KR102019713B1 - Re-work Tape - Google Patents
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- KR102019713B1 KR102019713B1 KR1020150190279A KR20150190279A KR102019713B1 KR 102019713 B1 KR102019713 B1 KR 102019713B1 KR 1020150190279 A KR1020150190279 A KR 1020150190279A KR 20150190279 A KR20150190279 A KR 20150190279A KR 102019713 B1 KR102019713 B1 KR 102019713B1
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J7/00—Adhesives in the form of films or foils
- C09J7/20—Adhesives in the form of films or foils characterised by their carriers
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
- B32B7/02—Physical, chemical or physicochemical properties
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
- B32B7/04—Interconnection of layers
- B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J7/00—Adhesives in the form of films or foils
- C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
- C09J7/38—Pressure-sensitive adhesives [PSA]
- C09J7/381—Pressure-sensitive adhesives [PSA] based on macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
- C09J7/385—Acrylic polymers
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J9/00—Adhesives characterised by their physical nature or the effects produced, e.g. glue sticks
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J2203/00—Applications of adhesives in processes or use of adhesives in the form of films or foils
- C09J2203/318—Applications of adhesives in processes or use of adhesives in the form of films or foils for the production of liquid crystal displays
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Polarising Elements (AREA)
- Adhesive Tapes (AREA)
- Chemical Kinetics & Catalysis (AREA)
Abstract
The present application provides a rework tape and a rework method. In the present application, a rework tape and a rework method using the same may be provided that have a low adhesion energy hard-adhesive surface or that can be effectively reworked even for a thin functional film.
Description
The present application relates to a rework tape and a rework method.
A display device such as an LCD (Liquid Crystal Display) device is attached with various functional films including a polarizing plate, a polarizer, a retardation film or a brightness enhancement film. Functional films are generally attached by adhesive or adhesive. If the attachment position or direction is wrong during the attachment process, it is necessary to peel off the attached functional films and attach the other functional film in the correct position or direction. Is commonly referred to as re-work. For the reworking operation, a method of attaching a film (rework film) including an adhesive layer or an adhesive layer on the upper part of a functional film that is incorrectly attached and peeling the functional film together with the rework film may be considered. However, recently, addition of various functional layers has developed functional films such as polarizing plates with low surface energy, and for thinner devices, functional films of thin thickness called so-called thin polarizing plates have been provided. In order to perform an effective rework operation on a functional film having a low surface energy or a thin thickness as described above, it exhibits proper adhesion to hard-adhesive surfaces having low surface energy, and tears due to external force even when peeling thin functional films. Properties that can peel off may be required.
The present application provides a rework film and a rework method.
This application is for rework tape. The rework tape of the present application may include a base sheet and an adhesive layer formed on at least one surface of the base sheet.
The rework tape may be applied to peel the film attached to the adherend. For example, the film may be peeled together by peeling the rework tape after the rework tape is attached to the surface of the film attached to the adherend.
As the base sheet, a base sheet designed such that a large peel radius of curvature can be maintained in comparison with the brittle fracture radius of curvature of the film to be reworked can be used.
As used herein, the term brittle fracture radius of curvature refers to the radius of curvature at which the film or sheet causes brittle fracture. The term brittle failure refers to a phenomenon in which a material is deformed in an elastic region to cause cracking, wherein the brittle fracture radius of curvature refers to the radius of curvature at the point where the crack first occurs in the film or sheet. can do.
As used herein, the term peel radius of curvature refers to the maximum radius of curvature in which the base sheet can be maintained without brittle fracture in the peeling process using the aforementioned rework tape. The peeling radius of curvature may be used, for example, in the same sense as the limiting radius of curvature. The term limit radius of curvature refers to the maximum radius of curvature in which a film or sheet can be maintained without brittle fracture. However, even if the limit curvature radius itself of the base sheet is lower than the brittle fracture radius of curvature of the film adhered to the adherend, even at a larger radius of curvature than the brittle fracture radius of curvature of the film through the use of a peeling roll or the like during the peeling process. Since there is also a case where it can be maintained without brittle fracture, the peeling radius of curvature is broader than the limiting radius of curvature.
The brittle fracture curvature radius, peeling radius of curvature and the radius of curvature of curvature of the transverse direction of the cut film or sheet after cutting the film or sheet to have a length of 40 mm and a length of 10 mm It can be evaluated by measuring the radius of curvature of the fold while folding at a speed of about 2 mm / sec or less so that both ends face each other. When measured in the above manner, the radius of curvature of the folded portion at the time when the crack first occurs in the folded portion is the brittle fracture radius of curvature, and the radius of curvature of the folded portion immediately before the cracking occurs is the peeling radius of curvature or It may be a limit radius of curvature.
When the film to which the rework tape is applied, i.e., the object to be peeled off is an optical functional film such as a polarizing plate, a polarizer, a brightness enhancement film, a viewing angle compensation film or a retardation film, an antireflection film, a color compensation film, a conductive film, or the like The brittle fracture curvature radius of the film is typically about 10 mm or less, about 9 mm or less, about 8 mm or less, about 7 mm or less, about 6 mm or less, about 5 mm or less, about 4 mm or less, about 3 mm or less, about 2 or less than or about 1.5 mm. The lower limit of the brittle fracture radius of curvature is not particularly limited, but may be, for example, about 0.1 mm or more or about 0.3 mm or more. Therefore, when the rework tape is applied to the rework operation of the optically functional film, the limit radius of curvature of the base sheet of the tape is larger than the brittle fracture radius of curvature of the film. In one example, the ratio B / A (ratio in the same unit) between the critical radius of curvature B of the base sheet and the brittle fracture radius of curvature A of the film may be about 1.3 or more or about 1.5 or more. . The upper limit of the ratio (B / A) is not particularly limited, and for example, the ratio (B / A) may be about 20 or less, about 18 or less, about 16 or less, about 14 or less, about 12 or less, or about 10 or less. , About 8 or less, about 6 or less, about 4 or less, or about 3 or less. In this range, appropriate rework can be undertaken.
In another example, the base sheet of the rework tape is any one in the range of 30 mm / min to 3 m / min with the rework tape attached to the film, i.e. the film to be peeled off attached to the adherend. It can be designed so that a large peel radius of curvature can be maintained at the speed and peel angle at any peel angle within the range of 30 degrees to 180 degrees compared to the brittle fracture radius of curvature of the film to be peeled off. Even in the above cases, the ratio B / A (ratio in the same unit) between the critical radius of curvature B of the base sheet and the brittle fracture radius of curvature A of the film may be about 1.3 or more or about 1.5 or more. have. The upper limit of the ratio (B / A) is not particularly limited, and for example, the ratio (B / A) may be about 20 or less, about 18 or less, about 16 or less, about 14 or less, about 12 or less, or about 10 or less. , About 8 or less, about 6 or less, about 4 or less, or about 3 or less. In this range, appropriate rework can be undertaken.
By designing the base sheet as described above, a phenomenon in which the functional film is torn during peeling or peeling occurs at the rework tape interface even during rework of a thin functional film such as a thin polarizing plate can be prevented. have. The manner in which the base sheet is designed to exhibit such a radius of curvature is not particularly limited. For example, in consideration of the type of the film to be peeled off, the thickness or elastic modulus of the base sheet is adjusted to adjust the limit radius of curvature, Alternatively, when the limit radius of curvature is relatively low, a method of applying a peeling roll to assist in maintaining the radius of curvature in the peeling process (rework process) may be applied.
For example, as the base sheet, a base sheet having a thickness of 130 μm or more, 135 μm or more, 140 μm or more, 145 μm or more, or 150 μm or more can be used. By adjusting the thickness of the base sheet thickly, it is possible to maintain a large radius of curvature in the rework process using the rework tape. The upper limit of the thickness of the base sheet is not particularly limited. That is, the thicker the base sheet can maintain a large radius of curvature during rework. In consideration of the thickness and workability of the general substrate sheet, the thickness of the substrate sheet is about 1,000 µm or less, 900 µm or less, 800 µm or less, 700 µm or less, 600 µm or less, 500 µm or less, 400 µm or less, 300 µm or less Or 250 µm or less.
As the base sheet, various kinds of base sheets may be used as long as the above conditions are satisfied. Substrate sheets that can be used include cellulose ester films such as triacetyl cellulose (TAC) films, polyester films such as PET (poly (ethylene terephthalate)) films and polycarbonate (PC) films, polyarylate films, polysulfone films, Polyolefin films such as polyether sulfone film, PE (poly (ethylene)) film or PP (poly (propylene)) film, polyvinylidene chloride film, polyvinyl alcohol film, EVA (ethylene vinyl alcohol) film, polystyrene film, nord Borneen resin film, polymethylpentene film, polyether ketone film, polyether ketone imide film, polyamide film, fluororesin film or acrylic film and the like can be exemplified, but is not limited thereto.
In at least one surface of the base sheet in the rework tape, an adhesive layer is formed. The term adhesive layer in the present application may mean a layer of viscoelastic material having adhesiveness or adhesiveness.
For example, the pressure-sensitive adhesive layer may have a pressure of 500 gf / 25 mm or more on a surface or surface energy of the film to be peeled up to 30 mN / m or a surface energy within a range of 0.1 to 30 mN / m. The adhesive force is an adhesive force measured at a peel rate of 300 mm / min and a peel angle of 180 degrees at room temperature with respect to the surface having the surface energy. In another example, the adhesive force may be about 550 gf / 25mm or more, 600 gf / 25mm or more, 650 gf / 25mm or more, 700 gf / 25mm or more, 750 gf / 25mm or more or about 800 gf / 25mm or more. In this range of adhesive force, the rework tape can perform an effective rework operation even for a functional film having a low adhesion energy-resistant surface. The higher the value of the adhesive force, the appropriate rework operation is possible, the upper limit is not particularly limited. For example, the adhesive force may be about 2,000 gf / 25mm or less, about 1,500 gf / 25mm or less, or about 1,000 gf / 25mm or less.
As used herein, the term room temperature is a warm or undecreased natural temperature, and may mean, for example, a temperature in a range of about 10 ° C to 30 ° C, about 23 ° C, or about 25 ° C. . In addition, in the present specification, when mentioning a physical property such as surface energy, adhesive force, or adhesive force that the measurement temperature may affect the result, the physical property may mean a physical property measured at room temperature unless otherwise specified. .
The pressure-sensitive adhesive layer can be formed using various materials, as long as the adhesive force as described above can be exhibited. For example, the pressure-sensitive adhesive layer may be an acrylic pressure-sensitive adhesive layer, a silicone pressure-sensitive adhesive layer, an epoxy pressure-sensitive adhesive layer or a rubber pressure-sensitive adhesive layer in a crosslinked or uncrosslinked state. The acrylic adhesive layer in the non-crosslinked state may mean a state in which an optical crosslinking agent such as a crosslinking agent for crosslinking an acrylic polymer, which is an adhesive resin, and a polyfunctional acrylate, are not included in the adhesive layer. When the pressure-sensitive adhesive layer containing the acrylic polymer is in a crosslinked state, its adhesive force may be lowered, so that proper rework operation may not be possible. The silicone pressure sensitive adhesive, epoxy pressure sensitive adhesive layer or rubber pressure sensitive adhesive layer may also be in a crosslinked state or a non-crosslinked state.
As the acrylic, silicone, epoxy, or rubber pressure sensitive adhesive layer, a known pressure sensitive adhesive may be applied without particular limitation.
For example, the acrylic pressure-sensitive adhesive layer may include an acrylic polymer in a non-crosslinked state. As used herein, the term acrylic polymer is a polymer containing a polymerized unit of an acrylic monomer as a main component, for example, 50% or more, 55% or more, 60% or more, 65% or more, 70% or more by weight of the acrylic monomer. , At least 75%, at least 80%, at least 85%, or at least 90%. In addition, in the present specification, the term polymer unit may mean a state in which the monomer forms the polymer skeleton of the polymer by a polymerization reaction. In addition, the term acrylic monomer herein may mean acrylic acid, methacrylic acid or derivatives thereof (eg, acrylic acid ester or methacrylic acid ester).
The acrylic polymer may have a weight average molecular weight in the range of 300,000 to 2 million, and in another example may be in the range of 300,000 to 1.5 million or 300,000 to 1.2 million. In the present specification, the weight average molecular weight is a conversion value with respect to standard polystyrene measured by GPC (Gel Permeation Chromatograph), and unless otherwise specified, the term molecular weight means weight average molecular weight. The acrylic polymer may be selected so that the desired molecular weight can be achieved in the aforementioned range or other ranges, and the specific range is not particularly limited.
The acrylic polymer may have a glass transition temperature of 0 ° C. or less, −10 ° C. or less, −20 ° C., −30 ° C., −40 ° C., or −50 ° C. or less. The glass transition temperature may also be about -200 ° C or higher, about -150 ° C or higher or about -100 ° C or higher. The glass transition temperature can be selected so that the desired adhesive force can be achieved in the above range or other range, and the specific range is not particularly limited.
An acrylic polymer can contain the polymer unit of a (meth) acrylic acid ester compound as a polymer unit.
As the (meth) acrylic acid ester compound, for example, alkyl (meth) acrylate can be used, and alkyl (meth) having an alkyl group having 2 to 12 carbon atoms in consideration of the cohesion, the glass transition temperature and the control of adhesiveness, etc. ) Acrylates can be used. Examples of such monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth ) Acrylate, sec-butyl (meth) acrylate, pentyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-ethylbutyl (meth) acrylate, n-octyl (meth) acrylate, iso Bornyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, lauryl (meth) acrylate, and the like, and one or more of the above may be included in the polymer.
The acrylic polymer may further include a polar monomer such as a monomer having a hydroxy group or a monomer having a carboxyl group as the polymerization unit. In the present application, the monomer having a hydroxyl group means a monomer which may be copolymerized with other monomers forming the acrylic polymer, and may provide a hydroxyl group at the side chain or the terminal of the polymer after copolymerization, and the monomer having a carboxyl group is the acrylic It may mean a monomer which may be copolymerized with other monomers forming a polymer and may provide a carboxyl group at the side chain or the terminal of the polymer after copolymerization.
Examples of the monomer having a hydroxy group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 6-hydroxyhexyl (meth). Hydroxyalkyl (meth) acrylates such as acrylate or 8-hydroxyoctyl (meth) acrylate, or 2-hydroxyethylene glycol (meth) acrylate or 2-hydroxypropylene glycol (meth) acrylate Hydroxyalkylene glycol (meth) acrylate etc. can be illustrated, As a monomer which has a carboxyl group, (meth) acrylic acid, 2- (meth) acryloyloxy acetic acid, 3- (meth) acryloyloxy propyl Acids, 4- (meth) acryloyloxy butyric acid, acrylic acid duplexes, itaconic acid, maleic acid or maleic anhydride and the like can be exemplified, but is not limited thereto. When the polar monomer is included, the polar monomer may be included in a ratio of about 0.01 to 20 parts by weight based on 100 parts by weight of the (meth) acrylic acid ester compound. In the present application, the term "parts by weight" may refer to a ratio of weights between components, unless otherwise specified. The polar monomer is, in another example, at least about 0.1 part by weight, at least about 1 part by weight, at least about 1.5 parts by weight, at least about 2 parts by weight, at least about 2.5 parts by weight, at least about 3 parts by weight, at least about 3.5 parts by weight, about 4 parts by weight or more, about 4.5 parts by weight or about 5 parts by weight or more, and about 15 parts by weight or less or about 10 parts by weight or less of the polymer.
The acrylic polymer may further comprise other comonomers as polymerized units in addition to the monomers as necessary. Comonomers which may be further included include (meth) acrylonitrile, (meth) acrylamide, N-methyl (meth) acrylamide, N-butoxy methyl (meth) acrylamide, N-vinyl pyrrolidone or Nitrogen-containing monomers such as N-vinyl caprolactam and the like; Alkoxy alkylene glycol (meth) acrylic acid ester, alkoxy dialkylene glycol (meth) acrylic acid ester, alkoxy trialkylene glycol (meth) acrylic acid ester, alkoxy tetraalkylene glycol (meth) acrylic acid ester, alkoxy polyethylene glycol (meth) acrylic acid Esters, phenoxy alkylene glycol (meth) acrylic acid esters, phenoxy dialkylene glycol (meth) acrylic acid esters, phenoxy trialkylene glycol (meth) acrylic acid esters, phenoxy tetraalkylene glycol (meth) acrylic acid esters or phenoxy Alkylene oxide group-containing monomers such as polyalkylene glycol (meth) acrylic acid ester and the like; Styrene-based monomers such as styrene or methyl styrene; Glycidyl group-containing monomers such as glycidyl (meth) acrylate; Or carboxylic acid vinyl esters such as vinyl acetate, but are not limited thereto. Such comonomers may be included in the polymer by selecting one or more kinds thereof as necessary. Such comonomer, for example, may be included in the acrylic polymer in a ratio of 20 parts by weight or less, or 0.1 to 15 parts by weight with respect to 100 parts by weight of the (meth) acrylic acid ester monomer.
The acrylic polymer can be prepared through a conventional polymerization method. For example, a monomer mixture prepared by blending necessary monomers according to the desired monomer composition may be prepared by solution polymerization, photo polymerization, bulk polymerization, suspension polymerization or emulsion polymerization. It can be prepared by applying to polymerization method such as (emulsion polymerization). If necessary in this process, a suitable polymerization initiator or a molecular weight regulator or chain transfer agent may be used together.
In the present application, the acrylic pressure sensitive adhesive layer does not include a crosslinking agent. However, if necessary, one selected from the group consisting of other known additives other than the crosslinking agent, for example, a tackifier, an epoxy resin, a curing agent, an ultraviolet stabilizer, an antioxidant, a colorant, a reinforcing agent, a filler, an antifoaming agent, a surfactant, and a plasticizer The above additive may be further included.
The kind of silicone pressure sensitive adhesive that may be included in the pressure sensitive adhesive layer in the rework tape of the present application is not particularly limited, and an adhesive capable of exhibiting the aforementioned adhesive force may be applied.
For example, a heat curable silicone pressure sensitive adhesive or an ultraviolet curable silicone pressure sensitive adhesive may be used as the silicone pressure sensitive adhesive. Examples of the heat-curable silicone pressure-sensitive adhesives include, but are not limited to, hydrosilylation reactions, silanol condensation reactions, alcohol desorption, oxim desorption, or acetate desorption silicone adhesives It doesn't happen. Further, examples of the ultraviolet curable silicone pressure sensitive adhesive include (meth) acrylic functional silicones (ex. Silicone compounds disclosed in Japanese Patent Application Laid-open No. 01-304108), silicones having vinyl groups and mercapto groups as functional groups (ex. Silicone compounds disclosed in Japanese Patent Application Laid-Open No. 53-37376), epoxy functional silicones (ex. Silicone compounds disclosed in Japanese Patent Application Laid-open No. 58-174418), vinyl ether functional silicones (ex. Crivello, JV, Eckberg, RP, USA) In the case of curing a composition comprising a silicone compound disclosed in Patent No. 4,617,238, silanol functional silicone (poly (silsesquioxane) or poly (silsesquioxane) and tetraphenoxysilane (Japanese Patent Laid-Open No. 06) -148887) and examples of the curable composition comprising a siloxane polymer and a base generating material (Japanese Patent Laid-Open Publication No. Hei 06-273936) and a silicone compound disclosed in Japanese Patent Laid-Open Publication No. Hei 07-69610), and the like. It is not to be limited to.
The method of forming the pressure-sensitive adhesive layer as described above on one surface of the base sheet is not particularly limited, and a known method may be applied.
The thickness of the pressure-sensitive adhesive layer in the rework tape is not particularly limited, and may be adjusted to an appropriate thickness in consideration of processability or adhesiveness.
The rework tape may further include a release tape that temporarily protects the surface of the pressure sensitive adhesive layer before the rework operation.
The present application also relates to a laminate in which such a tape is applied for a rework operation and a rework method using the laminate.
For example, the laminate includes a film attached to an adherend; And a rework tape attached to the film. The rework tape is formed on one surface of the base sheet and the base sheet designed to maintain a large radius of curvature compared to the brittle fracture radius of curvature of the film adhered to the adherend, and to the adherend of the optical film It may include a pressure-sensitive adhesive layer adhered to the surface of the optical film with a high adhesive force as compared to the adhesive force to.
As described above, the laminate or the film may be a display panel and various optical functional films attached to the panel, as described above.
For example, the film may be a general optical film, and may be a polarizing plate, a polarizer, a retardation film, a brightness enhancement film, a viewing angle compensation film, an antireflection film, a color compensating plate, or a conductive film. As described above, in the case of the rework tape of the present application, an effective rework operation is possible even for a film or a thin film having a hard-adhesive surface.
Moreover, the specific content about the base material sheet and the adhesive layer of the rework tape adhering to the said laminated body, for example, the range of peeling curvature radius or limit curvature radius, and ratio of the brittle fracture curvature radius of the said film (B / A), the adhesive force of the pressure-sensitive adhesive layer and the like may be applied in the same manner as described above.
The present application also relates to a rework method. The rework method can be performed using, for example, the rework tape or laminate.
The rework method may include, for example, peeling the rework tape from the laminate described above to peel the film from the adherend.
The method of performing the rework method of the present application is not particularly limited as long as the rework tape is applied, and a method applied in a known rework operation may be applied.
In one example, the rework operation may be performed while peeling the rework tape at any peeling speed in the range of 30 mm / min to 3 m / min and at any peeling angle in the range of 30 degrees to 180 degrees.
The present application provides a rework tape and a rework method. In the present application, a rework tape and a rework method using the same may be provided that have a low adhesion energy hard-adhesive surface or that can be effectively reworked even for a thin functional film.
1 is a view showing the rework operation of the first embodiment.
2 and 3 show the rework operation of Comparative Examples 1 and 2, respectively.
Hereinafter, the above will be described in detail through Examples and Comparative Examples, but the above range is not limited to the following Examples.
1. Weight average molecular weight of polymer
The weight average molecular weight and molecular weight distribution of the acrylic polymer were measured under the following conditions using GPC. The measurement result was converted into the calibration curve using standard polystyrene of Agilent system.
<Weight average molecular weight measurement conditions>
Meter: Agilent GPC (Agilent 1200 series, USA)
Column: Connect 2 PL Mixed B
Column temperature: 40 ℃
Eluent: tetrahydrofuran
Flow rate: 1.0 mL / min
Concentration: ~ 1 mg / mL (100 μL injection)
2. Calculation of glass transition temperature
Glass transition temperature (Tg) was calculated by the following formula according to the monomer composition.
<Formula>
1 / Tg = ΣWn / Tn
In the above formula, Wn is the weight fraction of each monomer of the polymer, Tn is the glass transition temperature when the monomer forms a homopolymer, and the right side of the formula is the weight fraction of the monomer used, the monomer forming the homopolymer. This is the result of summing the calculated numerical values (Wn / Tn) divided by the glass transition temperature shown in the case of each monomer and summing all the calculated numerical values.
3. Evaluation of adhesive force
The rework tape prepared in Examples or Comparative Examples was attached to an adherend having a surface energy of 30 mN / m or less (fluorine-coated surface of a fluorine-coated triacetyl cellulose (TAC) film), and the rework tape adhered to After the complex was cut to 2 mm in width and 10 mm in length, it was held at 25 ° C. for about 30 minutes, and then at the same temperature, the tape was peeled off at 300 mm / min along the longitudinal direction and at 180 °. It evaluated while peeling off.
4. Evaluation of the radius of curvature
The brittle fracture radius of curvature, peeling radius of curvature, or limit radius of curvature is about 2 mm / sec at both ends in the horizontal direction after cutting the film or sheet to be measured to have a length of 40 mm and a length of 10 mm. It was evaluated by measuring the radius of the fold with a vernier caliper while folding at speed. The radius of curvature at the time when the crack first occurs due to brittle fracture in the folded portion is defined as the brittle fracture radius of curvature, and the radius of curvature immediately before the crack occurs may be defined as a peeling radius of curvature or a limit radius of curvature.
Example 1.
Production of rework tape
Nitrogen gas was refluxed and n-butyl acrylate (n-BA) and acrylic acid (AA) were charged in a ratio of 95: 5 (n-BA: AA) in a 1L reactor equipped with a cooling device for easy temperature control. After ethyl acetate (EAc; ethyl aceate) was added as a solvent, nitrogen gas was purged for 60 minutes to remove oxygen. Thereafter, an appropriate amount of AIBN (azobisisobutyronitrile), an initiator, was added at a temperature capable of polymerization, and the reaction product was diluted with ethyl acetate after the polymerization reaction. An acrylic polymer having a weight average molecular weight of about 640,000 and a glass transition temperature of about -49 ° C. Solution A1 was prepared. Without adding an additional additive to the acrylic polymer solution (A1), it is coated on one surface of a PET (poly (ethylene terephthalate)) film as a base sheet and dried to form an adhesive layer having a thickness of about 25 μm, A release film was laminated on the pressure-sensitive adhesive layer to prepare a rework tape. The adhesive force on the TAC surface of the pressure-sensitive adhesive layer was about 841 gf / 25mm. In addition, a film having a thickness of about 188 μm was applied as the PET film. The radius of curvature of the PET film was about 2 mm.
Rework
As an optical film, the outermost TAC film which has a fluorine coating layer (the same film applied when measuring the adhesive force of a rework tape), Comprising: The TAC film whose surface energy of the surface of the said fluorine coating layer is 30 mN / m or less, The whole As a polarizing plate having a thickness of about 100 μm, a polarizing plate having a brittle fracture radius of curvature of about 1 mm was used. After attaching the polarizing plate to the glass substrate through the pressure-sensitive adhesive layer (adhesive area: 30cm × 40cm, adhesive force to the glass substrate of the pressure-sensitive adhesive layer: about 615 gf / 25mm) and then in an autoclave of 50 ° C. and 5 atmospheres. After about 30 minutes of treatment, and again left at 80 ℃ 1 hour, the rework operation was performed with the rework tape. In the rework operation, the rework tape was attached to the fluorine coating layer of the outermost TAC film of the polarizing plate and then examined whether the effective peeling was performed while the polarizing plate was peeled off together with the rework tape. 1 is a view showing a process of performing the rework as described above, as a result of which the effective rework operation is performed without tearing of the optical film or rework tape or peeling at the interface between the rework tape and the optical film. Confirmed.
Example 2.
A rework tape was manufactured in the same manner as in Example 1 except that the rework tape was formed by forming an adhesive layer on a PET film having a thickness of about 150 μm (limit curvature radius: about 1.5 mm). Walk work was performed. As a result of the rework operation, it was confirmed that an effective rework operation was performed without tearing of the optical film or the rework tape or peeling at the interface between the rework tape and the optical film.
Example 3.
As the pressure-sensitive adhesive in the preparation of the rework tape, a silicone pressure sensitive adhesive (manufacturer: Dow corning, trade name: Dow corning® 7567) having an adhesive force to the TAC surface of about 1160 gf / 25mm was applied as in Example 2 Rework tapes were prepared and rework operations were performed. As a result of the rework operation, it was confirmed that an effective rework operation was performed without tearing of the optical film or the rework tape or peeling at the interface between the rework tape and the optical film.
Comparative Example 1.
A rework tape was manufactured in the same manner as in Example 1, except that the rework tape was formed by forming an adhesive layer on a PET film having a thickness of about 125 μm (limit curvature radius: 1 mm) and rework. Work was performed. 2 is a view showing the rework operation. As a result of the rework operation, tearing occurred at the end of the optical film during the peeling process, so that the effective rework operation was not performed.
Comparative Example 2.
A rework tape was manufactured in the same manner as in Example 1, except that the rework tape was formed by forming an adhesive layer on a PET film (limit radius of curvature: 0.5 mm) having a thickness of about 100 μm, and rework Work was performed. 3 is a view showing the rework operation. As a result of the rework, effective rework was not performed since the rework was performed at the interface between the rework tape and the optical film.
Comparative Example 3.
The adhesive force to the surface of the TAC was about 220 gf / 25mm using a polymer polymerized with ethylhexyl acrylate (EHA) and acrylic acid (AA) at a weight ratio of 95: 5 (EHA: AA) in preparing the pressure-sensitive adhesive layer. A rework tape was produced in the same manner as in Example 2, except that gradually forming a layer to prepare a rework tape, and the rework operation was performed. As a result of the rework, effective rework was not performed since the rework was performed at the interface between the rework tape and the optical film.
Comparative Example 4.
In the preparation of the pressure-sensitive adhesive layer, a polymer obtained by polymerizing ethylhexyl acrylate (EHA), n-butyl acrylate (BA) and acrylic acid (AA) at a weight ratio of 65: 30: 5 (EHA: BA: AA) was used. The rework tape was prepared in the same manner as in Example 2, except that a rework tape was prepared by gradually forming a tackifier layer having an adhesive force on the TAC surface of about 659 gf / 25mm. As a result of the rework, no effective rework was performed, such as peeling at the interface between the rework tape and the optical film.
Claims (13)
The ratio (B / A) in the same unit of the brittle fracture curvature radius A of the film adhering to the adherend and the peeling curvature radius B of the base sheet is 1.3 or more,
The pressure-sensitive adhesive layer is 700 gf / 25mm or more, the adhesive force measured at any peeling rate and 180 degrees peeling angle in the range of 30 mm / min to 3 m / min with respect to the surface of the film adhered to the adherend,
The thickness of the said base sheet is 130 micrometers or more,
The pressure-sensitive adhesive layer is a rework tape of an acrylic pressure-sensitive adhesive layer in a non-crosslinked state.
The rework tape is a laminate according to claim 1.
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| Application Number | Priority Date | Filing Date | Title |
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| KR1020150190279A KR102019713B1 (en) | 2015-12-30 | 2015-12-30 | Re-work Tape |
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| Application Number | Priority Date | Filing Date | Title |
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| KR1020150190279A KR102019713B1 (en) | 2015-12-30 | 2015-12-30 | Re-work Tape |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008268255A (en) * | 2007-04-16 | 2008-11-06 | Konica Minolta Opto Inc | Reworking method for liquid crystal cell, and film for reworking |
| KR101596212B1 (en) | 2015-04-29 | 2016-02-23 | 주식회사 제이텍 | Adhesive film for removing optical clear adhesives, method for preparing the same, and remove method of optical clear adhesives on touch screen panel |
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| KR101415841B1 (en) * | 2012-08-23 | 2014-07-09 | 주식회사 엘지화학 | Hard coating film |
| EP2930218B1 (en) * | 2013-06-19 | 2019-10-16 | LG Chem, Ltd. | Pressure sensitive adhesive composition |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP2008268255A (en) * | 2007-04-16 | 2008-11-06 | Konica Minolta Opto Inc | Reworking method for liquid crystal cell, and film for reworking |
| KR101596212B1 (en) | 2015-04-29 | 2016-02-23 | 주식회사 제이텍 | Adhesive film for removing optical clear adhesives, method for preparing the same, and remove method of optical clear adhesives on touch screen panel |
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