JP2893852B2 - Metallic paint composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a novel and useful metallic coating composition. More specifically, the present invention relates to a metallic coating composition having excellent metallic feeling, which comprises using unique crosslinked particles called crosslinked urethane-urea particles as a specific compounding component of the present invention.

[Conventional technology]

From the viewpoint of environmental protection, it has become necessary to regulate the amount of solvent discharged. The paint industry has begun to use high solids resins with low solvent content to reduce solvent emissions. However, when this high solid type resin is used for a metallic base paint, since the metal powder is inevitably oriented in an unspecified direction, a coating film having a sufficiently satisfactory metallic feeling can be obtained. There was a disadvantage that it could not be obtained.

Of course, in order to solve such a drawback, there is a method of incorporating an acrylic microgel obtained by emulsion polymerization using an emulsifier, or a method of incorporating cellulose acetate butyrate (CAB). However, the latter has the problem that it is difficult to obtain it recently.

[Problems to be solved by the invention]

As described above, in actuality, as long as the conventional technique is followed, it is impossible to obtain a coating composition capable of exhibiting a metallic feeling.

For this purpose, the present inventors have enthusiastically started a research for an extremely practical metallic coating composition which can solve the above-mentioned disadvantages of the prior art.

Therefore, the problem to be solved by the present invention is, on the one hand, a grade that is actually required by various industries such as the automobile industry, that is, a highly practical paint that can exhibit a high-grade metallic feeling. It is to provide a composition.

[Means for solving the problem]

Therefore, the present inventors have focused on the problem to be solved by the invention as described above, and as a result of intensive studies, as a component, a specific crosslinked particle called crosslinked urethane-urea particles. The present invention has been completed by finding that a coating composition to be used has an excellent metallic feeling.

That is, the present invention intends to provide a metallic coating composition comprising, as essential components, a film-forming component, a crosslinked urethane-urea particle component, and a metal powder component, respectively.

Here, first, as the above-mentioned coating film forming component, of course, it is not particularly limited as long as it can form a coating film, including acrylic lacquer and thermoplastic emulsion resin, and further, As represented by a combination of a hydroxyl group-containing resin and a melamine resin, or a combination of a hydroxyl group-containing resin and a polyisocyanate,
Examples include a combination of resins having functional groups that can react with each other, or a thermosetting resin typified by an aluminized resin.

Next, as the above-mentioned crosslinked urethane-urea particles,
For example, it is obtained by reacting an isocyanate prepolymer having at least two isocyanate groups in one molecule with a polyamine compound having at least two amino groups in one molecule.

The isocyanate prepolymer is, for example, one obtained from diisocyanates and polyols having at least two hydroxyl groups in one molecule, and if only typical representative examples of such diisocyanates are given, 4,4'-diphenylmethane diisocyanate, toluene diisocyanate, 1,6-
Hexamethylene diisocyanate, isophorone diisocyanate or 4,4'-methylene bis (cyclohexyl isocyanate).

On the other hand, if only the typical polyols described above are exemplified, ethylene glycol, 1,3
-Aliphatic hydrocarbon diols having 2 to 10 carbon atoms such as propanediol, 1,4-butanediol, 1,5-pentanediol or neopentyl glycol; represented by monoglycerides of fatty acids derived from animal and vegetable oils. Diols having both a carboxylic acid represented by dimethylolpropionic acid and a hydroxyl group; diols having a sulfonic acid group such as dimethylolpropanesulfonic acid and a compound having both hydroxyl groups; polyoxyethylene glycol; An equimolar reaction product of polyoxyethylene glycol monomethyl ether, polyoxyethylene tetramethylene glycol or polyoxyethylene tetramethylene glycol monomethyl ether with the above-mentioned diisocyanates is reacted with one amine hydrogen such as diethanolamine and two amines. Diols obtained by reacting with a compound having an acid group; polyols such as glycerin, trimethylolpropane, 1,2,6-hexanetriol, pentaerythritol or sorbitol; phthalic acid, maleic acid, adipic acid or Polyester polyols obtained by an esterification reaction of at least one dicarboxylic acid selected from hexahydrophthalic acid or anhydrides thereof with diols as described above; or US Pat. No. 3,919,351. And the like, as well as adducts of the above polyol compounds with cyclic caprolactones such as ε-caprolactone.

The reaction between the diisocyanates and the polyols should be carried out in a molar ratio such that two isocyanate groups are present in one molecule of the isocyanate prepolymer to be produced.

As a solvent used in the reaction, any solvent having no active hydrogen may be used. If necessary, a metallic, basic or acidic urethanization catalyst represented by di-n-butyltin dioctoate, 1,4-diazabicyclo [2.2.2] octane or boron trifluoride may be used in a conventional manner. Can be used.

Further, if only typical examples of the polyamine compound having at least two amino groups in one molecule are given, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, tris (2-aminoethyl) Amine, 4-aminomethyl-1,8-diaminooctane, hydrazine or polyoxyalkyleneamine represented by "Jeffamine" (trademark of Texaco, USA).

The reaction between the isocyanate prepolymer and the polyamine compound can be performed in the presence of an aqueous medium.

Such an aqueous medium means water and / or a solvent that can be dissolved in water. When reacting in the presence of such a medium, a mixed solution of a polyamine compound and an aqueous medium is used.
There is a method of dropping an isocyanate prepolymer solution to form an aqueous dispersion, or a method of mixing an aqueous medium with the isocyanate prepolymer solution to form an aqueous dispersion and then dropping a polyamine compound.

If the isocyanate prepolymer has a carboxylate or sulfonic acid group, it must be neutralized with a tertiary amine compound.

When an aqueous medium is dropped into the isocyanate prepolymer solution to form an aqueous dispersion, a resin having an aqueous dispersing ability may be used.

Examples of such a resin having an aqueous dispersing ability include a polycarboxylic acid-based amine-neutralized resin and a resin having a polyoxyethylene chain.

An appropriate mixing ratio of the isocyanate prepolymer and the polyamine compound is such that the ratio of isocyanate group / amino group is 0.8 or more. By doing so, a favorable result is obtained in appearance.

The solution of the urethane-urea particles synthesized by the method as described above may be used, if necessary, such as toluene, xylene, methyl isobutyl ketone or methyl amyl ketone.
Azeotropic dehydration with an organic solvent that is not completely soluble in water,
It may be used in such a form that it is once mixed with the film-forming component and then azeotropically dehydrated with the organic solvent as described above.

The compounding amount of the urethane-urea particles to the film-forming component is
The range of 0.5 part by weight or more and 40 parts by weight or less based on 100 parts by weight of the solid content of the film-forming component is preferable from the viewpoint of the anti-sagging effect and the appearance of the film.

Aluminum flakes, stainless steel powder, gold powder, silver powder, copper powder, brass powder, nickel powder, and the like can be mentioned only as typical examples of the metal powder.

The resin composition of the present invention thus obtained contains, as necessary, a colorant such as an organic pigment or an inorganic pigment, a known and commonly used color separation inhibitor, an ultraviolet absorber, and various additives such as an antioxidant. Fibrous derivatives such as nitrocellulose and cellulose acetate butyrate (CAB); and various resins such as chlorinated polyethylene, chlorinated polypropylene, petroleum resin or chlorinated rubber.

〔Example〕

Next, the present invention by reference examples, examples and comparative examples,
Although described more specifically, the present invention is not limited to only these examples. In the following examples, “%” and “parts” are all based on weight unless otherwise specified.

Reference Example 1 (Preparation example of vinyl resin having water dispersing ability) A mixed liquid composed of 200 parts of styrene, 176 parts of methyl methacrylate, 24 parts of methacrylic acid, and 8 parts of tert-butyl peroxyoctoate was prepared. did. Stirrer,
60 parts of the above mixture and 400 parts of methyl ethyl ketone were charged into a nitrogen atmosphere flask equipped with a condenser, a nitrogen inlet tube and a dropping device, and after maintaining at 75 ° C. for 30 minutes, the remaining mixture was added to 5 parts. The reaction was carried out at the same temperature for 8 hours, and the nonvolatile content was 50% and the acid value was 20%.
And a target resin having a Gardner viscosity of W at 25 ° C. was obtained.

Reference Example 2 (Preparation Example of Urethane-Urea Particles) The following compound was charged into a nitrogen atmosphere flask equipped with a stirrer, a condenser, a nitrogen inlet tube, and a dropping device.

"Placcel 212-JI-1" [Polycaprolactone diol manufactured by Daicel Chemical Industries, Ltd .; Mn = 1,250] 178 parts Safflower oil-modified diol 108 parts Isophorone diisocyanate 186 parts The temperature was raised to 120 ° C. with stirring for 30 minutes. After holding,
0.05 parts of di-n-butyltin dioctate were added and the temperature was maintained for another hour.

After the temperature was lowered to 80 ° C., 500 parts of methyl ethyl ketone and 28 parts of dimethylolpropionic acid were added, and the mixture was heated and stirred at 75 ° C. for 7 hours to give a nonvolatile content of 51% and an acid value of 12%.
Thus, an isocyanate prepolymer having an isocyanate content of 1.3% and a Gardner viscosity of Z ₂ was obtained.

Then, 200 parts of this prepolymer and 100 parts of methyl ethyl ketone were stirred and mixed, and an aqueous solution consisting of 4.5 parts of triethylamine and 400 parts of water and an aqueous solution consisting of 1.67 parts of diethylenetriamine and 20 parts of water were gradually added dropwise.

Thereafter, the mixture was stirred at 70 ° C. for 1 hour and the solvent was removed under reduced pressure to obtain a urethane-urea particle dispersion having a nonvolatile content of 26% and a particle size of 1 μm or less. This is abbreviated as A-1.

Reference Example 3 (same as above) In the same apparatus as in Reference Example 2, "Macromonomer HS-6" (a diol having a polystyrene chain manufactured by Toagosei Chemical Industry Co., Ltd .; Mn = 6,000) 117 parts Methyl ethyl ketone 370 parts Isophorone diisocyanate 88 After mixing 0.01 parts of tin octenoate, the mixture was stirred at 80 ° C for 2 hours. Next, 150 parts of “Placcel 212-JI-1” was added, and the mixture was stirred for 3 hours.
Thereafter, 20 parts of dimethylolpropionic acid was added, and the mixture was kept for 5 hours to obtain an isocyanate prepolymer having a nonvolatile content of 40%, an acid value of 10, and an isocyanate content of 0.9%.

Thereafter, 200 parts of this prepolymer and 100 parts of ethyl ethyl ketone were stirred and mixed, and an aqueous solution consisting of 3.6 parts of triethylamine and 400 parts of water and an aqueous solution consisting of 1.67 parts of diethylenetriamine and 20 parts of water were gradually added dropwise.

Thereafter, after further stirring at 70 ° C. for 1 hour, the solvent was removed under reduced pressure to obtain a urethane-urea particle dispersion having a nonvolatile content of 20% and a particle diameter of 1 μm or less. Hereinafter, this is abbreviated as A-2.

REFERENCE EXAMPLE 4 (same as above) In a reactor similar to Reference Example 2, under nitrogen atmosphere, a vinyl resin having water dispersibility of 200 parts "Bernock DN-950" [a polyisocyanate manufactured by Dainippon Ink and Chemicals, Incorporated; After stirring and mixing 75 parts by weight of non-volatile content and 20 parts of Gardner viscosity KO 80 parts of methyl ethyl ketone, an aqueous solution consisting of 4 parts of triethylamine and 400 parts of water was gradually added dropwise to form a milky white dispersion, and then 2 parts of diethylenetriamine An aqueous solution consisting of 20 parts of water was gradually added dropwise, and the temperature was raised to 70 ° C. and reacted for 1 hour. Thereafter, the organic solvent was removed under reduced pressure to obtain a urethane-urea particle dispersion having a nonvolatile content of 30% and a particle diameter of 1 μm or less. Hereinafter, this is abbreviated as A-3.

Examples 1 to 3 and Comparative Examples 1 to 3 Using the respective resin solutions obtained in Reference Examples 2 to 4, paints were prepared at the composition ratios shown in Table 1 and sprayed separately. Painted.

The results for each coating are summarized in the table.

Footnotes in Table 1 1) After mixing with the main ingredient, azeotropic dehydration was performed using xylene.

2) Hydroxyl-containing acrylic resin manufactured by Dainippon Ink and Chemicals, Inc .; nonvolatile content of 50%, Gardner viscosity Z ₁ -Z ₃ 3) Hydroxyl-containing polyester resin manufactured by the same company;
65%, Gardner viscosity T 4) Hydroxyl group-containing acrylic resin manufactured by the same company;
%, Gardner viscosity W-Z 5) Butylated melamine resin manufactured by the same company;
Gardner Viscosity FJ 6) Polyisocyanate manufactured by the same company; non-volatile content 75%, Gardner Viscosity AD 7) Aluminum flakes manufactured by Toyo Aluminum Co., Ltd. 8) Metallic feeling measurement device “AL” manufactured by Kansai Paint Co.
The IV value measured by `` COPE LMR-100 '' is 180 to 24, respectively.
A range of 0 was defined as “good”, and a range exceeding 240 was defined as “excellent”.

9) For 15 seconds (Ford Cup), dilute the metallic paint of the composition shown in Table 1 with a thinner and spray-coat. After setting for 5 minutes, "Acridic A-310" / "Super Beckamine L-117-60""= 7/3 (solid ratio) of a clear paint was diluted with a thinner for 25 seconds (Ford Cup), spray-coated, baked at 140 ° C. for 20 minutes after setting for 10 minutes.

10) For 15 seconds (Ford Cup), dilute the metallic paint with the thinner in 15 minutes (spray paint) and spray-coat. After setting for 5 minutes, “Acridic BU-955” /
"Barnock DN-981" = 100/24 (solution ratio) clear paint consisting of 20 seconds (Ford Cup) diluted with thinner and spray-painted. After setting for 10 minutes,
Baking was performed at 80 ° C. for 30 minutes.

〔The invention's effect〕

As described above, the metallic coating composition of the present invention is particularly suitable for automobiles, in particular, as an enamel paint for automobiles, or as a clear paint, or a home appliance, since it has an excellent metallic feeling. It can be used for general baking, building, exterior use such as coil coating such as roof tiles or PCM, and for surface protection of porous materials such as glass, ceramic products, foamed concrete or woodwork products. it can.

Claims (9)

(57) [Claims] 1. A metallic coating composition comprising a film-forming component, crosslinked urethane-urea particles and metal powder. 2. The metallic coating composition according to claim 1, wherein the film-forming component is a combination of a hydroxyl group-containing resin and a melamine resin or a polyisocyanate. 3. The crosslinked urethane-urea particles are obtained by reacting an isocyanate prepolymer having at least two isocyanate groups in one molecule with a polyamine compound having at least two amino groups in one molecule. The metallic coating composition according to claim 1, wherein the coating composition is obtained. 4. An aqueous medium comprising the above crosslinked urethane-urea particles comprising an isocyanate prepolymer having at least two isocyanate groups in one molecule and a polyamine compound having at least two amino groups in one molecule. The metallic coating composition according to claim 1 or 2, which is obtained by reacting the composition. 5. An isocyanate prepolymer having at least two isocyanate groups per molecule in the presence of a resin capable of dispersing in water, wherein the crosslinked urethane-urea particles have at least two isocyanate groups per molecule. The metallic coating composition according to claim 1 or 2, which is obtained by reacting a polyamine compound having an amino group with an aqueous medium in an aqueous medium. 6. The crosslinked urethane-urea particles obtained by reacting a diisocyanate compound having two isocyanate groups in one molecule with a polyol having at least two hydroxyl groups in one molecule. 6. The metallic coating composition according to claim 3, wherein an isocyanate prepolymer having at least two isocyanate groups in a molecule is used. 7. The cross-linked urethane-urea particles according to claim 1, wherein at least one of the polyols having at least two hydroxyl groups in one molecule is a polyol having a carboxylic acid group or a sulfonic acid group. The metallic coating composition according to claim 6, which is obtained by converting these acid groups into an amine salt or a metal salt and then reacting the prepolymer with a polyamine compound. 8. The crosslinked urethane-urea particles are obtained by using a polyol having a polyoxyethylene chain as at least one of the polyols having at least two hydroxyl groups in one molecule. The metallic coating composition according to claim 6, which is a composition. 9. The crosslinked urethane-urea particles are obtained by using a monoglyceride of a fatty acid as at least one of the polyols having at least two hydroxyl groups in one molecule. Item 7. A metallic coating composition according to item 6.