KR20120073753A - Infrared ray shielding multi-layer film - Google Patents

Abstract

PURPOSE: An infrared blocking multilayer film is provided to save energy by being attached to a building or exterior glass of a vehicle. CONSTITUTION: An infrared blocking multilayer film is composed of two or more film stacks(1, 2). The average reflectivity of the infrared blocking multilayer film at a wavelength area of 900 to 1,300nm is over 70%. The film stacks are composed of reflective layers(1a, 2a) and protective layers(1b, 2b). The protective layers are laminated on both sides of the reflective layers. The reflecting layers alternately laminate first resin layers(1-1, 2-1) and second resin layers(1-2, 2-2) in a thickness direction more than 2layers.

Description

Infrared cut multilayer film {INFRARED RAY SHIELDING MULTI-LAYER FILM}

The present invention relates to a multilayer film having a higher blocking rate in a wider infrared range than an existing infrared blocking film that can be applied to an exterior glass of a building or an automobile.

Recently, several films have been proposed to lower the room temperature by blocking heat energy from the sun.

For example, a method of manufacturing a film using a material absorbing light in a specific region of infrared light and attaching the film to a glass surface to block thermal energy has been proposed.

However, in this type of film, increasing the blocking rate of infrared rays also blocks light in the visible region, causing cyanide problems, becoming very unstable to UV, and absorbing light in most infrared regions. There is a problem such that the temperature of the glass is increased to reduce the thermal barrier efficiency, the use of the building or automotive exterior glass is limited.

In addition, a method of depositing or coating a metallic material has been proposed. As it blocks not only the infrared region but also the communication region, it causes malfunction of electronic devices in a building or various devices of a vehicle such as a high pass, and has a very high visible light transmittance. There is a disadvantage that the cyan is very low.

Accordingly, an object of the present invention is to provide an infrared blocking film having a high blocking rate in a wide range of infrared rays and a low reflectance of visible light.

In order to achieve the above object, the present invention has a configuration in which two or more film stacks having different reflection wavelength ranges are stacked, and each film stack includes a reflective layer and a protective layer provided on both sides of the reflective layer. The reflective layer may include a first resin layer including polyethylene terephthalate (PET), and polymethyl methacrylate (PMMA), copolymerized polyethylene terephthalate (co-PET), polyethylene naphthalate (PEN), or a mixed polymer thereof. Provided is an infrared blocking multilayer film in which a second resin layer comprising a lamination is formed alternately, and the average reflectance in the 900-1300 nm wavelength region of the whole film is 50% or more.

The infrared blocking multilayer film according to the present invention exhibits excellent infrared blocking ratio in a wider infrared region than in the prior art, and does not include a metal material, and thus has a high transmittance in the visible region and hardly exhibits color . Therefore, it can be installed in the exterior glass of the building or automobile as an infrared blocking film to reduce energy consumption in summer or to prevent the loss of heating heat in winter.

1 is a cross-sectional view of an infrared blocking multilayer film according to an example of the present invention.
2 is a spectrum result obtained by irradiating light to the multilayer film prepared in Example 1.
3 is a spectrum result obtained by irradiating light to the multilayer film prepared in Comparative Example 3.

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

1 is a cross-sectional view showing an example of an infrared blocking film according to the present invention with reference to this, the infrared blocking multilayer film of the present invention is composed of two or more film stacks (1, 2), each film stack is a reflective layer (1a, 2a) and protective layers 1b, 2b laminated on both surfaces of the reflective layer. Each of the reflective layers 1b and 2b has a configuration in which the first resin layers 1-1 and 2-1 and the second resin layers 1-2 and 2-2 are alternately stacked in two or more layers in the thickness direction. .

In order for the infrared blocking film to be used industrially, various physical property values must be satisfied. Particularly, the required physical properties are high-order reflection or n-th order reflection generated due to the blocking rate in the IR region and the characteristics of light. In particular, in the case of the infrared ray blocking rate, the average reflectance for the 900-1300 nm range, which is a region where heat is substantially present, in the infrared region (800-2500 nm) needs to be 50% or more. In addition, when higher order reflection or n-th order reflection occurs, not only the film exhibits a specific range of colors but also the transparency decreases, so that the visible light reflectance in the high order reflection region does not exceed 40%.

The film of the present invention is characterized in that the average reflectance is 50% or more in the infrared wavelength region of 900 ~ 1,300nm, preferably the average reflectance in the wavelength range is 70% or more, more preferably 80% or more.

For example, the infrared blocking multilayer film includes a first film stack and a second film stack, the average reflectance over a wavelength range of 900 to 1,000 nm of the first film stack is 50% or more, and the second film stack It can be configured that the average reflectance over the wavelength range of 1,000 ~ 1,300nm of 50% or more.

In addition, the film of the present invention may have an average reflectance of visible light (400 ~ 780nm) is preferably less than 40% and more preferably less than 20% physical properties.

In the multilayer film of the present invention, the first resin layer constituting the reflective layer contains PET, and the second resin layer contains PMMA, co-PET, PEN or a mixed polymer thereof. In this case, the PET has a crystallinity of 0% to 80%, more preferably 10% to 70%, and most preferably 40% to 60%. In addition, the co-PET is preferably a copolymer of ethylene glycol (EG) and neopentyl glycol (NPG) as a glycol component, for example, the content of NPG in the glycol component may be copolymerized to 5 to 80 mol%, preferably Preferably it is 10-30 mol%, Most preferably, it copolymerizes with 15-25 mol%.

In addition, the protective layer preferably comprises PET.

In the said reflection layer, it is preferable that the weight ratio of a 1st resin layer and a 2nd resin layer is 1.5: 1-1: 1.5.

In the multilayer film of the present invention, the average thickness of the individual resin layers (first resin layer or second resin layer) constituting the reflective layer is preferably 50 nm to 800 nm, more preferably 60 nm to 200 nm.

It is preferable that the thickness of a 1st resin layer and a 2nd resin layer is comprised differently, For example, the ratio of the thickness of the 1st resin layer and the 2nd resin layer laminated alternately is 1: 0.3-1: 2 days. Can be. The average thickness of the first resin layer is 50 nm to 200 nm, and the average thickness of the second resin layer is 60 nm to 300 nm.

The thicknesses of the first resin layer and the second resin layer alternately stacked in the reflective layer may be configured to be constant, or may be configured to gradually increase or decrease. When laminating to a certain thickness, the reflectance can be increased in the infrared region, and when laminating with varying thickness, the reflecting region (nm) of the infrared can be widened.

The total thickness of the reflective layer is preferably 10 µm to 100 µm, more preferably 10 µm to 80 µm. In addition, the thickness of the protective layer is preferably 1 µm to 30 µm, particularly preferably 3.5 µm to 15.0 µm. By making thickness of a protective layer into the said range, the interlayer uniformity of a reflective layer can be maintained.

The infrared blocking multilayer film of the present invention comprises at least two film stacks (e.g., first film stack and second film stack), and the total thickness thereof is preferably different from each other, preferably the first film stack and the first film stack The thickness ratio of the two film stacks is 1: 1.1 to 1: 3, more preferably 1: 1.1 to 1: 2, and particularly preferably 1: 1.1 to 1: 1.5. When stacking a plurality of film stacks while gradually changing the thickness of the film stack, it is possible to widen the infrared reflecting area.

An example of the infrared blocking multilayer film of the present invention includes a first film stack and a second film stack, wherein the average thickness of the first resin layer in the first film stack is 70 to 120 nm and the average thickness of the second resin layer is 110-130 nm, the average thickness of the 1st resin layer in a said 2nd film stack is 110-160 nm, and the average thickness of a 2nd resin layer is 150-190 nm.

Although the total thickness of the infrared blocking film of this invention formed by laminating | stacking such many film stacks is not specifically limited, It is preferable that it is 10 micrometers-100 micrometers, and it is more preferable that it is 20 micrometers-80 micrometers.

The first resin layer and the second resin layer preferably contain different polymers having different refractive indices so that the difference in refractive index becomes 0.05 or more.

In addition, the film of the present invention can be biaxially stretched to further increase the refractive index difference between the resin layers, wherein the stretching ratio in the longitudinal and transverse directions is preferably 2.0 times to 5.0 times, and more preferably 3.0 times to 4.5 times. .

The film stack constituting the film of the present invention can be formed at the bottom of the feed block constituting the multilayer.

In the multilayer film of the present invention, each reflective layer is preferably composed of 50 to 400 layers, more preferably 70 to 250 layers. By setting the reflecting layer within the above range, the phenomenon in which color can be suppressed by minimizing the reflectance in the visible light region can be suppressed, and a high reflectance can be obtained at a wavelength of 900 to 1,300 nm in the infrared region.

Such an infrared blocking multilayer film of the present invention exhibits a higher infrared ray blocking rate in a wider infrared region than in the prior art, and since it does not contain a metal material, the transmittance in the visible ray region is high and hardly exhibits color. Infrared shielding film can be used to reduce energy consumption in summer or to prevent heat loss during winter.

Hereinafter, the present invention will be described in more detail based on the following examples. However, the following examples are only for illustrating the present invention, and the scope of the present invention is not limited thereto.

The resins used in the following examples and comparative examples are as follows:

PET-Manufacturer: SKC

PMMA-Manufacturer: LG chem, Normal Grade

co-PET-Manufacturer: SKC, Copolymerization Component: EG / NPG, Copolymerization Ratio: NPG 10 ~ 30mol%

PBT-manufacturer: LGChem, product name: Keflex BT

PEN-manufacturer: SKC

Example  One

Step 1) Preparation of Film Stack

As the first resin, a PET resin (40 to 60%) having a crystallinity of 75% or more is vacuum-air-conditioned at 120 ° C for at least 2 hours, vacuum-air-conditioned at 180 ° C for at least 3 hours, and then melted and extruded at about 200-300 ° C. The resin layer was produced. In addition, a second resin layer was prepared by melting and extruding PMMA resin as a second resin at a temperature of about 200 to 260 ° C.

The first resin layer and the second resin layer are alternately stacked by using a multilayer feed block, and the extrusion amount is controlled so that the weight ratio of the first resin layer and the second resin layer is maintained at 1: 1.1, and both outermost layers are formed. It became 2 resin layers, and the reflective layer which consists of 93 layers in total was formed. Thereafter, PET films were applied to both surfaces of the prepared reflective layer to form a protective layer, thereby completing the film stack.

Step 2) Distribute the Stack

The first film stack and the second film stack are made by dividing the prepared film stack in a longitudinal direction using a stack distributor, and the thickness of the first film stack is changed by using a device having a thickness ratio of 1: 1.5. After it was laminated to a second film stack, a total of 190 layers of multilayer film were completed through the die.

Step 3) Drawing Process

The obtained multilayer film was stretched 3.5 times in the longitudinal direction and 4.5 times in the transverse direction.

The total thickness of the finally produced multilayer film was 45 μm, and the thicknesses of the first film stack and the second film stack were 18 μm and 27 μm, respectively. In addition, the average thickness of the first resin layer constituting the reflective layer of the first film stack was about 110 nm, the average thickness of the second resin layer was about 120 nm, and the average thickness of the first resin layer constituting the reflective layer of the second film stack. Was about 150 nm and the average thickness of the second resin layer was about 160 nm.

Example 2

Except for changing the weight ratio of PET resin and PMMA resin to 1: 1.5 in the reflective layer, it was prepared according to the procedure of steps 1) to 3) of Example 1.

The total thickness of the finally produced multilayer film was 45 μm, and the thicknesses of the first film stack and the second film stack were 18 μm and 27 μm, respectively. In addition, the average thickness of the first resin layer constituting the reflective layer of the first film stack was about 100 nm, the average thickness of the second resin layer was about 130 nm, and the average thickness of the first resin layer constituting the reflective layer of the second film stack. Was about 130 nm and the average thickness of the second resin layer was about 180 nm.

Example 3

Except for changing the weight ratio of PET resin and PMMA resin to 1.5: 1 in the reflective layer, it was prepared according to the same procedure as in step 1) to 3) of Example 1.

The total thickness of the finally produced multilayer film was 45 μm, and the thicknesses of the first film stack and the second film stack were 18 μm and 27 μm, respectively. In addition, the average thickness of the first resin layer constituting the reflective layer of the first film stack was about 130 nm, the average thickness of the second resin layer was about 100 nm, and the average thickness of the first resin layer constituting the reflective layer of the second film stack was Was about 180 nm and the average thickness of the second resin layer was about 130 nm.

Example 4

Except for using a co-PET resin instead of PMMA resin in the reflective layer, it was prepared according to the same procedure as in step 1) to 3) of Example 1.

Example 5

Except for using a PEN resin instead of PMMA resin in the reflective layer, it was prepared according to the same procedure as in step 1) to 3) of Example 1.

Comparative Example 1

Except for changing the weight ratio of PET resin and PMMA resin to 1: 2 in the reflective layer, it was prepared according to the same procedure as in step 1) to 3) of Example 1.

The total thickness of the finally produced multilayer film was 45 μm, and the thicknesses of the first film stack and the second film stack were 18 μm and 27 μm, respectively. In addition, the average thickness of the first resin layer constituting the reflective layer of the first film stack was about 90 nm, the average thickness of the second resin layer was about 140 nm, and the average thickness of the first resin layer constituting the reflective layer of the second film stack. Was about 120 nm and the average thickness of the second resin layer was about 200 nm.

Comparative Example 2

Except for changing the weight ratio of PET resin and PMMA resin to 2: 1 in the reflective layer, it was prepared according to the same procedure as in step 1) to 3) of Example 1.

The total thickness of the finally produced multilayer film was 45 μm, and the thicknesses of the first film stack and the second film stack were 18 μm and 27 μm, respectively. In addition, the average thickness of the first resin layer constituting the reflective layer of the first film stack was about 140 nm, the average thickness of the second resin layer was about 90 nm, and the average thickness of the first resin layer constituting the reflective layer of the second film stack. Was about 200 nm and the average thickness of the second resin layer was about 120 nm.

Comparative Example 3

The same procedure as in Step 1) to 3) of Example 1 was performed except that the stack distribution of Step 2) was not performed.

Comparative Example 4

Except for using a co-PET resin instead of PMMA resin in the reflective layer, it was prepared according to the same procedure as in Comparative Example 1.

Comparative Example 5

Except for using a PBT resin instead of a PMMA resin for the reflective layer was prepared in the same procedure as in Comparative Example 1.

Comparative Example 6

Except for using a PBT resin instead of a PMMA resin in the reflective layer, it was prepared according to the same procedure as in step 1) to 3) of Example 1.

Comparative Example 7

Except for using a PEN resin instead of PMMA resin in the reflective layer, it was prepared according to the same procedure as in Comparative Example 1.

The structure of the multilayer film of the above Example and a comparative example was put together in following Table 1.

division 2nd resin
Kinds ¹⁾ resin
Weight ratio stack
Count ²⁾ stack
Thickness ratio Total thickness
(Μm) Floor
(layer) Example 1 PMMA 1: 1.1 2 1: 1.5 45 190 Example 2 PMMA 1: 1.5 2 1: 1.5 45 190 Example 3 PMMA 1.5: 1 2 1: 1.5 45 190 Example 4 co-PET 1: 1.1 2 1: 1.5 45 190 Example 5 PEN 1: 1.1 2 1: 1.5 45 190 Comparative Example 1 PMMA 1: 2 2 1: 1.5 45 190 Comparative Example 2 PMMA 2: 1 2 1: 1.5 45 190 Comparative Example 3 PMMA 1: 1.1 One - 27 95 Comparative Example 4 co-PET 1: 1.1 One - 27 95 Comparative Example 5 PBT 1: 1.1 One - 27 95 Comparative Example 6 PBT 1: 1.1 2 1: 1.5 45 190 Comparative Example 7 PEN 1: 1.1 One - 27 95 1) Resin weight ratio-weight ratio of the first resin layer and the second resin layer
2) Stack thickness ratio-thickness ratio of the first film stack and the second film stack

Test Example: Infrared Blocking Multilayer Film performance evaluation

The multilayer films produced in Examples and Comparative Examples were evaluated by the following test methods.

(1) infrared ray blocking rate

After cutting the multilayer film 10cm wide x 10cm long, the foreign matter on the surface of the film was removed and placed in a spectrometer (Hunterlab, Ultrascan ^TM Pro) and measured in the reflection mode, and measured in the 900 ~ 1,000nm region and 900 ~ 1,300 The average value of the infrared reflectance (%) in the nm region was respectively measured.

(2) color incidence

After cutting the multilayer film to a width of 21.0 cm x 29.7 cm in length, the foreign matter on the surface of the film was removed and placed in a light transmittance meter (Nippon Densho kukogy, NHD 5000W) to reflect visible light in the area of 400 to 780 nm (%). ) Was measured. [ASTM D 1003 MODE].

(3) reflection spectrum

After cutting the multilayer film 10cm wide x 10cm long, the foreign matter on the surface of the film was removed, and placed in a spectrometer (Hunterlab, Ultrascan ^TM Pro), measured in transmission mode, and the simulation results are shown in FIGS. 2 and 3. It was.

The test results of the multilayer films of the above Examples and Comparative Examples were summarized in Table 2 below.

division Infrared reflectance (%) Color incidence (%) 900-1000 nm 900-1300 nm Example 1 85 80 15 Example 2 82 78 25 Example 3 82 78 25 Example 4 60 55 12 Example 5 85 85 25 Comparative Example 1 82 78 45 Comparative Example 2 82 78 45 Comparative Example 3 84 45 15 Comparative Example 4 60 33 12 Comparative Example 5 50 20 12 Comparative Example 6 50 40 20 Comparative Example 7 80 50 25

As shown in Table 2, it can be seen that the infrared blocking multilayer film of the present invention according to the embodiment is excellent in the infrared blocking rate in the 900 ~ 1,300nm region as well as in the 900 ~ 1,000nm region. On the other hand, the conventional infrared blocking film according to the comparative example can be seen that the infrared blocking rate is low in the 900 ~ 1,300nm region or the visible light reflectance is high color.

Claims (12)

Two or more film stacks having different reflection wavelength ranges are stacked, and each film stack includes a reflective layer and a protective layer provided on both sides of the reflective layer, and the reflective layer is polyethylene terephthalate (PET). ) And a second resin layer comprising polymethyl methacrylate (PMMA), copolymerized polyethylene terephthalate (co-PET), polyethylene naphthalate (PEN), or a mixed polymer thereof. And formed, and the infrared reflecting multilayer film in which the average reflectance in the 900-1300 nm wavelength range of all the films shows 50% or more.
The method of claim 1,
The infrared blocking multilayer film, the infrared blocking multilayer film, characterized in that the average reflectance is 70% or more in the wavelength region of 900 ~ 1,300nm.
The method of claim 1,
Infrared blocking multilayer film, characterized in that the second resin layer comprises polymethyl methacrylate (PMMA).
The method of claim 1,
Infrared blocking multilayer film, characterized in that the protective layer comprises polyethylene terephthalate (PET).
The method of claim 1,
The refractive index difference between the said 1st resin layer and a 2nd resin layer is 0.05 or more, The infrared blocking multilayer film.
The method of claim 1,
The individual average thickness of the said 1st resin layer or the 2nd resin layer is 50 nm-800 nm, Infrared cut multilayer film.
The method of claim 1,
The weight ratio of the said 1st resin layer and the 2nd resin layer is 1.5: 1-1: 1.5, The infrared blocking multilayer film characterized by the above-mentioned.
The method of claim 1,
The infrared blocking multilayer film comprises a first film stack and a second film stack, and the infrared ray blocking multilayer, characterized in that the thickness ratio of the first film stack and the second film stack is 1: 1.1 to 1: 3. film.
The method of claim 1,
The infrared blocking multilayer film includes a first film stack and a second film stack, wherein the first film stack has an average reflectance of 50% or more over a wavelength range of 900 to 1,000 nm, and the second film stack has 1,000 An infrared blocking multilayer film, characterized in that the average reflectance over a wavelength range of ˜1,300 nm is 50% or more.
The method of claim 1,
The infrared blocking multilayer film, characterized in that stretched 3.0 to 4.5 times in the longitudinal and transverse directions, infrared blocking multilayer film.
The method of claim 1,
The reflective layer is composed of 50 to 400 layers, infrared blocking multilayer film.
The method of claim 1,
The infrared blocking multilayer film is an infrared blocking multilayer film, characterized in that it is used as an infrared blocking film to be constructed on the exterior glass of buildings or automobiles.

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