KR102382552B1 - Window film - Google Patents

Abstract

The present application relates to a window film and a window including the same. The window film sequentially includes a base layer, a first cured resin layer, an infrared reflective layer, and a second cured resin layer, and the infrared reflective layer includes a metal layer and a metal oxide layer. According to the present application, since the visible light transmittance is low and the visible light reflectance is also low at the same time, it may be provided to a window film that does not cause discomfort to the user.

Description

Window film

This application relates to a window film. Specifically, the present application relates to a window film that can be used for windows of buildings or vehicles.

In a building or vehicle, thermal insulation obtained by blocking external heat in summer and thermal insulation obtained by blocking the discharge of internal heat in winter are important characteristics that a solar control window film for buildings or vehicles should have.

In general, the solar control window film may secure heat shielding and thermal insulation through reflection or absorption of light. For example, the infrared reflective film has a reflective layer capable of reflecting infrared light, and the absorptive film includes a material capable of absorbing visible light and/or infrared light. Since the absorption film containing visible light and/or infrared absorbing material only blocks thermal energy through absorption of light energy, it has heat shielding properties but no thermal insulation properties. There is a problem of heat wave as it rises. Therefore, it is generally evaluated that the infrared reflective film is superior to the absorption film.

The infrared reflective film has an infrared reflective layer in which a metal layer and a metal oxide layer are alternately stacked, and a separate layer may be included above and/or below the infrared reflective layer to improve hardness or prevent contamination. For example, the lower portion of the infrared reflective layer may include a hard coating layer for improving hardness, and the upper portion of the reflective layer may include a protective coating layer capable of preventing damage to the film due to contamination or external stimuli caused by user contact.

The optical properties of the reflective film are mainly determined by the infrared reflective layer in which the metal layer and the metal oxide layer are alternately stacked. For example, the degree of reflection and/or transmission of the film with respect to light may be controlled by controlling the thickness of the infrared reflecting layer. However, when any one optical property of the film is changed by changing the thickness of the infrared reflective layer, other optical properties opposite to the changed optical properties also change, so a film that comprehensively satisfies the optical properties required by the user. becomes difficult to provide. For example, when the thickness of the metal layer is increased to lower the visible light transmittance of the film, the visible light reflectance of the film is also increased.

It is an object of the present application to provide a window film capable of improving heat insulation in summer and heat insulation in winter of a building or vehicle.

Another object of the present application is to provide a window film in which visible light transmittance is low, and an increase in visible light reflectance that may cause discomfort to a user is suppressed.

Another object of the present application is to provide a window including the window film.

The above and other objects of the present application can all be solved by the present application described in detail below.

In an example related to the present application, the present application relates to a window film. Specifically, the window film is an infrared reflective solar control film used to secure heat shielding properties in summer and/or heat insulation in winter. The window film (infrared reflective film) is a window film capable of not only securing heat-shielding properties and thermal insulation in relation to infrared rays, but also realizing low visible light transmittance and low visible light reflectance at the same time.

In the present application, "visible light or visible light" may mean light within a wavelength range of about 380 to 780 nm, and "infrared" encompasses near infrared rays within a wavelength range of about 780 to 2,500 nm and far infrared rays in a wavelength range of 2.5 μm to 25 μm can be used to mean In addition, "sunlight" may include the above-described visible light wavelength and infrared wavelength.

1 , the window film 100 of the present application sequentially includes a base layer 101 , a first cured resin layer 102 , an infrared reflective layer 103 , and a second cured resin layer 104 . . In addition, the infrared reflective layer 103 includes a metal layer and a metal oxide layer. The sequentially stacked layer configurations may be in direct contact with adjacent layers. Alternatively, a third configuration may be interposed between layers adjacent to each other.

The method of forming each layer is not particularly limited, but the cured resin layer may be formed by a wet coating method using a coating composition, and the metal layer and the metal oxide layer are formed by a dry method such as sputtering deposition, for example. can be

The window film may be attached to the window as shown in Fig. 2 (a). Specifically, the surface of the window 300 to be attached is washed, and the window film 100 is attached to the window through the adhesive 200 . At this time, the upper portion of the second cured resin layer 104 may be pressed using a tool such as a squeegee, and moisture or air bubbles may be removed between the window and door 300 and the base layer 101 . As a result, the base layer side of the window film may be located on the outdoor side, and the second cured resin layer of the window film may be located on the indoor side. The adhesive layer may be a component of a window film, and in this case, the film may further include a release layer capable of being peeled from the adhesive layer.

In one example, the window film may be a film satisfying the following conditions 1 and 2. Transmittance and reflectance related to conditions 1 and 2 may be measured according to the method described in relation to the following experimental examples.

Condition 1: Transmittance for visible light is within the range of 20% to 80%

Condition 2: The visible light reflectance measured outside the base layer of the window film is 20% or less

In general, in the case of an infrared reflective solar control film, it is common to have a high reflectance to infrared light due to the wavelength selectivity of the infrared reflective layer, and to have a high visible light transmittance and a low visible light reflectance at the same time. For example, in the case of a conventional film, the transmittance for visible light is at least 60% or more, 70% or more, or 75% or more, and the reflectance for visible light is generally within 15%. However, as the demand for window films having various visible light transmittances increases, the demand for products having low visible light transmittance even for an infrared reflective window film is increasing. For example, in the case of a vehicle window film, the need for a film satisfying a low visible light transmittance of 60% or 50% or less is increasing. However, when the thickness of the infrared reflective layer is adjusted to lower the visible light transmittance, the visible light reflectance increases, which may cause discomfort to the user. Due to the characteristics of the reflective window film, it is not easy to manufacture a product having a low visible light transmittance and sufficiently excellent other optical characteristics.

In this regard, the film of the present application may be a film that satisfies condition 1 and has a relatively low transmittance for visible light. For example, the visible light transmittance of the window film of the present application may be 75% or less, 70% or less, 65% or less, 60% or less, 55% or less, 50% or less, 45% or less, or 40% or less. At the same time, the window film of the present application has a low reflectance of visible light from the side of the base layer as satisfying condition 2 above. For example, in relation to condition 2, the visible light reflectance of the window film of the present application may be 15% or less or 10% or less. Therefore, it is possible not to give discomfort to a user or an observer who looks at the window to which the film is attached outdoors.

In one example, the window film may be a film satisfying Conditions 1 and 3 below. Transmittance and reflectance related to conditions 1 and 3 may be measured according to the method described in relation to the following experimental examples.

Condition 1: Transmittance for visible light is within the range of 20% to 80%

Condition 3: The visible light reflectance measured outside the second cured resin layer of the window film is 20% or less

When the window film satisfies Condition 1 and Condition 3 at the same time, it has a low visible light reflectance at the side of the second cured resin layer while lowering the transmittance for visible light. Accordingly, it is possible not to give discomfort to a user or an observer who looks at the window to which the film is attached in the room. For example, the specific value of the visible light transmittance according to Condition 1 is the same as described above, and in relation to Condition 3, the visible light reflectance of the window film of the present application may be 15% or less or 10% or less.

In another example, the window film may be a film satisfying all of the following Conditions 1 to 3. Transmittance and reflectance related to Conditions 1 to 3 may be measured according to the method described in relation to the following experimental examples.

Condition 1: Transmittance for visible light is within the range of 20% to 80%

Condition 2: The visible light reflectance measured outside the base layer of the window film is 20% or less

Condition 3: The visible light reflectance measured outside the second cured resin layer of the window film is 20% or less

When all of the conditions 1 to 3 are simultaneously satisfied, the window film has low visible light reflectance at the base layer side and the second cured resin layer side while lowering the transmittance for visible light. Accordingly, it is possible not to cause discomfort to a user or an observer who looks at the window to which the film is attached in each of the indoor and outdoor areas. When the window film satisfies all of the conditions 1 to 3, the specific value of the visible light transmittance according to Condition 1 is the same as described above, and the specific value of the visible light transmittance according to Conditions 2 and 3 may also be the same as described above.

As described above, the inventor of the present application has developed an infrared reflective window film without change in the configuration of the infrared reflective layer (eg, the thickness of the infrared reflective layer, etc.) and other optical properties are not deteriorated (eg, increase in reflectance). Specifically, the inventor of the present application has disclosed that, when the absorption rate for sunlight of the cured resin layer inside the window film, in particular, the absorption rate for visible and/or infrared light increases, the visible light while maintaining the heat insulation, which is an advantage of the infrared reflective window film. It was confirmed that the visible light transmittance of the window film could be lowered without increasing the reflectance.

In this regard, the window film of the present application may include at least one of a visible light absorber and an infrared absorber in the first cured resin layer. That is, when the first cured resin layer of the window film is manufactured, a resin composition including a visible light absorber and/or an infrared absorber may be used.

In one example, a material capable of absorbing light of a wavelength of 380 to 780 nm, more specifically, light of a wavelength of 480 to 630 nm, may be used as the visible light absorber. The kind of this material is not particularly limited. For example, a black dye may be used. In addition, general-purpose products known to have a visible light absorption function may be used without limitation, for example, BASF's Orasol Black X55 (maximum absorption wavelength = 580 nm) may be used.

In one example, as the infrared absorber, a material that absorbs some light included in the visible light region and light of a wavelength longer than that may be used. For example, a material capable of absorbing light in a wavelength range of 350 to 2,100 nm, specifically light in a wavelength range of 400 to 1,300 nm, and more specifically light in a wavelength range of 780 to 1,300 nm may be used. The type of the infrared absorber is not particularly limited, and for example, a metal complex-based dye, a phthalocyanine-based dye, a naphthalocyanine-based dye, a cyanine-based dye having a metal-complex form in the molecule, or a diimonium-based dye may be used. there is. In addition, general-purpose products known to have an infrared absorption function may be used without limitation, for example, NIR-850PTC-F (maximum absorption wavelength = 850 nm) of Kyung-In Corporation may be used.

In an example related to the present application, the above-mentioned infrared absorber and visible light absorber may be included only in the first cured resin layer, and may not be included in the second cured resin layer. When these absorbents are included in the second cured resin layer, problems may occur in the use stability of the window film, such as the absorbent smearing due to user contact or the like.

In one example, the first cured resin layer may include a visible light absorber in an amount of 30 parts by weight or less based on the solid content of the first cured resin layer. In the present application, the solid content may mean a non-volatile content remaining when the composition (coating solution) used to form the resin cured layer is applied and then heat-dried. That is, it may mean the remaining components excluding the solvent among the composition components. Specifically, the first cured resin layer may include 25 parts by weight or less, 20 parts by weight or less, 15 parts by weight or less, 10 parts by weight or less, or 5 parts by weight or less based on the solid content of the cured resin layer. The lower limit of the content of the visible light absorber is not particularly limited, but may be 0.1 parts by weight or more, 0.5 parts by weight or more, 1 parts by weight or more, or 1.5 parts by weight or more. In this specification, unless otherwise specified, "part by weight" means a weight ratio.

In one example, the first cured resin layer may include an infrared absorber in an amount of 30 parts by weight or less based on the solid content of the first cured resin layer. Specifically, the first cured resin layer may be included in an amount of 25 parts by weight or less, 20 parts by weight or less, 15 parts by weight or less, or 10 parts by weight or less, based on the solid content of the cured resin layer. The lower limit of the content of the infrared absorber is not particularly limited, but 0.1 parts by weight or more, 0.5 parts by weight or more, 1 parts by weight or more, 1.5 parts by weight or more, 2 parts by weight or more, 2.5 parts by weight or more, 3 parts by weight or more, 3.5 parts by weight or more or more, 4 parts by weight or more, 4.5 parts by weight or more, or 5 parts by weight or more.

The base layer is a component that serves as a support for the film, as long as it does not impair the properties of the window film described above, the specific type of the base layer is not particularly limited. For example, the base layer may include glass or a polymer resin.

In one example, the base layer may include a flexible resin to have flexible properties. For example, polyester resins such as polyethylene terephthalate resin, polyethylene naphthalate resin, polybutylene terephthalate resin, acetate resin, polyether sulfone resin, polycarbonate resin, polyimide resin, polyolefin resin Paper, (meth)acrylate-based resin, polyvinyl chloride-based resin, polystyrene-based resin, polyvinyl alcohol-based resin, polyarylate-based resin, or polyphenylene sulfide-based resin may be used for the base layer.

The thickness of the base layer is not particularly limited as long as it does not interfere with securing the optical properties of the window film and/or securing the flexibility of the base layer described above. For example, the base layer may have a thickness of 5 μm or more, 10 μm or more, 20 μm or more, or 30 μm or more. In addition, the base layer may have a thickness of 200 μm or less or 150 μm or less.

The infrared reflection layer including the metal oxide layer and the metal layer is a layer that imparts wavelength selectivity to light, such as transmission of visible light and reflection of infrared light, to the window film.

In one example, the metal layer is titanium (Ti), silver (Ag), platinum (Pt), gold (Au), copper (Cu), chromium (Cr), aluminum (Al), palladium (Pd) and / or Nickel (Ni) may be included. The metal layer may be a layer including only the metals listed above, or may be a layer including components other than those listed above but mainly containing the metal as a main component. The main component may mean a case in which the weight ratio of any one component constituting a layer to the layer is 85% or more.

In one example, the metal layer may include a plurality of lower metal layers. The lower metal layer may be configured to include one or more of the same metal components listed above. For example, each lower metal layer may include two or more metal components in one layer. In another example, a plurality of lower metal layers including different metal components may be stacked on each other to constitute the metal layer.

The thickness of the metal layer is not particularly limited as long as it does not interfere with securing the optical properties of the window film described above. For example, the thickness of the metal layer may be 50 nm or less, 45 nm or less, 40 nm or less, 35 nm or less, 30 nm or less, 25 nm or less, or 20 nm or less.

In one example, the thickness of the metal layer may be in the range of 5 nm to 20 nm. As described above, in the present application, in providing a window product having low visible light transmittance, a thin metal layer such as 20 nm or less in thickness may be used. Accordingly, it is possible to prevent an increase in reflectance for visible light and discomfort to the user.

In one example, the metal oxide layer is niobium (Nb), antimony (Sb), barium (Ba), gallium (Ga), germanium (Ge), hafnium (Hf), indium (In), lanthinium (La) , one of the oxides of magnesium (Mg), selenium (Se), silicon (Si), tantalum (Ta), titanium (Ti), vanadium (V), yttrium (Y), zinc (Zn), and tin (Sn) may include more than one. The metal oxide layer may be a layer made of only the oxide of the metal, or a layer including a metal oxide as a main component although other components than those listed above.

In one example, the metal oxide layer may include a plurality of lower metal oxide layers. The lower metal oxide layer may be configured to include at least one of the same metal oxide components as listed above. For example, each lower metal oxide layer may include two or more metal oxide components in one layer. In another example, a plurality of lower metal oxide layers including different metal oxide components may be stacked on each other to constitute the metal oxide layer.

The thickness of the metal oxide layer is not particularly limited as long as it does not interfere with securing the optical properties of the window film described above. For example, the metal oxide layer has a thickness of 5 nm or more, 10 nm or more, 15 nm or more, 20 nm or more, 25 nm or more, 30 nm or more, 35 nm or more, 40 nm or more, 45 nm or more, or 50 nm or more. can have The upper limit is not particularly limited, but may be, for example, 300 nm.

In the present application, the lamination form of the metal layer and the metal oxide layer is not particularly limited. For example, a metal layer and a metal oxide layer may be alternately stacked.

In one example, the thermal transmittance of the window film including the visible light absorber and/or the infrared absorber in the first cured resin layer may be 3.8 or less. For example, the thermal transmittance may be 3.75 or less, 3.70 or less, 3.65 or less, 3.60 or less, or 3.55 or less. The lower the thermal transmittance, the better, so the lower limit is not particularly limited. When the thermal transmittance rate is satisfied, it is possible to secure an appropriate level of thermal insulation required in winter. The thermal transmittance may be measured in the same manner as described in the following experimental examples. As can be seen in the following experimental examples, the example uses a cured resin layer using an absorbent, whereas the comparative example uses a cured resin layer that does not contain an absorbent, but the infrared reflection layer configuration of the example and the comparative example is the same It can be seen that the thermal transmittance coefficient shows almost the same value. This means that the resin layer including the absorber does not inhibit the inherent function of the infrared reflecting layer related to the thermal transmittance.

In one example, the shielding coefficient of the window film including the visible light absorber or the infrared absorber may be 0.600 or less. Specifically, it may be 0.590 or less, 0.580 or less, 0.570 or less, 0.560 or less, 0.550 or less, or 0.540 or less. The lower the shielding coefficient, the better, so the lower limit is not particularly limited. When the above shielding coefficient is satisfied, it is possible to secure an appropriate level of thermal insulation required in summer. The shielding coefficient may be measured in the same way as described in the following experimental examples.

In another example, the window film including the infrared absorber may have a lower shielding coefficient than the window film including the visible light absorber. In the case of a shielding coefficient, solar transmittance acts as the largest factor, because infrared absorbers can absorb a wider wavelength range than visible light absorbers (that is, have low transmittance to sunlight). For example, the shielding coefficient of the window film including the infrared absorber in the first cured resin layer may be 0.550 or less, 0.540 or less, 0.530 or less, 0.520 or less, 0.510 or less, or 0.505 or less.

In one example, the window film may have a solar radiation absorption in the range of 25% to 50%. The solar radiation absorptivity may be measured according to the method described in the following experimental examples. The solar radiation absorptivity can be secured by using a predetermined amount of a visible light absorbent and/or an infrared absorber in the first cured resin layer, as described in the present application.

The configuration of the first cured resin layer and the second cured resin layer is not particularly limited as long as the optical properties of the above-described window film are not hindered. For example, the first and cured resin layers may be formed from a composition further including a curable compound and/or inorganic particles in addition to a visible light absorber and an infrared absorber. And, for example, the second cured resin layer may be formed from a composition including a curable compound and/or inorganic particles. As the curable compound used in forming the cured resin layer, for example, a composition including a monofunctional or polyfunctional (meth)acrylate compound or a composition including an epoxy compound may be used.

In one example, the first cured resin layer may be formed from, for example, a photocurable type composition. As used herein, the term “photocurable composition” refers to a composition in which a curing process is induced by light irradiation, that is, irradiation with electromagnetic waves. The electromagnetic waves include microwaves, infrared (IR), ultraviolet (UV), X-rays, γ-rays or α-particle beams, proton beams, neutron beams, and electron beams. (electron beam) is used as a generic term for particle beams.

When the first cured resin layer is formed from a photocurable composition, the composition may include a photocurable oligomer. That is, the first cured resin layer may include an oligomer or other components to be described later in a cured state. As the photocurable oligomer, an oligomer component used for preparing a photocurable (eg, UV curable) composition in the art may be used without limitation. For example, the oligomer may include a urethane acrylate in which a polyisocyanate having two or more isocyanate groups in a molecule and a hydroxyalkyl (meth)acrylate are reacted; ester-based acrylate obtained by dehydration condensation reaction of polyester polyol and (meth)acrylic acid; an ester-based urethane acrylate obtained by reacting an ester-based urethane resin obtained by reacting a polyester polyol and a polyisocyanate with a hydroxyalkyl acrylate; ether-based acrylates such as polyalkylene glycol di(meth)acrylate; an ether-based urethane acrylate obtained by reacting an ether-based urethane resin obtained by reacting a polyether polyol and a polyisocyanate with a hydroxyalkyl (meth)acrylate; Alternatively, an epoxy acrylate obtained by addition reaction of an epoxy resin and (meth)acrylic acid may be used, but the present invention is not limited thereto.

In one example, the first cured resin layer may include an aliphatic urethane acrylate as a photocurable oligomer. In this case, the term aliphatic may be used to mean including an acyclic aliphatic unit and an aliphatic ring unit. For example, the aliphatic unit included in the aliphatic urethane acrylate may be a C1 to C30 aliphatic compound unit, and when the aliphatic is an aliphatic ring unit, it may be a C3 to C20 aliphatic compound unit.

As the aliphatic urethane acrylate, a reactant of a mixture comprising an aliphatic polyisocyanate, an aliphatic polyol and a hydroxyalkyl (meth)acrylate can be used. A method of forming the urethane acrylate using the raw material may use a known method, and the ratio between each component may be appropriately adjusted within a range that does not impair the purpose of the present application.

In one example, the first cured resin layer may include 35 parts by weight or more of the photocurable oligomer based on the solid content. Specifically, the first cured resin layer, based on 100 parts by weight of the solid content in the cured layer, 40 parts by weight or more, 45 parts by weight or more, 50 parts by weight or more, 55 parts by weight or more, 60 parts by weight or more, 65 parts by weight or more Or 70 parts by weight or more of the photocurable oligomer may be included. The upper limit of the content is not particularly limited, but may be, for example, 80 parts by weight or less.

In one example, the composition for forming the first cured resin layer may further include a photocurable monomer component. As the monomer component, a monomer having a reactive functional group such as a (meth)acryloyl group in a molecular structure may be used. In a non-limiting example, the monomer includes: alkyl (meth)acrylate; a hydroxyl group-containing monomer such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate or hydroxybutyl (meth)acrylate; a carboxyl group-containing monomer such as (meth)acrylic acid or β-carboxyethyl (meth)acrylate; alkoxy group-containing monomers such as 2-(2-ethoxyethoxy)ethyl (meth)acrylate; aromatic group-containing monomers such as benzyl (meth)acrylate or phenoxyethyl (meth)acrylate; a heterocyclic moiety-containing monomer such as tetrahydrofurfuryl (meth)acrylate or (meth)acryloyl morpholine; Or a polyfunctional acrylate may be mentioned, but is not limited thereto. In the above, the type of the alkyl (meth)acrylate is not particularly limited, and, for example, an alkyl (meth)acrylate having a linear or branched alkyl group having 1 to 14 carbon atoms may be used. Examples of such monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl ( meth)acrylate, sec-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-ethylbutyl (meth)acrylate, n- octyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, lauryl (meth) acrylate and tetradecyl (meth) acrylate, and one or more of the above Mixing may be used.

In one example, the composition for forming the first cured resin layer may include a polyfunctional acrylate as a photocurable monomer. Examples of the polyfunctional acrylate include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentylglycol di(meth)acrylate, polyethylene Glycol di (meth) acrylate, neopentylglycol adipate di (meth) acrylate, hydroxyl puivalic acid neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, ethylene oxide-modified di(meth)acrylate, di(meth)acryloxyethyl isocyanurate, allylated cyclohexyl Di (meth) acrylate, tricyclodecane dimethanol (meth) acrylate, dimethylol dicyclopentane di (meth) acrylate, ethylene oxide-modified hexahydrophthalic acid di (meth) acrylate, tricyclodecane dimethanol ( Meth) acrylate, neopentyl glycol-modified trimethylpropane di(meth)acrylate, adamantane di(meth)acrylate, or 9,9-bis[4-(2-acryloyloxyethoxy)phenyl ] a bifunctional acrylate such as fluorine; Trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propylene oxide trifunctional acrylates such as modified trimethylolpropane tri(meth)acrylate, trifunctional urethane (meth)acrylate, or tris(meth)acryloxyethyl isocyanurate; tetrafunctional acrylates such as diglycerin tetra(meth)acrylate or pentaerythritol tetra(meth)acrylate; pentafunctional acrylates such as propionic acid-modified dipentaerythritol penta(meth)acrylate; And dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate or urethane (meth) acrylate (ex. isocyanate monomer and trimethylolpropane tri (meth) acrylate of A hexafunctional acrylate such as a reactant may be used, but the present invention is not limited thereto.

In one example, the first cured resin layer may include 0.001 parts by weight or more of the photocurable monomer based on the solid content. Specifically, the first cured resin layer may include 0.005 parts by weight or more or 0.01 parts by weight or more of the photocurable monomer based on 100 parts by weight of the solid content in the cured layer. The upper limit of the content is not particularly limited, but may be, for example, 15 parts by weight or less or 10 parts by weight or less.

In one example, the resin composition used to form the first cured resin layer may include particles (inorganic filler). The particles allow the first cured resin layer to have an appropriate level of hardness. The kind of particles is not particularly limited. For example, the particles may be clay, talc, alumina, calcium carbonate, zirconia and/or silica particles. In one example, the particles may be used as colloidal particles dispersed in an organic solvent such as MEK.

In one example, the particles included in the first cured resin layer may have a diameter (particle diameter) within the range of 0.01 to 1 μm. More specifically, the particles may have an average particle diameter measured by a D50 particle size analyzer in the range of 5 to 100 nm or 8 to 40 nm.

In one example, the first cured resin layer may include 70 parts by weight or less of particles based on the solid content. Specifically, the first cured resin layer is 65 parts by weight or less, 60 parts by weight or less, 55 parts by weight or less, 50 parts by weight or less, 45 parts by weight or less, 40 parts by weight or less, or 35 parts by weight or less, based on 100 parts by weight of the solid content in the cured layer. Particles by weight or less may be included. The lower limit of the content is not particularly limited, but may be, for example, 5 parts by weight or more, 10 parts by weight or more, or 15 parts by weight or more. When the particle size and content range are satisfied, the first cured resin layer may secure an appropriate level of hardness.

The composition for forming the first cured resin layer may further include a photoinitiator. As the photoinitiator, any one can be used as long as it can initiate a polymerization reaction through light irradiation or the like. For example, alpha-hydroxyketone compounds (ex. IRGACURE 184, IRGACURE 500, IRGACURE 2959, DAROCUR 1173; Ciba Specialty Chemicals (manufactured by); phenylglyoxylate-based compounds (ex. IRGACURE 754, DAROCUR MBF; Ciba Specialty Chemicals (manufactured by Ciba Specialty Chemicals)); benzyl dimethyl ketal compounds (ex. IRGACURE 651; Ciba Specialty Chemicals (manufactured)); a-aminoketone-based compounds (ex. IRGACURE 369, IRGACURE 907, IRGACURE 1300; Ciba Specialty Chemicals (manufactured by)); monoacylphosphine-based compound (MAPO) (ex. DAROCUR TPO; Ciba Specialty Chemicals (manufactured by Ciba Specialty Chemicals)); bisacylphosphene compound (BAPO) (ex. IRGACURE 819, IRGACURE 819DW; Ciba Specialty Chemicals (manufactured by)); phosphine oxide compounds (ex. IRGACURE 2100; Ciba Specialty Chemicals (manufactured)); metallocene compounds (ex. IRGACURE 784; Ciba Specialty Chemicals (manufactured)); iodonium salt (ex. IRGACURE 250; Ciba Specialty Chemicals (manufactured by)); and mixtures of one or more of the above (ex. DAROCUR 4265, IRGACURE 2022, IRGACURE 1300, IRGACURE 2005, IRGACURE 2010, IRGACURE 2020; Ciba Specialty Chemicals (manufactured by Ciba Specialty Chemicals)) and the like, and one or more than one of the above may be used. , but is not limited thereto.

In one example, the first cured resin layer may contain 10 parts by weight or less of the photoinitiator based on the solid content. Specifically, the first cured resin layer, based on 100 parts by weight of the solid content in the cured layer, 10 parts by weight or less, 9 parts by weight or less, 8 parts by weight or less, 7 parts by weight or less, 6 parts by weight or less, or 5 parts by weight or less It may contain a photoinitiator of. The lower limit of the content is not particularly limited, but may be, for example, 0.1 parts by weight or more or 0.5 parts by weight or more.

The first cured resin layer may have a predetermined thickness at a level that secures an appropriate level of strength required for the window film and does not interfere with the optical properties of the above-described window film. For example, the first cured resin layer may have a thickness in a range of 0.5 μm to 10 μm.

The second cured resin layer is a protective coating layer capable of protecting the infrared reflecting layer, and is configured to prevent damage due to external stimuli occurring during the glass attachment construction and use of the window film. The second cured resin layer is configured to have stain resistance and scratch resistance.

In one example, the composition for forming the second cured resin layer may include a photocurable oligomer. That is, the second cured resin layer may include an oligomer or monomer component to be described later in a cured state. As the photocurable oligomer, the oligomer described in relation to the first cured resin layer may be used.

In one example, the composition for forming the second cured resin layer may include a photocurable monomer. As the photocurable monomer, those described in relation to the first cured resin layer may be used.

In one example, the composition for forming the second cured resin layer may include a phosphoric acid-based (meth)acrylate. The phosphoric acid-based (meth)acrylate may be a (meth)acrylate compound including at least one phosphoric acid group, and may include, for example, phosphate (meth)acrylate. When phosphoric acid-based (meth)acrylate is used, the adhesion of the second cured resin layer to the infrared reflective layer and durability reliability of the film can be secured.

In one example, the composition for forming the second cured resin layer may include 0.001 parts by weight or more of phosphoric acid-based (meth)acrylate based on solid content. Specifically, the second cured resin layer, based on 100 parts by weight of the solid content in the cured layer, 0.005 parts by weight or more, 0.01 parts by weight or more, 0.05 parts by weight or more, 0.1 parts by weight or more of phosphoric acid-based (meth) acrylate. can The upper limit of the content is not particularly limited, but may be, for example, 15 parts by weight or less or 10 parts by weight or less.

In one example, the composition for forming the second cured resin layer may include a fluorine-based (meth)acrylate. The fluorine-based (meth)acrylate may be, for example, a perfluorine compound such as perfluoropolyether acrylate. When the second cured resin layer includes a fluorine-based (meth)acrylate, the stain resistance property of the film may be improved.

In one example, the composition for forming the second cured resin layer may include 0.001 parts by weight or more of fluorine-based (meth)acrylate based on solid content. Specifically, the second cured resin layer, based on 100 parts by weight of the solid content in the cured layer, 0.005 parts by weight or more, 0.01 parts by weight or more, 0.05 parts by weight or more, 0.1 parts by weight or more, 0.5 parts by weight or more, or 1 parts by weight or more It may include a fluorine-based (meth)acrylate. The upper limit of the content is not particularly limited, but may be, for example, 15 parts by weight or less or 10 parts by weight or less.

In one example, the composition for forming the second cured resin layer may further include a thiol-based compound. Specifically, the second cured resin layer, based on 100 parts by weight of the solid content in the cured layer, 0.05 parts by weight or more, 0.1 parts by weight or more, 0.5 parts by weight or more, 1 parts by weight or more, 5 parts by weight or more, or 10 parts by weight The above thiol-based compound may be included. The upper limit of the content is not particularly limited, but may be, for example, 15 parts by weight or less or 10 parts by weight or less. In the present application, by adjusting the content ratio, O2 inhibition can be reduced during UV curing of the second cured resin layer, thereby improving scratch resistance and pencil hardness despite the thickness of the thin film. The thiol-based compound may provide excellent scratch resistance and pencil hardness to the second cured resin layer. The thiol-based compound may be, for example, a polyfunctional secondary thiol compound, but is not limited thereto. In one example, the thiol-based compound may include pentaerythritol tetrakis (3-mercaptobutylate).

In one example, the second cured resin layer may further include an inorganic filler. Specific types and particle size characteristics of the inorganic filler are the same as those described for the first cured resin layer. In addition, the content of the inorganic filler used in the second cured resin layer is the same as described in the first cured resin layer.

In one example, the second cured resin layer may include a photoinitiator. The type and content of the initiator are the same as those described in the first cured resin layer.

In one example, the thickness of the second cured resin layer may be 100 nm or less. When the thickness exceeds 100 nm, there may be a problem in that the optical properties of the film are lowered, such as a rainbow is observed in the appearance of the film, and the heat insulating properties are lowered.

In another example related to the present application, the present application relates to fittings including the window film. Windows and doors may refer to various windows or doors installed in openings, such as walls or doorways, to block the inside (inside) of a building from the outside (outside). The specific configuration of the window is not particularly limited.

According to the present application, there may be provided a window film having a low visible light transmittance and suppressing an increase in visible light reflectance that may cause discomfort to a user. When the film is used, it is advantageous in securing heat shielding properties through blocking sunlight in summer and insulating properties in winter. The window film may be used as a member for a building or vehicle.

1 schematically shows a layer configuration of a window film according to an example of the present application. According to the present application, the window film 100 including the base layer 101 , the first cured resin layer 102 , the infrared reflective layer 103 , and the second cured resin layer 104 may be provided.
Figure 2 shows an example in which a window film is attached to the windows and doors of a building according to an example of the present application. Specifically, Fig. 2 (a) shows the order in which the window film 100 is attached to the windows and doors 300 through an adhesive, and Fig. 2 (b) shows the window film attached to the windows in a building having windows. .

Hereinafter, the window film of the present application will be described in detail through Examples and Comparative Examples. However, the scope of the present application is not limited by the following examples.

Evaluation items and methods

* Visible light transmittance (%): For the films prepared in Examples and Comparative Examples, the visible light (380 to 780 nm) transmittance was measured according to KS L 2514.

* Visible light reflectance (indoor) (%): Visible light (380 to 780 nm) reflectance was measured according to KS L 2514 for the films prepared in Examples and Comparative Examples. The indoor reflectance means the reflectance measured on the overcoat layer side of the film.

* Visible light reflectance (outdoor) (%): Visible light (380 to 780 nm) reflectance was measured according to KS L 2514 for the films prepared in Examples and Comparative Examples. The outdoor reflectance means the reflectance at the side of the base layer.

*Solar radiation transmittance (%): For the films prepared in Examples and Comparative Examples, the transmittance of solar radiation (300 to 2,100 nm) was measured according to KS L 2514.

*Solar radiation absorption (%): For the films prepared in Examples and Comparative Examples, solar radiation (300 to 2,100 nm) absorption was measured according to KS L 2514.

* Shielding coefficient: The visible light shielding coefficient was measured according to KS L 2016 for the films prepared in Examples and Comparative Examples. The shielding coefficient indicates how much solar radiation is blocked by the film when it enters from the outside through the glass plate. Specifically, when the ratio of plate glass only (when no film is attached) is set to 1, the ratio of solar heat incident on the glass to which the film is attached is absorbed once and then passed including being re-radiated to the opposite side of the incident surface. is the coefficient representing Through the shielding coefficient, it is possible to evaluate the film's ability to block external heat in situations where it is particularly necessary to block external heat, such as in summer.

*Thermal transmittance (W/m ² ·K): For the films prepared in Examples and Comparative Examples, the thermal transmittance was measured according to KS L 2016. The heat transmittance is to measure the amount of heat that passes per 1 m ² of glass for 1 hour when the temperature difference between the two sides of the air is 1 ℃ when the side to which the film is attached is heated with respect to the glass to which the film is attached. That is, the thermal transmittance is an index measuring the degree to which internal heat moves through the glass window. Through the thermal transmittance rate, it is possible to evaluate the properties of the film to prevent the release of internal heat in situations where it is necessary to secure thermal insulation (to prevent the discharge of internal heat), such as in winter. The lower the number, the better the insulating properties.

The measurement results for the above items are shown in Table 1.

manufacture of film

Example One

A hard coating layer (first resin cured layer) having a thickness of 2 μm including a visible light absorber on a PET substrate having a thickness of 50 μm, a first metal oxide layer having a thickness of 15 nm, a metal layer having a thickness of 13 nm, a second metal having a thickness of 15 nm An oxide layer and a protective coating layer (second cured resin layer) having a thickness of 33 nm were sequentially formed. The detailed film manufacturing process is as follows.

The hard coat layer (first cured resin layer) was prepared by preparing a hard coat layer solution as follows and then applying it with a bar coater. Based on 100 parts by weight of the solid content in the hard coating layer, 60 parts by weight of a curable resin, 2.3 parts by weight of a visible light absorber (Orasol Black X55, maximum absorption wavelength = 580 nm BASF), 35.7 parts by weight of an inorganic filler (MEK-AC-2140Z, NISSAN CHEMICAL, Colloidal Silica) It is prepared by mixing dispersed in Organic Solvent, 10-15 nm in diameter) and 2 parts by weight of a photoinitiator (Irgacure 127, BASF, hydroxyacetophenone). As the 60 parts by weight of the curable resin, urethane acrylate oligomer (Miramer PU340, Miwon, aliphatic trifunctional acrylate) was used. The hard coating layer is an organic-inorganic hybrid layer prepared by applying with a bar coater, drying at 80° C., and UV curing using an ultra-high pressure mercury lamp under a nitrogen atmosphere at an accumulated light amount of 600 mJ/cm 2 .

The first metal oxide layer was formed as a ZnO layer with a thickness of 15 nm under the conditions of 1.5 W/cm ² and 3 mTorr using a DC sputter method.

The metal layer was formed of an Ag metal layer with a thickness of 13 nm under the conditions of 1.5 W/cm ² and 3 mTorr using a DC sputter method.

The second metal oxide layer was formed as a ZnO layer with a thickness of 15 nm under the conditions of 1.5 W/cm ² and 3 mTorr using a DC sputter method.

The protective coating layer (second cured resin layer) was prepared by preparing a coating layer solution as follows and then applying it with a bar coater. The protective coating layer solution contains 60 parts by weight of a curable resin and 38 parts by weight of an inorganic filler (MEK-AC-2140Z, NISSAN CHEMICAL, Colloidal Silica dispersed in Organic Solvent, 10-15 nm in diameter) and 2 parts by weight based on 100 parts by weight of the solid content in the protective coating layer. It is prepared by mixing negative photoinitiators (Irgacure 127, BASF, hydroxyacetophenone). When the 60 parts by weight of the curable resin component is 100 parts by weight, 1 part by weight of a phosphoric acid ester compound (trade name MIRAMER SC1400, Miwon, phosphate methacrylate), 10 parts by weight of a fluorine-based acrylate (DAC-HP, DAIKIN, perfluoro polyether acrylate), 20 It consists of a thiol-based compound (Karenz MT PE1, SHOWA DENKO, tetrafunctional secondary SH, pentaerythritol tetrakis (3-mercaptobutylate)) by weight of 69 parts by weight of a urethane acrylate oligomer (Miramer PU340, Miwon, aliphatic trifunctional acrylate). The protective coating solution prepared as described above was applied on the second metal oxide layer with a bar coater, dried at 80 ° C., and UV cured using an ultra-high pressure mercury lamp under a nitrogen atmosphere at an accumulated light amount of 400 mJ/cm ² , 33 A protective coating layer, which is an organic-inorganic hybrid layer with a thickness of nm, was formed.

Example 2

A film was prepared in the same manner as in Example 1, except that the first cured resin layer contained 8.5 parts by weight of a near-infrared absorber (NIR-850PTC-F, maximum absorption wavelength = 850 nm, Kyung-In Corporation) instead of the visible light absorber, and the physical properties were measured.

comparative example One

Physical properties were measured for a commercially available product (TSP-NS 70S (Mapro)).

comparative example 2

A film was prepared in the same manner as in Example 1, except that the first resin layer did not include a visible light absorber and the thickness of the Ag metal layer was increased to 21 nm, and physical properties were measured.

[Table 1]

Compared with Comparative Example 1 using a commercial product, it can be seen that the films of Examples 1, 2 and Comparative Example 2 have low visible light transmittance. In relation to securing low visible light transmittance, in Examples 1 and 2, a visible light absorber and a near-infrared absorber were used in the first cured resin layer without increasing the thickness of the metal layer, and Comparative Example 2 was obtained by increasing the thickness of the metal layer. will be. However, from Table 1, it can be seen that Comparative Example 2 has a high level of visible light reflectance (indoor/outdoor), and thus may cause discomfort to the user. On the other hand, Examples 1 and 2 showed a significantly lower level of reflectance of visible light compared to Comparative Example 2. This means that when the solar control film is manufactured according to the present application, low visible light transmittance can be secured without increasing the reflectance for visible light.

In addition, both the films used in Examples and Comparative Examples show similar values of thermal transmittance, which means that the film prepared according to the present application can provide winter thermal insulation properties that are generally required for a reflective infrared film.

On the other hand, in the case of Example 2 using the near-infrared absorber, since the absorption wavelength for sunlight is wider than Example 1 using the visible light absorber, the solar radiation transmittance is reduced, and accordingly, it can be seen that the shielding coefficient is lowered.

Claims (14)

base layer; a first cured resin layer; an infrared reflecting layer comprising a metal layer and a metal oxide layer; and a second cured resin layer in sequence, satisfying the following conditions 1 and 2 or satisfying the following conditions 1 and 3,
The first cured resin layer is a window film comprising at least one of a visible light absorber and an infrared absorber.
Condition 1: Transmittance for visible light is within the range of 20% to 80%
Condition 2: The visible light reflectance measured outside the base layer of the window film is 20% or less
Condition 3: The visible light reflectance measured outside the second cured resin layer of the window film is 20% or less base layer; a first cured resin layer; an infrared reflecting layer comprising a metal layer and a metal oxide layer; and a second cured resin layer in sequence, and satisfies all of the following conditions 1 to 3,
The first cured resin layer is a window film comprising at least one of a visible light absorber and an infrared absorber.
Condition 1: Transmittance for visible light is within the range of 20% to 80%
Condition 2: The visible light reflectance measured outside the base layer of the window film is 20% or less
Condition 3: The visible light reflectance measured outside the second cured resin layer of the window film is 20% or less delete The window film of claim 1 or 2, wherein the first cured resin layer contains a visible light absorber in an amount of 30 parts by weight or less based on the solid content of the first cured resin layer. The window film of claim 1 or 2, wherein the first cured resin layer contains an infrared absorber in an amount of 30 parts by weight or less based on the solid content of the second cured resin layer. The window film according to claim 1 or 2, wherein the thickness of the metal layer is in the range of 5 nm to 20 nm. 7. The method of claim 6, wherein the metal layer is titanium (Ti), silver (Ag), platinum (Pt), gold (Au), copper (Cu), chromium (Cr), aluminum (Al), palladium (Pd) and nickel A window film comprising at least one metal selected from (Ni). According to claim 1 or 2, wherein the metal oxide layer is niobium (Nb), antimony (Sb), barium (Ba), gallium (Ga), germanium (Ge), hafnium (Hf), indium (In), Lanthinium (La), magnesium (Mg), selenium (Se), silicon (Si), tantalum (Ta), titanium (Ti), vanadium (V), yttrium (Y), zinc (Zn), and tin (Sn) ) A window film comprising an oxide of one or more metals selected from the group comprising: 3. The window film according to claim 1 or 2, wherein the thermal transmittance is 3.8 or less. The window film according to claim 1 or 2, wherein the absorption of solar radiation is in the range of 25% to 50%. The window film of claim 1 or 2, wherein the first cured resin layer further comprises a photocurable oligomer, a photoinitiator, and an inorganic filler. The window film of claim 10 , wherein the first cured resin layer further comprises a photocurable monomer. The window film of claim 1 or 2, wherein the second cured resin layer includes a photocurable oligomer, phosphoric acid-based (meth)acrylate, fluorine-based (meth)acrylate, a thiol-based compound, a photoinitiator, and an inorganic filler. A window comprising the window film according to claim 1 or 2.

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