JP2001106760A - Urethane resin composition, adhesive and coating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cold-setting polyurethane resin composition usable in rainy weather or at high temperature and humidity, suitable as an adhesive and a coating material. SOLUTION: This urethane resin composition comprises (a) a polyisocyanate compound, (b) a polyol compound, (c) a hydroxide, (d) glycerol and (e) water. This two-pack type urethane resin composition comprises a first agent containing the component (a) and a second agent containing the component (b), the component (c), the component (d) and the component (e). The component (a) is preferably an unreacted isocyanate group-containing prepolymer obtained by reacting a polyol compound with a polyisocyanate compound. 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 does not foam even when the adherend is wet, and can be used under low temperature conditions without adding a curing accelerator for urethane resin such as amine, and has a sufficient adhesion. The present invention relates to a non-foamable or low-foamable room-temperature-curable urethane resin composition having water-soluble properties. More specifically, it cures at room temperature on the wet surface of civil engineering building materials such as concrete and mortar,
A two-part, room-temperature-curable urethane resin composition that exhibits excellent adhesiveness and is effective as a non-foaming or low-foaming adhesive, covering material, filler, lining material, waterproof material, joint material, and painted flooring material. About things.

[0002]

2. Description of the Related Art In the field of civil engineering and construction such as concrete and mortar, epoxy resins have been mainly used as adhesives and coating materials. 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.
Further, it was necessary to add a curing accelerator for epoxy resin to accelerate the curing.

[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, and the adhesive strength is low under a low temperature condition of 10 ° C. or less.

[0007] One-component moisture-curable urethane-based adhesives are used as tile adhesives and the like because of their easy handling.

[0008] However, when the tile or mortar is wet with rainwater or the like, or when it is in a wet state, there is a drawback that the adhesive strength is extremely low due to foaming, and the adhesive strength is low even under a low temperature condition of 10 ° C or less. .

As a method for preventing foaming of a one-pack type moisture-curable urethane-based adhesive, as disclosed in JP-A-9-3430, a metal hydroxide such as magnesium hydroxide, calcium hydroxide and aluminum hydroxide is used. A method has been proposed in which a substance is mixed with a urethane resin.

However, this method has a problem that the adhesive strength is low under a low temperature condition of 10 ° C. or less. In addition, there is a problem that the urethane resin gels or thickens under high temperature conditions in summer and storage stability decreases.

The present invention solves the above-mentioned problems of the prior art, and can be used under low-temperature conditions of 10 ° C. or less, preferably 5 ° C. or less, has sufficient adhesion, and is particularly useful in the field of civil engineering and construction. It is an object of the present invention to provide a two-part cold-curable urethane resin composition suitable for use in adhesives and coating materials.

[0012]

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, (d) glycerin and (e) water,
The component (a) is an aromatic polyisocyanate compound having an isocyanate group content of 9% or more. The component (a) is an unreacted component obtained by reacting a polyol compound with a polyisocyanate compound. The urethane resin composition which is a prepolymer having an isocyanate group, wherein the (c) hydroxide is a metal hydroxide and the (c) hydroxide is calcium hydroxide. It is a urethane resin composition. or,
(A) a first agent containing at least a polyisocyanate compound, and (b) a second compound containing at least a polyol compound other than glycerin, (c) a hydroxide, (d) glycerin, and (e) water. And a two-part type urethane resin composition. And it is an adhesive comprising the urethane resin composition. Further, it is a coating material comprising the urethane resin composition.

[0013]

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

As the polyisocyanate compound (a) used in the present invention, those having at least two isocyanate groups in one molecule are preferred.

Examples of the polyisocyanate compound having at least two isocyanate groups in one molecule include:
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.

The prepolymer Pa is used, for example, in the above reaction, 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.

Among these (a) polyisocyanate compounds, the resin properties of the cured product such as adhesiveness are sufficient.
An aromatic polyisocyanate having an isocyanate group content of 9% or more (based on JIS K7301) is preferable. 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 or more hydroxyl groups in one molecule include polyether polyols such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol, castor oil,
Modified castor oil such as bisphenol A modified castor oil and hydrogenated castor oil, modified polyether polyol such as bisphenol A modified polyethylene glycol and bisphenol A modified polypropylene glycol, acrylic polyol, polyester polyol, epoxy resin modified polyol, polycarbonate diol, and liquid polybutadiene diol And the like. Hydroxy group-containing liquid diene derivatives such as 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 above-mentioned (a) polyisocyanate compound with a polyol compound. .

The prepolymer Pb is used, for example, in the above reaction 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. The 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.

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

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

The amount of (d) glycerin used is preferably from 1 to 200 parts by mass, more preferably from 2 to 100 parts by mass, per 100 parts by mass of (c) hydroxide. If the amount is less than 1 part by mass, the adhesiveness, curing promotion property and foaming prevention effect may be insufficient. There is.

The water (e) used in the present invention promotes curing under low-temperature conditions and improves the adhesiveness.

(E) The amount of water used is (b) polyol 1
0.1 to 3 parts by mass is preferable with respect to 00 parts by mass,
0.5 to 2 parts by mass is more preferred. If the amount is less than 0.1 part by mass, the effect under low temperature conditions is not promoted, and the adhesion may be deteriorated. If the amount exceeds 3 parts by mass, the adhesion of the cured product to the substrate may be deteriorated.

In the present invention, the effect of preventing foaming is great.
It is more preferable not to use a curing accelerator such as an amine-based substance or an organometallic compound.

The urethane resin composition of the present invention may contain various additives, fillers, moisture absorbents, plasticizers, thixotropic 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 the two-pack type, it contains (a) a first agent containing at least a polyisocyanate compound, and (b) at least a polyol compound, (c) a metal hydroxide, (d) glycerin and (e) water. It is preferable to divide the second agent.

In the urethane resin composition of the present invention, the proportions of (a) the polyisocyanate compound and (b) the polyol used are (a) the number of moles of isocyanate groups of the polyisocyanate compound and (b) the number of moles of hydroxyl groups of the polyol. (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 ratio of the first and second agents in the two-pack type urethane resin composition also depends on the ratio of the number of moles of isocyanate groups of the polyisocyanate compound (a) to the number of moles of hydroxyl groups of the polyol (b). It is preferable to perform the above.

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

[0037]

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. Also, N
With respect to 100 parts by mass of the polyol or polyisocyanate compound in an amount such that the molar ratio of CO groups / OH groups = 1.3 / 1, 2
5 parts by weight of hydroxide, 3 parts per 100 parts by weight of hydroxide
A second agent consisting of 0 parts by mass of glycerin and 1 part by mass of water with respect to 100 parts by mass of the polyol 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) Polyisocyanate: MDI
(4,4, -diphenylmethane diisocyanate) polybutadiene-modified prepolymer, isocyanate group content 16%, commercial product Polyol: bisphenol A-modified castor oil having an average molecular weight of about 520, 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 foamability test on a wet surface and a high humidity. In the test, after taking out a sidewalk concrete plate (JIS A 5304) immersed in 5 ° C. water 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.
The composition was cured and cured for 7 days in an environment at a temperature of 5 ° 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.場合 indicates no foaming, Δ indicates slight foaming, and × indicates excessive foaming. (2) Adhesive strength The adhesive strength was evaluated by an adhesive strength in an adhesive strength test under a wet surface and high humidity. The test was carried out in accordance with the wet condition specified in JIS A 6024, 4.7 adhesive strength. That is,
After removing two pieces of mortar of 40 × 40 × 80 mm immersed in water at 5 ° 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 in an environment of 5% or more for 7 days. 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 with a spacer. (3) Acceleration of curing The urethane resin composition was allowed to stand all day and night to observe the curing state. 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 flat plate was evaluated. At 5 ° C, when it can be quickly and uniformly applied to the sidewalk concrete plate surface, it can be applied ○, slightly slower,
The case where slight unevenness was observed on the surface was evaluated as △, and the case where application was not possible and the surface was largely uneven was evaluated as x.

[0041]

[Table 1]

[0042]

According to the present invention, the two-part cold curing urethane resin composition of the present invention does not foam even when the adherend is wet.
In the following, it has sufficient adhesion and curing acceleration under low temperature conditions, preferably 5 ° C. or less. Thus, the two-part cold-curable urethane resin composition of the present invention exhibits excellent adhesion and curing acceleration properties, and has no or low foaming properties.
Suitable for use in civil engineering and construction under rainy weather or high temperature and high humidity, adhesives, coating materials, fillers, lining materials, waterproof materials,
It is effective as joint material and painted floor material.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) C09J 175/04 C09J 175/04 (72) Inventor Kiyonobu Maruhashi 306 Koyagicho, Takasaki City, Gunma Prefecture Within K Co., Ltd. (72) Inventor Sakae Kawasaki Within K 306 Koyagi-cho, Takasaki City, Gunma Prefecture Inside (72) Inventor Shuichi Wada Within 306 Oyagi-cho, Takasaki City, Gunma Prefecture, Inc. F term (reference) 4J002 CK021 DE028 DE056 DE076 DE086 DE096 DE146 EC057 FD206 FD207 FD208 4J034 BA08 CE01 DA01 DB04 DB07 DF01 DF02 DG03 DG04 DG06 DG14 DK02 DK09 DP18 DQ09 EA12 HA07 HC03 HC12 HC46 HC17 HC03 HC12 HC47 DG261 HA156 HA166 HA186 4J040 EF051 EF281 HA116 HA126 HA156

Claims (8)

[Claims] (1) (a) a polyisocyanate compound,
A urethane resin composition containing (b) a polyol compound other than glycerin, (c) a hydroxide, (d) glycerin, and (e) water. 2. The composition according to claim 1, wherein the component (a) has an isocyanate group content of 9
The urethane resin composition according to claim 1, which is an aromatic polyisocyanate compound of at least 10%. 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 (a) first agent containing at least a polyisocyanate compound, (b) a polyol compound other than glycerin, (c) a hydroxide, (d) glycerin and (e) water. A two-part type urethane resin composition containing the second part. 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.