KR102068891B1 - Photochromic film and light transmitting layered product comprising of the same - Google Patents

Abstract

The interlayer film for the light transmissive laminate according to an embodiment of the present invention includes a photochromic layer including a polyvinyl acetal resin, a plasticizer, and a photochromic dye, and the interlayer film for the light transmissive laminate further includes an ultraviolet absorber. . The photochromic interlayer film, light transmissive laminate, etc. of the present invention can maintain the photochromic properties for a long time while satisfying the mechanical properties such as penetration resistance and impact resistance, which are suitable for application to automotive glass, thereby opening automobiles, building It is widely used for materials.

Description

Photochromic interlayer, and light-transmitting laminated body including the same {{PHOTOCHROMIC FILM AND LIGHT TRANSMITTING LAYERED PRODUCT COMPRISING OF THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photochromic intermediate film, and a light transmissive laminate including the same, and to an intermediate film having photochromic properties and applicable to automobile glass bonding.

The phenomenon of color change in response to specific light is called photochromic, and the material causing such photochromic is called photochromic (photoreversible discoloring compound or photochromic compound).

Photochromic compounds are largely divided into pigment form and dye form or inorganic form and organic form. Photochromic compounds in the form of solutions or dispersions change from colorless to a specific color when exposed to sunlight or ultraviolet light and return to their original color in the dark or without strong UV radiation. Photochromic phenomena were discovered around 1840, but commercial studies began relatively recently.

In response to strong sunlight, there is a need for a discolored glass that turns into a darker glass when the light is strong and a lighter glass when the light is weak. However, the photochromic material required for manufacturing such discolored glass had a weak weather resistance, so there was a problem that the discoloration effect was reduced when used for outdoor use, and the manufacturing process was too complicated to be applied to mass production. In particular, there was a limit to the application for building materials or automotive opening that is difficult to replace easily.

Recently, various options using a camera are installed to improve driving safety of a vehicle. For example, LDWS (Line Departure Warning System) technology is equipped with a camera in front of a vehicle to recognize a lane and prevents an accident by notifying the driver with a warning sound or steering wheel vibration when leaving the lane without turning on a turn signal. Autonomous driving technology is often applied in a way that determines the surrounding environment based on camera recognition.

Korean Patent Publication No. 10-2013-0013225, 2013.02.06. Automotive glass using open, photochromic film Domestic Patent No. 10-0802891, 2008.02.01. Registration, photochromic film or plate manufacturing method

It is an object of the present invention to provide a photochromic interlayer having photochromic properties and applicable to automotive glass bonding, and a light transmissive laminate including the same.

In order to achieve the above object, an interlayer film for a light transmissive laminate according to an embodiment of the present invention is an interlayer film for a light transmissive laminate, which is an extruded film including a photochromic layer containing a polyvinyl acetal resin, a plasticizer, and a photochromic dye. The interlayer film for the light transmissive laminate includes an ultraviolet absorber.

The interlayer film for a light transmissive laminate according to another embodiment of the present invention is an interlayer film for a light transmissive laminate including a photochromic band layer including a polyvinyl acetal resin, a plasticizer, and a photochromic dye. Silver includes a ultraviolet absorber in the photochromic layer.

The ultraviolet absorber does not have a peak in the region of less than 325 nm in the absorption spectrum of more than 315 nm and in the region of less than 365 nm at 360 nm or more.
The ultraviolet absorbent has an absorption peak in the absorption spectrum in the range of 250 nm or more and less than 315 nm, in the range of 325 nm or more and less than 360 nm, or in the range of 365 nm or more.
Of 340nm Intensity 0.77 W / m ^2, after irradiating 8 hours 60 ℃ conditions, at 50 ℃ facilitate a test exposing a cycle that repeats four times containers dense Orientation weather resistance test, the permeability value is the smallest wavelength value λmin It may take more than 1,000 hours for the light transmittance in Ess to increase from half the light transmittance at the initial discoloration.
The interlayer film for the light transmissive laminate may be directly bonded to the glass through heat and pressure.

The interlayer film for the light transmissive laminate includes a polyvinyl acetal resin, a plasticizer, and a photochromic dye, and may include a photochromic layer having a delta E * value of 10 to 70 before and after a color change based on a Lab color coordinate.

The photochromic dye may be included in an amount of 0.001 to 10 wt% based on the entire photochromic layer.

The photochromic dye and the ultraviolet absorbent may be included in a weight ratio of 1: 0.1 to 10.

The polyvinyl acetal resin included in the photochromic layer may have an acetalization degree of 70 to 88 wt% and an acetyl group content of less than 2 wt%.

The polyvinyl acetal resin included in the photochromic layer may have an acetyl group content of 8 to 14 wt%.

The interlayer film for the light transmissive laminate may further include a first layer positioned on one surface of the photochromic layer.

The first layer may include 70 to 76% by weight of polyvinyl acetal resin, and 24 to 30% by weight of a plasticizer.

The interlayer film for the light transmissive laminate may further include a second layer positioned on the other surface of the photochromic layer.

The second layer may include 60 to 78 wt% of polyvinyl acetal resin, and 22 to 40 wt% of a plasticizer.

The interlayer film for the light transmissive laminate may further include a sound insulation layer on the other surface of the photochromic layer.

The sound insulation layer may include 60 to 72 wt% of polyvinyl acetal resin, and 28 to 40 wt% of a plasticizer.

The photochromic layer may include 70 to 74 wt% of the polyvinyl acetal resin, 25 to 29 wt% of the plasticizer, and 0.001 to 5 wt% of the photochromic dye.

The interlayer film for the light transmissive laminate may further include a first layer positioned on one surface of the photochromic layer, and the first layer may include some or all of the ultraviolet absorbent.

The interlayer film for the light transmissive laminate may further include a first layer positioned on one surface of the photochromic layer and a second layer positioned on the other surface of the photochromic layer.

The interlayer film for a light transmissive laminate including the photochromic band layer includes a first layer including a first polyvinyl acetal resin and a first plasticizer, and the photochromic band layer is included in the first layer to transmit the light. It may be located at the end of the interlayer film for the laminate.

The interlayer film for a light transmissive laminate including the photochromic band layer includes a first layer including a 1 polyvinyl acetal resin and a first plasticizer, and the photochromic band layer is included in the first layer to transmit the light transmissive layer. It may be located at the end of the interlayer film.

The interlayer film for the light transmissive laminate including the photochromic band layer may further include a second surface located on one surface of the first layer and a third layer located on the other surface of the first layer.

The interlayer film for a light transmissive laminate including the photochromic band layer includes a first layer, a sound insulation layer positioned on the first layer, and a second layer positioned on the sound insulation layer. A part thereof may be included in the first layer, the other part may be included in the sound insulation layer, and the remainder may be included in the third layer to be positioned at one end of the interlayer film for the light transmissive laminate.

The UV absorber may have an absorption peak in the absorption spectrum of more than 250 nm to less than 315 nm, more than 325 nm to less than 360 nm, or 365 nm or more.

According to another embodiment of the present invention, a light transmission laminate includes a first light transmission layer, a second light transmission layer, and the light transmission stack described above positioned between the first light transmission layer and the second light transmission layer. Body interlayers.

The light transmissive laminate may have a visible light transmittance of 70% or more before color change caused by the photochromic layer.

The light transmissive laminate may have a visible light transmittance of 70% or more before discoloration in the photochromic band layer.

The light transmitting laminate may have a visible light transmittance of 10 to 60% after color change caused by the photochromic layer.

The light transmitting laminate may have a visible light transmittance of 10 to 60% after color change caused by the photochromic band layer.

The light transmissive laminate may have a difference between 20% and 75% of the visible light transmittance before the color change occurs by the photochromic layer and the visible light transmittance after the color change occurs.

The light transmissive laminate may have a difference between 20% and 75% of the visible light transmittance before the color change occurs by the photochromic band layer and the visible light transmittance after the color change occurs.

The light transmissive laminate may have a color value difference (delta E * value) before and after discoloration of the photochromic layer from 10 to 70.

The light transmissive laminate may have a color value difference of 10 to 70 (delta E * value) before and after discoloration of the photochromic band layer.

The photochromic layer included in the interlayer for the light transmissive laminate may include 0.001 to 1.5 wt% of the photochromic dye, and the light transmissive laminate may be an automobile windshield.

The photochromic band layer included in the interlayer for the light transmissive laminate may include the photochromic dye in an amount of 0.001 to 1.5% by weight, and the light transmissive band layer may be a shade band of a vehicle windshield.

The photochromic layer included in the interlayer for the light transmissive laminate may contain 0.1 to 5% by weight of the photochromic dye, and the light transmissive laminate may be an automotive sunroof or a rear door.

The difference (delta E * value) between the color value measured in the state of discoloring the light transmitting laminate and the color value measured in the state of discoloration after ultraviolet irradiation of 2500 kJ may be 2 or less.

According to another embodiment of the present invention, an automotive imaging system includes an imaging unit positioned to face each other with an opening of a vehicle including the light transmissive laminate described above and a photochromic band layer on an upper end of the opening. The part may be configured to transfer an image, which is observed through the photochromic band layer of the opening, in which the visible light transmittance changes according to the amount of ultraviolet radiation, to be transferred to an electrical signal.

According to still another aspect of the present invention, there is provided an automotive imaging system including an imaging unit positioned to face an opening of a vehicle including the light transmissive laminate described above and a photochromic layer on one surface of the opening, wherein the imaging unit is provided. The image observed through the photochromic layer of the opening in which the visible light transmittance is changed according to the amount of ultraviolet radiation may be transferred to an electrical signal.

According to another embodiment of the present invention, an architectural imaging system includes an architectural opening including the light transmissive laminate described above and an imaging unit positioned to face each other with a photochromic layer on one side of the opening, wherein the imaging unit includes an ultraviolet irradiation amount. As a result, the image observed through the photochromic layer of the opening in which the visible light transmittance is changed may be transferred to an electrical signal.

The photochromic light transmissive interlayer and the light transmissive laminate including the same of the present invention can maintain photochromic properties for a relatively long time while satisfying mechanical properties such as penetration resistance and impact resistance suitable for application to automotive glass.

Figure 1 (a) and (b) is a conceptual diagram showing a cross-section of the light-transmitting laminate including the front photochromic layer and the light-transmitting laminate in accordance with an embodiment of the present invention, respectively.
Figure 2 (a) and (b) is a conceptual view showing a cross-section of the light-transmitting laminate including the front photochromic layer and the light-transmitting laminate in accordance with an embodiment of the present invention, respectively.
Figure 3 (a) and (b) is a conceptual diagram showing a cross-section of the light-transmitting laminate including the front photochromic layer and the light-transmitting laminate in accordance with an embodiment of the present invention, respectively.
Figure 4 (a), (b) and (c) is a conceptual diagram showing a cross-section of the light-transmitting laminate including a shade band photochromic layer according to an embodiment of the present invention and the intermediate film for a light-transmitting laminate, respectively.
Figure 5 (a) and (b) is a conceptual diagram showing a cross-section of the light-transmitting laminate including the shade band photochromic layer according to an embodiment of the present invention and the intermediate film for the light-transmissive laminate, respectively.
Figure 6 (a) and (b) is a conceptual diagram showing a cross-section of the light-transmitting laminate including a shade band photochromic layer according to an embodiment of the present invention and the intermediate film for a light-transmitting laminate, respectively.
Figure 7 is a graph showing the visible light transmittance of the laminated glass samples 1 to 10 including the photochromic layer prepared experimentally in the embodiment of the present invention.
8 is a graph showing light transmittance before and after discoloration of the laminated glass applied by changing the type of UV absorber among the laminated glass samples including the photochromic layer experimentally measured in the embodiment of the present invention.
9 is a photograph confirming the degree of discoloration immediately after the natural light exposure of the samples 1, 2, 3, 4, and 100 seconds after the natural light exposure prepared in Examples of the present invention ((a), (b), respectively).
Figure 10 is a photograph confirming the degree of discoloration immediately after the natural light exposure of the three-layer samples 2, 3, 4 and 100 seconds after the natural light exposure prepared in the embodiment of the present invention ((a), (b), respectively).

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Like parts are designated by like reference numerals throughout the specification.

As used herein, the terms "about", "substantially", and the like, are used at, or in close proximity to, numerical values when manufacturing and material tolerances inherent in the meanings indicated are intended to aid the understanding of the invention. Accurate or absolute figures are used to assist in the prevention of unfair use by unscrupulous infringers.

Throughout this specification, the term "combination of these" included in the expression of the makushi form means one or more mixtures or combinations selected from the group consisting of constituents described in the expression of the makushi form, wherein the constituents It means to include one or more selected from the group consisting of.

Throughout this specification, description of "A and / or B" means "A, B, or A and B".

Throughout this specification, terms such as “first”, “second” or “A”, “B” are used to distinguish the same terms from each other unless otherwise specified.

As used herein, B on A means that B is on direct contact with A, or B on A, with another layer in between, and B on a surface. It is limited to what does and is not interpreted.

In the present specification, a compound of a specific chemical structure system (row) is a compound containing the chemical structure as a core structure, and includes both a compound composed only of the chemical structure and a derivative thereof.

In the present specification, the singular forms “a,” “an” and “the” are intended to be interpreted in the context of the singular or plural, unless the context describes otherwise.

In order to secure higher stability when driving a car, it is necessary to secure a wider viewing angle, which is more demanding in LDWS technology using camera technology or in automatic driving technology. Therefore, there is a need to raise the installation position of the camera to the driver's field of view or more. However, the shades of dark-colored (blue, bronze, or charcoal) bands (Shade-Band, S) are designed to block the direct sunlight caused by sunlight and to help the driver by reducing the glare of the driver. / B) is present.

Currently applied S / B always blocks a certain percentage of visible light irrespective of the difference in the amount of light, so when the camera is located at the S / B position, it is sufficient for LDWS technology and automatic driving technology in cloudy weather or at night. No information was obtained. Therefore, it is difficult to install a camera at a higher position than the driver's field of view, and it is difficult to obtain information with a wide field of view. In addition, if a separate colored film is attached to the windshield of the car as well as the S / B, the recognition of the camera may be inaccurate depending on the weather or the season.

Accordingly, the inventors of the present invention, while continuing to research to solve these problems comprehensively, to produce a light transmissive interlayer having a weather resistance so that the photochromic properties are maintained for a relatively long time in response to light in the ultraviolet region while maintaining the photochromic properties for a relatively long time To complete the present invention.

1 to 6 is a conceptual view showing a cross-section of the light transmission laminated body 700 including the front photochromic layer 400 and the interlayer film 100 for a light transmissive laminate according to an embodiment of the present invention, or shade band photochromic A conceptual diagram showing a cross section of the light transmitting laminate 700 including the layer 450 and the interlayer film 100 for the light transmitting laminate.

In order to achieve the above object, the present invention will be described in detail with reference to the accompanying drawings.

The interlayer film 100 for a light transmissive laminate according to an embodiment of the present invention includes a photochromic layer 400 including a polyvinyl acetal resin, a plasticizer, and a photochromic dye. The photochromic layer 400 may further include a UV absorber.

The interlayer film 100 for the light transmissive laminate may be formed of the photochromic layer 400.

The interlayer film 100 for the light transmissive laminate may include the photochromic layer 400 and may further include a first layer 300 positioned on one surface of the photochromic layer 400.

The first layer 300 may further include a first ultraviolet ray blocking layer 350 including ultraviolet ray absorbing agent.

The interlayer film 100 for the light transmissive laminate may include the photochromic layer 400 and further include a second layer 320 positioned on the other surface of the photochromic layer 400.

The second layer 320 may further include a second ultraviolet blocking layer 370 having a UV blocking function by further including a UV absorber.

The first layer 300 and the second layer 320 may be skin layers that directly contact the light transmitting layers 200 and 600.

The photochromic layer 400 may be positioned to directly contact the light transmitting layers 200 and 600, and may be applied as a photochromic skin layer.

The interlayer film 100 for the light transmissive laminate may further include the sound insulation layer 500.

The sound insulation layer 500 may be located between the first layer 300 and the second layer 320.

The sound insulation layer 500 may be located between the first layer 300 and the photochromic layer 400.

The sound insulation layer 500 may be located between the second layer 320 and the photochromic layer 400.

The photochromic layer 400 may have a characteristic of a sound insulating layer at the same time, and may be applied as a sound insulating photochromic layer.

The interlayer film 100 for the light transmissive laminate may have a single layer structure, and may have a two-layer structure of a first layer-photochromic layer.

The interlayer film 100 for the light transmissive laminate may have a three-layer structure of a first layer, a photochromic layer, and a second layer.

The interlayer film 100 for the light transmissive laminate may have a three-layer structure of a first ultraviolet blocking layer, a photochromic layer, and a second ultraviolet blocking layer.

In this case, the photochromic layer may have physical properties of the sound insulating layer.

The interlayer film 100 for the light transmissive laminate may have a three-layer structure of a first layer, a sound insulation layer, and a photochromic layer. In this case, the photochromic layer may have physical properties of the skin layer.

The interlayer film 100 for the light transmissive laminate may have a four-layer structure of a first layer, a sound insulating layer, a photochromic layer, and a second layer.

The photochromic layer 400 included in the interlayer film 100 for the light transmissive laminate may have a color having the same density as a whole, and may have a gradient color that changes in color concentration from one end to the other end. .

The thickness of the interlayer film 100 for the light transmissive laminate may be 0.30 mm or more, 0.38 to 1.6 mm, and 0.6 to 1.2 mm. When the interlayer is formed at such a thickness, the interlayer for light transmissive laminate can be formed at a thin thickness while maintaining mechanical properties at a predetermined level or more.

When the interlayer 100 for the light transmissive laminate is formed in a three-layer structure including the sound insulation layer 500, the sound insulation layer 500 has a thickness of 10 to 24% of the thickness of the total interlayer for the light transmissive laminate. Can have The first layer 300 and the second layer 320 may each have a thickness of 38 to 45% of the total thickness of the interlayer film for the light transmissive laminate.

At least one of the first layer 300 and the second layer 320 may be applied as the photochromic layer 400.

At least one of the first layer 300 or the second layer 320 may be applied as the UV blocking layers 350 and 370.

The sound insulation layer 500 may have a photochromic layer function at the same time.

The interlayer film 100 for a light transmissive laminate according to an embodiment of the present invention includes a photochromic layer band layer 450 including a polyvinyl acetal resin, a plasticizer, and a photochromic dye. The photochromic band layer 450 may further include a UV absorber.

The interlayer film 100 for the light transmissive laminate includes the photochromic band layer 450 included as a part of the first layer 300.

The first layer may be a first ultraviolet ray blocking layer 350 having ultraviolet ray blocking function by a method further including a ultraviolet absorber.

Although the photochromic band layer 450 is depicted as a triangle having a vertex located at the center of the bottom and an pentagonal shape having a rectangle located at the bottom of the triangle in FIG. 4, the one end of the first layer 300 is illustrated. If it is formed in a relatively constant thickness in the form of a band, the shape is irrelevant.

In addition, the photochromic band layer 450 may have a color of one concentration as a whole, and may have a gradation color having a concentration gradient gradually decreasing from one end to the other end.

The thickness of the photochromic band layer 450 may be applied as long as the thickness of the photochromic band layer 450 is generally applied as a shade band, and the thickness or shape thereof is not particularly limited.

The interlayer film 100 for the light transmissive laminate may include a first layer 300 including the photochromic band layer 450 and a second layer 320 on the first layer.

The second layer 320 may be a second ultraviolet ray blocking layer 370 having ultraviolet ray blocking function by further including a ultraviolet absorber.

The interlayer film 100 for the light transmissive laminate is a part of the first layer 300 including the photochromic band layer 450, a sound insulation layer 500 on the first layer, and a sound insulation layer. The second layer 320 may be included.

The interlayer film 100 for the light transmissive laminate includes a first layer 300, a sound insulation layer 500 positioned on the first layer, and a second layer 320 positioned on the sound insulation layer. The layer 500 may include a photochromic band layer 450 at one end thereof.

The interlayer film 100 for the light transmissive laminate includes a first layer 300, a sound insulation layer 500 positioned on the first layer, and a second layer 320 positioned on the sound insulation layer. The second layer 320 may include a photochromic band layer 450 at one end thereof.

The interlayer film 100 for the light transmissive laminate includes a first layer 300, a sound insulation layer 500 positioned on the first layer, and a second layer 320 positioned on the sound insulation layer. Each of the first layer 300 and the second layer 320 may include a photochromic band layer 450 at one end thereof. In other words, the photochromic band layer 450 may be positioned over the two layers.

The interlayer film 100 for a light transmissive laminate including a first layer 300, a sound insulation layer 500 located on the first layer, and a second layer 320 located on the sound insulation layer is the light transmission. At one end of the interlayer film 100 for a laminate, the photochromic band layer 450 may be disposed on the first layer 300, the sound insulation layer 500, and the second layer 320.

The first layer 300 and the sound insulation layer 500 located on the first layer, the photochromic layer 400 located on one surface of the sound insulation layer, and the second layer located on the photochromic layer ( The interlayer film 100 for a light transmissive laminate including a 320 may include the first layer 300, the sound insulation layer 500, and the photochromic layer 400 at one end of the interlayer film 100 for a light transmissive laminate. And a photochromic band layer 450 positioned over the second layer 320. In this case, a darker photochromic band layer may be applied to the photochromic band, and a lighter photochromic layer may be applied to the front photochromic layer.

The thickness of the interlayer film 100 for the light transmissive laminate may be 0.30 mm or more, 0.38 to 1.6 mm, and 0.6 to 1.2 mm. When the interlayer film for the light transmissive laminate is formed at such a thickness, the interlayer film for the light transmissive laminate may be formed at a thin thickness while maintaining the mechanical properties at a predetermined level or more.

The sound insulation layer 500 may have a thickness of 10 to 24% of the total thickness of the interlayer for the light transmissive laminate. The first layer 300 and the second layer 320 may each have a thickness of 38 to 45% of the total thickness of the interlayer film for the light transmissive laminate.

A photochromic material is a substance in which the light absorption characteristics of molecules or crystals change color as a single chemical species isomers with different chemical bonding states by the action of light, and these changes are reversibly changed. In general, the photochromic material is colored when exposed to ultraviolet rays, and when the visible light is only irradiated, the photochromic material is inherently pale in color.

The photochromic dye is applied to the photochromic material as described above, specifically, azobenzene-based photochromic dye, diarylethene-based photochromic dye, fluoride-based photochromic dye, hexaaryl Any one selected from bixamidazole-based photochromic dyes, spiroperimidine-based photochromic dyes, spiropyran-based photochromic dyes, and spiro-Oxazine-based photochromic dyes Can be.

Since photochromic materials often lose their function in a short time when exposed to sunlight continuously, it is desirable to select a kind of material having excellent basic durability from the series of organic compound-based materials.

Examples of the photochromic dyes include products such as Polyshine Mid-Night Gray, Polyshine Blue, TCI's T0370, B5604, QCR's PDF200DB, PDF200K, PDF200K, PDF200RB, and the like. Can be applied.

The photochromic dye may be included in the photochromic layer 400 and may be included in the photochromic shade band layer 450 (photochromic band layer).

The photochromic dye may be included in 0.001 to 10% by weight, 0.001 to 5% by weight, and 0.01 to 3% by weight based on the entire photochromic layer 400 or the photochromic band layer 450. It may include. When the photochromic dye is applied at less than 0.001% by weight, the optical density may be poor, and the color may not appear well. When the photochromic dye is applied at more than 10% by weight, the solubility of the photochromic dye may occur. The amount of photochromic improvement of the interlayer film for the light transmissive laminate may be lowered compared to the amount of.

When the photochromic dye is applied to the entire interlayer film 100 for the light transmissive laminate, that is, when included in the front photochromic layer 450, the photochromic dye may be applied in 0.001 to 1.5% by weight and 0.005 to 1.0% by weight. It can be applied in%, can be applied in 0.005 to 0.8% by weight, can be applied in 0.08 to 0.5% by weight. When the photochromic dye is applied in such a range, sufficient photochromic effect can be obtained while sufficiently securing visible light transmittance so as to be suitable for application to an automobile windshield.

When the photochromic dye is applied to the entire interlayer 100 for the light transmissive laminate, that is, when included in the front photochromic layer 450, the photochromic dye may be included in 0.1 to 5% by weight and 0.5 to 4% by weight It may be included as. In the case where the photochromic dye is applied in this range, it is advantageous to apply to a light transmitting film requiring strong color development such as a sunroof.

When the photochromic dye is applied in the form of a band to one end of the interlayer film 100 for the light transmissive laminate, that is, when the shade band photochromic layer 450 is applied, the photochromic dye is applied at 0.001 to 5% by weight. It may be applied, 0.005 to 3% by weight, may be applied to 0.005 to 1.5% by weight, may be applied to 0.08 to 1.2% by weight. Such a content is good for the photochromic band layer 450 to implement a gradation form having a concentration ratio of the dye therein, and may induce a suitable level of color development and discoloration as a shade band.

When the photochromic dye is applied to all or a part of the interlayer film 100 for the light transmissive laminate, the photochromic dye may be included in an amount of 0.001 to 10% by weight, 0.005 to 8% by weight, and 0.007 to 1.5% by weight. It may be, and may comprise 1.5 to 4% by weight. When applying the photochromic dye in this range can be applied as a decorative glass that can be utilized as a building material of light or dark color.

The ultraviolet absorber is an additive having a property of absorbing and not transmitting ultraviolet rays of a specific wavelength. In the present invention, the ultraviolet ray absorbing function of the interlayer film 100 for the light transmissive laminate is ensured and the weather resistance of the photochromic dye is improved. Applicable for the purpose.

Chemisorb (Chemisorb) series, BASF's Tinuvin (Tinuvin) series, and the like as the ultraviolet absorber may be applied. Nuvin 329, Tinuvin 326, Tinuvin P and the like can be used.

Ultraviolet absorbers are designed to absorb light of wavelengths up to 400 nm. However, there is a difference in the wavelength band and the amount of ultraviolet light absorbed by each product. The inventors of the present invention, the photochromic dye absorbs ultraviolet rays, the structure thereof changes color and is often discolored, and in the case of the intermediate layer for the light transmissive laminate, the photochromic dye often contains an ultraviolet absorber. It was confirmed that discoloration was not good.

Thus, in the present invention, the ultraviolet absorber applied to the light absorbing layer or the photochromic band layer does not have a peak in the region of less than 325 nm at 315 nm and less than 365 nm at 360 nm or more in the absorption spectrum. do.

The above characteristics can be confirmed by measuring the light absorption spectrum of the ultraviolet absorbent dissolved in a chloroform solvent, for example, but is not limited thereto.

UV absorbers have one or two or more maximum absorption wavelengths in the region of 400 nm or less. Therefore, when the absorption spectrum does not have a peak in the region of 315 nm or more and less than 325 nm and the region of 360 nm or more and less than 365 nm, the degree of absorption is relatively weak even if the ultraviolet absorber absorbs ultraviolet rays in the region. Has features.

Specifically, the UV absorber may have an absorption peak in the absorption spectrum in the range of 250 nm or more to less than 315 nm, 325 nm or more to less than 360 nm, or 365 nm or more. In the case of applying the ultraviolet absorber having such characteristics, the photochromic effect in the photochromic layer or the photochromic band layer may be more clearly and rapidly progressed.

The ultraviolet absorbent may be one having no absorption peak in a region of less than 330 nm at 310 nm or more and a region of less than 370 nm at 355 nm or more. Specifically, the ultraviolet absorbent may have an absorption peak in the absorption spectrum in the range of 250 nm or more and less than 310 nm, 330 nm or more and less than 360 nm, or 370 nm or more and 400 nm or less. In the case of applying the ultraviolet absorber having such characteristics, it is possible to obtain a clear discoloration characteristics and at the same time to produce an interlayer film for a light transmissive laminate excellent in weather resistance.

The ultraviolet absorbent may include 0.002 to 12 wt% based on the entire layer to which the ultraviolet absorbent is applied, and may include 0.02 to 5 wt%.

In addition, the UV absorber may be applied according to the amount of application of the photochromic dye, the content of the photochromic dye and the ultraviolet absorber applied to the entire interlayer for the light transmissive laminate may be included in a weight ratio of 1: 0.1 to 10, 1: It may be included in the weight ratio of 0.15 to 4.5, 1: 1: may be included in the weight ratio. In such a ratio, the application can provide a further discoloration effect of the dye and at the same time further improve weather resistance.

The polyvinyl acetal resin may be a first polyvinyl acetal resin or a second polyvinyl acetal resin described below.

The polyvinyl acetal resin may be a polyvinyl acetal resin obtained by acetalizing polyvinyl alcohol having a degree of polymerization of 1,600 to 3,000 with aldehyde. In addition, in order to improve the mechanical properties such as the penetration resistance of the film to be produced, the degree of polymerization of the polyvinyl alcohol is preferably more than 1,600, more preferably more than 1,700.

The polyvinyl acetal resin may be one obtained by synthesizing polyvinyl alcohol and aldehyde, and the aldehyde is not particularly limited. For example, it may be selected from the group consisting of n-butylaldehyde, isobutyl aldehyde, n-barrel aldehyde, 2-ethyl butyl aldehyde, n-hexyl aldehyde and blend resins thereof. Specifically, the resin produced using n-butyl aldehyde has little difference in refractive index with glass, and is excellent in bonding strength with glass.

The first polyvinyl acetal resin has 4 to 6 carbon atoms of the acetal group, the content of the acetyl group in the main chain may be less than 2% by weight, it may be 0.001 to 1% by weight. In addition, the first polyvinyl acetal resin may have acetalization degree of 70 to 88% by weight, specifically 80 to 88% by weight. When applying the resin of such a feature may be excellent bonding force with the light transmitting laminated body such as glass.

The first polyvinyl acetal resin may be included in 70 to 76% by weight, specifically 70 to 74% by weight based on the entire layer included. In such a case, sufficient mechanical strength can be imparted to the interlayer film for the light transmissive laminate.

The second polyvinyl acetal resin has 4 to 6 carbon atoms in the acetal group, the content of the acetyl group in the main chain may be 8 to 14% by weight, specifically 10 to 12% by weight. In addition, the degree of acetalization may be 70 to 88% by weight, specifically 77 to 83% by weight. When the resin of such a characteristic is applied, it has the characteristic that it is excellent in miscibility with a plasticizer, and it is good to apply to a sound insulation layer.

The second polyvinyl acetal resin may be included in an amount of 60 to 72 wt%, specifically 60 to 68 wt%, based on the entire layer to which the second polyvinyl acetal resin is applied. When the second polyvinyl acetal resin is included in such a content, the layer may exhibit the properties of the sound insulating layer while maintaining a certain level or more of mechanical properties.

The polyvinyl acetal resin applied to the photochromic layer or photochromic band layer may be formed of the first polyvinyl acetal resin or the second polyvinyl acetal depending on the position or intended properties of the photochromic layer or photochromic band layer. Resins or mixtures thereof may be applied.

The plasticizer is, for example, triethylene glycol bis 2-ethylhexanoate (3G8), tetraethylene glycol diheptanoate (4G7), triethylene glycol bis 2-ethylbutyrate (3GH), triethylene glycol bis 2-ethyl Consisting of heptanoate (3G7), dibutoxyethoxyethyl adipate (DBEA), butyl carbitol adipate (DBEEA), dibutyl sebacate (DBS), bis 2-hexyl adipate (DHA) and mixtures thereof It may be selected from the group, specifically triethylene glycol bis 2-ethylhexanoate (3G8).

The plasticizer may be included in an amount of 24 to 30 wt%, specifically 25 to 29 wt%, based on the entire layer including the plasticizer. In this case, it is possible to form a layer having better mechanical properties, and when applied together with the first polyvinyl acetal resin, it is good to be applied as a skin layer because of excellent bonding strength and excellent mechanical properties when manufactured with a light-transmitting laminate such as glass. .

The plasticizer may be included in an amount of 22 to 40 wt%, specifically 30 to 38 wt%, based on the entire layer including the plasticizer. It is preferable that the plasticizer is included in the content in the above range in terms of improving impact resistance and sound insulation performance of the film. In this case, when applied together with the second polyvinyl acetal resin, it is possible to provide an interlayer film for a light transmissive laminate having excellent sound insulation properties and mechanical properties.

Specifically, when the photochromic layer includes a polyvinyl acetal resin, a plasticizer and a photochromic dye, the photochromic layer may be included in an amount of 70 to 74 wt%, 25 to 29 wt%, and 0.001 to 5 wt%, respectively. In this case, it is possible to obtain a photochromic layer having excellent mechanical properties such as penetration resistance and impact resistance, and at the same time having excellent color development and discoloration characteristics.

Specifically, when the polyvinyl acetal resin, the plasticizer, the photochromic dye and the ultraviolet absorber of the photochromic layer, 70 to 74% by weight, 25 to 29% by weight, 0.01 to 3% by weight and 0.02 to 4% by weight May be included. In this case, it is possible to obtain a photochromic layer having excellent mechanical properties such as penetration resistance and impact resistance, and at the same time having excellent color development and discoloration characteristics.

Specifically, when the photochromic layer includes a polyvinyl acetal resin, a plasticizer, and a photochromic dye, the photochromic layer may be included as 60 to 68 wt%, 30 to 38 wt%, and 0.001 to 5 wt%, respectively. In this case, it is possible to obtain a photochromic layer having sound insulating properties and at the same time excellent color development and color fading characteristics.

Specifically, when the polyvinyl acetal resin, the plasticizer, the photochromic dye and the ultraviolet absorber of the photochromic layer, 60 to 68% by weight, 30 to 38% by weight, 0.01 to 3% by weight and 0.02 to 4% by weight May be included. In this case, it is possible to obtain a photochromic layer having sound insulating properties and at the same time excellent color development and color fading characteristics.

The polyvinyl acetal film according to the present invention can be used within the range of not impairing the physical properties for the end use, if necessary, an additive selected from the group consisting of antioxidants, heat stabilizers, IR absorbers, glass bonding strength control agents and combinations thereof. .

The photochromic layer or the photochromic band layer (based on the darkest one end portion, which is the same below) is based on a result of measuring a sample laminated with two pieces of glass having a thickness of 2.1 cm. The visible light transmittance before the color change occurs due to 70% or more, and the visible light transmittance after the color change occurs may be 10 to 60%. This feature can adequately reduce the degree of light transmission by discoloration when discoloration caused by strong ultraviolet rays while sufficient visibility through the light-transmitting laminate is sufficient.

Specifically, the visible light transmittance before the color change generated by the photochromic layer or the photochromic band layer may be 70% to 90%, and the visible light transmittance after the color change occurs may be 10 to 40%. The photochromic layer having such a range is suitable for glass such as automotive windshield.

Specifically, the visible light transmittance before the color change generated by the photochromic layer is 50% to 69%, the visible light transmittance after the color change occurs may be 5 to 20%. The photochromic layer having such a range may be applied to dark colored glass such as automobile sunroofs and rear doors.

Specifically, the visible light transmittance before the color change generated by the photochromic band layer may be 50% to 80%, and the visible light transmittance after the color change occurs 10 to 40%. The photochromic layer having such a range is suitable for glass such as a shade band portion of an automobile windshield.

The light transmissive laminate may have a difference in visible light transmittance before color change caused by the photochromic layer and visible light transmittance after color change occur in a range of 20 to 75%, and may be 30 to 60%. In this case, the discoloration effect of the photochromic layer is more pronounced, so it is good to apply in an environment with strong UV.

The interlayer film for the light transmissive laminate may have a delta E * value of 10 to 70 before and after discoloration based on a Lab color coordinate.

Specifically, the interlayer film for the light transmissive laminate may have a delta E * value of 40 to 60 and 50 to 60 before and after discoloration based on Lab color coordinates, and in this case, having excellent weather resistance and sufficient photochromic effect. The interlayer film for a light transmissive laminate can be obtained.

The interlayer film for the light transmissive laminate may satisfy the impact resistance characteristics according to KS L 2007: 2008.

The interlayer film for the light transmissive laminate may satisfy the penetration resistance property according to KS L 2007.

The light transmissive laminate including the interlayer for the light transmissive laminate may have a L / F (loss factor) value of 0.32 or more at 20 ° C. and 2000 Hz.

The light transmissive interlayer may have a difference (delta E * value) between a color value measured in a discolored state and a color value measured in a discolored state after ultraviolet irradiation of 2500 kJ. That is, the interlayer may have a delta E * value change of 2 or less before and after UV irradiation of 2500 kJ.

The method of manufacturing the interlayer film for the light transmissive laminate may be prepared by putting each of the above components in an extruder, melt extruding, and coextrusion through a feed block, but is not limited thereto.

According to another embodiment of the present invention, a light transmission laminate includes a first light transmission layer, a second light transmission layer, and the light transmission stack described above positioned between the first light transmission layer and the second light transmission layer. Body interlayers.

The first light transmitting layer and the second light transmitting layer may each independently be a transparent glass or a transparent plastic.

The light transmitting laminate may have a visible light transmittance of 70% or more before a color change occurs by the photochromic layer, and a visible light transmittance of 10 to 60% after a color change occurs. This feature can adequately reduce the degree of light transmission by discoloration when discoloration caused by strong ultraviolet rays while sufficient visibility through the light-transmitting laminate is sufficient.

In detail, the light transmitting laminate has visible light transmittance of 70% to 90% before color change occurs by the photochromic layer or photochromic band layer, and visible light transmittance of 10 to 40% after color change occurs. Can be. The light transmissive laminate having such a range is suitable for application to glass such as automobile windshields.

Specifically, the light transmitting laminate may have a visible light transmittance of 50% to 69% before the color change occurs by the photochromic layer, and a visible light transmittance of 5 to 20% after the color change occurs. The light transmissive laminate having such a range is suitable to be applied to dark colored glass such as automobile sunroof and rear door.

Specifically, the light transmitting laminate may have a visible light transmittance of 50% to 80% before the color change occurs by the photochromic layer, and a visible light transmittance of 10 to 40% after the color change. The light transmissive laminate having such a range is suitable for glass such as a shade band portion of an automobile windshield.

The light transmissive laminate may have a difference in visible light transmittance before color change caused by the photochromic layer and visible light transmittance after color change occur in a range of 20 to 75%, and may be 30 to 60%. In this case, the discoloration effect of the photochromic layer is more pronounced, so it is good to apply in an environment with strong UV.

The interlayer film for the light transmissive laminate may have a delta E * value of 10 to 70 before and after discoloration based on a Lab color coordinate.

Specifically, the light transmitting laminate may have a color value difference (delta E * value) before and after discoloration of 40 to 60, and may be 50 to 60, and in this case, light having excellent weather resistance and sufficient photochromic effect A transparent laminated body can be obtained. The color value difference may be a delta E * value evaluated based on Lab color coordinates.

The light transmissive laminate may satisfy the impact resistance characteristics according to KS L 2007: 2008.

The light transmissive laminate may satisfy the penetration resistance characteristics according to KS L 2007.

The light transmissive laminate may have a L / F (loss factor) value of 0.32 or more at 20 ° C. and 2000 Hz.

The difference (delta E * value) between the color value measured in the state of discoloring the light transmitting laminate and the color value measured in the state of discoloration after ultraviolet irradiation of 2500 kJ may be 2 or less.

An automobile according to another embodiment of the present invention includes a laminated glass called tempered glass on various surfaces such as a front glass, a rear glass, a side glass, a sunroof, and a rear door as an opening, wherein at least one of the glasses One or more laminated glass to which the interlayer film for light transmitting laminate of the present invention is applied may be applied.

When the laminated glass which is the light-transparent laminated body of the present invention is applied to the opening of the vehicle as described above, the color of the glass varies according to the intensity of external light, especially ultraviolet rays, and thus the amount of visible light flowing through the glass can be controlled. .

The imaging system for a vehicle according to another embodiment of the present invention includes an imaging unit (not shown) positioned facing the opening of the vehicle to which the light-transmitting laminate of the present invention is applied and the photochromic band layer on the upper end of the opening. do. For example, a camera may be applied to the imaging unit, but is not limited thereto.

According to still another aspect of the present invention, there is provided an automotive imaging system including an imaging unit positioned to face an opening of a vehicle including the light transmissive laminate described above and a photochromic layer on one surface of the opening, wherein the imaging unit is provided. The image observed through the photochromic layer of the opening in which the visible light transmittance is changed according to the amount of ultraviolet radiation may be transferred to an electrical signal.

In the system, the color of the photochromic band layer (or photochromic layer) included in the windshield is controlled to be dark or light according to the intensity of external light, so that the imaging unit has a wide viewing angle regardless of external environment changes such as cloudy or dark days. Can be secured.

The image secured with a wider viewing angle may be converted into an electrical signal through an image pickup unit and transmitted to an automatic driving system or a lane keeping assist system.

According to another embodiment of the present invention, an architectural imaging system includes an architectural opening including the light transmissive laminate described above and an imaging unit positioned to face each other with a photochromic layer on one side of the opening, wherein the imaging unit includes an ultraviolet irradiation amount. As a result, the image observed through the photochromic layer of the opening in which the visible light transmittance is changed may be transferred to an electrical signal.

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

Components applied in the embodiment of the present invention are as follows.

First polyvinyl acetal resin: average degree of polymerization of polyvinyl alcohol 1700, acetate content 0.1% by weight, acetalization degree 83% by weight

Second polyvinyl acetal resin: average polymerization degree of polyvinyl alcohol 2000, acetate content 12% by weight, acetalization degree 78% by weight

1st UV absorber: Tinuvin 328, absorption peak wavelength 302, 343 nm (BASF)

2nd UV absorber: Tinuvin P, absorption peak wavelength 301, 341 nm (BASF)

-Third UV absorber: Tinuvin 1600, absorption peak wavelength 320 nm (BASF)

Photochromic Dye: Dye Polyshine Mid-Night Gray (Insilico)

Plasticizer: triethylene glycol bis 2-ethylenehexanoate (3G8) (provided by PROVIRON PROVIST 1766)

In the following,%, which is described without special description, means% by weight unless the context otherwise applies.

Experimental Example 1

1) Preparation of Interlayer for Front Photochromic Light Transmitted Laminate

Interlayer samples for light-transmissive laminates having the structure of FIG. (Thickness, 800 um each) was prepared.

Sample number First polyvinyl
Acetal resin Plasticizer 1st UV
Absorbent 2nd UV
Absorbent 3UV
Absorbent Photochromic
dyes One 72.856% 26.961% 0.148% - - 0.035% 2 72.715% 27.087% 0.148% - - 0.050% 3 72.791% 26.954% 0.155% - - 0.100% 4 72.848% 26.003% 0.149% - - 1.000% 5 71.760% 24.246% 1.000% - - 2.994% 6 72.965% 27.027% 0.004% - - 0.004% 7 72.660% 26.990% 0.300% - - 0.050% 8 72.800% 26.984% - 0.166% - 0.050% 9 72.942% 27.008% - - - 0.050% 10 72.853% 26.932% - - 0.165% 0.050%

2) Property evaluation of the front photochromic interlayer

After preparing a laminated glass laminated with a coextruded polyvinyl acetal film, which is a front photochromic interlayer prepared in Samples 1 to 10, the following physical properties were evaluated.

(Measurement of color development / discoloration color)

2.1T glass of 70 mm x 70 mm and each of the samples prepared above were laminated in a laminated structure of 2.1T glass-coextrusion film-2.1T glass for 15 minutes at a temperature of 130 ° C. in a laminator and bonded by pressing. Produced. Color L, a, b values of the laminated glass specimens were measured using a spectrophotometer (Hunter Lab, Ultrascan Pro).

The color (bleached state) measurement method in the non-UV irradiation state used a general transmission mode measurement method.

The color measurement method under UV irradiation was performed in the same manner as in the general transmission mode measurement method, but the measurement was performed within 10 seconds after discoloration using a potable UV generator for 10 seconds before measurement.

The measured data of each sample is summarized in Table 2 below.

Sample number Non-UV UV △ E * ¹⁾ L * D65 / 10 a * D65 / 10 b * D65 / 10 L * D65 / 10 a * D65 / 10 b * D65 / 10 One 93.47 -2.25 1.9 54.76 9.51 -20.22 46.1 2 93.31 -2.49 2.15 48.67 11.21 -22.35 52.7 3 92.68 -2.78 2.86 40.83 13.39 -24.86 61 4 88.25 -5.2 7.52 35.8 9.96 -19.63 61 5 80.25 -6.29 6.5 34.68 6.78 -16.07 52.5 6 94.24 -1.9 1.24 78.25 2.62 -8.57 19.3 7 93.62 -2.39 1.85 54.6 9.37 -19.85 46.2 8 93.48 -2.31 1.76 52.82 9.84 -20.59 48 9 93.32 -2.24 1.58 44.29 13.02 -24.56 57.6 10 93.28 -2.49 2.31 56.98 8.26 -18.23 43.1

값으로, 색좌표에서 각 점과 점 사이 거리를 의미하며, 색 변화의 정도를 나타낸다.One)

As a value, it means the distance between each point in the color coordinates and indicates the degree of color change.

Specifically, the delta E value is the color coordinate value (L ₂ , a ₂ , b ₂ ) after ultraviolet irradiation and the color coordinate value (L ₁ , a ₁ , b ₁ ) before and after photochromic change in the above equation. Are calculated by substituting

Referring to Table 2, when the results of Samples 1 to 5, which gradually increase the content of the photochromic dye while maintaining the content of the UV absorber, are examined, the higher the amount of the photochromic dye applied from Sample 1 to 5, the more non It can be seen that in the UV condition, the color coordinate value changes with a relatively constant tendency. On the other hand, under UV conditions, when the content of the photochromic dye was 3% by weight, the color of the film appeared relatively dark, and the color change did not appear sufficiently despite the ultraviolet irradiation. This is interpreted as a result showing that when the photochromic dye is used in excess of the threshold amount, the discoloration effect may be lowered despite the increase of the dye amount.

Examining the change in the delta E value for the samples 1 to 5 above, it was confirmed that the sample 1 to 4 has a gradually larger delta E value from 46.1 to 61.0. This means that the photochromic effect is gradually stronger as the content of the photochromic dye becomes higher. On the other hand, Sample 5 showed a slightly lower color fading effect compared to Sample 4, which indicates that the use of photochromic dyes above the threshold amount causes the color fading effect to be lowered despite the increase in dye amount. Shows. In addition, in the case of applying a small amount of the photo dye content, sample 6 shows that the delta E value of 19.3 is too small, and the intended photochromic effect is insignificant.

In addition, when samples 2 and 7 to 10 to which the same amount of photochromic dye was applied, the amount and type of UV absorbers appear to affect the color change of the photochromic samples. Specifically, when comparing the same first UV absorber as sample 9 without applying the first UV absorber, but comparing sample 2 with low concentration and sample 7 with high concentration, the delta E value gradually increased in the order of Sample 9- Sample 2- Sample 7. It can be seen that this decreases. When the same amount of photochromic dye was applied and the results of Samples 2, 8, and 10, which differed in the types of UV absorbers, were applied, it was confirmed that the degree of discoloration was affected by the type of UV absorbers applied. .

(Light transmittance measurement)

The light transmittance in the visible light region of the samples 1 to 10 was measured and shown in Table 3 below and FIG. 7.

Sample number Content (Wt%) Light transmittance (380 ~ 780um) Light transmittance difference
(“Non-UV”-“UV”) Photochromic dye UV absorbers Non-UV UV One 0.035% 0.148% 83.8 22.1 61.7 2 0.050% 0.148% 83.4 16.8 66.6 3 0.100% 0.155% 82 11.4 70.6 4 1.000% 0.149% 72.5 8.7 63.8 5 2.994% 1.000% 56.7 8.1 48.6 6 0.004% 0.004% 85.5 53 32.5 7 0.050% 0.300% 84.1 22 62.1 8 0.050% 0.166% 83.8 20.3 63.5 9 0.050% - 83.4 13.6 69.8 10 0.050% 0.165% 83.3 24.3 59

Referring to Table 3, the overall visible light transmittance of 70% or more in the non-UV conditions as a whole, and the visible light transmittance in the range of 10 to 60% in the UV conditions.

Referring to FIG. 7, 670 nm visible light region except for the case where the photochromic dye is applied at a high concentration in the non-UV condition indicated by the dotted line as a whole, except for the photochromic dye at the low concentration in the UV condition. The light transmittance of about 40% or less was shown in the table, and it was confirmed that photochromic properties were well exhibited under UV conditions.

In samples 1 to 6, when the photochromic dye concentration was differently applied, increasing the photochromic dye content from 0.035% to 0.1% by weight increased the difference in the light transmittance, resulting in a photochromic effect. The results were in proportion to the applied content. However, when the photochromic dyes were applied at 1% by weight and 3% by weight in Samples 4 and 5, respectively, the difference in light transmittance was found to be less than 0.1% by weight. As the amount of application of the photochromic dye increases, it is interpreted as a result showing that the degree of improvement of the discoloration effect may be lowered compared to increasing the amount of the dye.

Looking at the light transmission characteristics in the visible light region according to the type of ultraviolet absorber with reference to Figure 8, the visible light transmittance in the non-UV conditions in Sample 2, Sample 8 and Sample 10 showed almost similar transmittance. On the other hand, in the non-UV condition, the three types of UV absorbers were shown to have different visible light transmittances. The photochromic dyes did not show sufficient discoloration performance under the influence of UV absorbers.

Experimental Example 2

1) Preparation of photochromic S / B interlayer

Two twin screw extruders (manufacturer: SM Platec) and a feed-block for coextrusion were used to melt-extrude the composition of the lower layer A and the composition of the layer C to form a film.

A layer: composition comprising 70% by weight of the first polyvinyl acetal resin, 29% by weight of plasticizer, 1% by weight of the first UV absorber

Layer C: a composition comprising 72.79 wt% of a first polyvinyl acetal resin and 26.96 wt% of a plasticizer, 0.15 wt% of a first UV absorber, and 0.10 wt% of a photochromic dye

The extruded film is a coextrusion structure in which a single film is laminated by a feed block, and the layer structure is laminated in A / C / A, but the C layer is 200 mm wide in 1580 mm PVB film width so that only a part of the film appears. (See FIG. 4A). After forming the sheet in this form through the die of the extruder, it was cooled in a casting roll and wound to prepare a film to prepare the intermediate film of Sample 11.

2) Evaluation of Physical Properties of Photochromic S / B Interlayers

The intermediate film of Sample 11 was cut so that the part containing the photochromic material contained the darkest part of the color more than 20mm in width, and the experiment was conducted in the same manner as in Experiment 1 above.

The physical properties of the S / B portion to which the same composition as in Sample 3 was applied were evaluated to be about 88% or more equivalent to the results in Experimental Example 1, which is considered to be an effect of the concentration gradient formed during the preparation of S / B. In other words, it was confirmed that even when formed of S / B, properties similar to those of the front photochromic interlayer are realized.

Experimental Example 3

1) Measurement and result of weather resistance

Weatherability is based on the time it takes for the light transmittance at λ _min (the wavelength with the smallest transmittance value) to increase from half the light transmittance at the initial discoloration, i.e., if the light transmittance is 10% when discolored before the weathering test, The evaluation was based on the time taken for the light transmittance to increase by 55% during discoloration during the weathering test.

In the ATLAS UV 2000, an accelerated weathering tester, a UVA fluorescent lamp was used to irradiate 8 hours at a temperature of 0.77 W / m ² at 60 ° C for 340 nm, and then the specimen was subjected to a cycle of condensation at 50 ° C for 4 hours. After exposure, the sample was taken out in the middle of repeating the above process to measure the light transmittance upon discoloration.

The weather resistance measured in this way was evaluated as Fail for the case of 1,000 hours or more and less than 1,000 hours.

The specimen for measurement was a laminated structure of 2.1T glass of 70 mm x 70 mm and the interlayers of samples 1 to 10, each of which was heated in a laminator at a temperature of 130 ° C. for 15 minutes in a laminated structure of 2.1T glass-interlayer-2.1T glass. Bonded through to prepare a specimen.

Of Samples 1-10, Samples 1-8 were Pass and Samples 9 and 10 were Fail. These results are thought to be the result of the use of UV absorbers affecting the weatherability of photochromic dyes.

Penetration Assessment

The penetration resistance of the laminated glass was evaluated based on KS L 2007.

Each of the samples, 300 mm × 300 mm, 2.1 cm thick glass and interlayer, were prepared in a laminated structure of glass-interlayer-glass, prebonded by vacuum, and degassed and edge sealed. Thereafter, the specimen was prepared by bonding the specimen at 150 ° C. for 2 hours using an autoclave. Thereafter, a steel ball of 2.26 kg was dropped on the specimen, and the height (MBH) through which the specimen was penetrated was measured. In this case, when penetrating at a height less than 4 m, it is marked as Fail, and when penetrating at a height of 4 m or more, it is marked as Pass.

Evaluation Results The samples were all evaluated with a pass through pass.

(Impact resistance evaluation)

Based on KS L 2007: 2008, the presence or absence of the laminated glass of the Example and the comparative example was evaluated.

The process of manufacturing and bonding each of the 2.1 cm thick glass and the Example and Comparative Example interlayers into the laminated structure of the glass-interlayer-glass proceeded in the same manner as the above penetration resistance evaluation.

The low temperature evaluation was performed by storing 227 g of steel balls at a temperature of minus 20 ° C for 4 hours and then dropping them at a height of 9 m. If the impacted specimens were broken, the glass was scattered or the glass fell from the sheet. When the received specimen is not broken or the glass is scattered and the amount of glass falling from the sheet is less than 15 g, it is marked as Pass.

The room temperature evaluation is Fail if the specimen shocked at 10 m height is broken after storing 227 g of steel ball at 40 ° C. for 4 hours and the amount of glass falling or falling from the sheet is more than 15 g. When the amount of the glass falling from the sheet which is not broken or the glass is scattered is less than 15 g, it is designated as Pass.

Evaluation Results The samples were evaluated as impact resistance pass in both low temperature and room temperature evaluation.

Experimental Example 4

1) Photochromic experiment in natural light

Samples 1 to 4 prepared in Experimental Example 1 above were stored in the cow for a sufficient time, and photographed immediately after exposure to natural light (a) and after 100 seconds (b) after exposure to test the discoloration effect by natural light. (T in the photo stands for test sample). Referring to FIG. 9 showing the results, it was confirmed that the laminated glass changed to a considerably dark color after exposure to natural light, and it was also confirmed that the shade of the glass was changed depending on the content of the photochromic dye.

2) Preparation of 3-layer Front Photochromic Interlayer

Three-layer front photochromic interlayer samples 2 to 4 having the structure of FIG. 3B were prepared by coextrusion.

Three-layer sample 2, the first ultraviolet shielding layer and the second ultraviolet shielding layer, respectively, a laminated skin layer having a UV blocking function formed by applying the first polyvinyl acetal resin, a plasticizer and the first ultraviolet absorber, respectively. 300 μm thick, the photochromic layer was applied to the same composition as Sample 9 in Experimental Example 1 above, but prepared in 300 um thickness to prepare a total thickness of 900 um intermediate film.

In the three-layer sample 3, the three-layer sample 2 and the photochromic layer were applied to the same composition as the sample 2 in Experimental Example 1 above.

In the three-layer sample 4, the three-layer sample 2 and the photochromic layer were applied to the same composition as the sample 7 in Experimental Example 1 above.

Thus prepared samples were observed for the degree of photochromic in natural light as in 1) above and the results are shown in FIG. Referring to FIG. 10, it was confirmed that the photochromic effect appeared well even in the film having a three-layer structure.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of right.

100: interlayer film for light-transmitting laminate
200: first light transmitting layer
300: first layer
320: second layer
340: third floor
350: first ultraviolet blocking layer
370: second ultraviolet blocking layer
400: photochromic layer, front photochromic layer
450: photochromic band layer, shade band photochromic layer
500: sound insulation layer
600: second light transmitting layer
700: light transmission laminated body

Claims (11)

An interlayer film for a light transmissive laminate, which is an extruded film including a photochromic layer and applied for glass bonding,
The photochromic layer comprises a polyvinyl acetal resin, a plasticizer and a photochromic dye,
The polyvinyl acetal resin of the photochromic layer has acetalization degree of 70 to 88% by weight, acetyl group content of less than 2% by weight,
The interlayer film for the light transmissive laminate includes an ultraviolet absorber in the photochromic layer,
The ultraviolet absorber has an absorption peak in the absorption spectrum of more than 250 nm to less than 315 nm, more than 325 nm to less than 360 nm, or more than 365 nm,
The ultraviolet absorbents do not have peaks in the region of less than 325 nm in the absorption spectrum of more than 315 nm and in the region of less than 365 nm at 360 nm or more,
Of 340nm Intensity 0.77 W / m ^2, after irradiating 8 hours 60 ℃ conditions, at 50 ℃ facilitate a test exposing a cycle that repeats four times containers dense Orientation weather resistance test, the permeability value is the smallest wavelength value λmin The time it takes for the light transmittance of Esau to increase from half the light transmittance to half of its initial discoloration is over 1,000 hours,
The interlayer film for a light transmissive laminate is directly bonded to the glass through heat and pressure, the interlayer film for a light transmissive laminate. The method of claim 1,
The photochromic dye is contained in 0.001 to 10% by weight based on the entire photochromic layer, the interlayer for light transmission laminate. The method of claim 1,
The photochromic dye and the ultraviolet light absorbent is included in a weight ratio of 1: 0.1 to 10, the interlayer for light transmitting laminate. delete delete delete delete delete A light transmissive laminate comprising a first light transmitting layer, a second light transmitting layer, and the interlayer film for a light transmitting laminate according to claim 1, positioned between the first light transmitting layer and the second light transmitting layer. The method of claim 9,
The light transmissive laminate is a light transmissive laminate, wherein the visible light transmittance before color change occurs by the photochromic layer is 70% or more. The method of claim 9,
And wherein the light transmissive laminate has a difference in visible light transmittance before color change caused by the photochromic layer and visible light transmittance after color change occurs from 20 to 75%.

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