JP5288422B2 - Release film - Google Patents

Description

  The present invention relates to an optical semiconductor element or a release film used for resin molding of a semiconductor element, and particularly, for resin molding of an LED lens.

  For example, optical semiconductor elements such as LEDs, photoisolators, phototransistors, photodiodes, CCDs, CMOSs, and semiconductor elements such as transistors, ICs, LSIs, and super LSIs are encapsulated with silicone resin compositions or epoxy resin compositions. And sealed by resin molding.

  A molding apparatus is used for sealing the above-described optical semiconductor element and semiconductor element, and a sealing material made of a silicone resin composition or an epoxy resin composition is injected into the mold as a molding resin and molded.

  As a method for releasing the mold from the molded product, for example, a method in which a release film is interposed between the mold and the mold resin has been put into practical use (for example, see Patent Document 1). The mold release film is supplied Roll-to-Roll in the mold forming apparatus, enters the mold mold adjusted to the molding processing temperature, is sucked in vacuum and adheres to the mold mold, and then filled with mold resin. Is done. When the mold die is opened when the mold resin is cured after a certain time, the molded product is peeled off from the mold release film while the mold release film is sucked into the mold die. The release film includes, for example, a single layer made of a thermoplastic fluororesin tetrafluoroethylene-ethylene copolymer resin (ETFE resin) or a tetrafluoroethylene-hexafluoropropylene copolymer resin (FEP resin). A film is used (see, for example, Patent Document 2).

  However, when such a release film is used for molding an LED lens using a silicone resin composition as a mold resin, for example, for a shell-type lens shape having a bottom surface of about φ6 mm and a height of about 4 mm. Even if the mold film is sucked in a vacuum, the mold film may not be stretched. Even if the mold film is stretched, the mold film does not adhere to the mold mold, and there is a problem that the LED lens as designed can not be obtained. Further, when the elongation is improved by reducing the thickness of the release film, there is a problem that the release film is cut at the edge of the mold when sucked in vacuum.

  Moreover, the method of using the film which consists of a resin composition containing crystalline aromatic polyester which contains butylene terephthalate in a crystal | crystallization component is known as a mold release film (for example, refer patent document 3).

  However, as shown in Patent Document 3, when a film made of a resin composition containing a crystalline aromatic polyester containing butylene terephthalate is used for molding an LED lens, the release film is sucked in vacuum as shown in Patent Document 3. In this case, the film adheres to the mold, but is stretched beyond the yield point, so that the release film is partially thinned, and there is a problem that irregularities and wrinkles occur on the surface of the molded LED lens. For this reason, in resin mold molding of LED lenses, there is actually no film that can be suitably used as a release film.

JP-A-8-142105 JP 2001-310336 A JP 2007-224311 A

  The present invention has been made in view of the above, and is excellent in releasability from a mold and a molded product, and is excellent in mold shape transferability in which the shape of the mold is transferred to a molded product according to a design dimension. An object of the present invention is to provide a release film that can obtain the surface smoothness of a molded product and that also has heat resistance at a use temperature of around 140 ° C.

  Such an object is achieved by the present inventions (1) to (11) below.

  (1) A release film characterized by comprising a polyurethane elastomer alone having a JIS A hardness of 70 or more and a Vicat softening temperature of 100 to 180 ° C. or a thermoplastic elastomer composition mainly composed of the polyurethane elastomer. .

  (2) The release film according to (1), wherein the polyurethane elastomer is a thermoplastic polyurethane elastomer obtained by a reaction of three components of polyisocyanate, polyol and chain extender.

  (3) The polyol is one selected from a polymer polyol having a number average molecular weight of 500 to 10,000 belonging to the group consisting of polyester polyol, polyesteramide polyol, polycarbonate polyol, polyether polyol, polyether ester polyol, and polyolefin polyol. Or the film for mold release as described in (2) characterized by being plural.

  (4) The chain extender is selected from active hydrogen-containing compounds having a number average molecular weight of less than 500 belonging to low-molecular polyols, low-molecular polyamines, and low-molecular amino alcohols (2) or (3) Mold release film.

  (5) The thermoplastic elastomer composition is a composition containing a fluorosurfactant in a range of 0.05 to 5.0 parts by mass with respect to 100 parts by mass of the polyurethane elastomer (1). ) To (4).

  (6) The release film according to (5), wherein the fluorosurfactant is a perfluoroalkylsulfonic acid derivative compound having a melting point of 250 ° C. or lower and a decomposition temperature of 300 ° C. or higher.

  (7) The thermoplastic elastomer composition further includes one or more additives belonging to a lubricant, an anti-blocking agent, an antioxidant, and a phosphorus-based antioxidant (1) to (6). The release film according to any one of the above.

(8) The tensile elastic modulus of the film is in the range of 10 to 500 N / mm ² in both the film longitudinal direction (MD) and the film transverse direction (TD), according to any one of (1) to (7) Mold release film.

  (9) Ratio (MD) / (TD) of film longitudinal direction (MD) and film transverse direction (TD) at 50% modulus (50% Mo) of the film is in the range of 0.9 to 1.2. The film for mold release in any one of (1)-(8) characterized by these.

  (10) Ratio (100% Mo) / (50% Mo) of 50% modulus (50% Mo) and 100% modulus (100% Mo) of the film is the film longitudinal direction (MD) and the film transverse direction (TD). Both are the range of 1.0-1.6, The film for mold release in any one of (1)-(9) characterized by the above-mentioned.

  (11) The release film according to any one of (1) to (10), wherein the tensile elongation of the film exceeds 350% in both the film longitudinal direction (MD) and the film transverse direction (TD).

  According to the mold release film of the present invention, the mold mold and the molded product are excellent in releasability, and the mold shape is excellent in mold shape transfer that is transferred to the molded product according to the design dimensions. The surface smoothness of the molded product can be obtained, and furthermore, heat resistance can be provided.

It is a side view of a bullet type LED lens concerning an embodiment of the present invention. (A) It is a top view of the mold die of the bullet type LED lens which concerns on embodiment of this invention. (B) It is an AA arrow sectional view of Drawing 2 (a) of a metallic mold of a bullet type LED lens concerning an embodiment of the present invention. It is a figure which shows schematic structure of the film film manufacturing apparatus for mold release which concerns on embodiment of this invention. It is sectional drawing which shows the periphery of the material insertion hopper of the film manufacturing apparatus shown in FIG. 2 based on embodiment of this invention.

  As a result of various investigations to achieve the above object, the present inventors have found that among polyurethane elastomers, the JIS A hardness is 70 or more, the specific gravity is 1.05 to 1.30, and the Vicat softening temperature is 100 to 180 ° C. A release film consisting of a polyurethane elastomer alone or a thermoplastic elastomer composition containing the polyurethane elastomer as a main component is excellent in releasability from a mold or a molded product, and the shape of the mold is designed. It has been found that the mold shape transferability to be transferred to the molded product according to the dimensions is excellent, the surface smoothness of the molded product can be obtained, and furthermore, heat resistance can be provided.

  Furthermore, as a result of the investigation, the thermoplastic elastomer composition is made into a composition containing 0.05 to 5.0 parts by mass of a fluorosurfactant with respect to 100 parts by mass of the polyurethane elastomer. As a result, the inventors have found that the present invention is effective and have completed the present invention.

  The polyurethane-based elastomer in the present invention is a thermoplastic polyurethane-based elastomer obtained by a reaction of three components of polyisocyanate, polyol and chain extender.

  Examples of the polyisocyanate include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylene-1,4-diisocyanate, xylene-1,3-diisocyanate, 4,4'-diphenylmethane diisocyanate, 2 , 4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenyl ether diisocyanate, 2-nitrodiphenyl-4,4'-diisocyanate, 2,2'-diphenylpropane-4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,4'-diphenylpropane diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, naphthylene-1,4-dii Aromatic diisocyanates such as cyanate, naphthylene-1,5-diisocyanate, 3,3′-dimethoxydiphenyl-4,4′-diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, dodecane diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, etc. Aliphatic diisocyanates, cyclohexane diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylene diisocyanate, hydrogenated diphenylmethane diisocyanate, tetramethylxylene diisocyanate, norbornane diisocyanate methyl, and the above isocyanates The biuret , Dimers thereof, trimer, dimer, trimer, carbodiimide body, uretonimine body, can be mentioned adducts and the like obtained by the reaction of a bifunctional or higher functional polyols such as the isocyanate. Polyisocyanate in which a part of the isocyanate group is stabilized with a blocking agent having one active hydrogen in the molecule, such as methanol, n-butanol, benzyl alcohol, ethyl acetoacetate, ε-caprolactam, methyl ethyl ketone oxime, phenol, cresol, etc. Can also be mentioned. These can be used alone or in combination of two or more.

  The above-mentioned polyols are polymer polyols having a number average molecular weight of 500 to 10,000, and these include polyester polyols, polyester amide polyols, polycarbonate polyols, polyether polyols, polyether ester polyols, polyolefin polyols and the like. These polymer polyols can be used alone or in combination of two or more.

  Examples of the polyester polyol and polyesteramide polyol include those obtained by a condensation reaction from a polycarboxylic acid and a polyol, optionally in combination with a diamine or an amino alcohol.

  Examples of the polycarboxylic acid include oxalic acid, adipic acid, sebacic acid, dimer acid, hydrogenated dimer acid, phthalic acid, phthalic acid alkyl esters, trimellitic acid, maleic acid, fumaric acid, and itaconic acid. . Further, those obtained by ring-opening polymerization of cyclic esters such as butyrolactone, valerolactone and caprolactone are also included.

  Examples of the polyol include ethylene glycol, 1,2-propanedioe, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, and 1,5-pentane. Diol, 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,8- Octanediol, 1,9-nonanediol, 2,2-diethyl-1,3-propanediol, 2-n-butyl-2-ethyl-1,3-propanediol, 2,2,4-trimethyl-1, 3-pentanediol, 2-ethyl-1,3-hexanediol, 2-n-hexadecane-1,2-ethylene glycol, 2-n-eicosa -1,2-ethylene glycol, 2-n-octacosane-1,2-ethylene glycol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanedimethanol, or ethylene oxide or propylene oxide adduct of bisphenol A, hydrogenated bisphenol A, low molecular polyols such as 3-hydroxy-2,2-dimethylpropyl-3-hydroxy-2,2-dimethylpropionate, trimethylolpropane, glycerin and pentaerythritol. Examples of the diamine or amino alcohol include low molecular polyamines such as ethylenediamine, hexamethylenediamine, xylylenediamine, and isophoronediamine, and low molecular amino alcohols such as monoethanolamine, diethanolamine, and triethanolamine. Furthermore, lactone polyester polyols obtained by ring-opening polymerization of cyclic ester (lactone) monomers such as ε-caprolactone and γ-valerolactone using low molecular polyols, low molecular polyamines, and low molecular amino alcohols as initiators.

  Examples of the polycarbonate polyol include those obtained by a dealcoholization reaction, a dephenol reaction, or the like of a low molecular polyol used for the synthesis of the polyester polyol described above and diethylene carbonate, dimethyl carbonate, diethyl carbonate, diphenyl carbonate, or the like.

  As the polyether polyol, polyethylene glycol, polypropylene glycol obtained by ring-opening polymerization of ethylene oxide, propylene oxide, tetrahydrofuran, etc., using the low molecular polyol, low molecular polyamine, and low molecular amino alcohol used in the above polyester polyol as an initiator, Examples thereof include polytetramethylene ether glycol and the like, polyether polyols obtained by copolymerization thereof, and polyester ether polyols using the above-described polyester polyols and polycarbonate polyols as initiators.

  Examples of the polyether ester polyol include those obtained in the same manner as the polyester polyol except that the polyether is used for a part or all of the polyol used in the condensation reaction for obtaining the polyester polyol.

  Examples of the polyolefin polyol include hydroxyl group-containing polybutadiene, hydrogenated hydroxyl group-containing polybutadiene, hydroxyl group-containing polyisoprene, hydrogenated hydroxyl group-containing polyisoprene, hydroxyl group-containing chlorinated polypropylene, and hydroxyl group-containing chlorinated polyethylene.

  The chain extender is an active hydrogen-containing compound having a number average molecular weight of less than 500, and examples thereof include the low molecular polyols, the low molecular polyamines, and the low molecular amino alcohols.

  For the production of the polyurethane-based elastomer, a known production method such as a one-shot method, a prepolymer method, a batch reaction method, a continuous reaction method, a kneader method or an extruder method can be employed.

As for the hardness of the polyurethane elastomer used in the present invention, the JIS A hardness measured by the test method of JIS K 7311 is 70 or more. Furthermore, JIS
When the A hardness is 100 or more, it is preferable that the D hardness is applied and the upper limit is 70 or less of the D hardness. The JIS A hardness is preferably 80 or more, more preferably 90 or more. JIS
A When the hardness is less than 60, the rubber property becomes strong. Therefore, when the release film is transported in the molding apparatus, the release film is stretched and the transport is not stable. On the other hand, D
When the hardness exceeds 70, there is a problem that a gel derived from three components of a raw material polyisocyanate, a polyol and a chain extender is generated during extrusion molding.

  The Vicat softening temperature of the polyurethane elastomer used in the present invention is measured by the test method of JIS K7206 and is in the range of 100 to 180 ° C. The Vicat softening temperature is preferably 110 to 180 ° C, more preferably 120 to 180 ° C, and still more preferably 130 to 180 ° C. If the Vicat softening temperature is less than 100 ° C., it melts during use and has a problem. That is, heat resistance cannot be obtained. On the other hand, the upper limit of the Vicat softening temperature is 180 ° C., but a polyurethane elastomer having a Vicat softening temperature exceeding 180 ° C. has not been obtained.

The fluorosurfactant in the present invention is a perfluoroalkylsulfonic acid derivative. Specific examples of the perfluoroalkylsulfonic acid derivative include potassium trifluoromethanesulfonate (CF ₃ SO ₃ K), sodium trifluoromethanesulfonate (CF ₃ SO ₃ Na), lithium trifluoromethanesulfonate (CF ₃ SO ₃ Li), pentafluoroethane potassium acid _{(C 2 F 5 SO 3 K} ), sodium pentafluoroethane sulfonate _{(C 2 F 5 SO 3 Na} ), pentafluoroethane lithium sulfonate _{(C 2 F 5 SO 3 Li} ), heptafluoro propane potassium acid _{(C 3 F 7 SO 3 K} ), sodium heptafluoropropane sulfonate _{(C 3 F 7 SO 3 Na} ), heptafluoropropane lithium sulfonate _{(C 3 F 7 SO 3 Li} ), nonafluorobutanesulfonic potassium acid _{(C 4} F 9 SO ₃ ), Nonafluorobutanesulfonate sodium _{(C 4 F 9 SO 3 Na} ), perfluoroalkylsulfonic acid salts such as lithium nonafluorobutanesulfonate _{(C 4 F 9 SO 3 Li} ) and the like.

Also, bis (trifluoromethanesulfonyl) imide potassium salt ((CF ₃ SO ₂ ) ₂ NK), bis (trifluoromethanesulfonyl) imide sodium salt ((CF ₃ SO ₂₂ ) ₂ NNa), bis (trifluoromethanesulfonyl) imide ammonium Salt ((CF ₃ SO ₂ ) ₂ NNH ₄ ), bis (trifluoromethanesulfonyl) imide lithium salt ((CF ₃ SO ₂ ) ₂ NLi), bis (pentafluoroethanesulfonyl) imide potassium salt ((C ₂ F ₅ SO _{2) 2} NK), bis (pentafluoroethane sulfonyl) imide sodium salt _{((C 2 F 5 SO 2} ) 2 NNa), bis (pentafluoroethane sulfonyl) imide ammonium salt _{((C 2 F 5 SO 2} ) 2 NNH _4), bis (pentafluoroethane sulfonyl) imide lithium salt _{((C 2 F 5 SO 2} ) NLi), bis (heptafluoropropanesulfonyl) imide potassium salt _{((C 3 F 7 SO 2} ) 2 NK), bis (heptafluoropropanesulfonyl) imide sodium salt _{((C 3 F 7 SO 2} ) 2 NNa), bis (Nonafluorobutanesulfonyl) imide potassium salt ((C ₄ F ₉ SO ₂ ) ₂ NK), bis (nonafluorobutanesulfonyl) imide sodium salt ((C ₄ F ₉ SO ₂ ) ₂ NNa), cyclo-hexafluoropropane -1,3-bis (sulfonyl) imide potassium salt (CF ₂ (CF ₂ SO ₂ ) ₂ NK), cyclo-hexafluoropropane-1,3-bis (sulfonyl) imide sodium salt (CF ₂ (CF ₂ SO ₂ ) ₂ NNa) and other perfluoroalkylsulfonimide salts.

  Further, an ionic liquid having perfluoroalkylsulfonic acid as an anionic species, an ionic liquid having bis (perfluoroalkylsulfonyl) imide as an anionic species, an ionic liquid having bis (fluorosulfonyl) imide as an anionic species, cyclohexafluoropropane-1, Also included are ionic liquids using 3-bis (sulfonyl) imide as an anionic species.

Among the above-mentioned perfluoroalkylsulfonic acid derivatives, compounds having a melting point of 250 ° C. or lower and a decomposition temperature of 300 ° C. or higher can be suitably used. Specific examples thereof include potassium trifluoromethanesulfonate (CF ₃ SO ₃ K) and bis (trifluoromethanesulfonyl) imide potassium salt ((CF ₃ SO ₂ ) ₂ NK).

  The fluorosurfactant is mixed with the polyurethane elastomer for the purpose of imparting lubricity to the release film. Since the lubrication of the film surface is imparted by mixing the fluorosurfactant, the effect of smooth transfer of the release film in the molding apparatus is achieved, and the release film is in contact with the mold die. The effect of preventing wrinkles and the effect of improving the peelability from the silicone resin composition used as the mold resin can be obtained. The mixing amount is 0.05 to 5.0 parts by mass of the fluorosurfactant with respect to 100 parts by mass of the polyurethane elastomer. When the mixing amount is less than 0.05 parts by mass, the mixed effect does not appear. On the other hand, even if it exceeds 5.0 parts by mass, the effect is not increased, and there is a problem that the fluorosurfactant bleeds out or blooms out on the film surface and contaminates the surface of the molded product.

In the thermoplastic elastomer composition of the present invention, as long as the characteristics of the present invention are not impaired,
Other thermoplastic elastomers can be mixed. Examples of the thermoplastic elastomer include polyester elastomers, polyamide elastomers, polyvinyl chloride elastomers, styrene elastomers, and olefin elastomers. Such other thermoplastic elastomer may be coextruded to form an adhesive laminated film.

  The thermoplastic elastomer composition of the present invention includes, for example, a lubricant such as an amide wax, an anti-blocking agent such as silica, a phenolic antioxidant, a phosphorus antioxidant, etc., as long as the characteristics of the present invention are not impaired. Can be mixed.

The release film in the present invention has a tensile elastic modulus of 10 measured in accordance with JIS Z 1702 at a temperature of 23 ° C. and a tensile speed of 100 mm / min in both the film longitudinal direction (MD) and the film transverse direction (TD). The range is from 0.0 to 500 N / mm ² . This tensile modulus is preferably in the range of 20.0 to 400 N / mm ² , more preferably in the range of 30.0 to 300 N / mm ² . When the tensile modulus is less than 10.0 N / mm ^2, there is a problem that when the release film is pulled out from the wound body in the molding apparatus, the film is weak and loose. On the other hand, when the tensile elastic modulus exceeds 500 N / mm ² , when the release film is sucked in vacuum in the mold, there is a problem that the film does not stretch and does not adhere to the mold.

  In the present invention, the release film is a film longitudinal direction (MD) and a film transverse direction (50% modulus (50% Mo) of the film measured at a temperature of 23 ° C. and a tensile speed of 100 mm / min in accordance with JIS Z 1702. The ratio (MD) / (TD) to TD) is in the range of 0.90 to 1.20. This (MD) / (TD) is preferably in the range of 0.95 to 1.20. (MD) / (TD) is never less than 0.90 in a film formed by an extrusion method. On the other hand, when (MD) / (TD) exceeds 1.20, there is a problem that wrinkles are generated in the film when the release film is supplied to the mold in the molding apparatus.

  The release film in the present invention is a ratio of 50% modulus (50% Mo) to 100% modulus (100% Mo) of a film measured at a temperature of 23 ° C. and a tensile speed of 100 mm / min according to JIS Z 1702 ( 100% Mo) / (50% Mo) is in the range of 1.00 to 1.60 for both the film longitudinal direction (MD) and the film transverse direction (TD). This (100% Mo) / (50% Mo) is preferably in the range of 1.00 to 1.50. When (100% Mo) / (50% Mo) is less than 1.00, no increase in stress accompanying the increase in film elongation occurs, so uniform film elongation cannot be obtained, and the release film is molded gold. There is a problem that wrinkles are generated when vacuumed in the mold. On the other hand, when (100% Mo) / (50% Mo) exceeds 1.60, the increase in stress accompanying the increase in film elongation is large, and the film stretches until the release film adheres to the inner surface of the mold. There is a problem that does not cut.

  In the release film of the present invention, the tensile elongation of the film measured at a temperature of 23 ° C. and a tensile speed of 100 mm / min in accordance with JIS Z 1702 is 350% in both the film longitudinal direction (MD) and the film transverse direction (TD). That's it. This tensile elongation is preferably 400% or more. When the tensile elongation is less than 350%, there is a problem that the mold release film is cut at the edge of the mold when the mold release film is sucked in vacuum in the mold.

The release film composed of the thermoplastic elastomer composition described above can be formed by a conventionally known method such as a melt extrusion method or a melt cast method.
In the following example, a method for forming a release film by a melt extrusion method using a T-die will be described.

  The release film obtained by such a method uses a molding material of the thermoplastic elastomer composition, an extruder such as a single-screw extruder or a twin-screw extruder, according to the characteristics of the thermoplastic elastomer composition. In an atmosphere where the air in the gap between the extruder and the molding material is replaced with nitrogen gas, it is melt-kneaded and the release film melt-extruded from the lip portion at the tip of the T die placed at the tip of the extruder is taken up. Cool by pinching directly between the crimping roll and the cooling roll in the machine, or by inserting a separator from both or one side of the crimping roll and the cooling roll, and then cooling it. It is obtained by winding up sequentially.

  FIG. 3 is a configuration diagram showing an outline of a film production apparatus for producing a release film by the above-described method. 4 is a cross-sectional view of the periphery of the material charging hopper of the film manufacturing apparatus shown in FIG. In FIG. 3, the film manufacturing apparatus is generally configured to include a material charging hopper 2, an extruder 1, a T die 7, a take-up machine 11, and a winder 15. The material charging hopper 2 is configured to input a molding material, and as shown in FIG. 4, the nitrogen gas supply pipe 3 is connected to the extruder 1 of the material charging hopper 2 through the spacer 3a while being connected to the extruder 1. Inserted. The nitrogen gas supply pipe 3 is bent so as to be substantially along the central axis of the material charging port 1 c, and the tip thereof extends to the vicinity of the outer periphery of the extrusion screw 1 a in the extruder 1. Oxygen contained in the molding material fed from the material feeding hopper 2 or in the extruder 1 is supplied to the nitrogen gas supply pipe 3 when the molding material is mixed and stirred by the extrusion screw 1a of the extruder 1. It will be replaced with nitrogen gas.

  The extruder 1 mixes and stirs the molding material with the extrusion screw 1a, conveys it in the direction of arrow B, and heats and melts the molding material by electric heating means incorporated in the cylinder 1b of the extruder 1. The molding material thus melted and conveyed is fed to the filter means 5 through the connecting pipe 4 shown in FIG. The unmelted molding material is separated by the filter means 5 and the molten molding material is fed to the gear pump 6. In the gear pump 6, the molten molding material is pushed out to the T die 7 while increasing the pressure of the molten molding material. In the T die 7, the melt molding material is extruded at a predetermined pressure, and a film 8 having a predetermined thickness and a predetermined width is formed from the lip portion 7 a of the T die 7. The film 8 formed in this manner is adjusted to a predetermined thickness by the pressure-bonding roll 9 while being drawn on the outer peripheral surface of the cooling roll 10 of the take-up machine 11, and further cooled and solidified. It is conveyed to the winder 15.

  In the winder 15, the film 8 is guided by the guide rolls 15 a, 15 b, and 15 c and is wound by the winding tube 16. In addition, a thickness measuring device 14 is disposed between the conveying roll pairs 12 and 13 and the guide roll 15a, and the thickness measured by the thickness measuring device 14 is set so as to obtain a desired thickness. Based on this, the peripheral speed of the cooling roll 10 is adjusted and controlled. Thereby, the release film is formed.

  The release film may be formed in the surface shape of the film according to the surface shape required by the molded product. For example, when the surface of the LED or the like is a mirror surface, a release film in which the surface of the release film is a mirror surface is used. In addition, since ICs, LSIs, and the like have fine irregularities formed on the surface thereof, a release film having fine irregularities formed on the surface of the release film is used.

  As a method of forming the surface shape of the mold release film, when the surface is mirror-finished, the surface of the metal cooling roll described above is mirror-finished, and the mold release film in a molten state is placed on the cooling roll. There is a method in which the surface of the release film is mirror-finished by pressure bonding with a pressure roll. When using a separator, there is a method of using a mirror-finished PET film or OPP film as the separator and transferring the surface thereof.

  In FIG. 3, the separator 18a is supplied from the delivery roll 17a to the side of the pressure roll 9 of the film 8 in the direction of the arrow, and the separator 18b is supplied from the delivery roll 17b to the side of the cooling roll 10 of the film 8 in the direction of the arrow. By doing so, the surface shape of the film 8 can be transferred from the separator. After the film 8 having the separators 18a and 18b laminated on both surfaces is wound up once, the separators 18a and 18b are peeled off and the film 8 is wound up, whereby a release film having a predetermined surface shape can be obtained.

  When forming fine irregularities on the surface of the mold release film, fine irregularities are formed on the outer peripheral surface of the metal cooling roll described above, and the mold release film in a molten state is pressure-bonded to the cooling roll. There is a method of transferring fine irregularities formed on the outer peripheral surface of the cooling roll onto the surface of the release film when crimping with a roll. Moreover, when using a separator, there exists the method of using the PET film and OPP film which carried out the mat processing of the surface as a separator, and transferring the surface.

  When the surface of the release film is a mirror surface, the surface roughness is measured at a speed of 0.6 mm / second, a cutoff value of 0.8 mm, and an evaluation length of 8.0 mm in accordance with JIS B0601-2001. The surface may be appropriately formed so that the arithmetic average roughness Ra is 0.10 or less and the maximum height roughness Rz is 1.00 or less. When the arithmetic average roughness Ra is 0.10 or less and the maximum height roughness Rz is 1.00 or less, the surface of the molded product to which the surface of the release film is transferred becomes smooth.

  When fine irregularities are formed on the surface of the release film, the arithmetic average roughness Ra measured by the same method as described above is 0.5 or more, and the maximum height roughness Rz is 5.00 or more. The surface may be appropriately formed so that

  The release film of the present invention has a thickness in the range of 5 μm to 500 μm, preferably in the range of 10 μm to 400 μm, and may be appropriately selected according to the shape of the mold used. If the thickness of the mold release film is less than 5 μm, when following the mold during use, the mold release film will be stretched and thinned, or may be broken by the pressure of the mold resin. It is not preferable. In addition, when the thickness exceeds 500 μm, the thickness of the release film becomes an obstacle, and it becomes impossible to follow the mold mold having a fine structure, or the complicated shape of the mold mold is not transferred to the molded product. This is not preferable.

Examples of the release film of the present invention will be described below using Tables 1 and 2.
The release film according to the present invention is not limited to Examples 1 to 8.
Here, the following materials are used for the urethane elastomer 1, the fluorosurfactant 1 and the fluorosurfactant 2 shown in Tables 1 and 2.

(Urethane elastomer 1)
Miractolan E598PNAT: trade name, manufactured by Nippon Polyurethane Industry Co., Ltd., JIS A hardness 98, Vicat softening temperature 141 ° C
(Fluorosurfactant 1)
F-top EF-N112: trade name, manufactured by Mitsubishi Materials Corporation, bis (trifluoromethanesulfonyl) imide potassium salt ((CF ₃ SO ₂ ) ₂ NK), melting point 200 ° C.
(Fluorosurfactant 2)
F-top EF-12: Trade name, manufactured by Mitsubishi Materials Corporation, potassium trifluoromethanesulfonate (CF ₃ SO ₃ K), melting point 233 ° C.

  Hereinafter, production of a release film, peelability, heat resistance, mold size transferability, surface smoothness and actual usability will be described in detail based on Tables 1 and 2. The same applies to Comparative Examples 1 to 3 in Table 3.

(Preparation of release film)
The thermoplastic elastomer composition was supplied to a single screw extruder (manufactured by IK Corporation) having a diameter of 40 mm and L / D = 25, and a cylinder temperature of 180 ° C. or higher was used using a full flight extrusion screw having a compression ratio of 2.5. The mixture was melt-kneaded under a condition of 210 ° C. and continuously extruded from a T die having a width of 400 mm under a condition of a die temperature of 210 ° C. to 220 ° C. In the take-off machine, the extruded release film is supplied from the pressure-rolling roll side as a mat-processed PET film as a separator and from the cooling roll side as a mirror-finished PET film as a separator, and is sandwiched between the pressure-rolling roll cooling rolls. In the winder, both ends are cut with a slit blade, and the release film is wound on a winder tube, thereby having a thickness of 250 mm and a length of 50 m with the thicknesses shown in Tables 1 to 3. A mold film was produced. These release films were aged by leaving them in an atmosphere at 80 ° C. for 24 hours. After the aging was completed, the release film was rewound while peeling off the mat-processed PET film and the mirror-processed PET film of the separator to obtain a release film for evaluation.

(Method of evaluation)
Evaluation is made by using a mold die 30 having the lens shape shown in FIG. 1 and having the structure shown in FIGS. 2A and 2B, adsorbing a release film to the mold die 30, and then silicone. The resin composition was dropped and subjected to hot press molding, and peelability, heat resistance, mold size transferability, and surface smoothness were evaluated.

Specifically, the mold release film is stretched with respect to the mold 30 such that the matte surface of the mold release film is on the mold mold 30 side and the mirror surface is on the air side, and suction is performed in a vacuum. The film was adsorbed on the mold 30. Next, a silicone resin composition RHODORSIL RTV141 (manufactured by BLUESTAR SILICONES) is dropped on the release film, and a flat metal mold whose surface is hard chrome plated is pressed onto the film, and is sandwiched between the two molds. Molded. The molded laminate was evaluated for peelability between the release film and the cured silicone resin, heat resistance of the release film, and mold size transferability and surface smoothness of the cured silicone resin. Hot press molding was performed under conditions of a temperature of 140 ° C. and a pressure of 10 kg / cm ² for 5 minutes.

(Peelability)
Evaluation of peelability was "○" when the cured silicone resin composition could be peeled without remaining on the release film, and the silicone resin composition was partially broken and remained on the release film The case is shown as “×”.

(Heat-resistant)
The evaluation of heat resistance was performed by visually observing the release film from which the cured silicone resin composition was peeled off. If the film shape was maintained without melting or melting, it was melted in the release film. The case where fusing occurred was indicated as “x”.

(Mold dimension transferability)
The mold dimension transferability was evaluated by measuring the dimensions of the cured silicone resin composition. The lens height evaluation criteria is further within a range of -0.1 mm from the dimension obtained by reducing the thickness of the release film for a hole depth of 4 mm, that is, ((4-release film thickness) -0. 1) It was set to mm or more. A case where all the 25 lenses were within the standard was indicated by “◯”, and a case where even one lens did not satisfy the standard was indicated by “X”.

(Surface smoothness)
For surface smoothness, the surface state of the cured silicone resin composition was visually evaluated. The case where there was no unevenness or wrinkles on the surface of the silicone resin was indicated as “◯”, and the case where there were unevenness or wrinkles was indicated as “x”.

(Actual usability)
The actual usability was confirmed and evaluated by resin molding with a molding apparatus. Specifically, as a molding device, a molding apparatus G-LINE manual press (trade name) manufactured by Apic Yamada Co., Ltd., RHODORSIL RTV141 (manufactured by BLUESTAR SILICONES) was visually confirmed as a silicone resin composition. did.

  The evaluation of actual usability is that the film is supplied without loosening when the release film is transported in the mold forming apparatus, the film is not wrinkled at the time of adsorption, and after hot press molding, the release film The surface of the cured silicone resin composition is smooth with no irregularities and wrinkles, the mold release film is not torn or blown, the silicone resin composition remains free, and the mold The state where the mold was not soiled was indicated as “◯”, and the case where any of the molds was defective was indicated as “X”.

  As shown in Table 3, in Comparative Example 1, an ETFE film manufactured by Asahi Glass Co., Ltd. and Aflex (trade name) having a thickness of 100 μm were used as comparative objects. I couldn't. In Comparative Example 2, an ETFE film manufactured by Asahi Glass Co., Ltd. and Aflex (trade name) having a thickness of 25 μm were used for comparison, but the film was torn when adsorbed in the mold, and actual usability was obtained. There wasn't. In Comparative Example 3, for release of 50 μm in thickness comprising a high-trel 5577 (trade name) manufactured by Toray DuPont, a polyester / polyether copolymer, a D hardness of 55, and a thermoplastic elastomer composition having a Vicat softening temperature of 192 ° C. A film was used for comparison. The surface of the molded article made of the silicone resin composition was wrinkled, the surface smoothness was inferior, and the actual usability was not obtained.

  On the other hand, as shown in Tables 1 and 2, the release film of each example according to the present invention has heat resistance in addition to obtaining releasability, mold size transferability and surface smoothness. It is clear that it is excellent in performance and that practical use is given. From this, according to the present invention, it is possible to obtain a release film that is excellent in releasability from a molded product obtained by molding a mold resin, and that can provide a molded product having excellent shape and surface properties. .

  As mentioned above, although this invention was demonstrated using embodiment, it cannot be overemphasized that the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiments. Further, it is apparent from the scope of the claims that embodiments with such changes or improvements can also be included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Extruder 2 Material input hopper 3 Nitrogen gas supply pipe 4 Connection pipe 5 Filter 6 Gear pump 7 T die 7a Lip part 8 Film 9 Crimp roll 10 Cooling roll 11 Take-up machine 12, 13 Conveying roll pair 14 Thickness measuring device 16 rolls Pipes 17a, 17b Delivery rolls 18a, 18b Separator 20 Cannonball type LED lenses 21a, 21b Lead wire 30 Mold die 31 Lens molding recess

Claims (11)

  A release film characterized by comprising a polyurethane elastomer alone having a JIS A hardness of 70 or more and a Vicat softening temperature of 100 to 180 ° C. or a thermoplastic elastomer composition mainly composed of the polyurethane elastomer.   2. The release film according to claim 1, wherein the polyurethane elastomer is a thermoplastic polyurethane elastomer obtained by a reaction of three components of polyisocyanate, polyol and chain extender.   The polyol is one or more selected from polymer polyols having a number average molecular weight of 500 to 10000 belonging to the group consisting of polyester polyol, polyester amide polyol, polycarbonate polyol, polyether polyol, polyether ester polyol, and polyolefin polyol. The release film according to claim 2, wherein the film is a release film.   4. The mold release agent according to claim 2, wherein the early chain extender is selected from active hydrogen-containing compounds having a number average molecular weight of less than 500 belonging to low molecular polyols, low molecular polyamines, and low molecular amino alcohols. the film.   The thermoplastic elastomer composition is a composition containing a fluorosurfactant in a range of 0.05 to 5.0 parts by mass with respect to 100 parts by mass of the polyurethane elastomer. The film for mold release of any one of -4. The release film according to claim 5, wherein the fluorosurfactant is a perfluoroalkylsulfonic acid derivative compound having a melting point of 250 ° C. or lower and a decomposition temperature of 300 ° C. or higher.   The thermoplastic elastomer composition further includes one or more additives belonging to a lubricant, an anti-blocking agent, an antioxidant, and a phosphorus-based antioxidant. The release film according to item. The mold release according to any one of claims 1 to 7, wherein the film has a tensile modulus of elasticity in a range of 10 to 500 N / mm ² in both the film longitudinal direction (MD) and the film transverse direction (TD). Film.   The ratio (MD) / (TD) of film longitudinal direction (MD) and film transverse direction (TD) at 50% modulus (50% Mo) of the film is in the range of 0.9 to 1.2. The film for mold release according to any one of claims 1 to 8.   The ratio (100% Mo) / (50% Mo) of 50% modulus (50% Mo) to 100% modulus (100% Mo) of the film is 1. in both the film longitudinal direction (MD) and the film transverse direction (TD). It is the range of 0-1.6, The film for mold release of any one of Claims 1-9 characterized by the above-mentioned.   The film for mold release according to any one of claims 1 to 10, wherein the tensile elongation of the film exceeds 350% in both the film longitudinal direction (MD) and the film transverse direction (TD).

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