KR101541264B1 - Photocurable urethane (meth)acrylate and method for producing thereof - Google Patents

Abstract

According to an embodiment of the present invention, a photocurable urethane (meth)acrylate has a refractive index higher than a urethane (meth)acrylate-based compound prepared by using 1,4-cyclohexanedimethanol (1,4-CHDM) and is in a low-viscosity liquid phase at the room temperature to be easily used. The photocurable urethane (meth)acrylate has the high refractive index to reduce the rainbow effect of a cured coat layer and is in a low viscosity liquid phase to be synthesized in large quantities as well as being easily used in a photocurable resin composition preparation process. The photocurable urethane (meth)acrylate has the high refractive index to be utilized in the photocurable resin composition applied to an optical component material or as a surface coating material for a plastic film substrate used as an optical material. The present invention has transparency, high refractive index of the cured article, and high surface hardness as well as excellent penetration resistance, productivity, and heat resistance to be applied in optical products.

Description

[0001] PHOTOCURABLE URETHANE (METH) ACRYLATE AND METHOD FOR PRODUCING THEREOF [0002]

The present invention relates to a photo-curable urethane (meth) acrylate and a process for its preparation.

The photocurable coating resin should have good handling property after curing and it should be able to prevent appearance damage that may occur in the handling process, and should have excellent workability with no yellowing and suitable viscosity. Photocurable coating resins should have a high refractive index in order to secure high luminance. Representative examples of such resins include halogen-substituted resins, but they contain environmental harmful substances or harmful components This is being limited.

1,4-cyclohexanedimethanol (hereinafter referred to as "CHDM") is used as a diol component in the production of a urethane (meth) acrylate compound necessary for producing a photocurable coating resin, In addition, 1,4-cyclohexanedimethanol (CHDM) can be used in various applications for paints, textile plastics, and the like. 1,4-Cyclohexanedimethanol (CHDM) is a mixture of cis and trans structures from the constraints of its preparation method. When the mixing ratio of these is changed, the physical properties of the urethane (meth) acrylate derived therefrom Can be changed. In addition, the polycarbonate diol obtained by combining 1,4-cyclohexane dimethanol (CHDM) with 1,6-hexanediol has a high hydrophobicity from its structure, There is also a difficulty in introducing the water-soluble structure into the polyurethane production process in order to make the polyurethane water-soluble when producing the water-based polyurethane which is attracting attention. Further, 1,4-cyclohexane dimethanol (CHDM) has a cyclohexane ring structure in the molecule, and since such a cyclohexane ring structure has a flexible ring structure and the hydroxyl group is bonded to the cyclohexane ring via a methylene group, And the hardness of the polyurethane obtained therefrom was not high.

For example, 1,4-cyclohexanedimethanol (CHDM) is used in polyester synthesis to improve the reactivity and to improve the thermal stability, corrosion resistance, hydrolysis resistance, moldability, gloss, transparency, It is a high-value-added advanced raw material that increases the physical properties of polyester resins and promotes the development of new applications.

In addition, 1,4-cyclohexane dimethanol (CHDM) is used for coating resins containing hydroxy groups such as melamine and resol. In Korea, 1,4-cyclohexanedimethanol (CHDM) is used as a raw material for PETG (Polyethylene Terephthalate Glycol), which is a resin having excellent strength, processability and transparency. When 1,4-cyclohexanedimethanol (CHDM) , And it is used as a component of the polyester polyol for the PU binder. In addition, it is used for heat-resistant engineering plastics, paints, PU binders, and liquid crystals of electronic circuit boards.

The urethane (meth) acrylate-based compound produced by using 1,4-cyclohexane dimethanol (CHDM) having various uses as described above is excellent in high curing hardness, excellent adhesion with plastic and glass, It has disadvantages in that it is not accompanied by changes in appearance such as discoloration and deformation and exhibits high transparency, sublimation resistance and abrasion resistance in addition to high flexibility, but is a liquid having a high viscosity at room temperature.

In addition, the urethane (meth) acrylate prepared by using 1,4-cyclohexane dimethanol (CHDM) or the composition containing them may not be able to be produced on a large scale because of the high viscosity of the urethane (meth) (Meth) acrylate and the resulting compositions become opaque at low temperatures, resulting in poor transparency or a shape change of the cured coating film at a high temperature, which is insufficient as a photocurable coating resin.

Therefore, it has a hardness and a refractive index equal to or higher than those of a urethane (meth) acrylate compound produced using 1,4-cyclohexane dimethanol (CHDM), has a low viscosity and can be synthesized on a large scale, A urethane (meth) acrylate-based compound that is easy to use at the time of production is required.

The present invention provides a photo-curable urethane (meth) acrylate having a high hardness and a high refractive index and a low viscosity, which can be synthesized on a large scale and is easy to use, and a process for producing the same.

The photo-curable urethane (meth) acrylate according to an embodiment of the present invention is a material represented by the following formula (1)

[Chemical Formula 1]

According to another embodiment of the present invention, there is provided a process for preparing a photocurable urethane (meth) acrylate comprising the steps of: preparing a compound represented by the following formula (2);

(2)

A second step of adding the compound of Formula 2 and a reaction solvent to a reactor and stirring the mixture;

A third step of adding a diisocyanate to the reactor and stirring to form a urethane isocyanate prepolymer containing an isocyanate group; And

(Meth) acrylate by reacting the urethane isocyanate prepolymer with (meth) acrylate containing a hydroxyl group to prepare a photo-curable urethane (meth) acrylate of Formula 1 .

In the process for producing a photocurable urethane (meth) acrylate according to one aspect of the present invention, the reaction solvent is selected from the group consisting of toluene, methyl ethyl ketone (MEK) It can be a reactive diluent.

In the process for producing a photocurable urethane (meth) acrylate of the above formula (1) according to one aspect of the present invention, the polymerization inhibitor and the urethane reaction catalyst may be further introduced in the third step.

In the process for producing a photocurable urethane (meth) acrylate according to one aspect of the present invention, the polymerization inhibitor may be selected from the group consisting of methylhydroquinone (MQ), dibutylhydroxy toluene, Wherein the urethane reaction catalyst is any one selected from the group consisting of hydroquinone, hydroquinone monomethyl ether and phenothiazine, and the urethane reaction catalyst may be dibutyltin dilaurate. have.

In the process for producing a photocurable urethane (meth) acrylate of the above formula (1) according to one aspect of the present invention, the diisocyanate compound is an aromatic diisocyanate, an alicyclic diisocyanate, an aliphatic diisocyanate having a branched chain, A diisocyanate compound obtained by hydrogenating an aromatic diisocyanate, and the like.

In the process for producing a photocurable urethane (meth) acrylate according to one aspect of the present invention, the (meth) acrylate is at least one selected from the group consisting of hydroxyethyl acrylate (HEA), hydroxypropyl acrylate But are not limited to, hydroxypropyl acrylate (HPA), hydroxyethyl (meth) acrylate (HEMA), hydroxybutyl acrylate (HBA), caprolactone acrylate, And pentaerythritol triacrylate (PETA).

In the method for producing a photocurable urethane (meth) acrylate of the above formula (1) according to one aspect of the present invention, the internal temperature of the reactor is maintained at 80 캜 or lower in the third step.

The photocurable coating resin composition according to another embodiment of the present invention includes the photocurable urethane (meth) acrylate of the above formula (1).

The photocurable urethane (meth) acrylate according to one aspect of the present invention has a refractive index higher than that of a urethane (meth) acrylate compound prepared using 1,4-cyclohexane dimethanol (1,4-CHDM) It is present in liquid state with low viscosity at room temperature and convenient to use. In addition, the photocurable urethane (meth) acrylate according to one aspect of the present invention can reduce the rainbow effect of the cured coating due to its high refractive index, and can be synthesized on a large scale by being present in a liquid phase having a low viscosity, There is an advantage that it is easy to use in manufacturing a photocurable resin composition.

Further, since the photo-curable urethane (meth) acrylate according to one aspect of the present invention can secure a high refractive index, it can be usefully used in a photo-curable resin composition applied to an optical component material, and a plastic film It can be used as a surface coating material of a substrate, exhibit high transparency in a optical product, a refractive index and a surface hardness of a cured product, and exhibit excellent abrasion resistance, productivity, and heat resistance.

The urethane (meth) acrylate can not be made highly viscous in the production of urethane (meth) acrylate, and the generation of byproducts is small, so that a desired urethane (meth) acrylate can be produced at a high yield. As a result, the photo-curable resin composition (before curing) produced therefrom has no deterioration of the appearance of the resin due to opacity at low temperatures, has excellent adhesion with glass or plastic substrate, has high flexibility and high heat resistance. In addition, the cured product of the photo-curable resin composition containing urethane (meth) acrylate according to one aspect of the present invention has high transparency and little deformation or deterioration of color even at a high temperature.

1 is a schematic diagram showing a process of synthesizing a photo-curable urethane (meth) acrylate produced according to Example 1 on one side of the present invention.
2 is a ¹ H-NMR spectrum of a photo-curable urethane (meth) acrylate compound prepared according to Example 1 on one side of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may unnecessarily obscure the subject matter of the present invention. In addition, the terms described below are established in consideration of the functions of the present invention, and these may vary depending on the intention of the manufacturer or custom in the industry, and the definition should be based on the contents throughout the specification.

Hereinafter, a photocurable urethane (meth) acrylate according to one aspect of the present invention and a method for producing the same will be described in detail.

The photo-curable urethane (meth) acrylate according to one aspect of the present invention is represented by the following formula (1).

[Chemical Formula 1]

The photo-curable urethane (meth) acrylate according to one aspect of the present invention can be produced by reacting a urethane (meth) acrylate compound (3) prepared by using 1,4-cyclohexane dimethanol (CHDM) with a cyclohexane ring And an ester group (COO < - >) are further bonded.

(3)

The urethane (meth) acrylate prepared using 1,4-cyclohexane dimethanol (1,4-CHDM) is a high viscosity liquid at room temperature, whereas the photo-curable urethane (meth) acrylate according to one aspect of the present invention It is present as a liquid having a low viscosity at room temperature and is convenient to use in the production of urethane (meth) acrylate or in the manufacture of a photocurable resin composition containing the same. In addition, the photocurable urethane acrylate according to one aspect of the present invention can reduce the rainbow effect of the cured coating because of its high refractive index.

Further, the photocurable coating resin composition prepared using the photocurable urethane (meth) acrylate according to one aspect of the present invention has high refractive index and surface hardness and can be used as a surface coating material for a plastic film substrate used for an optical material , High transparency in optical products, high refractive index and surface hardness of cured products, and excellent properties of immersion, productivity and heat resistance.

The photo-curable urethane (meth) acrylate according to one aspect of the present invention is excellent in wear resistance and durability and can be used in a resin composition for hard coating.

Further, the photo-curing resin composition (before curing) prepared from the photo-curable urethane (meth) acrylate according to one aspect of the present invention does not deteriorate the appearance of the resin due to opacity at low temperature and has excellent adhesion with glass or plastic substrate And has high flexibility and high heat resistance. In addition, the cured product of the photo-curable resin composition containing urethane (meth) acrylate according to one aspect of the present invention has high transparency and little deformation or deterioration of color even at a high temperature.

The photocurable urethane (meth) acrylate according to one aspect of the present invention has a high refractive index and a low viscosity, and has a refractive index of 1.50 to 1.51 and a viscosity of 1,200 to 24,000 cps at 25 占 폚.

The photo-curable urethane (meth) acrylate according to one aspect of the present invention can improve the degree of curing and can form a film having excellent ablative resistance, corrosion resistance, abrasion resistance and hardness.

In the resin composition containing the photo-curable urethane (meth) acrylate according to one aspect of the present invention, the refractive index of the resin is high and the effect of increasing the brightness when applied to the prism sheet is large and the elastic force after curing is excellent. Can be prevented in advance, and it is possible to provide a photocurable resin composition which not only has a high viscosity at room temperature, but also can be easily worked by a worker, thereby maximizing mass productivity and having excellent vulcanization resistance.

A schematic diagram of a method for producing the photo-curable urethane (meth) acrylate of Formula 1 according to one aspect of the present invention is shown in FIG.

According to one aspect of the present invention, there is provided a process for preparing a photo-curable urethane (meth) acrylate of formula 1 comprising reacting 4- (hydroxymethyl) cyclohexylmethyl-4 '- (hydroxymethyl) cyclohexanecarboxylate (Hydroxymethyl) cyclohexylmethyl-4 '- (hydroxymethyl) cyclohexane carboxylate.

(2)

To prepare the photo-curable urethane (meth) acrylate of Formula 1 according to one aspect of the present invention, 4- (hydroxymethyl) cyclohexylmethyl-4 '- (hydroxymethyl) cyclohexanecarboxylate , The reaction solvent is introduced into the reactor. At this time, a polymerization inhibitor and a urethane reaction catalyst may be further added.

The reaction solvent used may be an organic solvent including toluene, methyl ethyl ketone (MEK), or an acrylate reactive diluent, and the acrylate reactive diluent may be mono-acrylate, di-acrylate , Tri-acrylate, or tetraacrylate, the polymerization inhibitor may be methylhydroquinone (MQ), and the urethane reaction catalyst may be dibutyltin dilaurate. As the polymerization inhibitor, dibutylhydroxy toluene, hydroquinone, hydroquinone monomethyl ether or phenothiazine may be used instead of methylhydroquinone.

Thereafter, a diisocyanate compound is further added to the reactor to react the diol compound of the formula (2) with the diisocyanate. In this step, it is preferable to react the diol compound of formula (2) with a diisocyanate followed by the addition of hydroxyethyl acrylate (HEA). Alternatively, diisocyanate and hydroxyethyl acrylate (HEA) And then adding a diol compound represented by the formula (2). The diisocyanate compound may be at least one selected from the group consisting of an aromatic diisocyanate, an alicyclic diisocyanate, an aliphatic diisocyanate having a branched chain, and a diisocyanate compound obtained by hydrogenating an aromatic diisocyanate.

Specifically, the diisocyanate compound used for producing the photo-curable urethane (meth) acrylate of Formula 1 according to one aspect of the present invention includes an aromatic diisocyanate, an alicyclic diisocyanate, and an aliphatic diisocyanate, Preferably, the aromatic diisocyanate may be toluene diisocyanate (TDI) or 4,4'-diphenylmethane diisocyanate (MDI), and the aliphatic diisocyanate may be 1,6-hexa But is not limited to, 1,6-hexamethylene diisocyanate (HDI).

Examples of the aliphatic diisocyanate include aliphatic diisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, Dimer diisocyanate, which is called an isocyanate group, but is not limited thereto.

Examples of the alicyclic diisocyanate include 1,4-cyclohexane diisocyanate, isophorone diisocyanate, 1-methyl-2,4-cyclohexane diisocyanate, 1-methyl-2,6-cyclohexane diisocyanate, -Dicyclohexylmethane diisocyanate or 1,3-bis (isocyanatomethyl) cyclohexane, but are not limited thereto.

Examples of the aromatic diisocyanate include xylylene diisocyanate, 4,4'-diphenyl diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, Isocyanate, isocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyldiisocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate , 1,5-naphthylene diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, polymethylene polyphenyl isocyanate, phenylene diisocyanate or m-tetramethyl xylylene diisocyanate , But is not limited thereto.

Preferably, the diisocyanate compound used to prepare the photocurable urethane (meth) acrylate of Formula 1 according to one aspect of the present invention is selected from the group consisting of isophorone diisocyanate (IPDI), 4,4'- Methylene dicyclohexyl diisocyanate (H12MDI), or hexamethylene diisocyanate (HMDI).

The reaction materials are used to prepare an isocyanate-terminated urethane prepolymer, which is then reacted with (meth) acrylate to prepare a photo-curable urethane (meth) acrylate of the formula (1). The (meth) acrylate may be at least one selected from the group consisting of hydroxyethyl acrylate (HEA), hydroxypropyl acrylate (HPA), hydroxyethyl (meth) acrylate (HEMA) But are not limited to, hydroxybutyl acrylate (HBA), caprolactone acrylate, and pentaerythritol triacrylate (PETA).

Further, in the process for producing a photocurable urethane (meth) acrylate of the above formula (1) according to one aspect of the present invention, in the third step of producing the urethane isocyanate prepolymer, Since the reaction is exothermic, the internal temperature of the reactor should be kept below 80 ° C, and the internal temperature of the reactor should be maintained at 50 ° C or higher for the reaction to occur. That is, the internal temperature of the reactor may be 50 ° C to 80 ° C.

Hereinafter, examples of the present invention and methods for producing urethane (meth) acrylate prepared by using 1,4-cyclohexane dimethanol (1,4-CHDM) (comparative examples) will be described in detail.

The photo-curable urethane (meth) acrylate of the formula (1)

4- (hydroxymethyl) cyclohexylmethyl-4 '- (hydroxymethyl) cyclohexane carboxylate of the formula 2: 4- (hydroxymethyl) cyclohexylmethyl-4'- (hydroxymethyl) cyclohexanecarboxylate

(2)

Example 1

A process for producing a photocurable urethane (meth) acrylate of the formula (1)

236 g (0.83 mol) of 4- (hydroxymethyl) cyclohexylmethyl-4 '- (hydroxymethyl) cyclohexanecarboxylate of the formula 2, 199 g (173 ml) of toluene, 173 ml of isophorone diisocyanate (IPDI, isophorone diisocyanate) (367 g, 1.65 mol) are placed in a four-neck 500 mL round flask reactor. After setting the internal temperature of the reactor to 40 ° C, 1 g of methylhydroquinone (MQ) as a polymerization inhibitor is completely dissolved in the reactor while stirring the reaction materials. After confirming that the reaction materials are dissolved, 0.2 g of dibutyltin dilaurate (DBTDL) is slowly added to the reactor as a catalyst. At this time, since an exothermic reaction occurs, the internal temperature of the reactor is controlled so as not to exceed 80 ° C. After the catalyst is added, the reaction is carried out at 80 ° C for 3 hours while gradually raising the temperature. After confirming that the 4- (hydroxymethyl) cyclohexylmethyl-4 '- (hydroxymethyl) cyclohexanecarboxylate of Formula 2 was exhausted, hydroxyethyl acrylate (HEA) 191 g (1.65 mol), and the mixture is further reacted at 80 ° C. for 3 hours. At this time, it is determined by titration that the NCO% (titration method using the -N = C = O group) is 0.2 or less, or the NCO peak in the IR phase of the reaction mixture disappears and the reaction is judged to be completed. After the lapse of 6 hours, the synthesis reaction is terminated while cooling slowly.

Isocyanate (NCO) titration

The isocyanate group concentration was measured as follows. This measurement was carried out with a stirrer with a 100 mL glass flask.

(Measurement of Blank Value)

To 15 mL of tetrahydrofuran (THF) was added 15 mL of a tetrahydrofuran (THF) solution (0.1 N) containing dibutylamine, and bromophenol blue (1% methanol dilution) After dropwise addition, the solution was colored with blue, and the solution was titrated with a 0.1 N aqueous HCl solution. The appropriate amount of aqueous HCl solution at the time point of discoloration was defined as Vb (mL).

(Measurement of actual isocyanate group concentration)

The sample was weighed in Ws (g), dissolved in 15 mL of tetrahydrofuran (THF) and 15 mL of a tetrahydrofuran (THF) solution (0.1 N) containing dibutylamine was added. After confirming that the solution had been solubilized, 3 drops of bromophenol blue (1% methanol diluted solution) were added and the solution was colored blue, and the solution was titrated with a 0.1 N aqueous HCl solution. The appropriate amount of aqueous HCl solution at the point of discoloration was defined as Vs (mL). The isocyanate group concentration in the sample was calculated by the following equation.

Isocyanate group concentration (% by weight) = (Vb-Vs) 占 1.005 占 0.42 占 Ws

Example 2

A process for producing a photocurable urethane (meth) acrylate of the formula (1)

236 g (0.83 mol) of 4- (hydroxymethyl) cyclohexylmethyl-4'- (hydroxymethyl) cyclohexanecarboxylate of Formula 2, 199 g (173 ml) of toluene (Toluene) 432 g (1.65 mol) of 4,4'-methylene dicyclohexyl diisocyanate (H12MDI) are put into a four-neck 500 mL round flask reactor. After setting the internal temperature of the reactor to 40 ° C, 1 g of methylhydroquinone (MQ) as a polymerization inhibitor is completely dissolved in the reactor while stirring the reaction materials. After confirming that the reaction materials are dissolved, 0.2 g of dibutyltin dilaurate (DBTDL) is slowly added to the reactor as a catalyst. At this time, since an exothermic reaction occurs, the internal temperature of the reactor is controlled so as not to exceed 80 ° C. After the catalyst is added, the reaction is carried out at 80 ° C for 3 hours while gradually raising the temperature. After confirming that the 4- (hydroxymethyl) cyclohexylmethyl-4 '- (hydroxymethyl) cyclohexanecarboxylate of Formula 2 was exhausted, hydroxyethyl acrylate (HEA) 191 g (1.65 mol), and the mixture is further reacted at 80 ° C. for 3 hours. At this time, it is determined by titration that the NCO% (titration method using the -N = C = O group) is 0.2 or less, or the NCO peak in the IR phase of the reaction mixture disappears and the reaction is judged to be completed. After the lapse of 6 hours, the synthesis reaction is terminated while cooling slowly.

Example 3

A process for producing a photocurable urethane (meth) acrylate of the formula (1)

236 g (0.83 mol) of 4- (hydroxymethyl) cyclohexylmethyl-4 '- (hydroxymethyl) cyclohexanecarboxylate of Formula 2, 199 g (173 ml) of toluene, 173 ml of hexamethylene diisocyanate 277 g (1.65 mol) of hexamethylene diisocyanate (HMDI) are introduced into a four-neck 500 mL round flask reactor. After setting the internal temperature of the reactor to 40 ° C, 1 g of methylhydroquinone (MQ) as a polymerization inhibitor is completely dissolved in the reactor while stirring the reaction materials. After confirming that the reaction materials are dissolved, 0.2 g of dibutyltin dilaurate (DBTDL) is slowly added to the reactor as a catalyst. At this time, since an exothermic reaction occurs, the internal temperature of the reactor is controlled so as not to exceed 80 ° C. After the catalyst is added, the reaction is carried out at 80 ° C for 3 hours while gradually raising the temperature. After confirming that the 4- (hydroxymethyl) cyclohexylmethyl-4 '- (hydroxymethyl) cyclohexanecarboxylate of Formula 2 was exhausted, hydroxyethyl acrylate (HEA) 191 g (1.65 mol), and the mixture is further reacted at 80 ° C. for 3 hours. At this time, it is determined by titration that the NCO% (titration method using the -N = C = O group) is 0.2 or less, or the NCO peak in the IR phase of the reaction mixture disappears and the reaction is judged to be completed. After the lapse of 6 hours, the synthesis reaction is terminated while cooling slowly.

Example 4

A process for producing a photocurable urethane (meth) acrylate of the formula (1)

236 g (0.83 mol) of 4- (hydroxymethyl) cyclohexylmethyl-4 '- (hydroxymethyl) cyclohexanecarboxylate of the formula 2, 199 g (173 ml) of toluene, 173 ml of isophorone diisocyanate (IPDI, isophorone diisocyanate) (367 g, 1.65 mol) are placed in a four-neck 500 mL round flask reactor. After setting the internal temperature of the reactor to 40 ° C, 1 g of methylhydroquinone (MQ) as a polymerization inhibitor is completely dissolved in the reactor while stirring the reaction materials. After confirming that the reaction materials are dissolved, 0.2 g of dibutyltin dilaurate (DBTDL) is slowly added to the reactor as a catalyst. At this time, since an exothermic reaction occurs, the internal temperature of the reactor is controlled so as not to exceed 80 ° C. After the catalyst is added, the reaction is carried out at 80 ° C for 3 hours while gradually raising the temperature. After confirming that the 4- (hydroxymethyl) cyclohexylmethyl-4 '- (hydroxymethyl) cyclohexanecarboxylate of Formula 2 was depleted, pentaerythritol triacrylate (PETA) 492 g (1.65 mol), and the mixture is further reacted at 80 ° C. for 3 hours. At this time, it is determined by titration that the NCO% (titration method using the -N = C = O group) is 0.2 or less, or the NCO peak in the IR phase of the reaction mixture disappears and the reaction is judged to be completed. After the lapse of 6 hours, the synthesis reaction is terminated while cooling slowly.

2 is a ¹ H-NMR spectrum of a photocurable monomer compound prepared according to Example 1 on one side of the present invention. Referring to FIG. 2, the methylene peak bonded to the ester functional group was observed at 3.5 to 3.9 ppm, and the hydrogen peak of the acrylate double bond was observed at 5.8 to 6.4 ppm. The photocurable urethane of formula (1) ) Acrylate compound was synthesized.

Comparative Example 1

A process for producing a photocurable urethane (meth) acrylate of the general formula (3)

120 g (0.83 mol) of 1,4-cyclohexanedimethanol, 1,4-CHDM, 199 g (173 ml) of toluene, isophorone diisocyanate (IPDI) 367 g (1.65 mol) is put into a four-neck 500 mL round flask reactor. After setting the internal temperature of the reactor to 40 ° C, 1 g of methylhydroquinone (MQ) as a polymerization inhibitor is completely dissolved in the reactor while stirring the reaction materials. After confirming that the reaction materials are dissolved, 0.2 g of dibutyltin dilaurate (DBTDL) is slowly added to the reactor as a catalyst. At this time, since an exothermic reaction occurs, the internal temperature of the reactor is controlled so as not to exceed 80 ° C. After the catalyst is added, the reaction is carried out at 80 ° C for 3 hours while gradually raising the temperature. After confirming that 1,4-cyclohexanedimethanol (1,4-CHDM) was exhausted from the reaction starting materials, 191 g (1.65 mol) of hydroxyethyl acrylate (HEA) was added and then added at 80 ° C. For 3 hours. At this time, it is determined by titration that the NCO% (titration method using the -N = C = O group) is 0.2 or less, or the NCO peak in the IR phase of the reaction mixture disappears and the reaction is judged to be completed. After the lapse of 6 hours, the synthesis reaction is terminated while cooling slowly.

Comparative Example 2

A process for producing a photocurable urethane (meth) acrylate of the general formula (3)

120 g (0.83 mol) of 1,4-cyclohexanedimethanol, 1,4-CHDM, 199 g (173 ml) of toluene, 174 ml of 4,4'-methylenedicyclohexyl diisocyanate (4,4'-Methylene dicyclohexyl diisocyanate, H12MDI) (432 g, 1.65 mol) are placed in a four-neck 500 mL round flask reactor. After setting the internal temperature of the reactor to 40 ° C, 1 g of methylhydroquinone (MQ) as a polymerization inhibitor is completely dissolved in the reactor while stirring the reaction materials. After confirming that the reaction materials are dissolved, 0.2 g of dibutyltin dilaurate (DBTDL) is slowly added to the reactor as a catalyst. At this time, since an exothermic reaction occurs, the internal temperature of the reactor is controlled so as not to exceed 80 ° C. After the catalyst is added, the reaction is carried out at 80 ° C for 3 hours while gradually raising the temperature. After confirming that 1,4-cyclohexanedimethanol (1,4-CHDM) was exhausted from the reaction starting materials, 191 g (1.65 mol) of hydroxyethyl acrylate (HEA) was added and then added at 80 ° C. For 3 hours. At this time, it is determined by titration that the NCO% (titration method using the -N = C = O group) is 0.2 or less, or the NCO peak in the IR phase of the reaction mixture disappears and the reaction is judged to be completed. After the lapse of 6 hours, the synthesis reaction is terminated while cooling slowly.

Comparative Example 3

A process for producing a photocurable urethane (meth) acrylate of the general formula (3)

120 g (0.83 mol) of 1,4-cyclohexanedimethanol, 1,4-CHDM, 199 g (173 ml) of toluene, 273 g of hexamethylene diisocyanate (HMDI) g (1.65 mol) is put into a four-neck 500 mL round flask reactor. After setting the internal temperature of the reactor to 40 ° C, 1 g of methylhydroquinone (MQ) as a polymerization inhibitor is completely dissolved in the reactor while stirring the reaction materials. After confirming that the reaction materials are dissolved, 0.2 g of dibutyltin dilaurate (DBTDL) is slowly added to the reactor as a catalyst. At this time, since an exothermic reaction occurs, the internal temperature of the reactor is controlled so as not to exceed 80 ° C. After the catalyst is added, the reaction is carried out at 80 ° C for 3 hours while gradually raising the temperature. After confirming that 1,4-cyclohexanedimethanol (1,4-CHDM) was exhausted from the reaction starting materials, 191 g (1.65 mol) of hydroxyethyl acrylate (HEA) was added and then added at 80 ° C. For 3 hours. At this time, it is determined by titration that the NCO% (titration method using the -N = C = O group) is 0.2 or less, or the NCO peak in the IR phase of the reaction mixture disappears and the reaction is judged to be completed. After the lapse of 6 hours, the synthesis reaction is terminated while cooling slowly.

Comparative Example 4

A process for producing a photocurable urethane (meth) acrylate of the general formula (3)

120 g (0.83 mol) of 1,4-cyclohexanedimethanol, 1,4-CHDM, 199 g (173 ml) of toluene, isophorone diisocyanate (IPDI) 367 g (1.65 mol) is put into a four-neck 500 mL round flask reactor. After setting the internal temperature of the reactor to 40 ° C, 1 g of methylhydroquinone (MQ) as a polymerization inhibitor is completely dissolved in the reactor while stirring the reaction materials. After confirming that the reaction materials are dissolved, 0.2 g of dibutyltin dilaurate (DBTDL) is slowly added to the reactor as a catalyst. At this time, since an exothermic reaction occurs, the internal temperature of the reactor is controlled so as not to exceed 80 ° C. After the catalyst is added, the reaction is carried out at 80 ° C for 3 hours while gradually raising the temperature. After confirming that 1,4-cyclohexanedimethanol (1,4-CHDM) was exhausted from the reaction mixture, 492 g (1.65 mol) of pentaerythritol triacrylate (PETA) was added thereto, For 3 hours. At this time, it is determined by titration that the NCO% (titration method using the -N = C = O group) is 0.2 or less, or the NCO peak in the IR phase of the reaction mixture disappears and the reaction is judged to be completed. After the lapse of 6 hours, the synthesis reaction is terminated while cooling slowly.

The physical property data of urethane (meth) acrylate prepared according to Comparative Examples 1 to 4 (Table 1) and Examples 1 to 4 (Table 2) are as follows.

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Appearance (25 ℃) Colorless transparent liquid Colorless transparent liquid Gel Colorless transparent liquid Viscosity (cps, 65 ° C) 2000 3500 - 3000 Refractive index (RI, 25 DEG C) 1.4890 1.4910 - 1.4830 Film properties after photocuring
(Substrate: glass, thickness: 250 占 퐉, photoinitiator: 5 phr,
Formulation: urethane (meth) acrylate / Irgacure 184 = 100/5) Pencil hardness 2H 2H - 6H Pendulum hardness 50 45 - 65

Example 1 Example 2 Example 3 Example 4 Appearance (25 ℃) Colorless transparent liquid Colorless transparent liquid Colorless transparent liquid Colorless transparent liquid Viscosity (cps, 25 캜)
Measured with a Brookfield Viscometer 15350 23350 1250 6450 Viscosity (cps, 65 ° C)
Brookfield viscometer side 1500 2900 650 2300 Refractive index (RI, 25 DEG C) 1.5050 1.5104 1.4992 1.5028 Film properties after photocuring
(Substrate: glass, thickness: 250 占 퐉, photoinitiator: 5 phr,
Formulation: urethane (meth) acrylate / Irgacure 184 = 100/5) Pencil hardness 5B <6B <6B 3H Pendulum hardness 15 11 11 -

Properties and Viscosity

The urethane (meth) acrylate prepared in the comparative example was a highly viscous liquid such that viscosity measurement at room temperature or 25 ° C was impossible, and viscosity was measured at 60 ° C as shown in Table 1.

On the other hand, urethane (meth) acrylates prepared according to embodiments of the present invention are colorless transparent liquids having a viscosity of 1250 to 23350 cps at 25 ° C and a viscosity of 650 to 2900 cps at 65 ° C. As a result, the viscosity of the urethane (meth) acrylate prepared according to one aspect of the present invention is significantly higher than that of other urethane (meth) acrylate-based compounds prepared from 1,4-cyclohexane dimethanol It is low.

Refractive index

The refractive index of the urethane (meth) acrylate prepared in the comparative example was 1.48 to 1.49, and the refractive index of the urethane (meth) acrylate prepared according to the embodiments of the present invention was It can be seen that the refractive index is relatively high from 1.50 to 1.51.

Hardness

In the above comparative table, the hardness shows the physical properties of the coating film measured after applying the urethane (meth) acrylate according to the comparative example and the example using a glass substrate and photo-curing. As shown in the above comparison table, the thickness of the coating film was 250 탆, and the photoinitiator was 5 phr (part per hundred, using 5 g of photoinitiator when 100 g of monomer was used).

The hardness is slightly higher than the urethane (meth) acrylate prepared in the comparative example, but the urethane (meth) acrylate prepared according to the embodiment of the present invention is comparable to the urethane It is possible to form a coating film having higher flexibility and impact resistance than the example.

That is, the urethane (meth) acrylate prepared in the comparative example is disadvantageous in that it is hard to use since it is excellent in hardness and hardness but is a liquid having a high viscosity at room temperature. However, the urethane (meth) acrylate Is a liquid having a low viscosity at room temperature, so that it is convenient to use, and the refractive index is high as described above, so that the rainbow phenomenon of the cured coating film can be reduced.

From this, it can be seen that the urethane (meth) acrylate prepared according to the embodiment of the present invention has a refractive index equal to or higher than that of the urethane (meth) acrylate of the comparative example already marketed and is a colorless transparent liquid at 25 캜, Is lower than that of the comparative example. As a result, it is possible to reduce the rainbow effect of the cured coating film, and it can be synthesized on a large scale by being present in a liquid state having a low viscosity, and it is advantageous in that it is easy to use in the manufacture of a photocurable resin composition.

Further, since the urethane (meth) acrylate does not increase in viscosity and generates byproduct, the desired urethane (meth) acrylate can be produced at a high yield. As a result, the photo-curable resin composition (before curing) produced therefrom has no deterioration of the appearance of the resin due to opacity at low temperatures, has excellent adhesion with glass or plastic substrate, has high flexibility and high heat resistance. In addition, the cured product of the photo-curable resin composition containing urethane (meth) acrylate according to one aspect of the present invention has high transparency and little deformation or deterioration of color even at a high temperature.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims (9)

A photocurable urethane (meth) acrylate compound represented by the following formula (1):
[Chemical Formula 1]

A first step of preparing a compound of the following formula (2);
(2)

A second step of adding the compound of Formula 2 and toluene to the reactor and stirring the mixture;
A third step of adding a diisocyanate compound to the reactor and stirring the resultant mixture to form a urethane isocyanate prepolymer containing an isocyanate group; And
And a fourth step of reacting the urethane isocyanate prepolymer with (meth) acrylate containing a hydroxyl group to produce urethane (meth) acrylate,
In the third step, the diisocyanate compound is preferably selected from the group consisting of 4,4'-Methylene dicyclohexyl diisocyanate (H12MDI), isophorone diisocyanate (IPDI), and hexamethylene diisocyanate (Hexamethylene diisocyanate, HMDI), and at least one selected from the group consisting of
Wherein the (meth) acrylate is at least one selected from the group consisting of hydroxyethyl acrylate (HEA) and pentaerythritol triacrylate (PETA). (Meth) acrylate.
delete 3. The method of claim 2,
In the third step, a polymerization inhibitor and a urethane reaction catalyst are further introduced,
The polymerization inhibitor may be any one selected from the group consisting of methylhydroquinone (MQ), dibutylhydroxy toluene, hydroquinone, and hydroquinone monomethyl ether ,
The process for producing a photocurable urethane (meth) acrylate of claim 1, wherein the urethane reaction catalyst is dibutyltin dilaurate.
delete delete delete 3. The method of claim 2,
The process for producing a photocurable urethane (meth) acrylate according to claim 1, wherein the temperature in the reactor is maintained at 50 ° C to 80 ° C in the third step.
A photocurable coating resin composition comprising a photocurable urethane (meth) acrylate of Chemical Formula 1 of claim 1.

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