JP2000281895A - Urethane resin composition, adhesive and coating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ordinary-temperature-curable urethane resin composition which can be used in rainy days or under the conditions of high temperature and high humidity and are suitable for adhesives and coating materials. SOLUTION: This urethane resin composition comprises (a) a polyisocyanate compound, (b) a hydroxide compound and (c) glycerol. Therein, the component (a) is preferably a prepolymer which is obtained by a polyol compound with a polyisocyanate compound and has unreacted isocyanate groups. The hydroxide compound (b) 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 room-temperature-curable urethane resin composition which is effective as a material, a joint material, and a coated floor 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 composed of a polyol compound, and has a better adhesion to various adherends than an epoxy resin. Thus, it is possible to design cured products having different hardnesses from hard to soft.

[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 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, or in a wet state, there is a drawback that the adhesive is remarkably reduced due to foaming.

As a method for preventing foaming of a one-component moisture-curable urethane adhesive, as disclosed in JP-A-9-3430, metal hydroxides such as magnesium hydroxide, calcium hydroxide and aluminum hydroxide are disclosed. Has been proposed to be mixed with a urethane resin. However, this method has a problem that the effect of preventing foaming is not sufficient, and the urethane resin is gelled or thickened, thereby lowering storage stability.

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, and has sufficient adhesion even when the adherend is wet. In particular, it is an object of the present invention to provide a room-temperature-curable urethane resin composition suitable for use as an adhesive or a covering material in the field of civil engineering.

[0010]

That is, the present invention provides a urethane resin composition containing (a) a polyisocyanate compound, (b) a hydroxide and (c) glycerin,
The component (a) is an urethane resin composition which is an aromatic polyisocyanate compound having an isocyanate group content of 9% by weight or more, wherein the component (a) is obtained by reacting a polyol compound with a polyisocyanate compound. (B) the urethane resin composition wherein the hydroxide is calcium hydroxide. 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.

(A) Examples of the polyisocyanate compound include aliphatic polyisocyanates such as hexamethylene diisocyanate and 2,2,4-trimethylhexamethylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate (hydrogenated MDI), isophorone diisocyanate, and the like. Alicyclic polyisocyanates such as methylcyclohexane-2,4-diisocyanate, methylcyclohexane-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 (XD
And aromatic polyisocyanates such as I) and naphthalene diisocyanate, and cyclized trimers of these polyisocyanates. These (a) polyisocyanate compounds can be used alone or in combination of two or more.

The (a) polyisocyanate compound used in the present invention includes an unreacted isocyanate group-containing prepolymer (Pa) obtained by previously reacting a polyol compound and (a) a polyisocyanate compound. included.

The polyol compound used in the above reaction preferably has at least two hydroxyl groups in one molecule.

Examples of the polyol compound include polyether polyols such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol, modified polyether polyols such as bisphenol A-modified polyethylene glycol and bisphenol A-modified polypropylene glycol, castor oil, bisphenol A modified castor oil and hydrogen. Examples include modified castor oil such as added castor oil, acrylic polyol, polyester polyol, epoxy resin-modified polyol, polycarbonate diol, and hydroxyl-containing liquid diene derivatives such as liquid polybutadiene diol. These polyol compounds can be used alone or in combination of two or more.

Among these (a) polyisocyanate compounds, the cured product such as adhesiveness has sufficient resin properties,
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.

The hydroxide (b) used in the present invention is preferably a metal hydroxide.

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 (b) used is preferably 5 to 200 parts by weight, more preferably 10 to 100 parts by weight, per 100 parts by weight of the polyisocyanate compound (a). 5
If the amount is less than parts by weight, the effect of preventing foaming may not be sufficient, and if it exceeds 200 parts by weight, workability such as applicability may be deteriorated.

The glycerin (c) used in the present invention has an antifoaming effect.

The amount of (c) 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 (b) hydroxide. If the amount is less than 1 part by weight, the effect of preventing foaming may be insufficient.
If the amount exceeds 00 parts by weight, the adhesion of the cured product to the substrate may be deteriorated.

In the present invention, a polyol compound or a curing accelerator may be further used. When using a polyol compound or a curing accelerator, the urethane resin composition of the present invention is
In terms of excellent storage stability, (a) a first agent containing at least a polyisocyanate compound, (b) a hydroxide,
(C) A two-part urethane resin composition divided into a second part containing at least glycerin and a curing accelerator may be used. Also, the urethane resin composition of the present invention may contain various additives, if necessary, known additives such as fillers, moisture absorbents, plasticizers, thixotropic agents, tackifiers, coupling agents and coloring agents. May be used.

[0024]

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 urethane resin composition comprising 100 parts by weight of polyisocyanate, 25 parts by weight of hydroxide, and glycerin in parts by weight shown in Table 1 with respect to 100 parts by weight of hydroxide was prepared.
Physical properties were evaluated. Table 1 shows the results.

(Raw materials used) Polyisocyanate: MDI-based polybutadiene-modified prepolymer (obtained by reacting a polyol compound and a polyisocyanate compound), isocyanate group content: 16% by weight, commercially available hydroxide: calcium hydroxide 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, the urethane resin composition of the experimental example was quickly applied to the surface of the sidewalk concrete plate so as to have a thickness of about 5 mm. And cured for 7 days in an environment at a temperature of 20 ° 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. ○: no foaming, △: slight foaming, ×: foaming too much
And (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
40mm x 40mm x 80 soaked in water at 0 ° C for 1 day
After removing the two pieces of mortar from the water, the two pieces of mortar were quickly bonded with the urethane resin composition of the experimental example, and cured and cured for 7 days in an environment at a temperature of 20 ° C. and a humidity of 85% or more. Thereafter, the adhesive strength was determined by a four-point bending strength test. The thickness of the resin composition layer is set at 1.
It was adjusted to be 0 mm. (3) Acceleration of curing The urethane resin composition of the experimental example was allowed to stand all day and night to observe the curing state. ○, when the urethane resin composition is cured,
The case where the composition did not cure was evaluated as x.

[0028]

[Table 1]

Experimental Example 2 An experiment was performed in the same manner as in Experimental Example 1 except that a urethane resin composition comprising 100 parts by weight of polyisocyanate and 7.5 parts by weight of glycerin was prepared without using a hydroxide.
Table 2 shows the results.

[0030]

[Table 2]

Experimental Example 3 Hydroxide 1 was prepared by replacing ethylene glycol with glycerin.
The operation was carried out in the same manner as in Experimental Example 1 except that 30 parts by weight was used per 100 parts by weight. Table 2 shows the results.

(Raw materials) Ethylene glycol: Commercial product

[0033]

[Table 3]

Experimental Example 4 In the evaluation of the presence or absence of foaming in Experimental Example 1 (1),
o. The workability of applying the urethane resin composition 1-1 to a sidewalk concrete plate was evaluated. Experiment No. The urethane resin composition of 1-1 could be quickly applied to the surface of a sidewalk concrete plate, and the workability was good.

[0035]

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

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08G 18/32 C08G 18/32 A (72) Inventor Kiyonobu Maruhashi 306 Koyagicho, Takasaki City, Gunma Prefecture・ Within K Co., Ltd. (72) Inventor Sakae Kawasaki 306 Koyagi-cho, Takasaki City, Gunma Prefecture Inside C K Co., Ltd. (72) Inventor Shuichi Wada 306 Oyagi-cho, Takasaki City, Gunma Prefecture C.K. F term (for reference) 4J002 CK041 DE076 DE086 DE096 DE146 EC057 GH00 GJ01 4J034 AA01 BA02 CA01 CA05 CB04 CC01 HC01 HC02 HC03 HC11 HC12 HC15 HC17 JA41 MA03 RA07 RA08 RA10 4J038 DG051 DG101 DG121 PCT DG 161 DG 161 161 EF131 EF151 EF181 EF201 EF251 EF321 HA136 HA146 HA156 HB11 JA12 JB04 KA09 MA06 NA12

Claims (6)

[Claims] (1) (a) a polyisocyanate compound,
A urethane resin composition containing (b) a hydroxide and (c) 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 (b) the hydroxide is calcium hydroxide. 5. An adhesive comprising the urethane resin composition according to claim 1. 6. A coating material comprising the urethane resin composition according to claim 1.