JP2005146080A - Mold release film and laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-silicone mold release film which allows melt molding, has a satisfactory releasability to a rubber-based adhesive and yet maintains a strong remaining adhesive force on the adhesion surface after released and a laminate including the mold release film. <P>SOLUTION: The mold release film is used to form a mold release layer contacting with an adhesive layer, obtained by melt extrusion molding of a non-silicone-based thermoplastic resin composition and has a release force to a rubber-based adhesive of 5-100 mN/cm. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a release film and a laminate, and more particularly, to a non-silicone release film used for forming a release layer in contact with an adhesive layer and a laminate including the release film.

  Release films are widely used for the purpose of protecting the adhesive surface and the adhesive surface. As a constituent resin of the release film itself, a silicone polymer containing a siloxane unit is generally used. However, since such a silicone-based mold release agent contains a siloxane-based low molecular weight substance that is easily volatilized in the air and oxidized, when applied to precision applications such as an electronic member, an oxide of the siloxane-based low molecular weight material is present. It may cause troubles to stick. Therefore, there is a demand for a film that does not have a siloxane source and has a release property equivalent to that of a silicone release film. Silicone polymers are used after being dissolved in an organic solvent, applied to a substrate, and then dried and cured. However, a release film (or sheet) by a solvent-free process is required from the demand for reducing the environmental load. It has been.

  The most frequently used non-silicone release agents are long-chain alkyl polymers obtained by adding alkyl isocyanate to polyvinyl alcohol and polyethyleneimine, and polyolefin resins.

Long-chain alkyl polymers have excellent releasability, but are not suitable for solvent-free processes such as extrusion, and are used by a method of pressure-bonding and transferring to a base film (Patent Document 1). However, the release film obtained by such a method is insufficient in performance. On the other hand, a releasable resin composition comprising a polyolefin resin and a release agent is also excellent in melt moldability (unnecessary agent), and the release film obtained by extrusion molding is used as an acrylic pressure-sensitive adhesive. On the other hand, it has excellent releasability. However, the releasability with respect to the rubber-based pressure-sensitive adhesive is insufficient.
JP 2001-129930 A

  The present invention has been made in view of the above circumstances, and its purpose is that it can be melt-molded, has sufficient releasability with respect to a rubber-based adhesive, and has a pressure-sensitive adhesive surface after peeling. An object of the present invention is to provide a non-silicone release film having a large residual adhesive force and a laminate including the release film.

  That is, the first gist of the present invention is a release film used for forming a release layer in contact with an adhesive layer, which is obtained by a melt extrusion method of a non-silicone thermoplastic resin composition. The release film has a release force of 5 to 100 mN / cm with respect to the rubber-based adhesive.

  The second gist of the present invention resides in a laminate comprising the release film and a base sheet.

  The third gist of the present invention resides in a laminate comprising the above release film and an adhesive sheet.

  The fourth gist of the present invention resides in a laminate comprising the above release film, a base sheet and an adhesive sheet.

  According to the present invention, a non-silicone release agent that can be melt-molded, has sufficient releasability with respect to a rubber-based adhesive, and has a large residual adhesive force on the adhesive surface after peeling. A laminate including a mold film and the release film is provided.

  Hereinafter, the present invention will be described in detail. First, the release film of the present invention will be described. In the present invention, the term “film” is used as a broad concept including a “sheet” thicker than the film.

  The release film of the present invention is used to form a release layer in contact with the adhesive layer, obtained by a melt extrusion molding method of a non-silicone thermoplastic resin composition, and has a release force against a rubber adhesive. 5 to 100 mN / cm. Conventionally, such a light mold release force for a rubber-based pressure-sensitive adhesive has been achieved in a release film by a coating method in which a release agent solution is applied to a base material, but a non-silicone mold release by a melt extrusion molding method. It was not achieved in the film.

  The release force for the rubber-based pressure-sensitive adhesive specified in the present invention is obtained by pressing the release film on the pressure-sensitive adhesive surface of the rubber-based pressure-sensitive adhesive sheet (polyisobutylene / PET film) according to the method described in the examples below. It means a value obtained by performing a peel test on the adhesive laminate.

  When the above releasing force is less than 5 mN / cm, it is too lightly peeled and peeled by its own weight, and when it exceeds 100 mN / cm, it is too heavyly peeled and is not suitable for lightly peeling applications. The above releasing force is preferably 5 to 50 mN / cm.

  Moreover, the residual adhesive rate of the release film of this invention is 70% or more normally as a value measured according to the method shown in the below-mentioned Example, Preferably it is 90% or more. The migration of the release component is remarkable, and the adherend surface is contaminated with the release agent when the adhesive sheet is attached again after peeling.

  Examples of the material for the release film of the present invention include a peelable polymer (A) having a long-chain alkyl group having 12 to 30 carbon atoms and a polar polymer (B), and a peelable polymer (A ) And the polar polymer (B) can be used in a release resin composition having a weight ratio of 0.1: 99.9 to 20:80. The polar polymer (B) imparts moldability to the peelable polymer (A).

  When the carbon number of the long-chain alkyl group of the peelable polymer (A) is less than 12, sufficient peelability cannot be obtained. In addition, a compound having a long-chain alkyl group having more than 30 carbon atoms has a high possibility that a desired structure cannot be obtained because the reactivity at the time of preparing the peelable polymer (A) is poor. Carbon number of the long chain alkyl group of the peelable polymer (A) is preferably 12-22.

  The weight average molecular weight of the peelable polymer (A) is usually 10,000 to 1,000,000, preferably 20,000 to 1,000,000. When the weight average molecular weight is less than 10,000, it may move to the adhesive surface side during use (peeling off), which may cause contamination. On the other hand, when the weight average molecular weight exceeds 1,000,000, it may not be dispersed in the polar polymer (B) described later, and good peelability and residual adhesive strength may not be exhibited.

The fraction of the long-chain alkyl group of the peelable polymer (A) is usually selected from the range of 10 to 80% by weight, preferably 15 to 80% by weight. The fraction of the long-chain alkyl group here refers to the weight percentage of the long-chain alkyl group moiety in one molecule of the peelable polymer (A). The structure of the compound can be identified from a primary structure analysis by ¹³ C-NMR.

  The releasable polymer (A) is a reactive compound having a long-chain alkyl group having 12 to 30 carbon atoms in a polymer having a reactive group in the presence of a catalyst such as a tin compound or a tertiary amine in a suitable heating solvent. Can be made to react. Examples of the reactive group include a hydroxyl group, an amine group, a carboxyl group, and a maleic anhydride group. Examples of the polymer having a reactive group include polyvinyl alcohol, an ethylene-vinyl alcohol copolymer, polyethyleneimine, and polyethylene. Examples thereof include amines and styrene maleic anhydride copolymers. Here, the polyvinyl alcohol includes a partially saponified product of polyvinyl acetate, and the ethylene-vinyl alcohol copolymer includes a partially saponified product of an ethylene-vinyl acetate copolymer. In addition, examples of the alkyl group of the reactive compound having a long-chain alkyl group include a lauryl group, a stearyl group, and a behenyl group. Examples of the reactive compound include acid chloride, isocyanate, amine, alcohol, and the like.

  In particular, a peelable polymer produced by utilizing the reaction of an alkyl isocyanate compound is suitable. In this case, polyvinyl alcohol (PVOH) or ethylene-vinyl alcohol copolymer (EVOH) is preferably used as the polymer having a reactive group (hydroxyl group). The degree of polymerization of PVOH is usually 100 to 2,500, preferably 150 to 2,000, the degree of saponification is usually 50 to 100%, preferably 70 to 100%, and the degree of polymerization of EVOH is Usually 300 to 10,000, preferably 300 to 1,000, degree of saponification is usually 50 to 100%, preferably 70 to 100%, ethylene content is usually 1 to 90 mol%, preferably 5 to 60 mol. %. The usage-amount of an alkyl isocyanate compound is 0.2-1.1 equivalent normally per hydroxyl group equivalent, Preferably it is 0.5-1.1 equivalent.

  The peelable polymer (A) is composed of the radical polymerizable unsaturated group monomer having a long-chain alkyl group (stearyl (meth) acrylate, behenyl (meth) acrylate, stearyl vinyl ether, etc.) and other various types. It can also be produced by copolymerizing monomers. For polymerization, known peroxides and azo initiators usually used in thermal polymerization can be used, the polymerization method is not limited, and melt polymerization, suspension polymerization, solution polymerization, emulsion polymerization, etc. It can be adopted as appropriate. Accordingly, the polymerization solvent is not particularly limited, and a solvent suitable for each polymerization method may be selected. Moreover, you may superpose | polymerize without a solvent. The copolymer structure may be a random structure or a block structure, and may include a graft structure.

  As the polar polymer (B), for example, a polymer containing an olefin monomer and a polar monomer as structural units can be used. “As a structural unit” is synonymous with “as a raw material monomer”. The structural unit from the olefin monomer imparts extrudability and substrate adhesion to the olefin resin to the releasable resin composition of the present invention. The constitutional unit from the polar monomer is effective in expressing adhesion to a base material mainly composed of a polar resin such as PET, PVOH, nylon, etc., and its surface energy is compared with the peelable polymer (A). Since it is high, the long-chain alkyl group part of the peelable polymer (A) that functions as a peelable component also functions to effectively exist on the surface.

  Examples of the olefin monomer include ethylene, propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1 Examples include α-olefins having 3 to 20 carbon atoms such as -heptene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene. Two or more of these may be used in combination. In particular, ethylene is preferable from the viewpoint of excellent copolymerizability.

  Examples of the polar monomer include vinyl acetate, vinyl alcohol, (meth) acrylic acid, various (meth) acrylates such as methyl (meth) acrylate, and maleic anhydride. Two or more of these may be used in combination, and vinyl acetate or methyl acrylate is particularly preferable.

  Preferred specific examples of the polar polymer (B) include copolymers of ethylene and (meth) acrylic compounds, copolymers of α-olefin and (meth) acrylic compounds, ethylene, α-olefin and (meth) acrylic compounds. Copolymer, copolymer of ethylene and vinyl acetate, copolymer of α-olefin and vinyl acetate, copolymer of ethylene and α-olefin and vinyl acetate, ethylene-vinyl acetate-methyl acrylate copolymer, A saponified product of these vinyl acetate copolymers may be mentioned. The “(meth) acrylic compound” is a general term for an acrylic compound and a methacrylic compound.

  The polar polymer (B) may contain a constituent unit other than the olefinic monomer and the polar monomer as a constituent unit. In any case, the ratio of the olefinic monomer and the polar monomer to the monomer contained as a whole structural unit is usually 90% by weight or more, preferably 95% by weight or more. In addition, the structural unit formed from the olefin monomer and the polar monomer does not necessarily have a structure incorporated in the main chain, and may have a structure in which a part is grafted to the main chain.

  The proportion of the polar monomer contained as a structural unit in the polar polymer (B) is usually 5 to 50% by weight, preferably 10 to 30% by weight, based on the monomer contained as a whole structural unit. When the proportion of the polar monomer unit is less than 5% by weight, there is a possibility that the substrate adhesion to a substrate having a polar group such as PET, PVOH, nylon or the like on the surface is not sufficiently generated. Moreover, when the ratio of a polar monomer unit exceeds 50 weight%, there exists a possibility that the thermal stability of polar polymer (B) may fall and it cannot become melt-molding.

  The melt index (MI) of the polar polymer (B) as described above is usually 0.1 to 200 g / 10 min, preferably 0.1 to 100 g / 10 min. If it is less than 0.1 g / 10 min, the fluidity is poor and melt molding is difficult, and if it exceeds 200 g / 10 min, the fluidity is too high and uniform melt molding is difficult. Here, MI is a value measured in accordance with JIS K6758 under the conditions of 190 ° C. and 2.16 kg load.

Further, in the present invention, as the polar polymer (B) other than the above, a polymer having an atomic group exhibiting a strong intermolecular interaction and various surface energies obtained from a contact angle of 30 mJ / m ² or more. Polymers can be used. Specific examples of such polymers include polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon 6 and nylon 66, polymethacrylates such as polymethyl methacrylate, polyethylene glycol, Examples include polyalkylene glycols such as polypropylene glycol, polyvinyl alcohol, polyimide, polyphenylene sulfide, polyphenylene ether, and the like. In the case of these polymers, MI at a temperature 15.0 ° C. higher than the melting point (for crystalline polymers) or the glass transition temperature (for non-crystalline polymers) (according to JIS K6758, 2.16 kg load) The value measured under conditions) is usually 0.1 to 200 g / 10 min, preferably 0.1 to 100 g / 10 min, for the same purpose as described above. The melting point and glass transition temperature are measured in accordance with JIS K7122-1987 “Method for measuring the heat of fusion after a certain heat treatment” in 3 (2) of “Method for measuring the heat of transition of plastics”.

  For the polar polymer (B), as necessary, a defoaming agent, a coatability improver, a thickener, a surfactant, a lubricant, an organic particle, an inorganic particle, an antioxidant, an ultraviolet absorber, a dye A pigment, a polymer compound, a cross-linking agent and the like may be added. In order to improve solvent resistance and heat resistance, heat treatment, UV curing, electron beam curing, or the like may be performed.

  The weight ratio of the peelable polymer (A) and the polar polymer (B) is usually 0.1: 99.9 to 20:80. When the ratio of the peelable polymer (A) is less than 0.1 parts by weight, the releasability is not sufficiently exhibited. On the other hand, when the ratio of the peelable polymer (A) exceeds 20 parts by weight, the performance has reached saturation, which is disadvantageous in cost, and depending on the compatibility with the polar polymer (B), the dispersion is poor. As a result, when used as a release layer, there is a possibility of causing cohesive failure at the time of peeling from the pressure-sensitive adhesive surface, and further, moldability and adhesion to a substrate are inferior. The weight ratio of the peelable polymer (A) and the polar polymer (B) is preferably 0.5: 99.5 to 10:90, more preferably 0.5: 99.5 to 5:95. .

  A known method can be used as the melt extrusion method for obtaining the release film of the present invention. That is, a pellet of release film material is prepared, and this is extruded into a film from a melt extruder. The thickness of the release film is not particularly limited as long as it can be melt-extruded, but is usually 0.1 to 100 μm, preferably 0.5 to 20 μm. When the thickness is 0.1 μm, it is difficult to obtain a uniform thickness, so that the peelability may be inferior. When the thickness exceeds 100 μm, the cost increases.

  Next, the laminated body of this invention is demonstrated. The laminated body of this invention consists of said release film, a base material sheet, and / or an adhesive sheet. That is, in the laminate of the present invention, the release film and the base sheet and / or the pressure-sensitive adhesive sheet are integrated by forming respective layers.

  As the layer structure, a release film / base sheet, a release film / adhesive sheet, a release film / base sheet / adhesive sheet, a release film / adhesive sheet / base sheet, a base sheet / release film / An adhesive sheet is mentioned. Moreover, in this invention, it can also be set as the laminated constitution of a double-sided release film or a double-sided adhesive sheet. Specifically, release film / base sheet / release film, release film / adhesive sheet / base sheet / adhesive sheet / release film, and the like can be mentioned. These are appropriately selected depending on the purpose of use.

  As the material for the above-mentioned base sheet, conventional materials such as polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyolefins such as polypropylene, polyethylene and polymethylpentene, films made of resin such as polycarbonate, glassine paper, high-quality paper Further, paper such as coated paper, impregnated paper, and synthetic paper, metal foil such as aluminum and stainless steel, and the like may be used as appropriate. The thickness of a base material is 10-100 micrometers normally, Preferably it is 25-50 micrometers. The base material may be subjected to corona treatment, plasma treatment, flame plasma treatment, or a primer layer in order to improve adhesion to the release film or the pressure-sensitive adhesive sheet. As the primer layer, a polymer material (so-called anchor coat agent) such as polyethylene, polypropylene, styrene copolymer, polyester, polyurethane, polyvinyl alcohol, polyethyleneimine, polyacrylate, polymethacrylate, and modified products thereof is used. I can do it.

  As the material of the above-mentioned pressure-sensitive adhesive sheet, materials generally called pressure-sensitive adhesives such as acrylic, rubber-based, polyurethane-based, and silicon-based materials are mainly used, but other pressure-sensitive adhesives can also be used. In the present invention, a rubber-based pressure-sensitive adhesive is preferably used.

  The laminate of the present invention is a method of co-extrusion of a release film material and a base sheet material and / or an adhesive sheet material, a method of extrusion laminating a release film material on a base sheet, It is manufactured by a method such as extrusion laminating the material of the pressure-sensitive adhesive sheet on the release film. Moreover, it can replace with multilayer coextrusion molding, a multilayer inflation molding, multilayer blow molding, etc. are employable.

  The release film of the present invention is a release film for adhesive sheets such as adhesive sheets for surface protection and adhesive sheets for dicing used when processing silicon wafers used in various adhesive tapes, semiconductor integrated circuits (ICs) and the like. Can be used as a mold film. Moreover, the laminated body of this invention can also be used as a release film for semiconductor resin sealing. That is, the release film of the present invention can be used between the sealed surface of the semiconductor chip and the mold.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to a following example, unless the summary is exceeded.

  The materials used in the following examples are as follows.

(1) Base polymer 1:
Polyethylene terephthalate (PET) with an intrinsic viscosity of 0.75 dl / g

(2) Base polymer 2:
Copolymer of C2, C3 and C6 polymerized with metallocene catalyst (“Kernel KS340T” manufactured by Nippon Polyethylene Co., Ltd .: density = 0.880 g / cc, MI = 3.5 g / 10 min) (PO)

(3) Base film:
A polyester film (PET film) produced as follows was used. That is, 0.1% by weight of amorphous silica is contained in pellets of base polymer 1 (PET), melt-extruded from a T-die onto a cast drum, rapidly cooled to below the glass transition point, and substantially amorphous. Got the sheet. The obtained amorphous sheet was stretched 3.5 times in the longitudinal direction at 80 ° C. with a roll stretching machine, and further stretched 4.0 times in the transverse direction at 100 ° C. with a tenter stretching machine. Subsequently, heat fixation was performed at 230 ° C. for 2 seconds while maintaining the constant width, and further 5% relaxation was performed in the width direction at 160 ° C. to obtain a 38 μm thick polyester film, which was subjected to corona treatment.

(4) Polar polymer 1:
Ethylene / vinyl acetate copolymer (EVA); ethylene content determined by H-NMR was 75% by weight, and MI was 0.9 g / 10 min.

(5) Polar polymer 2:
Ethylene / methyl acrylate copolymer (EMA) (“Lex Pearl RB RB5120” manufactured by Nippon Polyolefin Co., Ltd.); methyl acrylate content was 10 wt%, MI was 20 g / 10 min.

(6) Release polymer 1:
A PVOH compound prepared as follows was used. That is, 300 g of a saponified product of polyvinyl acetate (saponification degree: 92 mol%, polymerization degree: 350) was placed in a four-necked flask equipped with a mechanical stirrer, a cooling tube and a rubber septum, and dimethyl sulfoxide 3 1,000 g and 50 g of dimethylformamide were added and heated to dissolve uniformly. Subsequently, the inside of the system was heated to 90 ° C., and 750 g of octadecyl isocyanate was added dropwise to the reaction over 4 hours, followed by further heating for 4 hours to complete the reaction. The obtained reaction product was poured into methanol and precipitated, followed by filtration. It was composed of a modified product of a saponified product of polyvinyl acetate, and had an octadecyl group as a long-chain alkyl group, and had a weight average molecular weight of 70,000. The peelable polymer 1 was obtained. As a result of DSC measurement, the peelable polymer 1 had melting peaks at 70 ° C. and 110 ° C. The long-chain alkyl group fraction was 60%.

(7) Peelable polymer 2:
A stearyl methacrylate (SMA) compound produced as follows was used. Specifically, 160 g of stearyl methacrylate and 1 g of hydroxyl methacrylate were placed in a four-necked flask equipped with a canal stirrer, a condenser tube, and a rubber septum, and 700 g of toluene was added thereto, followed by heating to 70 ° C. did. A nitrogen stream was introduced into the system from the nitrogen introduction tube, and nitrogen substitution was performed for 30 minutes. Thereafter, 1.2 g of AIBN as a polymerization initiator was added to start the reaction, and 90 g of stearyl methacrylate was gradually added dropwise from the rubber septum to carry out a polymerization reaction for 10 hours. After adding 5 g, heating was performed at 70 ° C. for 4 hours to complete the polymerization reaction. In this way, a peelable polymer 2 having a weight average molecular weight of 70,000 having a stearyl group as a long-chain alkyl group, comprising a stearyl methacrylate / hydroxyl methacrylate copolymer, was obtained. The peelable polymer 2 had a melting point at 35 ° C. The long-chain alkyl group fraction was 75%.

(8) Rubber adhesive sheet and adhesive laminate:
The pressure-sensitive adhesive sheet and pressure-sensitive adhesive laminate produced as follows were used. That is, first, 80 parts by weight of toluene and 20 parts by weight of polyisobutylene having a weight average molecular weight of 750,000 were placed in a flask with a reflux tube, heated to 100 ° C. and uniformly heated and dissolved, and then cooled to 25 ° C. Using an applicator (for 100 mm) manufactured by Dazai Equipment Co., Ltd., the above adhesive solution was placed on a PET film (biaxially stretched polyethylene terephthalate film with a thickness of 38 μm) and the thickness of the adhesive solution at 60 ° C. was 100 μm and the width was It applied so that it might become 8 cm. After coating, after 2 seconds, after drying for 2 minutes in a safe bend dryer “N50-S5” manufactured by Satake Chemical Equipment Co., Ltd. heated to 100 ° C., it is taken out and cooled to room temperature. A pressure-sensitive adhesive sheet having a thickness of 20 μm was obtained.

Then, after 2 minutes, the pressure-sensitive adhesive sheet was placed so that the pressure-sensitive adhesive surface of the pressure-sensitive adhesive sheet was in contact with the surface of the release layer of the release film obtained in the examples and comparative examples described later, and a 2 kg roller was placed from above. The pressure-sensitive adhesive was bonded by reciprocating at a speed of 30 cm / min to obtain a pressure-sensitive adhesive laminate in which a pressure-sensitive adhesive sheet was provided on the release film. The laminate was subjected to a load of 20 gf / cm ² and allowed to stand at 40 ° C. for 3 days.

  The physical property measurement (evaluation) methods used in the following examples are as follows.

(1) Measurement of release force:
The pressure-sensitive adhesive laminate obtained in the above (8) was cut to a width of 25 mm with a cutter knife, allowed to stand at room temperature for 1 hour, and then peeled 180 ° at a tensile speed of 300 mm / min with a tensile tester. The value obtained by dividing the average peel load in the region by the width was taken as the release force. During the peel test, a PET film, which is a base material of the pressure-sensitive adhesive sheet, was attached to a crosshead and peeled. The number of test points was an average of 8 points.

(2) Measurement of residual adhesion rate:
Using the pressure-sensitive adhesive sheet obtained by peeling the release film from the adhesive laminate obtained in (8) above, according to the method of JIS-C-2107 (adhesive strength to stainless steel plate, 180 ° peeling method) Then, the adhesive force F was measured. The pressure-sensitive adhesive sheet was directly stuck on a stainless steel plate, and then the adhesive force F0 when peeled after leaving at 40 ° C. for 3 days was measured. The percentage of F with respect to F0 was defined as the residual adhesion rate.

(3) Evaluation of substrate adhesion:
The release films obtained in the examples and comparative examples described later are cut to a width of 100 mm and a length of 150 mm, and a razor blade is inserted in parallel with the interface between the release layer and the base material layer, and a 1 cm length cut is made. Put. When the end of the release layer and the base material layer is held and pulled so as to widen the cut (so that it becomes T-shaped peeling), the base material layer or the pressure-sensitive adhesive layer is coherently broken. When the cohesive failure was observed in some places, it was marked as Δ. The case where the substrate layer and the release layer were peeled off at the interface was marked with x.

(4) Measurement of long-chain alkyl fraction in peelable polymer:
The fraction of long-chain alkyl in the peelable polymer was determined by ¹³ C-NMR. The measurement sample was prepared as a uniform solution by dissolving the peelable polymer in deuterated toluene to 5 wt% and heating to 90 ° C. The measurement temperature was 90 ° C. The device used was “JSX-400” manufactured by JEOR.

(5) Measurement of polar monomer content in polar polymer:
The amount (% by weight) of the polar monomer in the polar polymer was determined by H-NMR. The measurement sample was prepared as a uniform solution by dissolving the polar polymer in deuterated dichlorobenzene so as to be 5% by weight and heating to 130 ° C. The measurement temperature was 130 ° C. The device used was “JSX-400” manufactured by JEOL Ltd.

(6) Measurement of weight average molecular weight of peelable polymer:
The molecular weight distribution was measured by GPC “model-150C” manufactured by Waters. As the column, three “AD80MS” manufactured by Showa Denko KK were used. The measurement sample was prepared by dissolving the peelable polymer in toluene so as to be 2 mg / ml. The measurement temperature was 110 ° C. The weight average molecular weight was expressed in terms of polystyrene.

(7) Measurement of melt flow rate (MFR):
Based on JIS K6924-2, the measurement was performed at 190 ° C. under a 2.16 kg load condition.

(8) Measurement of melt flow intex (MI):
Using a melt indexer manufactured by Takara Co., Ltd., measurement was performed at 190 ° C. under a 2.16 kg load condition in accordance with JIS K6758.

Example 1
The peelable polymer 1 and the polar polymer 1 are weighed so as to have a weight ratio of 2:98, and melted at a temperature of 210 ° C. and a rotation speed of 100 rpm using a biaxial kneader (“KZW15” manufactured by Technobel). A release agent pellet was obtained by kneading. The release agent pellets and base polymer 1 (PET) pellets were coextruded at resin temperatures of 280 ° C. and 200 ° C., respectively, to obtain a laminate having a release layer. The total thickness of the laminate was 100 μm, and the thickness of the release layer was 2 μm.

Example 2
The peelable polymer 1 and the polar polymer 2 were weighed so as to have a weight ratio of 3:97, and the same biaxial kneader as in Example 1 was used, and melt kneading was performed at a resin temperature of 200 ° C. and a rotation speed of 230 rpm. Thus, a release agent pellet was obtained. The release agent pellets and the base polymer 2 (PO) pellets were coextruded at resin temperatures of 200 ° C. and 230 ° C., respectively, to obtain a laminate having a release layer. The total thickness of the laminate was 100 μm, and the thickness of the release layer was 20 μm.

Example 3
The releasable polymer 2 and the polar polymer 2 are weighed so as to have a weight ratio of 5:95, and the same biaxial kneader as in Example 1 is used and melt kneaded at a resin temperature of 190 ° C. and a rotation speed of 200 rpm. Thus, a release agent pellet was obtained. This release agent pellet was extrusion laminated on a base film (PET film) as a release layer to obtain a laminate having a release layer. The running speed of the PET film was 20 m / min. The temperature of the cooling roll provided immediately after the die was set to 35 ° C. The thickness of the obtained release layer was 21 μm.

Comparative Example 1
The peelable polymer 1 and the PO (nonpolar polymer) used as the base polymer 2 were weighed so as to have a weight ratio of 2:98, and the same biaxial kneader as in Example 1 was used. A release agent pellet was obtained by melt-kneading at a resin temperature of 210 ° C. and a rotational speed of 300 rpm. This release agent pellet and base polymer 1 (PET pellet) were coextruded at 200 ° C. and 280 ° C. resin temperatures, respectively, to obtain a laminate having a release layer. The total thickness of the laminate was 100 μm, and the thickness of the release layer was 18 μm.

Claims (7)

   A release film used for forming a release layer in contact with an adhesive layer, which is obtained by a melt extrusion molding method of a non-silicone thermoplastic resin composition and has a release force of 5 for a rubber adhesive. A release film, which is ˜100 mN / cm.   The constituent material of the release film contains a peelable polymer (A) having a long-chain alkyl group having 12 to 30 carbon atoms and a polar polymer (B), and the peelable polymer (A) and the polar polymer The release film according to claim 1, which is a release resin composition having a weight ratio with (B) of 0.1: 99.9 to 20:80.   The peelable polymer (A) is obtained by adding an isocyanate having a long-chain alkyl group having 12 to 30 carbon atoms to polyvinyl alcohol and / or a styrene-vinyl alcohol copolymer or polyethyleneimine, and has a weight average molecular weight of 1. The release film according to claim 2, which is a polymer of ˜1 million.   The release polymer according to claim 2, wherein the polar polymer (B) contains 5 to 50% by weight of a polar monomer selected from olefin and vinyl acetate, vinyl alcohol, acrylate, methacrylate, acrylic acid, and maleic anhydride. Mold film.   A laminate comprising the release film according to any one of claims 1 to 4 and a base sheet.   A laminate comprising the release film according to any one of claims 1 to 4 and an adhesive sheet.   A laminate comprising the release film according to any one of claims 1 to 4, a base sheet, and an adhesive sheet.