, P-2000, P
A predetermined amount of b-20 and P-420 were added and stirred. Next, a predetermined amount of NS-100 was added, and the mixture was preliminarily mixed with a spatula, and then kneaded with three rolls to prepare a hardening material component. Note that the mixed solution of DOP and MOCA was heated and dissolved. In addition, the charged amount was set to be 1.5 times the scale in which the parts by weight in Table 1 were replaced with g.

(3) Evaluation A prepolymer component and a hardening material component of the type shown in Table 1 were charged into a 500 ml polypropylene beaker in the proportions shown in Table 1, and then mixed for 2 minutes with a dissolver stirrer. In addition to determining the pot life, a polyurethane sheet for measuring mechanical properties was prepared, and the mechanical properties were measured. The polyurethane sheet has a thickness of 1.5 to 1.5 on a flat aluminum plate coated with Teflon.
After coating with a spatula to 2.0mm, 20 ℃
And cured for 7 days. Table 1 shows the results
Shown in

The evaluations in Table 1 were made as follows. (1) Pot life; first liquid (A) and second liquid (B) at 20 ° C
And the time (minutes) required for the viscosity to reach 60,000 centipoise. (2) Swelling: A first layer of urethane was coated on a Teflon-coated flat aluminum plate so as to have a thickness of 1.2 mm and an area of 20 cm × 20 cm, and was cured at 20 ° C. and 60% humidity for 18 hours. , And further, the same kind of urethane is coated thereon with the same thickness and the same area,
The composition was cured for 2 hours under 50% humidity, and the presence or absence of blisters was visually checked. (3) Physical properties: After applying the composition, that is, a mixture of the first liquid (A) and the second liquid (B), cured at 20 ° C. for 7 days, and then measured according to JIS A6021.

[0027]

[Table 1]

As a result, Comparative Examples 1 to 3 show a conventional example using an aromatic amine obtained by adding a modified MOCA to MOCA in a hardening material component.
This indicates that blistering cannot be prevented unless the amount of CA reaches 50 mol%. However, the physical properties in this case are considerably reduced. Therefore, in order to prevent swelling by this method, physical properties are sacrificed.

According to Examples 1 to 3, it is found that the system obtained by adding DETDA to MOCA as the aromatic amine of the first liquid shows excellent workability, finishability, and physical properties. However,
Example 4 shows that excessive addition of DETDA shortens the pot life and deteriorates the workability.

When Example 1 and Comparative Example 3 are compared, M
If you add DETDA to OCA, MOCA
This indicates that the amount of amine added was smaller than that in the case where L-520 was added, blistering could be prevented, and physical properties were excellent.

According to Examples 5 and 6, the mixing ratio between the prepolymer component and the curing material component is 1: 1 as in Examples 1 to 3.
Not only that, it can be applied to a 1: 2 system.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J034 BA06 BA07 BA08 CA15 CC12 CC61 CC65 CC67 CD13 DA01 DB03 DB07 DF01 DF11 DG03 DG04 DG09 HA01 HA07 HC12 HC61 HC71 JA42 KA01 KB04 KC18 KD02 KE02 QA02 QA05 QB13 RA07 RA10 4J031 DG281 KA04 MA14 NA01 NA07 NA11 NA23 PA18

Claims (4)

[Claims] 1. A first liquid containing (A) an isocyanate group-terminated urethane prepolymer, and (B) 75 to 95 mol% of 4,4'-methylenebis (2-chloroaniline) and 25 to 5 mol% of diethyltoluenediamine. And a second liquid containing an aromatic polyamine, a polyol and an organometallic catalyst, wherein the equivalent ratio of the amino group of the aromatic polyamine to the hydroxyl group of the polyol in the second liquid is 1: 1 to 9: 1.
Wherein the equivalent ratio of the isocyanate groups in the first liquid to the total of amino groups and hydroxyl groups in the second liquid is in the range of 4: 5 to 2: 1. A composition for forming a coating film. 2. The isocyanate group-terminated urethane prepolymer of the first liquid is obtained by reacting a polyol with an excess amount of tolylene diisocyanate.
The composition for forming a cold-curable waterproof coating film according to the above. 3. Polypropylene ether polyol or polyethylene having a molecular weight of 400 to 8000.
The composition for forming a cold-setting waterproof coating film according to claim 2, which is a propylene ether polyol. 4. The composition for forming a room-temperature-curable waterproof coating film according to claim 2, wherein the isocyanate group-terminated urethane prepolymer has an isocyanate group content of 1.5 to 7% by weight.