CN111844992A

CN111844992A - Plastic laminate, method for producing same, and plastic molded body

Info

Publication number: CN111844992A
Application number: CN202010360758.1A
Authority: CN
Inventors: 赵洪烈; 冰广殷; 李敦徹; 具本哲
Original assignee: SKC Hi Tech and Marketing Co Ltd
Current assignee: Escape Mcavo Solutions Co ltd
Priority date: 2019-04-30
Filing date: 2020-04-30
Publication date: 2020-10-30
Anticipated expiration: 2040-04-30
Also published as: CN111844992B

Abstract

The plastic laminate according to the present invention includes the plastic film formed with the hard coating layer in a symmetrical structure, so that the generation of curling can be significantly reduced in a high temperature environment. Further, by adjusting the thickness, the composition, and the process conditions of each layer of the plastic laminate, not only dimensional stability but also properties such as stain resistance and printability can be further improved. In particular, a layer having a decorative function such as a coloring film, a color filter, a multilayer reflective polarizing film, a pattern layer, an inorganic deposition layer, etc. is used in the above plastic laminate to provide a desired aesthetic effect. Therefore, the plastic molded body molded by the plastic laminate not only has high durability, but also reduces the cost due to the multi-functional composite, and thus can be effectively used as a front cover or a rear cover of a mobile device instead of the conventional glass material.

Description

Plastic laminate, method for producing same, and plastic molded body

Technical Field

The present invention relates to a plastic laminate, a method for producing the same, and a plastic molded article. In particular, the present invention relates to covers of plastic material which may replace the glass material suitable for front or rear covers of mobile devices.

Background

A front cover or a rear cover of a mobile device is generally made of a glass material having advantages in terms of appearance, dimensional stability, and optical characteristics. However, a glass front cover or a glass rear cover used for a mobile device is easily broken and scattered by an external impact. In addition, according to the trend of increasing the area of mobile devices, when a cover made of glass is used, it is difficult to reduce the weight and the cost is increased (see korean patent laid-open publication No. 2017-5755).

Therefore, attempts have been made to develop a cover made of plastic instead of glass. In particular, plastic materials have the advantages of light weight, excellent impact resistance, no scattering at the time of fracture, and low cost.

On the one hand, the front cover or the rear cover functions to protect the mobile device from the external environment, and thus it is necessary to form a hard coating layer on the exposed surface of the plastic substrate layer to improve surface hardness and durability. In addition, since the cover of the mobile device is variously designed, the hard coating layer provided inside the device needs to have characteristics advantageous to mold or print.

Particularly, the back cover of the mobile device is differentiated by giving a stereoscopic color, a metallic texture, a gloss, and the like, but an additional subsequent processing process is required for realizing the design for the glass material, so that a research on how to use a plastic material instead of the glass material is currently being conducted.

Disclosure of Invention

Although a hard coating film of a plastic material for mobile devices has many advantages, it has problems in that curling occurs and dimensional stability is low due to a difference in interlayer heat shrinkage rate in a high temperature environment.

Therefore, the present inventors have conducted studies and as a result, have designed a plastic film having a hard coating layer into a symmetrical laminate structure, thereby significantly reducing the generation of curl in a high-temperature environment. In addition, by adjusting the thickness, the composition, and the process conditions of each layer of the laminate, not only dimensional stability but also characteristics such as antifouling property and printability can be further improved.

Accordingly, an object of the present invention is to provide a plastic laminate and a method for manufacturing the same, which can improve the low dimensional stability of the conventional hard coat film and improve various other characteristics. Further, the present invention has an object to provide a plastic molded article having high durability and low cost, which can replace a glass material suitably used for a front cover or a rear cover in a conventional mobile device, by using the above plastic laminated article.

In particular, an object of the present invention is to provide a plastic laminate in which a decorative layer is applied in a laminated structure to enhance aesthetic effects, and a plastic molded body obtained by using the plastic laminate.

In accordance with the above object, the present invention provides a plastic laminate comprising: a core substrate layer; a first sheet including a first base material layer and a first hard coat layer sequentially disposed on one surface of the core base material layer; and a second sheet including a second base material layer and a second hard coat layer sequentially disposed on the other surface of the core base material layer, the thickness ratio of the first sheet to the second sheet being 1:0.9 to 1: 1.1.

According to another object of the present invention, there is provided a method of manufacturing a plastic laminate, comprising: a step of forming a first hard coat layer on the first base material layer to obtain a first sheet; a step of forming a second hard coat layer on the second base material layer to obtain a second sheet; laminating the first sheet so that the first base material layer faces one surface of the core base material layer; and a step of laminating the second sheet so that the second base material layer faces the other surface of the core base material layer, wherein the thickness ratio of the first sheet to the second sheet is 1:0.9 to 1: 1.1.

According to an example, the thickness ratio of the first sheet to the second sheet is 1:0.9 to 1:1.1, the thickness of the core base material layer is 25 μm to 500 μm, the thickness of the first base material layer and the second base material layer is 10 μm to 200 μm, the thickness of the first hard coat layer and the thickness of the second hard coat layer are 3 μm to 6 μm, the first hard coat layer and the second hard coat layer each include a urethane acrylate oligomer resin having 6 to 10 functional groups or a resin derived therefrom, and a curl change in height of 0.3mm or less is generated at a corner of the plastic laminate after being left at 140 ℃ for 2 hours.

In particular, according to the present invention, in the plastic laminate, at least one layer constituting the plastic laminate is a decorative layer, or at least one decorative layer is included between layers constituting the plastic laminate or on the surface of the plastic laminate.

The present invention also provides a plastic molded article molded from the plastic laminate.

The plastic laminate according to the present invention includes a plastic film formed with a hard coating layer in a symmetrical structure, so that the generation of curling can be minimized also in a high temperature environment. Further, by adjusting the thickness, the composition, and the process conditions of each layer of the plastic laminate, not only dimensional stability but also properties such as stain resistance and printability can be further improved. In particular, a layer having a decorative function such as a coloring film, a color filter, a multilayer reflective polarizing film, a pattern layer, an inorganic deposition layer, etc. is used in the above plastic laminate, and thus a desired aesthetic effect can be provided.

Therefore, the plastic molded body molded by the plastic laminate has high durability, cost reduction due to multi-functional composite, and an aesthetic effect, and thus can be effectively used as a front cover or a rear cover in a mobile device instead of a conventional glass material.

Drawings

Fig. 1 is a schematic cross-sectional view of a plastic laminate according to an embodiment of the present invention.

Fig. 2 and 3 are schematic cross-sectional views of plastic laminates according to another embodiment of the present invention.

Fig. 4 is a cross-sectional schematic view of a reflective polarizing film according to an example.

Fig. 5 and 6 are schematic cross-sectional views of a plastic laminate according to still another embodiment of the present invention.

Description of reference numerals:

10: first sheet, 20: a second sheet of material comprising a second layer of material,

100: core substrate layer, 210: a first base material layer, a second base material layer,

220: second substrate layer, 220': a second substrate layer (decoration layer),

310: first hard coat layer, 320: a second hard coating layer, which is formed on the substrate,

410: first adhesive layer, 420: a second adhesive layer on the second side of the substrate,

420': a second adhesive layer (decorative layer),

500: pattern layer, 600: an inorganic deposition layer is formed on the surface of the substrate,

s: epidermal layer, M: a film laminate.

Detailed Description

The invention is described in more detail below with reference to the accompanying drawings. In the drawings, the size or gap may be exaggerated to help understanding, and descriptions obvious to those skilled in the art may be omitted.

In the following description of the examples, when it is proposed that one structural element is formed on or under another structural element, the case where one structural element is directly formed on or under another structural element or the case where another structural element is indirectly formed between the two structural elements is included.

In the present specification, when a structural element "includes" other structural elements, other structural elements may be included unless otherwise specified.

Referring to fig. 1, a plastic laminate according to the present invention includes: a core base material layer (100); a first sheet (10) including a first base material layer (210) and a first hard coat layer (310) which are sequentially provided on one surface of the core base material layer (100); and a second sheet (20) including a second base material layer (220) and a second hard coat layer (320) which are provided on the other surface of the core base material layer (100) in this order, wherein the thickness ratio of the first sheet (10) to the second sheet (20) is 1:0.9 to 1: 1.1.

In addition, the above plastic laminate further comprises: a first adhesive layer (410) provided between the core base material layer (100) and the first sheet (10); and a second adhesive layer (420) provided between the core base material layer (100) and the second sheet (20).

In addition, the above plastic laminate may further include one or more layers other than the above-mentioned layers to constitute a plurality of layers. Therefore, the total number of layers of the plastic laminate may be 5 or more, for example, 5 to 15, but is not particularly limited.

Each constituent layer is further specifically described below.

Core substrate layer

The core base material layer is located at the center of the plastic laminate, and functions as a support for the entire structure and provides moldability.

The core base material layer may include a polymer resin, and may include, for example, a transparent polymer resin.

Specifically, the core base material layer may include a polymer resin selected from polyethylene terephthalate (PET), Polyimide (PI), a cycloolefin polymer (COP), polyethylene naphthalate (PEN), Polyethersulfone (PES), Polycarbonate (PC), Polyetheretherketone (PEEK), polyphenylene sulfide (PPS), Polyamide (PA), polycyclohexylenedimethylene terephthalate (PCT), and polypropylene (PP), or an alloy resin thereof (e.g., a PC/PCT alloy resin or a PET/PCT alloy resin).

As a specific embodiment, the core substrate layer includes polycarbonate, polyethylene terephthalate (PET), polycyclohexylene dimethyl terephthalate (PCT), or an alloy resin thereof. More specifically, when the above-described core base material layer includes polycarbonate, it may be more advantageous to impart moldability and suppress curling.

When the thickness of the core base material layer is in the range of 25 μm to 1000 μm, it has a supporting force and moldability to the entire structure, while being advantageous to suppress curling.

For example, the thickness of the core base material layer may be 25 μm or more, 50 μm or more, 100 μm or more, 150 μm or more, 200 μm or more, 250 μm or more, or 300 μm or more. The thickness of the core base material layer may be 1000 μm or less, 700 μm or less, 600 μm or less, 500 μm or less, 450 μm or less, 300 μm or less, 250 μm or less, or 200 μm or less.

As specific examples, the thickness of the core substrate layer may be 25 μm to 500 μm, 50 μm to 500 μm, 100 μm to 500 μm, or 150 μm to 500 μm. As another embodiment, the thickness of the core substrate layer may be 100 μm to 1000 μm, 100 μm to 600 μm, 150 μm to 500 μm, 200 μm to 450 μm, 200 μm to 300 μm, or 300 μm to 500 μm.

First sheet and second sheet

The first sheet includes a first base material layer and a first hard coat layer sequentially disposed on one surface of the core base material layer. The second sheet includes a second base material layer and a second hard coat layer provided on the other surface of the core base material layer in this order.

The first base material layer and the second base material layer are used for supporting the first hard coating layer and the second hard coating layer, respectively.

The thickness ratio of the first sheet to the second sheet may be 1:0.9 to 1: 1.1. When the thickness ratio is within the range, the first sheet and the second sheet are formed in a symmetrical structure with the core base material layer as a center, thereby greatly suppressing the occurrence of curling. More specifically, the thickness ratio of the first sheet to the second sheet may be 1:0.99 to 1: 1.01.

The first sheet and the second sheet may be formed to have a symmetrical structure in a fine layer thickness.

Specifically, the thickness ratio of the first hard coat layer to the second hard coat layer may be 1:0.9 to 1:1.1, and the thickness ratio of the first base material layer to the second base material layer may be 1:0.9 to 1: 1.1.

More specifically, the thickness ratio of the first hard coat layer to the second hard coat layer may be 1:0.99 to 1:1.01, and the thickness ratio of the first base material layer to the second base material layer may be 1:0.99 to 1: 1.01.

When the thicknesses of the first substrate layer and the second substrate layer are each in the range of 10 μm to 500 μm, the hard coat layer can be supported well, while being advantageous in suppressing curling. For example, the thickness of the first base material layer and the second base material layer may be 10 μm or more, 25 μm or more, 50 μm or more, 75 μm or more, 100 μm or more, 150 μm or more, or 200 μm or more. The thickness of the first base material layer and the second base material layer may be 500 μm or less, 400 μm or less, 300 μm or less, 200 μm or less, or 150 μm or less. As a specific example, the thickness of the first substrate layer and the second substrate layer may be 10 μm to 300 μm, 10 μm to 200 μm, 75 μm to 200 μm, 25 μm to 500 μm, or 50 μm to 500 μm. As another embodiment, the thicknesses of the first substrate layer and the second substrate layer may be 10 μm to 500 μm, 50 μm to 300 μm, 100 μm to 200 μm, 100 μm to 150 μm, or 150 μm to 200 μm, respectively. Specifically, the thickness of the core base material layer may be 300 to 500 μm, and the thicknesses of the first base material layer and the second base material layer may be 75 to 200 μm.

The first hard coat layer and the second hard coat layer may have a thickness of 1 μm or more, 2 μm or more, 3 μm or more, 4 μm or more, or 5 μm or more, respectively. The first hard coat layer and the second hard coat layer may have a thickness of 50 μm or less, 30 μm or less, 20 μm or less, 10 μm or less, 8 μm or less, 7 μm or less, or 6 μm or less, respectively. For example, the thicknesses of the first hard coating layer and the second hard coating layer may be 1 μm to 50 μm, 1 μm to 30 μm, 1 μm to 20 μm, 1 μm to 10 μm, 3 μm to 10 μm, or 5 μm to 10 μm, respectively. Specifically, when the thickness of the first hard coat layer and the second hard coat layer is 3 μm to 6 μm, it is advantageous to suppress curling.

The first substrate layer and the second substrate layer may include a polymer resin, and specifically, may include a transparent polymer resin.

For example, the first substrate layer and the second substrate layer may include a polymer resin selected from polyethylene terephthalate (PET), Polyimide (PI), a cycloolefin polymer (COP), polyethylene naphthalate (PEN), Polyethersulfone (PES), Polycarbonate (PC), Polyetheretherketone (PEEK), polyphenylene sulfide (PPS), Polyamide (PA), polycyclohexylenedimethylene terephthalate (PCT), and polypropylene (PP), or an alloy resin thereof (e.g., a PC/PCT alloy resin or a PET/PCT alloy resin).

In one embodiment, the first substrate layer and the second substrate layer may respectively include polycarbonate, polyethylene terephthalate (PET), polycyclohexylene dimethyl terephthalate (PCT), or an alloy resin thereof. More specifically, when the first substrate layer and the second substrate layer include polycarbonate, it may be more advantageous to impart stability after molding and suppression of curling.

The first hard coat layer and the second hard coat layer are provided on the outer side of the plastic laminate to improve surface hardness, stain resistance, and printability.

The first hard coating layer and the second hard coating layer may include a thermoplastic resin, a thermosetting resin, an Ultraviolet (UV) curable resin, or the like, and preferably, may include an ultraviolet curable resin to increase surface hardness to exhibit high hard coatability.

As specific examples, the thermoplastic resin and the thermosetting resin may be an acrylic resin, a polyurethane resin, an epoxy resin, a urethane acrylate resin, an epoxy acrylate resin, a cellulose resin, an acetal resin, a melamine resin, a phenol resin, a silicon resin, a polyester resin, a polycarbonate resin, a polyethylene resin, a polystyrene resin, a polyamide resin, a polyimide resin, a mixture thereof, or the like.

The ultraviolet curable resin may be a photopolymerizable prepolymer that is crosslinked and cured by irradiation with ultraviolet light, and the photopolymerizable prepolymer may be a cationic polymerization type photopolymerizable prepolymer or a radical polymerization type photopolymerizable prepolymer. For example, the cationic polymerization type photopolymerizable prepolymer may be an epoxy resin, a vinyl ester resin, or the like, and the epoxy resin may be a bisphenol type epoxy resin, a phenol type epoxy resin, an alicyclic epoxy resin, an aliphatic epoxy resin, or a mixture thereof. Preferably, the above-mentioned radical polymerizable photopolymerizable prepolymer may use an acrylic prepolymer (hard prepolymer) having two or more acryloyl groups in one molecule and forming a three-dimensional network structure by crosslinking curing in consideration of hard coatability.

For example, the acrylic prepolymer may be urethane acrylate, polyester acrylate, epoxy acrylate, melamine acrylate, polyfluoroalkyl acrylate, silicone acrylate, a mixture thereof, and the like. For example, the urethane acrylate prepolymer may be esterified by reacting a urethane oligomer with (meth) acrylic acid, and the urethane oligomer may be obtained by reacting a polyether polyol or a polyester polyol with a polyisocyanate. For example, the polyester acrylate prepolymer may be obtained by esterifying hydroxyl groups of a polyester oligomer having hydroxyl groups at both ends, which is obtained by condensing a polycarboxylic acid and a polyhydric alcohol, with (meth) acrylic acid, or may be obtained by esterifying hydroxyl groups at the ends of an oligomer, which is obtained by adding an alkylene oxide to a polycarboxylic acid, with (meth) acrylic acid. For example, the epoxy acrylate prepolymer can be obtained by esterifying the oxirane ring of a low molecular weight bisphenol epoxy resin or a novolac epoxy resin with (meth) acrylic acid.

The additional functions required for each layer can be achieved by adding different additives to the first hard coating layer and the second hard coating layer, respectively. For example, the above-mentioned first hard coat layer may include an anti-fouling agent to prevent fingerprints, stains, scratches, etc., while having excellent surface hardness. In addition, the above-mentioned second hard coat layer may include a leveling agent to fulfill a function of facilitating mold formation or printing as a primer layer.

For example, the antifouling agent may include at least one selected from the group consisting of silicone polyether acrylate, polyether-modified acrylic functional siloxane, fluoropolyether, and fluoroacrylic compound, and the leveling agent may include at least one selected from the group consisting of non-silicone acrylic compound and fluoroacrylic compound.

The antifouling agent and the leveling agent may be added in an amount of 0.001 to 3 wt% or 0.01 to 1 wt%, respectively, based on the weight of each of the first hard coat layer and the second hard coat layer.

The first hard coat layer and the second hard coat layer may further include common additives such as an antioxidant, a light stabilizer, and a photoinitiator.

The first hard coat layer and the second hard coat layer may include urethane acrylate oligomer resins or resins derived therefrom having a functional group of 1 to 10, 2 to 10, 4 to 10, 6 to 10, or 4 to 8, and may further include organic silica or the like in order to improve abrasion resistance.

Specifically, the first hard coat layer and the second hard coat layer include urethane acrylate oligomer resin or resin derived therefrom having a thickness of 3 to 6 μm and 6 to 10 functional groups.

In addition, both the first hard coat layer and the second hard coat layer have excellent three-dimensional (3D) formability.

First and second adhesive layers

The first adhesive layer is provided between the core base material layer and the first sheet to improve adhesive force between the core base material layer and the first sheet and to impart moldability. The second adhesive layer is provided between the core base material layer and the second sheet to improve the adhesive force between the core base material layer and the second sheet and to impart moldability.

The thickness ratio of the first adhesive layer to the second adhesive layer may be 1:0.5 to 1: 1.5. When the thickness ratio is within the above range, the core base material layer has a more symmetrical structure on both sides, thereby suppressing the occurrence of curling. More specifically, the thickness ratio of the first adhesive layer and the second adhesive layer may be 1:0.9 to 1: 1.1.

The thickness of the first adhesive layer and the second adhesive layer may be 1 μm to 50 μm, 3 μm to 30 μm, 5 μm to 20 μm, 5 μm to 15 μm, 7 μm to 12 μm, or 8 μm to 12 μm. Specifically, the thickness of the first adhesive layer and the second adhesive layer may be 5 μm to 15 μm. When within the above thickness ratio range, it may have excellent surface adhesion while being more advantageous to suppress curling.

The first adhesive layer and the second adhesive layer may include an adhesive resin, and may further include a curing agent and/or a photoinitiator, respectively.

For example, the adhesive resin may be, but is not limited to, a resin that is cured by ultraviolet irradiation, and thus the first adhesive layer and the second adhesive layer may be manufactured by ultraviolet curing. The binder resin may be a resin that is not yellowed by ultraviolet light and has good dispersibility in an ultraviolet absorber. For example, the binder resin may be a polyester resin, an acrylic resin, an alkyd resin, an amino resin, or the like. The binder resin may be used alone, or two or more kinds of copolymers or mixtures thereof may be used. Among them, acrylic resins having excellent optical properties, weather resistance, adhesion to the base material layer, and the like are preferable. The binder resin may be Optically Clear Adhesive (OCA).

The curing agent may be any material capable of curing the binder resin, and is not particularly limited. Specifically, the above curing agent may comprise at least one selected from the group consisting of an isocyanate curing agent which is not yellowed by ultraviolet light, an epoxy curing agent and an aziridine curing agent. In addition, the content of the curing agent may include 0.2 to 0.5 wt%, 0.3 to 0.45 wt%, or 0.35 to 0.45 wt%, based on the respective weights of the first and second adhesive layers.

The photoinitiator may include at least one selected from the group consisting of benzophenones (benzophenones), thioxanthones (thioxanthones), α -hydroxyketones (α -hydroxy ketones), ketones (ketones), phenylacetates (phenylglyoxalates), and acryloylphosphine oxides (acryl phosphinides), for example. The photoinitiator may be included in an amount of 0.1 to 5.0 wt% based on the respective weight of the first adhesive layer and the second adhesive layer.

Change in curl and bendability

The above plastic laminate shows very little change in curl (curl) at high temperatures.

For example, the change in curl at the corners of the plastic laminate described above may be within 3.0mm, within 2.0mm, within 1.0mm, within 0.5mm, or within 0.3mm after being left at 140 ℃ for 2 hours. Specifically, the above plastic laminate had a curl change in the corner of a height of 0.3mm or less after being left at 140 ℃ for 2 hours.

Further, the change in curl at the corners of the plastic laminate may be within 3.0mm, within 2.0mm, within 1.0mm, within 0.5mm, or within 0.3mm after being left at 100 ℃ for 72 hours.

In addition, the plastic laminate can suppress the occurrence of cracks during thermoforming due to its excellent bendability. For example, the above plastic laminate may exhibit 7R or less, 6R or less, or 5R or less, specifically, may exhibit 1R to 7R, or 3R to 6R, when bending (bending) measurement is performed using a roll tester or the like.

Examples of laminated structures

According to one embodiment, the thickness ratio of the first sheet to the second sheet is 1:0.9 to 1:1.1, the thickness of the core base material layer is 25 μm to 500 μm, the thickness of the first base material layer and the second base material layer is 10 μm to 200 μm, the thickness of the first hard coat layer and the thickness of the second hard coat layer are 3 μm to 6 μm, the first hard coat layer and the second hard coat layer include a urethane acrylate oligomer resin having 6 to 10 functional groups or a resin derived therefrom, and a change in curl height of 0.3mm or less is present at a corner of the plastic laminate after being left at 140 ℃ for 2 hours.

In addition, the above plastic laminate further comprises: a first adhesive layer provided between the core base material layer and the first sheet; and a second adhesive layer provided between the core base material layer and the second sheet. The thickness ratio of the first hard coat layer to the second hard coat layer may be 1:0.9 to 1:1.1, the thickness ratio of the first base material layer to the second base material layer may be 1:0.9 to 1:1.1, and the thickness ratio of the first adhesive layer to the second adhesive layer may be 1:0.5 to 1: 1.5.

The total thickness of the above plastic laminate may be 100 μm to 1000 μm, 400 μm to 1000 μm, 500 μm to 900 μm, 500 μm to 750 μm, 700 μm to 900 μm, or 600 μm to 900 μm.

In addition, when the plastic laminate includes at least one decorative layer, it is preferable to maintain a laminated structure in which the core substrate layer is bilaterally symmetrical with respect to the center, and specifically, the ratio of the total thickness of the layers provided on one surface of the core substrate layer (for example, the thickness of the first sheet including the decorative layer) to the total thickness of the layers provided on the other surface of the core substrate layer (for example, the thickness of the second sheet including the decorative layer) may be 1:0.9 to 1: 1.1.

Composition of decorative function

According to the present invention, at least one of the plurality of layers constituting the plastic laminate is a layer having a decorative function (i.e., a decorative layer).

According to one embodiment, the plastic laminate comprises at least one decorative layer, or at least one decorative layer is comprised between the layers constituting the plastic laminate or on the surface of the plastic laminate.

That is, in the plastic laminate, the aforementioned plurality of layers (the core base material layer, the first base material layer, the second base material layer, the first hard coat layer, the second hard coat layer, the first adhesive layer, and the second adhesive layer) and/or the remaining layers may be configured as a decorative layer. Therefore, the plastic laminate according to the present invention is suitable for a decorative layer in a laminate that can replace a glass material to enhance aesthetic effects.

For example, at least any one of the core substrate layer, the first substrate layer, the second substrate layer, the first hard coat layer, the second hard coat layer, the first adhesive layer, and the second adhesive layer mentioned above may be used as the decorative layer. As a specific example, as shown in fig. 3, the second substrate layer of the plastic laminate may be a decorative layer (220'). Alternatively, the first sheet (i.e., the first base layer and the first hard coat layer) or the second sheet (i.e., the second base layer and the second hard coat layer) of the plastic laminate may be a decorative layer.

Alternatively, in the above plastic laminate, the remaining structural layer other than the above-mentioned layer may be a decorative layer. Specifically, the plastic laminate may further include at least one decorative layer on a surface of the first sheet or the second sheet. Further, a decorative layer may be provided between the core base material layer and at least one of the first base material layer and the second base material layer.

As an example, the plastic laminate of the present invention may include a colored (tint) film used as a decorative layer. The colored film is a film which shows a specific color by applying a dye or a pigment to a polymer film. For example, at least one layer constituting the above plastic laminate may be a decorative layer including a dye or a pigment. Specifically, at least one of the first hard coat layer and the second hard coat layer may be a decorative layer including a dye or a pigment, or a decorative layer including a dye or a pigment may be provided between at least one of the first substrate layer and the second substrate layer and the core substrate layer. Alternatively, at least one of the first adhesive layer and the second adhesive layer of the plastic laminate may be a decorative layer including a dye or a pigment. For example, as shown in fig. 2, the second adhesive layer of the above plastic laminate may be a decorative layer (420') including a dye or a pigment.

As another embodiment, in the plastic laminate according to the present invention, at least one of the first substrate layer and the second substrate layer may be a decorative layer selected from a color filter, a multilayer reflective polarizing film, a dichroic filter, a patterned film, and a deposited film.

The color filter refers to a film that adjusts the color of transmitted light by blocking the transmission of light in a specific wavelength band. The color filter may embody a color by absorbing a dye or pigment in a visible light region. The color filter may include at least one selected from a thermosetting resin and an Ultraviolet (UV) curable resin, and specifically, may include a thermosetting or ultraviolet curable urethane resin, an acrylic resin, an epoxy resin, and the like. In addition, the color filter may further include a dye or a pigment dispersion, and the pigment dispersion may include a pigment and an oligomer compound having at least one of 3 to 8 hydroxyl groups and carbonyl groups. The content of the dye may be 0.001 to 3 wt%, specifically 0.01 to 1 wt%, based on the total weight of the color filter, and the content of the pigment dispersion may be 2 to 5 wt%, specifically 2 to 4 wt%, based on the total weight of the color filter. The dye used in the color filter may be at least one dye having a band of an absorption wavelength of 380nm to 780nm, and the dye may be at least one dye selected from hydroxybenzotriazole (hydroxybenzotriazole) type, tetraazaporphyrin (tetrazaporphyrin) type, cyanine (cyanine) type, pyrromethene (pyrromeine) type, rhodamine (rhodamine) type, and borodipyrromethene (borodipyrromethene) type. The pigment used in the above color filter may have an average particle diameter of 30nm to 150nm, particularly 30nm to 100nm, or may have an absorption wavelength in a band of 380nm to 780 nm. The above-mentioned pigment may be contained in an amount of 0.1 to 10% by weight, specifically 0.2 to 4% by weight, based on the total weight of the pigment dispersion.

The multilayer reflective polarizing film is a film in which a desired optical effect is produced by a plurality of thin films stacked inside, and may be a Dual Brightness Enhancement Film (DBEF) in general. Specifically, the above-described multilayer reflective polarizing film may include at least two films having different optical properties in a stacked form. As shown in fig. 4, the multilayer reflective polarizing film may have a plurality of film laminates (M) in both skin layers (S). In this case, the different optical property of the film may be a refractive index or a phase difference.

The dichroic filter is an optical filter that selectively transmits light according to wavelength, and may include, for example, a high-pass filter that transmits light of high wavelength and reflects light of low wavelength, a low-pass filter that transmits light of low wavelength and reflects light of high wavelength, and the like. The dichroic filter described above may also include at least two films having different optical characteristics in a stacked form.

The patterned film is a film for realizing a design pattern such as a specific figure or a character, and may be formed into a desired pattern by ultraviolet curing after in-mold injection molding a polymer resin composition, and the composition may include a polymer resin obtained by polymerizing at least one selected from a urethane acrylic oligomer, an amine monomer, and a carboxyl monomer.

The deposited film is a film that uses a color of an inorganic substance or deposits an inorganic substance to generate a metallic luster or a reflective effect, and for example, at least one inorganic substance may be formed by non-conductive vacuum deposition (NCVM). The deposition film may include at least one inorganic substance selected from Nb, Si, Ti, In, Ag, and Sn.

The light shielding film may block light to further improve reflection efficiency. The light-shielding film may include a desired photograph, pattern, various colors, pattern, etc., as required. Specifically, the light shielding film may include black ink.

As another example, in the plastic laminate of the present invention, the surface of the second sheet may include a pattern layer as a decorative layer or a combination of the pattern layer and an inorganic deposition layer. Specifically, as shown in fig. 6, the decorative layer may be a combination of the pattern layer (500) and the inorganic deposition layer (600), the pattern layer (500) may be disposed on a surface of the second sheet (20), and the inorganic deposition layer (600) may be disposed on a surface of the pattern layer (500). At this time, the inorganic deposition layer may also serve as a planarization layer for reducing level differences of the pattern layer. Alternatively, a separate planarization layer other than the above-described inorganic deposition layer may also be provided.

The pattern layer is a layer for realizing a design pattern such as a specific figure or a character, and may be formed into a desired pattern by ultraviolet curing after in-mold injection molding a polymer resin composition, and the polymer resin composition may include a polymer resin obtained by polymerizing at least one selected from a urethane acrylic oligomer, an amine monomer, and a carboxyl monomer. As an example, as shown in fig. 5, a pattern layer (500) as a decorative layer may be provided on the surface of the plastic laminate. The thickness of the above-described pattern layer may be 10 μm to 20 μm, specifically, 10 μm to 17 μm, or 15 μm to 17 μm.

The inorganic deposition layer is a layer that uses a color of an inorganic substance or deposits an inorganic substance to generate a metallic luster or a reflective effect, and for example, at least one inorganic substance may be formed by non-conductive vacuum deposition (NCVM). The inorganic deposition layer may include at least one inorganic substance of Nb, Si, Ti, In, Ag, and Sn. The thickness of the above inorganic deposition layer may be 0.01 to 0.1 μm, and specifically, may be 0.02 to 0.05 μm.

In addition, the plastic laminate may further include a light-shielding printed layer on the outer side thereof. The light-shielding printed layer can block light to further improve the reflection efficiency. The light-shielding printing layer can comprise required photos, patterns, various colors, patterns and the like according to requirements. Specifically, the light-shielding printed layer may include black ink. The thickness of the light-shielding printed layer may be 10 μm to 50 μm, specifically, 15 μm to 20 μm.

Method for producing plastic laminate

The method for manufacturing the plastic laminate includes: a step of forming a first hard coat layer on the first base material layer to obtain a first sheet; a step of forming a second hard coat layer on the second base material layer to obtain a second sheet; laminating the first sheet so that the first base material layer faces one surface of the core base material layer; and a step of laminating the second sheet so that the second base material layer faces the other surface of the core base material layer, wherein the thickness ratio of the first sheet to the second sheet is 1:0.9 to 1: 1.1.

The plastic laminate thus manufactured has the structure as described above. According to one embodiment, the thickness ratio of the first sheet to the second sheet is 1:0.9 to 1:1.1, the thickness of the core base material layer is 25 μm to 500 μm, the thickness of the first base material layer and the second base material layer is 10 μm to 200 μm, the thickness of the first hard coat layer and the thickness of the second hard coat layer are 3 μm to 6 μm, the first hard coat layer and the second hard coat layer include urethane acrylate oligomer resin having 6 to 10 functional groups or resin derived therefrom, and a curl change of a height of 0.3mm or less is generated at a corner of the plastic laminate after being left at 140 ℃ for 2 hours.

The step of laminating the first sheet on one surface of the core base material layer and the step of laminating the second sheet on the other surface of the core base material layer may be performed sequentially or simultaneously.

Preferably, the step of laminating the first sheet on one surface of the core base material layer and the step of laminating the second sheet on the other surface of the core base material layer are performed simultaneously, which is more advantageous to suppress the occurrence of curl by forming a symmetrical structure.

In addition, the above plastic laminate may be manufactured as the above-mentioned plurality of layers or a plurality of layer structures including at least one layer in addition to the above-mentioned plurality of layers.

For example, the method for manufacturing the plastic laminate further includes a step of forming a first adhesive layer and a second adhesive layer on one surface and the other surface of the core base material layer, respectively, before the step of laminating the first sheet on one surface of the core base material layer and the step of laminating the second sheet on the other surface of the core base material layer. In this case, a thickness ratio of the first adhesive layer and the second adhesive layer may be 1:0.5 to 1: 1.5.

According to the present invention, at least one of the plurality of layers constituting the plastic laminate is a layer having a decorative function. According to one embodiment, at least one of the layers constituting the plastic laminate is a decorative layer, or at least one decorative layer is formed between the layers constituting the plastic laminate or on the surface of the plastic laminate. The types and properties of the decorative layer are as described above.

For example, at least one of the core base material layer, the first base material layer, the second base material layer, the first hard coat layer, the second hard coat layer, the first adhesive layer, and the second adhesive layer of the plastic laminate may be used as the decorative layer. That is, dyes, pigments, or the like may be added to these layers to form a decorative layer, or a decorative layer such as a color filter or a multilayer reflective polarizing film prepared in advance may be applied to these layers. In addition, an additional decorative layer may be further provided between at least one of the first substrate layer and the second substrate layer and the core substrate layer.

According to a specific embodiment, the method for manufacturing a plastic laminate further includes a step of adding a dye or a pigment to at least one of the first hard coat layer and the second hard coat layer to form a decorative layer, or a step of forming a decorative layer including a dye or a pigment between at least one of the first base material layer and the second base material layer and the core base material layer. Alternatively, the method for manufacturing the plastic laminate may further include a step of adding a dye or a pigment to at least one of the first adhesive layer and the second adhesive layer to form a decorative layer. Alternatively, a decorative layer such as a color filter or a multilayer reflective polarizing film may be applied to at least one of the first substrate layer and the second substrate layer to produce a plastic laminate.

In addition, the method for manufacturing the plastic laminated body further comprises a step of forming a pattern layer or a combination of the pattern layer and an inorganic deposition layer as a decorative layer on the surface of the second sheet. Specifically, the pattern layer may be formed by subjecting a polymer resin composition to in-mold injection molding or ultraviolet curing after pattern transfer with a pattern roll, and the inorganic deposition layer may be formed by non-conductive vacuum deposition (NCVM) of at least one inorganic substance.

Effect of Plastic laminate

It can be seen that the plastic laminate according to the present invention includes the plastic film formed with the hard coating layer in a symmetrical structure, so that the generation of curling can be minimized also in a high temperature environment. Further, by adjusting the thickness, the composition, and the process conditions of each layer of the plastic laminate, not only dimensional stability but also properties such as stain resistance and printability can be further improved. In particular, a layer having a decorative function such as a coloring film, a color filter, a multilayer reflective polarizing film, a pattern layer, an inorganic deposition layer, etc. is used in the above plastic laminate to provide a desired aesthetic effect.

Shaped body

The plastic molded article molded from the plastic laminate has high durability, is reduced in cost due to the multi-functional composite structure, and has an aesthetic effect. Therefore, the glass material can effectively replace the prior glass material and is suitable for the front cover or the rear cover of the mobile equipment.

The plastic molded body as described above can be produced by a method such as thermoforming (thermoforming) from a plastic laminate, and in the molding process, not only can the occurrence of curling due to the interlayer structure and composition of the plastic laminate be suppressed, but also cracks occurring in the bent portion of the edge (edge) can be suppressed.

Hereinafter, the effect of the symmetrical structure of the plastic laminate to suppress the generation of curl at high temperature is described by experimental examples. However, the following experimental examples are merely examples showing the relationship between the symmetrical structure of the plastic laminate and the generation of curling at high temperature, and the scope of the present invention is not limited to the structure of the plastic laminate shown in the experimental examples.

In the following experimental examples, a product of V7610 of SKC company was used as a polyethylene terephthalate (PET) film, and a product of CCL series of eca (I-component) company was used as a Polycarbonate (PC) film, unless otherwise specified.

Experimental example 1

1A, preparation of the film

PET films or PC films (samples 1-1 to 1-7) were prepared in monolayers of various thicknesses. In addition, films in which two of the above PET films or PC films were laminated were prepared (samples 1 to 9 and 1 to 11).

In addition, hard coating films (samples 1 to 8) were prepared by coating a Hard Coating (HC) resin composition having a thickness of about 15 μm on the above PET film. At this time, a hard coat resin composition was prepared by mixing 47.6 parts by weight of urethane acrylate oligomer type resin (MIRAMERPU620NT, meia (Miwon)) 1.7 parts by weight of a curing agent (Irgacure 184, Ciba (Ciba)) and 50.7 parts by weight of a solvent (toluene). The above hard coat resin composition is coated on the surface of the base layer using a Meyer bar coater or the like, and dried at 80 ℃ for 1 minute, and then at 400mJ/cm²Ultraviolet curing is performed under the conditions of (1).

In addition, two hard coat films prepared as described above were laminated so that the substrate layers thereof were in contact with each other (samples 1 to 10). When laminating the films, an adhesive having a thickness of about 5 μm is applied to the contact surface to perform adhesion. As the adhesive, an ultraviolet acrylate resin (TS-03, NCP Chem) was used, and after the adhesive was applied by using a Meyer bar coater or the like, the layers were laminated by using a laminator and then the thickness was 400mJ/cm ²Ultraviolet curing is performed under the conditions of (1).

1B, test

In order to measure the initial curl of each film sample produced, the maximum value of the flying height from the bottom of the film to the four corners was measured. Thereafter, the film was heat-treated at 100 ℃ for 72 hours, and the curl was measured in the same manner. The crimp change was calculated by subtracting the height of the initial crimp from the height of the crimp measured after heat treatment.

The structure and evaluation results of the above samples are shown in table 1 below.

[ TABLE 1 ]

Distinguishing	Layer structure (omitting adhesive layer)	Crimp change
			Sample 1-1	PET(125μm)	0mm
Samples 1 to 2	PET(188μm)	0mm
			Samples 1 to 3	PET(250μm)	0.3mm
Samples 1 to 4	PC(125μm)	0mm
			Samples 1 to 5	PC(200μm)	0mm
Samples 1 to 6	PC(250μm)	0mm
			Samples 1 to 7	PC(380μm)	0mm
Samples 1 to 8	HC(15μm)/PET(188μm)	34mm
			Samples 1 to 9	PET(188μm)/PET(188μm)	2mm
Samples 1 to 10	HC(15μm)/PET(188μm)/PET(188μm)/HC(15μm)	3mm
			Samples 1 to 11	PC(200μm)/PC(200μm)	0mm

As shown in table 1 above, the curl variation of the hard coating film is greater than that of the PET or PC single layer film. In addition, when two hard coating films are laminated in a symmetrical structure, although the curl change thereof is larger than that when two PET or PC films are laminated, the curl change thereof is significantly smaller than that when a single hard coating film is used.

Experimental example 2

2A, preparation of the film

PET films or PC films were prepared at various thicknesses. Films (samples 2-2, 2-4, 2-6 to 2-10) in which the above-described PET film and/or PC film were laminated were prepared.

Further, a hard coat film was prepared by coating a hard coat layer (HC) resin composition having a thickness of about 15 μm on the above PET film, and the hard coat film was laminated with the PET film and/or the PC film (samples 2-1, 2-3, 2-5). In this case, the preparation, application and curing conditions of the hard coating resin composition were the same as those of experimental example 1.

When laminating the films, an adhesive having a thickness of about 5 μm was applied to the contact surface to bond the films, and the type of the adhesive, the application conditions, and the curing conditions were the same as those in experimental example 1.

2B, test

For each film sample produced, the change in curl was tested in the same manner as in experimental example 1 described above, except that the heat treatment conditions were changed to 140 ℃ and 2 hours.

The structure and evaluation results of the above samples are shown in table 2 below.

[ TABLE 2 ]

Distinguishing	Layer structure (omitting adhesive layer)	Crimp change
			Sample 2-1	HC(15μm)/PET(250μm)/PC(125μm)/PET(250μm)	13.0mm
Sample 2-2	PET(250μm)/PC(125μm)/PET(250μm)	11.5mm
			Samples 2 to 3	HC(15μm)/PET(188μm)/PC(250μm)/PET(188μm)	11.5mm
Samples 2 to 4	PET(188μm)/PC(250μm)/PET(188μm)	9.5mm
			Samples 2 to 5	HC(15μm)/PET(125μm)/PC(380μm)/PET(125μm)	7.5mm
Samples 2 to 6	PET(125μm)/PC(380μm)/PET(125μm)	7.0mm
			Samples 2 to 7	PET(250μm)/PC(380μm)	18.0mm
Samples 2 to 8	PC(200μm)/PET(250μm)/PC(200μm)	3.5mm
			Samples 2 to 9	PC(250μm)/PC(300μm)	2.5mm
Samples 2 to 10	PET(250μm)/PET(250μm)	4.5mm

As shown in table 2 above, when the upper/lower layers form a symmetrical structure with the core layer as the center, the curl variation is smaller. In addition, the variation in curl was minimized when the thickness of the PC film (core layer) was 380 μm and the thickness of the PET film (base layer) was 125 μm.

Experimental example 3

3A, preparation of the film

A hard coating film was prepared by coating a hard coating layer (HC) resin composition with a thickness of about 15 μm on the above PET film, and the hard coating film was laminated with a PC film and a PET film (sample 3-1). In this case, the preparation, application and curing conditions of the hard coating resin composition were the same as those of experimental example 1.

Further, hard coat films (sample 3-2 to sample 3-5) were laminated on both surfaces of the PC film as a center, respectively. At this time, the thickness of the hard coat layer is controlled within a range of 9 μm to 15 μm by diluting the hard coat resin composition.

3B, test

The structure and evaluation results of the above samples are shown in table 3 below.

[ TABLE 3 ]

Distinguishing	Layer structure (omitting adhesive layer)	Crimp change
			Sample 3-1	HC(15μm)/PET(125μm)/PC(380μm)/PET(125μm)	7.5mm
Sample 3-2	HC(15μm)/PET(125μm)/PC(380μm)/PET(125μm)/HC(15μm)	5.5mm
			Samples 3 to 3	HC(13μm)/PET(125μm)/PC(380μm)/PET(125μm)/HC(13μm)	5.5mm
Samples 3 to 4	HC(11μm)/PET(125μm)/PC(380μm)/PET(125μm)/HC(11μm)	4.5mm
			Samples 3 to 5	HC(9μm)/PET(125μm)/PC(380μm)/PET(125μm)/HC(9μm)	3.5mm

As shown in table 3 above, when the hard coat films were laminated on and under the core layer as a center, the curl change was small. In addition, the smaller the thickness of the hard coat layer, the smaller the change in curl.

Experimental example 4

4A, preparation of film

A hard coating film was prepared by coating a Hard Coating (HC) resin composition having a thickness of about 9 μm on the above PET film. At this time, the following Hard Coat (HC) resin compositions were used for samples 4-1 to 4-3, respectively. In addition, the coating and curing conditions of the hard coat resin composition were the same as in experimental example 1 described above.

Sample 4-1: 25.4 parts by weight of urethane acrylate oligomer-type resin (solid content 100% by weight, MIRAMER PU620NT, Miwon Co., Ltd.), 1.7 parts by weight of a curing agent (Irgacure 184, Ciba Co., Ltd.), and 50.2 parts by weight of a solvent (toluene)

Sample 4-2: 47.6 parts by weight of urethane acrylate oligomer-type resin (solid content 70% by weight, D7, Miwon Co., Ltd.), 1.7 parts by weight of curing agent (Irgacure 184, Ciba Co., Ltd.), and 50.7 parts by weight of solvent (toluene)

Samples 4-3: 25.4 parts by weight of urethane acrylate oligomer-type resin (solid content 100% by weight, D9, Miwon Co., Ltd.), 1.7 parts by weight of curing agent (Irgacure 184, Ciba Co., Ltd.), and 50.2 parts by weight of solvent (toluene)

Hard coat films were laminated on both surfaces of the PC film, respectively. When laminating the films, an adhesive having a thickness of about 5 μm was applied to the contact surface to bond the films, and the type of the adhesive, the application conditions, and the curing conditions were the same as those in experimental example 1.

4B, test

The structure and evaluation results of the above samples are shown in table 4 below.

[ TABLE 4 ]

Distinguishing	Layer structure (omitting adhesive layer)	Crimp change
			Sample 4-1	HC(9μm)/PET(188μm)/PC(380μm)/PET(188μm)/HC(9μm)	3.5mm
Sample 4-2	HC(9μm)/PET(188μm)/PC(380μm)/PET(188μm)/HC(9μm)	2.0mm
			Sample 4-3	HC(9μm)/PET(188μm)/PC(380μm)/PET(188μm)/HC(9μm)	2.5mm

As shown in table 4, it was confirmed that the variation in curl was varied depending on the composition of the hard coating layer. Specifically, the resin (MIRAMER PU620NT) used for the hard coat layer in sample 4-1 was an oligomer for a high hardness hard coat layer having 6 functional groups, and the resin (D7) used for the hard coat layer in sample 4-2 was an oligomer for a flexible hard coat layer having 9 functional groups. Generally, the higher the hardness of the resin used for the hard coat layer, the higher the wear resistance, but there is a tendency to increase the generation of curling and cracking, and conversely, the lower the hardness of the resin, the lower the wear resistance, but there is a tendency to decrease the generation of curling and cracking. On the other hand, the resin (D9) used for the hard coat layer in sample 4-3 is an oligomer for a flexible hard coat layer having 6 functional groups, and improves the abrasion resistance by introducing the organic silica, while reducing the generation of curl and cracks.

Experimental example 5

5A, preparation of film

A hard coating film was prepared by coating a Hard Coating (HC) resin composition having a thickness of about 9 μm on the above PET film. At this time, the above-mentioned hard coat resin composition was prepared by mixing 47.6 parts by weight of urethane acrylate oligomer type resin (solid content 70% by weight, D7, Miwon), 1.7 parts by weight of curing agent (Irgacure 184, Ciba) and 50.7 parts by weight of solvent (toluene). The application and curing conditions of the hard coat resin composition were the same as in experimental example 1.

Hard coat films were laminated on both surfaces of the PC film, respectively. When laminating the films, the contact surface was coated with an adhesive having a thickness in the range of 5 μm to 10 μm for adhesion, and the kind of the adhesive, coating conditions, and curing conditions were the same as those in the above experimental example 1.

5B, test

The structure and evaluation results of the above samples are shown in table 5 below.

[ TABLE 5 ]

Distinguishing	Layer structure (omitting adhesive layer)	Thickness of adhesive	Crimp change
				Sample 5-1	HC(9μm)/PET(188μm)/PC(380μm)/PET(188μm)/HC(9μm)	5μm	2.0mm
Sample 5-2	HC(9μm)/PET(188μm)/PC(380μm)/PET(188μm)/HC(9μm)	7μm	1.0mm
				Samples 5 to 3	HC(9μm)/PET(188μm)/PC(380μm)/PET(188μm)/HC(9μm)	10μm	0.5mm

As shown in table 5, it was confirmed that the variation in curl varies depending on the thickness of the adhesive layer.

Experimental example 6

6A preparation of the film

The hard coating film is prepared by coating a Hard Coating (HC) resin composition having a thickness in the range of 6 to 9 μm on the above PET film. At this time, the following Hard Coat (HC) resin compositions were used for samples 6-1 to 6-3, respectively. In addition, the coating and curing conditions of the hard coat resin composition were the same as in experimental example 1 described above.

Sample 6-1: 47.6 parts by weight of urethane acrylate oligomer-type resin (solid content 70% by weight, D7, Miwon Co., Ltd.), 1.7 parts by weight of curing agent (Irgacure 184, Ciba Co., Ltd.), and 50.7 parts by weight of solvent (toluene)

Sample 6-2: 47.6 parts by weight of urethane acrylate oligomer-type resin (solid content 70% by weight, D7, Miwon Co., Ltd.), 1.7 parts by weight of curing agent (Irgacure 184, Ciba Co., Ltd.), and 56.8 parts by weight of solvent (toluene)

Samples 6-3: 47.6 parts by weight of urethane acrylate oligomer-type resin (solid content 70% by weight, D7, Miwon Co., Ltd.), 1.7 parts by weight of curing agent (Irgacure 184, Ciba Co., Ltd.), and 60.0 parts by weight of solvent (toluene)

Hard coat films were laminated on both surfaces of the PC film, respectively. When laminating the films, an adhesive having a thickness of about 10 μm was applied to the contact surface to bond the films, and the type of the adhesive, the application conditions, and the curing conditions were the same as those in experimental example 1.

6B, test

The structure and evaluation results of the above samples are shown in table 6 below.

[ TABLE 6 ]

Distinguishing	Layer structure (omitting adhesive layer)	Crimp change
			Sample 6-1	HC(9μm)/PET(188μm)/PC(380μm)/PET(188μm)/HC(9μm)	0.5mm
Sample 6-2	HC(7μm)/PET(188μm)/PC(380μm)/PET(188μm)/HC(7μm)	0.5mm
			Sample 6-3	HC(6μm)/PET(188μm)/PC(380μm)/PET(188μm)/HC(6μm)	0.0mm

As shown in table 6, it was confirmed that the variation in curl was varied depending on the thickness of the hard coat layer.

Experimental example 7

7A preparation of the film

A hard coating film was prepared by coating a Hard Coating (HC) resin composition having a thickness of 6 μm on the above PET film. At this time, the following Hard Coat (HC) resin compositions were used for the front surface/rear surface hard coats of samples 7-1 and 7-2, respectively. In addition, the coating and curing conditions of the hard coat resin composition were the same as in experimental example 1 described above.

Front surface/back surface hard coat of sample 7-1: 47.6 parts by weight of urethane acrylate oligomer-type resin (solid content 70% by weight, D7, Miwon Co., Ltd.), 1.7 parts by weight of curing agent (Irgacure 184, Ciba Co., Ltd.), and 60.0 parts by weight of solvent (toluene)

Front surface hard coat of sample 7-2: 47.6 parts by weight of urethane acrylate oligomer type resin (solid content 70% by weight, D7, Miwon Co.), 1.7 parts by weight of curing agent (Irgacure 184, Ciba Co.), 0.2 parts by weight of antifouling agent (KY-1203, ShinEtsu Co.), and 60.0 parts by weight of solvent (toluene)

Back surface hard coat of sample 7-2: 47.6 parts by weight of urethane acrylate oligomer type resin (solid content 70% by weight, D7, Miwon Co., Ltd.), 1.7 parts by weight of leveling agent (Flow-300; TEGO Co., Ltd.), and 60.0 parts by weight of solvent (toluene)

7B, test

For each film sample produced, the hardcoat layer was evaluated as follows.

-front surface hard coating: measuring contact angle with water

-rear surface hard coating: surface tension measurement Using a dyne Pen (dynepen, Acrotest Co., Ltd.)

The structure and evaluation results of the above samples are shown in table 7 below.

[ TABLE 7 ]

Distinguishing	Layer structure (omitting adhesive layer)	Contact angle	Surface tension
				Sample 7-1	HC(6μm)/PET(188μm)/PC(380μm)/PET(188μm)/HC(6μm)	53°	≤26dyne
Sample 7-2	HC(6μm)/PET(188μm)/PC(380μm)/PET(188μm)/HC(6μm)	110°	30dyne

As shown in table 7, the water contact angle was increased by adding the stain-proofing agent on the front surface hard coat layer, and thus, the stain-proofing or fingerprint-proofing property may be exhibited on the front surface exposed to the outside. In addition, the surface tension is increased by adding a leveling agent to the rear surface hard coat layer, in which case a mold or a print design for decoration may be easily formed.

Experimental example 8

8A, preparation of the film

Sample 4-1 prepared in Experimental example 4 and sample 7-1 prepared in Experimental example 7 were prepared.

8B, test

The prepared sample was subjected to thermoforming (thermoforming), and the generation of curl was observed. Specifically, molding evaluation was performed using a heat molding apparatus (SHT-HTFC 001, Sungho Tech Co., Ltd.) under the following conditions.

1) Forming temperature: 140 deg.C

2) And (3) forming time: preheating (10 seconds), shaping (15 seconds), cooling (60 seconds)

3) A thermoforming clamp: size (72.5mm x 155mm), edge curvature (4R)

The structure and evaluation results of the above samples are shown in table 8 below.

[ TABLE 8 ]

Distinguishing	Layer structure (omitting adhesive layer)	Of the crimp type	Crimp change
				Sample 4-1	HC(9μm)/PET(188μm)/PC(380μm)/PET(188μm)/HC(9μm)	Torsional crimp	≥5mm
Sample 7-1	HC(6μm)/PET(188μm)/PC(380μm)/PET(188μm)/HC(6μm)	Without curling	0mm

As shown in Table 8, sample 7-1 did not develop curl upon thermoforming. In addition, sample 7-1 found no cracks in the hard coat layer after thermoforming, but sample 4-1 found many cracks in the hard coat layer in the edge region.

Experimental example 9

9A preparation of the film

Samples 6-1 to 6-3 prepared in Experimental example 6 were prepared with different hard coating thicknesses.

9B, test

The prepared samples were evaluated for bendability (bending) using a spindle tester (Elcometer cylinder driver tester; model: K1506M 201). In addition, the prepared sample was subjected to heat molding, and whether or not cracks were generated was observed. In this case, the conditions for thermoforming were the same as in experimental example 8. The thickness of the hard coat layer of the above sample and the evaluation results are shown in table 9 below.

[ TABLE 9 ]

Distinguishing	Thickness of hard coat layer	Flexibility	Whether or not cracks are generated
				Sample 6-1	HC(9μm)	8R	Generation of edge cracks
Sample 6-2	HC(7μm)	6R	No generation of cracks
				Sample 6-3	HC(6μm)	5R	No generation of cracks

As shown in table 9, it was confirmed that the molding characteristics varied depending on the thickness of the hard coat layer. In particular, sample 6-3, which had a hard coat layer having a thickness of 6 μm, had the best bendability and did not generate cracks at the time of thermoforming.

Experimental example 10

10A preparation of the film

As the PET film, a product (V7610) having various thicknesses (50 μ M, 75 μ M, 100 μ M) manufactured by SKC was used, and as the PC film, a product having various thicknesses (30 μ M, 50 μ M) manufactured by SKC HT & M was used.

A hard coating film was prepared by coating a Hard Coating (HC) resin composition having a thickness of about 6 μm on the above PET film. At this time, the above hard coat resin composition used the hard coat resin composition of sample 6-3 in the above experimental example 6, and further, the preparation, application and curing conditions of the hard coat resin composition were the same as in the above experimental example 1.

10B, test

For each film sample produced, the change in curl was tested in the same manner as in experimental example 1 described above, except that the heat treatment conditions were changed to 140 ℃ and 2 hours. The structure and evaluation results of the above samples are shown in table 10 below.

[ TABLE 10 ]

Distinguishing	Layer structure (omitting adhesive layer)	Crimp change
			Sample 10-1	HC(6μm)/PET(50μm)/PC(30μm)/PET(50μm)/HC(6μm)	≒0mm
Sample 10-2	HC(6μm)/PET(50μm)/PC(50μm)/PET(50μm)/HC(6μm)	≒0mm
			Sample 10-3	HC(6μm)/PET(75μm)/PC(30μm)/PET(75μm)/HC(6μm)	≒0mm
Sample 10-4	HC(6μm)/PET(75μm)/PC(50μm)/PET(75μm)/HC(6μm)	≒0mm
			Sample 10-5	HC(6μm)/PET(100μm)/PC(30μm)/PET(100μm)/HC(6μm)	≒0mm
Sample No. 10-6	HC(6μm)/PET(100μm)/PC(50μm)/PET(100μm)/HC(6μm)	≒0mm

As shown in Table 10, even when the thicknesses of the PET film and the PC film were controlled to be 100 μm or less, no change in curl was observed at high temperatures in the case of the plurality of laminates (samples 10-1 to 10-6) having a thickness of 6 μm and each having a symmetrical structure.

Experimental example 11

11A, preparation of the film

Sample 11-1: a laminate was prepared in the same preparation steps and process conditions as those of sample 7-2 in experimental example 7, except that a PET film having a thickness of 125 μm was used.

Sample 11-2: a laminate was prepared in the same preparation procedure and process conditions as those of the above sample 11-1, except that the other surface of the front surface hard coat layer (the surface of the PET film on which the hard coat layer was not formed) was further coated with a coloring (tint) coating composition to a thickness of 6 μm. The colored coating composition was prepared by mixing 80 parts by weight of a urethane acrylate oligomer (UV1700B, NIPPON GOHSEI Co.), 15 parts by weight of pentaerythritol triacrylate (M340, Miwon Co.) and 5 parts by weight of a photoinitiator (Irgacure-184, Ciba Co.), diluting the mixture by adding methyl ethyl ketone so that the solid content became 20% by weight, and further adding 1.2% by weight of BO260(Iridose Co.) and 0.8% by weight of Y-1(SKC HT & M Co.).

11B, test

For each film sample produced, the change in curl was tested in the same manner as in experimental example 1 described above, except that the heat treatment conditions were changed to 140 ℃ and 2 hours. The structure and evaluation results of the above samples are shown in table 11 below.

[ TABLE 11 ]

As shown in table 11, even when a colored layer for decoration was introduced, it was confirmed that the curl change hardly occurred under the high temperature (140 ℃ and 2 hours) condition as long as the laminate maintained the thickness ratio between the two hard coat films (i.e., the first sheet and the second sheet) laminated on both surfaces of the core base material layer as a center within a certain range and controlled the thickness/composition of each layer within a desired range.

In addition, even when a decorative layer is formed by adding a dye or a pigment to the hard coat layer and/or the adhesive layer of the laminate sample subjected to the above test, or when a decorative film such as a color filter is used as the base layer, it was confirmed that the curl change hardly occurs under the high temperature (140 ℃ and 2 hours) condition as long as the laminate can maintain the symmetrical structure and the thickness/composition of each layer is controlled within the desired range.

Claims

1. A plastic laminate, comprising:

A core substrate layer;

the first sheet comprises a first substrate layer and a first hard coating layer which are sequentially arranged on one surface of the core substrate layer; and the number of the first and second groups,

a second sheet including a second base material layer and a second hard coat layer sequentially disposed on the other surface of the core base material layer,

the thickness ratio of the first sheet to the second sheet is 1:0.9 to 1:1.1, the thickness of the core substrate layer is 25 μm to 500 μm, the thickness of the first substrate layer and the second substrate layer is 10 μm to 200 μm, the thickness of the first hard coating layer and the second hard coating layer is 3 μm to 6 μm, and the first hard coating layer and the second hard coating layer include urethane acrylate oligomer resin having 6 to 10 functional groups or resin derived therefrom, a curl change of a height of 0.3mm or less is generated at a corner of the plastic laminate after being left at 140 ℃ for 2 hours,

at least one layer constituting the plastic laminate is a decorative layer, or at least one decorative layer is included between layers constituting the plastic laminate or on the surface of the plastic laminate.

2. The plastic laminate as claimed in claim 1, wherein at least one of the first hard coat layer and the second hard coat layer is a decorative layer including a dye or a pigment; alternatively, the first and second electrodes may be,

And a decorative layer comprising dye or pigment is arranged between at least one of the first base material layer and the second base material layer and the core base material layer.

3. The plastic laminate of claim 1, wherein at least one of the first substrate layer and the second substrate layer is a decorative layer selected from the group consisting of a color filter, a multilayer reflective polarizing film, a dichroic filter, a patterned film, and a deposited film.

4. The plastic laminate of claim 3, wherein the multilayer reflective polarizing film and the dichroic filter comprise at least two films having different optical properties in a stack.

5. The plastic laminate as claimed in claim 1, wherein the second sheet includes a pattern layer as a decorative layer or a combination of a pattern layer and an inorganic deposition layer on a surface thereof in the plastic laminate.

6. The plastic laminate as claimed in claim 5, wherein the decorative layer is a combination of the pattern layer and the inorganic deposition layer,

the pattern layer is arranged on the surface of the second sheet material,

the inorganic deposition layer is disposed on a surface of the pattern layer.

7. The plastic laminate as claimed in claim 5, wherein the pattern layer comprises a polymer resin formed by polymerization of at least one selected from the group consisting of a urethane acrylic oligomer, an amine-based monomer, and a carboxyl-based monomer.

8. The plastic laminate according to claim 5, wherein the inorganic deposition layer comprises at least one inorganic substance selected from the group consisting of Nb, Si, Ti, In, Ag, and Sn.

9. The plastic laminate as claimed in claim 1, further comprising:

a first adhesive layer disposed between the core base material layer and the first sheet; and the number of the first and second groups,

a second adhesive layer disposed between the core base material layer and the second sheet,

the thickness ratio of the first adhesive layer to the second adhesive layer is 1:0.5 to 1: 1.5.

10. The plastic laminate as claimed in claim 9, wherein at least one of the first adhesive layer and the second adhesive layer is a decorative layer comprising a dye or a pigment.

11. The plastic laminate of claim 1, wherein the first hard coat layer and the second hard coat layer further comprise an organo-silica.

12. The plastic laminate as claimed in claim 1, wherein the core substrate layer, the first substrate layer and the second substrate layer respectively comprise polycarbonate, polyethylene terephthalate, polycyclohexylenedimethylene terephthalate, or an alloy resin thereof,

the first hard coat layer includes an antifouling agent, the second hard coat layer includes a leveling agent,

the antifouling agent is at least one selected from organosilicon polyether acrylate, polyether modified acrylic functional siloxane, fluoropolyether and fluoroacrylic acid compound,

the leveling agent is at least one selected from non-organic silicon acrylic compounds and fluorine acrylic compounds.

13. The plastic laminate as claimed in claim 1, wherein the core substrate layer has a thickness of 300 μm to 500 μm,

the thickness of the first base material layer and the second base material layer is 75-200 μm.

14. A method of manufacturing a plastic laminate, comprising:

a step of forming a first hard coat layer on the first base material layer to obtain a first sheet;

a step of forming a second hard coat layer on the second base material layer to obtain a second sheet;

a step of laminating the first sheet so that the first base material layer faces one surface of the core base material layer; and the number of the first and second groups,

A step of laminating the second sheet so that the second substrate layer faces the other surface of the core substrate layer,

at least one layer constituting the plastic laminate is a decorative layer, or at least one decorative layer is formed between the layers constituting the plastic laminate or on the surface of the plastic laminate.

15. The method of manufacturing a plastic laminate according to claim 14, further comprising:

a step of adding a dye or a pigment to at least one of the first hard coat layer and the second hard coat layer to form a decorative layer, or a step of forming a decorative layer including a dye or a pigment between at least one of the first substrate layer and the second substrate layer and the core substrate layer.

16. The method of manufacturing a plastic laminate according to claim 14, further comprising:

a step of forming a pattern layer or a combination of a pattern layer and an inorganic deposition layer as a decorative layer on the surface of the second sheet.

17. The method of manufacturing a plastic laminate according to claim 16, wherein the pattern layer is formed by subjecting a polymer resin composition to in-mold injection molding or ultraviolet curing after transferring a pattern to a pattern roll,

forming the inorganic deposition layer by non-conductive vacuum deposition of at least one inorganic substance.

18. The method of manufacturing a plastic laminate according to claim 14, wherein the step of laminating a first sheet on one surface of the core substrate layer and the step of laminating a second sheet on the other surface of the core substrate layer are performed simultaneously.

19. A plastic molded body, characterized by being molded from the plastic laminate according to claim 1.

20. The plastic molded body as claimed in claim 19, wherein the plastic molded body is suitable for a front cover or a rear cover of a mobile device.