JPH1067964A - Surface finish coating composition and its application method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a surface finishing coating material composition having excellent the surface tackiness, adhesiveness and weatherability by using a polyurethane prepolymer used a specific isocyanate as a principal agent and a hydroxyl group-containing (meth)acrylic polymer as a hardener. SOLUTION: This composition is composed of (A) a principal agent mainly comprising an isocyanate group-terminal polyurethane prepolymer obtained by reacting (i) a polyol having >=2 functional group number (e.g. polyoxypropylene glycol) with (ii) xylylene diisocyanate and (B) a hardener mainly comprising a hydroxyl group-containing (meth)acrylic polymer. Preferably, a hydroxyl group number of the component (i) is 2-4 and a molecular weight per a hydroxyl group is 300-1,000. The component (i) may be reacted with l the component (ii) in an equivalent ratio of 1.5-2. Preferably, the component B is obtained by polymerizing a hydroxyl groupcontaining monomer with a (meth)acrylic monomer. As the former monomer, a hydroxyl group- containing (meth)acrylic monomer such as 2-hydroxyethyl (meth)acrylate is preferably used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a surface finish coating composition and a method for applying the same. Particularly suitable as a finish paint with excellent surface tackiness, adhesiveness and weather resistance when used as a finish paint composition for two-pack waterproofing materials and coated flooring materials with a large amount of plasticizer, suitable for two-pack cold curing. A surface finish coating composition.

[0002]

2. Description of the Related Art Acrylic urethane finishing paint compositions are known for their waterproofness, flooring,
It is used as a finish paint for a wide range of building materials such as sealing materials and elastic pavement materials.

[0003] This acrylic urethane-based finish coating composition is usually prepared by reacting a polyol with a polyisocyanate having no aromatic ring, an agent A mainly composed of a polyurethane prepolymer having a terminal isocyanate group, and a hydroxyl group-containing agent. Even now, two-part, room-temperature-curable compositions comprising a (meth) acrylic polymer and a B agent having a main component as a main component are still mainstream.

[0004]

Heretofore, Agent A has conventionally included polyether polyols such as polyoxypropylene glycol and polyoxytetramethylene glycol, or adipate and lactone polyester polyols, and hexamethylene diisocyanate and isophorone diisocyanate. In general, a solution of an isocyanate group-terminated polyurethane prepolymer obtained by a reaction with a polyisocyanate having no aromatic ring, which is diluted with a solvent, having an isocyanate group content of 1.0 to 5.0% by weight has been used.

On the other hand, agents B include styrene, acrylonitrile, acrylic acid, methyl acrylate, n-butyl acrylate, 2-hydroxyethyl acrylate,
Hydroxyl-containing (meth) acrylic polymer obtained by copolymerizing hydroxyethyl methacrylate or the like is diluted with a solvent, and further, pigments, fillers, catalysts, various stabilizers, plasticizers,
A solution to which a solvent was added was used.

[0006] Such a finish coating composition comprising a combination of a polyisocyanate having no aromatic ring and a hydroxyl group-containing (meth) acrylic polymer has an advantage of extremely excellent weather resistance. However, dioctyl phthalate (DO) used in urethane-based two-part waterproofing materials and painted flooring materials
Plasticizers such as P) tended to migrate, tackiness remained on the surface of the finished paint, and the adhesiveness tended to deteriorate significantly.

[0007]

The present invention is the following invention which has solved the above-mentioned problems. From an A agent mainly composed of an isocyanate group-terminated polyurethane prepolymer obtained by reacting a polyol having 2 or more functional groups with xylylene diisocyanate, and a B agent mainly composed of a hydroxyl group-containing (meth) acrylic polymer. Two-part cold curing surface finish coating composition. A method for applying a surface finishing coating composition, comprising applying the coating composition on a cured product of a urethane-based two-part cold-setting composition.

In the present invention, by using xylylene diisocyanate, migration of a plasticizer is suppressed, and yellowing resistance and weather resistance can be maintained without deteriorating adhesiveness. This is because the use of xylylene diisocyanate introduces an aromatic ring into the finish coating composition, so that the affinity with a plasticizer such as DOP migrated from a base such as a waterproof material is greatly improved, and the plasticizer It is thought that the transfer to the painted surface was suppressed.

As a result of repeated studies on polyisocyanates other than xylylene diisocyanate, the present inventors have found that the use of xylylene diisocyanate is excellent in surface tackiness, adhesion and weather resistance.
For example, tolylene diisocyanate has an aromatic ring, and similarly has an improved affinity for a plasticizer and can suppress migration of the plasticizer, but the yellowing resistance and weather resistance are significantly deteriorated. In the case of tetramethylxylylene diisocyanate, the adhesiveness is poor.

Examples of the polyol which is used as a raw material of the agent A in the present invention include polyether polyols such as polyoxypropylene glycol and polyoxytetramethylene glycol, and polyester polyols such as adipate and lactone.

The number of hydroxyl groups is preferably from 2 to 4. The molecular weight per hydroxyl group is preferably from 40 to 2,000. Considering the elongation characteristics of the cured coating film, the molecular weight per hydroxyl group is 300 ~
1,000 is more preferred.

The surface finish coating composition of the present invention is preferably applied to the surface of a urethane-based two-part waterproofing material or a coated flooring material, and is used for the urethane-based two-parting waterproofing material or a coated flooring material. It is preferable that the composition be similar to that described above.

The above polyol is reacted with xylylene diisocyanate to obtain an isocyanate group-terminated polyurethane prepolymer. It is preferable that the polyol and the xylylene diisocyanate are reacted at an equivalent ratio (the number of NCO groups / the number of OH groups) of 1.5 or more and less than 2.0. 2.0
In the above case, a large amount of the monomer xylylene diisocyanate remains, which is not preferable in terms of the working environment at the time of coating.

Usually, the agent A is preferably used by adding a solvent to the above isocyanate group-terminated polyurethane prepolymer and diluting it to a concentration of 20 to 50% by weight. As the solvent, xylene, toluene, ethyl acetate, butyl acetate, cellosolve acetate, cyclohexanone, ethylbenzene and the like are used. Further, the agent A may contain an isocyanate component other than the isocyanate group-terminated polyurethane prepolymer.

The hydroxyl group-containing (meth) acrylic polymer used in the agent B is preferably a polymer obtained by polymerizing a hydroxyl group-containing monomer and a (meth) acrylic monomer. In the present specification, (meth) acrylic refers to both methacrylic and acrylic. The same applies to (meth) acrylate and (meth) acrylic acid.

The monomer containing a hydroxyl group is also preferably a (meth) acrylic monomer.
And hydroxyethyl (meth) acrylate. As the (meth) acrylic monomer, methyl (meth) acrylate, ethyl (meth) acrylate, n-
Examples thereof include (meth) acrylic acid esters such as butyl (meth) acrylate, acrylonitrile, and (meth) acrylic acid. Further, a vinyl monomer other than the above may be copolymerized, and examples thereof include styrene.

The molecular weight per hydroxyl group of the hydroxyl group-containing (meth) acrylic polymer is preferably from 500 to 8,000, particularly preferably 1 to 8,000, in order to obtain compatibility with the isocyanate group-terminated polyurethane prepolymer and proper elongation of the cured coating film. 000 ~
4,000 is preferred.

The agent B is used by adding a solvent to the above-mentioned hydroxyl group-containing (meth) acrylic polymer and diluting it to a concentration of 40 to 80% by weight. As the solvent, xylene, toluene, ethyl acetate, butyl acetate, cellosolve acetate, cyclohexanone, ethylbenzene and the like are used.

Additives such as pigments, catalysts, various stabilizers, and the like can be further added to the agent B. Examples of the pigment include inorganic pigments such as chromium oxide and titanium oxide, and organic pigments such as phthalocyanine pigment and carbon black. An organic metal such as tin octoate, tin naphthenate, lead neodecanoate, dibutyltin dilaurate, and zinc octoate may be added to accelerate curing after application. further,
Stabilizers such as antioxidants and ultraviolet absorbers commonly used in polyurethane resins can be blended.

The mechanical strength of the cured coating film can be maximized by mixing the agent A and the agent B so that the equivalent ratio becomes 1.0 to 2.0.

The surface finish coating composition of the present invention is preferably applied to the surface of a urethane-based two-part waterproofing material or a coated flooring material.

As the urethane-based two-pack type room temperature-curable composition in the construction method of the present invention, a urethane-based two-pack type waterproofing material, a coated flooring material and the like can be usually used.

The urethane two-pack type room temperature curable composition comprises a main component mainly composed of an isocyanate group-terminated polyurethane prepolymer obtained by reacting a polyol having two or more functional groups with a polyisocyanate, and an active hydrogen compound such as a polyamine. And a curing agent component having the formula: As the polyol having two or more functional groups, a polyol used as a raw material of the agent A is preferable. As the polyisocyanate, an aliphatic polyisocyanate, an alicyclic polyisocyanate, or an aromatic polyisocyanate is preferable, and an aromatic polyisocyanate such as tolylene diisocyanate or 4,4'-diphenylmethane diisocyanate is particularly preferable.

Usually, a plasticizer is contained in the curing agent component. DOP is generally used as a plasticizer. The present invention
It is suitable as a surface finish coating composition of a urethane two-part cold curing composition containing DOP as a plasticizer. DOP, which is a plasticizer, accounts for 10% by weight or more, particularly 15% by weight of the composition.
It is particularly suitable for a surface finishing coating composition of a urethane-based two-part cold-setting composition containing at least 10% by weight.

As described above, the use of xylylene diisocyanate as the agent A in the finish coating composition of the present invention suppresses the transfer of a plasticizer such as DOP, and does not cause tackiness on the surface. Without deteriorating the yellowing resistance and weather resistance.

[0026]

【Example】

"Waterproofing material 1" 800 g of polyoxypropylene diol having a molecular weight of 2,000 and 200 g of polyoxypropylene triol having a molecular weight of 3,000
A polyurethane prepolymer having an isocyanate group content of 3.5% by weight obtained by adding 4 g and reacting was used as a main ingredient.

38.56 g of 4,4-methylene-bis (2-chloroaniline) previously melted by heating and 89.96 g of polyoxypropylene diol having a molecular weight of 2,000
Calcium carbonate 600g, DOP 171.48g, xylene 30g, titanium oxide 50g, carbon black 1
0 g and 10 g of lead octanoate (lead content 24%) were mixed to obtain a curing agent.

The main agent and the curing agent were mixed at a 1/2 weight ratio [the number of NCO groups / (the number of NH ₂ groups + the number of OH groups) = 1.1] and used as a waterproof material 1. DOP content in waterproofing material 1 is 1
1.43% by weight.

"Waterproofing material 2" Using the same base material as waterproofing material 1, 33.7 g of diethyltoluenediamine, 550 g of calcium carbonate, 326.3 g of DOP, 30 g of xylene,
A mixture of 50 g of titanium oxide and 10 g of carbon black was used as a curing agent. 1/2 weight ratio [N
The number of CO groups / (the number of NH ₂ groups + the number of OH groups) = 1. The DOP content in the waterproof material 2 is 21.75% by weight.

"B agent" The B agent of the finish coating composition was obtained by copolymerizing styrene, n-butyl acrylate and 2-hydroxyethyl methacrylate.
A solution having a solid content of 60% by weight and a hydroxyl value of 14 mgKOH / g obtained by mixing titanium oxide, carbon black and toluene with a copolymer having a molecular weight of 2,000 per hydroxyl group was used.

Example 1 To 273 g of polyoxytetramethylene glycol having a molecular weight of 690, 127 g of xylylene diisocyanate (equivalent ratio 1.7) was added, and the mixture was placed in a reaction vessel.
The reaction was carried out at 0 ° C. for 4 hours, and the isocyanate group content was 5.
8% by weight of polyurethane prepolymer was obtained. To this
00g of toluene was added and dissolved to obtain Agent A. This A
Agent B and Agent B were mixed at a 2/3 weight ratio (equivalent ratio of 1.5) to obtain a finished paint.

Example 2 106 g of xylylene diisocyanate (equivalent ratio: 1.9) was added to 294 g of polyoxytetramethylene glycol having a molecular weight of 1,000, and the mixture was reacted in a reaction vessel at 70 ° C. for 4 hours to obtain an isocyanate group content of 5. 6% by weight of polyurethane prepolymer was obtained. To this, 600 g of toluene was added and dissolved to obtain Agent A. The A agent and the B agent were mixed at a 2/3 weight ratio (equivalent ratio of 1.5) to obtain a finish paint.

Example 3 90 g of xylylene diisocyanate (equivalent ratio: 1.75) was added to 270 g of polyoxytetramethylene glycol having a molecular weight of 1,000, and the mixture was reacted at 70 ° C. for 4 hours in a reaction vessel to obtain an isocyanate group content of 4. 7% by weight of polyurethane prepolymer was obtained. To this, 40 g of a trimethylolpropane adduct of hexamethylene diisocyanate (trade name: Coronate HL, manufactured by Nippon Polyurethane Co., Ltd.) and 600 g of toluene were added and dissolved to obtain Agent A. The A agent and the B agent were mixed at a 2/3 weight ratio (equivalent ratio: 1.5) to obtain a finish paint.

Example 4 (Comparative Example) To 283 g of polyoxytetramethylene glycol having a molecular weight of 690, 117 g of hexamethylene diisocyanate (equivalent ratio 1.7) was added.
The reaction was carried out at 80 ° C. for 5 hours in a reaction vessel to obtain a polyurethane prepolymer having an isocyanate group content of 5.8% by weight. To this, 600 g of toluene was added and dissolved to obtain Agent A. The A agent and the B agent were added in a 2/3 weight ratio (equivalent ratio of 1.
The mixture was mixed in 5) to obtain a finish paint.

Example 5 (Comparative Example) 144 g of isophorone diisocyanate (equivalent ratio: 1.75) was added to 256 g of polyoxytetramethylene glycol having a molecular weight of 690, and the mixture was reacted at 80 ° C. for 5 hours in a reaction vessel. An amount of 5.8% by weight of polyurethane prepolymer was obtained. To this, 600 g of toluene was added and dissolved to obtain Agent A. 2/3 weight ratio of this agent A and agent B (equivalent ratio 1.5)
To obtain a finished paint.

Example 6 (Comparative Example) 247 g of polyoxytetramethylene glycol having a molecular weight of 690 was added to 153 g of tetramethylxylylene diisocyanate (equivalent ratio: 1.7).
5) was added, and the reaction was carried out at 80 ° C. for 5 hours in a reaction vessel.
A polyurethane prepolymer having an isocyanate group content of 5.6% by weight was obtained. To this, 600 g of toluene was added and dissolved to obtain Agent A. The A agent and the B agent were mixed at a 2/3 weight ratio (equivalent ratio: 1.5) to obtain a finish paint.

Example 7 (Comparative Example) To 238 g of polyoxytetramethylene glycol having a molecular weight of 690, 162 g of hydrogenated diphenylmethane diisocyanate (equivalent ratio 1.8) was added, and the reaction was carried out at 80 ° C. for 5 hours in a reaction vessel. A polyurethane prepolymer having a group content of 5.7% by weight was obtained. To this, 600 g of toluene was added and dissolved to obtain Agent A. The A agent and the B agent were mixed at a 2/3 weight ratio (equivalent ratio: 1.5) to obtain a finish paint.

Example 8 (Comparative Example) 118 g of tolylene diisocyanate having a 2,4-isomer content of 80% in 282 g of polyoxytetramethylene glycol having a molecular weight of 690
(Equivalent ratio: 1.65), and the mixture was reacted at 70 ° C. for 3 hours in a reaction vessel to obtain a polyurethane prepolymer having an isocyanate group content of 5.6% by weight. To this, 600 g of toluene was added and dissolved to obtain Agent A. The A agent and the B agent were mixed at a 2/3 weight ratio (equivalent ratio: 1.5) to obtain a finish paint.

[Test Method] Under a condition of 20 ° C. and 65% RH, a waterproof material 1 or a waterproof material 2 was applied as a base material to a 30 cm square slate plate at 2.5 kg / m ² , and after 48 hours, various finish paints were applied with a brush. The coating was performed so as to be 0.2 kg / m ² . One day, three days, and five days after the application of the finish paint, a surface tackiness test (A), an adhesion test (B), and a xylene cutter test (C) were performed. Table 1 shows the test results for the waterproof material 1 and Table 2 shows the test results for the waterproof material 2.

Various finish paints are applied to an aluminum plate by spraying at a concentration of 0.2 kg / m ² and left for one week, and then the gloss retention and the color difference (weather resistance) after irradiation with a weather meter (WOM) for 1000 hours. (D)) was measured. Table 3 shows the results.

"Evaluation method" (A) Surface tackiness test: A finish paint was applied to the waterproof base material, and the surface tackiness after curing (after 24 hours) was observed with a finger. The results are shown as ○: no tack, Δ: slight tack, ×: marked tack.

(B) Adhesion test: 1 mm interval with a razor, 1
Zero cuts are made vertically and horizontally to make a grid of 1 mm square x 100 pieces, and a cellophane tape (Nichiban) is adhered to the entire surface, then peeled off at a stretch in the vertical direction, and the final paint is adhered. The sex was examined. The result was represented by the number of squares that did not peel.

(C) Xylene cutter test: Xylene was dropped on the cross section after the tape peeling test was completed, scratched with a razor blade, the state of peeling of the finished paint was examined, and the solvent (xylene) resistance was examined. . The results were as follows: ○: no peeling, Δ:
Half-face peeling, ×: Denotes whole peeling.

(D) Weather resistance test: black panel temperature 6
An accelerated weathering test by WOM was performed under water spray conditions of 3 ° C., 60% RH and 12 minutes per hour. Changes in gloss retention and color difference after irradiation for 1000 hours were measured.

[0045]

[Table 1]

[0046]

[Table 2]

[0047]

[Table 3]

[0048]

As described above, in the two-part curable acrylic urethane-based finish coating composition of the present invention, by using xylylene diisocyanate as the agent A, migration of a plasticizer such as DOP can be suppressed. Also, since yellowing resistance and weather resistance can be maintained without causing surface tack and deteriorating adhesiveness, it can be sufficiently applied to a waterproof material containing a large amount of a plasticizer.

Claims (4)

[Claims] 1. An agent A mainly composed of an isocyanate group-terminated polyurethane prepolymer obtained by reacting a polyol having two or more functional groups with xylylene diisocyanate, and a hydroxyl group-containing (meth) acrylic polymer as a main component. A two-pack, room-temperature-curable surface finish coating composition comprising a B agent. 2. The method according to claim 1, wherein the hydroxyl group-containing (meth) acrylic polymer is
The coating composition according to claim 1, which is a polymer obtained by polymerizing a hydroxyl group-containing monomer and a (meth) acrylic monomer. 3. A method for applying a surface finishing coating composition, comprising applying the coating composition according to claim 1 on a cured product of a urethane-based two-part cold curing composition. 4. The method according to claim 3, wherein the urethane two-part cold-setting composition contains a plasticizer.