TW201343870A - Film to be applied to window - Google Patents

Abstract

A film which is to be applied to a window and which bears a substrate, a pressure-sensitive adhesive layer and a separator in this order, wherein the pressure-sensitive adhesive layer exhibits a storage modulus of 4.5104 to 2.0105 Pa at 20 DEG C. The film may further bear a functional layer such as a hard coat on the reverse surface of the substrate, namely, on the surface thereof that is reverse to the surface on which the pressure-sensitive adhesive layer is present. The pressure-sensitive adhesive layer of the film suffers little cratering, namely, forms few dents or depressions even when the film is stored in the form of a roll. Therefore, the film can attain good surface appearance when applied to a window.

Description

Window adhesive film

The present invention relates to a film for window bonding having a support, an adhesive layer, and a separator in sequence.

In recent years, most of the films have been adhered to a window attached to the glass surface of a window of a building. These films are adhered for the purpose of preventing entry of ultraviolet rays or infrared rays, coloring or decorating the glass, preventing scattering of the glass when it is broken, and making it impossible for the intruder to break the glass.

Such a film for window adhesion basically has a structure in which an adhesive sheet having an adhesive layer formed on a base film is formed (Patent Document 1). Patent Document 1 discloses an anti-scattering anti-adhesion sheet having a hard coat layer on the opposite surface of the adhesive layer of the base film, and is described in order to prevent the adhesive sheet from being punched. The floating coating of the hard coating layer is peeled off to set the storage modulus (0 ° C) of the adhesive within a predetermined range.

(Patent Document 1) Japanese Laid-Open Patent Publication No. 2011-168652 (Patent Application No. 1)

However, in order to facilitate the bonding of the window glass, in order to facilitate the bonding of the window glass, the adhesive layer and the spacer are usually bonded to each other and wound up and stored in a roll shape. When it is attached to the window glass, the spacer is peeled off from the adhesive layer, and the adhesive layer is adhered to the window glass.

In the film for window sticking which is wound up in a roll shape, the coating film of the adhesive layer has a problem called a crater, which is called a crater, or a squat, and has a problem of poor appearance.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a film for window adhesion which can reduce the occurrence of potholes in an adhesive layer and which exhibits a good appearance.

The inventors of the present invention have found out the following cases in order to solve the above problems. First of all, it can be understood that the pits of the adhesive layer are generated in the adhesive layer located close to the core when being wound up and stored in a roll shape, but are not produced in the adhesive layer close to the surface layer of the roll. The difference caused by the place where the pothole is generated is considered to be caused by the difference in the pressure applied to the adhesive layer on the core side and the surface side of the reel, and is applied to the adhesion in the state of the roll. When the pressure of the layer is related to the occurrence of potholes, it can be understood that when pressure is applied to the adhesive layer, pits are generated due to deformation of the adhesive layer. And found the following situation: the hardness of the adhesive layer By setting the specific hardness, the function as the adhesive layer is not lowered, and the pressure of the reel state can be prevented to prevent the occurrence of potholes.

That is, the film for window adhesion of the present invention has a support, an adhesive layer, and a spacer in this order, and is characterized in that the storage elastic modulus of the adhesive layer at 20 ° C is 4.5 × 10 ⁴ Pa or more.

Further, in the film for window adhesion of the present invention, it is preferable that the storage layer has a storage modulus of 2.0 × 10 ⁵ Pa or less at 20 °C.

Moreover, it is preferable that the film for window adhesion of the present invention has a functional layer on the opposite side of the surface of the support having the adhesive layer.

When the film for window adhesion of the present invention is wound up and stored in a roll shape by using an adhesive layer having a specific storage modulus, the occurrence of pits in the adhesive layer can be reduced, and a good appearance can be exhibited.

The film for window adhesion of the present invention has a support, an adhesive layer and a spacer in this order, and the storage elastic modulus of the adhesive layer at 20 ° C is 4.5 × 10 ⁴ Pa or more. Hereinafter, embodiments of each component will be described.

As a support body used for the film for window adhesion of this invention, a plastic film is mentioned. As the plastic film, polyester (polyester), polycarbonate (polycarbonate), acrylic acid (acrylic), cellulose triacetate, polypropylene, polyethylene, polyvinyl chloride, polystyrene, polyamide, poly Polyimide, vinylidene-vinyl chloride copolymer, and the like. Further, such a support may be a support containing various ultraviolet absorbers, oxidation inhibitors, aging preventive agents, slipping agents, and the like which are generally used, or may have a support layer containing the layers. body.

The thickness of the support varies depending on the use, so it cannot be generalized, but is preferably from 10 μm to 350 μm, more preferably from 30 μm to 188 μm.

The adhesive layer is laminated on one surface of the support and has a hardness that does not deform under a predetermined pressure. The predetermined pressure refers to the pressure applied to the core side in the state of being wound up and stored in a roll shape, although it varies depending on the diameter of the roll or the diameter of the core, but specifically refers to the width of the roll. The pressure generated when the tension is about 10 kg to 30 kg is applied.

In order to set such hardness, the storage modulus of the adhesive layer at 20 ° C is 4.5 × 10 ⁴ Pa or more, preferably 4.9 × 10 ⁴ Pa or more, and more preferably 5.3 × 10 ⁴ Pa or more. By providing such an adhesive layer on the support, when the adhesive layer and the spacer are bonded together and stored in a roll shape, the generation of the pits of the adhesive layer is lowered and a good appearance can be exhibited.

Further, the storage elastic modulus of the adhesive layer at 20 ° C is preferably 2.0 × 10 ⁵ Pa or less, more preferably 1.8 × 10 ⁵ Pa or less, still more preferably 1.6 × 10 ⁵ Pa or less. When the storage modulus at 20 ° C of the adhesive layer is 2.0 × 10 ⁵ Pa or less, sufficient adhesion can be easily obtained.

The storage modulus (20 ° C) of the above adhesive layer can be prepared by adjusting the adhesive constituting the adhesive layer with its molecular weight and additives. Further, when the adhesive layer is formed by coating or drying, it may be adjusted by an additional heating step. First explain the material.

As the adhesive, a natural resin-based adhesive, a synthetic resin-based adhesive, or the like can be used, and an acrylic adhesive, a silicone adhesive, or a urethane adhesive is preferably used. A synthetic resin such as an agent is an adhesive. Among them, an acrylic adhesive having weather resistance and easy crosslinkability for handling is preferably used.

The storage modulus of the adhesive itself tends to become higher when the molecular weight of the adhesive is larger, and becomes lower when the molecular weight is smaller. The weight average molecular weight of the adhesive is preferably 300,000 or more, more preferably 400,000 or more, and more preferably 500,000 or more, and the upper limit is preferably 900,000 or less, more preferably 800,000 or less, and more preferably 700,000 or less. . By setting the lower limit of the weight average molecular weight of the adhesive to 300,000 or more and the upper limit to 900,000 or less, the storage elastic modulus of the adhesive at 20 ° C can be easily adjusted to 4.5 × 10 ⁴ Pa or more.

Further, when the storage modulus of the adhesive itself is low, the storage modulus can be improved by using a crosslinking agent. Further, in addition to the crosslinking agent, the storage modulus can be improved by using a crosslinking accelerator.

As the crosslinking agent, an isocyanate crosslinking agent, an epoxy crosslinking agent, an imine crosslinking agent, a chelate or the like can be used. A suitable ratio of the adhesive to the crosslinking agent is preferably 0.01 parts by weight or more, more preferably 0.1 parts by weight or more, even more preferably 0.4 parts by weight or more, based on 100 parts by weight of the adhesive. The upper limit is preferably 10 parts by weight or less, more preferably 5 parts by weight or less, still more preferably 1 part by weight or less. When the crosslinking agent component is 0.01 parts by weight or more, the storage modulus of the adhesive layer at 20 ° C can be set to 4.5 × 10 ⁴ Pa or more. On the other hand, when it is 10 parts by weight or less, the adhesion is excellent.

As the crosslinking accelerator, a tin-based crosslinking accelerator, an aluminum-based crosslinking accelerator, or the like can be used. A suitable ratio of the crosslinking agent to the crosslinking accelerator is preferably 0.1 part by weight or more, more preferably 1 part by weight or more, more preferably 1 part by weight or more based on 100 parts by weight of the crosslinking agent component. The upper limit is preferably 50 parts by weight or less, more preferably 40 parts by weight or less, still more preferably 10 parts by weight or less. By setting the cross-linking accelerator component to 0.1 part by weight or more, the crosslinking reaction between the adhesive and the crosslinking agent can be made faster, and the storage elastic modulus of the adhesive layer at 20 ° C can be adjusted to 4.5 × 10 ⁴ Pa or more. . On the other hand, when it is 50 parts by weight or less, the viscosity of the liquid after the preparation of the adhesive, the crosslinking agent, and the crosslinking accelerator is increased, and the coating is facilitated.

The thickness of the adhesive layer is not particularly limited, but is preferably from 2 μm to 60 μm, more preferably from 5 μm to 40 μm, in view of adhesion, peeling property, and the like of the film for window adhesion to an adhesive. If When it is 5 μm or less, the adhesiveness is unstable, and if it is 40 μm or more, the adhesive oozes out from the side of the film, and a problem occurs in handling.

In the adhesive layer, in addition to the adhesive, the crosslinking agent and the crosslinking accelerator, a retarder, a pigment, a dye, a coloring agent, a matting agent, a charge preventing agent, a flame retardant, an antifungal agent may be added. , rust inhibitor, antibacterial agent, ultraviolet absorber, light stabilizer, heat stabilizer, oxidation inhibitor, plasticizer, leveling agent, flow regulator, defoamer, dispersant, fluorescent whitening An additive such as a agent, a storage stabilizer, or a silane coupling agent. However, the amount of such additives added is preferably in a range that does not inhibit the effect of the adhesive layer.

The adhesive layer is generally formed by dissolving or dispersing the above-mentioned adhesive, a cross-linking agent and/or a crosslinking accelerator, and other additives as needed, as a coating liquid, and The coating liquid is applied to a support and dried by a known coating method. Further, after coating and drying, when it is heated at 60 ° C to 130 ° C for 12 hours to 48 hours as needed, the storage modulus of the adhesive layer at 20 ° C can be adjusted to 4.5 × 10 ⁴ Pa or more.

The film for window adhesion of the present invention has a structure in which an adhesive layer is formed on one surface layer of the support, and the adhesive layer and the spacer are bonded to each other.

Examples of the substrate bonded to the spacer of the adhesive layer include polyester, polyethylene, polypropylene, paper, and the like. In the case where the spacer using such a substrate is not easily peeled off from the adhesive layer, it is preferred to provide a release treatment layer on the surface in contact with the adhesive layer. As a method of setting the mold release layer, It can be formed by mixing a resin having a good mold release property such as a fluorine-based or decane-based compound or a mold release agent such as a silicone oil in a resin, and dissolving or decomposing it in a solvent. The coating liquid is applied, and the coating liquid is applied and dried by a known coating method.

In the method for producing a film for window adhesion according to the present invention, an adhesive layer is formed on one surface of the support, and the surface on which the adhesive layer is formed is laminated with respect to the surface of the release treatment layer on which the spacer is formed. .

The opposite side of the surface on which the adhesive layer for the film for window adhesion of the present invention is laminated has a functional layer.

The functional layer is, for example, a cured film for the wound prevention film, and a photocatalyst layer containing a photocatalytic material for a self-cleaning film such as a photocatalyst film, and an ultraviolet absorbing layer for the ultraviolet absorbing film. In the case of the infrared absorbing film, there is an infrared absorbing layer, and if it is a decorative film, there is an image receiving layer, if it is a colored film, there is a colored layer, and if it is a blur preventing film, there is a defrosting layer. These layers can be used in accordance with the intended use.

A cured film as an example of a functional layer will be described. As the resin constituting the cured film, a curable resin such as a thermosetting resin having good transparency and an ionizing radiation curable resin is preferably used.

The thermosetting resin and the radiation-hardening resin are, for example, a polyester resin, an acrylic resin, or an amine amide group. Acid ethyl ester resin, polyester acrylate resin, polyurethane acrylate resin, epoxy acrylate resin, urethane resin, epoxy resin, polycarbonate resin, melamine A melamine resin, a phenol resin, an anthrone resin, a fluorine resin, or the like.

Further, a thermoplastic resin may be mixed in the curable resin. The hardness of the cured film can be adjusted by adding a thermoplastic resin.

In addition, examples of the thermoplastic resin include an acrylic resin, a polyester resin, a cellulose resin, an ethylene resin, a polyethylene resin, a polystyrene resin, and a polypropylene resin. It can be used alone or in combination from such resins.

In such a cured film, an ultraviolet absorber or an infrared ray absorbing agent or the like may be added, whereby an ultraviolet absorbing function or an infrared absorbing function may be provided in addition to the wound preventing function.

[Examples]

Hereinafter, the present invention will be further described by way of examples. In addition, "parts" and "%" are used as weight basis unless otherwise indicated.

1. Production of film for window bonding

As a support, one of a polyethylene terephthalate film (manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., product name: T600E) having a thickness of 50 μm On the surface, the adhesive layer coating liquid (Examples 1 to 2, Comparative Examples 1 to 2) at the position of Table 1 was applied by a die coater method, and dried at 100 ° C for 2 minutes. This formed an adhesive layer having a dry film thickness of 20 μm. Then, the surface on which the adhesive layer was formed was bonded to the release-treated surface of a spacer (manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., product name: MRF), and wound into a roll shape (diameter of the core: 152 mm, The diameter of the reel: 391 mm, the width of the reel: 960 mm), thereby producing the films for window adhesion of Examples 1 to 2 and Comparative Examples 1 to 2.

2. Evaluation

With respect to the film for window adhesion obtained in the examples and comparative examples of Table 1, the storage elastic modulus of the adhesive layer at 20 ° C was measured. Moreover, the occurrence of (2) the pits of the adhesive layer was evaluated. The results are shown in Table 2.

(1) Storage modulus of the adhesive layer at 20 ° C

Sample preparation and measurement of storage modulus were carried out as follows. The coating liquid of the adhesive layer was applied to a release-treated surface of a spacer (manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., product name: MRF) and dried to form an adhesive layer having a film thickness of 20 μm. Next, the adhesive layer was peeled off from the release-treated surface of the spacer, and 30 pieces of the adhesive after peeling were laminated, thereby forming a sheet sample having a thickness of 600 μm composed only of the adhesive layer. Further, the formed sheet sample was spun into a cylindrical shape having a diameter of 25 mm, whereby a test piece having a diameter of 25 mm and a thickness of 600 μm composed only of an adhesive layer was produced. Then, the test piece was twisted using a viscoelasticity measuring device (Phycica MCR301: Anton Paar) and the storage modulus of the adhesive layer at 20 ° C was measured by a shearing method at a frequency of 1 Hz.

(2) the generation of pits in the adhesive layer

The production of the pits of the adhesive layer was evaluated as follows. The film of 10 m in length on the side of the core of the film for the roll-on window is used, and the defect detector (manufactured by Nagase Industry Co., Ltd., model name: SCANTEC 7000) is used to detect each square. The number of potholes with a diameter of 1 mm or more.

3. Inspection

The following can be understood from Table 2.

The adhesive layer of the film for window adhesion of Examples 1 and 2 has a storage modulus of at least 4.5 × 10 ⁴ Pa at 20 ° C, and the amount of the pits of the adhesive layer is less than 1 / m ² and the appearance is good. . Further, by the adhesive layer having a storage modulus at 20 ° C of 2.0 × 10 ⁵ Pa or less, sufficient adhesion can be obtained.

On the other hand, in the adhesive layers of the film for film adhesion of Comparative Examples 1 and 2, the storage modulus at 20 ° C was 4.5 × 10 ⁴ Pa or less, and the number of pits generated in the adhesive layer was 1 / m ² or more. And the appearance is bad.

Claims (6)

A film for window adhesion, which is a film for window adhesion in which a support body, an adhesive layer and a spacer are sequentially provided, wherein the adhesive layer has a storage modulus of at least 4.5×10 ⁴ Pa at 20° C. The film for window adhesion according to the first aspect of the invention, wherein the adhesive layer has a storage modulus at 20 ° C of 2.0 × 10 ⁵ Pa or less. The film for window adhesion according to the first aspect of the invention, wherein the adhesive layer comprises an acrylic adhesive having a cross-linking property of a weight average molecular weight of 300,000 or more and 900,000 or less. The film for window adhesion according to claim 1 or 2, wherein the adhesive layer comprises: an adhesive; and 0.01 part by weight or more of a crosslinking agent based on 100 parts by weight of the adhesive; The crosslinking accelerator is 0.1 part by weight or more based on 100 parts by weight of the adhesive. The film for window adhesion according to claim 1, wherein the support has a functional layer on a surface opposite to a surface of the support having the adhesive layer. A film for window adhesion, which is a film for window adhesion according to claim 1 or 2, and which is a film for window bonding which is wound into a roll shape.