JP2001106758A - Urethane resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a urethane resin being a two-pack type polyurethane resin capable of developing a long pot life and quick curability, having excellent workability, usable for a coating material, casting material, adhesive material, etc., having excellent weather resistance and durability. SOLUTION: This urethane resin composition comprises (A) a monoalkyltin trisfatty acid salt and (B) a dialkyltin difatty acid salt as a curing catalyst in a urethane resin composition composed of a polyisocyanate compound obtained from an aliphatic or alicyclic diisocyanate and a polyhydroxy compound containing two or more hydroxy groups. The urethane resin composition has quick curability and a long pot life.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-pack type urethane resin composition, and more particularly to a urethane composition having a long pot life and a short curing time. Suitable for applications such as objects and adhesive compositions.

[0002]

2. Description of the Related Art Conventionally, in the case of a two-pack type urethane composition, when a polyhydroxyl compound (polyol) component as a main component and a polyisocyanate component as a curing agent are mixed and cured, the curing and drying properties are promoted. For this reason, a curing catalyst is used. Conventionally used curing catalysts include organometallic tin compounds such as dibutyltin dilaurate and tertiary amine salts such as triethylenediamine.
However, when these catalysts are used in large amounts in order to enhance curability, gelling occurs in a short time after compounding of the urethane composition, and in the case of paints, there are drawbacks such as a decrease in the appearance of the coating film, and such catalysts are practically used. Was unbearable. In addition, when a tertiary amine salt is used, a unique odor and discoloration of the urethane composition occur, which is a problem.

It has been pointed out that in the case of a base having an acid value, the use of dibutyltin dilaurate does not improve the curability. JP-A-54-153900 discloses a method of extending the pot life using an aromatic carboxylic acid for improving the curability and the pot life.
The method of using the aromatic carboxylic acid compound and the organotin compound disclosed in Japanese Patent Application Laid-Open Publication No. H11-216, in which the curability and the pot life are extended is known, but sufficient curability is obtained under drying conditions of 80 ° C. or less for about 20 minutes. I couldn't get it. Also, Japanese Patent Application Laid-Open No. 2-151
No. 651 discloses a method using an organic tin monocarboxylate and a sulfur-containing organic carboxylic acid compound, but this method has a disadvantage that the urethane resin is colored. Japanese Patent Application Laid-Open No. 9-279092 discloses a method in which a zinc octylate compound alone or in combination with an organotin compound is used as a urethane curing catalyst. There is a drawback that a compound must be used, which is not preferable in terms of safety and health.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a two-part urethane composition which has excellent curability under low-temperature, short-time drying conditions and excellent workability with a long pot life. To provide things.

[0005]

Means for Solving the Problems As a result of diligent studies, the present inventors have found that the problem can be solved by using two kinds of specific organotin compounds as a curing catalyst for urethane resin. It was completed. That is, the present invention relates to a urethane resin composition comprising a polyisocyanate compound from an aliphatic or alicyclic diisocyanate and a polyhydroxyl compound having two or more hydroxyl groups (A)
The present invention relates to a urethane resin composition comprising a monoalkyltin tris fatty acid salt and (B) a dialkyltin difatty acid salt.

Hereinafter, the present invention will be described in detail. Examples of the polyisocyanate compound from an aliphatic or alicyclic diisocyanate used in the present invention include the following. For example, 1,6-hexamethylene diisocyanate (hereinafter abbreviated as HDI), 3,5,5-trimethyl-
3-isocyanatomethylcyclohexane (hereinafter referred to as IP
A biislet having an isocyanate group at the terminal derived from a diisocyanate such as DI), a polyisocyanate having an isocyanurate, urethane, or allophanate group is used. Specific examples thereof include Duranate TPA-100 and THA manufactured by Asahi Kasei Corporation.
-100, 24A-100, 22A-75PX, E402-90T, P-301-75E, TSA-
100; Desmodur N3200, N3390, N-75 manufactured by Sumitomo Bayer Urethane Co., Ltd .; Coronate HX, HL manufactured by Nippon Polyurethane Co., Ltd .; Takenate D170N, D140N manufactured by Takeda Pharmaceutical Co., Ltd .; Mitsubishi Mytec NY215A manufactured by Chemical Co., Ltd .; Bestnat T1890 manufactured by Fever, and the like.

Examples of the polyhydroxyl compound having two or more hydroxyl groups include hydroxyl group-containing acrylic copolymers (acrylic polyols), polyester polyols, polyether polyols, polycaprolactone polyols, polycarbonate polyols, fluorinated polyols and the like. What is used for this purpose, such as a main component (polyol) of a liquid urethane resin paint, can be used.

The ratio of the polyisocyanate to the polyhydroxyl compound is preferably such that the ratio of the isocyanate group equivalent to the hydroxyl group equivalent (NCO / OH ratio) is in the range of 0.5 to 2.0, preferably 0.7 to 1 .5.

The (A) monoalkyltin tris fatty acid salt and (B) the dialkyltin difatty acid salt used in the present invention include:
Specific examples include but are not limited to the following. Examples of the monoalkyltin tris fatty acid salt of (A) include monomethyltin triacetate, monomethyltin tris (butanoic acid), monomethyltin tris (octanoic acid), monomethyltin tris (decylate), and monomethyltin tris ( Octadecanoic acid) salt, monobutyltin tris (butanoic acid) salt, monobutyltin tris (octanoic acid)
Salt, monobutyltin tris (decylate), monobutyltin tris (octadecanoate), monooctyltin tris (butanoate), monooctyltin tris (octanoate)
Salts, monooctyltin tris (decylate), monooctyltin tris (octadecanoate) and the like.

The dialkyltin difatty acid salt of (B) includes dimethyltin di (butanoic acid) salt, dimethyltin di (octanoic acid) salt, dimethyltin di (dodecanoic acid) salt, dimethyltin di (decylic acid) salt And dibutyltin di (butanoate), dibutyltin di (octanoate), dibutyltin di (decylate), and dibutyltin di (dodecanoate).

The amount of the tin compound (A) or (B) used in the present invention is usually 0.001 part by weight based on 100 parts by weight of the solid content of the polyisocyanate and the polyhydroxyl compound.
It is 1 to 10 parts by weight, preferably 0.01 to 1 part. The ratio of the monoalkyltin tris fatty acid salt of (A) to the dialkyltin difatty acid salt of (B) is 9/1 to 1
Although it can be used in a weight ratio of / 9. In actual use, the ratio may be determined according to the temperature conditions for curing the urethane resin composition. For example, when the urethane resin composition is cured at a temperature exceeding 40 ° C., (A) /
When the ratio of (B) is 9/1 to 5/5 and the amount of the compound of (A) is large, a urethane resin composition having excellent curability and a long pot life can be obtained. When the curing temperature is 4
When the temperature is lower than 0 ° C., the ratio of (A) / (B) is 5/5 to 5/5.
Preferably, the weight ratio is 1/9.

These compounds (A) and (B) may be added after mixing the two-part urethane resin composition, or may be mixed in advance on the polyisocyanate side or the polyhydroxyl compound side. Further, the use of a colorant such as a pigment or the like, a UV absorber, an antioxidant, a light stabilizer, a cellulose derivative, or the like usually used in the art in the urethane resin composition does not cause any problem.

[0013]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto. In the examples, “parts” are all parts by weight. Polyisocyanate compounds used in the examples,
As the polyhydroxyl compound, the following compounds were used unless otherwise limited. Duranate TPA-100 (an HDI-based polyisocyanate having an isocyanurate structure, manufactured by Asahi Kasei Corporation, NCO = 23.1%, solid content = 100%) Duranate 24A-100 (a pellet structure manufactured by Asahi Kasei Corporation) HDI-based polyisocyanate having N
CO = 23.3%, solid content = 100%) Duranate 22A-75PX (an HDI-based polyisocyanate having a pellet structure manufactured by Asahi Kasei Corporation)
NCO = 16.5%, solid content = 75% Vestnat T1890L (IPDI polyisocyanate having an isocyanurate structure manufactured by Huls, NC
O = 12.0%, solid content = 70%) Acrydic A801 (Dainippon Ink & Chemicals, Inc.)
Acrylic polyol, hydroxyl value = 50, acid value = 0.
3, solid content = 50%)

As the curability, the value of the gel fraction described below was used as an index. Measurement method of gel fraction: A urethane resin film coated on a polypropylene plate and cured under predetermined conditions is placed in a 400-mesh stainless steel mesh, and immersed in acetone at 20 ° C. for 24 hours, and then weighed. The remaining fraction is used as the value. The pot life is
This is the time until the viscosity of the compounded urethane resin becomes twice the initial viscosity. The gelation time is the time until the compounded urethane resin loses its fluidity.

(Example 1) Acrydic A801 and duranate TPA-100 were mixed in 100 parts and 16 parts, respectively, and thinner (xylene / n-butyl acetate = 1 /).
1) and add Ford Cup No. 4 was adjusted to give an outflow viscosity of 13.5 seconds. 2.5 parts of a 10% xylene solution of monobutyltin tris (2-ethylhexanoate) and 1 part of dibutyltin di (laurate)
0.1 part of a 0% chitrene solution was added. Pot life and Table 1
The gel fraction at the time of curing under the predetermined conditions shown in (1) was measured.

(Example 2) Duranate T in Example 1
PA-100, 1 duranate 22A-75PX
Example 1 was changed to 9.3 parts and the catalyst solutions shown in Table 1 were added.
Table 1 shows the results obtained by performing the same operations as in the above. (Example 3) Duranate TPA-100 in Example 1
Was changed to 12 parts of duranate TPA-100 and 8.7 parts of Vestanato T1890L, and the same operation as in Example 1 was carried out by adding the catalyst solution shown in Table 1 to the results shown in Table 1. (Comparative Examples 1 to 3) Example 1 was changed to the catalyst solution shown in Table 1.
Table 1 shows the results obtained by performing the same operations as in the above.

[0017]

[Table 1] (Note) 1. 1. Catalyst solution A: 10% xylene solution of monobutyltin tris (2-ethylhexanoate) Catalyst solution B; 10% xylene solution of dibutyltin dilaurate

Example 4 700 parts of Praxel 303 (manufactured by Daicel Chemical Industries, Ltd.), ethylene glycol,
300 parts and dibutyltin di (lauric acid) salt, 0.4 part,
Monobutyltin tris (2-ethylhexanoate) salt, 0.1.
25 parts of the mixed solution A consisting of 8 parts and duranate 24A-
When 100 and 75 parts were mixed and the viscosity was measured, it was 2 Pa · s at 20 ° C. The gelation time of this urethane resin solution was 3 hours at 20 ° C. The same urethane resin liquid was mixed again, placed in a 1000 mL polypropylene beaker, defoamed under vacuum for 60 minutes, and the mixed liquid was poured on a glass plate and cured at 60 ° C. for 1 hour. Observation of the appearance of the cured product showed that a good urethane resin molded product without bubbles was obtained.

Comparative Example 4 The use of the monobutyltin tris (2-ethylhexanoate) salt of Example 4 was stopped, and the amount of dibutyltin di (laurate) salt was changed to 1.2 parts. The same was done. The gelation time of this urethane resin liquid was 45 minutes at 20 ° C. Place in a 1000 mL polypropylene beaker, degas under vacuum for 30 minutes,
The appearance of the cured product after flowing the mixture on a glass plate and curing at 60 ° C. for 1 hour was observed. As a result, a large number of air bubbles were observed and the product was not suitable for use as a urethane resin molded product.

(Example 5) 100 parts of a commercially available urethane paint for repairing automobiles, the main ingredient (manufactured by Kansai Paint Co., Ltd.) of base coat clear of ethane PG60 and duranate TPA-10
After adding 0, 15 parts and 90 parts of thinner, 1.0 part of a 10% xylene solution of monobutyltin tris (2-ethylhexanoate) salt and 0.7 part of a 10% xylene solution of dibutyltin dilaurate are added. Paint was made. The pot life of this paint was 5 hours. 40 ° C and 60 ° C
The gel fraction after baking for 20 minutes each was 65%,
85%. (Comparative Example 5) The pot life of the paint in the case where the catalyst solution was not added in Example 5 was 16 hours, 40 ° C and 60 ° C.
The gel fraction after baking for 20 minutes each was 2% and 5%, respectively.
%Met.

Example 6 Duranate TPA-100
In a solvent of xylene / butyl acetate = 1/1 with resin content of 75%
A polyisocyanate solution was prepared by adding 10 parts of a 10% xylene solution of monobutyltin tris (2-ethylhexanoic acid) salt and 5 parts of a 10% xylene solution of dibutyltin dilaurate to 100 parts of the diluted solution. This solution was sealed with nitrogen and stored at 40 ° C. for one month, and the results of measurement of coloration and viscosity change are shown in Table 2. Comparative Example 6 In Example 6, 2-ethylhexyl thioglycolate was used instead of dibutyltin dilaurate.
The results obtained in the same manner as in Example 6 except that the amount was changed to 5 parts are shown in Table 2, and there was large coloring.

[0022]

[Table 2] (Note) 1. Color (APHA) was measured by the method specified in ASTM D1209. 2. The viscosity is a value measured at 25 ° C.

[0023]

Industrial Applicability The present invention provides a two-part urethane resin composition which exhibits curability in a short time and has a long working life and good workability by using two specific tin catalysts. Is obtained. The urethane resin composition of the present invention is useful for applications such as urethane paints, adhesives and casting compositions.

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Claims (1)

[Claims] 1. A urethane resin composition comprising a polyisocyanate compound obtained from an aliphatic or alicyclic diisocyanate, a polyhydroxyl compound having two or more hydroxyl groups, and a urethane curing catalyst, wherein the urethane curing catalyst is (A) a monoalkyltin A urethane resin composition comprising two kinds of tris fatty acid salt and (B) dialkyltin difatty acid salt.