JP2013176988A - Glass scattering prevention film for flat panel display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass scattering prevention film that can safely protect a thin glass base substance in a display against external damage, prevent glass from scattering, and have a thickness of less than 15 μm, a haze of less than 5%, and an adhesive strength of 1-10 N/inch.SOLUTION: A glass scattering prevention film is formed by laminating sequentially a release layer 13, an adhesive layer 12, a base film layer 10 and an antistatic layer 10. The adhesive layer comprises an acrylic adhesive prepared by cross-linking an adhesive copolymer with a cross-linking agent. The adhesive copolymer comprises a monomer, a comonomer, and a functional group-containing monomer. The glass scattering prevention film prevents glass for a display from being scattered even when the glass is broken, has a thickness of 15 μm except the release layer and a haze of less than 5%, and can be built in a display device and enables an efficient inspection process.

Description

  The present invention relates to a glass anti-scattering film, and more specifically to a glass anti-scattering film having a total thickness of less than 15 μm excluding the release layer so that it can be incorporated into a display device.

  The present invention also prevents damage during processing or transport to glass substrates incorporated in flat panel displays such as liquid crystal (LC) displays, plasma displays, organic electroluminescence (EL) displays, etc., and also prevents glass scattering. The present invention relates to a glass scattering prevention film.

  Glass is widely used in cathode ray tube (CRT) displays and flat panel displays such as LC displays, plasma displays, organic EL displays, field emission displays, etc. due to its high light transmission, gas barrier properties and dimensional stability. ing. However, glass has the problem that it is fragile and easily scatters.

  In order to solve this problem, many techniques have been suggested, including affixing a thermoplastic resin film to glass. For example, Korean Patent Application No. 2000-0011455 discloses that a polyester-based pressure sensitive adhesive is coated on one side of a base film so that the film can be easily removed from the glass for a long time. Disclosed is a glass anti-scattering film that is weather resistant and resistant to glass scattering, wherein the adhesive is completely removed from the surface of the glass even after application. However, this conventional film is still inadequate for preventing glass scattering and is too thick to be incorporated into flat panel displays such as LC displays, plasma displays, organic EL displays and the like.

Korean Patent Application Publication No. 2000-0011455 Specification

  Thus, it is possible to safely protect the thin glass substrate in the display from external damage, prevent glass scattering, and have a thickness of less than 15 μm, a haze of less than 5%, and an adhesion of 1 to 10 N / inch. It is an object of the present invention to provide a film.

  According to one aspect of the present invention, there is provided a glass anti-scattering film comprising an orderly laminated structure of a release layer, an adhesive layer, a base film layer, and an antistatic layer, wherein the adhesive layer crosslinks the adhesive copolymer with a crosslinking agent. Wherein the adhesive copolymer is i) 60-80% by weight of a monomer selected from the group consisting of ethyl acrylate, butyl acrylate and mixtures thereof; ii) vinyl acetate, acrylonitrile, 15 to 35% by weight of a comonomer selected from the group consisting of acrylamide, styrene, methyl methacrylate, methyl acrylate and mixtures thereof; and iii) methacrylic acid, acrylic acid, hydroxyethyl methacrylate, hydroxypropyl methacrylate, methacrylic acid Dimethylaminoethyl, acrylamide Methylol acrylamide, glycidyl methacrylate, maleic anhydride, mesaconic anhydride and glass scattering preventing film comprising 1 to 5% by weight functional group-containing monomer selected from the group consisting of mixtures is provided.

  Preferably, the total thickness of this glass anti-scattering film excluding the release layer is less than 15 μm. Further, the base film can have a thickness of 4-10 μm and the adhesive layer can have a thickness of 3-10 μm. Also, the glass anti-scatter film can have a haze of less than 5% and the base film can have a haze of less than 7%.

FIG. 1 shows a cross section of a glass scattering protective film according to an embodiment of the present invention (10: base film layer, 11: antistatic layer, 12: adhesive layer, 13: release layer).

The above and other objects and features of the present invention will become apparent from the following description of the invention in conjunction with the accompanying drawings.
Hereinafter, the present invention will be described in detail with reference to the drawings.

  According to an embodiment of the present invention, the glass scattering protective film includes a release layer 13, an adhesive layer 12, a base film layer 10, and an antistatic layer 11, which are sequentially laminated, and the adhesive layer is an acrylic adhesive. including.

Adhesive Layer In the glass anti-scatter film, the adhesive layer 12 preferably comprises an acrylic adhesive to ensure the desired adhesion.

  Acrylic adhesives are (a) copolymerization of monomers, comonomers and functional group containing monomers using initiators to obtain adhesive copolymers; and then (b) crosslinking agents and additives to obtain acrylic adhesives. Can be made by crosslinking the adhesive copolymer.

  In the adhesive copolymer, the monomer may be selected from the group consisting of ethyl acrylate, butyl acrylate, and mixtures thereof. Preferably, the amount of monomer is 60-80% by weight based on the weight of the adhesive copolymer. When this amount is within the above range, the acrylic adhesive can be applied more rapidly and the workability can be further improved.

  The comonomer may be selected from the group consisting of vinyl acetate, acrylonitrile, acrylamide, styrene, methyl methacrylate, methyl acrylate and mixtures thereof. Preferably, the amount of comonomer is 15 to 35% by weight based on the weight of the adhesive copolymer. When this amount satisfies the above range, the adhesive force of the adhesive layer can be enhanced.

  Functional group-containing monomers include methacrylic acid, acrylic acid, hydroxyethyl methacrylate, hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, acrylamide, methylolacrylamide, glycidyl methacrylate, maleic anhydride, mesaconic anhydride and mixtures thereof. The group can be selected. Preferably, the amount of functional group-containing monomer is 1 to 5% by weight, based on the weight of the adhesive copolymer. When this amount is within the above range, the adhesive force to the substrate can be further improved, and the change in the adhesive force over time can be reduced.

  Initiators are azo-based compounds such as 2,2-azobisisobutyronitrile and 2,2-azobis (2-methylpropionamidine) sulfate; peroxides such as persulfate, di-N-octa Noyl peroxide and t-butyl hydroperoxide; and mixtures thereof, preferably 2,2-azobisisobutyronitrile. Preferably, the amount of initiator is from 0.01 to 0.5% by weight based on the weight of the adhesive copolymer. When this amount is within the above range, the coating processability can be improved due to the good solubility of the components, and the cohesiveness of the adhesive layer can be enhanced due to the increased storage modulus. .

  The cross-linking agent used for the cross-linking reaction also functions to increase heat resistance, adhesive strength and cohesion, resulting in reduced changes in adhesive strength under high temperature / humidity conditions, and The adhesive layer has the advantage that glass scattering can be effectively prevented when the glass substrate is broken by external impact. The cross-linking agent can be selected from the group consisting of polyisocyanates, melamines, epoxy compounds, aziridines, metal chelate compounds and mixtures thereof. More specifically, the crosslinking agent is xylene diisocyanate, isocyanate, diethylenetriamine, triethylenetetramine, phthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic acid anhydride, pyromellitic dianhydride, succinic acid. It may be selected from the group consisting of acid anhydride, hexamethylene diisocyanate, triethylene melamine, hexamethylol melamine, and mixtures thereof. Metal chelate compounds can consist of metals such as Al, Sn, Fe, Ti and Ni and chelating agents such as methyl acetoacetate and ethyl lactate. The cross-linking agent includes one or more metal chelate compounds.

  The amount of crosslinking agent is 0.1 to 5.0 parts by weight based on 100 parts by weight of the adhesive copolymer. If the cross-linking agent satisfies the above range, sufficient cross-linking can occur to increase the cohesiveness of the adhesive layer, the adhesive can be completely removed from the surface of the object, and wetting is achieved. Can be improved, thus increasing the initial adhesion.

  The additive added to the adhesive copolymer may be selected from the group consisting of UV inhibitors, light stabilizers, antioxidants and mixtures thereof. More specifically, the UV inhibitor can be selected from the group consisting of benzotriazole, triazine, benzophenone and mixtures thereof, and the light stabilizer is selected from the group consisting of amines, benzoates and mixtures thereof. Can be done. The amount of the additive is 0.1 to 3.0 parts by weight based on 100 parts by weight of the adhesive copolymer, but this amount is not particularly limited as long as the additive does not deteriorate the properties of the adhesive layer.

  A solvent may be used to produce the acrylic adhesive. The solvent can be selected from the group consisting of methyl ethyl ketone, acetone, ethyl acetate, cyclohexane, n-hexane, toluene, xylene, methanol, ethanol, water, and mixtures thereof.

  The adhesive layer can be formed by applying an acrylic adhesive on the surface of the target substrate. Roll coating, gravure coating, reverse coating, spray coating, dip coating, knife coating, slot die coating, etc. may be used to apply the acrylic adhesive to the substrate. Preferably, die coating is used to form a stable coating layer.

  In order to provide a thin film, the thickness of the adhesive layer 12 can be 3 to 10 μm, preferably 4 to 7 μm. If this thickness is within the above range, it is easier to ensure agglomeration and to achieve the desired adhesion, and to eliminate film removal during the process of cutting the glass substrate for display. Such drawbacks can be reduced.

  Furthermore, the adhesive layer can have an adhesion of 1 to 10 N / inch, preferably 3 to 7 N / inch, when peeled from the glass substrate at 180 °. When the adhesive is within the above range, defects such as detachment of edges during cutting of the glass substrate and introduction of impurities when the film is attached to the glass substrate can be reduced. Also, even if the regeneration process occurs because of these defects, the adhesive can be completely removed from the surface of the glass and damage to the base film can be reduced.

Release Layer In a glass anti-scattering film, the release layer 13 can include a release film that functions to protect the adhesive layer when the film is affixed to a glass substrate for a display. In some cases, it is easily removed. The release film can be any film coated with a silicone-based release composition.

  The silicone-based release composition can include a silicone material, a silicone curing agent, a catalyst, and the like. The silicone material can be vinyl polysiloxane, hexenyl polysiloxane containing vinyl groups, and the like. The silicone curing agent can be hydrogen polysiloxane or the like. The catalyst can be one known in the art, for example, a Pt chelate compound.

  The silicone-based release composition can be of any type, such as addition, condensation, and UV cure types, and is not particularly limited to any one type. The molecular structure can be either linear or branched or both.

  The silicone base release composition can be diluted with a solvent to a total solids content of 0.5 to 3% by weight, as applied on the base film. The solvent is not limited as long as the solids are sufficiently dispersed to be applied on the base film. When the total solid content is within the above range, a uniform silicone coating layer can be formed, the adhesive layer does not peel off, and the coating layer leveling is uniform, so that a uniform thickness is achieved. Achieve.

  The peel strength of the release layer comprising the silicone-based release composition is preferably 3-8 gf / inch. A typical release layer is 31B tape available from Nitto Denko Corporation or RF02N available from SKC Hearth Display Films Company Limited.

Base Film Layer In the glass anti-scattering film, the base film layer 10 can be transparent in order to efficiently perform the inspection process after manufacturing the display device. Base film layers are polyethylene terephthalate (PET) film, polyethylene naphthalate (PEN) film, polyethylene (PE) film, silica (Si) -deposited film, aluminum (Al) -deposited film, and polyvinyl chloride (PVC) film , Preferably selected from the group consisting of PET films.

  The thickness of the base film can be 4 to 10 μm. If this thickness satisfies the above range, the strength of the base film is ensured, thus facilitating achieving the desired yield in the manufacturing process, and a total thickness of less than 15 μm excluding the release layer. It makes it easy to produce a glass anti-scattering film having

  The haze of the base film layer is preferably less than 7%, more preferably 1-7%, so that the total haze of the glass anti-scattering film can be less than 5%, preferably 1-5%.

Antistatic Layer The glass anti-scattering film preferably includes an antistatic layer 11. This antistatic layer serves to prevent defects that may occur due to the incorporation of impurities when the glass anti-scattering film is applied to the glass substrate and when the glass substrate is cut. An antistatic layer can be formed on the substrate surface opposite the adhesive-coated surface.

  As long as the antistatic layer has sufficient antistatic properties, the antistatic layer is not particularly limited. Preferably, the antistatic layer can be formed by coating an antistatic composition comprising a conductive polymer so as to minimize the coating thickness. The conductive polymer can be selected from the group consisting of polythiophene, polypyrrole, polyaniline, polyethylenedioxythiophene (PEDOT), and mixtures thereof.

  In addition to the conductive polymer, the antistatic composition can further comprise an aqueous polyurethane resin, alcohol and / or distilled water to increase processability. The antistatic composition can also include an aqueous or organic binder resin, which resin has at least one functional group selected from the group consisting of acrylic groups, urethane groups, amide groups, hydroxyl groups, and silane groups. The antistatic composition can further comprise a waterproofing or antifouling agent.

Properties and Effects Since thin display devices are continually increasing and glass anti-scattering films are adapted to be incorporated into the device, the total thickness of the glass anti-scattering film excluding the release layer is preferably 15 μm. Is less than.

  The glass scattering prevention film preferably has a haze of less than 5% in order to ensure transparency. When this transparent film is incorporated into a display device, the inspection can be easily performed.

  The glass anti-scattering film of the present invention is effective in preventing the adsorption of impurities due to the antistatic layer.

  The adhesive layer also includes an acrylic adhesive, thereby ensuring high transparency, showing good adhesion to the substrate, and improving moisture resistance and heat resistance.

  Further, since the total thickness of the glass anti-scattering film excluding the release layer is less than 15 μm, the glass anti-scattering film can be mounted on a display.

  The glass anti-scattering film can reduce the damage of the glass substrate for the display due to external impact, and can prevent the glass from being scattered even when the glass is broken.

  Also, since the glass anti-scattering film has a low haze of less than 5%, the inspection process can be performed efficiently even after it is incorporated into a display device.

  The following is a description of specific examples of the present invention. In this example, these properties were measured by the following method. The results are shown in Table 1 below.

1) Evaluation of adhesive strength (peel strength) and reliability A glass anti-scattering film was attached to a mother glass substrate, and then pressed by a single mutual movement using a 2 kg roll, and 50% R.D. H. For 30 minutes. Next, using an adhesion test apparatus (AR-1000, Chem Instruments), the adhesive strength (N / N) when this glass anti-scattering film was peeled off at a peeling speed of 300 mm / min under the condition of a peeling angle of 180 °. Inch) was measured. The adhesive remaining on the mother glass was observed with the naked eye.

  To test for reliability, the film was tested at 60 ° C. and 90% R.D. H. The adhesion was measured after standing for 500 hours under these conditions and the resistance / moisture resistance of the adhesive layer was evaluated.

2) Measurement of haze and total light transmittance After the release film is removed, a glass scattering prevention film is attached to a haze meter (NDH-5000, Nippon Denshoku Industries Co., Ltd.) so that the adhesive layer faces the integrating sphere. , And the baseline was set to air conditioning, then haze and total light transmission were measured.

Preparation Example 1: Preparation of Adhesive Copolymer 70 parts by weight butyl acrylate, 25 parts by weight methyl methacrylate, and 5 parts by weight methacrylic acid in a solvent mixture of ethyl acetate and toluene (1: 1 v / v) To this was added 0.2 parts by weight of 2,2-azobisisobutyronitrile as an initiator. The resulting mixture was reacted under stirring at 65 ° C. for 7 hours under a nitrogen atmosphere to obtain an adhesive copolymer.

Production Example 2: Production of Adhesive Copolymer 70 parts by weight of 2-ethylhexyl acrylate, 25 parts by weight of isodecyl methacrylate, and 5 parts by weight of crotonic acid are solvents of ethyl acetate and toluene (1: 1 v / v). To the mixture was added 0.2 parts by weight of 2,2-azobisisobutyronitrile as an initiator. The resulting mixture was reacted under stirring at 65 ° C. for 7 hours under a nitrogen atmosphere to obtain an adhesive copolymer.

Example 1 Production of Glass Anti-scattering Film 100 parts by weight of the adhesive copolymer obtained in Production Example 1, 0.5 part by weight of triethylene melamine as a crosslinking agent, and 1 part by weight of benzophenone as a UV inhibitor are mixed. An acrylic adhesive was obtained by stirring for a minute. This acrylic adhesive was applied onto a silicone-coated release film (RF02N, SKC Hearth Display Films) and then dried at 100 ° C. for 2 minutes to obtain a dry adhesive layer having a thickness of 4 μm.

  This adhesive layer was laminated on the surface of a PET base film (SC42, SKC) having a thickness of 5.6 μm. 100 parts by weight aqueous polyurethane resin solution (Ecoat P-1030, EChem Tech) having a solid content of 3.5% by weight and containing PEDOT, 3 parts by weight aziridine-based crosslinker (CX-100, Magtec), Another surface of the base film was coated with an antistatic composition comprising 45 parts by weight distilled water and 160 parts by weight methanol.

The antistatic layer was dried at 90 ° C. for 2 minutes to obtain a glass anti-scattering film having a total thickness of 9.6 μm and a surface resistance of 10 ⁷ Ω / m ² excluding the release layer.

Example 2: Production of glass anti-scattering film Glass scattering with a dry adhesive layer thickness of 7 μm, excluding the release layer and a total thickness of 12.6 μm and a surface resistance of 10 ⁷ Ω / m ² The procedure of Example 1 was repeated except that the prevention film was obtained.

Example 3: Manufacture of glass anti-scattering film Glass scattering with a dry adhesive layer thickness set to 9 μm, with the exception of the release layer, a total thickness of 14.6 μm and a surface resistance of 10 ⁷ Ω / m ² The procedure of Example 1 was repeated except that the prevention film was obtained.

Comparative Example 1: Production of glass anti-scattering film 100 parts by weight of the adhesive copolymer obtained in Production Example 2, 0.2 parts by weight of toluene diisocyanate (AL, Saiden Chemical Company Limited), and 1 part by weight of benzophenone Were mixed and stirred for 30 minutes to obtain an acrylic adhesive. This acrylic adhesive was applied onto a silicone-coated release film (RF02N, SKC Hearth Display Films) and then dried at 100 ° C. for 2 minutes to obtain a dry adhesive layer having a thickness of 7 μm.

  This adhesive layer is laminated on one surface of a PET base film (SC42, SKC) having a thickness of 5.6 μm and has a total thickness of 12.6 μm excluding the release layer. Got.

Comparative Example 2: Production of glass anti-scattering film The adhesive copolymer obtained in Production Example 2 was used as the adhesive copolymer, and 0.2 part by weight of toluene diisocyanate (AL, Syden Chemical Company Limited) was used as the crosslinking agent. And the thickness of the dry adhesive layer was set to 10 μm, and a glass scattering prevention film having a total thickness of 15.6 μm and a surface resistance of 10 ⁷ Ω / m ² excluding the release layer was obtained. The procedure of Example 1 was repeated.

  As shown in Table 1, the glass anti-scattering films of Examples 1 to 3 according to the present invention showed only a slight change in the adhesion after the reliability test, and after the glass anti-scattering film was incorporated into the device. Even the inspection could be done because of its high total light transmittance and low haze. Furthermore, the initial adhesion increased as the thickness of the adhesive layer increased.

  On the other hand, since the glass anti-scattering films of Comparative Examples 1 and 2 have a low glass transition temperature and use a monomer having a functional group-containing monomer containing a hydroxyl group, a desired adhesive force cannot be obtained, Therefore, this film may be undesirably peeled when the mother glass is cut. Furthermore, the glass anti-scattering film of Comparative Example 1 exhibits low total light transmittance and high haze due to light scattering based on the surface roughness of the base film, which is the antistatic coating on the opposite side of the PET substrate. Was not formed, which makes it difficult to perform the inspection process, and thus this film cannot be applied to display devices.

  Thus, the glass anti-scattering films of Examples 1-3 according to the present invention are very effective in protecting the mother glass for displays due to its excellent optical and adhesive properties.

10 Base film layer 11 Antistatic layer 12 Adhesive layer 13 Release layer

Claims (9)

A glass anti-scattering film comprising a laminated structure in the order of a release layer, an adhesive layer, a base film layer and an antistatic layer,
The adhesive layer comprises an acrylic adhesive made by cross-linking an adhesive copolymer with a cross-linking agent;
The adhesive copolymer is: i) 60-80% by weight of a monomer selected from the group consisting of ethyl acrylate, butyl acrylate, and mixtures thereof;
ii) 15-35% by weight of a comonomer selected from the group consisting of vinyl acetate, acrylonitrile, acrylamide, styrene, methyl methacrylate, methyl acrylate and mixtures thereof; and iii) methacrylic acid, acrylic acid, hydroxyethyl methacrylate, 1 to 5% by weight of a functional group-containing monomer selected from the group consisting of hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, acrylamide, methylolacrylamide, glycidyl methacrylate, maleic anhydride, mesaconic anhydride, and mixtures thereof
A glass scattering prevention film comprising:   The glass scattering prevention film according to claim 1, wherein the crosslinking agent is selected from the group consisting of polyisocyanate, melamine, epoxy compound, aziridine, metal chelate compound, and a mixture thereof.   The glass scattering prevention film according to claim 2, wherein the crosslinking agent is used in an amount of 0.1 to 5.0 parts by weight based on 100 parts by weight of the adhesive copolymer.   The glass scattering prevention film according to claim 1, wherein the adhesive layer has an adhesive force of 1 to 10 N / inch.   The base film is a polyethylene terephthalate (PET) film, a polyethylene naphthalate (PEN) film, a polyethylene (PE) film, a silica (Si) -deposition film, an aluminum (Al) -deposition film, and a polyvinyl chloride (PVC) film The glass scattering prevention film according to claim 1, which is selected from the group consisting of:   The glass scattering prevention film according to claim 1, wherein the base film has a thickness of 4 to 10 μm and a haze of less than 7%.   The glass scattering prevention film according to claim 1, wherein the release layer has a peel strength of 3 to 8 gf / inch.   The glass scattering prevention film according to claim 1, wherein the glass scattering protection film has a haze of less than 5%.   The glass anti-scattering film according to claim 1, wherein the antistatic layer comprises a conductive polymer selected from the group consisting of polythiophene, polypyrrole, polyaniline, polyethylenedioxythiophene, and a mixture thereof.

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