KR20140024562A - Hard coating composition and hard coating film using the same - Google Patents

Abstract

The present invention relates to a hard coating composition and a hard coating film using the same and, more specifically, to a hard coating composition and a hard coating film of which hardness, adhesion, bending resistance, and wear resistance are improved by using a urethane acrylate oligomer containing polycarbonate diol as a main component of the hard coating composition.

Description

Hard coating composition and hard coating film using the same {Hard Coating Composition and Hard Coating Film Using the Same}

The present invention relates to a hard coating composition and a hard coating film using the same, and more particularly, to a hard coating composition for producing a hard coating film for display protection and a hard coating film for display protection manufactured using the hard coating composition. will be.

In general, 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 have been widely used as glass in the past, but they are heavy and fragile And there was a disadvantage that the defective rate was considerably high when processing the product.

To replace this, thermoplastic and thermosetting polymers are used, which have been used to form various structures characterized by high hardness and high light transmittance.

However, since many thermosetting and thermoplastic polymers as described above are excellent in stiffness, dimensional stability, transparency, and impact resistance, structures made from the above polymers are less prone to scratches, abrasion, hardness And the like.

Therefore, in order to protect the resin products from physical or mechanical damage, it was used by using a tempered glass or by coating a wear-resistant hard coat layer on the plastic surface. Although excellent in scratch resistance, discoloration, cracking, low mechanical strength (impact strength, tensile strength and elongation), and various disadvantages such as fragile after coating, it has caused various defects in product processing.

The main object of the present invention is to provide a hard coating composition for improving the hardness, adhesion, flex resistance and wear resistance of the hard coating layer formed of the hard coating composition as a hard coating composition for various display protection.

The present invention also provides a hard coat film having improved hardness, adhesion, flex resistance, and wear resistance using the hard coat composition.

In order to achieve the above object, the present invention includes a urethane acrylate oligomer, a photocurable material and a photopolymerization initiator, the urethane acrylate oligomer provides a hard coating composition characterized in that it contains a polycarbonate diol. .

In the present invention, the urethane acrylate oligomer containing the polycarbonate diol may be a hard coating composition, characterized in that the weight average molecular weight of 6,000 ~ 10,000g / mol.

In the present invention, with respect to 100 parts by weight of the urethane acrylate oligomer, it may be a hard coating composition comprising 20 to 60 parts by weight of the photocurable material and 3 to 10 parts by weight of the photopolymerization initiator.

In the present invention, the urethane acrylate oligomer may be a hard coating composition, characterized in that it is contained in 2 to 6 mol% polycarbonate diol.

The present invention also provides a hard coat film formed by applying the hard coat composition on one or both sides of the substrate.

When the hard coating composition according to the present invention is coated and used on the surface of the plastic substrate, it is a photo-curable, environmentally friendly, excellent transparency, no warpage, it is possible to obtain a coating layer excellent in both scratch resistance and strength. The hard coating film manufactured using the hard coating composition can prevent breakage, which is a disadvantage of the tempered glass, and can be applied in various ways to the product which used the existing tempered glass because it can achieve a light weight of the product.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In general, the nomenclature used herein is well known and commonly used in the art.

Throughout this specification, when an element is referred to as "including " an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise.

In one aspect, the present invention relates to a hard coating composition comprising a urethane acrylate oligomer, a photocurable material and a photopolymerization initiator, wherein the urethane acrylate oligomer contains polycarbonate diols.

Hereinafter, the present invention will be described in more detail.

The hard coating composition according to the present invention is a composition for forming a hard coating layer of a hard coating film for various display protection, and includes a urethane acrylate oligomer, a photocurable material and a photopolymerization initiator, the urethane acrylate oligomer is a polycarbonate diol By containing it, the hardness, adhesiveness, bending resistance, and abrasion resistance of a hard coat layer can be improved.

The hard coating composition according to the present invention preferably includes 20 to 60 parts by weight of the photocurable material and 3 to 10 parts by weight of the photopolymerization initiator with respect to 100 parts by weight of the urethane acrylate oligomer in consideration of forming the hard coating layer. If, based on 100 parts by weight of the urethane acrylate oligomer, when the photocurable material is included in less than 20 parts by weight, it is not possible to obtain a hardness suitable for the hard coating layer, and if it exceeds 60 parts by weight, the hardness is high, but the mixing of the raw material There is a problem of poor sex. If the photopolymerization initiator is contained in an amount of less than 3 parts by weight based on 100 parts by weight of the urethane acrylate oligomer, photo-curing may not be properly performed and a blocking phenomenon may occur. When the amount exceeds 10 parts by weight, There may arise a problem that an initiator is precipitated on the surface when left standing for a long time by the initiator.

Meanwhile, the photocurable material is dipentaerythritol pentaacrylate, trihydroxyethyl isocyanurate triacrylate, isocyanurate di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerytate Lithitol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl Isocyanurate, propionic acid modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate and caprolactone modified dipentaerythritol hexa (meth) acrylate It is also possible to use 1 type or in combination of 2 or more types as a functional acrylate. .

In addition, a photoinitiator can be divided into the photoinitiator with respect to a radical polymerization type photopolymerizable prepolymer or a photopolymerizable monomer, and the photoinitiator with respect to a cationic polymerization type photopolymerizable prepolymer.

The photopolymerization initiator for the radically polymerized photopolymerizable prepolymer or photopolymerizable monomer is benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether. , Acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropane-1 -One, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propane-1-one, 4- (2-hydroxyethoxy) Phenyl-2 (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2 Tertary-butyl anthraquinone, 2-aminoanthraquinone, 2-methyl thioxanthone, 2-ethyl thioxanthone, 2-chloro thioxanthone, 2,4-dimethyl thioxanthone, 2,4-diethyl Thio It is 1 type, or 2 or more types of mixtures chosen from the group which consists of a Santon, benzyl dimethyl ketal, acetophenone dimethyl ketal, and p-dimethylamine benzoic acid ester, The photoinitiator for the said cationic polymerization type photopolymerizable prepolymer is aromatic oxosulfonium A compound in which one or two or more of onium such as ions and aromatic iodonium ions, and anions such as tetrafluorobolet, hexafluorophosphate, hexafluoroantimonate and hexafluoroarsenate are combined Can be.

Urethane acrylate oligomer according to the present invention is characterized in that it contains a polycarbonate diol to improve the physical properties such as water resistance, heat resistance, chemical resistance, weather resistance, and the like to improve the hardness of the hard coating layer through the improvement of mechanical strength. That is, by including the polycarbonate diol in the urethane acrylate oligomer, the crosslinking degree and molecular weight of the hard coating composition can be increased to improve heat resistance, flexibility and hardness. By such heat resistance, flexibility and hardness, the hard coat film made of the hard coating composition of the present invention can prevent phenomena such as curling due to heat treatment, cracking due to bending during processing, and peeling.

Here, the content of the polycarbonate diol is 2 to 6 mol% with respect to 100% by weight of the urethane acrylate oligomer. If the content of the polycarbonate diol is less than 2 mol%, the increase in the degree of crosslinking for improving the hardness is low. Heat resistance and flexibility When the improvement effect is insignificant, when it exceeds 6 mol%, a gelling phenomenon occurs, which makes it difficult to control the viscosity of the hard coating solution, which may cause problems during film processing.

The polycarbonate diol is not particularly limited as the polycarbonate diol used in the present invention. Polycarbonate diols can be synthesized by reacting phosgene, diaryl carbonate or ethylene carbonate with a diol compound or bisphenol compound. As an example of the said diol compound, 1, 3- propane diol, 1, 4- butane diol, 1, 5- pentane diol, 1, 6- hexane diol, 3-methyl -1,5-pentane diol, 1,8-octane diol, 2-methyl-1,8-octane diol, 1,9-nonane diol, 1,10-decane diol, 1,4-cyclohexane dimethanol, 1,3-cyclohexane dimethanol, 1,4-cyclohexane diol, 1,3-cyclohexane diol, tricyclohexane dimethanol, pentacyclopenta Alkylene diols having 2 to 12 carbon atoms such as decane dimethanol, 1,4-butane diol, 1,6-hexane diol, and 1,12-dodecane diol; There may be mentioned polyethers such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polybutylene glycol, polyhexamethylene glycol, polyheptamethylene glycol, and polydecamethylene glycol. Diol. Moreover, as an example of a bisphenol compound, bisphenol A, bisphenol F, methylene bis (4-hydroxyphenyl), etc. are mentioned, for example. A mixture of two or more of the diol compounds, a mixture of two or more of the bisphenol compounds, or a mixture of a diol compound and a bisphenol compound may also be used.

In addition, the said polycarbonate diol may be synthesize | combined, or a commercial item may be used. As a commercial item of the polycarbonate, PCDL T6002, PCDL T6001, PCDL T5652, PCDL T5651, PCDL T5650J, PCDL T4672, PCDL T4671, PCDLT4692, PCDL T4691 (above, Asahi Kasei Chemicals Co., Ltd. product), PLACCEL CD-205, PLACCEL 205PL, PLACCEL 205HL, PLACCEL 210, PLACCEL 210PL, PLACCEL 210HL, PLACCEL 220, PLACCEL 220PL or PLACCEL 220HL (above, Daisel Kagaku Kogyo Co., Ltd.), and Japan Kuraray Co., Ltd.

The weight average molecular weight of the polycarbonate diol is preferably 3,000 to 15,000 g / mol, more preferably 6,000 to 10,000 g / mol. If the weight average molecular weight of the polycarbonate diol is less than 3,000 g / mol, heat resistance of the hard coating film may be lowered. If the weight average molecular weight of the polycarbonate diol is more than 15,000 g / mol, compatability with the acrylate oligomer have.

The urethane acrylate oligomer containing the polycarbonate diol as described above preferably has a weight average molecular weight of 6,000 to 10,000 g / mol in consideration of the hardness of the hard coat film, and if the weight average molecular weight is less than 6,000 g / mol In this case, the hard coating layer may be soft, and thus the hard coating function, such as scratch resistance and film strength, may be degraded. When the weight average molecular weight exceeds 10,000 g / mol, the scratch coating is excellent, but the hardening shrinkage is increased. There is a problem that the curling phenomenon can not be suppressed and the viscosity is considerably high, such as workability deterioration.

Polyurethane acrylate oligomer containing polycarbonate diol according to the present invention is a polyhydric alcohol, such as pentaerythritol, dipentaerythritol, tripentaerythritol, reaction catalysts such as dibutyl tin dilaurate and the like, hexamethylene diisocyanate, isophorone diisocyanate When a urethane prepolymer having an end isocyanate is prepared using aliphatic isocyanates such as an isocyanate, and then an acrylate compound such as hydroxy ethyl acrylate or hydroxy propyl methacrylate is added to the terminal to completely consume the isocyanate. After the reaction can be prepared.

The method for preparing a hard coating composition according to the present invention may be prepared by mixing the polycarbonate diol-containing urethane acrylate oligomer, a photocurable material, and a photopolymerization initiator with a solvent.

Here, the solvent is alcohol such as methanol, ethanol, propanol, isopropanol, ketones such as methyl ethyl ketone, methyl isobutyl ketone, esters such as methyl acetate, ethyl acetate, aromatic compounds such as toluene, benzene, xylene, ethers It may be one kind or a mixture of two or more kinds of solvents, and the content of the solvent may be used without limitation so long as it can dissolve the urethane acrylate oligomer, photocurable material and photopolymerization initiator containing diol sufficiently. .

In another aspect, the present invention relates to a hard coat film formed by applying the hard coat composition on one or both surfaces of a substrate.

The hard coat film according to the present invention may be applied to one or both sides of the substrate, the hard coating composition prepared as described above, and may be prepared after UV irradiation. In this case, the hard coating composition may be coated on a substrate by any one of spray, dip coating, spin coating, screen coating, inkjet printing, pad printing, knife coating, kiss coating, bar coating and gravure coating. This may be made, and the thickness of the hard coating layer formed of the hard coating composition may be easily adjusted according to the type of the substrate, the use, and the like.

In addition, the substrate may be formed of inorganic materials such as glass, quartz, glass wafers, silicon wafers and the like, polyethylene sulfonate (PES) film, polyethylene terephthalate (PET) film, polycarbonate (PC) and polymethylmethacrylate , Surlyn (manufactured by BFGoodrich of the United States), and the like can be coated on various transparent substrates such as organic synthetic resin films.

Specifically, the hard coating composition according to an embodiment of the present invention is a plastic liquid crystal display material surface and a flat panel display liquid crystal screen surface, computer monitor screen and safety glasses surface, other glass, polycarbonate and acrylic plate, polyethylene phthalate or polyethylene sulfonate film It can be used for the transparent substrate surface, such as.

The urethane acrylate oligomer, photocurable material and photoinitiator as described above, wherein the urethane acrylate by applying a hard coating composition containing a polycarbonate diol to the hard coating film, hardness, adhesion, flex resistance and wear resistance It is excellent in this and can provide the hard coat film which can reduce the curl by surface treatment.

In particular, the hardness of the hard coat film is evaluated by the pencil hardness, preferably 3H or more. The reason is that pencil hardness of 3H or more is required in order to provide scratch resistance to external contact or impact. For this reason, the hardness of the hard coat film of the present invention preferably has a mechanical strength of 3H or more.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited to the following Examples.

< Example  1>

1-1: Urethane Acrylate Oligomer  synthesis

58.86 g (0.436 mol) of pentaerythritol (Aldrich), 700 g (0.18 mol) of polycarbonate diol (PCDL) in a 5,000 µl four-necked flask equipped with an oil bath, thermometer, reflux cooler, and dropping funnel, dibutyl tin di 0.03 g of laurate was added thereto, stirred and mixed at 70 ° C. for 30 minutes, and then 338 g (2.014 mol) of hexamethylene diisocyanate was added in three steps at 1 hour intervals, and then the reaction proceeded for 3 hours. A urethane prepolymer was prepared. At this time, the value of R (N = C = O / OH, ratio of isocyanate group and hydroxyl group) of the urethane prepolymer whose terminal is isocyanate is 1.91.

Thereafter, the temperature of the reactor was lowered to 50 캜 to prevent thermal polymerization of the vinyl group, and then 205 g (1.744 mol) of hydroxyethyl acrylate was added thereto and stirred for 5 hours until the isocyanate group was completely consumed. Using the FT-IR spectrum, it was confirmed that there was no residual isocyanate at the characteristic peak of N = C = O near 2270 cm ^-1 , and the reaction was terminated to produce about 1,300 g of urethane acrylate oligomer.

1-2: Hard coating  Composition manufacturing

33.3 parts by weight of dipentaerythritol pentaacrylate (Kyoa Synthesis, M-402) based on 100 parts by weight of the urethane acrylate oligomer synthesized in Example 1-1, trihydroxyethyl isocyanurate triacrylate (donga synthesis) , M-315) 16.6 parts by weight, 5 parts by weight of 1-hydroxy cyclohexyl phenyl ketone as a photopolymerization initiator and 234 parts by weight of methyl ethyl ketone as a solvent were mixed at 60 ° C. for 1 hour to prepare a hard coating composition.

1-3: Hard coating  Film manufacturing

The hard coating composition prepared in Example 1-2 was applied to one surface of a polyethylene terephthalate (KOLON, thickness 188㎛) as a base material, and then dried in an oven at 80 ° C. for 3 minutes, and an ultraviolet irradiation device (Fusion, 600 mJ / 2 cm) was mounted on the type-D bulb to irradiate 500mJ / ㎠ in the direction of applying the hard coating composition to prepare a hard coating film (thickness 193㎛).

< Comparative Example  1>

A hard coat film was prepared in the same manner as in Example 1, except that the polycarbonate diol used in Example 1-1 was not used.

< Comparative Example  2>

A hard coat film was prepared in the same manner as in Example 1, except that dipentaerythritol was used instead of pentaerythritol used in Example 1-1, and a polycarbonate diol was not used.

< Comparative Example  3>

A hard coat film was prepared in the same manner as in Example 1 except that tripentaerythritol was used instead of pentaerythritol used in Example 1-1 and a polycarbonate diol was not used.

The hard coating films prepared in the above Examples and Comparative Examples were evaluated as follows. The results are shown in Table 1.

(1) pencil hardness

The hard coating films prepared in the Examples and Comparative Examples were measured for hardness using a pencil hardness tester of IMOTO, Japan.

[Measuring conditions]

a. Speed of 30mm / min

b. The loads are 500gf and 750gf

c. Japan's IMOTO pencil hardness tester

(2) scratch resistance

When the hard coating film prepared in the above Examples and Comparative Examples was subjected to minimal pressure using the basis weight of a Big Heart test apparatus manufactured by IMOTO, Japan, scratches of the hard coat film were measured. The degree of damage caused by scratches was judged by naked eyes and the criteria were as follows.

Poor scratch resistance ← X <Δ <○ <◎ → excellent scratch resistance

(3) Adhesion (Cross Cut)

Using the knife on the coated surface of the hard coating film prepared in the above Examples and Comparative Examples, 11 straight lines were drawn horizontally and vertically at intervals of 1 mm to make 100 squares, and then a tape (3M Scotch magic tape) was used The peeling test was carried out and the criteria are as follows.

Adhesion poor ← X <Δ <○ <◎ → Good adhesion

(4) Flexibility

The hard coating film prepared in the above Examples and Comparative Examples was wound around a 20-mm rod to check whether cracks occurred on the surface. The criteria were as follows.

Flexibility poor ← X <△ <○ <◎ → Flexibility

division Thickness (㎛) Pencil hardness Scratch resistance
Adhesiveness
Flexibility
Load 500gf Load 750gf Example 1 193 3H 3H ◎ ◎ ◎ Comparative Example 1 193 2.5H 3H X ◎ X Comparative Example 2 193 2.5H 3H ○ X ○ Comparative Example 3 193 2H 2H ○ ○ X

As shown in Table 1, the hard coat film prepared in Example 1 was superior in hardness, scratch resistance, adhesion, and flexibility as compared with the hard coat film prepared in Comparative Example. In particular, in Example 1, hardness at 500 gf and 750 gf at the hardness measurement was 3H, and the hard coating film according to the present invention had a high strength property, which is a physical property indispensably required as a protective film for protecting a display. I could confirm.

Therefore, the hard coating film prepared using the hard coating composition according to the present invention can be applied as a display protective film requiring strength, in particular by using a urethane acrylate oligomer containing polycarbonate diol It was found that the hard coating film is the optimum.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (5)

A urethane acrylate oligomer, a photocurable material, and a photopolymerization initiator, wherein the urethane acrylate oligomer comprises a polycarbonate diol.
The hard coating composition of claim 1, wherein the urethane acrylate oligomer containing polycarbonate diol has a weight average molecular weight of 6,000 to 10,000 g / mol.
The hard coating composition of claim 1, comprising 20 to 60 parts by weight of the photocurable material and 3 to 10 parts by weight of the photopolymerization initiator with respect to 100 parts by weight of the urethane acrylate oligomer.
The hard coating composition of claim 1, wherein the urethane acrylate oligomer contains 2 to 6 mol% of polycarbonate diol.
Hard coating film formed by applying the hard coating composition of any one of claims 1 to 4 on one or both sides of the substrate.