JP2019073691A - Resin composition, sheet, laminate using the same, and image display device - Google Patents

Abstract

The present invention provides a resin composition having excellent adhesive strength, holding power, bendability, and water vapor barrier properties.
A resin composition comprising an isobutylene polymer (A) and a specific acrylate polymer (B), wherein at least one maximum point of loss tangent (tan δ) at a shear frequency of 1 Hz is -30. Resin composition in the range of ° C to -15 ° C 【Selection chart】 None

Description

  The present invention relates to a resin composition having excellent adhesive strength, holding power, bendability, and water vapor barrier property, a sheet using the resin composition, a laminate using the sheet, and an image display It relates to the device.

In recent years, curved or bendable display devices using organic light emitting diodes (OLEDs) and quantum dots (QDs) have been developed and are being widely commercialized.
In such a display device, a plurality of film-like structural members are bonded by a transparent optical adhesive (OCA) sheet. However, acrylic OCA sheets conventionally used have problems such as various problems due to insufficient moisture proof performance, corrosion and migration of metal electrodes, and new material type OCA sheets have been required.

Polyisobutylene can be mentioned as a polymeric material which may solve the above-mentioned subject.
Polyisobutylene has the feature that it is particularly high in water vapor barrier properties as a general-purpose soft resin, but its cohesion is too small to be applied to a resin composition, so problems such as adhesive residue, low temperature flow and lack of holding power was there.

  As one of the methods of using such polyisobutylene having low cohesion, there is a method of improving cohesion by polymerizing (meth) acrylate after mixing monomers such as (meth) acrylate with polyisobutylene. Are known.

  For example, Patent Document 1 discloses a pressure-sensitive adhesive composition containing a sealing resin such as polyisobutylene, a polyfunctional (meth) acrylate, and a specific silane compound, which is obtained from the pressure-sensitive adhesive composition. The adhesive film is described to have excellent water vapor barrier properties and transparency.

Japanese Patent Application Publication No. 2016-527377

  However, although the pressure-sensitive adhesive sheet composed of polyisobutylene and a multifunctional acrylate disclosed in Patent Document 1 described above can have excellent water vapor barrier properties, the pressure-sensitive adhesive sheet is sandwiched between resin films such as PET to perform a bending test. In this case, there is a problem that bending marks are formed due to flow or buckling.

  An object of the present invention is to provide a new resin composition which has good adhesion, holding power, bendability and can realize excellent water vapor barrier properties.

  The present invention is a resin composition comprising an isobutylene polymer (A) and an acrylate polymer (B), wherein at least one maximum point of loss tangent (tan δ) at a frequency of 1 Hz is -30 ° C to- The resin composition is characterized in that it is in the range of 15 ° C., and the acrylate polymer (B) has at least two kinds of monofunctional acrylate components different in R in the following formula (1).

（式中、Ｒは炭素数１２〜３０の炭化水素基、Ｒ’は水素（Ｈ）又はメチル基（ＣＨ_３）をそれぞれ表す）

(Wherein R represents a hydrocarbon group having 12 to 30 carbon atoms, R ′ represents hydrogen (H) or methyl group (CH ₃ ), respectively)

  The resin composition proposed by the present invention comprises an isobutylene polymer (A) and a specific acrylate polymer (B), and has at least one maximum point of loss tangent (tan δ) at shear frequency of 1 Hz -30. By being in the range of ° C to -15 ° C, it is possible to obtain a resin composition excellent in adhesion, retention strength, bendability, and water vapor barrier property. Furthermore, by forming, for example, a sheet from the resin composition and using the sheet as a component of an image display device or the like, it is possible to contribute to thinning and flexibility of the image display device or the like.

  Hereinafter, the present invention will be described in detail. However, the contents of the present invention are not limited to the embodiments described below.

<Resin composition>
A resin composition according to an embodiment of the present invention (hereinafter sometimes referred to as "the present resin composition") is an isobutylene polymer (A) (hereinafter sometimes referred to as "the A polymer") and an acrylate A resin composition comprising a base polymer (B) (hereinafter sometimes referred to as "polymer B"), wherein at least one local maximum point of loss tangent (tan δ) at a shear frequency of 1 Hz is -30 ° C-- It is a resin composition which is in the range of 15 ° C. and in which the acrylate polymer (B) has at least two kinds of monofunctional acrylate components different in R in the following formula (1).

（式中、Ｒは炭素数１２〜３０の炭化水素基、Ｒ’は水素（Ｈ）又はメチル基（ＣＨ_３）をそれぞれ表す）

(Wherein R represents a hydrocarbon group having 12 to 30 carbon atoms, R ′ represents hydrogen (H) or methyl group (CH ₃ ), respectively)

  In the resin composition, it is important that at least one maximum point of loss tangent (tan δ) at shear frequency of 1 Hz is in the range of -30 to -15 ° C.

In recent years, the demand for an optical adhesive (OCA) for a foldable display is increasing, but when the user of the display folds, the glass transition temperature (Tg) is around 0 ° C. In one conventional acrylic OCA, there may be a problem that buckling occurs at the bonding interface. This is influenced by the dynamic visco-elasticity of the OCA in the frequency range in which humans bend. Therefore, it is necessary to further lower the Tg of OCA and to lower the elastic modulus in the low temperature region. Although depending on the thickness and the lamination configuration, the Tg of the foldable OCA is preferably -15 ° C or less, more preferably -20 ° C or less.
Further, from the viewpoint of adhesion at around normal temperature, Tg of the foldable OCA is preferably -30 ° C or more.

  As described later, the polymer B has at least two kinds of monofunctional acrylate components different in R in the above formula (1), whereby the maximum point of the loss tangent (tan δ) is in the range of -30 ° C to -15 ° C. It is easy to In addition, the maximum point of the loss tangent (tan δ) can be appropriately adjusted by selecting the type of the polymer A and the acrylate constituting the polymer B and the component ratio thereof. Moreover, the maximum point of loss tangent can be adjusted in the range of -30 to -15 degreeC also by adding the tackifier mentioned later. However, it is not limited to such a method.

With respect to a resin composition comprising an isobutylene polymer and an acrylate polymer, an ester part having a large number of carbon atoms (for example, 12 or more carbon atoms) from the viewpoint of compatibility with an isobutylene polymer as an acrylate polymer It is preferable to use an acrylate polymer having an acrylate unit structure having
However, a monofunctional (meth) acrylate having a hydrocarbon group having 12 or more carbon atoms, which is a precursor for obtaining such a polymer, has a glass transition temperature (Tg) of the polymer having a general monofunctional ( It is characterized in that it is relatively higher than meta) acrylate, and the resulting resin composition also has a high Tg.
In the present invention, the term “Tg of a monomer such as acrylate” means the Tg of a homopolymer consisting only of the monomer.

Here, specifically, the Tg of a commercially available homopolymer of a monofunctional (meth) acrylate having a hydrocarbon group having 12 or more carbon atoms is shown. The higher the carbon number, the higher the Tg, and it can be seen that the Tg is greater than -15 ° C in all cases.
・ Lauryl acrylate (C12 straight chain, polymer Tg: −3 ° C.)
・ Hexadecyl acrylate (C16 straight chain, polymer Tg: 35 ° C)
Stearyl acrylate (C18 straight chain, polymer Tg: 30 ° C.)
・ Behenyl acrylate (C22 straight chain, polymer Tg: 50 ° C)

Moreover, compared with the linear thing of carbon number which has branch introduce | transduced into the hydrocarbon group, Tg of a homopolymer falls, However, Tg of the commercially available branched alkyl acrylate shown below is -15 It is over ° C.
・ Isostearyl acrylate (C18 branched, polymer Tg: 15 ° C (DMA))

In addition to these monofunctional (meth) acrylates having a hydrocarbon group of 12 or more carbon atoms, polyfunctional (meth) acrylates and the like can be added for crosslinking. With respect to the polyfunctional (meth) acrylate also, from the viewpoint of compatibility with the isobutylene polymer, (meth) acrylates having hydrocarbon groups as described below are selected, and the Tg of the obtained resin composition is further increased. Become.
・ 1,9-nonanediol diacrylate (C9 linear difunctional, polymer Tg: 68 ° C.)
・ 1,10-decanediol diacrylate (C10 linear difunctional, polymer Tg: 91 ° C.)
Tricyclodecane dimethanol diacrylate (C12 alicyclic difunctional, polymer Tg: 190 ° C.)

It is known that the Tg of an acrylate copolymer can be determined using the following FOX equation.
Formula of FOX: 1 / Tg = W1 / T1 + W2 / T2 +... Wn / Tn
In this formula, Tg: theoretical glass transition temperature (K), W1, W2 ... Wn is a mass fraction of each monomer, T1, T2 ... Tn is the measured glass transition temperature of each monomer (K ).

That is, even with an acrylate polymer containing isostearyl acrylate having a relatively low polymer Tg in its main structural unit, the Tg of a minor component such as polyfunctional (meth) acrylate or the interaction with an isobutylene polymer As a result, the actual Tg of the resin composition did not fall below -15.degree.
As described above, when it is intended to obtain a resin composition comprising an isobutylene-based polymer and an acrylate-based polymer having good compatibility, the maximum point of the loss tangent at a frequency of 1 Hz shear of the resin composition is -15. The fact is that the temperature exceeds .degree. C., and it has been difficult to adjust the temperature to -15.degree. C. or less.

  In the present invention, by using at least two types of monofunctional (meth) acrylates as constituent materials of the acrylate polymer (B), it is possible to dramatically lower the Tg of the obtained resin composition. This is considered to be due to a change in interaction between side chains composed of long chain hydrocarbon groups of the acrylate polymer. This result is a special phenomenon that exhibits a Tg much lower than that expected from the FOX equation above. The present invention embodies a sheet that follows without buckling due to bending by a resin composition in which at least one local maximum point of loss tangent (tan δ) at shear frequency of 1 Hz is in the range of -30 ° C to -15 ° C. It is possible to obtain a resin composition which is excellent in adhesion, retention and water vapor barrier properties.

  In addition, the resin composition has a maximum value of loss tangent at shear frequency of 1 Hz in the range of −30 to −15 ° C. at a local maximum value of loss tangent at shear frequency of 1 Hz at 0.5 or more. It is more preferable than the point of adhesive security. Among them, it is more preferable that the ratio is 0.55 or more, and more preferably 0.6 or more.

  The loss tangent (tan δ) at 100 ° C. of the present resin composition is preferably 0.6 or less, and more preferably 0.5 or less. It becomes possible to express sufficient high temperature holding power as it is 0.6 or less.

In the present resin composition, the acrylate polymer (B) is preferably contained in a proportion of 5 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the isobutylene polymer (A). Above all, 8 parts by mass or more and 90 parts by mass or less, more preferably 10 parts by mass or more and 80 parts by mass or less are more preferable.
When the content of the acrylate-based polymer (B) is 5 parts by mass or more, the cohesion of the present resin composition is effectively improved, and good adhesion and retention of the present resin composition are exhibited. Moreover, if content of a (meth) acrylate type polymer (B) is 100 mass parts or less, favorable transparency can be expressed.

As long as the resin composition is a composition containing an isobutylene polymer (A) and an acrylate polymer (B), the state and the form thereof are arbitrary.
For example, it may be in the form of liquid, gel, solid or other state.

  The present resin composition can also be in various forms such as a sheet, a rod, a hollow, and other shapes. Among them, for example, an unstretched sheet used as a pressure-sensitive adhesive sheet can be mentioned.

When the resin composition has a sheet-like shape, the thickness is not particularly limited. For example, it is 0.01 mm or more, more preferably 0.03 mm or more, and still more preferably 0.05 mm or more. On the other hand, the upper limit is preferably 1 mm or less, more preferably 0.7 mm or less, and still more preferably 0.5 mm or less.
If the thickness is 0.01 mm or more, the handling property is good, and if the thickness is 1 mm or less, the thickness can be reduced.

(Glass-transition temperature)
The resin composition preferably has a single glass transition temperature (Tg).
In a multi-component system consisting of at least A polymer and B polymer, it is rare that the glass transition temperature (Tg) is single as in a single material. However, since the resin composition can improve the compatibility between the polymer A and the polymer B, it is possible to make the glass transition temperature (Tg) single. The single glass transition temperature makes it possible to enhance the transparency of the resin composition.
Here, "glass transition temperature" refers to the temperature at which the peak of the main dispersion of loss tangent (tan δ) appears. Therefore, when only one maximum point of the loss tangent (tan δ) in shear at a frequency of 1 Hz is observed, it can be considered that the glass transition temperature (Tg) is single.

(Total light transmittance, haze)
The total light transmittance of the resin composition when molded to a thickness of 100 μm is preferably 85% or more, more preferably 88% or more, and still more preferably 90% or more.
The haze of the resin composition when molded to a thickness of 100 μm is preferably 10 or less, more preferably 2 or less, and particularly preferably 1 or less. When the haze is 10 or less, the sheet can be used for a display device depending on the application.

(Water vapor permeability)
The present resin composition is required to have a water vapor transmission rate as low as possible in order to suppress the deterioration of the light emitting element due to water and to improve the life of the display device. From this point of view, the water vapor transmission rate under an environment with a temperature of 40 ° C. and a relative humidity of 90% RH converted to a thickness of 100 μm (when the thickness is 100 μm) of the present resin composition is 20 g / m ² · 24 h or less It is more preferably 15 g / m ² · 24 h or less, particularly preferably 10 g / m ² · 24 h or less. The lower limit is not particularly limited, but is generally 0.5 g / m ² · 24 h or more.
When the water vapor transmission rate is 20 g / m ² · 24 h or less, the water vapor from the outside can be prevented and suppressed from reaching the object to be sealed, and the water vapor barrier property becomes good. In order to make the water vapor transmission rate fall in the above range, it is preferable that the polyisobutylene-based polymer (A) contained in the resin composition is contained in an appropriate amount.

Here, the water vapor transmission rate can be measured according to JIS K7129B.
For example, when the thickness is A μm and the water vapor transmission rate is Bg / (m ² · day), the water vapor transmission rate in terms of 100 μm is obtained by applying to a formula of B × A / 100. be able to.

(HSP distance)
In addition, the resin composition has a Hansen solubility parameter (HSP) distance between the isobutylene polymer (A) and the monofunctional (meth) acrylate constituting the acrylate polymer (B) of 5.0 or less. Is preferable, 4.5 or less is more preferable, and 3.8 or less is particularly preferable.
If the HSP distance is 5.0 or less, the compatibility between the isobutylene polymer (A) and the (meth) acrylate polymer (B) becomes good, and the deterioration of transparency due to bleeding out and increase of the dispersion diameter It can be suppressed.

Here, "Hansen's solubility parameter (HSP)" is an index indicating the solubility of one substance in another substance.
The HSP is a three-dimensional space in which the solubility parameter introduced by Hildebrand is divided into three components of a dispersion term δD, a polar term δP, and a hydrogen bond term δH. The dispersion term δD shows the effect due to the dispersion force, the polar term δP shows the effect due to the dipolar force, and the hydrogen bond term δH shows the effect due to the hydrogen bond force,
δD: Energy derived from intermolecular dispersion force δP: Energy derived from intermolecular polarity force δH: Energy derived from intermolecular hydrogen bonding force. (Here, each unit is MPa ^0.5 .)

The definition and calculation of HSP are described in the following documents.
Charles M. Hansen, Hansen Solubility Parameters: A Users Handbook (CRC Press, 2007).

  The dispersion term reflects the van der Waals force, the polarization term reflects the dipole moment, and the hydrogen bonding term reflects the action of water, alcohol and the like. Then, it can be determined that the vectors having similar HSPs have high solubility, and the similarity of the vectors can be determined by the distance of the Hansen solubility parameter (HSP distance). In addition, Hansen's solubility parameter can be used not only for determining solubility but also as an indicator for determining how easily a substance is present in another substance, that is, how good the dispersibility is.

  In the present invention, HSP [δD, δP, δH] can be easily estimated from its chemical structure by using, for example, computer software Hansen Solubility Parameters in Practice (HSPiP). Specifically, it is obtained from the chemical structure by the Y-MB method, which is implemented in HSPiP.

HSP distance (Ra) is, for example, a solute (in this invention (meth) acrylate-based polymer (B)) to the HSP _{(δD 1, δP 1, δH} 1) and the solvent (polyisobutylene resin in the present invention (A) the HSP of) (δD _2, δP _2, when a delta] H _2), can be calculated by the following equation.
HSP distance (Ra) = {4 × ( δD 1 -δD 2) 2 + (δP 1 -δP 2) 2 + (δH 1 -δH 2) 2} 0.5

(Isobutylene-based polymer (A))
The isobutylene polymer (A) constituting the present resin composition is a polymer having an isobutylene skeleton in its main chain or side chain, and has a structural unit of the following formula (2).

  The isobutylene polymer (A) has the function of improving the water vapor barrier property of the resin composition.

  Examples of isobutylene polymers (A) include polyisobutylene, which is a homopolymer of isobutylene, polybutene, a copolymer of isobutylene and isoprene, a copolymer of isobutylene and n-butene, a copolymer of isobutylene and butadiene, and a copolymer of these Examples thereof include halogenated butyl rubber and the like obtained by brominating or chlorinating a polymer. These polymers can be used singly or in combination of two or more.

  Among these, polyisobutylene, polybutene, and an isobutylene / isoprene copolymer are preferable from the viewpoint of improving the durability and weatherability of the present resin composition and from the viewpoint of reducing the water vapor transmission rate.

The isobutylene / isoprene copolymer comprises, in its molecule, an isobutylene-derived repeating unit [-CH ₂ -C (CH ₃ ) _2- ] and an isoprene-derived repeating unit [-CH ₂ -C (CH ₃ ) = CH- CH ₂ -] is a synthetic rubber having a.
The content of the repeating unit derived from isoprene in the isobutylene / isoprene copolymer is usually 0.1 to 99% by mole, preferably 0.5 to 50% by mole, and more preferably to all the repeating units. And 1 to 10 mol%.
If the repeating unit derived from isoprene in the isobutylene / isoprene copolymer is in the above range, a resin composition having excellent moisture resistance can be obtained, which is preferable.

  The type of isobutylene / isoprene copolymer is not particularly limited, and examples thereof include regenerated isobutylene / isoprene copolymer and synthetic isobutylene / isoprene copolymer. Among these, synthetic isobutylene / isoprene copolymer is preferable.

Examples of the synthesis method of the isobutylene polymer include a method of polymerizing a monomer component such as isobutylene in the presence of a Lewis acid catalyst such as aluminum chloride and boron trifluoride.
Moreover, a commercial item can also be used as an isobutylene type polymer (A). As commercial products, Vistanex (manufactured by Exxon Chemical Co.), Hycar (manufactured by Goodrich), Oppanol (manufactured by BASF), Tetrax (manufactured by JXTG), IP solvent (manufactured by Idemitsu Co., Ltd.), Nichiishi Polybutene (manufactured by JXTG) And the like.

The weight average molecular weight (Mw) of the isobutylene polymer (A) is preferably 50,000 to 2,000,000 g / mol, more preferably 100,000 to 1,500,000 g / mol, further preferably 100, It is 000 to 1,000,000 g / mol.
By being an isobutylene polymer (A) having a weight average molecular weight (Mw) of 50,000 g / mol or more, the flowability of the adhesive composition becomes appropriate, and after being formed into a sheet, it is easy to maintain the shape Become. Moreover, a uniform resin composition is easy to be obtained by being an isobutylene type polymer (A) whose weight average molecular weight (Mw) is 2,000,000 g / mol or less.
Here, the weight average molecular weight (Mw) is a value measured by gel permeation chromatography using tetrahydrofuran as a solvent (GPC analysis) and converted to standard polystyrene.

Moreover, the isobutylene polymer (A) which comprises this resin composition can also be used combining an isobutylene polymer (A) of 2 or more types in which weight average molecular weights differ.
By using an isobutylene polymer having a weight average molecular weight of less than 100,000 g / mol and an isobutylene polymer having a weight average molecular weight of 100,000 g / mol or more in combination, an isobutylene polymer having a bimodal molecular weight distribution is also obtained. Good.
Thus, even if the raw materials are separate raw materials, the weight average molecular weight of the whole isobutylene polymer (A) is preferably 100,000 to 2,000,000 g / mol, more preferably 100,000 to 1,500. The amount may be 1,000 g / mol, more preferably 100,000 to 1,000,000 g / mol.

  Examples of commercial products having a weight average molecular weight of less than 100,000 g / mol include trade names: Tetrax (JXTG), trade names: Hymol (JXTG), IP Solvent (manufactured by Idemitsu Co., Ltd.), and weight average molecular weight Examples of commercially available products having a molecular weight of 100,000 g / mol or more include trade name: Opanol (BASF).

(Acrylate polymer (B))
The acrylate polymer (B) has the function of imparting excellent adhesion and retention to the present resin composition.

  The acrylate polymer (B) constituting the present resin composition has at least two types of monofunctional acrylate components different in R in the following formula (1).

（式中、Ｒは炭素数１２〜３０の炭化水素基、Ｒ’は水素（Ｈ）又はメチル基（ＣＨ_３）をそれぞれ表す）

(Wherein R represents a hydrocarbon group having 12 to 30 carbon atoms, R ′ represents hydrogen (H) or methyl group (CH ₃ ), respectively)

Regarding the acrylate polymer (B), it is preferable to satisfy the following (i) and (ii).
(I) The content ratio of the monofunctional acrylate component (total content of two or more monofunctional acrylate components) is 70 parts by mass or more with respect to 100 parts by mass of the acrylate polymer (B).
(Ii) It contains at least two types of monofunctional acrylate components having R of different carbon numbers.

The content ratio of the monofunctional acrylate (total content of two or more monofunctional acrylate components) is preferably 70 parts by mass or more, more preferably 80 parts by mass with respect to 100 parts by mass of the acrylate polymer (B). The content is at least parts by mass, particularly preferably 90 parts by mass.
By the content rate of the said monofunctional acrylate being 70 mass parts or more, the cohesive force of this resin composition is improved effectively, and the favorable adhesive force of this resin composition and holding power are expressed.

In the above formula (1), R is not particularly limited as long as it is a hydrocarbon group having 12 to 30 carbon atoms, and may contain a double bond, a triple bond, or an aromatic ring. From the viewpoint of long-term stability, R is preferably a hydrocarbon group not containing a double bond, a triple bond or an aromatic ring.
Specific examples of R in the above formula (1) include, for example, decyl group (C ₁₀ ), undecyl group (C ₁₁ ), dodecyl group (C ₁₂ ), tridecyl group (C ₁₃ ), tetradecyl group (C ₁₄ ) And pentadecyl group (C ₁₅ ), hexadecyl group (C ₁₆ ), heptadecyl group (C ₁₇ ), octadecyl group (C ₁₈ ), nonadecyl group (C ₁₉ ) and the like.

Here, the acrylate-based polymer (B) preferably contains at least two types of the monofunctional acrylate components having R of different carbon numbers.
By including at least two types of monofunctional acrylate components having R having different carbon numbers, it becomes easy to make the maximum point of the loss tangent (tan δ) in the range of -30 ° C to -15 ° C.
There is no limitation as long as at least two acrylates different in R are contained, but three or more acrylates may be used.

Moreover, it is preferable that the acrylate polymer (B) which comprises this resin composition satisfy | fills following (iii).
(Iii) It contains at least one monofunctional acrylate component in which R in the above formula (1) is a branched alkyl group.

By including at least one kind of monofunctional acrylate component in which R in the above formula (1) is a branched alkyl group, the maximum point of loss tangent (tan δ) of the present resin composition can be in the range of -30 ° C to -15 ° C. It will be easier to do. Furthermore, it has the advantage that it is hard to crystallize in a normal temperature region and it becomes easy to express transparency.
The branched alkyl group is not particularly limited. For example, isodecyl group (C ₁₀ ), isoundecyl group (C ₁₁ ), isododecyl group (C ₁₂ ), isotridecyl group (C ₁₃ ), isotetradecyl group (C ₁₄ ), Branched alkyl groups such as isopentadecyl group (C ₁₅ ), isohexadecyl group (C ₁₆ ), isoheptadecyl group (C ₁₇ ), isooctadecyl (isostearyl) group (C ₁₈ ), isononadecyl group (C ₁₉ ) are preferred. Used.
The branched alkyl group may be either secondary or tertiary, and the position of the branch and the number of branches are not particularly limited as long as they can be chemically stable.

  With respect to the content of the monofunctional acrylate component in which R in the above formula (1) is a branched alkyl group, the content of the monofunctional acrylate component in which R is a branched alkyl group with respect to 100 parts by mass of the acrylate polymer (B) The proportion (total content of two or more monofunctional acrylate components) is preferably 30 parts by mass to 80 parts by mass, and more preferably 35 parts by mass to 75 parts by mass. If it is 30 mass parts or more, it will become easy to express transparency of this resin composition. On the other hand, if it is 80 mass parts or less, it will become easy to make the maximum point of the loss tangent (tan-delta) of this resin composition into the range of -30 degreeC--15 degreeC.

  Hereinafter, the acrylate monomer which is a monomer which comprises an acrylate type polymer (B) is demonstrated.

  The monofunctional (meth) acrylate which becomes an acrylate polymer (B) by a curing reaction is shown in the following formula (3).

（式中、Ｒは炭素数１２〜３０の炭化水素基、Ｒ’は水素（Ｈ）又はメチル基（ＣＨ_３）をそれぞれ表す）

(Wherein R represents a hydrocarbon group having 12 to 30 carbon atoms, R ′ represents hydrogen (H) or methyl group (CH ₃ ), respectively)

As described above, the HSP of the monofunctional (meth) acrylate is preferably at a position at which the HSP distance with the isobutylene polymer (A) is 5.0 or less, and more preferably at a position of 4.5 or less preferable.
Examples of monofunctional (meth) acrylates having an HSP distance of 5.0 or less with the isobutylene polymer (A) include isostearyl (meth) acrylate, isohexadecyl (meth) acrylate, stearyl (meth) acrylate, Hexadecyl (meth) acrylate, isotetradecyl (meth) acrylate, tetradecyl (meth) acrylate, isododecyl (meth) acrylate, dodecyl (meth) acrylate, isodecyl (meth) acrylate and the like can be mentioned.

  Further, it is preferable that at least one type of R in the formula (3) is a branched alkyl group. By including at least one monofunctional acrylate component in which R is a branched alkyl group, it is easy to make the maximum point of the loss tangent (tan δ) of the present resin composition in the range of -30 ° C to -15 ° C. Become. Furthermore, it has the advantage that it is hard to crystallize in a normal temperature region and it becomes easy to express transparency. The branched alkyl group may be secondary or tertiary, and the position of the branch and the number of branches are not particularly limited as long as they can be chemically stable.

  With respect to the precursor composition before curing (hereinafter referred to as “curable composition”), 70 parts by mass or more of monofunctional acrylate having a unit structure of the above-mentioned formula (3) with respect to 100 parts by mass of acrylate Preferably, it is 80 parts by mass or more, more preferably 90 parts by mass or more.

  The curable composition preferably contains a small amount of polyfunctional acrylate in order to improve the transparency and cohesion of the present resin composition.

The multifunctional acrylate is an acrylate having two or more acryloyloxy groups and in which at least acryloyloxy groups are bonded to each other via a hydrocarbon group.
The structure of a bifunctional aliphatic (meth) acrylate monomer as an example of a polyfunctional acrylate monomer is shown to following Formula (4).

In the above formula (4), R is hydrogen (H) or a methyl group (CH ₃ ).

The content of the multifunctional acrylate is preferably 0.5% by mass or more and less than 10% by mass, more preferably 1% by mass or more or less than 9% by mass, based on the curable composition. More preferably, it is 2% by mass or more or less than 8% by mass.
By setting the content of the polyfunctional acrylate to 0.5% by mass or more, it is possible to improve the transparency and cohesion of the present resin composition, but by setting it to less than 10% by mass, the present resin composition The plateau elastic modulus and Tg of the product can be kept low, and the bending aptitude can be expressed.

The HSP distance of the polyfunctional (meth) acrylate used in the present invention is preferably 9.0 or less, and more preferably 8.0 or less, from the isobutylene polymer (A). .
By setting the HSP distance in the above range, it is possible to suppress problems related to transparency and adhesion such as bleed out.

  In the above formula (4), X is preferably an aliphatic hydrocarbon group or an alicyclic hydrocarbon group.

  Moreover, as polyfunctional (meth) acrylates used in the present resin composition, linear chains such as 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, hydrogenated polybutadiene acrylate and the like Di (meth) acrylate having an alkyl group; di (meth) acrylate having an alicyclic skeleton such as tricyclodecanediol di (meth) acrylate and tricyclodecanedimethanol di (meth) acrylate can be mentioned. However, it is not limited to these.

  On the other hand, in the above formula (4), X may be a hydrocarbon group containing multiple bonds. As such a polyfunctional acrylate, trade name: BAC-45 (manufactured by Osaka Organic Chemical Co., Ltd., polybutadiene terminated diacrylate) can be mentioned.

  Moreover, polyfunctional urethane acrylate can also be used as polyfunctional acrylate. From the viewpoint of compatibility with the component (A), urethane acrylates having an aliphatic polymer such as polybutadiene in the backbone are preferred. As a commercial item, trade name: CN9014 NS (Sartmar) etc. can be mentioned.

  As described above, in the above formula (4), X is not particularly limited, but in view of transparency and the like, X is preferably a hydrocarbon group consisting of a single bond.

  The polyfunctional acrylate is not limited to a difunctional acrylate, and a polyfunctional (meth) acrylate having a (meth) acryloyl group of 3, 4 or more than 4 may be used, but the long-term stability of the sheet, the resin It is preferable that it is a bifunctional (meth) acrylate from the viewpoint of the ease of carrying out Tg reduction of a composition.

  The polyfunctional (meth) acrylate may be used alone or in combination of two or more.

The resin composition may further comprise a tackifier to enhance adhesion.
However, the content of the tackifier is preferably less than 10% by mass in order to prevent problems such as a decrease in high-temperature cohesion due to the addition of the tackifier and yellowing. By setting it in this range, the present resin composition excellent in high temperature cohesion can be obtained. The tackifier may be any compound or mixture of compounds that enhances the adhesion of the present resin composition.

As the tackifier, for example, aliphatic hydrocarbon tackifier represented by terpene tackifier, aromatic hydrocarbon tackifier represented by phenol tackifier, rosin tackifier Alicyclic hydrocarbon-based tackifier represented, tackifier composed of these hydrocarbon-based copolymers, epoxy-based tackifier, polyamide-based tackifier, ketone-based tackifier, and hydrogen of these An additive etc. can be mentioned. Among these, from the viewpoint of compatibility, an adhesive comprising an aliphatic hydrocarbon-based tackifier, an aromatic hydrocarbon-based tackifier, an alicyclic hydrocarbon-based tackifier, or a hydrocarbon-based copolymer thereof A imparting agent is preferred. In particular, aliphatic hydrocarbon-based tackifiers are preferred.
Moreover, these tackifiers can be used 1 type or in combination of 2 or more types.

The resin composition may contain a softening agent.
Softeners can, for example, adjust the viscosity of the composition to improve processability.

Examples of softeners that can be used include petroleum hydrocarbons such as aromatic type, paraffin type and naphthene type, liquid polybutene, liquid rubber such as hydrogenated liquid polyisoprene and derivatives thereof, vaseline, and petroleum type Asphalt can be mentioned. However, it does not limit to these.
In embodiments that use a softener, one type of softener or a combination of softeners can be used.
In the resin composition, the liquid polyisobutylene resin is treated as an isobutylene polymer (A).

In addition, the resin composition can be cured with a curing accelerator, filler, coupling agent, UV absorber, UV stabilizer, HALS, antioxidant, stabilizer, rust inhibitor, or some combination of these. You may add to a composition.
The amount of these additives is typically preferably selected so as not to adversely affect the cure of the resin composition or to adversely affect the physical properties of the curable composition.

<Method of producing the present resin composition>
Hereinafter, the manufacturing method of this resin composition is demonstrated.
However, the following description is an example of a method for producing the present resin composition, and the present resin composition is not limited to one produced by such a production method.

The present resin composition is, for example, a resin composition obtained by curing the curable composition described below.
The present resin composition is prepared, for example, by preparing a curable composition containing the polymer A and at least two monofunctional (meth) acrylate components, polymerizing the acrylate component to cure the curable composition. The present resin composition can be prepared by appropriately processing it as necessary. When the curable composition is prepared, at least two monofunctional (meth) acrylate components are polymerized to form an acrylate polymer (B).
However, the method for producing the present resin composition is not limited to such a production method.

  The curable composition which is a precursor of the present resin composition is a curable composition containing an isobutylene polymer (A) and an acrylate monomer, and as the acrylate monomer, R is different in the following formula (3) It is a curable composition containing at least two types of monofunctional acrylate monomers.

（式中、Ｒは炭素数１２〜３０の炭化水素基、Ｒ’は水素（Ｈ）又はメチル基（ＣＨ_３）をそれぞれ表す）

(Wherein R represents a hydrocarbon group having 12 to 30 carbon atoms, R ′ represents hydrogen (H) or methyl group (CH ₃ ), respectively)

For example, an isobutylene polymer (A), a monofunctional acrylate monomer, a polymerization initiator and optional components can be added to a temperature-controllable kneader (eg, single screw extruder, twin screw extruder, planetary mixer, twin screw mixer, The curable composition which is a precursor can be prepared by kneading using a pressure kneader or the like.
Various additives such as a silane coupling agent, an antioxidant, a HALS, a rust inhibitor, an ultraviolet absorber and the like are blended with a resin in advance to obtain a curable composition by mixing various raw material resins, and then extruded. The material may be supplied to the machine, or all materials may be melt mixed and then supplied, or a master batch may be prepared and supplied in which only the additive is concentrated on the resin.

In order to impart curability, as described above, the curable composition preferably contains a polymerization initiator.
The polymerization initiator is not particularly limited as long as it can be used for the polymerization reaction of acrylate. For example, those activated by heat and those activated by active energy rays can be used. Further, any of those which generate radicals to cause radical reactions and those which generate cations and anions to cause addition reactions can be used.
A preferred polymerization initiator is a photoinitiator, and the choice of photoinitiator generally depends at least in part on the specific components used in the curable composition, and the desired cure rate.

Examples of the photopolymerization initiator include acetophenone, benzoin, benzophenone, benzoyl compound, anthraquinone, thioxanthone, phosphine oxide such as phenyl and diphenyl phosphine oxide, ketone and acridine.
Specifically available as LUCIRIN (BASF), such as ethyl-2,4,6-trimethylbenzoyl diphenyl phosphinate available under the tradenames DAROCUR (Ciba Specialty Chemicals), IRGACURE (Ciba Specialty Chemicals) and LUCIRIN TPO Photopolymerization initiators can be mentioned.

  As a photoinitiator, what has an excitation wavelength range in 400 nm or more can also be selected and used. Specific examples of the photopolymerization initiator include α-diketones such as camphor quinone and 1-phenyl-1,2-propanedione; 2,4,6-trimethyl benzoyl diphenyl phosphine oxide, bis (2,4,6- Acyl phosphine oxides such as trimethyl benzoyl) -phenyl phosphine oxide; 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, 2-methyl-1- (4-methylthiophenyl)- Α-aminoalkylphenones such as 2-morpholinopropan-1-one; or bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole) Examples include titanocenes such as titanocene compounds such as 1-yl) phenyl) titanium. Among them, α-diketones and acyl phosphine oxides are preferable from the viewpoints of good polymerization activity and less harmful to the living body, and camphor quinone and 2,4,6-trimethyl benzoyl diphenyl phosphine oxide are more preferable. preferable.

On the other hand, a thermal polymerization initiator can be used in addition to the photopolymerization initiator to form a crosslinked structure.
Examples of thermal polymerization initiators include azo compounds, quinines, nitro compounds, acyl halides, hydrazones, mercapto compounds, pyrilium compounds, imidazoles, chlorotriazines, benzoins, benzoin alkyl ethers, diketones, phenones, and dilauroyl peroxides and NOFCo. . And organic peroxides such as 1,1-di (t-hexylperoxy) -3,3,5-trimethylcyclohexane available as PERHEXA TMH.

  The polymerization initiator is often used at a concentration of about 0.01 to about 10% by weight, or about 0.01 to about 5% by weight, based on the total weight of the curable composition. A mixture of polymerization initiators may be used.

  As a method for forming the curable composition into a sheet, known methods such as dry lamination, extrusion casting using a T-die, extrusion lamination, calender method, inflation method and the like can be adopted. Among them, a method of melt-forming, for example, an extrusion casting method and an extrusion laminating method are preferable in terms of handling properties and productivity.

When selecting melt molding without using a solvent, as a curable composition for melt molding, the storage elastic modulus (G ') at a shear frequency of 1 Hz in an uncured state is 50,000 Pa or more at 20 ° C. And preferably not more than 10,000 Pa at 160 ° C.
If G 'at 20 ° C is in the above range, the shape can be maintained at room temperature after molding. Moreover, if G 'in 160 degreeC is the said range, it can shape | mold, without entraining a bubble.

  The elastic modulus (storage elastic modulus) G 'and the viscosity (loss elastic modulus) G "and tan δ = G" / G' at various temperatures can be measured using a strain rheometer.

The molding temperature at the time of melt molding is appropriately adjusted depending on the flow characteristics, film forming properties and the like, but is preferably 80 to 230 ° C., more preferably 90 to 160 ° C.
In the case of melt molding, the thickness of the sheet can be appropriately adjusted by the lip gap of the T-die, the sheet take-up speed, and the like.

Moreover, it is preferable to set it as the laminated body provided with the release film in the at least single side | surface of a sheet | seat from a viewpoint of blocking prevention and foreign material adhesion prevention. As described later, this laminate is cured by irradiation with heat and / or active energy rays, whereby a laminate provided with a release film on at least one side of a sheet containing the present resin composition can be obtained. .
If necessary, embossing or various asperities (conical, pyramidal, hemispherical, etc.) may be processed. In order to improve adhesion to various adherends, the surface may be subjected to various surface treatments such as corona treatment, plasma treatment and primer treatment.

The present resin composition can be produced by curing the curable composition by irradiating it with heat and / or active energy rays. In particular, a sheet formed of the curable composition can be irradiated with heat and / or active energy rays to produce a sheet containing the present resin composition.
Here, as the active energy ray to be irradiated, ionizing radiation such as alpha ray, beta ray, gamma ray, neutron ray, electron beam, ultraviolet ray, visible ray and the like can be mentioned, among them, damage suppression to the optical device constituting member or the like Ultraviolet light is preferable from the viewpoint of reaction control. The irradiation energy of the active energy ray, the irradiation time, the irradiation method and the like are not particularly limited, as long as the polymerization initiator can be activated to polymerize the (meth) acrylate component.

  Moreover, as a result of adding paraffin and isoparaffin as a softening agent, when the viscosity of the curable composition is sufficiently low, the resin composition is coated on the film by solventless coating using a die coater or a comma coater. You may get it.

Moreover, as another embodiment of the manufacturing method of the sheet | seat containing a curable composition, the said curable composition can be melt | dissolved in an appropriate solvent, and can also be implemented using various coating methods. However, in this embodiment, consideration must be taken in terms of manufacturing cost such as solvent recovery.
When the coating method is used, a sheet containing the present resin composition can also be obtained by heat curing in addition to the above-described active energy ray irradiation curing.

  When molding by a coating method is selected, in addition to active energy ray curing, a cured composition can be easily obtained by heat curing, and when a thermosetting composition is used, it has a decomposition temperature higher than the drying temperature of the solvent A polymerization initiator is selected.

  In the case of coating, the thickness of the sheet can be adjusted by the coating thickness and the solid content concentration of the coating liquid.

<Laminated body for image display device configuration, image display device>
The sheet containing the present resin composition can be formed into a laminate for image display device construction by laminating an image display device constituent member on at least one side thereof, and an image is formed using the laminate for image display device construction The display device can be configured.

Any one or more of the group consisting of a touch panel, an image display panel, a surface protection panel, a retardation film, a polarizing film, a color filter, and a flexible substrate are laminated on at least one side of a sheet containing the present resin composition It can be set as the laminated body for image display apparatuses provided with the following structure.
An image display apparatus can be configured using the laminate for an image display apparatus configuration which is any one type or a combination of two or more types.

Furthermore, it can also be set as the image display apparatus provided with the sheet | seat containing this resin composition. For example, in a top emission type flexible OLED display, a light emitting layer is formed on a resin substrate such as polyimide, and the light emitting layer side is a display surface, but by arranging the main sealing material on the non display surface side of the resin substrate, It is possible to prevent the penetration of water from the non-display surface side and the moisture absorption of the polyimide, which can contribute to prolonging the lifetime of the OLED. In addition, the influence of the deformation of the display surface and the external force can be suppressed.
By providing a sheet containing the present resin composition, it can be used as a foldable image display device.

<Explanation of the phrase>
In the present specification, when expressing as “X to Y” (X and Y are arbitrary numbers), “preferably greater than X” or “preferably Y” with the meaning of “X or more and Y or less” unless otherwise stated. Also includes the meaning of "smaller".
Also, when expressed as “X or more” (X is an arbitrary number) or “Y or less” (Y is an arbitrary number), “greater than X is preferable” or “preferably less than Y” It also includes the intention.

  The present invention is further illustrated by the following examples, which are not intended to limit the present invention in any way.

  The compounds and materials used in each example are shown below.

[Isobutylene-based polymer (A)]
· (A) -1: Opanol N50SF (manufactured by BASF, polyisobutylene, Mw: 565,000 g / mol, (HSP δD: 15.1, δP: 0, δH: 0))
-(A) -2: Tetrax 3T (manufactured by JXTG, polyisobutylene, Mw: 49,000 g / mol, (HSP δD: 15.1, δP: 0, δH: 0))
・ (A) -3: IP solvent 2835 (Idemitsu Co., isobutylene polymer)
· (A) -4: Nichiishi Polybutene HV-300 (manufactured by JXTG, polybutene, number average molecular weight: 1,400)

[Monomer of Acrylate Polymer (B)]
(I) Monofunctional (meth) acrylate (B) -1: S-1800 ALC (manufactured by Shin-Nakamura Chemical Co., Ltd., isostearyl acrylate, an acrylate in which one acryloyloxy group is added to a branched alkyl having 18 carbon atoms). HSP distance from component (A): 3.74)
· (B) -2: Blenmer CA (manufactured by NOF Corporation, hexadecyl acrylate, acrylate having one acryloyloxy group added to linear alkyl having 16 carbon atoms. HSP distance from component (A): 4.08 )
-(B)-3: Blenmer VA (manufactured by NOF Corporation, Behenyl Acrylate, an acrylate obtained by adding one acryloyloxy unit to a linear alkyl having 22 carbon atoms. HSP distance from component (A): 3.61)

(Ii) Multifunctional (meth) acrylate (B) -4: CD 595 (Sartmar, 1,10-decanediol diacrylate, HSP distance from component (A): 6.65)
・ (B) -5: A-DCP (manufactured by Shin-Nakamura Chemical Co., Ltd., tricyclodecane dimethanol diacrylate, HSP distance from component (A): 7.77)
· (B) -6: CN 9014 NS (Sartmar company, polybutadiene-based bifunctional urethane acrylate)

[Tackifier (C)]
・ (C) -1: YS resin PX800 (Yashara Chemical Co., terpene resin)

[Polymerization initiator]
(D) -1: Darocure TPO (manufactured by BASF, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide)

<Method of Producing Sheet-like Curable Composition>
The isobutylene polymer, monofunctional (meth) acrylate, polyfunctional (meth) acrylate, tackifier, and polymerization initiator are mixed until the composition becomes uniform according to the composition described in Table 1 and Table 2 The curable composition which is a precursor of a resin composition was obtained.
Subsequently, the curable composition is spread between two sheets of release-treated polyethylene terephthalate film (manufactured by Mitsubishi Chemical Corporation, Diafoil MRF 38, thickness: 38 μm), provided with a release film on both sides, and cured. A sheet-like curable composition having a thickness of about 100 μm of the base composition layer was obtained.

Next, with the release film laminated, the resulting sheet-like curable composition is irradiated with ultraviolet light using a high pressure mercury lamp so that the integrated light quantity of 365 nm is 2000 mJ / cm ^2, and 23 ° C. 50% By curing at RH for 15 hours or more, a laminate including a sheet (sample) made of a resin composition containing an acrylate polymer formed by polymerizing monofunctional (meth) acrylate in an intermediate layer was obtained.

<Evaluation test of curable composition and uncured sheet>
(HSP, HSP distance (Ra))
HSP was obtained from the chemical structure by the Y-MB method, which is implemented in HSP integrated software HSPiP (trade name).
HSP distance (Ra) is, when the the HSP of (meth) acrylate monomer _{(δD 1, δP 1, δH} 1) and then, isobutylene polymer to the HSP _{(A) (δD 2, δP} 2, δH 2) , It calculated by the following formula.
HSP distance (Ra) = {4 × ( δD 1 -δD 2) 2 + (δP 1 -δP 2) 2 + (δH 1 -δH 2) 2} 0.5

(Dynamic viscoelasticity)
The release film on both sides of the obtained laminate is peeled off, and a plurality of sheets (samples) are stacked to produce a sheet having a thickness of about 2 mm, which is punched into a circle having a diameter of 20 mm as a rheometer (Eiko Seiki Co., Ltd. Using a company-made MARS, adhesive jig: 20 20 mm parallel plate, strain: 0.1%, frequency: 1 Hz, temperature: -70 to 150 ° C, heating rate: 3 ° C / min. Thus, the storage modulus (G ′), loss modulus (G ′ ′) and loss tangent (tan δ) of the sheet (sample) were obtained.

(Foldability evaluation)
The release film on both sides of the obtained laminate is peeled off, and a PET film with a thickness of 100 μm and a PET film with a thickness of 50 μm are bonded on both sides, and the bonded product is autoclaved (60 ° C, gauge pressure 0.2 MPa, 20 minutes ) And finish-paste to prepare a sample for evaluation.
U-bending was repeatedly performed on a 50 μm-thick PET side according to IEC 63715 using DLDML-FS manufactured by Yuasa System Co., Ltd. as a sample for evaluation. Test conditions were 20 ° C., frequency 1 Hz, R = 3 mm, 100,000 times, and the bendability was evaluated based on the following criteria.
○: No buckling or flow marks are found after bending 100,000 times.
X: Either buckling or flow marks are observed after bending 100,000 times.

(Adhesion test)
One release film of the obtained sheet (sample) was peeled off, and a 50 μm polyethylene terephthalate film (manufactured by Mitsubishi Resins Co., Ltd., Diafoil T100, thickness 50 μm) was laminated as a backing film to prepare a laminate.
The laminated product was cut into a length of 150 mm and a width of 10 mm, and then the remaining release film was peeled off, and the exposed adhesive surface was roll-crimped to soda lime glass. The bonded product was subjected to an autoclave treatment (60 ° C., gauge pressure 0.2 MPa, 20 minutes) for final bonding, and a sample for adhesive strength measurement was prepared.

The adhesive force (N / cm) with the glass when it peels off the said peeling force measurement sample at peeling angle 180 degrees and peeling speed 60 mm / min was measured, and the following references | standards evaluated.
○: adhesive strength of 1 N / cm or more ×: adhesive strength of less than 1 N / cm The results for the obtained resin compositions are shown in Tables 3 and 4, respectively.

(Holding test)
A sheet (sample) having a thickness of 100 μm prepared in Examples and Comparative Examples is cut into 40 mm × 50 mm, the release film on one side is peeled off, and a polyethylene terephthalate film for backing (manufactured by Mitsubishi Resins Co., Ltd., Diafoil S-100) After affixing a thickness of 38 μm on the back with a hand roller, this was cut into strips 25 mm wide × 100 mm long to obtain test pieces.
Next, the remaining release film was peeled off and attached to a SUS plate (120 mm × 50 mm × thickness 1.2 mm) with a hand roller so that the adhesion area was 25 mm × 25 mm.

Thereafter, the test piece is aged under an atmosphere of 40 ° C. for 15 minutes, and then a 1 kgf weight is vertically attached to the test piece and hung, and then the weight falling time (minute) is measured. It evaluated by the standard.
○: not falling within 30 minutes Δ: exceeding 10 minutes, falling within 30 minutes (within the practical range)
×: dropped within 10 minutes

  The results for the resin compositions obtained are shown in Table 3 and Table 4.

(Haze)
The haze is based on JIS K7361 according to JIS K7361-1 using a haze meter (NDH 5000 manufactured by Nippon Denshoku Kogyo Co., Ltd.) in a state where glass is attached to both sides of a sheet (sample), according to JIS K7136 The haze was respectively measured in the same manner. The results for the resin compositions obtained are shown in Table 3 and Table 4.

(Dampproof)
After measuring the thickness of the obtained sheet (sample), the release PET on both sides is peeled off, and instead, a PET non-woven fabric is attached, and the water vapor transmission rate of 90% Rh at 40 ° C is measured by JIS K7129B method. It evaluated by the evaluation criteria.
○: A water vapor transmission rate of 20 g / m ² · 24 h or less in 100 μm conversion ×: A water vapor transmission rate of 20 g / m ² · 24 h in 100 μm conversion

In addition, in the case of a cured sheet having a thickness of A μm and a water vapor transmission rate of B (g / m ² · 24 h), the equation of A × B / 100 is used to compare those with slightly different thicknesses. It fitted and calculated | required the value of 100 micrometers conversion. The results for the resin compositions obtained are shown in Table 3 and Table 4.

<Production example using solvent>
In the composition of Example 1 described in Table 1, the isobutylene polymer, monofunctional (meth) acrylate, polyfunctional (meth) acrylate, tackifier and polymerization initiator are uniformly mixed to obtain a resin of the present invention The curable composition which is a precursor of a composition was obtained.
100 parts by mass of the obtained curable composition was transferred to a light shielding container, and 200 parts by mass of heptane was added and dissolved to obtain a uniform coating liquid.
Subsequently, the coating solution is spread on the release surface side of the release-treated polyethylene terephthalate film (Differif MRF 38, thickness: 38 μm, manufactured by Mitsubishi Chemical Co., Ltd.), and the dryer at 120 ° C. After drying for another 15 minutes, another release-treated PET film is laminated using a hand roller, and a sheet-like sheet having a thickness of about 100 μm of the curable composition layer is provided with a release film on both sides. A curable composition was obtained.
Then, with the resulting sheet-like curable composition was laminated a release film, it is irradiated to 365nm of accumulated light quantity is 2000 mJ / cm ² of ultraviolet rays by a high-pressure mercury lamp, 23 ° C. 50% RH By curing for at least 15 hours, a laminate having a sheet (sample) made of a resin composition containing an acrylate polymer formed by polymerizing monofunctional (meth) acrylate in an intermediate layer was obtained.
There were no differences in various physical properties and evaluation items compared to the production method without using a solvent.

The sheets obtained in Examples 1 to 6 all have local maximum points of loss tangent (tan δ) at a frequency of 1 Hz shear in the range of -30 ° C to -15 ° C, and excellent adhesion and retention strength , Bendability and water vapor barrier property.
Examples 1 to 5 were more significant as to the holding power as compared with Example 6. Moreover, in comparison with Example 5, Examples 1 to 4 were more significant than the point of the haze (transparency). However, even the haze of Example 5 has practicality.
The sheets obtained in Comparative Examples 1 to 3 and Comparative Example 5 do not have maximum points of loss tangent (tan δ) in shear at a frequency of 1 Hz in the range of -30 ° C to -15 ° C, and are bendable. Buckling was observed at all during the evaluation.
In Comparative Example 4 in which an acrylate-based polymer composed only of a multifunctional acrylate was used, adhesion strength and holding power were inferior, and after flow was observed in evaluation of bendability.

Claims (11)

A resin composition comprising an isobutylene polymer (A) and an acrylate polymer (B), wherein at least one maximum point of loss tangent (tan δ) in shear at a frequency of 1 Hz is in the range of -30 ° C to -15 ° C. In
The resin composition in which the said acrylate polymer (B) has at least 2 types of monofunctional acrylate components in which R differs in following Formula (1).

(Wherein R represents a hydrocarbon group having 12 to 30 carbon atoms, R ′ represents hydrogen (H) or methyl group (CH ₃ ), respectively) The resin composition according to claim 1, wherein the acrylate polymer (B) satisfies the following (i) and (ii).
(I) The content ratio of the monofunctional acrylate component is 70 parts by mass or more with respect to 100 parts by mass of the acrylate polymer (B).
(Ii) It contains at least two types of the monofunctional acrylate components having the R having different carbon numbers. The resin composition according to claim 1, wherein the acrylate polymer (B) satisfies the following (iii).
(Iii) It contains at least one kind of the monofunctional acrylate component in which R in the above formula (1) is a branched alkyl group.   The content ratio of the monofunctional acrylate component in which R in the above formula (1) is a branched alkyl group is 30 parts by mass to 80 parts by mass with respect to 100 parts by mass of the acrylate polymer (B). The resin composition as described. A curable composition comprising an isobutylene polymer (A) and an acrylate monomer, wherein the curable composition comprises, as the acrylate monomer, at least two monofunctional acrylate monomers having different R in the following formula (3).

(Wherein R represents a hydrocarbon group having 12 to 30 carbon atoms, R ′ represents hydrogen (H) or methyl group (CH ₃ ), respectively)   A resin composition obtained by curing the curable composition according to claim 5.   A sheet comprising the resin composition according to any one of claims 1 to 4 or claim 6.   A laminate comprising a release film on at least one side of the sheet according to claim 7.   A touch panel, an image display panel, a surface protection panel, a retardation film, a polarizing film, a color filter, and at least one of the group consisting of a flexible substrate are laminated on at least one side of the sheet according to claim 7 A laminated body for an image display device, comprising:   The image display apparatus provided with the sheet | seat of Claim 6.   The image display device according to claim 10, wherein the image display device can be bent.