JP2001181567A - Polyurethane curable composition, method for manufacturing polyurethane elastomer and spraying waterproofing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyurethane curable composition used for spray coating hardly influenced by water in a substrate, homogeneously curable and excellent in chemical resistance. SOLUTION: The polyurethane curable composition used for spray coating comprises at least two components: a main agent component containing an isocyanate group-containing compound and a curing agent component containing a castor oil-based polyol.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyurethane curable composition, a method for producing a polyurethane elastomer, and a spray waterproofing method.

[0002]

2. Description of the Related Art There is known a waterproofing method by spray coating, which comprises spraying a two-component polyurethane curable composition onto a base such as a concrete frame or a steel plate using a high-pressure two-component collision-mixing spray device. Have been.

[0003] Construction bases of the spray waterproofing method include concrete roofs, metal roofs, open corridors, stairs, stadium stands, factory floors, parking lots, floors and walls of underground buildings and sewage treatment plants, and pools. There is a concrete base and a metal base such as the inner surface.

A two-component polyurethane curable composition as a raw material contains a main component containing an isocyanate group-terminated polyurethane prepolymer obtained by reacting a low molecular weight polyisocyanate compound with a polyoxyalkylene polyol, and a polyol and a diamine. It often consists of a combination with a hardener component. Examples of using a curing agent component include diethyltoluenediamine and a polyoxyalkylene polyol with diethyltoluenediamine are known.

[0005]

However, in the known composition, when applied to an underground concrete having a large amount of moisture, the hardener component tends to absorb moisture, and as a result, the The isocyanate group-containing compound reacts with moisture before the polyol, the reaction ratio is not balanced, and a uniform coating film cannot be obtained, and further, the reaction with moisture generates carbon dioxide gas, resulting in pinholes and swelling. was there. When a polyoxyalkylene polyol was used, the water resistance, acid resistance, and alkali resistance were slightly insufficient when the cured coating film was exposed to water for a long period of time. Accordingly, there has been a strong demand for a polyurethane curable composition which is hardly affected by the moisture content of the base and which cures homogeneously and which has excellent chemical resistance and is used for spray coating.

[0006]

The present invention is the following invention which has been made to solve the above-mentioned problems. A polyurethane curable composition for use in spray painting, comprising at least two components, a main component containing an isocyanate group-containing compound and a curing component containing a castor oil-based polyol. A method for producing a polyurethane elastomer, comprising spray-coating the curable polyurethane composition with a high-pressure two-component collision-mixing spraying apparatus. A polyurethane-based waterproofing material comprising at least two components, a main component containing an isocyanate group-containing compound and a hardener containing a castor oil-based polyol, is spray-painted on a base using a high-pressure two-component collision-mixing spraying device. Spray waterproof construction method.

[0007]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, as the isocyanate group-containing compound, a low molecular weight polyisocyanate compound having two or more isocyanate groups, and an isocyanate group-terminated prepolymer obtained by reacting the low molecular weight polyisocyanate compound with a polyol , And the like.

Examples of the low molecular weight polyisocyanate compound include aliphatic polyisocyanates such as hexamethylene diisocyanate, alicyclic polyisocyanates such as isophorone diisocyanate, tolylene diisocyanate, and the like.
4,4'-diphenylmethane diisocyanate (MD
I) aromatic polyisocyanates such as polyphenyl polymethylene polyisocyanate (crude MDI);
And carbodiimide modified products and isocyanurate modified products thereof alone or in combination of two or more. MD such as MDI, crude MDI and carbodiimide-modified MDI
I-based polyisocyanate compounds are preferred.

Further, as the isocyanate group-containing compound, an isocyanate group-terminated prepolymer obtained by reacting the above low molecular weight polyisocyanate compound with a polyol can also be used. It is preferable to use an isocyanate group-terminated prepolymer for accelerating curing and improving viscosity by improving compatibility with the curing agent component. Further, a mixture of a low molecular weight polyisocyanate compound and an isocyanate group-terminated prepolymer may be used.

The polyol used for producing the isocyanate group-terminated prepolymer includes polyoxyalkylene polyol, polybutadiene polyol, hydrogenated polybutadiene polyol, castor oil polyol,
One or two or more polyols selected from the above are preferred. Castor oil-based polyols or mixtures of castor oil-based polyols with other polyols are preferred. Castor oil-based polyols alone or mixtures of castor oil-based polyols and polyoxyalkylene polyols are particularly preferred. In the case of a mixture, the ratio of the castor oil-based polyol in the mixed polyol is preferably 70% by mass or more.

In the present invention, castor oil-based polyol refers to castor oil or a modified polyol obtained by further introducing a hydroxyl group into castor oil. The number of functional groups is 2 or more, and 3 is preferable. Further, the hydroxyl value is preferably from 60 to 400,
60 to 200 are particularly preferred. If the number of functional groups is less than 2 or the hydroxyl value is less than 60, the resulting cured product tends to have insufficient mechanical strength. When the hydroxyl value exceeds 400, the elasticity and elongation of the cured product are poor.

Further, as the polyoxyalkylene polyol, those having 2 to 4 functional groups and a hydroxyl value of 30 to 200 can be used. Examples include polyoxypropylene diol and polyoxypropylene triol.

The isocyanate group-terminated prepolymer is prepared by mixing a low molecular weight polyisocyanate compound and a polyol in an amount of 70 to 9 with an isocyanate group excess over a stoichiometric ratio.
It is obtained by reacting at 0 ° C. An unreacted low molecular weight polyisocyanate compound may be contained.

In the present invention, the curing agent component contains a castor oil-based polyol. As the castor oil-based polyol, those described above can be used. Those having 3 functional groups are particularly preferred, and those having a hydroxyl value of 100 to 250 are particularly preferred. Specifically, U-click H-30 manufactured by Ito Oil Co., Ltd.
(Hydroxyl value 160, number of functional groups 3), Youclick H-5
7 (hydroxyl value 100, number of functional groups 3), Youclick H-
52 (hydroxyl value 200, number of functional groups 3) is preferred.

The hardener component may contain other polyols in addition to the castor oil-based polyol. A polyol selected from a polyoxyalkylene polyol, a polybutadiene-based polyol, a hydrogenated polybutadiene polyol, and the like can be used by mixing with a castor oil-based polyol. However, from the viewpoint of chemical resistance and curability, it is particularly preferable to avoid using a polyoxyalkylene polyol in combination, and it is most preferable that no polyol other than castor oil-based polyol is contained.

In the present invention, the curing agent component preferably contains a polyamine. Aromatic polyamines are particularly preferred. Such aromatic polyamines include 4,4′-
Examples thereof include diphenylmethanediamine and diethyltoluenediamine, and diethyltoluenediamine is particularly preferred. Diethyltoluenediamine is usually used as a mixture of 3,5-diethyl-toluene-2,4-diamine and 3,5-diethyl-toluene-2,6-diamine. The ratio of the polyol and the polyamine in the curing agent component is such that the polyol / polyamine (mass ratio) is 20/80 to 1
00/0 is preferred, and 60/40 to 90/10 is particularly preferred.

In the present invention, the ratio of the isocyanate group contained in the main component to the hydroxyl group contained in the curing agent component is such that the molar ratio of isocyanate group / hydroxyl group is 1 to 1.3, and more preferably 1 to 1.2. Preferably, If it is less than 1, sufficient mechanical strength of the cured coating film may not be obtained or tackiness may remain on the coating film surface. If it exceeds 1.3,
Excess isocyanate groups tend to foam under the influence of moisture, and the cured coating film tends to become brittle.

Further, the polyurethane curable composition of the present invention may contain a compounding agent such as a filler, a plasticizer and a pigment, if necessary. Further, stabilizers such as antioxidants, ultraviolet absorbers, dehydrating agents, light stabilizers, flame retardants, defoamers and catalysts commonly used in polyurethane resins can be blended. These can optionally be blended with the main component or the hardener component, and in some cases, a third component other than the main component and the hardener component.
As a component, it can be blended when mixing the main component and the curing agent component. Usually, the polyurethane curable composition of the present invention preferably comprises two components, a main component and a curing agent component.

As the filler, calcium carbonate, talc,
Examples include clay, silica, carbon, and glass balloon. When the filler is used, the amount of the filler is preferably 5 to 60% by mass in the polyurethane curable composition, and is preferably 15 to 15% by mass.
45% by mass is preferred. Examples of the pigment include inorganic pigments such as chromium oxide and titanium oxide, and organic pigments such as a phthalocyanine pigment. When a filler or a pigment is used, it is preferable to mix it with the curing agent component.

As the catalyst, a known urethanation catalyst can be used. Examples of the catalyst include a tertiary amine catalyst, an organotin compound catalyst, and an organic lead compound catalyst. Preferably, no catalyst is used. As the plasticizer, dioctyl phthalate, dibutyl phthalate, butylbenzyl phthalate, dioctyl adipate, chlorinated paraffin, petroleum plasticizer and the like can be used. When a plasticizer is used, the amount used is preferably 1 to 20% by mass, particularly preferably 1 to 10% by mass in the polyurethane curable composition.

As the high-pressure two-component collision-mixing type spraying apparatus in the method for producing a polyurethane elastomer of the present invention, H-2000, H-3500, FF-H made by Gasmer Co., Ltd.
1600, a two-component high-pressure discharge mixing machine MODEL HF-100 manufactured by Toho Machine Industry Co., Ltd. In addition, GX-7 gun, GX-
7-400, and a prober gun manufactured by Glasscraft Corporation. Further, in the production method of the present invention, it is preferable that each of the main component and the curing agent component is heated to about 30 to 90 ° C. and mixed.

The foundation on which the spraying waterproofing method of the present invention is applied includes concrete roofs, open corridors, stairs, stadium stands, factory floors, parking lots, floors and walls of underground buildings and sewage treatment plants, and pools. And a metal base such as a metal roof. Concrete foundations are particularly preferred. The waterproofing method of the present invention
Since the influence of moisture is small, it can be applied to a substrate with a lot of moisture.

[0023]

Examples (Examples 1 to 4) and Comparative Examples (Examples 5 to 7)
The present invention will be specifically described below, but the present invention is not limited thereto. The spray coating was performed using a gasmer H-2000 high-pressure spray machine as a spraying apparatus and a prober gun manufactured by Glass Craft as a spray gun. Further, the main component and the curing agent component were heated to 50 ° C. and used. The coating thickness was 2 mm.
The performance of the obtained cured coating film was evaluated by the following method.

<Appearance of wet base coat> 300 mm square, 60
Using a mortar plate having a thickness of
It was immersed for a period of time and spray-coated on the one immediately after being taken out. After the spray coating, the swelling of the cured coating film after 7 days had passed and the internal condition were observed and compared.

<Coating physical properties> According to JIS A6021,
After curing on the release film for 7 days after spray coating, the mechanical properties of the cured coating film obtained were measured. In the table, H indicates Shore A hardness, Ts indicates tensile strength (unit: N / mm ² ), and E indicates elongation at break (unit:%).

<Chemical resistance> According to JIS A5705,
In a 48-hour spot test using (1) 10% by mass hydrochloric acid, (2) 10% by mass sodium hydroxide, and (3) xylene, changes in the coating film after 7 days were observed. . The evaluation results were ◎: no change, ：: almost no change, Δ: slight swelling, ×: swelling.

Example 1 Castor oil-based polyol A (number of functional groups: 2.0, hydroxyl value: 80.6 mgKOH / g) 58.2
41.8 parts of MDI was added to parts by mass (hereinafter, referred to as parts).
The reaction was carried out at a molar ratio of isocyanate group / hydroxyl group = 4.0, and the isocyanate group content was 10.5% by mass.
A prepolymer having a viscosity of 2,000 cP (20 ° C.)
Prepolymer B) was obtained.

A mixture of 50 parts of prepolymer B and 50 parts of carbodiimide-modified MDI was used as a main component.
18 parts of diethyltoluenediamine and castor oil-based polyol C (2.7 functional groups, hydroxyl value 160 mg KOH /
g) A mixture of 82 parts was used as a curing agent component. Volume ratio of main component / hardener = 1/1 (isocyanate group /
Spray coating was performed while mixing at a ratio such that the molar ratio of hydroxyl groups = about 1.1).

(Example 2) A mixture of 50 parts of prepolymer B and 50 parts of crude MDI was used as a main component, and a mixture of 19 parts of diethyltoluenediamine and 81 parts of castor oil-based polyol C was used as a curing agent component. And Volume ratio of main component / hardener = 1/1 (isocyanate group /
Spray coating was performed while mixing at a ratio such that the molar ratio of hydroxyl groups = about 1.1).

EXAMPLE 3 90 of carbodiimide-modified MDI
A liquid obtained by mixing 10 parts of dioctyl phthalate in each part was used as a main component, and a mixture of 30 parts of diethyltoluenediamine and 70 parts of castor oil-based polyol C was used as a curing agent component.
Spray coating was performed while mixing at a ratio of the main component component / hardener component volume ratio = 1/1 (molar ratio of isocyanate group / hydroxyl group = about 1.17).

(Example 4) A liquid obtained by mixing 50 parts of prepolymer B with 50 parts of carbodiimide-modified MDI was used as a main component, and 20 parts of diethyltoluenediamine, 74.4 parts of castor oil-based polyol C, and a flame retardant (Tris Monochloropropyl phosphate (3 parts), chromium oxide pigment paste (2 parts), light stabilizer (manufactured by Ciba Geigy: TINUVIN)
B75) 0.3 parts and a mixture of 0.3 parts of lead 2-ethylhexanoate (lead content 24%) were used as a curing agent component. The spray coating was performed while mixing at a ratio of the main component component / hardener component volume ratio = 1/1 (molar ratio of isocyanate group / hydroxyl group = about 1.1).

Example 5 To 57 parts of polyol D (polyoxypropylene diol having a hydroxyl value of 56 mg KOH / g obtained by adding propylene oxide to propylene glycol), 39 parts of MDI and 4 parts of carbodiimide-modified MDI were added to Molar ratio of isocyanate group / hydroxyl group =
The reaction was carried out at a ratio of 5.96 to obtain a prepolymer having an isocyanate group content of 11.9% by mass and a viscosity of 2,200 cP (20 ° C.).

Using this prepolymer as a main component, 16 parts of diethyltoluenediamine, 84 parts of polyol D, and 0.5 parts of lead 2-ethylhexanoate (lead content 24%) were added.
The mixture was used as a curing agent component. Spray coating was carried out while mixing at a ratio of the main component component / hardener component volume ratio = 1/1 (molar ratio of isocyanate group / hydroxyl group = about 1.07).

Example 6 The same procedure was performed as in Example 5 except that lead 2-ethylhexanoate was not added.

(Example 7) 75 parts of carbodiimide-modified MDI was reacted with 25 parts of polyol D at a molar ratio of isocyanate group / hydroxyl group = 21, and the isocyanate group content was 20.9% by mass and the viscosity was 340 cP (20 ° C.). ) Was obtained.

Using this prepolymer as a main component, 32 parts of diethyltoluenediamine, 68 parts of polyol D, and 0.5% of lead 2-ethylhexanoate (lead content 24%) were added.
The mixture was used as a curing agent component. The spray coating was performed while mixing at a ratio of the main component / hardener component = 1/1 (molar ratio of isocyanate group / hydroxyl group = about 1.16).

[0037]

[Table 1]

[0038]

According to the present invention, by using a hardener component containing a castor oil-based polyol, the compatibility between the main component and the hardener component is improved, and as a result, it is hardly affected by moisture even under a high moisture condition. Therefore, appearance is not impaired by foaming or the like. Furthermore, even if a catalyst is not used, the curability is excellent. Further, the obtained polyurethane elastomer has an effect of being excellent in chemical resistance.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J034 CA15 CB03 CB07 CC12 CC61 CC65 CC67 DA01 DB03 DB07 DG04 EA12 GA06 GA23 GA33 HA01 HA02 HA06 HA07 HB06 HC03 HC12 HC17 HC22 HC26 HC35 HC46 HC52 HC61 HC63 HC64 HC67 HC71 HC73 JA42 KA01 KB02 KC17 KC18 KD12 KE02 QB11 QB15 RA07 RA10 4J038 DG061 DG101 DG131 DG271 DG281 DG291 DG301 NA03 PB05 PC04

Claims (6)

[Claims] 1. A polyurethane curable composition for spray coating, comprising at least two components, a main component containing an isocyanate group-containing compound and a curing agent containing a castor oil-based polyol. 2. The curable composition according to claim 1, wherein the curing agent component further comprises a polyamine. 3. A method for producing a polyurethane elastomer, comprising spray-coating the polyurethane curable composition according to claim 1 using a high-pressure two-component collision-mixing spraying apparatus. 4. The method according to claim 3, wherein the curing agent component further contains diethyltoluenediamine. 5. A polyurethane waterproofing material comprising at least two components, a main component containing an isocyanate group-containing compound and a hardener containing a castor oil-based polyol, is spray-coated on the substrate using a high-pressure two-component collision-mixing spraying device. Spray waterproofing method characterized by doing. 6. The method according to claim 5, wherein the curing agent component further contains diethyltoluenediamine.