KR0157228B1 - Uv-curable coating composition for color-board - Google Patents

Abstract

The present invention relates to a UV-curable coating composition for color board, more specifically 30 to 60% by weight of oligomers having at least two or more acrylic groups, at least one monofunctional, bifunctional. 30 to 50% by weight of tri- or tetrafunctional acrylic monomer, 2 to 15% by weight of inorganic pigment. A coating composition consisting of 2 to 7% by weight of photoinitiator, 0.5 to 1.5% by weight of surface energy regulator and 0.5 to 1.5% by weight of dispersant is coated on a board substrate, and then UV-cured to prepare a color board. The color board is excellent in handwriting, durability and stain resistance.

Description

UV Curing Coating Composition for Color Board

The present invention relates to a UV curable coating composition for color boards, and more particularly to a UV curable coating composition for producing a color board excellent in writing, durability and stain resistance.

Recently, whiteboards are being manufactured and used in various sizes, replacing the existing blackboards. The reason is that the white board can overcome the limitations of the blackboard, which has the disadvantage that the chalk used in the existing blackboard is harmful to the human body by generating dust, difficult to remove the writing marks, and should be used only as a stationary product. . However, the surface of the whiteboard is mostly treated with silicon-based chemicals, so the manufacturing cost is high, and after a certain period of time, it is very difficult to remove the contaminants of the aqueous tools. In addition, there is a serious manufacturing limitation that only white is applied, such as the name of the board. Recently, there is a demand for manufacturing color boards that have excellent surface properties such as handwriting, durability, and stain resistance, are easy to remove writing marks, and can diversify colors. In particular, it is required to manufacture a UV curable color board that can be applied to a variety of substrates from the surface material of silicon using a thermal curing or ultraviolet curing method.

Accordingly, the present inventors have diligently studied the phenomenon related to the above-mentioned problems, and as a result, when using a coating agent in which a specific amount of monomer and other additives are mixed using an aliphatic urethane acrylate oligomer or an epoxy acrylate oligomer, a color board having excellent surface properties It has been found that can be prepared using a variety of board substrates, the present invention was completed based on the above findings.

Accordingly, an object of the present invention is to solve the above problems to provide a UV curable coating composition for color boards excellent in handwriting, durability and stain resistance.

Another object of the present invention to provide a color board coated with the coating composition.

The coating composition of the present invention for achieving the above object is 30 to 60% by weight of oligomer having at least two or more acrylic groups, at least one or more monofunctional, bifunctional, trifunctional or tetrafunctional acrylic monomers 30 to 50 wt%, inorganic pigment 2-15 wt%, photoinitiator 2-7 wt%, surface energy regulator 0.5-1.5 wt% and dispersant 0.5-1.5 wt%,

Looking at the present invention in more detail as follows.

As an oligomer used for the composition of this invention, it is a bifunctional to polyfunctional acrylic resin which has at least 2 or more acryl groups, for example. Urethane acrylate, polyether acrylate or novolak epoxy acrylate may be used, and the amount is preferably 30 to 60% by weight. If less than 30% by weight, the hardened coating film has poor physical properties and durability. It will worsen and the adhesion will also fall. In addition, when it exceeds 60% by weight, the viscosity of the resin composition is so high that coating is impossible.

According to the invention. At least one mono-, bi-, tri- or tetra-functional acrylic monomer may be used as the acyl-based monomer, preferably 2-hydroxy propyl acrylate (2-HPA), 1,6 Hexanedioldiacrylate (HDDA), polyethyleneglycoldiacrylate (PEGDA), trimethylol propane triacrylate (TMPTA) and pentaerythritol tetraacrylate (PETIA). The amount of the monomer used in the total composition is preferably 30 to 50% by weight, but less than 30% by weight results in poor adhesion and surface appearance. It becomes difficult to control the physical properties of the coating film, and if it exceeds 50% by weight, the basic physical properties of the cured coating film is lowered, and the fouling resistance is poor.

On the other hand, the amount of the inorganic pigment added to the composition is preferably used 2 to 15% by weight. If it is less than 2% by weight, concealing power and desired color expression are impossible, and if it exceeds 15% by weight, the viscosity of the coating agent is too high, the workability is lowered, and the physical properties of the coating film are lowered.

Examples of the photoinitiator used in the present invention include benzophenone, I-hydroxycyclohexyl phenyl ketone (IRG-184), bisacylphosphine oxide (BAPO), and CGI-1700 available from Ciba, Switzerland. Or triphosphine oxide of BASF, Germany. The photoinitiator is added in 2 to 7% by weight based on the total composition, when less than 2% by weight, the curing time is very long, productivity is lowered, deformability due to heat is worsened, and when it exceeds 7% by weight UV stability and curing The film properties are degraded.

The amount of the surface energy modifier and the dispersant used in the composition according to the present invention is preferably added in an amount of 0.5 to 1% by weight. If the amount is less than 0.5% by weight, it is difficult to control the adhesion and the surface properties thereof. The surface energy modifier moves to the surface of the coating and needs surface cleaning after curing. It is preferable to use eFKa-46 from Efka Chemical Co., Ltd., and EB-350 from Sun-UCB Co., Ltd. as the surface energy regulator.

As a material which can manufacture the color board substrate which concerns on this invention, methacrylate resin (PMMA) and polycarbonate (PC). Vinyl chloride synthetic resin (PVC). Polypropylene foamed resin (PP) or acrylonitrile butadiene styrene (ABS) -based synthetic resins may be used, and existing whiteboard substrates may also be used.

On the other hand, the surface energy modifier added in a small amount to the composition according to the present invention, when applied to a substrate such as polypropylene, acrylonitrile butadiene styrene or poly carbonate, without damaging the physical properties of the entire coating film and Reaction can lead to an improvement in surface hardness. Thus, it is possible to maintain the adhesion without pretreatment of the substrate surface, as well as to adjust the substrate wetting, the adhesion and the hardness of the coating surface.

According to the present invention, using the gravure roll, rubber roll, steel roll or curtain coater on the board substrate is applied to a coating film thickness of 30 ~ 100um, and cured using ultraviolet energy to produce a color board substrate can do. In this case, when the thickness of the coating film is less than 30um, hiding power is lowered, and when the thickness of the coating film is more than 100um, the appearance is poor, and the coating method and curing are restricted, which may cause problems in productivity.

Although the effects of the present invention will be described in more detail with reference to the following examples and comparative examples, the scope of the present invention is not limited to the following examples.

Example 1

Using a gravure roll on a 7 mm thick board processed with a hard vinyl chloride resin, a coating composition having a composition shown in Table 1 below was formed to form a coating having a thickness of 30 μm, and then cured with ultraviolet rays emitted from a medium pressure mercury lamp to prepare a color board. It was.

In Table 1, the oligomer was PASO-051 manufactured by Hanwha General Chemical Co., Ltd., and the acrylate monomer was mixed with HDDA and PETIA of Sunkyung-UCB in a ratio of 1: 1. -HPA was prepared by mixing at a ratio of 1. The pigment was used by mixing the inorganic blue of I.C.I of UK and the rutite base of DuPont of USA in the ratio of 1: 3. The photoinitiator was used by mixing 1: 1 IRG-184 of Siva, Switzerland, and TPO of BASF, and eFKa-46 of Efka Chemical. In addition, the surface energy regulator used EB-350 of Sunkyung-UCB.

Example 2

Using a curtain coater on a 4mm-thick board processed with a transparent polycarbonate resin, using a coating composition having the composition shown in Table 2 below to form a 60um film thickness in an ultraviolet atmosphere using a medium pressure mercury lamp and a metal halide lamp simultaneously. The coating film was cured to prepare a color board.

In Table 2, the oligomer used was CNl12C60, which is an epoxy novolak oligomer of Sartomer, USA, and an acrylate monomer was mixed and used in a ratio of 1: 1 by 2-HPA and Japan-UCB TMPTA.

As the pigment, the inorganic YELLOW of I.C.I. of England and the rutile base of DuPont of USA were used at a ratio of 1: 4. Photoinitiator, dispersant and surface energy regulator was the same as in Example 1.

Example 3

Except that the vinyl chloride resin board in Example 1 was used as the polycarbonate resin board of Example 2 was carried out in the same manner.

Example 4

The polycarbonate resin board was carried out in the same manner as in Example 2, except that the acrylonitrile budadiene styrene (ABS) resin board was used.

Example 5

Except that the photoinitiator in Example 2 was used as CGI-1700 of CIBA, Switzerland.

Comparative Example 1

Instead of the composition of Example 1, the surface was coated with a RC-based silicone compound of Goldschmidt, Germany, and then UV-cured to prepare a board.

Comparative Example 2

Instead of the composition of Example 2, the coating was cured after coating with a thermosetting silicone compound manufactured by Shin-Etsu Corp. of Japan.

The physical properties of the coating films according to Examples 1 to 5 and Comparative Examples 1 and 2 were measured, and the results are shown in Table 3. In Table 3, staining resistance was written using an oil-based magic pen, and then washed three times with acetone soaked in gauze, and the adhesive force was generated by cutting 100 grids in an area of 1 square centimeter by the method described in ASTM method. This is the result of desorption experiment with Scotch tape. Handwriting is the result of comparing the writing state using the water-based pen used for the whiteboard, the surface appearance is the result of measuring the surface cured by a microscope. In addition, durability is the result observed through the California sand dripping test, and chemical-resistance is the result measured 5 minutes after methyl ethyl ketone was dripped.

As can be seen from Table 3, the color board according to Examples 1 to 5 has better stain resistance, surface strength, writeability, and durability of the chemical resistance than the board according to Comparative Examples 1 and 2, and also has adhesive strength. As a result, the new color board using the composition according to the present invention not only compensates for the disadvantages of the existing white board, but also has an effect of greatly improving durability, stain resistance, and the like.

Claims (5)

30 to 60% by weight of oligomers having at least two acrylic groups, 30 to 50% by weight of at least one monofunctional, bifunctional, trifunctional or tetrafunctional acrylic monomer, 2 to 15% by weight of inorganic pigments, 2-7 wt% of one photoinitiator selected from the group consisting of benzophenone, 1-hydroxy-cyclohexyl phenylketone (IRG-184), bisacylphosphine oxide (BAPO), CGI-1700, and triphosphine oxide, UV-curable coating composition for a color board, characterized in that consisting of 0.5 to 1.5% by weight of EB-350 and 0.5 to 1.5% by weight as a surface energy regulator. The UV curable coating composition for color board according to claim 1, wherein the oligomer is urethane acrylate, polyether acrylate or epoxy acrylate of novolak structure. The method of claim 1, wherein the acrylic monomer is 2-hydroxyethyl acrylate (2-HEA), 1,6-hexanediol diacrylate (HDDA), polyethylene glycol diacrylate (PEGDA), trimethylol propane triacryl UV curable coating composition for color boards, characterized in that one or more selected from the group consisting of latex (TMPTA) and pentaerythritol tetraacrylate (PETIA), Colorboard coated with a composition of claim 1 in a thickness of 30 ~ 100㎛ on the substrate. The method of claim 4, wherein the substrate is methacrylate resin (PMMA), polycarbonate (PC), vinyl chloride-based synthetic resin (PVC), polypropylene foamed resin (PP), acrylonitrile butadiene styrene (ABS) Color board, characterized in that the synthetic resin or white board.