JP6926675B2 - Active energy ray-curable paint composition for decorative board and decorative board using this - Google Patents

Description

The present invention relates to an active energy ray-curable coating composition for a decorative board having low gloss and excellent stain resistance and recoating property, and a decorative board obtained by coating the surface of the composition and curing the composition.

Conventionally, the surface of base materials such as paper, plastic, glass, metal, wood, and ceramic has been coated to protect the surface by adding various functions and design properties such as high hardness and stain resistance. There is. In recent years, the demand for active energy ray-curable high-nonvolatile paints has been increasing in response to environmental problems. Among them, low-gloss coatings are preferred for products used for floors, walls and ceilings, and there are many opportunities to be exposed to contamination, so coatings with excellent stain resistance are required.

As a method for obtaining a low-gloss coating film, a method of adding hard porous particles such as silica to the coating material is known, but the volume reduction due to solvent volatilization is small in the highly non-volatile content type coating material, which is particularly low. Since it is difficult to obtain a glossy coating film and it is necessary to increase the amount of hard porous particles added, there is a problem that the stain resistance is lowered due to the adhesion between the porous particles and the contaminants. Further, when the gloss is lowered by adding wax or the like, there is a problem that sufficient low gloss cannot be obtained, and it has been said that it is difficult to achieve both low gloss and excellent stain resistance.

As an active energy ray-curable coating composition having both low gloss and stain resistance, for example (Patent Document 1) in which an active energy ray-polymerizable monomer, a polyfunctional monomer, and an oligomer component are combined with a base resin can be mentioned. It is premised that sometimes nitrogen purging is performed to perform two-step irradiation in which the oxygen concentration is changed to the normal concentration and the low concentration, and the finish "gloss" of the paint composition after painting, curing and drying is high, and the market needs. Does not match. It is desired to develop an active energy ray-curable coating composition for a decorative board, which does not require nitrogen purging and has both a low gloss that is not too high and stain resistance.
Further, when the paint composition is used for an interior building material or the like, it is necessary to repair scratches and the like generated during construction, and for that purpose, recoatability of the repair paint is required, and the above-mentioned low gloss, stain resistance and repair It is difficult to maintain all of the aptitude with the prior art.

Japanese Unexamined Patent Publication No. 2004-51653

An object of the present invention is an active energy ray-curable coating composition for a decorative board having excellent low gloss, stain resistance, and recoating property, and an active energy ray-curing composition for a decorative board obtained by coating the surface of the composition and curing the composition. The purpose is to provide a mold coating composition.

As a result of diligent studies, the present inventors have excellent low gloss, stain resistance, and recoatability by containing an active energy ray-polymerizable bifunctional monomer, a photopolymerization initiator, and a specific silica as a matting agent. We have found that we can obtain a polymerized coating, and have arrived at the present invention.

That is, the present invention is an active energy ray-curable coating composition containing an active energy ray-polymerizable bifunctional monomer, a photopolymerization initiator, and a matting agent, wherein the matting agent has a melting point of 70. Provided is an active energy ray-curable coating composition for a decorative board, which is silica surface-treated with an organic wax having a temperature of ° C. or higher.

The present invention also relates to an active energy ray-curable coating composition for a decorative board, wherein the content of the active energy ray-polymerizable bifunctional monomer is 30 to 80% by mass of the total amount of the coating composition.

Further, in the present invention, the active energy ray-polymerizable bifunctional monomer is selected from the group consisting of tricyclodecanedimethanol diacrylate, ethylene oxide-modified bisphenol A di (meth) acrylate, and propylene oxide-modified bisphenol A di (meth) acrylate. The present invention relates to one or more active energy ray-curable coating compositions for decorative plates.

The present invention also relates to an active energy ray-curable coating composition for a decorative board, wherein the content of silica surface-treated with the organic wax is 1 to 10% by mass of the total amount of the coating composition.

The present invention also provides a decorative board coated with the active energy ray-curable coating composition for a decorative board on the surface and cured.

Provided are an active energy ray-curable coating composition for a decorative board having excellent low gloss, stain resistance, and recoating property, and an active energy ray-curable coating composition for a decorative board obtained by coating the surface of the composition and curing the composition. can do.

The present invention is an active energy ray-curable coating composition for a decorative board, which comprises an active energy ray-polymerizable bifunctional monomer, a photopolymerization initiator, and a matting agent. By providing an active energy ray-curable coating composition for a decorative plate, which is silica surface-treated with an organic wax having a melting point of 70 ° C. or higher, the effect of the present invention is exhibited.

First, in the active energy ray-curable coating composition for a decorative board of the present invention, an active energy ray-polymerizable bifunctional monomer is essential.

The content of the active energy ray-polymerizable bifunctional monomer is preferably 30 to 80% by mass based on the total amount of the coating composition. When the content is 30% by mass or more, suitable stain resistance can be easily obtained, and when it is 80% by mass or less, low glossiness can be easily obtained.

Examples of the bifunctional monomer include 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, neopentanediol di (meth) acrylate, and 1,6-hexanediol di (meth). Acrylate, 1,9-nonanediol di (meth) acrylate, ethylene glycol di (meth) acrylicate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tri Cyclodecanedimethanol di (meth) acrylate, ethylene oxide (hereinafter abbreviated as EO) modified neopentyl glycol di (meth) acrylate, propylene oxide (hereinafter abbreviated as PO) modified neopentyl glycol di (meth) acrylate, bisphenol A di (hereinafter abbreviated as PO) Meta) acrylate, EO modified bisphenol A di (meth) acrylate, PO modified bisphenol A di (meth) acrylate, epichlorohydrin (hereinafter abbreviated as ECH) modified bisphenol A di (meth) acrylate, EO modified bisphenol S di (meth) acrylate, Hydroxypivalic acid ester neopentyl glycol di (meth) acrylate, caprolactone-modified hydroxypivalic acid ester neopentyl glycol di (meth) acrylate, neopentyl glycol-modified trimethylolpropandi (meth) acrylate, stearic acid-modified pentaerythritol di (meth) Examples thereof include acrylate, dicyclopentenyl diacrylate, EO-modified dicyclopentenyl di (meth) acrylate, and di (meth) acryloyl isocyanurate. These monomers can be used in one or more mixed systems, among which tricyclodecanedimethanol di (meth) acrylate, EO-modified bisphenol A di (meth) acrylate, PO-modified bisphenol A di (meth) acrylate. It is preferable to use acrylate, 1,6-hexanediol di (meth) acrylate, and tripropylene glycol di (meth) acrylate alone, and tricyclodecanedimethanol diacrylate, EO-modified bisphenol A diacrylate, and PO-modified bisphenol A di acrylate. It is more preferable to use the acrylate alone, and it is most preferable to use the tricyclodecanedimethanol diacrylate alone.

Next, in the active energy ray-curable coating composition for a decorative board of the present invention, silica surface-treated with an organic wax having a melting point of 70 ° C. or higher is essential as a matting agent.

The matting agent is silica surface-treated with an organic wax having a melting point of 70 ° C. or higher, and it is essential that all of the silica has a melting point of 70 ° C. or higher even when the surface is treated with a plurality of organic waxes. Examples of the organic wax having a melting point of 70 ° C. or higher include microcrystalline wax, oxidized microcrystalline wax, and polyethylene. Of these, synthetic amorphous silicon dioxide treated with microcrystallin oxide is more preferred. This is because the use of synthetic amorphous silicon dioxide treated with an organic wax having a melting point of 70 ° C. or higher has the advantage that the bleeding on the coating film surface is small, and even if the bleeding occurs, the adverse effect on the recoatability is small.

The content of silica surface-treated with an organic wax having a melting point of 70 ° C. or higher used in the active energy ray-curable coating composition for a decorative board of the present invention is 1 to 20% by mass of the total amount of the coating composition. It is preferably 1 to 10% by mass, more preferably 1 to 10% by mass. When the content is 1% by mass or more, a suitable matting effect can be easily obtained, and when the content is 20% by mass or less, stain resistance can be easily obtained.

In the active energy ray-curable coating composition for decorative boards of the present invention, resin beads can also be added. Typical examples of the resin beads include urethane beads, acrylic beads, silicon beads, styrene beads and the like. When these resin beads are used, they can be appropriately used in a range of preferably 1 to 30% by mass, more preferably about 5 to 25% by mass, based on the total amount of the coating composition.

In the active energy ray-curable coating composition for decorative boards of the present invention, wax can also be added. Typical examples of wax include polyethylene, polypropylene, polyethylene oxide, amide, modified polyethylene, modified polypropylene, modified amide, polyterolafluoroethylene and the like. When these waxes are used, they can be appropriately used in the range of 1 to 10% by mass, more preferably about 3 to 8% by mass, based on the total amount of the coating composition.

Further, in the active energy ray-curable coating composition for a decorative board of the present invention, an active energy ray-polymerizable oligomer can also be added. Typical examples of the oligomer include urethane acrylate, epoxy acrylate, polyester acrylate, polyether acrylate, acrylic acrylate, unsaturated polyester and the like, and all of them can be used in one kind or a mixed system of two or more kinds. .. Of these, urethane acrylate or polyester acrylate is preferable for the purpose of low gloss.

When the oligomer is used in the active energy ray-curable coating composition for a decorative board of the present invention, it is preferably 0.5 to 15% by mass of the total amount of the coating composition. When the content is 0.5% by mass or more, suitable leveling property and coating film transferability at the time of coating can be easily obtained, and when it is 15% by mass or less, low gloss can be easily obtained.

In addition to the above, the coating composition of the present invention includes a monofunctional monomer having one (meth) acryloyl group in the structure and a polyfunctional monomer having three or more (meth) acryloyl groups, if necessary. May be appropriately contained. The monofunctional monomer and the polyfunctional monomer are preferably 20% by mass or less, and more preferably 10% by mass or less in the total amount of the coating composition.

Examples of the photopolymerization initiator used in the active energy ray-curable coating composition for decorative plates of the present invention include an alkylphenone-based photopolymerization initiator, an acylphosphine oxide-based photopolymerization initiator, and an intramolecular hydrogen abstraction-type photopolymerization initiator. It can be widely used from agents, oxime ester-based photopolymerization initiators, and other blend-type photopolymerization initiators. Of these, an intramolecular hydrogen abstraction type photopolymerization initiator is preferable.

To give an example of the alkylphenone-based photopolymerization initiator, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1 -Phenyl-Propane-1-one, 1- [4- (2-Hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1-one, 2-Hydroxy-1- {4- [ 4- (2-Hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propane-1-one, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropane-1- On, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- ( 4-morphonyl) phenyl] -1-butanone, triarylsulfonium hexafluorophosphate, triarylsulphonium tetrakis- (pentafluorophenyl) porate and the like can be mentioned.

Examples of the acylphosphine oxide-based photopolymerization initiator include bis- (2,6-dichlorobenzoyl) phenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -2,5-dimethylphenylphosphine oxide, and bis. -(2,6-dichlorobenzoyl) -4-propylphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -1-naphthylphosphine oxide, bis- (2,6-dimethoxybenzoyl) phenylphosphine oxide , Bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, Bis- (2,6-dimethoxybenzoyl) -2,5-dimethylphenylphosphine oxide, Bis- (2, 4,6-trimethylbenzoyl) Bisacylphosphine oxides such as phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,6-dimethoxybenzoyl-diphenylphosphine oxide, 2,6- Monoacylphosphine oxides such as dichlorobenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoyl-phenylphosphinic acid methyl ester, 2-methylbenzoyl-diphenylphosphine oxide, pivaloylphenylphosphinic acid isopropyl ester Among these, bisacylphosphine oxides such as 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and bis- (2,4,6-trimethylbenzoyl) phenylphosphine oxide are preferable. In particular, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide has a UV absorption wavelength that matches the emission wavelength region of the ultraviolet light emitting diode, so that suitable curability can be obtained and a cured film is obtained. It is more preferable because it causes less yellowing.

Examples of the intramolecular hydrogen abstraction type photopolymerization initiator include phenylglycylic acid methyl ester, oxyphenylacetic acid and 2- [2-oxo-2-phenylacetoxyethoxy] ethyl ester, oxyphenylacetic acid and 2- (2- (2-). Examples include a mixture of hydroxyethoxy) ethyl esters. Among them, the mixture of oxyphenylacetic acid, 2- [2-oxo-2-phenylacetoxyethoxy] ethyl ester, oxyphenylacetic acid and 2- (2-hydroxyethoxy) ethyl ester has very little residual odor after UV curing. It is a liquid type low volatile photopolymerization initiator, which shows almost no yellowing after curing, and is most preferable for the active energy ray-curable coating composition for decorative plates of the present invention.

Examples of the oxime ester-based photopolymerization initiator include 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], etanone, 1- [9-ethyl-6- ( 2-Methylbenzoyl) -9H-carbazole-3-yl]-, 1- (O-acetyloxime) and the like can be mentioned.

These photopolymerization initiators may be used alone or in combination of two or more.
The total content of the photopolymerization initiator used is preferably 0.1 to 10% by mass of the total amount of the coating composition. If the content is less than 0.1% by mass, there is almost no effect of improving the curability, and if it exceeds 10% by mass, further improvement of the curability commensurate with the added amount cannot be expected, and it is dissolved in the coating composition. It is difficult to do so, and it is not preferable because it causes a decrease in the fluidity of the coating material and a deterioration in storage stability due to the precipitation of the initiator.

The active energy ray-curable coating composition for a decorative board of the present invention is further provided with various functions as necessary within a range not deviating from the object of the present invention. Additives such as defoamers, leveling agents, dispersants, antioxidants, coupling agents, organic solvents and chelating agents can be added.

The production of the active energy ray-curable coating composition for a decorative board of the present invention can be carried out by a conventionally known method. As an example, an active energy ray-polymerizable monomer and / or oligomer, a photopolymerization initiator, and silica, and if necessary, a paint additive can be produced in this order by a method such as mixing and stirring.

The viscosity range of the active energy ray-curable coating composition for a decorative board of the present invention varies depending on the coating method, but is preferably 40 to 2000 mPa · s at a liquid temperature of 40 ° C. For example, the range of 200 to 1500 mPa · s is preferable at a liquid temperature of 40 ° C. The viscosity was measured by Rion Co., Ltd. Viscometer VT-04.

The active energy rays irradiated to cure the active energy ray-curable coating composition for a decorative plate of the present invention include ultraviolet rays, electron beams, γ rays, ionizing radiation, electromagnetic waves, and the like, and ultraviolet rays are particularly preferable. When irradiating ultraviolet rays, a known ultraviolet irradiation device equipped with a high-pressure mercury lamp, an excimer lamp, a metal halide lamp, or the like can be used. The intensity of the ultraviolet rays to be irradiated is preferably ^{~, 100 to 400 mJ / cm 2.}

The base material to which the active energy ray-curable coating composition for decorative board of the present invention is applied is a wooden floor material (floor material), vinyl chloride (PVC), olefin, paper material, calcium silicate board, cement board, etc. Examples thereof include a magnesium oxide plate and an aluminum oxide plate. A calcium silicate board is particularly preferable as a base material when used as a decorative board. Layers for exhibiting design, smoothness and adhesion may be provided on these substrates.

Conventionally known methods can be applied as the coating method of the active energy ray-curable coating composition for decorative boards of the present invention, and among them, the most representative ones are roll coat, gravure coat, bar coat, and flow. There are coats and dip coats. Above all, the coating amount when coating by the roll coating coating method is preferably 1 to 20 μm, more preferably 1 to 11 μm as the cured coating film.

The decorative board coated with the active energy ray-curable coating composition for a decorative board of the present invention on the surface and cured is effective not only in terms of design but also in terms of flame retardancy, and should be utilized as a flame-retardant decorative board. You can also.

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. Unless otherwise specified below, the numbers in the table shall represent parts by mass.

<Measuring method of melting point of surface treatment wax of matting agent>
The melting point of the matting agent is measured under the following conditions using a differential scanning calorimeter X-DSC-7000 (manufactured by Hitachi High-Tech Science Corporation).
Heating rate: 10 ° C / min
Measurement start temperature: 20 ° C
Measurement end temperature: 200 ° C
The melting points of indium and zinc are used for temperature correction of the device detector, and the heat of fusion of indium is used for the correction of calorific value.
Specifically, about 1 mg of wax separated and extracted from a matting agent is precisely weighed, placed in an aluminum pan, and an empty aluminum pan is used as a reference to perform differential scanning calorimetry. In the measurement, the temperature is raised to 200 ° C., then lowered to 30 ° C., and then raised again. In this second temperature rise process, the peak temperature of the maximum endothermic peak of the DSC curve in the temperature range of 30 ° C. to 200 ° C. is defined as the melting point of the wax. The maximum endothermic peak is the peak having the largest endothermic amount.

(Examples 1 to 18 / Comparative Examples 1 to 7)
According to the compositions of Tables 1 to 4, active energy ray-curable coating compositions for decorative boards were blended and prepared by a dispersion stirrer.

(Example 1)
67 parts of tricyclodecanedimethanol diacrylate (A-DCP manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), which is a bifunctional monomer, and 6.7 parts of silica synthetic amorphous silicon dioxide surface-treated with microcrystallin oxide having a melting point of 74 ° C. 4. Photopolymerization initiator IRGACURE754 (manufactured by BASF, a mixture of oxyphenylacetic acid, 2- [2-oxo-2-phenylacetoxyethoxy] ethyl ester, oxyphenylacetic acid and 2- (2-hydroxyethoxy) ethyl ester). Paint A was prepared with 2 parts, 5 parts of polypropylene wax, 17 parts of acrylic beads, and 0.4 parts of a dispersant.

Similarly, Examples 2 to 18 were similarly adjusted according to the compositions in Tables 1 to 3.

For the comparative example, the same adjustment was made according to the composition in Table 4.
For Comparative Example 1, silica treated with organic wax having a melting point of 58 ° C. was used instead of silica synthetic amorphous silicon dioxide surface-treated with microcrystallin oxide having a melting point of 74 ° C.
For Comparative Example 2, untreated silica was used instead of these.
In Comparative Example 3, silica was not added.
For Comparative Example 4, EBECRY1290 (bifunctional aliphatic urethane acrylate) manufactured by Daicel Ornex Co., Ltd. was further added to the wax-treated silica surface-treated with an organic wax having a melting point of 58 ° C.
In Comparative Example 5, New Frontier R-1901 (9-functional aliphatic acrylate) manufactured by Daiichi Kogyo Co., Ltd. was further added to the wax-treated silica surface-treated with an organic wax having a melting point of 58 ° C.
In Comparative Example 6, EBECRY1290 (hexafunctional aliphatic urethane acrylate) manufactured by Daicel Ornex Co., Ltd. was further added to untreated silica without surface treatment.
In Comparative Example 7, New Frontier R-1901 (9-functional acrylate) manufactured by Daiichi Kogyo Co., Ltd. was further added to the untreated silica without surface treatment.

[Preparation of decorative board for evaluation]
With the floor as the base material, each paint is heated to 40 ° C, adjusted with a natural roll coater at a coating speed of 15 m / min so that the coating amount becomes 5 g / m ² , and then applied with a high-pressure mercury lamp. It was cured by irradiating with ultraviolet rays having an intensity of 450 mJ / cm ^2. Each of the obtained cured coating films of the decorative board was tested according to the method described below. Only for the evaluation of curability, the illuminance was changed stepwise to determine the illuminance to be tack-free. Tack-free refers to a state in which a finger is pressed against an ultraviolet-irradiated coating film with a load of 50 g, and after the finger is released, the paint does not adhere to the finger or a fingerprint mark is not left on the coating film. UV-NR1 manufactured by GS Yuasa was used for the illuminance measurement.

[Evaluation test method]
(1) Gloss measurement Gloss was measured with VG2000 (manufactured by Nippon Denshoku), and the results were shown at 0 to 100 gloss. The gloss measurement condition was an incident angle of 60 ° and a reflection angle of 60 °.
According to the measured gloss value (lower, less glossy, higher, glossier), the evaluation was divided into the following four stages.
⊚: Gross value is lower than 15.0 ○: Gross value is 15.0 or more and less than 25.0 Δ: Gross value is 25.0 or more and less than 30.0 ×: Gross value is higher than 30.0

(2) Stain resistance test Black ink (manufactured by Pilot) was applied to the coating film, left for 4 hours, wiped off with water and a solvent, and then the stain marks were visually judged in the following four stages.
◎: Contamination marks can be completely wiped off ○: Contamination marks can be almost wiped off △: Residual color can be confirmed on the entire contamination marks ×: Significant residual colors can be confirmed on the entire contamination marks

(3) Recoatability (repair suitability)
When Linleyol, a water-based wax, is waxed and dried using an applicator over the cured film of the active energy ray-curable paint composition of a decorative board, and then the wax surface is peeled off using cellophane tape. The residual rate of wax was visually determined in the following four stages.
◎: Wax does not peel off at all and 100% remains ○: 90% of the entire wax remains but 10% peels off △: Half of the entire wax remains, but more than 10% to half Peeled ×: More than half of the whole wax ~ Most of the wax is peeled off

(4) The curable ◎: 100mJ / cm ² or more becomes tack-free at 250 mJ / cm less than ² ○: 250mJ / cm ² or more becomes tack-free at 400 mJ / cm less than ² △: 400mJ / cm ² or more 450 mJ / × become tack-free in less than cm ^2: a tack-free at 450mJ / cm ² or more 600mJ / cm less than ²

・ＥＢＥＣＲＹ１２９０：６官能脂肪族ウレタンアクリレート（重量平均分子量
１，０００）、ダイセル・オルネクス（株）社製
・ニューフロンティアＲ−１９０１：９官能アクリレート、第一工業（株）社製

EBECRY1290: 6-functional aliphatic urethane acrylate (weight average molecular weight 1,000), manufactured by Daicel Ornex Co., Ltd.-New Frontier R-1901: 9 functional acrylate, manufactured by Daiichi Kogyo Co., Ltd.

In the examples, an active energy ray-curable coating composition for a decorative board, which has low gloss (gloss), stain resistance, and recoating property while maintaining sufficient curability, and a surface coated with the composition and cured. Can provide a decorative board.

Claims (5)

An active energy ray-curable coating composition for a decorative board containing an active energy ray-polymerizable bifunctional monomer, a photopolymerization initiator, and a matting agent, wherein the matting agent is microcrystallin oxide having a melting point of 70 ° C. or higher. An active energy ray-curable coating composition for a decorative board, which is a treated synthetic amorphous silicon dioxide. The active energy ray-curable coating composition for a decorative board according to claim 1, wherein the content of the active energy ray-polymerizable bifunctional monomer is 30 to 80% by mass of the total amount of the coating composition. The active energy ray-polymerizable bifunctional monomer is one or more selected from the group consisting of tricyclodecanedimethanol diacrylate, ethylene oxide-modified bisphenol A di (meth) acrylate, and propylene oxide-modified bisphenol A di (meth) acrylate. The active energy ray-curable coating composition for a decorative board according to claim 1 or 2. The active energy ray-curable type for a decorative plate according to any one of claims 1 to 3, wherein the content of the synthetic amorphous silicon dioxide treated with the microcrystallin oxide is 1 to 10% by mass of the total amount of the coating composition. Paint composition. A decorative board obtained by coating the surface of the active energy ray-curable coating composition for a decorative board according to claims 1 to 4 and curing the decorative board.