TW202102359A - Layered film - Google Patents

Abstract

The present invention pertains to a layered film that provides uniform adhesive force with respect to adherend having varying surface profiles, that can be used for a wide variety of uses, and that exhibits excellent adherend dependency. This layered film has a substrate and a resin layer A disposed at least on one-surface side of the substrate, and fulfills the conditions (a), (b) and (c). (a) The resin layer A side has a probe tack maximum value F of 0.2-2.5 g/mm2 at 23 DEG C. (b) When said layered film is subjected to a load removal test by means of nano-indentation at a maximum load of 1 mN at 26 DEG C, the ratio of residual displacement hp (in units of [mu]m) to maximum displacement hm (in units of [mu]m) at the resin layer A side is 0.50-0.90. (c) The resin layer A has a melting point Tm in a range of at least 50 DEG C.

Description

Laminated film

The present invention relates to a laminated film with excellent adherence dependence, which exhibits a certain adhesive force to various adherends with different surface shapes regardless of the shape of the adherend.

For products made of various materials such as synthetic resin, metal, glass, etc., in order to prevent damage or contamination during processing, transportation, and storage, a protective sheet or film may be attached to the surface for treatment. Generally, a surface protective film having an adhesive layer formed on a support base made of thermoplastic resin or paper is used, and the adhesive layer is bonded to the adherend for use.

In particular, in recent years, the spread of liquid crystal displays and touch panel elements is progressing, and these are composed of a large number of optical sheets or optical films containing synthetic resin. Since this optical member must minimize disadvantages such as optical strain, in order to prevent damage or contamination that may cause the disadvantages, a surface protective film is often used.

In terms of the characteristics of this surface protective film, it is required that it is not easy to peel off from the adherend under the influence of environmental changes such as temperature and humidity or less stress; when peeling off from the adherend, the adherend does not Residual adhesive and adhesive components; it can be easily peeled off after processing or use.

Among the above-mentioned optical components, for the adherends with uneven surfaces such as diffusers and ridges, the market has been flooded with various surface shapes, and there is a need for a solution that has different surface shapes. The adherend exhibits the same adhesive force and can be used universally as a surface protective film, that is, the development of a surface protective film with little dependence on the adherend is sought.

Regarding the surface protection film used for the adherend having the uneven shape on the surface, the techniques described in Patent Documents 1 and 2 can be cited. [Prior Technical Literature] [Patent Literature]

Patent Document 1 　 JP 2007-253435 A Patent Document 2 　 JP 2013-117019 A

[The problem to be solved by the invention]

However, none of the techniques described in Patent Document 1 or 2 described in Patent Document 1 or 2 of the aforementioned surface protective film for an adherend having uneven surfaces on the surface of the adherend fails to improve the poor adhesion caused by the difference in the uneven shape of the adherend, that is, the so-called quilt. Attachment dependency.

Therefore, the problem of the present invention is to solve the above-mentioned problems. That is, it is to provide a laminated film with excellent adherence dependence, which exhibits the same adhesive force to adherends with different surface shapes and can be used universally. [Means used to solve the problem]

The above-mentioned problems can be solved by the following.

A laminated film which has a base material and a resin layer A on at least one surface thereof, and satisfies the following (a), (b), and (c).

(a) The maximum probe viscosity F at 23°C on the resin layer A side is 0.2 g/mm ² or more and 2.5 g/mm ² or less.

(b) The ratio of the residual displacement hp (unit μm) to the maximum displacement hm (unit μm) (hp/hm) when the resin layer A side is subjected to a load-unloading test using nanoindentation at 26°C and a maximum load of 1mN is 0.50 or more and 0.90 or less.

(c) The resin layer A has a melting point Tm at 50°C or higher. [Effects of Invention]

According to the present invention, in view of the above-mentioned problems, it is possible to provide a laminated film which is excellent in adherence dependence and exhibits good adhesion characteristics to various adherends having different surface shapes.

[Form to implement invention]

Hereinafter, the embodiments of the present invention will be described. However, the present invention is not limited to the embodiments described below.

The present invention is a laminated film having a base material and a resin layer A on at least one side of the base material. Here, the so-called resin layer A is a layer containing at least a resin arranged on at least one surface side of the base material, and it is a layer satisfying the following (a), (b), and (c). Moreover, the resin layer A may contain a resin, and the type of resin is not particularly limited, but it is preferable to select the resin in the resin layer A so that the laminated film satisfies the following (a), (b), and (c). In addition, the preferable aspect of the resin contained in the resin layer A is mentioned later.

(a) The maximum probe viscosity F at 23°C on the resin layer A side is 0.2 g/mm ² or more and 2.5 g/mm ² or less.

(b) The ratio of the residual displacement hp (unit μm) to the maximum displacement hm (unit μm) (hp/hm) when the resin layer A side is subjected to a load-unloading test using nanoindentation at 26°C and a maximum load of 1mN is 0.50 or more and 0.90 or less.

(c) The resin layer A has a melting point Tm at 50°C or higher.

In the laminated film of the present invention, the maximum probe viscosity F at 23°C on the resin layer A side is 0.2 g/mm ² or more and 2.5 g/mm ² or less. The maximum probe viscosity F is more preferably 0.3 g/mm ² or more, and still more ^{preferably 0.4 g/mm 2} or more. In addition, the maximum probe viscosity F is more preferably 2.0 g/mm ² or less, and still more ^{preferably 1.5 g/mm 2} or less.

When the maximum probe viscosity F on the resin layer A side is less than 0.2 g/mm ² , when the laminate film of the present invention is used as a surface protective film, there may be cases where sufficient adhesive strength cannot be obtained. In addition, when the maximum value F of the probe viscosity on the resin layer A side is greater than 2.5g/mm ² , the adhesive force becomes too large, or especially the adhesive force to the adherend with small surface roughness. , And there are cases where the dependency of the attached body becomes too large.

The maximum probe viscosity F can be controlled by adjusting the material constituting the resin layer A described later or the flexibility, thickness, surface roughness, etc. of the resin layer A, for example, by making the resin layer A hard, The method of thinning the thickness of the resin layer A and the method of increasing the surface roughness of the resin layer A to reduce the maximum probe viscosity F and control it to 0.2g/mm ² or more and 2.5g/mm ² or less .

The laminated film of the present invention is the ratio of the residual displacement hp (unit μm) to the maximum displacement hm (unit μm) when the resin layer A side is subjected to a load-unloading test using nanoindentation at 26°C and a maximum load of 1 mN (hp /hm; hereinafter referred to as hp/hm) is 0.50 or more and 0.90 or less. The hp/hm is more preferably 0.60 or more, and still more preferably 0.70 or more. In addition, hp/hm is more preferably 0.80 or less.

When the hp/hm is less than 0.50, when the resin layer A side of the laminated film of the present invention is attached to the adherend, the resin layer A is not easy to follow the irregularities of the adherend, and the adhesive force becomes too small, or especially for the surface If the roughness is large, the adhesion of the attached body becomes smaller, and the dependency of the attached body may become too large. When hp/hm exceeds 0.90, the adhesive force may become too large. The hp/hm can be controlled by the material constituting the resin layer A described later.

The resin layer A in the laminated film of the present invention has a melting point Tm above 50°C, and more preferably has a melting point Tm above 100°C. In addition, when the resin layer A of the present invention has two or more melting points, the melting point on the high temperature side is taken as the melting point Tm of the resin layer A of the present invention. The upper limit of Tm is not particularly set, but it is substantially preferably 180°C or lower. When the Tm is less than 50°C or the resin layer A does not have a melting point, after the laminated film of the present invention is attached to the adherend, it is stored at a high temperature or over time, there is contact between the resin layer A and the adherend When the area increases and the adhesive force becomes too large. When Tm exceeds 180°C, when the resin layer A is molded by melt extrusion, the viscosity may become too high and productivity may deteriorate.

As a method for making the resin layer A have a Tm at 50° C. or higher, a method of adding a crystalline resin having a melting point of 50° C. or higher to the material constituting the resin layer A can be cited. That is, a method of making the resin layer A contain a crystalline resin having a melting point of 50° C. or higher can be cited. As a suitable crystalline resin contained in the resin layer A, for example, a crystalline olefin-based resin is preferable from the viewpoint of compatibility with other components used in the resin layer A or productivity. Specific examples of the olefin resin will be described later.

The maximum value F of the probe viscosity, the hp/hm measured by nanoindentation, and the melting point Tm of the resin layer A can be measured by the method described in the examples.

The storage elastic modulus G'(A) of the resin layer A of the present invention at 50°C and 1 Hz is preferably 1.5 MPa or more, more preferably 2.0 MPa or more, and still more preferably 2.5 MPa or more. The upper limit of the storage elastic modulus G'(A) is not particularly set, but it is preferably 30 MPa from the viewpoint of adhesion characteristics such as adhesion.

From the viewpoint of suppressing the increase in the contact area between the resin layer A and the adherend during storage at a high temperature or over time after the laminated film of the present invention is attached to the adherend, the increase in adhesive force is suppressed, It is preferable that the storage elastic modulus G'(A) of the resin layer A is 1.5 MPa or more. In addition, the storage elastic modulus G'(A) of the resin layer A can be measured by the method described in the examples.

In addition, the storage elastic modulus G'(A) of the resin layer A can be controlled by adjusting the material constituting the resin layer A. For example, as a method to increase the storage elastic modulus G'(A), the resin layer A Examples of the aspect containing the styrene-based elastomer include: a method of further increasing the molecular weight of the styrene-based elastomer; a method of using a crystalline resin having a melting point of 50°C or higher as the resin in the resin layer A ; A method of using an aromatic copolymer or an unhydrogenated product or a partially hydrogenated product of an aliphatic/aromatic copolymer as the resin in the resin layer A, etc.

The arithmetic average roughness Ra(A) of the resin layer A side of the present invention is preferably 0.20 μm or more, more preferably 0.30 μm or more, and particularly preferably 0.40 μm or more. In addition, the arithmetic average roughness Ra(A) is preferably 0.80 μm or less, more preferably 0.70 μm or less, and particularly preferably 0.60 μm or less. From reducing the dependency of the adherend, or after bonding the laminated film of the present invention to the adherend, the contact area between the resin layer A and the adherend is prevented from increasing when stored at high temperature or over time, From the viewpoint of controlling the increase in adhesive force, it is preferable to make the arithmetic average roughness Ra(A) 0.20 μm or more. In addition, the arithmetic average roughness Ra(A) of the resin layer A side can be measured by the method described in the examples. In addition, the arithmetic average roughness Ra(A) of the resin layer A side can be controlled by, for example, the material constituting the resin layer A, the material constituting the base material, and the thickness of the resin layer A, which will be described later.

As described above, the laminated film of the present invention has a base material and a resin layer A on at least one side of the base material. Here, the resin layer A refers to a layer having a finite thickness, and preferably has adhesiveness at room temperature.

The so-called resin layer A has adhesiveness, which means that a SUS304 plate with an arithmetic average roughness Ra of 0.2 μm and a ten-point average roughness Rz of 2.8 μm is used with a roller press (Special pressing made by Yasuda Seiki Seisakusho Co., Ltd.) Roller) After bonding the resin layer A side of the laminated film with an adhesion pressure of 0.35 MPa, when measuring the adhesion between the resin layer A and the SUS304 board, it has an adhesion of 1g/25mm or more. The adhesiveness of the resin layer A is more preferable if it is 2g/25mm or more, and it is even more preferable if it is 5g/25mm or more. The higher the adhesiveness of the resin layer A, the better, and there is no particular upper limit, but if it exceeds 1000g/25mm, it may become difficult to peel off after lamination and workability may decrease. Therefore, the upper limit is preferably about 1000g/25mm. .

The position of the resin layer A is not particularly limited as long as it is arranged on at least one side of the substrate, but it is preferably arranged on the outermost layer on at least one side of the laminated film of the present invention. By arranging the adhesive resin layer A on the outermost layer of the laminated film, the laminated film and the adherend can be bonded via the resin layer A. In addition, the resin layer A is not particularly limited as long as it is arranged on at least one side of the base material. Therefore, it does not matter if the base material and the resin layer A are directly connected to each other. For example, easy Follow other layers like layers.

As long as the effect of the present invention is not impaired, the resin layer A is not particularly limited, and may include acrylic, silicone, natural rubber, synthetic rubber, and other elastomers. Among these, from the viewpoint of recyclability, it is preferable to use a thermoplastic synthetic rubber-based adhesive, and among them, a styrene-based elastomer is more preferable.

In the present invention, the so-called styrene elastomer refers to a resin having a storage elastic modulus G'(25) of 10 MPa or less at 25°C and 1 Hz and containing at least a styrene component as a monomer component. As suitable styrene elastomer contained in the resin layer A, for example, styrene·butadiene copolymer (SBR), styrene·isoprene·styrene copolymer (SIS), styrene ･Styrene･conjugated diene copolymers such as butadiene･styrene copolymer (SBS) and their hydrogenated products (such as hydrogenated styrene･butadiene copolymer (HSBR) or styrene･ethylene butadiene copolymer Ene·styrene triblock copolymer (SEBS), styrene·ethylene butene diblock copolymer (SEB)), styrene·isobutylene copolymer (for example, styrene·isobutylene·styrene triblock copolymer (SIBS) or styrene/isobutylene diblock copolymer (SIB), or a mixture of these). Among the foregoing, styrene and conjugated diene copolymers such as styrene, butadiene, and styrene copolymer (SBS), and hydrogenated products thereof, and styrene and isobutylene copolymers are preferably used. In addition, only one type of styrene-based elastomer may be used, or two or more types may be used in combination.

The content of the styrene-based elastomer suitably contained in the resin layer A in the resin layer A is preferably 40% by mass or more, and more preferably 50% by mass or more when the entire resin layer A is 100% by mass. In addition, the content of the styrene-based elastomer in the resin layer A is preferably 95% by mass or less, more preferably 90% by mass or less, and still more preferably 75% by mass or less. By setting the content of the styrene-based elastomer in the resin layer A within the above-mentioned preferred range, when the laminated film of the present invention is used as an adhesive film, good adhesive properties can be obtained.

The melt flow rate (MFR, measured at 230°C and 2.16 kg) of the styrene elastomer suitable for inclusion in the resin layer A is preferably 3 g/10 min or more, more preferably 7 g/min or more, More preferably, it is 10 g/10 minutes or more. In addition, the MFR of the styrene-based elastomer is preferably 50 g/10 minutes or less, more preferably 30 g/10 minutes or less, and still more preferably 20 g/10 minutes or less. By setting the MFR of the styrene elastomer suitable for the resin layer A within the above-mentioned range, the productivity is excellent, or the laminated film of the present invention exhibits good adhesive properties when used as a surface protective film.

In addition, the content of the styrene component in the styrene-based elastomer suitable for the resin layer A, when the entire styrene-based elastomer is 100% by mass, is preferably 5 mass% or more, more preferably 8 mass% or more . In addition, the content of the styrene component in the styrene-based elastomer is preferably 55% by mass or less, and more preferably 40% by mass or less. When the content of the styrene component in the styrene elastomer is within the above range, when the laminated film of the present invention is bonded to the adherend, it exhibits good adhesion, or suppresses adhesive residue, etc. Good adhesion properties.

The resin layer A of the present invention preferably contains an olefin resin having a melt flow rate (MFR, measured at 230°C and 2.16 kg) of 0.01 g/10 min or more and 1.5 g/10 min or less. Since the resin layer A contains an olefin resin with an MFR of 0.01 g/10 min or more and 1.5 g/10 min or less, the elastomer of the matrix component of the resin layer A forms a structure in which the olefin resin is dispersed as a domain component , And the arithmetic average roughness Ra(A) of the resin layer A side can be better controlled, and the adherence dependency can be reduced when the laminated film of the present invention is used as an adhesive film. The MFR of the olefin resin in the resin layer A is more preferably 0.1 g/10 minutes or more, and still more preferably 0.2 g/10 minutes or more. In addition, the MFR of the olefin-based resin is more preferably 1.3 g/10 minutes or less, and still more preferably 1.0 g/10 minutes or less. When the MFR is less than 0.01 g/10 minutes, the olefin-based resin may aggregate due to poor dispersion of the domain components and become fish eyes (FE, Fish Eye). On the other hand, when the MFR exceeds 1.5 g/10 minutes, the dispersibility of the domain components becomes high, and it may be difficult to adjust the arithmetic average roughness Ra(A) of the resin layer A within the range specified in the present application. Examples of olefin resins suitable for inclusion in the resin layer A include low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, ultra-high molecular weight polyethylene, low crystallinity or Amorphous ethylene･α-olefin copolymer, crystalline polypropylene, low crystalline polypropylene, amorphous polypropylene, propylene･α-olefin copolymer, propylene･ethylene･α-olefin copolymer, polybutene, 4-Methyl-1-pentene･α-olefin copolymer, ethylene･(meth)ethyl acrylate copolymer, ethylene･methyl(meth)acrylate copolymer, ethylene･(meth)acrylate n-butyl ester Copolymers and ethylene/vinyl acetate copolymers. Among the above, crystalline polypropylene, low-crystalline polypropylene, amorphous polypropylene, propylene･α-olefin copolymer, propylene･ethylene･α-olefin are preferably used. Polypropylene resins such as copolymers. These olefin resins may be used alone or in combination. In addition, the α-olefin is not particularly limited as long as it can be copolymerized with ethylene, propylene, and 4-methyl-1-pentene. Examples thereof include ethylene, propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-pentene, 1-heptene. Among these, the olefin-based resin in the resin layer A is particularly preferably crystalline polypropylene. In addition, the olefin-based resin referred to here may be one that conforms to the olefin-based elastomer described later. On the other hand, the olefin-based resin referred to here does not contain the above-mentioned styrene-based elastomer.

The content of the olefin-based resin in the resin layer A is, when the entire resin layer A is 100% by mass, it is preferably 5 mass% or more, more preferably 7 mass% or more, and still more preferably 10 mass% or more. In addition, the content of the olefin-based resin in the resin layer A is preferably 35% by mass or less, more preferably 30% by mass or less, and particularly preferably 25% by mass or less. By keeping the content of the olefin resin in the resin layer A within the above range, it is possible to better adjust the arithmetic average roughness Ra(A) of the resin layer A side while ensuring good productivity. When the laminated film of the invention is used as an adhesive film, the adherence becomes less dependent, and the adhesive properties are improved.

The resin layer A of the present invention preferably contains an olefin-based elastomer. In addition, the olefin-based elastomer in the present invention refers to an olefin-based resin having a storage elastic modulus G'(25) of 10 MPa or less at 25°C and 1 Hz, and/or a tanδ(25) at 25°C and 1 Hz Olefin resin of 0.5 or more. That is, the olefin-based elastic system has a certain storage elastic modulus G'(25) or a certain tanδ (25) olefin-based resin, so those that conform to the olefin-based elastomer also conform to the aforementioned olefin-based resin. In addition, as described above, the olefin-based resin does not contain a styrene-based elastomer, and therefore, a part of the olefin-based elastomer of the olefin-based resin does not contain the above-mentioned styrene-based elastomer.

The resin layer A of the present invention preferably contains an olefin-based elastomer, and among the aforementioned olefin-based elastomers, it is more preferable to include an olefin-based elastomer having a tanδ (25) of 0.5 or more at 25°C and 1 Hz. The tanδ(25) of the olefin-based elastomer is more preferably 1.0 or more, particularly preferably 1.5 or more. By including the above-mentioned olefin-based elastomer in the resin layer A of the present invention, the maximum value F of the probe viscosity and the hp/hm obtained by nanoindentation on the resin layer A side can be better controlled.

Examples of such olefin-based elastomers suitable for the resin layer A include amorphous polypropylene, low-crystalline polypropylene, amorphous polybutene, 4-methyl-1-pentene and α-olefin copolymer However, it is preferable to use amorphous polypropylene or 4-methyl-1-pentene･α-olefin copolymer.

The content of the olefin-based elastomer in the resin layer A of the present invention, when the resin layer A is 100% by mass, is preferably 3% by mass or more, more preferably 5% by mass or more. In addition, the content of the olefin-based elastomer in the resin layer A is preferably 30% by mass or less, and more preferably 20% by mass. When the content of the olefin-based elastomer in the resin layer A exceeds 30% by mass, the adhesion to the adherend may become too low.

From the viewpoint of improving the adhesion to the adherend, the resin layer A of the present invention preferably contains a tackifier. As the tackifier, those conventionally used in this application can be used. For example, petroleum resins such as aliphatic copolymers, aromatic copolymers, aliphatic and aromatic copolymers, or alicyclic copolymers can be used. Terpene-based resins, terpene-phenol-based resins, rosin-based resins, alkylphenol-based resins, xylene-based resins, or hydrogenated products thereof are generally used in this application. The content of the tackifier is preferably 5% by mass or more, and more preferably 10% by mass or more when the entire resin layer A is 100% by mass. In addition, the content of the tackifier is preferably 40% by mass or less, and more preferably 30% by mass or less when the entire resin layer A is 100% by mass.

Among the above-mentioned tackifiers, the resin layer A of the present invention more preferably contains at least an aromatic copolymer or an aliphatic/aromatic copolymer. Furthermore, the aforementioned aromatic copolymer or aliphatic/aromatic copolymer is preferably an unhydrogenated or partially hydrogenated aromatic copolymer or an unhydrogenated or partially hydrogenated aliphatic/aromatic copolymer. In addition, the partial hydrogenation here means that the hydrogenation rate is 1% by mass or more and less than 90% by mass, and the so-called non-hydrogenation means that the hydrogenation rate is 0% by mass or more and less than 1% by mass. In addition, the hydrogenation rate of the aforementioned partially hydrogenated aromatic copolymer or partially hydrogenated aliphatic/aromatic copolymer is more preferably less than 80% by mass, still more preferably less than 70% by mass, and particularly preferably less than 50% by mass . When the resin layer A contains the aforementioned unhydrogenated or partially hydrogenated aromatic copolymer or unhydrogenated or partially hydrogenated aliphatic/aromatic copolymer, the value of the maximum probe viscosity F can be better controlled , So that the dependence of the attached body becomes smaller. In addition, unhydrogenated or partially hydrogenated aromatic copolymers or unhydrogenated or partially hydrogenated aliphatic/aromatic copolymers, especially those with a softening point of 80°C or higher are more suitable. That is, the resin layer A of the laminated film of the present invention particularly preferably contains an unhydrogenated or partially hydrogenated aromatic copolymer and/or an unhydrogenated or partially hydrogenated aliphatic/aromatic copolymer with a softening point of 80°C or higher . In addition, the hydrogenation rate can be ^{calculated by nuclear magnetic resonance spectroscopy (1} H-NMR spectroscopy) measurement.

Furthermore, in addition to the above, other components such as lubricants and other additives may be appropriately added to the resin layer A of the present invention within a range that does not impair the purpose of the present invention.

As a lubricant for the resin layer A of the present invention, in order to prevent the wafers from adhering and agglomerating when the styrene-based elastomer is chipped, the adhesion is adjusted by adhering to the surface of the wafer or depositing on the surface of the resin layer A , Or added in order to obtain good extrudability when the resin layer A is melt-extruded. Therefore, for example, fatty acid metal salts such as calcium stearate or magnesium levulinate or ethylene distearate are added. , Fatty acid amides such as hexamethylene bisstearate, or waxes such as polyethylene wax, polypropylene wax, and paraffin wax. When the entire resin layer A is 100% by mass, the content of the lubricant is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 3% by mass or less.

In addition, examples of the above-mentioned other additives include nucleating agents, antioxidants, heat-resistance imparting agents, weathering agents, antistatic agents, and the like. These additives may be used alone or in combination. When the entire resin layer A is 100% by mass, the total content is preferably 3% by mass or less, more preferably 2% by mass or less.

In addition, for the purpose of controlling the arithmetic average roughness Ra(A) of the resin layer A, the resin layer A of the present invention may contain particles. As the particles in the resin layer A, for example, inorganic particles, organic particles, etc. can be used, and organic particles that are less likely to damage the adherend when they are bonded to the adherend are preferred. Examples of organic particles include acrylic resin particles, styrene resin particles, polyolefin resin particles, polyester resin particles, polyurethane resin particles, polycarbonate resin particles, and polyamide resin particles. -Based resin particles, silicone-based resin particles, fluorine-based resin particles, or copolymerized resin particles of two or more monomers used in the synthesis of the above-mentioned resins, etc., which may be used alone or in combination.

The average particle diameter of the particles in the resin layer A, from the viewpoint of better controlling the arithmetic average roughness Ra(A) and adhesion characteristics of the resin layer A, is preferably 0.1 μm or more, more preferably 1.0 μm or more, More preferably, it is 2.0 μm or more. In addition, the average particle diameter of the particles in the resin layer A is preferably 20.0 μm or less, more preferably 15.0 μm or less, and particularly preferably 10.0 μm or less.

The thickness of the resin layer A of the present invention is preferably 1.0 μm or more, more preferably 2.0 μm or more, from the viewpoint of ensuring adhesion to the adherend. In addition, the thickness of the resin layer A is preferably 6.0 μm or less from the viewpoint of reducing the dependency of the adherend or suppressing the increase in adhesion due to time or heating after being attached to the adherend. It is more preferably 5.0 μm or less, and still more preferably 3.0 μm or less.

The laminated film of the present invention has a substrate. The so-called base material here refers to a layer with a finite thickness. The material of the substrate is not particularly limited. For example, an olefin-based resin or an ester-based resin can be used. Among them, from the viewpoint of productivity or processability, an olefin-based resin is preferably used as a main component. The main component mentioned here refers to the highest mass% (the highest content) of all components constituting the base material.

As for the olefin resin contained as the main component in the base material, for example, low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, low crystalline or amorphous Ethylene･α-olefin copolymer, polypropylene, propylene･α-olefin copolymer, propylene･ethylene･α-olefin copolymer, ethylene･(meth)ethyl acrylate copolymer, ethylene･(meth)methyl acrylate Among these copolymers, ethylene and n-butyl (meth)acrylate copolymers, and ethylene and vinyl acetate copolymers, polypropylene is particularly suitable. In addition, these may be used alone or in combination. In addition, the α-olefin is not particularly limited as long as it can be copolymerized with propylene or ethylene, and examples include 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene. , 1-pentene, 1-heptene. In addition, the olefin-based resin referred to here may be one that conforms to the above-mentioned olefin-based elastomer. On the other hand, the olefin-based resin referred to here does not contain the above-mentioned styrene-based elastomer.

Among the above-mentioned olefin-based resins, in order to control the arithmetic average roughness Ra(A) of the resin layer A within a desired range, it is preferable that the base material has a structure in which the main component of the matrix resin is dispersed. In order to form the above-mentioned structure, for example, the main component of the base material is polypropylene and the method of adding incompatible polyolefins to it, or the use of commercially available block polypropylene, the so-called block copolymer or Impact copolymer method.

The melt flow rate (MFR, measured under the conditions of 230°C and 2.16 kg) of the resin used for the substrate of the present invention is relatively high from the standpoint of productivity or the stability during lamination with adjacent layers. It is preferably 0.5 g/10 minutes or more, more preferably 1 g/10 minutes or more, and still more preferably 2 g/10 minutes or more. In addition, the MFR of the resin used for the base material is preferably 30 g/10 minutes or less, more preferably 25 g/10 minutes or less, and still more preferably 20 g/10 minutes or less from the same viewpoint as described above.

The substrate of the present invention preferably contains a styrene-based elastomer. That is, the base material of the laminated film of the present invention particularly preferably contains an olefin-based resin and a styrene-based elastomer. By including the styrene-based elastomer in the base material, when the styrene-based elastomer is used in the resin layer A, the affinity between the base material and the resin layer A is improved, and the interface between the base material and the resin layer A can be improved Follow force. When the entire substrate is 100% by mass, the content of the styrene-based elastomer in the substrate is preferably 1% by mass or more, and more preferably 2% by mass or more. In addition, the content of the styrene-based elastomer in the substrate is preferably 20% by mass or less, and more preferably 10% by mass or less. In addition, as the styrene-based elastomer used for the substrate of the present invention, conventional ones can be used, for example, the same as the above-mentioned styrene-based elastomer suitable for the resin layer A can be used.

As a method of containing the styrene-based elastomer in the base material of the present invention, for example, the present laminated film containing the styrene-based elastomer in the resin layer A is recovered, and the recycled raw material is added to the base material. From the viewpoint of resin recycling or production cost reduction, using this method is a better method.

Furthermore, in the substrate of the present invention, various kinds of nucleating agents, lubricants, antioxidants, weathering agents, antistatic agents, pigments, etc. may be appropriately added within the range that does not impair the characteristics of the laminated film of the present invention. additive. In addition, the base material of the present invention may further contain an easy-to-adhesive component for stacking well with the resin layer A of the present invention.

The thickness of the substrate constituting the laminated film of the present invention can be appropriately adjusted according to the required characteristics of the laminated film, but from the viewpoint of transportability or productivity during manufacture or use, it is preferably 5 μm or more, more preferably 10 μm or more, more preferably 20 μm or more. In addition, the thickness of the substrate constituting the laminated film is preferably 200 μm or less, more preferably 100 μm or less, and still more preferably 80 μm or less from the same viewpoint as described above.

The laminated film of the present invention preferably has the resin layer B on the side of the substrate opposite to the surface having the resin layer A. The resin layer B here is a layer disposed on the side of the substrate opposite to the side having the resin layer A, and it is a layer containing at least a resin, and is a layer different from the resin layer A. That is, the resin layer B is a layer that does not satisfy at least one of the aforementioned (a), (b), and (c). The resin layer B preferably has mold releasability, and refers to a layer with a finite thickness.

The position of the resin layer B is not particularly limited as long as it is arranged on the side of the surface opposite to the surface having the resin layer A of the base material. Therefore, it does not matter if the base material and the resin layer B are directly connected to each other. Between the material and the resin layer B, another layer is provided.

The resin used for the resin layer B of the laminated film of the present invention includes, for example, an olefin resin or an ester resin. Among them, from the viewpoint of productivity or processability, an olefin resin is preferably used as a main component. The main component mentioned here refers to the component with the highest mass% (the one with the highest content) among the components constituting the resin layer B of the laminated film.

Examples of olefin-based resins suitable for resin layer B include low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, low-crystalline or amorphous ethylene and α-olefin copolymer Polypropylene, propylene･α-olefin copolymer, propylene･ethylene･α-olefin copolymer, ethylene･(meth)ethyl acrylate copolymer, ethylene･(meth)methyl acrylate copolymer, ethylene･( Meth) butyl acrylate copolymer, ethylene·vinyl acetate copolymer. These can be used alone or in combination. In addition, the α-olefin is not particularly limited as long as it can be copolymerized with propylene or ethylene, and examples include 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene. , 1-pentene, 1-heptene. Among the above-mentioned polyolefin resins, from the viewpoint of imparting mold releasability by controlling the roughness of the resin layer B, it is preferable that the main component constituting the resin layer B is polypropylene, and the non-phase is added thereto. The method of dissolving polyolefin, or using commercially available block polypropylene, that is, the so-called block copolymer or impact copolymer. As for the olefin resin in the resin layer B, only 1 type may be used, and 2 or more types may be used together. In addition, the olefin-based resin referred to here may be one that conforms to the above-mentioned olefin-based elastomer. On the other hand, the olefin-based resin referred to here does not contain the above-mentioned styrene-based elastomer.

The melt flow rate (MFR, measured under the conditions of 230°C and 2.16 kg) of the resin used in the resin layer B of the present invention, from the standpoint of productivity or the stability of the adjacent layer when laminated, etc., It is preferably 0.5 g/10 minutes or more, more preferably 1 g/10 minutes or more, and still more preferably 2 g/10 minutes or more. In addition, the MFR of the resin used in the resin layer B is preferably 30 g/10 minutes or less, more preferably 25 g/10 minutes or less, and still more preferably 20 g/10 minutes or less from the same viewpoint as described above.

As the material constituting the resin layer B, a slip agent such as fluorine resin, silicone resin, fatty acid metal salt, fatty acid amide, inorganic particles, and organic particles may be further added as a release agent.

Since the laminated film of the present invention has the resin layer B, the laminated film can be wound in a good winding state when the laminated film is wound into a roll in the manufacturing step or the cutting step, or the film can be wound from the roll during cutting or use. The force at the time of unwinding does not become too large, and the unwinding can be performed well. In addition, as another method of imparting mold releasability to the surface opposite to the resin layer A in the laminated film of the present invention, a method of adding the above-mentioned slip agent and the like to the substrate without providing the resin layer B can also be cited, but from production From the viewpoint of performance, cost, and mold release effect, the method of providing the resin layer B is more preferable.

The arithmetic average roughness Ra(B) of the resin layer B of the laminated film of the present invention is preferably 0.1 μm or more, more preferably 0.2 μm or more. The upper limit of the arithmetic average roughness Ra(B) of the resin layer B is not specifically set, but if the thickness is more than 2 μm, the decrease in thickness accuracy or strength may become a problem.

The laminated film of the present invention has a base material and a resin layer A on at least one surface thereof, but as described above, it is preferable to have a resin layer B on the side opposite to the side having the resin layer A. In addition, in the range that does not impair the effects of the present invention, the laminated film of the present invention may be provided with other layers other than the base material, resin layer A, and resin layer B, but it is preferable that the resin layer A and the resin layer B are located separately The outermost surface of the laminated film. In addition, the thickness of the laminated film of the present invention is preferably 10 μm or more, more preferably 25 μm or more, from the viewpoint of transportability or productivity during manufacture or use. In addition, the thickness of the laminated film is preferably 250 μm or less, and more preferably 100 μm or less from the same viewpoint as described above.

Next, the manufacturing method of the laminated film of this invention is demonstrated.

The manufacturing method of the laminated film of the present invention is not particularly limited. For example, in the case of a three-layer laminated structure having a resin layer A, a base material, and a resin layer B in this order, the resin composition constituting each layer is extruded individually The machine performs melt extrusion to integrate the layers in the nozzle, which is the so-called co-extrusion method; or the above resin layer A, base material, and resin layer B are separately melt-extruded, and then laminated by the lamination method However, from the viewpoint of productivity, it is preferable to manufacture by a co-extrusion method. The materials constituting each layer may be those obtained by mixing each component with a Henschel mixer or the like, or those obtained by kneading all or part of the materials of each layer in advance. Regarding the co-extrusion method, conventional methods such as inflation method and T-die method can be used, but from the viewpoint of excellent thickness accuracy or surface shape control, the hot-melt co-extrusion method using T-die method is particularly preferred .

In the case of manufacturing by a co-extrusion method, the constituent components of the resin layer A, the base material, and the resin layer B are extruded from each melt extruder. At this time, the extrusion temperature of the resin layer A is preferably 250°C or lower, more preferably 230°C or lower, and still more preferably 220°C or lower. When the extrusion temperature of the resin layer A exceeds 250°C, there are cases where the arithmetic average roughness Ra(A) of the resin layer A side cannot be controlled within the desired range. The lower limit is not particularly set, but at a resin temperature of less than 180°C, the melt viscosity is too high, so productivity may decrease.

The resin layer A, the base material, and the resin layer B are laminated and integrated inside the T-shaped mold and are co-extruded. Then, it is cooled and solidified with a metal cooling roll, formed into a film shape, and wound into a roll shape, thereby obtaining a laminated film.

The laminated film of the present invention can be used as a surface protective film for the production, processing, and transportation of synthetic resin plates, metal plates, glass plates, etc., for scratch prevention and pollution prevention. It is preferably used as a diffuser or a sheet, etc. It is used as a surface protective film for optics with uneven surface. In addition, it can be suitably used as a surface protection film for bonding to an adherend having a surface with a surface connected to the resin layer A with arithmetic average roughness Ra of 0.1 μm or more and 2 μm or less. [Example]

Hereinafter, the present invention will be described in further detail based on examples, but the present invention is not limited to these examples. In addition, the measurement and evaluation of various physical properties were performed by the following methods.

(1) Surface roughness The arithmetic average roughness Ra(A) of the resin layer A side, the arithmetic average roughness Ra(B) of the resin layer B, the arithmetic average roughness Ra(X) of the attached body X, and the ten-point average roughness of the attached body X Rz(X), the arithmetic average roughness Ra(Y) of the attached body Y, and the ten-point average roughness Rz(Y) of the attached body Y are measured using high-precision fine shape measurement made by Kosaka Research Institute Co., Ltd. (SURFCORDER ET4000A), based on JIS B0601-1994, for laminated films and adherends in the width direction of 2mm and the longitudinal direction of 0.2mm, the scanning direction is regarded as the width direction, and the longitudinal direction is 10μm apart. 21 For the second measurement, perform a three-dimensional analysis and evaluation. In addition, a diamond needle with a tip radius of 2.0 μm was used for measurement with a measuring force of 100 μN and a cut-off value of 0.8 mm.

(2) Maximum probe viscosity Using the Tackiness Tester TAC1000 manufactured by RHESCA, a 5mm diameter SUS probe was contacted from the resin layer A side of the laminated film under the following conditions, and the maximum load at the time of peeling was read, and the load per unit area was calculated by dividing by the area of the probe. The test was carried out 5 times for each type of laminated film, and the average value was taken as the maximum probe viscosity F on the resin layer A side of the laminated film. Temperature: 23℃ Hold time after sample setting: 5 minutes Contact speed, peeling speed: 2mm/sec Contact time: 2 seconds.

(3) The ratio of the remaining displacement hp to the maximum displacement hm measured by nanoindentation hp/hm Using the Nano Indentation Tester ENT-2100 manufactured by ELIONIX, under the following conditions, using a Berkovich indenter (tip triangular pyramid), under the following conditions for each type of laminated film, from the thickness of the laminated film The A side of the resin layer was subjected to an indentation test using load-unloading test 10 times. Calculate hp/hm from the maximum displacement hm (unit μm) and the remaining displacement hp (unit μm), and the average value of hp/hm obtained from 10 measurements is taken as the hp/hm on the resin layer A side of the laminated film Value. Temperature: 26℃ Maximum load: 1mN Load speed･Unload speed: 0.1mN/s Load-load at the beginning of the unloading test: 0mN Holding time under maximum load: 1 second Surface detection method: tilt method Surface detection threshold coefficient: 1.5 Spring correction: real-time spring correction.

(4) Melting point Using a stainless steel spatula, only the resin layer A was scraped from the laminated films shown in the examples and comparative examples, and 5 mg was weighed as a sample for measurement. After that, the sample was collected on an aluminum pan, and a differential scanning calorimeter (RDC220 manufactured by Seiko Instruments Inc.) was used to increase the temperature from room temperature to 250°C at a rate of 20°C/min in a nitrogen atmosphere, and then hold it at 250°C for 5 minutes. Cool down to 20°C at 20°C/min. In addition, the temperature was raised again to 250° C. at 40° C./minute thereafter, and the temperature of the endothermic peak obtained at this time was used as the melting point Tm of the resin layer A.

(5) Storage elastic modulus Using a spatula made of stainless steel, only the resin layer A was scraped from the laminated films shown in the examples and comparative examples, and the resin layer A was melt-molded to a thickness of 1 mm, which was used as a sample. The measurement system uses a rheometer AR2000ex manufactured by TA INSTRUMENTS. After the temperature is lowered from 200°C to -20°C at a rate of 20°C/min, the temperature is increased from -20°C to 100°C at a rate of 10°C/min while the frequency is 1Hz and strain 0.01% makes it undergo dynamic shear deformation, and the storage elastic modulus G'at 50° C. during the heating process is taken as the storage elastic modulus G'(A) of the resin layer A.

In addition, pellets of olefin resin and styrene elastomer were melt-molded to a thickness of 1 mm, and the storage elastic modulus G'at 25° C. during the temperature rise process measured in the same manner as above was taken as G'(25) .

(6) Thickness Using the slicing method, an ultra-thin section having a width of 5 mm in a cross section in the width direction-thickness direction of the laminated film was produced, and the cross section was plated with platinum to prepare an observation sample. Next, using a field emission scanning electron microscope (S-4800) manufactured by Hitachi, Ltd., the cross-section of the laminated film was observed at an acceleration voltage of 2.5kV, and the thickness of the substrate, resin layer A, and resin layer B and the laminated layer were measured from anywhere in the observed image. The total thickness of the film. Regarding the observation magnification, when measuring the thickness of the resin layers A and B, it was set to 5,000 times, and when measuring the thickness of the base material and the laminated film, it was set to 1,000 times. In addition, the same measurement was performed 10 times in total, and the average value was used as the thickness of each of the substrate, the resin layers A and B, and the total thickness of the laminated film.

(7)tanδ(25) After the olefin-based resin pellets were melt-molded to a thickness of 1mm, the measurement system was performed using a rheometer AR2000ex manufactured by TA INSTRUMENTS, and the temperature was lowered from 200°C to -20°C at a rate of 20°C/min, while at a rate of 10°C/min The temperature was raised from 20°C to 40°C, while dynamic shear deformation was performed at a frequency of 1 Hz and a strain of 0.01%, and the tanδ at 25°C during the heating process was taken as tanδ(25).

(8) Softening point The softening point is measured according to the ring and ball method specified in JIS K-2207:2006.

(9) Melt flow rate (MFR) The melt flow rate (MFR) was measured using a melt index meter manufactured by Toyo Seiki Seisakusho Co., Ltd. in accordance with JIS K7210-1997 at a temperature of 230°C and a load of 2.16 kg/cm ² . The unit is g/10 minutes.

(10) The bonding of the laminated film to the attached body The resin layer A side of the laminated films of the examples and comparative examples that were stored and adjusted for 24 hours at a temperature of 23°C and a relative humidity of 50% using a roll press (a special pressure roller made by Yasuda Seiki Seisakusho Co., Ltd.) , And the attached body is attached with an adhesive pressure of 0.35MPa. The attached system uses two types of rough surfaces (attached body X, attached body Y) formed on the opposite side of the acrylic sheet. In addition, the arithmetic average roughness Ra(X) of the attached body X is 0.2μm, the ten-point average roughness Rz(X) is 2.2μm, and the arithmetic average roughness Ra(Y) of the attached body Y is 0.4μm. The point average roughness Rz(Y) is 3.2.

(11) Adhesion After storing the bonded sample obtained in (10) above for 24 hours in a room at 23°C, a tensile tester (ORIENTEC Co., Ltd. "TENSILON" universal testing machine) was used at a tensile speed of 300 mm/min and a peeling angle of 180 ° Carry out adhesion measurement. For one type of laminated film, the adhesion of the adherend X and the adherend Y was measured. In addition, the adhesive force ratio of the adherend X and the adherend Y is calculated according to the following formula (P1). Adhesive force ratio = Adhesive force with the attached body X/Adhesive force with the attached body Y･･･Equation (P1) The adhesion of the adherend X and the adherend Y was evaluated using the following three-stage standards. ◎: 5g/25mm or more and less than 15g/25mm ○: 3g/25mm or more and less than 5g/25mm, or 15g/25mm or more and less than 25g/25mm ×: less than 3g/25mm, or more than 25g/25mm In addition, the closer the adhesion ratio of the adherend X to the adherend Y calculated according to the formula (P1) is 1, the more excellent the adherence dependence of the laminated film is, and the evaluation was performed in the following three stages. ◎: 0.5 or more and less than 2.0 ○: 0.3 or more and less than 0.5, or 2.0 or more and less than 4.0 ×: Less than 0.3, or 4.0 or more.

(12) Adhesion after heating and storage Among the bonded samples obtained in (10) above, the samples bonded to the adherend X were stored in a hot air dryer at 50°C for 100 hours, and then stored under the conditions of a temperature of 23°C and a relative humidity of 50% After 1 time, using a tensile tester (Orientec Co., Ltd. "TENSILON" universal testing machine), the adhesive force was measured at a tensile speed of 300 mm/min and a peeling angle of 180°. According to the following formula (P2), the ratio of the adhesion strength after heating and storage at 50°C and the adhesion strength after storage at 23°C of the adherend X calculated in (11) above was calculated as the adhesion enhancement magnification. Adhesion enhancement ratio = Adhesive strength after storage at 50°C/Adhesive strength after storage at 23°C･･･Formula (P2) The closer the adhesion enhancement magnification calculated from the formula (P2) is to 1, the better the stability during heat storage of the laminated film, and the evaluation was performed in the following three stages. ◎: 0.5 or more and less than 1.6 ○: 0.3 or more and less than 0.5, or 1.6 or more and less than 2.5 ×: Less than 0.3, or 2.5 or more.

(Example 1) The constituent resins of each layer are prepared as follows.

Substrate: 97% by mass of commercially available block polypropylene with MFR of 8.5g/10min, 3% by mass of styrene elastomer (SEBS manufactured by Asahi Kasei, "TAFTEC" H1052, MFR 13g/10min, G '(25)≦10MPa).

Resin layer A: 70% by mass styrene elastomer (SEBS manufactured by Asahi Kasei, "TAFTEC" H1052, MFR 13g/10 min, G'(25)≦10MPa), 15% by mass high melt tension polypropylene (Japan "WAYMAX" MFX8 manufactured by Polypropylene Corporation, MFR 1g/10min, G'(25)>10MPa, tanδ(25)<0.5), 15% by mass tackifier (manufactured by Arakawa Chemical Industry, "Archon" M115, aromatic It is a copolymer, softening point 115°C, hydrogenation rate <90%), using a biaxial extruder kneading and wafering.

Resin layer B: 95% by mass of the same as the commercially available block polypropylene used for the substrate, and 5% by mass of a commercially available silicone-based surface modifier as a release agent.

Next, the constituent resins of each layer were put into each extruder of the T-mold composite film forming machine with 3 extruders, and each was adjusted so that the resin layer A was 3.5 μm, the base material was 30 μm, and the resin layer B was 5 μm. The output of the extruder is laminated in this order, extruded from a composite T-die at an extrusion temperature of 200°C, cast on a roll whose surface temperature is controlled at 40°C, and wound into a film to obtain Laminated film.

After that, the obtained laminated film was evaluated by the above-mentioned method. In addition, the thickness of the base material was 30 μm, the thickness of the resin layer B was 5 μm, and the arithmetic average roughness Ra(B) of the resin layer B was 0.20 μm.

(Example 2) The composition constituting the resin layer A is set to: 70% by mass of styrene elastomer ("TAFTEC" H1052), 15% by mass of high melt tension polypropylene ("WAYMAX" MFX8), and 5 mass% of tackifier " Archon" M115, 10% by mass tackifier "FTR" 8100 (manufactured by Mitsui Chemicals, aromatic copolymer, softening point 100°C, hydrogenation rate <90%), except that the same as in Example 1 Way to obtain a laminated film.

(Example 3) The composition constituting the resin layer A is set to: 60% by mass of styrene elastomer ("TAFTEC" H1052), 15% by mass of high melt tension polypropylene ("WAYMAX" MFX8), and 5 mass% of tackifier "Archon" M115, 10% by mass tackifier "FTR" 8100, 10% by mass olefin elastomer (Mitsui Chemicals "ABSORTOMER" EP-1001, MFR 10g/10min, G'(25) 33MPa, tanδ (25) 1.9) Except for this, in the same manner as in Example 1, a laminated film was obtained.

(Example 4) The composition constituting the resin layer A is set to: 80% by mass styrene elastomer ("TAFTEC" H1052), 10% by mass high melt tension polypropylene ("WAYMAX" MFX8), and 10% by mass tackifier Except for "Archon" M115, a laminated film was obtained in the same manner as in Example 1.

(Example 5) The composition constituting the resin layer A is set to: 70% by mass of styrene elastomer ("TAFTEC" H1052), 10% by mass of high melt tension polypropylene ("WAYMAX" MFX8), and 10% by mass of tackifier Except for "Archon" M115 and a 10% by mass olefin-based elastomer ("ABSORTOMER" EP-1001), a laminated film was obtained in the same manner as in Example 1.

(Example 6) The composition constituting the resin layer A is set to: 79.5% by mass of styrene elastomer ("TAFTEC" H1052), 10% by mass of high melt tension polypropylene ("WAYMAX" MFX8), and 10% by mass of tackifier Except for "Archon" M115, 0.5% by mass of commercially available ethylene distearate (EBSA), a laminated film was obtained in the same manner as in Example 1.

(Example 7) Among the composition constituting the resin layer A, high-density polyethylene ("Nipolon Hard" 7300A manufactured by Tosoh Corporation, density 952kg/m ³ , MFR 2g/10 minutes, G'(25)>10MPa, Except for tanδ(25)<0.5) instead of high melt tension polypropylene ("WAYMAX" MFX8), a laminated film was obtained in the same manner as in Example 1.

(Example 8) The composition constituting the resin layer A is set to: 70% by mass of styrene elastomer ("TAFTEC" H1052), 15% by mass of high melt tension polypropylene ("WAYMAX" MFX8), and 15% by mass of tackifier Except for "Archon" P125 (manufactured by Arakawa Chemical Industry, aromatic copolymer, softening point 125°C, hydrogenation rate ≧90%), a laminated film was obtained in the same manner as in Example 1.

(Example 9) A laminated film was obtained in the same manner as in Example 1, except that the thickness of the resin layer A was 2.8 μm.

(Example 10) The composition constituting the resin layer A is set to: 70% by mass of styrene elastomer ("TAFTEC" H1052), 15% by mass of high melt tension polypropylene ("WAYMAX" EX8000, MFR 1.5g/10 min, G '(25)>10MPa, tanδ(25)<0.5), 5 mass% tackifier "Archon" M115, 5 mass% tackifier "FTR" 8100 (manufactured by Mitsui Chemicals, aromatic copolymer, softening Except that the temperature is 100° C. and the hydrogenation rate is less than 90%), a laminated film was obtained in the same manner as in Example 1.

(Comparative example 1) The composition constituting the resin layer A is set to: 90% by mass of styrene elastomer ("TAFTEC" H1052), and 10% by mass of the tackifier "Archon" M115, except that it is the same as in Example 1. The way to obtain the laminated film.

(Comparative example 2) The composition constituting the resin layer A is set to: 94% by mass of styrene elastomer ("TAFTEC" H1052), 5% by mass of high melt tension polypropylene ("WAYMAX" MFX8), and 1% by mass of commercially available Except for ethylene distearate (EBSA), a laminated film was obtained in the same manner as in Example 1.

(Comparative example 3) The composition of the resin layer A is set to: 69% by mass of styrene elastomer ("TAFTEC" H1052), 15% by mass of high melt tension polypropylene ("WAYMAX" MFX8), and 15% by mass of tackifier ("Archon" M115), 1% by mass of commercially available ethylene distearate (EBSA), and making the thickness of the resin layer A 2.5 μm, except in the same manner as in Example 1 Obtain a laminated film.

(Comparative Example 4) The composition of the base material is set to 97% by mass of homopolypropylene (manufactured by Sumitomo Chemical Co., Ltd., "Nobrene" FLX80E4, MFR 8g/10 min), and 3% by mass of styrene elastomer ("TAFTEC" H1052), and the composition constituting the resin layer A is set to: 20% by mass styrene elastomer ("TAFTEC" H1052), 80% by mass olefin elastomer ("ABSORTOMER" EP-1001), except for this Otherwise, in the same manner as in Example 1, a laminated film was obtained.

(Comparative Example 5) The composition constituting the resin layer A is set to: 70% by mass of styrene elastomer ("TAFTEC" H1052), 15% by mass of high melt tension polypropylene ("WAYMAX" MFX3, MFR 9g/10 minutes, G' (25)>10MPa, tanδ(25)<0.5), 15% by mass of the tackifier "Archon" M115, except that the laminated film was obtained in the same manner as in Example 1.

[Table 1] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Substrate Block polypropylene quality% 97 97 97 97 97 97 FLX80E4 quality% H1052 quality% 3 3 3 3 3 3 Resin layer A H1052 quality% 70 70 60 80 70 79.5 MFX8 quality% 15 15 15 10 10 10 7300A quality% M115 quality% 15 5 5 10 10 10 P125 quality% 8100 quality% 10 10 EP-1001 quality% 10 10 EBSA quality% 0.5 thickness μm 3.5 3.5 3.6 3.6 3.5 3.5 Ra(A) μm 0.44 0.45 0.43 0.33 0.35 0.33 F g/mm ² 1.7 1.5 1.1 2.2 1.6 1.2 hp/hm - 0.73 0.72 0.75 0.58 0.63 0.59 Tm °C 154 154 155 154 153 154 G'(A) MPa 3.0 3.5 3.4 1.7 1.6 1.7 Evaluation results Adhesion (after storage at 23℃) Attached body X Numerical value g/25mm 12 9 7 twenty one 11 8 determination ◎ ◎ ◎ ○ ◎ ○ Attached body Y Numerical value g/25mm 6 5 5 6 5 3 determination ◎ ◎ ◎ ◎ ◎ ○ Adhesion ratio (attached body A/attached body B) Numerical value 2.0 1.8 1.4 3.5 2.2 2.7 determination ○ ◎ ◎ ○ ○ ○ Adhesion (after storage at 50℃) Attached body X Numerical value g/25mm 18 12 9 50 twenty three 13 Adhesion hyperplasia magnification Numerical value 1.5 1.3 1.3 2.4 2.1 1.6 determination ◎ ◎ ◎ ○ ○ ○

[Table 2] Example 7 Example 8 Example 9 Example 10 Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 Substrate Block polypropylene quality% 97 97 97 97 97 97 97 97 FLX80E4 quality% 97 H1052 quality% 3 3 3 3 3 3 3 3 3 Resin layer A H1052 quality% 70 70 70 70 90 94 69 20 70 MFX8 quality% 15 15 5 15 EX8000 quality% 15 MFX3 quality% 15 7300A quality% 15 M115 quality% 15 15 15 10 15 15 P125 quality% 15 8100 quality% EP-1001 quality% 80 EBSA quality% 1 1 thickness μm 3.4 3.6 2.8 3.5 3.5 3.4 2.5 3.5 3.5 Ra(A) μm 0.39 0.44 0.52 0.28 0.22 0.25 0.55 0.14 0.25 F g/mm ² 2.0 2.1 0.8 1.7 3.8 2.2 0.1 0.8 2.0 hp/hm - 0.75 0.73 0.72 0.73 0.52 0.47 0.7 0.85 0.51 Tm °C 130 154 154 154 - 154 155 - 155 G'(A) MPa 2.8 2.2 3.0 3.0 1.3 1.4 3.0 0.4 1.1 Evaluation results Adhesion (after storage at 23℃) Attached body X Numerical value g/25mm 15 16 6 20 45 25 4 3 40 determination ○ ○ ◎ ○ X X ○ ○ X Attached body Y Numerical value g/25mm 7 7 4 6 10 4 0 2 8 determination ◎ ◎ ○ ◎ ◎ ○ X X ◎ Adhesion ratio (attached body A/attached body B) Numerical value 2.1 2.3 1.5 3.3 4.5 6.25 - 1.5 5.0 determination ○ ○ ◎ ○ X X - ◎ X Adhesion (after storage at 50℃) Attached body X Numerical value g/25mm 25 28 8 46 122 62 5 13 120 Adhesion hyperplasia magnification Numerical value 1.7 1.8 1.3 2.3 2.7 2.5 1.3 4.3 3.0 determination ○ ○ ◎ ○ X X ◎ X X

Examples 1 to 9 satisfying the requirements of the present invention have good adhesion to any adherend, and they are laminated films with low adherence and excellent suppression of adhesion enhancement. On the other hand, Comparative Examples 1 and 2 have high adhesion to the adherend X, and they are laminated films that have poor adherence to the adherend and tend to adhere strongly. In addition, the adhesion of Comparative Example 3 to the adherend Y was insufficient. In addition to the insufficient adhesion to the adherend Y, Comparative Example 4 is also a laminated film that tends to increase adhesion. [Industrial availability]

The laminated film of the present invention is excellent in adhesion characteristics such as adherence to the adherend, so it can be suitably used as a surface protective film for products made of synthetic resin, metal, glass and other materials with various surface shapes. .

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no.

Claims (9)

A laminated film, which is a laminated film having a substrate and a resin layer A on at least one side thereof, which satisfies the following (a), (b), (c); (a) the resin layer A side at 23°C The maximum probe viscosity F is 0.2g/mm ² or more and 2.5g/mm ² or less; (b) The residual displacement of the resin layer A side in the load-unload test using nanoindentation at 26°C and a maximum load of 1mN The ratio (hp/hm) of hp (unit μm) to the maximum displacement hm (unit μm) is 0.50 or more and 0.90 or less; (c) The resin layer A has a melting point Tm above 50°C. The laminated film of claim 1, wherein the storage elastic modulus G'(A) of the aforementioned resin layer A at 50°C and 1 Hz is 1.5 MPa or more. The laminated film of claim 1 or 2, wherein the arithmetic average roughness Ra(A) of the resin layer A side is 0.20 μm or more and 0.80 μm or less. The laminated film according to any one of claims 1 to 3, wherein the aforementioned resin layer A contains a styrene-based elastomer having a melt flow rate of 3 g/10 min or more and 50 g/10 min or less in 230° C. and 2.16 kg. The laminated film according to any one of claims 1 to 4, wherein the resin layer A includes an olefin resin having a melt flow rate of 0.01 g/10 min or more and 1.5 g/10 min in 2.16 kg at 230°C. The laminated film according to any one of claims 1 to 5, wherein the resin layer A includes an olefin-based elastomer having a tanδ (25) of 0.5 or more at 25°C and 1 Hz. The laminated film according to any one of claims 1 to 6, wherein the resin layer A comprises an unhydrogenated or partially hydrogenated aromatic copolymer with a softening point of 80°C or higher and/or an unhydrogenated or partially hydrogenated aliphatic/aromatic Family copolymer. The laminated film according to any one of claims 1 to 7, wherein the aforementioned base material comprises an olefin-based resin and a styrene-based elastomer. The laminated film according to claims 1 to 8, wherein the substrate has a resin layer B on the side opposite to the side having the resin layer A.