KR20120125699A - Pressure sensitive adhesive composition and pressure sensitive adhesive film comprising of the same - Google Patents

Abstract

PURPOSE: A non-acrylic acid type adhesive composition and an adhesive film including the same with low resistance rate change are provided to enhance adhesive force with ITO surface. CONSTITUTION: A non-acrylic acid type adhesive composition satisfies chemical formula 1 and 2. The chemical formula 1 is as follows: resistance change rate(%) for ITO surface <= 15. The chemical formula 2: release strength &ge; 1000 g/in. The non-acrylic acid type adhesive composition includes the weight-average molecular weight of 500-10,000. The content of the additive is 0.01-5 weight% based on the total weight of the composition. The adhesive film for touch panels includes an adhesive composition or a cured product. The thickness of the adhesive film is 10-200 microns. [Reference numerals] (AA) Comparative embodiment 2; (BB) Practical embodiment 2; (CC) Initial; (DD) Day 1; (EE) Day 5; (FF) Day 10; (GG) Day 30

Description

Pressure sensitive adhesive composition and pressure sensitive adhesive film comprising of the same}

The present invention relates to a pressure-sensitive adhesive composition of the non-acrylic acid type and an adhesive film comprising the same.

In recent years, mobile phone terminals such as mobile phones or PHS terminals and mobile communication terminals such as PDA terminals have formed a large market. The technical goals pursued in the mobile communication terminal may be thinner, lighter, lower power consumption, higher resolution, and higher brightness.

In particular, a terminal equipped with a touch panel or a touch screen as an input device is based on a transparent conductive plastic film, for example, a polyethylene terephthalate film, in terms of weight reduction and prevention of cracking, and on one surface thereof, indium tin oxide (ITO) or the like. The film in which the conductive thin film was formed has the structure laminated | stacked on the conductive glass, a reinforcing material, a deco film, etc. by the adhesive layer.

The pressure-sensitive adhesive used for the attachment of the transparent conductive film in the touch screen or the touch panel includes a step absorbency capable of absorbing the printing step caused by the decor film; Durability that can suppress the occurrence of curls or bubbles when exposed to harsh conditions such as high temperature or high humidity conditions; Cutting ability to suppress squeaking or pressing when cutting; And physical properties such as excellent adhesion to various substrates, and in addition, various physical properties such as optical properties, workability and warpage resistance are required.

For example, in the case of a capacitive touch panel, the adhesive film is designed to directly adhere to the conductive layer (ex. ITO). The pressure-sensitive adhesive layer applied to the capacitive type described above is required to suppress the change in resistance of the transparent electrode such as ITO.

The pressure-sensitive adhesive used in the conventional touch panel prioritizes the adhesion with the ITO surface, and in many cases, acrylic acid such as -COOH group is applied to the monomer composition of the resin. However, when the adhesive having such a composition is attached to the ITO surface and used, there is a tendency to increase the ITO resistance. In particular, under high temperature and high humidity conditions, there is a problem of rapidly increasing ITO resistance in response to moisture. On the contrary, when the non-acrylic acid type adhesive is used, there is a problem in that the adhesion to the ITO surface is weak.

An object of the present invention is to provide an adhesive composition having excellent adhesion with an ITO surface while using an acid-free aromatic hydrocarbon additive, and also to provide an adhesive film or a touch panel using the same.

In one embodiment, the present invention as an adhesive composition for a touch panel,

It provides a pressure-sensitive adhesive composition that satisfies the conditions of the general formulas 1 and 2, and comprises an aromatic hydrocarbon additive of the non-acrylic acid type having a weight average molecular weight of 500 to 10,000.

[Formula 1]

% Change in resistance to ITO plane ≤ 15

[Formula 2]

Peel strength ≥ 1000 g / in.

In another embodiment, an adhesive film or a touch panel using the pressure-sensitive adhesive composition is provided.

The present invention provides a pressure-sensitive adhesive composition that does not lower the adhesion to the ITO surface while using an acid-free additive, which can be formulated in the form of a pressure-sensitive adhesive film, and can be applied to touch panels of various structures or shapes. .

1 is a cross-sectional view showing a general laminated structure of a touch panel;
2 is a schematic view showing a laminated structure of an adhesive film according to an embodiment of the present invention;
3 is a graph comparing and measuring the resistance change rate with respect to the ITO surface of the pressure-sensitive adhesive film.

The present invention relates to a pressure-sensitive adhesive composition for a touch panel, comprising a non-acrylic acid type aromatic hydrocarbon additive having a weight average molecular weight of 500 to 10,000, satisfying the conditions of the following general formulas (1) and (2). .

[Formula 1]

% Change in resistance to ITO plane ≤ 15

[Formula 2]

Peel Strength ≥ 1000 g / in

Hereinafter, the adhesive composition of this invention is demonstrated concretely.

The pressure-sensitive adhesive composition according to the present invention includes an aromatic hydrocarbon additive of the non-acrylic acid type, which means that it does not include a carboxyl group inside the chemical structure of the additive. Since the carboxyl group is a functional group capable of imparting high glass transition temperature and adhesion, the monomer mainly used as an additive or in the pressure-sensitive adhesive, but the present inventors have an additive having a carboxyl group in the pressure-sensitive adhesive composition, the pressure-sensitive adhesive formed of the composition as described above When applied to a touch panel or the like, the pressure-sensitive adhesive was found to have a problem that the effect of suppressing the resistance change of the transparent electrode is very weak.

In contrast, the pressure-sensitive adhesive composition according to the present invention is an acid-free composition, and has an effect of suppressing a change in resistance to the ITO surface. In one embodiment, the pressure-sensitive adhesive composition, the resistance change rate for the ITO surface is 15% or less, more specifically 10% or less. In addition, in the present invention, the lower limit of the resistance change rate is not particularly limited. That is, in the present invention, the lower the value of the resistance change rate, the more the adhesive film is applied to the touch panel or the screen can exhibit an excellent effect.

In addition, the pressure-sensitive adhesive composition according to the present invention is an acid-free type pressure-sensitive adhesive composition and at the same time excellent peeling force. In one embodiment, the pressure-sensitive adhesive composition, the peel strength to the ITO surface is more than 1000 g / in, more specifically 1100 g / in. The pressure-sensitive adhesive composition according to the present invention is applied to a touch panel or a touch screen, even when exposed to various environments in the manufacturing, storage, transport and sales process, while suppressing the resistance change of the transparent electrode of the touch panel, at the same time can implement an excellent adhesive force Can be.

The aromatic hydrocarbon additive according to the present invention may be a non-acrylic acid type aromatic hydrocarbon additive having a weight average molecular weight of 500 to 10,000. The type of anti-aromatic hydrocarbon additive according to the present invention is not particularly limited, and various additives containing an aromatic ring in the structure may be used. In the aromatic hydrocarbon additive, the remaining side chains other than the aromatic ring are for controlling the molecular weight. Specifically, the aromatic hydrocarbon additive may include at least one functional group selected from the group consisting of phenyl, naphthalene, anthracene, phenanthrene, pyrene and the like in the structure. For example, Eastman's piccotex® and the like may be used as the additive. The additive may be prepared from a mixture of purified aromatics.

In one embodiment, the content of the additive may be 0.01 to 5% by weight, more specifically 0.5 to 3% by weight based on the total weight of the composition. When the content of the additive is increased, the peeling force is increased to improve the adhesive performance, but the workability is worsened as the pressure-sensitive adhesive becomes too soft after curing. Therefore, the content of the additive should be limited to a certain level, on the contrary, when the content of the additive is too small, the effect of improving the peeling force may be insignificant.

It is preferable that the resin component which comprises the adhesive composition which concerns on this invention does not contain a carboxyl group as a crosslinkable functional group. For example, when the pressure-sensitive adhesive layer is composed of acrylic resin, it is preferable not to use a monomer having a carboxyl group, such as acrylic acid, as the monomer forming the acrylic resin. Since the carboxyl group is a functional group capable of imparting high glass transition temperature and adhesive force to the pressure-sensitive adhesive, the functional group mainly used for the pressure-sensitive adhesive, but the inventors of the present invention, the resin having a carboxyl group is present in the pressure-sensitive adhesive composition, the pressure-sensitive adhesive formed of the composition as described above When applied to a touch panel or the like, the pressure-sensitive adhesive has found that the effect of suppressing the resistance change of the transparent electrode is very weak.

In the present invention, the pressure-sensitive adhesive composition, for example, pressure-sensitive adhesive composition comprising an acrylic resin and a multifunctional crosslinking agent; Or it may be a cured product of the silicone pressure-sensitive adhesive composition.

In the present invention, when the pressure-sensitive adhesive composition includes an pressure-sensitive adhesive composition containing an acrylic resin and a polyfunctional crosslinking agent, the acrylic resin may be, for example, a polymer of a monomer mixture containing a (meth) acrylic acid ester monomer and a crosslinkable monomer. In this case, the crosslinkable monomer may be a crosslinkable monomer composed of a hydroxyl group-containing monomer.

In the present invention, "crosslinkable monomer composed of hydroxy group-containing monomer" means that the crosslinkable monomer included in the monomer mixture includes only hydroxy group-containing monomers among the crosslinkable monomers conventional in the adhesive field. That is, when a carboxyl group-containing monomer, a nitrogen-containing monomer, etc. are used as a crosslinkable monomer, it is excluded from the range of the said term. As mentioned above, when the said monomer mixture contains especially a carboxyl group-containing monomer, there exists a possibility that the effect which a pressure-sensitive adhesive suppresses the resistance change of a transparent electrode may fall.

In the present invention, the type of the (meth) acrylic acid ester monomer is not particularly limited, and may be, for example, alkyl (meth) acrylate. In this case, when the alkyl group contained in the monomer is too long, the cohesive force of the cured product may be lowered, and the glass transition temperature and the adhesiveness may become difficult to control. Therefore, the alkyl group having 1 to 14 carbon atoms, preferably 1 to 8 carbon atoms Alkyl (meth) acrylates having 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, Isooctyl (meth) acrylate, isobonyl (meth) acrylate, isononyl (meth) acrylate, etc. are mentioned, In the present invention, a mixture of one or more of the above can be used.

In the present invention, the (meth) acrylic acid ester monomer included in the monomer mixture is preferably composed of a monomer having at least a part hydrophobic. Such hydrophobic monomers can increase the wettability of the pressure-sensitive adhesive to improve durability, and at the same time, improve the moisture resistance and double the effect of suppressing the resistance change of the transparent electrode. Typically the hydrophobicity or hydrophilicity of a monomer is associated with the polarity of that monomer. For example, when a monomer has high polarity, it has high affinity with polar solvents, such as water and alcohol, and is classified as a hydrophilic monomer. On the contrary, when the monomer exhibits nonpolarity, the affinity with the hydrophilic solvent may be greatly reduced, and thus may be classified as a hydrophobic monomer. Typically, when a monomer contains atoms such as oxygen or nitrogen, a non-uniform distribution of electrons present in the monomer is induced, and such monomers are classified as hydrophilic monomers. From this point of view, in the case of the (meth) acrylic acid ester monomer, it is generally polarized by an ester bond or a carbon-carbon double bond, thereby exhibiting hydrophilicity. However, if the backbone included in the (meth) acrylic acid ester monomer is properly controlled, the inherent polarity of the monomer can be effectively canceled, and thus the monomer can act as a non-polar hydrophobic monomer as a whole. have. Accordingly, in the present invention, examples of the hydrophobic monomer that can be used may be an alkyl (meth) acrylate having an alkyl group having 4 to 20 carbon atoms, preferably 4 to 16 carbon atoms. Such monomers are non-polar due to the characteristics of the alkyl group constituting the skeleton, and exhibit high resistance to polar substances (ex. Moisture). Accordingly, the polymer of such a monomer can impart excellent moisture resistance to the pressure-sensitive adhesive. In addition, the hydrophobic monomers exhibit excellent resistance to UV or thermal degradation, and thus the durability of the pressure-sensitive adhesive of the present invention can be significantly improved. Specific examples of such hydrophobic monomers that can be used in the present invention include octyl (meth) acrylate, 4-methyl-2-pentyl (meth) acrylate, 2-methylbutyl (meth) acrylate, isoamyl (meth ) Acrylate, sec-butyl (meth) acrylate, n-butyl (meth) acrylate, ethylhexyl (meth) acrylate, decyl (meth) acrylate, isononyl (meth) acrylate, stearyl (meth) And at least one selected from the group consisting of acrylate, lauryl (meth) acrylate, isotridecyl (meth) acrylate, cyclohexyl (meth) acrylate and isobornyl (meth) acrylate. Consisting of ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, lauryl (meth) acrylate and stearyl (meth) acrylate. It can be used at least one selected from the group.

In the present invention, the ratio of the hydrophobic monomer contained in the (meth) acrylic acid ester monomer is not particularly limited. That is, in the present invention, the entirety of the (meth) acrylic acid ester monomer may be composed of the hydrophobic monomer, and only some of the (meth) acrylic acid ester monomers may be composed of the hydrophobic monomer. When a part of the (meth) acrylic acid ester monomer is composed of a hydrophobic monomer, the content thereof is not particularly limited, and may be appropriately controlled in consideration of a desired moisture resistance improving effect and the like.

In the present invention, the crosslinkable monomer included in the monomer mixture means a monomer having a polymerizable functional group (eg, carbon-carbon double bond) and a crosslinkable functional group in the molecular structure at the same time, and as described above, the first pressure-sensitive adhesive layer When forming the above, it is preferable that the crosslinkable monomer is constituted only of the hydroxy group-containing monomer containing a hydroxy group as the crosslinkable functional group. In this case, the kind of hydroxy group-containing monomer that can be used is not particularly limited, and for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth ) Acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 2-hydroxyethylene glycol (meth) acrylate and 2-hydroxypropylene glycol (meth) acrylate It may be one kind or a mixture of two or more selected from the group consisting of.

In the present invention, the monomer mixture is 70 to 95 parts by weight of the (meth) acrylic acid ester monomer and 5 to 30 parts by weight of the crosslinkable monomer, preferably 80 to 90 parts by weight of the (meth) acrylic acid ester monomer Parts and 10 parts by weight to 25 parts by weight of the crosslinkable monomer. If the content of the (meth) acrylic acid ester monomer in the monomer mixture is less than 70 parts by weight, the initial adhesive force may be lowered. If the content is more than 95 parts by weight, the durability may be caused due to the decrease in cohesion. In addition, when the content of the crosslinkable monomer in the monomer mixture is less than 5 parts by weight, physical properties such as durability and durability of the cured product may deteriorate. When the content of the crosslinkable monomer exceeds 30 parts by weight, surface migration phenomenon may occur or flow characteristics may decrease or There is a fear that peeling or lifting occurs due to an increase in cohesion.

In this invention, the method of polymerizing the monomer mixture containing each component mentioned above and manufacturing acrylic resin is not specifically limited. In the present invention, for example, a general polymerization method such as solution polymerization, photopolymerization, bulk polymerization, suspension polymerization or emulsion polymerization can be used.

In the present invention, the acrylic pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive composition may include a polyfunctional crosslinking agent together with the acrylic resin.

The type of the multifunctional crosslinking agent that can be used in the present invention is not particularly limited, and for example, a general crosslinking agent such as an isocyanate compound, an epoxy compound, an aziridine compound, and a metal chelate compound can be used, of which isocyanate type Preference is given to using compounds, but not limited thereto. Examples of the isocyanate compound include tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isoborone diisocyanate, tetramethylxylene diisocyanate or naphthalene diisocyanate, or at least one of the above isocyanate compounds. And one or more kinds of reactants of a polyol (ex. Trimethylol propane). Examples of the epoxy compounds include ethylene glycol diglycidyl ether, triglycidyl ether, trimethylolpropane triglycidyl ether, N, N, N ', N'-tetraglycidyl ethylenediamine and glycerin digly At least one selected from the group consisting of cyl ether; Examples of aziridine compounds include N, N'-toluene-2,4-bis (1-aziridinecarboxamide), N, N'-diphenylmethane-4,4'-bis (1-aziridinecarboxes) Mid), triethylene melamine, bisisoprotaloyl-1- (2-methylaziridine), and tri-1-aziridinylphosphine oxide. Examples of the metal chelate compound include compounds in which one or more kinds of polyvalent metals such as aluminum, iron, zinc, tin, titanium, antimony, magnesium, and vanadium are coordinated with acetyl acetone, ethyl acetoacetate, or the like. However, it is not limited thereto.

In the present invention, the multifunctional crosslinking agent may be included in an amount of 0.01 to 10 parts by weight, preferably 0.01 to 5 parts by weight, based on 100 parts by weight of the acrylic resin. If the content of the polyfunctional crosslinking agent is less than 0.01 part by weight, the cohesive force of the cured product may be lowered. If the content of the multifunctional crosslinking agent is more than 10 parts by weight, the durability may be lowered such as delamination or lifting.

In the present invention, the acrylic pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive composition may further include a silane coupling agent as necessary. The coupling agent may improve adhesion and adhesion stability to the adherend, thereby improving heat resistance and moisture resistance. In addition, when appropriately added, the coupling agent may improve the adhesion reliability under high temperature or high humidity.

As a kind of silane coupling agent which can be used by this invention, for example, (gamma)-glycidoxy propyl trimethoxy silane, (gamma)-glycidoxy propylmethyl diethoxy silane, (gamma)-glycidoxy propyl triethoxy Silane, 3-mercaptopropyltrimethoxy silane, vinyltrimethoxy silane, vinyltriethoxy silane, γ-methacryloxypropyltrimethoxy silane, γ-methacryloxypropyltriethoxy silane, γ-aminopropyl Trimethoxy silane, γ-aminopropyltriethoxy silane, 3-isocyanatepropyltriethoxy silane, or γ-acetoacetatetripropyltrimethoxy silane, and the like, or a mixture of two or more thereof, but is not limited thereto. .

In the present invention, when the silane coupling agent is included in the pressure-sensitive adhesive composition, it may be included in an amount of 0.005 parts by weight to 5 parts by weight based on 100 parts by weight of the acrylic resin. If the content of the silane coupling agent is less than 0.005 parts by weight, the effect of the addition of the coupling agent may be insignificant. If the content of the silane coupling agent is more than 5 parts by weight, the durability may be lowered such as bubbles or peeling phenomenon.

In the present invention, the acrylic pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive composition may further include a tackifying resin as necessary.

As tackifying resin in this invention, For example, Hydrocarbon-type resin or its hydrogenated substance; Rosin resins or their hydrogenated materials; Rosin ester resins or hydrogenated substances thereof; Terpene resins or hydrogenated substances thereof; Terpene phenol resins or hydrogenated substances thereof; One kind or a mixture of two or more kinds of polymerized rosin resins or polymerized rosin ester resins may be used, but is not limited thereto.

In the present invention, when the pressure-sensitive adhesive composition includes a tackifying resin, it may be included in an amount of 1 part by weight to 100 parts by weight based on 100 parts by weight of the acrylic resin. When the content of the tackifying resin is less than 1 part by weight, the effect due to the addition of the tackifying resin may be insignificant. When the content of the tackifying resin exceeds 100 parts by weight, the compatibility or cohesion improvement effect may be lowered.

In the present invention, the acrylic pressure-sensitive adhesive composition constituting the first pressure-sensitive adhesive layer is an epoxy resin, a crosslinking agent, an ultraviolet stabilizer, an antioxidant, a colorant, a reinforcing agent, a filler, an antifoaming agent, a surfactant, and a plasticizer within a range that does not affect the effect of the invention. It may further comprise one or more additives selected from the group consisting of.

In the present invention, the pressure-sensitive adhesive composition may be a silicone pressure-sensitive adhesive composition in some cases. In this case, the kind of silicone pressure-sensitive adhesive composition to be used is not particularly limited, and may be, for example, a heat curable composition or an ultraviolet curable composition.

In one example of the present invention, the heat curable silicone-based composition may include a composition cured by a hydrosilylation reaction; Compositions cured by condensation reaction of silanol; Or an alcohol desorption type, an oxim desorption type, or an acetic acid desorption type silicone-based composition, but is not limited thereto. Moreover, as an example of an ultraviolet curable silicone type composition, (meth) acryl functional silicone, silicone which has a vinyl group and a mercapto group as a functional group, epoxy functional silicone, vinyl ether functional silicone, silanol functional silicone (poly (silsesqui) Oxane) or a composition comprising poly (silsesquioxane) and tetraphenoxysilane, or a curable composition including a siloxane polymer and a base generating material, but is not limited thereto.

In one example of the present invention, the silicone pressure-sensitive adhesive composition, an addition-curable silicone composition, specifically (i) an organopolysiloxane having two or more alkenyl groups in the molecule, (ii) two or more silicon-bonded hydrogen atoms in the molecule The branch may be a composition comprising an organopolysiloxane and (iii) a platinum based curing catalyst.

In the addition-curable silicone composition, the organopolysiloxane (i) contains at least two alkenyl groups in one molecule as main components of the silicone-based cured product. In this case, specific examples of the alkenyl group include a vinyl group, allyl group, butenyl group, pentenyl group, hexenyl group, or heptenyl group, and the like, but a vinyl group is preferable, but is not limited thereto. (i) In the organopolysiloxane, the bonding position of the aforementioned alkenyl group is not particularly limited. For example, the alkenyl group may be bonded to the terminal of the molecular chain and / or the side chain of the molecular chain.

Further, in (i) organopolysiloxane, examples of the substituent which may be included in addition to the alkenyl described above include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group or heptyl group; Aryl groups such as phenyl group, tolyl group, xylyl group or naphthyl group; Aralkyl groups such as benzyl or phenentyl; Halogen-substituted alkyl groups such as chloromethyl group, 3-chloropropyl group or 3,3,3-trifluoropropyl group.

In the present invention, (i) the organopolysiloxane may have any molecular structure, including, for example, linear, branched, cyclic, networked or linear form partly branched. In the present invention, it is preferable to have a linear molecular structure among the above molecular structures, but is not limited thereto.

More specific examples of (i) organopolysiloxane that can be used in the present invention include molecular chain sock end trimethylsiloxane group blockade dimethylsiloxane-methylvinylsiloxane copolymer, molecular chain sock end trimethylsiloxane group blockade methylvinylpolysiloxane, molecular chain sock. Short Trimethylsiloxane Group Blocked Dimethylsiloxane-Methylvinylsiloxane-Methylphenylsiloxane Copolymer, Molecular Chain Socks End dimethylvinylsiloxane Group Blocked Dimethylpolysiloxane, Molecular Chain Socks End Dimethylvinylsiloxane Group Blocked Methylvinylpolysiloxane, Molecular Chain Socks End Dimethylvinylsiloxane Group blocked dimethylsiloxane-methylvinylsiloxane copolymer, a molecular chain, both ends dimethylvinylsiloxy group blocked dimethylsiloxane-methylvinylsiloxane-methylphenylsiloxane copolymer, and R ¹ ₂ SiO siloxane units and R ^{1 ₂} R ₂ SiO represented by _1/2 siloxane units represented by _1/2 and SiO _4/2 O containing a siloxane unit represented by the Organopolysiloxane _{^{copolymer, R 1 2 R 2 SiO 1}} /2 climb comprising a siloxane unit represented by the siloxane unit, and SiO _4/2 represented by the organopolysiloxane _{^{copolymer, R 1 R 2 SiO 2/}} 2 siloxane represented by but it is the units and R ¹ SiO _3/2, organopolysiloxane copolymer and a mixture of two or more of the above containing a siloxane unit represented by the siloxane units, or R ² SiO _3/2 represented by, but is not limited thereto.

In the above, R ¹ is a hydrocarbon group other than an alkenyl group, and specifically, an alkyl group such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group or heptyl group; Aryl groups such as phenyl group, tolyl group, xylyl group or naphthyl group; Aralkyl groups such as benzyl or phenentyl; Halogen substituted alkyl groups such as chloromethyl group, 3-chloropropyl group or 3,3,3-trifluoropropyl group. In addition, R2 is an alkenyl group, and specifically, may be a vinyl group, allyl group, butenyl group, pentenyl group, hexenyl group, or heptenyl group.

In the addition-curable silicone-based composition, (ii) the organopolysiloxane may serve to crosslink the (i) organopolysiloxane. In the organopolysiloxane (ii), the bonding position of the hydrogen atom is not particularly limited, and may be, for example, bonded to the terminal and / or side chain of the molecular chain. Further, in the (ii) organopolysiloxane, the type of substituents that may be included in addition to the silicon-bonded hydrogen atom is not particularly limited, and examples thereof include alkyl groups, aryl groups, and the like, as mentioned in (i) organopolysiloxanes. Aralkyl group, a halogen substituted alkyl group, etc. are mentioned.

On the other hand, (ii) the organopolysiloxane may have any molecular structure, such as (i) organopolysiloxane, including linear, branched, cyclic, networked, linear or partially branched. have. In the present invention, it is preferable to have a linear molecular structure among the above molecular structures, but is not limited thereto.

More specific examples of the (ii) organopolysiloxane which can be used in the present invention include molecular chain sock end trimethylsiloxane group blocked methylhydrogenpolysiloxane, molecular chain sock end trimethylsiloxane group blocked dimethylsiloxane-methylhydrogen copolymer, molecule Chain Socks End Trimethylsiloxane Group Blockade Dimethylsiloxane-Methylhydrogensiloxane-Methylphenylsiloxane Copolymer, Molecular Chain Socks End Dimethylhydrogensiloxane Blockade Dimethylpolysiloxane, Molecular Chain Socks End Dimethylhydrogensiloxane Blockade Dimethylsiloxane-Methylphenylsiloxane Copolymer , the siloxane unit represented by a molecular chain, both ends dimethyl hydrogen siloxane group containment methylphenyl polysiloxane, R _{¹ 3} SiO _^1/2 siloxane units and R ¹ ₂ HSiO _1/2 siloxane units and SiO _4/2 represented by the represented by the containing organopolysiloxane copolymer, R ¹ ₂ HSiO siloxane stage represented by _1/2 Above and SiO _4/2 represented by the organopolysiloxane copolymer, R ¹ HSiO _2/2 siloxane units, or HSiO _3/2 and siloxane units represented by R ¹ SiO _3/2 represented by containing a siloxane unit represented by the Organopolysiloxane copolymers comprising siloxane units and mixtures of two or more of the above, but are not limited thereto. In the above, R ¹ is a hydrocarbon group other than an alkenyl group, and specifically, an alkyl group such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group or heptyl group; Aryl groups such as phenyl group, tolyl group, xylyl group or naphthyl group; Aralkyl groups such as benzyl or phenentyl; Halogen substituted alkyl groups such as chloromethyl group, 3-chloropropyl group or 3,3,3-trifluoropropyl group.

In one aspect of the invention, the content of (ii) organopolysiloxane is not particularly limited as long as it is included to the extent that appropriate curing can be achieved. For example, (ii) the organopolysiloxane may be contained in an amount such that 0.5 to 10 silicon-bonded hydrogen atoms are included with respect to one alkenyl group included in (i) the organopolysiloxane. If the number of silicon atom-bonded hydrogen atoms is less than 0.5, the curing of the curable silicone compound may be insufficient, and if more than 10, the heat resistance of the cured product may be lowered.

In the addition-curable silicone-based composition (iii) the platinum-based curing catalyst, for example, platinum fine powder, platinum black, platinum-supported silica fine powder, platinum-supported activated carbon, chloroplatinic acid, platinum tetrachloride, alcohol solution of chloroplatinic acid, complex of platinum and olefin Fine powder of platinum and alkenylsiloxane such as 1,1,1,3,3-tetramethyl-1,3-divinyldisiloxane, and a particle diameter containing these platinum or platinum compounds of less than 10 µm Polystyrene resin, nylon resin, polycarbonate resin, silicone resin, etc.), but is not limited thereto.

The content of the catalyst described above in the addition-curable silicone-based composition of the present invention is not particularly limited, and may be included, for example, in an amount of 0.1 to 500 ppm, preferably 1 to 50 ppm by weight in the total silicone-based composition. When content of the said catalyst is less than 0.1 ppm, there exists a possibility that sclerosis | hardenability of a composition may fall, and when it exceeds 500 ppm, there exists a possibility that economy may fall.

In one aspect of the present invention, the addition-curable silicone compound is 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyne- from the viewpoint of improving its storage stability, handleability and workability. Alkyne alcohols such as 3-ol and phenylbutynol; Enyne compounds such as 3-methyl-3-penten-1-yne and 3,5-dimethyl-3-hexen-1-yne; 1,2,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetrahexenylcyclotetrasiloxane And a hardening inhibitor such as benzotriazole. The content of the hardening inhibitor may be appropriately selected from a range that does not impair the object of the invention, for example, it may be included in the range of 10 ppm to 50,000 ppm by weight.

The present invention provides an adhesive film for a touch panel including the adhesive composition.

The configuration of the pressure-sensitive adhesive film is not particularly limited, and includes, for example, a pressure-sensitive adhesive layer formed on one side or both sides of the base film, and the pressure-sensitive adhesive layer may include the pressure-sensitive adhesive composition described above.

The specific kind of the base film used in the present invention is not particularly limited, and for example, a general plastic film in this field may be used. In the present invention, for example, polyethylene terephthalate film, polytetrafluoroethylene film, polyethylene film, polypropylene film, polybutene film, polybutadiene film, vinyl chloride copolymer film, polyurethane film, Ethylene-vinyl acetate films, ethylene-propylene copolymer films, ethylene-ethyl acrylate copolymer films, ethylene-methyl acrylate copolymer films, polyimide films and the like can be used.

The method of hardening each adhesive composition mentioned above by this invention and manufacturing the said adhesive film is not specifically limited. In this invention, an adhesive layer can be manufactured by the method of apply | coating the said adhesive composition or the coating liquid manufactured using the same to a suitable process base material by normal means, such as a bar coater, for example, and hardening. In the present invention, the curing process is preferably performed after sufficiently removing the bubble-inducing components such as volatile components or reaction residues contained in the pressure-sensitive adhesive composition or coating liquid. As a result, the crosslinking density or molecular weight of the pressure-sensitive adhesive is too low, the elastic modulus is lowered, and bubbles present at the pressure-sensitive interface in the high temperature state become large, thereby preventing problems such as forming scattering bodies therein.

In addition, the method of curing the pressure-sensitive adhesive composition or the coating liquid is not particularly limited, and for example, curing through appropriate heating, drying and / or aging processes, or curing by electromagnetic wave irradiation such as ultraviolet rays (UV). The method can be adopted.

In the present invention, the pressure-sensitive adhesive layer may be manufactured through the above-described process, and the laminate may be manufactured to laminate the pressure-sensitive adhesive film. If necessary, one pressure-sensitive adhesive layer may be formed first, and another pressure-sensitive adhesive layer may be directly formed thereon. The pressure-sensitive adhesive film can be produced.

In the present invention, if necessary, the corona treatment may be performed in the process of forming the pressure-sensitive adhesive layer, and the corona treatment may use a known means commonly used in the art.

In the present invention, the thickness of the base film as described above is not particularly limited, and may be appropriately selected depending on the intended use. For example, the thickness of the base film in the present invention may be 12 ㎛ to 50 ㎛, preferably 20 ㎛ to 40 ㎛ or so.

The adhesive film may have a thickness of 10 to 200 μm, specifically 50 μm to 150 μm, and more preferably 50 μm to 100 μm. In the present invention, by controlling the thickness of the pressure-sensitive adhesive film in a predetermined range, the pressure-sensitive adhesive can exhibit physical properties such as excellent heat resistance and resistance change suppressing ability, while configuring the touch panel or the touch screen to be thinner.

In addition, the present invention provides a touch screen or a touch panel including the adhesive film. The touch panel to which the adhesive film of the present invention is applied may be a resistive touch panel or a capacitive touch panel. In addition, as long as the adhesive film of the present invention is applied, the specific structure of the touch panel to which the adhesive film of the present invention is applied or the method of forming the same is not particularly limited, and a general configuration in this field may be adopted.

1 is a cross-sectional view illustrating a general application structure of a touch screen panel. Referring to FIG. 1, a touch panel 100, a display 200, and a main board 300 may be stacked, and the touch panel 100 and the main board 300 may be connected to an FPC (Flexible Printed Circuit) 110. It is connected by the structure. In addition, the laminated structure surrounds the edge portion by the bezel 400. The pressure-sensitive adhesive composition or pressure-sensitive adhesive film according to an embodiment of the present invention may be located between each component constituting the touch screen panel, for example, on the top 500 or the bottom 600 of the touch panel 100. Can be located.

Figure 2 shows a cross-sectional structure of the adhesive film according to an embodiment of the present invention. Referring to FIG. 2, the pressure-sensitive adhesive film according to the present invention may have a single layer structure, but may have a structure in which the first pressure-sensitive adhesive layer 10 and the second pressure-sensitive adhesive layer 30 are formed on the top and bottom of the base film 20, respectively. have. If necessary, any one of the first pressure sensitive adhesive layer 10 and the second pressure sensitive adhesive layer 30 can be omitted.

The present invention will be described in more detail with reference to the following examples. The embodiments of the present invention are only for the detailed description of the present invention, and are not intended to limit the scope thereof.

Example  One

55 parts by weight of ethylhexyl acrylate (EHA), 25 parts by weight of methyl acrylate (MA), and hydroxyethyl acrylate (HEA) 20 in a 1 L reactor equipped with a refrigeration device for nitrogen gas reflux and for easy temperature control. By weight, ethyl acetate (EAc) was added as a solvent. Subsequently, nitrogen gas was purged for about 1 hour for oxygen removal, the temperature was kept at 62 ° C, the mixture was homogenized, and then azobisisobutyronitrile diluted to 50% concentration in ethyl acetate as a reaction initiator. (AIBN) 0.03 part by weight was added. Subsequently, the mixture was reacted for about 8 hours to prepare a resin composition.

To 100 parts by weight of the resin composition prepared, an aromatic hydrocarbon additive (Eastman PICCOTEX® 1.0 parts by weight is added, 0.5 parts by weight of a bifunctional isocyanate-based crosslinking agent and 0.3 parts by weight of an epoxy-based silane coupling agent as a polyfunctional crosslinking agent, to mix the pressure-sensitive adhesive composition The coating solution was coated on a release surface of a release-treated PET film (thickness: 50 μm), dried at a temperature of about 100 ° C. for about 5 minutes, and then subjected to appropriate conditions. It matured at and formed the adhesive layer.

The prepared pressure-sensitive adhesive layer was laminated using a roller of 2 kg at room temperature, thereby preparing a pressure-sensitive adhesive film having a thickness of 35 μm.

Example  2

An adhesive film was prepared in the same manner as in Example 1, except that 2.5% by weight of an aromatic hydrocarbon additive (Eastman PICCOTEX®) was blended.

Comparative example  One

55 parts by weight of ethylhexyl acrylate (EHA), 25 parts by weight of methyl acrylate (MA), and hydroxyethyl acrylate (HEA) 20 in a 1 L reactor equipped with a refrigeration device for nitrogen gas reflux and easy temperature control. Parts by weight were added, and ethyl acetate (EAc) was added as a solvent. Subsequently, nitrogen gas was purged for about 1 hour for oxygen removal, the temperature was kept at 62 ° C, the mixture was homogenized, and then azobisisobutyronitrile diluted to 50% concentration in ethyl acetate as a reaction initiator. (AIBN) 0.03 part by weight was added. Subsequently, the mixture was reacted for about 8 hours to prepare a resin composition.

As a polyfunctional crosslinking agent, 0.5 weight part of bifunctional isocyanate type crosslinking agents and 0.3 weight part of epoxy type silane coupling agents were mix | blended with respect to 100 weight part of prepared resin compositions, and the adhesive composition was prepared, and it diluted with the solvent and prepared the coating liquid. The prepared coating solution was coated on a release treated surface of a release treated PET film (thickness 50 μm), dried at a temperature of about 100 ° C. for about 5 minutes, and aged at an appropriate condition to form an adhesive layer.

The prepared pressure-sensitive adhesive layer was laminated using a roller of 2 kg at room temperature, thereby preparing a pressure-sensitive adhesive film having a thickness of 35 μm.

Comparative example  2

Comparative Example 1, except that 55 parts by weight of ethylhexyl acrylate (EHA), 20 parts by weight of methyl acrylate (MA), 20 parts by weight of hydroxyethyl acrylate (HEA), and 5 parts by weight of acrylic acid were added. An adhesive film was prepared in the same manner as the above.

Comparative example  3

Adhesive film in the same manner as in Comparative Example 1, except that 55 parts by weight of ethylhexyl acrylate (EHA), 20 parts by weight of methyl acrylate (MA) and 25 parts by weight of hydroxyethyl acrylate (HEA) were added. Was prepared.

Experimental Example  1: Comparison of resistance change rate

Samples were prepared for the pressure-sensitive adhesive films prepared in Examples 1 to 3 and Comparative Examples 1 and 2 to measure the resistance change rate. Specifically, an ITO layer is formed on one surface, and a size of 5 cm x 3 cm (width x length), and on the ITO surface of the conductive film having a silver electrode layer having a width of 1 cm at both edge portions, is compared with Examples and The adhesive film produced in the example was cut and attached to a size of 4 cm x 3 cm (width x length). The adhesive film was produced to cover half of the silver electrode formed on the ITO surface.

Immediately after the sample was prepared, the initial resistance Ri of the ITO was measured using 3324 Cardhitester (manufactured by Hioki). The same sample was then left for 10 days in a constant temperature and humidity chamber (temperature: 60 ° C. and relative humidity 90% R.H.), and then the resistance value Rl of the ITO was measured using the same measuring instrument. Based on the measured result, the resistance change rate was converted into%.

Resistance change rate (%) = [(resistance after 30 days-initial resistance) / initial resistance] X 100

The converted results are shown in Figure 1 and Table 1.

Resin composition After 30 days,% change in resistance EHA MA HEA AA additive Example 1 55 25 20 - 1.0 5% Example 2 55 25 20 - 2.5 6% Comparative Example 1 55 25 20 - - 5% Comparative Example 2 55 20 20 5 - 145% Comparative Example 3 55 20 25 - - 6%

From the results of FIG. 1 and Table 1, the conventional pressure-sensitive adhesive composition (comparative example 2) containing acrylic acid (AA) showed a resistance change rate of 145%, which is significantly higher than the case where no acrylic acid was added. .

Experimental Example  2: Peel force  compare

Samples were prepared for the pressure-sensitive adhesive films prepared in Examples 1 to 3 and Comparative Examples 1 and 2 to compare and measure the peel force. Specifically, each sample was cut to 2.5 cm wide and then 2 kg rolls were reciprocated four times to attach on the ITO face. After attachment for 1 day at room temperature, 180 ° peeling force (g / in) was measured. As a backing film, untreated PET having a thickness of 50 μm was used. When the results of Experimental Example 1 and Experimental Example 2 are combined, it is as shown in Table 2 below.

Resin composition 180 ° peeling (g / in) EHA MA HEA AA additive Example 1 55 25 20 - 1.0 1,124 Example 2 55 25 20 - 2.5 1,233 Comparative Example 1 55 25 20 - - 620 Comparative Example 2 55 20 20 5 - 1,110 Comparative Example 3 55 20 25 - - 650

From the results in Table 2, the conventional pressure-sensitive adhesive composition (Comparative Example 2) containing acrylic acid (AA) was found to be unstable due to a very high resistance change rate, whereas the pressure-sensitive adhesive compositions (Comparative Examples 1 and 3) without containing acrylic acid were peeled off. It can be seen that the force is significantly reduced. On the other hand, although the adhesive composition which concerns on this invention is not mix | blended with acrylic acid, it turns out that peeling force is comparatively excellent and resistance change rate is also low.

10: first pressure-sensitive adhesive layer 20: base film
30: second pressure sensitive adhesive layer 100: touch panel
110: FPC 200: display
300: motherboard 400: bezel
500, 600: Adhesive film insertion position

Claims (7)

As an adhesive composition for touch panels,
The pressure-sensitive adhesive composition which satisfies the following general formulas 1 and 2 and comprises an aromatic hydrocarbon additive of a non-acrylic acid type having a weight average molecular weight of 500 to 10,000:
[Formula 1]
% Change in resistance to ITO plane ≤ 15
[Formula 2]
Peel strength ≥ 1000 g / in. The method of claim 1,
The amount of the additive is 0.01 to 5% by weight based on the total weight of the composition of the pressure-sensitive adhesive composition. The adhesive film for touch panels containing the adhesive composition of Claim 1 or 2 or its hardened | cured material. The method of claim 3, wherein
It includes an adhesive layer formed on one side or both sides of the base film,
The adhesive layer contains the said adhesive composition or its hardened | cured material. The method of claim 3, wherein
The adhesive film is 10-200 micrometers in thickness. The method of claim 4, wherein
The thickness of the base film is 12 to 50 ㎛ adhesive film. Touch panel comprising an adhesive film according to claim 3.

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