JP2000327906A - Urethane resin composition, adhesive and coating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a room temperature setting urethane resin composition usable in rainy weather or a hot and humid condition and suitable as an adhesive and a coating material. SOLUTION: This urethane resin composition contains (a) a polyisocyanate compound, (b) a polyol compound, (c) a hydroxide and (d) glycerol. The composition is a two-pack type urethane resin composition composed of the 1st agent containing the component (a) and the 2nd agent containing the components (b), (c) and (d). The component (a) is preferably a prepolymer having unreacted isocyanate group and produced by reacting a polyol compound with a polyisocyanate compound and the hydroxide (c) is preferably calcium hydroxide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can be used in rainy weather or under high temperature and high humidity, and has no foaming or low foaming temperature-curable urethane resin composition having sufficient adhesion even when the adherend is wet. About. More specifically, it cures at room temperature on the wet surface of civil engineering building materials such as concrete and mortar, exhibits excellent adhesiveness, and has non-foaming or low-foaming adhesives, coating materials, fillers, lining materials, and waterproofing. The present invention relates to a two-part, room-temperature-curable urethane resin composition that is effective as a material, a joint material, and a coated flooring material.

[0002]

2. Description of the Related Art Conventionally, epoxy resin is mainly used in the field of civil engineering and construction such as concrete and mortar. However, epoxy resin has the drawback that concrete and mortar are wet with rainwater, etc., and when wet, adhesive strength is significantly reduced.When using epoxy resin, the surface of concrete, mortar, etc. is burned. And so on.

[0003] The cured product of epoxy resin is very hard,
When elasticity is required, an elasticity-imparting agent can be added to the epoxy resin to impart elasticity, but there is a drawback that the production cost becomes extremely high.

The two-part cold curing urethane resin is composed of a first liquid composed of a polyisocyanate compound and a second liquid mainly composed of a polyol compound, and is more adherent to various adherends than an epoxy resin. A cured product having good force and different hardness from hard to soft can be designed.

[0005] However, the two-part cold-setting urethane resin also has the drawback that concrete and mortar are wetted by rainwater or the like when they are wet, or when they are wet, they are foamed and adhesive strength is significantly reduced. The use of was limited. As a method for preventing foaming of a two-part, room-temperature-curable urethane-based resin, as disclosed in JP-A-62-280278, a method in which a moisture absorbent such as zeolite, calcium oxide, and silica gel is blended has been proposed. .

[0006]

However, this method has a problem that the effect of preventing foaming is not sufficient.

[0007] One-component moisture-curable urethane-based adhesives are used as tile adhesives and the like because of their easy handling. However, when the tile or mortar is wet with rainwater or the like and is in a wet state, there is a disadvantage that foaming is caused and adhesive strength is significantly reduced.

As a method for preventing foaming of a one-pack type moisture-curable urethane-based adhesive, as disclosed in JP-A-9-3430, metal hydroxides such as magnesium hydroxide, calcium hydroxide and aluminum hydroxide are used. A method has been proposed in which a substance is mixed with a urethane resin. However,
In this method, there is a problem that the effect of preventing foaming is not sufficient, and the urethane resin is gelled or thickened and storage stability is reduced.

The present invention solves the above-mentioned problems of the prior art, and can be used in rainy weather or under high temperature and high humidity.
Another object of the present invention is to provide a two-part, room-temperature-curable urethane resin composition which has sufficient adhesion even when the adherend is wet, and is particularly suitable for use as an adhesive or a coating material in the field of civil engineering and construction. .

[0010]

That is, the present invention provides (a)
A urethane resin composition comprising a polyisocyanate compound, (b) a polyol compound other than glycerin, (c) a hydroxide and (d) glycerin, wherein the component (a) has an isocyanate group content of 9% by weight or more. The urethane resin composition, which is an aromatic polyisocyanate compound, wherein the component (a) is an unreacted isocyanate group-containing prepolymer obtained by reacting a polyol compound with a polyisocyanate compound. (C) the urethane resin composition wherein the hydroxide is a metal hydroxide, (c) the urethane resin composition wherein the hydroxide is calcium hydroxide, and (a) a polyisocyanate compound (B) a polyol compound other than glycerin, (c)
A two-part urethane resin composition containing a hydroxide and (d) a second part containing at least glycerin. Further, it is an adhesive made of the urethane resin composition, and a coating material made of the urethane resin composition.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The polyisocyanate compound (a) used in the present invention preferably has at least two isocyanate groups in one molecule.

The polyisocyanate compound having at least two isocyanate groups in one molecule includes:
Aliphatic polyisocyanates such as hexamethylene diisocyanate and 2,2,4-trimethylhexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate (hydrogenated MDI), isophorone diisocyanate, methylcyclohexane-2,4-diisocyanate and methylcyclohexane- Alicyclic polyisocyanates such as 2,6-diisocyanate (hydrogenated TDI) and 1,3-diisocyanatemethylcyclohexane (hydrogenated XDI), 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), phenylene diisocyanate, xylene diisocyanate (XDI)
And aromatic polyisocyanates such as naphthalene diisocyanate, and cyclized trimers of these polyisocyanates. These (a) polyisocyanate compounds can be used alone or in combination of two or more.

The polyisocyanate compound (a) used in the present invention includes a polyol compound described below and (a)
It includes a prepolymer (Pa) having an unreacted isocyanate group, which is obtained by previously reacting with a polyisocyanate compound. This prepolymer Pa is
For example, in the above reaction, obtained by selecting the amount of the polyol compound and the polyisocyanate compound to be used, so that the number of moles of isocyanate groups in the polyisocyanate compound is larger than the number of moles of hydroxyl groups in the polyol compound used. The prepolymer Pa can be used alone or in combination with another polyisocyanate compound.

[0015] Among these (a) polyisocyanate compounds, the resin properties of a cured product such as adhesiveness are sufficient.
Isocyanate group content (based on JIS K3701)
Is preferably 9% by weight or more of an aromatic polyisocyanate. Furthermore, in terms of reactivity, workability, resin properties of the cured product, safety, and workability such as handling, a prepolymer Pa having an unreacted isocyanate group obtained by reacting a polyol compound and a polyisocyanate compound is obtained. preferable.

As the polyol compound (hereinafter referred to as a polyol compound) other than glycerin (b) used in the above reaction, a compound having at least two or more hydroxyl groups in one molecule is preferable.

Examples of the polyol compound having at least two hydroxyl groups in one molecule include polyether polyols such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol, bisphenol A-modified polyethylene glycol and bisphenol A.
Modified polyether polyols such as modified polypropylene glycol, castor oil, modified castor oils such as bisphenol A modified castor oil and hydrogenated castor oil, acrylic polyols, polyester polyols, epoxy resin modified polyols, polycarbonate diols, and hydroxyl-containing liquid diene such as liquid polybutadiene diol And the like. These polyol compounds can be used alone or in combination of two or more.

The (b) polyol compound used in the present invention includes an unreacted hydroxyl-containing prepolymer (Pb) obtained by previously reacting the aforementioned (a) polyisocyanate compound with a polyol compound. included. This prepolymer Pb, for example, in the above reaction, the amount of the polyol compound and the polyisocyanate compound used so that the number of moles of hydroxyl groups in the polyol compound is larger than the number of moles of isocyanate groups in the polyisocyanate compound used. This prepolymer Pb can be used alone or in combination with other polyol compounds.

The average molecular weight of these polyol compounds (b) is preferably 50 or more from the viewpoint of effect and price, and is preferably 50 or more.
0 to 8000 is more preferable.

As the (c) hydroxide used in the present invention, a metal hydroxide is preferable.

Examples of the metal hydroxide include metal hydroxides such as calcium hydroxide, magnesium hydroxide, aluminum hydroxide, cobalt hydroxide, potassium hydroxide and sodium hydroxide, and may be used alone or in combination of two or more. Can be used. Of these, calcium hydroxide is preferred because of its great foaming prevention effect.

The amount of the hydroxide (c) used is preferably from 5 to 200 parts by weight, more preferably from 10 to 100 parts by weight, per 100 parts by weight of the polyisocyanate compound (a). 5
If the amount is less than part by weight, the adhesiveness and the effect of preventing foaming may not be sufficient. If the amount is more than 200 parts by weight, workability such as applicability may be deteriorated.

Glycerin (d) used in the present invention has an effect of preventing foaming.

The amount of (d) glycerin used is preferably from 1 to 200 parts by weight, more preferably from 2 to 100 parts by weight, based on 100 parts by weight of (c) hydroxide. When the amount is less than 1 part by weight, the adhesiveness, the curing acceleration property, and the foam preventing effect may be insufficient. There is a risk.

In the present invention, the effect of preventing foaming is great.
(A) a curing accelerator such as an amine-based substance or an organometallic compound;
It is preferable to use 2 parts by weight or less based on 100 parts by weight of the polyisocyanate compound, and it is more preferable not to use a curing accelerator.

The urethane resin composition of the present invention may contain various additives, fillers, moisture absorbents, plasticizers, thixotropy agents, tackifiers, coupling agents, coloring agents, and the like, if desired. May be used.

The urethane resin composition of the present invention is preferably used as a two-part type from the viewpoint of excellent storage stability. In the case of a two-pack type, (a) a first agent containing at least a polyisocyanate compound and (b) a second agent containing at least a polyol compound, (c) a metal hydroxide and (d) glycerin. It is preferable to divide.

In the urethane resin composition of the present invention, (a) the number of moles of the isocyanate group of the polyisocyanate compound and (b) the number of moles of the hydroxyl group of the polyol are as follows. (Hereinafter referred to as NCO group / OH group molar ratio),
It is preferably from 0.8 to 1.6, and more preferably from 1.0 to 1.4.
Is more preferable. If it is less than 0.8, it is difficult to cure and the adhesiveness may be small. If it exceeds 1.6, the cured product becomes hard, brittle, foams, the viscosity increases, and the workability may decrease. The use ratio of the first agent and the second agent in the two-pack type urethane resin composition is also the same as described above for the ratio between the number of moles of isocyanate groups of the polyisocyanate compound (a) and the number of moles of hydroxyl groups of the polyol (b). It is preferable to do so.

As an embodiment when a two-part type urethane resin composition is used, a method in which the first part and the second part which are separately stored are mixed at the time of use to perform adhesion or coating, or the first part and the second part are used. And a method in which the agents are separately applied to the adherend, contacted, cured and contacted.

[0030]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to experimental examples, but the present invention is not limited to only experimental examples.

Experimental Example 1 A first agent comprising a polyisocyanate was prepared. or,
From an amount of a polyol having an NCO group / OH group molar ratio shown in Table 1, 25 parts by weight of a hydroxide based on 100 parts by weight of a polyisocyanate compound, and 30 parts by weight of glycerin based on 100 parts by weight of a hydroxide. A second agent was prepared. The physical properties of the room-temperature-curable urethane resin composition obtained by mixing the first agent and the second agent were evaluated. Table 1 shows the results.

(Raw materials used) Polyisocyanate: MDI (4,4, -diphenylmethane diisocyanate) polybutadiene modified prepolymer, isocyanate group content 16% by weight, commercially available polyol: bisphenol A having an average molecular weight of about 520
Modified castor oil, hydroxyl value 216 mg-KOH / g, commercial product Hydroxide: calcium hydroxide, commercial product Glycerin: commercial product

(Evaluation Method) (1) Presence or Absence of Foaming Evaluation was made based on the presence or absence of foaming in a foaming test on a wet surface and a high humidity. In the test, after taking out a sidewalk concrete plate (JIS A 5304) immersed in water at 20 ° C. for 1 day from the water, a urethane resin composition was quickly applied to the surface of the sidewalk concrete plate so as to have a thickness of about 5 mm, and a temperature of 20 ° C. Cured and cured for 7 days in an environment at a temperature of 85 ° C and a humidity of 85%. Thereafter, the presence or absence of foaming on the surface coated with the urethane resin composition was visually evaluated. ○ when there is no foaming
The case where foaming was slight was evaluated as Δ, and the case where foaming was large was evaluated as x. (2) Adhesive strength The adhesive strength was evaluated by an adhesive strength in an adhesive strength test on a wet surface and high humidity. The test was carried out in accordance with the wet condition specified in JIS A6024 at 4.7 bond strength. That is, 2
After removing two pieces of mortar of 40 × 40 × 80 mm immersed in water at 0 ° C. for one day from the water, the two pieces of mortar were quickly bonded with a urethane resin composition, and the temperature was 20 ° C. and the humidity was 8
Hardened and cured for 7 days in an environment of 5% or more. Thereafter, the adhesive strength was determined by a four-point bending strength test. The thickness of the resin composition layer was adjusted to be 1.0 mm by a spacer. (3) Acceleration of curing The urethane resin composition was allowed to stand all day and night, and the state of curing was observed. The case where the urethane resin composition was cured was evaluated as ○, the case where it was almost cured was evaluated as Δ, and the case where it was not cured was evaluated as ×. (4) Workability In (1) Evaluation of the presence or absence of foaming in Experimental Example 1, the workability of applying the urethane resin composition to a sidewalk concrete plate was evaluated. ○: when it could be applied quickly and uniformly to the sidewalk concrete plate surface, Δ: when it could be applied a little later, and when the surface was slightly uneven, 塗布: when it could not be applied and the surface had many unevenness × And

[0034]

[Table 1]

EXPERIMENTAL EXAMPLE 2 100 parts by weight of a hydroxide and 100 parts by weight of a hydroxide shown in Table 2 with respect to 100 parts by weight of a polyol and a polyisocyanate compound in a molar ratio of NCO group / OH group = 1.31. The procedure was performed in the same manner as in Experimental Example 1 except that a second agent consisting of 30 parts by weight of glycerin was prepared. Table 2 shows the results.

[0036]

[Table 2]

Experimental Example 3 25 parts by weight of hydroxide per 100 parts by weight of polyol and polyisocyanate compound in an amount of NCO group / OH group molar ratio = 1.31 and 100 parts by weight of hydroxide The procedure was performed in the same manner as in Experimental Example 1 except that the second agent consisting of glycerin in parts by weight shown in Table 3 was prepared. Table 3 shows the results.

[0038]

[Table 3]

EXPERIMENTAL EXAMPLE 4 A first agent comprising the polyisocyanate shown in Table 4 was prepared, and an NCO group / OH group molar ratio of 1.31 was used as the polyol and polyisocyanate compound 10 shown in Table 4.
The procedure was performed in the same manner as in Experimental Example 1, except that a second agent consisting of 25 parts by weight of hydroxide relative to 0 parts by weight and glycerin of 30 parts by weight relative to 100 parts by weight of hydroxide was prepared. Table 4 shows the results.

(Raw materials used) Polyisocyanate: isophorone diisocyanate,
Commercially available polyol: bisphenol A having an average molecular weight of about 590
Modified polypropylene glycol, hydroxyl value 190 mg-
KOH / g, commercial product

[0041]

[Table 4]

[0042]

The two-part cold-curable urethane resin composition of the present invention does not foam even when the adherend is wet, and has sufficient adhesion. As described above, the two-part cold-curable urethane resin composition of the present invention exhibits excellent adhesiveness and has no or low foaming properties, so that it can be used in civil engineering construction applications in rainy weather or under high temperature and high humidity. It is effective as an adhesive, coating material, filler, lining material, waterproof material, joint material, and painted floor material.

Continuing on the front page (72) Inventor Kiyonobu Marubashi 306 Koyagi-cho, Takasaki-shi, Gunma CRL K.K. (72) Inventor Shuichi Wada 306 Koyagi-cho, Takasaki-shi, Gunma F-term in CRL Co., Ltd. HA206 JA21 NA11 PB05 PC04 4J040 EF051 EF111 EF131 EF151 EF181 EF201 EF251 EF301 EF321 HA136 HA156 HB11 JA13 LA01 LA07 LA08 NA12

Claims (8)

[Claims] (1) (a) a polyisocyanate compound,
A urethane resin composition containing (b) a polyol compound other than glycerin, (c) a hydroxide, and (d) glycerin. 2. Component (a) having an isocyanate group content of 9
The urethane resin composition according to claim 1, which is an aromatic polyisocyanate compound in an amount of at least% by weight. 3. The component (a) is a prepolymer having an unreacted isocyanate group, obtained by reacting a polyol compound with a polyisocyanate compound.
Or the urethane resin composition according to 2. 4. The urethane resin composition according to claim 1, wherein (c) the hydroxide is a metal hydroxide. 5. The urethane resin composition according to claim 1, wherein (c) the hydroxide is calcium hydroxide. 6. A second agent comprising at least (a) a first agent containing at least a polyisocyanate compound, (b) a polyol compound other than glycerin, (c) a hydroxide and (d) glycerin. And a two-part urethane resin composition. 7. An adhesive comprising the urethane resin composition according to claim 1. 8. A coating material comprising the urethane resin composition according to claim 1.