TWI499639B - A release agent composition, a release film, and a subsequent film using the same - Google Patents

Description

Release agent composition, release film and adhesive film using the same

The present invention relates to a release agent composition, a release film, and an adhesive film therewith, and more particularly to a release film suitable for protecting an adhesive film such as an anisotropic conductive adhesive film and for forming the release film. A release agent composition useful as a release layer.

Conventionally, a release film having a release coating film (release layer) on one side of a polyester film isothermal base substrate has been widely used as a protective film for an adhesive film of various adhesive films.

Usually, the adhesive film of the film is applied to the base film by applying a coating liquid containing a reactive adhesive and a solvent onto the surface of the base film, and then heating and removing the solvent.

On the other hand, a release film laminated on the surface of the adhesive film and used as a protective film is usually produced by using a white biaxially stretched polyester film using a metal oxide or the like as a filler as a release substrate. The base material is coated with a hardening type polyoxo-based release agent in a state of being dissolved in a solvent on one surface or both surfaces, and dried and cured to form a release layer (Patent Document 1).

The polyfluorene oxide used in the above-mentioned hardened polyoxo-based release agent is generally required to prevent adhesion to the surface of the adhesive film and to minimize the transfer of polyfluorene to the release base substrate on the back side. Therefore, polyfluorene is mainly used in the following types: polydimethyl methoxy alkane having an -OH group at the end and polydimethyl methoxy oxane having a -H group at the end using an organotin catalyst (hydroxy polydimethylene) a type in which a condensation reaction is carried out to form a three-dimensional crosslinked structure, or a platinum catalyst is used to carry out an addition reaction of a polydimethylsiloxane having a vinyl group introduced into a terminal with a hydroxypolydimethyloxane. Type of person.

Further, when a laminate film is provided with a release film, for example, when the adhesive film is an anisotropic conductive film having an anisotropic conductive film as an adhesive film, ITO (Indium tin oxide) of the liquid crystal panel is used. When the electrode of the indium tin oxide is connected to the TAB, the release film of the one side of the anisotropic conductive film is first peeled off, and the anisotropic conductive film is heated and pressurized (pre-compression bonded) to the ITO electrode of the liquid crystal panel. Then, the release base film on the other side of the anisotropic conductive film is peeled off, and the TAB is heated and pressed (formally crimped) onto the pre-compression bonding film to surely bond the liquid crystal panel to the TAB. . At this time, in order to stably perform the movement, supply, and peeling of the adhesive film, the release film plays an important role.

In the formation of the release layer of the release film, a polyfluorene-based release agent is usually used in order to reduce the surface energy thereof. However, in the case of using the usual polyfluorene oxide, the affinity between the release layer and the adhesive film coated thereon is poor, and the adhesion force of the release layer and the adhesive film is weak overall, and the peeling of the two starts. The part is strong, and there is a so-called Jerky phenomenon which is unstable during the period from the start of peeling to the end of peeling. If a sharp pull phenomenon occurs, a problem that a part of the adhesive film is peeled off from the peeling film side to the release layer side occurs in a portion where a large peeling force is required.

In order to solve this problem, it is also conceivable to use a special release film having a small release effect, but in this case, a so-called blocking phenomenon in which the release effect is too small to adhere to the release film which becomes a cover layer may occur. Therefore, there is a problem that not only the stable movement and supply of the adhesive film but also the peeling ability is unstable, and the performance as the adhesive film is greatly impaired.

Patent Document 1: Japanese Laid-Open Patent Publication No. 2002-220431

The present invention has been made in order to solve the problems of the prior art described above, and an object of the invention is to provide a release film which can be smoothly peeled off without causing a sharp pull phenomenon when peeling off the release film from the adhesive film, and does not cause separation. The release layer of the film adheres to the adhesion layer of the adhesive layer of the adhesive film without impairing the properties of the adhesive film.

The present inventors have made intensive studies to solve this problem, and as a result, it has been found that when a release agent composition for forming a release layer of a release film contains a polyoxyxylene resin and an alkoxy-containing decane-modified polyurethane resin, When the film is formed, a so-called sea-island structure can be obtained, and a majority of the islands of the sea-island structure-cerium oxide-polyurethane hybrid composite are dispersed in a sea in which a main component, that is, a polyfluorene-oxygen resin, forms a continuous phase, whereby the release layer and the adhesive film are formed. The present invention has been completed by locally increasing the affinity to obtain the desired peel strength and improving the jerk phenomenon or the adhesion phenomenon.

The present invention based on this finding is a release agent composition containing a polyoxyxylene resin, an alkoxy-containing decane-modified polyurethane resin, and a solvent.

In the release agent composition, the alkoxy-containing decane-modified polyurethane resin preferably has a solid content ratio of 0.5% by weight or more and 50% by weight or less, more preferably 1.25% by weight or more and 20% by weight or less. situation.

Further, the release film of the present invention has a release base substrate and a release layer provided on one of the release base substrates, and the release layer is a cured film of the release agent composition.

The adhesive film of the present invention has a release base substrate, a release layer disposed on the other side of the release base substrate, and an adhesive layer disposed on the release layer, wherein the release layer is the release agent composition Hardened film. As a preferable aspect of the adhesive film, an aspect in which the adhesive layer is formed of an anisotropic conductive adhesive in which conductive particles are dispersed in a binder resin can be used.

The method for producing a release film of the present invention is characterized in that a release agent composition containing a polyoxyxylene resin, an alkoxy-containing decane-modified polyurethane resin, and a solvent is applied onto a release base substrate to form a release agent. The method of the layer.

If the release agent composition of the present invention is formed on a release base substrate to form a release layer, the release layer constitutes a sea-island structure which exists in the sea in which the continuous phase of the polyoxyl resin is formed. An island of a majority of thermoplastic resins formed from a mixture of cerium oxide and polyurethane. As a result, the affinity of the release layer and the adhesive film is locally increased. Thereby, when the release film is peeled off from the film, the film can be smoothly peeled off without causing a sharp pull phenomenon, and the release layer of the release film can be adhered to the adhesive layer of the adhesive film without causing damage. The release layer of the release film is then stripped from the adhesive layer of the adhesive film by the properties of the film.

Further, according to the release agent composition of the present invention, the desired peel strength can be obtained by adjusting the addition amount of the alkoxy-containing decane-modified polyurethane resin.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

The release agent composition of the present invention comprises a polyoxyxylene resin, an alkoxy-containing decane-modified polyurethane resin, and a solvent, and preferably the resin component is dissolved in a solvent.

The polyoxynoxy resin used in the present invention is not particularly limited, and an addition reaction type polyoxyxylene resin can be suitably used from the viewpoint of reactivity and stability. Examples of the addition reaction type polyoxynoxy resin include a known polydimethylsiloxane having an alkenyl group (for example, a vinyl group or a hexenyl group) in the molecule. Specific examples of the addition reaction type polyfluorene oxide include materials such as trade names X52-9201B, KS847, and KS830 of Shin-Etsu Chemical Co., Ltd.

Further, the release agent composition of the present invention may contain an addition reaction type polyfluorene hardening catalyst which has been used in the past, and a platinum-based curing catalyst known in the art is preferably used. Examples of the platinum-based curing catalyst include chloroplatinic acid, a wrong salt of chloroplatinic acid and an olefin, a compound of chloroplatinic acid and an alcohol, and the like.

As the alkoxy-containing decane-modified polyurethane resin used in the present invention, those described in Japanese Patent Application No. 2002-220431 can be suitably used. Among them, a polyether-based polyurethane resin, a polycarbonate-based polyurethane, a polyester-based polyurethane, or the like can be used as the polyurethane resin.

The alkoxy-containing decane-modified polyurethane resin has a cured product having a gelatinized fine cerium oxide site (a high-order network structure of a decane bond).

The content of the alkoxy-containing decane-modified polyurethane resin in the release agent composition of the present invention is not particularly limited, and the alkoxy-containing decane-modified polyurethane can be obtained from the viewpoint of reliably achieving the effects of the present invention. The resin is preferably 0.5% by weight or more and 50% by weight or less, more preferably 1.25 % by weight or more and 20% by weight or less, further preferably 2.5% by weight or more and 12.5% by weight or less, and particularly preferably 2.5, based on the ratio of the solid content of the resin. Weight% or more and 7.5% by weight or less.

When the content of the alkoxy-modified decane-modified polyurethane resin cerium oxide-polyurethane mixed composite is too small, the affinity with the adhesive film is insufficient, and the adhesion phenomenon cannot be prevented. On the other hand, if it is too much, the coating property is too large. And the deterioration of the release property is not good.

Further, in the release agent composition of the present invention, in addition to the alkoxy-containing decane-modified polyurethane resin which forms the ceria-polyurethane mixed composite, other decane which forms a cerium oxide-mixed organic polymer may be used. Modified resin. For example, an epoxy resin, a phenol resin, a polyvinyl alcohol resin, an acrylic resin, a polystyrene resin, a polyvinyl acetate resin, a polyamidene resin, or a polyamide can also be used. A constituent of an amine resin or the like.

Further, the release agent composition of the present invention may contain an additive such as a solvent, a release controlling agent, or a filler. The solvent is not particularly limited, and toluene, MEK (methyl ethyl ketone), IPA (Isopropyl alcohol), butanol, acetone, and the like can be appropriately combined from the viewpoint of ensuring good solubility and film formability. MIBK (Methyl isobutyl ketone, methyl isobutyl ketone) and the like.

The release agent composition of the present invention can be produced by uniformly mixing the above components by a conventional method.

The release film of the present invention is a cured film in which the release agent composition of the present invention is formed on one surface of a release base substrate, and Fig. 1 is a cross-sectional view showing an example of the release film of the present invention.

As shown in Fig. 1, the release film 1 of the present embodiment is composed of a release base substrate 2 and a release layer 3 provided on one of the release base substrates 2.

Here, as the release base substrate 2, for example, PET (polyethylene terephthalate), PEN (polyethylene naphthalate), OPP (biaxially oriented polypropylene), or the like can be suitably used.

The release layer 3 can be formed by applying the above-described release agent composition of the present invention to the release base substrate 2, and drying it, heating it, and hardening it.

The release layer 3 obtained by hardening the release agent composition of the present invention has a sea-island structure which is in the sea of the continuous phase formed by the polyoxyn resin, and is dispersed with a thermoplastic formed by the ceria-polyurethane hybrid composite. The island of most of the resin. Therefore, the release layer 3 has an improved affinity with the adhesive film as compared with the release layer of the island in which the cerium oxide-polyurethane mixed composite is not dispersed.

In the case of the present invention, the thickness of the release layer 3 is not particularly limited, and is preferably 0.05 μm or more and 0.5 μm or less from the viewpoint of both release property and economy.

The adhesive film of the present invention is provided with an adhesive layer on the release layer of the release film of the present invention, and Fig. 2 is a cross-sectional view showing an example of the adhesive film of the present invention.

As shown in Fig. 2, the adhesive film 10 of this example is formed by providing the adhesive layer 4 on the release layer 3 of the release film 1.

The adhesive layer 4 may be provided with a resin layer of adhesiveness, thermoplasticity, thermosetting property, and photocurability in the same manner as the known adhesive film, and the resin component may contain an epoxy resin, a phenoxy resin, an acrylic resin, or the like. The resin composition for forming the adhesive layer 4 may suitably contain a polymerization initiator, a solvent or the like.

Further, the adhesive layer 4 may be formed of an anisotropic conductive film by including the conductive particles in the adhesive layer 4, and the adhesive film 10 may be an anisotropic conductive adhesive film (ACF).

As a method of producing the adhesive film 10, a resin composition for forming an adhesive layer is applied onto the release layer 3 of the release film 1, and dried and cured.

The thickness of the adhesive layer 4 is not particularly limited, and is preferably 0.005 mm or more and 0.05 mm or less from the viewpoint of adhesiveness and economy.

Example

Hereinafter, the invention will be specifically described by way of examples, but the invention is not limited to the examples.

Example 1

Alkoxy-containing decane modified polyurethane resin solution (solid content: 25%) (Iuliano U302, manufactured by Arakawa Chemical Industry Co., Ltd.) 10 parts by weight, 30% addition reaction type polyoxyl solution (KS-847, Shin-Etsu 27 parts by weight, a platinum hardening catalyst (PL-50T, manufactured by Shin-Etsu Chemical Co., Ltd.), 0.8 parts by weight, 30 parts by weight of toluene, and 33 parts by weight of MEK were uniformly mixed to prepare a release agent composition.

Further, in the case of the present embodiment, the ratio of the solid content component of the release agent composition (excluding the catalyst) was 20% by weight of the alkoxy-containing decane-modified polyurethane resin, and 80% by weight of the polyoxyxylene resin.

The obtained release agent composition was applied to one side of a 50 μm thick PET film which is a film substrate by using a wire bar to have a dry thickness of 0.1 μm, and placed in an oven at a temperature of 160 ° C. After holding for 1 minute, remove it from the oven. Thus, a release film having a release layer provided on one side of the release base substrate was obtained.

<a. Initial peel strength to the adhesive film>

The acrylic adhesive film for test (T4090, manufactured by Sony Chemicals & Information Co., Ltd.) was bonded to the release layer of the release film obtained in Example 1, and cut into strips having a length of 200 mm and a width of 50 mm. The obtained long strip sample carried a load of 2 kg, and this state was maintained at 70 ° C for 20 hours. After the aging was completed, the T-die peeling test was performed at 25 ° C, and the initial peel strength (N/5 cm) was measured using a peel strength tester (Tensilon, manufactured by Orientec Co., Ltd.).

<b. Initial peel strength of the adhesive film ADH>

On one of the release films obtained in Example 1, a film ADH (reactive adhesive containing an epoxy-based curing agent) was applied, and the film was kept in an oven at 80 ° C for 1 minute to remove the solvent. Thereafter, the ADH coating film on the release film was bonded to an acrylic adhesive film (PP tape, manufactured by Nitto Denko Corporation), and cut into strips having a length of 200 mm and a width of 50 mm, and a T-die was performed at 25 ° C. In the peeling test, the initial peel strength (N/5 cm) was measured using a peel strength tester (Tensilon, manufactured by Orientec Co., Ltd.). The results are shown in Table 1.

<c. Adhesion>

In the above test for the initial peel strength of the adhesive film ADH, the occurrence of adhesion was investigated based on the incidence of adhesion to the cover film (the laminate of the film ADH and the acrylic adhesive film), and the following evaluation criteria were used. Conduct an evaluation.

[evaluation benchmark]

A: The incidence of adhesion to the cover film is 1% or less.

B: The incidence of adhesion to the cover film is 1% or more and less than 10%.

C: The incidence of adhesion to the cover film is 10% or more.

The results are shown in Table 1.

<d. 急拉>

In the above test b. For the initial peel strength of the film ADH, the ratio of the difference between the maximum value (Max) and the minimum value (Min) in the peel force chart to the average peel force (Ave) is R (R = 100). × (Max-Min)/Ave) The state of occurrence of the jerk was studied and evaluated according to the following evaluation criteria.

[evaluation benchmark]

A: The value of R is 20% or less (the level of no problem in practical application)

B: The value of R is 20% or more and less than 50%.

C: R value is 50% or more

The results are shown in Table 1.

<e. Initial residual adhesion rate>

The acrylic adhesive film which was peeled off in the initial peel strength test of the adhesive film was attached to a smooth stainless steel plate by a hand roller, and the peel strength (residual peel strength) was measured by the above method. ).

The acrylic adhesive film for testing which was not used in the above-described manner was attached to a smooth stainless steel plate by a hand roll, and the peel strength (reference peel strength) was measured by the above method. Then, the initial residual adhesion ratio (%) was calculated as the ratio of the residual peel strength to the reference peel strength. The results are shown in Table 1.

<Example 2>

In addition to 10 parts by weight of the alkoxy-containing decane-modified polyurethane resin solution (Iuliano U302, manufactured by Arakawa Chemical Industries Co., Ltd.) of Example 1, the other alkoxy-containing decane-modified polyurethane resin solution (Iuliano U301, Arakawa Chemical) was formulated. A sample was prepared in the same manner as in Example 1 except that 10 parts by weight of the product was produced by Industrial Co., and the same experiment was carried out. The results are shown in Table 1.

<Comparative Example 1>

20 parts by weight of a 10% ethyl cellulose solution (N100, manufactured by Hercules Co., Ltd.) was added to replace 10 parts by weight of the above alkoxy-containing decane-modified polyurethane resin (Iuliano U302, manufactured by Arakawa Chemical Industries Co., Ltd.). A sample was prepared in the same manner as in Example 1 and the same experiment was carried out. The results are shown in Table 1.

Further, in the case of Comparative Example 1, the blending ratio of cellulose was 20% by weight based on the total of the resin solid content of the release agent composition, and the ratio of the resin solid content of the release agent composition was 20%. The wt% polyoxyl resin is about 80%.

<Comparative Example 2>

A sample was prepared in the same manner as in Example 1 except that the above alkoxy-containing decane-modified polyurethane resin (Iuliano U302, manufactured by Arakawa Chemical Industries Co., Ltd.) was not added, and the same experiment was carried out. The results are shown in Table 1.

<Comparative Example 3>

20 parts by weight of a 10% by weight (toluene/MEK=1:1) solution of a polyester resin (Elitel VE3200, manufactured by Unitika Co., Ltd.) was added to replace the above alkoxy-containing decane-modified polyurethane resin (Iuliano U302, Arakawa Chemical Industry Co., Ltd. A sample was prepared in the same manner as in Example 1 except that 10 parts by weight of the product was produced, and the same experiment was carried out. Further, in the case of Comparative Example 3, the ratio of the solid content component of the release agent composition (excluding the catalyst) was 20% by weight of the polyester resin and 80% by weight of the polyoxyxylene resin. The results are shown in Table 1.

<Comparative Example 4>

20 parts by weight of a 10% by weight sol (toluene) of cerium oxide (DF-5VLD, manufactured by Ronson Co., Ltd.) was prepared in place of the above alkoxy-containing decane-modified polyurethane resin (Iuliano U302, manufactured by Arakawa Chemical Industries Co., Ltd.) 10 A sample was prepared in the same manner as in Example 1 except for the parts by weight, and the same experiment was carried out. Further, in the case of Comparative Example 4, the ratio of the solid content component of the release agent composition (excluding the catalyst) was 20% by weight of the polyester resin and 80% by weight of the polyoxyxylene resin. The results are shown in Table 1.

<f. Dependence of ACF peel strength on the addition amount of alkoxy-containing decane modified polyurethane resin>

Use the following as the ACF.

First, 50 parts by weight of a phenoxy resin (YP50, manufactured by Tohto Kasei Co., Ltd.), 50 parts by weight of an epoxy resin (828, manufactured by Hosei Co., Ltd.), 100 parts by weight of an imidazole-based curing agent (HX3941HP, manufactured by Asahi Kasei Co., Ltd.), and decane. A coupling agent (A187, manufactured by Momentive Advanced Materials Japan Co., Ltd.), 3.2 parts by weight, and 0.5 parts by weight of polybutadiene particles having an average particle diameter of 100 nm were dissolved in a toluene solvent to prepare an insulating adhesive resin, that is, a binder solution.

Then, 3.5 parts by weight of benzoguanamine particles having an average particle diameter of 5 μm as conductive particles were added to 100 parts by weight of the binder solution to form a binder.

Further, the adhesive was applied onto a PET film for peeling so that the thickness after drying became 25 μm to obtain an anisotropic conductive film. The anisotropic conductive adhesive film was cut into strips having a width of 2 mm to prepare a sample of ACF.

In the release film of the above-mentioned Example 1, the amount of the alkoxy-containing decane-modified polyurethane resin solution (Iuliano U302, manufactured by Arakawa Chemical Industries Co., Ltd.) was set to 20% by weight, 40% by weight, 60% by weight, 80% by weight, the ACF peel strength was measured by the above method "b. Initial peel strength to the adhesive film ADH". The result is shown in Fig. 3.

<g. Dependence of ACF peel strength and cellulose addition amount>

A test of a release film of 20% by weight, 40% by weight, 60% by weight, and 80% by weight of a 10% ethylcellulose solution (N100, manufactured by Hercules) in the release film of the above Comparative Example 1 Thus, the peel strength of ACF was measured by the above method using the same ACF as the above f. The result is shown in Fig. 4.

<h. Dependence of residual adhesion rate on the addition amount of alkoxy-containing decane modified polyurethane resin>

In the above-mentioned Example 1, the amount of the alkoxy-containing decane-modified polyurethane resin solution (Iuliano U302, manufactured by Arakawa Chemical Industries Co., Ltd.) was set to 20% by weight, 40% by weight, 60% by weight, and 80% by weight. Using the same ACF as the above f, the residual adhesion ratio was measured in the same manner as in the above-described method. The result is shown in Fig. 5.

<i. Dependence of ACF residual adhesion rate and cellulose addition amount>

In the same manner as in Comparative Example 1 in which the amount of the 10% ethylcellulose solution (N100, manufactured by Hercules) was 20% by weight, the 10% ethylcellulose solution was prepared to be 40% by weight, 60% by weight, or 80% by weight. The residual film was measured in the same manner as in the above-described method using the same ACF as that of the above-mentioned f. The result is shown in Fig. 6.

<evaluation>

It is shown in Fig. 3 that in the embodiment in which the alkoxy-containing decane-modified polyurethane resin is contained in the polyoxynoxy resin, if the content of the alkoxy-containing decane-modified polyurethane resin is increased, the film can be bonded to the film. The peel strength is increased to achieve the desired value.

Further, in the present embodiment, as shown in Fig. 5, even when the content of the alkoxy-containing decane-modified polyurethane resin was increased to 60% by weight, the residual adhesion ratio was more than 90%, and no decrease was observed.

On the other hand, as shown in Fig. 4, in Comparative Example 1 in which ethylcellulose was contained in the polyoxyxene resin, even when the content of ethylcellulose was increased, the peeling strength to the adhesive film did not rise. Instead, there is a tendency to decline.

Further, in Comparative Example 1, by containing ethyl cellulose, as shown in Fig. 6, the residual adhesion ratio was lowered to about 80%.

On the other hand, in the case where the polyester is contained in the polyoxyxene resin as in Comparative Example 3, even if the content of the polyester is increased, the peeling strength against the adhesive film does not increase.

Further, when the cerium oxide was contained in the polyfluorene oxide as in Comparative Example 4, the peeling strength against ACF was much smaller than that in the examples, and even if the content of cerium oxide was increased, the peeling strength against the adhesive film did not increase.

From the above results, according to the present invention, it is possible to prevent the peeling strength from being unstable and to prevent the peeling strength from being unstable, and to ensure the stable peeling strength without greatly impairing the performance of the adhesive film.

[Industrial availability]

The release film of the present invention is useful for protecting an adhesive film such as an anisotropic conductive adhesive film, and the release agent composition of the present invention is useful for forming a release layer of a release film.

1. . . Release film

2. . . Release substrate

3. . . Release layer

4. . . Subsequent layer

10. . . Next film

Fig. 1 is a cross-sectional view showing an example of a release film of the present invention.

Fig. 2 is a cross-sectional view showing an example of a film of the present invention.

Fig. 3 is a graph showing the dependence of the ACF peel strength on the amount of addition of the ceria-polyurethane hybrid composite.

Fig. 4 is a graph showing the dependence of the ACF peel strength on the amount of ethylcellulose solution added.

Fig. 5 is a graph showing the dependence of the ACF residual adhesion ratio on the amount of the alkoxy-containing decane-modified polyurethane resin solution.

Fig. 6 is a graph showing the dependence of the ACF residual adhesion ratio on the amount of ethyl cellulose solution added.

Claims (8)

A release agent composition comprising a polyoxyxylene resin, an alkoxy-containing decane-modified polyurethane resin, and a solvent, wherein the content of the alkoxy-containing decane-modified polyurethane resin is 0.5 by weight based on the ratio of the solid content component % or more and 50% by weight or less. The release agent composition of claim 1, which forms a sea-island structure by film formation, wherein the sea-island structure is a ceria-polyurethane mixed composite dispersed in an island shape in a continuous phase formed of a polyoxyl resin. . A release film having a release base substrate and a release layer disposed on one side of the release base substrate, the release layer being the release agent composition of claim 1 or 2 Hardened film. The release film of claim 3, wherein the release layer has a sea-island structure, and the sea-island structure is a ceria-polyurethane hybrid composite dispersed in an island shape in a continuous phase formed of a polyoxyl resin. An adhesive film comprising a release base substrate, a release layer disposed on one side of the release base substrate, and an adhesive layer disposed on the release layer, wherein the release layer is the first item of the patent application scope Or a cured film of the release agent composition of item 2. An adhesive film according to claim 5, wherein the release layer has a sea-island structure, and the sea-island structure is a ceria-polyurethane mixed composite dispersed in an island shape in a continuous phase formed of a polyoxyl resin. The adhesive film of claim 5 or 6, wherein the adhesive layer is composed of an anisotropic conductive adhesive in which conductive particles are dispersed in a binder resin. A method for producing a release film by coating a release agent composition of the first or second aspect of the patent application on a release base substrate to harden it to form a release layer.