JP2005161191A5 - - Google Patents

Description

Surprisingly, the inventors of the present invention have made extensive studies on the catalytic effect and the influence on environmental water, etc., regarding the metal compound that exhibits an effect as a curing catalyst as described above in connection with the waterproof two-component polyurethane coating film. The organic acid bismuth salt has an excellent effect as a catalyst, and the waterproof two-component polyurethane coating film obtained by using the organic acid bismuth salt has been found to have very little elution of bismuth into water, leading to the present invention. .
That is, the present invention
1. A two-component polyurethane coating film obtained by reacting a main agent containing a terminal isocyanate group-containing urethane prepolymer, an active hydrogen-containing compound, and a curing agent containing a curing catalyst by a spray method, wherein the catalyst is an organic acid A waterproof two-component polyurethane coating film characterized by being a bismuth salt and having very little bismuth eluted from the coating film into the water,
2. A two-component polyurethane coating film obtained by reacting a main agent containing a terminal isocyanate group-containing urethane prepolymer, an active hydrogen-containing compound, and a curing agent containing a curing catalyst by a spray method, wherein the catalyst is an organic acid Waterproof, characterized in that bismuth is a bismuth salt, and the amount of bismuth eluted into the water from the coating is below the limit of detection of bismuth in the Ministry of Health and Welfare Notification No. 45 dissolution test. Two-component polyurethane coating,
3. The waterproof two-component polyurethane coating film according to 1 or 2, wherein the amount of the organic acid bismuth salt is 0.002 to 0.1% by weight, based on the total amount of the main agent and the curing agent, as metal bismuth,
4). The waterproof polyurethane coating film according to any one of items 1 to 3, wherein the analysis of the amount of bismuth eluted from the coating film into water is inductively coupled plasma mass spectrometry, and the detection limit value is 0.001 mg / L.
5. A concrete irrigation structure comprising the waterproof two-component polyurethane coating film according to any one of items 1 to 4.

Surprisingly, the waterproof two-component polyurethane coating film of the present invention has a very small amount of bismuth of an organic acid bismuth salt used as a curing catalyst to elute from the coating film into water. The amount of lead eluted from the coating film used as a catalyst is remarkably small.
Therefore, the waterproof two-component polyurethane coating film of the present invention does not use a harmful metal compound as a catalyst, and even if bismuth is regarded as a category of heavy metal, elution from the coating film is extremely small.
That is, the waterproof polyurethane coating film of the present invention is extremely useful in terms of environmental hygiene and energy saving because the coating film of the present invention can be applied by a two-component spray method.
Further, when a fatty acid ester is used in the main agent and / or curing agent, it is not necessary to use a plasticizer that has been conventionally used as a suspected environmental hormone.
As described above, the present invention is extremely useful industrially as a substitute for a conventionally used waterproof two-component polyurethane coating film from the viewpoint of environmental hygiene and workability.

The above main agent and curing agent, plasticizers suitable plastic which has been used in the production of conventional polyurethane resins, for example, phthalic acid dibutyl ester (DBP), phthalate -n- octyl ester (DnOP), phthalic Acid di (2-ethylhexyl) ester (DOP), adipic acid di (2-ethylhexyl) ester (DOA) and the like can be used .
In the waterproof two-component polyurethane coating film of the present invention, the fatty acid ester used for the main agent and / or curing agent is, for example, stearic acid methyl ester, palmitic acid methyl ester, lauric acid methyl ester, olein. Fatty acid esters derived from synthesis such as acid methyl esters, or esterified products of naturally derived fatty acids such as beef tallow fatty acid methyl ester, nuka fatty acid methyl ester, plant fatty acid methyl ester, palmitic acid butyl ester and plant fatty acid butyl ester (hereinafter, Simply referred to as a naturally occurring fatty acid ester).
Preferred are naturally occurring fatty acid esters, and more preferred are Nuka fatty acid esters.

These fatty acid esters may be used for either the main agent or the curing agent, or both.
When used in the waterproof two- component polyurethane coating film of the present invention, the amount of these fatty acid esters used is 1 to 25% by weight based on the total amount of the main agent and the curing agent.
If it is less than 1% by weight, the viscosity is too high, which is not preferable for the spray method. On the other hand, if it exceeds 25% by weight, it adversely affects the properties of the cured product.
The fatty acid esters are preferably added separately for the main agent and the curing agent so that the viscosities of the main agent and the curing agent are approximately similar.
When the fatty acid ester is added to the main agent, the amount of the fatty acid ester used is 1 to 50% by weight based on the total amount of the main agent, and does not exceed 25% by weight based on the total amount of the main agent and the curing agent. A small amount is preferred.
When added to both the main agent and the curing agent, when added to both, the main agent is 1 to 50% by weight with respect to the total amount of the main agent, the curing agent is 1 to 20% by weight with respect to the total amount of the curing agent, and the main agent and the curing agent. It is 1 to 25 weight% with respect to the total amount with an agent.
Moreover, when adding fatty acid ester to a hardening | curing agent, it is 1 to 20 weight% with respect to the whole quantity of a hardening | curing agent, and is 1 to 25 weight% with respect to the total amount of a main ingredient and a hardening | curing agent.

The curing agent used in the present invention contains an active hydrogen-containing compound and an organic acid bismuth salt .
The active hydrogen-containing compound is usually a polyol having two or more hydroxyl groups in one molecule or a polyamine having two or more amino groups in one molecule, and the polyol and polyamine may be used in combination.
Examples of the polyol include polyhydric alcohols having a relatively low molecular weight, polyether polyols, polyester polyols, polyether polyols, and modified polyester polyols.

As the catalyst contained in the curing agent used in the present invention, an organic acid bismuth salt is used. Examples thereof include fatty acid bismuth salts having 8 to 20 carbon atoms and other organic acid bismuth salts .
Examples of the fatty acid bismuth salt having 8 to 20 carbon atoms include bismuth salts such as octylic acid, neodecanoic acid, and neododecanoic acid, and other organic acid bismuth salts include abietic acid, neoabietic acid, d-pimaric acid, Bismuth salts of alicyclic organic acids such as iso-d-pimalic acid, podocarpic acid and bismuth resin acid mainly composed of two or more of these, fragrances such as benzoic acid, cinnamic acid, p-oxycinnamic acid And bismuth salts of group organic acids.
The amount of the organic acid bismuth salt used is 0.002 to 0.1% by weight, preferably 0.002 to 0.05% by weight, as metal bismuth, based on the total amount of the main agent and the curing agent. The organic acid bismuth salt is contained in the curing agent. In a hardening | curing agent, it can adjust and contain so that it may become the said usage-amount with respect to the total amount by the quantity ratio of the main ingredient made to react and a hardening | curing agent. In the coating film of the present invention, since the main agent and the curing agent can be reacted in an amount ratio of 1: 4 to 4: 1 , for example, in the curing agent when the main agent and the curing agent are reacted at 1: 4. , Bismuth metal, 0025 to 0.125 % by weight, and in the curing agent at 1: 1, 0.004 to 0.2% by weight as metal bismuth, and further 4: 1 What is necessary is just to adjust so that 0.01-0.5 weight% may be contained in the hardening agent at the time as metal bismuth.

The organic acid bismuth salt used in the present invention may further contain an organic acid exhibiting an effect such as a promoter. Examples of the organic acid include aromatic carboxylic acids such as benzoic acid, phthalic acid, and o-chlorobenzoic acid, and aliphatic carboxylic acids such as 2-ethylhexanoic acid, octylic acid, stearic acid, oleic acid, and linoleic acid. . Preferably, 2-ethylhexanoic acid is excellent in compatibility with the polyol and easy to use and is frequently used.
When the organic acid is used in combination with the organic acid bismuth salt, the amount of the organic acid added is 0.01 to 5% by weight, preferably 0.01 to 1% by weight, based on the total amount of the curing agent.

The waterproof two-component polyurethane coating film of the present invention is obtained by spraying the above-mentioned main agent and curing agent on a construction object by a high-pressure two-component spraying device, and reacting and curing.
The amount of the main agent and the curing agent used here is a volume ratio of 4: 1 to 1: 4 , and NCO Index (equivalent ratio of NCO groups in the terminal isocyanato group-containing urethane prepolymer and active hydrogen in the curing agent) ) Is in the range of 0.9 to 1.3, preferably 1 to 1.2.
When a fatty acid ester is used as necessary in the present invention, the viscosity of the main agent containing the terminal isocyanate group-containing urethane prepolymer, and the viscosity of the curing agent containing the active hydrogen-containing compound and the catalyst containing the organic acid metal salt are conventional. Since it is lower than when using the plasticizer that has been used, the heating temperature of the main agent and the curing agent to be sent to the spray gun can be set to a lower and appropriate reaction temperature in the high-pressure two-component spraying device, The heating time for reaching the predetermined temperature can be shortened. As a result, the amount of spraying work per day can be increased.

The bismuth eluting from the coating film of the present invention into water is determined as follows.
1. Leaching operation Specimens (for example, a main agent and a curing agent are prepared by the method shown in the Examples, and these two liquids are sprayed onto a polypropylene plate using a spray to create a coating film. Peel off and cut to 5 x 5 cm to make a specimen.) Wash with running water for 1 hour with tap water (tap water supplied from a public water supply facility that complies with water quality standards for tap water), and then with purified water. Wash once. Next, it is immersed in a leaching solution (pH 7.0 ± 0.1, hardness 45 ± 5 mg / L, alkalinity 35 ± 5 mg / L, residual chlorine 1.0 ± 0.2 mg / L) at about 23 ° C. The conditioning operation is performed by repeating the operation of replacing the immersed liquid after standing for 24 hours twice. After conditioning, the specimen is immersed in the leaching solution and allowed to stand at about 23 ° C. for 72 hours, and the resulting solution is used as the leaching solution.
Also, leave the leaching solution under the same conditions to make a blank test solution.

2. Measuring method The amount of bismuth in the leachate is measured by inductively coupled plasma mass spectrometry with a detection lower limit of 0.001 mg / L.
Waterproof two-Polyurethane coating of the present invention, the amount of elution of bismuth measured in this way is less than 0.001 mg / L which is the detection limit.
On the other hand, in a known waterproof two-component polyurethane coating film obtained using organic acid lead as a curing catalyst, lead eluted in water measured by the same method exceeds the detection limit value.
Waterproof 2-part polyurethane coatings of the present invention the organic bismuth is obtained as the curing catalyst as described above, the elution amount of bismuth in water is less Te order pole.

Hereinafter, in order to explain the present invention concretely, examples and comparative examples will be described.
Example 1
a) Method for producing coating film As main agents, Cosmonate PH (Pure MDI: manufactured by Mitsui Takeda Chemical Co., Ltd.) 41.731 parts by weight, Cosmonate LK (carbodiimide-modified MDI; manufactured by Mitsui Takeda Chemical Co., Ltd.) 10.432 parts by weight, and Actol D-2000 (polypropylene ether diol having a number average molecular weight of 2000: manufactured by Mitsui Takeda Chemical Co., Ltd.), 42.836 parts by weight, and presence of fine ester R-1000 (Nuka fatty acid ester: manufactured by Miyoshi Oil & Fats Co., Ltd.), 5.000 parts by weight The mixture was reacted for 3 hours at 90 ° C. to obtain a prepolymer having an NCO% of 15.0 and a viscosity of 450 mPa · s / 25 ° C.
On the other hand, as a curing agent, Actcol D-1000 (polypropylene ether diol having a number average molecular weight of 1000: manufactured by Mitsui Takeda Chemical Co., Ltd.) 84.651 parts by weight, Ethacure # 100 (diethyltoluenediamine: manufactured by Albemarle Asano) 14.299 parts by weight , Pcat B-7 (resin acid bismuth: bismuth metal content 7%: manufactured by Nippon Chemical Industry Co., Ltd.) 0.500 parts by weight, 2-ethylhexanoic acid 0.050 parts by weight, tinuvin B-75 (three kinds of mixed liquid stabilizers) : Manufactured by Ciba Geigy Co., Ltd.) 0.500 parts by weight was mixed to prepare a mixed solution having a viscosity of 300 mPa · s / 25 ° C.
The main agent (A) and the curing agent (B) were sprayed using an H-20 spray machine manufactured by Gasmer, Inc. at A / B = 1/1 (volume ratio) and NCO Index 1.1. Liquid feeding to the spray machine was performed by applying a 0.5 MPa air pressure to a Graco supply pump (air driven 2: 1 type). The spray machine was used at a stationary pressure of 14 MPa and a spraying pressure of 10 to 12 MPa.
The temperature of the liquid was adjusted to a main agent primary heater 60 ° C., a curing agent primary heater 60 ° C., and a hose heater 60 ° C.
The spray gun was sprayed using a round chamber # 1 of a glass gun probler gun.
As the mold, a polypropylene plate having a thickness of about 1.5 mm was used, and lamination was performed 3 to 5 times to form a coating film having a thickness of about 2 mm.
b) Extraction of bismuth from coating film Leaching operation The coating film was peeled off from the polypropylene plate and cut to 5 × 5 cm to prepare a specimen. This was washed with running water (Tama City, Tokyo) for 1 hour and then washed with purified water three times. Next, it is immersed in a leaching solution (pH 7.0 ± 0.1, hardness 45 ± 5 mg / l, alkalinity 35 ± 5 mg / l, residual chlorine 1.0 ± 0.2 mg / l) at about 23 ° C. The conditioning operation was repeated twice by replacing the immersed liquid after standing for 24 hours. After conditioning, the specimen was immersed in the leaching solution and allowed to stand at about 23 ° C. for 72 hours, and the resulting solution was used as the leaching solution.
The leaching solution was allowed to stand under the same conditions as a blank test solution.
2. Measurement method The amount of bismuth in the leachate was measured by inductively coupled plasma mass spectrometry with a detection lower limit of 0.001 mg / L.
The amount of bismuth eluted in the leachate was 0.001 mg / L or less, which is the detection limit.
The results are shown in Table 1.
Examples 2-5
A coating film was formed in the same manner as in Example 1, except that the materials used and the amounts used were changed as shown in Table 1. The amount of bismuth eluted by the same method was measured. The amount of bismuth eluted in the leachate was 0.001 mg / L or less, which is the detection limit. The results are shown in Table 1.
Comparative Examples 1-2
In the same manner as in Example 1, a lead catalyst was used, and the coating material was formed by changing the materials to be used and the amounts used thereof as shown in Table 1. The amount of lead eluted by the same method was measured. The amount of lead eluted in the leachate was as shown in Table 1.

Claims (1)

A two-component polyurethane coating film obtained by reacting a main agent containing a terminal isocyanate group-containing urethane prepolymer, an active hydrogen-containing compound, and a curing agent containing a curing catalyst by a spray method, wherein the catalyst is an organic acid a bismuth salt, bismuth eluted from the coating film in water is below the detection limit of bismuth with WARNING 示第 45 No. dissolution test ministry of Health and Welfare, bismuth eluted from the coating film in water is equal to or very few Waterproof two-component polyurethane coating.