JP2018051956A - Transparent film producing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent film producing method that produces a transparent film made of a thermoplastic resin with a small melt flow rate by use of an extrusion molding method.SOLUTION: The transparent film producing method includes extrusion molding a thermoplastic resin at an extrusion temperature of Tg+30°C or higher and lower than Tg+70°C, the thermoplastic resin containing a thermoplastic polymer, having a melt flow rate of from 20 g/10 min to 100 g/10 min at 190°C under 2.16 kg load, and having a glass transition temperature Tg.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a transparent film.

  A thermoplastic resin having a low melt flow rate is conventionally known (see Patent Document 1).

JP 2014-208475 A

  The inventor tried to produce a transparent film made of a thermoplastic resin having a low melt flow rate by using an extrusion molding method. In the extrusion molding method, generally, a resin is melted, extruded from a die, formed into a film, and cooled to obtain a film. Such an extrusion molding method is an industrially excellent film manufacturing method because it is excellent in productivity.

  However, it has been difficult to produce a transparent film by the above-described thermoplastic resin having a low melt flow rate by an extrusion molding method under conventional general temperature conditions. Specifically, according to the conventional extrusion molding method under general temperature conditions, flow unevenness, foreign matters due to gelation, and surface irregularities were easily formed on the film. Here, “flow unevenness” indicates streaks formed discontinuously in the film flow direction at random positions. The “foreign matter due to gelation” refers to a lump of gel formed by thermal degradation of the resin. Furthermore, “surface irregularities” indicate protrusions and depressions formed on the surface of the film. When the flow unevenness, foreign matters due to gelation, and surface irregularities were formed, the haze of the film was likely to increase, and it was difficult to produce a transparent film.

  The present invention was devised in view of the above problems, and provides a method for producing a transparent film, which can produce a transparent film made of a thermoplastic resin having a low melt flow rate using an extrusion molding method. Objective.

  In the conventional extrusion molding method, it has been common technical knowledge to extrude a resin at an extrusion temperature about 100 ° C. higher than the glass transition temperature of the resin. If the resin is extruded at a temperature lower than the extrusion temperature, the resulting film tends to become cloudy and it is difficult to obtain a transparent film, so conventionally, the resin is extruded at a high temperature as described above. I was going.

On the other hand, the present inventor tried to produce a film by extruding a thermoplastic resin having a low melt flow rate at a predetermined extrusion temperature lower than before. As a result, surprisingly, it was possible to suppress the occurrence of white turbidity while performing extrusion at a low temperature, and to easily produce a transparent film having a small haze. From this result, the present inventor has found that a transparent film can be easily produced by extruding a thermoplastic resin having a low melt flow rate at a predetermined extrusion temperature based on the glass transition temperature of the thermoplastic resin. Discovered and completed the present invention.
That is, the present invention includes the following.

[1] A thermoplastic resin containing a thermoplastic polymer, having a melt flow rate of 20 g / 10 min to 100 g / 10 min at a temperature of 190 ° C. and a load of 2.16 kg, and having a glass transition temperature Tg is Tg + 30 ° C. A method for producing a transparent film, comprising extrusion molding at an extrusion temperature of Tg + 70 ° C. or more.
[2] The thermoplastic polymer is one or more kinds of polymers selected from the group consisting of a block copolymer of an aromatic vinyl compound and a chain conjugated diene, and a hydride of the block copolymer. ,
The block copolymer has the aromatic vinyl compound unit as a main component, and two or more polymer blocks [A] per molecule of the block copolymer, and the chain conjugated diene compound unit as a main component. One or more polymer blocks [B] per molecule of the block copolymer,
The ratio (wA / wB) of the weight fraction wA of all polymer blocks [A] to the weight fraction wB of all polymer blocks [B] in the entire block copolymer is 20 / 80-60 / 40. The method for producing a transparent film according to [1].
[3] The thermoplastic polymer is a hydride of the block copolymer,
The method for producing a transparent film according to [2], wherein the hydrogenation rate of the hydride is 90% or more of the total unsaturated bonds of the block copolymer.
[4] The method for producing a transparent film according to [2] or [3], wherein the hydride of the block copolymer has an alkoxysilyl group.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of a transparent film which can manufacture the transparent film which consists of a thermoplastic resin with a small melt flow rate using an extrusion molding method can be provided.

  Hereinafter, the present invention will be described in detail with reference to embodiments and examples. However, the present invention is not limited to the following embodiments and exemplifications, and can be implemented with any modifications without departing from the scope of the claims of the present invention and the equivalents thereof.

  In the following description, a “long” film refers to a film having a length of 5 times or more, preferably 10 times or more, and specifically, a film width. Refers to a film having a length that can be wound or stored in a roll. Although the upper limit of the width of a long film is not specifically limited, For example, it can be 100,000 times or less with respect to the width of a film.

[1. Overview of Transparent Film Manufacturing Method]
The method for producing a transparent film of the present invention includes extruding a thermoplastic resin containing a thermoplastic polymer and having a predetermined melt flow rate at an extrusion temperature within a predetermined range.

[2. Melt flow rate of thermoplastic resin]
The melt flow rate of the thermoplastic resin at a temperature of 190 ° C. and a load of 2.16 kg is usually 20 g / 10 min to 100 g / 10 min, preferably 30 g / 10 min to 90 g / 10 min, more preferably 40 g / 10 min to 80 g. / 10 minutes. It is one of the advantages of the present invention that a transparent film formed of a thermoplastic resin having a small melt flow rate as described above can be produced by an extrusion method.

  The melt flow rate of the resin can be measured based on JIS-K-7210 using a melt indexer at a temperature of 190 ° C. and a load of 2.16 kg.

[3. Thermoplastic polymer]
As the thermoplastic polymer, any polymer can be used as long as a thermoplastic resin having a melt flow rate in the above-described range can be obtained. Especially, as a thermoplastic polymer, a block copolymer and its hydride are preferable. The block copolymer and its hydride may be modified with a chemical species such as alkoxysilane, carboxylic acid, carboxylic anhydride, and the like. Usually, the properties of the block copolymer and its hydride can be adjusted by the type and ratio of the polymer block contained in the molecular structure.

  As the block copolymer, a block copolymer of an aromatic vinyl compound and a conjugated diene is preferable. Here, the block copolymer of an aromatic vinyl compound and a conjugated diene is a polymer block [A] having an aromatic vinyl compound unit as a main component and a polymer block having a chain conjugated diene compound unit as a main component. A block copolymer having [B]. The aromatic vinyl compound unit refers to a structural unit having a structure formed by polymerizing an aromatic vinyl compound. Furthermore, the chain conjugated diene compound unit refers to a structural unit having a structure formed by polymerizing a chain conjugated diene compound.

  Among them, as a thermoplastic polymer, the main component is an aromatic vinyl compound unit, two or more polymer blocks [A] per molecule of a block copolymer, and a chain conjugated diene compound unit. A block copolymer having one or more polymer blocks [B] per molecule of the block copolymer and one or more kinds of polymers selected from the group consisting of hydrides of the block copolymers are preferred. . At this time, the hydride of the block copolymer may have an alkoxysilyl group.

(2.1. Block copolymer)
The polymer block [A] of the block copolymer has an aromatic vinyl compound unit. Examples of the aromatic vinyl compound corresponding to the aromatic vinyl compound unit include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-diisopropylstyrene, 2,4- Examples include dimethylstyrene, 4-t-butylstyrene, 5-t-butyl-2-methylstyrene, 4-monochlorostyrene, dichlorostyrene, 4-monofluorostyrene, 4-phenylstyrene, and the like. One of these may be used alone, or two or more of these may be used in combination at any ratio. Especially, the thing which does not contain a polar group in terms of hygroscopicity is preferable. Furthermore, styrene is particularly preferable from the viewpoint of industrial availability and impact resistance.

  The polymer block [A] may have only an aromatic vinyl compound unit, or may contain an arbitrary structural unit in combination with the aromatic vinyl compound unit. The content of the aromatic vinyl compound unit in the polymer block [A] is preferably 90% by weight or more, more preferably 95% by weight or more, and particularly preferably 99% by weight or more. By increasing the amount of the aromatic vinyl compound unit in the polymer block [A] as described above, the heat resistance of the transparent film can be increased.

  Examples of the arbitrary structural unit in the polymer block [A] include a chain conjugated diene compound unit, a structural unit having a structure formed by polymerizing a vinyl compound other than an aromatic vinyl compound, and the like.

  Examples of the chain conjugated diene compound corresponding to the chain conjugated diene compound unit include the same examples as the examples of the chain conjugated diene compound corresponding to the chain conjugated diene compound unit included in the polymer block [B]. Can be mentioned. Moreover, a chain | strand-shaped conjugated diene compound may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  Examples of vinyl compounds other than aromatic vinyl compounds include: chain vinyl compounds; cyclic vinyl compounds; vinyl compounds having a nitrile group, alkoxycarbonyl group, hydroxycarbonyl group, or halogen group; unsaturated cyclic acid anhydrides; Examples thereof include saturated imide compounds. Among them, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-eicosene, 4-methyl-1-pentene, Those that do not contain a polar group, such as chain olefins such as 4,6-dimethyl-1-heptene, and cyclic olefins such as vinylcyclohexane, are preferred in terms of hygroscopicity. Among these, a chain olefin is more preferable, and ethylene and propylene are particularly preferable. Moreover, these may be used individually by 1 type and may be used combining two or more types by arbitrary ratios.

  The content of any structural unit in the polymer block [A] is preferably 10% by weight or less, more preferably 5% by weight or less, and particularly preferably 1% by weight or less.

  The number of polymer blocks [A] in one molecule of the block copolymer is preferably 2 or more, preferably 5 or less, more preferably 4 or less, and particularly preferably 3 or less. The plurality of polymer blocks [A] in one molecule may be the same as or different from each other.

  When a plurality of different polymer blocks [A] exist in one molecule of the block copolymer, the weight average molecular weight of the polymer block having the maximum weight average molecular weight in the polymer block [A] is expressed as Mw (A1). And the weight average molecular weight of the polymer block having the smallest weight average molecular weight is Mw (A2). At this time, the ratio “Mw (A1) / Mw (A2)” between Mw (A1) and Mw (A2) is preferably 2.0 or less, more preferably 1.5 or less, and particularly preferably 1.2 or less. It is. Thereby, the dispersion | variation in various physical-property values can be suppressed small.

  On the other hand, the polymer block [B] of the block copolymer has a chain conjugated diene compound unit. Examples of the chain conjugated diene compound corresponding to the chain conjugated diene compound unit include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and the like. One of these may be used alone, or two or more of these may be used in combination at any ratio. Among them, those not containing a polar group are preferable in terms of hygroscopicity, and 1,3-butadiene and isoprene are particularly preferable.

  The polymer block [B] may have only a chain conjugated diene compound unit or may contain an arbitrary structural unit in combination with the chain conjugated diene compound unit. The content of the chain conjugated diene compound unit in the polymer block [B] is preferably 90% by weight or more, more preferably 95% by weight or more, and particularly preferably 99% by weight or more. By increasing the amount of the chain conjugated diene compound unit in the polymer block [B] as described above, the impact resistance of the transparent film at low temperature can be improved.

  Examples of the arbitrary structural unit in the polymer block [B] include an aromatic vinyl compound unit and a structural unit having a structure formed by polymerizing a vinyl compound other than the aromatic vinyl compound. As the structural unit having a structure formed by polymerizing these aromatic vinyl compound units and vinyl compounds other than the aromatic vinyl compound, for example, it may be contained in the polymer block [A]. What was illustrated is mentioned.

  The content of any structural unit in the polymer block [B] is preferably 10% by weight or less, more preferably 5% by weight or less, and particularly preferably 1% by weight or less. In particular, by reducing the content of the aromatic vinyl compound unit in the polymer block [B], it is possible to improve the low temperature flexibility of the transparent film and to improve the low temperature impact resistance of the transparent film. it can.

  The number of polymer blocks [B] in one molecule of the block copolymer is usually 1 or more, but may be 2 or more. When the number of polymer blocks [B] in the block copolymer is 2 or more, the polymer blocks [B] may be the same as or different from each other.

  Further, when a plurality of different polymer blocks [B] are present in one molecule block copolymer, the weight average molecular weight of the polymer block having the largest weight average molecular weight in the polymer block [B] is expressed as Mw ( B1), and the weight average molecular weight of the polymer block having the smallest weight average molecular weight is Mw (B2). At this time, the ratio “Mw (B1) / Mw (B2)” between Mw (B1) and Mw (B2) is preferably 2.0 or less, more preferably 1.5 or less, and particularly preferably 1.2 or less. It is. Thereby, the dispersion | variation in various physical-property values can be suppressed small.

The block copolymer block may be a chain block or a radial block. Among these, a chain type block is preferable because of its excellent mechanical strength.
When the block copolymer has a chain-type block form, the stickiness of the transparent film can be suppressed to a desired low value because both ends thereof are the polymer block [A].

  A particularly preferable block form of the block copolymer is a triblock in which the polymer block [A] is bonded to both ends of the polymer block [B] as represented by [A]-[B]-[A]. Copolymer; as represented by [A]-[B]-[A]-[B]-[A], the polymer block [B] is bonded to both ends of the polymer block [A], and A pentablock copolymer in which the polymer block [A] is bonded to the other end of the both polymer blocks [B]. In particular, a triblock copolymer of [A]-[B]-[A] is particularly preferable because it can be easily produced and physical properties such as viscosity can be in a desired range.

  The ratio (wA / wB) of the weight fraction wA of all polymer blocks [A] to the weight fraction wB of all polymer blocks [B] in the entire block copolymer falls within a predetermined range. Specifically, the ratio (wA / wB) is preferably 20/80 or more, more preferably 30/70 or more, preferably 60/40 or less, more preferably 55/45 or less. The heat resistance of a transparent film can be improved by making said ratio wA / wB more than the lower limit of the said range. Moreover, the softness | flexibility of a transparent film can be improved by making it below an upper limit. Therefore, when a transparent film is used as a sealing material, the sealing ability can be stably and favorably maintained. Furthermore, since the sealing temperature can be lowered by lowering the glass transition temperature of the block copolymer, thermal deterioration of the light emitting element due to sealing can be suppressed.

The weight average molecular weight (Mw) of the block copolymer is preferably 40,000 to 200,000, more preferably 45,000 to 150,000, and particularly preferably 50,000 to 100,000.
The molecular weight distribution (Mw / Mn) of the block copolymer is preferably 3 or less, more preferably 2 or less, particularly preferably 1.5 or less, and preferably 1.0 or more. Here, Mn represents a number average molecular weight.
The weight average molecular weight and molecular weight distribution of the polymer can be measured as values in terms of polystyrene by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

  As an example of the manufacturing method of a block copolymer, when manufacturing the block copolymer which has three polymer blocks, for example, the following manufacturing methods 1 and 2 are mentioned. Here, the material called “monomer composition” includes not only a mixture of two or more substances but also a material composed of a single substance.

(Production Method 1) A first step of polymerizing a monomer composition (a1) containing an aromatic vinyl compound to form a polymer block [A];
At one end of the polymer block [A], the monomer composition (b1) containing a chain conjugated diene compound is polymerized to form the polymer block [B], and the diblock of [A]-[B] A second step of forming a polymer;
And a third step of polymerizing the monomer composition (a2) containing an aromatic vinyl compound at the terminal on the block [B] side of the diblock polymer to obtain a block copolymer. However, the monomer composition (a1) and the monomer composition (a2) may be the same or different.

(Manufacturing method 2) The 1st process of polymerizing the monomer composition (a1) containing an aromatic vinyl compound, and forming polymer block [A],
At one end of the polymer block [A], the monomer composition (b1) containing a chain conjugated diene compound is polymerized to form the polymer block [B], and the diblock of [A]-[B] A second step of forming a polymer;
And a third step of obtaining a block copolymer by coupling the ends of the diblock polymer on the polymer block [B] side with a coupling agent.

  As a method for polymerizing the monomer composition to obtain each polymer block, for example, radical polymerization, anion polymerization, cation polymerization, coordination anion polymerization, coordination cation polymerization and the like can be used. From the viewpoint of facilitating the polymerization operation and the hydrogenation reaction in the subsequent step, a method in which radical polymerization, anion polymerization, cation polymerization and the like are performed by living polymerization is preferable, and a method in which living polymerization is performed by living anion polymerization is particularly preferable.

The polymerization of the monomer composition is preferably 0 ° C. or higher, more preferably 10 ° C. or higher, particularly preferably 20 ° C. or higher, and preferably 100 ° C. or lower, more preferably 80 ° C. in the presence of a polymerization initiator. Hereinafter, it can be performed particularly preferably in a temperature range of 70 ° C. or less.
In the case of performing living anionic polymerization, as a polymerization initiator, for example, monoorganolithium such as n-butyllithium, sec-butyllithium, t-butyllithium, hexyllithium; dilithiomethane, 1,4-dilithiobutane, 1,4- Polyfunctional organolithium compounds such as dilithio-2-ethylcyclohexane; One of these may be used alone, or two or more of these may be used in combination at any ratio.

As the form of the polymerization reaction, for example, solution polymerization and slurry polymerization can be used. In particular, when solution polymerization is used, reaction heat can be easily removed.
When solution polymerization is performed, an inert solvent in which the polymer obtained in each step can be dissolved can be used as the solvent. Examples of the inert solvent include aliphatic hydrocarbon solvents such as n-pentane, isopentane, n-hexane, n-heptane, and isooctane; alicyclic carbonization such as cyclopentane, cyclohexane, methylcyclopentane, methylcyclohexane, and decalin. A hydrogen solvent; aromatic hydrocarbon solvents such as benzene and toluene; and the like. One of these may be used alone, or two or more of these may be used in combination at any ratio. Among them, it is preferable to use an alicyclic hydrocarbon solvent as a solvent because it can be used as it is as an inert solvent for the hydrogenation reaction and the solubility of the block copolymer is good. The amount of the solvent used is preferably 200 to 2000 parts by weight with respect to 100 parts by weight of all the monomers used.

  When each monomer composition includes two or more types of monomers, for example, a randomizer can be used in order to prevent only one component chain from becoming long. In particular, when the polymerization reaction is performed by anionic polymerization, it is preferable to use, for example, a Lewis base compound as a randomizer. Examples of Lewis base compounds include ether compounds such as dimethyl ether, diethyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, diphenyl ether, ethylene glycol diethyl ether, and ethylene glycol methyl phenyl ether; and tetramethylethylenediamine, trimethylamine, triethylamine, pyridine, Tertiary amine compounds; alkali metal alkoxide compounds such as potassium-t-amyl oxide and potassium-t-butyl oxide; phosphine compounds such as triphenylphosphine; One of these may be used alone, or two or more of these may be used in combination at any ratio.

(2.2. Hydride of block copolymer)
The hydride of the block copolymer is obtained by hydrogenating the unsaturated bond of the block copolymer described above. By hydrogenating and using the block copolymer, the amount of outgas generated from the transparent film can be effectively reduced. Here, the unsaturated bond of the block copolymer includes both the main chain carbon-carbon unsaturated bond and the side chain carbon-carbon unsaturated bond of the block copolymer. Furthermore, the unsaturated bond of the block copolymer includes both an aromatic carbon-carbon unsaturated bond and a non-aromatic carbon-carbon unsaturated bond.

The hydrogenation rate of the hydride of the block copolymer is preferably 90% or more, more preferably 97% or more, and particularly preferably 99% or more of the total unsaturated bonds of the block copolymer. The higher the hydrogenation rate, the better the heat resistance and light resistance of the transparent film. Here, the hydrogenation rate of the hydride can be determined by measurement by ¹ H-NMR.

  In particular, the hydrogenation rate of the non-aromatic unsaturated bond is preferably 95% or more, more preferably 99% or more. By increasing the hydrogenation rate of the non-aromatic carbon-carbon unsaturated bond, the light resistance and oxidation resistance of the transparent film can be further increased.

  The hydrogenation rate of the aromatic carbon-carbon unsaturated bond is preferably 90% or more, more preferably 93% or more, and particularly preferably 95% or more. Since the glass transition temperature of the polymer block obtained by hydrogenating the polymer block [A] is increased by increasing the hydrogenation rate of the carbon-carbon unsaturated bond of the aromatic ring, the heat resistance of the transparent film is effectively improved. Can be increased. Furthermore, since the photoelastic coefficient of the transparent film can be lowered, when the transparent film is used as a sealing material, it is possible to suppress the unintended retardation during sealing.

The weight average molecular weight (Mw) of the hydride of the block copolymer is preferably 40,000 to 200,000, more preferably 45,000 to 150,000, and particularly preferably 50,000 to 100,000.
The molecular weight distribution (Mw / Mn) of the hydride of the block copolymer is preferably 3 or less, more preferably 2 or less, particularly preferably 1.5 or less, and preferably 1.0 or more.
When the weight average molecular weight Mw and molecular weight distribution Mw / Mn of the hydride of the block copolymer are in the above ranges, the mechanical strength and heat resistance of the transparent film can be improved.

  In the hydride of the block copolymer, the weight fraction wA that the total polymer block obtained by hydrogenating the polymer block [A] occupies the entire hydride and the total obtained by hydrogenating the polymer block [B]. The ratio (wA / wB) of the polymer block to the weight fraction wB in the entire hydride is usually the same value as the ratio wA / wB in the block copolymer before hydrogenation.

  The hydride of the block copolymer preferably has an alkoxysilyl group in its molecular structure. The hydride having an alkoxysilyl group of the block copolymer can be obtained, for example, by bonding an alkoxysilyl group to a hydride of a block copolymer having no alkoxysilyl group. In this case, an alkoxysilyl group may be directly bonded to the hydride of the block copolymer, and may be bonded via a divalent organic group such as an alkylene group.

  A hydride having an alkoxysilyl group is particularly excellent in adhesion to materials such as glass, inorganic substances, and metals. Therefore, when sealing a light emitting element with a transparent film, the adhesiveness of a transparent film and a light emitting element can be made especially high. Therefore, the transparent film can maintain a sufficient adhesive force even after being exposed to a high temperature and high humidity environment for a long time.

The introduction amount of the alkoxysilyl group is preferably 0.1 parts by weight or more, more preferably 0.2 parts by weight or more, particularly preferably 100 parts by weight of the hydride of the block copolymer before the introduction of the alkoxysilyl group. It is 0.3 parts by weight or more, preferably 10 parts by weight or less, more preferably 5 parts by weight or less, and particularly preferably 3 parts by weight or less. When the introduction amount of the alkoxysilyl group is within the above range, it is possible to suppress an excessive increase in the degree of cross-linking between the alkoxysilyl groups decomposed with moisture, so that the adhesiveness of the transparent film can be maintained high.
The amount of alkoxysilyl group introduced can be measured by ¹ H-NMR spectrum. In addition, when the introduction amount of the alkoxysilyl group is measured, if the introduction amount is small, the number of integrations can be increased.

  The molecular weight of the hydride having an alkoxysilyl group in the block copolymer is usually larger than the molecular weight of the hydride in the block copolymer before introducing the alkoxysilyl group because the amount of the alkoxysilyl group to be introduced is small. It does not change. However, when introducing an alkoxysilyl group, since the hydride of the block copolymer is usually subjected to a modification reaction in the presence of a peroxide, the crosslinking reaction and cleavage reaction of the hydride proceed, and the molecular weight distribution is There is a tendency to change greatly.

The weight average molecular weight of the hydride having an alkoxysilyl group of the block copolymer is preferably 40,000 to 200,000, more preferably 45,000 to 150,000, particularly preferably 50,000 to 100,000. is there.
The molecular weight distribution (Mw / Mn) of the hydride having an alkoxysilyl group of the block copolymer is preferably 3.5 or less, more preferably 2.5 or less, particularly preferably 2.0 or less, Is 1.0 or more.
When the weight average molecular weight Mw and molecular weight distribution Mw / Mn of the hydride having an alkoxysilyl group of the block copolymer are in this range, good mechanical strength and tensile elongation of the transparent film can be maintained.

  A method for producing a hydride of a block copolymer usually includes hydrogenating the above-described block copolymer. As the hydrogenation method, a hydrogenation method that can increase the hydrogenation rate and has less chain-breaking reaction of the block copolymer is preferable. Examples of such a preferable hydrogenation method include hydrogenation using a hydrogenation catalyst containing at least one metal selected from the group consisting of nickel, cobalt, iron, titanium, rhodium, palladium, platinum, ruthenium, and rhenium. There is a method of performing the conversion. A hydrogenation catalyst may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios. As the hydrogenation catalyst, either a heterogeneous catalyst or a homogeneous catalyst can be used. The hydrogenation reaction is preferably performed in an organic solvent.

The heterogeneous catalyst may be used as it is, for example, as a metal or a metal compound, or may be used by being supported on a suitable carrier. Examples of the carrier include activated carbon, silica, alumina, calcium carbonate, titania, magnesia, zirconia, diatomaceous earth, silicon carbide, calcium fluoride, and the like. The supported amount of the catalyst is preferably 0.1% by weight or more, more preferably 1% by weight or more, preferably 60% by weight or less, more preferably 50% by weight or less based on the total amount of the catalyst and the carrier. is there. The specific surface area of the supported catalyst is preferably 100m ² / g~500m ² / g. Furthermore, the average pore diameter of the supported catalyst is preferably 100 mm or more, more preferably 200 mm or more, preferably 1000 mm or less, preferably 500 mm or less. Here, the specific surface area can be obtained by measuring the nitrogen adsorption amount and using the BET equation. The average pore diameter can be measured by a mercury intrusion method.

As the homogeneous catalyst, for example, a catalyst obtained by combining a nickel, cobalt, titanium or iron compound and an organometallic compound; an organometallic complex catalyst such as rhodium, palladium, platinum, ruthenium or rhenium;
Examples of the nickel, cobalt, titanium, or iron compound include acetylacetonato compounds, carboxylates, and cyclopentadienyl compounds of each metal.
Examples of the organometallic compound include organoaluminum compounds such as alkylaluminum such as triethylaluminum and triisobutylaluminum, aluminum halide such as diethylaluminum chloride and ethylaluminum dichloride, and alkylaluminum hydride such as diisobutylaluminum hydride; And organic lithium compounds.
Examples of organometallic complex catalysts include transition metal complexes such as dihydrido-tetrakis (triphenylphosphine) ruthenium, dihydrido-tetrakis (triphenylphosphine) iron, bis (cyclooctadiene) nickel, and bis (cyclopentadienyl) nickel. Is mentioned.

  The amount of the hydrogenation catalyst used is preferably 0.01 parts by weight or more, more preferably 0.05 parts by weight or more, particularly preferably 0.1 parts by weight or more with respect to 100 parts by weight of the block copolymer. The amount is preferably 100 parts by weight or less, more preferably 50 parts by weight or less, and particularly preferably 30 parts by weight or less.

  The temperature of the hydrogenation reaction is preferably 10 ° C or higher, more preferably 50 ° C or higher, particularly preferably 80 ° C or higher, preferably 250 ° C or lower, more preferably 200 ° C or lower, particularly preferably 180 ° C or lower. . By performing the hydrogenation reaction in such a temperature range, the hydrogenation rate can be increased and the molecular cleavage of the block copolymer can be reduced.

  The hydrogen pressure during the hydrogenation reaction is preferably 0.1 MPa or more, more preferably 1 MPa or more, particularly preferably 2 MPa or more, preferably 30 MPa or less, more preferably 20 MPa or less, and particularly preferably 10 MPa or less. . By performing the hydrogenation reaction at such a hydrogen pressure, the hydrogenation rate can be increased, the molecular chain breakage of the block copolymer can be reduced, and the operability is improved.

  By hydrogenating the block copolymer as described above, a hydride of the block copolymer is obtained as a product. The product after the hydrogenation reaction may be used as it is to form a transparent film. Moreover, you may use in order to form a transparent film, after giving arbitrary processes to the product after a hydrogenation reaction further as needed. For example, you may perform the process which introduce | transduces an alkoxy silyl group with respect to the product after hydrogenation reaction as needed.

  As a method for introducing an alkoxysilyl group into a hydride of a block copolymer, for example, a hydride of a block copolymer before introducing an alkoxysilyl group, an ethylenically unsaturated silane compound, a peroxide A method of reacting in the presence can be used.

  As the ethylenically unsaturated silane compound, those capable of graft polymerization with a hydride of a block copolymer and capable of introducing an alkoxysilyl group into the hydride of the block copolymer can be used. Examples of such ethylenically unsaturated silane compounds include vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, dimethoxymethylvinylsilane, diethoxymethylvinylsilane, p-styryltrimethoxysilane, p-styryltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-acryloxypropyltri Examples include methoxysilane, 3-acryloxypropyltriethoxysilane, and 2-norbornen-5-yltrimethoxysilane. Of these, vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, dimethoxymethylvinylsilane, diethoxymethylvinylsilane, and p-styryltrimethoxysilane are preferable. Moreover, an ethylenically unsaturated silane compound may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  The amount of the ethylenically unsaturated silane compound is preferably 0.1 parts by weight or more, more preferably 0.2 parts by weight or more with respect to 100 parts by weight of the hydride of the block copolymer before introducing the alkoxysilyl group. The amount is particularly preferably 0.3 parts by weight or more, preferably 10 parts by weight or less, more preferably 5 parts by weight or less, and particularly preferably 3 parts by weight or less.

  Examples of the peroxide include dibenzoyl peroxide, t-butyl peroxyacetate, 2,2-di- (t-butylperoxy) butane, t-butylperoxybenzoate, t-butylcumyl peroxide, Milperoxide, di-t-hexyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxyhexane), di-t-butyl peroxide, 2,5-dimethyl-2,5- Organic peroxides such as di (t-butylperoxy) hexane-3, t-butylhydroperoxide, t-butylperoxyisobutyrate, lauroyl peroxide, dipropionyl peroxide, p-menthane hydroperoxide Can be mentioned. Among them, those having a 1-minute half-life temperature of 170 ° C. to 190 ° C. are preferable, for example, t-butylcumyl peroxide, dicumyl peroxide, di-t-hexyl peroxide, 2,5-dimethyl-2,5- Di (t-butylperoxyhexane), di-t-butyl peroxide and the like are preferable. Moreover, a peroxide may be used individually by 1 type and may be used in combination of 2 or more type.

  The amount of the peroxide is preferably 0.01 parts by weight or more, more preferably 0.2 parts by weight or more, particularly preferably 100 parts by weight of the hydride of the block copolymer before introducing the alkoxysilyl group. Is 0.3 parts by weight or more, preferably 5 parts by weight or less, more preferably 3 parts by weight or less, and particularly preferably 2 parts by weight or less.

  The method of reacting the hydride of the block copolymer and the ethylenically unsaturated silane compound in the presence of a peroxide can be performed using, for example, a heating kneader and a reactor. As a specific example, a block copolymer hydride, an ethylenically unsaturated silane compound and a peroxide mixture are heated and melted at a temperature equal to or higher than the melting temperature of the block copolymer hydride in a biaxial kneader. Then, by kneading for a desired time, an alkoxysilyl group can be introduced into the hydride of the block copolymer. The specific temperature during kneading is preferably 180 ° C. or higher, more preferably 190 ° C. or higher, particularly preferably 200 ° C. or higher, preferably 240 ° C. or lower, more preferably 230 ° C. or lower, particularly preferably 220 ° C. or lower. It is. The kneading time is preferably 0.1 minutes or more, more preferably 0.2 minutes or more, particularly preferably 0.3 minutes or more, preferably 15 minutes or less, more preferably 10 minutes or less, particularly preferably. 5 minutes or less. When using a continuous kneading facility such as a twin-screw kneader or a single-screw extruder, kneading and extrusion can be performed continuously with the residence time being in the above range.

[4. Arbitrary ingredients]
The thermoplastic resin may further contain an optional component in combination with the above-described thermoplastic polymer.
As an arbitrary component, an ultraviolet absorber is mentioned, for example. By using an ultraviolet absorber, the light resistance of the transparent film can be improved. Examples of the ultraviolet absorber include benzophenone ultraviolet absorbers, salicylic acid ultraviolet absorbers, and benzotriazole ultraviolet absorbers.

  Examples of the benzophenone-based ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid trihydrate, 2-hydroxy-4- Octyloxybenzophenone, 4-dodecaloxy-2-hydroxybenzophenone, 4-benzyloxy-2-hydroxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxy Examples include benzophenone.

  Examples of the salicylic acid ultraviolet absorber include phenyl salicylate, 4-t-butylphenyl-2-hydroxybenzoate, phenyl-2-hydroxybenzoate, 2,4-di-t-butylphenyl-3,5-di -T-butyl-4-hydroxybenzoate, hexadecyl-3,5-di-t-butyl-4-hydroxybenzoate and the like.

Examples of the benzotriazole ultraviolet absorber include 2- (2-hydroxy-5-methylphenyl) 2H-benzotriazole and 2- (3-t-butyl-2-hydroxy-5-methylphenyl) -5-chloro. -2H-benzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) -5-chloro-2H-benzotriazole, 2- (3,5-di-t-butyl-2-hydroxy Phenyl) -2H-benzotriazole, 5-chloro-2- (3,5-di-t-butyl-2-hydroxyphenyl) -2H-benzotriazole, 2- (3,5-di-t-amyl-2) -Hydroxyphenyl) -2H-benzotriazole, 2- (2-hydroxy-5-t-octylphenyl) -2H-benzotriazole, 2- (2-hydroxy- -Octylphenyl) -2H-benzotriazole, 2- (2H-benzotriazol-2-yl) -4-methyl-6- (3,4,5,6-tetrahydrophthalimidylmethyl) phenol, 2,2 ' -Methylenebis [4- (1,1,3,3-tetramethylbutyl) -6-[(2H-benzotriazol-2-yl) phenol]] and the like.
One type of ultraviolet absorber may be used alone, or two or more types may be used in combination at any ratio.

  The amount of the ultraviolet absorber is preferably 0.01 parts by weight or more, more preferably 0.02 parts by weight or more, particularly preferably 0.04 parts by weight or more, preferably 100 parts by weight of the thermoplastic polymer. Is 1 part by weight or less, more preferably 0.75 part by weight or less, and particularly preferably 0.5 part by weight or less. By using the ultraviolet absorber above the lower limit of the above range, the light resistance of the transparent film can be improved, and even if it is used in excess of the upper limit, further improvement is hardly obtained.

Moreover, as an arbitrary component, a plasticizer is mentioned, for example. By using a plasticizer, physical properties such as the melt flow rate, glass transition temperature, and elastic modulus of the thermoplastic resin can be adjusted. Examples of the plasticizer include polyisobutene, hydrogenated polyisobutene, hydrogenated polyisoprene, hydrogenated 1,3-pentadiene petroleum resin, hydrogenated cyclopentadiene petroleum resin, hydrogenated styrene / indene petroleum resin, and the like.
A plasticizer may be used individually by 1 type and may be used combining two or more types by arbitrary ratios.

  The amount of the plasticizer is preferably 40 parts by weight or less with respect to 100 parts by weight of the thermoplastic resin, and can be selected according to the purpose of adjusting the resin characteristics.

  Moreover, as an arbitrary component, antioxidant is mentioned, for example. Examples of the antioxidant include phosphorus antioxidants, phenolic antioxidants, sulfur antioxidants, and the like, and phosphorus antioxidants with less coloring are preferable.

  Examples of phosphorus antioxidants include triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, tris (nonylphenyl) phosphite, tris (dinonylphenyl) phosphite, tris (2,4-di-). -T-butylphenyl) phosphite, 10- (3,5-di-t-butyl-4-hydroxybenzyl) -9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide Phosphite compounds; 4,4′-butylidene-bis (3-methyl-6-tert-butylphenyl-di-tridecyl phosphite), 4,4′-isopropylidene-bis (phenyl-di-alkyl (C12 -C15) diphosphite compounds such as phosphite); 6- [3- (3-t-butyl) 4-hydroxy-5-methylphenyl) propoxy] -2,4,8,10-tetrakis-t-butyldibenzo [d, f] [1.3.2] dioxaphosphine, 6- [3- ( 3,5-di-t-butyl-4-hydroxyphenyl) propoxy] -2,4,8,10-tetrakis-t-butyldibenzo [d, f] [1.3.2] dioxaphosphine, etc. Can be mentioned.

  Examples of phenolic antioxidants include pentaerythrityl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 3,9-bis {2- [ 3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl} -2,4,8,10-tetraoxaspiro [5,5] undecane, 1, A compound such as 3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene can be exemplified.

Examples of the sulfur-based antioxidant include dilauryl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, laurylstearyl- 3,3′-thiodipropionate, pentaerythritol-tetrakis- (β-lauryl-thio-propionate), 3,9-bis (2-dodecylthioethyl) -2,4,8,10-tetraoxaspiro [ 5,5] can include compounds such as undecane.
An antioxidant may be used individually by 1 type and may be used combining two or more types by arbitrary ratios.

  The amount of the antioxidant is preferably 0.01 parts by weight or more, more preferably 0.05 parts by weight or more, particularly preferably 0.1 parts by weight or more, preferably 100 parts by weight of the thermoplastic polymer. Is 1 part by weight or less, more preferably 0.5 part by weight or less, and particularly preferably 0.3 part by weight or less. By using antioxidant more than the lower limit of the said range, the thermal stability of a transparent film can be improved, and even if it uses excessively exceeding an upper limit, it is difficult to obtain the further improvement.

Furthermore, as an arbitrary component, metal compounds, such as an inorganic metal compound and an organometallic compound; Water | moisture-content trapping agent; Light stabilizer; Lubricant; Inorganic filler;
Arbitrary components may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

[5. Physical properties of thermoplastic resin]
The glass transition temperature Tg of the thermoplastic resin is preferably 30 ° C. or higher, more preferably 50 ° C. or higher, particularly preferably 70 ° C. or higher, preferably 200 ° C. or lower, more preferably 180 ° C. or lower, particularly preferably 160 ° C. It is as follows. The thermoplastic resin can have multiple glass transition temperatures. In that case, it is preferable that the highest glass transition temperature of the resin falls within the above range. When the glass transition temperature Tg of the thermoplastic resin is within the above range, it is possible to balance the adhesiveness of the transparent film and the performance maintenance of the light emitting element after sealing.

The glass transition temperature of the resin can be measured by the following method.
A resin pellet is press-molded to produce a test piece having a length of 50 mm, a width of 10 mm, and a thickness of 1 mm. Using this test piece, based on JIS-K7244-4 method, using a viscoelasticity measuring device, a dynamic viscoelastic property was measured at a temperature rising rate of 5 ° C / min in a temperature range of -100 ° C to + 150 ° C. taking measurement. The dynamic viscoelastic characteristics were obtained as a graph with the horizontal axis representing temperature and the vertical axis representing loss tangent tan δ. The glass transition temperature Tg can be obtained from the peak top temperature on the high temperature side of the loss tangent tan δ in this dynamic viscoelastic property.

[6. Extrusion process]
The manufacturing method of a transparent film includes extrusion-molding the thermoplastic resin mentioned above. Usually, a molten thermoplastic resin is extruded into a film by extruding it from a die. And a long transparent film is obtained by cooling the shape | molded thermoplastic resin.

At this time, the extrusion temperature of the thermoplastic resin is usually Tg + 30 ° C. or higher, preferably Tg + 35 ° C. or higher, more preferably Tg + 40 ° C. or higher, usually Tg + 70 ° C., preferably Tg + 65 ° C., more preferably Tg + 60 ° C. or lower. . Here, Tg represents the glass transition temperature of the thermoplastic resin. When the thermoplastic resin has a plurality of glass transition temperatures, Tg represents the highest glass transition temperature of the resin. When the extrusion temperature is less than the lower limit of the above range, surface irregularities are formed on the surface of the film obtained by extrusion molding, haze increases, and it is difficult to obtain a transparent film. On the other hand, when the extrusion temperature is equal to or higher than the upper limit of the above range, a large amount of foreign matter due to flow unevenness and gelation is generated and haze increases, so that it is difficult to obtain a transparent film. On the other hand, when the extrusion temperature is in the above range, a transparent film having a small haze can be easily produced. Moreover, if it is the extrusion temperature of the said range, normally, generation | occurrence | production of the defect by a foreign material can be suppressed effectively.
Here, the extrusion temperature of the thermoplastic resin is the temperature of the thermoplastic resin at the time of extrusion from the die, and can usually be measured as the temperature of the thermoplastic resin in the die.

Usually, the film-like molten thermoplastic resin extruded from a die is brought into close contact with a cooling roll. The method for bringing the resin into close contact with the cooling roll is not particularly limited, and examples thereof include an air knife method, a vacuum box method, and an electrostatic contact method.
The number of cooling rolls is not particularly limited, but is preferably 2 or more. Further, examples of the arrangement method of the cooling roll include, but are not limited to, a linear type, a Z type, and an L type. Further, the way of passing the molten resin extruded from the die through the cooling roll is not particularly limited.

  The degree of adhesion of the extruded film-like resin to the cooling roll may change depending on the temperature of the cooling roll. Specifically, when the temperature of the cooling roll is high, the adhesion tends to be good, but when the temperature is too high, the film-like resin may not be easily peeled off from the cooling roll. Therefore, the cooling roll temperature is preferably Tg ° C or lower, more preferably Tg-10 ° C or lower, and preferably Tg-100 ° C or higher.

[7. Any process]
The method for producing a transparent film may further include an optional step in combination with the step of extruding a thermoplastic resin as described above. For example, the method for producing a transparent film may include a step of stretching the obtained transparent film. In addition, for example, the method for producing a transparent film includes a step of subjecting the surface of the obtained transparent film to surface treatment such as corona treatment, plasma treatment, chemical treatment, and coating treatment with an arbitrary coating solution. Also good.

[8. Transparent film]
A transparent film is obtained by the manufacturing method described above. This transparent film is excellent in transparency. Here, being excellent in transparency means that haze is small. The specific haze of the transparent film is preferably 0.5% or less, more preferably 0.4% or less, particularly preferably 0.2% or less, and ideally 0.0%.

The haze of the film can be measured by the following method.
A 50 mm square piece of film is cut out from both widthwise ends of the film and the widthwise center. The haze of each of the three obtained film pieces is measured using a haze meter in accordance with JIS K 7136. And the value of the haze of a film can be calculated | required as an average of the haze of a film piece.

  Transparent films usually have less outgas. Therefore, when the transparent film is heated from 25 ° C. to 120 ° C. under a temperature rising condition of 10 ° C./min, the amount of water generated from the transparent film is usually small. Specifically, the water content is preferably 50 ppm or less, more preferably 45 ppm or less, and particularly preferably 40 ppm or less. Here, the unit “ppm” of the water content represents the water content ratio on a weight basis, and represents the ratio to the weight of the transparent film before the temperature rise.

  Moreover, when the transparent film is heated from 25 ° C. to 120 ° C. under a temperature rising condition of 10 ° C./min, the total amount of outgas other than moisture generated from the transparent film is usually small. Specifically, the total amount of outgas other than moisture is preferably 500 ppm or less, more preferably 450 ppm or less, and particularly preferably 400 ppm or less. Here, the unit “ppm” of the total amount of outgas other than moisture represents the ratio of the total amount of outgas other than moisture on a weight basis, and represents the ratio to the weight of the transparent film before the temperature rise. Examples of the outgas other than moisture include components derived from low molecular weight additives such as plasticizers, antioxidants, and ultraviolet absorbers contained in the transparent film.

The transparent film with less outgas as described above is a dark film immediately after sealing the organic EL element when used as a sealing material for an organic electroluminescence element (hereinafter sometimes referred to as “organic EL element” as appropriate). Spot generation can be effectively suppressed.
The amount of outgas of the transparent film can be measured by a gas chromatograph mass spectrometer.

  The total light transmittance of the transparent film is preferably high. The specific total light transmittance is preferably 70% or more, more preferably 80% or more, and particularly preferably 90% or more. The total light transmittance can be measured in a wavelength range of 400 nm to 700 nm using an ultraviolet / visible spectrometer.

  The thickness of the transparent film is preferably 40 μm or less, more preferably 30 μm or less, and particularly preferably 20 μm or less. In general, in a thick film, even if it contains foreign matter due to gelation, the foreign matter is easily embedded in the film. Therefore, in the conventional thick film, even if it contains a foreign material, it is difficult to form protrusions on the surface and the haze is difficult to increase. However, in the conventional thin film, when a foreign substance caused by gelation is included, a protrusion is formed on the surface by the foreign substance, and the haze tends to increase. On the other hand, in the manufacturing method mentioned above, since generation | occurrence | production of the foreign material by gelatinization is suppressed, even if it is a thin transparent film, it is hard to form a protrusion on the surface, Therefore, a small haze can be achieved easily. Therefore, it is preferable that the transparent film is thin as described above from the viewpoint of effectively utilizing the advantage that the haze can be reduced even if it is thin. The lower limit of the thickness of the transparent film is not particularly limited, but is preferably 2 μm or more, more preferably 3 μm or more, and particularly preferably 5 μm or more from the viewpoint of improving the sealing performance when used as a sealing material.

  The application of the transparent film is not limited and can be used for any application. Especially, it is preferable to use as an optical film from a viewpoint of utilizing high transparency effectively. Examples of the optical film include a protective film such as a polarizing plate protective film; a sealing material film for a light emitting element; and the like. Especially, it is preferable to use a transparent film as a sealing material film.

  When sealing a light emitting element with a transparent film, sealing is usually performed by attaching a transparent film to the light emitting element. At the time of the bonding, usually, a transparent film is placed on the surface of the light emitting element, and the transparent film is pressure-bonded to the light emitting element at a predetermined sealing temperature. Thereby, a transparent film adheres to a light emitting element, and sealing of a light emitting element is achieved.

  Sealing is usually performed at a temperature higher than the glass transition temperature Tg of the thermoplastic resin contained in the transparent film. The specific sealing temperature is preferably Tg + 5 ° C. or higher, more preferably Tg + 10 ° C. or higher, and particularly preferably Tg + 20 ° C. or higher. Thus, at a temperature higher than the glass transition temperature Tg, the transparent film is sufficiently flexible. Therefore, even when the surface of the light-emitting element is not flat, the transparent film can be easily adhered to the element surface without a gap, so that good sealing can be realized. The upper limit of the sealing temperature is preferably Tg + 150 ° C. or lower, more preferably Tg + 120 ° C. or lower, particularly preferably Tg + 100 ° C. or lower. Thereby, the thermal deterioration of the light emitting element by the heat | fever in the case of sealing can be suppressed.

  The pressure applied for pressure bonding is preferably 0.01 MPa or more, more preferably 0.05 MPa or more, particularly preferably 0.1 MPa or more, preferably 1 MPa or less, more preferably 0.75 MPa or less, particularly preferably. 0.5 MPa or less. By making the pressure equal to or higher than the lower limit value of the range, the transparent film can be easily adhered to the light emitting element, and by making the pressure equal to or lower than the upper limit value of the range, generation of dark spots can be effectively performed. Can be suppressed.

  The sealing is preferably performed in a reduced pressure environment. Thereby, the penetration | invasion of the water | moisture content and oxygen to the light emitting element sealed can be suppressed further effectively. The specific degree of vacuum of the sealing environment is preferably 100 Pa or less, more preferably 75 Pa or less, and particularly preferably 50 Pa or less.

  The sealing is preferably performed in a dry room where dry air having a dew point temperature of −40 ° C. or less is introduced. Thereby, the penetration | invasion of the water | moisture content and oxygen to the light emitting element sealed can be suppressed further effectively.

  Examples of the optical element to be sealed as described above include photoelectric conversion elements such as organic EL elements and solar cell elements. Among these, an organic EL element is preferable.

Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the following examples, and can be implemented with any modifications without departing from the scope of the claims of the present invention and the equivalents thereof.
In the following description, “%” and “part” representing amounts are based on weight unless otherwise specified. In addition, the operations described below were performed in a normal temperature and pressure atmosphere unless otherwise specified.

[Evaluation method]
[Measuring method of melt flow rate of resin]
The melt flow rate of the resin was measured under the conditions of a temperature of 190 ° C. and a load of 2.16 kg using a melt indexer (“F-F01” manufactured by Toyo Seiki Seisakusho) based on JIS-K-7210.

[Measurement method of glass transition temperature (Tg) of resin]
A resin pellet was press-molded to prepare a test piece having a length of 50 mm, a width of 10 mm, and a thickness of 1 mm. Using this test piece, based on JIS-K7244-4 method, using a viscoelasticity measuring device (“ARES” manufactured by TA Instruments Japan Co., Ltd.), a temperature range of −100 ° C. to + 150 ° C. Then, the dynamic viscoelastic properties were measured at a heating rate of 5 ° C./min. The glass transition temperature Tg was determined from the peak top temperature on the high temperature side of the loss tangent tan δ in this dynamic viscoelastic property.

[Method for measuring haze of film]
A 50 mm square film piece was cut out from both widthwise ends of the film and the widthwise center. The haze of each of the obtained three film pieces was measured using a haze meter (“NDH-2000” manufactured by Nippon Denshoku Industries Co., Ltd.). The haze value of the film was obtained as the average of the haze of the film pieces. Based on the obtained haze value, the following criteria were used for evaluation.
“◎”: Haze is 0.2% or less.
“◯”: haze is greater than 0.2% and 0.5% or less.
"X": Haze is larger than 0.5%.

[Method for evaluating foreign matter on film]
A glass plate having a length of 50 mm, a width of 50 mm, and a thickness of 0.1 mm was prepared. The glass plate and the film were overlapped and thermocompression bonded to produce a foreign matter evaluation sample. The thermocompression bonding was performed using a vacuum laminator (manufactured by Joyo Engineering Co., Ltd.) under pressure bonding conditions of a heating temperature of 110 ° C., a pressure of 0.8 kN, a degree of vacuum of 1.3 Pa, and a holding time of 5 minutes. The produced sample was observed at a magnification of 200 times using an optical microscope (OLYMPUS "BX51"). In a portion where there is a foreign substance on the film, the film and the glass plate may not be in close contact with each other, and bubbles may be formed. Therefore, the number of bubbles having a major axis of 300 μm or more was counted in the observed image. Based on the number of bubbles, evaluation was performed according to the following criteria.
“◎”: The number of bubbles is less than two.
“◯”: The number of bubbles is 2 or more and less than 5.
"X": The number of bubbles is 5 or more.

[Example 1]
(Manufacture of block copolymer)
A reactor equipped with a stirrer was prepared, and the inside thereof was sufficiently purged with nitrogen. In this reactor, 550 parts of dehydrated cyclohexane, 25.0 parts of dehydrated styrene, and 0.59 part of n-dibutyl ether were added, and 1.14 parts of n-butyllithium (15% cyclohexane solution) was stirred at 60 ° C. Was added to initiate the polymerization. Then, it was made to react at 60 degreeC for 60 minutes, stirring. Then, when the polymerization conversion rate of the obtained reaction mixture was measured, the polymerization conversion rate at this time was 99.5% (the polymerization conversion rate was measured by gas chromatography analysis. The same applies hereinafter. .)

Next, 50.0 parts of dehydrated isoprene was added to the reactor, and stirring was continued for 30 minutes. The polymerization conversion rate at this point was 99.5%.
Thereafter, 25.0 parts of dehydrated styrene was further added to the reactor and stirred for 60 minutes. The polymerization conversion rate at this point was almost 100%. Here, 0.5 part of isopropyl alcohol was added to the reactor to stop the reaction, and a solution (i) containing a block copolymer was obtained. The resulting block copolymer had a weight average molecular weight (Mw) of 47,000, a molecular weight distribution (Mw / Mn) of 1.03, a weight fraction wA of the styrene polymer block and a weight fraction wB of the isoprene polymer block. Ratio wA / wB = 50/50.

(Hydrogenation treatment)
Next, the solution (i) was transferred to a pressure resistant reactor equipped with a stirring device. To this heat-resistant reactor, 3.0 parts of a diatomaceous earth supported nickel catalyst (“T-8400RL” manufactured by Zude Chemie Catalysts) and 100 parts of dehydrated cyclohexane were added as hydrogenation catalysts. The inside of the reactor was replaced with hydrogen gas, and hydrogen was supplied while stirring the solution. A hydrogenation reaction was performed at a temperature of 190 ° C. and a pressure of 4.5 MPa for 6 hours. Thus, the block copolymer was hydrogenated to obtain a solution (iii) containing a hydride (ii) of the block copolymer. The weight average molecular weight (Mw) of the hydride (ii) of the block copolymer in the solution (iii) was 48,000, and the molecular weight distribution (Mw / Mn) was 1.04.

  After completion of the hydrogenation reaction, the solution (iii) was filtered to remove the hydrogenation catalyst. Thereafter, the filtered solution (iii) was added with pentaerythrityl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (Songnox 1010 manufactured by SONGWON), which is a phenolic antioxidant. ] 1.0 part of xylene solution in which 0.1 part was dissolved was added and dissolved to obtain a solution (iv).

  Next, the solution (iv) was filtered through a metal fiber filter (pore size: 0.4 μm, manufactured by Nichidai) to remove minute solids. Thereafter, from the filtered solution (iv), cyclohexane, xylene and other volatile components, which are solvents, are removed at a temperature of 260 ° C. and a pressure of 0.001 MPa or less using a cylindrical concentration dryer (“Contro” manufactured by Hitachi, Ltd.). To obtain a molten polymer. The molten polymer was continuously filtered at a temperature of 260 ° C. with a polymer filter (manufactured by Fuji Filter) equipped with a stainless sintered filter having a pore diameter of 5 μm connected to the concentration dryer. Thereafter, the molten polymer was extruded from the die into a strand shape, cooled, and then cut by a pelletizer to produce 96 parts of a block copolymer hydride (v) pellet. The hydride (v) of the obtained block copolymer had a weight average molecular weight (Mw) of 48,000 and a molecular weight distribution (Mw / Mn) of 1.04. The hydrogenation rate was almost 100%.

(Introduction treatment of alkoxysilyl group)
With respect to 100 parts of the block copolymer hydride (v) pellets, 2.0 parts of vinyltrimethoxysilane and 2,5-dimethyl-2,5-di (t-butylperoxy) hexane ( 0.2 parts of “Perhexa (registered trademark) 25B” manufactured by NOF Corporation was added to obtain a mixture. This mixture was kneaded using a twin screw extruder (“TEM37B” manufactured by Toshiba Machine Co., Ltd.) at a resin temperature of 200 ° C. and a residence time of 60 seconds to 70 seconds, extruded into a strand shape, air-cooled, and then cut with a pelletizer. Then, 97 parts of a hydride (vi) pellet having an alkoxysilyl group of the block copolymer was obtained. In the following description, the hydride (vi) having an alkoxysilyl group may be referred to as “modified hydride (vi)” as appropriate.

Ten parts of the resulting modified hydride (vi) pellets were dissolved in 100 parts of cyclohexane and then poured into 400 parts of dehydrated methanol to coagulate the modified hydride (vi). The coagulated denatured hydride (vi) was filtered off and dried in vacuo at 25 ° C. to isolate 9.5 parts of the denatured hydride (vi) crumb. The isolated crumb was observed for FT-IR spectrum and ¹ H-NMR spectrum. In the FT-IR spectrum, a new absorption band derived from the Si—OCH ₃ group was observed at 1090 cm ⁻¹ , and a new absorption band derived from the Si—CH ₂ group was observed at 825 cm ⁻¹ and 739 cm ⁻¹ . . The location of these absorption bands, ^{1075 cm} -1 is the position of the absorption band of vinyltrimethoxysilane, a 808cm ^-1, and 766cm ^-1 with different positions. In the ¹ H-NMR spectrum (in deuterated chloroform), an absorption band based on a proton of a methoxy group was observed at 3.6 ppm. From the peak area ratio in these spectra, it was confirmed that 1.8 parts of vinyltrimethoxysilane was bonded to 100 parts of the hydride (v) of the block copolymer.

(Manufacture of resin pellets for film production)
To 100 parts by weight of the modified hydride (vi) pellets, 0.5 part of 2-hydroxy-4-n-octoxybenzophenone as an ultraviolet absorber was added to obtain a mixture. This mixture was extruded in a strand shape at a resin temperature of 190 ° C. using a twin screw extruder (“TEM37BS” manufactured by Toshiba Machine Co., Ltd.) equipped with a side feeder to which a liquid material can be added. In this extrusion, the mixture in the biaxial stretching machine is passed through the side feeder, and polyisobutene as a plasticizer (“Nisseki Polybutene LV-100” manufactured by JX Nippon Mining & Energy Co., Ltd., number average molecular weight 500) is modified with hydrogen. The compound (vi) was continuously added so as to have a ratio of 10 parts by weight to 100 parts by weight. The extruded mixture was air-cooled and then cut by a pelletizer to obtain resin pellets containing modified hydride (vi) and polyisobutene. The pellets were heat-treated at 80 ° C. for 4 hours using a hot air dryer in which air was circulated.

(Manufacture of transparent film)
An extrusion molding apparatus including a leaf disk polymer filter (filtration accuracy: 10 μm), a single-screw extruder having a screw diameter of 50 mm, and a T-die was prepared. Using this extrusion molding apparatus, the heat-treated pellets were melt-extruded into a film at an extrusion temperature of 170 ° C. within 1 hour after the heat treatment. The extruded film-like resin was cooled by passing through three cooling drums (diameter 250 mm, drum temperature 30 ° C., take-off speed 0.35 m / s) to obtain a transparent film having a thickness of 20 μm and a width of 600 mm.

[Example 2]
During the production of the transparent film, the extrusion temperature was changed to 140 ° C. Except for the above, the transparent film was produced and evaluated by the same operation as in Example 1.

[Example 3]
During the production of resin pellets for film production, the amount of plasticizer relative to 100 parts by weight of the modified hydride (vi) was changed to 15 parts by weight. Except for the above, the transparent film was produced and evaluated by the same operation as in Example 1.

[Example 4]
During the production of resin pellets for film production, the amount of plasticizer relative to 100 parts by weight of the modified hydride (vi) was changed to 15 parts by weight. Further, the extrusion temperature was changed to 135 ° C. during the production of the transparent film. Except for the above, the transparent film was produced and evaluated by the same operation as in Example 1.

[Example 5]
The alkoxysilyl group was not introduced into the hydride (v) of the block copolymer. That is, in the production of resin pellets for film production, block copolymer hydride (v) pellets were used instead of modified hydride (vi) pellets. Further, the extrusion temperature was changed to 175 ° C. during the production of the transparent film. Except for the above, the transparent film was produced and evaluated by the same operation as in Example 1.

[Example 6]
No plasticizer was used in the production of resin pellets for film production. Moreover, the extrusion temperature was changed to 180 ° C. during the production of the transparent film. Except for the above, the transparent film was produced and evaluated by the same operation as in Example 1.

[Example 7]
During the production of resin pellets for film production, the amount of plasticizer relative to 100 parts by weight of the modified hydride (vi) was changed to 20 parts by weight. Moreover, the extrusion temperature was changed to 150 ° C. during the production of the transparent film. Except for the above, the transparent film was produced and evaluated by the same operation as in Example 1.

[Comparative Example 1]
During the production of the transparent film, the extrusion temperature was changed to 130 ° C. Except for the above, the transparent film was produced and evaluated by the same operation as in Example 1.

[Comparative Example 2]
During the production of the transparent film, the extrusion temperature was changed to 200 ° C. Except for the above, the transparent film was produced and evaluated by the same operation as in Example 1.

[Comparative Example 3]
During the production of resin pellets for film production, the amount of plasticizer relative to 100 parts by weight of the modified hydride (vi) was changed to 15 parts by weight. Moreover, the extrusion temperature was changed to 120 ° C. during the production of the transparent film. Except for the above, the transparent film was produced and evaluated by the same operation as in Example 1.

[Comparative Example 4]
During the production of resin pellets for film production, the amount of plasticizer relative to 100 parts by weight of the modified hydride (vi) was changed to 15 parts by weight. Moreover, the extrusion temperature was changed to 190 ° C. during the production of the transparent film. Except for the above, the transparent film was produced and evaluated by the same operation as in Example 1.

[Comparative Example 5]
The alkoxysilyl group was not introduced into the hydride (v) of the block copolymer. That is, in the production of resin pellets for film production, block copolymer hydride (v) pellets were used instead of modified hydride (vi) pellets. Also, no plasticizer was used in the production of resin pellets for film production. Furthermore, the extrusion temperature was changed to 200 ° C. during the production of the transparent film. Except for the above, the transparent film was produced and evaluated by the same operation as in Example 1.

[Comparative Example 6]
During the production of resin pellets for film production, the amount of plasticizer relative to 100 parts by weight of the modified hydride (vi) was changed to 40 parts by weight. Further, the extrusion temperature was changed to 130 ° C. during the production of the transparent film. Except for the above, the transparent film was produced and evaluated by the same operation as in Example 1.

[result]
The results of the examples and comparative examples are shown in Table 1 and Table 2 below. In the following table, the meanings of the abbreviations are as follows.
St-Ip-St: A block copolymer of styrene-isoprene-styrene.
wA / wB: Ratio of the weight fraction wA of all polymer blocks [A] to the weight fraction wB of all polymer blocks [B] in the entire block copolymer.
Hydrogenation rate: Hydrogenation rate of a hydride of a block copolymer relative to 100% of all unsaturated bonds of the block copolymer.
Silane modification rate: introduction amount of alkoxysilyl groups with respect to 100 parts by weight of hydride of the block copolymer before introduction of alkoxysilyl groups.
MFR: Melt flow rate of resin.
Tg: Glass transition temperature of resin.

Claims (4)

  A thermoplastic resin containing a thermoplastic polymer, having a melt flow rate of 20 g / 10 min to 100 g / 10 min at a temperature of 190 ° C. and a load of 2.16 kg, and having a glass transition temperature Tg is Tg + 30 ° C. or higher and Tg + 70 ° C. A method for producing a transparent film, comprising extruding at an extrusion temperature of less than. The thermoplastic polymer is at least one polymer selected from the group consisting of a block copolymer of an aromatic vinyl compound and a chain conjugated diene, and a hydride of the block copolymer,
The block copolymer has the aromatic vinyl compound unit as a main component, and two or more polymer blocks [A] per molecule of the block copolymer, and the chain conjugated diene compound unit as a main component. One or more polymer blocks [B] per molecule of the block copolymer,
The ratio (wA / wB) of the weight fraction wA of all polymer blocks [A] to the weight fraction wB of all polymer blocks [B] in the entire block copolymer is 20 / 80-60 / The method for producing a transparent film according to claim 1, which is 40. The thermoplastic polymer is a hydride of the block copolymer,
The manufacturing method of the transparent film of Claim 2 whose hydrogenation rate of the said hydride is 90% or more of the total unsaturated bond of the said block copolymer.   The method for producing a transparent film according to claim 2 or 3, wherein the hydride of the block copolymer has an alkoxysilyl group.