KR20220163058A - Adhesive film for deco, and electronic display and electronic device including the same - Google Patents

Abstract

An adhesive film for decoration, and electronic displays and electronic devices including the same are disclosed. The adhesive film for decoration contains: a polyurethane-based base layer; an adhesive layer disposed on one side of the substrate layer; and a hard coating layer disposed on the other side of the base layer, wherein the polyurethane-based base layer may have a storage modulus of 700 MPa or less at a temperature of 25℃ and 0.2 % strain.

Description

Adhesive film for deco, and electronic display and electronic device including the same {Adhesive film for deco, and electronic display and electronic device including the same}

It relates to an adhesive film for decoration, and an electronic display and electronic device including the same.

The adhesive film for decoration is applied to an electronic display device, for example, a back cover of a smartphone. Recently, as the supply of electronic display devices rapidly expands, consumer requirements are gradually becoming more sophisticated. As a high-end strategy, various designs are being designed. In order to implement the design, a method of implementing the design on an adhesive film and attaching it to the glass of the smartphone back cover is used in addition to the method of directly implementing the design on the glass of the electronic display device, for example, the smartphone back cover. However, the adhesive film for decoration including a general polymer resin base layer is expanded and contracted by a strong force applied when laminated with the curved surface of an electronic display device, causing wrinkles or/and bubbles to occur.

Therefore, there is still a need for an adhesive film for decoration without air bubbles or/and wrinkles when laminating the curved surfaces of glass-based adherends or/and polymer resin-based adherends, and electronic displays and electronic devices including the same.

One aspect is to provide an adhesive film for decoration without bubbles or/and wrinkles when the curved surfaces of a glass-based adherend or/and a polymer resin-based adherend are laminated.

Another aspect is provided with an electronic display including the adhesive film for decoration.

In another aspect, an electronic device including the electronic display is provided.

According to one aspect,

Polyurethane-based base layer;

an adhesive layer disposed on one side of the substrate layer; and

Including; hard coating layer disposed on the other side of the base layer,

The polyurethane-based base layer has a storage modulus of 700 MPa or less at 25 °C and 0.2% strain, and an adhesive film for decoration is provided.

The polyurethane-based substrate layer may have a thickness of 20 μm to 100 μm.

The polyurethane-based base layer may be a cured layer derived from a composition including a urethane-based pre-polymer having a carboxy group functional group.

A non-conductive polymer resin layer may be further included between the polyurethane-based base layer and the hard coating layer.

The non-conductive polymer resin layer may be a polyester resin, a triacetyl cellulose resin, a polycarbonate resin, an alkylcarbonate resin, a polyurethane resin, a polyacrylate resin, a cycloolefin resin, an acrylic styrene resin, or a combination thereof.

The thickness of the non-conductive polymer resin layer may be 40 μm or less.

The hard coating layer may have a thickness of 1 μm or less and a surface energy of 36 dyne/cm or more.

When the adhesive film is laminated to a polycarbonate adherend having a curvature radius of 5 mm, a curvature angle of 90 °, and a height of 10 mm, the adhesive film may have no wrinkles.

According to other aspects,

An electronic display including the above-described adhesive film for decoration is provided.

According to another aspect,

An electronic device including the aforementioned electronic display is provided.

An adhesive film for decoration according to one aspect includes a polyurethane-based base layer; an adhesive layer disposed on one side of the substrate layer; and a hard coating layer disposed on the other side of the base layer. The polyurethane-based base layer may have a storage modulus of 700 MPa or less at 25 °C and 0.2% strain. Such an adhesive film for decoration can provide a film without bubbles or/and wrinkles when the curved surfaces of a glass-based adherend or/and a polymer resin-based adherend are laminated.

1 is a schematic cross-sectional view of an adhesive film for decoration according to a comparative embodiment.
2 is a schematic cross-sectional view of an adhesive film for decoration according to one embodiment.
3 is a schematic cross-sectional view of an adhesive film for decoration according to another embodiment.
Figure 4 shows the curved surface of the polycarbonate adherend to which the adhesive film for decoration produced by Examples 1 to 3 and Comparative Examples 1 to 3 is laminated to evaluate the appearance of the film after the curved surface is laminated.

Hereinafter, an adhesive film for decoration, and an electronic display and electronic device including the same will be described in detail with reference to the embodiments and drawings of the present invention. These examples are only presented as examples to explain the present invention in more detail, and it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples. .

Unless defined otherwise, 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 case of conflict, the present specification, including definitions, will control.

Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described herein.

In this specification, the term "include" means that other components may be further included without excluding other components unless otherwise stated.

The term "combination of these" as used herein means a mixture or combination of one or more of the recited elements.

The term “and/or” as used herein is meant to include any and all combinations of one or more of the items listed in relation to it. The term "or" as used herein means "and/or". The expression "at least one" or "one or more" in front of elements in this specification does not mean that the list of entire elements can be supplemented and individual elements of the description can be supplemented.

In this specification, when an element is referred to as being disposed “on” or “above” another element, one element may be directly disposed on the other element, or elements intervened between the elements may be present. may exist. On the other hand, when an element is referred to as being disposed “directly on” or “directly over” another element, intervening elements may not be present.

As used herein, "~ polymer (resin)" or "~ copolymer (resin)" means "~ polymer (resin)", "~ copolymer (resin)", or/and "~ polymer (resin) or copolymer It is a broad concept that includes all "derivatives of polymers (resins)".

An adhesive film for decoration according to one embodiment includes a polyurethane-based base layer; an adhesive layer disposed on one side of the substrate layer; and a hard coating layer disposed on the other side of the substrate layer, wherein the polyurethane-based substrate layer may have a storage modulus of 700 MPa or less at 25° C. and 0.2% strain. The adhesive film for decoration may provide a film without bubbles or/and wrinkles when the curved surfaces of a glass-based adherend or/and a polymer resin-based adherend are laminated.

1 is a schematic cross-sectional view of an adhesive film for decoration according to a comparative embodiment. 2 is a schematic cross-sectional view of an adhesive film for decoration according to one embodiment.

Referring to FIG. 1 , in the adhesive film 10 for decoration according to a comparative embodiment, a polymer resin base layer 1, an adhesive layer 2, and a release film 3 are sequentially arranged. When the decorative adhesive film 10 is laminated to the curved surface of a glass-based adherend or/and a polymer resin-based adherend, wrinkles occur on the curved surface due to lack of flexibility. In addition, the decorative adhesive film 10 expands with a strong force even if wrinkles do not occur immediately after being laminated on the curved surface of the glass-based adherend or/and the polymer resin-based adherend, and wrinkles occur as it contracts with a restoring force after a certain period of time has elapsed. .

Referring to FIG. 2, the decorative adhesive film 20 according to an embodiment includes a polyurethane-based base layer 11, and an adhesive layer 12 and a release film 13 disposed on one side of the base layer 11. And, the hard coating layer 14 is disposed on the other side of the base layer 11. The decorative adhesive film 20 includes a polyurethane base layer 11 having a storage modulus of 700 MPa or less at 25 ° C. and 0.2% strain, thereby maximizing flexibility and minimizing restoring force. It is possible to provide a film without bubbles or/and wrinkles when laminating the curved surfaces of the adherend or/and the polymer resin-based adherend.

When the decorative adhesive film 20 is laminated to a polycarbonate adherend having a curvature radius of 5 mm, a curvature angle of 90 °, and a height of 10 mm, the adhesive film may have no wrinkles.

Polyurethane-based base layer 11, adhesive layer 12, release film 13, hard coating layer 14, etc. constituting the decorative adhesive film 20, and electronic displays and electronic devices including them The explanation is as follows.

<Polyurethane base material layer 11, etc.>

The polyurethane-based base layer 11 is formed by curing a composition obtained by adding and mixing a urethane-based copolymer resin having a crosslinkable carboxyl functional group, a curing agent, and an organic solvent.

The urethane-based copolymer resin having a crosslinkable carboxy group functional group may be a compound produced through addition polymerization of acrylic acid, alcohol, and isocyanate.

The curing agent may be at least one selected from an isocyanate-based curing agent, an oxazoline-based curing agent, an epoxy-based curing agent, a carbonyl imide-based curing agent, and a melamine-based curing agent.

The organic solvent may include alcohols such as methanol, ethanol, propanol, and isopropanol; ketones such as methyl ethyl ketone and methyl isobutyl ketone; esters such as methyl acetate and ethyl acetate; Aromatic compounds, such as toluene, benzene, and xylene; Or ethers, etc. may be used, but is not limited thereto. The organic solvent may be used alone or in combination of two or more solvents.

The composition may include one or more additives such as an ultraviolet absorber, a lubricant, a leveling agent, an antifoaming agent, a polymerization accelerator, an antioxidant, a flame retardant, an infrared absorber, a surfactant, and a surface modifier.

The polyurethane-based base layer 11 may be in the form of a film or sheet. For example, the polyurethane-based base layer 11 may be in the form of a film.

The polyurethane-based base layer 11 may have a storage modulus of 700 MPa or less at 25 °C and 0.2% strain. If the storage modulus exceeds 700 MPa, the restoring force is strong, and wrinkles may occur while shrinking by inertia after bonding the curved surfaces of the glass-based adherend or/and the polymer resin-based adherend.

The polyurethane-based base layer 11 may have a thickness of 20 μm to 100 μm. If the thickness of the polyurethane-based base layer 11 is less than 20 μm, handling of the adhesive film 20 for decoration is not good, so that pressing or bending may occur. If the thickness of the polyurethane-based substrate layer 11 exceeds 100 μm, pressure applied after laminating the curved surfaces of the glass-based adherent or/and the polymer resin-based adherend is not uniform, and air bubbles may be generated on the curved surface.

3 is a schematic cross-sectional view of an adhesive film for decoration according to another embodiment.

Referring to FIG. 3, the decorative adhesive film 30 according to another embodiment includes a polyurethane-based base layer 21, and an adhesive layer 22 and a release film 23 on one side of the base layer 21. , and a non-conductive polymer resin layer 25 and a hard coating layer 24 are disposed on the other side of the substrate layer 21 .

The non-conductive polymer resin layer 25 may be in the form of a film or sheet. The non-conductive polymer resin layer 25 may be a polymer film of a polyester resin, a triacetyl cellulose resin, a polycarbonate resin, an alkylcarbonate resin, a polyurethane resin, a polyacrylate resin, a cycloolefin resin, an acrylic styrene resin, or a combination thereof. can

The non-conductive polymer resin layer 25 uses a material having high transparency, high visible light transmittance, and low haze value. The non-conductive polymer resin layer 25 may have visible light transmittance of 70% or more or 80% or more in the visible light range (400 to 700 nm). The non-conductive polymer resin layer 25 may have a haze value of 3% or less or 1% or less.

The non-conductive polymeric resin layer 25 may contain various additives, for example, colorants such as dyes and pigments, ultraviolet absorbers, or/and antioxidants to facilitate production and coating within a range that does not impair the effects of the present invention. can If necessary, the non-conductive polymer resin layer 25 may be subjected to various surface treatments such as corona discharge treatment or in-line coating treatment.

The thickness of the non-conductive polymer resin layer 25 may be 40 μm or less. If the thickness of the non-conductive polymeric resin layer 25 exceeds 40 μm, flexibility is lowered and is not suitable for laminating the curved surface of a glass-based adherend or/and a polymer resin-based adherend.

<Adhesive layer 12>

The adhesive layer 12 is a (meth)acrylic acid ester-based monomer having a crosslinkable functional group such as a hydroxyl group, a carboxy group, an amino group, or an amide group, a monomer including ethylenically unsaturated carboxylic acid, or a combination thereof, and (meth)acrylic acid having no crosslinkable functional group. It is formed by curing a composition obtained by adding and mixing a monomer including an ester-based monomer, a curing agent, and an organic solvent.

Examples of the (meth)acrylic acid ester-based monomer having the crosslinkable functional group include (meth)acrylic acid 2-hydroxyethyl, (meth)acrylic acid 2-hydroxypropyl, (meth)acrylic acid 3-hydroxypropyl, (meth)acrylic acid (meth)acrylic acid hydroxyalkyl ester monomers such as 2-hydroxybutyl, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; Acryl amides, such as (meth)acrylamide, N-methyl (meth)acrylamide, and N-methylol (meth)acrylamide; (meth)acrylic acid monomethyl amino ethyl, (meth)acrylic acid monoalkyl amino ester; Acrylic acid, methacrylic acid, etc. are mentioned. Examples of the ethylenically unsaturated carboxylic acid include crotonic acid, maleic acid, itaconic acid, and citraconic acid.

Examples of the (meth)acrylic acid ester-based monomer having no crosslinkable functional group include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and pentyl (meth)acrylate. rate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, and palmityl (meth)acrylate. The (meth)acrylic acid ester-based monomer having no crosslinkable functional group may be used alone or in combination of two or more.

The curing agent may be at least one selected from an isocyanate-based curing agent, an oxazoline-based curing agent, an epoxy-based curing agent, a carbonyl imide-based curing agent, and a melamine-based curing agent. The curing agent may be included in an amount of 0.5 to 1.0 parts by weight based on 100 parts by weight of the entire adhesive layer 12 . If the content of the curing agent is within the above range, the adhesive strength does not decrease, and durability does not decrease in a heat-resistant and moisture-resistant environment and pressing when winding the product does not occur.

The organic solvent may include alcohols such as methanol, ethanol, propanol, and isopropanol; ketones such as methyl ethyl ketone and methyl isobutyl ketone; esters such as methyl acetate and ethyl acetate; Aromatic compounds, such as toluene, benzene, and xylene; Or ethers, etc. may be used, but is not limited thereto. The organic solvent may be used alone or in combination of two or more solvents.

If necessary, the composition may include a UV absorber and the like.

Examples of the UV absorber include a resorcinol monobenzoate-based UV absorber, a salicylate-based UV absorber, a hydroxybenzoate-based UV absorber, or a formamidine-based UV absorber.

The thickness of the adhesive layer 12 may be 15 to 50 μm. If the thickness of the adhesive layer 12 is within the above range, defects due to pressing can be prevented and the adhesive strength of the adhesive layer can be properly maintained.

The adhesive layer 12 may have a glass transition temperature (T _g ) of greater than -15 to 0 °C in order to remove air bubbles after being laminated to a glass-based adherend and to suppress pressing by external foreign substances. If the glass transition temperature of the adhesive layer 12 is less than -15 °C, the cohesive force of the polymer resin constituting the adhesive layer is weak, so it is not possible to secure the adhesive force to the glass-based adherend required. If the glass transition temperature of the adhesive layer 12 is greater than 0 °C, the cohesive force of the polymer resin constituting the adhesive layer is too strong, resulting in zipping between the adhesive layer and the glass-based adherend, resulting in wettability and adhesiveness to the adherend. this may deteriorate.

The adhesive layer 12 may have an adhesive force of 15 N/inch or more to glass in order to prevent glass from scattering when the glass-based adherend is broken. For example, the adhesive layer 12 may have an adhesive force of 15 to 30 N/inch to a glass-based adherend. When the adhesive strength of the adhesive layer 12 to the glass-based adherend is within the above range, a sufficient anti-scattering effect may be obtained, and a rework process for recycling glass may be facilitated in the event of a process failure.

<Release film (13)>

The adhesive layer 12 may further include a release film 13 on the adhesive layer 12 .

As the release film 13, any release film usable in the art can be used. For example, the release film 13 may be a polyester-based film.

<Hard coating layer 14>

The hard coating layer 14 is formed by curing a composition in which a reactive oligomer, a reactive monomer, an inorganic particle, a photoinitiator, and an organic solvent are added and mixed.

The reactive oligomer may be at least one selected from ultraviolet curable urethane acrylate-based compounds, silicone acrylate-based compounds, polyester acrylate-based compounds, and melamine acrylate-based compounds. The reactive oligomer may have a weight average molecular weight (Mw) of 1,000 to 30,000.

The reactive monomer is 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, Bisphenol A-ethylene glycol diacrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, neopentyl Glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, pentaerythritol tri(meth)acrylate , propylene oxide-modified trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, propionic acid-modified dipentaerythritol penta(meth)acrylate, and caprolactone At least one monomer selected from modified dipentaerythritol hexa(meth)acrylate may be included.

Ink printing or UV resin printing is performed on the surface of the hard coating layer 14 for design processing of electronic display devices. At this time, as the inorganic particles, silica or alumina capable of improving wettability by increasing the surface energy of the hard coating layer 14 may be used to secure wettability and adhesion of the printed layer. As the inorganic particles, those not surface-treated with organic compounds such as silane coupling agents, polyols, alkylolamines, and titanate coupling agents are used. The surface-treated inorganic particles may have reduced adhesion with the printed layer.

The photoinitiators include 1-hydroxy-cyclohexyl-phenylketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-hydroxy-1-[4-(2-hydroxyethoxy ) Phenyl] -2-methyl-1-propanone, methylbenzoyl formate, α, α-dimethoxy-α-phenylacetophenone, 2-benzoyl-2- (dimethylamino) -1- [4- (4- Morpholinyl) phenyl] -1-butanone, 2-methyl-1- [4- (methylthio) phenyl] -2- (4-morpholinyl) -1-propanone diphenyl (2,4,6 -Trimethylbenzoyl)-phosphine oxide, or bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, etc. may be mentioned, but is not limited thereto. In addition, examples of the photoinitiator include Irgacure 184, Irgacure 500, Irgacure 651, Irgacure 369, Irgacure 907, Darocur 1173, Darocur MBF, Irgacure 819, Darocur TPO, Irgacure 907, or Esacure KIP 100F. have. These photoinitiators may be used alone or in combination of two or more different types.

The organic solvent may include alcohols such as methanol, ethanol, propanol, and isopropanol; ketones such as methyl ethyl ketone and methyl isobutyl ketone; esters such as methyl acetate and ethyl acetate; Aromatic compounds, such as toluene, benzene, and xylene; And ethers, etc. may be used, but are not limited thereto. In addition, the organic solvent may be used alone or in combination of two or more.

The composition may include one or more additives such as a UV absorber, a lubricant, a leveling agent, an antifoaming agent, a polymerization accelerator, an antioxidant, a flame retardant, an infrared absorber, a surfactant, and a surface modifier. However, the composition does not include silicon-based or fluorine-based additives such as a leveling agent or a surfactant to improve adhesion to the metal deposited on the hard coating layer 14 . When a silicone-based or fluorine-based additive is included in the composition, the surface energy is lowered, which lowers the adhesion with the printed layer.

The hard coating layer 14 may have a thickness of 1 μm or less and a surface energy of 36 dyne/cm or more. When the thickness of the hard coating layer 14 exceeds 1 μm, cracks may occur in the hard coating layer 14 when the curved surfaces of the glass-based adherend or/and the polymer resin-based adherend are laminated due to high hardness.

An electronic display according to another embodiment may include the above-described adhesive films 20 and 30 for decoration. Examples of the electronic display may include an indoor and outdoor video display device, a portable personal terminal, a vehicle navigation device, a remote controller, an unmanned vehicle driving display device, or a drone control panel.

An electronic device according to another embodiment may include the above-described adhesive films 20 and 30 for decoration. The electronic device may include a mobile device or a communication electronic device.

Hereinafter, the configuration of the present invention and its effects will be described in more detail through Examples and Comparative Examples. However, these examples are intended to explain the present invention in more detail, and it will be obvious that the scope of the present invention is not limited to these examples.

[Example]

Preparation Example 1: Composition for forming a polyurethane base layer

A composition for forming a polyurethane base layer was prepared by mixing the following materials in a mixing tank equipped with an agitator.

100 parts by weight of urethane-based copolymer resin (Samhwa Paint, SU-924) having a carboxy group functional group

· Epoxy-based curing agent (Samhwa Paint, SC5EX) 10 parts by weight

20 parts by weight of a mixed solvent of methyl ethyl ketone and toluene (1:1 weight ratio)

Preparation Example 2: Composition for forming a polyurethane base layer

A composition for forming a polyurethane base layer was prepared by mixing the following materials in a mixing tank equipped with an agitator.

100 parts by weight of urethane-based copolymer resin (Samhwa Paint, SU-924) having a carboxy group functional group

Epoxy curing agent (Samhwa Paint, SC5EX) 10 parts by weight

20 parts by weight of a mixed solvent of methyl ethyl ketone and toluene (1:1 weight ratio)

Preparation Example 3: Composition for Forming a Hard Coating Layer

A composition for forming a hard coat layer was prepared by mixing the following materials in a mixing tank equipped with an agitator.

Urethane acrylate-based reactive oligomer, 1,3-butanediol di(meth)acrylate reactive monomer, and 1-hydroxy-cyclohexyl-phenylketone photoinitiator mixed resin (Toyo-Ink, LCH-2243) 100 parts by weight

30 parts by weight of non-surface-treated silica inorganic particles (Yungil Hwaseong, YGD-40) with an average particle diameter of about 40 nm

30 parts by weight of a mixed solvent of methyl isobutyl ketone and propylene glycol monoethyl ether (1:1 weight ratio)

Preparation Example 4: Composition for forming an adhesive layer

A composition for forming an adhesive layer was prepared by mixing the following materials in a mixing tank equipped with a stirrer.

100 parts by weight of acrylic adhesive (Cosmotech, CMT-6106)

Epoxy curing agent (Cosmotech, NA-30) 1 part by weight

20 parts by weight of a mixed solvent of methyl ethyl ketone and toluene (1:1 weight ratio)

Example 1: Adhesive film for decoration

The composition for forming a polyurethane substrate layer of Preparation Example 1 was applied with a bar coater on one side of a 50 um thick release film (Toray Advanced Materials, Lumiror) and dried at 120 ° C. for 90 seconds to obtain a 25 μm thick polyurethane substrate layer was formed. The composition for forming a hard coating layer of Preparation Example 3 was applied to one surface of the polyurethane base layer with a bar coater and cured by irradiation with UV at a light amount of 300 mJ/cm ² to form a hard coating layer having a thickness of 1 um.

Separately, the composition for forming an adhesive layer of Preparation Example 4 was applied with a bar coater on one side of a 125 um thick release film (Toray Advanced Materials, Lumiror) and dried at 120 ° C. for 90 seconds to obtain a 25 um thick adhesive layer was formed.

The 50 um thick release film was removed from the laminate in which the polyurethane base layer and the hard coating layer were formed, and the 125 um thick release film on which the adhesive layer was formed was laminated to produce an adhesive film for decoration as shown in FIG. 2 .

Example 2: Adhesive film for decoration

An adhesive film for decoration was prepared in the same manner as in Example 1, except that a polyurethane substrate layer having a thickness of 50 μm was formed.

Example 3: Adhesive film for decoration

An adhesive film for decoration was prepared in the same manner as in Example 1, except that a polyurethane substrate layer having a thickness of 75 μm was formed.

Comparative Example 1: Adhesive film for decoration

An adhesive film for decoration was prepared in the same manner as in Example 1, except that a polyurethane substrate layer having a thickness of 125 μm was formed.

Comparative Example 2: Adhesive film for decoration

An adhesive film for decoration was manufactured in the same manner as in Example 1, except that a polyurethane base layer having a thickness of 125 μm was formed using the composition for forming a polyurethane base layer of Preparation Example 2.

Comparative Example 3: Adhesive film for decoration

The composition for forming an adhesive layer of Preparation Example 4 was applied with a bar coater on one side of a 50 um-thick polyethylene terephthalate (PET) film (Toray Advanced Materials), dried at 120 ° C. for 90 seconds, and then a 125 um-thick release film was laminated to produce an adhesive film for decoration as shown in FIG.

Evaluation Example 1: Evaluation of physical properties

The physical properties of the decorative adhesive films prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were evaluated in the following manner, and the results are shown in Table 1.

(1) Measurement of thickness (㎛)

The thicknesses of the polyurethane substrate layer, the PET substrate layer, the hard coating layer, and the adhesive layer used in each of the decorative adhesive films were measured using Nikon's MF-1001 Micrometer, respectively.

(2) Measurement of surface energy

The surface energy of the hard coating layer used in each decorative adhesive film was measured using acrotest, TEST Pens Pink.

(3) Measurement of storage modulus

Samples were prepared by cutting the polyurethane base layer or PET base layer used in each of the decorative adhesive films into 15 mm X 5 mm. For each sample, the storage modulus was measured at 25 °C and 0.2% strain. For the measurement, KU LEUVEN, DMA Q600 was used.

(4) Evaluation of film appearance after laminating curved surfaces

When each adhesive film for decoration was laminated to a curved surface with a radius of curvature of 5 mm, a curvature angle of 90 °, and a height of 10 mm of a polycarbonate adherend, the appearance of the film related to the occurrence of wrinkles and bubbles was evaluated. The curved surface of the polycarbonate adherend is as shown in FIG. 4 .

PET base layer Polyurethane
base layer adhesive layer hard coating layer curved surface
Appearance of film after lamination
evaluation thickness
(μm) save
module
Russ
(MPa) thickness
(μm) save
module
Russ
(MPa) thickness
(μm) thickness
(μm) surface energy
(dyne/cm) Example 1 - - 25 700 25 One 36 no wrinkles Example 2 - - 50 700 25 One 36 no wrinkles Example 3 - - 75 700 25 One 36 no wrinkles Comparative Example 1 - - 125 700 25 One 36 no wrinkles/
with bubbles Comparative Example 2 - - 50 800 25 One 36 wrinkled Comparative Example 3 50 2400 0 - 25 - - wrinkled/
with bubbles

Referring to Table 1, the decorative adhesive films prepared in Examples 1 to 3 did not generate wrinkles or bubbles in the film appearance evaluation after being laminated to the curved surface of the polycarbonate adherend. In comparison, Comparative Example 1 including a polyurethane base layer having a thickness of more than 100 μm, Comparative Example 2 including a polyurethane base layer having a storage modulus of more than 700 MPa, and a PET base layer having a storage modulus of more than 700 MPa. In Comparative Example 3, wrinkles or/and bubbles occurred in the evaluation of the film appearance after being laminated to the curved surface of the polycarbonate adherend, respectively.

1: polymer resin substrate layer, 2, 12, 22: adhesive layer
3, 13, 23: release film, 10, 20, 30: adhesive film for decoration
11, 21: polyurethane base layer, θ: curvature angle
r: radius of curvature, h: height

Claims (10)

polyurethane-based base layer;
an adhesive layer disposed on one side of the substrate layer; and
Including; hard coating layer disposed on the other side of the base layer,
The polyurethane-based base layer has a storage modulus of 700 MPa or less at 25 ° C. and 0.2% strain. According to claim 1,
The thickness of the polyurethane-based base layer is 20 ㎛ to 100 ㎛, the adhesive film for decoration. According to claim 1,
The polyurethane-based base layer is a cured layer derived from a composition containing a urethane-based pre-polymer having a carboxy group functional group, an adhesive film for decoration. According to claim 1,
Further comprising a non-conductive polymer resin layer between the polyurethane-based base layer and the hard coating layer, the adhesive film for decoration. According to claim 4,
The non-conductive polymer resin layer is a polyester resin, a triacetyl cellulose resin, a polycarbonate resin, an alkylcarbonate resin, a polyurethane resin, a polyacrylate resin, a cycloolefin resin, an acrylic styrene resin, or a combination thereof, an adhesive film for decoration . According to claim 1,
The thickness of the non-conductive polymer resin layer is 40 ㎛ or less, the adhesive film for decoration. According to claim 1,
The thickness of the hard coating layer is 1 μm or less and the surface energy is 36 dyne / cm or more, the adhesive film for decoration. According to claim 1,
When the adhesive film is laminated to a polycarbonate adherend having a radius of curvature of 5 mm, a curvature angle of 90 °, and a height of 10 mm, the adhesive film is wrinkle-free. An electronic display comprising the adhesive film for decoration according to any one of claims 1 to 8. An electronic device comprising an electronic display according to claim 9 .

Images