KR20210129409A - Photocurable type transparent coating composition for pcm - Google Patents

Abstract

The present invention relates to a photocurable transparent paint composition for PCM with improved weather resistance and, more specifically, to a photocurable transparent paint composition for PCM with improved weather resistance that has eco-friendly characteristics and transparency while solving problems such as gloss reduction, yellowing phenomenon, harmfulness to the human body, quality deterioration, etc. due to the use of the conventional photoinitiator and, in particular, improves main performance such as weather resistance, etc. by synthesizing a self-photocurable intermediate using a Michael addition reaction, preparing a self-photocurable polyurethane acrylate oligomer using the self-photocurable intermediate, and applying the self-photocurable polyurethane acrylate oligomer to the photocurable transparent coating composition for PCM.

Description

Photocurable transparent paint composition for PCM with improved weather resistance {PHOTOCURABLE TYPE TRANSPARENT COATING COMPOSITION FOR PCM}

The present invention synthesizes a self-photocurable intermediate using a Michael addition reaction, prepares a self-photocurable polyurethane acrylate oligomer using the same, and applies it to a photocurable transparent coating composition for PCM, It relates to a photocurable transparent paint composition for PCM with improved weather resistance, which solves various problems caused by the use of conventional photoinitiators, as well as has eco-friendly properties and transparency, and can improve major performance such as weather resistance.

In general, PCM (Pre-Coated Metal) is a steel sheet that has already been coated before processing. Generally, it is produced by using zinc steel as the main material, complete pre-treatment, double coating by the latest coating method, and heat treatment and drying twice. In addition, the coating film has excellent adhesion and has a beautiful surface, so it has excellent workability that does not cause peeling of the coating film even after roll forming, bending, and press working. .

On the other hand, PCM is a product production process in that it is possible to commercialize the coated coil and sheet by post-processing the coated coil and sheet by pre-processing clear or color coating in the state of coil and sheet. It has a changed character.

Currently, most of the companies that produce PCM are manufacturing PCM using oil-based coating agents that generally contain organic solvents. In general, oil-based coatings have the advantage of being inexpensive and having excellent physical properties. causes

The above problems are not only the PCM manufacturing process but also international environmental regulations such as the Kyoto Protocol, the Metropolitan Air Quality Management Act, the Air Conservation Act, etc. is in progress

In response to this, attempts have been made to introduce photocurable coatings into PCM manufacturing by advanced domestic and foreign companies since the 2000s. However, it was not commercialized due to the problems of adhesion to the base and the appearance quality.

To solve this problem, in Patent Document 1, isobornyl acrylate, acryloyl morpholine and tetrahydrofurfuryl acrylate, or isobornyl acrylate, acryloyl morpholine, N,N-dimethyl acrylamide and 30-50 wt% of a monomer mixture consisting of tetrahydrofurfuryl acrylate; 5-10% by weight of photoinitiator; It relates to a colored UV-curable transparent paint composition for PCM comprising 40 to 60% by weight of a 2 to 4 functional urethane acrylate, 2 to 5% by weight of a pigment, and 1 to 5% by weight of an additive, and is more transparent than the conventional paint composition for PCM. A colored UV-curable transparent paint composition for PCM that can implement color, is easy to remove air bubbles remaining in the coating film during silkscreening, and has excellent processability and physical properties of the coating film after formation of the coating film was proposed.

However, the prior art using a photoinitiator as described above is a low-molecular-weight polyfunctional compound that can be easily absorbed through the skin when the conventional photoinitiator is decomposed, and the photoinitiator remains after curing due to rapid curing. There was a problem that could be harmful to the health of workers and lower the final quality.

Patent Document 1: Republic of Korea Patent Publication No. 10-1635359 "Colored UV-curable transparent paint composition for PCM"

In order to solve the above problems, the present invention synthesizes a self-photocurable intermediate by using a Michael addition reaction and prepares a self-photocurable polyurethane acrylate oligomer using the same, and then PCM By applying it to a photocurable transparent paint composition for a photoinitiator, it solves problems such as gloss deterioration, yellowing phenomenon, human hazard, and quality deterioration due to the use of conventional photoinitiators, while also having eco-friendly characteristics and transparency, and in particular, main performance such as weather resistance. The challenge is to make it better.

The present invention relates to a photocurable paint composition for PCM, 55 to 75 wt% of a self-photocurable polyurethane acrylate oligomer, 20 to 30 wt% of IBOA (isobornyl acrylate) as a reactive diluent, and 1,6-hexanediol diacrylate (HDDA) A photocurable transparent paint composition for PCM with improved weather resistance, characterized in that it contains 3 to 10% by weight, 1.5 to 3.5% by weight of TMPEOTA (trimethylolpropane triacrylate), and 0.5 to 1.5% by weight of additives, as a means to solve the problem .

Here, the self-photocurable polyurethane acrylate oligomer is PCD (polycarbonate diol) 0.1 to 0.6 mol%, self-photocurable intermediate 0.1 to 0.6 mol%, TMP (trimethylolpuopane) 0.1 to 0.5 mol%, IPDI (Isophorone diisocyanate) 1 It is preferable to include ~ 3 mol% and 0.5 to 1.5 mol% of HEMA (hydroxy ethyl methacrylate).

And the self-photocurable intermediate is 2-HPA (2-hydroxypropyl acrylate) or 2-HEA (2-hydroxyethyl acrylate) 1-3 mol%, EAA (ethyl acetoacetate) 0.5-1.5 mol% and catalyst (NaCO) 0.001 It is preferable to include ~ 0.005 mol%.

The present invention solves problems such as gloss reduction, yellowing phenomenon, human harm, and quality deterioration due to the use of conventional photoinitiators, and has eco-friendly properties and transparency, and in particular, there is an effect that can improve main performance such as weather resistance. .

The present invention for achieving the above effect relates to a photocurable transparent coating composition for PCM with improved weather resistance. It should be noted that will be omitted so as not to distract from

Hereinafter, the photocurable transparent paint composition for PCM with improved weather resistance according to the present invention will be described in detail as follows.

The present invention is a self-photocurable polyurethane acrylate oligomer 55 to 75% by weight, IBOA (isobornyl acrylate) 20 to 30% by weight as a reactive diluent, HDDA (1,6-hexanediol diacrylate) 3 to 10% by weight, TMPEOTA (trimethylolpropane) triacrylate) 1.5 to 3.5 wt% and 0.5 to 1.5 wt% of the additive are reacted.

The self-photocurable polyurethane acrylate oligomer is added to allow photocuring without using a photoinitiator, and a self-photocurable intermediate is synthesized using a Michael addition reaction, and trimethylolpuopane (TMP) ), IPDI (isophorone diisocyanate), and HEMA (hydroxy ethyl methacrylate) as an oligomer produced by reacting, more specifically, PCD (polycarbonate diol) 0.1 to 0.6 mol%, self-photocurable intermediate 0.1 to 0.6 mol%, TMP ( Trimethylolpuopane) 0.1 ~ 0.5 mol%, IPDI (Isophorone diisocyanate) 1-3 mol% and HEMA (hydroxy ethyl methacrylate) 0.5 ~ 1.5 mol% is made by reacting.

Here, the self-photocurable intermediate is 1- to 3 moles of 2-HPA (2-hydroxypropyl acrylate) or 2-HEA (2-hydroxyethyl acrylate) as shown in [Scheme 1] below using a Michael addition reaction. %, 0.5 to 1.5 mol% of EAA (ethyl acetoacetate) and 0.001 to 0.005 mol% of catalyst (NaCO) are reacted.

[Scheme 1]

That is, the Michael addition reaction is that Michael donor and Michael acceptor deprotonated through a catalyst are synthesized through a conjugate addition reaction, and the synthesized When the compound is irradiated with ultraviolet rays, the α carbon site of the carbonyl group is in an excited state, and the α carbon bond is cleaved and two radicals are generated at the same time (Norrish Type I). Through this, the crosslinking reaction proceeds. Accordingly, the self-photocurable intermediate is self-photocurable through a Michael addition reaction, and the paint composition including the self-photocurable intermediate is cured by light (ultraviolet rays) as shown in [Scheme 2] below.

[Scheme 2]

Here, when the content of each material is out of the above range, there is a fear that the photocuring property is insufficient. In addition, the additive is a well-known additive, and an antifoaming agent for removing air bubbles generated during roll coating operation, a leveling agent affecting the appearance and surface scratching properties of the coating film, and a wetting agent for increasing the wettability of the paint, etc. can be used, and here It is not limited to, and it is possible to selectively apply a variety of known additives according to the use, environment, or application of PCM.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not necessarily limited only by the following examples.

1. Preparation of intermediates capable of self-photocuring

(Production Example 1)

2 mol% of 2-HPA (Aldrich), 1 mol% of EAA (TCI) and 0.005 mol% of NaCO (Aldrich) were added to a 1 L four-necked round flask reactor equipped with a stirrer and a nitrogen inlet. Thereafter, the mixture was reacted at 30° C. for 14 days under a nitrogen atmosphere while stirring at a speed of 200 to 300 rpm. Finally, a liquid product having a transparent light yellow color was obtained, and it was used as it is without going through a purification process.

(Production Example 2)

1 mol% of 2-HEA (Aldrich), 0.5 mol% of EAA (TCI) and 0.001 mol% of NaCO (Aldrich) were added to a 1 L four-necked round flask reactor equipped with a stirrer and a nitrogen inlet. Thereafter, the mixture was reacted at 30° C. for 14 days under a nitrogen atmosphere while stirring at a speed of 200 to 300 rpm. Finally, a liquid product having a transparent light yellow color was obtained, and it was used as it is without going through a purification process.

(Production Example 3)

3 mol% of 2-HEA (Aldrich), 1.5 mol% of EAA (TCI) and 0.005 mol% of NaCO (Aldrich) were added to a 1 L four-necked round flask reactor equipped with a stirrer and a nitrogen inlet. Thereafter, the mixture was reacted at 30° C. for 14 days under a nitrogen atmosphere while stirring at a speed of 200 to 300 rpm. Finally, a liquid product having a transparent light yellow color was obtained, and it was used as it is without going through a purification process.

2. Preparation of self-photocurable polyurethane acrylate oligomer

(Production Example 4)

In a 1 L 5-neck separation reactor equipped with a stirrer and a nitrogen inlet, 0.490 mol% of PCD (Aldrich) degassed at 80° C. using a vacuum oven and 0.210 mol% of the intermediate according to Preparation Example 1 were added, and uniform for 1 hour mixed thoroughly. After that, 2 mol% of IPDI (Aldrich) was slowly added dropwise for 1 hour in a nitrogen atmosphere, and 0.3 mol% of TMP (Aldrich) was added thereto, followed by reaction for about 3 hours. When the NCO content of the reactant reached the theoretically calculated value, the reaction temperature was lowered to 75° C., and 1 mol% of HQ (hydroquinone) and 2-HEA (Aldrich) were slowly added dropwise and reacted for 3 hours. The reaction was terminated when the peak at 2,270 cm-1, which is the characteristic peak of NCO on FT-IR, completely disappeared.

(Preparation Example 5)

In a 1 L 5-neck separation reactor equipped with a stirrer and a nitrogen inlet, 0.1 mol% of PCD (Aldrich) degassed at 80° C. using a vacuum oven and 0.1 mol% of the intermediate according to Preparation Example 2 were added and uniform for 1 hour mixed thoroughly. After that, 1 mol% of IPDI (Aldrich) was slowly added dropwise for 1 hour in a nitrogen atmosphere, and 0.1 mol% of TMP (Aldrich) was added thereto, followed by reaction for about 3 hours. When the NCO content of the reactant reached the theoretically calculated value, the reaction temperature was lowered to 75° C., and 0.5 mol% of HQ (hydroquinone) and 2-HEA (Aldrich) were slowly added dropwise and reacted for 3 hours. The reaction was terminated when the peak at 2,270 cm-1, which is the characteristic peak of NCO on FT-IR, completely disappeared.

(Production Example 6)

In a 1 L 5-neck separation reactor equipped with a stirrer and a nitrogen inlet, 0.6 mol% of PCD (Aldrich) degassed at 80° C. using a vacuum oven and 0.6 mol% of the intermediate according to Preparation Example 3 were added and uniform for 1 hour. mixed thoroughly. After that, 3 mol% of IPDI (Aldrich) was slowly added dropwise for 1 hour in a nitrogen atmosphere, and 0.5 mol% of TMP (Aldrich) was added thereto, followed by reaction for about 3 hours. When the NCO content of the reactant reached the theoretically calculated value, the reaction temperature was lowered to 75° C. and 1.5 mol% of HQ (hydroquinone) and 2-HEA (Aldrich) were slowly added dropwise and reacted for 3 hours. The reaction was terminated when the peak at 2,270 cm-1, which is the characteristic peak of NCO on FT-IR, completely disappeared.

3. Manufacture of photocurable transparent paint for PCM

(Example 1)

59.8% by weight of the self-photocurable polyurethane acrylate oligomer according to Preparation Example 4, 29.7% by weight of IBOA (Aldrich) as a reactive diluent, 2% by weight of HDDA (Aldrich), 7% by weight of TMPEOTA (Aldrich) and additives (A leveling agent, an antifoaming agent, and a wetting agent are mixed in a 1:1 weight ratio) 1.5 wt% was reacted to prepare a paint, and then coated on an iron plate to a thickness of 30 μm using an applicator. After stabilization, nitrogen was injected into the coated iron plate using an ultraviolet curing device equipped with a metal halide lamp, and then cured under a light quantity condition of ^{3,000 mJ/cm 2 .}

(Example 2)

55 wt% of a self-photocurable polyurethane acrylate oligomer according to Preparation Example 5, 30 wt% of IBOA (Aldrich) as a reactive diluent, 10 wt% of HDDA (Aldrich), 3.5 wt% of TMPEOTA (Aldrich) and additives (A leveling agent, an antifoaming agent, and a wetting agent are mixed in a 1:1 weight ratio) 1.5 wt% was reacted to prepare a paint, and then coated on an iron plate to a thickness of 30 μm using an applicator. After stabilization, nitrogen was injected into the coated iron plate using an ultraviolet curing device equipped with a metal halide lamp, and then cured under a light quantity condition of ^{3,000 mJ/cm 2 .}

(Example 3)

75% by weight of the self-photocurable polyurethane acrylate oligomer according to Preparation Example 6, 20% by weight of IBOA (Aldrich) as a reactive diluent, 3% by weight of HDDA (Aldrich), 1.5% by weight of TMPEOTA (Aldrich) and additives (A leveling agent, an antifoaming agent and a wetting agent are mixed in a 1:1 weight ratio) 0.5% by weight was reacted to prepare a paint, and then coated on an iron plate to a thickness of 30 μm using an applicator. After stabilization, nitrogen was injected into the coated iron plate using an ultraviolet curing device equipped with a metal halide lamp, and then cured under a light quantity condition of ^{3,000 mJ/cm 2 .}

(Comparative Example 1)

Referring to Patent Document 1, 8 g of a photoinitiator mixture of 1-hydroxy-cyclohexyl-phenyl-ketone (CIBA, IRGACURE184) and benzyldimethyl ketal (Miwon Corporation, BK6), isobornyl acrylate, acryloyl mor 42 g of a monomer mixture obtained by mixing polyin and tetrahydrofurfuryl acrylate in a 75:20:5 weight ratio, 42 g of a urethane acrylate mixture of EBECRYL8309 (ENTIS), EBECRYL8402 (ENTIS) and EBECRYL9259 (ENTIS), leveling agent and wetting agent 4 g of an additive mixture mixed in a 4:3 weight ratio, and 4 g of a pigment having a particle size of 100 to 150 nm (NSP-VH, manufactured by NIKKO-BICS.) is stirred, filtered (200 mesh), and then the paint viscosity is about 40 to 50 seconds (Podcup #4) was prepared and then coated on a steel plate with an applicator to a thickness of 30 μm. After stabilizing the coated film at room temperature for about 1 minute, using an ultraviolet curing device equipped with a metal halide lamp. Nitrogen was injected into the coated iron plate and then cured under a light quantity condition of ^{3,000 mJ/cm 2 .}

4. Evaluation of photocurable transparent paint for PCM

The main performances of the paints according to Examples 1, 2, 3 and Comparative Example 1 were evaluated, and the evaluation criteria and results are shown in [Table 1] below.

division unit Example 1 Example 2 Example 3 Comparative Example 1 test standard Seon Young-seong %/mm 85 85 85 68 DOI Meter
measurement TVOC emissions mg/m ² h One One One 40 ISO 16000 weather resistance ΔE
(500hrs) 2 2 2 2 ASTM G155 Bend Test T One One One One KS B0804 Hardness pencil hardness F F F F JIS K6718 adherence B 5B 5B 5B 4B KSM ISO2409 CCET mm 6 6 6 6 ASTM D3359-93 boiling tolerance B 5B 5B 5B 5B 98℃, 1 hour light fastness ΔE 2 2 2 5 ASTM D822

As shown in [Table 1], it can be seen that Examples 1, 2, and 3 according to the present invention are very excellent in main performance such as weather resistance compared to Comparative Example 1.

As described above, the photocurable transparent paint composition for PCM with improved weather resistance according to the present invention has been described through the above preferred examples and its excellence has been confirmed, but those skilled in the art can use the present invention described in the claims below. It will be understood that various modifications and variations of the present invention can be made without departing from the spirit and scope of the invention.

Claims (3)

In the photocurable coating composition for PCM,
Self-photocurable polyurethane acrylate oligomer 55 ~ 75% by weight, IBOA (isobornyl acrylate) 20 ~ 30% by weight as a reactive diluent, HDDA (1,6-hexanediol diacrylate) 3 ~ 10% by weight, TMPEOTA (trimethylolpropane triacrylate) 1.5 A photocurable transparent coating composition for PCM with improved weather resistance, characterized in that it comprises ~ 3.5 wt% and 0.5 to 1.5 wt% of an additive.
The method of claim 1,
Self-photocurable polyurethane acrylate oligomer,
PCD (polycarbonate diol) 0.1 to 0.6 mol%, self-photocurable intermediate 0.1 to 0.6 mol%, TMP (trimethylolpuopane) 0.1 to 0.5 mol%, IPDI (Isophorone diisocyanate) 1 to 3 mol%, and HEMA (hydroxy ethyl methacrylate) 0.5 A photocurable transparent coating composition for PCM with improved weather resistance, characterized in that it comprises ~ 1.5 mol%.
3. The method of claim 2,
The self-photocurable intermediate is,
2-HPA (2-hydroxypropyl acrylate) or 2-HEA (2-hydroxyethyl acrylate) 1 to 3 mol%, EAA (ethyl acetoacetate) 0.5 to 1.5 mol%, and catalyst (NaCO) 0.001 to 0.005 mol% A photocurable transparent coating composition for PCM with improved weather resistance, characterized in that.