JPH0486701A - Retroreflective sheet having ultra-high weatherability - Google Patents

Abstract

PURPOSE:To improve durability and reflection intensity level by successively laminating high-refraction glass beads and focus layer film on a surface layer consisting of a fluororesin film and coating a metallic layer on a focus layer film. CONSTITUTION:The surface layer 1, an intermediate layer film 2, a binder layer 4, the glass beads 3, the focus layer film 5, and a metallic layer 6 are successively laminated. The binder layer 4 has the function to fix the glass beads to the surface layer 1 and the focus layer film 5 is provided to optimize the refraction of light in such a manner that incident rays are refracted through the respective layers from the surface layer to the glass beads and are then reflected by the metallic layer 6 so as to be efficiently recurred as the reflected rays parallel with the incident rays. The films to be used as the surface layer 1 are exemplified by independent monomers of fluoroolefins or copolymers, etc. of fluoroolefins. The degradation in gloss, the degradation in the reflection intensity, color fading, are extremely lessened in this way and abnormality, such as crazing or scaling, is not admitted. The excellent durability is thus obtd.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention uses a fluororesin film for the surface layer, has ultra-high weather resistance for outdoor use, and has greatly improved reflection strength. This relates to reflective sheets. The reflective sheet of the present invention can be attached to various objects such as road signs using an adhesive or pressure-sensitive adhesive or by means such as thermal lamination to impart a retroreflective effect.

[Prior art and problem to be solved by the present invention 1 Conventionally, the surface layer of a retroreflective sheet has been made of alkyd resin, polyester resin, acrylic resin, polyurethane resin,
Films based on various synthetic resins such as polyvinyl chloride resins have been used. However, retroreflective sheets with surface layers obtained from such synthetic resins have drawbacks such as reduced gloss, cracks, and easy staining after exposure for a relatively short period of time, and improvement in long-term durability is desired. was.

In addition, since the above-mentioned resins have a relatively high refractive index, even if glass beads with a high refractive index are used as a component of the retroreflective sheet, a sufficiently satisfactory level of reflection intensity can be obtained. I couldn't.

[Means for Solving the Problems] The present invention has been developed as a result of extensive research in view of the current situation.
The present inventors have discovered that by using a fluororesin film as the surface layer, a retroreflective sheet with extremely excellent durability and greatly improved reflection intensity level can be obtained, and the present invention has been completed.

That is, the present invention provides: (1) an ultra-high weather-resistant reflective film in which high refractive glass beads and a focal layer film are sequentially laminated on a surface layer made of a fluororesin film, and a metal layer is further formed on the focal layer film; Ultra-high weather resistance, with a surface layer made of fluororesin film, a binder layer, high refractive glass beads, and a focal layer film laminated in sequence, and a metal layer coated on top of the focal layer film. Retroreflective sheet, ■ An intermediate layer film, a binder layer, high refractive glass beads, and a focal layer film are sequentially laminated on a surface layer made of a fluororesin film, and a metal layer is further formed on the focal layer film. This invention relates to an ultra-high weather resistant retroreflective sheet.

First, the retroreflective sheet referred to in the present invention is as shown in Figs. 1 and 2.
Refers to a sheet having a structure as shown in FIG.

That is, the retroreflective sheet having the structure shown in FIG. 1 includes a surface layer (1), an intermediate layer film (2), a binder layer (4), glass beads (3), and a focal layer film (
5) and a metal layer (6) are sequentially laminated.

The retroreflective sheet having the structure shown in Figure 2 consists of a surface layer (7), a binder layer (4), and glass beads (3).
, a focal layer film (5) and a metal layer (6) are sequentially laminated. In addition, the retroreflective sheet having the structure shown in FIG. 3 has a surface layer (
8), glass beads (3), a focal layer film (5) and a metal layer (6) are laminated in this order.

Here, the binder layer has the function of fixing the glass beads to the surface layer, and the focal layer film is a film in which the incident light passes through each layer from the surface layer to the glass beads, is refracted, and is then reflected by the metal layer. It is provided to optimize the refraction of light so that it returns efficiently as a reflected ray parallel to the incident ray.

Next, each layer constituting the retroreflective sheet of the present invention will be explained.

The film used as the surface layer [(1), (7), (8)] in the present invention is mainly composed of a fluororesin obtained by using fluoroolefins as a fluorine monomer component. Specific examples of the resin include homopolymers of fluoroolefins such as polyvinylidene fluoride, hnylidene fluoride-tetrafluoroethylene-hexafluoropropylene copolymers, and copolymers of fluoroolefins, as well as various types of resins. Examples include copolymers of fluoroolefins and monomers other than fluoroolefins.

Among these, copolymers of fluoroolefins or copolymers of fluoroolefins and monomers other than fluoroolefins are preferred because they have good solubility in general-purpose solvents and are easy to work with in manufacturing reflective sheets. Copolymers are particularly preferred (hereinafter these are also referred to as fluoroolefin copolymers).

Specific examples of the fluoroolefins used in preparing such fluoroolefin copolymers include vinyl fluoride, vinylidene fluoride, trifluoroethylene, tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, and Cr. -C1
Examples thereof include (per)fluoroalkyl trifluorovinyl ether represented by m.

By copolymerizing two or more of these fluoroolefins, a copolymer containing only fluoroolefins as a monomer component can be obtained. Moreover, a fluoroolefin copolymer soluble in a solvent can be prepared by copolymerizing the above-mentioned fluoroolefins and monomers copolymerizable with them.

Specific vinyl monomers copolymerizable with such fluoroolefins include methyl vinyl ether,
Alkyl or ncroalkyl vinyl ethers such as ethyl vinyl ether, n-methyl vinyl ether, cyclohexyl vinyl ether, cyclopentyl vinyl ether; vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pivalate, vinyl versitric acid, vinyl benzoate, pt-butyl Carboxylic acid vinyl esters such as vinyl benzoate, nclohexanecarpon vinyl, and impropenyl acetate: 2-hydroxyethyl vinyl ether, 3-hydroxyethyl allyl ether, 4-hydroxybutyl vinyl ether, 2-hydroxyethyl allyl ether, 2-hydroxy Monomers containing a hydroxyl group such as ethyl (meth)acrylate; Monomers containing a carboxyl group such as acrylic acid and methacrylic acid; N,
N-dimethylaminoethyl (meth)acrylate, N,
Monomers having an amine group such as N-dimethylaminoethyl vinyl ether; monomers having an epoxy group such as glycidyl hinyl ether, glycidyl (meth)acrylate, nitrimethoxyvinylsilane, triethquin vinylsilane, 2-trimethoxyethyl vinyl ether ,
Monomers having a hydrolyzable silyl group such as γ-methacryloxypropyltrimethoxysilane; vinyl monomers having a silyloxy group such as 2-trimethylsilyloxyethyl vinyl ether and 4-trimethylsilyloxybutyl vinyl ether; trimethylsilyl ( Meta)
Acrylate, monomers having a silyloxycarbonyl group such as vinyl-5-trimethylsilyloxycarbonylpentanoate; furthermore, ethylene, propylene,
Examples include vinyl chloride and various alkyl (meth)acrylates.

Among these monomers, from the viewpoint of copolymerizability, coating film performance, etc.
It is particularly preferable to use vinyl esters and vinyl ethers that do not have functional groups as essential components, and further,
If necessary, it may be copolymerized with a monomer having a reactive functional group as described above.

Suitable copolymers of fluoroolefins and monomers other than fluoroolefins used in carrying out the present invention include fluoroolefins 15 to 70
Weight %, vinyl monomer containing reactive functional group 0-3
0% by weight and other monomers copolymerizable with these 5
~85% by weight is copolymerized.

If the amount of fluoroolefin used is less than 15% by weight, the effect of improving durability and reflection intensity will be insufficient;
Exceeding this is not preferred because the solubility in general-purpose solvents decreases and workability deteriorates.

In addition, the weight average molecular weight of the copolymer used is 5°000 to 400% from the viewpoint of workability and film durability.
．． 000, and more preferably within the range of 7,000 to 30o, ooo.

Specific examples of such fluoroolefin copolymers and preparation methods are disclosed in JP-A-53-96088;
JP 57-34107, JP 59-102962,
JP 61-113607, JP 61-57609,
JP-A No. 61-141713, JP-A No. 62-84137,
JP 62-18574, O1 JP 64-2945
This is as described in Publication No. 0, etc.

In addition, as a method for preparing the fluoroolefin copolymer used in the present invention, a pre-prepared copolymer containing a fluoroolefin and carboxylic acid vinyl ester as essential components is hydrolyzed to convert it into a polymer having hydroxyl groups. Alternatively, a method may be employed in which a dibasic acid anhydride is added to a fluoroolefin polymer having a hydroxyl group to convert it into a polymer having a carboxyl group.

Among the above-mentioned fluoroolefin copolymers, typical commercially available copolymers containing hydroxyl groups as reactive functional groups include fluoroolefin copolymers manufactured by Dainippon Ink and Chemicals Co., Ltd.
-700, K-701゜K-702, K-703,
K-704, Lumiflon LP-100 manufactured by Asahi Glass Co., Ltd.
LF-200, LF-300, LF-400, LF-5
00, LF-600, Central Glass Co., Ltd. Cefural Coat Al0IB, A-201TB, A, -1007M
There are B, etc.

The fluororesin film, which is the surface layer of the retroreflective sheet of the present invention, can also be prepared from the above-mentioned fluoroolefin copolymer and acrylic polymer.

The acrylic polymer referred to herein refers to a homopolymer or copolymer containing an acrylic ester or a methacrylic ester as an essential component, and both those with and without reactive functional groups as described above are included. Available for use.

Various known and commonly used acrylic polymers can be used, but from the viewpoint of durability and workability, the weight average molecular weight is 5.000 to 400.000, and more preferably 7.00 to 7.00.
Particularly preferred are those having a value of 000 to 300.000.

When a fluoroolefin copolymer and an acrylic polymer are used together as the resin for the surface layer, the ratio of the former to the latter is preferably 30:0 to 98:2, more preferably 40:2, by weight. Preferably, the ratio is within the range of 60 to 95:5. If the amount of the acrylic polymer used is less than 2%, the desired properties of the acrylic polymer will not be exhibited, and if it exceeds 70% by weight, the effect of improving durability and reflection intensity will be insufficient, which is not preferable.

When forming the reflective sheet of the present invention, the fluoroolefin copolymer and the acrylic polymer are used in a form dissolved in an organic solvent. When the fluoroolefin copolymer or the acrylic polymer to be blended has a reactive functional group as described above, a curing agent having a functional group that reacts with the reactive functional group may be blended. . When the reactive functional group has a hydrolyzable nuryl group, a curing catalyst such as an acid, a base, or various organic tin compounds can be added. Furthermore, when a curing agent is added as described above, a catalyst suitable for promoting the curing reaction can also be added.

When the reactive functional group of the fluoroolefin copolymer is a hydroxyl group or a silyloxy group,
If the reactive functional group is an epoxy group, use a polycarboxylic compound, a polysilyloquine compound, a polyamine compound, etc. when the reactive functional group is a carboxyl group or In the case of a silyl oxine carbonyl group, a polyepoxy compound, epoxysilane compound, metal chelate compound, etc. can be blended as a curing agent, and in the case of a reactive functional group or an amine group, a polyepoxy compound or an epoxysilane compound can be blended as a curing agent. .

When adding an amine resin as a curing agent to a fluoroolefin copolymer or a blend of a fluoroolefin copolymer and an acrylic polymer, 5 to 100 parts of the amine resin is added to 100 parts by weight of the base resin component. It is preferable to add 10 to 60 parts by weight.

In addition, when blending a curing agent other than an amino resin, the amount of functional group in the curing agent is The base amount is 0.2 to 2.
The curing agent may be blended in an amount of 5 equivalents, more preferably 0.5 to 1.5 equivalents.

It is possible to further improve long-term durability by adding an ultraviolet absorber and/or an antioxidant to the composition used to form the above-mentioned surface layer so that the surface layer contains these. can.

As such ultraviolet absorbers, known and commonly used ones can be used, and typical examples include hydroquine benzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, oxyanilide compounds, unsaturated nitrile compounds, etc. . Typical antioxidants include hindered amine compounds, hindered amine compounds, and phosphite compounds.

In addition, known and commonly used organic solvents can be used; specifically, ester-based solvents such as ethyl acetate, butyl acetate, and ethyl cellosolve acetate; aromatic hydrocarbon-based solvents such as toluene, quinolene, and ethylbenzene; hexane, heptane, Aliphatic or alicyclic hydrocarbons such as octane, nclohexane, and ethylnclohexane; alcohols such as methanol, ethanol, in70panol, n-butanol, and imbutanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone Examples include solvents.

Among these, when using a polyisocyanate compound as a curing agent, the use of alcohol-based solvents must be avoided.

Typical paints used to form the intermediate layer film (2) or binder layer (4) constituting the reflective sheet having the structure shown in FIG. A fluoroolefin copolymer containing , a polyester resin, an alkyd resin, a polyurethane resin, an acrylic polymer having a reactive functional group as a base resin component, and a curing agent and/or a curing catalyst such as those mentioned above are blended. Can be mentioned. Here, each of the above-mentioned base*fat components may be used alone or as a mixture of two or more. Paint types include solution type, non-aqueous dispersion type, water soluble type,
Any aqueous dispersion type can be used, but a solution type is particularly preferred.

Next, the glass beads (3) constituting the retroreflective sheet of the present invention have a particle diameter of 5 to 300 μm, more preferably 20 to 100 μm, and a refractive index of 1.90 to 2.40, more preferably 2.10 to 2.10. 2.30 is used. When the particle size of the heather is less than 5 μm, the required thickness of the focal layer becomes extremely thin, making it difficult to control the thickness. On the other hand, if the thickness exceeds 300 μm, the required thickness of the focal layer becomes extremely thick, and due to the flow of the resin during the heating process during molding, it is difficult to mold the resin concentrically with the spherical diameter of the glass beads. Have difficulty. If the refractive index is less than 1.9, the required thickness of the focal layer becomes extremely thick;
It is difficult to mold resin concentrically with the spherical diameter of the glass beads. Furthermore, when producing beads with a refractive index exceeding 2.4, it is extremely difficult to industrially produce transparent glass beads with high precision while preventing crystallization.

Typical paints used to form the focal layer film of each retroreflective sheet include those whose base polymer components are polyurethane resin, polyvinyl acetal resin, acrylic resin, alkyd resin, and polyester resin. These can be used as non-crosslinked types, or can be used as thermosetting types by adding curing agents such as amino resins, epoxy resins, polyisocyanates, and block polyisocyanates. The form of the paint for the focal layer that loosens is the intermediate layer film (2).
Alternatively, various paints similar to those for the binder layer (4) can be used.

Next, a method for manufacturing a retroreflective sheet of the present invention will be outlined.

The manufacturing of the reflective sheet shown in FIG. 1 consists of: 1. Applying the paint for the surface layer on a support film such as polyethylene terephthalate film or process paper so that the dry film thickness is 2 to 100 μm, preferably 5 to 80 μm. , a step of drying in an undried state or at room temperature or by heating; Alternatively, a process of drying by heating, ■ After applying the above-mentioned Painter Calendar paint so that the dry film thickness is 10 to 90% of the particle size of the glass beads used, the solvent is evaporated by drying at room temperature or by heating. Steps: ■ Embedding glass beads and further heating and drying as necessary; ■ Applying the above-mentioned focal layer film paint to obtain the optimum dry film thickness for the focal layer film, and then drying at room temperature or heating. This is accomplished through six steps: drying (the optimal dry film thickness of the focal layer varies depending on the particle size of the crow heather, but is approximately 10 to 70 μm); and (2) forming a reflective layer consisting of a metal layer. Here, the metal layer in the final step can be formed of the following metal, and its thickness varies depending on the metal used, but is preferably 50 to 2,000, preferably 100 to 1.0
There are 00 people. If the thickness of the metal layer is thinner than 50 people, it will not be able to serve its purpose as a reflective layer because the metal layer will not have sufficient hiding properties.On the other hand, if it exceeds 2000 people, the metal layer will This is undesirable because it tends to cause corrosion and also increases costs.

The method of providing the metal layer is not particularly limited, and includes ordinary vapor deposition method, sputtering method, transfer method,
Plasma method etc. can be used. In particular, from the viewpoint of workability, vapor deposition and sputtering methods are preferably used. The metal used to form such a metal layer is not particularly limited, and examples include metals such as aluminum, gold, silver, copper, nickel, chromium, magnesium, and zinc. Considering workability, ease of forming a metal layer, light reflection efficiency, durability, etc., aluminum, chromium, or nickel is particularly preferred. Note that the metal layer may be formed of an alloy of two or more metals.

In addition, the drying conditions after paint application in each of the above steps ■■■ and ■ depend on the type of base resin used as a paint raw material, the type of reactive functional group in the base resin, the type of curing agent, and the type of solvent. The decision will be made accordingly.

The manufacturing process of the reflective sheet shown in FIG. 2 is exactly the same as the manufacturing process of the reflective sheet shown in FIG. It can be implemented.

The reflective sheet shown in FIG. 3 is first coated on the support film as described above to a dry film thickness of 100 μm to 100 μm, preferably 20% of the particle size of the glass beads used. After applying the above-mentioned surface layer forming paint to a thickness of 80 μm, the solvent is evaporated by drying at room temperature or heating, and the subsequent steps after embedding glass beads are carried out exactly as in the case of Fig. 1. It can be manufactured in the same manner.

The coating in each of the above steps may be applied by spray coating, or by using a coating device such as a knife coater, comma coater, roll coater, reverse roll coater, or 70-coater.

Also, it is possible to obtain a non-colored retroreflective sheet by using a clear paint containing no pigment as the paint used to form each layer of each reflective sheet of the present invention, as shown in (1) in Fig. 1. , (2), (4), (5) each layer, (7), (4), (5) each layer in Figure 2, (8) in Figure 3,
(5) A colored retroreflective sheet can also be obtained by using a colored paint containing a pigment as the paint forming each layer. Pigments used to obtain such colored paints include organic pigments such as phthalocyan blue, phthalone green, quinacridone red or banza yellow, and inorganic pigments such as iron oxide red, iron oxide yellow, titanium yellow and cobalt blue. Known and commonly used pigments are used.

In the thus obtained retroreflective sheet of the present invention, after the metal layer is formed as described above, a pressure-sensitive adhesive layer or an adhesive layer is formed on the metal layer, and if necessary, the pressure-sensitive adhesive layer is formed. The final product can also be made by laminating a release paper on the film or the like.

The present invention will be explained below with reference to Examples, and the numerical values described are based on weight unless otherwise specified.

The methods of the tests conducted in Examples and Comparative Examples are as follows.

■ Using a reflection intensity colorimeter (manufactured by Tokyo Kogaku Kikai Co., Ltd.), JIS
Reflection performance was measured in accordance with the measurement of reflection performance of Z 9117.

■ Gloss level digital variable angle gloss needle (manufactured by Suga Test Instruments Co., Ltd.)
Measurement was performed according to method 3 (60 degree specular gloss) specified in JIS Z 8741 (specular gloss measurement method).

(2) Hue Using a 3M color computer (manufactured by Suga Test Instruments Co., Ltd.), color was measured in accordance with the measurement of condition a in 4.3.1 of JIS Z 8722.

■ Weather resistant QUV (The Q-Panel Company)
One cycle consisted of 4 hours of UV light irradiation at a black panel temperature of 60°C and 4 hours of dew condensation at a black panel temperature of 50°C. After 2000 hours and 4
Measurements were taken after 00 hours had elapsed, and appearance inspection was conducted to check for blisters, cracks, scale formation, peeling of edges, corrosion, contamination, etc.

■ Weather resistance (Sunshine Weather-Ometer) JIS Z using Ducycle Sunyain Super Long Life Weather-Ometer (Suga Test Instruments Co., Ltd.)
It was exposed and measured by the method shown in 7.5 (2) of 9117. Measurements were taken after 2,000 hours and 4,000 hours had elapsed, and the external appearance was checked for blisters, cracks, scale formation, peeling at edges, contamination, etc.

[Example 1] In preparing the resin composition for the surface layer (1), a fluororesin was used as a fluororesin, Fluorofuit-703 (manufactured by Dainippon Ink and Chemicals Co., Ltd., weight average molecular weight 4o, ooo, solid hydroxyl value 72, non-volatile content 60%), amino resin as a curing agent, Super Beckamine J-820-60 (manufactured by Inu Nippon Ink Chemical Co., Ltd., non-volatile content 60%), Fuicure 3525 (Kusunoki Kasei) as a curing catalyst. Co., Ltd.)
Tinuvin 900 (manufactured by Ciba Geigy) was used as an ultraviolet absorber, and Tinuvin 292 (manufactured by Ciba Geigy) was used as an antioxidant.

Compounding of resin composition for surface layer (1) Fluorofit K-703 100 parts Super Beckamine J-820-6030 parts Fuikure 3525 2 parts Tinuvin 900
1 part Tinuvin 2921 parts The above composition was applied on a support film to a dry film thickness of 25 μm, and dried by heating at 140°C for 5 minutes,
A surface layer film was obtained.

The resin composition for the intermediate layer film (2) is a fluororesin,
Fluorinated -700 (manufactured by Dainippon Ink & Chemicals Co., Ltd., weight average molecular weight 70,000, solid hydroxyl value 4)
8, non-volatile content 50%) 100 parts, amino resin, Sumimaru M-100c (manufactured by Sumitomo Chemical Co., Ltd., non-volatile content 1)
00%) and 1.7 parts of Fuicure 3525.

This composition was applied onto the surface layer (1) to a dry film thickness of 25 μm.
The intermediate layer film (2) was prepared by coating the film in an amount of m and drying it by heating at 140°C for 5 minutes.

A resin composition for the binder layer (4) was prepared from 100 parts of Fluorofat-700, 12 parts of Sumimaru M-100C, and 1.3 parts of Fukiure 3525.

This composition was applied onto the intermediate layer film (2) to a dry film thickness of 50% of the spherical diameter of the glass beads (3), and dried at room temperature to volatilize the solvent. After that, glass heath (3) was embedded and further dried at 140°C for 5 minutes.

As the glass beads (3), high refractive glass beads containing titanium oxide as a main component and having a refractive index of 2.23 and a particle size of 67 to 73 μm were used.

The resin composition for the focal layer film (5) was mixed with 100 parts of polyurethane resin, Burnock L8-974 (manufactured by Inu Nippon Ink Chemical Industry Co., Ltd.) and Super Beckamine J-82.
Prepared from 0-6010 parts.

This composition was applied onto the glass beads (3) to a dry film thickness of 16 mm.
It was coated to a thickness of μm, dried at 100°C for 10 minutes, and then heated and dried at 140°C for 10 minutes.

A retroreflective sheet having the structure shown in FIG. 1 was prepared by using aluminum Ramura as the metal layer (6) and depositing it on the focal layer film (4) by vacuum evaporation to a thickness of 500 mm.

On the surface of the metal layer (6) of the reflective sheet thus obtained,
100 parts by weight of acrylic adhesive Finetac 5PS1016 (manufactured by Dainippon Ink & Chemicals Co., Ltd.) and crosslinking agent D
N-750-45 (manufactured by Dainippon Ink and Chemicals Co., Ltd.)
Apply 1 part by weight of the mixed solution and dry to a thickness of about 35 μm.
A pressure-sensitive adhesive layer (9) was formed, and a release paper (lO) whose coated surface was coated with silicone was bonded to the pressure-sensitive adhesive layer to obtain a final product.

[Example 21] The resin composition for the surface layer (1) used in Example 1 was applied onto a support film so that the dry film thickness was 50 μm, and 1
A surface layer (7) was prepared by drying at 40° C. for 5 minutes.

Next, in the same manner as in Example 1, a binder layer (4),
A reflective sheet having the structure shown in FIG. 2 was prepared by sequentially forming a glass bead layer (3), a focal layer film (5), and a metal layer (6). Further, an adhesive layer was formed on the reflective sheet thus obtained in the same manner as in Example 1, and then a release paper was attached thereto to obtain a final product.

[Example 31] The composition for the surface layer (8) was mixed with 100 parts of Fluonet hK-700, 15 parts of Sumimaru M-100c, 1.3 parts of Fukiure 3525, 1 part of Tinuhin 900, and 1 part of Tinuvin 292. Prepared from part.

Next, this composition was applied onto a support film to a dry film thickness of 50 μm.
m, evaporate the solvent, and add glass beads (
3) was embedded in the coating film so that 50% of its sphere diameter was buried in the coating film, and then dried at 140° C. for 5 minutes. Furthermore, a focal layer film (5) and a metal layer (6) were formed in this order to produce a reflective sheet having the structure shown in FIG. 3. Reflection obtained in this way.

After forming an adhesive layer on the adhesive layer in the same manner as in Example 1, a release paper was attached to the adhesive layer to obtain a final product.

[Example 41 The resin composition for the surface layer had a weight average molecular weight of 45°000.
Hexafluoropropylene/ethyl vinyl ether/Beover 9/monovinyl adipate = 50/15/2
0/l 5 (weight ratio) copolymer solution (Beover 9:
Branched fatty acid heptanyl ester manufactured by Shell, Netherlands;
Solvent: 100 parts of toluene/n-butanol (70/30 weight ratio mixed solvent, non-volatile content: 50%), 7 parts of sorbitol polyglynodyl ether with an epoxy equivalent of 170
0.6 parts of diazabicyclooctane, 1 part of Tinuvin 900 and 1 part of Tinuvin 292.

This composition was applied onto a support film so that the dry film thickness was 50 μm, and the composition was heated and dried at 140°C for 5 minutes.
A surface layer (7) was obtained. Next, in the same manner as in Example 1, a binder layer (4), a glass piece layer (3), a focal layer film (5), and a metal layer (6) were sequentially formed to obtain a reflective sheet having the structure shown in FIG. Created. Next, an adhesive layer was formed on this reflective sheet in the same manner as in Example 1, and then a release paper was attached.

[Example 5] The resin composition for the surface layer had a weight average molecular weight of 30°000.
Tetrafluoroethylene/vinyl pivalate/ethyl vinyl ether/trimethoxysilylethyl vinyl ether = 40/25/15/20 (weight ratio) copolymer solution (solvent: toluene/n-butanol - 70/30 weight ratio mixture) 100 parts of solvent, non-volatile content: 50%), 0.5 part of dibutyltin diacetate and ultraviolet absorber di-
It was prepared from one part of Sorb 102 (manufactured by Shiraishi Calcium Co., Ltd.).

This composition was applied onto a support film so that the dry film thickness was 50 μm, and was dried by heating at 140° C. for 5 minutes to obtain a surface layer (7). Next, in the same manner as in Example 1, a binder layer (4), a glass piece layer (3), a focal layer film (5), and a metal layer (6) were sequentially formed to obtain a reflective sheet having the structure shown in FIG. Created. Furthermore, after forming an adhesive layer on this reflective notebook in the same manner as in Example ①,
Pasted with release paper.

[Example 6] The resin composition for the surface layer was adjusted to -700 to 1
00 parts, weight average molecular weight 20,000 inbutyl methacrylate/n-butyl acrylate/β-hydroxyethyl methacrylate = 65/20/15 (weight ratio) copolymer solution (solvent: toluene/butyl acetate-7
0/30 weight ratio mixed solvent, non-volatile content: 50%)
Part, Burnock DN-980 (polyisocyanate resin manufactured by Inu Nippon Ink Chemical Industry Co., Ltd., non-volatile content = 75%,
Isocyanate content: 15.0%), 1 part of Tinuvin 900 and 1 part of Tinuvin 292.

This composition was applied onto a support film to a dry film thickness of 50 μm, dried at 140°C for 5 minutes, and the surface 11
I got 1(7). Then, in the same manner as in Example 1, a binder layer (4), a glass bead layer (3), a focal layer film (5), and a metal layer (6) were sequentially formed to obtain a reflective sheet having the structure shown in FIG. Created. Furthermore, after forming an adhesive layer on this reflective sheet in the same manner as in Example 1,
Pasted with release paper.

[Comparative Example 11 The resin composition for the surface layer was
1-50 (polyester resin manufactured by Dainippon Ink & Chemicals Co., Ltd.) 100! , Super Beckamin J-820-
60 and 1 part of Beckamine P-198 (manufactured by Dainippon Ink and Chemicals Co., Ltd.). This composition was applied onto a support film to a dry film thickness of 50 μm, and dried at 140° C. for 5 minutes to obtain a surface layer (7).

Next, the resin composition for the binder layer (4) was mixed with 100 parts of Veraflite M-6401-50, 10 parts of Super Beckamin J-820-60, and Beckamin P-198.
It was prepared from 0.5 part of. This composition was applied onto the surface layer film (7) to a dry film thickness of 50% of the spherical diameter of the glass beads (3), and dried at room temperature to volatilize the solvent. , embedded glass beads (3),
Further, drying was performed at 140°C for 5 minutes.

Thereafter, a focal layer film (5) and a metal layer (6) were sequentially formed in the same manner as in Example 1 to create a reflective sheet having the structure shown in FIG. After forming an adhesive layer, a release paper was attached to obtain the final product.

[Effects of the present invention] The retroreflective sheet of the present invention exhibits extremely small reductions in gloss, reflection intensity, and discoloration compared to conventional retroreflection sheets in which polyester resin films and the like have been used as the surface layer. In addition, no abnormalities such as cracking or scale formation were observed, and it has excellent durability.

In addition, the refractive index of the fluororesin film is higher than that of alkyd resin.
Since the refractive index is lower than that of polyester resins, acrylic resins, etc., it exhibits high reflection intensity as shown in Table 1.

As described above, according to the present invention, as a result of using a fluororesin film with a low refractive index as the surface layer film, when forming the focal layer film concentrically with the spherical diameter of the glass beads, the film of the focal layer film is The thickness can be made thinner, and higher reflection intensity can be obtained with more stable precision than before.

As described above, the retroreflective sheet of the present invention used as the surface layer of the fluororesin film has extremely excellent durability.
It also has a high reflection intensity and has extremely high utility value.

[Brief explanation of the drawing]

1, 2, and 3 are cross-sectional views of the retroreflective sheet of the present invention. In the figure, 1.7 and 8 are surface layers, 2 is an intermediate layer, 3 is glass beads, 4 is a binder layer, 5 is a focal layer film, and 6 is a metal layer. Figure 1 Figure 2 Figure 3 Procedural amendments November 19, 1990 Director General of the Patent Office Toshi Uematsu 1 Display of the case 1990 Patent Application No. 201141 2 Name of the invention Recurrence with ultra-high weather resistance Relationship with the case of the person who corrects the reflective sheet Patent applicant name Kiwa Chemical Industry Co., Ltd.

Claims (1)

[Claims] 1. Ultra-high weather resistance in which high refractive glass beads and a focal layer film are sequentially laminated on a surface layer made of a fluororesin film, and a metal layer is further formed on the focal layer film. Retroreflective sheet. 2. Ultra-high weather resistance retroreflection with a binder layer, high refractive glass beads, and a focal layer film laminated in sequence on a surface layer made of a fluororesin film, and a metal layer adhered on top of the focal layer film. sheet. 3. Ultra-high weather resistance in which an intermediate layer film, a binder layer, high refractive glass beads, and a focal layer film are sequentially laminated on a surface layer consisting of a fluororesin film, and a metal layer is further formed on the focal layer film. Gender reflective sheeting. 4. The ultra-high weather resistance retroreflective sheet according to any one of claims 1, 2, and 3, wherein the fluororesin film is formed from a fluoroolefin copolymer that is soluble in a solvent. 5. The ultra-high weather resistance according to any one of claims 1, 2, and 3, wherein the fluororesin film is formed from a solvent-soluble fluoroolefin copolymer and a solvent-soluble acrylic polymer. Gender reflective sheeting. 6. The ultra-high weather resistant recursive film according to any one of claims 1, 2 and 3, wherein the fluororesin film is formed from a solvent-soluble fluoroolefin copolymer having a reactive functional group. Gender reflective sheet. 7. The fluororesin film is formed by a reaction between a solvent-soluble fluoroolefin copolymer having a reactive functional group and a curing agent and/or curing catalyst that reacts with the reactive functional group. The ultra-high weather resistance retroreflective sheet according to any one of claims 1, 2 and 3. 8. The fluororesin film contains a solvent-soluble fluoroolefin copolymer having a reactive functional group, an acrylic polymer having the same reactive functional group as the reactive functional group, and the reactive functional group. The ultra-high weather resistance retroreflective sheet according to any one of claims 1, 2, and 3, which is formed by a reaction with a curing agent and/or a curing catalyst that reacts with a functional group. 9. Claims 6, 7, and 8, wherein the reactive functional group is at least one selected from the group consisting of a hydroxyl group, an epoxy group, a carboxyl group, an amino group, a hydrolyzable silyl group, a silyloxy group, and a silyloxycarbonyl group. The ultra-high weather resistance retroreflective sheet according to any of the above. 10. The curing agent according to claim 7 or 8, wherein the curing agent is at least one selected from the group consisting of polyisocyanates, block polyisocyanates, amino resins, polyepoxy compounds, polyamine compounds, polycarboxy compounds, and polysilyloxycarbonyl compounds. Ultra-high weather resistance retroreflective sheet. 11. Claims 1 and 2, wherein the fluororesin film contains an ultraviolet absorber and/or an antioxidant.
, 3. The ultra-high weather resistance retroreflective sheet according to any one of 3.