KR101967147B1 - Composition For Hard Coating and Hard Coating film Including Cured Product Of The Same As The Coating Layer - Google Patents

Abstract

The present invention relates to an epoxy resin composition comprising an alicyclic epoxy group in a molecular structure, An alkoxysilane having a Q structure of silane; And a siloxane resin chemically bonded by a compound including an alkoxy metal compound, and a hard coat film comprising the cured product thereof as a coating layer.

Description

[0001] The present invention relates to a hard coating film comprising a resin composition for hard coating and a cured product of the resin composition as a coating layer (Composition For Hard Coating and Hard Coating Film Including Cured Product of The Same As The Coating Layer)

The present invention relates to a hard coating film comprising a resin composition for hard coating and a cured product thereof as a coating layer.

In general, glass has been used extensively as a material for important commercial products including optical functional products such as windows for various electronic products, touch screens for computers, lenses, automobile sunroofs, optical screens, light guide plates and LED front plates. However, glass is heavy, fragile, and has a defect rate which is considerably high at the time of processing a product. Therefore, there is a wide variety of materials that can overcome the drawbacks of glass.

Under such circumstances, the transparent polymer film has been widely used as a core material in the optical and transparent display industry, and is emerging as a substitute for glass in the display industry due to its light weight and ease of processing. However, since the polymer film has a lower surface hardness than that of the glass and thus has a disadvantage that the abrasion resistance is insufficient, a hard coating technique for improving the surface hardness of the polymer film, that is, hard coating technology is considered as an important issue.

The materials used for the hard coating are largely classified into organic, inorganic, and inorganic composite materials. Organic materials have the advantages of flexibility and moldability due to the nature of the organic material, but they have a disadvantage of low surface hardness. And transparency, but it has disadvantages such as poor flexibility and moldability. As a result, organic and inorganic composite materials that have both advantages of both materials are currently in the limelight, and various studies are under way, but the merits of both materials are not yet fully realized.

Usually, a coating agent used for hard coating is a light or thermosetting coating agent. Photocurable coatings can be cured in a shorter time than thermosetting coatings and can be cured at room temperature, thus being used as a surface protective coating for various plastic products. In order for such a coating to be usefully used for optical applications, it is required to have good adhesion to a film in addition to hardness and to be free from curl phenomenon and rainbow phenomenon. In particular, the curl phenomenon can be a serious disadvantage in the roll-to-roll process, which is a mass production process, and is a particularly demanded property because it may cause problems in future durability even when it is provided as a product.

As a conventional technique in which a light or heat curable coating agent is applied to an optical product, Korean Patent Laid-Open Publication No. 2010-0041992 provides a hard hard coating film composition comprising an ultraviolet curable polyurethane acrylate oligomer. It is significant that the patent minimizes the curling phenomenon and solves the rainbow phenomenon due to optical interference, but it can not overcome the limit of low surface hardness as a hard coating film.

In addition, International Publication No. WO2013-187699 discloses a high hardness siloxane resin composition containing an alicyclic epoxy group, a process for producing the same, and an optical film containing the cured product. The above-mentioned prior art has achieved a high hardness of 9 H, but the use of a single monomer and the weatherability due to the use of a cationic initiator may be a problem, and a problem may arise due to the curling phenomenon.

As described above, when the surface hardness of the hard coat layer is improved by forming a dense network between the molecules, there arises a problem that curling and cracking occur due to increased shrinkability, and when the curl and crack are eliminated, the surface hardness limit can not be overcome do. Therefore, the development of a high-hardness coating material having no curl and easy processing is also an urgent necessity for wider use of the polymer film.

Accordingly, the present invention provides a resin composition for hard coating comprising an alkoxysilane containing an alicyclic epoxy, an alkoxysilane including a Q structure of silane such as TEOS (tetraethyl orthosilicate), and a siloxane resin in which an alkoxy metal compound is chemically bonded And a cured product of the resin composition as a coating layer to provide a hard coating film excellent in hardness, adhesion and abrasion resistance.

A first preferred embodiment of the present invention for solving the above problems is an alkoxysilane represented by the following general formula (1); An alkoxysilane represented by the following formula (2); And a siloxane resin chemically bonded by a compound including an alkoxy metal compound represented by the following formula (3).

???????? R ¹ _n Si (OR ² ) _{4 -n} ????? (1)

<Formula 2> Si (OR ³⁾ _m

<Formula 3> M (OR ⁴⁾ _x

However, in the above Chemical Formulas 1 to 3 R ¹ is a C1 to C3 comprising an alicyclic epoxy group M is a metal element selected from aluminum, titanium and zinc, n is an integer of 1 to 3, m is 4, x is a linear alkylene group, R ² to R ⁴ are C1 to C4 linear or branched alkyl groups, Is an integer of 2 to 4.

The present invention also relates to a base film; And a hard coating film formed on at least one side of the base film and including a cured product of the resin composition for hard coating of the first embodiment as a hard coating layer.

According to the present invention, by introducing an alkoxysilane having an Q structure of silane and an alkoxy metal compound together into an alkoxysilane having an alicyclic epoxy group, a hard coating resin composition capable of improving surface hardness and minimizing curling can be provided can do. Particularly, the resin composition for hard coating of the present invention includes a Q structure of silane, whereby the crosslinking during the polymerization reaction of the alicyclic organic material can be densely carried out to secure an excellent surface hardness, and securing an intermolecular space by an alkoxy metal compound Since the curling phenomenon is minimized during curing, it can be formed as a cured product on the surface of the film to provide a hard coat film of excellent performance.

The present invention relates to an alkoxysilane represented by the following general formula (1); An alkoxysilane represented by the following formula (2); And a siloxane resin chemically bonded by a compound including an alkoxy metal compound represented by the following formula (3).

???????? R ¹ _n Si (OR ² ) _{4 -n} ????? (1)

<Formula 2> Si (OR ³⁾ _m

<Formula 3> M (OR ⁴⁾ _x

However, in the above Chemical Formulas 1 to 3 R ¹ is a C1 to C3 comprising an alicyclic epoxy group M is a metal element selected from aluminum, titanium and zinc, n is an integer of 1 to 3, m is 4, x is a linear alkylene group, R ² to R ⁴ are C1 to C4 linear or branched alkyl groups, Is an integer of 2 to 4.

More specifically, the alicyclic epoxy group contained in R ¹ of Formula 1 preferably has an alicyclic structure composed of C3 to C8 alicyclic alkyl groups. However, in the case of the C3 to C5 alicyclic structure, the curling phenomenon may occur due to the decrease in the intermolecular spacing, and in the case of alicyclic C7 to C8, the epoxy curing reaction may be delayed and the C6 alicyclic epoxy group But the present invention is not necessarily limited thereto.

In the present invention, the epoxy-based monomer represented by the above formula (1) has a low curing shrinkage ratio, which is very significant from the standpoint of suppressing curling and ensuring excellent surface hardness. If the formula (1) is an acrylic monomer, it can exhibit a fast curing rate and a high hardness, but the contraction ratio is high and the curling probability can be increased. When the monomer of formula (1) is an isocyanate-based monomer, the flexibility is high due to its high modulus of elasticity, and thus the curling probability is low, but it can exhibit low surface hardness.

On the other hand, according to the present invention, the compound of formula (1) is an epoxy-based monomer, which has a high surface hardness relative to an isocyanate group and a curing shrinkage ratio lower than that of an acrylic group. In particular, since the compound of formula (1) of the present invention is an alicyclic epoxy-based monomer, securing the intermolecular space when cured is more advantageous than the linear epoxy-based monomer, the resin composition for hard coating of the present invention suppresses hardening shrinkage, .

As a result, the siloxane resin of the present invention can densely cross-link siloxane molecules having various molecular weights during photopolymerization or thermal polymerization, and as a result, it is possible to provide a hard-coated cured product having high hardness.

In the present invention, the alkoxysilane represented by the general formula (1) is preferably selected from the group consisting of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane and 2- , 4-epoxycyclohexyl) ethyltripropoxysilane may be more preferable.

The alkoxysilane represented by the general formula (2) includes a chemical bonding structure such as the silane Q structure, that is, the siloxane structure in which Si does not have an alkoxy functional group, in the molecular structure, thereby securing an excellent hardness.

<Structure 1>

That is, when the Q structure found in the molecular structure of the glass is included in the molecular structure, the resin composition of the present invention can achieve hardness similar to that of glass upon curing.

In the present invention, the alkoxysilane represented by Formula 1 and the alkoxysilane represented by Formula 2 are preferably in a molar ratio of 99: 1 to 20:80, more preferably 85:15 to 45:55 It is easy to prevent gelation during polymerization while maintaining high hardness. If the compound of the formula (1) is used alone, physical properties of a pencil hardness of 4H or more are difficult to be realized. If the compound of the formula (2) is present in the above range, gelation may occur during polymerization and polymerization control becomes difficult.

However, when a siloxane resin is prepared using only the compound of formula (1) and the compound of formula (2), curling due to curing shrinkage upon curing can inevitably be followed. Accordingly, it is preferable that the siloxane resin of the present invention further comprises an alkoxy metal compound represented by Chemical Formula 3 to form a chemical bond. The alkoxy metal compound is chemically bonded to the alkoxysilane, and by including the metal element in the molecular structure, the intermolecular space can be further secured, thereby minimizing the curing shrinkage and drastically reducing curling.

In the present invention, it is preferable that the alkoxy metal compound represented by the formula (3) is contained in an amount of 0.1 to 5.0 mol% based on 100 mol% of the total of the alkoxysilane represented by the formula (1) and the alkoxysilane represented by the formula (2). If the amount of the alkoxy metal compound is less than the above range, the curl suppressing effect may be insignificant. If the reaction temperature is lowered or the polymerization is stopped within a short time, addition of up to 5.0 mol% metal compound is possible. However, when it is contained in an amount exceeding 5.0 mol%, the gelation rapidly proceeds, and the viscosity of the resin is likely to rise at a high rate, and the processability may be significantly lowered due to the strong solvent resistance, May not be large. It is more preferable that the alkoxy metal compound is contained in an amount of 0.2 mol% to 3.0 mol%.

In the present invention, the siloxane resin forming reaction is carried out by hydrolysis and condensation between the compounds of formulas 1, 2 and 3 and may proceed at room temperature. However, in order to accelerate the reaction, Lt; / RTI &gt; As a catalyst for carrying out the hydrolysis and condensation reaction during the reaction, an acid catalyst such as hydrochloric acid, acetic acid, hydrogen fluoride, nitric acid, and sulfuric acid iodic acid, a base such as ammonia, potassium hydroxide, sodium hydroxide, barium hydroxide, imidazole A catalyst, and an amberite may be used. These catalysts may be used alone or in combination. The amount of the catalyst is not particularly limited, but 0.0001 to about 10 parts by weight based on 100 parts by weight of the siloxane resin may be added.

When the hydrolysis and condensation reaction proceeds, alcohol as a by-product is produced. By eliminating it, the reverse reaction can be reduced and the reaction can proceed more quickly, and the reaction rate can be controlled through the reaction. Since the siloxane resin synthesized by the condensation reaction secures an intermolecular space at the time of crosslinking, curling due to curing shrinkage can be prevented and dense crosslinking by the Q structure of the silane can be performed, so that a high surface hardness can be realized .

The siloxane resin thus produced preferably has a weight average molecular weight of 3,000 to 50,000 and a polydispersion index (PDI) of 1.5 to 7.0. The weight average molecular weight (Mw) and the number average molecular weight (Mn) of polystyrene were determined by gel permeation chromatography (GPC) (model name e2695, manufactured by Waters Co.) Value. More specifically, 20 μl of the solution was dissolved in tetrahydrofuran so as to have a concentration of 1% of the polymer to be measured, and the solution was introduced at a flow rate of 1.0 mL / min and analyzed at 30 ° C. In addition, two columns of Waters Styragel HR3 were connected in series, and the detector was measured at 40 占 폚 using an RI detector (Waters, 2414).

The resin composition for hard coating of the present invention may further contain an initiator for the polymerization of the siloxane resin in addition to the siloxane resin. Examples of the initiator include a photopolymerization initiator such as an organic metal salt, a thermal polymerization initiator such as amine and imidazole An initiator, or a cationic polymerization agent can be used. However, the amount of the initiator to be added is preferably about 0.5 to 5 parts by weight based on 100 parts by weight of the resin composition. When the content of the hard coat layer is less than 0.5 parts by weight, hardening time of the hard coat layer to obtain sufficient hardness is increased to decrease the efficiency. When the amount of the hard coat layer exceeds 5 parts by weight, the yellow coatability of the hard coat layer is increased, have.

In addition, the resin composition for hard coating of the present invention may further contain an antioxidant or a leveling agent for suppressing an oxidation reaction due to a polymerization reaction, and may further include a surfactant can do. In particular, an organic solvent may be further added to control the viscosity of the siloxane resin to facilitate workability and to control the thickness of the coating film.

The amount of the organic solvent to be added is not particularly limited and examples of usable organic solvents include ketones such as acetone, methyl ethyl ketone, methyl butyl ketone, and cyclohexanone, and cellosolves such as methyl cellosolve and butyl cellosolve. , Or ethers such as ethyl ether and dioxane, alcohols such as isobutyl alcohol, isopropyl alcohol, butanol and methanol, halogenated hydrocarbons such as dichloromethane, chloroform and trichlorethylene, and n-hexane, benzene, toluene and the like And a solvent composed of hydrocarbons and the like.

Further, the present invention relates to a base film; And a coating layer laminated on at least one surface of the base film and cured to harden the resin composition for hard coating. The hard coating film according to the present invention can be used for a hard coating film having hardness, adhesiveness, abrasion resistance, etc. Physical properties are excellent, and phenomena such as curling which occurs during manufacturing and heating treatment, cracking due to bending during processing and peeling and the like can be prevented.

More specifically, the hard coating film of the present invention can exhibit surface hardness of 5H to 9H according to the ASTM D3363 measurement standard in the direction in which the coating layer is formed, and is allowed to stand for 24 hours under conditions of 25 ° C and 50% The curl value at which the edges of the film are spaced apart from the horizontal bottom may be 30 mm, which is particularly suitable for use as a display protective film.

In the present invention, it is possible to further perform a process of making the surface uniform by a separate heat treatment before photopolymerization or thermal polymerization curing. Such additional heat treatment can further improve the hardness of the hard coating layer. In this case, in the case of photopolymerization, the heat treatment may be performed at a temperature of 40 ° C or more and about 200 ° C or less for 2 minutes to 60 minutes depending on the substrate, and in the case of thermal polymerization, But it is not limited thereto. Further, since the photo-polymerization heat treatment is 50mJ / cm ² or more 20,000mJ / cm ² or less, more preferably 200mJ / cm ² more than 5,000mJ / cm ² It may be advantageous in terms of ensuring sufficient hardness and further suppressing yellowing.

Examples of the method of applying the hard coating resin composition to a substrate include spraying, dip coating, spin coating, die coating, comma coating, screen coating, inkjet printing, pad printing, knife coating, kiss coating, bar coating and gravure coating The thickness of the hard coating layer formed of the hard coating resin composition can be easily controlled according to the kind of the base material and the application. In the present invention, it is 2 to 60 탆, preferably 10 to 30 탆 It is possible to secure both the hardness and the bendability of the hard coating film at a thickness of 占 퐉.

Although not limited thereto, in the present invention, the base film may be a polyethylene sulfonate (PES) film, a polyethylene terephthalate (PET) film, a polycarbonate (PC) film, a polymethylmethacrylate (PMMA) film, , Manufactured by BF Goodrich Co., USA) and a polyimide (PI) film may be laminated alone or in combination of two or more thereof.

In addition, the resin composition for hard coating of the present invention may be applied to inorganic substrates such as glass, quartz, glass wafers, and silicon wafers to form hard coating layers, depending on the purpose.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are for the purpose of illustrating the present invention more specifically, and the present invention is not limited thereto. The reason why only the TEOS is used in the alkoxysilane represented by the formula (2) in this embodiment and the comparative example is that TEOS is cheap and easy to obtain, and even if other alkoxy groups are used, the Q structure is obtained in the molecular structure of the polymerization product Do.

Example 1.

The mixture of KBM-303 (Shinetsu), TEOS (Sigma-Aldrich) and H ₂ O was mixed in a ratio of 365.87 g: 2.50 g: 40.66 mL and put into a 500 mL flask. Then, 0.06 g of sodium hydroxide was added as a catalyst, (Sigma-Aldrich), and the mixture was stirred at 60 ° C for 10 hours. Thereafter, the solution was filtered using a 0.45-μm Teflon filter to obtain a siloxane resin (weight average molecular weight: 5000, polydispersity index: 2.0). Next, 3 parts by weight of IRGACURE 250 (BASF) as a photoinitiator was added to 100 parts by weight of the siloxane resin to obtain a resin composition for hard coating.

Example 2.

The mixture was mixed with KBM-303 (Shinetsu), TEOS (Sigma-Aldrich) and H ₂ O at a ratio of 332.61 g: 29.69 g: 41.87 mL, put into a 500 mL flask, 0.06 g of sodium hydroxide was added as a catalyst, (Sigma-Aldrich), and the mixture was stirred at 60 ° C for 10 hours. Thereafter, the solution was filtered using a 0.45-μm Teflon filter to obtain a siloxane resin (weight average molecular weight 10,000, polydispersity index 2.2). Next, 3 parts by weight of IRGACURE 250 (BASF) as a photoinitiator was added to 100 parts by weight of the siloxane resin to obtain a resin composition for hard coating.

Example 3.

The mixture was mixed with KBM-303 (Shinetsu), TEOS (Sigma-Aldrich) and H ₂ O at a ratio of 295.66 g: 59.37 g: 43.22 mL and put into a 500 mL flask. Then, 0.06 g of sodium hydroxide was added as a catalyst, (Sigma-Aldrich), and the mixture was stirred at 60 ° C for 10 hours. Thereafter, the solution was filtered using a 0.45-μm Teflon filter to obtain a siloxane resin (weight average molecular weight 15,000, polydispersity index 3.0). Next, 3 parts by weight of IRGACURE 250 (BASF) as a photoinitiator was added to 100 parts by weight of the siloxane resin to obtain a resin composition for hard coating.

Example 4.

A mixture of KBM-303 (Shinetsu), TEOS (Sigma-Aldrich), and H ₂ O was mixed at a ratio of 184.79 g: 146.87 g: 47.28 mL and placed in a 500 mL flask. Then, 0.06 g of sodium hydroxide was added as a catalyst, (Sigma-Aldrich), and the mixture was stirred at 60 ° C for 10 hours. Thereafter, the solution was filtered using a 0.45-μm Teflon filter to obtain a siloxane resin (weight average molecular weight: 37,000, polydispersity index: 4.3). Next, 3 parts by weight of IRGACURE 250 (BASF) as a photoinitiator was added to 100 parts by weight of the siloxane resin to obtain a resin composition for hard coating.

Example 5.

The mixture was mixed with KBM-303 (Shinetsu), TEOS (Sigma-Aldrich) and H ₂ O at a ratio of 73.91 g: 234.37 g: 51.33 mL, and the mixture was added to a 500 mL flask. Then, 0.06 g of sodium hydroxide was added as a catalyst, (Sigma-Aldrich), and the mixture was stirred at 60 ° C for 10 hours. Thereafter, the solution was filtered using a 0.45-μm Teflon filter to obtain a siloxane resin (weight average molecular weight: 50000, polydispersity index: 6.2). Next, 3 parts by weight of IRGACURE 250 (BASF) as a photoinitiator was added to 100 parts by weight of the siloxane resin to obtain a resin composition for hard coating.

Example 6.

The mixture was mixed with KBM-303 (Shinetsu), TEOS (Sigma-Aldrich) and H ₂ O at a ratio of 73.91 g: 234.37 g: 51.33 mL and put into a 500 mL flask. Then, 0.06 g of sodium hydroxide was added as a catalyst, (Sigma-Aldrich), and stirred at 60 ° C for 3 hours to prevent gelation, siloxane resin (weight average molecular weight 3500, polydispersity index 1.8) was easily obtained without gelation. Thereafter, the resultant was filtered using a 0.45-μm Teflon filter to obtain a siloxane resin. Next, 3 parts by weight of IRGACURE 250 (BASF) as a photoinitiator was added to 100 parts by weight of the siloxane resin to obtain a resin composition for hard coating.

Example 7.

The mixture of KBM-303 (Shinetsu), TEOS (Sigma-Aldrich) and H ₂ O was mixed at a ratio of 295.66 g: 53.12 g: 43.22 mL, placed in a 500 mL flask, 0.06 g of sodium hydroxide was added as a catalyst, (Sigma-Aldrich), and the mixture was stirred at 60 ° C for 10 hours. Thereafter, the solution was filtered using a 0.45-μm Teflon filter to obtain a siloxane resin (weight average molecular weight: 28,000, polydispersity index: 3.2). Next, 3 parts by weight of IRGACURE 250 (BASF) as a photoinitiator was added to 100 parts by weight of the siloxane resin to obtain a resin composition for hard coating.

Example 8.

KBN-303 (Shinetsu), TEOS (Sigma-Aldrich), and H ₂ O were mixed at a ratio of 295.66 g: 601.87 g: 43.22 mL, placed in a 500 mL flask, 0.06 g of sodium hydroxide was added as a catalyst, (Sigma-Aldrich), and the mixture was stirred at 60 ° C for 10 hours. Thereafter, the solution was filtered using a 0.45-μm Teflon filter to obtain a siloxane resin (weight average molecular weight: 24,000, polydispersity index: 2.8). Next, 3 parts by weight of IRGACURE 250 (BASF) as a photoinitiator was added to 100 parts by weight of the siloxane resin to obtain a resin composition for hard coating.

Example 9.

The mixture was mixed with KBM-303 (Shinetsu), TEOS (Sigma-Aldrich) and H ₂ O at a ratio of 184.79 g: 146.87 g: 48.54 mL, placed in a 500 mL flask, 0.06 g of sodium hydroxide was added as a catalyst, (Sigma-Aldrich). When stirring was carried out at 60 ° C for 10 hours, the mixture became difficult to control and the stirring time was shortened to 5 hours. Thereafter, the solution was filtered using a 0.45-μm Teflon filter to obtain a siloxane resin (weight average molecular weight 30000, polydispersity index 5.2). Next, 3 parts by weight of IRGACURE 250 (BASF) as a photoinitiator was added to 100 parts by weight of the siloxane resin to obtain a resin composition for hard coating.

Example 10.

The mixture of KBM-303 (Shinetsu), TEOS (Sigma-Aldrich) and H ₂ O in the ratio of 258.70 g: 90.62 g: 44.57 mL was added to a 500 mL flask, and 0.06 g of sodium hydroxide was added as a catalyst. Titanium isopropoxide (Sigma-Aldrich), and the mixture was stirred at 60 ° C for 10 hours. Thereafter, the solution was filtered using a 0.45-μm Teflon filter to obtain a siloxane resin (weight average molecular weight: 18,000, polydispersity index: 3.9). Next, 3 parts by weight of IRGACURE 250 (BASF) as a photoinitiator was added to 100 parts by weight of the siloxane resin to obtain a resin composition for hard coating.

Comparative Example 1

The mixture was mixed with KBM-403 (Shinetsu), TEOS (Sigma-Aldrich) and H ₂ O (Sigma-Aldrich) at a ratio of 350.96 g: 2.50 g: 40.66 mL, put into a 500 mL flask, , 0.85 g of Titanium isopropoxide (Sigma-Aldrich) was added, and the mixture was stirred at 60 캜 for 10 hours. Thereafter, the solution was filtered using a 0.45-μm Teflon filter to obtain a siloxane resin (weight average molecular weight 4,000, polydispersity index 1.8). Next, to the obtained siloxane resin, 3 parts by weight of IRGACURE 250 (BASF), which is a photoinitiator, relative to 100 parts by weight of the siloxane resin was added to obtain a resin composition for hard coating.

Comparative Example 2

KBN-303 (Shinetsu), TEOS (Sigma-Aldrich), and H ₂ O were mixed at a ratio of 295.66 g: 60.94 g: 43.22 mL, placed in a 500 mL flask, 0.06 g of sodium hydroxide was added as a catalyst, Stir for 10 hours. Thereafter, the solution was filtered using a 0.45-μm Teflon filter to obtain a siloxane resin (weight average molecular weight: 21,000, polydispersity index: 2.3). Next, 3 parts by weight of IRGACURE 250 (BASF) as a photoinitiator was added to 100 parts by weight of the siloxane resin to obtain a resin composition for hard coating.

Comparative Example 3

The mixture of KBM-303 (Shinetsu), Titanium isopropoxide (Sigma-Aldrich) and H ₂ O was mixed in a ratio of 365.87 g: 4.26 g: 40.66 mL, and put into a 500 mL flask. Then, 0.06 g of sodium hydroxide was added as a catalyst, Lt; 0 &gt; C for 10 hours. Thereafter, the solution was filtered using a 0.45-μm Teflon filter to obtain a siloxane resin (weight average molecular weight: 5000, polydispersity index: 2.6). Next, 3 parts by weight of IRGACURE 250 (BASF) as a photoinitiator was added to 100 parts by weight of the siloxane resin to obtain a resin composition for hard coating.

Comparative Example 4

KBM-303 (Shinetsu), TEOS (Sigma-Aldrich), and H ₂ O were mixed in a ratio of 36.96 g: 281.25 g: 52.68 mL, placed in a 500 mL flask and reacted with 0.06 g of sodium hydroxide as a catalyst, When stirring was carried out at 60 ° C for 10 hours, gelation became difficult and the reaction time was shortened to 5 hours by stirring. Thereafter, the solution was filtered using a 0.45-μm Teflon filter to obtain a siloxane resin (weight average molecular weight: 48,000, polydispersity index: 6.8). Next, 3 parts by weight of IRGACURE 250 (BASF) as a photoinitiator was added to 100 parts by weight of the siloxane resin to obtain a resin composition for hard coating.

<Measurement example>

The resin compositions for hard coatings of Examples 1 and 2 and Comparative Examples 1 to 10 were laminated on one surface of a 75 μm thick polyethylene terephthalate film (manufacturer: Kolon, product name: HP34P) Dried in an oven at 80 ° C for 30 minutes, irradiated with 1,000 mJ / cm 2 at an illuminance of 80 mW / cm 2 in a direction in which the hard coating composition was applied with an ultraviolet irradiator, and then heat-treated in an oven at 85 ° C for 24 hours To prepare a hard coating film.

Then, the prepared hard coating film was subjected to physical property evaluation according to the following method. The results are shown in Table 1 below.

 (1) Surface hardness: The pencil hardness was measured at a rate of 180 mm / min under a load of 750 gf according to ASTM D3363 using a pencil hardness tester manufactured by IMOTO, Japan.

(2) Curl generation: The coated film was cut into 100 mm × 100 mm, left at 25 ° C. and 50% RH for 24 hours, and then placed on a plane, and the one side of each edge was measured as the maximum distance from the plane .

(3) Abrasion resistance: A film cut into 20 cm × 5 cm on a flat surface was fixed with an adhesive tape (3M) so that the coated surface was facing upward, and then the surface was reciprocated 1000 times at a load of 1 kgf and a speed of 15 RPM by a rod wound with # 0000 non- And whether or not scratches occurred is judged to be defective when scratches occur, and is judged to be good when scratches do not occur, and is reflected in Table 1 below.

Surface hardness Abrasion resistance Curl (mm) ^{1 )} 10um 20um 30um 10um 20um 30um 10um 20um 30um Example 1 6H 6H 7H Good Good Good 0 0 0 Example 2 6H 7H 7H Good Good Good 0 0 0 Example 3 6H 7H 8H Good Good Good 0 0 One Example 4 7H 8H 9H Good Good Good One 2 2 Example 5 8H 8H 9H Good Good Good 8 10 12 Example 6 8H 8H 9H Good Good Good 9 11 13 Example 7 6H 7H 8H Good Good Good 0 0 One Example 8 6H 7H 8H Good Good Good 0 0 One Example 9 7H 8H 9H Good Good Good 0 One One Example 10 7H 8H 8H Good Good Good 0 One One Comparative Example 1 2H 2H 3H NG NG NG 10 15 20 Comparative Example 2 6H 7H 8H Good Good Good 13 17 22 Comparative Example 3 3H 4H 5H NG NG NG 0 0 0 Comparative Example 4 8H 9H 9H Good Good Good 20 25 30

1) For curl ± 2 ~ 3mm error range

As can be seen from Table 1, Examples 3 to 10 showed excellent surface hardness and abrasion resistance as compared to Comparative Example 1 using alkoxysilane having a general epoxy group rather than alicyclic epoxy group. In particular, in Comparative Example 1, since alkoxysilane having an alicyclic epoxy group was not included in spite of the addition of an alkoxy metal, the curl characteristics as well as the surface hardness were not greatly improved. In Comparative Example 2, the surface hardness was improved by increasing the addition amount of TEOS, but it was also confirmed that the curl characteristic was not improved by the addition of the alkoxy metal. On the other hand, Examples 1 and 2 showed that the addition of alkoxy metal significantly improved the curl, though the addition of TEOS was small and the hardness was slightly lower than that of Comparative Example 2.

In Comparative Example 3, surface hardness and abrasion resistance were relatively low due to the absence of TEOS. In Comparative Example 4, surface hardness and abrasion resistance were sufficiently secured. However, the ratio of TEOS was too high, The metal compound was not added and the effect of improving the curl characteristic was not significant. On the contrary, in Examples 1 to 10, it was confirmed that the surface hardness, abrasion resistance and curl characteristics were improved in comparison with Comparative Examples 3 and 4 in all cases.

Therefore, it has been confirmed through experimentation that the hard coating film prepared using the hard coating resin composition of the present invention is excellent in hardness, abrasion resistance, and curling characteristics, and thus can be suitably used as a display protective film.

However, Examples 5 and 6, in which the content of TEOS is 75 mol% or more based on the total amount of alkoxysilane and the amount of titanium isopropoxide is 0.2 to 5.0 mol% based on the total amount of alkoxysilane, 4 and 7 to 10, there was no change in hardness and abrasion resistance, but the curl characteristic was slightly behind. Thus, in Examples 3, 7 and 8 in which the content of TEOS is from 17 mol% to 20 mol% based on the total amount of alkoxysilane and the alkoxy metal is contained from 0.2 mol% to 3 mol% relative to the total amount of alkoxysilane, It is more preferable that the content of TEOS is 29 mol% to 52 mol% based on the total amount of alkoxysilane and that the alkoxy metal is included in an amount of 1 mol% to 5.0 mol% based on the total amount of alkoxysilane Respectively.

Claims (8)

An alkoxysilane represented by the following formula (1);
An alkoxysilane represented by the following formula (2); And
A siloxane resin chemically bonded by compounds comprising an alkoxy metal compound represented by the following formula (3)
The alkoxysilane represented by Formula 1 and the alkoxysilane represented by Formula 2 have a molar ratio of 83:17 to 80:20,
Wherein the alkoxy metal compound represented by the general formula (3) is contained in an amount of 0.2 mol% to 3.1 mol% based on 100 mol of the total of the alkoxysilane represented by the general formula (1) and the alkoxysilane represented by the general formula :
???????? R ¹ _n Si (OR ² ) _4-n ?????
<Formula 2> Si (OR ³⁾ _m
<Formula 3> M (OR ⁴⁾ _x
Wherein R ¹ is a C1 to C3 linear alkylene group containing an alicyclic epoxy group, R ² to R ⁴ are C1 to C4 linear or branched alkyl groups, and M is selected from aluminum, titanium and zinc N is an integer of 1 to 3, m is 4, and x is an integer of 2 to 4.
delete delete The resin composition for hard coating according to claim 1, wherein the siloxane resin has a weight average molecular weight of 3,000 to 50,000 and a polydispersion index (PDI) of 1.5 to 7.0.
The hard coating resin composition according to claim 1, wherein the resin composition for hard coating further comprises at least one additive selected from the group consisting of an organic solvent, a photoinitiator, a thermal initiator, an antioxidant, a leveling agent, Composition.
A base film; And a hard coating film formed on at least one side of the base film, wherein the hard coating layer comprises a cured product of the resin composition of any one of claims 1, 4, and 5 as a hard coating layer.
The hard coating film according to claim 6, wherein the hard coating film has a surface hardness of 5H to 9H in a direction in which a coating layer is formed according to ASTM D3363 measurement standard
The hard coating film according to claim 6, wherein the hard coating film is cut into 100 mm X 100 mm and left for 24 hours under conditions of 25 ° C and 50% RH, and then the maximum value of the distance of one side of each edge from the plane when placed on a plane is 30 mm By weight or less.