JP5476680B2 - Release film - Google Patents

Description

The present invention relates to a release film.

The mold release film is sandwiched between the mold and the resin in order to release the resin (sealing material) from the mold after molding in the molding process of the resin using a molding apparatus. Used to release the molded resin and mold. However, when a general-purpose PET film or a highly heat-resistant polyimide film is used as the release film, the film elongation is small and the followability to the mold becomes insufficient, and the film is likely to be wrinkled. . In addition, the wrinkles of the generated film are transferred to the mold resin, the surface of the product is roughened, and the yield is reduced.

For the purpose of improving productivity and yield, a mold release film for resin molding made of a thermoplastic tetrafluoroethylene copolymer has been proposed (see Patent Document 1). Further, a release film for sealing a semiconductor chip is proposed, which is a laminated film in which a film made of a fluororesin is laminated on at least one surface of a base film made of a stretched polyester resin film (patent) Reference 2).

Further, a release laminated film having a layer made of a modified polyolefin resin and a layer made of an adhesive fluororesin laminated on at least one surface of the layer and interposed between a press plate of a press machine and a printed substrate. Has been proposed (see Patent Document 3). This release film is a release film for laminated press molding that presses a thermosetting adhesive at the time of lamination molding of wiring boards at high temperature and high pressure to mold the laminated product without deviation. In order to prevent the prepreg from flowing out, it is necessary to have cushioning properties, and the film thickness is about 0.1 mm.

JP 2001-310336 A JP 2006-49850 A International Publication No. 2005/115751 Pamphlet

However, with the improvement of the mold shape and sealing material, the mold release film has better followability and strength to the mold shape than the conventional mold release film, and also has low gas permeability. Is required.

An object of the present invention is to provide a release film excellent in followability to the shape of a mold, strength, and low gas permeability in view of the above-mentioned present situation.

The present invention comprises three layers of a fluorine-containing polymer layer, a fluorine-free polymer layer, and a fluorine-containing polymer layer, and the fluorine-free polymer layer is a three-layer intermediate layer, The total thickness is 70 μm or less, and the fluorine-containing polymer is at least one adhesive selected from the group consisting of a carbon-carbon double bond, a carbonyl group, a hydroxyl group, a cyano group, a sulfonic acid group, and an epoxy group. It is a release film characterized by having a functional functional group.

The present invention is described in detail below.

The release film of the present invention is characterized by comprising three layers of a fluorine-containing polymer layer, a fluorine-free polymer layer, and a fluorine-containing polymer layer.

Since the release film of the present invention has a fluorine-free polymer layer as an intermediate layer, it has excellent strength and low gas permeability, and further has a fluorine-containing polymer layer on both sides of the fluorine-free polymer layer. Excellent mold release properties for both molds and sealing materials. The mold release film of the present invention having such characteristics is a mold release resin mold used for injecting and curing a thermosetting resin (sealing material) into a mold to obtain a mold-shaped molded product. It can also be called a mold film.

The mold tends to have a deeper and more angular shape than before for the purpose of increasing the effective area and improving productivity. For example, although the conventional metal mold was R0.2 to 0.3, a metal mold reduced to R0.1 has been studied. In order to follow such a shape of the mold, it is required to follow the shape of the mold at an unprecedented level. Further, a release film that is required to follow the shape of such a mold is required to have unprecedented strength.

Since the total thickness of the three layers is 70 μm or less, the release film of the present invention is excellent in followability to the mold shape. When the thickness exceeds 70 μm, the follow-up is insufficient particularly in the angular shape portion of the mold, and wrinkles may occur or the shape of the molded product may be distorted.

The thickness of the release film of the present invention is preferably 50 μm or less, and preferably 15 μm or more in order to ensure the necessary strength.

In the release film of the present invention, the thickness of the fluorine-free polymer layer is preferably 10 to 45 μm, and the thickness of the fluorine-containing polymer layer is preferably 3 to 15 μm.

On the other hand, when the film is thinned as described above, the strength tends to be insufficient. However, since the release film of the present invention has a fluorine-free polymer layer, even if it is a thin film as described above, it has extremely excellent strength.

The release film of the present invention has releasability with respect to the sealing material. Although it does not specifically limit as said sealing material, An epoxy resin and a silicone resin are mentioned.

In recent years, worldwide interest in environmental issues has been increasing, and development of sealing materials corresponding to the environment has been promoted. Examples of such an environmentally friendly sealing material include a sealing material that does not contain lead, a sealing material that does not contain a halogen compound and an antimony compound that have been used as a flame retardant.

These environmentally friendly sealing materials have a higher melting point than conventional sealing materials, and generate pyrolysis gas when heated. When the pyrolysis gas permeates the release film, the mold in a high temperature environment is corroded to reduce the yield, so that the release film is required to have low gas permeability.

Since the release film of the present invention has a fluorine-free polymer layer, it does not allow the pyrolysis gas generated from the environmentally friendly sealing material to pass therethrough and can suppress the corrosion of the mold.

The release film of the present invention is further characterized in that the fluorine-containing polymer has an adhesive functional group. In a release film having a conventional laminated structure, an adhesive that is not thermosetting or thermosetting has been used in order to ensure adhesion between layers. When an adhesive that is not thermosetting is used, there is a problem that the adhesive is eluted from the release film during heating and causes contamination. In addition, when a thermosetting adhesive is used, there is a problem that when the film is stretched, the adhesion between the layers is lowered and delamination occurs. The release film of the present invention is excellent in adhesion to a fluorine-free polymer without using an adhesive.

In the release film of the present invention, the fluoropolymers constituting two of the three layers may be the same or different. The most preferable embodiment of the release film of the present invention is a release layer in which a fluorine-containing polymer layer, a fluorine-free polymer layer, and a fluorine-containing polymer layer are laminated in this order, and the layers are firmly bonded. It is a film.

The fluoropolymer has at least one adhesive functional group selected from the group consisting of a carbon-carbon double bond, a carbonyl group, a hydroxyl group, a cyano group, a sulfonic acid group, and an epoxy group.

The adhesive functional group has affinity or reactivity with a fluorine-free polymer. In the present specification, the term “affinity” means a property showing an interaction with a fluorine-free polymer such as a PI film that does not lead to a change in chemical structure, such as hydrogen bond, van der Waals force, etc. “Reactivity” means a property of changing a chemical structure such as a functional group.

The adhesive functional group is usually one that the fluorine-containing polymer has in the main chain or side chain.

Examples of the carbonyl group include a carbonate group, a halogenoformyl group, a formyl group, a carboxyl group, a carbonyloxy group [—C (═O) O—], an acid anhydride group [—C (═O) O—C ( = O)-], isocyanate group, amide group [-C (= O) -NH-], imide group [-C (= O) -NH-C (= O)-], urethane bond [-NH-C (═O) O—], carbamoyl group [NH ₂ —C (═O) —], carbamoyloxy group [NH ₂ —C (═O) O—], ureido group [NH ₂ —C (═O) — It may be a carbonyl group constituting a carbonyl group-containing functional group such as NH—] or an oxamoyl group [NH ₂ —C (═O) —C (═O) —].

The carbonate group is a group having a bond represented by [—OC (═O) O—], and —OC (═O) O—R group (wherein R is an organic group, a group IA atom, A IIA group atom or a VIIB group atom). Examples of the organic group in R in the above formula include an alkyl group having 1 to 20 carbon atoms, an alkyl group having 2 to 20 carbon atoms having an oxygen molecule constituting an ether bond, and preferably 1 to 8 carbon atoms. Or an alkyl group having 2 to 4 carbon atoms and having an oxygen molecule constituting an ether bond. Examples of the carbonate group include —OC (═O) O—CH ₃ , —OC (═O) O—C ₃ H ₇ , —OC (═O) O—C ₈ H ₁₇ , —OC (═O ) O-CH ₂ CH ₂ OCH ₂ CH _{3 and the} like.

The halogenoformyl group is represented by —COY (wherein Y represents a VIIB group atom), and —COF, —COCl and the like are preferable.

The fluorine-containing polymer preferably has a carbonyl group because it is advantageous in terms of heat resistance, mechanical properties, productivity, and cost, and is easily introduced and has a high reactivity. And at least one carbonyl group-containing functional group selected from the group consisting of halogenoformyl groups.

When the fluorine-containing polymer has only carbonate groups at the polymer chain end or side chain, the carbonate groups are extremely stable in the temperature range from room temperature (20 ° C.) to the molding temperature, so that the pellets can be handled easily. There is. In addition, there is a great difference in the reaction rate and the ease of reaction between the carbonate group and the carboxylic acid halide group. Therefore, when the fluorine-containing polymer has both a carbonate group and a carboxylic acid halide group, there is an advantage that the range of adhesion reaction conditions is widened and the adhesive strength is increased.

In addition, the above-mentioned fluorine-containing polymer is not only composed of a polymer chain having an adhesive functional group at one end or both ends of one polymer chain, but also has an adhesive functional group at one end or both ends. It may be a mixture of a polymer chain having a polymer chain not containing an adhesive functional group.

The number of the above-mentioned adhesive functional groups can be appropriately selected depending on the type, shape, application, required adhesive strength, difference in the type of the above-mentioned fluoropolymer, and the like. It is 3 or more per ⁶ pieces and less than 1000 pieces.

In the present specification, the number of the “adhesive functional groups” is measured by performing an infrared absorption spectrum analysis according to the method for measuring the number of carbonyl group-containing functional groups described in International Publication No. 99/45044. Is.

The number of adhesive functional groups is preferably 10 or more per 1 × 10 ⁶ main chain carbon atoms, more preferably 20 or more, and preferably 1000 or less.

When the number of the above-mentioned adhesive functional groups is 10 or more per 1 × 10 ⁶ main chain carbon atoms, the fluorine-free polymer can be used without performing a surface treatment or the like usually performed when the fluorine-containing polymer is bonded. Shows surprisingly strong adhesion.

When the number of the adhesive functional groups is 1000 or less per 1 × 10 ⁶ main chain carbon atoms, it is possible to suppress the generation of gas due to the chemical change of the adhesive functional groups, and to increase the adhesive force, Variation in adhesive force can be suppressed. Moreover, the heat resistance and chemical resistance of the fluorine-containing polymer can be improved.

The fluorine-containing polymer is a polymer (homopolymer or copolymer) having a repeating unit derived from at least one fluorine-containing ethylenic monomer.

The fluorine-containing ethylenic monomer is an olefinically unsaturated monomer having at least one fluorine atom, and specifically includes tetrafluoroethylene, vinylidene fluoride, chlorotrifluoroethylene, vinyl fluoride, hexafluoropropylene, hexa fluoro isobutene, formula ^{_{(ii): CH 2 = CX}} 1 (CF 2) n X 2 (ii)
[Wherein, X ¹ is H or F, X ² is H, F or Cl, and n is an integer of 1 to 10. ], A perfluoro (alkyl vinyl ether) and the like.

The fluorine-containing polymer may be a copolymer having the fluorine-containing ethylenic monomer unit and an ethylenic monomer unit having no fluorine.

The fluorine-containing ethylenic monomer and the ethylenic monomer having no fluorine are in an amount ratio of 10 to 100 mol% (for example, 30 to 100 mol%) and 0 to 90 mol% (for example, 0 to 70 mol%). Good.

The ethylenic monomer having no fluorine is preferably selected from ethylenic monomers having 5 or less carbon atoms in order not to lower the heat resistance and chemical resistance. Specific examples include ethylene, propylene, 1-butene, 2-butene, vinyl chloride, and vinylidene chloride.

Of these, a fluorine-containing polymer having a tetrafluoroethylene unit as an essential component in terms of heat resistance, and a fluorine-containing polymer having a vinylidene fluoride unit as an essential component in terms of molding processability are preferred.

In the fluorine-containing polymer, the crystal melting point or glass transition point of the polymer can be adjusted by selecting the type, combination, composition ratio, etc. of the fluorine-containing ethylenic monomer. It can be either of things. The properties of the fluorine-containing polymer can be appropriately selected according to the purpose and use of the adhesion and the purpose and use of the laminate.

Preferred examples of the fluoropolymer include (I) a copolymer containing tetrafluoroethylene units and ethylene units, (II) a polymer containing vinylidene fluoride units, and (III) tetrafluoroethylene. Units and Formula (i): CF ₂ = CF-Rf ¹ (i)
[Wherein, Rf ¹ is CF ₃ or ORf ² (Rf ² is a C 1-5 perfluoroalkyl group). ] The copolymer containing the unit of the monomer shown by this is mentioned.

As a copolymer (I) containing a tetrafluoroethylene unit and an ethylene unit, the tetrafluoroethylene unit is 20 to 90 mol% (for example, 20 to 60 mol) with respect to the whole monomer excluding the adhesive functional group-containing monomer described later. %), 10 to 80 mol% (for example, 20 to 60 mol%) of ethylene units, and a copolymer having a carbonyl group-containing functional group composed of 0 to 70 mol% of monomer units copolymerizable therewith.

As the copolymerizable monomer, hexafluoropropylene, chlorotrifluoroethylene, formula (ii): CH ₂ = CX ¹ (CF ₂ ) _n X ² (ii)
[Wherein, X ¹ is H or F, X ² is H, F or Cl, and n is an integer of 1 to 10. ], A perfluoro (alkyl vinyl ether), a propylene etc. are mention | raise | lifted and these 1 type (s) or 2 or more types are normally used.

Among these, (I-1) a copolymer having a carbonyl group-containing functional group comprising tetrafluoroethylene units 62 to 80 mol%, ethylene units 20 to 38 mol%, and other monomer units 0 to 10 mol%, (I-2) A carbonyl group-containing functional group comprising 20 to 80 mol% of tetrafluoroethylene units, 10 to 80 mol% of ethylene units, 0 to 30 mol% of hexafluoropropylene units, and 0 to 10 mol% of other monomer units. The copolymer having the tetrafluoroethylene / ethylene copolymer is preferable because it can maintain the excellent performance of the tetrafluoroethylene / ethylene copolymer, can have a relatively low melting point, and has excellent adhesion to a fluorine-free polymer.

As a polymer (II) containing a vinylidene fluoride unit, 10 to 100 mol% of vinylidene fluoride units, 0 to 80 mol% of tetrafluoroethylene units, based on the whole monomer excluding the adhesive functional group-containing monomer described later, A copolymer having a carbonyl group-containing functional group composed of 0 to 30 mol% of one or more units of hexafluoropropylene or chlorotrifluoroethylene is a preferred example.

More specifically,
(II-1) Polyvinylidene fluoride (PVdF) having a carbonyl group-containing functional group, (II-2) A carbonyl group-containing functional group comprising 30 to 99 mol% of vinylidene fluoride units and 1 to 70 mol% of tetrafluoroethylene units. (II-3) having a carbonyl group-containing functional group consisting of vinylidene fluoride units 60 to 90 mol%, tetrafluoroethylene units 0 to 30 mol%, and chlorotrifluoroethylene units 1 to 20 mol% Copolymer, (II-4) Copolymer having a carbonyl group-containing functional group comprising vinylidene fluoride units 60 to 99 mol%, tetrafluoroethylene units 0 to 30 mol%, hexafluoropropylene units 1 to 10 mol% , (II-5) vinylidene fluoride units 15-60 mol%, tetrafluoroethylene units 35-80 Le%, a copolymer having a carbonyl group-containing functional groups consisting of 5-30 mole% hexafluoropropylene units and the like.

Fluorine-containing polymer (II) having a carbonyl group-containing functional group containing a vinylidene fluoride unit is excellent in weather resistance and can be molded and processed at low temperature, so it does not have much heat resistance. Lamination with a polymer or the like is also possible.

As the polymer (III), (III-1) a carbonyl group comprising 65 to 95 mol%, preferably 75 to 95 mol% of tetrafluoroethylene units, 5 to 35 mol% of hexafluoropropylene units, and preferably 5 to 25 mol%. copolymer having a containing functional groups, (III-2) tetrafluoroethylene units 70 to 97 ^{_{mol%, CF 2 = CFORf 2 (}} Rf 2 is a perfluoroalkyl group having 1 to 5 carbon atoms) units 3 to 30 mol% A copolymer having a carbonyl group-containing functional group consisting of: (III-3) a carbonyl group-containing functional group consisting of a tetrafluoroethylene unit, a hexafluoropropylene unit, and a CF ₂ = CFORf ² (Rf ² is the same as above) unit. A copolymer having a hexafluoropropylene unit and a CF ₂ = CFORf ² unit of 5 to 3 A copolymer of 0 mol% is preferred.

These are also so-called perfluoro copolymers and are most excellent in heat resistance, chemical resistance, water repellency, non-adhesiveness, electrical insulation and the like among fluorine-containing polymers.

The mold with which the release film of the present invention comes into contact tends to have a deeper and more angular shape than before for the purpose of improving productivity. Also, the mold temperature tends to be higher. Accordingly, it is preferable that the release film has not only excellent strength but also excellent followability to the mold in a high temperature environment. Therefore, as the fluorine-containing polymer, a copolymer (I) containing a tetrafluoroethylene unit and an ethylene unit is particularly preferred from the viewpoint of excellent tensile elongation at high temperatures.

The fluoropolymer preferably has a melting point equal to or higher than the molding temperature at the time of molding. For example, since the semiconductor sealing material is molded at about 180 ° C., the melting point is preferably 200 ° C. or higher. Moreover, since the light emitting diode sealing material is molded at about 135 to 150 ° C., even if the melting point is less than 200 ° C., it can be used if it is 180 ° C. or higher.

In the present specification, the melting point is a temperature at the maximum value of the melting peak obtained by measuring with a differential scanning calorimeter (manufactured by Seiko) at a heating rate of 10 ° C./min.

The fluoropolymer can be obtained by introducing an adhesive functional group when producing a fluoropolymer by polymerization, but the method for introducing the adhesive functional group is not particularly limited. For example, (1) adhesion A method of copolymerizing an adhesive functional group-containing monomer having an adhesive functional group, (2) polymerization in an aqueous medium such as emulsion polymerization in the presence of a polymerization initiator having an adhesive functional group, and A method of introducing an adhesive functional group derived from the polymerization initiator; (3) an adhesive functional group obtained by changing a carbon-carbon single bond in a polymer chain to a double bond during polymerization or by heating after polymerization or the like; And the like, and the like.

In the method (1), for example, an adhesive functional group-containing monomer is copolymerized by a known method with a fluorine-containing monomer of the type and blending depending on the target fluorine-containing polymer and, optionally, a fluorine-free monomer. Can be done.

The copolymerization method is not particularly limited, and may be, for example, random copolymerization performed by introducing an adhesive functional group-containing monomer into the system when forming a polymer chain with another comonomer such as a fluorine-containing monomer. Further, block copolymerization or graft copolymerization may be used. Examples of graft copolymerization include a method of adding the unsaturated carboxylic acids to a fluoropolymer.

The “adhesive functional group-containing monomer” means a polymerizable compound having an adhesive functional group and may or may not have a fluorine atom. In the present specification, the above-mentioned “fluorine-containing monomer” and “fluorine-free monomer” do not have the adhesive functional group.

As the adhesive functional group-containing monomer (B), for example, when the adhesive functional group is a carbonyl group, perfluoroacrylic acid fluoride, 1-fluoroacrylic acid fluoride, acrylic acid fluoride, 1-trifluoromethacrylic acid fluoride. And monomers having fluorine such as perfluorobutenoic acid; monomers having no fluorine such as acrylic acid, methacrylic acid, acrylic acid chloride, and vinylene carbonate.

Examples of the adhesive functional group-containing monomer further include unsaturated carboxylic acids. In the present specification, the unsaturated carboxylic acids include at least one carbon-carbon unsaturated bond that enables copolymerization (hereinafter, also referred to as “copolymerizable carbon-carbon unsaturated bond”) in one molecule. And a compound having at least one carbonyloxy group [—C (═O) —O—] in one molecule. In particular, the copolymerizable carbon-carbon unsaturated bond is 1 What is one in a molecule | numerator is preferable.

Examples of the unsaturated carboxylic acids include aliphatic unsaturated carboxylic acids and acid anhydrides thereof. The aliphatic unsaturated carboxylic acid may be an aliphatic unsaturated monocarboxylic acid or an aliphatic unsaturated polycarboxylic acid having two or more carboxyl groups.

As said aliphatic unsaturated monocarboxylic acid, C3-C20 aliphatic monocarboxylic acid etc., such as propionic acid, acrylic acid, methacrylic acid, crotonic acid, those acid anhydrides, etc. are mentioned, for example. Examples of the aliphatic unsaturated polycarboxylic acid include maleic acid, fumaric acid, mesaconic acid, citraconic acid [CAC], itaconic acid, aconitic acid, itaconic anhydride [IAH] and citraconic anhydride [CAH].

As a polymerization initiator in the method of said (2), following formula (1)-(4):

[Wherein, R and R ′ are linear or branched monovalent saturated hydrocarbon groups having 1 to 15 carbon atoms, or linear or branched groups having 1 to 15 carbon atoms containing an alkoxy group at the terminal. A monovalent saturated hydrocarbon group, R ″ is a linear or branched divalent saturated hydrocarbon group having 1 to 15 carbon atoms, or a straight chain having 1 to 15 carbon atoms containing an alkoxy group at the end, or Represents a branched divalent saturated hydrocarbon group.] Is preferably used.

In particular, di-n-propyl peroxydicarbonate, t-butyl peroxyisopropyl carbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, and the like are preferable.

The amount of peroxycarbonate used varies depending on the type of polymer (composition, etc.), the molecular weight, the polymerization conditions, and the type of peroxycarbonate to be used, but is 0 with respect to 100 parts by mass of the polymer obtained by polymerization. 0.05 to 20 parts by mass, particularly 0.1 to 10 parts by mass is preferable.

As the polymerization method, suspension polymerization in an aqueous medium using a fluorine-containing solvent industrially and using peroxycarbonate as a polymerization initiator is preferable, but other polymerization methods such as solution polymerization, emulsion polymerization, Bulk polymerization can also be employed.

In suspension polymerization, a fluorine-containing solvent may be used in addition to water. Examples of the fluorine-based solvent used for suspension polymerization include hydrochlorofluoroalkanes (for example, CH ₃ CClF ₂ , CH ₃ CCl ₂ F, CF ₃ CF ₂ CCl ₂ H, CF ₂ ClCF ₂ CFHCl), chlorofluoroalkanes ( For example, CF ₂ ClCFClCF ₂ CF ₃ , CF ₃ CFClCFClCF ₃ ), perfluoroalkanes (eg, perfluorocyclobutane, CF ₃ CF ₂ CF ₂ CF ₃ , CF ₃ CF ₂ CF ₂ CF ₂ CF ₃ , CF ₃ CF ₂ CF ₂ CF ₂ CF ₂ CF ₃ ) can be used, among which perfluoroalkanes are preferred. The amount of the fluorine-based solvent is preferably 10 to 100% by mass with respect to water from the viewpoint of suspension stability during polymerization and economy.

The polymerization temperature is not particularly limited, but may be 0 to 100 ° C.

The polymerization pressure is appropriately determined according to other polymerization conditions such as the type, amount and vapor pressure of the solvent to be used, and the polymerization temperature, but may usually be 0 to 100 kgf / cm ² G.

In the production of the fluorine-containing polymer, in order to adjust the molecular weight, conventional chain transfer agents such as hydrocarbons such as isopentane, n-pentane, n-hexane and cyclohexane; alcohols such as methanol and ethanol; carbon tetrachloride and chloroform , Halogenated hydrocarbons such as methylene chloride and methyl chloride can be used.

The content of the terminal carbonate group can be controlled by adjusting the polymerization conditions. In particular, it can be controlled by the amount of peroxycarbonate used as a polymerization initiator, the amount of chain transfer agent used, the polymerization temperature, and the like.

In order to obtain a fluorine-containing polymer having a carboxylic acid halide group at the polymer molecule end, various methods can be employed. For example, the carbonate group of the aforementioned fluorine-containing polymer having a carbonate group at the end is thermally decomposed (desorbed). Carbonic acid).

Although it varies depending on the type of carbonate group and the type of fluorine-containing polymer, it is preferable that the polymer itself is heated to 270 ° C. or higher, preferably 280 ° C. or higher, particularly preferably 300 ° C. or higher. The upper limit of the heating temperature is preferably not higher than the thermal decomposition temperature of the portion other than the carbonate group of the fluoropolymer, specifically 400 ° C or lower, particularly preferably 350 ° C or lower.

The fluorine-containing polymer is preferably used alone as an adhesive material because it does not impair the adhesiveness, heat resistance, chemical resistance, etc. of the polymer itself, but it does not impair the performance depending on the purpose and application. Various fillers such as inorganic powder, glass fiber, carbon fiber, metal oxide, or carbon can be blended. In addition to the filler, a pigment, an ultraviolet absorber, and other optional additives can be mixed. In addition to additives, other fluorine-containing polymers, resins such as thermoplastic resins and thermosetting resins, and synthetic rubbers can also be blended to improve mechanical properties, improve weather resistance, impart design, Prevention, moldability improvement, etc. become possible.

The release film of the present invention has a fluorine-free polymer layer.

Examples of the fluorine-free polymer include polyester, polyamide, polyphenylene sulfide, acrylic, vinyl acetate, polyolefin, vinyl chloride, polycarbonate, styrene, polyurethane, acrylonitrile butadiene styrene copolymer (ABS), polyimide, polyamideimide, Polyetheretherketone (PEEK), polyethersulfone (PES), polysulfone, polyphenylene oxide (PPO), polyaramid, polyacetal, polyetherimide, silicone resin, epoxy resin, phenolic resin, amino resin, unsaturated polyester, cellulose derivative Etc.

Among these, a polymer material having a functional group having reactivity or affinity for the adhesive functional group in the molecule is preferable in terms of adhesiveness to the above-mentioned fluoropolymer. In the present invention, the functional group having reactivity with the adhesive functional group refers to a functional group that can react with the adhesive functional group at the time of molding to form a chemical bond when molding conditions described later are adopted. The functional group having an affinity for the adhesive functional group is a functional group capable of expressing a certain degree of intermolecular force with a polar group such as a carbonate group or a carboxylic acid halide group, and other than a carbon atom and a hydrogen atom. Is a functional group having at least one atom. Specifically, functional groups such as hydroxyl groups, carboxyl groups, carboxylates, ester groups, carbonate groups, amino groups, amide groups, imide groups, mercapto groups, thiolate groups, sulfonic acid groups, sulfonates, and epoxy groups. What has is preferable. (1) Polymer material with excellent heat resistance can withstand the high molding temperature required for fluorine-containing polymers and maintain the heat resistance of the entire laminate. It is preferable at the point which can obtain the laminated body which matched the characteristics of these. (2) It is preferable that it is a thermoplastic resin since it can be simultaneously bonded and molded with the above-mentioned fluoropolymer, that is, it can be melt-molded in multiple layers, and the crystal melting point is 270 ° C. or less. Furthermore, multilayer resins such as coextrusion can be applied to a thermoplastic resin having a temperature of 230 ° C. or lower, and the obtained laminate is preferable in that it exhibits excellent adhesion.

The non-fluorine-containing polymer is excellent in strength and low gas permeability, from polyamide, polyester, polycarbonate, polyvinyl chloride, polyacryl, polyvinyl acetate, polyolefin, polyvinyl alcohol, and ethylene / vinyl alcohol copolymer. More preferably, it is at least one selected from the group consisting of:

The fluorine-free polymer is more preferably at least one selected from the group consisting of polyamide and an ethylene / vinyl alcohol copolymer in that it is particularly excellent in low gas permeability.

Examples of the polyamide include (1) polyamide resin, (2) polyamide elastomer, and (3) polyamide resin alloy.

Specific examples are as follows.

(1) Ring-opening polymerization of cycloaliphatic lactam; condensation polymerization of aliphatic and / or alicyclic diamine and aliphatic and / or alicyclic dicarboxylic acid; condensation polymerization of aminocarboxylic acid; dimerization of unsaturated fatty acid A polyamide-based resin synthesized by copolymerization of a so-called dimer acid, a short-chain dibasic acid, and a diamine, which mainly contains a dicarboxylic acid having 36 carbon atoms obtained by

For example, nylon 6, nylon 66, nylon 11, nylon 12, nylon 610, nylon 612, nylon 6/66, nylon 66/12, nylon 46 and metaxylylenediamine / adipic acid polymer, or monomers constituting these And copolymers of dimer acids and blends thereof.

The average molecular weight of the polyamide resin is usually 5,000 to 500,000. Among these polyamide resins, nylon 6/66 is preferably used for the release film of the present invention.

(2) A polyamide elastomer which is an ABA block type polyether ester amide, polyether amide and polyester amide elastomer having a polyamide component as a crystalline hard segment and a polyether or polyester as a soft segment. This is obtained, for example, by a condensation reaction of lauryl lactam with dicarboxylic acid and polytetramethylene glycol.

The number of carbons of the repeating unit in the polyamide of the hard segment part, the chemical structure of the repeating unit of the soft segment part and the ratio thereof, or the molecular weight of each block can be freely designed from the viewpoint of flexibility and elastic recovery.

(3) Polyamide alloy (3.1) Polyamide / polyolefin alloy For example, DuPont Zytel ST, Asahi Kasei Corporation Leona 4300, Mitsubishi Chemical Corporation Nopamid ST220, Unitika Nylon EX1020, etc.

(3.2) Polyamide / polypropylene alloy For example, Systemer S manufactured by Showa Denko KK

(3.3) Polyamide / ABS alloy For example, Toyolac SX manufactured by Toray Industries, Inc.

(3.4) Polyamide / polyphenylene ether alloy For example, Noryl GTX600 manufactured by Japan GE Plastics, Remalloy B40 manufactured by Mitsubishi Chemical Corporation, and the like.

(3.5) Polyamide / polyarylate alloy For example, X9 manufactured by Unitika Co., Ltd. may be mentioned.

The release film of the present invention can be obtained from the fluorine-containing polymer and the fluorine-free polymer.

The fluorine-containing polymer and the fluorine-free polymer can be firmly bonded by hot-melt bonding because the fluorine-containing polymer has an adhesive functional group. Typical bonding methods include a hot roll method, a hot press method, a high frequency heating method, a vacuum pressure bonding method (such as a vacuum press), a pneumatic method, and a coextrusion method.

For example, a fluorine-containing polymer film may be prepared using a fluorine-containing polymer, overlapped with a film of a fluorine-free polymer, and bonded by hot melt bonding.

The coextrusion method is a method in which the fluorine-containing polymer and the non-fluorine-containing polymer are molded by coextrusion at a molding temperature, that is, a temperature at which the resin temperature during molding exceeds the respective crystal melting point or glass transition point. The coextrusion method is preferable in that the adhesion between the fluorine-containing polymer and the non-fluorine-containing polymer and the shaping into the target shape can be simultaneously and continuously achieved, so that the productivity is excellent and the adhesion performance is also good.

For these reasons, it is important to select a thermoplastic resin having a crystal melting point or a glass transition point of 270 ° C. or lower, and further a thermoplastic resin having a temperature of 230 ° C. or lower for both the fluorine-containing polymer and the fluorine-free polymer. Is preferable in terms of good.

Furthermore, it is preferable that the molding temperature, that is, the resin temperature at the time of molding is 350 ° C. or lower, and further 300 ° C. or lower, in terms of improving the interlayer adhesion and the appearance of the molded product.

When the molding temperature (resin temperature) is not higher than the crystal melting point or glass transition point of the fluorine-containing polymer or fluorine-free polymer, the fluidity of either the fluorine-containing polymer or fluorine-free polymer becomes insufficient, Adhesion between layers may not be sufficiently achieved, or appearance defects such as rough skin on the surface of the molded product may occur. If the molding temperature is too high, adhesion failure between layers or peeling may occur, or appearance defects such as foaming, rough skin, or coloring may occur at the surface of the molded body or at the interface between layers.

The release film of the present invention is sandwiched between a sealing material and a mold of a molding machine in the molding of a semiconductor sealing material or a light emitting diode sealing material, and the sealing material and the mold are released. It can be used as a mold release film for molding.

Since the release film of the present invention has the above-described configuration, it has high strength, low gas permeability, and excellent mold followability.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

Examples 1 and 2
Adhesive fluororesin ETFE pellets (Daikin Kogyo Neoflon ETFE EP-7000, melting point 255 ° C., MFR 20.6 g / 10 min (297 ° C., 49 N)) and fluorine-free resin pellets nylon 6.66 Novamide 2430J (Mitsubishi Engineer) 2 type 3 layer film was molded using a co-extruder equipped with a multi-die under the conditions shown in Table 1 to obtain a release film.

Example 3
Molded in the same manner as in Example 1 except that the fluororesin having adhesive properties was changed to EFEP pellets (Neoflon EFEP RP-5000, melting point 196 ° C., MFR 25.1 g / 10 min (265 ° C., 49 N) manufactured by Daikin Industries, Ltd.). A release film was obtained.

Comparative Examples 1 and 2
As the release film, ETFE, FEP (Neoflon ETFE, FEP film manufactured by Daikin Industries, Ltd.) was used.

Comparative Example 3
A release film was obtained by molding in the same manner as in Example 3 except that the thickness was 75 μm.

About the obtained release film, it evaluated by the following method, respectively.

Tensile strength (MPa) and tensile elongation (%)
Measurement was carried out by the method described in JIS K 7127 except that 23 ± 2 ° C. in 3.2 test temperature of JIS K 7127 was changed to 175 ° C. Measured for MD and TD. A 10 mm wide test piece was cut from the film and measured with a Tensilon universal testing machine (Orientec Co., Ltd.) at a speed of 500 mm / min.

Tear strength (N / mm)
It measured by the method as described in the trouser tear method of JISK7121-1. Measured for MD and TD. A test piece having a width of 50 mm and a length of 150 mm is cut from the film, and a test piece having a slit length of 75 mm is formed at the center of the test piece, and the test piece is made at a speed of 200 mm / min with a Tensilon universal testing machine (Orientec) It was measured.

Three sides of a 10cm square film with gas barrier properties are sealed with a heat-sealing machine to create a bag-like material, and a certain amount of sealing epoxy resin (environmental countermeasure product) is put therein, and the remaining portion is sealed, A sealed sample was made. The sample was placed in a dedicated sealed bottle, and the outgas after heating at 180 ° C. for 30 minutes was measured by GC-MS (Claras 500 (manufactured by Perkin Elmer)) by a head space sampling method. The gas barrier property was evaluated by comparing the outgas amount of the pyrolysis gas from the epoxy resin, with ○ indicating that the amount was small and × indicating that the amount was large.

Releasability, mold followability After mold release film is set in a mold at a constant temperature by a resin mold molding method, vacuum suction is applied from the hole at the top of the mold, and the release film follows the top shape of the mold. , Close contact. An uncured epoxy resin and silicone resin for sealing were made to flow there and held for 120 to 300 seconds to cure the resin, then the mold was opened and the molded product was demolded.

In the evaluation of releasability, a case where the releasability at the time of demolding was good was evaluated as “◯”, and a case where a tear occurred was evaluated as “X”. Evaluation of mold followability evaluates whether the film follows the mold shape completely, the film can withstand the molding pressure, and the molded product shape is molded as the mold shape. The case where there was no tearing was rated as “◯”, and the case where the shape of the molded product was poor, or the case where streaks, burrs, etc. occurred due to film tearing was marked as “X”.

The results are shown in Table 2.

The release film of the present invention can be suitably used for molding a sealing material such as a semiconductor and a light emitting diode.

Claims (2)

It consists of three layers: a fluoropolymer layer, a non-fluorine polymer layer, and a fluoropolymer layer,
The fluorine-free polymer layer is a three-layered intermediate layer,
The total thickness of the three layers is 70 μm or less,
The fluoropolymer has at least one adhesive functional group selected from the group consisting of a carbon-carbon double bond, a carbonyl group, a hydroxyl group, a cyano group, a sulfonic acid group, and an epoxy group,
The fluoropolymer is a copolymer containing a tetrafluoroethylene unit and an ethylene unit,
The release film for resin molding, wherein the fluorine-free polymer is nylon 6.66 . The release film according to claim 1, wherein the fluoropolymer has 3 or more adhesive functional groups per 1 × 10 ⁶ main chain carbon atoms.