JP7259208B2 - Resin composition, molding, laminate and image display device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin composition using a butene polymer, a molded article, a laminate and an image display device using the resin composition.

In recent years, curved image display devices using organic light emitting diodes (OLEDs) and quantum dots (QDs) and bendable image display devices have been developed and are being widely commercialized.
Such a display device has a structure in which a plurality of film-like structural members are bonded together with a transparent optical adhesive (OCA) sheet. However, conventionally used acrylic transparent optical adhesive (OCA) sheets have various problems due to lack of moisture-proof performance, and problems such as corrosion and migration of metal electrodes. There is also a problem that the impact resistance of the image display device is insufficient, and there has been a demand for a transparent optical adhesive (OCA) sheet of a new material system.

Examples of polymeric materials that may solve the above problems include butene-based polymers, that is, polymers containing butene or isobutene as a polymer component.
A sheet using a butene-based polymer such as polybutene or polyisobutene as a main component resin is excellent in water vapor barrier properties, low dielectric constant properties, and impact resistance, and is a particularly noteworthy material.
However, due to its molecular structure, butene-based polymers have high intermolecular friction and are excellent in converting impact into thermal energy. , had problems such as poor low-temperature fluidity.

Therefore, it has been proposed to solve this problem by combining the butene polymer (A) with the component (B), for example, an acrylate polymer.
For example, Patent Document 1 discloses an adhesive encapsulating composition comprising a polyisobutylene resin having a weight average molecular weight of greater than 300,000 g/mol and a polyfunctional (meth)acrylate monomer, and this adhesive composition It is described that the adhesive film obtained from the product has excellent water vapor barrier properties and transparency.

Japanese Patent Publication No. 2011-526629

However, although the pressure-sensitive adhesive sheet disclosed in Patent Document 1 can have excellent water vapor barrier properties, it has large loss tangent (tan δ) values at 80° C. and 100° C., so it does not have sufficient high-temperature holding power. Not only is there a concern that it does not have it, but the impact resistance is not sufficient. Thus, ensuring impact resistance has been a notable issue for sheets using butene-based polymers.

Accordingly, the present invention relates to a resin composition using a butene polymer having water vapor barrier properties as a main component resin, and a new resin composition capable of effectively improving impact resistance while maintaining low dielectric constant properties. It is intended to provide a resin composition.

The present invention relates to a resin composition containing a butene polymer (A) having a number average molecular weight (Mn) of less than 5000 and an acrylic polymer, which is obtained by dynamic viscoelasticity measurement in a shear mode at a frequency of 1 Hz. A resin composition is proposed in which the maximum value of the loss tangent (tan δ) is 30° C. or less and the temperature range in which the loss tangent (tan δ) is 1 or more is 20° C. or more.

Since the resin composition proposed by the present invention is a resin composition containing a butene polymer (A) having a number average molecular weight (Mn) of less than 5000, it is excellent in water vapor barrier properties and low dielectric constant properties. Moreover, the temperature of the maximum value of the loss tangent (tan δ), that is, the temperature at which the impact resistance is most excellent is 30 ° C. or less, that is, the room temperature or less, and the temperature range in which the loss tangent (tan δ) is 1 or more is 20. °C or higher, the impact resistance at room temperature can be effectively improved.
Therefore, the resin composition proposed by the present invention can suitably form constituent members of image display devices and the like, and can contribute to, for example, thinning of image display devices and the like.

Next, the present invention will be described based on embodiments. However, the present invention is not limited to the embodiments described below.

[This resin composition]
A resin composition according to an example of the embodiment of the present invention (referred to as "this composition") is a resin composition containing a butene-based polymer (A) having a number average molecular weight (Mn) of less than 5,000.
By containing the butene-based polymer (A) of less than 5000, the composition has a high storage elastic modulus at low temperatures and a low storage modulus at high temperatures, so excellent adhesiveness and holding power can be obtained.
The loss tangent (tan δ), storage modulus (G′), relative permittivity, total light transmittance and haze of the composition described below were obtained by curing the composition as shown in the examples described later. later value.

<Loss tangent (tan δ)>
The composition preferably has a maximum value of loss tangent (sometimes referred to as “tan δ”) obtained by dynamic viscoelasticity measurement in shear mode at a frequency of 1 Hz at 30° C. or less.
The fact that the maximum point of the loss tangent (tan δ) is 30° C. or less, that is, in the low temperature range to the normal temperature range means that the glass transition temperature is in the low temperature range to the normal temperature range. The stress when deformation is applied is reduced, and a resin composition having excellent impact resistance can be obtained. However, if the maximum value is too low, the impact resistance may decrease.
Therefore, in the present composition, the maximum value of the loss tangent (tan δ) at a frequency of 1 Hz is preferably 30 ° C. or lower, especially -70 ° C. or higher, especially -60 ° C. or higher or 20 ° C. or lower, especially - More preferably, the temperature is 50°C or higher or 10°C or lower.

The maximum value of the loss tangent (tan δ) is the peak value in the tan δ curve, that is, the maximum value in a predetermined range or the entire range among the inflection points that change from positive (+) to negative (-) when differentiated. is the meaning of the value of

Furthermore, the present composition has a maximum value of loss tangent (tan δ) obtained by dynamic viscoelasticity measurement in a shear mode at a frequency of 1 Hz, and the maximum value at 30 ° C. or less is 1.0 or more. It is preferable for the development of durability, that is, impact resistance.
From this point of view, the maximum value is preferably 1.0 or more, more preferably 1.1 or more, and more preferably 1.2 or more.

In the present composition, the temperature range in which the loss tangent (tan δ) obtained by dynamic viscoelasticity measurement in a shear mode at a frequency of 1 Hz is 1 or more is preferably 20° C. or more, more preferably 30° C. or more. . The temperature range in which the loss tangent (tan δ) is 1 or more is preferably as wide as possible.
Since the present composition has a wide temperature range in which the loss tangent (tan δ) is 1 or more, it can absorb impacts at wide frequencies in a wide temperature range, and can exhibit impact resistance.

The composition preferably has a loss tangent (tan δ) at 100° C. of 0.3 or less in shear measurement at a frequency of 1 Hz to prevent flow.
From such a viewpoint, the present composition preferably has a loss tangent (tan δ) at 100° C. in shear measurement at a frequency of 1 Hz of 0.3 or less, more preferably 0.28 or less, and more preferably 0.25 or less. Even more preferable.

Incidentally, when a butene-based polymer (A) having a number average molecular weight (Mn) of 10,000 or more, particularly 20,000 or more is used, the loss tangent (tan δ) is 1 or more at least at -30 to 30°C, and , the loss tangent (tan δ) at 100° C. is difficult to be 0.3 or less.

In order to adjust the maximum point of loss tangent (tan δ) in the present composition, the molecular weight, type and blending amount of the butene polymer (A) can be selected variously. Also, in order to adjust the loss tangent (tan δ) at 100° C., various types and blending amounts of the acrylic polymer (B) and/or other resins such as urethane resins can be selected.
Furthermore, the loss tangent can also be adjusted with a tackifier (C), which will be described later.

<Storage modulus (G')>
The composition preferably has a storage modulus (G') of 2,000 Pa or more at 20°C and 200,000 Pa or less at 100°C, which is obtained by dynamic viscoelasticity measurement in a shear mode at a frequency of 1 Hz.
If the G' at 20°C is within the above range, the resin composition can have good handleability. Moreover, when G' at 100° C. is within the above range, good flexibility can be obtained.
From such a viewpoint, in the present composition, the storage elastic modulus (G') in shear at a frequency of 1 Hz is preferably 2,000 Pa or more at 20 ° C., especially 3,000 Pa or more or 200,000 Pa or less. Above all, it is more preferably 4,000 Pa or more or 100,000 Pa or less.
In addition, the storage elastic modulus (G′) at 100° C. is preferably 200,000 Pa or less, especially 2,000 Pa or more or 150,000 Pa or less, especially 3,000 Pa or more or 100,000 Pa or less. is more preferred.

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

In the present composition, in order to adjust the storage modulus (G') within the above range, it is possible to adjust the amount of the acrylic polymer blended, its glass transition temperature, and the addition of a tackifier. .

<Glass transition temperature>
The composition preferably has a single glass transition temperature (Tg).
A multi-component system containing at least components (A) and (B) rarely has a single glass transition temperature (Tg) like a single material. However, as will be described later, by selecting and mixing a resin (B) having good compatibility with the butene polymer (A), the glass transition temperature (Tg) can be made uniform. Having a single glass transition temperature makes it possible to further enhance the transparency of the present composition.
The “glass transition temperature” is the temperature at which the peak of the principal dispersion of the loss tangent (tan δ) appears. Therefore, when only one maximum point of the loss tangent (tan δ) obtained by dynamic viscoelasticity measurement is observed in a shear mode with a frequency of 1 Hz, in other words, when the tan δ curve exhibits a unimodal shape, the glass transition temperature ( Tg) can be assumed to be unity.

<Dielectric constant>
The composition preferably has a dielectric constant of 3.0 or less.
If the relative dielectric constant is 3.0 or less, malfunctions can be reduced when the present composition is used, for example, as a member of a touch panel.
From this point of view, the composition preferably has a dielectric constant of 3.0 or less, more preferably 1.5 or more or 2.9 or less, and more preferably 1.6 or more or 2.8 or less. .
As a method for adjusting the dielectric constant, for example, changing the blending amount of the butene polymer (A) can be mentioned.

<Total light transmittance, haze>
The composition preferably has a total light transmittance of 85% or more, more preferably 88% or more, and even more preferably 90% or more.
The composition preferably has a haze of 2% or less, more preferably 1% or less, and particularly preferably 0.5% or less.
Since the composition has a haze of 2% or less, it can be used for image display devices.

As a method for adjusting the total light transmittance range or the haze range of the present composition, the type of the butene polymer (A) may be adjusted, or the butene polymer (A) may be It can also be adjusted by adding another resin (B) and adjusting the type and amount of the other resin (B).

<Composition of the present composition>
The composition can also be formed from the butene-based polymer (A). However, from the viewpoint of adjusting the loss tangent (tan δ) of the present composition, the butene polymer (A) and the acrylic polymer (B) are combined, and the butene polymer (A) and the acrylic polymer ( It is preferable to adjust the type and amount of B) respectively. Addition of a tackifier (C) is also preferable from the viewpoint of adjusting the loss tangent (tan δ) of the present composition.
Therefore, first, the butene polymer (A), the acrylic polymer (B) combined therewith, and the tackifier (C) will be described in order.

<Butene polymer (A)>
The butene-based polymer (A) used in the present composition preferably has an iso-butene unit as a structural unit from the viewpoint of enhancing internal friction and moisture resistance.
More specifically, it is preferably a polymer having 5 to 100% by mass of an iso-butene unit represented by the following formula (1). More preferably, it is 99 mass % or less.

Examples of preferred copolymerization components of iso-butene units include n-butene, isoprene, styrene, vinyl ether, etc. Particularly preferred is n-butene.

When the butene-based polymer (A) contains n-butene units, the content is preferably 0.1 to 50% by mass, more preferably 1% by mass or more or 40% by mass or less. .

Examples of the butene-based polymer (A) include brominated or chlorinated copolymers. These polymers can be used singly or in combination of two or more.

Examples of a method for synthesizing a butene polymer include a method of polymerizing a monomer component such as isobutylene in the presence of a Lewis acid catalyst such as aluminum chloride or boron trifluoride.

By containing the butene-based polymer (A) having a number average molecular weight (Mn) of less than 5,000, the present composition can maintain water vapor barrier properties and low dielectric constant properties. However, if the number average molecular weight (Mn) is too low, it may become difficult to retain the shape.
Therefore, the number average molecular weight (Mn) of the butene polymer (A) is preferably less than 5000, more preferably 10 or more, more preferably 100 or more, and more preferably 500 or more.

As the butene polymer (A), two or more butene polymers having different number average molecular weights (Mn) can be used in combination.
For example, a butene polymer having a number average molecular weight (Mn) of less than 5,000 and a butene polymer having a number average molecular weight (Mn) of 5,000 or more are used in combination, and the number average of the butene polymer (A) as a whole is The molecular weight (Mn) may be adjusted to fall within the above range.

<Acrylic polymer (B)>
In the present composition, the acrylic polymer (B) combined with the butene polymer (A) has, as structural units, a monofunctional (meth)acrylate unit represented by the following formula (2) and a polyfunctional (meth)acrylate It is preferred to have each unit.

In formula (2) above, R represents a long-chain alkyl group having 10 or more carbon atoms. In the above formula, R' is preferably hydrogen (H) or a methyl group ( _CH3 ).

The long-chain alkyl group (R) having 10 or more carbon atoms means, for example, an alkyl group having 10 or more carbon atoms in the main chain, and examples thereof include a decyl group (C ₁₀ ), an undecyl group (C ₁₁ ), a dodecyl group ( C ₁₂ ), tridecyl group (C ₁₃ ), tetradecyl group (C ₁₄ ), pentadecyl group (C ₁₅ ), hexadecyl group (C ₁₆ ), heptadecyl group (C ₁₇ ), octadecyl group (C ₁₈ ), nonadecyl group (C ₁₉ ) and the like. Although the upper limit of the number of carbon atoms in the main chain is not particularly defined, if it is 20 or less, preferably 18 or less, crystallization between monofunctional (meth)acrylates is difficult to occur, so transparency due to low haze and high total light transmittance It becomes easier to express sexuality.

As long as the main chain has 10 or more carbon atoms, the long-chain alkyl group (R) may have a branched alkyl group. In general, a branched alkyl group is less likely to crystallize in a room temperature range than a straight chain alkyl group, and is more likely to exhibit transparency.

It is also effective to use two or more different long-chain alkyl groups in combination to suppress crystallization and improve transparency.

As for the Hansen solubility parameter (HSP) of the monofunctional (meth)acrylate, the HSP distance to the butene polymer (A) is preferably 5.0 or less, more preferably 4.5 or less, and further preferably 3. 0.8 or less is particularly preferred.
If the HSP distance between the butene-based polymer (A) and the monofunctional acrylate of the acrylate-based polymer is 5.0 or less, the compatibility between the butene-based polymer (A) and the acrylate-based polymer is good, and bleeding occurs. It is possible to suppress deterioration of transparency due to outflow and increase in dispersion diameter.

Here, the "Hansen Solubility Parameter (HSP)" is an index representing the solubility of a substance in another substance.
HSP divides the solubility parameter introduced by Hildebrand into three components, a dispersion term δD, a polar term δP, and a hydrogen bonding term δH, and expresses them in three-dimensional space. The dispersion term δD indicates the effect of the dispersion force, the polar term δP indicates the effect of the dipole force, and the hydrogen bonding term δH indicates the effect of the hydrogen bonding force,
δD: Energy derived from intermolecular dispersion force δP: Energy derived from intermolecular polar 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 references.
Charles M. Hansen, Hansen Solubility Parameters: A Users Handbook (CRC Press, 2007).

The dispersion term reflects the van der Waals force, the polar term the dipole moment, and the hydrogen bond term the action of water, alcohol, etc., respectively. It can be judged that substances with similar HSP vectors have high solubility, and the degree of vector similarity can be judged from the distance of the Hansen solubility parameter (HSP distance). In addition, the Hansen solubility parameter can be used not only as an index for judging solubility, but also as an index for judging how easily a certain substance exists in another certain substance, that is, how good the dispersibility is.
In the present invention, HSP[δD, δP, δH] can be easily estimated from its chemical structure, for example, by using computer software Hansen Solubility Parameters in Practice (HSPiP). Specifically, it is determined from the chemical structure by the Y-MB method implemented in HSPiP. If the chemical structure is unknown, it can be determined by the sphere method implemented in HSPiP from the results of dissolution tests using a plurality of solvents.
The HSP distance (Ra) is, for example, the HSP of the solute (e.g. acrylic polymer) is (δD ₁ , δP ₁ , δH ₁ ), and the HSP of the solvent (e.g. butene polymer (A)) is (δD ₂ , δP ₂ , δH ₂ ), it can be 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

One type of monofunctional (meth)acrylate may be used, or several types may be used in combination.

The content of the monofunctional (meth)acrylate structural unit is preferably 60 to 90% by mass, more preferably 70% by mass or more or 90% by mass or less, relative to the entire acrylic polymer component. By setting the content in the above range, the cohesive force can be enhanced while exhibiting transparency.

The content of the monofunctional (meth)acrylate structural unit in the present composition is preferably 5% by mass or more, preferably 10% by mass or more, and more preferably 15% by mass or more. When the content is 5% by mass or more, the creep resistance of the sheet can be enhanced. On the other hand, the upper limit is preferably 40% by mass or less, more preferably 38% by mass or less, and particularly preferably 35% by mass or less. In the present composition, when the content of the monofunctional (meth)acrylate structural unit is 40% by mass or less, the water vapor barrier property can be enhanced.

The present composition preferably contains a polyfunctional (meth)acrylate unit as a monomer component of the acrylic polymer in order to develop the molecular chain network of the acrylic polymer and adjust the tan δ of the composition.

A polyfunctional acrylate is a (meth)acrylate that has two or more (meth)acryloyloxy groups and at least the (meth)acryloyloxy groups are bonded to each other via a hydrocarbon group. As an example of polyfunctional (meth)acrylate, the structure of bifunctional aliphatic (meth)acrylate is shown in formula (3) below.

In formula (3) above, R is hydrogen (H) or a methyl group (CH ₃ ).
X is an aliphatic hydrocarbon group or an alicyclic hydrocarbon group.

The Hansen solubility parameter (HSP) of the polyfunctional (meth)acrylate is preferably at a position where the HSP distance with the butene polymer (A) is 9.0 or less, more preferably at a position of 8.0 or less. preferable.
By setting the HSP distance within the above range, troubles related to transparency and adhesiveness such as bleeding out can be suppressed.

In the polyfunctional (meth)acrylate, the aliphatic hydrocarbon group or alicyclic hydrocarbon group (X) is preferably a hydrocarbon group containing no multiple bond from the viewpoint of long-term stability of the sheet.

Polyfunctional (meth)acrylates used in the present composition include 1.9-nonanediol di(meth)acrylate, 1.10-decanediol di(meth)acrylate, hydrogenated polybutadiene (meth)acrylate and other straight chain di(meth)acrylates having an alkyl group; di(meth)acrylates having an alicyclic skeleton such as tricyclodecanediol di(meth)acrylate and tricyclodecanedimethanol di(meth)acrylate. However, it is not limited to these.

Moreover, a polyfunctional urethane acrylate can also be used as a polyfunctional (meth)acrylate. From the viewpoint of compatibility with component (A), urethane acrylates having an aliphatic polymer such as polybutadiene as a skeleton are preferable.
Commercially available products include trade name: CN9014 NS (Sartomer), trade name: BAC-45 (manufactured by Osaka Organic Chemical Co., Ltd., polybutadiene-terminated diacrylate).

Polyfunctional (meth)acrylates are not limited to difunctional (meth)acrylates, and polyfunctional (meth)acrylates having 3, 4, or more than 4 (meth)acryloyl groups may be used. Among them, bifunctional (meth)acrylates are preferable from the viewpoint of long-term stability of the sheet and easy availability of acrylates.

In addition, polyfunctional (meth)acrylate may use only 1 type, or may use several types together.

The content of the polyfunctional (meth)acrylate structural unit is preferably 0.5% by mass or more and less than 10% by mass, and more preferably 1% by mass or more or less than 9% by mass. Among them, it is more preferably 2% by mass or more or less than 8% by mass.
When the content of the polyfunctional (meth)acrylate structural unit is 0.5% by mass or more, it is possible to adjust the network of the component (B), while when it is less than 10% by mass, bleeding out can be reduced, and in combination with the monofunctional (meth)acrylate, the transparency can be enhanced.

(Content ratio of acrylic polymer)
The acrylic polymer (B) combined with the butene polymer (A) is preferably contained in a proportion of 5 to 100 parts by mass per 100 parts by mass of the butene polymer (A).
When the content of the acrylate-based polymer is 5 parts by mass or more, the cohesive force of the present composition can be effectively improved. Moreover, when the content of the (meth)acrylate polymer is 100 parts by mass or less, a low dielectric constant and impact resistance can be exhibited.
From this point of view, the acrylate polymer (B) is preferably contained in a proportion of 5 to 100 parts by mass with respect to 100 parts by mass of the butene polymer (A). Among them, it is more preferable to contain at a ratio of 10 parts by mass or more or 80 parts by mass or less.

<Tackifier (C)>
The present composition may contain a tackifier (C) to adjust the temperature of the maximum value of tan δ (glass transition temperature). 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 cohesive strength and yellowing due to the addition of the tackifier. By setting the amount within this range, the present composition having excellent high-temperature cohesive strength can be obtained.
The tackifier can be any compound or mixture of compounds that enhances the adhesive properties of the composition.

Examples of the tackifier (C) include aliphatic hydrocarbon-based tackifiers typified by terpene-based tackifiers, aromatic hydrocarbon-based tackifiers typified by phenol-based tackifiers, and rosin-based tackifiers. Alicyclic hydrocarbon-based tackifiers represented by imparting agents, tackifiers composed of these hydrocarbon-based copolymers, epoxy-based tackifiers, polyamide-based tackifiers, ketone-based tackifiers, and These hydrogenated products and the like can be mentioned. Among these, from the viewpoint of compatibility, an aliphatic hydrocarbon-based tackifier, an aromatic hydrocarbon-based tackifier, an alicyclic hydrocarbon-based tackifier, and an adhesive made of these hydrocarbon-based copolymers An imparting agent is preferred. Aliphatic hydrocarbon-based tackifiers are particularly preferred.
Moreover, these tackifiers can be used singly or in combination of two or more.

<Other ingredients>
The composition may contain softening agents.
Softeners can, for example, adjust the viscosity of the composition to improve processability.

Examples of softening agents that can be used include petroleum hydrocarbons such as aromatic, paraffinic, and naphthenic types, liquid rubbers or derivatives thereof, petroleum jelly, and petroleum asphalt. However, it is not limited to these.
In embodiments using a softening agent, a single softening agent or a combination of softening agents can be used.
In addition, in this composition, liquid polybutene is treated as a butene-based polymer (A).

The composition may contain an antirust agent.
Triazoles and benzotriazoles are particularly preferable as rust preventives, and can prevent the transparent electrodes on the touch panel from corroding.

The content of the rust inhibitor in the present composition is preferably 0.01 to 5% by mass, more preferably 0.1% by mass or more or 3% by mass or less.
Since the HSP of this composition is separated from the antirust agent, the effect can be exhibited even at a content of 0.01% by mass. On the other hand, transparency can be maintained by adjusting the content to 5% by mass or less.

The composition may contain a silane coupling agent.
As the type of silane cupping agent, those containing a glycidyl group, or those containing a (meth)acrylic group or a vinyl group are particularly preferred. By containing these, the adhesiveness with the adherend is improved, and the foaming phenomenon under a moist and hot environment can be suppressed.

The content of the silane coupling agent in the present composition is preferably 0.01 to 3% by mass relative to the present composition, more preferably 0.1% by mass or more or 1% by mass or less. . Depending on the adherend, the effect of the silane coupling agent can be exhibited even at a content of 0.01% by mass. On the other hand, transparency can be maintained by adjusting the content to 3% by mass or less.

The composition may also contain acrylamides.
By containing acrylamide, it is possible to improve the adhesion to the adherend as with the silane coupling agent. It is preferable to use the silane coupling agent separately or in combination according to the adherend and application.
Particularly preferred acrylamides include acryloylmorpholine, dimethylacrylamide, diethylacrylamide, dimethypaminopropylacrylamide, isopropylacrylamide and hydroxyethylacrylamide.

The content of acrylamide in the composition is preferably 0.01 to 20% by mass, more preferably 0.1% by mass or more or 10% by mass or less. Depending on the adherend, the effect of acrylamide can be exhibited even at a content of 0.01% by mass. On the other hand, transparency can be maintained by adjusting the content to 20% by mass or less.

The composition may also contain other curing accelerators, fillers, coupling agents, UV absorbers, UV stabilizers, antioxidants, stabilizers, or some combination thereof added to the curable composition. good.
These contents are preferably selected so as not to adversely affect the present composition, which is typically a cured product.

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

The present composition is, for example, a butene polymer (A) and an acrylic polymer (B), optionally a tackifier (C), a polymerization initiator, an uncured composition containing other components, etc. The present composition can be produced by preparing, curing the butene-based polymer (A) and the resin (B) by cross-linking, ie, polymerization reaction, and applying appropriate processing as necessary. However, it is not limited to such a manufacturing method.

When preparing the uncured composition, the raw materials are kneaded using a temperature-controllable kneader (e.g., single-screw extruder, twin-screw extruder, planetary mixer, twin-screw mixer, pressure kneader, etc.). do it.
When mixing various raw materials, various additives such as silane coupling agents and antioxidants may be blended in advance with the resin and then supplied to the extruder, or all the materials may be melt-mixed in advance. Alternatively, a masterbatch in which only the additive is concentrated in the resin in advance may be prepared and supplied.

To impart curability, the uncured composition preferably contains a polymerization initiator, as described above.
The polymerization initiator is not particularly limited as long as it can be used for the polymerization reaction. For example, those activated by heat and those activated by active energy rays can be used. Any of those that generate radicals and cause radical reactions, and those that generate cations and anions and cause addition reactions can be used.
Preferred polymerization initiators are photoinitiators, and the choice of photoinitiator generally depends, at least in part, on the specific ingredients used in the curable composition, and the desired rate of cure.

Examples of photoinitiators include acetophenones, benzoins, benzophenones, benzoyl compounds, anthraquinones, thioxanthones, phosphine oxides, such as phenyl and diphenylphosphine oxides, ketones, and acridines.
Specifically, LUCIRIN (BASF) such as ethyl-2,4,6-trimethylbenzoyldiphenylphosphinate available under the trade names DAROCUR (Ciba Specialty Chemicals), IRGACURE (Ciba Specialty Chemicals) and LUCIRIN TPO. A photoinitiator can be mentioned.

As the photopolymerization initiator, one having an excitation wavelength range of 400 nm or more can be selected and used. Specific photopolymerization initiators include α-diketones such as camphorquinone and 1-phenyl-1,2-propanedione; acylphosphine oxides such as trimethylbenzoyl)-phenylphosphine 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- Titanocenes such as titanocene compounds such as 1-yl)phenyl)titanium and the like can be mentioned. Among these, α-diketones and acylphosphine oxides are preferable, and camphorquinone and 2,4,6-trimethylbenzoyldiphenylphosphine oxide are more preferable from the viewpoint of good polymerization activity and little harm to living bodies. preferable.

On the other hand, for forming the crosslinked structure, a thermal polymerization initiator can be used in addition to the photopolymerization initiator.
Examples of thermal initiators include azo compounds, quinine, nitro compounds, acyl halides, hydrazones, mercapto compounds, pyrylium compounds, imidazoles, chlorotriazines, benzoin, benzoin alkyl ethers, diketones, phenones, dilauroyl peroxide and NOF. Co. and organic peroxides such as 1,1-di(t-hexylperoxy)-3,3,5-trimethylcyclohexane, available as PERHEXA TMH from Epson.

Polymerization initiators are often used at concentrations of from about 0.01 to about 10 weight percent, or from about 0.01 to about 5 weight percent, based on the total weight of the uncured composition. Mixtures of polymerization initiators may be used.

<Molded product and its manufacturing method>
Next, a molded article (“main molded article”) made of the present resin composition and a method for producing the same will be described. However, the following description is an example of the method of manufacturing the present molded article, and the present molded article is not limited to those manufactured by such a manufacturing method.

The molded article is a molded article made of a resin composition.
There are no particular restrictions on its shape. In particular, in the case of application to an image display device, it is preferable to use a sheet-like molded body because it is a thin film. A sheet made of this resin composition is hereinafter referred to as "this sheet".

The thickness of this sheet is not particularly limited. If the thickness of the present sheet is 0.01 mm or more, the handleability is good, and if the thickness is 1 mm or less, it can contribute to thinning of the laminate.
Therefore, the thickness of the present sheet is preferably 0.01 mm or more, more preferably 0.03 mm or more, particularly 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, particularly 0.5 mm or less.

The molded article is an uncured composition containing, for example, a butene polymer (A) and an acrylic polymer (B), and optionally a tackifier (C), a polymerization initiator, other components, and the like. The resin composition is prepared, molded into a molded body, the butene polymer (A) and the resin (B) are crosslinked, that is, polymerized, and cured, and if necessary, the molded body is processed as appropriate. can be made. However, it is not limited to such a manufacturing method.

Methods for preparing the uncured composition are, for example, as described above.

Methods for molding the uncured composition into a molded body include known methods such as wet lamination, dry lamination, extrusion casting using a T-die, extrusion lamination, calendering, inflation, injection molding, and injection. A curing method or the like can be employed. Among them, the wet lamination method, the extrusion casting method, and the extrusion lamination method are suitable for producing a sheet from the standpoint of handleability, productivity, and the like.

When melt molding using no solvent is selected, the uncured composition for melt molding must have a storage modulus (G′) in shear at a frequency of 1 Hz in the uncured state of 50,000 Pa or more at 20°C. , 10,000 Pa or less at 160°C.
If G' at 20°C is within the above range, the shape can be maintained at room temperature after molding. Further, when G' at 160° C. is within the above range, molding can be performed without entrainment of air bubbles.

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

It is preferable that the molding temperature during melt molding is appropriately adjusted according to the flow characteristics, the film-forming properties, and the like. From the viewpoint of thermal stability of the uncured composition, it is preferably 20 to 230°C, more preferably 20 to 160°C.
In the case of melt molding, the thickness of the molded body can be appropriately adjusted by the lip gap of the T-die, the take-up speed of the molded body, the clearance of lamination rolls, and the like.

Moreover, when the composition contains a polymerization initiator, a cured product can be produced by curing the composition by irradiating it with heat and/or active energy rays. In particular, the molded article can be produced by irradiating the molded composition with heat and/or active energy rays.
Here, the active energy rays to be irradiated include α-rays, β-rays, γ-rays, ionizing radiation such as neutron beams and electron beams, ultraviolet rays, and visible rays. Ultraviolet rays are suitable from the viewpoint of reaction control.
Moreover, the irradiation energy, irradiation time, irradiation method, and the like of the active energy ray are not particularly limited as long as the acrylate component can be polymerized by activating the polymerization initiator.

Moreover, as another embodiment of the method for producing the present molded article, the composition can be dissolved in an appropriate solvent and various coating techniques can be used as described later. However, in this embodiment, it is necessary to consider manufacturing costs such as solvent recovery.
When a coating method is used, the present sheet can also be obtained by thermal curing in addition to the active energy ray irradiation curing described above.

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 thickness of the coating and the solid content concentration of the coating liquid.

From the viewpoint of blocking prevention and foreign matter adhesion prevention, a laminate having a configuration in which a release layer is laminated on at least one side of the present molded article can also be used.
At this time, the release layer can be formed by applying a resin composition containing a known release agent. For example, a composition containing a releasing agent composed of a silicone-based, fluorine-based, or long-chain alkyl-based composition having a releasing effect, or a releasing resin obtained by graft-modifying the above-mentioned component having a releasing effect to a polymer. A release layer can be formed by applying a substance.

Also, if necessary, embossing or various irregularities (conical, pyramidal, hemispherical, etc.) processing may be performed. In addition, various surface treatments such as corona treatment, plasma treatment and primer treatment may be performed on the surface for the purpose of improving adhesion to various adherends.

[Laminate for configuring image display device, image display device]
By laminating an image display device constituent member on at least one side of the present molded body, a laminate for forming an image display device can be formed, and an image display device is constituted using the laminate for forming an image display device. can do.

At least one side of the molded body has a structure in which 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. It can be a laminate for an image display device.
An image display device can be configured using the laminate for image display device construction comprising any one of these or a combination of two or more of them.

Further, the image display device may have the molded product provided on the display surface side and/or the non-display surface side as the image display device constituent member. 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 becomes the display surface. Intrusion of water from the surface side and moisture absorption of the polyimide can be prevented, and this can contribute to prolonging the life of the OLED. In addition, deformation of the display surface and influence of external force can be suppressed.

[Fiber-reinforced plastic laminate]
This molded article can also be laminated with fiber reinforced plastic (FRP) to obtain a laminate having impact resistance and vibration damping properties. The laminate can be used in various fields other than image display devices.
At this time, fiber reinforced plastic (FRP) is a composite material in which fiber is put into plastic to improve strength, and examples of the fiber include synthetic fiber, cellulose, carbon fiber, glass fiber, and ceramic fiber. can be mentioned.

[Description of phrases, etc.]
In general, "sheet" is defined in JIS as a thin, flat product whose thickness is small relative to its length and width. A thin flat product with an extremely small thickness and an arbitrarily limited maximum thickness, usually supplied in the form of a roll (Japanese Industrial Standard JIS K6900). However, the boundary between a sheet and a film is not clear, and there is no need to distinguish between the two in the present invention. “Film” shall be included even in cases where
In addition, the expression "panel" such as an image display panel, a protective panel, etc. includes a plate, a sheet and a film.

In this specification, when described as "X to Y" (X and Y are arbitrary numbers), unless otherwise specified, "X or more and Y or less" and "preferably larger than X" or "preferably It also includes the meaning of "smaller than Y".
In addition, when described as "X or more" (X is an arbitrary number), it includes the meaning of "preferably greater than X" unless otherwise specified, and is described as "Y or less" (Y is an arbitrary number). If not otherwise specified, it also includes the meaning of "preferably smaller than Y".

The invention is further illustrated by the following examples. However, the present invention is not limited to the examples shown below.

<Example/Comparative example>
In Examples 1 to 4 and Comparative Examples 1 to 4, a resin composition blended at the mass ratio shown in Table 1 was prepared, and a release film with a thickness of 100 μm subjected to silicone release treatment (PET film manufactured by Mitsubishi Chemical Corporation ), and the resin composition was spread out in a sheet form to a thickness of 100 μm.
Next, a release film (PET film manufactured by Mitsubishi Chemical Corporation) having a thickness of 75 μm that has been subjected to silicone release treatment is laminated on the sheet-shaped resin composition to form a laminate, and a metal halide lamp irradiation device (Ushio Denkisha, UVC-0516S1, lamp UVL-8001M3-N) was used to irradiate light so that the total irradiation amount at a wavelength of 365 nm was 2000 mJ/cm ² , and a release film was applied to both the front and back sides of the sheet (sample). A sheet laminate was obtained.

Details of raw materials are as follows.

(Butene polymer)
・Butene polymer with Mn less than 5000: iso-butene 96% by mass, n-butene 4% by mass, number average molecular weight (Mn) 1,660, weight average molecular weight (Mw) 3,720, HSP: δD15.1, δP0 .0, δH0.1
IP Solvent 2835: C16-C24 isoparaffin 100% by mass, number average molecular weight (Mn) 130 or less, mass average molecular weight (Mw): 300 or less, HSP: δD15.1, δP0.0, δH0.0
Tetrax 3T: poly iso-butene, number average molecular weight (Mn) 21,400, weight average molecular weight (Mw) 49,000, HSP: δD15.1, δP0.0, δH0.0
・Opanol N50: poly iso-butene, number average molecular weight (Mn) 235,400, weight average molecular weight (Mw) 565,000, HSP: δD15.1, δP0.0, δH0.0

(Acrylate polymer, structural unit)
・NK Ester S1800ALC: manufactured by Shin-Nakamura Chemical Co., Ltd., isostearyl acrylate, HSP: δD16.2, δP1.7, δH2.5
・Blemmer CA: manufactured by NOF Corporation, cetyl acrylate, HSP: δD16.1, δP2.2, δH2.8
・NK Ester A-DOD-N: Shin-Nakamura Chemical Co., Ltd., 1,10-decanediol diacrylate, HSP: δD16.3, δP3.8, δH4.9

(Styrene-based thermoplastic elastomer (SEBS))
・SEBS (26.5 mass% styrene, 25.7 mass% ethylene, 47.8 mass% butene copolymer, mass average molecular weight (Mw) 270,000)
(urethane acrylate polymer)
・CN9014NS: Bifunctional urethane acrylate of hydrogenated polybutadiene manufactured by Sartomer

(petroleum resin)
・Quinton CX495: Made by Zeon, petroleum resin (antioxidant)
· Irganox 1076: manufactured by BASF, hindered phenol-based antioxidant (photopolymerization initiator)
・Omnirad TPO-G: Acylphosphine oxide photopolymerization initiator manufactured by BASF

<Mass average molecular weight (Mw) and number average molecular weight (Mn)>
It was measured under the following conditions by gel permeation chromatography (GPC).
GPC measurement device: WATERS 150-GPC (manufactured by WATERS)
Temperature: 140°C
Solvent: o-dichlorobenzene Concentration: 0.05% (injection volume: 500 microliters)
Column: Shodex GPC AT-807/S 1 piece, Tosoh TSK-GEL GMH6-HT 2 piece Dissolution condition: 160° C., 2.5 hours Calibration curve: Measure a standard sample of butene polymer and use conversion constant and calculated by the cubic.

In addition, in the measurement of the mass average molecular weight (Mw) and number average molecular weight (Mn) of the butene polymer of Comparative Example 1, when the hexane extract was measured by GPC, the peak was bimodal. It was divided into 1) and 2), and the respective molecular weights are shown in the table.

<Storage shear modulus G' and loss tangent tan δ>
The storage shear modulus G' and the loss tangent tan δ were obtained by removing the release film (PET film) from the sheet laminates obtained in Examples and Comparative Examples using a rheometer ("MARS" manufactured by Eiko Seiki Co., Ltd.), A compact having a thickness of about 2 mm was obtained by laminating a plurality of sheets (samples). This molded body was used as a sample (circular with a thickness of 2 mm and a diameter of 20 mm) and measured under the following measurement conditions. The storage elastic modulus G' (100°C) at °C was determined. Also, the value of the maximum point of the loss tangent tan δ, the values at 0° C. and 100° C., and the temperature range and the temperature range in which tan δ is 1 or more were determined. Table 2 shows the results.

(Measurement condition)
・Adhesive jig: Φ25mm parallel plate ・Distortion: 0.1%
・Frequency: 1Hz
・Measurement temperature: -50 to 200°C
・Temperature increase rate: 3°C/min

<Falling ball impact test>
A sheet (sample) obtained by removing the release PET having a thickness of 75 μm from the sheet laminate obtained in Examples and Comparative Examples was applied to one side of a soda lime glass plate having a thickness of 0.4 mm, a length of 70 mm, and a width of 50 mm. to obtain a glass laminate (PET 100 µm/main molded product 100 µm/glass 400 µm). A sphere with a diameter of 10 mm (high carbon chromium steel: JIS G4805) was made to collide with the obtained glass laminate from the PET side by free fall from a height of 120 cm, and cracking of the glass was evaluated. Each sample was evaluated three times and evaluated according to the following criteria. Table 2 shows the results.
◯ (good): It was not cracked even once.
△ (usual): Cracked 1-2 times.
x (poor): Cracked all three times.

<Low temperature fluidity evaluation>
The sheet laminates obtained in Examples and Comparative Examples were cut and stored flat for one week, and then the cross section of the cut was observed with an optical microscope to see how much the molded body protruded from the cut portion. evaluated. Table 2 shows the results.
◯ (good): The protrusion was less than 100 μm.
× (poor): A protrusion of 100 μm or more was observed.

<Oil migration evaluation>
When the release PET was peeled off from the sheet laminates obtained in Examples and Comparative Examples, and a filter paper was pasted on the peeled portion, the filter paper absorbed oil droplets. The item was evaluated as "○ (good)". Table 2 shows the results.

<Dielectric constant>
One of the release PET films of the sheet laminates obtained in Examples and Comparative Examples was peeled off and adhered to a SUS plate (65 mm×65 mm×1 mm thick). The remaining release film was peeled off, and a 45 mmφ aluminum foil was roll-pressed to prepare a sample for relative permittivity measurement. Using the prepared sample, the dielectric constant was measured at 23° C., 50% RH and a frequency of 100 kHz in accordance with JIS K6911 using an LCR meter (HP4284A, manufactured by Agilent Technologies). Table 2 shows the results.

<Haze>
A haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., NDH5000) was used to laminate a sheet (sample) obtained by removing the release PET from the sheet laminate obtained in Examples and Comparative Examples with glass on both sides. Total light transmittance and haze were measured according to JIS K7361-1 and JIS K7136, respectively. Table 2 shows the results.

Examples 1 to 4 in which the number average molecular weight of the butene polymer is less than 5000 have a larger maximum value of tan δ than Comparative Examples 1 and 3 in which butene with a large molecular weight is used, and the temperature at which tan δ is 1 or more. I found it to be too wide. A falling ball impact test showed that Example 1 had better impact resistance.
In Comparative Example 4, tan δ is 1 or more in a wide temperature range, but the number average molecular weight of the butene polymer is 5000 or more. As a result, tan δ at 100° C. becomes large, and it flows, so it can be considered that the shape of the sheet cannot be maintained.

Claims (9)

A molded article made of a resin composition containing a butene polymer (A) having a number average molecular weight (Mn) of less than 5000 and an acrylic polymer,
The acrylic polymer comprises, as a structural unit, a monofunctional (meth)acrylate containing a branched alkyl group having 10 or more carbon atoms in the main chain,
Containing 5 to 100 parts by mass of the acrylic polymer with respect to 100 parts by mass of the butene polymer (A),
The maximum value of the loss tangent (tan δ) obtained by dynamic viscoelasticity measurement in a shear mode at a frequency of 1 Hz is 30°C or less, and the temperature range in which the loss tangent (tan δ) is 1 or more is 20°C or more. A molded body characterized by The molded article according to claim 1 , wherein the acrylic polymer contains a polyfunctional (meth)acrylate as a structural unit. 3. The compact according to claim 1 , wherein the loss tangent (tan .delta.) has a maximum value of 1.0 or more. The molded article according to any one of claims 1 to 3 , wherein the loss tangent (tan δ) at 100°C obtained by dynamic viscoelasticity measurement in shear mode at a frequency of 1 Hz is 0.3 or less. The molded article according to any one of claims 1 to 4 , which has a dielectric constant of 3.0 or less. A laminate comprising a release layer laminated on at least one side of the molded article according to any one of claims 1 to 5 . A laminate comprising a sheet of fiber-reinforced plastic laminated on at least one side of the molded article according to any one of claims 1 to 5 . Any one 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 on at least one side of the molded article according to any one of claims 1 to 5 . A laminate for an image display device having a structure in which one kind or two or more kinds are laminated. An image display device comprising the molded article according to any one of claims 1 to 5 .