TW202208571A - Reinforcing film, optical member, and electronic member - Google Patents

Abstract

Provided is a reinforcing film that exhibits light peelability at the initial stage of attachment to an adherend, can have greatly increased adhesive strength thereafter, and has bending recovery and bending holding power. The reinforcing film comprises an adhesive layer. The adhesive layer contains a polymer (A) and a polymer (B). The polymer (B) contains a monomer unit having a polyorganosiloxane skeleton and a (meth)acrylic monomer unit. The adhesive layer has a surface elastic modulus of 1-20 kPa at 23 DEG C. The polymer (B) has a weight average molecular weight of 10,000-100,000.

Description

Reinforcing film, optical member, and electronic member

The present invention relates to a reinforcing film, and an optical member and an electronic member to which the reinforcing film is bonded. This application claims priority based on Japanese Patent Application No. 2020-134190 filed on August 6, 2020, the entire contents of which are incorporated herein by reference.

Adhesives are widely used in portable electronic devices such as mobile phones, smart phones, tablet personal computers, etc., and other electronic Machines and other uses. For example, the adhesive sheet is used as a reinforcing material (reinforcing film) that imparts rigidity or impact resistance to optical members, electronic members, and the like constituting the above-mentioned apparatus. As a document which discloses such a prior art, patent documents 1 and 2 are mentioned.

In addition, in recent years, portable electronic devices that can be bent or rolled have attracted attention, and development of a flexible device (typically organic EL (Electroluminescence) or Adhesive sheets for image display devices such as liquid crystal display devices) and the like (Patent Documents 3 to 6).

On the other hand, focusing on the performance of the adhesive, an adhesive sheet has recently been proposed, which can exhibit a low adhesive force in the initial stage of being attached to an adherend, and then significantly increase the adhesive force (Patent Document 7). . According to the adhesive sheet having such characteristics, the re-adhesion property (secondary workability), which is useful for suppressing the yield reduction caused by misapplied or damaged adhesive sheet, can be exhibited before the adhesive force is increased, and the adhesive force can be improved. After rising, it exhibits strong adhesiveness suitable for the original purpose of the adhesive sheet. prior art literature Patent Literature

Patent Document 1: Japanese Patent No. 6366199 Patent Document 2: Japanese Patent No. 6366200 Patent Document 3: Japanese Patent No. 6376271 Patent Document 4: Japanese Patent Application Laid-Open No. 2016-108555 Patent Document 5: Japanese Patent Application Laid-Open No. 2017-095657 Patent Document 6: Japanese Patent Application Laid-Open No. 2017-095659 Patent Document 7: Japanese Patent No. 6373458

[Problems to be Solved by Invention]

The reinforcing film can also be used for the above-mentioned flexible device. For example, in the manufacture of the above-mentioned flexible device, the components constituting the device are often thin, so it is desirable to stick an adhesive sheet as a reinforcing film for reinforcement to prevent defects caused by device deformation, or to improve the operation. sex. Since the flexible device can be repeatedly bent or bent, the reinforcing film used for the flexible device is required to have the property of recovering its shape normally even when it is repeatedly bent (bending recovery), and to have no peeling. and other undesirable characteristics (bending retention force). Such a reinforcing film with bending recovery and bending retention force can be used for various purposes including flexible devices, so the scope of application is less restricted and more useful.

For example, an adhesive having a structure such as that proposed in Patent Document 7, which exhibits a low adhesive force at the initial stage of attachment, and then greatly increases its adhesive force, is also preferably used as a reinforcing film to have bending recovery properties and Bend retention. As one method of improving the bending holding force, for example, a method of appropriately setting the storage elastic modulus of the adhesive is considered. However, if the storage elastic modulus of the adhesive designed to increase the adhesive force as described above is changed, both the initial low adhesive force and the adhesive force after the increase will be affected. Furthermore, in addition to the bending retention force, the bending recovery property is also considered, and it is not easy to satisfy all these properties. As for the adhesive which shows low adhesive force in the initial stage of attachment, and then greatly increases the adhesive force, it is useful in practical application as long as the bending recovery and bending retention can be improved.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a reinforcing film which can exhibit light peeling properties at the initial stage of being attached to an adherend, and can significantly increase the adhesive force thereafter, and has bending recovery properties and bending properties. Retentivity. Moreover, another object of this invention is to provide the optical member and the electronic member to which the said film for reinforcement was bonded. [Technical means to solve problems]

According to the present specification, a reinforcing film provided with an adhesive layer can be provided. The said adhesive layer contains a polymer (A) and a polymer (B). The said polymer (B) contains the monomer unit which has a polyorganosiloxane skeleton, and a (meth)acrylic-type monomer unit. Moreover, the surface elastic modulus of the said adhesive layer at 23 degreeC is 1-20 kPa. Furthermore, the weight average molecular weight of the said polymer (B) is 10,000-100,000.

According to the above configuration, since the adhesive layer contains the polymer (A) and the polymer (B) containing the monomer unit having a polyorganosiloxane skeleton, it can exhibit light peelability at the initial stage of being attached to the adherend, After that, the adhesive force was greatly increased. Furthermore, by using the polymer (B) having a weight-average molecular weight in the range of 10,000 to 100,000, it is possible to achieve a better balance between light peeling properties in the initial stage of attachment and increased adhesion. Moreover, the said reinforcement film has a bending recovery property and a bending retention force. Specifically, a reinforcing film having a surface modulus of elasticity at 23° C. (23° C. surface modulus of elasticity) of the adhesive layer of 1 kPa or more exhibits the above-mentioned adhesive properties and has good flexural recovery. In addition, by making the surface modulus of elasticity at 23°C of the adhesive layer to be 20 kPa or less, the above-mentioned adhesive properties are exhibited and good bending retention force is obtained, so even when used in a state of repeated bending, it is not easy to Defects such as peeling occur.

In some preferred aspects of the technology disclosed herein (including reinforcing films, optical components, and electronic components, the same below), the bulk modulus G' ₂₃ of the adhesive layer at 23°C is 10-200 kPa. With the adhesive having a bulk modulus of elasticity G' ₂₃ in this range, the adhesive force at the initial stage of attachment tends to be in a suitable range excellent in light peelability. In addition, it is excellent in workability, and in general, it tends to be easy to achieve both strain relaxation properties and bending recovery properties in the normal temperature region.

In some preferred aspects, the bulk modulus G' ₈₀ of the adhesive layer at 80°C is 5-100 kPa. Adhesives having a bulk modulus of elasticity _G'80 in this range are generally easy to achieve both flexural recovery and flexural retention. For example, even when used at a high temperature of about 80° C., it can have elasticity suitable for bending recovery, and has a holding force to achieve bending retention.

In some preferred aspects, the tanδ ₈₀ of the above-mentioned adhesive layer at 80° C. is 0.10˜0.60. The adhesive whose tanδ ₈₀ (loss elastic modulus G'' ₈₀ at 80°C/storage elastic modulus G' ₈₀ at 80°C) of 0.10 or more is likely to exhibit an adhesive force suitable for maintaining bending. Moreover, by making the said tan delta ₈₀ into 0.60 or less, it becomes easy to suppress the plastic deformation of an adhesive agent, and a favorable bending recovery property is obtained. In addition, even when the reinforcing film is kept in a bent state for a long time, the retention force (bending retention force) that does not peel off from the adherend is easily exhibited.

The above-mentioned polymer (A) is preferably an acrylic polymer. The effects of the technology disclosed herein are easily and well achieved by the adhesive layer comprising the polymer (A) as an acrylic polymer and the polymer (B) comprising a monomer unit having a polyorganosiloxane skeleton .

In some preferred aspects, the content of the polymer (B) in the adhesive layer is 0.5 to 5 parts by weight relative to 100 parts by weight of the polymer (A). By setting the amount of the polymer (B) to 0.5 parts by weight or more with respect to 100 parts by weight of the polymer (A), it is easy to obtain light peelability in the initial stage of attachment. By making the quantity of the said polymer (B) into 5 weight part or less, it becomes easy to achieve the objective adhesive force improvement. Moreover, by making the usage-amount of a polymer (B) into the said range, it becomes easy to implement|achieve favorable bending recovery property and bending retention force.

In some preferred aspects, the molar ratio ([NCO]/[OH]) of isocyanate groups and hydroxyl groups contained in the adhesive layer is 0.002-0.03. The pressure-sensitive adhesive layer having a molar ratio ([NCO]/[OH]) of 0.002 or more tends to be excellent in flexural recovery and also tends to be excellent in processability. Moreover, by making the said molar ratio ([NCO]/[OH]) into 0.03 or less, there exists a tendency for a suitable adhesive force improvement to be easy to implement. Furthermore, in the adhesive layer, the isocyanate group and the hydroxyl group may exist in a state in which at least a part of them is chemically bonded (crosslinked). The above-mentioned adhesive layer contains, for example, a cross-linking agent. In this configuration, the above-mentioned isocyanate group may be, for example, a part of the cross-linking agent, and the above-mentioned hydroxyl group may be, for example, a part of the polymer (A).

The reinforcing film disclosed here is suitable as a reinforcing film for imparting rigidity or impact resistance to optical members when processing or conveying optical members such as polarizers and wave plates, for example. Therefore, according to this specification, it is possible to provide an optical member to which any of the reinforcing films disclosed herein are bonded.

Moreover, the film for reinforcement disclosed here is suitable also as a film for reinforcement of electronic components of apparatuses, such as a portable electronic apparatus, for example. Therefore, according to this specification, it is possible to provide an electronic component to which any of the reinforcing films disclosed herein are bonded.

Hereinafter, preferred embodiments of the present invention will be described. Matters necessary for implementing the present invention other than those specifically mentioned in this specification can be understood by the practitioner based on the instructions for implementing the invention described in this specification and the technical common sense at the time of application. The present invention can be implemented based on the contents disclosed in this specification and common technical knowledge in the field. In addition, in the following drawings, the same reference numerals may be used to describe members and parts that perform the same functions, and overlapping descriptions may be omitted or simplified in some cases. In addition, the embodiment described in the drawings is modeled for clearly explaining the present invention, and does not necessarily accurately represent the size or scale of the product actually provided.

In addition, in this specification, "acrylic polymer" refers to a polymer containing a monomer unit derived from a (meth)acrylic monomer in the polymer structure, and typically refers to a polymer containing more than 50% by weight of A ratio of polymers containing monomeric units derived from (meth)acrylic monomers. Moreover, a (meth)acrylic-type monomer system means the monomer which has at least one (meth)acryloyl group in 1 molecule. Here, the "(meth)acryloyl group" includes the meaning of an acryl group and a methacryloyl group. Therefore, the concept of the so-called (meth)acrylic monomer here can include both a monomer having an acryl group (acrylic monomer) and a monomer having a methacryloyl group (methacrylic monomer) . Similarly, in this specification, "(meth)acrylic acid" includes the meaning of acrylic acid and methacrylic acid, and "(meth)acrylate" includes the meaning of acrylate and methacrylate.

<Structure example of reinforcement film> The reinforcing film disclosed here has the form of an adhesive sheet having an adhesive surface formed of an adhesive. The adhesive sheet used as the reinforcing film contains an adhesive layer. The reinforcing film disclosed herein may be in the form of a substrate-attached adhesive sheet with the above-mentioned adhesive layer on one or both surfaces of a supporting substrate, or may be a substrate-less adhesive without a supporting substrate. The form of the sheet. Hereinafter, the supporting substrate may also be simply referred to as a "substrate". In addition, in this specification, a "reinforcing film" means an adhesive sheet (reinforcing adhesive film) for reinforcing an adherend as described later. For example, the reinforcing film can be in the form of an adhesive sheet without a base material, after one adhesive surface is attached to a support material, etc., and the other adhesive surface is attached to the adherend as a reinforcement object for reinforcement, so it is not limited to the base. The form of the adhesive sheet of the material. In this respect, it can be understood as a broader concept than the following "reinforcing film" in the form of an adhesive sheet with a base material.

The structure of the reinforcing film of one embodiment is schematically shown in FIG. 1 . The reinforcing film 1 is constituted in the form of a single-sided adhesive sheet with a substrate, and includes a sheet-like support substrate 10 having a first surface 10A and a second surface 10B, and an adhesive provided on the side of the first surface 10A. agent layer 21. The adhesive layer 21 is fixed to the first surface 10A side of the support substrate 10 . The reinforcing film 1 is used by attaching the adhesive layer 21 to the adherend. As shown in FIG. 1 , the reinforcing film 1 before use (ie, before being attached to the adherend) can be a constituent element of the reinforcing film 100 with a release liner, and the reinforcing film 100 with a release liner is an adhesive The surface (adhesive surface) 21A of the adhesive layer 21 is in contact with at least the release liner 31 whose side opposite to the adhesive layer 21 is a releasable surface (release surface). As the release liner 31 , for example, by providing a release layer formed of a release treatment agent on one side of a sheet-like base material (liner base material), one formed so that the single side becomes a release surface can be favorably used. Alternatively, the release liner 31 may be omitted, and the second surface 10B of the support base 10 may be used as the release surface, and the adhesive surface 21A may be in contact with the second support base 10 by winding the reinforcing film 1 . The form of the surface 10B (roll form). When the reinforcing film 1 is attached to the adherend, the release liner 31 or the second surface 10B of the support substrate 10 is peeled off from the adhesive surface 21A, and the exposed adhesive surface 21A is crimped to the adherend.

The structure of the reinforcing film of another embodiment is schematically shown in FIG. 2 . The reinforcing film 2 is constituted in the form of a double-sided adhesive sheet with a substrate, and includes a sheet-like support substrate 10 having a first surface 10A and a second surface 10B, and an adhesive provided on the side of the first surface 10A The layer 21 and the adhesive layer 22 disposed on the second surface 10B side. The adhesive layer (first adhesive layer) 21 is fixed to the first surface 10A of the support substrate 10 , and the adhesive layer (second adhesive layer) 22 is fixed to the second surface 10B of the support substrate 10 . The reinforcing film 2 is used by attaching the adhesive layers 21 and 22 to different parts of the adherend. The positions where the adhesive layers 21 and 22 are attached may be the respective positions of different components, or may be different positions within a single component. As shown in FIG. 2 , the reinforcing film 2 before use can be a constituent element of the reinforcing film 200 with a release liner, and the reinforcing film 200 with a release liner is the surface (the first adhesive surface) of the adhesive layer 21 . ) 21A and the surface (second adhesive surface) 22A of the adhesive layer 22 are in contact with the release liners 31 and 32, which are at least the sides opposite to the adhesive layers 21 and 22, respectively, forming the release surface. As the release liners 31 and 32 , for example, one surface of a sheet-like base material (liner base material) can be preferably used by providing a release layer formed of a release treatment agent on one surface of the sheet-like base material (liner base material) so that the single surface becomes a release surface. By. Alternatively, the release liner 32 may be omitted, and the release liner 31 having both sides as the release surface may be used, and the second adhesive surface 22A may be in contact with the release liner by overlapping the reinforcing film 2 and winding it in a spiral shape. Reinforcing film with a release liner in the form (roll form) of the back surface of the pad 31 .

The structure of the reinforcing film of another embodiment is schematically shown in FIG. 3 . The reinforcing film 3 is constituted in the form of a double-sided adhesive sheet without a base material composed of an adhesive layer 21 . The reinforcing film 3 is attached to the first adhesive surface 21A including one surface (first surface) of the adhesive layer 21 and the second adhesive surface 21B including the other surface (second surface) of the adhesive layer 21 . It is used by different parts of the adherend. As shown in FIG. 3 , the reinforcing film 3 before use can be a constituent element of the reinforcing film 300 with a release liner, and the reinforcing film 300 with a release liner is the first adhesive surface 21A and the second adhesive surface) 21B is in contact with at least the form of the release liners 31 and 32 whose sides opposite to the adhesive layer 21 are the release surfaces, respectively. Alternatively, the release liner 32 may be omitted, and the release liner 31 having both sides as the release surface may be used, and the second adhesive surface 21B may be in contact with the release liner by overlapping the reinforcing film 3 and winding it in a spiral shape. Reinforcing film with a release liner in the form (roll form) of the back surface of the pad 31 .

In addition, the film for reinforcement may be in a roll form, a single-piece form, or a form in which it is cut, punched, and processed into an appropriate shape according to the application or usage. The adhesive layer in the technology disclosed herein is typically formed continuously, but is not limited thereto, and may be formed in regular or random patterns such as dots, strips, etc., for example.

<Adhesive layer> The reinforcement film disclosed here is provided with the adhesive layer which consists of a polymer (A) and a polymer (B). Such an adhesive layer can be formed from an adhesive composition containing a polymer (A) that is a complete polymer or a partial polymer of the monomer raw material A, and a polymer (B). The form of the adhesive composition is not particularly limited, and for example, various forms such as solvent type, water dispersion type, hot melt type, active energy ray curing type (eg, photocurable type) can be used.

(Surface elastic modulus at 23°C) The adhesive layer disclosed herein is characterized in that its surface (adhesive surface) has a surface modulus of elasticity at 23°C (surface modulus of elasticity at 23°C) in the range of 1 to 20 kPa. By making the above-mentioned surface elastic modulus at 23° C. to be 1 kPa or more, the adhesive properties based on the inclusion of the polymer (A) and the polymer (B) can be realized, and a good bending recovery can be obtained. Moreover, by making the said surface elastic modulus 20 kPa or less, the said adhesive property can be achieved, and a favorable bending retention force can be exhibited.

From the viewpoint of improving flexural recovery, the above-mentioned 23°C surface elastic modulus is preferably 2 kPa or more, more preferably 3 kPa or more, still more preferably 4 kPa or more (for example, 5 kPa or more), and may be 8 kPa or more. , which may be 10 kPa or more, or 12 kPa or more (for example, 14 kPa or more). The higher the surface elastic modulus, the more excellent the initial light peelability tends to be. In addition, from the viewpoint of achieving satisfactory bending resilience and bending retention force and exhibiting a satisfactory increase in adhesive force, the above-mentioned surface modulus of elasticity at 23°C is preferably 15 kPa or less, preferably 12 kPa or less, more preferably 9 kPa Hereinafter, it is more preferably 7 kPa or less (for example, 6 kPa or less), and may be 4 kPa or less.

The 23°C surface elastic modulus of the adhesive layer can be determined by the type or characteristics (molecular weight or glass transition temperature, molecular structure, etc.) of the polymer (A), the type (chemical structure, etc.) or characteristics (molecular weight, etc.) of the polymer (B). (or glass transition temperature, etc.), usage amount, type or usage amount of crosslinking agent, etc. The 23°C surface elastic modulus of the adhesive layer was measured by the method described in the following examples.

(23°C bulk elastic modulus G' ₂₃ ) The bulk elastic modulus G' ₂₃ (23°C bulk elastic modulus G' ₂₃ ) of the adhesive layer at 23°C can be within the range that satisfies the above-mentioned 23°C surface elastic modulus It can be set appropriately within the range, and is not limited to a specific range. In some aspects, the 23°C bulk elastic modulus G' ₂₃ of the adhesive layer is preferably set to 10 kPa or more. By making the said bulk elastic modulus _G'23 into a predetermined value or more, the adhesive force in the initial stage of sticking easily becomes a suitable range which is excellent in light peelability. In addition, it is excellent in workability, and generally has a tendency to be excellent in bending recovery properties in the normal temperature region. The above-mentioned bulk modulus G' ₂₃ is preferably 15 kPa or more, more preferably 20 kPa or more, still more preferably 25 kPa or more, particularly preferably 30 kPa or more. In other aspects, the bulk modulus G' ₂₃ may be greater than 50 kPa, greater than or equal to 80 kPa, or greater than or equal to 100 kPa.

In some aspects, the 23°C bulk modulus G' ₂₃ of the adhesive layer is preferably set to be 200 kPa or less. The adhesive whose bulk modulus G' ₂₃ is below a predetermined value generally tends to be excellent in strain relaxation in the normal temperature region, and also tends to exhibit an increase in adhesive force. The above-mentioned bulk modulus G' ₂₃ is preferably 150 kPa or less, more preferably 90 kPa or less. In some preferred aspects, the bulk modulus of elasticity G' ₂₃ may be below 60 kPa, or below 40 kPa (eg, below 35 kPa).

(80°C bulk modulus G' ₈₀ ) The bulk modulus G' _{80 of the adhesive layer at 80°C (80°C bulk modulus G' 80 )} is within the range that satisfies the above-mentioned 23°C surface modulus It can be set appropriately within the range, and is not limited to a specific range. In some aspects, the 80°C bulk modulus G' ₈₀ of the adhesive layer is preferably 5 kPa or more. By setting the above-mentioned bulk modulus G' ₈₀ to a predetermined value or more, it is generally easy to improve the flexural recovery, and even when used under high temperature conditions, it is possible to have elasticity suitable for the flexural recovery. In some preferred aspects, the bulk modulus of elasticity G' ₈₀ may be greater than or equal to 7 kPa, greater than or equal to 9 kPa, or greater than or equal to 10 kPa. In other aspects, the bulk modulus G' ₈₀ may be greater than 15 kPa, greater than or equal to 30 kPa, or greater than or equal to 50 kPa.

In some aspects, the 80°C bulk modulus G' ₈₀ of the adhesive layer is preferably set to 100 kPa or less. By limiting the above-mentioned bulk modulus _G'80 to a predetermined value or less, it is generally easy to obtain a good bending holding force, and it is easy to achieve both the bending resilience and the bending holding force. For example, under various environments including high temperature conditions, it has elasticity suitable for bending recovery, and has a subsequent retention force to achieve bending retention force. The above-mentioned bulk modulus G' ₈₀ is preferably 90 kPa or less, more preferably 60 kPa or less. In some aspects, the above-mentioned bulk modulus G' ₈₀ may be 20 kPa or less, 16 kPa or less, or 14 kPa or less (eg, 12 kPa or less).

(80°C tanδ ₈₀ ) The tanδ ₈₀ (80°C tanδ ₈₀ ) of the adhesive layer at 80°C is appropriately set within the range satisfying the above-mentioned 23°C surface elastic modulus, and is not limited to a specific range. In some aspects, the 80°C tanδ ₈₀ of the adhesive layer is preferably set to 0.10 or more. The higher the above-mentioned tanδ ₈₀ , the easier it is for the adhesive to exert an adhesive force suitable for bending retention. The above-mentioned tanδ ₈₀ is preferably 0.20 or more. In some preferred aspects, the above-mentioned tanδ ₈₀ may be greater than or equal to 0.30, greater than or equal to 0.40, or greater than or equal to 0.45.

In some aspects, the 80°C tanδ ₈₀ of the adhesive layer is preferably 0.60 or less. By making the said tan δ ₈₀ to be 0.60 or less, the plastic deformation of the adhesive can be suppressed, and good bending recovery properties can be easily obtained. In addition, even when the reinforcing film is kept in a bent state for a long time, it is easy to exhibit a holding force that does not peel off from the adherend. Further, the increase in adhesive force is also likely to be in a suitable range. The above-mentioned 80°C tanδ ₈₀ may be 0.55 or less. In other aspects, the 80°C tanδ ₈₀ may be 0.50 or less, or 0.35 or less.

The 23°C bulk modulus G' ₂₃ , 80°C bulk modulus G' ₈₀ and 80°C tanδ ₈₀ of the adhesive layer can be determined by the type or characteristics of the polymer (A) (molecular weight, glass transition temperature, molecular structure, etc. ), the type (chemical structure, etc.) or characteristics (molecular weight or glass transition temperature, etc.) of the polymer (B), the amount used, the type or amount of the crosslinking agent, etc. are adjusted. The 23°C bulk modulus G' ₂₃ , 80°C bulk modulus G' ₈₀ and 80°C tanδ ₈₀ of the adhesive layer were measured by the methods described in the following examples.

(Polymer (A)) As the polymer (A), acrylic polymers, rubber-based polymers, polyester-based polymers, urethane-based polymers, polyether-based polymers, and polysiloxane-based polymers known in the field of adhesives can be used One or two or more of various polymers that exhibit rubber elasticity in the room temperature region, such as polymers, polyamide-based polymers, and fluorine-based polymers. In the reinforcing film disclosed herein, the polymer (A) is typically the main component of the polymer component contained in the adhesive layer, that is, the component that occupies more than 50% by weight, for example, it may occupy 75% of the above-mentioned polymer component. % by weight or more. In some aspects, the above-mentioned polymer (A) is a component that occupies more than 50% by weight of the entire adhesive layer, can be a component that occupies more than 70% by weight, can occupy more than 80% by weight, and can occupy 90% by weight. The component of 95 weight% or more (for example, 97 weight% or more) may be sufficient as the component of weight % or more.

The glass transition temperature TA of the polymer ( _A ) is not particularly limited, and can be selected so as to obtain preferable properties in the reinforcing film disclosed herein. In several aspects, polymers ( _A ) with a TA of less than 0°C may be used well. Since the adhesive containing such a polymer (A) exhibits moderate fluidity (for example, the mobility of the polymer chain contained in the adhesive), it is suitable for increasing the adhesive force to a predetermined value or more by heating The reinforcing film. The reinforcing films disclosed herein can perform well using polymers ( _A ) whose TA is less than -10°C, less than -20°C, less than -30°C, or less than -35°C. In some aspects, _TA may not reach -40°C or -50°C. In some preferred aspects, _TA is below -55°C, more preferably below -58°C, further preferably below -62°C, and also below -65°C (eg below -66°C). The lower limit of T _A is not particularly limited. From the viewpoint of the availability of materials or the improvement of the cohesive force of the adhesive layer, a polymer (A) having a _TA of -80°C or higher and -70°C or higher is usually preferably used. In some aspects, T _A may be, for example, -63°C or higher, -55°C or higher, -50°C or higher, or -45°C or higher.

Here, in this specification, the glass transition temperature (Tg) of the polymer (for example, the glass transition temperature of the polymer (A), the following polymer (B), etc.) refers to the nominal value described in the literature or catalogue, etc. Or the Tg determined according to Fox's formula based on the composition of the monomer raw materials used to prepare the polymer. Fox's formula means a relational formula between the Tg of the copolymer and the glass transition temperature Tgi of the homopolymer obtained by homopolymerizing each of the monomers constituting the copolymer, as shown below. 1/Tg=Σ(Wi/Tgi) In the above formula of Fox, Tg represents the glass transition temperature of the copolymer (unit: K), Wi represents the weight fraction of the monomer i in the copolymer (copolymerization ratio on a weight basis), and Tgi represents the average of the monomer i. The glass transition temperature of the polymer (unit: K). When the target polymer whose Tg is specified is a homopolymer, the Tg of the homopolymer is the same as the Tg of the target polymer.

As the glass transition temperature of the homopolymer for calculating Tg, the value described in a known document was used. Specifically, the numerical value in "Polymer Handbook" (3rd edition, John Wiley & Sons, Inc., 1989) can be exemplified. Regarding the monomers for which plural values are described in the above-mentioned polymer handbook, the highest value is used.

The value obtained by the following measurement method was used as the glass transition temperature of the homopolymer of the monomer which is not described in the said polymer manual. Specifically, 100 parts by weight of monomers, 0.2 parts by weight of 2,2'-azobisisobutyronitrile, and ethyl acetate as a polymerization solvent were put into a reactor equipped with a thermometer, a stirrer, a nitrogen introduction pipe, and a reflux condenser. 200 parts by weight was stirred for 1 hour while flowing nitrogen gas. After removing oxygen in the polymerization system in this way, the temperature was raised to 63° C., and the reaction was performed for 10 hours. Then, it cooled to room temperature, and obtained the homopolymer solution of 33 weight% of solid content concentration. Next, the homopolymer solution was cast-coated on a release liner and dried to prepare a test sample (a sheet-like homopolymer) having a thickness of about 2 mm. This test sample was punched out into a disk shape with a diameter of 7.9 mm and sandwiched between parallel plates, and a shear strain with a frequency of 1 Hz was applied using a viscoelasticity tester (manufactured by TA Instruments Japan, model name "ARES"). , while measuring the viscoelasticity by shear mode at a heating rate of 5°C/min in a temperature range of -70°C to 150°C, and set the temperature corresponding to the peak top temperature of tanδ as the Tg of the homopolymer.

The weight-average molecular weight (Mw) of the polymer (A) is usually preferably about 20×10 ⁴ or more, but is not particularly limited. By the polymer (A) of this Mw, it is easy to obtain the adhesive which shows good cohesion. From the viewpoint of obtaining higher cohesion, in some preferred aspects, the Mw of the polymer (A) may be, for example, 30×10 ⁴ or higher, 40×10 ⁴ or higher, or 50×10 ⁴ or higher, It may be 60×10 ⁴ or more, or 80×10 ⁴ or more. In addition, the Mw of the polymer (A) is usually preferably about 500×10 ⁴ or less. Since the polymer (A) of Mw is easy to form an adhesive showing moderate fluidity (movability of polymer chains), it is suitable for realizing a reinforcing film with a low adhesive force in the initial stage of attachment and a large increase in the adhesive force. It is also preferable from the viewpoint of improving the compatibility with the polymer (B) that the Mw of the polymer (A) is not too high. In some preferred aspects, the Mw of the polymer (A) may be, for example, 250×10 ⁴ or less, 200×10 ⁴ or less, 150×10 ⁴ or less, 100×10 ⁴ or less, or is 70×10 ⁴ or less.

In addition, in this specification, Mw of a polymer (A) and the following polymer (B) can be calculated|required by polystyrene conversion by gel permeation chromatography (GPC). More specifically, Mw can be measured according to the method and conditions described in the following examples.

As the polymer (A) in the reinforcing film disclosed herein, an acrylic polymer can be suitably used. When an acrylic polymer is used as a polymer (A), there exists a tendency for favorable compatibility with a polymer (B) to be easily obtained. When the compatibility between the polymer (A) and the polymer (B) is good, it can help to reduce the initial adhesion and improve the adhesion after heating by improving the mobility of the polymer (B) in the adhesive layer. So better. In addition, acrylic polymers with a high degree of freedom in molecular design are suitable as adhesive materials that can improve adhesive properties, bending recovery and bending retention force in a balanced manner.

The acrylic polymer may be, for example, a polymer containing 50% by weight or more of a monomer unit derived from an alkyl (meth)acrylate, that is, a monomer component (monomer raw material A) for preparing the acrylic polymer. 50% by weight or more of the total amount is a polymer of alkyl (meth)acrylate. As the alkyl (meth)acrylate, an alkyl (meth)acrylate having a linear or branched alkyl group having 1 to 20 carbon atoms (ie, C _1-20 ) can be suitably used. The ratio of the C _1-20 alkyl (meth)acrylate in the monomer raw material A may be, for example, 50 wt % or more, or 60 wt % or more, in terms of easily obtaining a balance of properties. In some preferred aspects, the ratio of (meth)acrylic acid C _1-20 alkyl ester in the monomer raw material A is 70% by weight or more, more preferably 80% by weight or more, and more preferably 85% by weight or more , particularly preferably 90% by weight or more. By using the acrylic polymer composed of the monomers, it is easy to obtain an adhesive that balances the rise in adhesive force, the resilience to bending, and the retention force for bending. Moreover, the ratio of the C _1-20 alkyl (meth)acrylate in the monomer raw material A may be, for example, 99.9 wt % or less, 98 wt % or less, or 95 wt % or less. In some aspects, the ratio of C _1-20 alkyl (meth)acrylate in the monomer raw material A may be, for example, 90 wt % or less, 85 wt % or less, or 80 wt % or less.

Non-limiting specific examples of C _1-20 alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, (meth)acrylate ) Isopropyl acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, 2nd butyl (meth)acrylate, 3rd butyl (meth)acrylate, pentyl (meth)acrylate ester, isoamyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, (meth)acrylate ) Isooctyl acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate , Dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, (meth)acrylic acid cetyl ester, heptadecyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, nonadecyl (meth)acrylate, (meth)acrylate ) eicosyl acrylate, etc.

Among these, it is preferable to use at least a C _1-18 alkyl (meth)acrylate, and it is more preferable to use at least a C _1-14 alkyl (meth)acrylate. In some aspects, the acrylic polymer may contain a C _4-12 alkyl (meth)acrylate (preferably a C _4-10 alkyl acrylate, such as a C _6-10 alkyl acrylate) At least one of them is used as a monomer unit. For example, an acrylic polymer containing one or both of n-butyl acrylate (BA) and 2-ethylhexyl acrylate (2EHA) is preferable, and an acrylic polymer containing at least 2EHA is particularly preferable.

In some preferred aspects, the ratio of C _6-10 alkyl acrylate (suitably C _8-9 alkyl acrylate, typically 2EHA) in the monomer raw material A used to prepare the acrylic polymer is: 70% by weight or more, more preferably 80% by weight or more, still more preferably 85% by weight or more, particularly preferably 90% by weight or more. Acrylic polymers of this monomer composition are particularly suitable for achieving the effects of the techniques disclosed herein. In addition, the ratio of C _6-10 alkyl acrylate (suitably C _8-9 alkyl acrylate, typically 2EHA) in the monomer raw material A may be, for example, 99.9 wt % or less, resulting in low initial adhesion and bending. From the viewpoint of recovery properties, it may be 98% by weight or less, or 95% by weight or less.

In addition, in some preferred aspects, in the monomer raw material A used to prepare the acrylic polymer, it is preferable to limit the C _1-3 alkyl (meth)acrylate (such as C ₁ -alkane (meth)acrylate) base ester, typically methyl methacrylate (MMA)). C _1-3 alkyl (meth)acrylates (such as C ₁ alkyl (meth)acrylates, typically MMA) tend to have relatively high Tg, and those containing acrylic polymers using the above-mentioned monomer components The cohesiveness of the adhesive tends to become high. By limiting the amount of C _1-3 alkyl (meth)acrylate used, the cohesive force of the adhesive can be moderately reduced, and the elastic modulus (typically surface elasticity) suitable for taking into account the bending retention force or the increase in adhesive force can be well achieved. modulus). From this point of view, the ratio of C _1-3 alkyl (meth)acrylate (for example, C ₁ alkyl (meth)acrylate, typically MMA) in the above-mentioned monomer raw material A is preferably 8% by weight Hereinafter, it is preferably 6 wt % or less, more preferably 3 wt % or less, and still more preferably 1 wt % or less (for example, 0 to 0.3 wt %).

The monomer raw material A may contain the (meth)acrylic-acid alkylester as a main component, and may contain other monomer (copolymerizable monomer) which can be copolymerized with the (meth)acrylic-acid alkylester as needed. As a copolymerizable monomer, a monomer having a polar group (for example, a carboxyl group, a hydroxyl group, a nitrogen atom-containing ring, etc.) can be preferably used. Monomers with polar groups can help introduce cross-linking points to the acrylic polymer or improve the cohesion of the acrylic polymer. A comonomer can be used individually by 1 type or in combination of 2 or more types.

Non-limiting specific examples of the copolymerizable monomer include the following. Hydroxyl-containing monomers: such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12 (meth)acrylate -Hydroxylauryl ester, (meth)acrylic acid (4-hydroxymethylcyclohexyl) methyl ester, etc. (meth)acrylic acid hydroxyalkyl ester, etc. Monomers with rings containing nitrogen atoms: e.g. N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinyl Pyrimidine, N-vinylpiperidine, N-vinylpyridine, N-vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N-(meth)acryloyl-2-pyrrolidone , N-(meth)acryloylpiperidine, N-(meth)acryloylpyrrolidine, N-(meth)acryloylpyrrolidine, N-vinylpyridinium, N-vinyl-3 -𠰌olinone, N-vinyl-2-caprolactam, N-vinyl-1,3-㗁𠯤-2-one, N-vinyl-3,5-𠰌linedione, N-ethylene Pyrazole, N-vinylisoxazole, N-vinylthiazole, N-vinylisothiazole, N-vinylisothiazole, etc.; For example, N-(meth)acryloyloxymethylenesuccinimide, N-(meth)acryloyl-6-oxyhexamethylenesuccinimide, N-(methyl) Acryloyl-8-oxyhexamethylene succinimide and other monomers with succinimide skeleton; For example, N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-phenylmaleimide, etc. maleimides; and For example N-methyliconimide, N-ethyliconimide, N-butyliconimide, N-octyliconimide, N-2-ethylhexyliconimide Iconimide such as imide, N-cyclohexyl iconimide, N-lauryl iconimide, etc. Carboxyl group-containing monomers: for example, acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itonic acid, maleic acid, fumaric acid, crotonic acid, methacrylic acid, and the like. Acid anhydride group-containing monomers: such as maleic anhydride, itaconic anhydride. Epoxy group-containing monomers: such as epoxy group-containing acrylates such as glycidyl (meth)acrylate or (meth)acrylate-2-ethyl glycidyl ether, allyl glycidyl ether, (methyl) Acrylic Glycidyl Ether, etc. Cyano group-containing monomers: such as acrylonitrile, methacrylonitrile, etc. Isocyanate group-containing monomer: for example, 2-isocyanatoethyl (meth)acrylate, etc. Amide group-containing monomers: such as (meth)acrylamide; N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N- Dipropyl (meth) acrylamide, N,N-diisopropyl (meth) acrylamide, N,N-di (n-butyl) (meth) acrylamide, N,N-di (Tertiary butyl) (meth) acrylamide, etc. N,N-dialkyl (meth) acrylamide; N-ethyl (meth) acrylamide, N-isopropyl (methyl) Acrylamide, N-butyl (meth) acrylamide, N-n-butyl (meth) acrylamide, etc. N-alkyl (meth) acrylamide; N-vinylacetamide, etc. N -Vinyl carboxamides; monomers with hydroxyl and amide groups, such as N-(2-hydroxyethyl)(meth)acrylamide, N-(2-hydroxypropyl)(meth)propylene Amide, N-(1-hydroxypropyl)(meth)acrylamide, N-(3-hydroxypropyl)(meth)acrylamide, N-(2-hydroxybutyl)(methyl) N-Hydroxyalkyl (meth)acrylamides such as acrylamide, N-(3-hydroxybutyl)(meth)acrylamide, and N-(4-hydroxybutyl)(meth)acrylamide ; Monomers with alkoxy and amide groups, such as N-methoxymethyl (meth) acrylamide, N-methoxyethyl (meth) acrylamide, N-butoxymethyl N-alkoxyalkyl(meth)acrylamides such as alkoxy(meth)acrylamides; in addition, N,N-dimethylaminopropyl(meth)acrylamides and the like. Aminoalkyl (meth)acrylates: such as aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, N,N-di(meth)acrylate Ethylaminoethyl ester, tert-butylaminoethyl (meth)acrylate. Alkoxy-containing monomers: such as 2-methoxyethyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, (methyl)acrylate ) Propoxyethyl acrylate, butoxyethyl (meth)acrylate, ethoxypropyl (meth)acrylate and other (meth)acrylate alkoxyalkyl esters; (meth)acrylate methoxy (meth)acrylic acid alkoxyalkylene glycol esters, such as ethylene glycol ester and methoxypolypropylene glycol (meth)acrylate. Monomers containing sulfonic acid groups or phosphoric acid groups: such as styrene sulfonic acid, allyl sulfonic acid, sodium vinyl sulfonate, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (methyl) ) acrylamide propanesulfonic acid, sulfopropyl (meth)acrylate, (meth)acryloyloxynaphthalenesulfonic acid, 2-hydroxyethylacryloylphosphate, and the like. (Meth)acrylates with alicyclic hydrocarbon groups: such as cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, isoflurane (meth)acrylate, dicyclopentyl (meth)acrylate Wait. (Meth)acrylate having an aromatic hydrocarbon group: for example, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, and the like. Vinyl ethers: vinyl alkyl ethers such as methyl vinyl ether or ethyl vinyl ether. Vinyl esters: such as vinyl acetate, vinyl propionate, etc. Aromatic vinyl compounds: for example, styrene, α-methylstyrene, vinyltoluene, and the like. Olefins: such as ethylene, butadiene, isoprene, isobutylene, etc. In addition, (meth)acrylates containing heterocycles such as tetrahydrofuran methyl (meth)acrylate, (meth)acrylates containing halogen atoms such as vinyl chloride or (meth)acrylates containing fluorine atoms, polysiloxanes, etc. Silicon atom-containing (meth)acrylates such as (meth)acrylates, (meth)acrylates obtained from terpene compound derivative alcohols, and the like.

When using such a copolymerizable monomer, the usage-amount is not specifically limited, Usually, it is suitable to be 0.01 weight% or more of the monomer raw material A. The usage-amount of a comonomer can be 0.1 weight% or more of the monomer raw material A from a viewpoint of exhibiting the effect by using a copolymerizable monomer more favorably, and 1 weight% or more may be sufficient as it. In some preferred aspects, the content of the comonomer in the monomer raw material A is 3 wt % or more, more preferably 5 wt % or more, and still more preferably 7 wt % or more (eg, 8 wt % or more). The higher the amount of the comonomer used, the higher the cohesiveness and the higher the bending recovery. Moreover, the usage-amount of a copolymerizable monomer can be 50 weight% or less of the monomer raw material A, Preferably it is 45 weight% or less. Thereby, the cohesive force of the adhesive can be prevented from becoming too high, and the stickiness at normal temperature (25°C) can be improved. In some preferred aspects, the amount of the comonomer used is 20 wt % or less of the monomer raw material A, more preferably 15 wt % or less (eg, 12 wt % or less), and may also be 10 wt % or less. By limiting the amount of comonomer used, the cohesive force of the adhesive is reduced, and the elastic modulus (typically, the surface elastic modulus) is in an appropriate range, and it is easy to obtain excellent bending retention force and increase the adhesion force.

In several aspects, monomer feed A may comprise a monomer having a nitrogen-containing ring. By using a monomer having a nitrogen-containing ring, the cohesion or polarity of the adhesive can be adjusted, and the adhesive force after heating can be appropriately improved. By including the monomer having a nitrogen atom-containing ring in the monomer raw material A, the compatibility of the polymer (A) formed from the monomer raw material A and the polymer (B) tends to improve. Thereby, it becomes easy to obtain the reinforcement film which can raise the adhesive force significantly by heating.

The monomer having a nitrogen atom-containing ring can be appropriately selected from, for example, the above-mentioned examples, and can be used alone or in combination of two or more. In some aspects, the monomer raw material A preferably contains at least one monomer selected from the group consisting of N-vinyl cyclic amides and cyclic amides having (meth)acryloyl groups as Monomers with rings containing nitrogen atoms.

Specific examples of N-vinyl cyclic amides include N-vinyl-2-pyrrolidone, N-vinyl-2-piperidone, N-vinyl-3-piperidinone, N-Vinyl-2-caprolactam, N-vinyl-1,3-㗁𠯤-2-one, N-vinyl-3,5-𠰌linedione, etc. Particularly preferred are N-vinyl-2-pyrrolidone and N-vinyl-2-caprolactam. Specific examples of the cyclic amide having a (meth)acryloyl group include N-(meth)acryloyl-2-pyrrolidone, N-(meth)acrylopiperidine, N-(meth)acryloylpyrrolidine, N-(meth)acryloylpyrrolidine, and the like. As a preferable example, N-acryloyl molybdenum (ACMO) can be mentioned.

The amount of the monomer having a nitrogen atom-containing ring to be used is not particularly limited, but is usually preferably 40 wt % or less of the monomer raw material A, may be 30 wt % or less, may be 20 wt % or less, or may be It is 10 weight% or less. In some preferred aspects, the content of the monomer having a nitrogen atom-containing ring in the monomer raw material A is 7 wt. % or less, more preferably 5 wt % or less, still more preferably 3 wt % or less (for example, 1.5 wt % or less). Moreover, the usage-amount of the monomer which has a nitrogen atom containing ring is normally 0.01 weight% or more of monomer raw material A (preferably 0.1 weight% or more, for example, 0.5 weight% or more). From the viewpoint of obtaining an appropriate cohesion force and elastic modulus, in some aspects, the use amount of the monomer having a nitrogen atom-containing ring may be 0.8% by weight or more of the monomer raw material A, and may also be 1.0% by weight. % by weight or more.

In some preferred aspects, the monomer raw material A comprises a hydroxyl-containing monomer. By using hydroxyl-containing monomers, the cohesion or polarity of the adhesive can be adjusted, and thus the elastic modulus (typically the surface elastic modulus) can be adjusted, and the effects of the techniques disclosed herein can be well achieved. In addition, the hydroxyl-containing monomer provides a reaction point with the following cross-linking agent (eg, an isocyanate-based cross-linking agent), which can improve the cohesion of the adhesive through the cross-linking reaction.

As the hydroxyl group-containing monomer, 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, N-(2-hydroxyethyl) can be suitably used group) (meth)acrylamide, etc. Among these, as a preferable example, 2-hydroxyethyl acrylate (HEA), 4-hydroxybutyl acrylate (4HBA), and N-(2-hydroxyethyl) acrylamide (HEAA) are mentioned. From the viewpoint of obtaining a cohesive force suitable for bending recovery and bending retention, 4HBA is particularly preferred.

The usage-amount of a hydroxyl-containing monomer is not specifically limited, Usually, it is suitable to be 40 weight% or less of the monomer raw material A, and may be 30 weight% or less, and may be 20 weight% or less. In some preferred aspects, from the viewpoint of reducing the cohesion force and thus reducing the elastic modulus (typically the surface elastic modulus), the content of the hydroxyl-containing monomer in the monomer raw material A is 15% by weight or less, more preferably It is 12 weight% or less (for example, 10 weight% or less). By limiting the use amount of the hydroxyl-containing monomer, the mobility of the polymer (B) in the adhesive layer is improved, and the adhesive force is easily increased. In some other aspects, the content of the hydroxyl group-containing monomer can also be set to 5 wt % or less of the monomer raw material A. Moreover, the usage-amount of a hydroxyl-containing monomer is suitably 0.01 weight% or more of monomer raw material A (preferably 0.1 weight% or more, for example, 0.5 weight% or more). From the viewpoint of obtaining a moderate cohesion force and elastic modulus, in some preferred aspects, the amount of the hydroxyl-containing monomer used is 1% by weight or more of the monomer raw material A, more preferably 3% by weight or more, and more Preferably it is 5 weight% or more, Especially preferably, it is 7 weight% or more (for example, 8 weight% or more).

In some aspects, as a copolymerizable monomer, a monomer having a nitrogen atom-containing ring and a hydroxyl group-containing monomer can be used in combination. In this case, the total amount of the monomer having a nitrogen atom-containing ring and the hydroxyl group-containing monomer can be, for example, 0.1% by weight or more, preferably 1% by weight or more, and more preferably 3% by weight of the monomer raw material A. above, more preferably 5 wt % or more, particularly preferably 7 wt % or more (for example, 9 wt % or more), 10 wt % or more, 15 wt % or more, 20 wt % or more, You may make it 25 weight% or more. In addition, the total amount of the monomer having a nitrogen atom-containing ring and the hydroxyl group-containing monomer can be, for example, 50% by weight or less of the monomer raw material A, or preferably 30% by weight or less. In some preferred aspects, the total amount of the monomer having a nitrogen atom-containing ring and the hydroxyl group-containing monomer is 20 wt% or less of the monomer raw material A, more preferably 15 wt% or less (for example, 12 wt% or less) .

In the aspect in which the monomer raw material A combines a monomer having a nitrogen atom-containing ring and a hydroxyl group-containing monomer, the content (W _N ) of the monomer having a nitrogen atom-containing ring in the monomer raw material A and the The relationship (weight basis) of the hydroxyl monomer content (W _OH ) is not particularly limited. W _N /W _OH may be, for example, 0.01 or more, usually preferably 0.05 or more, 0.10 or more, or 0.12 or more. Moreover, W _N /W _OH may be, for example, 10 or less, usually 1 or less, preferably 0.50 or less, 0.30 or less, 0.20 or less, or 0.15 or less.

In some aspects, the monomer raw material A preferably does not contain a monomer having a polyorganosiloxane skeleton (monomer S1) that can be used well as a constituent of the monomer raw material B described below, or the monomer The content of the monomer material A is less than 10% by weight (more preferably less than 5% by weight, for example, less than 2% by weight). With the monomer raw material A having such a composition, a reinforcing film that satisfies both the secondary processability in the initial stage and the strong adhesiveness after the adhesive force is raised can be well realized. For the same reason, in some other aspects, the monomer raw material A preferably does not contain the monomer S1, or when the monomer S1 is contained, its content (weight basis) is lower than that in the monomer raw material B. The content of monomer S1.

The method for obtaining the polymer (A) is not particularly limited, and various polymerization methods such as solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization, and photopolymerization can be appropriately employed, for example. In several aspects, solution polymerization methods may well be employed. The polymerization temperature during solution polymerization can be appropriately selected according to the type of monomer and solvent used, the type of polymerization initiator, etc., for example, it can be set to about 20°C to 170°C (typically about 40°C to 140°C) .

The initiator used for the polymerization can be appropriately selected from previously known thermal polymerization initiators, photopolymerization initiators, and the like according to the polymerization method. The polymerization initiators may be used alone or in combination of two or more.

As the thermal polymerization initiator, for example, azo-based polymerization initiators (for example, 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, 2,2'-azobis-2-methylbutyronitrile, ,2'-azobis(2-methylpropionic acid) dimethyl ester, 4,4'-azobis-4-cyanovaleric acid, azobisisovaleronitrile, 2,2'-azobis (2-Amidinopropane) dihydrochloride, 2,2'-azobis[2-(5-methyl-2-imidazolin-2-yl)propane]dihydrochloride, 2,2'- Azobis(2-methylpropionamidine)disulfate, 2,2'-azobis(N,N'-dimethylisobutylamidine)dihydrochloride, etc.); potassium persulfate, etc. Sulfate; peroxide-based polymerization initiators (for example, dibenzyl peroxide, 3-butyl peroxymaleate, lauryl peroxide, etc.); redox-based polymerization initiators, etc. The usage amount of the thermal polymerization initiator is not particularly limited, for example, relative to 100 parts by weight of the monomer component (monomer raw material A) used in the preparation of the acrylic polymer, it can be set as 0.01 part by weight to 5 parts by weight, or 100 parts by weight. The amount within the range of 0.05 parts by weight to 3 parts by weight is preferable.

系光聚合起始劑、醯基氧化膦系光聚合起始劑等。光聚合起始劑之使用量並無特別限制，例如相對於100重量份單體原料A，可設為0.01重量份～5重量份、較佳為0.05重量份～3重量份之範圍內之量。The photopolymerization initiator is not particularly limited, and for example, a benzoin ether-based photopolymerization initiator, an acetophenone-based photopolymerization initiator, an α-ketol-based photopolymerization initiator, and an aromatic sulfonic acid chloride can be used. Photopolymerization initiators, photoactive oxime-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzophenone-based photopolymerization initiators, ketal-based photopolymerization initiators Polymerization initiator, 9-oxysulfur 𠮿

It is a photopolymerization initiator, an acylphosphine oxide-based photopolymerization initiator, and the like. The usage amount of the photopolymerization initiator is not particularly limited, for example, it can be set in the range of 0.01 to 5 parts by weight, preferably 0.05 to 3 parts by weight relative to 100 parts by weight of the monomer raw material A .

In some aspects, the polymer (A) may be a partial polymer (a partial polymer ( The form of polymer slurry) is contained in the adhesive composition for forming the adhesive layer. The adhesive composition containing the polymer slurry can be applied to a predetermined object to be coated and then irradiated with ultraviolet rays to complete the polymerization. That is, the said polymer slurry can be understood as a polymer (A) precursor. The adhesive layer disclosed here can be formed using, for example, an adhesive composition containing the above-mentioned polymer slurry and the polymer (B).

(Polymer (B)) The polymer (B) in the technology disclosed herein contains a monomer having a polyorganosiloxane skeleton (hereinafter, also referred to as "monomer S1") and a monomer component of a (meth)acrylic monomer ( Polymers of monomeric starting materials B). The polymer (B) can be referred to as a copolymer of the monomer S1 and a (meth)acrylic monomer. The polymer (B) may be used alone or in combination of two or more. The low polarity and mobility of the polymer (B) derived from the polyorganosiloxane structure of the monomer S1 can be used to suppress the initial adhesion force to the adherend, and by heating, the The adhesive force increase delay agent that increases the adhesive force functions. It does not specifically limit as monomer S1, Any monomer containing a polyorganosiloxane skeleton can be used. Monomer S1 promotes the polymer (B) to lean on the surface of the adhesive layer in the reinforcing film before use (before it is attached to the adherend) due to its low polarity due to its structure, showing the initial stage of lamination. Light peeling (low tack). As the monomer S1, a structure having a polymerizable reactive group at one end can be suitably used. The polymer (B) which has a polyorganosiloxane skeleton in a side chain is formed by the structure containing such a monomer S1 unit and a (meth)acrylic-type monomer unit. The polymer (B) of this structure tends to have lower initial adhesion and higher adhesion after heating due to the mobility and ease of movement of the side chains. In addition, in some aspects, monomer S1 can be preferably used with a polymerizable reactive group at one end and no functional group at the other end that causes a crosslinking reaction with the polymer (A). The polymer (B) obtained by copolymerizing the monomer S1 of this structure is likely to have lower initial adhesion and higher adhesion after heating due to the mobility of the polyorganosiloxane structure derived from monomer S1 .

[化2]

此處，上述通式(1)、(2)中之R³ 為氫或甲基，R⁴ 為甲基或1價有機基，m及n為0以上之整數。As the monomer S1, for example, a compound represented by the following general formula (1) or (2) can be used. More specifically, X-22-174ASX, X-22-2426, X-22-2475, KF-2012 etc. are mentioned as a single terminal reactive polysiloxane oil manufactured by Shin-Etsu Chemical Co., Ltd. Monomer S1 may be used alone or in combination of two or more. [hua 1]

[hua 2]

Here, in the general formulae (1) and (2), R ³ is hydrogen or a methyl group, R ⁴ is a methyl group or a monovalent organic group, and m and n are integers of 0 or more.

The functional group equivalent of the monomer S1 can adopt an appropriate value within the range in which the desired effect is obtained by using the monomer S1, and is not limited to a specific range. From the viewpoint of sufficiently suppressing the initial adhesion, the functional group equivalent is, for example, 100 g/mol or more, or 200 g/mol or more, preferably 300 g/mol or more (for example, 500 g/mol or more), preferably 800. g/mol or more, more preferably 1500 g/mol or more. In a particularly preferred aspect, from the viewpoint of both the low adhesiveness at the initial stage of attachment and the increase in the adhesive force after heating, the functional group equivalent is 2000 g/mol or more, more preferably 2500 g/mol or more, and can be used. It is 3000 g/mol or more, may be 4000 g/mol or more, and may be 5000 g/mol or more. In other aspects, the functional group equivalent may be above 9000 g/mol, above 12000 g/mol, or above 15000 g/mol.

From the viewpoint of sufficiently improving the adhesive force, the functional group equivalent weight is preferably, for example, 30,000 g/mol or less, may be 20,000 g/mol or less, may be less than 15,000 g/mol, or may be less than 10,000 g/mol. In some preferred aspects, the functional group equivalent of the monomer S1 is 7000 g/mol or less, more preferably 5500 g/mol or less, further preferably 4500 g/mol or less, may be 4200 g/mol or less, or It can be below 3500 g/mol. If the functional group equivalent of the monomer S1 is within the above range, the compatibility in the adhesive layer (for example, the compatibility with the base polymer) tends to be good, and the polyorganosiloxane of the polymer (B) The mobility of the alkane skeleton (chain) is good, and it is easy to adjust the mobility of the polymer (B) to an appropriate range, and it is easy to realize an adhesive layer that combines low initial adhesion and increased adhesion after heating.

Here, the "functional group equivalent" refers to the weight of the main skeleton (eg, polydimethylsiloxane) bonded to each functional group. The notation unit g/mol is converted to 1 mol of the functional group. The functional group equivalent of the monomer S1 can be calculated from, for example, the spectral intensity of ¹ H-NMR (proton NMR) by nuclear magnetic resonance (NMR). The functional group equivalent weight (g/mol) of the monomer S1 based on the spectral intensity of ¹ H-NMR can be calculated based on the general structure analysis method related to the spectral analysis of ¹ H-NMR, if necessary, referring to the description of Japanese Patent No. 5951153. conduct. In the functional group equivalent of the monomer S1, the above-mentioned functional group means a polymerizable functional group (for example, an ethylenically unsaturated group such as a (meth)acryloyl group, a vinyl group, and an allyl group).

In addition, when two or more monomers with different functional group equivalents are used as the monomer S1, the arithmetic mean value can be used as the functional group equivalent of the monomer S1. That is, the functional group equivalent of monomer S1 including n types of monomers (monomer S1 ₁ , monomer S1 ₂ , monomer S1 _n ) having different functional group equivalents can be calculated by the following formula. The functional group equivalent of the monomer S1 (g/mol) = (the functional group equivalent of the monomer S1 ₁ × the preparation amount of the monomer S1 ₁ + the functional group equivalent of the monomer S1 ₂ × the preparation amount of the monomer S1 ₂ +・・・+ Functional group equivalent of monomer S1 _n × compounded amount of monomer S1 _n )/( compounded amount of monomer S1 ₁ + compounded amount of monomer S1 ₂ +・・・+ compounded amount of monomer S1 _n )

The content of the monomer S1 can adopt an appropriate value within the range in which the desired effect is exhibited by using the monomer S1, and is not limited to a specific range. From the viewpoint of sufficiently suppressing the initial adhesion, in some aspects, the content of the monomer S1 in the total amount of the monomer components (monomer raw materials B) used to prepare the polymer (B) may be, for example, 5 % by weight or more is preferably at least 10% by weight, more preferably at least 12% by weight, further preferably at least 15% by weight, and particularly preferably at least 15% by weight, from the viewpoint of better exerting the effect as an adhesion increase retarder. 18% by weight or more, and may be 20% by weight or more. In addition, from the viewpoint of polymerization reactivity or compatibility, the content of the monomer S1 in the monomer raw material B may be, for example, 80% by weight or less, preferably 60% by weight or less, preferably 50% by weight or less, More preferably, it is 40% by weight or less, and still more preferably 30% by weight or less. By setting the polymerization ratio of the monomer S1 to an appropriate range, an increase in adhesive force can be appropriately expressed.

The monomer raw material B contains the (meth)acrylic monomer which can be copolymerized with the monomer S1 in addition to the monomer S1. The mobility of the polymer (B) in the adhesive layer can be appropriately adjusted by using one or two or more (meth)acrylic monomers. Moreover, it can also contribute to improving the compatibility of a polymer (B) and a polymer (A). The polymer (B) containing the (meth)acrylic monomer unit can be well compatible with the acrylic polymer, so it is easy to achieve initial adhesion by improving the mobility of the polymer (B) in the adhesive layer decrease and increase in adhesion after heating.

In the polymer (B) used in the technique disclosed herein, the composition of the (meth)acrylic monomer contained in the monomer raw material B is preferably set based on the composition of the (meth)acrylic monomer The glass transition temperature _TB1 of the polymer (A) is higher than the glass transition temperature TA of the polymer ( _A ). T _B1 can be set to be higher than 0°C, for example. Here, the glass transition temperature T _B1 based on the composition of the (meth)acrylic monomer refers to the composition based only on the (meth)acrylic monomer in the monomer component used for preparing the polymer (B), by Tg obtained by Fox formula. T _B1 can only target the (meth)acrylic monomers in the monomer components used to prepare the polymer (B), and apply the above-mentioned Fox formula, according to the glass of the homopolymer of each (meth)acrylic monomer. The transition temperature and the weight fraction of each (meth)acrylic-based monomer in the total amount of the (meth)acrylic-based monomer were calculated. The initial adhesion is easily suppressed by the polymer (B) having a relatively high glass transition temperature T _B1 (typically higher than 0° C.). In addition, by the polymer (B) having a relatively high glass transition temperature T _B1 (typically higher than 0° C.), it is easy to obtain a reinforcing film with a relatively large increase in adhesive force.

In some preferred aspects, T _B1 is 10°C or higher, more preferably 30°C or higher, still more preferably 40°C or higher, and may be 45°C or higher. When T _B1 becomes high, there exists a tendency for the adhesive force in the initial stage of attachment to be suppressed better generally. The reason for this is considered to be the movement of the polyorganosiloxane moiety due to the fact that T _B1 is the polymer (B) having a predetermined temperature or higher, as the temperature rises to room temperature or a high temperature region to some extent higher than room temperature The improvement of the property or mobility is effectively suppressed by the monomer unit derived from the (meth)acrylic monomer contained in the polymer (B), so that the above-mentioned polyorganosiloxane structural moiety can be better maintained. The presence of resulting low adhesion. From the viewpoint of maintaining the low tackiness in the initial stage of attachment with better stability, in some aspects, T _B1 may be, for example, 50°C or higher, 55°C or higher, or 60°C or higher. Moreover, T _B1 may be 120 degrees C or less, for example, and 100 degrees C or less may be sufficient as it. When T _B1 becomes low, there exists a tendency for the increase of adhesive force by heating to become easy. In some preferred aspects, T _B1 is, for example, 90°C or lower, more preferably 70°C or lower, further preferably 60°C or lower, and particularly preferably 55°C or lower (eg, 50°C or lower).

The total amount of the monomer S1 and the (meth)acrylic monomer in the total amount of the monomer components used to prepare the polymer (B) accounts for the ease of exhibiting the effect by appropriately setting T _B1 . The ratio may be, for example, 50% by weight or more, 70% by weight or more, 85% by weight or more, 90% by weight or more, 95% by weight or more, or substantially 100% by weight.

The glass transition temperature TB of the polymer ( _B ) is not particularly limited, and it can be selected so as to obtain preferable properties in the reinforcing film disclosed herein. The TB of the polymer ( _B ) may be, for example, less than 50°C, 30°C or lower, 20°C or lower, 15°C or lower, or 10°C or lower. When the TB of the polymer ( _B ) is lowered, the mobility (typically, thermokinetic properties) of the polymer (B) is improved, and the adhesive force can be greatly improved. In some preferred aspects, the TB of the polymer ( _B ) is below 5°C, may be less than 0°C, may be below -5°C, and may be below -10°C. In addition, in some aspects, the TB of the polymer ( _B ) may be, for example, -40°C or higher, or -30°C or higher. The higher the TB, the more the polymer ( _B ) which is biased toward the surface side of the adhesive layer when attached to the adherend, contributes to lowering the initial adhesive force, and tends to be more excellent in light peelability at the initial stage of attachment. In some preferred aspects, the TB of the polymer ( _B ) is -20°C or higher, and may also be -15°C or higher. By setting TB to an appropriate range, the light peelability in the initial stage of attachment and the increase in the adhesive force after heating can be controlled to _a suitable range.

In some aspects, the composition of the monomer components used to prepare the polymer (B) can be set such that T _B1 is higher than T _B , ie, T _B1 - T _B is greater than 0°C. According to such a composition, the effect of adjusting the mobility of the polymer (B) by the composition of the (meth)acrylic-based monomer contained in the monomer component can be easily and appropriately exhibited. T _B1 -TB may be, for example, about 40° _C to 100°C, or about 50°C to 90°C. In some preferred aspects, T _B1 -TB is 45° _C or higher, more preferably 50°C or higher, and still more preferably 55°C or higher (eg, 58°C or higher). In addition, from the viewpoint of appropriately expressing the effect of containing the polymer ( _B ), _TB1 -TB is preferably 80°C or lower, more preferably 70°C or lower, still more preferably 65°C or lower (for example, 62°C or lower). ).

From the viewpoint of easily controlling the mobility of the polymer (B) in the adhesive layer, in some aspects, the composition of the monomer components used to prepare the polymer (B) can be set to be In the relationship between the glass transition temperature TA of _A ), TB is higher than _TA by 20° _C or more, that is, TB- _TA is 20° _C or more. In some preferred aspects, _{T B} -TA is, for example, 30°C or higher, more preferably 40°C or higher, still more preferably 50°C or higher, may be 60°C or higher, or 70°C or higher. In addition, from the viewpoint of increasing the adhesive force, T _B - T _A may be, for example, 130° C. or lower, or 120° C. or lower, preferably 100° C. or lower, more preferably 80° C. or lower, and still more preferably 65° C. Below, it may be 55°C or lower, or 45°C or lower.

As a (meth)acrylic-type monomer which can be used for the monomer raw material B, (meth)acrylic-acid alkylester is mentioned, for example. The term "alkyl" as used herein refers to a chain (including linear and branched) alkyl groups (groups), excluding the following alicyclic hydrocarbon groups. For example, as a constituent component of the monomer raw material B, one or two or more of the monomers exemplified above with respect to the alkyl (meth)acrylate that can be used in the polymer (A) can be used. In some aspects, the monomer raw material B may contain a C _4-12 alkyl (meth)acrylate (preferably a C _4-10 alkyl (meth)acrylate, such as a C _6- (meth)acrylate) ₁₀ alkyl esters) at least one. In other aspects, the monomer raw material B may contain a C _1-18 alkyl methacrylate (preferably a C _1-14 alkyl methacrylate, such as a C _1-10 alkyl methacrylate) at least one of them. The monomer raw material B may contain, for example, one or two or more selected from MMA, n-butyl methacrylate (BMA), and 2-ethylhexyl methacrylate (2EHMA) as a (meth)acrylic monomer.

As another example of the said (meth)acrylic-type monomer, the (meth)acrylate which has an alicyclic hydrocarbon group is mentioned. For example, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, iso(meth)acrylate, dicyclopentyl (meth)acrylate, 1-adamantyl (meth)acrylate can be used esters, etc. In some aspects, the monomer raw material B may contain at least one selected from the group consisting of dicyclopentyl methacrylate, isophthalic methacrylate, and cyclohexyl methacrylate as a (meth)acrylic monomer.

The content of the above-mentioned alkyl (meth)acrylate and the above-mentioned (meth)acrylate having an alicyclic hydrocarbon group in the monomer raw material B may be, for example, 10% by weight or more and 95% by weight or less, or 20% by weight or more. % by weight or less, 30% by weight or more and 90% by weight or less, 40% by weight or more and 90% by weight or less, or 50% by weight or more and 85% by weight or less. The use of an alkyl (meth)acrylate may become advantageous from the viewpoint of the easiness of increasing the adhesive force by heating. In some aspects, the content of the (meth)acrylate having an alicyclic hydrocarbon group may be less than 50% by weight of the monomer raw material B, may be less than 30% by weight, may be less than 15% by weight, and may be less than 10% by weight. % by weight, but may be less than 5% by weight. The (meth)acrylate which has an alicyclic hydrocarbon group may not be used.

In some preferred aspects, the above-mentioned (meth)acrylic monomer as a constituent of the monomer raw material B may include a monomer M2 whose Tg of the homopolymer is 50° C. or higher. In the polymer (B), by copolymerizing the monomer S1 and the monomer M2, it is easy to appropriately control the mobility or mobility of the polyorganosiloxane structural moiety accompanying the temperature rise, and at the same time realize the initial light peeling property (secondary). Processability) and increased adhesion after heating. In some aspects, the Tg of the homopolymer of monomer M2 can be above 60°C, can be above 70°C, can be above 80°C, and can also be above 90°C. In addition, the upper limit of the Tg of the homopolymer of the monomer M2 is not particularly limited, but is usually preferably 200° C. or lower from the viewpoint of the ease of synthesis of the polymer (B). In some aspects, the Tg of the homopolymer of monomer M2 may be, for example, 180°C or lower, 150°C or lower, or 120°C or lower.

As the monomer M2, for example, one that satisfies the Tg of the homopolymer can be used from among the (meth)acrylic monomers exemplified above. For example, one or two or more monomers selected from the group consisting of alkyl (meth)acrylate and (meth)acrylate having an alicyclic hydrocarbon group can be used. As the alkyl (meth)acrylate, an alkyl methacrylate having an alkyl group of 1 to 4 carbon atoms can be suitably used.

In the aspect in which the monomer raw material B includes the monomer M2, the content of the monomer M2 may be, for example, 5 wt % or more of the monomer raw material B, 10 wt % or more, 15 wt % or more, or 20 wt %. % or more, may be 25% by weight or more, or may be 30% by weight or more. In some aspects, the content of the monomer M2 may be more than 35% by weight of the monomer raw material B, may be more than 40% by weight, may be more than 45% by weight, may be more than 50% by weight, and may be more than 55% by weight %above. Moreover, the content of the monomer M2 may be, for example, 90 wt % or less, usually 80 wt % or less, preferably 75 wt % or less, 70 wt % or less, or 65 wt % or less. In some preferred aspects, the content of the monomer M2 is 60 wt % or less (eg, 50 wt % or less, typically 42 wt % or less). In the polymer (B), by restricting the copolymerization ratio of the monomer M2 having a Tg of 50°C or higher to a predetermined value or less, it is possible to achieve a good performance after heating based on the mobility of the polymer (B) around 50°C. Adhesion increases. From the same viewpoint, the content of the monomer M2 in the monomer raw material B may be 35 wt % or less, 25 wt % or less, or 15 wt % or less (eg, 5 wt % or less).

The content of the above-mentioned monomer M2 is suitable, for example, when the monomer M2 contains one or two selected from the group consisting of alkyl (meth)acrylate and the above-mentioned (meth)acrylate having an alicyclic hydrocarbon group The aspect of the above monomer, or the aspect in which the monomer M2 includes one or two or more monomers selected from alkyl (meth)acrylate (eg, alkyl methacrylate). As a preferred example of this aspect, the aspect in which the above-mentioned monomer M2 includes MMA can be exemplified.

In some aspects, the above-mentioned (meth)acrylic monomers may also include monomer M3 whose homopolymer Tg is less than 50°C (typically above -20°C and less than 50°C). By using the monomer M3, it is easy to obtain a reinforcing film that balances the adhesive force and the cohesive force after the adhesive force is increased. The monomer M3 is preferably used in combination with the monomer M2 from the viewpoint of easily exhibiting this effect.

As the monomer M3, for example, among the (meth)acrylic-based monomers exemplified above, one that satisfies the Tg of the homopolymer can be used. For example, one or two or more monomers selected from the group consisting of alkyl (meth)acrylates can be used.

In the aspect in which the monomer raw material B includes the monomer M3, the content of the monomer M3 may be, for example, 5 wt % or more of the monomer raw material B, 10 wt % or more, 15 wt % or more, or 20 wt %. % or more, 25% by weight or more, 30% by weight or more, or 35% by weight or more. In addition, the content of the monomer M3 is usually preferably 70% by weight or less of the monomer raw material B, and may be 60% by weight or less, or 50% by weight or less. The content of the above-mentioned monomer M3, for example, can be well applied to the aspect in which the monomer M3 contains one or two or more monomers selected from alkyl (meth)acrylate (eg, alkyl methacrylate).

In some aspects of the reinforcing film disclosed herein, the monomer raw material B is preferably a homopolymer whose Tg is higher than 170°C and whose content is 30% by weight or less. Here, in this specification, the so-called content of the monomer is X wt % or less, and unless otherwise specified, the concept includes the aspect in which the monomer content is 0 wt %, that is, the monomer does not substantially contain the monomer. manner. In addition, the term "substantially not containing" means that at least the above-mentioned monomer is not intentionally used. If the copolymerization ratio of the monomer whose Tg of the homopolymer is higher than 170°C becomes high, the mobility of the polymer (B) tends to be insufficient, and it may be difficult to increase the adhesive force by heating to a temperature range higher than 50°C.

In some aspects, the monomer raw material B preferably contains at least MMA as a (meth)acrylic monomer. The polymer (B) obtained by copolymerizing MMA can easily obtain a reinforcing film with a large adhesive force after heating. The ratio of MMA to the total amount of (meth)acrylic monomers contained in the monomer raw material B may be, for example, 5% by weight or more, 10% by weight or more, 20% by weight or more, or 30% by weight. % by weight or more, and may be 40% by weight or more. In addition, the ratio of MMA to the total amount of the monomer raw material B is usually preferably 95% by weight or less. The ratio of the total amount may be 75% by weight or less, 65% by weight or less, 60% by weight or less, or 55% by weight or less (eg, 50% by weight or less).

As another example of the monomer which can be contained together with the monomer S1 in the monomer unit which comprises the polymer (B), the carboxyl group-containing monomer exemplified above as the monomer which can be used for the polymer (A) can be mentioned. , Anhydride group-containing monomers, hydroxyl group-containing monomers, epoxy group-containing monomers, cyano group-containing monomers, isocyanate group-containing monomers, amide group-containing monomers, monomers with rings containing nitrogen atoms ( N-vinyl cyclic amides, cyclic amides with (meth)acrylamides, monomers with succinimide skeleton, maleimides, iconimides, etc. ), aminoalkyl (meth)acrylates, vinyl esters, vinyl ethers, olefins, (meth)acrylates with aromatic hydrocarbon groups, (meth)acrylates containing heterocycles, halogen-containing (meth)acrylates of atoms, (meth)acrylates obtained from alcohols derived from terpene compounds, and the like.

As still another example of the monomer which can be contained together with the monomer S1 in the monomer unit which comprises the polymer (B), ethylene glycol di(meth)acrylate, diethylene glycol di(methyl) ) acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate Oxyalkylene di(meth)acrylates such as (meth)acrylates; monomers having a polyoxyalkylene skeleton, for example, at one end of a polyoxyalkylene chain such as polyethylene glycol or polypropylene glycol, A polymerizable polyoxyalkylene group having a polymerizable functional group such as a (meth)acryloyl group, a vinyl group, and an allyl group, and an ether structure (alkyl ether, aryl ether, aryl alkyl ether, etc.) at the other end Ethers; Methoxyethyl (Meth)acrylate, Ethoxyethyl (Meth)acrylate, Propoxyethyl (Meth)acrylate, Butoxyethyl (Meth)acrylate, (Meth) (meth)alkoxyalkyl acrylates such as ethoxypropyl acrylate; salts such as alkali metal (meth)acrylates; poly(meth)acrylates such as trimethylolpropane tri(meth)acrylate : halogenated vinyl compounds such as vinylidene chloride and 2-chloroethyl (meth)acrylate; 2-vinyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2 - Monomers containing oxazoline groups such as isopropenyl-2-oxazoline; base monomers; (meth)acrylic acid-2-hydroxyethyl ester, (meth)acrylic acid-2-hydroxypropyl ester, adducts of lactones and (meth)acrylic acid-2-hydroxyethyl ester, etc. Hydroxyl-containing vinyl monomers; fluorine-substituted (meth)acrylic acid alkyl esters and other fluorine-containing vinyl monomers; 2-chloroethyl vinyl ether, monochlorovinyl acetate and other vinyl monomers containing reactive halogens; such as Vinyltrimethoxysilane, γ-(meth)acryloyloxypropyltrimethoxysilane, allyltrimethoxysilane, trimethoxysilylpropylallylamine, 2-methoxyethoxy Organosilicon-containing vinyl monomers of trimethoxysilane; and macromonomers having radically polymerizable vinyl groups at the ends of the monomers obtained by polymerizing vinyl groups. These can be copolymerized with the monomer S1 singly or in combination of two or more.

In some aspects, as the polymer (B), one that does not have a functional group that causes a crosslinking reaction with the polymer (A) can be suitably used. In other words, the polymer (B) is preferably contained in the adhesive layer in a form not chemically bonded to the polymer (A). The adhesive layer containing the polymer (B) in this form has good mobility of the polymer (B) when heated, and is suitable for increasing the adhesive force increase ratio. The functional group for cross-linking reaction with the polymer (A) may vary depending on the type of functional group possessed by the polymer (A), such as epoxy group, isocyanate group, carboxyl group, alkoxysilyl group , amine groups, etc.

The Mw of the polymer (B) used in the technique disclosed herein is in the range of 10,000 to 100,000. When the Mw of the polymer (B) is 10,000 or more, the polymer (B) does not remain on the surface of the adhesive layer during heating, and an excellent increase in adhesive force is exhibited. The Mw of the polymer (B) is preferably 12,000 or more, more preferably 15,000 or more, still more preferably 20,000 or more, particularly preferably 22,000 or more, and most preferably 25,000 or more. In other aspects, the Mw of the polymer (B) may be 30,000 or more, 50,000 or more, or 70,000 or more. In addition, by using the polymer (B) having Mw of 100,000 or less, the compatibility or mobility of the polymer (B) in the adhesive layer is adjusted to an appropriate range, and the light peelability at the initial stage of attachment becomes excellent. In some preferred aspects, the Mw of the polymer (B) is preferably 80,000 or less, more preferably 60,000 or less, more preferably 40,000 or less (for example, 30,000 or less), may be 25,000 or less, and may be 20,000 or less. . By setting the Mw of the polymer (B) to an appropriate range, an adhesive excellent in both the light peeling property and the adhesive force increasing property in the initial stage of sticking can be obtained.

In certain preferred aspects, the Mw of polymer (B) is preferably lower than the Mw of polymer (A). Thereby, it becomes easy to implement|achieve the reinforcement film which combines favorable secondary workability in the initial stage of attachment and the increase of the adhesive force after heating. In some aspects, the Mw of the polymer (B) may be, for example, 0.8 times or less, 0.75 times or less, 0.5 times or less, or 0.3 times or less of the Mw of the polymer (A). In some preferred aspects, the ratio of the Mw _B of the polymer (B) to the Mw _A of the polymer (A) (Mw _B /Mw _A ) is 0.3 or less, more preferably 0.2 or less, and still more preferably 0.1 Below, it is especially preferable that it is 0.06 or less (for example, 0.05 or less). Moreover, the ratio (Mw _B /Mw _A ) is, for example, preferably 0.010 or more, preferably 0.020 or more, more preferably 0.03 or more, and still more preferably 0.04 or more. By setting the Mw of the polymer (A) and the Mw of the polymer (B) to suitable ranges, the effects of the techniques disclosed herein can be better achieved. In other aspects, the Mw of the polymer (B) may also be 0.03 times or less (eg, 0.02 times or less) of the Mw of the polymer (A).

The polymer (B) can be produced by polymerizing the above-mentioned monomers by known methods such as solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization, and photopolymerization, for example.

In order to adjust the molecular weight of the polymer (B), a chain transfer agent may be used as necessary. Examples of the chain transfer agent to be used include octyl mercaptan, lauryl mercaptan, tertiary nonyl mercaptan, tertiary (dodecyl) mercaptan, mercaptoethanol, α-thioglycerol, and the like. Compounds with mercapto groups; thioglycolic acid, methyl thioglycolic acid, ethyl thioglycolic acid, propyl thioglycolic acid, butyl thioglycolic acid, tert-butyl thioglycolic acid, thioethanol 2-ethylhexyl thioglycolate, octyl thioglycolic acid, isooctyl thioglycolic acid, decyl thioglycolic acid, dodecyl thioglycolic acid, thioglycolic acid ester of ethylene glycol, new Thioglycolic acid ester of pentanediol, thioglycolic acid ester of pentaerythritol, etc.; α-methylstyrene dimer, etc. A chain transfer agent can be used individually by 1 type or in combination of 2 or more types.

The usage amount of the chain transfer agent is not particularly limited. Usually, the chain transfer agent is contained in an amount of 0.05 to 20 parts by weight, preferably 0.1 to 15 parts by weight, and more preferably 0.2 parts by weight relative to 100 parts by weight of the monomer. parts by weight to 10 parts by weight. By adjusting the addition amount of the chain transfer agent in this way, a polymer (B) with a preferable molecular weight can be obtained. In some preferred aspects, the chain transfer agent is used in an amount of 5 parts by weight or less relative to 100 parts by weight of monomers, more preferably 1 part by weight or less, and still more preferably 0.8 parts by weight or less.

As a method for adjusting the molecular weight of the polymer (B), various previously known methods including the use of the above-mentioned chain transfer agent can be used alone or in an appropriate combination. The same is true for the molecular weight of the polymer (A). Non-limiting examples of such methods include the choice of polymerization method, the choice of the type or amount of polymerization initiator, the choice of polymerization temperature, the choice of the type or amount of polymerization solvent in the solution polymerization method, the choice of the type or amount of polymerization solvent in the photopolymerization method, The choice of light irradiation intensity, etc. Those skilled in the art can understand how to obtain a polymer having a desired molecular weight based on the description of the description of the present application including the following specific examples and the technical common sense at the time of the application of the present application.

In the reinforcing film disclosed herein, the usage amount of the polymer (B) can be, for example, 0.1 part by weight or more with respect to the usage amount of the polymer (A) 100 parts by weight, to obtain a higher effect (suitably a sticker). From the viewpoint of initial light peelability), it is preferably 0.3 part by weight or more, more preferably 0.5 part by weight or more, still more preferably 0.8 part by weight or more, and may be 1.0 part by weight or more. In some aspects, the usage-amount of the said polymer (B) may be, for example, 2 parts by weight or more, 3 parts by weight or more, or 4 parts by weight or more, from the viewpoint of improving secondary processability, etc. , may be set to 5 parts by weight or more. Moreover, the usage-amount of the polymer (B) may be, for example, 75 parts by weight or less, 30 parts by weight or less, 10 parts by weight or less, or 8 parts by weight relative to 100 parts by weight of the polymer (A). parts by weight or less. In some preferred embodiments, the amount of the polymer (B) used is 5.0 parts by weight or less, more preferably 3.0 parts by weight, relative to 100 parts by weight of the polymer (A), from the viewpoint of increasing the adhesive force suitable for achieving the target. It is less than or equal to 2.5 parts by weight, more preferably less than or equal to 1.5 parts by weight (for example, less than or equal to 1.2 parts by weight). By making the usage-amount of a polymer (B) into the said range, it becomes easy to implement|achieve favorable bending recovery property and a bending retention force, and the light peeling property and adhesive force increase property in the initial stage of attachment are more compatible.

The adhesive layer may contain a polymer (any polymer) other than the polymer (A) and the polymer (B) as necessary within the range that does not greatly impair the performance of the reinforcing film disclosed herein. The usage-amount of such an arbitrary polymer is normally 20 weight% or less of the whole polymer component contained in an adhesive layer, and may be 15 weight% or less, and may be 10 weight% or less. In some aspects, the use amount of the above-mentioned arbitrary polymer may be 5 wt % or less of the whole polymer component, 3 wt % or less, or 1 wt % or less. The adhesive layer may be substantially free of polymers other than the polymer (A) and the polymer (B).

(crosslinking agent) In the adhesive layer, a cross-linking agent may be used to adjust cohesion and the like as needed. As the cross-linking agent, a well-known cross-linking agent in the field of adhesives can be used, for example, epoxy-based cross-linking agent, isocyanate-based cross-linking agent, polysiloxane-based cross-linking agent, oxazoline-based cross-linking agent , aziridine-based cross-linking agent, silane-based cross-linking agent, alkyl etherified melamine-based cross-linking agent, metal chelate-based cross-linking agent, etc. Isocyanate-based cross-linking agents, epoxy-based cross-linking agents, and metal chelate-based cross-linking agents are suitably used. An isocyanate-based crosslinking agent can be favorably used as a crosslinking agent that suitably balances bending recovery and bending retention. A crosslinking agent can be used individually by 1 type or in combination of 2 or more types.

As the isocyanate-based crosslinking agent, a polyfunctional isocyanate (meaning a compound having an average of 2 or more isocyanate groups per molecule, including those having an isocyanurate structure) can be preferably used. The isocyanate-based crosslinking agent may be used alone or in combination of two or more.

As an example of a polyfunctional isocyanate, aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, etc. are mentioned. Specific examples of the aliphatic polyisocyanates include 1,2-ethylidene diisocyanate; 1,2-tetramethylene diisocyanate, 1,3-tetramethylene diisocyanate, 1,4- Tetramethylene diisocyanates such as tetramethylene diisocyanate; 1,2-hexamethylene diisocyanate, 1,3-hexamethylene diisocyanate, 1,4-hexamethylene diisocyanate, 1,5 - Hexamethylene diisocyanate such as hexamethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,5-hexamethylene diisocyanate; 2-methyl-1,5-pentane diisocyanate , 3-methyl-1,5-pentane diisocyanate, lysine diisocyanate, etc.

Specific examples of the alicyclic polyisocyanates include isophorone diisocyanate; Hexyl diisocyanate; cyclopentyl diisocyanate such as 1,2-cyclopentyl diisocyanate and 1,3-cyclopentyl diisocyanate; hydrogenated xylylene diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate , hydrogenated tetramethylxylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, etc.

Specific examples of aromatic polyisocyanates include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenyl Methane diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenyl ether diisocyanate, 2-nitrodiphenyl-4,4'-diisocyanate, 2,2'-diisocyanate Phenylpropane-4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,4'-diphenylpropane diisocyanate, isophenylene diisocyanate, p-phenylene diisocyanate, naphthylene-1,4-diisocyanate, naphthylene-1,5-diisocyanate, 3,3'-dimethoxydiphenyl-4,4'-diisocyanate, benzenediol Methyl-1,4-diisocyanate, xylylene-1,3-diisocyanate, etc.

As a preferable polyfunctional isocyanate, the polyfunctional isocyanate which has an average of 3 or more isocyanate groups per molecule can be illustrated. The isocyanate with more than 3 functions can be a multimer (such as dimer or trimer) of isocyanate with 2 or more functions, or a derivative (such as the addition reaction product of polyol and more than 2 molecules of polyfunctional isocyanate). ), polymers, etc. For example, dimer or trimer of diphenylmethane diisocyanate, isocyanurate body of hexamethylene diisocyanate (trimeric adduct of isocyanurate structure), trimeric Reaction product of methylolpropane and toluene diisocyanate, reaction product of trimethylolpropane and hexamethylene diisocyanate, trimethylolpropane adduct of xylylene diisocyanate, isophorone diisocyanate Trimethylolpropane adduct of hexamethylene diisocyanate, trimethylolpropane adduct of hexamethylene diisocyanate, polymethylene polyphenyl isocyanate, polyether polyisocyanate, polyester polyisocyanate, and the like and various Adducts of polyols, polyfunctional isocyanates such as polyisocyanates polyfunctionalized by isocyanurate bonds, biuret bonds, allophanate bonds, and the like.

Examples of commercial products of the above-mentioned polyfunctional isocyanates include: "Duranate TPA-100" manufactured by Asahi Kasei Chemical Co., Ltd.; "Coronate L", "Coronate HL", "Coronate HK", "Coronate Coronate HX", "Coronate 2096"; trade names "Takenate D110N", "Takenate D120N", "Takenate D140N", "Takenate D160N" manufactured by Mitsui Chemicals Co., Ltd.

Examples of epoxy-based crosslinking agents include bisphenol A, epichlorohydrin-type epoxy-based resins, ethylene glycol glycidyl ether, polyethylene glycol diglycidyl ether, glycerol diglycidyl ether, and glycerol triglycidyl ether. Glyceryl ether, 1,6-hexanediol glycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl aniline, diamine glycidyl amine, N,N,N',N'-tetraglycidyl m-xylylenediamine and 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, etc. These can be used alone or in combination of two or more.

The metal chelate compound includes aluminum, iron, tin, titanium, nickel, etc. as the metal component, and acetylene, methyl acetoacetate, ethyl lactate, etc., as the chelate compound. These can be used alone or in combination of two or more.

The usage-amount in the case of using a crosslinking agent is not specifically limited, For example, it can be set as the quantity exceeding 0 weight part with respect to 100 weight part of polymer (A). Moreover, the usage-amount of a crosslinking agent can be 0.01 weight part or more with respect to 100 weight part of polymer (A), for example, Preferably it is 0.05 weight part or more. By increasing the amount of the crosslinking agent used, the adhesive force at the initial stage of attachment is suppressed, and the secondary processability tends to be improved. There is a tendency to be excellent in bending recovery and workability. In some aspects, relative to 100 parts by weight of polymer (A), the amount of crosslinking agent used may be 0.1 part by weight or more, 0.5 part by weight or more, or 0.8 part by weight or more. On the other hand, from the viewpoint of appropriately allowing the mobility of the polymer (B) to obtain an increase in the adhesive force after heating, the amount of the crosslinking agent used is usually 15 parts by weight relative to 100 parts by weight of the polymer (A). The weight part or less may be 10 parts by weight or less, or 5 parts by weight or less.

The technique disclosed here can be implemented well in the aspect which uses at least an isocyanate type crosslinking agent as a crosslinking agent. From the viewpoint of achieving both good secondary processability in the initial stage of attachment and an increase in adhesive force after heating, in some aspects, the amount of the isocyanate-based crosslinking agent to be used relative to 100 parts by weight of the polymer (A) can be, for example, It is 0.01 part by weight or more, preferably 0.05 part by weight or more, more preferably 0.07 part by weight or more, may be 0.10 part by weight or more, and may be 0.15 part by weight or more (for example, 0.20 part by weight or more). By increasing the use amount of the isocyanate-based crosslinking agent, moderate cohesion force and elastic modulus can be obtained, and there is a tendency that bending recovery properties and processability are also excellent. In addition, the usage amount of the isocyanate-based crosslinking agent can be, for example, 5 parts by weight or less, preferably less than 1.0 parts by weight, more preferably less than 0.5 parts by weight, relative to 100 parts by weight of the polymer (A). Preferably it is less than 0.3 weight part, More preferably, it is less than 0.2 weight part (for example, 0.15 weight part or less). Thereby, the cohesive force of the adhesive, and thus the elastic modulus (typically, the surface elastic modulus), is moderately reduced, a good bending retention force can be obtained, and an increase in the adhesive force after heating is also easily obtained.

When the isocyanate-based crosslinking agent is used in the composition that the adhesive layer contains a hydroxyl group-containing monomer as a monomer unit, the molar ratio ([NCO]/[OH] of the isocyanate group and the hydroxyl group contained in the adhesive layer ), for example, can be set to 0.001 or more, but is not particularly limited. By increasing the usage amount of the isocyanate-based crosslinking agent relative to the hydroxyl group-containing monomer in this manner, the elastic modulus (typically, the surface elastic modulus) of the adhesive becomes a suitable range, and the bending recovery tends to be improved. Moreover, there exists a tendency to be excellent also in workability. In some preferred aspects, the molar ratio ([NCO]/[OH]) is 0.002 or more, more preferably 0.004 or more, further preferably 0.006 or more (for example, 0.007 or more), may be 0.010 or more, may be 0.020 or more, and may be 0.030 or more. Moreover, the said molar ratio ([NCO]/[OH]) may be 1.0 or less, for example, and 0.10 or less may be sufficient as it. By limiting the above-mentioned molar ratio to a predetermined value or less, a cross-linked structure suitable for greatly increasing the adhesive force after heating with respect to the adhesive force in the initial stage of attachment can be favorably formed. In some preferred aspects, the molar ratio ([NCO]/[OH]) is 0.030 or less, more preferably 0.015 or less, still more preferably 0.012 or less (for example, 0.009 or less), and may also be 0.005 or less. Furthermore, in the adhesive layer, the isocyanate group and the hydroxyl group may exist in a state of chemical bonding (crosslinking) in at least a part of them. More specifically, the above-mentioned isocyanate group may exist in a chemically bonded (cross-linked) state with the above-mentioned hydroxyl group. On the other hand, a part of the hydroxyl group may be chemically bonded to the isocyanate group, and the other part may not be chemically bonded (crosslinked) to the isocyanate group.

In some preferred aspects, the adhesive layer includes a catalyst. The purpose of adding the catalyst may be to promote the hardening of the adhesive layer when forming the adhesive layer, and typically to make any of the above-mentioned cross-linking reactions proceed more efficiently. Therefore, the above-mentioned catalysts are also called hardening catalysts or cross-linking catalysts. By adding a catalyst, the initial hardening can be accelerated and the side reaction that causes bubbles on the surface of the adhesive layer can be suppressed. Examples of catalysts include organometallic compounds such as iron-based catalysts, tin-based catalysts, titanium-based catalysts, zirconium-based catalysts, lead-based catalysts, cobalt-based catalysts, and zinc-based catalysts, and tertiary catalysts. Amine compounds, etc. These and the like may be used alone or in combination of two or more. Among them, an iron-based catalyst and a tin-based catalyst are preferable in terms of the balance between the reaction speed and the pot life, and an iron-based catalyst is particularly preferable.

As the iron-based catalyst, for example, iron acetylacetonate, iron 2-ethylhexanoate, etc. may be mentioned. The iron-based catalysts may be used alone or in combination of two or more.

Examples of the tin-based catalyst include dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin maleate, dibutyltin dilaurate, dibutyltin diacetate, dibutyltin sulfide, Tributyltin methoxide, tributyltin acetate, triethyltin ethoxide, tributyltin ethoxide, dioctyltin oxide, dioctyltin dilaurate, tributyltin chloride, tributyltin trichloroacetate, 2-ethyl Tin base caproate, etc. The tin-based catalyst may be used alone or in combination of two or more.

The usage amount of the catalyst is not particularly limited, but can be, for example, 0.0001 part by weight or more, preferably 0.001 part by weight or more, more preferably 0.003 part by weight or more, and more preferably 0.006 part by weight or more, particularly preferably 0.008 part by weight or more. By using an appropriate amount of catalyst, the generation of air bubbles in the adhesive layer can be suppressed, and a smooth adhesive surface can be easily obtained. Moreover, the usage-amount of a catalyst can be 1 weight part or less with respect to 100 weight part of polymer (A), for example, and 0.1 weight part or less may be sufficient as it. In some preferred aspects, relative to 100 parts by weight of the polymer (A), the usage amount of the catalyst is 0.03 parts by weight or less, more preferably 0.02 parts by weight or less, more preferably 0.01 parts by weight or less, or 0.005 parts by weight or less. By appropriately limiting the content of the catalyst relative to 100 parts by weight of the polymer (A), it is easy to achieve a suitable increase in adhesive force.

When a catalyst is used in the composition that the adhesive layer contains a hydroxyl group-containing monomer as a monomer unit, the amount of the catalyst used can be set as the molar ratio of the catalyst contained in the adhesive layer to the hydroxyl group ([catalyst] /[OH]) is, for example, 1.0×10 ^-6 or more, and the above molar ratio is preferably 1.0×10 ^-5 or more, more preferably 1.0×10 ^-4 or more, and still more preferably 2.0×10 ^-4 or more , 3.0×10 ⁻⁴ or more is particularly preferable, but it is not particularly limited. By using an appropriate amount of catalyst, the generation of air bubbles in the adhesive layer can be suppressed, and a smooth adhesive surface can be easily obtained. In addition, the molar ratio ([catalyst]/[OH]) may be, for example, 5.0×10 ⁻² or less, or 5.0×10 ⁻³ or less. In some preferred aspects, the molar ratio ([catalyst]/[OH]) is 3.0×10 ^-3 or less, more preferably 1.0×10 ^-3 or less, and still more preferably 5.0×10 ^-4 or less , may be 3.0×10 ^-4 or less. By appropriately limiting the content of the catalyst, it is easy to achieve a suitable increase in adhesion.

(Adhesion imparting resin) An adhesion-imparting resin may be contained in the adhesive layer as needed. The adhesion-imparting resin is not particularly limited, and examples thereof include rosin-based adhesion-imparting resins, terpene-based adhesion-imparting resins, phenol-based adhesion-imparting resins, hydrocarbon-based adhesion-imparting resins, ketone-based adhesion-imparting resins, and polyamide-based adhesion-imparting resins. Adhesion imparting resin, epoxy-based adhesion imparting resin, elastic system adhesion imparting resin, etc. The adhesion-imparting resin may be used alone or in combination of two or more.

The content of the adhesion-imparting resin is not particularly limited, and can be set in such a way that appropriate adhesion performance is exhibited according to the purpose or application. The content of the adhesion-imparting resin (when two or more types of adhesion-imparting resins are contained, the total amount thereof) can be, for example, about 5 to 500 parts by weight relative to 100 parts by weight of the polymer (A). Moreover, the technique disclosed here can be implemented well in the aspect which restricts the usage-amount of the adhesion-imparting resin. For example, relative to 100 parts by weight of the polymer (A), the content of the adhesion imparting resin can be set to less than 20 parts by weight, less than 10 parts by weight, less than 3 parts by weight, less than 1 part by weight (0 parts by weight) ~ less than 1 part by weight), in some aspects, the adhesive layer is substantially free of adhesion-imparting resin.

In addition, the adhesive layer in the technology disclosed herein may also contain leveling agents, plasticizers, softeners, colorants (dyes, pigments, etc.), fillers, as necessary, within the range that does not significantly hinder the effects of the present invention. Antistatic agents, anti-aging agents, ultraviolet absorbers, antioxidants, light stabilizers, preservatives, etc. can be used as well-known additives for adhesives.

The adhesive layer constituting the reinforcing film disclosed herein may be a hardened layer of the adhesive composition. That is, the adhesive layer can be formed by applying (for example, coating) an adhesive composition such as a water-dispersed, solvent-based, photocurable, and hot-melt-type adhesive composition to an appropriate surface and then appropriately performing a curing treatment. In the case of performing two or more hardening treatments (drying, cross-linking, polymerization, cooling, etc.), these may be performed simultaneously or in multiple stages. In an adhesive composition using a partial polymer (polymer slurry) of a monomer raw material, a final copolymerization reaction is typically performed as the above-mentioned curing treatment. That is, a partial polymer is subjected to further copolymerization to form a complete polymer. For example, in the case of a photocurable adhesive composition, light irradiation is performed. If necessary, curing treatment such as crosslinking and drying may be performed. For example, when it is necessary to dry with a photocurable adhesive composition, photocuring may be performed after drying. In an adhesive composition using a complete polymer, typically, as the above-mentioned curing treatment, treatments such as drying (heat drying) and crosslinking are performed as necessary.

For the application of the adhesive composition, for example, a gravure roll coater, a reverse roll coater, a touch roll coater, a dip roll coater, a bar coater, a knife coater, a spray coater, etc. can be used. It is implemented with a commonly used coating machine.

The thickness of the adhesive layer is not particularly limited, but can be set to, for example, 6 μm or more. In some aspects, the thickness of the adhesive layer may be greater than 8 μm, greater than 10 μm, greater than or equal to 15 μm, greater than or equal to 20 μm, or greater than 20 μm. By increasing the thickness of the adhesive layer, the adhesive force tends to increase after heating. Also, in some aspects, the thickness of the adhesive layer may be, for example, 300 μm or less, 200 μm or less, 150 μm or less, 100 μm or less, 70 μm or less, 50 μm or less, It may be 40 μm or less. If the thickness of the adhesive layer is not too large, it can be advantageous from the viewpoints of thinning of the reinforcing film and prevention of cohesion failure of the adhesive layer. A reinforcing film having an adhesive layer having a thickness within the above-mentioned range can achieve a balance of adhesive properties such as adhesive force, or flexural recovery and flexural retention. Furthermore, when the first and second surfaces of the base material are provided with reinforcing films for the first adhesive layer and the second adhesive layer, the thickness of the above-mentioned adhesive layer is at least suitable for the thickness of the first adhesive layer. thickness. The thickness of the second adhesive layer can also be selected from the same range. Furthermore, in the case of a reinforcing film without a base material, the thickness of the reinforcing film is the same as the thickness of the adhesive layer.

＜Supporting substrate＞ The reinforcing film of some aspects may be in the form of a substrate-attached adhesive sheet having an adhesive layer on one side or both sides of the support substrate. The material of the support substrate is not particularly limited, and can be appropriately selected according to the purpose of use of the reinforcing film, the state of use, and the like. Non-limiting examples of substrates that can be used include resin films such as plastic films; foams such as polyurethane foams, polyethylene foams, and polychloroprene foams. Formed foam sheet; various fibrous substances (can be natural fibers such as hemp, cotton, synthetic fibers such as polyester and vinylon, semi-synthetic fibers such as acetate, etc.) or formed by blending, etc. Woven and non-woven fabrics; Japanese paper, Dowling paper, kraft paper, crepe paper and other papers; aluminum foil, copper foil and other metal foils, etc. A base material composed of these composites may also be used. As an example of such a composite base material, the base material of the structure which laminated|stacked metal foil and the said plastic film, the plastic base material reinforced with inorganic fibers, such as glass cloth, can be mentioned, for example.

As a base material of the reinforcement film disclosed here, various film base materials can be used favorably. The above-mentioned film substrate may be a porous substrate such as a foamed film or a non-woven sheet, a non-porous substrate, or a substrate having a structure in which a porous layer and a non-porous layer are laminated. . In some aspects, as the above-mentioned film substrate, a resin film including a (self-supporting or unrelated) resin film capable of independently maintaining a shape can be suitably used as a base film. The term "resin film" here refers to a non-porous structure, and typically refers to a resin film substantially free of air bubbles (non-porous). Therefore, the concept of the above-mentioned resin film is distinguished from a foamed film or a nonwoven fabric. As said resin film, the thing which can maintain a shape independently (self-supporting type, or non-correlation) can be used suitably. The above-mentioned resin film may be a single-layer structure, or may be a multi-layer structure of two or more layers (eg, a three-layer structure).

Examples of the resin material constituting the resin film include polyester, polyolefin, nylon 6, nylon 66, polyamide (PA) such as partially aromatic polyamide, polyimide (PI), polyamide Imide (PAI), Polyetheretherketone (PEEK), Polyetheretherketone (PES), Polyphenylene Sulfide (PPS), Polycarbonate (PC), Polyurethane (PU), Ethylene Acetic Acid Fluorine resins such as vinyl ester copolymer (EVA) and polytetrafluoroethylene (PTFE), acrylic resins, polyacrylates, polystyrene, polyvinyl chloride, polyvinylidene chloride, and other resins. The above-mentioned resin film may be formed using a resin material containing one of such resins alone, or may be formed using two or more resin materials blended. The above-mentioned resin film may be unstretched or stretched (for example, uniaxially stretched or biaxially stretched).

As a preferable example of the resin material which comprises a resin film, a polyimide-type resin, a polyester-type resin, a PPS resin, and a polyolefin-type resin are mentioned. Here, the polyimide-based resin refers to a resin containing polyimide in a ratio exceeding 50% by weight. Likewise, polyester-based resins refer to resins containing polyester in a ratio of more than 50 wt %, PPS resins refer to resins containing PPS in a ratio of more than 50 wt %, and polyolefin-based resins refer to resins containing more than 50 wt % Resins containing polyolefins.

Specific examples of polyester-based resins include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), and polyethylene naphthalate. Butylene diformate, etc.

As the polyolefin resin, one type of polyolefin may be used alone, or two or more types of polyolefin may be used in combination. The polyolefin can be, for example, a homopolymer of α-olefin, a copolymer of two or more α-olefins, a copolymer of one or more α-olefins and other vinyl monomers, and the like. Specific examples include ethylene-propylene copolymers such as polyethylene (PE), polypropylene (PP), poly-1-butene, poly-4-methyl-1-pentene, and ethylene-propylene rubber (EPR). ethylene-propylene-butene copolymer, ethylene-butene copolymer, ethylene-vinyl alcohol copolymer, ethylene-ethyl acrylate copolymer, etc. Either low density (LD) polyolefins and high density (HD) polyolefins can be used. Examples of polyolefin resin films include unstretched polypropylene (CPP) films, biaxially stretched polypropylene (OPP) films, low-density polyethylene (LDPE) films, and linear low-density polyethylene (LLDPE) films. Film, medium density polyethylene (MDPE) film, high density polyethylene (HDPE) film, polyethylene (PE) film blended with two or more polyethylene (PE), polypropylene (PP) and polyethylene (PE) film blended Ethylene (PE) PP/PE blended film, etc.

As a specific example of the resin film which can be suitably used as the base film of the film for reinforcement disclosed here, a PI film, a PET film, a PEN film, a PPS film, a PEEK film, a CPP film, and an OPP film are mentioned.

In the resin film, light stabilizers, antioxidants, antistatic agents, colorants (dyes, pigments, etc.), fillers, lubricating agents, anti-sticking agents, etc. can be formulated as necessary within the range that does not significantly hinder the effects of the present invention. well-known additives such as linking agents. The compounding quantity of an additive is not specifically limited, According to the objective etc., it can set suitably.

The manufacturing method of a resin film is not specifically limited. For example, conventionally known general resin film forming methods such as extrusion molding, inflation molding, T-die die casting, and calender roll molding can be suitably employed.

The said base material may consist of such a base film substantially. Alternatively, the above-mentioned base material may include an auxiliary layer in addition to the above-mentioned base film. Examples of the above-mentioned auxiliary layers include: optical property adjustment layers (such as coloring layers, antireflection layers), printing layers or lamination layers for imparting desired appearance to substrates, antistatic layers, primer layers , peeling layer and other surface treatment layers.

The thickness of the base material is not particularly limited, and can be selected according to the purpose of use of the reinforcing film, the state of use, and the like. The thickness of the base material may be, for example, 1000 μm or less. In some aspects, the thickness of the base material may be, for example, 500 μm or less, 300 μm or less, 250 μm or less, or 200 μm or less, from the viewpoint of the handleability or processability of the reinforcing film. . From the viewpoint of miniaturization or weight reduction of products to which the reinforcing film is applied, in some aspects, the thickness of the substrate may be, for example, 160 μm or less, 130 μm or less, 100 μm or less, or 90 μm or less. μm or less, 80 μm or less, 60 μm or less, 50 μm or less, 25 μm or less, 10 μm or less, or 5 μm or less. When the thickness of the base material becomes smaller, the flexibility of the reinforcing film or the followability to the surface shape of the adherend tends to increase. In addition, from the viewpoint of workability and workability, the thickness of the base material may be, for example, 2 μm or more, 5 μm or more, 10 μm or more, 20 μm or more, or 25 μm or more or more. 25 μm. In some aspects, the thickness of the substrate can be, for example, 30 μm or more, 35 μm or more, 55 μm or more, 70 μm or more, 75 μm or more, 90 μm or more, or 120 μm or more. For example, a base material having a thickness of 30 μm or more can be suitably used for the reinforcing film.

If necessary, corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, coating with a primer (primer) to form a primer layer and other previously known surfaces can also be performed on the first surface of the substrate. deal with. Such surface treatment may be a treatment for improving the grip of the adhesive layer to the substrate. For example, in the reinforcement film provided with the base material which contains a resin film as a base film, the base material which performed this grip property improvement process can be used favorably. The above surface treatments can be applied individually or in combination. The composition of the primer used for the formation of the primer layer is not particularly limited, and can be appropriately selected from known ones. The thickness of the undercoat layer is not particularly limited, and is usually suitably about 0.01 μm to 1 μm, preferably about 0.1 μm to 1 μm. As another process which can be performed with respect to the 1st surface of a base material as needed, an antistatic layer formation process, a colored layer formation process, a printing process, etc. are mentioned.

When the reinforcing film disclosed here is in the form of a single-sided adhesive sheet with an adhesive layer only on the first side of the base material, the second side of the base material can also be subjected to peeling treatment or antistatic treatment as required. Treatment and other previously known surface treatments. For example, by surface-treating the back surface of the base material with a peeling agent (typically, by providing a peeling layer formed with a peeling agent), the reinforcing film in the form of a roll can be disassembled. The roll force becomes lighter. As the release treatment agent, polysiloxane-based release treatment agent, long-chain alkyl-based release treatment agent, olefin-based release treatment agent, fluorine-based release treatment agent, fatty acid amide-based release treatment agent, molybdenum sulfide, silicon dioxide can be used. powder, etc. Furthermore, corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, etc. may also be applied to the second surface of the base material for the purpose of improving printability, reducing light reflectivity, and improving lamination properties. . Furthermore, in the case of a double-sided adhesive sheet, the second surface of the base material may be subjected to the same surface treatment as exemplified above as the surface treatment that can be applied to the first surface of the base material, if necessary. In addition, the surface treatment performed on the first surface of the base material and the surface treatment performed on the second surface may be the same or different.

<Characteristics of Reinforcing Film> In the reinforcing film disclosed here, it is preferable that the initial adhesive force N ₂₃ measured after being bonded to a stainless steel sheet and kept at 23° C. for 30 minutes is limited to a predetermined value or less. In some aspects, the adhesion N ₂₃ is, for example, preferably less than 500 gf/25 mm, more preferably less than 400 gf/25 mm, more preferably less than 300 gf/25 mm, especially preferably 250 gf /25 mm or less (for example, 200 gf/25 mm or less), or 150 gf/25 mm or less. It is preferable from the viewpoint of secondary workability that the adhesive force N ₂₃ is lower. The lower limit of the adhesive force N ₂₃ is not particularly limited, for example, it may be 1 gf/25 mm or more. Adhesion force N ₂₃ is generally suitable to be 10 gf/25 mm or more from the viewpoint of workability of attaching to an adherend or preventing positional displacement before the adhesive force increases. From the viewpoint of improving the adhesion after heating, etc., in some aspects, the adhesion N ₂₃ may be, for example, 20 gf/25 mm or more, 50 gf/25 mm or more, 80 gf/25 mm or more, or more. Can be over 100 gf/25 mm (eg over 150 gf/25 mm).

Adhesion force N ₂₃ [gf/25 mm] was obtained by crimping a stainless steel (SUS) plate as an adherend and standing for 30 minutes in an environment of 23°C and 50% RH, Under the same environment (ie, at 23°C), the 180° peel adhesion was measured under the conditions of a peel angle of 180 degrees and a tensile speed of 300 mm/min. The adherend can use SUS304BA board. During the measurement, a suitable backing material (for example, a PET film with a thickness of about 25 μm) may be attached to the reinforcing film of the measurement object as necessary for reinforcement. More specifically, the adhesive force N ₂₃ can be measured according to the measurement method of the initial adhesive force described in the following examples.

The reinforcing film disclosed here can increase the adhesive force by heating, for example, it can show an adhesive force N ₆₀ of 300 gf/25 mm or more, that is, after being attached to a stainless steel plate and kept at 60° C. for 60 minutes, Adhesion measured at 23°C. In some aspects, the adhesion N ₆₀ is 400 gf/25 mm or more, preferably 500 gf/25 mm or more. The reinforcing film satisfying this characteristic is attached to the adherend, and the adhesive force is increased to a predetermined value or more by heating. According to the techniques disclosed herein, strong adhesion can be achieved by heating. In some preferred aspects, the adhesive force N ₆₀ is 600 gf/25 mm or more, more preferably 700 gf/25 mm or more, may be 800 gf/25 mm or more, or 900 gf/25 mm or more. The upper limit of the adhesive force N ₆₀ is not particularly limited. From the viewpoint of ease of manufacture or economy of the reinforcing film, in some aspects, the adhesion N ₆₀ may be, for example, 3000 gf/25 mm or less, 1500 gf/25 mm or less, or 1000 gf /25 mm or less.

The adhesive force N ₆₀ [gf/25 mm] was obtained by pressing the SUS plate as the adherend and holding it for 60 minutes in an environment of 60°C, and then in an environment of 23°C and 50% RH. It was left to stand for 30 minutes, and then the 180° peel adhesion was measured under the conditions of a peel angle of 180 degrees and a tensile speed of 300 mm/min in the same environment. Similar to Adhesion N ₂₃ , SUS304BA board can be used for the adherend. During the measurement, a suitable backing material (for example, a PET film with a thickness of about 25 μm) may be attached to the reinforcing film of the measurement object as necessary for reinforcement. More specifically, the adhesive force N ₆₀ can be measured according to the method for measuring the adhesive force after heating described in the following examples.

The ratio of the adhesion force N ₆₀ [gf/25 mm] to the adhesion force N ₂₃ [gf/25 mm], that is, the adhesion force increase ratio N ₆₀ /N ₂₃ is not particularly limited. In some aspects, N ₆₀ /N ₂₃ is preferably 1.5 or more, preferably 2.0 or more, more preferably 2.5 or more, still more preferably 3.0 or more (eg, 3.5 or more), and may exceed 5.0 (eg, more than 7.0). With the reinforcing film having a large N ₆₀ /N ₂₃ , good secondary workability can be exhibited in the initial stage of attachment, and the adhesive force can be greatly increased by subsequent heating or the like. The upper limit of N ₆₀ /N ₂₃ is not particularly limited, but is usually 100 or less, and may be 30 or less, 15 or less, or 10 or less from the viewpoint of the easiness of manufacture of the reinforcing film and economical efficiency. In some aspects, N ₆₀ /N ₂₃ may be, for example, 5 or less, 3 or less, or 2 or less.

Furthermore, the adhesive force after heating of the reinforcing film disclosed herein represents a characteristic of the reinforcing film, and does not limit the usage of the reinforcing film. In other words, the use state of the reinforcing film disclosed here is not limited to the state of heating at 60°C for 60 minutes. Typically, it is used in the form of treatment above 23°C to 25°C). In this state of use, the adhesive force is also increased for a long time, and a firm joint can be realized. In addition, the reinforcing film disclosed herein can be heated at a temperature exceeding 30° C. (eg, about 50 to 70° C.) or higher than 60° C. at any time after attachment to promote an increase in adhesion. The heating temperature in this heat treatment is not particularly limited, and can be set in consideration of workability, economical efficiency, the heat resistance of the base material of the reinforcing film or the adherend, and the like. The above-mentioned heating temperature may be less than 150°C, for example, 120°C or lower, 100°C or lower, 80°C or lower, or 70°C or lower. Moreover, the said heating temperature can be 40 degreeC or more, 45 degreeC or more, 50 degreeC or more, 55 degreeC or more, 60 degreeC or more, or 70 degreeC or more, for example, 80 degreeC or more, and 100 degreeC or more. The heating time is not particularly limited, but may be, for example, 3 hours or less, 1 hour or less, 30 minutes or less, or 10 minutes or less. Moreover, the heating time may be, for example, 1 minute or more, 15 minutes or more, 30 minutes or more, or 1 hour or more. Alternatively, the heat treatment for a longer period of time may be performed within the limit that the reinforcing film or the adherend does not undergo significant thermal degradation. In addition, the heat treatment may be performed at one time, or may be performed in a plurality of times.

<Reinforcing film with base material> When the reinforcing film disclosed herein is in the form of an adhesive sheet with a base material, the thickness of the reinforcing film may be, for example, 1000 μm or less, 600 μm or less, 350 μm or less, or 250 μm or less. From the viewpoint of miniaturization, weight reduction, and thinning of products to which the reinforcing film is applied, in some aspects, the thickness of the reinforcing film may be, for example, 200 μm or less, 175 μm or less, or 140 μm or less. , which may be 120 μm or less, or 100 μm or less (for example, less than 100 μm). Moreover, from the viewpoint of workability and the like, the thickness of the reinforcing film may be, for example, 5 μm or more, 10 μm or more, 15 μm or more, 20 μm or more, 25 μm or more, or 30 μm or more. μm or more. In some aspects, the thickness of the reinforcing film may be, for example, 50 μm or more, 60 μm or more, 80 μm or more, 100 μm or more, or 120 μm or more. The upper limit of the thickness of the reinforcement film is not specifically limited. Further, the thickness of the reinforcing film refers to the thickness of the part attached to the adherend. For example, in the reinforcing film 1 having the structure shown in FIG. 1 , it refers to the thickness from the adhesive surface 21A of the reinforcing film 1 to the second surface 10B of the substrate 10 , excluding the thickness of the release liner 31 .

The reinforcing film disclosed here is preferably implemented in a state in which the thickness Ts of the support substrate is larger than the thickness Ta of the adhesive layer, that is, in a state in which Ts/Ta is larger than 1, for example. Ts/Ta may be, for example, 1.1 or more, 1.2 or more, 1.5 or more, or 1.7 or more, but it is not particularly limited. For example, by increasing Ts/Ta, even if the film for reinforcement is made thinner, there is a tendency that a favorable effect is easily exhibited. In some aspects, Ts/Ta can be greater than 2 (eg greater than 2), greater than or equal to 2.5, or greater than or equal to 2.8. Moreover, Ts/Ta may be 50 or less, for example, and 20 or less may be sufficient as it. Ts/Ta may be, for example, 10 or less, 8 or less, or 5 or less, from the viewpoint of easily exhibiting a high post-heating adhesive force even if the reinforcing film is made thinner.

The above-mentioned adhesive layer is preferably fixed to the support substrate. Here, the term "fixing" means that in the reinforcing film whose adhesive force increases after being attached to the adherend, the adhesive layer exhibits sufficient grip on the support substrate, so that the reinforcing film can be peeled off from the adherend. The interface between the adhesive layer and the support substrate does not peel off. The adherend and the support base can be firmly integrated with the base material-attached reinforcing film fixed to the support base by the adhesive layer. As a preferred example of the reinforcing film in which the adhesive layer is fixed to the base material, there may be mentioned reinforcement in which no peeling (scratch failure) occurs between the adhesive layer and the supporting base material when the above-mentioned post-heating adhesive force is measured. Use film. The reinforcing film that does not cause grip failure when the adhesive force is measured after heating is a preferred example of the reinforcing film in which the adhesive layer is fixed to the substrate.

The reinforcing film disclosed herein can be favorably produced, for example, by a method including sequentially the steps of: bringing a liquid adhesive composition into contact with the first surface of the substrate; and applying the above-mentioned adhesive on the first surface. The composition hardens to form an adhesive layer. The hardening of the above-mentioned adhesive composition may be accompanied by one or more of drying, cross-linking, polymerization, cooling, etc. of the adhesive composition. According to the method of forming the adhesive layer by hardening the liquid adhesive composition on the first surface of the substrate in this way, and by sticking the hardened adhesive layer on the first surface of the substrate, the adhesive layer is formed on the first surface of the substrate. Compared with the method of disposing the adhesive layer on one side, the adhesion of the adhesive layer to the substrate can be improved. Taking advantage of this, a reinforcing film in which the adhesive layer is fixed to the base material can be suitably produced.

In some aspects, as a method of bringing the liquid adhesive composition into contact with the first surface of the substrate, a method of directly coating the above-described adhesive composition on the first surface of the substrate can be employed. By making the first side (adhesive side) of the adhesive layer hardened on the first side of the base material abut against the peeling side, the second side of the adhesive agent layer can be fixed on the first side of the base material and The first surface of the adhesive layer is in contact with the peeling surface of the reinforcing film. As the above-mentioned release surface, the surface of a release liner, the back surface of a substrate subjected to release treatment, or the like can be used.

Also, for example, in the case of a photocurable adhesive composition using a partial polymer (polymer slurry) of a monomer raw material, for example, after the adhesive composition is applied to the release surface, the The first side of the base material is coated with the adhesive composition, so that the first side of the base material is contacted with the uncured adhesive composition, and in this state, the first side and the peeling side sandwiched between the base material The adhesive composition in between is irradiated with light to be hardened, thereby forming an adhesive layer.

In addition, the method exemplified above does not limit the manufacturing method of the film for reinforcement disclosed here. At the time of manufacture of the reinforcement film disclosed here, the suitable method which can make an adhesive layer adhere to the 1st surface of a base material can be used individually by 1 type or in combination of 2 or more types. Examples of such a method include: as described above, the liquid adhesive composition is hardened on the first surface of the substrate to form an adhesive layer, or the first surface of the substrate is subjected to an increase in the adhesive layer. The method of surface treatment of grip, etc. For example, in the case where the adhesion of the adhesive layer to the substrate can be sufficiently improved by methods such as providing a primer layer on the first surface of the substrate, the cured adhesive layer can also be attached to the substrate. The method for the first side of the base material is used to manufacture a reinforcing film. In addition, by selecting the material of the substrate or selecting the composition of the adhesive, the adhesion of the adhesive layer to the substrate can also be improved. In addition, by applying a temperature higher than room temperature to the reinforcing film having the adhesive layer on the first side of the substrate, the adhesion of the adhesive layer to the substrate can be improved. The temperature for improving the grip property may be, for example, about 35°C to 80°C, about 40°C to 70°C or more, or about 45°C to 60°C.

The reinforcing film disclosed herein is an adhesive sheet having a first adhesive layer disposed on the first side of the substrate and a second adhesive layer disposed on the second side of the substrate (ie, double-sided adhesive In the case of the form of a flexible adhesive sheet with a base material), the first adhesive layer and the second adhesive layer may have the same structure or may have different structures. When the compositions of the first adhesive layer and the second adhesive layer are different, the difference may be, for example, a difference in composition or a difference in structure (thickness, surface roughness, formation range, formation pattern, etc.). For example, the second adhesive layer may be an adhesive layer without polymer (B). In addition, the surface elastic modulus of the surface of the second adhesive layer (second adhesive surface) at 23° C. may be outside the range of 1-20 kPa (eg, over 20 kPa), or may be greater than 30 kPa.

<Reinforcement film with release liner> The reinforcing film disclosed here can take the form of an adhesive product in which the surface (adhesive surface) of the adhesive layer is brought into contact with the release surface of the release liner. Therefore, the present specification can provide a reinforcing film with a release liner including any of the reinforcing films disclosed herein, and a release liner having a release surface abutting on the adhesive surface of the reinforcing film.

The thickness of the release liner is not particularly limited, but is usually preferably about 5 μm to 200 μm. If the thickness of the release liner is within the above-mentioned range, the workability of sticking to the adhesive layer and the workability of peeling from the adhesive layer are excellent, which is preferable. In some aspects, the thickness of the release liner may be, for example, 10 μm or more, 20 μm or more, 30 μm or more, or 40 μm or more. Moreover, from the viewpoint of facilitating the peeling from the adhesive layer, the thickness of the release liner may be, for example, 100 μm or less, or 80 μm or less. If necessary, a known antistatic treatment such as a coating type, a kneading type, and a vapor deposition type may be applied to the release liner.

The release liner is not particularly limited. For example, it can be used as a release liner having a release layer on the surface of a liner substrate such as a resin film or paper (which may be paper laminated with a resin such as polyethylene), or a release liner containing a release layer such as Release liners, etc. of resin films formed of low-adhesion materials of fluorine-based polymers (polytetrafluoroethylene, etc.) or polyolefin-based resins (polyethylene, polypropylene, etc.). In terms of excellent surface smoothness, a release liner having a release layer on the surface of a resin film serving as a liner base material, or a release liner including a resin film formed of a low-adhesion material can be favorably used. The resin film is not particularly limited as long as it can protect the adhesive layer, and examples thereof include polyethylene films, polypropylene films, polybutene films, polybutadiene films, and polymethylpentene films. , polyvinyl chloride film, vinyl chloride copolymer film, polyester film (PET film, PBT film, etc.), polyurethane film, ethylene-vinyl acetate copolymer film, etc. For the formation of the above-mentioned release layer, for example, polysiloxane-based release treatment agents, long-chain alkyl-based release treatment agents, olefin-based release treatment agents, fluorine-based release treatment agents, fatty acid amide-based release treatment agents, molybdenum sulfide, and carbon dioxide can be used. Silicon powder and other well-known peeling treatment agents. In particular, it is preferable to use a polysiloxane-based release treatment agent.

The thickness of the peeling layer is not particularly limited, but is generally preferably about 0.01 μm to 1 μm, preferably about 0.1 μm to 1 μm. The formation method of a peeling layer is not specifically limited, A well-known method corresponding to the kind of peeling treatment agent used, etc. can be used suitably.

＜Use＞ For example, the reinforcing film provided in this specification can exhibit good secondary processability in the initial stage of being attached to the adherend, and thus can contribute to suppressing a decrease in yield or improving the quality of a product including the reinforcing film. Moreover, after the said reinforcement film is attached to the to-be-adhered body, the adhesive force can be raised significantly by ageing or heating. For example, by heating at an appropriate timing after being attached to the adherend, the reinforcing film can be firmly adhered to the adherend. Taking advantage of this feature, the reinforcing films disclosed herein can be used favorably in various fields to reinforce members included in various articles.

For example, the reinforcing film disclosed here can be used in the form of a base-attached adhesive sheet provided with an adhesive layer on at least the first side of a film-like base material having a first side and a second side, and can be suitably used for sticking. A reinforcing film that reinforces the adherend in the adherend. In this reinforcement film, as the said film base material, what contains a resin film as a base film can be used favorably. Moreover, it is preferable that the said adhesive bond layer is fixed to the 1st surface of a film-like base material from a viewpoint of improving the reinforcement performance. For example, optical components used in optical products or electronic components used in electronic products have been increasingly integrated, compact, lightweight, and thin, and multiple thin optical components with different linear expansion coefficients or thicknesses can be laminated. /Electronic components. By attaching the above-mentioned reinforcing film to such a member, moderate rigidity can be imparted to the above-mentioned optical member/electronic member. Thereby, in the manufacturing process and/or the product after manufacture, it is possible to suppress curling or bending caused by the stress that may be generated between the plurality of members having different linear expansion coefficients or thicknesses. In addition, in the manufacturing process of optical products/electronic products, when the thin optical member/electronic member is subjected to shape processing such as cutting processing as described above, the processing is performed by attaching a reinforcing film to the member. , which can alleviate the local stress concentration of optical components/electronic components accompanying processing, and can reduce the risk of cracks, cracks, and peeling of laminated components. The operation of attaching a reinforcing member to an optical member/electronic member can also help to relieve local stress concentration when the member is transported, laminated, rotated, etc., or to suppress bending or bending caused by the member's own weight. Further, devices such as optical products or electronic products including the above-mentioned reinforcing film are in the stage of being used by consumers in the market, even if the device is dropped, placed under a heavy object, or collided with flying objects, etc. In the event of accidental stress, the stress applied to the device can also be alleviated by including a reinforcing film in the device. Therefore, by including the reinforcing film in the above-mentioned device, the durability of the device can be improved.

In addition, the reinforcing film disclosed here can be used favorably in a state of being attached to a member constituting various portable devices (portable devices), for example. The so-called "carrying" here does not just mean being able to carry, but means having a degree of portability that an individual (standard adult) can carry relatively easily. In addition, examples of the so-called portable devices here include: mobile phones, smart phones, tablet PCs, notebook PCs, various portable devices, digital cameras, digital video cameras, audio devices (portable music players) , voice recorder, etc.), computers (calculators, etc.), portable game consoles, electronic dictionaries, electronic notepads, electronic books, in-vehicle information devices, portable radios, portable TVs, portable printers, portable scanners Portable electronic devices such as instruments, portable modems, etc., in addition, may also include mechanical watches or pocket watches, flashlights, magnifying glasses, etc. Examples of the members constituting the above-mentioned portable electronic equipment include optical films, display panels, and the like used for thin-layer displays such as liquid crystal displays, and image display devices such as film-type displays. The reinforcing film disclosed here can be used satisfactorily in the form of being attached to various members in automobiles, household electrical appliances, and the like.

In addition, since the reinforcing film disclosed here has bending recovery and bending retention force, it can take advantage of its advantages and can be well used for sticking to components capable of bending (for example, flexible devices such as flexible displays; A form of a component of a machine that may also be referred to as a rollable device or a foldable device. As such an apparatus, the above-mentioned various portable apparatuses (portable apparatuses) are mentioned, for example. Examples of members constituting the above-mentioned portable electronic equipment include optical films and display panels used in image display devices such as liquid crystal displays and organic EL (electroluminescence) displays. The reinforcing film disclosed herein can be favorably used in such a portable electronic device for reinforcing a member constituting the device (typically, an image display device called a flexible device or a foldable device, etc.).

In addition, the reinforcing film disclosed here is suitable for, for example, reinforcement of optical members used as components of liquid crystal display panels, plasma display panels (PDPs), organic EL displays, and the like at the time of manufacture, at the time of transportation, and the like. use. It is useful as a reinforcing film applied to optical members such as polarizing plates (polarizing films) for liquid crystal display panels, wavelength plates, retardation plates, optical compensation films, brightness enhancement films, light diffusing sheets, and reflective sheets.

In addition, the use of the reinforcing film disclosed here is not particularly limited, and it can be used for various uses for the purpose of imparting rigidity, impact resistance, and the like. The reinforcing films disclosed herein can be used not only for flexible device applications as described above, but also for other applications that do not include flexible devices. The fact that the reinforcement film has bending recovery and bending retention force means that the application scope of the reinforcement film is less restricted, and the practical application is more advantageous. [Example]

Hereinafter, some embodiments of the present invention will be described, but the present invention is not intended to be limited to those shown in the specific examples. In addition, "part" and "%" in the following description are based on weight unless otherwise specified.

[Synthesis of polymer (A)] (Synthesis example A1) In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen introduction tube and a condenser, 90.2 parts of 2-ethylhexyl acrylate (2EHA), 8.6 parts of 4-hydroxybutyl acrylate (4HBA), and N-acryloyl acrylate were added. 1.2 parts of oxoline (ACMO), 0.2 part of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator, and ethyl acetate as a polymerization solvent, while stirring slowly, introduce nitrogen gas into the flask. The liquid temperature was maintained at about 65° C. to carry out the polymerization reaction for 6 hours to prepare a solution of acrylic polymer A1 with a polymer concentration of 35%. The weight average molecular weight (Mw) of the acrylic polymer A1 was 540,000.

(Synthesis example A2) Solution polymerization was carried out in the same manner as in Synthesis Example A1, except that the monomer composition was changed to 2EHA/4HBA/ACMO/butyl acrylate (BA) = 86.1 parts/9.7 parts/1.8 parts/2.4 parts, thereby obtaining an acrylic type Solution of polymer A2.

(Synthesis example A3) A solution of the acrylic polymer A3 was obtained by performing solution polymerization in the same manner as in Synthesis Example A1 except that the monomer composition was changed to BA/4HBA=96 parts/4 parts.

(Synthesis example A4) Except changing the monomer composition to 2EHA/2-hydroxyethyl acrylate (HEA)/methyl methacrylate (MMA)/N-vinyl-2-pyrrolidone (NVP)=65 parts/15 parts/7 parts A solution of acrylic polymer A4 was obtained by performing solution polymerization in the same manner as in Synthesis Example A1 except for /13 parts.

[Synthesis of polymer (B)] (Synthesis example B1) 101.15 parts of ethyl acetate, 40 parts of MMA, 20 parts of n-butyl methacrylate (BMA), 20 parts of 2-ethylhexyl methacrylate (2EHMA), and the functional group equivalent of 900 g/mol of polyorganic organic 8.7 parts of methacrylate monomer with siloxane skeleton (trade name: X-22-174ASX, manufactured by Shin-Etsu Chemical Co., Ltd.), methacrylic acid containing polyorganosiloxane skeleton with functional group equivalent of 4600 g/mol 11.3 parts of ester monomer (trade name: KF-2012, manufactured by Shin-Etsu Chemical Industry Co., Ltd.) and 0.09 part of thioglycerol as a chain transfer agent were put into the fourth part equipped with stirring blade, thermometer, nitrogen introduction pipe, condenser and dropping funnel in the flask. Then, after stirring at 70 degreeC for 30 minutes under nitrogen atmosphere, 0.2 part of AIBN as a thermal polymerization initiator was injected|thrown-in, and reaction was performed at 70 degreeC for 3 hours. Then, after stirring at 80 degreeC for 30 minutes, 0.1 part of AIBN was further injected|thrown-in, and it was made to react at 80 degreeC for 2 hours. Then, 0.05 part of AIBN was added, and it was made to react at 80 degreeC for 2 hours, and the polymer B1 was obtained. The Mw of the obtained polymer B was 90200.

(Synthesis Examples B2 to B6) The usage amount of the chain transfer agent (thioglycerol) was changed to 0.11 part (synthesis example B2), 0.3 part (synthesis example B3), 0.5 part (synthesis example B4), and 0.6 part (synthesis example B4) with respect to 100 parts of monomer raw materials B5), 0.7 parts (synthesis example B6), 0.8 parts (synthesis example B7), 1.5 parts (synthesis example B8), 0.03 parts (synthesis example B9), 8 parts (synthesis example B10), and other Polymers B2 to B10 were prepared in the same manner as in Example B1. Regarding the weight average molecular weight (Mw) of the obtained polymer (B), the polymer B2 was 83,800, the polymer B3 was 44,800, the polymer B4 was 32,200, the polymer B5 was 27,600, the polymer B6 was 24,500, and the polymer B7 20,000 for polymer B8, 12,600 for polymer B8, 127,000 for polymer B9, and 2,960 for polymer B10.

In addition, the Mw of each said polymer was measured under the following conditions using a GPC apparatus (Tosoh company make, HLC-8220GPC), and was calculated|required by polystyrene conversion. [GPC conditions] ・Sample concentration: 0.2 wt% (tetrahydrofuran (THF) solution) ・Sample injection volume: 10 μl ・Eluent: THF, flow rate: 0.6 ml/min ・Measurement temperature: 40℃ ・Pipe string: Sample column: TSKguardcolumn SuperHZ-H (1) + TSKgel SuperHZM-H (2) Reference column: TSKgel SuperH-RC (1 piece) ・Detector: Differential Refractometer (RI)

[Production of Reinforcing Membrane] <Example 1> 100 parts of acrylic polymer A1, 2.0 parts of polymer B1, and 0.10 parts of isocyanate compound C1 (trade name "Coronate HX", manufactured by Tosoh Corporation) as a crosslinking agent in terms of solid content were added, and diluted with ethyl acetate to The solid content of the whole was 30%, and the acrylic adhesive solution of this example was obtained. A release liner (trade name "DIAFOIL MRF75", manufactured by Mitsubishi Chemical Corporation) containing a polyester resin with a thickness of 75 μm which was subjected to polysiloxane treatment on one side was prepared, and the acrylic acid obtained above was coated on the polysiloxane treated surface. The adhesive solution was dried at 130° C. for 1 minute to form an adhesive layer with a thickness of 25 μm. Then, a polyimide substrate (trade name "Upilex 50S", manufactured by Ube Industries, Ltd.) with a thickness of 50 μm was pasted on the surface of the obtained adhesive layer to obtain the reinforcing film of this example. The reinforcing film has the form of an adhesive sheet with a release liner, that is, it has an adhesive layer on one surface of the base material, and the release surface of the release liner is in contact with the adhesive surface. Furthermore, for the reinforcing film of this example, according to the amount of OH in the adhesive layer (the number of moles of hydroxyl groups in the acrylic polymer A1) and the amount of NCO (the number of moles of the isocyanate groups of the isocyanate compound), The molar ratio ([NCO]/[OH]) was calculated and found to be 0.008.

<Examples 2 to 8> Using Polymer B2 (Example 2), Polymer B3 (Example 3), Polymer B4 (Example 4), Polymer B5 (Example 5), Polymer B6 (Example 6), Polymer B7 ( Example 7) The acrylic adhesive solution of each example was obtained in the same manner as in Example 1, except that the polymer B8 (Example 8) was used instead of the polymer B1. A reinforcing film of each example was produced in the same manner as the production of the reinforcing film of Example 1 except that these acrylic adhesive solutions were used, respectively.

<Examples 9 to 12> As shown in Table 1, the usage-amount of the isocyanate compound C1 was changed to 0.015 part (Example 9), 0.05 part (Example 10), 0.20 part ( Except Example 11) and 0.60 part (Example 12), it carried out similarly to Example 7, and obtained the acrylic adhesive solution of each example. A reinforcing film of each example was produced in the same manner as the production of the reinforcing film of Example 1 except that these acrylic adhesive solutions were used, respectively.

<Example 13> Except having changed the usage-amount of polymer B5 to 1.0 part with respect to 100 parts of acrylic polymer A1 as shown in Table 1, it carried out similarly to Example 5, and obtained the acrylic adhesive solution of this example. The reinforcing film of this example was produced in the same manner as the production of the reinforcing film of Example 1 except that the obtained acrylic adhesive solution was used.

<Examples 14 to 16> As shown in Table 1, the usage amount of polymer B7 was changed to 1.0 parts (Example 14), 3.0 parts (Example 15), and 6.0 parts (Example 16) with respect to 100 parts of acrylic polymer A1. Other than that, it carried out similarly to Example 7, and obtained the acrylic adhesive solution of each example. A reinforcing film of each example was produced in the same manner as in the production of the reinforcing film of Example 1, except that these acrylic adhesive solutions were used, respectively.

<Example 17> The acrylic adhesive solution of this example was obtained in the same manner as in Example 7 except that the acrylic polymer A2 was used instead of the acrylic polymer A1. The reinforcing film of this example was produced in the same manner as the production of the reinforcing film of Example 1 except that the obtained acrylic adhesive solution was used.

<Example 18> Instead of the acrylic polymer A1, an acrylic polymer A3 was used, and an isocyanate compound C2 (trade name "Takenate D110N", manufactured by Mitsui Chemicals Corporation) was used as a crosslinking agent, and the isocyanate compound C2 was solid in 100 parts of the acrylic polymer A3. The acrylic pressure-sensitive adhesive solution of this example was obtained in the same manner as in Example 7, except that it was 0.07 part in terms of physical components. The reinforcing film of this example was produced in the same manner as the production of the reinforcing film of Example 1 except that the obtained acrylic adhesive solution was used.

<Examples 19 to 20> Except having changed the usage-amount of isocyanate compound C2 to 0.09 part (Example 19) and 0.395 part (Example 20) in terms of solid content with respect to 100 parts of acrylic polymer A3 as shown in Table 1 , the acrylic adhesive solution of each example was obtained in the same manner as in Example 18. A reinforcing film of each example was produced in the same manner as the production of the reinforcing film of Example 1 except that these acrylic adhesive solutions were used, respectively.

<Comparative Examples 1 to 2> The acrylic adhesive solution of each example was obtained in the same manner as in Example 1, except that the polymer B9 (Comparative Example 1) and the polymer B10 (Comparative Example 2) were used instead of the polymer B1. A reinforcing film of each example was produced in the same manner as the production of the reinforcing film of Example 1 except that these acrylic adhesive solutions were used, respectively.

<Comparative Example 3> Instead of the acrylic polymer A1, the acrylic polymer A4 was used, and an isocyanate compound C2 (trade name "Takenate D110N", manufactured by Mitsui Chemicals Corporation) was used as a crosslinking agent, and the isocyanate compound C2 was solid with respect to 100 parts of the acrylic polymer A4 The acrylic pressure-sensitive adhesive solution of this example was obtained in the same manner as in Example 7, except that it was 0.50 part in terms of physical components. The reinforcing film of this example was produced in the same manner as the production of the reinforcing film of Example 1 except that the obtained acrylic adhesive solution was used.

<Comparative Examples 4 to 5> Except having changed the usage-amount of isocyanate compound C2 to 1.10 parts (Comparative Example 4) and 2.50 parts (Comparative Example 5) in terms of solid content with respect to 100 parts of acrylic polymer A4 as shown in Table 1 , the acrylic adhesive solution of each example was obtained in the same manner as in Comparative Example 3. A reinforcing film of each example was produced in the same manner as the production of the reinforcing film of Example 1 except that these acrylic adhesive solutions were used, respectively.

<Evaluation> [Surface Elastic Modulus] The reinforcing film of each example was aged at 50° C. for 1 day, and the surface elastic modulus was measured. The release liner protecting the adhesive surface was peeled off, and a nano-indenter device (Triboindenter manufactured by Hysitron Inc.) was used to press an indenter on the surface of the adhesive layer to a depth of 6 μm. The maximum load (Pmax) [GPa/mm ² ] was obtained by measuring with the instrument. Substitute it into the following formula, Surface hardness [GPa]=Pmax/A Calculate the surface hardness, convert it into [kPa] unit, and record it as the surface elastic modulus at 23°C (23°C surface elastic modulus). The measurement conditions are as follows. Furthermore, in the above formula, A is the contact projected area of the indenter [mm ² ]. (Measurement conditions) Approaching speed of indenter: 5 μm/s Maximum displacement: 6 μm Pressing speed: 5 μm/s Extraction speed: 5 μm/s Indenter used: Conical (spherical indenter: radius of curvature 10 μm) Measurement method : Single push-in measurement Measurement temperature: Room temperature (23°C)

8 mm，製作圓柱狀顆粒，作為測定用樣品。 將上述測定樣品固定於

8 mm平行板之治具，利用動態黏彈性測定裝置(TA Instruments公司製造之「ARES」)，於以下條件下測定儲存彈性模數G'、損耗彈性模數G''及損耗正切tanδ，求出23℃下之儲存彈性模數G'₂₃ [kPa]、80℃下之儲存彈性模數G'₈₀ [kPa]及80℃下之tanδ(80℃下之損耗彈性模數G''₈₀ /80℃下之儲存彈性模數G'₈₀ )。 ・測定模式：剪切模式 ・溫度範圍 ：-70℃～200℃ ・升溫速度 ：5℃/min ・頻率：1 Hz 再者，儲存彈性模數G'相當於材料變形時作為彈性能量儲存之部分，係表示硬度之程度之指標。損耗彈性模數G''相當於材料變形時因內部摩擦等而散逸之損失能量部分，表示黏性程度。[Bulk modulus of elasticity G' and tanδ] A release liner R1 (trade name "DIAFOIL MRF75", manufactured by Mitsubishi Chemical Corporation) with a thickness of 75 μm polysiloxane-treated on one side was prepared and made of polyester resin. The silicone-treated surface was coated with the acrylic adhesive solution of each example, and dried at 130° C. for 1 minute to form an adhesive layer with a thickness of 25 μm. Next, a release liner R2 (trade name "DIAFOIL MRE75", manufactured by Mitsubishi Chemical Corporation) containing a polyester resin with a thickness of 75 μm and having been subjected to polysiloxane treatment on one side was used as the adhesive layer side with the polysiloxane treated surface. It was coated on the surface of the obtained adhesive layer, and was aged at 50° C. for 1 day. Only the obtained adhesive layer was taken out, laminated to a thickness of about 1 mm, and punched out

8 mm, cylindrical pellets were prepared and used as samples for measurement. The above-mentioned measurement samples were fixed in

For a jig of an 8 mm parallel plate, use a dynamic viscoelasticity measuring device (“ARES” manufactured by TA Instruments) to measure the storage elastic modulus G', the loss elastic modulus G'' and the loss tangent tanδ under the following conditions, and find The storage elastic modulus G' ₂₃ [kPa] at 23 °C, the storage elastic modulus G' ₈₀ [kPa] at 80 °C and the tanδ at 80 °C (loss elastic modulus G'' ₈₀ / Storage elastic modulus at 80°C G' ₈₀ ).・Measuring mode: Shearing mode ・Temperature range: -70℃～200℃ ・Heating rate: 5℃/min ・Frequency: 1 Hz Furthermore, the storage elastic modulus G' corresponds to the part of elastic energy stored when the material is deformed , which is an indicator of the degree of hardness. The loss elastic modulus G'' is equivalent to the part of the lost energy dissipated due to internal friction, etc. when the material is deformed, and represents the degree of viscosity.

[Initial Adhesion] The reinforcing film of each example was aged at 50° C. for one day, and was cut into a measurement sample of 25 mm in width×140 mm in length together with a release liner. The release liner was peeled off from the said measurement sample, the adhesive surface was exposed, and the 2 kg hand roll was reciprocated once, and it was press-bonded to the stainless steel plate (SUS304BA plate) which is the to-be-adhered body. The measurement sample thus crimped to the adherend was left to stand at an ambient temperature of 23°C for 30 minutes, and then a tensile tester (manufactured by Shimadzu Corporation, trade name "Autograph AG-Xplus HS 6000 mm/min high-speed mode (AG- 50NX plus)"), under the conditions of peeling angle of 180 degrees and peeling speed (stretching speed) of 300 mm/min, measure the load when peeling the reinforcing film from the above adherend, and record the average load at the time of measurement as the initial stage Adhesion [gf/25 mm].

[Adhesion after heating] For the reinforcing film of each example, a measurement sample was prepared in the same manner as in the above-mentioned initial adhesive force measurement, and it was crimped to the adherend. Then, the measurement sample crimped to the adherend was heated at an ambient temperature of 60° C. for 60 minutes. After that, it was left to stand at an ambient temperature of 23°C for 30 minutes, using a tensile tester (manufactured by Shimadzu Corporation, trade name "Autograph AG-Xplus HS 6000mm/min high-speed mode (AG-50NX plus)"), at a peeling angle of 180 Under the conditions of 300 mm/min of peeling speed and peeling speed (tensile speed), the load when peeling off the reinforcing film from the adherend was measured, and the average load during the measurement was recorded as the adhesive force after heating [gf/25 mm].

6 mm，於此狀態下固定，於80℃下進行15小時加熱。然後，放置於室溫(23℃)，確認充分冷卻後，解除上述測定樣品之彎折狀態之固定，自固定解除起10分鐘以內，使用分度器，測定彎折之上述測定樣品之彎曲角度[°]，評價彎曲回復性。再者，彎曲角度係測定樣品之打開角度(測定樣品自彎折狀態打開之側之角度)，越接近於180°，則具有越優異之彎曲回復性，彎曲角度越接近於0°，則彎曲回復性越差。 繼而，作為彎曲保持力之評價，目視確認測定樣品之彎曲部有無「剝離」，將未確認到「剝離」之情形評價為「○」，將確認到「剝離」之情形評價為「×」。[Bending retention test] The reinforcing films of each example were aged at 50° C. for 1 day, then the release liner was peeled off, and a polyimide substrate with a thickness of 25 μm (trade name “” Upilex 25S", manufactured by Ube Kosan Co., Ltd.), was heated at 60°C for 60 minutes to make it adhere. Next, the obtained measurement sample (layered body) was folded with the 25 μm substrate side as the inner side.

6 mm, fixed in this state, and heated at 80°C for 15 hours. Then, it was placed at room temperature (23°C), and after confirming that it was sufficiently cooled, the fixing of the bending state of the above-mentioned measurement sample was released, and within 10 minutes after the fixing was released, the bending angle [° ] to evaluate the bending recovery. Furthermore, the bending angle is the opening angle of the measurement sample (the angle at which the sample is opened from the bending state), the closer to 180°, the better the bending recovery, and the closer the bending angle is to 0°, the more bending The less responsive. Next, as the evaluation of the bending retention force, the presence or absence of "peeling" in the curved portion of the measurement sample was visually confirmed, the case where "peeling" was not confirmed was evaluated as "○", and the case where "peeling" was confirmed was evaluated as "x".

Table 1 shows the evaluation results of the reinforcing film of each example. Table 1 also shows the outline of the composition of the adhesive layer of each example.

[Table 1] Table 1 Polymer (A) Polymer (B) cross-linking agent Molar ratio [NCO]/[OH] Surface modulus of elasticity 23℃[kPa] Bulk modulus of elasticity 23°C [kPa] Bulk modulus of elasticity 80°C [kPa] tanδ 80℃ Initial adhesion [gf/25 mm] Adhesion after heating [gf/25 mm] Bending resilience [°] Bend retention type number of copies type Mw number of copies type number of copies Example 1 A1 100 B1 90,200 2.0 C1 0.10 0.008 5.2 34 11 0.51 342 1205 90 ○ Example 2 A1 100 B2 83,800 2.0 C1 0.10 0.008 5.2 33 12 0.52 278 1227 90 ○ Example 3 A1 100 B3 44,800 2.0 C1 0.10 0.008 5.1 34 11 0.51 264 763 90 ○ Example 4 A1 100 B4 32,200 2.0 C1 0.10 0.008 5.2 33 12 0.50 149 902 95 ○ Example 5 A1 100 B5 27,600 2.0 C1 0.10 0.008 5.1 33 11 0.52 131 1022 90 ○ Example 6 A1 100 B6 24,500 2.0 C1 0.10 0.008 5.1 33 11 0.50 170 1095 95 ○ Example 7 A1 100 B7 20,000 2.0 C1 0.10 0.008 5.1 33 11 0.51 256 821 90 ○ Example 8 A1 100 B8 12,600 2.0 C1 0.10 0.008 5.1 33 11 0.51 210 635 90 ○ Example 9 A1 100 B7 20,000 2.0 C1 0.015 0.001 1.2 33 8 0.79 325 2144 35 ○ Example 10 A1 100 B7 20,000 2.0 C1 0.05 0.004 2.7 33 11 0.60 368 877 50 ○ Example 11 A1 100 B7 20,000 2.0 C1 0.20 0.016 6.9 33 14 0.41 209 607 90 ○ Example 12 A1 100 B7 20,000 2.0 C1 0.60 0.049 10.8 41 twenty four 0.23 128 463 100 ○ Example 13 A1 100 B5 27,600 1.0 C1 0.10 0.008 4.8 33 12 0.51 155 944 115 ○ Example 14 A1 100 B7 20,000 1.0 C1 0.10 0.008 4.8 32 12 0.52 221 750 115 ○ Example 15 A1 100 B7 20,000 3.0 C1 0.10 0.008 5.6 38 13 0.51 283 651 65 ○ Example 16 A1 100 B7 20,000 6.0 C1 0.10 0.008 6.8 39 14 0.51 185 495 60 ○ Example 17 A2 100 B7 20,000 2.0 C1 0.10 0.008 5.3 34 12 0.51 262 832 90 ○ Example 18 A3 100 B7 20,000 2.0 C2 0.07 0.028 15.1 81 52 0.25 275 547 105 ○ Example 19 A3 100 B7 20,000 2.0 C2 0.09 0.036 15.5 96 63 0.24 245 404 105 ○ Example 20 A3 100 B7 20,000 2.0 C2 0.395 0.160 17.8 114 88 0.13 186 331 110 ○ Comparative Example 1 A1 100 B9 127,000 2.0 C1 0.10 0.008 5.2 34 11 0.52 417 1582 90 ○ Comparative Example 2 A1 100 B10 2,960 2.0 C1 0.10 0.008 5.1 33 12 0.51 109 74 90 ○ Comparative Example 3 A4 100 B7 20,000 2.0 C2 0.50 0.013 26.2 250 61 0.31 330 735 80 × Comparative Example 4 A4 100 B7 20,000 2.0 C2 1.10 0.028 28.1 251 73 0.24 92 1227 105 × Comparative Example 5 A4 100 B7 20,000 2.0 C2 2.50 0.063 36.0 316 115 0.13 57 796 110 ×

As shown in Table 1, the adhesives of Examples 1 to 20 contain a polymer (A) and a polymer (B), and the Mw of the polymer (B) is in the range of 10,000 to 100,000. Compared with Comparative Examples 1 to 2 in which the Mw of the polymer (B) was outside the range of 10,000 to 100,000, the reinforcing films of these examples had a better balance between the lower initial adhesive force and the increase in the adhesive force after heating. In addition, the 23°C surface elastic modulus of the adhesive layers of the reinforcing films of Examples 1 to 20 was in the range of 1 to 20 kPa, and the flexural recovery and flexural retention were also good. On the other hand, in Comparative Examples 3 to 5 in which the surface elastic modulus at 23° C. was outside the range of 1 to 20 kPa, peeling was confirmed in the bending retention test.

More specifically, according to the comparison of Examples 1 to 8, the lower the Mw of the polymer (B) is in the range of 100,000 or less, the lower the initial adhesion is, and the lowest initial stage is shown in the range of Mw of 20,000 to 30,000. Adhesion. The adhesive force after heating is higher in the range of Mw of 80,000 to 100,000 and the range of Mw of 20,000 to 30,000. In Examples 5 and 6, the lower initial adhesion and the increase in the adhesion after heating were improved in the most balanced manner. On the other hand, in Comparative Example 1 in which the Mw of the polymer (B) exceeded 100,000, the initial adhesion was high and the light peelability was poor. In addition, in Comparative Example 2 in which the Mw of the polymer (B) was less than 10,000, the adhesive force did not increase after heating. The reason is considered that the low molecular weight polymer (B) forms WBL (Weak Boundary Layer) on the surface of the adhesive layer, and also stays on the surface of the adhesive layer after heating.

In addition, according to the comparison of Examples 9 to 12, it was confirmed that the higher the surface elastic modulus at 23°C of the adhesive layer was in the range of 1 to 20 kPa, the more the bending recovery tended to be improved, and the initial adhesion and heating tended to be improved. Tendency to lower post-adhesion. The bending recovery properties of Examples 10 to 12 are better than those of Example 9, the surface elastic modulus at 23°C is above 2 kPa, and the tanδ ₈₀ at 80°C is in the range of 0.10 to 0.60. In addition, in Example 12, both the surface elastic modulus and the bulk elastic modulus were relatively high, and the increase in adhesive force after heating was relatively low compared to Examples 9 to 11. In addition, in Examples 9-11, the ₂₃ degreeC bulk elasticity modulus G'23 of an adhesive bond layer was found to have no difference. In addition, the ₈₀ degreeC bulk elasticity modulus G'80 in Examples 1-8, 10 is about the same level. Regarding Examples 1 to 12, it can be said that the correlation between the surface elastic modulus at 23° C. and the bending recovery is higher than that of the bulk elastic modulus. Furthermore, in Examples 1 to 12, in the adhesive layers of Examples 1 to 8 and 10 to 11, in which the initial adhesive force, the adhesive force after heating, the flexural recovery and the flexural retention force were improved in a more balanced manner, the isocyanic acid was The molar ratio ([NCO]/[OH]) of the group to the hydroxyl group is in the range of 0.002 to 0.03.

Moreover, according to the comparison of Examples 13-16, it was confirmed that the adhesive force tends to fall as the usage-amount of a polymer (B) increases. In Examples 13 to 15, the initial adhesive force was less than 400 gf/25 mm, and the adhesive force after heating was 500 gf/25 mm or more, which better took into account the light peelability at the initial stage of attachment and the increase in adhesive force after heating. Moreover, in Examples 13-14 (especially Example 13), the outstanding adhesive force improvement was confirmed. Moreover, when the usage-amount of a polymer (B) increases, the 23 degreeC surface elastic modulus becomes high, and there exists a tendency for bending recovery to fall. Moreover, from the results of Examples 17 to 20, it was confirmed that even if the type of the polymer (A) of the adhesive or the type of the crosslinking agent were changed, the desired effect could be achieved. Compared with Examples 19-20, Examples 17-18 showed a larger increase in adhesive force after heating.

As mentioned above, although the specific example of this invention was demonstrated in detail, it is only an illustration, and does not limit the scope of the patent application. The technology described in the scope of claims includes various changes and modifications of the specific examples illustrated above.

1,2,3: Reinforcing film 10: Support substrate 10A: The first side 10B: Second side 21: Adhesive layer (first adhesive layer) 21A: Adhesive side (first adhesive side) 21B: Adhesive Surface (Second Adhesive Surface) 22: Adhesive layer (second adhesive layer) 22A: Adhesive side (second adhesive side) 31, 32: Release liner 100, 200, 300: Reinforcing film with release liner

FIG. 1 is a cross-sectional view schematically showing a configuration of a reinforcing film according to an embodiment. FIG. 2 is a cross-sectional view schematically showing the configuration of a reinforcing film according to another embodiment. 3 is a cross-sectional view schematically showing the configuration of a reinforcing film according to another embodiment.

1: Reinforcing film

10: Support substrate

10A: The first side

10B: Second side

21: Adhesive layer (first adhesive layer)

21A: Adhesive side (first adhesive side)

31: Release Liner

100: Reinforcing film with release liner

Claims (7)

A reinforcing film, which has an adhesive layer, The above-mentioned adhesive layer comprises polymer (A) and polymer (B), The above-mentioned polymer (B) includes a monomer unit having a polyorganosiloxane skeleton and a (meth)acrylic monomer unit, The surface elastic modulus of the above-mentioned adhesive layer at 23°C is 1-20 kPa, The weight average molecular weight of the said polymer (B) is 10,000-100,000. The reinforcing film of claim 1, wherein the bulk modulus G' ₂₃ of the adhesive layer at 23°C is 10-200 kPa, and the bulk modulus G' ₈₀ at 80°C is 5-100 kPa, And tanδ ₈₀ at 80°C is 0.10 to 0.60. The reinforcing film according to claim 1 or 2, wherein the polymer (A) is an acrylic polymer. The reinforcing film according to any one of claims 1 to 3, wherein the content of the polymer (B) in the adhesive layer is 0.5 to 5 parts by weight relative to 100 parts by weight of the polymer (A). The reinforcing film according to any one of claims 1 to 4, wherein the molar ratio ([NCO]/[OH]) of the isocyanate group and the hydroxyl group contained in the adhesive layer is 0.002 to 0.03. An optical member to which the reinforcing film according to any one of claims 1 to 5 is attached. An electronic component to which the reinforcing film according to any one of claims 1 to 5 is attached.

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