KR101064583B1 - Non-crosslinked foamable interleaving film - Google Patents

Abstract

The present invention relates to an uncrosslinked foamed interlayer film, and more particularly, to a non-crosslinked foamed polyethylene base film including 100 parts by weight of low density polyethylene, 10 to 300 parts by weight of ethylene vinyl acetate and 0.01 to 1 parts by weight of a blowing agent; A polyethylene coating layer formed by applying a low-density polyethylene melt on both sides of the base film and then cooling it; And it relates to a non-crosslinked foamed interlayer film having a conductive coating layer formed on the polyethylene coating layer. The interlayer film of the present invention can protect them more efficiently when loading and taking out the glass for LCD or PDP.

Interlayer film, polyethylene base, coating layer

Description

Non-crosslinked foamable interleaving film

The present invention relates to a non-crosslinked foamable slip paper film, and to a non-crosslinked foamable slip paper film which can protect them more efficiently when loading and taking out glass for LCD or PDP.

On the glass for manufacturing the panel for LCD or PDP, various thin films are formed on the upper part of the clean room, which requires high cleanliness. Therefore, these glasses need to be protected when transported from producer to consumer. To this end, even if two or more people load and take out the glass by hand, glass breakage occurs frequently as the size of these glasses grows and thins, and foreign substances present between the glasses cause surface damage to the glass. .

In order to prevent this, widely used methods include using only a gap between the glass and a method of attaching and transporting a glass protective film on the surface of each glass. In the case of using the glass protective film, there is an advantage of reducing the scratch on the glass surface as compared to the method using the interlayer paper. However, if you do not use the kanji, the glass is laminated after the glass is moved one by one when the other glass is moved together to break the work or worse by falling or fall, so the use of kanji is required.

The use of such paper is desirable in terms of protecting the glass for LCD or PDP, but the manufacturing cost of the paper is additionally generated, and the cost of using the paper is added to the glass manufacturing cost, and materials such as colorants contained in the paper are There is a problem that it is harmful to the environment and cost of disposal because it comes out and contaminates the glass surface, or because a large amount of paper is used.

Therefore, the inventors of the present invention, while trying to develop an economical and environmentally friendly interlayer film, coating a polyethylene coating layer on both sides of the polyethylene base film, and to develop a non-crosslinked foamable interlayer film provided with a conductive coating layer, they are economic and easy The present invention was completed by confirming that there is little generation of foreign matter contained therein, and recycling is possible, thereby reducing the harmfulness to the environment.

An object of the present invention is to provide a non-crosslinked foamed interstitial film that is hardly generated of foreign matters contained in the interleaf paper, and is recyclable, thereby reducing the risk to the environment.

The present invention to solve the above problems, non-crosslinked foamed polyethylene base film; Polyethylene coating layers formed on both sides of the base film; And it provides a non-crosslinked foamed interlayer film having a conductive coating layer formed on the polyethylene coating layer.

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

In the non-crosslinked foamed interlayer film of the present invention, the polyethylene used in the base film preferably includes low density polyethylene, linear low density polyethylene, ultra low density polyethylene, or metallocene polyethylene, wherein a foaming agent is included therein. It can be produced by molding a master batch comprising an inflation film molding apparatus. More specifically, the base film is preferably the result of extruding a master batch composition containing low density polyethylene, ethylene vinyl acetate and a blowing agent by an inflation film forming apparatus, wherein the blowing agent is more preferably azobisformamide. .

In addition, in the non-crosslinked foamable slip paper of the present invention, the polyethylene coating layer is preferably low density polyethylene, the conductive coating layer preferably comprises a conductive polymer or metal particles, and the base film further comprises a colorant. It is desirable to.

The non-crosslinked foamed slip paper according to the present invention is to protect the surface of these glasses during loading or withdrawal of glass used for manufacturing LCD or PDP, and to improve work processability. By using the base film to form a base material can be recycled to minimize the impact on the environment, the base film can be economically manufactured using an inflation film forming apparatus, etc., which can be included in the base film By forming a coating layer on the surface in order to minimize the influence of the colorant, it is possible to reduce the surface damage of the glass due to foreign matter.

The non-crosslinked foamed slip paper film according to the present invention has a polyethylene coating layer formed on both sides of the base film and a conductive coating layer formed on the polyethylene coating layer as shown in FIG.

The inflation film forming apparatus is an apparatus for producing a sheet by extrusion, which makes it possible to economically and inexpensively prepare the non-crosslinked foamable polyethylene base film. The base film obtained by such a device preferably has a thickness of 5 to 1000 µm, and if the thickness is less than 5 µm, it is difficult to provide a sufficient buffering effect for protecting the glass. Not preferred.

The master batch for forming the base film is ethylene vinyl acetate (EVA), polypropylene (PP), metallocene polyethylene (Metallocene PE), polyvinyl alcohol (in order to increase the economy and the surface texture of the foam (foam) PVA), a polystyrene (PS), an acrylonitrile-butadiene-styrene copolymer (ABS), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), etc. can further add 1 or more types. The content of the thermoplastic resin is 10 to 300 parts by weight, preferably 30 to 200 parts by weight, more preferably 50 to 150 parts by weight based on 100 parts by weight of the polyethylene resin.

The foaming agent included in the master batch composition imparts foamability to the base film to enable low density and impart sufficient buffering property. As such a blowing agent, gases such as organic or inorganic pyrolysis blowing agents, water, hydrocarbon-based and flon-based solvents, nitrogen, carbon dioxide, propane, butane and the like can be used. Examples of the thermally decomposable blowing agent include inorganic blowing agents such as sodium hydrogen carbonate, sodium carbonate, ammonium hydrogen carbonate, ammonium carbonate and sodium nitrite N, N'-dimethyl-N, N'-dinitrosoterephthalamide, N, N ' Azo compounds benzenesulfonylhydrazide, such as nitroso compounds azodicarbonamide, such as dinitrosopentamethylenetetramine, azobisisobutyronitrile, azocyclohexylnitrile, azodiaminobenzene, and barium azodicarboxylate Sulfonylhydrazide compounds and calcium azides such as toluenesulfonylhydrazide, p, p'-oxybis (benzenesulfonylhydrazide), diphenylsulfon-3,3'-disulfonylhydrazide, and 4,4 Azide compounds, such as "-diphenyl disulfonyl azide and p-toluenesulfonyl azide, etc. are mentioned. In particular, inorganic pyrolytic blowing agents such as sodium bicarbonate, sodium carbonate, ammonium bicarbonate, ammonium carbonate and sodium nitrite are thermally decomposed at high temperature to release carbon dioxide and water, and then a small amount of inorganic residue such as sodium ions or ammonium ions is retained. This inorganic residue has the same effect as the addition of a nucleating agent. Thus, the cells are formed in a fine size and the cell distribution is also uniform. The content of the blowing agent is preferably used in an amount of 0.01 to 1 parts by weight based on 100 parts by weight of polyethylene. When the content of the blowing agent is less than 0.01 parts by weight, the expansion ratio is lowered. The surface is rough and, in severe cases, the cell may be destroyed.

In addition, a foaming aid can be further added to the masterbatch composition for forming the base film of this invention as needed. Examples of the foaming aid include metal compounds such as zinc, calcium, lead, iron and barium compounds, organic acids such as citric acid, salicylic acid, phthalic acid and stearic acid, urea or derivatives thereof. The foaming aid lowers the decomposition temperature of the foaming agent, promotes the decomposition promoting of the foaming agent, and has functions such as uniformity of bubbles. In addition, the master batch composition may further participate in an inorganic porous powder, such as a zeolite powder, or a resin having a large adsorption amount of an inorganic gas, for example, a polycarbonate resin, which adsorbs an inorganic gas.

The master batch composition may include fillers, heat stabilizers, anti-aging agents, weather stabilizers, charge stabilizers, metal soaps, lubricants (such as waxes), pigments, dyes, nucleating agents, flame retardants, antiblocking agents, and the like without departing from the object of the present invention. Various known additives can be added. As a filler, the filler normally used for shaping | molding of rubber | gum and a thermoplastic resin can be used. Examples of such fillers are calcium carbonate, calcium silicate, clay, kaolin, talc, silica, diatomaceous earth, mica, asbestos, barium sulfate, aluminum sulfate, calcium sulfate, magnesium carbonate, disulphide Acid molybdenum, graphite, alumina, etc. are mentioned. Examples of known heat stabilizers, anti-aging agents and weathering stabilizers include phenolic, sulfite, phenylalkane, phosphite, and amine compounds.

If necessary, the base film may be further distinguished from the color of the glass by further including a colorant to give a colored color. As such a colorant, any colorant used in the art may be used without limitation. In particular, since a separate conductive coating layer is formed on the outer surface of the base film, it is not necessary to use an expensive conductive coloring agent, for example, conductive carbon black, etc., and it is possible to use a low-cost general coloring agent, for example, general carbon black. Such a colorant may be used in an amount of 0.01 to 1 part by weight based on 100 parts by weight of polyethylene, and when the content of the colorant is less than 0.01 part by weight, it is difficult to obtain a sufficient coloring effect. Not.

Since such a colorant will interfere with film formation when the particle size is too large, it is preferable that the particle size is as small as possible, for example, it is more preferable to use a colorant having a particle size of 40 nm or less.

In addition, the colorant may bury the surface of the glass when using the interlayer film, causing surface damage. In the present invention, since the protective layer is further formed on the surface even when such a colorant is used, there is little concern that the colorant may come out. The advantage of being able to minimize the surface damage of the.

The base film formed as described above has a foaming property so that the surface is not smooth and has a relatively rough surface, which causes a problem of forming thicker conductive coating layers later, so that the polyethylene between the base film and the conductive coating layer It is preferable to form a base film having a smooth surface by forming a coating layer to fill pores and the like present on the surface.

Such polyethylene coating layer may be formed by evenly applying a polyethylene melt, for example, a low density polyethylene melt or a linear low density polyethylene melt on both sides of the base film, and then cooling and stabilizing it. The application process is not particularly limited, but a sprayer, a brush, or a barcode (mechanized applicator) can be used, and the content thereof can be used in an amount sufficient to smooth the surface of the base film, and the viscosity of the melt In some cases, the coating step may be repeated several times.

After forming the polyethylene coating layer on both sides of the base film, to form a conductive coating layer thereon to prepare a non-crosslinked foamed interlayer film according to the present invention. The conductive coating layer imparts conductivity to the base film, thereby preventing the foreign matter such as dust from being adsorbed on the glass surface or the interleaf paper surface due to friction caused by loading or taking out of the glass.

Such a conductive coating layer may be formed by mixing a conductive polymer or metal particles together with a photocurable binder to prepare a coating composition, applying the same on a base film having the polyethylene coating layer, and then photocuring the same.

As the conductive polymer constituting the conductive coating layer, polythiophene, polypyrrole, polyaniline, or the like may be used. Any metal particles having conductivity may be used without limitation, but silver nanoparticles are preferably used.

The photocurable binder may include, for example, an acrylic, urethane, urethane, acrylic monomer or oligomer or an organic-inorganic hybrid sol-gel photocurable resin, and the like, and a monomer having a photopolymerization reactor. It is also possible to use in combination with photoinitiators.

In the non-crosslinked foamed interlayer film according to the present invention obtained by the above process, a polyethylene coating layer and a conductive coating layer are further formed on both sides of the non-crosslinked foamable base film mainly based on polyethylene. By manufacturing a base film, by using a non-crosslinked foam can be recycled, the material contained in the inner film is protected by the outer coating layer it is possible to minimize the occurrence of foreign matter. Therefore, the glass of a large display device such as an LCD or a PDP can be usefully used as a protection for transferring, loading or taking out.

Hereinafter, the present invention will be described in more detail based on the following examples. However, the following examples are only for illustrating the present invention, and the present invention is not limited to the following examples and may be changed to other embodiments equivalent to substitutions and equivalents without departing from the technical spirit of the present invention. Will be apparent to those of ordinary skill in the art.

≪ Example 1 >

100 parts by weight of low density polyethylene (BF415, LG Chemical Co., Ltd.) (density 0.924 g / cm 3, MI 2.0 g / mim, melting point 105 ° C.), 50 parts by weight of ethylene vinyl acetate (EF320, LG Chemical Co., Ltd.), ethylene vinyl acetate ( 50 parts by weight of EF443, manufactured by LG Chemical Co., Ltd., 0.1 parts by weight of azobisformamide as a blowing agent to prepare a master batch, and then extruded with an inflation film forming apparatus to prepare a base film having a thickness of 50 µm.

Separately, a melt of low density polyethylene (LDPE) (ELC Chemical FB0300 (melting temperature: 150 ° C., melt index: 0.3 g / 10 min) at 170 ° C. was prepared and uniformly coated on both sides of the base film with a barcode of 25 μm. It was air dried to form a polyethylene coating layer.

A composition for forming a conductive coating layer containing polypyrrole [polyethylenedioxythiophene (PEDT), tetraethoxysilane (TEOS), isopropanol (IPA) was adjusted to pH 2 using 0.1 N nitric acid at a composition ratio of 2: 2: 6. , And sufficiently mixed at room temperature for about 3 hours] is uniformly coated on both sides of the base film on which the polyethylene coating layer is formed with a barcode of 25 μm, and then irradiated with UV light at 480 nm to photocure to form a conductive coating layer having a thickness of 100 μm. By forming, the desired uncrosslinked foamable slip paper film was formed.

<Example 2>

100 parts by weight of low density polyethylene (BF415, manufactured by LG Chemical), 50 parts by weight of ethylene vinyl acetate (EF320, manufactured by LG Chemical, Inc.), 50 parts by weight of ethylene vinyl acetate (EF443, manufactured by LG Chemical, Inc.), azobisporamide as a blowing agent. 0.1 parts by weight and 0.1 parts by weight of normal carbon black were blended to prepare a master batch, and then extruded by an inflation film forming apparatus to prepare a base film having a thickness of 50 μm.

Separately, a melt of low density polyethylene (LDPE) (ELC Chemical FB0300 (melting temperature: 150 ° C., melt index: 0.3 g / 10 min) at 170 ° C. was prepared and uniformly coated on both sides of the base film with a barcode of 25 μm. It was air dried to form a polyethylene coating layer.

A composition for forming a conductive coating layer containing silver nanoparticles having an average particle diameter of 10 nm [silver nano, polyethylenedioxythiophene (PEDT), tetraethoxysilane (TEOS), isopropanol (IPA) at a composition ratio of 1: 2: 2: 6. Adjusted to pH 2 using 0.1 N nitric acid, and sufficiently mixed at room temperature for about 3 hours] after uniformly applying a 25 μm barcode to both surfaces of the base film on which the polyethylene coating layer was formed, and then irradiating with 480 nm ultraviolet light. To form a conductive coating layer having a thickness of 100 μm, thereby forming a desired non-crosslinked expandable interlayer film.

Experimental Example

Tensile strength (ASTM D 412: 2003, tensile elongation (ASTM D 412: 2003), tear strength (ASTM D 1004), thickness (ASTM D 1777: 1996) for the interlayer film obtained in Examples 1 and 2 , Density (ASTM D 790), dry heat dimensional change rate (80 ℃, 1 hour) and surface resistance (KS M 3015: 2003, applied voltage 500V, 60 seconds) was measured and the results are shown in Table 1 below.

division Example 1 Example 2 Tensile Strength (MPa) Vertical 6.9 7.1 horizontal 4.3 4.4 Tensile Elongation (%) Vertical 393.3 396.2 horizontal 205.0 205.1 Tear strength (N / mm) Vertical 44.6 44.5 horizontal 35.4 35.5 Thickness (mm) 0.51 0.52 Density (g / ㎠) 0.500 0.521 Dry heat dimensional change rate Vertical -1.0 -0.9 horizontal +0.2 +0.1 Surface resistivity (Ω) surface 4.7 × 10 ⁷ or less 4.7 × 10 ⁷ or less Back side 4.7 × 10 ⁷ or less 4.7 × 10 ⁷ or less

As shown in Table 1, it can be seen that the non-crosslinked foamed interlayer film according to the present invention has sufficient strength and elongation as interlayer paper, has excellent dimensional stability even at high temperature, and exhibits excellent antistatic property with low surface resistance.

In addition, the surface of the non-crosslinked foam paper was measured by a known method such as acetone solvent treatment or by a method such as optical microscope observation, it was confirmed that no substance was buried. Specifically, as a result of wiping the film surface with acetone on the cotton, as a result of the wrong coating, the surface color is changed, and the cloudy coating liquid is also stained, but in the non-crosslinked foamed interlayer film prepared in Examples 1 and 2 The phenomenon did not occur. Or after rubbing strongly about 20 times with the film of this invention using the cotton swab wet | cleaned with IPA, the same result was obtained even if the friction part and the cotton swab were observed under the microscope.

1 is a schematic view showing a section of the samurai T foamed Kanji film according to the present invention.

Claims (7)

An uncrosslinked foamed polyethylene base film comprising 100 parts by weight of low density polyethylene, 10 to 300 parts by weight of ethylene vinyl acetate and 0.01 to 1 part by weight of a blowing agent; A polyethylene coating layer formed by applying a low-density polyethylene melt on both sides of the base film and then cooling it; And An uncrosslinked foamable slip paper film having a conductive coating layer formed on the polyethylene coating layer. delete delete The method of claim 1, And the blowing agent is azobisporamide. delete The method of claim 1, The conductive coating layer is non-crosslinkable foam paper, characterized in that it comprises a conductive polymer or metal particles. The method of claim 1, And the base film further comprises a colorant.

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