KR20100103386A - Metallic coating composition - Google Patents

Abstract

PURPOSE: A metallic paint composition is provided to properly align a glittering material for forming a coating layer with the superior brightness as a result. CONSTITUTION: A metallic paint composition contains an unsaturated group-containing urethane resin composition, an organic solvent, and a glittering material. The unsaturated group-containing urethane resin composition is a reaction product of a compound with active hydrogen, an alicyclic or aromatic polyisocyanate compound, and a (meth)acrylate compo with the active hydrogen. The reaction product includes a urethane bond or a (meth)acryloyl group.

Description

Metallic Coating Composition {METALLIC COATING COMPOSITION}

This invention relates to the metallic coating composition which can orientate a bright material favorably and can form the coating film excellent in the bright feeling.

In metallic paints, when the coatings of automobiles, general industries, etc. are steel sheets, the acrylic melamine resin, which is a baking coating, is a plastic plate, such as a PC or a mobile phone. Each is widely used.

However, isocyanate-curable urethane resins used in plastic paints require a reaction time (a few hours time to final curing) until the resin is cured. Moreover, since this is generally low (soft) in coating film hardness, the appearance of being able to form a high hardness coating film from the standpoint of flaw prevention etc. is desired. On the other hand, since baking coating requires application of high temperature, it is not suitable for plastic use.

Among various resins for coatings, ultraviolet curable resins are cured for a short time (tens of seconds) by irradiation with ultraviolet rays, and in the meantime, the temperature of the coating object is raised to such an extent that the plastic can withstand it, and thus it is widely used in plastic applications. Especially in the case of ultraviolet curable resin containing a polyfunctional acrylate oligomer, it is known that a coating film of high hardness can be formed.

However, the conventional ultraviolet curable resin comprised of such a low molecular weight acrylate oligomer, when these are used for metallic coatings, sufficient viscosity increase accompanying the volatilization of the solvent required in order to suppress the movement of the bright material after spray coating, The drying necessary for fixing the bright material could not be expected, and therefore, it was difficult to obtain a metallic coating film having a good brightness and excellent brightness.

Accordingly, it is an object of the present invention to provide a metallic coating composition capable of orienting a bright material satisfactorily and forming a coating film excellent in brightness as a result.

MEANS TO SOLVE THE PROBLEM The present inventors apply a metallic coating composition which consists of the following specific unsaturated-group-containing urethane resin compound (a), an organic solvent, and a bright material to a to-be-coated object by spray coating, and a viscosity rises suitably with the volatilization of an organic solvent, Therefore, it was found that the movement of the bright material was stopped, and then the bright material was pressed by shrinkage of the coating film accompanying drying, and as a result, good orientation of the bright material was realized and a metallic coating film having excellent brightness was formed.

The unsaturated group-containing urethane resin compound (a) in the present invention has a compound (A) having a molecular weight of 300 or less having an active hydrogen of 2 or more, an alicyclic or aromatic polyisocyanate compound (B) and an active hydrogen (meth ) It is a reaction product of an acrylate compound (C). This reaction product has a urethane bond and a (meth) acryloyl group in a molecule | numerator, 3000 or more, Preferably it is the molecular weight of 3000-30000, 2 or more, Preferably it is 2-10 unsaturated groups, and 2 million mPa * s It can be characterized by having the above-mentioned viscosity (preferably the viscosity which shows wax shape at normal temperature).

The unsaturated group-containing urethane resin compound (a) is not particularly limited to the structure as long as it satisfies the above conditions as a reaction product of the compound (A), the compound (B), and the compound (C). It is preferable that it is functional and is higher viscosity. Preferable examples of the unsaturated group-containing urethane resin compound (a) include reacting cyclohexyldimethanol as the compound (A) with isophorone diisocyanate as the compound (B) and dipentaerythritol pentaacrylate as the compound (C). Polymer obtained by, i.e.

Compound (C)-Compound (B)-(Compound (A)-Compound (B)) x-Compound (C)

(X is the number of repeating units). The unsaturated group-containing urethane resin compound (a) having such a structure is synthesized in the form of an organic solution.

The compound (A) should just be a compound with a molecular weight of 300 or less which has two or more hydroxyl groups. Polyhydric alicyclic alcohols such as cyclohexyl dimethanol, tricyclodecane dimethanol, decahydronaphthalene dimethanol, tetralin dimethanol, norbornene dimethanol, pentacyclododecane dimethanol and the like; Ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol And polyhydric aliphatic alcohols such as 1,10-decanediol, 3-methyl-1,5-pentanediol, neopentylglycol, 2-methyl-1,8-octanediol and the like.

The compound (B) should just be a compound in which an alicyclic or aromatic structure is contained in polyisocyanate. For example, tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, xylylene diisocyanate, xylene diisocyanate, 4,4-methylenebis (cyclohexyl isocyanate) methylcyclohexane-2,4 (or 2,6 ) -Isocyanate, 1,3- (isocyanatemethyl) cyclohexane, isophorone diisocyanate, 1,5-naphthalene diisocyanate, polymethylene polyphenylene diisocyanate, triphenylmethanetriisocyanate, naphthalene diisocyanate, 1,3- Cyclohexylene diisocyanate, tolylene diisocyanate polymer, a diphenylmethane diisocyanate polymer, etc. are mentioned.

The compound (C) should just be a compound which has a (meth) acrylate group and active hydrogen in a molecule | numerator. For example, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 3-hydroxy butyl acrylate, polyethylene glycol monoacrylate, pentaerythritol triacrylate, di Hydroxy acrylates such as pentaerythritol pentaacrylate and 2-hydroxy-1-acryloxy-3-methacrylate; (Meth) acrylic acid adduct of propylene glycol diglycidyl ether; (Meth) acrylic acid adduct of 1,6-hexanediol diglycidyl ether; (Meth) acrylic acid adduct of 1,4-butanediol diglycidyl ether; (Meth) acrylic acid adduct of 1,5-pentanediol diglycidyl ether; (Meth) acrylic acid adduct of 1,7-heptane diol diglycidyl ether; And (meth) acrylic acid adducts of 1,8-octanediol diglycidyl ether.

Moreover, the (meth) acrylic acid addition product of neopentyl glycol diglycidyl ether, the (meth) acrylic acid addition product of bisphenol A diglycidyl ether, and the (meth) acrylic acid addition of hydrogenated bisphenol A diglycidyl ether Water and the like.

The metallic coating composition of this invention mix | blends the organic solvent and bright bright material with the above unsaturated group containing urethane resin compound (a).

The organic solvent is not particularly limited as long as it can dissolve the unsaturated group-containing urethane resin compound (a) and can be sprayed. For example, methyl ethyl ketone, butyl acetate, ethyl acetate, methyl isobutyl Ketone, toluene, ethyl glycol acetate, butyl acetate, etc. can be used preferably. The usage-amount of an organic solvent will be an amount required in order to make a coating composition the sprayable viscosity, or an amount less than it. In the latter case, it is necessary to adjust the viscosity of the composition to the sprayable viscosity by adding an organic solvent prior to spray coating. The bright material is not particularly limited as long as it is a pigment that gives the coating film a brightness such as a metal. Generally, aluminum, other metal pigments, pearl pigments, and the like are preferably used.

As for the usage-amount of a bright bright material, 5-35 weight part is preferable with respect to 100 weight part (solid content) of an unsaturated-group-containing urethane resin compound (a).

The metallic coating composition of the present invention may be blended with an appropriate amount of conventional additives such as antisettling agents, leveling agents and the like, as necessary.

The metallic coating composition of the present invention is usually applied to a coating object by spray coating. In that case, when the viscosity of a composition is high, it is necessary to adjust the viscosity to 10 to 18 second (20 degreeC) viscosity by sprayable viscosity, for example, pod cup # 4, by adding an organic solvent. By spray-coating a coating film having a thickness of 5 to 30 µm, preferably 10 to 20 µm, and then irradiating with ultraviolet rays, a metallic coating film having good alignment of the bright material and excellent brightness can be obtained.

Next, embodiment of this invention is described concretely. In the following, both parts and% are based on weight.

Example 1

Unsaturated group-containing urethane resin compound (a) and methyl ethyl ketone by weight

100 parts of solution containing 60% to 40% of ratio

ALPASTE 5620NS Part 16

(Aluminum pigment paste manufactured by Toyo Aluminum Industry Co., Ltd .; solid content 70%)

IRGACURE 184 (Ciba's photoinitiator) 4 parts

NS-5500 (sedimentation inhibitor manufactured by Kusumoto Mars Co., Ltd.) 10 parts

The said metal component was disperse | distributed in butyl acetate and adjusted to the viscosity of 12 second (20 degreeC) with the pod cup # 4, and the metallic coating composition of this invention was prepared.

The said unsaturated group containing urethane resin compound (a) is the said general obtained by making cyclohexyl dimethanol as a compound (A), isophorone diisocyanate as a compound (B), and dipentaerythritol pentaacrylate as a compound (C) react. As a polymer of a structural formula, it has a molecular weight of 9200 and an unsaturated group of 10, a viscosity is 2 million mPa * s or more, and it is wax shape at normal temperature.

Example 2

Unsaturated group-containing urethane resin compound (a) and methyl ethyl ketone by weight

120 parts of solution containing 50% to 50% of ratio

ALPASTE 5620NS (transfer) part 16

IRGACURE 184 (transfer) part 4

NS-5500 (Transfer) part 10

The metallic coating composition of this invention was prepared by disperse | distributing the said component in butyl acetate and adjusting it to the viscosity of 12 second (20 degreeC) with the pod cup # 4.

The said unsaturated group containing urethane resin compound (a) is the said general obtained by making cyclohexyl dimethanol as a compound (A), isophorone diisocyanate as a compound (B), and 2-hydroxyethyl acrylate as a compound (C) react. As a polymer of a formula, it has a molecular weight of 3900 and 2 unsaturated groups, has a viscosity of 2 million mPa * s or more, and is wax shape at normal temperature.

Comparative example

This comparative example illustrates the prior art which consists of a urethane oligomer of low molecular weight.

Comparative Resin-1 60parts

ALPASTE 5620NS (transfer) part 16

IRGACURE 184 (transfer) part 4

NS-5500 (Transfer) part 10

The said metal component was disperse | distributed in butyl acetate and it adjusted to the viscosity of 14 second (20 degreeC) with the pod cup # 4, and the metallic coating composition of the prior art was prepared.

The said comparative resin-1 has the said structural formula (a value of x is small) obtained by making cyclohexyl dimethanol as a compound (A), isophorone diisocyanate as a compound (B), and pentaerythritol triacrylate as a compound (C) react. ) Has a molecular weight of 1500 and an unsaturated group of 6, has a viscosity of 35000 mPa · s and is liquid at room temperature.

Test Example

The metallic coating compositions of Examples 1, 2 and Comparative Examples were respectively applied by air spray to a polycarbonate plate and dried at 60 ° C. for 10 minutes, and then 1400 using a metal halide lamp of 120 W / cm as a light source. By irradiating an ultraviolet-ray with the accumulated light quantity of mJ / cm <2>, the metallic coating film of thickness 12micrometer was produced. For each coating film, the flop index and visual brightness, adhesiveness, and pencil hardness were measured, and the results are shown in Table 1 below.

The flop index was measured using the flop index measuring device (X-Rite MA-68II) by the X-Rite company. Although it differs slightly according to the kind of brightness | luminance material, generally, when a flop index is 20 or more, it can be evaluated that there exists the outstanding brightness feeling like a metal.

In the evaluation of the brightness by the naked eye, ○ indicates that the brightness is excellent (the orientation unevenness of the bright material is hardly observed), and × is the lack of the brightness (the orientation unevenness of the bright material is observed). Each means. The adhesiveness of the coating film is cut to reach the substrate by a cutter, to make 100 cross cut coating films each having a size of 1 mm × 1 mm, to attach the adhesive cellophane tape to the surface thereof, and then to the coating film surface after peeling it rapidly. It was measured by observing. (Circle) means that peeling of a crosscut coating film was not observed at all, and x means that peeling of a crosscut coating film was observed 10 or more, respectively.

The pencil hardness of the coating film produced the coating film on the tin plate according to the said coating conditions, and measured after ultraviolet irradiation.

Example 1 Example 2 Comparative example Flop index of metallic coating 20 22 12 Brightness (visual) ○ ○ × Adhesion between Metallic Coating Film and Polycarbonate Plate ○ ○ ○ Pencil hardness 3H H 3H

As apparent from the above test results, by using the metallic coating composition of the present invention comprising the unsaturated group-containing urethane resin compound (a), an organic solvent, and a bright material, a metallic coating film having excellent alignment of bright materials and excellent brightness can be obtained. have.

Claims (9)

A metallic coating composition comprising an unsaturated group-containing urethane resin compound (a), an organic solvent and a bright material, the compound (A) having a molecular weight of 300 or less having an active hydrogen of which the unsaturated group-containing urethane resin compound (a) is 2 or more, and It is a reaction product of an alicyclic or aromatic polyisocyanate compound (B) and the (meth) acrylate compound (C) which has active hydrogen, The reaction product has a urethane bond and a (meth) acryloyl group in a molecule | numerator, 3000 or more A composition characterized by having a molecular weight and at least two unsaturated groups. The method of claim 1,
The reaction product of compound (A), compound (B) and compound (C) is a general formula

(Where x is the number of repeat units)
A composition which is a polymer having a structure represented by. The method of claim 1,
The compound (A) is a polyhydric alicyclic alcohol or a polyhydric aliphatic alcohol. The method of claim 3, wherein
The polyhydric alicyclic alcohol is cyclohexyl dimethanol, tricyclodecane dimethanol, decahydronaphthalene dimethanol, tetralin dimethanol, norbornene dimethanol or pentacyclododecane dimethanol. The method of claim 3, wherein
Polyhydric aliphatic alcohols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1, 9-nonanediol, 1,10-decanediol, 3-methyl-1,5-pentanediol, neopentylglycol or 2-methyl-1,8-octanediol. The method of claim 1,
Compound (B) is tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, xylylene diisocyanate, xylene diisocyanate, 4,4-methylenebis (cyclohexyl isocyanate) methylcyclohexane-2,4 (or 2, 6) -diisocyanate, 1,3- (isocyanatemethyl) cyclohexane, isophorone diisocyanate, 1,5-naphthalene diisocyanate, polymethylene polyphenylene diisocyanate, triphenylmethanetriisocyanate, naphthalene diisocyanate, 1,3 A composition which is a cyclohexylene diisocyanate, a tolylene diisocyanate polymer or a diphenylmethane diisocyanate polymer. The method of claim 1,
Compound (C) is hydroxyacrylate, the (meth) acrylic acid addition product of propylene glycol diglycidyl ether, the (meth) acrylic acid addition product of 1,6-hexanediol diglycidyl ether, and 1, 4- butanediol di (Meth) acrylic acid adduct of glycidyl ether, (meth) acrylic acid adduct of 1,5-pentanediol diglycidyl ether, (meth) acrylic acid adduct of 1,7-heptane diol diglycidyl ether, (Meth) acrylic acid adduct of 1,8-octanediol diglycidyl ether, (meth) acrylic acid adduct of neopentyl glycol diglycidyl ether, (meth) acrylic acid adduct of bisphenol A diglycidyl ether, or The composition which is a (meth) acrylic acid addition product of hydrogenated bisphenol A diglycidyl ether. The method of claim 7, wherein
Hydroxyethyl acrylate is 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 3-hydroxybutyl acrylate, polyethylene glycol monoacrylate, pentaerythritol triacrylate Or dipentaerythritol pentaacrylate or 2-hydroxy-1-acryloxy-3-methacrylate. The method of claim 1,
A composition comprising, as a solid content of the unsaturated group-containing urethane resin compound (a), 5 to 35 parts by weight of the bright bright material and the amount of solvent required to make the composition a sprayable solution, or less than that.