KR20030078237A - UV curable oriental lacquer coating composition and method for preparing oriental lacquer coating using the same - Google Patents

Abstract

PURPOSE: A UV curing lacquer composition and a method for preparing a lacquer coating by using the composition are provided, to improve the curing velocity and to allow a coating with a thickness of 50 micrometers or more to be formed even with one coating. CONSTITUTION: The UV curing lacquer composition comprises 60-93 wt% of a lacquer solution; 0.1-30 wt% of a UV curing silicon compound represented by the formula 1; 5-30 wt% of an acrylate-based oligomer, acrylate-based monomer or vinyl ether-based monomer having at least one acryl group; and 1-7 wt% of a photoinitiator, wherein R1 and R7 which are identical or different each other, are H, a methyl group, an ethyl group, an acrylate group, an epoxy group or a vinyl ether group; l, m and n are an integer of 1-10; R6 is OH or H; R2, R3, R4 and R5 which are identical or different one another, are a methyl group, a methoxy group, an ethoxy group, a phenyl group, an ester group, a methyl chlorinated phenyl group, a methylphenyl group or a linear or branched molecular chain having an alkyl group of C4-C18.

Description

UV curable lacquer composition and manufacturing method of lacquer coating using same {UV curable oriental lacquer coating composition and method for preparing oriental lacquer coating using the same}

The present invention relates to a UV-curable lacquer composition and a method for manufacturing a lacquer coating film using the same, and more particularly, by adding a UV-curable silicone compound having a siloxane with excellent gas permeability and UV-curable structure simultaneously to a lacquer composition. It is possible to harden a thick film of 50 μm or more, preferably 100 μm or more by coating, and to provide a fast curing speed and excellent UV coating type lacquer composition having excellent coating properties and a method of manufacturing a lacquer coating film using the same.

Lacquer is a natural film-forming material obtained from lacquer trees, and has been widely applied for thousands of years in Korea, China, and Japan to wooden furniture and mineral materials such as porcelain bowls and stone bowls. In addition, lacquer is the most environmentally friendly paint because it does not cause any pollution since it does not use organic solvents, compared to general paints, it is a natural material with elegant luster that is durable and hard to withstand indoors.

However, while the lacquer has the advantages described above, there is a problem in storage because the color is changed by contact with air, especially when exposed to the outdoors, weather resistance is greatly reduced. In addition, since curing proceeds by the enzymatic oxidation reaction of laccase, 5 to 10 coatings are required to obtain thick film hardening and excellent coating surface properties. .

In order to solve such a problem, conventionally, by extracting urushiol present in the lacquer solution and thermosetting according to the molecular weight to form a coating film thickly with one coat (see Korean Patent Publication No. 2001-11478) and blended with general synthetic resin Although a method of forming a coating film (see Korean Laid-Open Patent Publication No. 2000-24493) has been developed, all of them have environmental problems because not only the lacquer intrinsic property is lowered but also a general organic solvent is used as a diluent.

Therefore, the present inventors have been researching for many years to increase the commercial use of lacquer as an industrial coating, and as a result found that the conventional problem can be solved by incorporating an organic compound having a siloxane structure and a UV-curable structure into the lacquer composition. The present invention has been completed.

Accordingly, it is an object of the present invention to provide an ultraviolet curable lacquer composition comprising an ultraviolet curable siloxane compound capable of thickening the film while maximizing the unique properties of the lacquer.

Another object of the present invention is to shorten the curing time and at the same time to provide a method for producing a high-performance lacquer coating having excellent coating properties required as other paints.

UV-curable lacquer composition according to the present invention to achieve the above object, 60 to 93% by weight lacquer; 0.1 to 30% by weight of an ultraviolet curable silicone compound represented by Formula 1 below; 5 to 30% by weight of an acrylate oligomer, an acrylate monomer, or a vinyl ether monomer having at least one or more acrylic groups; And 1 to 7% by weight of photoinitiator.

Wherein R ₁ and R ₇ are the same as or different from each other hydrogen, methyl, ethyl, acrylate, epoxy or vinyl ether, l, m and n are integers from 1 to 10, R ₆ is hydroxyl or hydrogen, R ₂ , R ₃ , R ₄ and R ₅ are the same or different from each other and are straight or branched molecular chains having methyl, methoxy, ethoxy, phenyl, ester, methylchlorinated phenyl, methylphenyl or alkyl groups having 4 to 18 carbon atoms.

Method for producing a lacquer coating according to the present invention for achieving the above another object, the step of applying the above-mentioned UV-curable lacquer composition; And irradiating the UV-curable lacquer composition with ultraviolet light having an illuminance in the range of 33 mW / cm ² to 1000 mW / cm ² , and having a light quantity in the range of 30 mJ / cm ² to 500 mJ / cm ² . Curing by enzymes at a temperature of and a relative humidity of 50-80%.

Hereinafter, the present invention will be described in more detail.

As described above, the ultraviolet curable lacquer composition according to the present invention is a lacquer; UV-curable silicone compound represented by the formula (1); Acrylate oligomers, acrylate monomers or vinyl ether monomers having at least one or more acrylic groups; And photoinitiators.

The lacquer used in the present invention is not subject to the origin of Korea, China, Japan, Southeast Asia, etc., these lacquer can be applied to all but slightly different composition depending on the origin. The content of the lacquer used in the present invention is 60 to 93% by weight, when the content is less than 60% by weight, the intrinsic physical properties of the lacquer coating is lowered, and when the content exceeds 93% by weight, the curing rate is too delayed.

In addition, the ultraviolet curable silicone compound used by this invention is represented by following General formula (1). The siloxane structure is excellent in wear resistance, weather resistance, leveling property, mold release property and gas permeability, in particular gas permeability is a great advantage in the curing process of lacquer.

Formula 1

Wherein R ₁ and R ₇ are the same as or different from each other hydrogen, methyl, ethyl, acrylate, epoxy or vinyl ether, l, m and n are integers from 1 to 10, R ₆ is hydroxyl or hydrogen, R ₂ , R ₃ , R ₄ and R ₅ are the same or different from each other and are straight or branched molecular chains having methyl, methoxy, ethoxy, phenyl, ester, methylchlorinated phenyl, methylphenyl or alkyl groups having 4 to 18 carbon atoms.

The amount of the ultraviolet curable siloxane compound used is preferably 0.1 to 30% by weight based on the final product. If the content is less than 0.1% by weight does not have a significant effect on the curing rate and physical properties improvement, if the content exceeds 30% by weight there is a problem that the surface energy is separated, such as phase separation.

The acrylate oligomer having at least one acrylic group usable in the present invention is selected from the group consisting of urethane acrylate, epoxy acrylate, polyester acrylate and silicone acrylate, the amount of which is 5 to 3% by weight Especially, 5-20 weight% is preferable.

In addition, the monomer usable in the present invention is preferably a monofunctional to polyfunctional acrylate monomer or a vinyl ether monomer, and as the acrylate monomer, hydroxyethyl acrylate (HEA) and hydroxyethyl methacrylate ( HEMA), 1,6-hexanedioldiacrylate (HDDA), tripropylene glycoldiacrylate (TPGDA), trimethylol propane triacrylate (TMPTA), pentaerythritol triacrylate (PETA) and dipenta At least one selected from the group consisting of ritritol hexaacrylate (DPHA) and the like, and the vinyl ether monomers include butanediol monovinyl ether, 1,4-cyclohexane dimethanol mono vinyl ether, triethylene glycol divinyl ether, and the like. Selected from the group consisting of: In this case, the amount is preferably 5 to 30% by weight based on the final product.

The photoinitiator is a free radical photoinitiator, a compound obtained by mixing 1-hydroxy cyclohexylphenyl ketone, 1-hydroxy cyclohexylphenyl ketone and benzophenone in a weight ratio of 1: 1, 2-hydroxy-2-methyl-1 -Phenyl-propan-1-one, and α, α-dimethoxy-α'-hydroxy acetophenone; and the like; Irgacure 184, Darocur 1173, or Kolon Emulsion UVICURE 204 from Shivagai, Switzerland Products. The amount of the photoinitiator is preferably 1 to 7% by weight based on the final product, if the content is less than 1% by weight in the unreacted material, the physical properties are lowered, if it exceeds 7% by weight unreacted initiator remains Weather resistance is lowered. Alternatively, cationic photoinitiators and other additives may also be used. As the other additives, a conventional dispersant may be further included.

The ultraviolet curable lacquer composition according to the present invention comprising the above-described components is applied, and the irradiance of the ultraviolet lamp is in the range of 33 mW / cm ² to 1000 mW / cm ² and the amount of light is 30 mJ / The lacquer coating film according to the present invention can be produced by irradiating ultraviolet rays in the range of cm ² to 500 mJ / cm ² and curing with an enzyme under a temperature of 20 to 45 ° C. and a relative humidity of 50 to 80%. If the UV intensity is less than 30 mJ / cm ^2, ultraviolet curing is not performed. If the UV intensity exceeds 500 mJ / cm ² , the physical properties of the lacquer coating film are deteriorated.

The ultraviolet lamp may use a medium pressure mercury lamp, a high pressure mercury lamp, a metal halide lamp and a xenon lamp. In addition, when the irradiance of the ultraviolet lamp is less than 33 mW / cm ² it is difficult to fully cure the ultraviolet ray, and when it exceeds 1000 mW / cm ² it will lower the coating properties.

In the case of forming a coating film by a conventional method of a conventional lacquer liquid, when the coating film thickness is formed to 10 μm or more, the surface of the coating film is very rough and many problems as coating occur, but the lacquer coating film according to the present invention obtained by the above-described method is used only once. As a coating film, a coating film having a thickness of 50 µm or more, preferably 100 µm or more and having a very good surface state can be obtained.

The present invention will be described in more detail with reference to the following examples and comparative examples, but the following examples do not limit the scope of the present invention.

Example 1

To 85% by weight of a lacquer solution, 5% by weight of an ultraviolet curable silicone compound represented by the following formula (2), 5% by weight of trimethylol propane triacrylate, and 5% by weight of a 1: 1 mixture of a short wavelength photoinitiator and a long wavelength photoinitiator were added and stirred at room temperature. A curable lacquer composition was obtained. The composition was applied to a PET film using an applicator at about 77 μm, followed by UV curing at a strength of 150 mJ / cm ² in a medium pressure mercury lamp, followed by drying under enzyme conditions of 70% at room temperature and relative humidity. Was performed.

Wherein n = 3.

Example 2

Except that 80% by weight of lacquer solution, 10% by weight of the ultraviolet curable silicone compound represented by the formula (2), 5% by weight of trimethylol propane triacrylate, and 5% by weight of a 1: 1 mixture of a short wavelength photoinitiator and a long wavelength photoinitiator. It carried out similarly to Example 1.

Example 3

The same procedure as in Example 1 was carried out except that the thickness of the lacquer coating film was applied at 120 μm.

Example 4

It carried out similarly to Example 2 except having applied the thickness of the lacquer coating film at 120 micrometers.

Example 5

It carried out similarly to Example 1 except having made ultraviolet intensity 300 mJ / cm <^2> .

Example 6

It carried out similarly to Example 2 except having set the ultraviolet intensity to 300 mJ / cm ² .

Example 7

The photoinitiator was carried out in the same manner as in Example 1, except that 5 wt% of the single wavelength photoinitiator was used alone.

Comparative Example 1

The lacquer was applied to the PET film with a thickness of about 10 μm, and then cured under a condition of 25 ° C. and 70% relative humidity.

Comparative Example 2

It carried out similarly to the said Comparative Example 1 except having applied the lacquer coating film to the thickness of 77 micrometers.

Comparative Example 3

It carried out similarly to the said Comparative Example 1 except having applied the lacquer coating film to the thickness of 120 micrometers.

Experimental Example

The lacquer compositions of Examples 1 to 7, and Comparative Examples 1 to 3 were measured by the following items and methods, and the results are shown in Table 1.

[Metric]

Pencil Hardness: ASTM D 3363-74

Glossiness: ASTM D 523

Curing time: Measuring hardening time of coating film using Sheen's BK 3 curing speed measuring instrument

Surface energy (mN / m): Surface energy measurement by Lewis-exid formula

Surface condition Pencil hardness Glossiness Surface energy Curing time (hr) Example 1 ◎ 4H 98 36 5 Example 2 ◎ 3H 92 39 7 Example 3 ◎ 3H 90 37 6 Example 4 ◎ 2H 89 38 8 Example 5 ◎ 3H 100 37 7 Example 6 ◎ 2H 94 39 8 Example 7 ○ 1H 90 41 10 Comparative Example 1 ◎ HB 83 47.07 12 Comparative Example 2 × Not measurable Not measurable Not measurable Uncured Comparative Example 3 × Not measurable Not measurable Not measurable Uncured Surface condition-◎: Very good, ○: Good, ×: Poor

As can be seen from the above examples and comparative examples, in the case of the lacquer composition to which the ultraviolet curable silicone compound according to the present invention is added, a coating film having a very good surface condition of 50 μm or more, preferably 100 μm or more in one coating. Can be prepared. In addition, compared with the conventional case where the curing proceeds only by the enzymatic oxidation of laccase, the overall coating properties and the curing properties are excellent. Therefore, since the thick film can be cured at once while maximizing the intrinsic properties of the lacquer coating film, the production process time can be greatly shortened, thereby improving productivity.

All simple modifications and variations of the present invention fall within the scope of the present invention, and the specific scope of the present invention will be apparent from the appended claims.

Claims (7)

60 to 93% by weight of lacquer; 0.1 to 30% by weight of an ultraviolet curable silicone compound represented by Formula 1 below; 5 to 30% by weight of an acrylate oligomer, an acrylate monomer or a vinyl ether monomer having at least one acrylic group; And UV curable lacquer composition comprising 1 to 7% by weight of the photoinitiator: Formula 1 Wherein R ₁ and R ₇ are the same as or different from each other hydrogen, methyl, ethyl, acrylate, epoxy or vinyl ether, l, m and n are integers from 1 to 10, R ₆ is hydroxyl or hydrogen, R ₂ , R ₃ , R ₄ and R ₅ are the same or different from each other and are straight or branched molecular chains having methyl, methoxy, ethoxy, phenyl, ester, methylchlorinated phenyl, methylphenyl or alkyl groups having 4 to 18 carbon atoms. The UV-curable lacquer composition of claim 1, wherein the acrylate oligomer is at least one selected from the group consisting of urethane acrylate, polyester acrylate, epoxy acrylate and silicone acrylate. According to claim 1, wherein the acrylate monomer is hydroxy ethyl acrylate (HEA), hydroxyethyl methacrylate (HEMA), 1,6-hexanediol diacrylate (HDDA), tripropylene glycol diacrylate Ultraviolet light, characterized in that at least one selected from the group consisting of (TPGDA), trimethylol propane triacrylate (TMPTA), pentaerythritol triacrylate (PETA) and dipentaerythritol hexaacrylate (DPHA) Curable lacquer composition. The ultraviolet curable type according to claim 1, wherein the vinyl ether monomer is at least one selected from the group consisting of butanediol monovinyl ether, 1,4-cyclohexane dimethanol mono vinyl ether, and triethylene glycol divinyl ether. Lacquer composition. The photoinitiator of claim 1, wherein the photoinitiator mixes 1-hydroxycyclohexylphenyl ketone, 1-hydroxycyclohexylphenyl ketone, and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide in a weight ratio of 1: 1. UV-curable lacquer composition, characterized in that it is selected from the group consisting of a compound, and 2-hydroxy-2-methyl-1-phenyl-propan-1-one. Applying an ultraviolet curable lacquer composition according to claim 1; And The ultraviolet curable lacquer composition is irradiated with ultraviolet light in the range of 33 mW / cm ² to 1000 mW / cm ² , and the amount of light is 30 mJ / cm ² to 500 mJ / cm ² to 20-45 ° C. Method for producing a lacquer coating film comprising the step of curing with an enzyme under the temperature and the relative humidity conditions of 50 to 80%. The method of claim 6, wherein the ultraviolet lamp is a medium pressure mercury lamp, a high pressure mercury lamp, a metal halide lamp, and a xenon lamp.