Optical laminate

Abstract

The present disclosure provides an optical laminate which exhibits improved adhesive strength and scratch resistance together with excellent hardness and fingerprint resistance properties, by further including a fingerprint-resistant layer including an organosilane having excellent adhesion strength with the hard coating layer and an anti-fouling function on the hard coating layer including the transparent support substrate layer and the hard coating layer.

Claims

1. An optical laminate comprising: a support substrate layer having a thickness of 30 to 100 μm; a hard coating layer disposed on both surfaces of the support substrate layer and having a thickness of 60 to 100 μm; and a fingerprint-resistant layer disposed on at least one surface of the hard coating layer and having a thickness of 10 nm to 5 μm, wherein the fingerprint-resistant layer includes a cured product of a composition comprising a binder resin and an organic silane compound and wherein the organic silane compound has at least one organic functional group selected from the group consisting of an epoxy group, a (meth)acryloxy group, a mercapto group and an amino group, and wherein the hard coating layer includes an epoxy polysiloxane of Chemical Formula 1,
(R.sup.1SiO.sub.3/2).sub.a(R.sup.2SiO.sub.3/2).sub.b(OR).sub.c  [Chemical Formula 11] in the Chemical Formula 1, R.sup.1 is a glycidyl group represented by Chemical Formula 2; or glycidoxypropyl group, ##STR00004## in the Chemical Formula 2, Ra is selected from the group consisting of a substituted or unsubstituted alkylene group having 1 to 6 carbon atoms, a substituted or unsubstituted alkenylene group having 2 to 20 carbon atoms, a substituted or unsubstituted alkynylene group having 2 to 20 carbon atoms, —Rb— CH═CH— COO-Rc-; -Rd-OCO—CH═CH—Re—, —RfORg-, —RhCOORi-, and -RjOCORk-, Rb to Rk are each independently a single bond, or a substituted or unsubstituted alkylene group having 1 to 6 carbon atoms, R.sup.2 is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted arylalkyl group having 7 to 20 carbon atoms, a substituted or unsubstituted alkylaryl group having 7 to 20 carbon atoms, an epoxy group or a hydrogen atom, R is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and a, b, and c are each 0<a<1, 0≤b<1 and 0<c<1.

2. The optical laminate of claim 1, wherein the organic silane compound is contained in an amount of 0.1 to 5.0% by weight based on the total weight of the composition.

3. The optical laminate of claim 1, wherein the binder resin is at least one selected from the group consisting of a perfluoro polyether compound and a fluoro modified silicone compound.

4. The optical laminate of claim 1, wherein in the Chemical Formula 1, a, b and c satisfy 0.7≤a/(a+b)≤1, 0≤b<0.5 and 0<c<0.5.

5. The optical laminate of claim 1, wherein in the Chemical Formula 2, Ra is a methylene group.

6. The optical laminate of claim 1, wherein in the Chemical Formula 1, the R.sup.2 is substituted with one or more substituents selected from the group consisting of an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 12 carbon atoms, an amino group, an acryl group, a methacryl group, a halogen group, a mercapto group, an ether group, an ester group, an acetyl group, a formyl group, a carboxyl group, a nitro group, a sulfonyl group, an urethane group, an epoxy group, an oxetane group and a phenyl group.

7. The optical laminate of claim 1, wherein the hard coating layer further includes an elastomeric polymer.

8. The optical laminate of claim 7, wherein the elastomeric polymer includes at least one selected from the group consisting of alkanediol having 1 to 20 carbon atoms, polyolefin polyol, polyester polyol, polycaprolactone polyol, polyether polyol and polycarbonate polyol.

9. The optical laminate of claim 1, wherein the hard coating layer further comprises a reactive monomer including at least one functional group capable of crosslinking with the epoxy polysiloxane of the Chemical Formula 1.

10. The optical laminate of claim 9, wherein the reactive monomer includes any one selected from the group consisting of bisphenol A diglycidyl ether, 4-vinylcyclohexene dioxide, cyclohexene vinyl monooxide, (3,4-epoxycyclohexyl)methyl 3,4-epoxycyclohexylcarboxylate, 3,4-epoxycyclohexylmethyl methacrylate, 3,4-epoxycyclohexanecarboxylate, 2-(3,4-epoxycyclohexyl)-1,3-dioxolane, bis(3,4-epoxycyclohexylmethyl)adipate, p-butyl phenol glycidyl ether, butyl glycidyl ether, cresyl glycidyl ether, allyl glycidyl ether, phenyl glycidyl ether, diglycidyl ether, butanediol diglycidyl ether, limonene dioxide, vinylcyclohexene dioxide, diethylene glycol diglycidyl ether, 3-methyloxetane, 2-methyloxetane, 3-oxetanol, 2-methyleneoxetane, 3-methyl-3-hydroxymethyloxetane, 3-ethyl-3-hydroxymethyloxetane, 3,3-oxetanedimethane thiol, 2-ethylhexyl oxetane, 4-(3-methyloxetane-3-yl)benzonitrile, N-(2,2-dimethylpropyl)-3-methyl-3-oxetanemethanamine, N-(1,2-dimethylbutyl)-3-methyl-3-oxetanemethanamine, xylylene bisoxetane, 3-ethyl-3[{(3-ethyloxetane-3-yl)methoxy}methyl]oxetane, (3-ethyloxetane-3-yl)methyl (meth)acrylate, and 4-[(3-ethyloxetane-3-yl)methoxy]butan-1-ol, or a mixture of two or more thereof.

11. The optical laminate of claim 1, wherein the support substrate layer includes a plastic resin and wherein the plastic resin includes one or more resins selected from the group consisting of polyester-based resin, cellulose-based resin, polycarbonate-based resin, acrylic-based resin, styrene-based resin, polyolefin-based resin, polyimide-based resin, polyether sulfone-based resin and sulfone-based resin.

12. A polarizing plate comprising the optical laminate of claim 1.

13. A display device comprising the optical laminate of claim 1.

14. A cover window of a display device comprising the optical laminate of claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 schematically illustrates an optical laminate according to one embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(2) Hereinafter, embodiments of the present disclosure will be described in more detail by way of examples. However, these examples are provided for illustrative purposes only and are not intended to limit the scope of the present disclosure.

(3) Hereinafter, each compound used in the following Preparation Examples is as follows:

(4) (a) Epoxypolysiloxane:

(5) Epoxy polysiloxane 1 prepared according to the following method was used.

(6) 3-Glycidoxypropyltrimethoxysilane (KBM-403, Shin Etsu), water and toluene were put as a silane monomer in a 1000 mL 3-neck flask, and stirred. (KBM-403:water=1 mol: 0.2 mol). To the resulting mixed solution, a basic catalyst (TMAH) was added in an amount of 1 part by weight based on 100 parts by weight of the silane monomer, and the mixture was reacted at 100° C. to produce an epoxy polysiloxane 1 of the following composition including 100 mol % of glycidoxypropyl modified silicone (below, GP). (Mw: 2,700 g/mol, Mn: 2,100 g/mol, epoxy equivalent weight: 5.9 g/eq)
(R.sup.1SiO.sub.3/2).sub.a(R.sup.2SiO.sub.3/2).sub.b(OR).sub.c

(7) (b) reactive monomer: bisphenol A diglycidyl ether (manufactured by Alfa) was used.

(8) (c) elastomers: polycaprolactone diol having the following structure was used.

(9) (Mw=2,000 g/mol, manufactured by Sigma Aldrich)

(10) ##STR00003##

(11) (in Chemical Formula 3, n is determined from the Mw value)

Preparation Example 1

(12) Each component was mixed to produce a resin composition (coating liquid) for forming a hard coating layer. At this time, based on 100 parts by weight of the epoxy polysiloxane, 3 parts by weight of an iodonium-based compound (Omnicat 250™, manufactured by BASF) as an initiator, 10 parts by weight of toluene as a solvent, and 0.2 parts by weight of a fluorine-based compound (RS55™, manufactured by MEGAFACE) as an additive were used. (below, H/C-1)

Preparation Example 2

(13) After mixing in the same manner as in Preparation Example 1, 1 part by weight of perfluoro-modified silane, 0.05 part by weight of aminoethyl(aminopropyl)trimethoxysilane, and 5 parts by weight of trifluorotoluene were further mixed to give a coating solution (H/C-2).

Preparation Example 3

(14) 15 wt % of perfluoropolyethylene-modified silane (Mw: 4,400), 0.7 wt % of aminoethyl(aminopropyl)trimethoxysilane, and 84.3 wt % of trifluorotoluene were used to prepare a composition for forming a fingerprint-resistant layer. (below, AF-1)

Preparation Example 4

(15) 15 wt % t of perfluoropolyethylene polymethacrylate (Mw: 5,300), 0.7 wt % aminoethyl(aminopropyl)trimethoxysilane and 84.3 wt % of trifluorotoluene were used to prepare a composition for forming a fingerprint-resistant layer. (below, AF-2)

Preparation Example 5

(16) A composition for forming a fingerprint-resistant layer was prepared in the same manner as in Preparation Example 3. except for aminoethyl(aminopropyl)trimethoxysilane. That is, 15 wt % of perfluoropolyethylene modified silane 1 and 85 wt % of trifluorotoluene were used. (below, AF-3).

Examples 1 to 4

(17) The resin composition having the composition shown in Table 1 below was used to form a hard coating layer on the upper and lower surfaces of the support substrate, and then the compositions for forming an fingerprint-resistant layer of Preparation Examples 4 and 5 were coated on the upper surface to produce a fingerprint-resistant layer (AF layer).

(18) In detail, the second resin composition for forming a lower coating layer described in Table 1 below was coated onto one surface of a PET substrate having a size of 15 cm×20 cm and a thickness of 50 μm, and then photocuring was performed using a UV lamp (irradiation dose: 400 mJ/cm.sup.2) to produce a lower hard coating layer (below, HC 2 layer). In addition, the first resin composition for forming an upper coating layer described in Table 2 below was coated onto on the opposite side of the PET substrate on which the lower coating layer was formed, and then photocuring was performed using a UV lamp (irradiation dose: 400 mJ/cm.sup.2) to produce an upper hard coating layer (below, HC 1 layer). Thereafter, the resin composition for forming a fingerprint-resistant layer of Preparation Example 4 or 5 was coated onto on the upper coating layer, and then photocuring was performed using a UV lamp (irradiation dose: 400 mJ/cm.sup.2) to produce a fingerprint-resistant layer (below, AF layer). According to the above procedure, an optical laminate having a total thickness of 250.01 to 251 μm was prepared.

Comparative Example 1

(19) As described in Table 1 below, the resin composition prepared in Preparation Examples 1 and 2 was coated onto both surfaces of a PET substrate having a size of 15 cm×20 cm and a thickness of 50 μm, and then photocuring was performed using a UV lamp (irradiation dose: 200 mJ/cm.sup.2) for 10 seconds to produce the upper and lower hard coating layers on the both surfaces of the substrate. In addition, the composition AF-3 of Preparation Example 5 was coated onto the upper coating layer to form an AF layer.

Comparative Examples 2 and 3

(20) A hard coat film was prepared in the same manner as in Example 1, except for using only the resin composition for forming the upper and lower coating layer as shown in Table 1 below.

(21) TABLE-US-00001 TABLE 1 Comparative Comparative Comparative Example 1 Example 2 Example 3 Example 4 Example 1 Example 2 Example 3 First resin Preparative Preparative Preparative Preparative Preparative — — composition Example 3 Example 3 Example 3 Example 4 Example 5 for forming (AF-1) (AF-1) (AF-1) (AF-2) (AF-3) fingerprint- resistant layer First resin Preparative Preparative Preparative Preparative Preparative Preparative Preparative composition Example 1 Example 1 Example 1 Example 1 Example 1 Example 1 Example 2 for forming (H/C-1) (H/C-1) (H/C-1) (H/C-1) (H/C-1) (H/C-1) (H/C-2) upper coating layer Second Preparative Preparative Preparative Preparative Preparative Preparative Preparative resin Example 2 Example 2 Example 2 Example 2 Example 2 Example 2 Example 2 composition (H/C-1) (H/C-1) (H/C-1) (H/C-1) (H/C-1) (H/C-1) (H/C-1) for forming lower coating layer

Experimental Example

(22) The physical properties of the optical laminates produced in Examples 1 to 4 and the general hard coat film produced in Comparative Examples 1 to 3 were measured by the following method, and the results are shown in Tables 2 and 3 below.

(23) 1) Pencil Hardness

(24) The hardness without scratches was confirmed after moving the pencil back and forth five times at under a load of 1.0 kg using a pencil hardness tester in accordance with standard JIS K5400.

(25) 2) Adhesion

(26) The adhesion (adhesive strength) between the fingerprint-resistant layer and the upper coating layer (AF-H/C1 layer) was evaluated by a cross-hatch test method.

(27) A cross-cut test was performed in accordance with the ASTM D3002/D3359 standard which is a cross-cut test standard. Specifically, the specimens were cut in 11 rows with a knife in the horizontal and vertical directions at intervals of 1 mm, to form 100 square grids each having 1 mm in width and length. Then, when Nichiban CT-24 adhesive tape was adhered to the cut surface and then removed, the state of the surfaces detaching together was measured and evaluated according to the following criteria.

(28) <Cross-Hatch Adhesive Strength Evaluation Criteria>

(29) 5B: When detached surface dose not exist

(30) 4B: When the detached surface is within 5% of the total area

(31) 3B: When the detached surface is within 5 to 15% of the total area

(32) 2B: When the detached surface is within 15 to 35% of the total area

(33) 1B: When the detached surface is within 35 to 65% of the total area

(34) 0B: When almost all detach

(35) 3) Water contact angle

(36) After coating, the contact angle of the coated surface was measured using a contact angle measuring device. The size of one water droplet at the time of contact angle measurement was set to 3 μl, and in order to confirm the uniformity of the coating, the contact angle at 5 points per coated sample was measured and averaged.

(37) 4) Fingerprint Wiping-Off Property

(38) Fingerprints were adhered to the surface of the optical laminate prepared above, and the surface was wiped with a clean wiper and evaluated according to the following criteria.

(39) ⊚: When completely wiped within 3 times

(40) ∘: Wen completely wiped within 10 times

(41) x: When not wiped

(42) 5) Scratch Resistance

(43) After rubbing the surface back and forth 1,000 times with a steel wool (#0000) under a load of 500 g, it was visually confirmed whether or not the coating film was worn (scratch, haze), and when no deformation occurred, it was determined as “O.K.”, and when abrasion or deformation occurred, it was determined as “N.G.”.

(44) TABLE-US-00002 TABLE 2 Example 1 Example 2 Example 3 Example 4 Composition AF layer AF-1 AF-1 AF-1 AF-2 of structure H/C 1 layer H/C-1 H/C-1 H/C-1 H/C-1 Substrate PET PET PET PET PET H/C 2 layer H/C-1 H/C-1 H/C-1 H/C-1 Thickness AF layer  10 nm  15 nm   1 nm  15 nm H/C 1 layer 100 μm 100 μm 100 μm 100 μm H/C 2 layer 100 μm 100 μm 100 μm 100 μm Adhesion 5B 5B 5B 5B (AF-H/C1 interlayer) Pencil hardness (750 kgf) 8H 8H 8H 8H Water contact angle 115° 115° 115° 114° Fingerprint wiping-off ⊚ ⊚ ⊚ ⊚ property Scratch resistance O.K. O.K. O.K. O.K. Note) Substrate thickness: 50 μm H/C 1 layer: upper coating layer H/C 2 layer: lower coating layer

(45) TABLE-US-00003 TABLE 3 Comparative Comparative Comparative Example 1 Example 2 Example 3 Composition AF layer AF-3 — — of structure H/C 1 layer H/C-1 H/C-1 H/C-2 Substrate PET PET PET H/C 2 layer H/C-1 H/C-1 H/C-1 Thickness AF layer  15 nm — — H/C 1 layer 100 μm 100 μm 100 μm H/C 2 layer 100 μm 100 μm 100 μm Adhesion 0B — — (AF-H/C1 interlayer) Pencil hardness (750 kgf) 8H 8H 8H Water contact angle 114° 60° 111° Fingerprint wiping-off ⊚ × ○ property Scratch resistance N.G. O.K. N.G. Note) Substrate thickness: 50 μm H/C 1 layer: upper coating layer H/C 2 layer: lower coating layer

(46) As a result of the experiment, the optical laminates of Examples 1 to 4 included a hard coating layer having a specific composition (i.e., an upper coating layer and a lower coating layer) on both surfaces of the substrate, and particularly included an fingerprint-resistant layer having a specific composition on the upper coating layer, and thereby, exhibited improved fingerprint wiping-off property and scratch resistance. Specifically, since Examples 1 to 4 include the composition of organosilane that can induce adhesion with the binder resin to the fingerprint-resistant layer, the adhesive strength and scratch resistance can be improved. In addition, Examples 1 to 4 showed hardness and water contact angle equivalent to or higher than the conventional ones.

(47) On the other hand, Comparative Example 1 includes the fingerprint-resistant layer but does not include the composition of the present disclosure, the adhesion of the fingerprint-resistant layer and the upper coating layer was reduced, and scratch resistance was poor. In addition, Comparative Examples 2 to 3 do not include a fingerprint-resistant layer, the water contact angle, fingerprint wiping-off property and scratch resistance were generally poor compared to Examples 1 to 4. Further, in Comparative Example 3, a hard coating layer was formed using an organosilane compound, but it was not formed by the configuration of the fingerprint-resistant layer formed separately from the upper and lower hard coating layer as in the present disclosure, the adhesive strength and scratch resistance was poor.