KR20060060922A - Reflective reflector sheet - Google Patents

Abstract

The present invention relates to a retroreflective sheet, wherein the retroreflective sheet of the present invention is a base sheet layer (4) and a diffusion layer (3) laminated on one side of the base sheet layer and a metal deposition layer (1) laminated on the top surface of the diffusion layer. It consists of.

An object of the present invention is to provide a retroreflective sheet excellent in reflection efficiency and reflection performance.

Retroreflective sheet, diffusion layer, metal deposition layer, blocking prevention layer, reflection efficiency

Description

Retroreflective Sheeting {REFLECTIVE REFLECTOR SHEET}

1 is a cross-sectional view of a retroreflective sheet according to the present invention.

[Description of main part of drawing]

1: metal deposition layer

2: diffused particles

3: diffusion layer

4: sheet

5: Blocking prevention layer

6: diffused particles

7: resin

The present invention relates to a retroreflective sheet, wherein the retroreflective sheet of the present invention is a diffusion layer 3 laminated on one side of the base sheet layer 4 and the base sheet layer 4 and a metal deposition layer laminated on the upper surface of the diffusion layer. It consists of (1).

The retroreflective sheet utilizes the principle of retroreflective reflection of incident light incident from an external light source back to the light source in parallel with the incident light. Retroreflective reflection is performed by total internal reflection of the tube at three sides perpendicular to the cube corner. Is done.

Recently, retroreflective sheeting is widely used for decorative materials, reflective tapes for safety, reflective belts, road signs, warning reflectors. When driving a car at night, the light from the headlights of the car illuminates the road sign, the road sign reflects the incident light, and the light reflected from the road sign is returned back to the driver's direction. Signs can be identified.

The retroreflective sheet currently used has a disadvantage in that it is difficult to manufacture because the form is very complicated. Republic of Korea Patent Publication No. 20020096570, No. 20000018066, No. 20010067764, No. 20010067756, etc. As a method of manufacturing a conventional retroreflective sheet is a retroreflective sheet is a glass or poly methyl methacrylate (poly methyl methacrylate) One sheet of the sheet was processed in the form of a sheet made of an optically transparent material, and the cube corners were continuously arranged on one surface of the sheet. The method described above is a method using glass beads, which is a principle of uniformly applying fine glass beads on a fabric or film at a density of about 130,000 per square inch to return incident light to the direction of the light source, in particular, reflection performance and recursion. In order to improve the performance of the reflection, a special coating is applied on the back of the glass beads. However, this method has a problem in durability because the adhesion of the glass beads to the film is inferior.

Meanwhile, Korean Patent Laid-Open Publication Nos. 20040020952 and 20020096161 disclose a method of manufacturing a reflective sheet or a retroreflective sheet by forming a microprism structure. Specifically, in such a method, a triangular pyramid-shaped lens is used in the above patents. It plays the same role as a bead, and the incident light is refracted by the inclined plane inside the prism in turn, returning to the light parallel to the light source, and having retroreflective performance. However, this method also has a problem in durability because the triangular pyramid-shaped prism is easy to damage.

An object of the present invention is to provide a retroreflective sheet containing a diffusion layer containing particles in order to solve the above problems and excellent reflection efficiency and reflection performance by diffusion by the particles.

In order to achieve the above object, the retroreflective sheet of the present invention includes a diffusion sheet 3 laminated on one side of the base sheet layer 4 and the base sheet layer 4 and a metal deposition layer 1 stacked on the upper surface of the diffusion layer. It consists of. The retroreflective sheet of the present invention is shown in FIG.

The retroreflective sheet of the present invention may further include a blocking prevention layer laminated on one side of the substrate sheet layer, which is different from the diffusion layer of the base sheet layer.

Hereinafter, each layer constituting the retroreflective sheet of the present invention will be described in detail.

<Sheet>

The base sheet 4 is preferably formed of one selected from the group consisting of polycarbonate, polypropylene, polyethylene terephthalate, polyethylene, and epoxy, and its thickness is preferably 25 to 400 micrometers. This is because the mechanical properties of the sheet are insufficient at a thickness of 25 micrometers or less, and when the thickness is 400 micrometers or more, the reflectance may be lowered due to absorption of light in the base sheet. For this reason, the thickness of the base sheet is more preferably 50 to 300 micrometers.

Diffusion layer

The diffusion layer 3 is composed of a resin and particles contained in the resin. By containing the particles in the diffusion layer 3 as described above, the diffusion layer 3 uniformly diffuses the light rays transmitted from the back surface to the surface, so that light incident from various directions can be totally reflected in the opposite direction of the incident and returned. This can improve retroreflective performance.

Particles 2 contained in the diffusion layer 3 are particles having a property of diffusing light rays, and are largely classified into inorganic particles and organic particles. Specific examples of the inorganic particles include silicate glasses such as silica and magnesium silicate, and titanium oxide (TiO ₂ ). Or mixtures thereof. Specific materials for the organic particles are preferably selected from the group consisting of homopolymers or copolymers of acryl, ethylene, styrene and propylene and terpolymer particles. The particles 2 contained in the diffusion layer 3 are used alone or in combination by selecting one or two or more kinds of the particles listed above.

The resin contained in the diffusion layer 3 is preferably selected from the group consisting of polymers, copolymers and terpolymers of acrylic, urethane and epoxy melamine, and the thickness of the diffusion layer (particles) Means a thickness of the resin portion except for) is preferably applied to 1 to 50 micrometers. The reason is that the reflection efficiency is lowered when it is 1 micrometer or less, and when it is 50 micrometers or more, desorption occurs due to particle deposition. Particles and resin are mix | blended according to the thickness of a desired diffusion layer in 10 weight part-300 weight part of particles per 100 weight part of resin.

<Metal deposition layer>

The metal deposition layer 1 is preferably formed of a metal having excellent processability of the deposition process and excellent reflection performance, and specifically, aluminum, chromium, antimony, indium, tin, or the like may be used.

In addition, the thickness of the metal deposition layer 1 is preferably 1 nanometer to 1 micrometer, because the reason is that the light transmittance is increased when the thickness is less than 1 nanometer, the reflectance may be relatively low, when more than 1 micrometer This is because there is a problem in that the deposition layer becomes thick, resulting in poor processability and low thickness uniformity in the deposition process.

The metal deposition layer 1 is selected from the group consisting of sputtering, electron beam, ion-plating, spray pylolysis, and chemical vapor deposition. The paper may be formed by dry coating. In addition, there is a wet coating method, but when the coating film is formed by the wet coating method, since the uniformity of the thickness is lowered and the reflectance falls, the dry coating method is preferable.

<Blocking prevention layer>

The retroreflective sheet of the present invention may further contain an antiblocking layer on one side of the substrate sheet layer on the other side of the substrate sheet layer.

The blocking phenomenon is that when two layers of film are stacked and pressure is applied to the top surface, cohesive force is created on the two films, and the film is pulled in opposite directions. Refers to a phenomenon that indicates resistance. The cause of this phenomenon is a complex compound, such as the force due to static electricity, mutual affinity, smooth surface structure, the effect of which varies depending on the environment in which the film is placed. These phenomena cause problems such as winding up during manufacture and production of film, impossibility of winding up, deterioration or lower work efficiency when processing film, and many manufacturing methods have been devised.

In order to solve this problem, the retroreflective sheet of the present invention may include a blocking prevention layer having a resin and particles dispersed therein. In this case, the resin uses the same polymer composition as the resin of the diffusion layer 3, and the same material as the material of the diffusion layer may be used as the material of the particles.

It is preferable that the compounding ratio of particle | grains and resin is mix | blended according to the thickness of a desired antiblocking layer within the range of 0.1 weight part-10 weight part of particles per 100 weight part of resin. It is preferable that the thickness of such a blocking prevention layer 5 is 0.1-10 micrometers. The reason is that when the thickness is 0.1 micrometer or less, the coating layer is thin and the adhesive strength of the particles is weakened. When the thickness is 10 micrometers or more, the product is thickened and the particles do not protrude so that the workability improvement effect is deteriorated. .

Many of the particles dispersed in the anti-blocking layer protrude very little from the bottom of the resin. Therefore, when laminating | stacking this retroreflective sheet, the lower end of this protruding particle abuts on the surface of a lower layer, and the whole surface of a retroreflective sheet does not contact. As a result, blocking is prevented and unevenness of the surface is removed.

The reflective sheet according to the present invention manufactured as described above may be attached to another substrate or coated with a deposition surface or a transparent adhesive coating for coloring.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments. The following examples are intended to further clarify the technical spirit of the present invention, and are not intended to limit the scope of the technical spirit of the present invention.

<Example 1>

As a base film, 125 micrometers in thickness PET FCTT (made by Kolon) was used. 200 parts by weight of GR300T (manufactured by Negami), acrylic particles having an average particle diameter of 25 µm, and 100 parts by weight of acrylic resin 52-666 (manufactured by Aekyung Chemical Co., Ltd.) and 150 parts by weight of methyl ethyl ketone solvent were dispersed in a mill (manufactured by Ika). After the coating was applied to one side of the base film by a gravure coating method having a thickness of 30 μm, a diffusion layer was prepared.

5 parts by weight of MR2HG (manufactured by Soken), acrylic particles having an average particle diameter of 2 μm, and 500 parts by weight of methyl ethyl ketone solvent were added to 100 parts by weight of acrylic resin 52-666 (manufactured by Aekyung Chemical Co., Ltd.). The anti-blocking layer was prepared by applying a gravure coating method to a thickness of 2㎛.

Aluminum (Al) was dry-coated to an optical thickness of 50 nm by DC magnetron sputtering to a diffusion layer of a double coated film to prepare a metal deposition layer.

Thus, three kinds of coating films were formed on the base film to prepare a reflective sheet having a high reflectance.

<Example 2>

As a base film, 125 micrometers in thickness PET FCTT (made by Kolon) was used. 200 parts by weight of GM2001 (manufactured by Ganz), acrylic particles having an average particle diameter of 20 µm per 100 parts by weight of acrylic resin 52-666 (manufactured by Aekyung Chemical Co., Ltd.), and 150 parts by weight of methyl ethyl ketone solvent were dispersed in a milling machine (manufactured by Ika). After the coating was applied to one side of the base film by a gravure coating method with a thickness of 25 μm, a diffusion layer was prepared.

5 parts by weight of MR2HG (manufactured by Soken), acrylic particles having an average particle diameter of 2 μm, and 500 parts by weight of methyl ethyl ketone solvent were added to 100 parts by weight of acrylic resin 52-666 (manufactured by Aekyung Chemical Co., Ltd.) on the opposite side of the diffusion layer thus prepared. The coating was applied in a thickness of 2 μm to prepare an antiblocking layer.

Aluminum (Al) on the diffusion layer of the double-coated film was dry-coated to an optical thickness of 10nm by DC magnetron sputtering method to prepare a metal deposition.

The acrylic adhesive layer was coated on the deposition layer of the reflective sheet prepared by the above method by a comma coating method, and the composite sheet was laminated with a protective film to prepare a reflective sheet.

<Example 3>

As a base film, 125 micrometers in thickness PET FCTT (made by Kolon) was used. 200 parts by weight of GM2001 (manufactured by Ganz), acrylic particles having an average particle diameter of 20 µm, and 100 parts by weight of acrylic resin 52-666 (manufactured by Aekyung Chemical Co., Ltd.) and 150 parts by weight of methyl ethyl ketone solvent were dispersed using a milling machine (manufactured by Ika). After the coating was applied to one side of the base film by a gravure coating method with a thickness of 25 μm, a diffusion layer was prepared.

Aluminum (Al) on the diffusion layer of the double-coated film was dry-coated to an optical thickness of 10nm by DC magnetron sputtering method to prepare a metal deposition.

The acrylic adhesive layer was coated on the deposition layer of the reflective sheet prepared by the above method by a comma coating method, and the composite sheet was laminated with a protective film to prepare a reflective sheet.

Comparative Example 1

As a base film, 125 micrometers thick polyethylene terephthalate base film FCTT (made by Kolon) was used. 40 parts by weight of MPB-HM5 (manufactured by Kolon) and 200 parts by weight of methyl ethyl ketone solvent, acrylic particles having an average particle diameter of 0.5 μm, per 100 parts by weight of acrylic resin 52-666 (manufactured by Aekyung Chemical Co., Ltd.) After the dispersion, the coating was applied to one side with a thickness of 0.8 μm by gravure coating to prepare a diffusion layer.

Aluminum (Al) was dry-coated to an optical thickness of 50 nm by DC magnetron sputtering on the diffusion layer of the double-coated base film to prepare a metal deposition layer.

5 parts by weight of MR2HG (Soken), an acrylic particle having an average particle diameter of 2 μm, and 500 parts by weight of methyl ethyl ketone solvent were added to 100 parts by weight of acrylic resin 52-666 (product of Aekyung Chemical Co., Ltd.) on the opposite side of the prepared diffusion layer. It applied to a thickness of 2㎛ by the method to prepare a blocking prevention layer.                     

In the same manner as above, three kinds of coating films were formed on the base film to prepare a reflective sheet.

Comparative Example 2

PET FCTT (manufactured by Kolon) having a thickness of 125 µm was used as the base film. 200 parts by weight of MPB-HX50 (manufactured by Kolon) and 150 parts by weight of methyl ethyl ketone solvent, acrylic particles having an average particle diameter of 50 µm, per 100 parts by weight of acrylic resin 52-666 (manufactured by Aekyung Chemical Co., Ltd.) After the dispersion, the gravure coating method was applied to one side of the base film with a thickness of 56 μm to prepare a diffusion layer.

5 parts by weight of MR2HG (manufactured by Soken), acrylic particles having an average particle diameter of 2 μm, and 500 parts by weight of methyl ethyl ketone solvent were added to 100 parts by weight of acrylic resin 52-666 (manufactured by Aekyung Chemical Co., Ltd.) on the opposite side of the diffusion layer. It applied to 2 micrometers thick, and prepared the blocking prevention layer.

Aluminum (Al) was dry-coated to an optical thickness of 50 nm by DC magnetron sputtering on top of the diffusion layer of the double-coated base film to prepare metal deposition.

Thus, three types of coating films were formed on the base film to prepare a reflective sheet.

Comparative Example 3

As a base film, the 125-micrometer-thick PET base film FCTT (made by Kolon) was used. 200 parts by weight of GM2001 (manufactured by Ganz), acrylic particles having an average particle diameter of 20 μm, and 150 parts by weight of methyl ethyl ketone solvent were added per parts by weight of acrylic resin 52-666 (manufactured by Aekyung Chemical Co., Ltd.) and dispersed by a milling machine (manufactured by Ika). Thereafter, by applying a gravure coating method on one side of the base film with a thickness of 25㎛ to prepare a diffusion layer.

5 parts by weight of MR2HG (manufactured by Soken), acrylic particles having an average particle diameter of 2 μm, and 500 parts by weight of methyl ethyl ketone solvent were added to 100 parts by weight of acrylic resin 52-666 (product of Aekyung Chemical Co., Ltd.) on the opposite side of the diffusion layer thus prepared. The coating was applied in a thickness of 2 μm to prepare an antiblocking layer.

Aluminum (Al) was dry-coated to an optical thickness of 0.5 nm by DC magnetron sputtering on top of the diffusion layer of the double-coated base film to prepare a metal deposition layer.

Thus, three types of coating films were formed on the base film to prepare a reflective sheet.

<Comparative Example 4>

As a base film, the 125-micrometer-thick PET film FCTT (made by Kolon) was used. 200 parts by weight of GM2001 (manufactured by Ganz) and 150 parts by weight of methyl ethyl ketone solvent, which are acrylic particles having a surface average particle diameter of 20 μm, per 100 parts by weight of acrylic resin 52-666 (manufactured by Aekyung Chemical Co., Ltd.) After the dispersion, a gravure coating method was applied to one side of the base film with a thickness of 25 μm to prepare a diffusion layer.

5 parts by weight of acrylic resin 52-666 (manufactured by Aekyung Chemical Co., Ltd.), acrylic particles having an average particle diameter of 2 μm, and 5 parts by weight of methyl ethyl ketone solvent, 500 parts by weight of acrylic resin, Injected and applied to a thickness of 2㎛ by the gravure coating method to prepare a blocking prevention layer.

The reflective sheet was manufactured by forming three kinds of coating films on the base film without going through the metal deposition layer manufacturing process.

Comparative Example 5

As a base film not coated with a diffusion layer, a 125 μm-thick PET film FCTT (manufactured by Kolon Co., Ltd.) was used to dryly coat aluminum (Al) with an optical thickness of 0.5 nm by DC magnetron sputtering to prepare a reflective sheet.

Comparative Example 6

As a reflective film made of glass beads used in the related art, a crystal reflective coating (manufactured by Kolon Glotech) was used.

Evaluation methods for the aforementioned examples and comparative examples are as follows.

Visible light reflectance

If there is a protective film, peel the protective film and attach it to the next 3 mm thick glass plate. If there is no protective film, the prepared retroreflective sheet is placed on a UV spectrometer (Shimadzu, UV-3101PC) sample holder to allow light to travel from the blocking layer direction. The reflectance in the visible light region of 380 or more and 780 nm or less was measured with the incident angle of 8 degrees.

TABLE 1

Film thickness % Reflectance by Wavelength                                          Diffusion Layer (μm) Metal Deposition Layer (nm) Anti-blocking layer (㎛) 380nm 580 nm 780 nm Example 1 30 50 2 92.1 91.6 90.5 Example 2 25 10 2 91.8 91.4 90.3 Example 3 25 10 0 92.0 91.5 90.4 Comparative Example 1 0.8 50 2 86.5 85.1 83.8 Comparative Example 2 56 50 2 88.4 87.0 86.2 Comparative Example 3 25 0.5 2 70.6 69.1 67.5 Comparative Example 4 25 0 2 1.5 2.3 1.3 Comparative Example 5 0 50 0 88.1 87.0 86.1 Comparative Example 6 Crystal reflective coating (KOLON Glotech Co., Ltd.) when using a conventional glass bead retroreflective sheet 72.1 68.3 65.8

As shown in Table 1 above, when the diffusion layer and the metal deposition layer are coated and laminated in the range of the thickness defined in the present invention, it can be seen that the reflectance is remarkably increased in the visible wavelength compared with the comparative example of the prior art. In particular, in Comparative Example 4 without applying the metal deposition layer, it can be seen that the reflectance is remarkably low.

In addition, when the anti-blocking layer is absent, it can be seen that in Example 3, the reflectance is higher than that in Example 2 having the anti-blocking layer.

The retroreflective sheet according to the present invention can be modified and applied in various forms within the scope of the technical idea of the present invention and is not limited to the above preferred embodiment. The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is a matter of course that it is not limited, and should be determined including not only the claims described below but also the claims and equivalents.

In the retroreflective sheet of the present invention, a metal deposition layer is laminated on a diffusion layer having acrylic particles on one surface of the base sheet, so that the reflectance for each light wavelength is 90% or more, which is excellent in reflection efficiency and reflection performance.

In addition, the method according to the present invention is excellent in durability due to the high adhesion of the particles and the deposition layer exhibiting reflection performance, and the method according to the present invention is excellent in durability since there is no fragile structure such as a prism structure.

Claims (10)

Base sheet layer 4; A diffusion layer (3) comprising a resin and particles (2) dispersed in the resin and formed on one surface of the base sheet layer (4); And And a metal deposition layer (1) laminated on the upper surface of the diffusion layer. The method of claim 1, Particles (2) dispersed in the resin of the diffusion layer (3) is a retroreflective sheet, characterized in that it comprises at least one material selected from the group consisting of silica, titanium oxide, aluminum oxide, zinc oxide, magnesium silicate. The method of claim 1, Particles 2 dispersed in the resin of the diffusion layer 3 is characterized in that it comprises at least one material selected from the group consisting of homopolymer, copolymer or terpolymer particles of acrylic, ethylene, styrene, propylene. Retroreflective sheet. The method of claim 1, The resin constituting the diffusion layer (3) is a retroreflective sheet, characterized in that it comprises at least one material selected from the group consisting of polymers, copolymers and terpolymers of acrylic, urethane and epoxy melamine. The method of claim 1, The thickness of the diffusion layer (3) is retroreflective sheet, characterized in that 1 to 50 micrometers. The method of claim 1, The metal deposition layer (1) is a retroreflective sheet, characterized in that it comprises at least one material selected from the group consisting of aluminum, chromium, antimony, indium and tin. The method of claim 6, The thickness of the metal deposition layer (1) is a retroreflective sheet, characterized in that 1 nanometer to 1 micrometer. The method of claim 1, The retroreflective sheet further includes a anti-blocking layer (5) on a back surface side of the surface on which the diffusion layer of the base sheet layer is laminated. The method of claim 8, The anti-reflective layer (5) is a retroreflective sheet, characterized in that it comprises a resin and particles dispersed in the resin. The method of claim 8, The anti-reflective sheet (5) has a thickness of 0.1 to 10 micrometers.

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