KR102014206B1 - UV curable composition having excellent flexibility and hardness and method of manufacturing - Google Patents

Abstract

The present invention relates to a UV curable composition and a manufacturing method thereof and, more specifically, to a method for manufacturing a UV curable composition mixed with a UV prepolymer, an organic-inorganic complex oligomer, a photoinitiator and a leveling agent, and to a UV curable composition manufactured by the method.

Description

UV curable composition having excellent flexibility and hardness and method of manufacturing

The present invention relates to a UV-curable composition and a manufacturing method, and more particularly, UV-curable composition that can improve the surface hardness by adding an organic-inorganic composite oligomer to a UV coating resin consisting of a UV prepolymer, a photoinitiator, and a leveling agent And a method for producing the same.

There is a growing interest in environmental protection such as the emission of environmentally harmful substances around the world, and as the interest in environmentally friendly coating systems and coatings is increasing, researches on these are being actively conducted.

At present, the environmentally friendly coating system that is attracting attention is four systems, such as powder coating system, aqueous type system, UHS system, and photocurable system, among which photocurable system is attracting attention as the most famous coating technology.

Photocurable systems are a technique that converts monomers and oligomers into polymers by means of a UV light source by a chemical reaction called photopolymerization. Since the photocurable system is not cured by heat but cured by UV light source, unlike conventional coating agents using organic solvents (volatile organic compounds), no volatile organic compounds are generated even when the organic solvent is not added. .

Accordingly, research and development for introducing a photocurable coating agent into PCM (Pre-Coated Metal) manufacturing have been actively conducted. The photocurable coating agent contains a compound (photoinitiator) sensitive to the UV region, and the photoinitiator in the coating agent starts a rapid reaction to crosslink the composition to form a coating film in the form of reticular polymer.

Curable coating agent content of the volatile organic compound is close to zero, due to the nature of the coating process can be expected to increase the productivity and workability by forming a coating film in a short time. In addition, shorter process steps can be secured than when oil-based coatings are used, and the cost of the coating equipment and equipment space can be reduced by minimizing the accompanying coating line. Have.

However, the photocurable coating agent generally used is susceptible to damage due to the impact or friction of the coating film due to its weak surface hardness during transportation or processing, indoors and exteriors, which adversely affects work efficiency and product life. There is a problem that causes.

Korean Registered Patent Publication No. 1790491

An object of the present invention is to provide a UV curable composition and a manufacturing method excellent in flexibility and surface hardness that can realize a coating film having excellent surface hardness without generating volatile organic compounds. .

UV curable composition according to the present invention for solving the above problems is characterized in that it comprises a UV prepolymer, an organic-inorganic composite oligomer, a photoinitiator, and a leveling agent.

Here, the organic-inorganic composite oligomer includes a silane oligomer, a solvent, a polymerization derivative, and a dilution solvent, wherein the silane oligomer is 3-acryloxypropyltrimethoxysilane (APTMS) or 3- Acryloxypropyltriethoxysilane (3-Acryloxypropyltriethoxysilane, APTES); The solvent is any one of acetone, ethanol, and isopropyl alcohol; The polymerization derivative is in tetramethylammonium hydroxide (TMAH), tetrabutylammonium hydroxide (TBAH), and tetra-n-butylammonium fluoride (TBAF). Which one; The diluting solvent is 1,6-hexanediol diacrylate (1,6-Hexanediol diacrylate, HDDA), trimethylolpropane triacrylate (ethoxylated bisphenol A diacrylate) ), Diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, ethoxylated 1,6-hexanediol diacrylate Ethoxylated 1,6-Hexanediol diacrylate, Polypropylated Neopentyl glycol diacrylate, Tripropylene glycol diacrylate, Ethoxylated trimethylolpropane triacrylic Ethoxylated trimethylolpropane tricrylate, propoxy Propoxylate trimethylolpropane triacrylate, Pentaerythritol triacrylate, Ethoxylated pentaerythritol tetraacrylate, Dipentaerythritol pentaacrylate, It may be one of dipentaerythritol hexaacrylate, and ethoxylated dipentaerythritol hexaacrylate.

In addition, the method for producing a UV curable composition according to the present invention is characterized by mixing a UV prepolymer, an organic-inorganic composite oligomer, a photoinitiator, and a leveling agent.

Here, 6 to 12 parts by weight of the organic-inorganic composite oligomer; UV prepolymer, photoinitiator, and leveling agent are mixed in 94 to 88 parts by weight, the organic-inorganic composite oligomer is a first step of preparing a first mixture by mixing and stirring a silane oligomer and a solvent, water to the first mixture A second step of preparing a second mixture by addition and stirring, a third step of preparing a third mixture by adding and stirring a polymerization derivative to the second mixture, and adding and stirring a diluent solvent to the third mixture to prepare a fourth mixture And a fifth step of concentrating the fourth mixture to remove volatiles to obtain an organic-inorganic complex oligomer, wherein the silane-based oligomer is 3-acryloxypropyltrimethoxysilane (3- Acryloxypropyltrimethoxysilane, ATPMS); The solvent is acetone; The polymerization derivative is tetramethylammonium hydroxide (TMAH); The dilution solvent is 1,6-hexanediol diacrylate (1,6-Hexanediol diacrylate, HDDA), the 3-acryloxypropyltrimethoxysilane (ATPMS): acetone: water Tetramethylammonium hydroxide (TMAH): 1,6-hexanediol diacrylate (1,6-Hexanediol diacrylate, HDDA) is 43 ~ 47 parts by weight: 31 ~ 35 parts by weight: 9 ~ 11 Weight part: 0.8-1.2 weight part: It is preferable to add at 8-12 weight part.

The UV curable composition for PCM according to the present invention does not generate volatile organic compounds upon curing, and has an advantage of greatly improving surface hardness without affecting adhesion or processability of the substrate and the coating film.

1 is a flow chart illustrating a method for preparing an organic-inorganic composite oligomer of the present invention.
2 is a method for evaluating coating film adhesion.
3 is a conceptual diagram for explaining a processability measurement method.

 The terms “comprise,” “have,” or “comprise” in this application are intended to indicate that there is a feature, number, step, component, part, or combination thereof described on the specification, but one or more other. It should be understood that it does not exclude in advance the possibility of the presence or addition of features or numbers, steps, actions, components, parts or combinations thereof.

 In addition, unless otherwise defined, all terms used herein including technical or scientific terms have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Hereinafter, the UV curable composition having excellent flexibility and hardness according to the present invention and a manufacturing method thereof will be described.

The UV curable composition according to the present invention is composed of a UV coating resin consisting of a UV prepolymer, a photoinitiator, and a leveling agent, and an organic-inorganic composite oligomer.

The UV prepolymer is a low viscosity polymer resin or oligomer having low polymerization degree, and may be, for example, a low viscosity urethane acrylate resin.

The photoinitiator is added to the UV paint, and absorbs energy from the ultraviolet light source to initiate the polymerization reaction, may be a diazonium salt (Hydroxy-ketone), but is not limited thereto.

Leveling agent is an additive that enters a small amount of paint or ink. It is a material to prevent and improve the occurrence of coating defects such as orange peel craters that may occur on the surface of paint by controlling the flow of paint or ink. May be a reactive silicone containing an acrylic acid functional group.

The organic-inorganic composite oligomer includes a silane oligomer, a solvent, a polymerization derivative, a diluent solvent, and contributes to improvement of physical properties such as surface hardness of the coated layer.

Referring to FIG. 1, which is a flowchart illustrating a method of preparing an organic-inorganic composite oligomer, the organic-inorganic composite oligomer manufacturing method according to the present invention prepares a first mixture by mixing and stirring a silane-based oligomer and a solvent. Step 1 to prepare a second mixture by adding and stirring water to the first mixture to prepare a second mixture, step 3 to prepare a third mixture by adding and stirring a polymerization derivative to the second mixture, dilution solvent in the third mixture And a fourth step of preparing a fourth mixture by stirring, and a fifth step of concentrating the fourth mixture to remove volatiles to obtain an organic-inorganic composite oligomer.

In the first step, the silane oligomer may be 3-acryloxypropyltrimethoxysilane (APTMS) or 3-acryloxypropyltriethoxysilane (APTES), preferably 3-acryloxypropyltrimethoxysilane (APTMS).

Herein, the silane oligomer is preferably included in an amount of 43 to 47 parts by weight. When the silane-based oligomer is less than 43 parts by weight, it is difficult to form the oligomer due to insufficient hydrolysis. On the contrary, when the silane oligomer is more than 47 parts by weight, the viscosity increases or gelates due to excessive hydrolysis.

The solvent is any one of acetone, ethanol, and isopropyl alcohol, preferably acetone.

The solvent is preferably mixed at 31 to 35 parts by weight. If the solvent is less than 31 parts by weight, hydrolysis does not proceed uniformly due to a decrease in the dispersibility of the silane, whereas if it exceeds 35 parts by weight, the hydrolysis of the silane is inhibited, so it is preferably included in the above range.

The water in the second step is for hydrolysis, it is preferable to mix 9 to 11 parts by weight.

If the water is less than 9 parts by weight of the hydrolysis is insufficient, the oligomer is not formed well, on the contrary, if it exceeds 11 parts by weight, the viscosity is increased or gelated due to excessive hydrolysis is preferably included in the above range.

The polymerization derivative in the third step is tetramethylammonium hydroxide (TMAH), tetrabutylammonium hydroxide (TBAH), and tetra-n-butylammonium fluoride (Tetra-n- butylammonium fluoride (TBAF), preferably Tetramethylammonium hydroxide (TMAH).

The polymerization derivative is preferably mixed at 0.8 to 1.2 parts by weight. If the polymerization derivative is less than 0.8 parts by weight, the polymerization of the hydrolyzed silane is insufficient, and if it exceeds 1.2 parts by weight, it is preferable that the polymerization derivative is included in the above range because of excessive growth of the chain and particles due to the excessive polymerization of the hydrolyzed silane. .

The diluting solvent in the fourth step is 1,6-hexanediol diacrylate (HDD), trimethylolpropane triacrylate ethoxylated bisphenol A diacryl Ethoxylated bisphenol A diacrylate, Diethylene glycol diacrylate, Triethylene glycol diacrylate, Polyethylene glycol diacrylate, Ethoxylated 1,6 Hexanelated 1,6-Hexanediol diacrylate, Polypropylated Neopentyl glycol diacrylate, Tripropylene glycol diacrylate, ethoxylated Ethoxylated trimethylolpropane tric rylate), propoxylate trimethylolpropane triacrylate, pentaerythritol triacrylate, ethoxylated pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate (Dipentaerythritol pentaacrylate), dipentaerythritol hexaacrylate, and ethoxylated dipentaerythritol hexaacrylate, preferably 1,6-hexanediol diacrylate (1,6-Hexanediol diacrylate, HDDA).

Here, the diluting solvent is preferably mixed to 8 to 12 parts by weight. When the dilution solvent is less than 8 parts by weight, the viscosity is excessively high after concentration, making it difficult to disperse the UV prepolymer and lacking a functional group that combines with the silane coupled with the UV prepolymer, thereby deteriorating surface hardness, coating film adhesion and curability When it exceeds 12 parts by weight, the content of the organic-inorganic component synthesized in the organic-inorganic composite oligomer is insufficient, so that the surface hardness is lowered.

The organic-inorganic composite oligomer prepared as described above is mixed with a UV prepolymer, a photoinitiator, and a leveling agent, which is a UV coating resin, to obtain a UV curing composition.

Here, the organic-inorganic composite oligomer and the UV coating resin are preferably mixed at a ratio of 6 to 12 parts by weight: 94 to 88 parts by weight, and the coating film having the desired physical properties may not be formed outside the above range.

Meanwhile, the UV prepolymer, photoinitiator, and leveling agent of the resin for UV coating are preferably mixed in a ratio of 90.8 to 96.6 wt%: 3.2 to 8.4 wt%: 0.2 to 0.8 wt%, 95 wt%: 4.5 wt%: It is more preferable that it is 0.5 weight%.

Hereinafter, preferred examples are provided to help understanding of the present invention. However, the following examples are merely provided to more easily understand the present invention, and the contents of the present invention are not limited thereto.

Example 1

3-acryloxypropyltrimethoxysilane (ATPMS) and acetone (Acetone) were stirred at 400 rpm for 10 minutes. After adding water and stirring at 350rpm for 30 minutes, tetramethylammonium hydroxide (TMAH) was added thereto, followed by stirring at 350rpm for 12 hours.

1,6-hexanediol diacrylate (HDDA) was added to the reaction solution, and the mixture was stirred and stirred at 400 rpm for 1 hour, followed by dilution using a vacuum evaporator to remove volatiles. A concentrated final organic-inorganic composite oligomer was obtained.

6 parts by weight of the organic-inorganic composite oligomer thus prepared and 94 parts by weight of the resin for UV coating were mixed to prepare a final photocuring coating for PCM.

At this time, the resin for UV coating is composed of 95% by weight of UV prepolymer, a urethane acrylate resin, 0.5% by weight of acrylic polymer as a leveling agent, and 4.5% by weight of diazonium salt as a photoinitiator, based on the entire UV coating resin.

Example 2

91 parts by weight of the resin for UV coating, 9 parts by weight of the organic-inorganic composite oligomer was prepared under the same conditions as in Example 1.

Example 3

88 parts by weight of the resin for UV coating, 12 parts by weight of the organic-inorganic composite oligomer was prepared under the same conditions as in Example 1.

Comparative Example 1

Prepared only with UV coating resin without addition of organic-inorganic composite oligomers.

Comparative Example 2

Except 97 parts by weight of the resin for UV coating, 3 parts by weight of the organic-inorganic composite oligomer was prepared under the same conditions as in Example 1.

Comparative Example 3

85 parts by weight of the resin for UV coating, 15 parts by weight of the organic-inorganic composite oligomer was prepared under the same conditions as in Example 1.

Comparative Example 4

82 wt parts of the resin for UV coating and 18 wt parts of the organic-inorganic composite oligomer were prepared under the same conditions as in Example 1.

Experimental Example

Bar coating was applied to PCM (Pre-Coated Metal) with a thickness of 10 μm to evaluate UV curing rate, pencil hardness, processability, surface crack occurrence, and coating adhesion.

UV curing conditions were cured using a belt type UV curing machine, the belt speed was 2m (2m / min) per minute, the amount of light 1890mJ, the illuminance was 672mW.

Pencil hardness was measured by KS M ISO 15184: 2013 evaluation method, coating film adhesion was measured by KS M ISO 2409: 2013 evaluation method (see Fig. 2), and the workability measurement method and surface crack generation whether the coated PCM substrate as shown in FIG. When bending, the inner radius of the folded portion was bent to have a corresponding thickness and then checked for damage to the coating film.

When 6 to 12 parts by weight of the organic-inorganic composite oligomer was mixed, compared to Comparative Example 1 in which the organic-inorganic composite oligomer was added and only coated with a resin for UV coating, the pencil hardness was increased by two or more steps. No cracks occurred. In addition, addition of the organic-inorganic composite oligomer had no effect on UV curing rate or adhesion.

However, even when the organic-inorganic composite oligomer was added, the pencil hardness was increased by only one step in Comparative Example 2, in which 3 parts by weight was added. Can be.

In Comparative Example 4, in which 18 parts by weight of the organic-inorganic composite oligomer was mixed, the pencil hardness was increased by three stages, but the workability was greatly reduced due to the increase in rigidity, and cracks were also generated on the surface.

UV Coating Resin Organic-inorganic complex oligomers UV
Curing Speed Pencil hardness Machinability
(mm) surface
crack Adhesion Example 1 94 parts by weight 6 parts by weight Episode 2 H 2 Not Occurred 0 Example 2 91 parts by weight 9 parts by weight Episode 2 H 2 Not Occurred 0 Example 3 88 parts by weight 12 parts by weight Episode 2 H 2 Not Occurred 0 Comparative Example 1 100 parts by weight 0 parts by weight Episode 2 B 2 Not Occurred 0 Comparative Example 2 97 parts by weight 3 parts by weight Episode 2 HB 2 Not Occurred 0 Comparative Example 3 85 parts by weight 15 parts by weight Episode 2 H 3 Not Occurred 0 Comparative Example 4 82 parts by weight 18 parts by weight Episode 2 2H 5 Occur 0

* UV coating resin is composed of 95% by weight of UV prepolymer, 4.5% by weight of photoinitiator, and 0.5% by weight of leveling agent based on the entire UV coating resin.

The specific parts of the present invention have been described in detail above, and for those skilled in the art, these specific descriptions are merely preferred embodiments, and the scope of the present invention is not limited thereto. It is apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the art, and such variations and modifications are within the scope of the appended claims.

Claims (4)

6-12 parts by weight of the organic-inorganic complex oligomer; And
94 to 88 parts by weight of a UV coating resin comprising a UV prepolymer, a photoinitiator, and a leveling agent,
The organic-inorganic composite oligomer may be a silane-based oligomer which is 3-acryloxypropyltrimethoxysilane (APTMS) or 3-acryloxypropyltriethoxysilane (3-Acryloxypropyltriethoxysilane, APTES); Solvents of any one of acetone, ethanol, and isopropyl alcohol; Polymerization of any one of tetramethylammonium hydroxide (TMAH), tetrabutylammonium hydroxide (TBAH), and tetra-n-butylammonium fluoride (TBAF) derivative; 1,6-hexanediol diacrylate (HDDA), trimethylolpropane triacrylate ethoxylated bisphenol A diacrylate, diethylene Diethylene glycol diacrylate, Triethylene glycol diacrylate, Polyethylene glycol diacrylate, Ethoxylated 1,6-hexanediol diacrylate (Ethoxylated 1 , 6-Hexanediol diacrylate, Polypropylated Neopentyl glycol diacrylate, Tripropylene glycol diacrylate, Ethoxylated trimethylolpropane tricrylate), propoxylate trimes Propropoxylated trimethylolpropane triacrylate, Pentaerythritol triacrylate, Ethoxylated pentaerythritol tetraacrylate, Dipentaerythritol pentaacrylate, Dipentaerythritol Dimethyl acrylate (Dipentaerythritol hexaacrylate) and ethoxylated dipentaerythritol hexaacrylate (Ethoxylated dipentaerythritol hexaacrylate), a diluent solvent,
The UV prepolymer is a urethane acrylate resin,
The photoinitiator is a diazonium salt (Hydroxy-ketone),
The leveling agent is a UV curable composition, characterized in that the reactive silicone containing acrylic acid functional group.
delete 6-12 parts by weight of the organic-inorganic complex oligomer; And
94-88 parts by weight of a UV coating resin comprising a UV prepolymer of urethane acrylate resin, a photoinitiator of diazonium salt (Hydroxy-ketone), and a leveling agent of reactive silicone containing acrylic acid functional groups,
The organic-inorganic composite oligomer is a first step of preparing a first mixture by mixing and stirring 3-acryloxypropyltrimethoxysilane (ATPMS) and acetone (ATPMS), by adding water to the first mixture and stirring A second step of preparing a second mixture, a third step of preparing a third mixture by adding and stirring tetramethylammonium hydroxide (TMAH) to the second mixture, and a 1,6-hexanediol die in the third mixture A fourth step of preparing a fourth mixture by adding and stirring acrylate (HDDA), and a fifth step of concentrating the fourth mixture to remove volatiles,
3-Acryloxypropyltrimethoxysilane (ATPMS): Acetone: Water: Tetramethylammonium hydroxide (TMAH): 1,6-hexanediol diacrylate (1 , 6-Hexanediol diacrylate, HDDA) 43 to 47 parts by weight: 31 to 35 parts by weight: 9 to 11 parts by weight: 0.8 to 1.2 parts by weight: 8 to 12 parts by weight of the manufacturing method of the UV curable composition. delete

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