TWI621515B - Mold release film and method for manufacturing the same - Google Patents

Abstract

An object of the present invention is to obtain a release property (peelability) of an adhesive such as an acrylic resin-based adhesive, an epoxy resin-based adhesive, or the like, and also has no release property of a release layer, and is non-polluting. Sex release film. The present invention relates to a release film and a method for producing the same, wherein the release film is characterized in that it is on one side of a substrate layer, and the laminate layer has a density of 865 to 880 kg/m ³ and a melting point (Tm) of 70 ° C. The following release layer of ethylene and a random copolymer (B) of an α-olefin having 6 or more carbon atoms.

Description

Release film and method of manufacturing same

The present invention relates to a release film which is excellent in mold release property (peelability) of an adhesive such as an acrylic resin-based adhesive, an epoxy resin-based adhesive, and the like, and a method for producing the same.

In the adhesive tape wound in a coil form, the back surface of the substrate is subjected to release treatment so that the adhesive layer is easily peeled off from the back surface of the substrate, or the pressure-sensitive property for bonding of various articles is followed. The sheet is provided with a mold release liner for the purpose of protecting the adhesive layer for the purpose of use.

In the manufacturing process of a printed wiring board, a flexible printed wiring board, or a multilayer printed wiring board, it is used when hot-pressing a copper-clad laminate or a copper foil via a prepreg or a heat-resistant film. Release film. Further, in the manufacturing process of the flexible printed circuit board, a coverlay film or a reinforcing plate is thermocompressed to form a circuit using an epoxy resin thermosetting adhesive or a thermosetting adhesive sheet. Circuit board for flexible printed circuit board body, in order to prevent The cover film and the hot platen are then used as a release film.

As a release agent for the release treatment of the back surface of such a substrate or a release liner such as a surface of an adhesive layer, or a release film for a manufacturing process of a printed wiring board, silicone is generally used. It is a release agent. For example, an anthrone-based release agent such as dimethylpolysiloxane is applied onto the surface of a substrate (surface having no adhesive layer), and is irradiated with temperature, light, electron beam, or the like. Crosslinking, a method of improving the release property of the surface of the substrate and the adhesive layer in contact with the release film.

However, in the case of a roll-shaped adhesive tape, there is a low molecular weight fluorenone resin or a decane which is contained in an oxime-based release agent applied to the surface of the substrate (the surface having no adhesive layer). The oxime compound such as silicone oil is transferred to the adjacent adhesive layer to lower the adhesive performance. In addition, in the case of a pressure-sensitive adhesive sheet, if it is used for fixing electronic parts, etc., the fluorenone compound transferred to the adhesive layer generates a fluorinated gas, which may cause corrosion or malfunction of the electronic device. The problem.

As a method for solving the above problems, a method of replacing an anthrone-based release agent with an ethylene ‧ α-olefin random copolymer having a density of 0.80 to 0.90 g/cm ³ and a melting point of 80 ° C or less has been proposed (Patent Document 1) Japanese Laid-Open Patent Publication No. 55-65281; the ethylene-α‧ olefin copolymer resin having a crystallinity of 40% or less is formed by a support substrate for a release sheet and a polyolefin resin layer interposed therebetween. A method of releasing a release sheet which is characterized by a release agent layer (Patent Document 2: Japanese Laid-Open Patent Publication No. Hei 6-99551). Further, as a method for improving the extrusion processability of the ethylene/α-olefin random copolymer, it has been proposed to use a vinyl ‧ α-olefin random copolymer having a density of 0.80 to 0.90 g/cm ³ in the release agent layer and A method of synthesizing a composition of a polyethylene resin having a density of 0.902 to 0.912 g/cm ³ using a metallocene catalyst (Patent Document 3: Patent No. 4531911).

However, the ethylene ‧ α -olefin random copolymer having a density of 0.80 to 0.90 g/cm ³ described in Patent Document 1 or Patent Document 2 or a crystallinity of 40% or less (density of 0.8 to 0.95 g/cm ³ ) is used. In the case of a vinyl ‧ α -olefin random copolymer as a release layer, there is still a concern that the release property from the acrylic resin-based adhesive layer is poor.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Laid-Open Patent Publication No. 55-65281

[Patent Document 2] Japanese Patent Laid-Open No. 6-99551

Patent Document 3: Japanese Patent No. 4531911

An object of the present invention is to obtain a release property (peelability) of an adhesive such as an acrylic resin-based adhesive, an epoxy resin-based adhesive, or the like, and also has no release property of a release layer, and is non-polluting. Sex release film.

The present invention relates to a release film and a method for producing the same, wherein the release film is characterized in that it is on one side of a substrate layer, and the laminate layer has a density of 865 to 880 kg/m ³ and a melting point (Tm) of 70 ° C. The following release layer of ethylene and a random copolymer (B) of an α-olefin having 6 or more carbon atoms.

The release film of the present invention has a peel strength of 0.3 to 0.4 N/50 mm, which is excellent in peeling strength with respect to an adhesive such as an acrylic resin adhesive, an epoxy resin adhesive, or the like, and is excellent in peelability. Since the release layer adheres and has a non-fluorenone-based release layer, it does not have contamination due to the ruthenium compound, and the non-contaminating residual adhesion ratio is also about 90%, which is good. Further, the release layer of the release film of the present invention is also excellent in writeability.

<Substrate layer>

The base material layer constituting the release film of the present invention contains various known thermoplastic resins such as polyolefin (polyethylene, polypropylene, poly-4-methyl‧1-pentene, poly-1-butene, etc.); Polyester (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate); polyamine (nylon 6, nylon 66, polyhexamethylene diamine) (polyadipamide)), polyvinyl chloride; polyimine; saponified product of ethylene, vinyl acetate copolymer; polyvinyl alcohol; polyacrylonitrile; polycarbonate; polystyrene; ionomer; a mixture of membranes, etc. Among these thermoplastic resins, polyesters such as polyethylene terephthalate, polybutylene terephthalate or polyethylene naphthalate; polyamines; extensibility of polypropylene, etc., A thermoplastic resin with good transparency.

The substrate layer of the present invention may be a non-stretched film, or may be a one-axis stretch film or a biaxially stretched film.

Further, the substrate layer of the present invention may be one layer or a plurality of layers of two or more layers.

Among these base materials, a biaxially stretched film of polyester including polyethylene terephthalate, polybutylene terephthalate or polyethylene naphthalate is excellent in solvent resistance and heat resistance. Especially good.

In order to improve the adhesion to the release layer, the surface of the substrate layer of the present invention may be previously subjected to, for example, corona treatment, plasma treatment, undercoat treatment, and primer coating. Surface activation treatment such as primer coat treatment or frame treatment.

<ethylene‧α-olefin random copolymer (B)>

The ethylene ‧ α-olefin random copolymer (B) constituting the release layer constituting the release film of the present invention has a density of 865 to 880 kg/m ³ , preferably 867 to 875 kg/m ³ ; and a melting point (Tm) The carbon number of 70 ° C or less, preferably 65 ° C or less, and the carbon number is 6 or more, preferably 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, or the like. It is a random copolymer of 6 to 10, more preferably an α-olefin having 8 to 10 carbon atoms.

In the present invention, the copolymer having a melting point (Tm) of 70 ° C or less is a vinyl ‧ α-olefin random copolymer containing a melting point (Tm) which is not clearly expressed, that is, has no melting point (Tm).

A vinyl ‧ α-olefin random copolymer having a density of more than 880 kg/m ³ or a random copolymer of ethylene ‧ α-olefin having a melting point (Tm) exceeding 70 ° C is present even if it is used for a release layer of a release film ‧ Doubt about the poor peelability of the adhesive layer.

Further, an ethylene ‧ α-olefin random copolymer having a density of more than 880 kg/m ^{3 or} an ethylene ‧ α-olefin random copolymer having a melting point (Tm) of more than 70° C. is insoluble in an organic solvent such as toluene or hexane. Therefore, it is difficult to form a release layer having a uniform thickness.

When the density and the melting point (Tm) of the ethylene ‧ α -olefin random copolymer (B) of the present invention fall within the above range, the ethylene content is not particularly limited, but the ethylene content usually falls within the range of 85 to 92 mol%. In the range.

The ethylene ‧ α-olefin random copolymer (B) of the present invention usually has a melt flow rate (MFR) (load: 2160 g, temperature: 190 ° C) of 0.1 to 50 g/10 minutes, preferably 0.2 Within the range of 20g/10 points.

The ethylene ‧ α-olefin random copolymer (B) of the present invention is produced by various known production methods, and specifically, ethylene or α-olefin is randomly copolymerized by using a vanadium catalyst or a metallocene catalyst. be made of.

Further, the ethylene ‧ α-olefin random copolymer (B) of the present invention is produced and sold from Mitsui Chemicals Co., Ltd. under the trade name of TAFMER H5030 as a vinyl ‧ 1-octene random copolymer.

<release film>

The release film of the present invention is obtained by laminating a release layer containing the ethylene ‧ α-olefin random copolymer (B) on one side of the base material layer.

The thickness of the base material layer of the release film of the present invention is usually from 10 to 200 μm, preferably from 15 to 100 μm, more preferably from 25 to 50 μm.

The thickness of the release layer of the release film of the present invention is usually from 0.025 to 0.20 μm, preferably from 0.050 to 0.15 μm, more preferably from 0.075 to 0.125 μm. When the thickness of the release layer is less than 0.025 μm, the peeling strength of the adhesive/adhesive agent such as an acrylic resin adhesive, an epoxy resin adhesive, or the like may exceed 1 N/50 mm. On the other hand, when the thickness of the mold release layer is increased, the peel strength is further lowered, but the state of the surface of the release layer is deteriorated, the smoothness is lowered, and the operation is performed. Suspicion of reduced sexuality.

The release film of the present invention is also characterized in that the thickness of the release layer is as thin as 0.050 to 0.15 μm.

In the release film of the present invention, the peel strength of the adhesive, such as an acrylic resin adhesive, an epoxy resin adhesive, or the like, is usually 0.1 to 1 N/50 mm, preferably 0.1 to 0.7 N/ Within the range of 50mm.

<Method for Producing Release Film>

The release film of the present invention is obtained by coating and drying a solution of the ethylene ‧ α-olefin random copolymer (B) of the present invention on one side of a substrate layer obtained in advance.

The production method of the present invention is a method of applying and drying a solution of the ethylene ‧ α -olefin random copolymer (B), so that the thickness of the release layer can be as thin as 0.025 to 0.20 μm , preferably 0.050 to 0.15 μ. m is therefore preferred.

The solvent for adjusting the solution of the ethylene ‧ α-olefin random copolymer (B) may, for example, be an aliphatic hydrocarbon such as n-decane, n-heptane or n-hexane; or an aromatic hydrocarbon such as toluene or xylene; An alicyclic hydrocarbon such as naphthalene or tetrahydronaphthalene; an organic solvent such as methyl ethyl ketone or methyl isobutyl ketone or a mixed solvent thereof; preferably a toluene ‧ methyl isobutyl ketone mixed solvent (9/ 1: mass ratio).

As a method of applying a solution of the ethylene‧α-olefin random copolymer (B) to the substrate layer, a method of applying the solution to the surface of the substrate layer, a method of immersing the substrate layer in the solution, and a method may be employed. Various known coating methods, such as a method of spraying the solution on the surface of the material layer.

For example, an air knife coater method olefin random copolymer (B) solution (air knife coater) - as a coating on the substrate layer ‧ α ethylene; direct gravure coater (direct gravure coater), gravure offset ( Gravure offset), arc gravure coater, gravure reverse and gravure coater; top feed reversal coater (top Feed reverse coater), bottom feed reverse coater, reverse roll coater such as nozzle feed reverse coater; five-roll coater (5) -roll coater; lip coater; bar coater; bar reverse coater; various known coatings such as die coaters machine, and ethylene ‧ α - olefin random copolymer (B) solution (solid content) gauge becomes 0.05 ~ 10g / m ^2, coating can be preferred to be 0.1 ~ 5g / m ² and a .

The coating temperature of the solution can be usually carried out at a normal temperature, for example, 10 to 40 ° C, preferably 15 to 30 ° C, but the ethylene ‧ α-olefin random copolymer (B) is difficult to dissolve in the solvent at normal temperature Depending on the solvent used, it can also be heated to a temperature less than the boiling point.

Further, the coated solution is usually dried at a temperature of 70 to 120 ° C, preferably 90 to 100 ° C.

Example

Next, the present invention will be more specifically described by the examples, but the present invention is not limited by the examples.

The ethylene ‧ α-olefin random copolymer used in the examples and the comparative examples is as follows.

(1) Ethylene ‧ α-olefin random copolymer (B)

(1-1) Ethylene ‧ 1-octene random copolymer (B1)

Density = 870 kg/m ³ , melting point (Tm) = 62 ° C, MFR = 5.0 g/10 min (manufactured by Mitsui Chemicals, Inc.: trade name TAFMER H5030S).

(2) Ethylene ‧ α-olefin random copolymer

(2-1) Ethylene ‧ 1-butene random copolymer (C1)

Density = 893 kg/m ³ , melting point (Tm) = 82 ° C, MFR = 3.6 g / 10 min (Mitsui Chemical Co., Ltd.; trade name TAFMER A4090S)

(2-2) Ethylene ‧ propylene random copolymer (C2)

Density = 869 kg/m ³ , melting point (Tm) = 38 ° C, MFR = 3.0 g/10 min (manufactured by Mitsui Chemicals, Inc.: trade name TAFMER P-0280)

(2-3) Ethylene ‧ 1-butene random copolymer (C3)

Density = 870 kg/m ³ , melting point (Tm) = 52 ° C, MFR = 3.6 g / 10 min (manufactured by Mitsui Chemicals, Inc.: trade name TAFMER A4070S).

The physical properties and the like of the examples and comparative examples were determined by the following evaluation methods.

<Evaluation method>

(1) Determination of melting point (Tm) (°C)

5 mg of the fine scale sample was heated from -50 ° C to 200 ° C at a temperature increase rate of 10 ° C / min using a differential scanning calorimeter (DSC Q100) manufactured by TA Instruments, and held at 10 ° C for 10 minutes. The cooling rate of the fraction was cooled to -50 ° C, and after 5 minutes, the temperature was raised again at a temperature elevation rate of 10 ° C /min, and the temperature of the maximum peak indicated by the melting endothermic curve was taken as the melting point.

(2) Preparation of solution

The ethylene ‧ α-olefin random copolymer described above was prepared at a normal temperature to prepare a solution having a concentration of 1% by mass of toluene/methyl isobutyl ketone=9/1 (mass ratio).

(3) Peeling force [N/50mm]

The release film obtained in the examples and the comparative examples was placed on a water platform with the release layer facing upward, and an adhesive tape "No. 31B" (manufactured by Nitto Denko Corporation) was attached to the release layer, and cut into The size of 200 mm × 50 mm was further placed on the upper side of the adhesive tape so as to be 20 g/cm ² , and aging was performed at 70 ° C for 20 hours.

After the aging, the tensile tester was used to perform 180° peeling at a tensile speed of 300 mm/min, and the average peeling load in the field of peeling stability was divided by the value of the adhesive tape width as the peeling force.

(4) Residual adhesion rate [%]: The release film obtained in the examples and the comparative examples was placed on the water platform with the release layer facing upward, and the adhesive tape "No. 31B" was attached to the release layer. (manufactured by Nitto Denko Co., Ltd.), and cut into a size of 200 mm × 50 mm, and the upper portion of the adhesive tape was loaded at 20 g/cm ² , and aged at 70 ° C for 20 hours.

After aging, the release film was peeled off, and the adhesive tape was pressed back and forth to the stainless steel plate three times with a 2 kg rubber roller, and heat-treated at 70 ° C for 2 hours. Thereafter, the adhesion force F was measured in accordance with the method of JIS-C-2107 (adhesion to stainless steel sheets, 180° peeling method). F is obtained by directly adhering the adhesive tape "No. 31B" to the stainless steel plate and the percentage of the adhesion force F0 (F/F0 × 100) at the time of peeling off as the residual adhesion ratio.

(5) Coating property (appearance)

The release surface of the obtained release film was visually confirmed to be ○ when a uniform film was formed, and × when no uniform film was formed.

[Example 1]

Using a wire rod (meyer bar) No. 4, which will be used as a release layer and described above. A solution of the ethylene ‧ 1-octene random copolymer (B1) adjusted in a method is applied to a biaxially-oriented polyethylene terephthalate film having a thickness of 31 μm and a stretching ratio of 3 × 3 as a substrate film ( One side of the product manufactured by Toray Industries, Inc., trade name LIMIRROR R58) was dried in an oven at 95 ° C for 20 seconds to obtain a release film.

The obtained release film was evaluated by the method described above. The results are shown in Table 1.

[Comparative Example 1]

The ethylene ‧ 1-butene random copolymer (C1) was used in place of the ethylene ‧ 1-hexene random copolymer (B1) used in Example 1, but C1 was insoluble in toluene/methyl isobutyl ketone, The release film cannot be obtained.

[Comparative Example 2]

The mold release was carried out in the same manner as in Example 1 except that the ethylene ‧ propylene random copolymer (C2) was used instead of the ethylene ‧ 1-hexene random copolymer (B1) used in Example 1. membrane. The results of the obtained release film are shown in Table 1.

[Comparative Example 3]

The same procedure as in Example 1 was carried out except that the ethylene ‧ 1-butene random copolymer (C3) was used instead of the ethylene ‧ 1-hexene random copolymer (B1) used in Example 1, and A release film was obtained. The results of the obtained release film are shown in Table 1.

As is clear from Table 1, the release strength of the release film obtained by using the ethylene/α-olefin random copolymer (B) of the present invention is 0.34 N/50 mm, and the mold release property is excellent. The peeling strength of the release film of the ethylene ‧ α-olefin random copolymer of the invention is as strong as 11.5 N/50 mm, and the mold release property is not good.

[Usage possibilities]

The release film of the present invention is excellent in mold release property and can be used as a release film for an acrylic adhesive or an epoxy adhesive, and is used for a back grind tape or a dicing tape for semiconductor manufacturing engineering. A mold release film or an industrial release film such as a printed wiring board, a flexible printed wiring board, or a multilayer printed wiring board.

Claims (3)

A release film characterized in that it is on one side of a base material layer, and the laminate comprises ethylene having a density of 865 to 880 kg/m ³ , a melting point (Tm) of 70 ° C or less, and an α -olefin having a carbon number of 8 or more. The release layer of the random copolymer (B), wherein the release layer has a thickness of 0.025 μm to 0.15 μm . The release film of claim 1, wherein the substrate layer is a polyester film. A method for producing a release film, comprising: a random copolymer of ethylene having a density of 865 to 880 kg/m ³ , a melting point (Tm) of 70 ° C or less, and an α -olefin having a carbon number of 8 or more (B) The solution is applied and dried on one side of the substrate layer, and the thickness after drying is in the range of 0.025 μm to 0.15 μm .