JP7765205B2 - Adhesive film and method for producing adhesive film - Google Patents

Description

The present invention relates to an adhesive film and a method for manufacturing an adhesive film.

Acid-modified polyolefin resins have traditionally been known as materials that adhere to various types of adherends. For example, Patent Document 1 discloses an adhesive resin composition containing an acid-modified polyolefin resin and a cyclic polyolefin resin.

Regarding the use of cyclic olefin resins, for example, Patent Document 2 describes how interposing a layer primarily composed of a polypropylene-based resin and/or a polyethylene-based resin between a cyclic olefin resin layer and a functional resin layer achieves both releasability and adhesion to the functional resin layer.

Patent No. 6809899 Patent No. 6323598

Adhesive films that are heated to high temperatures for bonding are required to have good adhesion to the adherend and to be able to maintain their dimensions. The invention described in Patent Document 1 describes the heat seal strength of packaging films, but does not consider dimensional retention at all. The invention described in Patent Document 2 requires good releasability from the functional resin layer, and does not place importance on adhesion to the adherend.

The present invention was made in consideration of the above circumstances, and aims to provide an adhesive film and a method for manufacturing an adhesive film that can achieve both adhesion to an adherend and dimensional retention of the adhesive film even at high temperatures.

To solve the above problems, the present invention provides an adhesive film having a cyclic olefin resin layer as a heat-resistant layer and an adhesive layer on at least one side of the heat-resistant layer, the adhesive layer containing a modified polyolefin resin as an essential component and further containing at least one resin having a styrene structure or a cyclic hydrocarbon structure, and the glass transition temperature of the cyclic olefin resin contained in the cyclic olefin resin layer is 130°C or higher.

The adhesive layer may contain 3 to 50 parts by weight in total of at least one of the resins having a styrene structure or a cyclic hydrocarbon structure, per 100 parts by weight of the adhesive layer.
The modified polyolefin resin of the adhesive layer may be modified with an unsaturated carboxylic acid component, and 100 parts by weight of the modified polyolefin resin may contain 0.01 to 2 parts by weight of the unsaturated carboxylic acid component.

The modified polyolefin resin may be a modified polyethylene resin or a modified polypropylene resin.
The adhesive layer may contain 1 to 15 parts by weight of a thermoplastic elastomer resin in 100 parts by weight of the adhesive layer.
The adhesive film may have a second adhesive layer on the adhesive layer, which is adhered to an adherend of the adhesive film.

The present invention also provides a method for producing the adhesive film, which includes the steps of melting and kneading the material for the heat-resistant layer in a melt extruder and extruding the heat-resistant layer into a film, and melting and kneading the material for the adhesive layer in a melt extruder and extruding the adhesive layer onto at least one side of the heat-resistant layer by extrusion lamination.

The present invention also provides a method for manufacturing the adhesive film, which includes the steps of melt-kneading the materials for the heat-resistant layer and the adhesive layer in an extruder and simultaneously extruding them to form a film of the heat-resistant layer and the adhesive layer with the adhesive layer laminated on at least one side of the heat-resistant layer.

The present invention also provides a method for producing the adhesive film, which includes the steps of melting and kneading the material for the heat-resistant layer in a melt extruder and extruding the heat-resistant layer into a film, melting and kneading the material for the adhesive layer in a melt extruder and extruding the adhesive layer into a film, and pressing the adhesive layer onto at least one side of the heat-resistant layer with a heated roll to laminate it.

According to the present invention, it is possible to achieve both adhesion to the adherend and dimensional retention of the adhesive film, even at high temperatures.

FIG. 1 is a cross-sectional view showing a first embodiment of an adhesive film. FIG. 4 is a cross-sectional view showing a second embodiment of the adhesive film. FIG. 10 is a cross-sectional view showing a third embodiment of the adhesive film.

The present invention will be described below based on a preferred embodiment.

As shown in Figures 1 to 3, adhesive films 10, 20, and 30 of the embodiments have an adhesive layer 12 on at least one side of a heat-resistant layer 11. As with adhesive film 10 shown in Figure 1, an adhesive layer 12 may be provided on one side of the heat-resistant layer 11. As with adhesive film 20 shown in Figure 2, adhesive layers 12 may be provided on both sides of the heat-resistant layer 11. These adhesive layers 12 may be used to adhere the adhesive films 10 and 20 to an adherend (not shown).

As shown in Figure 3, the adhesive film 30 may have a second adhesive layer 13 on the adhesive layer 12, which is adhered to the adherend. The second adhesive layer 13 may be laminated on the adhesive layer 12 on at least one side of the heat-resistant layer 11. Although not specifically shown, the adhesive layer 12 and the second adhesive layer 13 may be laminated on both sides of the heat-resistant layer 11, respectively.

The heat-resistant layer 11 is a cyclic olefin resin layer. The cyclic olefin resin layer contains at least a cyclic olefin resin as an essential component. Examples of cyclic olefin resins include polymers of various cyclic olefin monomers, copolymers of cyclic olefin monomers with other monomers such as ethylene, hydrogenated products thereof, and copolymers of cyclic olefins with other monomers. The cyclic olefin resin may be a cycloolefin polymer (COP) or a cycloolefin copolymer (COC).

Cyclic olefin monomers include monocyclic olefins, bicyclic olefins, tricyclic olefins, tetracyclic olefins, pentacyclic olefins, hexacyclic olefins, and the like.
Examples of the monocyclic olefin include cyclopentene, cyclohexene, cycloheptene, cyclooctene, cyclopentadiene, and cyclohexadiene.
Examples of the bicyclic olefin include norbornene, norbornadiene, methylnorbornene, dimethylnorbornene, ethylnorbornene, chlorinated norbornene, chloromethylnorbornene, trimethylsilylnorbornene, phenylnorbornene, cyanonorbornene, dicyanonorbornene, methoxycarbonylnorbornene, pyridylnorbornene, nadic anhydride, and nadic imide.
Examples of tricyclic olefins include dicyclopentadiene, dihydrodicyclopentadiene, and alkyl-, alkenyl-, alkylidene-, and aryl-substituted products thereof.
Examples of the tetracyclic olefin include dimethanohexahydronaphthalene, dimethanooctahydronaphthalene, and alkyl, alkenyl, alkylidene, and aryl substituted derivatives thereof.
Pentacyclic olefins include tricyclopentadiene and its alkyl, alkenyl, alkylidene, and aryl substituted derivatives.
Hexacyclic olefins include hexacycloheptadecene and its alkyl, alkenyl, alkylidene, and aryl substituted derivatives.
These cyclic olefin monomers are preferably monomers having at least one norbornene structure. The cyclic olefin monomers may be hydrocarbon-based monomers or may have a functional group such as an ester group.

The polymerization method and mechanism of the monomer molecules in cyclic olefin resins may be ring-opening polymerization or addition polymerization. Furthermore, when multiple types of monomers are used in combination, known polymerization methods and mechanisms can be used. They may be blended together at the monomer stage and copolymerized. After some monomers have polymerized to a certain extent, other monomers may be blended to perform block copolymerization.

Cyclic olefin resins may contain monomers other than cyclic olefin monomers, such as monomer units based on α-olefins. Examples of α-olefins include ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, and 1-octene. Cyclic olefin resins may be amorphous polymers, such as homopolymers of cyclic olefin monomers, copolymers of two or more cyclic olefin monomers, or copolymers of at least one cyclic olefin monomer and at least one α-olefin having 2 to 10 carbon atoms. Two or more cyclic olefin monomers may be used, or two or more monomers other than cyclic olefin monomers may be used.

The cyclic olefin resin layer that forms the heat-resistant layer 11 preferably contains a cyclic olefin resin with a high glass transition temperature (Tg). Specifically, the Tg of the cyclic olefin resin is preferably 130°C or higher. The Tg of the cyclic olefin resin can be adjusted by the monomer composition copolymerized with the cyclic olefin resin, etc.

The cyclic olefin resin layer of the heat-resistant layer 11 may contain only a cyclic olefin resin as a resin component. The cyclic olefin resin layer of the heat-resistant layer 11 may contain a resin component other than a cyclic olefin resin. The cyclic olefin resin layer of the heat-resistant layer 11 may contain one or more types of cyclic olefin resin in a total amount of 50% by weight or more, or even 70 to 100% by weight. The heat-resistant layer 11 may be formed solely from a cyclic olefin resin layer, or a heat-resistant layer made of a cyclic olefin resin layer may be used in combination with other heat-resistant layers.

When the cyclic olefin resin layer of the heat-resistant layer 11 contains other resin components in addition to the cyclic olefin resin, the other resin components are preferably resins obtained by polymerizing monomers having at least one of the following structures: ethylene, styrene, cyclic hydrocarbon, etc. The other resin components may be resins obtained by copolymerizing at least one monomer selected from the group consisting of a monomer having an ethylene structure, a monomer having a styrene structure, and a monomer having a cyclic hydrocarbon structure, or may be homopolymers of these monomers.

Monomers having an ethylene structure include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, butadiene, and isoprene. Resins polymerized from these monomers having an ethylene structure include polyolefins such as polyethylene and polypropylene.

Examples of monomers having a styrene structure include styrene-based monomers such as styrene, methylstyrene, and vinyltoluene. Resins obtained by polymerizing these monomers having a styrene structure include polystyrene and styrene-based elastomers. Examples of styrene-based elastomers include one or more of the following: styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-isoprene-butadiene-styrene block copolymer (SIBS), styrene-ethylene-butylene-olefin crystalline block copolymer (SEBC), and hydrogenated styrene-butadiene rubber (HSBR).

The monomer having a cyclic hydrocarbon structure may be a monomer having the above-mentioned styrene structure, an aromatic olefin monomer such as indene, or a cyclic olefin monomer. However, a resin polymerized from a monomer having a cyclic hydrocarbon structure is a resin other than a cyclic olefin resin. Examples of resins polymerized from a monomer having a cyclic hydrocarbon structure include C5 to C9 petroleum resins and C9 petroleum resins.

By including other resin components in the cyclic olefin resin layer, the brittleness caused by the cyclic olefin resin can be suppressed and flexibility can be improved. When the heat-resistant layer 11 of the cyclic olefin resin layer includes other resin components, it is preferable that the heat-resistant layer 11 contains 5 to 30 parts by weight of a resin polymerized from a monomer having at least one of the following structures: ethylene, styrene, or a cyclic hydrocarbon, per 100 parts by weight of the total amount of the heat-resistant layer 11.

The adhesive layer 12 contains a modified polyolefin resin as an essential component and further contains at least one resin having a styrene structure or a cyclic hydrocarbon structure. The adhesive layer 12 may be a resin layer adjacent to the cyclic olefin resin layer of the heat-resistant layer 11. Because the modified polyolefin resin has high adhesive properties, it is an essential component for imparting adhesive properties to the adhesive layer 12.

The modified polyolefin resin used in the adhesive layer 12 may be one or more of acid-modified polyolefin resin, hydroxy-modified polyolefin resin, chlorinated polyolefin resin, etc. Among these, acid-modified polyolefin resin modified with an unsaturated carboxylic acid component is preferred. The modified polyolefin resin of the adhesive layer 12 preferably contains 0.01 to 2 parts by weight of the unsaturated carboxylic acid component per 100 parts by weight of the modified polyolefin resin.

The unsaturated carboxylic acid component may be a carboxyl group-containing monomer having a free carboxylic acid group, or an acid anhydride group-containing monomer having a latent carboxylic acid group. Examples of carboxyl group-containing monomers include α,β-unsaturated carboxylic acid monomers such as acrylic acid, methacrylic acid, maleic acid, nadic acid, fumaric acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, tetrahydrophthalic acid, and endo-bicyclo[2.2.1]-5-heptene-2,3-dicarboxylic acid (endic acid). Examples of acid anhydride group-containing monomers include unsaturated dicarboxylic acid anhydride monomers such as maleic anhydride, nadic acid, itaconic anhydride, citraconic anhydride, and endic acid anhydride. The modified polyolefin resin may be a resin in which one type of unsaturated carboxylic acid component is copolymerized, or a resin in which two or more types of unsaturated carboxylic acid components are copolymerized.

Methods for producing modified polyolefin resins include graft-modifying unmodified polyolefin resins with functional group-containing monomers by melt-kneading, and copolymerizing olefin monomers with functional group-containing monomers. Functional group-containing monomers are monomers other than olefins that have polar functional groups, such as unsaturated carboxylic acid components, hydroxy-substituted olefins, and chlorinated olefins. At least a portion of the modified polyolefin resin can be an acid-modified polyolefin resin obtained by graft-modifying an unsaturated carboxylic acid component using a radical polymerization initiator. Examples of radical polymerization initiators include organic peroxides and aliphatic azo compounds.

Examples of olefin monomers used in modified polyolefin resins include one or more of ethylene, propylene, 1-butene, isobutylene, 1-hexene, 1-octene, and α-olefins. Modified polyolefin resins may include modified polyethylene resins, modified polypropylene resins, modified poly-1-butene resins, and modified polyisobutylene resins. Examples of unmodified polyolefin resins used in graft-modifying modified polyolefins include polyethylene, polypropylene, poly-1-butene, polyisobutylene, random copolymers of propylene and ethylene or α-olefins, and block copolymers of propylene and ethylene or α-olefins.

The modified polyethylene resin used in the adhesive layer 12 is preferably a resin in which 50 parts by weight or more of ethylene is copolymerized with 100 parts by weight of the modified polyethylene resin. The modified polyethylene resin is copolymerized with a functional group-containing monomer such as an unsaturated carboxylic acid component. Furthermore, the modified polyethylene resin may also be copolymerized with olefin monomers other than ethylene, such as propylene, 1-butene, 1-hexene, and 1-octene.

The modified polypropylene resin used in the adhesive layer 12 is preferably a resin in which 50 parts by weight or more of propylene is copolymerized with 100 parts by weight of the modified polypropylene resin. The modified polypropylene resin is copolymerized with a functional group-containing monomer such as an unsaturated carboxylic acid component. Furthermore, the modified polypropylene resin may also be copolymerized with olefin monomers other than propylene, such as ethylene, 1-butene, 1-hexene, and 1-octene.

In addition to the modified polyolefin resin, the adhesive layer 12 contains at least one resin having a styrene structure or a cyclic hydrocarbon structure. This improves the adhesion between the heat-resistant layer 11 and the adhesive layer 12. The adhesive layer 12 preferably contains 3 to 50 parts by weight of at least one resin having a styrene structure or a cyclic hydrocarbon structure per 100 parts by weight of the total adhesive layer 12. The adhesive layer 12 also preferably contains 50 to 97 parts by weight of the modified polyolefin resin per 100 parts by weight of the total adhesive layer 12.

Resins having a styrene structure include copolymers of a monomer having a styrene structure with other monomers. Examples of monomers having a styrene structure include styrene-based monomers such as styrene, methylstyrene, and vinyltoluene. Examples of monomers other than styrene-based monomers include aliphatic olefins such as ethylene, propylene, α-olefins, butadiene, and isoprene. Resins having a styrene structure may be resins in which residual unsaturated bonds after polymerization have been reduced or saturated by hydrogenation. Resins having a styrene structure may also be styrene-based elastomers. The proportion of styrene-based monomers in resins having a styrene structure may be, for example, 10 to 50% by weight.

Examples of styrene-based elastomers used in the adhesive layer 12 include one or more of styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-isoprene-butadiene-styrene block copolymer (SIBS), styrene-ethylene-butylene-olefin crystalline block copolymer (SEBC), and hydrogenated styrene-butadiene rubber (HSBR). In styrene-based elastomers, the blocks containing styrene constitute the hard blocks, and the blocks containing aliphatic olefin constitute the soft blocks.

Resins having a cyclic hydrocarbon structure include copolymers of a monomer having a cyclic hydrocarbon structure with another monomer. Monomers having a cyclic hydrocarbon structure may include monomers having a styrene structure, monomers having a norbornene structure, and other monomers having an alicyclic hydrocarbon structure or an aromatic hydrocarbon structure. Monomers having a cyclic hydrocarbon structure other than a styrene structure or a norbornene structure include indene, allylbenzene, and cycloolefins. Other monomers not having a cyclic hydrocarbon structure include aliphatic olefins such as ethylene, propylene, α-olefins, butadiene, and isoprene.

At least a portion of the resin having a cyclic hydrocarbon structure may be a resin having a styrene structure. The resin having a cyclic hydrocarbon structure may be a resin not having a styrene structure. At least a portion of the resin having a cyclic hydrocarbon structure may be a cyclic olefin resin. The resin having a cyclic hydrocarbon structure may not contain a cyclic olefin resin. The resin having a cyclic hydrocarbon structure may be, for example, a C5 to C9 petroleum resin, a C9 petroleum resin, etc.

The adhesive layer 12 may contain a thermoplastic elastomer resin. The thermoplastic elastomer resin may be a styrene-based elastomer that also serves as the resin having a styrene structure described above. The thermoplastic elastomer resin may be a resin different from the resin having a styrene structure and the resin having a cyclic hydrocarbon structure described above. For example, the thermoplastic elastomer resin may be an olefin-based elastomer. Examples of olefin-based copolymers that can be used for the olefin-based elastomer include aliphatic olefin copolymers such as propylene-ethylene copolymer, ethylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer, propylene-ethylene-1-butene copolymer, and propylene-1-butene copolymer.

When the adhesive layer 12 contains at least one styrene-based elastomer as a resin having a styrene structure, it may further contain a thermoplastic elastomer resin other than a styrene-based elastomer. The content of the thermoplastic elastomer resin is preferably within the range of 1 to 15 parts by weight per 100 parts by weight of the total amount of the adhesive layer 12.

When a second adhesive layer 13 is laminated on the adhesive layer 12, any desired adhesive resin can be used for the second adhesive layer 13 as long as it can be laminated on the adhesive layer 12. Examples of adhesive resins include, but are not limited to, acid-modified polyolefins, epoxy adhesives, and olefin-based heat sealing agents. The second adhesive layer 13 may contain two or more types of adhesive resins, or may contain resin components other than the adhesive resins.

Each layer constituting the adhesive films 10, 20, and 30, i.e., the heat-resistant layer 11, the adhesive layer 12, and the second adhesive layer 13, may contain various additives such as antioxidants, UV absorbers, antistatic agents, lubricants, and antiblocking agents for desired purposes. Any of the heat-resistant layer 11, the adhesive layer 12, and the second adhesive layer 13 may be composed without any or one or more of these additives.

The manufacturing method of adhesive films 10, 20, and 30 is not particularly limited, but examples include methods of forming or laminating each layer by extrusion molding, inflation molding, thermal lamination, extrusion lamination, dry lamination, etc. For example, when manufacturing adhesive films 10 and 20 having a heat-resistant layer 11 and an adhesive layer 12, the heat-resistant layer 11 may be formed first, the adhesive layer 12 may be formed first, or the heat-resistant layer 11 and adhesive layer 12 may be formed simultaneously.

A first example of a manufacturing method includes the steps of melt-kneading the material for heat-resistant layer 11 in a melt extruder and extruding the heat-resistant layer 11 into a film, and melt-kneading the material for adhesive layer 12 in a melt extruder and laminating the adhesive layer 12 on at least one side of heat-resistant layer 11 by extrusion lamination. According to the first example manufacturing method, heat-resistant layer 11 has higher heat resistance than adhesive layer 12, making manufacturing easier than when adhesive layer 12 is first molded and then extrusion-laminated onto heat-resistant layer 11. Furthermore, in the first example, it is easier to adjust the film thickness of each layer than in the second example described below. Furthermore, in the first example, adhesive layer 12 is laminated to heat-resistant layer 11 in a molten state, improving adhesion between layers compared to the third example described below.

A second example of a manufacturing method includes a process in which the materials for heat-resistant layer 11 and adhesive layer 12 are melt-kneaded in an extruder and simultaneously extruded to form a film of heat-resistant layer 11 and adhesive layer 12 with adhesive layer 12 laminated on at least one side of heat-resistant layer 11. Compared to the first example described above and the third example described below, the second example manufacturing method requires only one extrusion molding step, shortening the work process. Furthermore, because heat-resistant layer 11 and adhesive layer 12 are laminated in a molten state, adhesion between the layers is improved.

A third example of a manufacturing method includes the steps of melt-kneading the material for heat-resistant layer 11 in a melt extruder and extruding the heat-resistant layer 11 into a film; melt-kneading the material for adhesive layer 12 in a melt extruder and extruding the adhesive layer 12 into a film; and pressing the adhesive layer 12 onto at least one side of the heat-resistant layer 11 with a heated roll to laminate the layer. According to the third example manufacturing method, the heat-resistant layer 11 and the adhesive layer 12 can be molded separately and laminated in any desired combination as needed, facilitating design changes and manufacturing management. The order in which the heat-resistant layer 11 and the adhesive layer 12 are formed into a film is not particularly limited, and they can also be performed simultaneously.

When adhesive layers 12 are provided on both sides of the heat-resistant layer 11, the adhesive layers 12 on each side may be laminated to the heat-resistant layer 11 using the same method or different methods. The adhesive layers 12 on both sides may be resin layers with different compositions or thicknesses, or may be resin layers with the same composition or thickness. The thicknesses of the heat-resistant layer 11 and adhesive layer 12 are not particularly limited, but examples include approximately 1 to 300 μm for each layer of the heat-resistant layer 11 or adhesive layer 12. The thicknesses of the adhesive films 10, 20, and 30 are not particularly limited, but examples include approximately 10 to 500 μm.

When manufacturing an adhesive film 30 having a second adhesive layer 13, the adhesive layer 12 may be formed before the second adhesive layer 13, the second adhesive layer 13 may be formed before the adhesive layer 12, or the adhesive layer 12 and the second adhesive layer 13 may be formed simultaneously. The method for forming the second adhesive layer 13 is not particularly limited, and may be the same as the method for forming the adhesive layer 12, or may be a different method from the method for forming the adhesive layer 12. In the first to third examples of the manufacturing method described above, the second adhesive layer 13 may be formed in the same manner as the adhesive layer 12.

The substrate to which the adhesive films 10, 20, and 30 are applied is not particularly limited, but examples include various materials such as resin, rubber, metal, glass, and ceramics. Because the adhesive layer 12 contains a modified polyolefin resin as an essential component, it can adhere well to metal substrates. Examples of metals include, but are not limited to, iron, copper, aluminum, stainless steel, chromium, and nickel. The surface of the substrate may be a treated surface that has been subjected to a surface treatment such as textured processing or chemical conversion coating.

The present invention has been described above based on preferred embodiments, but the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present invention.

The present invention will be explained in detail below using examples.

(Resin used)
The following resins were used for the heat-resistant layer and adhesive layer. When showing the resin compositions in Table 1, the numerical values of the compounding ratios in parts by weight are added to the right of the symbols for the following components. For example, "A-1 100" indicates that 100 parts by weight of A-1 was used.

"A-1" is a cyclic olefin resin with a Tg of 145°C and an MFR of 10g/10min (260°C, 2.16kg).
"A-2" is a cyclic olefin resin with a Tg of 178°C and an MFR of 1.5g/10min (260°C, 2.16kg).
"A-3" is a cyclic olefin resin with a Tg of 105°C and an MFR of 26g/10min (260°C, 2.16kg).
"B-1" is polyethylene (LLDPE) with a melting point of 120°C.

"C-1" is an acid-modified polypropylene (PP) with a melting point of 140°C and an MFR of 7.0 g/10 min (230°C, 2.16 kg).
"C-2" is an acid-modified polyethylene (PE) with a melting point of 120°C and an MFR of 6g/10min (230°C, 2.16kg).
"D-1" is a styrene-containing resin (SEBS) with a styrene content of 43% and an MFR of 3.0 g/10 min (230°C, 2.16 kg).
"D-2" is a C9 hydrocarbon resin, which is a copolymer of vinyltoluene and indene.

(Methods for producing adhesive films of Examples 1 to 7 and Comparative Examples 1 and 2)
The resin for the heat-resistant layer and the resin for the adhesive layer were dry-blended in pellet form in a mixer with the compositions shown in Table 1. The resin for the heat-resistant layer was melt-kneaded at 300°C for 2 minutes, and the resin for the adhesive layer was melt-kneaded at 270°C for 2 minutes, and then an adhesive film of a predetermined thickness was obtained by two-layer co-extrusion molding. In Table 1, this two-layer co-extrusion molding method is designated as "P-1."

(Method for producing adhesive film of Example 8)
The resin for the heat-resistant layer and the resin for the adhesive layer were dry-blended in pellet form in a mixer with the composition shown in Table 1. The resin for the heat-resistant layer was melt-kneaded at 300°C for 2 minutes, and then extrusion-molded to obtain a film for the heat-resistant layer. Next, the resin for the adhesive layer was melt-kneaded at 270°C for 2 minutes, and then extrusion-laminated onto the film for the heat-resistant layer to obtain an adhesive film of a predetermined thickness. In Table 1, this extrusion lamination method is designated "P-2."

(Method for producing adhesive film of Example 9)
The resin for the heat-resistant layer and the resin for the adhesive layer were dry-blended in pellet form in a mixer with the composition shown in Table 1. The resin for the heat-resistant layer was melt-kneaded at 300°C for 2 minutes, and then extrusion-molded to obtain a film for the heat-resistant layer. Next, the resin for the adhesive layer was melt-kneaded at 270°C for 2 minutes, and then extrusion-molded to obtain a film for the adhesive layer. The obtained film for the heat-resistant layer and the film for the adhesive layer were overlapped and heat-pressed with a heated roll at 270°C to obtain an adhesive film of a predetermined thickness. In Table 1, this thermal lamination method is designated "P-3".

(Method for measuring adhesive strength)
An adhesive film with a heat-resistant layer thickness of 20 μm, an adhesive layer thickness of 80 μm, and a total thickness of 100 μm was used as the sample. Aluminum foil with a thickness of 50 μm was used as the adherend. These were cut to a size of 50 mm x 50 mm, and the adherend was placed on the sample. The sample was then heated and pressed from the adherend side at a temperature of 170 ° C, a pressure of 0.1 MPa, and a time of 10 sec. The sample was then cut to a width of 15 mm. The adhesive strength of the sample heated and pressed to the adherend was measured using a tensile tester (Shimadzu Corporation, product name: Autograph (registered trademark) AG-X20kN) at a speed of 300 mm / min, a width of 15 mm, and a measurement temperature of 110 ° C. using a 180 ° peel method.

(Method for measuring linear expansion coefficient)
An adhesive film with a heat-resistant layer thickness of 20 μm, an adhesive layer thickness of 80 μm, and a total thickness of 100 μm was used as a sample. The sample was cut to a size of 4 mm x 50 mm, and both ends in the longitudinal direction were fixed to chucks, with the distance between the chucks set to 20 mm. The sample was heated from 23°C to 110°C at a tension of 0.01 N/mm and a heating rate of 5°C/min, and then held at 110°C for 5 minutes, after which the linear expansion coefficient of the sample was measured. In Table 1, values exceeding 200 × 10 ^-6 /°C are indicated as ">200".

(result)
The above results are summarized in Table 1.

The adhesive films of Examples 1 to 9 exhibited high adhesive strength and a low thermal expansion coefficient even at high temperatures, demonstrating that they were able to achieve both excellent adhesion to the adherend and dimensional retention of the adhesive film.

In the adhesive film of Comparative Example 1, the adhesive layer had sufficient adhesion to the adherend, but the adhesion between the heat-resistant layer and the adhesive layer was insufficient, resulting in weak adhesive strength at high temperatures.
The adhesive film of Comparative Example 2 had a low heat resistance of the heat-resistant layer and was poor in dimensional retention at high temperatures.

10, 20, 30...adhesive film, 11...heat-resistant layer, 12...adhesive layer, 13...second adhesive layer.

Claims (6)

A cyclic olefin resin layer is provided as a heat-resistant layer,
an adhesive layer on at least one surface of the heat-resistant layer;
the adhesive layer contains an acid -modified polyolefin resin as an essential component and further contains at least one styrene-based elastomer ;
The adhesive layer contains 3 to 50 parts by weight of the at least one styrene-based elastomer in total per 100 parts by weight of the adhesive layer,
An adhesive film, wherein the glass transition temperature of the cyclic olefin resin contained in the cyclic olefin resin layer is 130°C or higher. The adhesive film according to claim 1, wherein the acid -modified polyolefin resin of the adhesive layer is an acid-modified polyolefin resin modified with an unsaturated carboxylic acid component, and the acid-modified polyolefin resin contains 0.01 to 2 parts by weight of the unsaturated carboxylic acid component per 100 parts by weight of the acid -modified polyolefin resin. The adhesive film according to claim 1 or 2 , wherein the acid -modified polyolefin resin is an acid -modified polyethylene resin or an acid -modified polypropylene resin. A method for producing the adhesive film according to any one of claims 1 to 3 ,
a step of melt-kneading the material of the heat-resistant layer in a melt extruder and extruding the heat-resistant layer into a film;
a step of melt-kneading a material for the adhesive layer in a melt extruder and laminating the adhesive layer on at least one surface of the heat-resistant layer by extrusion lamination;
A method for producing an adhesive film comprising the steps of: A method for producing the adhesive film according to any one of claims 1 to 3 ,
A method for manufacturing an adhesive film, comprising the steps of melt-kneading the materials of the heat-resistant layer and the adhesive layer in an extruder, respectively, and extruding and molding them simultaneously to form the heat-resistant layer and the adhesive layer into a film with the adhesive layer laminated on at least one side of the heat-resistant layer. A method for producing the adhesive film according to any one of claims 1 to 3 ,
a step of melt-kneading the material of the heat-resistant layer in a melt extruder and extruding the heat-resistant layer into a film;
a step of melt-kneading the material of the adhesive layer in a melt extruder and extruding the adhesive layer into a film;
a step of laminating the adhesive layer on at least one surface of the heat-resistant layer by pressing with a hot roll;
A method for producing an adhesive film comprising the steps of: