CN105008126A - Release film for LED manufacturing - Google Patents

Abstract

A mold release film for LED production, which is obtained by laminating a coating layer on a multilayer film, and which is characterized in that: the multilayer film has polybutylene terephthalate resin layers (layers A) serving as both outer layers and a polyester elastomer layer (layer B) serving as an inner layer; the coating layer is laminated on at least one of the layers A, which are arranged as both outer layers of the multilayer film, and contains a reaction product that is obtained from 100 parts by mass of a fluorine-containing copolymer (C) and 5-25 parts by mass of a crosslinking agent (D) having 2 or more isocyanate groups; the fluorine-containing copolymer (C) is configured from a fluoroolefin, a cyclohexyl group-containing acrylate and a hydroxyl group-containing vinyl ether; and the coating thickness is 0.1-0.3 [mu]m.

Description

Release film for LED manufacturing

technical field

The present invention relates to a release film, and in particular to a release film used in the manufacture of LEDs. In particular, it relates to a release film used when molding a silicone resin into a small lens of an LED.

Background technique

Release films are widely used in industry. Especially in the manufacturing process of IC and LED substrates, etc., when encapsulating or molding a lens on a circuit, in order to prevent the mold resin or resin constituting the lens from adhering to the mold, fluorine-based films, silicone-coated polycarbonate, etc. can be used. Release films such as ethylene terephthalate film, polymethylpentene film, polypropylene film, etc.

However, fluorine-based films conventionally used as release films have excellent heat resistance, release properties, and non-polluting properties, but they are expensive, and they are difficult to burn and produce toxic gases when they are discarded or incinerated after use. gas this problem. In addition, in the silicone-coated polyethylene terephthalate film and polymethylpentene film, the silicone and low-molecular polymer contained in the film migrate to the substrate, contaminating the copper circuit on the substrate, May impair quality. In addition, the polypropylene film has poor heat resistance and insufficient mold releasability.

Therefore, polybutylene terephthalate, polytrimethylene terephthalate, and polyethylene A block copolymer of butylene terephthalate and polyether forms a film of a release layer (Patent Documents 1 and 2) and a film having a buffer layer (Patent Documents 1 and 3).

However, in such a mold release film, mold release property, heat resistance, and followability at the time of molding cannot fully be made compatible. That is, when the mold release and heat resistance are emphasized, the followability during molding is ignored, and the cracks of the mold release film are transferred to the surface of the molded lens when the mold release film is cracked during molding, and the transmission of light rate decreased. On the other hand, when emphasis is placed on followability during molding, the release film will be stretched or wrinkled during winding or cutting due to its low modulus of elasticity, in addition to a decrease in release properties and a decrease in the lubricity of the film surface. The overall operability is poor.

prior art literature

patent documents

Patent Document 1: Japanese International Publication No. 05/002850

Patent Document 2: Japanese Patent Laid-Open No. 2010-155451

Patent Document 3: Japanese Patent Laid-Open No. 2009-073195

Contents of the invention

The object of the present invention is to provide a mold release film which is excellent in moldability, mold release, heat resistance, and non-contamination, and in particular has a high level of followability when molding LED lenses and is compatible with lenses constituting LEDs. The release property of the silicone resin is excellent, and the workability of the sheet winding and cutting is excellent.

The inventors of the present invention conducted intensive studies to solve the above-mentioned problems, and as a result, found that a laminated film containing a specific fluorine-based resin and a cross-linked resin layer is laminated on a laminated film including a polybutylene terephthalate resin layer and a polyester elastomer layer. The mold release film obtained by coating the reaction product of the agent can achieve both contradictory properties of followability during molding and mold release properties, and the present invention has been completed.

That is, the gist of the present invention is as follows.

A kind of release film that is used for LED manufacture, is the release film that laminates coating on laminated film, it is characterized in that,

The two outer layers of the laminated film are a polybutylene terephthalate resin layer (A layer), and the inner layer contains a polyester elastomer layer (B layer),

The coating is laminated on at least one of the A layers of the two outer layers of the laminated film, and contains 100 parts by mass of a fluorine-containing copolymer (C) and 5 to 25 parts by mass of a cross-linked copolymer having two or more isocyanate groups. The reaction product formed by the coupling agent (D),

The fluorine-containing copolymer (C) is represented by the fluoroolefin shown in the following formula (1), the cyclohexyl-containing acrylate shown in the formula (2), and the hydroxyl-containing vinyl group shown in the formula (3). Ether is a constituent,

The thickness of the coating is 0.1-0.3 μm.

(In the formula, X is F or H, Y is H, Cl, F, CF ₃ .)

(In the formula, R ¹ is H or CH ₃ .)

(In the formula, R ² is an alkylene or cyclohexylene group with 2 to 5 carbon atoms.)

According to the present invention, it is possible to obtain a mold release film that is excellent in formability, mold releasability, and heat resistance. In particular, it is possible to obtain a high level of conformability when molding an LED lens and a silicone resin constituting an LED lens. Excellent mold releasability, and excellent operability during sheet winding and cutting.

In addition, compared with polymethylpentene and polytetrafluoroethylene-ethylene copolymer, the generation of outgassing is less, and the coating containing the reaction product of a specific fluorine-containing copolymer and a crosslinking agent contributes to the Since there is little movement, it is also excellent in non-polluting properties.

detailed description

Hereinafter, the present invention will be described in detail.

The release film of the present invention is a release film formed by laminating a coating layer on a laminated film. The two outer layers of the laminated film are polybutylene terephthalate resin layers (layer A), and the inner layer contains a polyester resin layer. A laminated film of an elastomer layer (layer B).

＜Polybutylene terephthalate resin layer (layer A)＞

In the present invention, the polybutylene terephthalate resin layer (A layer) is arranged on both outer layers of the laminated film, and a coating layer is laminated on at least one of the A layer to form a release layer to function. If there is no polybutylene terephthalate resin layer (layer A), the release property of the release film during molding will be reduced. or die bonding, thereby contaminating it.

In the present invention, for the polybutylene terephthalate resin (A) constituting the polybutylene terephthalate resin layer (A layer), the dicarboxylic acid component is terephthalic acid, and the diol component is 1,4-Butanediol polyester. In the present invention, the polybutylene terephthalate resin (A) can be copolymerized within a range not impairing its melting point and crystallization characteristics.

Examples of dicarboxylic acid components that can be copolymerized include isophthalic acid, phthalic acid, 2,6-naphthalene dicarboxylic acid, isophthalic acid-5-sodium sulfonate, oxalic acid, succinic acid, and adipic acid , sebacic acid, azelaic acid, dodecanedioic acid, dimer acid, maleic anhydride, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, cyclohexanedicarboxylic acid, etc. Dicarboxylic acid, 4-hydroxybenzoic acid, ε-caprolactone, lactic acid, etc.

In addition, examples of the diol component that can be copolymerized include ethylene glycol, diethylene glycol, 1,3-propanediol, neopentyl glycol, 1,6-hexanediol, cyclohexanedimethanol, triethylene glycol, Alcohol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide adducts of bisphenol A or bisphenol S, etc.

In addition, a small amount of a trifunctional compound such as trimellitic acid, trimellitic acid, pyromellitic acid, trimethylolpropane, glycerol, pentaerythritol, or the like can be used as a copolymerization component.

The polybutylene terephthalate resin (A) is preferably fully crystallized on a casting roll during film formation. Therefore, it is preferable that the crystallization rate index of polybutylene terephthalate resin (A) is 50-130 degreeC. The crystallization rate index is an index showing the crystallization rate during cooling after melting. If the crystallization rate index exceeds 130°C, that is, if the crystallization rate is slow during cooling after melting, it becomes difficult to impart heat resistance to the laminated film, and peeling failure occurs when the crystallization treatment is directly heated with a roller.

＜Polyester elastomer layer (layer B)＞

In the present invention, the polyester elastomer layer (B layer) is a layer contained in the inner layer of the laminated film, and the polyester elastomer (B) constituting this layer may be a polyester-based elastomer, preferably a polyester component. A copolymer with a diol component having an ether bond.

As a monomer usable as a polyester component of the polyester elastomer (B), in addition to terephthalic acid and 1,4-butylene glycol constituting the polybutylene terephthalate resin (A), Compounds that are exemplified as monomer components that can be copolymerized with polybutylene terephthalate resin (A) are exemplified. As the aromatic dicarboxylic acid component that constitutes the polyester component, isophthalic acid, Phthalic acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, 4,4'-diphenyl dicarboxylic acid, diphenoxyethane dicarboxylic acid, 5-sulfo Phthalic acid, or these ester-forming derivatives.

These dicarboxylic acid components and diol components may use 2 or more types together.

Examples of the diol component having an ether bond constituting the polyester elastomer (B) include ethylene glycol, propylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, neopentyl glycol, Diols, aliphatic diols such as decamethylene glycol, alicyclic diols such as 1,4-cyclohexanedimethanol and tricyclodecane dihydroxymethanol, xylene glycol, bis(p-hydroxy)diol Benzene, bis(p-hydroxyphenyl)propane, 2,2-bis[4-(2-hydroxyethoxy)phenyl]propane, bis[4-(2-hydroxyethoxy)phenyl]sulfone, 1,1- Aromatic diols such as bis[4-(2-hydroxyethoxy)phenyl]cyclohexane, 4,4'-dihydroxy-p-terphenyl, 4,4'-dihydroxy-p-quaterphenyl, etc. 2 polymers and their polymers, polyoxymethylene.

The diol component having an ether bond is preferably polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol, or ethylene oxide from the viewpoint of the content of oxygen atoms that tend to increase etherability. Copolymers with propylene oxide, ethylene oxide addition polymers of polypropylene glycol, copolymers of ethylene oxide and tetrahydrofuran, etc. Moreover, it is preferable that these number average molecular weights are about 300-6000.

In addition, the polyester elastomer (B) may be copolymerized with trifunctional or higher polyfunctional carboxylic acid components, polyfunctional oxyacid components, polyfunctional hydroxyl components, etc. in a range of 5 mol% or less.

The polyester elastomer (B) can be produced by a known method. For example, a lower alcohol diester of a dicarboxylic acid, an excess of a low molecular weight diol, and a diol component having an ether bond are subjected to a transesterification reaction in the presence of a catalyst, and polycondensation of the resulting reaction product is carried out. method; or a method of esterifying dicarboxylic acid and excess low molecular weight diol and diol components with ether bonds in the presence of a catalyst, and polycondensing the resulting reaction product; in addition, pre-prepared Any method may be adopted for the polyester component, a method of adding a diol component having an ether bond thereto to randomize it by transesterification, and the like.

To polybutylene terephthalate resin (A) and polyester elastomer (B), organic or inorganic dyes, pigments, matting agents, heat stabilizers, Flame retardant, antistatic agent, defoaming agent, color correcting agent, antioxidant, ultraviolet absorber, crystal nucleating agent, whitening agent, lubricant, impurity catcher, thickener, surface adjustment material, etc. Among them, a heat stabilizer and a scavenger containing low-molecular-weight volatile impurities are preferable. As a heat stabilizer, preferably 5-valent and/or 3-valent phosphorus compounds, hindered phenolic compounds, etc., as a low-molecular-weight volatile impurity capture agent, preferably polyamides, polyesteramide polymers, oligomers, Low-molecular-weight compounds with amide or amine groups, etc.

＜Laminated film＞

In the present invention, the two outer layers of the laminated film must be a polybutylene terephthalate resin layer (A layer), and the inner layer contains a polyester elastomer layer (B layer).

In the present invention, the thickness of the layer A in the laminated film is preferably 5 to 100 μm. If the thickness of the A layer is less than 5 μm, the flexibility will deteriorate, and if it exceeds 100 μm, it will become excessive quality. On the other hand, the thickness of the B layer is preferably 10 to 50 μm. It should be noted that the thickness of the above-mentioned layer refers to the thickness of a single layer constituting the laminated film. For example, in the case of two types of 3-layer constitution consisting of A layer/B layer/A layer, including two A layers, it is It refers to the thickness of each layer, not the total of the two layers.

In the present invention, the overall thickness of the laminated film is preferably 30 to 100 μm. If the overall thickness is less than 30 μm, the strength and rigidity of the sheet will decrease, and handling will also become difficult. On the other hand, if the overall thickness exceeds 100 μm, the followability to the surface shape of the mold during molding will be reduced. The overall thickness of the laminated film is more preferably 40 to 80 μm, still more preferably 45 to 60 μm.

In the present invention, as a preferred structure of the laminated film, it is not particularly limited as long as layer A is arranged on both outer layers and layer B is included in the inner layer, for example, three layers consisting of two types of layer A/layer B/layer A constitute. However, it is not limited to these, and the inner layer may have layers other than the B layer, or may have the A layer or a plurality of B layers.

As a preferred thickness ratio in the three-layer constitution of the above-mentioned A layer/B layer/A layer, it is 1/1 to 6/1. If it is in this range, the B layer can fully exhibit the function as the supporting layer of the A layer, In addition, heat resistance, embedding properties, and the like can be achieved at the time of hot pressing at a high temperature.

The mold release film of this invention is used so that the layer A in which the coating layer was laminated|stacked may be arrange|positioned at the lens formation side. In this case, the surface of layer A is preferably smooth. In addition, the surface layer of the laminated film on the side opposite to the lens formation side may be smooth, or may be provided with slipperiness and anti-blocking properties for workability. In addition, for the purpose of removing air during lens molding, an appropriate embossing pattern may be provided on at least one side of the laminated film. Such embossing can be given by surface processing of the cooling roll.

The heat shrinkage rate at 180° C. of the laminated film in the present invention is preferably 2% or less, more preferably 1.5% or less in MD. For TD, it is preferably 1% or less, more preferably 0.5% or less. Since the laminated film has such a thermal shrinkage rate, even if the release film comes into contact with a mold during molding, it is difficult to form wrinkles, and the heat resistance and dimensional stability at the time of manufacturing an LED lens are good. A laminated film having such a thermal shrinkage rate can be produced by the following method.

Next, a method for producing the laminated film will be described.

As a method for producing a laminated film, methods such as a water-cooled or air-cooled co-extrusion inflation method, a co-extrusion T-die method, etc. are mentioned, for example. Among them, the method of forming a film by the co-extrusion T-die method is preferable from the viewpoint of excellent thickness control of each layer.

In the production of a laminated film, it is preferable to provide a crystallization step for the purpose of imparting predetermined thermal characteristics to the film to improve heat resistance, mold release properties, and dimensional stability. Examples of the crystallization method include heating crystallization and orientation crystallization. In the use of the release film of the present invention, since dimensional stability at high temperature is required, it is preferable that the laminated film is not substantially oriented but crystallized by heating. Examples of methods for crystallization by heating include a method of extruding from a T-die and then cooling while crystallizing; a method of once solidifying after extrusion, and then heating directly with a roll, or indirectly heating with hot air, infrared rays, etc. . The latter method of crystallization by reheating is not only cumbersome, but also may cause poor peeling with a roll, or the film may loosen and deteriorate in film quality when heated with hot air or infrared rays. Therefore, the former method of crystallization while cooling is preferred. In the case of crystallization while cooling, it is necessary to set the temperature of the cooling roll in consideration of the crystallization rate, and for the resin composition in the present invention, the temperature of the cooling roll is preferably 30 to 100°C, more preferably 50 to 80°C .

＜Coating＞

In the release film of the present invention, it is necessary to laminate a fluorine-based coating layer on at least one of the A layers disposed on both outer layers of the laminated film. The mold release film of this invention is used so that the surface of this coating may become a lens formation side. The coating layer may be laminated on both sides of the A layer disposed on both outer layers of the laminated film, and in this case, the compositions of the two coating layers may be the same or different.

In the present invention, the coating contains a reaction product formed by 100 parts by mass of a fluorinated copolymer (C) and 5 to 25 parts by mass of a crosslinking agent (D) having 2 or more isocyanate groups, and the fluorinated copolymer ( C) must be composed of fluoroolefins, cyclohexyl-containing acrylates, and hydroxyl-containing vinyl ethers.

In addition, the thickness of the coating must be 0.1 to 0.3 μm. If the thickness of the coating is less than 0.1 μm, sufficient releasability cannot be obtained. On the other hand, if the thickness exceeds 0.3 μm, cracks will occur in the stretched coating when the LED lens is molded, causing damage to the lens. A bad case where a crack shape is transferred.

In the present invention, the fluoroolefin constituting the fluorine-containing copolymer (C) is an olefin having at least two fluorine atoms in the molecule represented by formula (1), such as vinylidene fluoride, tetrafluoroethylene, trifluoroethylene, or Vinyl chloride, hexafluoropropylene, etc. These fluoroolefins may be used alone or in combination of two or more.

(In the formula, X is F or H, Y is H, Cl, F, CF ₃ .)

The cyclohexyl group-containing acrylate is represented by formula (2), and specifically, cyclohexyl acrylate and cyclohexyl methacrylate are preferable, and cyclohexyl methacrylate is preferable.

(In the formula, R ¹ is H or CH ₃ .)

Hydroxyl-containing vinyl ethers are represented by formula (3), and specific examples include hydroxymethyl vinyl ether, hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, hydroxy ring Hexyl vinyl ether and the like are preferably hydroxybutyl vinyl ether, hydroxyethyl vinyl ether, and hydroxycyclohexyl vinyl ether. These hydroxyl group-containing vinyl ethers may be used alone or in combination of two or more.

(In the formula, R ² is an alkylene group or cyclohexylene group having 2 to 5 carbon atoms.)

Regarding the preferred copolymerization ratios of the components constituting the fluorine-containing copolymer (C) of the present invention, the fluoroolefin is 40 to 90 mol%, the cyclohexyl-containing acrylate is 1 to 30 mol%, and the hydroxyl-containing vinyl ether is 1 to 30 mol%.

When the proportion of fluoroolefin is less than 40 mol%, the release property of the coating laminated on the A layer is reduced, and when it is more than 90 mol%, the solubility of the obtained fluorinated copolymer (C) to the solvent is reduced, Difficult to apply on laminated film.

If the ratio of cyclohexyl-containing acrylate is less than 1 mol%, the storage stability of the solution of the obtained fluorinated copolymer (C) may decrease, and when it exceeds 30 mol%, the fluorinated copolymer (C) may The rate of aggregation is sometimes reduced.

If the proportion of hydroxyl-containing vinyl ether is less than 1 mol%, the obtained fluorinated copolymer (C) is difficult to react with the crosslinking agent (D), and when it is more than 30 mol%, the fluorinated copolymer (C) ) Copolymerization becomes difficult.

In the present invention, the fluorine-containing copolymer (C) is formed by using the above-mentioned fluoroolefin, cyclohexyl-containing acrylate, and hydroxyl-containing vinyl ether as constituents, and may be present in an amount of no more than 20 mol% depending on the purpose of use. The range further contains other copolymerizable ingredients. Examples of copolymerizable components include alkyl vinyl ethers such as ethyl vinyl ether, butyl vinyl ether, and cyclohexyl vinyl ether, olefins such as ethylene and propylene, vinyl chloride, and vinylidene chloride. Halogenated olefins, vinyl acetate, vinyl n-butyrate, vinyl tert-carbonate and other carboxylic acid vinyl esters.

The fluorinated copolymer (C) in the present invention is produced by copolymerizing the above constituent components using a polymerization initiator in the presence or absence of a solvent. As a polymerization initiator, a water-soluble polymerization initiator or an oil-soluble polymerization initiator can be suitably used according to the kind of solvent used for polymerization.

As the water-soluble polymerization initiator, for example, persulfates such as potassium persulfate, hydrogen peroxide, or redox initiators composed of combinations thereof with reducing agents such as sodium bisulfite and sodium thiosulfate, and combinations thereof Inorganic initiators such as inorganic initiators that coexist with a small amount of iron, ferrous salt, and silver nitrate, organic initiators such as dibasic acid salts such as succinic acid peroxide, dipglutaric acid peroxide, and monosuccinic acid peroxide, etc. agent etc.

In addition, as the oil-soluble initiator, for example, peroxyester-type peroxides such as tert-butyl peroxyisobutyrate and tert-butyl peroxyacetate, diisopropyl peroxycarbonate, di-n-propyl peroxycarbonate, etc., can be used. Such as dialkyl peroxydicarbonate, benzoyl peroxide, azobisisobutyronitrile, etc.

The usage-amount of these polymerization initiators is suitably selected according to the kind, copolymerization reaction conditions, etc., Preferably it is 0.005-5 mass % with respect to monomer whole quantity, Preferably it is 0.1-1 mass %.

The polymerization method of the fluorinated copolymer (C) is not particularly limited, for example, bulk polymerization method, suspension polymerization method, emulsion polymerization method, solution polymerization method and the like can be used. Among them, as the polymerization method, a solution polymerization method using ketones such as methyl ethyl ketone, esters such as ethyl acetate, and saturated halogens having one or more fluorine atoms, etc. Substituted hydrocarbons, etc. are used as solvents. When copolymerizing in an aqueous medium, generally, a suspending agent or an emulsifier is used as a dispersion stabilizer, and when an alkaline buffer is added, the pH of the reaction liquid during polymerization is 4, preferably 6 or more.

The reaction temperature during the polymerization reaction is usually in the range of -30 to 150°C and is appropriately selected according to the type of the polymerization initiator and the polymerization medium. For example, when the polymerization is carried out in an aqueous medium, it is usually 0 to 100°C, preferably 10 to 90 ℃ range selection.

In addition, the reaction pressure is not particularly limited, but it is usually selected in the range of 9.8×10 ⁴ to 9.8×10 ⁶ N/m ² , preferably in the range of 9.8×10 ⁴ to 5.9×10 ⁶ N/m ² . The copolymerization reaction can be performed by further adding an appropriate chain transfer agent.

In the present invention, the coating layer contains a reaction product formed of the above-mentioned fluorinated copolymer (C) and a crosslinking agent (D) having two or more isocyanate groups.

Examples of the crosslinking agent (D) having two or more isocyanate groups include diisocyanates such as hexamethylene diisocyanate and isophorone diisocyanate, triisocyanates such as tris(phenyl isocyanate) phosphorothioate, Polyisocyanate containing isocyanurate, etc.

The ratio of the fluorine-containing copolymer (C) to the cross-linking agent (D) having two or more isocyanate groups is 5 to 25 parts by mass of the cross-linking agent (D) relative to 100 parts by mass of the fluorine-containing copolymer (C). ). When the crosslinking agent (D) is more than 25 parts by mass, the coating becomes too hard, cracks are generated during molding, and the releasability with the silicone resin constituting the lens is greatly reduced. On the other hand, if the crosslinking agent (D) is less than 5 parts by mass, the curing of the fluorinated copolymer (C) becomes insufficient, and components of the coating layer migrate to the silicone resin constituting the lens to contaminate the lens.

The reaction product comprising the fluorinated copolymer (C) and the crosslinking agent (D) having two or more isocyanate groups constituting the coating layer can be obtained by the following method.

As a method of laminating a coating layer containing the above reaction product on layer A of the laminated film, a method of dissolving the fluorine-containing copolymer (C) and the crosslinking agent in an organic solvent (E) having a boiling point of 150° C. or higher is preferable. The coating solution obtained in (D) is coated, and then, the fluorinated copolymer (C) and the crosslinking agent (D) are reacted by heat and aging treatment when the organic solvent is dried.

The concentration of the fluorinated copolymer (C) in the coating solution is preferably 5 to 80% by mass, more preferably 10 to 60% by mass.

As the organic solvent constituting the coating liquid, by using an organic solvent (E) having a boiling point of 150° C. or higher, the drying temperature of the coating can be increased, and the fluorine-containing copolymer (C) and the crosslinking agent (D) in the coating can be accelerated. )Reaction.

As the organic solvent (E), cyclohexanone (boiling point: 156°C), cyclohexanol (boiling point: 161°C), methylcyclohexanone (boiling point: 170°C), methylcyclohexanol (boiling point: 174°C) and the like can be used. By using these organic solvents, it is possible to obtain a releasable film having the same performance as a set of fluorine-containing films or sheets (Teflon (registered trademark) series) and having a flat coating surface.

When preparing the coating liquid, solvents other than the organic solvent (E) may be used in combination. Examples of such solvents include aromatic hydrocarbons such as xylene and toluene, alcohols such as n-butanol, esters such as butyl acetate and ethyl acetate, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ethyl Glycol ethers such as cellosolve, various commercially available thinners, and the like.

The coating liquid composed of fluorine-containing copolymer (C), crosslinking agent (D), and organic solvent (E) can be prepared by using a ball mill, paint mixer, sand mill, three-roll mill, kneader, etc. At this time, pigments, dispersion stabilizers, viscosity regulators, leveling agents, ultraviolet absorbers, and the like may be added.

Examples of the method of applying a coating solution consisting of a fluorinated copolymer (C), a crosslinking agent (D), and an organic solvent (E) to layer A of a laminated film include gravure coating and wire bar coating. , die coating, curtain coating, air knife coating and other coating methods. As conditions for drying the coating liquid, conditions for heating to 150 to 220° C. are preferable. Furthermore, as conditions for obtaining a reaction product by reacting the fluorinated copolymer (C) and the crosslinking agent (D), it is preferable to perform aging in an environment of 40 to 90° C. for 12 to 72 hours in addition to the drying described above.

Example

Hereinafter, the present invention will be described based on examples.

The raw materials of the films in Examples and Comparative Examples are as follows.

(1) Polybutylene terephthalate resin (A)

5010CS: Polybutylene terephthalate resin (manufactured by Mitsubishi Engineering Plastics, NOVADURAN 5010CS)

(2) Polyester elastomer (B)

4767N: PBT polyether block copolymer, Tg-35°C (manufactured by Toray DuPont, Hytrel 4767N)

6347: PBT polyether block copolymer, Tg3°C (manufactured by Toray DuPont, Hytrel 6347)

(3) Others

・NEH-2050: Polyethylene terephthalate resin (manufactured by Japan ester company, NEH-2050)

・Aflex: Polytetrafluoroethylene-ethylene copolymer film, thickness 50 μm (manufactured by Asahi Glass Co., Ltd., Aflex LM)

The evaluation method of moldability in the present invention is shown below.

A mold release film was attached so that the coating layer became the bottom surface along the upper mold including the flat portion and the cavity serving as the large and small lens portion. A printed circuit board (or a ceramic plate) is placed at a predetermined position on a lower mold that is a flat mold, and a metered amount of silicone resin is injected into an ellipse near the center with a syringe on the board. The lower mold is raised to contact the upper mold, and the molding pressure is applied to shape the LED lens.

The lower die is lowered, and the LED lens is taken out. At this time, the lens of the LED and the release film were naturally peeled off, and the lens whose surface shape of the lens of the LED was in the shape of the upper mold was evaluated as moldability ◯. The case where the release film and the lens of the LED did not peel off or the release film was cracked, and the lens of the LED was not molded into a normal shape was evaluated as moldability ×.

Example 1

5010CS (for A layer formation) and 4767N (for B layer formation) were melt-extruded in two independent extruders at 260°C, and the respective melts were confluently laminated into (A)/(B) using a feed block )/(A) 3 layers, and then extrude into a sheet with a T die, stick to a cooling roll adjusted to 80°C for 4 seconds and then cool, so that the layer thickness (A layer/B layer/A layer) is 12.5/25/12.5 (μm) laminated film.

Fluorinated olefins, cyclohexyl-containing acrylates, and hydroxyl-containing vinyl ethers as constituents of fluorinated copolymers (manufactured by Kanto Denka Kogyo Co., Ltd., KD200, fluoroolefin/cyclohexyl-containing acrylate/hydroxyl-containing 12 mass parts of hexamethylene diisocyanate (HMDI) as a crosslinking agent was dissolved in 100 mass parts of solid content of a 30 mass % ethyl acetate solution of vinyl ether), and 35 mass parts of hexamethylene diisocyanate (HMDI) as a crosslinking agent was used. The coating solution was prepared using cyclohexanone (boiling point: 156° C.) as an organic solvent with a boiling point and 20 parts by mass of butyl acetate (boiling point: 126° C.).

The obtained coating liquid was applied to the above laminated film with a wire bar coater. Next, after heat treatment at 165°C for 1 minute, heat treatment at 70°C for 48 hours to react the fluorine-containing copolymer and the crosslinking agent to form a coating on the laminated film, thereby obtaining a release film with a coating thickness of 0.15 μm. membrane.

Embodiment 2～5, comparative example 1～6

Except for changing the resin for layer A, the resin for layer B, the layer structure, the composition of the coating liquid, and the thickness of the coating layer as described in Table 1, a release film was obtained in the same manner as in Example 1. .

Reference example

Molding was performed using a polytetrafluoroethylene-ethylene copolymer film (manufactured by Asahi Glass Co., Ltd., Aflex LM) as a release film, and the formability was evaluated.

[Table 1]

In all of Examples 1 to 5, a mold release film having moldability equivalent to the conventionally used fluororesin film (reference example) was obtained.

In contrast, Comparative Example 1 did not use polybutylene terephthalate resin as the resin constituting the laminated film, and because the thickness and composition of the coating layers of Comparative Examples 2 to 5 were outside the scope of the present invention, and because the comparison In Example 6, no coating was provided, and thus the desired moldability was not obtained.

Claims (1)

1., for the mold release film that LED manufactures, be in the mold release film of the stacked coating of stacked film, it is characterized in that,

Two skins of stacked film are polybutylene terephthalate (PBT) resin bed and A layer, comprise polyester elastomer layer and B layer at internal layer,

Coat layer is stacked at least one of two the outer field A layers being configured at stacked film, and containing the reaction product formed by the fluorinated copolymer C of 100 mass parts and the crosslinking agent D with more than 2 NCOs of 5 ~ 25 mass parts,

Fluorinated copolymer C with the vinyl ethers containing the hydroxyl shown in the acrylate of cyclohexyl and formula (3) shown in the fluoroolefin shown in following formula (1), formula (2) for constituent,

The thickness of coating is 0.1 ~ 0.3 μm,

In formula, X is F or H, Y is H, Cl, F, CF ₃,

In formula, R ^lfor H or CH ₃,

In formula, R ²for alkylidene or the cyclohexylidene of carbon number 2 ~ 5.