KR102034380B1 - Branched polyorganosiloxane and Ultraviolet-curable hard coating composition comprising the same - Google Patents

Abstract

The present invention relates to branched polyorganosiloxane, a method for manufacturing the same, and an ultraviolet curable hard coating composition comprising the same. More specifically, the present invention relates to a hard coating composition and a hard coating film in which branched polyorganosiloxane is manufactured by hydrosilylation of polydimethylsiloxane having a monohydride end group to a polyorganosiloxane having a vinyl end group and adding the same to an acrylate coating composition to improve hardness, hydrophobicity, and flexible properties.

Description

Branched polyorganosiloxane and UV curable hard coating composition comprising same {Branched polyorganosiloxane and Ultraviolet-curable hard coating composition comprising the same}

The present invention relates to a branched polyorganosiloxane, a method for preparing the same, and an ultraviolet curable hard coating composition comprising the same, and more particularly, to a poly (vinylmethyl-dimethyl) siloxane having a vinyl end group, having a monohydride end group. The present invention relates to a hard coating composition in which a polydimethylsiloxane is subjected to hydrosilylation to prepare a branched polyorganosiloxane, and added to the acrylate coating composition to improve hardness, hydrophobicity, and flexible properties.

The acrylate coating liquid used as the hard coating agent has excellent wear resistance and optical properties, but it is limited to the high hardness hard coating material which is required for the recent display, and the coated film has a disadvantage in particular because of its poor flexibility. . In order to compensate for this, a method of using an organic-inorganic hybrid composite material having both excellent flexibility and moldability of organic materials and wear resistance and transparency of inorganic materials as a coating agent has been used. However, this method shows a problem that the surface hardness can be obtained, but the bending property is rather poor due to the inorganic properties. In order to overcome this, a lot of researches have recently been made on hard coating liquids containing silicone compounds having flexibility while maintaining surface hardness.

Silicone compounds used as hard coating additives are composed of siloxane (Si-O-Si) bonds whose main skeleton is inorganic, so they have excellent properties such as heat resistance, cold resistance, abrasion resistance, chemical resistance, weather resistance, and high electrical insulation. It has a molecular structure that simultaneously improves flexibility and processability by reducing crosslinking between molecules by introducing two organic substituents into the main skeleton. Depending on the type of these organic substituents, it is possible to prepare a variety of modified silicone compounds, both of which are polydimethylsiloxane (PDMS) consisting of methyl groups is the most widely used silicone compound. In addition, in the field of hard coatings, poly (vinylmethyl-methyl) siloxane (PVMS) having a vinyl group as a substituent is applied to induce optical crosslinking with an acrylate coating agent to simultaneously realize flexibility and excellent surface hardness of acrylate. It's going on. In this case, the bending property is increased due to the elastic properties of silicon and the surface hardness is also increased by the crosslinking of silicon and acrylate. However, there is a limitation in obtaining a hard surface such as an organic-inorganic hybrid coating, which requires further research.

Meanwhile, although the hard coating resin compositions including siloxane resins are disclosed in Korean Patent Publication Nos. 10-2007-0056922, 10-2014-0004568, and Korean Patent No. 10-1818487, the characteristics such as hardness and workability are different. There is a limit to the practical industrial application because it cannot be implemented sufficiently.

Republic of Korea Patent Publication No. 10-2007-0056922 Republic of Korea Patent Publication No. 10-2014-0004568 Republic of Korea Patent Publication No. 10-1818487

The technical problem to be achieved by the present invention is to provide a novel branched polyorganosiloxane excellent in processability and flexibility while maintaining the properties of the silicon and its manufacturing method.

In addition, another technical problem to be achieved by the present invention is to provide an ultraviolet curable hard coating composition in which a branched polyorganosiloxane is added to an acrylate coating composition and a hard coating film having improved hardness and warpage.

In order to solve the above problems, the present invention is a branched polyorganosiloxane prepared by hydrosilylation reaction of a polydimethylsiloxane having a monohydride end group to a poly (vinylmethyl-dimethyl) siloxane having a vinyl end group And methods for producing the same.

The present invention also provides a UV curable hard coating composition comprising a branched polyorganosiloxane, an acrylate monomer, a photoinitiator and a solvent, and a hard coating film formed by UV curing the same.

Since the polyorganosiloxane according to the present invention has a structure in which the polydimethylsiloxane branch is bonded, it is possible to control the amount of the vinyl group to determine the degree of reaction with the acrylate, and at the same time to control the molecular weight of the coating thin film of the desired physical properties This has the advantage of being available. In addition, the coating film obtained by ultraviolet curing the acrylate hard coating composition comprising the branched polyorganosiloxane according to the present invention is a surface hardness, hydrophobicity and flexibility while maintaining the elasticity, weather resistance, processing characteristics and optical properties of the silicone material This improves and is suitable for use as a flexible display protective film.

1 is a schematic diagram showing a process of synthesizing branched polyorganosiloxane (BVPVMS) according to an embodiment of the present invention.
2 is a 1 H-NMR spectrum and FT-IR spectrum of branched polyorganosiloxane (BVPVMS) synthesized according to an embodiment of the present invention.
3 is a graph showing the change in the amount of branched vinyl groups with time while changing the reaction temperature and time and the amount of catalyst according to an embodiment of the present invention.
Figure 4 shows the H-PDMS H peak decreased with the reaction time from the 1H-NMR spectrum of BVPVMS reacted by the H ratio of H-PDMS to 2 ~ 100% of the vinyl group present in VPVMS according to an embodiment of the present invention ( 4.7 ppm) is a graph showing percentage of size.
5 is a graph showing the measurement results of the molecular weight and yield of the branched polyorganosiloxane (BVPVMS) synthesized according to the embodiment of the present invention.
Figure 6 is a graph showing the results of measuring the surface hardness of the coating film prepared with an acrylate coating liquid containing a branched polyorganosiloxane (BVPVMS) according to an embodiment of the present invention.
7 is a graph showing the results of measuring the contact angle of the coating film to which the branched polyorganosiloxane (BVPVMS) is added according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to embodiments and drawings.

The manufacturing method of the branched polyorganosiloxane which concerns on this invention has a monohydride terminal group represented by following [Formula 2] in the poly (vinylmethyl- dimethyl) siloxane which has a vinyl terminal group represented by following [Formula 1]. It is characterized in that it is carried out by hydrosilylation reaction of polydimethylsiloxane.

[Formula 1]

[Formula 2]

Wherein m is an integer from 0 to 520, n is an integer from 5 to 166, and p is an integer from 11 to 13.

The hydrosilylation reaction according to the invention can be carried out under one or more catalysts selected from the group consisting of Pt, Pd and Rh, of which Pt is preferred. In addition, the content of the Pt catalyst to be used is 0.6 to 2.0% by weight is appropriate, considering the effect on the product or economical, it is preferable to use about 0.6% by weight.

In addition, the hydrosilylation reaction is preferably performed for 12 to 72 hours at a temperature range of 50 to 70 ℃. In the preparation of the branched polyorganosiloxane according to the present invention, the reaction temperature and the time range of each step can be appropriately adjusted according to the required molecular weight, and the like, but are not particularly limited thereto, and each reaction is less than the temperature and time range. When the reaction is performed under conditions, the reaction for the synthesis of the polymer does not proceed sufficiently, and when the reaction is performed under temperature and time conditions exceeding the above ranges, a cost increase problem may occur due to a decrease in process efficiency due to a long time reaction. It is preferable to carry out.

As such, hydrosilylation reaction of polydimethylsiloxane having a monohydride end group with poly (vinylmethyl-dimethyl) siloxane having a vinyl end group produces a branched polyorganosiloxane, and the weight of the resulting polymer Average molecular weights range from 7,000 to 180,000.

Meanwhile, the UV-curable hard coating composition according to the present invention includes a branched polyorganosiloxane, an acrylate monomer, a photoinitiator and a solvent prepared by the manufacturing method, and specifically 2.5 to 20% by weight of the branched polyorganosiloxane, acrylic It is appropriate to form a hard coating film having excellent hardness and flexibility that includes 30 to 70% by weight of the rate monomer, 0.5 to 2.0% by weight of the photoinitiator and 30 to 70% by weight of the solvent.

As the acrylate monomer usable in the present invention, for example, methyl methacrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate Latex, phenyl methacrylate, benzyl methacrylate, methyl acrylate, ethyl acrylate, 2-hydroxyethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acryl And the mixture thereof, and the like, but are not particularly limited thereto, and any monomer commonly used in the acrylate coating liquid may be used.

In addition, the photoinitiator usable in the present invention is benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylmethane- 1-1one, anisolemethyl ether, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenyl ketone, α-hydroxyketone, 4-phenoxy Sidichloroacetone, 4-t-butyldichloroacetophenone, 2-methyl-2-hydroxypropiophenone, 1- [4- (2-hydroxyethyl) phenyl] -2-hydroxy-2-methylpropane- 1-one, 1-phenyl-1,1-propanedione-2- (o-ethoxycarbonyl) -oxime, benzoin, benzyl, benzophenone, benzoylbenzoic acid, 3,3`-methyl-4-methoxy Benzophenone, polyvinyl benzophenone, α-hydroxycyclohexylbenzophenone, benzyl methyl ketal, thioxanthone, 2-chloro thioxanthone, 2-methyl thioxanthone, 2,4-dimethyl thioxanthone, isopropyl Thioxanthone, 2,4-dichloro Thioxanthone, 2,4-diethyl thioxanthone, 2,4-diisopropyl thioxanthone, dodecyl thioxanthone, and mixtures thereof, and the like, but are not particularly limited thereto. Any initiator used for the chemical conversion can be used.

Surface hardness of the hard coating film prepared by ultraviolet curing the hard coating composition according to the invention is characterized in that the pencil hardness of 1H to 3H, the contact angle of the coating film is 71 to 95 ° to increase the hydrophobicity. In addition, the hard coating film according to the present invention is expected to be applicable to products such as a hard coating film for flexible display because of its excellent flexibility.

Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the following examples are presented by way of example to aid the understanding of the present invention, and the scope of the present invention should not be construed as being limited thereto.

Example 1 Synthesis of Branched Polyorganosiloxane

A 250 ml three-necked flask was equipped with a stirrer, thermometer, reflux cooler and nitrogen inlet, 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane (D4 ^{vi, me} ) and 1 After changing the ratio of, 3-divinyltetramethyldisiloxane (VMS) was added, and 0.3wt% of the catalyst was added to the reactant, and reacted for 2 hours under 120 ℃, nitrogen stream. Thereafter, the neutralizing tris (2-chloroethyl) phosphate was neutralized by adding 6wt% of the catalyst, and the product was removed by vacuum distillation with a vacuum evaporator to remove unreacted poly (vinylmethyl-dimethyl) siloxane. (VPVMS) was prepared.

Then, the ratio of polydimethylsiloxane (H-PDMS) having a VPVMS and a monohydride terminal group prepared above was changed in a 250 ml three-necked flask equipped with a reflux cooler, a nitrogen inlet, a thermometer, and a stirrer, and compared with the reactants. 0.6% of the catalyst was added and toluene was added 5 times of the reactant, followed by reacting for 72 hours under 70 ° C. and a nitrogen stream. After the reaction, toluene was removed by vacuum distillation by vacuum evaporation under reduced pressure to prepare branched poly (vinylmethyl-dimethyl) siloxane (BVPVMS).

1 is a schematic diagram showing a process of synthesizing branched polyorganosiloxane (BVPVMS) according to an embodiment of the present invention. Figure 2 shows the 1H-NMR spectrum and FT-IR spectrum of the synthesized BVPVMS. Synthesis was well confirmed by decreasing the H peak of vinyl (Si-CH = CH ₂ ) bound to siloxane at 5.6 ~ 6.2ppm and the H peak of H-PDMS near 4.7ppm decreased with reaction time before reaction. It was confirmed that it was progressed. In addition, vinyl (Si-CH = CH ₂₎ peak, 958cm at 1615-1590cm ^{-1 - 1} and 3056cm CH at ^{-1 (Si-CH = CH 2} ) peaks are synthesized to confirm the decrease and disappear as the reaction proceeds, This proved to be good.

Figure 3 is a graph showing the change in the amount of vinyl branched by synthesizing by varying the reaction temperature and time and the amount of catalyst in order to confirm the optimum synthesis conditions of BVPVMS. As shown in this graph, when 72 hours were reached regardless of the temperature conditions of 50 ° C, 60 ° C, and 70 ° C, all vinyls in the VPVMS reacted, and the reaction temperature was not significantly different. Although the reaction proceeded well at the amount of the catalyst at more than 0.6wt%, it was judged that 0.6 wt% was suitable considering the effect of the addition of too much catalyst on the physical properties of the product.

Figure 4 shows the percentage of H-PDMS H peak (4.7 ppm) size decreased with the reaction time from the 1H-NMR spectrum of BVPVMS reacted with the H ratio of H-PDMS to 2 ~ 100% relative to the vinyl group present in VPVMS It is a graph showing. As shown in this graph, regardless of the molecular weight of the VPVMS used, the H peak of the applied H-PDMS disappeared completely, that is, it was found that it took 72 hours for the H-PDMS to react with the vinyl of the VPVMS. In addition, as the amount of H-PDMS added according to the reaction vinyl of VPVMS increased, the reaction of VPVMS occurred quickly. From these results, when VPVMS and H-PDMS were reacted for 72 hours, the number of vinyl groups present in BVPVMS capable of photocrosslinking with the acrylic lake coating agent was controlled by the amount of H-PDMS added, and the number of PDMS bound to branches at the same time. And BVPVMS molecular weight can be controlled together.

5 is a graph showing the results of measurement of the synthesized BVPVMS molecular weight and yield measured by GPC. As shown in this graph, as the amount of H-PDMS reacted increased, that is, the more H-PDMS added reacted with the VPVMS vinyl group, the more branches produced in the VPVMS main chain, resulting in higher molecular weight. It can be seen that the yield is also increased by the increase of. On the other hand, as the VPVMS molecular weight used in the hydrosilylation reaction increased, yield of BVPVMS was lowered.

Example 2: Preparation of Hard Coating Compositions Comprising Branched Polyorganosiloxanes

The coating solution was prepared by adding VPVMS and BVPVMS prepared in Example 1 to M600 (Dipentaerythritol Hexaacrylate) of US yarn. M600 1.876g, VPVMS (BVPVMS) 0.1g (5wt% of total coating solution), BYK-UV3570 0.004g (0.2wt% of total coating solution), Irgacure 184 0.02g (1wt% of total coating solution) and solid state In order to control the dispersion of the phosphorescent photoinitiator and the thickness of the coating film, MEK 2g was added and mixed to prepare a coating solution.

Example 3: Preparation of Hard Coating Film by UV Irradiation

The coating solution prepared in Example 2 was applied onto a PET film (100 μm thick film of SKC) and coated with a thickness of 20 μm using a wire bar (# 9). After drying for 1 minute in a reflux dryer at 80 ℃ to remove solvent (MEK) (coating thickness 10μm), using a UV Curing System of Jinyong company, UV light source has a constant intensity of 383mW / cm2 of 2 levels, belt speed is 3m / It set to min and hardened.

6 wt% of BVPVMS synthesized in FIG. 6 was added to the acrylate coating solution to prepare a hard coating solution, which was then coated on a PET film at a constant thickness, and the surface hardness was obtained by obtaining a coating film by UV curing. The surface coated with acrylate (M600) alone without the addition of siloxane compound showed 1H surface hardness, whereas the addition of vinyl-containing VPVMS increased the surface hardness to 2H regardless of the molecular weight of VPVMS. It can be seen that the surface hardness increases to 3H due to the increase in surface hardness due to the branch formed when the number of branches is larger than 20% of the total vinyl groups of VPVMS.

7 is a graph showing the results of measuring the contact angle of the coating film added BVPVMS. Contact angle measurement was measured using a contact angle measuring device (Phoenix 300) of Surface Electro Optics. A drop of distilled water was dropped on the surface of the coating film using a contact angle meter and the contact angle was measured through a camera. As shown in this graph, the contact angle of the acrylate coating film was about 71 degrees, and when BVPVMS was added, the contact angle was confirmed to increase to 95 degrees.

Table 1 shows the results of measuring the flexibility of the coating film having a thickness of 8 μm and 16 μm. As can be seen from the result, the acrylate coating liquid has a disadvantage in that the flexibility is not good. To compensate for this drawback, BVPVMS was added to show the flexibility of silicon. Cracks did not appear on all coating surfaces when measured by winding on rods with a diameter of 8 mm. On the other hand, when the coating film with a thickness of 8 μm was measured by winding a 5 mm rod, cracks were generated only on the surface coated with nothing, and cracks did not occur on the surface coated with BVPVMS. In addition, when the coating film having a thickness of 16 μm was measured by winding a 5 mm rod, cracks did not occur as the molecular weight and the amount of the added siloxane increased. As a result, the flexibility was increased due to the influence of siloxane bond and eggplant of BVPVMS used as an additive.

Claims (15)

A UV curable hard coating composition comprising a branched polyorganosiloxane, an acrylate monomer, a photoinitiator, and a solvent, wherein the branched polyorganosiloxane has a poly (vinylmethyl-dimethyl) having a vinyl end group represented by the following [Formula 1]: UV-curable hard coating composition characterized in that it is prepared by hydrosilylation reaction of siloxane and polydimethylsiloxane having a monohydride end group represented by the following [Formula 2]:
[Formula 1]

[Formula 2]

Where
m is an integer of 0-520, n is an integer of 5-166, p is an integer of 11-13. The method of claim 1,
The hydrosilylation reaction is UV curable hard coating composition, characterized in that carried out under one or more catalysts selected from the group consisting of Pt, Pd, Rh. The method of claim 2,
UV-curable hard coating composition, characterized in that the catalyst is Pt. The method of claim 3,
The content of the Pt catalyst is UV curable hard coating composition, characterized in that 0.6 to 2.0% by weight. The method of claim 1,
The hydrosilylation reaction is UV curable hard coating composition, characterized in that carried out for 12 to 72 hours in a temperature range of 50 to 70 ℃. delete The method of claim 1,
UV-curable hard coating composition, characterized in that the weight average molecular weight of the branched polyorganosiloxane is 7,000 to 180,000. delete The method of claim 1,
An ultraviolet curable hard coating composition comprising 2.5 to 20% by weight of branched polyorganosiloxane, 30 to 70% by weight of acrylate monomer, 0.5 to 2.0% by weight of photoinitiator, and a residual amount of solvent. The method of claim 1,
The acrylate monomer is methyl methacrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate. At least one selected from the group consisting of acrylate, methyl acrylate, ethyl acrylate, 2-hydroxyethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate and benzyl acrylate UV curable hard coating composition, characterized in that. The method of claim 1,
The photoinitiator is benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylmethane-1-1one, Anisolemethyl ether, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenyl ketone, α-hydroxyketone, 4-phenoxydichloroacetone, 4 -t-butyldichloroacetophenone, 2-methyl-2-hydroxypropiophenone, 1- [4- (2-hydroxyethyl) phenyl] -2-hydroxy-2-methylpropan-1-one, 1 -Phenyl-1,1-propanedione-2- (o-ethoxycarbonyl) -oxime, benzoin, benzyl, benzophenone, benzoylbenzoic acid, 3,3'-methyl-4-methoxybenzophenone, polyvinyl Benzophenone, α-hydroxycyclohexylbenzophenone, benzyl methyl ketal, thioxanthone, 2-chloro thioxanthone, 2-methyl thioxanthone, 2,4-dimethyl thioxanthone, isopropyl thioxanthone, 2 , 4-dichlorothioxanthone, 2,4-diethyl tea UV-curable hard coating composition, characterized in that at least one selected from the group consisting of oxaanthone, 2,4-diisopropyl thioxanthone and dodecyl thioxanthone. The hard coating film of claim 1, wherein the hard coating composition is formed by UV curing. The method of claim 12,
The surface hardness of the coating film is a hard coating film, characterized in that 1H to 3H in pencil hardness. The method of claim 12,
Hard coating film, characterized in that the contact angle of the coating film is 71 to 95 °. The method of claim 12,
Hard coating film, characterized in that applied to the hard coating film for flexible display.

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