JPH01203475A - Polyurethane-base synthetic resin coating - Google Patents

Abstract

PURPOSE:To obtain the above coating having improved interlaminar adhesivity without deteriorating other properties as a coating film, by compounding a urethanized material having radically polymerizable group and isocyanate group. CONSTITUTION:The objective coating contains a urethanized material having polymerizable isocyanate group. The urethanized material is preferably a compound having radically polymerizable unsaturated group and unreacted isocyanate group and produced by the addition reaction of a polyisocyanate such as tetramethylene diisocyanate with a hydroxyl-containing polymerizable compound. The amount of the hydroxyl group of the polymerizable compound is 0.1-0.9 equivalent based on 1 equivalent of the isocyanate group of the polyisocyanate.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a polyurethane synthetic resin coating. In particular, it relates to a polyurethane-based synthetic resin paint with good interlayer adhesion between an undercoat film and a topcoat film.

(Prior art) Polyurethane-based synthetic resin paints contain (1
) There are those that combine acrylic polyol, polyester polyol or polyether polyol with polyisocyanate, and (2) there are those that are used as urethane acrylates in photo-curable paints and electron beam-curable paints. Furthermore, in recent years, a combination of a fluorine-based polyol and a polyisocyanate has been used.

In most of these cases, when applying multiple coats, the vehicle for the base coat and the vehicle for the top coat are often the same in order to improve interlayer adhesion between the base coat and top coat. Even in that case, since it is a thermosetting resin paint, it is necessary to adjust the degree of crosslinking between the undercoat and topcoat, slow curing speed, and the type and amount of added pigments and other additives, as well as appropriate painting conditions. This is often solved by selecting

(Problems to be Solved by the Invention) When applying polyurethane-based synthetic resin paints, interlayer adhesion between the undercoat film and the topcoat film often poses a problem.

For example, on the contact surface between a coating film whose composition is a vehicle that is a combination of acrylic polyol and polyisocyanate and an unsaturated polyester resin coating film, interlayer adhesion is maintained regardless of which coat is used as the undercoat or the topcoat. is not good.

This is especially noticeable when the clear material does not contain pigments or when the contact surface is a Heisei surface.

Furthermore, the interlayer adhesion between a paint containing a vehicle that is a combination of an acrylic polyol, a polyester polyol, a fluorine-based polyol, or a polyisocyanate as a component and a photopolymerizable acrylate resin paint is also poor.

If the interlayer adhesion of the coating film is poor, it will cause the top coat to peel off, making it impossible to obtain a coating with excellent water resistance, chemical resistance, and weather resistance.

The object of the present invention is to improve this interlayer adhesion to a polyurethane-based synthetic resin paint with strong and good adhesion. Of course, whether the undercoat and topcoat are of different types or of the same type, the adhesion to the substrate, interlayer adhesion between the undercoat and topcoat, and the physical and chemical properties of the paint film must be good. Must be.

(Means for Solving the Problems) The present invention has been made by conducting research on a paint that improves the above-mentioned interlayer adhesion and does not impair other properties as a paint film.
We were able to obtain the desired paint shown below.

Among polyurethane-based synthetic resin paints, polyurethane-based synthetic resin paints are characterized by containing a urethane compound containing polymerizable isocyanate groups. Polyurethane-based synthetic resin paints here refer to synthetic resins having hydroxyl groups and/or polymerizable unsaturated groups. It refers to a paint whose main vehicle is a urethane compound containing a polymerizable isocyanate group or a urethane compound containing a polymerizable isocyanate group and a polyisocyanate.

Examples of synthetic resins having hydroxyl groups and/or polymerizable unsaturated groups include acrylic polyols, polyester polyols, alkyd polyols, fluorine polyols, polyether polyols, triazine polyols, amine-containing polyols, unsaturated polyester resins, and photopolymerizable acrylates. One type or two or more types of resins can be selected and used.

The polymerizable isocyanate group-containing urethane compound used in the present invention includes a compound having an unsaturated group that undergoes radical polymerization, an isocyanate group, and a urethane group produced by the reaction of the isocyanate group with a hydroxyl group. It can be produced by urethanizing a part of the isocyanate group of isocyanate with a polymerizable compound having a hydroxyl group.

For example, when an unsaturated polyester resin paint for ultraviolet curing is applied as a top coat to a dried film of a paint whose base coat is a vehicle containing a combination of acrylic polyol and polyisocyanate, the interlayer adhesion may fail. bad.

In this case, as a top coat, an unsaturated polyester resin paint for UV curing or an unsaturated polyester resin paint for UV curing is applied as a top coat to the dry coating film of the paint whose composition is a vehicle comprising an acrylic polyol and a urethane compound containing a polymerizable isocyanate group according to the present invention. When applying a paint mixture of an unsaturated polyester resin paint and a urethane compound containing a polymerizable isocyanate group,
The interlayer adhesion between them will be good.

These also apply to polyester polyols, alkyd polyols, fluorine polyols, polyether polyols, photopolymerizable acrylic resin paints, etc. When mixing urethane compounds containing polymerizable isocyanate groups, the same procedure as in the above example is applied. It can be effective.

The polymerizable isocyanate group-containing urethane compound used in the present invention is one of the isocyanate groups of the polyisocyanate.
Addition reaction is performed so that the hydroxyl group of the polymerizable compound having a hydroxyl group is 0.1 to 0.9 equivalent to the equivalent amount, and the unsaturated group that undergoes radical polymerization and the unreacted A urethane compound with an isocyanate group. Further, in order to promote this addition reaction, known amounts of tertiary amines such as triethylamine, triethanolamine, and diethylaminoethyl methacrylate, and tin compounds such as dibutyltin dilaurate and stannous octoate may be added.

The polyisocyanates used herein are well known to those skilled in the art and include known aliphatic polyisocyanates, cycloaliphatic polyisocyanates, and aromatic polyisocyanates. Examples of these are tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, o-, m- and p-xysol diisocyanate, 2,4-tlene diisocyanate, 2,6
-Tolene diisocyanate, diphenylmethane 4,4'
-diisocyanate, lysine diisocyanate, m- and p-phenylene diisocyanate, diphenyl ether diisocyanate, di(2-ethyl isocyanate)
-bicyclo[2.2.1]-hept-5-ene-2,3
-dicarboxylate, dicyclohexyl-4,4'-
Methane diisocyanate, 1,5-naphthylene diisocyanate, 2,4,6-triisocyanate toluene,
Examples include polymethylene polyphenylisocyanate.

Further, there are adducts obtained by urethanizing an excess of these polyisocyanates with a polyhydric alcohol, and polyisocyanates containing isocyanurate rings, polyisocyanates containing biuret groups, polyisocyanates containing allophanate groups, and the like.

Next, examples of polymerizable compounds having a hydroxyl group include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, hydroxybentyl acrylate, hydroxybentyl methacrylate, Glycerin diallyl ether, trimethylolpropane diallyl ether, pentaerythritol triallyl ether, addition reaction product of glycidyl acrylate and acrylic acid, addition reaction product of glycidyl acrylate and methacrylic acid, addition reaction product of glycidyl methacrylate and acrylic acid, glycidyl methacrylate and Addition reaction products with methacrylic acid, addition reaction products between glycidyl acrylate and glycidyl methacrylate and fat and oil fatty acids,
Addition reaction products between glycidyl acrylate and glycidyl methacrylate and neo acids, addition reaction products between acrylic acid and methacrylic acid and monoepoxy compounds such as Cardura E10 (product of Yuka Shell Chemical Co., Ltd.), and addition reaction products between acrylic acid and methacrylic acid and bisphenol A. Examples include addition reaction products with epoxy resins having one hydroxyl group in the molecule obtained by a polybond reaction with epichlorohydrin.

In the reaction between the polyisocyanate and the polymerizable compound having a hydroxyl group to obtain the polymerizable isocyanate group-containing urethanized product used in the present invention, a polymerization inhibitor such as hydroquinone, hydroquinone monomethyl ether, etc. .1% by weight added, room temperature ~ 1
It can be easily completed under the condition of 60°C. The reaction is carried out without a solvent or in an organic solvent such as toluene, xylene, ethyl acetate, butyl acid, methyl isobutyl ketone, or also in the presence of a polymerization inhibitor. It can also be carried out in a reactive solvent such as methafurylate, 2-ethylhexyl acrylate, diallyl phthalate.

Synthetic resins having hydroxyl groups and/or polymerizable unsaturated groups used in the polyurethane synthetic resin coating of the present invention include acrylic polyols, polyester polyols, alkyd polyols, fluorine polyols, polyether polyols, triazine polyols, and amines. There are polyols contained therein, unsaturated polyester resins, photopolymerizable acrylic resins, and the like, and their contents will be described in sequence below.

Acrylic polyol is a polymerizable compound having a hydroxyl group, acrylic ester, methacrylic ester,
A hydroxyl group-containing acrylic resin obtained by copolymerizing polymerizable monomers such as styrene, acrylonitrile, vinyl acetate, acrylic acid, and methacrylic acid. or,
This also includes those grafted with nitrocellulose, cellulose acetobutyrate, etc. The copolymerization reaction is usually carried out in an organic solvent, but it can also be produced by performing a bulk polymerization reaction, making it into a powder, and dissolving it in an organic solvent.

Polyester polyols are polyhydric alcohols such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, phthalic anhydride,
Polybasic acids such as maleic anhydride, adipic acid, and isophthalic acid are added in such a way that the number of equivalents of hydroxyl groups is in excess of the number of equivalents of carboxyl groups, and hydroxyl groups and ester bonds are formed in the molecules obtained by polycondensation reaction. A polyester resin with It is usually used after being dissolved in an organic solvent for the reaction-completed species.

Alkyd polyols include coconut oil, castor oil, tall oil,
Hydroxyl groups are obtained by reacting oils and fats such as rice sugar oil with polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin, and pontaerythritol, and polybasic acids such as phthalic anhydride, maleic anhydride, and isophthalic acid. It is a polyester resin with This is also usually used after being dissolved in an organic solvent after the reaction is completed.

The fluorine-based polyol is a hydroxyl group-containing fluororesin that is soluble in organic solvents.

Polyether polyols are polymers of glycols such as ethylene glycol, propylene glycol, and neopentyl glycol.

Triazine polyol is a polyol that has a triazine skeleton in its molecule, and amine-containing polyol is a polyol that has a secondary amine in its molecule.

Unsaturated perester resins are made of unsaturated dibasic acids such as maleic anhydride and fumaric acid and alcohols such as ethylene glycol, propylene glycol, butylene glycol, glycerin monoallyl ether, trimethylolpropane diallyl ether, and pentaerythritol diallyl ether. A polycondensate obtained by reacting saturated dibasic acids such as phthalic anhydride and adipic acid with styrene, α
- Dissolved in polymerizable monomers such as methyl styrene, methyl methacrylate, ethyl methacrylate, butyl methacrylate, diallyl phthalate, etc., and cured at room temperature with a redox catalyst, or benzoin, benzoin alkyl ether, benzophenone, isopropylthioxanthone, benzyl dimethyl ketal , acetophenone diethyl ketal, 2-hydroxy-2-methylphenylpropane, and other photopolymerization initiators, and can be cured by ultraviolet irradiation.Solventless or 20% by weight
It is a resin having a curing component of 80% by weight or more of the following organic solvent.

In addition, in order to promote the photopolymerization reaction, a tertiary substance such as triethylamine or triethanolamine may be added to the photopolymerization initiator.
It is also possible to use photosensitizers such as grade amines, triphenylfosquin, and β-thiodiglycol in combination.

When a urethane compound containing a polymerizable isocyanate group is mixed with an unsaturated polyester resin, the unsaturated group that undergoes radical polymerization acts in the same way as a polymerizable monomer to introduce urethane bonds into the cured resin, resulting in polyurethane synthesis. A resin coating can be formed.

The photopolymerizable acrylic resin has a photopolymerizable acrylic prepolymer and a monofunctional monomer or a polyfunctional monomer as main vehicles.

This resin is cured in a few seconds by electron beam irradiation, and when the same photopolymerization initiator or photopolymerization initiator and photosensitization accelerator as mentioned above for unsaturated polyester resin is added to this resin, it can be cured by ultraviolet irradiation. It hardens in a few seconds to tens of seconds.

Photopolymerizable acrylic prepolymers include (1) polyester acrylates, such as esterified products of 1 mole of trimeletic acid, 3 moles of diethylene glycol, and 3 moles of acrylic acid; (2) urethane acrylates, such as 1 mole of trimethylolpropane and propylene. 3 moles of glycol, 3 moles of tolylene diisocyanate and 2-
Reactant with urethane bond of 3 moles of hydroxyethyl acrylate. However, there are no unreacted isocyanate groups. (3) Epoxy acrylate, such as a polycondensate of bisphenol A and epichlorohydrin, which is a reaction product of 1 mol of epoxy resin having 2 epoxy groups and 2 mol of acrylic acid, (4) Silicone resin acrylate, such as dimethacrylate of polysiloxane, ( 5) Polyether acrylate, (6) Alkyd acrylate, (7)
) Unsaturated acrylic resin, etc.

Examples of monofunctional monomers and polyfunctional monomers include reaction diluents for photopolymerizable acrylic prepolymers, such as 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, phenoxyethyl acrylate, , 3-dioxolane acrylate, diethylaminoethyl methacrylate, glycidyl methacrylate, N-vinylpyrrolidone, diethylene glycol diacrylate, neopentyl glycol diacrylate, butanediol diacrylate, trimethylolpropane trimethacrylate, and styrene, α-methylstyrene, ethyl acrylate, Examples include methyl methacrylate.

The polyurethane-based synthetic resin paint of the present invention can be used by mixing a synthetic resin containing a hydroxyl group and/or a polymerizable unsaturated group as its main vehicle with a urethane compound containing a polymerizable isocyanate group in any proportion. can.

Furthermore, since the urethane compound containing a polymerizable isocyanate group used in the present invention is also a synthetic resin having a polymerizable unsaturated group, the urethane compound containing a polymerizable isocyanate group and a monofunctional monomer or a polyfunctional monomer are mainly used. A paint used as a vehicle is also included in the polyurethane-based synthetic resin paint of the present invention and can be used.

In addition to the above-mentioned essential vehicle components, the polyurethane synthetic resin paint of the present invention includes various cellulose derivatives, urethanized oils, conventional organic solvents, various coloring pigments, Pigments, metal powders, plasticizers, leveling agents, various fragrances, and the like can be used by mixing known amounts. In addition, the photopolymerization initiator and photosensitization accelerator should be
Each can be used within the range of 0.01 to 10% by weight.

The polyurethane synthetic resin paint of the present invention can be produced by kneading selected components by a conventional method.

The polyurethane synthetic resin paint of the present invention has a
It is possible to finish with two coats, or to apply multiple coats such as a base coat and a top coat, or a base coat, a middle coat, and a top coat. The undercoating paint used for overcoating is not limited to the polyurethane-based synthetic resin paint of the present invention, and may be of other types. Similarly, the top coat or intermediate coat paint for overcoating may be of other types. Coating methods include conventional methods such as roll coating, curtain flow coating, dipping, spraying, ironing, and brush coating, and known methods such as natural drying, heat drying, ultraviolet irradiation with a mercury lamp, and electron beam irradiation. It can be cured and dried by the following method.

The polyurethane-based synthetic resin paint of the present invention can be applied to wooden products of arbitrary shapes such as panels, coils, molded articles, sheets, films, and tubes, secondary cement products, metals, plastics, paper, leather, glass, fibers, and textiles. It can be applied to any acceptable substrate, such as.

The present invention will be explained below with reference to Examples. However, all numbers indicate parts by weight.

Example. 1, 2 a) 75% polyisocyanate and 25% ethyl acetate solution obtained by reacting 3 mol of tolylene diisocyanate and 1 mol of trimethylolpropane (Japan Polyurethane Industries, trade name "Coronate L", NCD content 13) ．．
2%) and a 1% ethyl acetate solution of 2-hydroxyethyl methacrylate and hydroquinone monomethyl ether in the proportions shown in Table 1 below were placed in a reaction vessel, and the temperature was raised while stirring and maintained at about 80°C. The reaction between the isocyanate groups of the polyisocyanate and the hydroxyl groups of 2-hydroxyethyl methacrylate is monitored while quantifying the amount of remaining hydroxyl groups.

The reaction is completed in about 3 hours, yielding urethane compounds having a polymerizable unsaturated group and an unreacted isocyanate group, that is, urethane compounds "A" and "B" containing polymerizable isocyanate groups. These "a" and "b" may be used after being isolated and purified, but they can also be used as they are.

The NCO content of “i” and “ro” obtained here is
They are 7.70% and 3.45%, respectively.

b) The polymerizable isocyanate group-containing urethane compounds "A" and "B" obtained in a) were treated with unsaturated polyester resin "Eporax 2101-70 (manufactured by Nippon Shokubai Chemical Industry Co., Ltd.,
(viscosity: 9 voids) and the formulation shown in Table 2 below to obtain UV-curable polyurethane synthetic resin paints 2 and 2.

Example. 3 c) Acrylic acid 72 Cardura E-10 250 Hydroquinone monomethyl ether 0.16
Put 322.16 in total into a reaction container and gradually raise the temperature while stirring until about 8.
Keep at 5°C to 95°C. The reaction between the carboxyl group of acrylic acid and the epoxy group of Cardura E-10 is monitored while quantifying the amount of remaining carboxyl group. The reaction is completed in 5 hours, and an adduct AE having one hydroxyl group and one polymerizable unsaturated group is obtained.

d) A total of 900 of the adduct AE 302 Coronate L 598 obtained in c) is placed in a reaction vessel, and a polymerizable isocyanate group-containing urethane compound "C" is obtained by the same operation as in a).

The NCD content of this "Ha" is 5.85%.

e) Using "C" obtained in step d) and an unsaturated polyester resin, they are mixed in the following formulation to obtain an ultraviolet curable polyurethane synthetic resin paint 3.

d) “Ha” obtained by 480 Eporac 21
01-70 320 styrene
200 benzoin-isobutyl ether 30
Total: 1030 Example 4 Acrylic polyol "Dianal PS" (manufactured by Mitsubishi Rayon, non-volatile content 48%, viscosity P.OH
A two-component polyurethane-based synthetic resin paint 4 is prepared by combining a formulation using 32) as a paint base and the polymerizable isocyanate group-containing urethane compound "I" obtained in a) as a curing agent.

Base Dianal PS 450 Toluene 70 Calcium carbonate 250 Talc 180 Rutile type titanium base 20 Iron oxide yellow 30 Total 1000 "I" obtained from hardening agent a) 130 Ethyl acetate 20 Total 150 Base: Mixing ratio of hardening agent Use at a ratio of 100:15.

In contrast to Examples 1 to 4 above, a case in which a urethane compound containing a polymerizable isocyanate group is not used will be described below as a comparative example.

Comparative example. 1, 2, 3 The hydroxyl groups of 2-hydroxyethyl methacrylate and the hydroxyl groups of the adduct AE obtained in c) of Example 3 are equivalent to the isocyanate groups of Coronate L with a droplet containing 13.2% NCO. The ingredients were blended as shown in Table 3 below, and the same operations as described in a) of Examples 1 and 2 were carried out to obtain a polymerizable urethane compound 3M having no unreacted isocyanate groups. This is a type of urethane acrylate.

Comparative Examples 1, 2, and 3, including those using this polymerizable urethane compound 3M, are mixed with each component according to the formulations shown in Table 4 below to prepare ultraviolet curing resins.

As can be seen from the above table, Comparative Example 1 uses only unsaturated polyester resin. Comparative Example 2 has a composition in which a polysocyanate having no polymerizable unsaturated groups is added to an unsaturated polyester resin, and Comparative Example 3 has a composition in which a polymerizable urethane compound having no isocyanate groups is added. be.

Comparative example. 4 In the two-component polyurethane synthetic resin paint in Example 4, a polyisocyanate having no polymerizable unsaturated groups was used as a curing agent, and the composition was as shown below.

base Same as described in Example 4 hardening agent Coronate L 76 Ethyl acetate 24 Total 100 A mixing ratio of base:curing agent=100:10 is used.

A coated plate was created using each of the paints of the above examples and comparative examples,
Perform a coating film performance test.

First, coated plates were prepared using polyurethane-based synthetic resin paints 1, 2, 3, and 4 obtained in Examples 1 to 4.

A mixture of the base and curing agent of Example 4 at a predetermined mixing ratio was applied to the surfaces of three sheets of plywood for formwork with a thickness of 12 mm.
Rub and paint. 7g/■2 for the first coat, 1 at room temperature
Dry for 5 minutes, second coat 5g/■ 2 total 12g/■
2 coats and forced drying in a hot air drying oven kept at 50-60°C for 16 minutes.

Next, paints 1, 2, and 3 of Examples 1, 2, and 3 were applied using a roller so that the amount of coating was 6 g/■2, and the coatings were heated using an ultraviolet irradiation device equipped with an 80 W/cm mercury lamp. When irradiating for 9 seconds at a distance of 15 cm from the paint surface, the surfaces of paints 1, 2, and 3 harden and dry.

Next, using the paints obtained in Comparative Examples 1 to 4, coated plates are prepared according to the method for producing coated plates in the examples.

The following coating film performance tests were conducted on these coated plates, and the results are shown in Table 5.

Test items and test methods ○Hardness: Measured by pencil hardness.

○Adhesion…Cut 10 squares with a width of 1mm using a cutter knife.
Make 0 pieces, attach cellophane tape from above, and peel it off vigorously. The greater the number of pieces that do not peel off, the better the adhesion is judged to be.

○Alkali resistance: The entire coated plate is immersed in a 3% sodium carbonate solution, pulled out after 48 hours, washed with water, and then dried. If there are no abnormalities on the painted surface, it is judged as passing.

Example. 5. Prepare polyurethane synthetic resin paint 5 having the following composition.

"A" obtained from base a) 40 Eporac 2101-70 40 Styrene 19 Cobalt octate 1 Total 100 Hardening agent Methyl ethyl ketone peroxide 55% dimethyl phthalate solution 2 Total 2 Base: Hardening agent mixing ratio = 100: 2 The obtained polyurethane synthetic resin paint 5 is a two-component paint that cures and dries at room temperature, consisting of a base and a curing agent, whereas the polyurethane synthetic resin paint 1 of Example 1 is an ultraviolet curable type.

The coating performance test using this will be described below.

After applying the two-component acrylic polyurethane paint of Comparative Example 4 twice on the surface of the plywood for formwork using the above-mentioned coating plate preparation method, 6 g/■2 of this polyurethane-based synthetic resin paint 5 was applied.
When applied at room temperature, it dries with fingers after 1 hour, and hardens and dries after 2 days. Its hardness is H, adhesion is 1
00/100, and the alkali resistance was also passed and good.

In the above Examples and Comparative Examples, the case where the formwork plywood was painted was explained. Painted formwork plywood is subject to strict requirements for its actual use, such as adhesion of the coating film to the plywood substrate and interlayer adhesion when multiple coats are applied.

Example. 6. Make a polyurethane-based synthetic resin paint 6 for ultraviolet curing with the following composition.

"A" obtained in a) 30 "B" obtained in a) 30 Styrene 40 Benzoin ethyl ether 3 Total 103 This is used as an undercoat and a topcoat on birch plywood with a thickness of 12 mm.

First, 3 g/cm2 was applied as an undercoat, and UV rays were irradiated for 9 seconds using an 80 W/cm mercury lamp at a distance of 15 cm from the lamp to cure and dry.

Next, as a top coat, 3 g/2 is applied thereon and cured by irradiating ultraviolet rays for 9 seconds in the same manner as the undercoat.

The obtained coating film was subjected to the same coating film performance test as in the above-mentioned example, and as a result, it had a pencil hardness of 5H and good adhesion.

Example. 7. Prepare a two-component polyurethane synthetic resin paint 7 using the following formulation.

Base Dianal PS 770 Dioctyl phthalate 10 Ethyl acetate 110 Toluene 110 Total 1000 Curing agent "I" obtained from a) 220 Ethyl acetate 30 Total 250 Use the base:curing agent at a mixing ratio of 100:25.

This polyurethane-based synthetic resin paint 7 and the polyurethane-based synthetic resin paint 1 of Example 1 were applied alternately as a top coat and a base coat on birch plywood with a thickness of 12 mm. Using ester resin paint,
Painted plates (a), (b), (c) according to the painting process in Table 7
Create.

The results of surface hardness and adhesion tests on the resulting cured and dried coating films are shown at the bottom of Table 7.

The coated plate (c) of the comparative example has some problems in interlayer adhesion compared to the coated plates (a) and (b) using the polyurethane synthetic resin paint of the present invention.

Note. 1. Irradiate for 9 seconds with a 2.80 W/cm mercury lamp at a distance of 15 cm for 16 minutes at 50 to 60°C.

3. Air dry for 2 days at room temperature of 20°C.

Examples 6 and 7 can be applied to fields such as floor building materials, interior wall materials, furniture, and decorative boards.

In addition, in the case of paints that use the photopolymerizable acrylic resin as the main vehicle, the amount of conventional organic solvents in the paint is 0 to 80% by weight, similar to general organic solvent-based paints, from the viewpoint of painting workability.
You can put up to

Alternatively, as an example of painted formwork plywood in Examples 1 to 4, a two-component polyurethane synthetic resin paint consisting of a base and a hardening agent was applied as the undercoat, and an ultraviolet curable polyurethane synthetic resin paint was applied as the top coat. However, the present invention is not limited to this. For example, on the contrary, the undercoat is a translucent UV-curable polyurethane synthetic resin paint containing an extender pigment, and the topcoat is a two-component polyurethane paint consisting of a base containing colored pigments as the main pigment and a curing agent. It is also possible to finish by painting with a translucent colored ultraviolet curable polyurethane synthetic resin paint or a semi-transparent UV-curable polyurethane synthetic resin paint with a small amount of lake pigment added.

Claims (1)

[Claims] A polyurethane-based synthetic resin paint characterized by containing a urethane compound containing a polymerizable isocyanate group.