KR20150066660A - Pressure sensitive adhesive composition - Google Patents

Abstract

The present invention relates to an adhesive composition, an adhesive film, and a conductive laminate. Provided in the present invention is an adhesive composition forming an adhesive layer having proper level of low rate and high rate peeling force for various objects. Provided in the present invention is an adhesive composition forming an adhesive layer having proper adhesive properties and peeling properties from a material applied in a high temperature process such as an ITO film for example by having excellent heat resistance.

Description

[0001] PRESSURE SENSITIVE ADHESIVE COMPOSITION [0002]

The present application relates to a pressure-sensitive adhesive composition, a pressure-sensitive adhesive film and a conductive laminate.

In general, a protective film for protecting the surface of a metal product or a plastic plate is widely used. As the pressure-sensitive adhesive for a protective film, an acrylic pressure-sensitive adhesive is widely used for reasons of weatherability and transparency. Polarizers, plastic plates, household appliances, automobiles, and the like have been used as a protective film. Recently, protective films have been applied in the production of conductive films such as ITO (Indium Tin Oxide) films. The ITO film is a thin functional film, which is an intermediate product, and is ultimately applied to touch panels and other functions. On one side of the ITO film, ITO is coated in an amorphous state, and crystallization through a heat treatment process enables functional implementation.

Accordingly, the back surface of the ITO coating layer of the ITO film, which does not normally require a heat treatment step, is protected by a protective film. However, since the ITO crystallization process proceeds at a high temperature of 100 DEG C or more, adhesion and reliability in heat resistance of the protective film are required. In addition, since the touch panel and other functional films constituting the liquid crystal display are damaged during a high-temperature heat treatment process at 100 ° C or more, only the ITO film is thermally treated and then subjected to a laminating process. Inevitably, do. The protective film applied to the back surface of the ITO coating layer of the ITO film also serves to prevent scratches on the surface during the transfer process. The ITO film is easily deformed by the stress generated in the peeling, and the ITO coating layer may be damaged and defective. For this reason, the protective film to be applied to the ITO film requires low-speed peeling force property for the purpose of minimizing the stress generated in the film at the film peeling speed (high-speed peeling) to prevent deformation of the film. In order to attain the above object, a cross-linking agent may be additionally introduced in the production of an adhesive film. However, the injection ratio of the cross-linking agent may be high, which may lead to a problem that the pot life is lowered.

The present application provides a pressure-sensitive adhesive composition, a pressure-sensitive adhesive film and a conductive laminate.

Exemplary pressure-sensitive adhesive compositions can realize a structure of Interpenetrating Polymer Network (hereinafter referred to as " IPN ") through a crosslinking reaction. As used herein, the term " pricking reaction of a pressure-sensitive adhesive composition " means a physical or chemical reaction capable of converting a pressure-sensitive adhesive composition derived from a light irradiation, aging, drying or heating process into a pressure-sensitive adhesive. In the present application, the term " light irradiation " means irradiation of an electromagnetic wave which can cause radical polymerization reaction by affecting a radical polymerizing group. In this case, the electromagnetic wave includes microwaves, infrared rays (IR) Ray beam and gamma ray as well as particle beams such as an alpha-particle beam, a proton beam, a neutron beam and an electron beam.

The term " IPN structure " in the present application means a case where two or more crosslinking structures are simultaneously implemented in the pressure-sensitive adhesive. For example, when the pressure-sensitive adhesive composition comprises a crosslinkable polymer, a crosslinking agent, a radically polymerizable compound and an initiator, the crosslinked structure formed by the reaction of the polymer and the polyfunctional crosslinking agent (hereinafter sometimes referred to as "first crosslinked structure" (Hereinafter also referred to as " second cross-linking structure ") realized by polymerization reaction of a radically polymerizable compound derived from a polymerization initiator together with a cross-linking agent. However, the components of the pressure-sensitive adhesive composition for implementing the IPN structure in the present application are not limited to the above-described kinds.

Such a pressure-sensitive adhesive composition may include, for example, a crosslinkable polymer and a multi-functional crosslinking agent. The term " crosslinkable polymer " as used above means a polymer to which a crosslinkable functional group capable of reacting with a polyfunctional crosslinking agent is added to the resin. In the above, the crosslinkable functional group and the crosslinking agent may be selected so that they react with each other by a reaction other than the radical reaction to realize a crosslinked structure, and for example, they react by drying or aging to form a crosslinked structure can do.

The polymer may have, for example, a weight average molecular weight of 1,000,000 or less. In the above, the weight average molecular weight means a polystyrene reduced value measured by GPC (gel permeation chromatography). The lower limit of the weight average molecular weight of the polymer is not particularly limited, and can be adjusted within a range of, for example, 200,000 or 300,000 or more.

The specific composition of the polymer is not particularly limited. As the polymer, for example, a polymer containing a (meth) acrylic acid ester monomer and a polymerization unit derived from a monomer capable of forming a homopolymer having a glass transition temperature of 25 ° C or higher can be used. As used herein, the term monomers means all kinds of compounds capable of forming a polymer through a polymerization reaction, and a polymer containing polymerized units derived from certain monomers may mean a polymer formed by polymerizing any of the above monomers .

As the (meth) acrylic acid ester compound, for example, alkyl (meth) acrylate can be used. (Meth) acrylate having an alkyl group having 1 to 20 carbon atoms, 1 to 14 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms in consideration of the control of the cohesion, the glass transition temperature and the tackiness . The alkyl group in the above may be, for example, straight chain, branched chain or cyclic. Examples of such monomers are methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, sec-butyl acrylate, 2- methylheptyl acrylate, pentyl acrylate, (Meth) acrylate, isobornyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, isobornyl And lauryl (meth) acrylate. Of these, one or more of the above can be selected so as to secure the glass transition temperature. Examples of the (meth) acrylate compound (A) include, but are not limited to, an alkyl group having 1 to 20 carbon atoms, 1 to 14 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms, Alkyl methacrylate may be used.

A monomer capable of forming a homopolymer having a glass transition temperature of 25 ° C or higher (hereinafter, simply referred to as a hard monomer) can be copolymerized with the (meth) acrylic acid ester monomer, and when the homopolymer is formed, Any type can be used as long as it can exhibit a glass transition temperature in the range. Such monomers are contained in the polymer, for example, even when the pressure-sensitive adhesive is maintained in a high-temperature condition, appropriate properties can be maintained.

Examples of the hard monomer include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, isobornyl acrylate, isobornyl methacrylate , Acrylamide or n, n-dimethylacrylamide, and the like, but the present invention is not limited thereto.

In one example, the polymer may comprise from 70 to 98.5 parts by weight of the (meth) acrylic acid ester monomer and from 0.5 to 20 parts by weight of the hard monomer. Such a range may be advantageous in providing a pressure-sensitive adhesive which secures proper physical properties such as cohesive force and heat resistance. As used herein, the term " weight portion " means the ratio of the weight between the components unless otherwise specified. Therefore, it is preferable that the weight (A) of the (meth) acrylic acid ester monomer and the hard (meth) acrylate monomer are in the range of 70 to 98.5 parts by weight and the hard monomer is 0.5 to 20 parts by weight, May mean that the polymer is formed from a mixture of monomers comprising each monomer such that the ratio (A: B) of the weight (B) of the monomers is " 70 to 98.5: 0.5 to 20 ".

The polymer may contain a polymerization unit derived from a copolymerizable monomer having a crosslinkable functional group (hereinafter, simply referred to as a crosslinkable monomer). In the present specification, the copolymerizable monomer having a crosslinkable functional group has, for example, a moiety copolymerizable with other monomers contained in the polymer such as the (meth) acrylic acid ester monomer, and has a crosslinkable functional group, May mean a compound capable of imparting a functional group. Examples of the crosslinkable functional group include a hydroxyl group, a carboxyl group, an isocyanate group, a glycidyl group, an amine group, an alkoxysilyl group or a vinyl group, and in general, a hydroxyl group or a carboxyl group can be used.

A wide variety of monomers having copolymerizable sites, including cross-linkable functional groups, as previously described in the art are known, and all of these monomers can be used in the polymers. Examples of the copolymerizable monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) Hydroxyalkyl (meth) acrylate or 2-hydroxypropyleneglycol (meth) acrylate such as hydroxyalkyl (meth) acrylate or 8-hydroxyoctyl (Meth) acrylate, and the like can be used, but the present invention is not limited thereto. Hydroxyalkyl acrylate or hydroxyalkylene glycol acrylate among the above monomers may be used in consideration of reactivity with other monomers forming the block and ease of controlling the glass transition temperature, but the present invention is not limited thereto.

When the crosslinking monomer is included, the proportion thereof is not particularly limited. For example, the polymer may include 70 to 98.5 parts by weight of the (meth) acrylic acid ester monomer, 0.5 to 20 parts by weight of the hard monomer, And polymerized units derived from 1 to 10 parts by weight of the crosslinkable monomer. In this range, the pressure-sensitive adhesive composition can realize an appropriate crosslinking structure.

The polymer may further comprise any other comonomer, if necessary, for example, for the control of suitable physical properties and the like. Examples of the comonomer include an alkoxyalkylene glycol (meth) acrylate ester, an alkoxydialkylene glycol (meth) acrylate ester, an alkoxytrialkylene glycol (meth) acrylate ester, an alkoxytetraalkylene glycol (meth) (Meth) acrylic acid esters, phenoxy alkylene glycol (meth) acrylic acid esters, phenoxy alkylene glycol (meth) acrylic acid esters, phenoxy trialkylene glycol (meth) acrylic acid esters, phenoxy tetraalkylene glycols Alkylene oxide group-containing monomers such as (meth) acrylic acid esters or phenoxypolyalkylene glycol (meth) acrylic acid esters; Styrene-based monomers such as styrene or methylstyrene; Glycidyl group-containing monomers such as glycidyl (meth) acrylate; And carboxylic acid vinyl esters such as vinyl acetate, but are not limited thereto. These comonomers may be included in the polymer by selecting one kind or more than two types as appropriate according to need. Such comonomers may be included in the polymer in a proportion of, for example, 20 parts by weight or less, or 0.1 part by weight to 15 parts by weight, based on the total weight of the other compounds used as polymerized units in the polymer.

The polymer may be obtained by selecting a desired monomer among the above-described monomers and then subjecting the mixture of the monomers having the desired proportions of the selected monomers to a solution polymerization, a photo polymerization, a bulk polymerization, suspension polymerization, or emulsion polymerization, for example.

The pressure-sensitive adhesive composition may include a multifunctional crosslinking agent capable of reacting with the polymer to form a crosslinked structure.

The kind of the specific crosslinking agent that can be used in the present application is not particularly limited and may be selected in consideration of the kind of the crosslinkable functional group contained in the polymer. As the crosslinking agent, for example, common crosslinking agents such as an isocyanate crosslinking agent, an epoxy crosslinking agent, an aziridine crosslinking agent and a metal chelate crosslinking agent may be used. For example, isocyanate crosslinking agents may be used, but are not limited thereto. Specific examples of the isocyanate crosslinking agent include tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isoboron diisocyanate, tetramethylxylene diisocyanate, naphthalene diisocyanate, and any one of the above polyols (ex. Trimethylol propane); and the like; Specific examples of the epoxy crosslinking agent include ethylene glycol diglycidyl ether, triglycidyl ether, trimethylolpropane triglycidyl ether, N, N, N ', N'-tetraglycidylethylenediamine and glycerin diglycidyl ether ≪ RTI ID = 0.0 > and / or < / RTI > Specific examples of the aziridine crosslinking agent include N, N'-toluene-2,4-bis (1-aziridinecarboxamide), N, N'-diphenylmethane-4,4'- (2-methylaziridine), tri-1-aziridinylphosphine oxide, triethylenemalamine, bisisoproparyl-1- (2-methyl aziridine) no. Specific examples of the metal chelate crosslinking agent include compounds in which a polyvalent metal such as aluminum, iron, zinc, tin, titanium, antimony, magnesium and / or vanadium is coordinated to acetylacetone or ethyl acetoacetate , But is not limited thereto.

The crosslinking agent may be contained in an amount of 0.01 to 10 parts by weight or 0.01 to 5 parts by weight based on 100 parts by weight of the polymer. If the proportion of the cross-linking agent is less than 0.01 part by weight, the cohesive force of the pressure-sensitive adhesive may be deteriorated. If it exceeds 10 parts by weight, the interlaminar peeling or peeling phenomenon may occur.

The pressure-sensitive adhesive composition may further comprise a multifunctional radically polymerizable compound containing two or more, for example, two to six, radically polymerizable functional groups together with the above components for the purpose of implementing the IPN structure, Lt; RTI ID = 0.0 > of < / RTI >

The kind of the above compound is not particularly limited. For example, as the radically polymerizable functional group, a multi-functional acrylate having 2 to 6 (meth) acryloyl groups can be used.

Examples of the polyfunctional acrylate include, but are not limited to, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) , Neopentylglycol adipate di (meth) acrylate, hydroxyl puivalic acid neopentyl glycol di (meth) acrylate, dicyclopentanyl (meth) acrylate, ) Di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylate, ethylene oxide modified di (meth) acrylate, di (meth) acryloxyethyl isocyanurate, allyl (Meth) acrylate such as cyclohexyl di (meth) acrylate, tricyclodecane dimethanol (meth) acrylate, dimethylol dicyclopentanedi (meth) acrylate, ethylene oxide modified hexahydrophthalic acid di (Meth) acrylate, neopentyl glycol-modified trimethylpropane di (meth) acrylate, adamantane di (meth) acrylate or 9,9-bis [4- (2-acryloyloxyethoxy) phenyl] fluorine; and the like; (Meth) acrylates such as trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri Trifunctional acrylates such as modified trimethylolpropane tri (meth) acrylate, trifunctional urethane (meth) acrylate or tris (meth) acryloxyethylisocyanurate; Tetrafunctional acrylates such as diglycerin tetra (meth) acrylate or pentaerythritol tetra (meth) acrylate; Pentafunctional acrylates such as propionic acid-modified dipentaerythritol penta (meth) acrylate; And dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate or urethane (meth) acrylate (e.g., an isocyanate monomer and trimethylolpropane tri And hexafunctional acrylates such as a reaction product, but are not limited thereto.

In the present application, one or more of the above-mentioned polyfunctional acrylates may be used in combination. Particularly, acrylates having a molecular weight of 5,000 or less, 4,000 or less, 3,000 or less, 2,000 or 1,000 or less, and trifunctional or more May be advantageous in terms of durability implementation, but is not limited thereto.

As the polyfunctional acrylate, a polyfunctional acrylate having a cyclic structure and / or a urethane bond among the molecular structures may be used. The ring structure included in the acrylate is not particularly limited and includes a carbon cyclic structure or a heterocyclic structure; Or a monocyclic or polycyclic structure. Specifically, examples of the ring structure included in the polyfunctional acrylate include a cycloalkyl ring structure having 3 to 12 carbon atoms, preferably 3 to 8 carbon atoms, such as cyclopentane, cyclohexane, cycloheptane, and the like, The ring structure may contain one or more, for example, 1 to 5 or 1 to 3, in the acrylate, and may also contain one or more hetero atoms such as O, S or N.

Specific examples of the polyfunctional acrylate containing a cyclic structure include monomers having an isocyanurate structure such as tris (meth) acryloxyethyl isocyanurate, isocyanurate-modified urethane acrylate (e.g., A reaction product of an isocyanate compound having a structure (e.g., isobornyl diisocyanate) and an acrylate compound (e.g., trimethylol propane tri (meth) acrylate or pentaerythritol tri (meth) acrylate) But is not limited to.

The radically polymerizable compound in the pressure-sensitive adhesive composition may be contained in an amount of 3 to 25 parts by weight based on 100 parts by weight of the polymer. An IPN capable of securing suitable physical properties in this range can be realized.

In the pressure-sensitive adhesive composition, the kind of the radical initiator capable of inducing the polymerization reaction of the radically polymerizable compound is not particularly limited. For example, as the radical initiator, at least one selected from the group consisting of a photoinitiator and a thermal decomposition agent may be used, and if necessary, a photoinitiator and a thermal initiator may be used at the same time. The initiator may be included in an amount of, for example, 0.1 to 10 parts by weight, based on 100 parts by weight of the radically polymerizable compound, but is not limited thereto.

The photoinitiator may be any as long as it can induce polymerization reaction of the radically polymerizable compound described above in the course of curing by irradiation with light to realize the second crosslinking structure. For example, benzoin, hydroxy ketone, amino ketone or phosphine oxide photoinitiators can be used. Specific examples thereof include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether , Benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, dimethyl anino acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy- Methyl-1 - [4- (methylthio) phenyl] -2-morpholino-propane-1-one, 1-hydroxycyclohexyl phenyl ketone, (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4-nonocydiethylaminobenzophenone, dichlorobenzophenone, 2 2-ethyl anthraquinone, 2-t-butyl anthraquinone, 2-amino anthraquinone, thioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4- Dimethyl t (2-hydroxy-2-methyl-1- [4- (1-methylvinyl) -1,3-dihydrothiazonato, benzyldimethyl ketal, acetophenone dimethyl ketal, p- Phenyl] propanone] and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide. In the present application, one kind or more kinds of the above can be used, but the present invention is not limited thereto.

The thermal initiator is also not particularly limited, and may be suitably selected in consideration of physical properties to be implemented. For example, a thermal initiator having a 10-hour half-life temperature of 40 ° C or higher and lower than 100 ° C may be used. By setting the half-life temperature of the thermal initiator as described above, a pot-life can be sufficiently secured and the drying temperature for decomposition of the thermal initiator can be appropriately maintained.

The kind of the thermal initiator is not particularly limited as long as it has the above physical properties, and for example, a conventional initiator such as an azo compound, a peroxide compound or a redox compound can be used. Examples of the azo compound in the above include 2,2-azobis (2-methylbutyronitrile), 2,2-thrylazobis (isobutyronitrile), 2,2-trisazobis (2,4- 2-methyl azo bis (2-methylpropionate) and 2,2-azo bis (4-methoxy-2, Dimethylvaleronitrile), and the like, and examples of the peroxide compound include inorganic peroxides such as potassium persulfate, ammonium persulfate or hydrogen peroxide; Peroxides such as diacyl peroxide, peroxydicarbonate, peroxy ester, tetramethyl butyl peroxyneodecanoate (ex Perocta ND, NOF), bis (4-butylcyclohexyl) peroxydicarbonate ex (Peroyl TCP, NOF), di (2-ethylhexyl) peroxycarbonate, butyl peroxyneodecanoate (eg Perbutyl ND, NOF), dipropyl peroxydicarbonate (Peroyl NPP, NOF), diisopropyl peroxydicarbonate (e.g., peroyl IPP, NOF), diethoxyethyl peroxy dicarbonate (ex Peroyl EEP, NOF) Peroyl OEP, NOF), hexyl peroxydicarbonate (e.g., Perhexyl ND, NOF), dimethoxybutyl peroxydicarbonate (e.g., peroyl peroxydicarbonate) MBP, NOF), bis (3-methoxy-3-methoxybutyl) peroxy dicarbonate (ex Peroyl SOP, NOF), dibutyl peroxydicarbonate, dicetyl ) Peroxydicar Perhydroxypivalate (e.g., Perhexyl PV, NOF) may be added to the reaction mixture, for example, Perbutyl (NOF), trimethylhexanoyl peroxide (e.g., Peroyl 355, NOF), dimethylhydroxybutyl peroxyneodecanoate (ex Luperox Butyl peroxyneodecanoate (ex Luperox 10M75, Atofina), amyl peroxyneodecanoate (ex Luperox 546M75, Atofina), t-butyl peroxide (Luperox 546M75, Alofina), t-butyl peroxypivalate, t-amyl peroxy-2-ethylhexanoate, lauryl perox Organic peroxides such as sodium perborate, sodium perborate, dilauroyl peroxide, didecanoyl peroxide, benzoyl peroxide or dibenzoyl peroxide, Examples of the star-based compound include, but are not limited to, a mixture of a peroxide compound and a reducing agent. In the present application, one kind or a mixture of two or more kinds of azo type, peroxide type or redox type compound as described above can be used.

The pressure-sensitive adhesive composition may further comprise, if necessary, one or more components selected from the group consisting of silane coupling agents, tackifier resins, epoxy resins, ultraviolet stabilizers, antioxidants, colorants, reinforcing agents, fillers, defoamers, surfactants and plasticizers in addition to the above- The above additives may further be included.

The present application is also directed to an adhesive film. An exemplary pressure-sensitive adhesive film may include a base film and a pressure-sensitive adhesive layer formed on one or both surfaces of the base film and including the pressure-sensitive adhesive composition in which IPN is implemented.

Such a pressure-sensitive adhesive film can be used as a protective film, for example, a protective film of a conductive film such as an ITO film.

The above-described pressure-sensitive adhesive composition can exhibit appropriate peeling properties for various adherends in a crosslinked structure, that is, in a state in which IPN is implemented, whereby the pressure-sensitive adhesive film can exhibit excellent peeling properties.

For example, the pressure-sensitive adhesive film may satisfy the following expression (1).

[Equation 1]

5 gf / in ≤ X ≤ 40 gf / in

In the formula (1), X is a value obtained by attaching the pressure-sensitive adhesive layer to a PET film, maintaining the pressure-sensitive adhesive layer at a temperature of 23 ° C and a relative humidity of 50% for 24 hours, The peeling force is measured by the peeling speed in the film.

The peeling force can be measured specifically in the manner described in the following examples.

As the base film in the adhesive film, a general film or sheet known in this field can be used. For example, a polyester film such as polyethylene terephthalate or polybutylene terephthalate, a polytetrafluoroethylene film, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a poly (vinyl chloride) film or a polyimide film And the like. Such a film may be composed of a single layer, or two or more layers may be laminated, and in some cases, a functional layer such as an antifouling layer or an antistatic layer may further be included. From the viewpoint of improving the adhesion of the substrate, a surface treatment such as a primer treatment may be performed on one surface or both surfaces of the substrate.

The thickness of the base film may be suitably selected depending on the application and is not particularly limited, and may be generally formed to a thickness of 5 to 500 탆 or 10 to 100 탆.

The thickness of the pressure-sensitive adhesive layer included in the pressure-sensitive adhesive sheet is not particularly limited, and may be, for example, 2 m to 100 m or 5 m to 50 m.

The method for forming the pressure-sensitive adhesive layer is not particularly limited, and for example, a pressure-sensitive adhesive composition or a coating solution prepared therefrom may be coated on a base film or the like by a conventional means such as a bar coater and cured, A method of coating on the surface of the base material and curing the base material, and transferring the base material film onto the base material film.

The process of forming the pressure-sensitive adhesive layer is preferably performed after sufficiently removing the bubble-inducing component such as the volatile component or the reaction residue in the pressure-sensitive adhesive composition or the coating liquid. Accordingly, the crosslinking density or the molecular weight of the pressure-sensitive adhesive is too low to lower the elastic modulus, and bubbles existing between the glass plate and the pressure-sensitive adhesive layer at high temperature are increased to form scattering bodies therein.

Also, the method of curing the pressure-sensitive adhesive composition in the above process is not particularly limited. For example, a process of appropriately aging a polymer and a crosslinking agent included in the composition, and a method of inducing activation of a radical initiator Such as ultraviolet irradiation or application of heat, can be carried out sequentially or simultaneously at an appropriate time.

The present application is also directed to a conductive laminate, and the conductive laminate may have the adhesive film adhered thereto. The adhesive film may be attached to the laminate as a protective film.

The structure or the like of the conductive laminate is not particularly limited, and for example, a structure having an ordinary ITO film or the like can be applied. For example, the laminate includes a base layer, a conductive layer formed on one surface of the base layer, And a coating layer formed on the other surface of the substrate layer, wherein the adhesive film is adhered to the coating layer by a pressure-sensitive adhesive layer.

The kind of the conductive layer and the coating layer to be applied in the above is not particularly limited, and a known material can be applied.

For example, the conductive layer may be a layer containing indium tin oxide, a so-called ITO layer, and the coating layer may be a hard coating layer or an antireflection layer.

In the present application, a pressure-sensitive adhesive composition capable of forming a pressure-sensitive adhesive layer exhibiting an appropriate level of low-speed and high-speed peeling force for various adherends can be provided. In the present application, a pressure-sensitive adhesive composition having excellent heat resistance and capable of forming a pressure-sensitive adhesive layer exhibiting a pressure-sensitive adhesive property and a pressure-sensitive adhesive property which are suitable for a material to be applied to a high temperature process such as an ITO film can be provided.

Hereinafter, the pressure-sensitive adhesive composition will be described in detail by way of examples and comparative examples, but the scope of the pressure-sensitive adhesive composition is not limited by the following examples.

1. Measurement of solid content

The solid content of the acrylic copolymer polymerization solution was measured by placing the polymer solution on a disposable aluminum dish and measuring the weight. After drying for about 3 hours at a temperature of about 120 캜 in an experimental oven, the weight of the dried article was measured, Percentages were calculated.

2. Measurement of viscosity

About 200 g of the polymerization solution of the polymerized acrylic copolymer or the coating liquid (pressure-sensitive adhesive composition) in which the crosslinking agent was blended was placed in a 250-mL glass bottle, and the mixture was placed in a thermostatic chamber maintained at 23 DEG C for 30 minutes, , Viscosity was measured in the RPM section to maintain the confidence interval torque using a rotating viscometer (Brookfield viscometer DV-II +).

3. House time ( pot life )

The viscosity of the coating liquid was evaluated at the time of 0 hours and 24 hours from the time when the coating liquid (pressure-sensitive adhesive composition) was prepared by blending a crosslinking agent into the acrylic copolymer, and the pot life time characteristics were evaluated according to the following criteria .

<Evaluation Criteria>

O: after 24 hours, the viscosity change was less than 30% at the time of preparing the coating liquid (0 hour)

X: After 24 hours, the viscosity change relative to the time of preparing the coating liquid (0 hour) is 30% or more

4. Exfoliation  Measure

The pressure-sensitive adhesive sheet prepared in Examples and Comparative Examples was coated on a hard coating layer of a PET (poly (ethylene terephthalate)) film in which amorphous ITO (Indium Tin Oxide) was deposited on one side and a hard coating layer was formed on the opposite side, according to JIS Z 0237 And attached with a roller of 2 kg. Thereafter, the sample was stored at a temperature of 23 ° C and a relative humidity of 65% for 24 hours, and then cut into pieces having a length of 25 mm and a length of 120 mm. Thereafter, the specimen was fixed on a glass substrate, and the initial peel force was measured by peeling the pressure-sensitive adhesive sheet from the hard coat layer in the transverse direction at a peel angle of 180 degrees and a peel rate of 0.3 m / min using a tensile tester. After that, specimens were prepared in the same manner as in the initial peeling force measurement for the same specimens kept at 150 ° C for 1 hour, and peel strengths were measured at peeling speeds of 0.3 m / min, 20 m / min and 40 m / min Respectively. The peel force was measured on two identical specimens and the average value was adopted. The results are shown in Table 2 below.

Manufacturing example  1. Preparation of acrylic copolymer (A)

To a 1 L reactor equipped with a cooling device for refluxing nitrogen gas and easily controlling the temperature, 83 weight parts of 2-ethylhexyl acrylate, 10 weight parts of methyl methacrylate, 2 weight parts of 4-hydroxybutyl acrylate, And 5 parts by weight of hydroxyethyl acrylate were charged, and 100 parts by weight of ethyl acetate was added as a solvent. Then, nitrogen gas was purged for 1 hour to remove oxygen. A reaction initiator (AIBN, azobisisobutyronitrile) was added to react for about 8 hours. Then, the reaction product was diluted with ethyl acetate to obtain an acrylic copolymer having a weight average molecular weight of 350,000 (A). The acrylic copolymer (A) had a viscosity of about 3,200 cP and a solid content of about 45%.

Manufacturing example  2. Preparation of acrylic copolymer (B)

88 parts by weight of 2-ethylhexyl acrylate, 3 parts by weight of methyl methacrylate, 5 parts by weight of n, n-dimethylacrylamide, 2 parts by weight of 4-hydroxybutyl acrylate and 2 parts by weight of 2-hydroxyethyl acrylate An acrylic copolymer (B) was prepared in the same manner as in Production Example 1, except that the acrylic copolymer (B) was used. The acrylic copolymer (B) had a molecular weight of 300,000, a viscosity of about 2,700 cP, and a solid content of about 45%.

Manufacturing example  3. Preparation of acrylic copolymer (C)

(C) was obtained in the same manner as in Production Example 1, except that 93 parts by weight of 2-ethylhexyl acrylate, 2 parts by weight of 4-hydroxybutyl acrylate and 5 parts by weight of 2-hydroxyethyl acrylate were used, . The copolymer (C) had a molecular weight of 350,000, a viscosity of about 3,000 cP, and a solid content of about 45%.

Manufacturing example  4. Preparation of acrylic copolymer (D)

(D) was obtained in the same manner as in Production Example 1, except that 83 parts by weight of 2-ethylhexyl acrylate, 2 parts by weight of 4-hydroxybutyl acrylate, and 15 parts by weight of 2-hydroxyethyl acrylate were used, . The copolymer (D) had a molecular weight of 700,000, a viscosity of about 3,800 cP, and a solid content of about 45%.

Example  One

Preparation of pressure-sensitive adhesive composition

5.0 parts by weight of a mixture of an isoboron diisocyanate crosslinking agent and a hexamethylene diisocyanate crosslinking agent (MHG-80B, manufactured by Asahi K.K.) as a crosslinking agent, 0.1 part by weight of a polyfunctional acrylate ( , 2 parts by weight of a radical polymerization initiator (Irgacure 651, manufactured by BASF), 2 parts by weight of ethylhexyl peroxydicarbonate as a curing retarder, 5 parts by weight of acetylacetone as a curing retarder and 20 parts by weight of methyl ethyl ketone 20 By weight were uniformly blended to prepare a pressure-sensitive adhesive composition.

Production of pressure-sensitive adhesive sheet

The pressure-sensitive adhesive composition thus prepared was coated on one side of a PET (polyethylene terephthalate) film and dried to form a uniform coating layer having a thickness of about 20 μm. Subsequently, the adhesive layer was maintained at about 90 DEG C for about 3 minutes to induce a crosslinking reaction on the coating layer to produce a pressure-sensitive adhesive sheet. Thereafter, in consideration of the kind and content of the photopolymerizable compound (multifunctional acrylate) contained in the coating layer and the content of the photoinitiator, ultraviolet rays (UV) are irradiated with a metal halide lamp under a condition that sufficient polymerization reaction can occur, . The UV-irradiated coating layer was aged in a 40 ° C oven for 4 days.

Example  2 to 6 and Comparative Example  1 to 4

A pressure-sensitive adhesive composition was prepared in the same manner as in Example 1, except that the composition of the pressure-sensitive adhesive composition was changed as shown in Table 1 below.

Example Comparative Example One 2 3 4 5 6 One 2 3 4 Acrylic copolymer A A A A B B A C C D Cross-linking agent 5.0 5.0 5.0 5.0 5.0 5.0 10.0 5.0 10.0 15.0 Polyfunctional acrylate 10.0 10.0 15.0 10.0 8.0 10.0 10.0 LI 2.0 0.5 0.5 2.0 TI 1 2.0 1.5 1.5 TI 2 2.5 TI 3 0.5 AA 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 Component Ratio Unit: 100 parts by weight of copolymer
Crosslinking agent: MHG-80B, manufactured by Asahi
Polyfunctional acrylate: M300,
LI: Irgacure 651, manufactured by BASF
TI1: Ethylhexyl peroxydicarbonate
TI2: trimethylhexanoyl peroxide
TI3: Di-3-methoxybutyl peroxydicarbonate
AA: Acetyl Acetone

Example Comparative Example One 2 3 4 5 6 One 2 3 4 Housework time O O O O O O O O X X Peel force
Before heat treatment Peeling speed 0.3m / min 25 25 22 18 29 22 20 30 25 20 Heat treatment
150?
1 hours 0.3m / min 25 19 19 15 22 20 32 42 33 35 20m / min 35 20 19 15 25 20 185 50 210 35 40 m / min 38 24 20 18 25 20 270 65 320 30 Unit of peeling force: gf / 25mm

Claims (16)

(Meth) acrylic acid ester monomer and a polymerization unit derived from 0.5 to 20 parts by weight of a monomer capable of forming a homopolymer having a glass transition temperature of 25 占 폚 or higher and a crosslinking agent, Wherein the crosslinkable polymer network structure can be realized through the reaction. The thermoplastic resin composition according to claim 1, wherein the monomer capable of forming a homopolymer having a glass transition temperature of 25 占 폚 or higher is methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert- Acrylate, isobornyl acrylate, isobornyl methacrylate, acrylamide or n, n-dimethyl acrylamide. The pressure-sensitive adhesive composition according to claim 1, wherein the polymer further comprises polymerized units derived from 1 to 10 parts by weight of a crosslinkable functional group-containing copolymer monomer. The pressure-sensitive adhesive composition according to claim 1, wherein the polymer has a weight-average molecular weight of not more than 1,000,000. The pressure-sensitive adhesive composition according to claim 1, wherein the crosslinking agent is an isocyanate crosslinking agent, an epoxy crosslinking agent, an aziridine crosslinking agent, or a metal chelate crosslinking agent. The pressure-sensitive adhesive composition according to claim 1, further comprising a multifunctional radically polymerizable compound having two or more radically polymerizable functional groups. The pressure-sensitive adhesive composition according to claim 6, wherein the radically polymerizable compound is a polyfunctional acrylate having 2 to 6 (meth) acryloyl groups. The pressure-sensitive adhesive composition according to claim 6, wherein the multifunctional radically polymerizable compound is contained in a proportion of 3 parts by weight to 25 parts by weight based on 100 parts by weight of the polymer. The pressure-sensitive adhesive composition according to claim 6, further comprising a radical photoinitiator or a radical thermal initiator. The pressure-sensitive adhesive composition according to claim 9, wherein the radical photoinitiator or the radical thermal initiator is contained in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the radical polymerizable compound. A base film; And a pressure-sensitive adhesive layer formed on one side or both sides of the base film, wherein the pressure-sensitive adhesive layer comprises the pressure-sensitive adhesive composition according to claim 1, wherein a network of interpenetrating polymer networks is realized. The adhesive film according to claim 11, which satisfies the following formula (1):
[Equation 1]
5 gf / in &amp;le; X &amp;le; 40 gf / in
In the formula (1), X is a value obtained by attaching the pressure-sensitive adhesive layer to a PET film, maintaining the pressure-sensitive adhesive layer at a temperature of 23 ° C and a relative humidity of 50% for 24 hours, The peeling force is measured by the peeling speed in the film. A conductive laminate to which the adhesive film of claim 12 is attached. 14. The semiconductor device of claim 13, further comprising: a base layer; a conductive layer formed on one side of the base layer; And a coating layer formed on the other surface of the substrate layer, wherein an adhesive film is adhered to the coating layer. 15. The conductive laminate according to claim 14, wherein the conductive layer comprises indium tin oxide. 15. The conductive laminate according to claim 14, wherein the coating layer is a hard coating layer or an antireflection layer.