KR102056600B1 - Crosslinkable composition - Google Patents

Abstract

The present application relates to a crosslinkable composition. The crosslinkable composition of the present application can form a pressure-sensitive adhesive excellent in durability reliability, stress relief and reworkability. Incidentally, when the crosslinkable composition is used, for example, the coating process can be efficiently carried out even in a state where the coating solid content is kept high, thereby maintaining excellent productivity and forming an adhesive having excellent thickness uniformity and the like. Can be. The crosslinkable composition can be used for an optical film such as, for example, a polarizing plate.

Description

Crosslinkable composition

The present application relates to crosslinkable compositions and uses thereof.

The crosslinkable composition can be applied to various applications. For example, the crosslinkable composition can be used to form an adhesive or an adhesive. Such an adhesive or an adhesive may, for example, bond a display panel and an optical film or a conductive film to each other in a display device such as a liquid crystal display device (LCD), an organic light emitting display (OLED), or a plasma display panel (PDP). It can be used for use.

The main physical properties required in the composition to be applied to the above applications include cohesive force, adhesive force, reworkability, low light leakage properties and stress relaxation properties, and in Patent Documents 1 to 3 and the like, crosslinking properties for achieving the above properties A composition is proposed.

As various display devices have recently been thinned, components applied to the display apparatus, for example, glass substrates, conductive films, and other optical films tend to be thin, and such a thin component includes a large problem in the past. The problem by the bending which has not been made is large.

Patent Document 1: Republic of Korea Patent No. 1023839 Patent Document 2: Republic of Korea Patent No. 1171976 Patent Document 3: Republic of Korea Patent No. 1171977

The present application relates to a crosslinkable composition and its use. In the present application, there is provided a crosslinkable composition capable of forming a layer having the required physical properties such as cohesion, adhesive force, reworkability, low light leakage property and stress relaxation, and at the same time excellent in curvature suppression ability, particularly at high temperature. Can be.

The term crosslinkable composition means a composition comprising a component capable of forming a crosslinked structure. In the above, the crosslinked structure may mean chemical crosslinked structure or physical crosslinked structure. The crosslinkable composition of the present application comprises a block copolymer capable of forming physical crosslinking itself by so-called phase separation or self-assembly characteristics, and by introducing a crosslinkable functional group capable of chemical crosslinking into the block copolymer, if necessary It is possible to simultaneously form a physical crosslinked structure and a chemical crosslinked structure.

Such a crosslinkable composition may be, for example, an adhesive composition or an adhesive composition. In the above, the pressure-sensitive adhesive composition or adhesive composition may refer to a composition including a cross-linked structure or a composition capable of exhibiting properties of the pressure-sensitive adhesive or adhesive before the cross-linked structure is formed.

When the crosslinkable composition is used as an adhesive composition or an adhesive composition, the crosslinkable composition may be included as a main component of the adhesive or adhesive composition. In the present specification, that a component is included as a main component in a certain subject means that the component in the subject is 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, It may mean a case containing 75 wt% or more, 80 wt% or more, 85 wt% or more, or 90 wt% or more. The upper limit of the content in the object of the component included as the main component is not particularly limited, and may be, for example, about 100% by weight. In addition, when the present application refers to the content of components in a composition, the content is based on the solids content of the composition.

Exemplary crosslinkable compositions can include block copolymers. As used herein, the term “block copolymer” may refer to a copolymer comprising blocks of different polymerized monomers. The crosslinkable composition may contain the block copolymer as a main component. In the present specification, when the crosslinkable composition includes the block copolymer as the base polymer, it may mean that the crosslinkable composition includes the block copolymer as a main component. Accordingly, the crosslinkable composition is 50% by weight, 55% by weight, 60% by weight, 65% by weight, 70% by weight, 75% by weight, 80% by weight of the block copolymer based on weight Or more, 85% by weight or more, or 90% by weight or more, and an upper limit of the ratio may be about 100% by weight. Weight percentages are based on the solids weight of the crosslinkable composition.

In one example, the block copolymer may include a first block having a glass transition temperature of 40 ° C. or more and a second block having a glass transition temperature of 0 ° C. or less. In the present specification, the "glass transition temperature of a predetermined block" of the block copolymer may mean a glass transition temperature measured from a polymer formed of only monomers included in the block or a glass transition temperature calculated based on the monomers. In one example, the glass transition temperature of the first block may be 50 ° C. or more, 60 ° C. or more, 65 ° C. or more, or 70 ° C. or more. The upper limit of the glass transition temperature of the first block is not particularly limited, but for example, the glass transition temperature may be about 150 ° C. or less, 140 ° C. or less, 130 ° C. or less or 120 ° C. or less. In addition, the glass transition temperature of the second block may be -10 ° C or less, -20 ° C or less, -30 ° C or less, -35 ° C or less, or -40 ° C or less. The lower limit of the glass transition temperature of the second block is not particularly limited. For example, the glass transition temperature of the second block is -80 ° C or higher, -70 ° C or higher, -60 ° C or higher, or -55 ° C. It may be more than enough. The block copolymer including at least two kinds of blocks may form an appropriate phase-separated structure. Such a block copolymer exhibits appropriate cohesion according to temperature change, while maintaining excellent physical properties such as durability, light leakage prevention properties, and reworkability, while suppressing warpage by causing the layer of the crosslinkable composition to exhibit excellent stress relaxation and flexibility. It can have a characteristic to.

In the block copolymer, the first block may have, for example, a number average molecular weight (Mn) of 2,500 to 150,000. The number average molecular weight of the first block may mean, for example, the number average molecular weight of the polymer prepared by polymerizing only the monomer forming the first block. The number average molecular weight referred to in the present specification can be measured by, for example, the method shown in the Examples by using GPC (Gel Permeation Chromatograph). In another example, the number average molecular weight of the first block may be at least 5,000, at least 7,000, at least 9,000, at least 10,000, at least 15,000, at least 20,000, at least 25,000, or at least about 30,000. In another example, the number average molecular weight of the first block may be about 130,000 or less, 110,000 or less, 100,000 or less, 90,000 or less, 80,000 or less, 70,000 or less, or about 65,000 or less.

The block copolymer may have a number average molecular weight of 50,000 to 300,000. The number average molecular weight of the block copolymer may in another example be at least 90,000, at least 100,000, at least 150,000 or at least about 200,000. The number average molecular weight of the block copolymer may also be about 280,000 or less, about 260,000 or less, or about 250,000 or less in another example.

The block copolymer may have a molecular weight distribution (PDI; Mw / Mn), that is, a ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) in the range of 1.0 to 4.0. The molecular weight distribution may in another example be at least about 1.2, at least about 1.4 or at least about 1.5. In addition, the molecular weight distribution may be about 3.5 or less, about 3 or less, or about 2.5 or less in another example.

By adjusting the molecular weight characteristics as described above it is possible to better maintain the above-mentioned physical properties.

In one example, the block copolymer may be a crosslinkable copolymer having a crosslinkable functional group. As a crosslinkable functional group, a hydroxyl group, a carboxyl group, an isocyanate group, a glycidyl group, etc. can be illustrated, For example, a hydroxyl group can be used.

When including a crosslinkable functional group, the functional group may be included in, for example, a second block having a low glass transition temperature. In one example, the first block having a high glass transition temperature may not include a crosslinkable functional group, and only the second block may include a crosslinkable functional group. When the crosslinkable functional group is included in the second block, the block copolymer capable of forming physical crosslinks by phase separation on its own has a crosslinking point at the soft portion to form a chemical crosslinked structure, thereby maintaining the above-described physical properties more effectively. Can be.

The type of monomers forming the first block and the second block in the block copolymer is not particularly limited as long as the above glass transition temperature is secured by the combination of the monomers.

In one example, the first block may include a polymerized unit derived from a (meth) acrylic acid ester monomer. In the present specification, that the monomer is included in the polymer or the block as a polymerized unit may mean that the monomer forms a backbone, for example, a main chain or a side chain of the polymer or block through a polymerization reaction. As said (meth) acrylic acid ester monomer, an alkyl (meth) acrylate can be used, for example. In one example, in consideration of the cohesion, glass transition temperature and adhesion control, etc., alkyl having an alkyl group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms or 1 to 4 carbon atoms ( Meta) 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, and lauryl (meth) acrylate, and the like, and the glass transition temperature of one or more of the above is ensured. It can be selected to use. Although not particularly limited, the monomers forming the first block in consideration of the ease of glass transition temperature control and the like are methacrylic acid ester monomers, for example, alkyl methacrylate, specifically, 1 Alkyl methacrylates having an alkyl group having from 20 to 1, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms or 1 to 4 carbon atoms can be used.

For example, the first block may include the alkyl methacrylate as a main component. Accordingly, the alkyl methacrylate may be at least 50 wt%, at least 55 wt%, at least 60 wt%, at least 65 wt%, at least 70 wt%, 75 based on the weight of the total monomer units forming the first block. At least 80% by weight, at least 85% by weight or at least 90% by weight may be included in the first block, and the upper limit of the ratio may be about 100% by weight.

The second block in the block copolymer may also include polymerized units derived from (meth) acrylic acid ester monomers. Although not particularly limited, the monomer forming the second block in consideration of the ease of glass transition temperature control, etc. may be an acrylic acid ester monomer, for example, an alkyl acrylate, specifically, 1 to 20 carbon atoms. Alkyl acrylates having an alkyl group having 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms or 1 to 4 carbon atoms can be used.

For example, the second block may contain the alkyl acrylate as a main component. Accordingly, the alkyl acrylate may be at least 50 wt%, at least 55 wt%, at least 60 wt%, at least 65 wt%, at least 70 wt%, 75 wt%, based on the weight of the total monomer units forming the second block. Or at least 80%, at least 85% or at least 90% by weight of the second block, and the upper limit of the ratio may be about 100% by weight.

The second block of the block copolymer may further include, for example, a copolymerizable monomer having a crosslinkable functional group. For example, the second block may include polymerized units derived from 90 parts by weight to 99.9 parts by weight of the (meth) acrylic acid ester monomer and 0.1 parts by weight to 10 parts by weight of the copolymerizable monomer having a crosslinkable functional group. . In the present specification, the unit weight part may mean a ratio of weights between components. For example, as described above, the second block may include polymerized units derived from 90 to 99.9 parts by weight of the (meth) acrylic acid ester monomer and 0.1 to 10 parts by weight of the copolymerizable monomer having a crosslinkable functional group. And the ratio (A: B) based on the weight of the (meth) acrylic acid ester monomer (A) and the copolymerizable monomer (B) having a crosslinkable functional group forming the polymerized unit of the second block is from 90 to 99.9: It may mean the case of 0.1 to 10.

As a copolymerizable monomer which has a crosslinkable functional group, for example, it has a site | part which can be copolymerized with the other monomer contained in a block copolymer like the said (meth) acrylic acid ester monomer, and also the above-mentioned crosslinkable functional group, an example For example, the monomer which has a hydroxyl group etc. can be used. Copolymerizable monomers having such crosslinkable functional groups are variously known in the field of pressure-sensitive adhesives, and all of these monomers may be used in the polymer. For example, as a copolymerizable monomer which has a hydroxyl group, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxy Hydroxyalkyl (meth) acrylates such as hexyl (meth) acrylate or 8-hydroxyoctyl (meth) acrylate, or 2-hydroxyethylene glycol (meth) acrylate or 2-hydroxypropylene glycol (meth) Hydroxyalkylene glycol (meth) acrylates such as acrylate may be used, but is not limited thereto. In consideration of the reactivity with other monomers forming the second block, the ease of controlling the glass transition temperature, etc., hydroxyalkyl acrylate or hydroxyalkylene glycol acrylate may be used among the above monomers. no.

The first block and / or the second block may further comprise other optional comonomers, if necessary, for example, for the control of the glass transition temperature, and the monomers may be included as polymerized units. have. As said comonomer, it is (meth) acrylonitrile, (meth) acrylamide, N-methyl (meth) acrylamide, N-butoxy methyl (meth) acrylamide, N-vinyl pyrrolidone, or N-vinyl capro Nitrogen-containing monomers such as lactams 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 comonomers may be included in the block copolymer, for example, in a ratio of 20 parts by weight or less, or 0.1 to 15 parts by weight, relative to the weight of other monomers in each block.

The block copolymer may include, for example, 10 parts by weight to 50 parts by weight of the first block and 50 parts by weight to 90 parts by weight of the second block. By adjusting the ratio of the weight between the first block and the second block as described above, it is possible to provide a crosslinkable composition and an adhesive of excellent physical properties. In another example, the block copolymer may include 5 parts by weight to 45 parts by weight of the first block and 55 parts by weight to 95 parts by weight of the second block, or 5 parts by weight to 45 parts by weight of the first block and 60 parts by weight of the second block. 95 parts by weight may be included.

In another example, the ratio of the second block based on the total content of the first and second blocks included in the block copolymer may be about 50 wt% to 90 wt%. The ratio may in another example be at least about 55% or at least about 60% by weight.

In one example, the block copolymer may be a diblock copolymer including the first and second blocks, that is, a block copolymer including only two blocks of the first and second blocks. . By using a diblock copolymer, the durability, stress relaxation property, and reworkability of an adhesive can be maintained more excellently.

The method for producing the block copolymer is not particularly limited and can be prepared in a conventional manner. The block polymer may be polymerized by, for example, a Living Radical Polymerization (LRP) method, for example, an organic rare earth metal complex may be used as a polymerization initiator, or an organic alkali metal compound may be used as a polymerization initiator. Anion polymerization method synthesized in the presence of an inorganic acid salt such as a salt, anion polymerization method synthesized in the presence of an organoaluminum compound using an organoalkali metal compound as a polymerization initiator, atom transfer radical polymerization using an atom transfer radical polymerizer as a polymerization controller Method (ATRP), activators regenerated by electron transfer (ARRP), which uses an atomic transfer radical polymerizer as a polymerization control agent and performs polymerization under an organic or inorganic reducing agent that generates electrons for continuous activator regeneration Atomic radical polymerization (ATRP), inorganic Reducing agent A reversible addition-cracking chain transfer polymerization method using a reversible addition-cracking chain transfer agent (RAFT) or a method using an organic tellurium compound as an initiator, etc., and an appropriate method can be selected and applied from these methods.

The crosslinkable composition may further include a crosslinking agent capable of crosslinking the block copolymer. As a crosslinking agent, the crosslinking agent which has at least two functional groups which can react with the crosslinkable functional group contained in the said block copolymer can be used. As such a crosslinking agent, an isocyanate crosslinking agent can be used.

In the present application, in order to impart optimum flexibility to the crosslinked structure formed by the block copolymer and improve the properties of the crosslinking agent, as the crosslinking agent, (B) a polyfunctional isocyanate crosslinking agent having no polyalkylene oxide chain; And (C) a mixture of polyfunctional isocyanate crosslinkers having polyalkylene oxide chains. The crosslinking agent (C) may be bifunctional. The polyfunctional or bifunctional mentioned above means the case where a crosslinking agent has two or more isocyanate groups, or the case where it has two. In the above (B) isocyanate crosslinking agent, for example, two or more isocyanate groups, 2 to 10, 2 to 9, 2 to 8, 2 to 7, 2 to 6, 2 Dogs or five or three to five.

(B) As an isocyanate crosslinking agent, diisocyanate, such as tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isoborone diisocyanate, tetramethyl xylene diisocyanate, or naphthalene diisocyanate, for example. A compound or a compound obtained by reacting the diisocyanate compound with a polyol can be used. As the polyol, for example, trimethylol propane can be used. For example, a variety of known isocyanate crosslinking agents are known in the field of production of pressure-sensitive adhesives.

As the (C) isocyanate crosslinking agent, for example, a compound represented by the following formula (1) can be used.

[Formula 1]

In Formula 1, A is an alkylene or alkylidene group having 1 to 4 carbon atoms, Ar ₁ and Ar ₂ are aryl groups substituted with one isocyanate group, L ₁ and L ₂ are linkers, and n is in the range of 2 to 60. It is the number within.

As the alkylene group or alkylidene group of A in Formula 1, an ethylene group or a propylene group may be exemplified.

Meanwhile, the aryl groups of Ar ₁ and Ar ₂ include one benzene ring structure, two or more benzene rings connected by sharing one or two carbon atoms, or connected by an arbitrary linker. The monovalent residue derived from the compound or its derivative (s) can be illustrated. Such aryl group may be, for example, an aryl group having 6 to 30 carbon atoms, 6 to 25 carbon atoms, 6 to 21 carbon atoms, 6 to 18 carbon atoms, or 6 to 13 carbon atoms, unless otherwise specified. Examples of the aryl group may include, but are not limited to, a phenyl group or a benzyl group.

In Formula 1, the aryl groups of Ar ₁ and Ar ₂ may be the same or different aryl groups from each other, and are each substituted with one isocyanate group. The aryl group may include other substituents in addition to the isocyanate group. In this case, examples of other substituents that may be included include, but are not limited to, an alkyl group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. For example, when the aryl group of Ar ₁ and Ar ₂ is a phenyl group, the isocyanate group is substituted at an ortho, meta, or para position based on a portion linked with L ₁ or L _2. It may be.

On the other hand, as a linker of L ₁ or L ₂ which may be the same or different from each other above, an oxygen atom, a sulfur atom, -NR _1- , -S (= 0) _2- , a carbonyl group, an alkylene group, an alkenylene group , Alkynylene group, -C (= O) -X _1- , -X ₁ -C (= O)-, -NR ₁ -C (= O) -X ₁ -or -X ₁ -C (= O) -NR ₁ -can be illustrated. In the above, R ₁ may be hydrogen, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group or an aryl group, and X ₁ may be an oxygen atom, a sulfur atom, an alkylene group, an alkenylene group or an alkynylene group.

As the alkyl group or the alkoxy group, a linear, branched or cyclic alkyl group or alkoxy group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms or 1 to 4 carbon atoms may be exemplified. It may be in a substituted or unsubstituted state.

As the alkylene group, a straight, branched or cyclic alkylene group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms or 1 to 4 carbon atoms may be exemplified, which may be substituted or It may be in an unsubstituted state.

As the alkenylene group, alkynylene group, alkenyl group or alkynyl group in the above, C2-C20, C2-C16, C2-C12, C2-C8 or C2-C4 linear, branched or cyclic Alkenylene groups, alkynylene groups, alkenyl groups or alkynyl groups may be exemplified, which may be in a substituted or unsubstituted state.

In addition, in the above range of the aryl group, the above-described range of the aryl group of Ar1 and Ar2 may be applied in the same manner except for the part substituted with an isocyanate group.

In Formula 1, n may be in the range of 2 to 60 or 10 to 60, and specifically, may be adjusted in a range satisfying the number average molecular weight described below.

As the (C) isocyanate crosslinking agent, the number average molecular weight may be in the range of about 500 to 10,000. In another example, the number average molecular weight may be about 700 or more, about 900 or more, about 1,100 or more, about 1,300 or more, about 1,500 or more, about 1,700 or more, or about 1,900 or more. In another example, the number average molecular weight may be about 9,000 or less, about 8,000 or less, about 7,000 or less, about 6,000 or less, about 5,000 or less, about 4,000 or less, or about 3,000 or less. In this range, the effect by addition of the crosslinking agent of said (C) can be ensured more excellently.

The crosslinkable composition may include the (B) isocyanate crosslinking agent in a ratio of 0.01 to 2 parts by weight based on 100 parts by weight of the block copolymer. The ratio of the (B) isocyanate crosslinking agent may be, in another example, about 0.03 parts by weight or more, about 0.05 parts by weight or more, or about 0.06 parts by weight or more.

In addition, the crosslinkable composition may include the (C) isocyanate crosslinking agent in a ratio of 0.01 to 5 parts by weight based on 100 parts by weight of the block copolymer. The ratio of the (C) isocyanate crosslinking agent may be, in another example, about 0.03 parts by weight, about 0.05 parts by weight, about 0.06 parts by weight, about 0.08 parts by weight, about 0.1 parts by weight or about 0.15 parts by weight or more. The ratio may be about 4.5 parts by weight or less, about 4 parts by weight or less, about 3.5 parts by weight or less, about 3 parts by weight or less, about 2.5 parts by weight or less, about 2 parts by weight or less, about 1.5 parts by weight or less, or about 1 part by weight. It may be up to parts by weight.

In order to maximize the desired effect, the ratio of the crosslinking agent of (B) and (C) may be adjusted.

For example, the ratio of the crosslinking agent of (B) and (C) may be adjusted so that K in Equation 1 is in the range of 0.5 to 100.

[Equation 1]

K = C / B

In Formula 1, B is a weight part relative to 100 parts by weight of the (A) block copolymer of the (B) crosslinking agent, and C is a weight part relative to 100 parts by weight of the (A) block copolymer of the (C) crosslinking agent.

K in Equation 1 may be 0.7 or more, 0.9 or more, 1.1 or more, 1.3 or more, 1.5 or more, or about 1.65 or more in another example. Also, in another example, K may be 80 or less, 60 or less, 40 or less, 30 or less, 10 or less, 9 or less, or 8 or less.

In the calculation of Equation 1, for example, when the crosslinking agent corresponding to the crosslinking agent (B) is two or more in the composition, or the crosslinking agent corresponding to the crosslinking agent (C) is two or more in the composition, Substituted B and C are the total weight of the crosslinking agent.

In another example, the ratio of the crosslinking agents of (B) and (C) may be adjusted such that M in Formula 2 is 0.01 or more.

[Formula 2]

M = (42 × B _NCO × B) / B _MW + (84 × C) / C _Mn

In Formula 2, B is a weight part relative to 100 parts by weight of the (A) block copolymer of the (B) crosslinking agent, C is a weight part relative to 100 parts by weight of the (A) block copolymer of the (C) crosslinking agent, and B _NCO is the number of isocyanate groups in the (B) crosslinking agent, B _MW is the molecular weight of the (B) crosslinking agent, and C _Mn is the number average molecular weight of the (C) crosslinking agent.

In the calculation of Equation 2, for example, when two or more types of crosslinking agents corresponding to the crosslinking agent (B) are present in the composition, (42 x B _NCO x B) / B _MW is calculated separately for each of the crosslinking agents and summed. Is introduced into Equation 2. In addition, in calculation of Formula (2), even if there are two or more types of crosslinking agents corresponding to (C) crosslinking agent, (84 * C) / C _Mn is computed separately for each of those crosslinking agents, and sums them and introduces into formula (2).

M in Equation 2 may be at least about 0.015 or at least about 0.018 or at least about 0.02 in another example. In Formula 2, M may be about 10 or less, 9 or less, 8 or less, 7 or less, 6 or less, 5 or less, 4.5 or less, 4 or less, 3.5 or less, 3 or less, 2.5 or less, 2 or less, 1.5 or less, It may be 1 or less, 0.5 or less, 0.4 or less, 0.3 or less, 0.2 or less, 0.1 or less, 0.09 or less, 0.08 or less, 0.07 or less, 0.06 or less, 0.05 or less, 0.04 or less or 0.035 or less.

Within the range as described above, the desired physical properties for the crosslinkable composition can be more excellently secured.

The crosslinkable composition may further include a polyfunctional epoxy compound or a polyfunctional aziridine compound as a component that ensures interlayer adhesion when the crosslinkable composition is applied to various laminated structures.

As such a compound, for example, ethylene glycol diglycidyl ether, triglycidyl ether, trimethylolpropane triglycidyl ether, N, N, N ', N'- tetraglycidyl ethylenediamine or glycerin digly Epoxy compounds such as cyl ether; Or N, N'-toluene-2,4-bis (1-aziridinecarboxamide), N, N'-diphenylmethane-4,4'-bis (1-aziridinecarboxamide), triethylene Aziridine compounds such as melamine, bisisoprotaloyl-1- (2-methylaziridine) or tri-1-aziridinylphosphineoxide and the like can be exemplified, but is not limited thereto.

The crosslinkable composition may include the epoxy or aziridine compound within the range of 0.01 parts by weight to 10 parts by weight with respect to 100 parts by weight of the block copolymer, but this may be adjusted in consideration of the desired effect.

The crosslinkable composition may further comprise an ionic compound. As the ionic compound, for example, a metal salt or an ionic liquid can be applied. In the above, the ionic liquid means an ionic compound present in the liquid phase at room temperature.

As the metal salt in the above, for example, a salt containing an alkali metal cation or an alkaline earth metal cation can be used. As the cation, lithium ions (Li ⁺ ), sodium ions (Na ⁺ ), potassium ions (K ⁺ ), rubidium ions (Rb ⁺ ), cesium ions (Cs ⁺ ), beryllium ions (Be ^{2 +} ), magnesium ions ( Mg ^{2 +} ), calcium ions (Ca ^{2 +} ), strontium ions (Sr ^{2 +} ) and barium ions (Ba ^{2 +} ), and the like, or two or more kinds thereof may be exemplified. For example, lithium ions, sodium ions, Lithium ions may be used in consideration of one or more kinds of potassium ions, magnesium ions, calcium ions and barium ions, or ionic stability and mobility.

As the anion contained in the ionic compound is _{^{PF 6 -, AsF -, NO}} 2 -, fluoride (F ^-), chloride (Cl ^-), bromide (Br ^-), iodide (I ^-), perchlorate (ClO ₄ ^-), hydroxide (OH ^-), carbonate (CO ₃ ^2-), nitrate (NO ₃ ^-), trifluoromethane sulfonate (CF ₃ SO ₃ ^-), sulfonate (SO ₄ ^-), hexafluorophosphate (PF ₆ ^-), methyl benzene sulfonate _{(CH 3 (C 6 H 4} ) SO 3 -), p- toluenesulfonate _{(CH 3 C 6 H 4 SO} 3 -), tetraborate (B ₄ O ₇ ^{2 -),} carboxymethyl sulfonate _{(COOH (C 6 H 4)} SO 3 -), sulfonate as a triple (CF ₃ SO ₂ ^-), benzo carbonate ^{_{(C 6 H 5 COO -)}} , acetate ( a), a triple acetate _{^{- CH 3 COO (CF 3 COO}} -), tetrafluoroborate (BF ₄ ^-), tetra-benzyl borate _{(B (C 6 H 5)} 4 -) or tris pentafluoroethyl trifluoromethyl phosphate _{(P (C 2 F 5)} 3 F 3 -) or the like can be illustrated.

In another example, an anion or bisfluorosulfonylimide represented by the following Chemical Formula 2 may be used as the anion.

[Formula 2]

[X (YO _m R _f ) _n ] ^-

In formula (2), X is a nitrogen atom or a carbon atom, Y is a carbon atom or a sulfur atom, R _f is a perfluoroalkyl group, m is 1 or 2, and n is 2 or 3.

In Formula 2, when Y is carbon, m is 1, when Y is sulfur, m is 2, n is 2 when X is nitrogen, and n may be 3 when X is carbon.

Anions or bis (fluorosulfonyl) imides of formula (2) exhibit high electronegativity due to perfluoroalkyl group (R _f ) or fluorine group, and also include unique resonance structures, forming weak bonds with cations At the same time, it has hydrophobicity. Therefore, while an ionic compound shows the outstanding compatibility with other components of compositions, such as a polymer, it can provide high antistatic property even with a small amount.

R _f of Formula 2 may be a perfluoroalkyl group having 1 to 20 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms or 1 to 4 carbon atoms, in which case the perfluoroalkyl group is linear, branched or It may have a cyclic structure. The anion of the formula (2) may be a sulfonyl metide, sulfonylimide, carbonyl metide, or carbonyl imide anion, and specifically, tristrifluoromethanesulfonylmethide and bistrifluoromethanesulfide Ponylimide, bisperfluorobutanesulfonylimide, bispentafluoroethanesulfonylimide, tristrifluoromethanecarbonylmide, bisperfluorobutanecarbonylimide or bispentafluoroethanecarbonyl It may be a kind of imide or the like or a mixture of two or more thereof.

As the ionic liquid, for example, as a cation, N-ethyl-N, N-dimethyl-N-propylammonium, N, N, N-trimethyl-N-propylammonium, N-methyl-N, N, N -Tributylammonium, N-ethyl-N, N, N-tributylammonium, N-methyl-N, N, N-trihexylammonium, N-ethyl-N, N, N-trihexylammonium, N-methyl Quaternary ammonium such as -N, N, N-trioctylammonium or N-ethyl-N, N, N-trioctylammonium, phosphonium, pyridinium, imidazolium, blood An organic salt containing pyrolidinium or piperidinium, etc. together with the anion component may be used.

The crosslinkable composition may simultaneously contain the metal salt and the ionic liquid, if necessary.

The content of the ionic compound in the crosslinkable composition is not particularly limited, and for example, may be present in a ratio of 0.01 to 15 parts by weight relative to 100 parts by weight of the block copolymer. The proportion of the ionic compound can be changed in consideration of the desired antistatic property and compatibility between components.

The crosslinkable composition may further include a silane coupling agent. As a silane coupling agent, the silane coupling agent which has a beta-cyano group or an acetoacetyl group can be used, for example. Such a silane coupling agent may, for example, allow the pressure-sensitive adhesive formed by a low molecular weight copolymer to exhibit excellent adhesion and adhesion stability, and also to maintain excellent durability and the like in heat and moisture resistant conditions. have.

As a silane coupling agent which has a beta-cyano group or an acetoacetyl group, the compound represented by following formula (3) or 4 can be used, for example.

[Formula 3]

(R ¹ ) _n Si (R ² ) _(4-n)

[Formula 4]

(R ³ ) _n Si (R ² ) _(4-n)

In Formula 3 or 4, R ¹ is a beta-cyanoacetyl group or a beta-cyanoacetylalkyl group, R ³ is an acetoacetyl group or an acetoacetylalkyl group, R ² is an alkoxy group, n is 1 to 3 Is the number of.

In Formula 3 or 4, the alkyl group may be an alkyl group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms or 1 to 4 carbon atoms, and the alkyl group may be linear, branched or cyclic. have. In addition, in Formula 3 or 4, the alkoxy group may be an alkoxy group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms, and the alkoxy group is linear, branched, or cyclic. It may be a phase.

In addition, n in Formula 3 or 4 may be, for example, 1 to 3, 1 to 2, or 1.

As the compound of the formula (3) or (4), for example, acetoacetylpropyl trimethoxy silane, acetoacetylpropyl triethoxy silane, beta-cyanoacetylpropyl trimethoxy silane or beta-cyanoacetylpropyl triethoxy silane Etc. may be illustrated, but is not limited thereto.

In the crosslinkable composition, the silane coupling agent may be included in an amount of 0.01 to 5 parts by weight or 0.01 to 1 part by weight based on 100 parts by weight of the block copolymer, and may effectively impart desired properties to the pressure-sensitive adhesive within this range. .

A crosslinkable composition may further contain a tackifier as needed. As the tackifier, for example, a hydrocarbon resin or a hydrogenated substance thereof, a rosin resin or a hydrogenated substance thereof, a rosin ester resin or a hydrogenated substance thereof, a terpene resin or a hydrogenated substance thereof, a terpene phenol resin or a hydrogenated substance thereof, a polymerized rosin resin or One kind or a mixture of two or more kinds such as a polymerized rosin ester resin may be used, but is not limited thereto. The tackifier may be included in the crosslinkable composition in an amount of 100 parts by weight or less based on 100 parts by weight of the block copolymer.

The crosslinkable composition may also further comprise one or more additives selected from the group consisting of epoxy resins, curing agents, ultraviolet stabilizers, antioxidants, colorants, reinforcing agents, fillers, antifoams, surfactants and plasticizers, if desired.

The crosslinkable composition can be used as an adhesive composition for a protective film. In the use of each crosslinkable composition mentioned below, the pressure-sensitive adhesive composition may include the crosslinkable composition as a main component based on the solid content. The protective film can be used, for example, in applications for protecting the surface of various optical films.

The crosslinkable composition may also be used as an adhesive composition for a conductive film.

The crosslinkable composition may be an adhesive composition for an optical film. The pressure-sensitive adhesive composition for an optical film may, for example, laminate optical films such as a polarizing film, a retardation film, an anti-glare film, a wide viewing angle compensation film, or a brightness enhancement film to each other, or the optical film or a laminate thereof such as a liquid crystal panel or the like. It can be used for attachment to adherends. In one example, the crosslinkable composition may be used as an adhesive composition for a polarizing plate and used for attaching a polarizing film to a liquid crystal panel.

The present application also relates to a pressure-sensitive adhesive optical laminate. Exemplary optical laminates include optical films; And it may include a pressure-sensitive adhesive layer formed on one side or both sides of the optical film. The pressure-sensitive adhesive layer may be, for example, a pressure-sensitive adhesive layer for attaching the optical film to another optical film such as a liquid crystal panel or a touch panel of an LCD device. In addition, the pressure-sensitive adhesive layer may include the crosslinkable composition of the present application described above. The crosslinkable composition may be included in the pressure-sensitive adhesive layer in a state of implementing a crosslinking structure. The crosslinkable composition may be included as a main component of the pressure-sensitive adhesive composition. In the above, as the optical film, a polarizing film, a retardation film, a brightness enhancement film, a conductive film, or the like, or a laminate in which two or more kinds are laminated in the above may be exemplified.

The present application also relates to a pressure-sensitive adhesive polarizing plate. The polarizing plate may have, for example, a structure in which the optical film is a polarizing film in the adhesive optical laminate.

The kind of polarizing film included in the polarizing plate is not particularly limited, and for example, a general kind known in the art such as polyvinyl alcohol-based polarizing film can be used without limitation.

The polarizing film is a functional film capable of extracting only light vibrating in one direction from incident light while vibrating in various directions. Such a polarizing film may be a form in which a dichroic dye is adsorbed and oriented in a polyvinyl alcohol-based resin film, for example. Polyvinyl alcohol-type resin which comprises a polarizing film can be obtained by gelatinizing polyvinylacetate-type resin, for example.

In this case, the polyvinylacetate resin which can be used may include not only a homopolymer of vinyl acetate but also a copolymer of vinyl acetate and other monomers copolymerizable with the above. Examples of the monomer copolymerizable with vinyl acetate include one or two or more kinds of unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids and acrylamides having an ammonium group, but are not limited thereto. no.

The degree of gelation of the polyvinyl alcohol-based resin is usually 85 mol% to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be further modified, for example, polyvinyl formal or polyvinyl acetal modified with aldehydes may be used. In addition, the degree of polymerization of the polyvinyl alcohol-based resin may be about 1,000 to 10,000 or about 1,500 to 5,000.

The polarizing film is a step of stretching, for example, uniaxially or biaxially stretching the polyvinyl alcohol-based resin film as described above, dyeing the polyvinyl alcohol-based resin film with a dichroic dye, adsorbing the dichroic dye, and dichroism. The polyvinyl alcohol-based resin film to which the dye is adsorbed may be produced through a process of treating with a boric acid aqueous solution, and a process of washing with water after treating with a boric acid aqueous solution.

As the dichroic dye, iodine or a dichroic organic dye may be used.

The polarizing plate may further include a protective film attached to one side or both sides of the polarizing film, and in this case, the pressure-sensitive adhesive layer may be formed on one side of the protective film. The type of protective film is not particularly limited, and includes, for example, a cellulose film such as triacetyl cellulose (TAC); Polyester film such as polycarbonate film or PET (poly (ethylene terephthalet)); Polyether sulfone-based film; Alternatively, a film having a laminated structure of one layer or two or more layers, such as a polyethylene film, a polypropylene film or a polyolefin-based film produced using a resin having a cyclo or norbornene structure, an ethylene-propylene copolymer, or the like can be used. In particular, it is more effective in improving heat resistance durability when applying a PET-, polyolefin-based film, acrylic film with good moisture barrier properties.

The polarizing plate may further include one or more functional layers selected from the group consisting of a protective layer, a reflective layer, an antiglare layer, a retardation plate, a wide viewing angle compensation film, and a brightness enhancing film.

In the present application, a method of forming the pressure-sensitive adhesive layer on the polarizing plate or the optical film as described above is not particularly limited, and for example, a method of directly coating the crosslinkable composition on the polarizing plate or the optical film and curing to realize a crosslinking structure is used. Alternatively, a method of coating and curing the crosslinkable composition on a release treatment surface of a release film to form a crosslinked structure, and then transferring the same to a polarizing plate or an optical film may be used.

The method of coating the crosslinkable composition in the above is not particularly limited, and for example, a method of applying the crosslinkable composition by a conventional means such as a bar coater may be used.

In the coating process, the multifunctional crosslinking agent included in the crosslinkable composition is preferably controlled from the crosslinking reaction of the functional group from the viewpoint of performing a uniform coating process, so that the crosslinking agent is cured and cured after the coating operation. By forming a crosslinked structure, the cohesive force of the pressure-sensitive adhesive may be improved, and adhesive properties and cuttability may be improved.

The coating process is also preferably carried out after sufficiently removing the bubble-inducing components such as volatile components or reaction residues in the crosslinkable composition, so that the crosslinking density or molecular weight of the pressure-sensitive adhesive is too low to lower the elastic modulus, and at a high temperature. In the bubble between the glass plate and the adhesive layer is increased to prevent the problem of forming a scattering body therein.

The method of implementing the crosslinking structure by curing the crosslinkable composition subsequent to the coating is not particularly limited. For example, the coating layer may be appropriately selected so that a crosslinking reaction between the block copolymer included in the coating layer and the multifunctional crosslinking agent may be induced. It may be carried out in a manner such as maintaining at a temperature.

In one embodiment of the pressure-sensitive adhesive optical film, the pressure-sensitive adhesive layer may be provided on the optical film through a lower coating layer. As the undercoat layer, a known undercoat layer can be applied, and for example, a undercoat layer containing a polymer can be applied. When the undercoat is applied in this manner, the pressure-sensitive adhesive of the above-described type including a mixture of the crosslinking agents of (B) and (C) may be used as the pressure-sensitive adhesive. You can also apply.

As such an undercoat layer, for example, a polymer having a primary amino group at the terminal can be used. As such a polymer, a polymer derived from a poly (meth) acrylic acid ester or a polyethyleneimine material having a primary amino group at the terminal, etc. This can be used.

The undercoat may further comprise 0.01 to 500 parts by weight of antioxidant based on 100 parts by weight of the polymer, if necessary. As such an antioxidant, one or more selected from known types such as phenolic, phosphorus, sulfur and amine antioxidants can be used.

Such an undercoat layer can be formed by a well-known method, for example, can apply | coat the undercoat layer forming paint to well-known coating methods, such as a coating method, a dipping method, or a spray method.

The present application also relates to a display device, for example an LCD device.

The exemplary display device may include a liquid crystal panel and the polarizing plate or the optical laminate attached to one or both surfaces of the liquid crystal panel. The polarizing plate or the optical laminate may be attached to the liquid crystal panel by the pressure-sensitive adhesive described above.

The liquid crystal panel in the apparatus may be, for example, a passive matrix panel such as twisted nematic (TN) type, super twisted nematic (STN) type, ferroelectic (F) type or polymer dispersed (PD) type; Active matrix panels such as two-terminal or three-terminal; All known panels, such as an In Plane Switching (IPS) panel and a Vertical Alignment (VA) panel, can be applied.

Further, other configurations of the liquid crystal display device, for example, upper and lower substrates such as a color filter substrate or an array substrate, are not particularly limited, and a configuration known in the art may be employed without limitation.

Provided are crosslinkable compositions and uses of the present application. Specifically, in the present application, a crosslinkable composition capable of forming a layer having excellent curvature suppression ability, in particular, high curvature suppression ability at high temperatures, while ensuring excellent properties such as cohesion, adhesive force, reworkability, low light leakage property, and stress relaxation property. This may be provided. The crosslinkable composition may be used, for example, for an optical film such as a polarizing plate or the like for a conductive film.

Hereinafter, the crosslinkable composition will be described in detail with reference to Examples and Comparative Examples, but the scope of the crosslinkable composition is not limited by the following examples.

1. Molecular weight evaluation

The number average molecular weight (Mn) and the molecular weight distribution (PDI) were measured under the following conditions using GPC, and in the preparation of the calibration curve, the measurement results were converted using standard polystyrene of Agilent system.

<Measurement conditions>

Meter: Agilent GPC (Agilent 1200 series, U.S.)

Column: Connect 2 PL Mixed B

Column temperature: 40 ℃

Eluent: THF (Tetrahydrofuran)

Flow rate: 1.0 mL / min

Concentration: ~ 1 mg / mL (100 μL injection)

2. Evaluation of durability

The polarizing plates prepared in Examples and Comparative Examples were cut to have a width of about 180 mm and a length of about 220 mm to prepare a specimen, and then attached to glass to prepare a sample. At the time of attachment, the applied pressure was about 5 Kg / cm ² and the work was performed in a clean room to prevent the inflow of foreign substances or bubbles. Heat resistance and moisture resistance were evaluated by the following criteria by observing the occurrence of bubbles and peeling after leaving the sample at 60 ° C. and 90% relative humidity conditions for 1,000 hours, and heat resistance also after the sample was kept at 80 ° C. for 1,000 hours. The occurrence of bubbles and peeling was observed and evaluated according to the following criteria.

The heat-and-moisture resistance and the heat resistance were evaluated after each sample was left at the above conditions for 24 hours at room temperature.

<Evaluation Criteria>

A: No bubble and peeling occurrence

B: Bubbles and / or peeling slightly occur

C: Large amount of bubbles and / or exfoliation

3. Calculation of glass transition temperature

The glass transition temperature (Tg) of each block of the block copolymer was calculated according to the following formula.

<Formula>

1 / Tg = ΣWn / Tn

In the above formula, Wn is a weight fraction of the monomer used in each block and the like, and Tn represents a glass transition temperature that appears when the monomer used forms a homopolymer.

In other words, the right side of the above formula is a result of adding up the calculated values after calculating all the monomers (Wn / Tn) divided by the glass transition temperature when the monomer forms the homopolymer (Wn / Tn). to be.

4. measuring distance

The polarizing plates prepared in Examples and Comparative Examples were cut so as to have a width of about 35 mm and a length of about 400 mm, and then laminated on Corning's alkali-free glass (width: 40 mm, length: 410 mm, thickness: 0.7 mm). Samples were prepared by attachment. The sample was then held for 72 hours at constant temperature and humidity conditions at 25 ° C. and 50% relative humidity, and then left to stand again in an oven at 60 ° C. for 70 hours to measure the distance. The distance was set to the distance which the sample was high on the flat bottom, and the other end floated off the floor in the state which contacted one end to the bottom.

Preparation Example 1 Preparation of Block Copolymer (A)

0.1 g EBiB (ethyl 2-bromoisobutyrate) and 14.2 g methyl methacrylate (MMA) were mixed in 6.2 g ethyl acetate (EAc). The flask containing the mixture was sealed with a rubber membrane, purged with nitrogen at about 25 ° C. for about 30 minutes, and dissolved oxygen was removed by bubbling. Thereafter, 0.002 g of CuBr ₂ , 0.005 g of tris (2-pyridylmethyl) amine) and 0.017 g of V-65 (2,2'-azobis (2,4-dimethyl valeronitrile)) were added to the oxygen-free mixture. The reaction was started by immersing in a reactor at about 67 ° C. (polymerization of the first block). A mixture of 155 g of butyl acrylate (BA), 0.8 g of hydroxybutyl acrylate (HBA) and 250 g of ethyl acetate (EAc) previously bubbled with nitrogen at a time when the conversion rate of methyl methacrylate is about 75% Was added in the presence of nitrogen. Thereafter, 0.006 g of CuBr2, 0.012 g of TPMA, and 0.05 g of V-65 were added to the reaction flask, and a chain extension reaction was performed (polymerization of the second block). Block copolymers were prepared by exposing the reaction mixture to oxygen and terminating the reaction by dilution in an appropriate solvent when the conversion of monomer (BA) reached 80% or more (in the process V-65 takes into account its half-life). Appropriately divided to the end of the reaction).

Preparation Examples 2 to 4. Preparation of Block Copolymers (A2 to A4)

The types of raw materials and additives used in the polymerization of the first block are adjusted as shown in Table 1, and the types of raw materials and additives used in the polymerization of the second block are adjusted as shown in Table 2 below. Prepared a block copolymer in the same manner as in Preparation Example 1.

Block copolymer A1 A2 A3 A4
First
block MMA Rate 100 80 60 70 BMA ratio 0 20 40 30 Tg (℃) 110 90 72 80 Mn (× 10000) 3.8 4.3 4.9 5.8 PDI 1.27 1.34 1.38 1.41 2nd
block BA ratio 99.5 97 94 95 HBA Ratios 0.5 3 6 5 Tg (℃) -47 -46.2 -47.5 -47 block
Public
coalescence Mn (× 10000) 20.6 22.3 24.1 20.4 PDI 1.7 1.8 2.1 2.1 1st block: 2nd block (weight ratio) 10.5: 89.5 10.1: 89.9 11.2: 88.8 34.7: 65.3 Rate unit: parts by weight
BA: butyl acrylate (monopolymer Tg: about -45 ° C)
HBA: 4-hydroxybutyl acrylate (monopolymer Tg: about -80 ° C)
MMA: methyl methacrylate (monopolymer Tg: about 110 ° C.)
BMA: butyl methacrylate (monopolymer Tg: about 27 ° C)
Tg: glass transition temperature
Mn: number average molecular weight
PDI: molecular weight distribution

Preparation Example 5 Preparation of Random Copolymer (B)

10 parts by weight of methyl methacrylate (MMA), 87.3 parts by weight of n-butyl acrylate and 2.7 parts by weight of 4-hydroxybutyl acrylate were added to a 1 L reactor equipped with a refrigeration system for easy reflux of nitrogen gas and for temperature control. Then, n-dodecyl mercaptan was added in an amount of 300 ppm as a molecular weight regulator, and then 120 parts by weight of ethyl acetate was added as a solvent. Subsequently, nitrogen gas was purged for about 60 minutes to remove oxygen, and 0.1 parts by weight of AIBN (azobisisobutyronitrile) as a reaction initiator was added while maintaining the temperature at 60 ° C, and reacted for about 8 hours to prepare a random copolymer. The number average molecular weight (Mn) of the prepared random copolymer (B) was about 93,000, and the molecular weight distribution (PDI) was about 4.6.

Example 1

Preparation of Coating Liquid (Crosslinkable Composition)

Polyfunctional isocyanate crosslinking agent (Coronate L, made by Japan NPU, number of isocyanate groups (B _NCO ): 3, molecular weight (B _MW ): about 741 g / mol based on 100 parts by weight of the solid content of the block copolymer (A1) of Preparation Example 1 ) 0.1 part by weight, difunctional isocyanate crosslinking agent having polypropylene glycol units (Sigma Aldrich, CAS No. 9057-91-4, number average molecular weight (Mn, C _Mn ): about 2300) 0.18 part by weight and DBTDL (Dibutyltin dilaurate) 0.1 weight part was mixed, ethyl acetate was mix | blended as a solvent, and it adjusted so that coating solid content might be about 30 weight%, and the coating liquid (crosslinkable composition) was prepared.

Preparation of Adhesion Polarizer

The prepared coating solution was coated on a release treated surface of release PET (poly (ethylene terephthalate)) (MRF-38, manufactured by Mitsubishi) having a thickness of 38 μm, which was release-treated so that the thickness after drying was about 23 μm. And held for about 3 minutes. After drying, on the release PET on the WV liquid crystal layer of a polarizing plate (TAC / PVA / TAC laminated structure: TAC = triacetylcellulose, PVA = polyvinyl alcohol polarizing film) coated with a WV (Wide View) liquid crystal layer on one side. The formed coating layer was laminated to prepare an adhesive polarizing plate.

Examples 1 and 7 and Comparative Examples 1-7

A crosslinkable composition (coating solution) and an adhesive polarizing plate were prepared in the same manner as in Example 1 except that each component and ratio were adjusted as shown in Table 2 or 3 below when preparing the crosslinkable composition (coating solution).

Example One 2 3 4 5 6 7 polymer Kinds A1 A1 A1 A1 A2 A3 A4 content 100 100 100 100 100 100 100 Crosslinking agent (B) content 0.1 0.08 0.08 0.15 0.1 0.1 0.1 Crosslinking agent (C) content 0.18 0.26 0.56 0.26 0.18 0.18 0.18 M in Equation 2 0.024 0.023 0.034 0.035 0.024 0.024 0.024 K in Equation 1 1.8 3.25 7 1.73 1.8 1.8 1.8 DBTDL Content 0.1 0.1 0.1 0.1 0.1 0.1 0.1 Content unit: parts by weight
Crosslinking agent (B): Coronate L, Japan NPU company
Crosslinking agent (C): Tolylene 2,4-diisocyanate terminated poly (propylene glycol) (number average molecular weight: 2,300, Sigma Aldrich, CAS No. 9057-91-4)
DBTDL: dibutyltin dilaurate

Comparative example One 2 3 polymer Kinds B B B content 100 100 100 Crosslinking agent (B) content 0.01 0.1 4 Crosslinking agent (C) content 0.01 0.18 0.01 M in Equation 2 0.002 0.024 0.681 K in Equation 1 One 1.8 0.003 DBTDL Content 0.1 0.1 0.1 Content unit: parts by weight
Crosslinking agent (B): Coronate L, Japan NPU company
Crosslinking agent (C): Tolylene 2,4-diisocyanate terminated poly (propylene glycol) (number average molecular weight: 2,300, Sigma Aldrich, CAS No. 9057-91-4)
DBTDL: dibutyltin dilaurate

Physical property evaluation results for each of the Examples and Comparative Examples are as shown in Tables 4 and 5.

Example One 2 3 4 5 6 7 Heat resistance A A A A A A A Moisture Resistant Heat A A A A A A A 휜 Distance (mm) 8 7 9 8 8 7 8

Comparative example One 2 3 Heat resistance C B A Moisture Resistant Heat C A A 휜 Distance (mm) 5 18 24

Claims (13)

(A) a block copolymer having a first block having a glass transition temperature of 40 ° C. or more and a second block having a glass transition temperature of 0 ° C. or less , wherein only the second block includes a hydroxy group as a crosslinkable functional group ; (B) a polyfunctional isocyanate crosslinker having no polyalkylene oxide chain; And (C) a bifunctional isocyanate crosslinking agent having a polyalkylene oxide chain represented by the following formula (1 ),
K in the following formula 1 is in the range of 0.5 to 100,
Crosslinkable composition wherein M of Formula 2 is 0.01 or more:
[Equation 1]
K = C / B
[Formula 2]
M = (42 × B _NCO × B) / B _MW + (84 × C) / C _Mn
In Formulas 1 and 2, B is part by weight based on 100 parts by weight of the (A) block copolymer of the (B) crosslinking agent, and C is part by weight based on 100 parts by weight of the (A) block copolymer of the (C) crosslinking agent. , B _NCO is the number of isocyanate groups in the (B) crosslinking agent, B _MW is the molecular weight of the (B) crosslinking agent, C _Mn is the number average molecular weight of the (C) crosslinking agent :
[Formula 1]

In Formula 1, A is an alkylene or alkylidene group having 1 to 4 carbon atoms, Ar ₁ and Ar ₂ are aryl groups substituted with one isocyanate group, L ₁ and L ₂ are linkers, and n is in the range of 2 to 60. Is the number within . delete The polyfunctional isocyanate crosslinking agent according to claim 1, wherein tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isoborone diisocyanate, tetramethylxylene diisocyanate and naphthalene diisocyanate A crosslinkable composition, which is a reactant of any one isocyanate compound selected from the group consisting of or a polyol with at least one isocyanate compound selected from the group. delete The crosslinkable composition according to claim 1, wherein the (B) isocyanate crosslinking agent is included in a ratio of 0.01 to 2 parts by weight based on 100 parts by weight of the block copolymer. The crosslinkable composition according to claim 1, wherein the (C) isocyanate crosslinking agent is contained in a ratio of 0.01 to 5 parts by weight based on 100 parts by weight of the block copolymer. The crosslinkable composition according to claim 1, further comprising a polyfunctional epoxy compound or a polyfunctional aziridine compound. The crosslinkable composition of claim 1, further comprising an ionic compound. The crosslinkable composition according to claim 8, wherein the ionic compound comprises a metal salt and an ionic liquid. Optical film; And a pressure-sensitive adhesive layer present on one or both surfaces of the optical film, the cross-linkable composition of claim 1 crosslinked. Polarizing film; And a pressure-sensitive adhesive layer present on one side or both sides of the polarizing film, the cross-linkable composition of claim 1 cross-linked. delete Display panel; And an adhesive optical laminate of claim 10 or an adhesive polarizing plate of claim 11 attached to one or both surfaces of the display panel.