KR102031213B1 - Method for producing resin film and resin film with fewer fine scratches - Google Patents

Abstract

[Problem] The present invention aims to add an improvement in a drying step of a resin film in order to prevent small scratches of the resin film.
[Solution] The present invention is a step in which a resin film obtained by applying a resin varnish on a support is peeled off from a support, followed by drying. The manufacturing method of the resin film which makes contact with a guide roll is provided. Moreover, this invention is a resin film which consists of a polyimide, polyamide, or polyamideimide, and the said resin film exists in which the micro scratches of the size of 40-400 micrometers in size exist in the frequency of 100-1,000 pieces / cm <2>. The area | region which has an area | region and the generation | occurrence | production area of the said micro flaw provides 10% or less with respect to the area of the whole film, The resin film characterized by the above-mentioned.

Description

Manufacturing method of resin film and resin film with few micro scratches {METHOD FOR PRODUCING RESIN FILM AND RESIN FILM WITH FEWER FINE SCRATCHES}

This invention relates to the manufacturing method of a resin film, especially the manufacturing method of the high visibility transparent resin film, and the resin film with few micro scratches.

As a transparent member of devices, such as a liquid crystal display device and a solar cell, a transparent resin film may be used. As this transparent resin film, the polyimide film which has high heat resistance may be used (patent document 1).

Moreover, when obtaining a transparent polyimide film, after apply | coating the varnish containing polyimide on a support body, peeling a support body and drying, and laminating | stacking a protective layer further is performed.

Japanese Unexamined Patent Application Publication No. 10-310639

By the way, the process of drying a polyimide film is peeling a polyimide film from a support body, drying in the state which has moved the film by the guide roll, and attaching a protective film after drying to protect a polyimide film, However, when moving on a guide roll and drying, very small scratches (for example, micro scratches and friction scratches) which are difficult to recognize normally are formed in a polyimide film. Such scratches should be avoided in polyimide films in which a high degree of transparency used under a bright light source is required in polyimide films.

Then, the present inventors investigate in order to prevent the said small scratch, and aim at adding the improvement in the drying process of a polyimide film.

That is, in the process of peeling a resin film obtained by apply | coating a resin varnish on a support body after peeling from a support body, this invention WHEREIN: The anti-support body surface which was not in contact with the support body surface before the said resin film was peeled from a support body. The manufacturing method of the resin film which makes a side contact a guide roll is provided.

The resin varnish preferably contains at least one polymer selected from the group consisting of polyimide, polyamideimide and polyamide.

The present invention is also a resin film composed of polyimide, polyamide or polyamideimide,

The said resin film has the generation | occurrence | production area | region where the micro scratches of the size of 40-400 micrometers in size exist in the frequency of 100-1,000 piece / cm <2>,

The micro scratches are defects that can be visualized by irradiating light of illuminance higher than 3,000 lumens from the flow direction of the film, and

The area | region where the said micro flaws generate | occur | produce provides the resin film characterized by the above-mentioned with respect to the area of the whole film.

In the present invention, in the drying step, minor scratches, in particular, micro scratches can be prevented by contacting the guide roll with the ring retaining surface side, which is not in contact with the support surface, before the resin film is separated from the support. In a drying process, a support body and a protective film are peeled so that drying may advance more, and it drys only by a resin film, However, at the time of peeling, a solvent still remains, especially the part which contacted the support remains more solvent, It is thought that micro scratches will occur when the back surface contacts the guide roll. In the present invention, it has been found that minute scratches are reduced by contacting the guide roll on the opposite side with the guide roll without contacting the support peeling surface. Since the surface which is not a support body peeling surface advances rather than a support body peeling surface, when this surface is contacted with a guide roll and dried, a micro flaw decreases. By preventing the minute scratches, the diffuse reflection of the light is reduced, and the backlight power can be reduced when the light is transmitted by the backlight or the like.

In this invention, you may provide an additional drying process after the drying process which contact | connects said guide roll. In this additional drying step, drying is already progressed, so that small scratches rarely occur.

BRIEF DESCRIPTION OF THE DRAWINGS It is process drawing describing the manufacturing process of the resin film of this invention.
It is a figure which shows typically the process of the manufacturing method of the resin film of this invention.
3 is a photograph showing micro scratches on the surface of a resin film.

EMBODIMENT OF THE INVENTION Below, some embodiment of this invention is described in detail using FIGS. However, the manufacturing method of the resin film of this invention is not limited to the aspect of FIGS.

BRIEF DESCRIPTION OF THE DRAWINGS It is process drawing describing the manufacturing process of the resin film of this invention. As shown in FIG. 1, the resin film of this invention is manufactured through the process of varnishing, pre-film forming, support body peeling, and drying. In the process of varnishing, resin is melt | dissolved or disperse | distributed in a solvent, a resin varnish is formed, In the pre-film-forming process, the obtained resin varnish is apply | coated on a support body using a coating apparatus, and simply dried, and then a protective film is formed on a resin film It coat | covers on and sets it as a laminated film once. This laminated | multilayer film is then moved to a support body peeling process, and a support body is peeled so that there may be no peeling trace. What consists of a resin film and a protective film obtained at the peeling process transfers to the drying process of FIG. 1, and peels a protective film, and dries a resin film.

In the process of varnishing of Fig. 1, as described above, the resin is dissolved or dispersed in a solvent to form a resin varnish, but the resin used in the production method of the present invention is, for example, a polyimide polymer (polyimide). And polyamideimide), polyamide, polyester, poly (meth) acrylate, acetyl cellulose, polyethylene terephthalate, polyethylene naphthalate, cycloolefin polymer and copolymers thereof. In view of excellent transparency, heat resistance and various mechanical properties, the polyimide polymer and the polyamide are preferably polyimide. One type of resin contained may be sufficient and two or more types may be sufficient as it. Although the resin film obtained may be colored or a colorless resin film, it is a colorless and transparent resin film suitably.

In this specification, a polyimide is a polymer mainly using the repeating structural unit containing an imide group, a polyamide is a polymer mainly consisting of the repeating structural unit containing an amide group, and a polyimide type polymer is a polyimide and an imide The polymer which mainly uses the structural unit containing a group and the structural unit containing an amide group is shown.

The polyimide-type polymer of this invention can manufacture the tetracarboxylic acid compound and diamine compound mentioned later as a main raw material, and has a repeating structural unit represented by following formula (10). Here, G is a tetravalent organic group and A is a divalent organic group. The structure represented by two or more types of formulas (10) in which G and / or A are different may be included. Moreover, the polyimide polymer which concerns on this embodiment contains the structure represented by Formula (11), Formula (12), and Formula (13) in the range which does not impair the various physical properties of the obtained polyimide polymer film. You may be.

[Formula 1]

G and G ¹ is a tetravalent organic group, preferably a hydrocarbon group or a fluorine-substituted hydrocarbon groups organic group which may be substituted, the following formula 20, formula 21, formula 22, formula ( The group represented by 23, Formula (24), Formula (25), Formula (26), Formula (27), Formula (28), or Formula (29) and a tetravalent C6-C6 hydrocarbon group are illustrated. In the formula, * represents a bond, Z represents a single bond, -O-, -CH _2- , -CH ₂ -CH _2- , -CH (CH ₃ )-, -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -Ar-, -SO _2- , -CO-, -O-Ar-O-, -Ar-O-Ar-, -Ar-CH ₂ -Ar-, -Ar-C ( CH ₃ ) ₂ -Ar- or -Ar-SO ₂ -Ar-. Ar represents the C6-C20 arylene group which may be substituted by the fluorine atom, and a phenylene group is mentioned as a specific example.

[Formula 2]

G ² is a trivalent organic group, preferably an organic group which may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group, and the above formulas (20), (21), (22) and (23) , A group wherein any one of the bonds of the group represented by formula (24), formula (25), formula (26), formula (27), formula (28) or formula (29) is substituted with a hydrogen atom and the number of trivalent carbon atoms Six or less chain hydrocarbon groups are exemplified.

G ³ is a divalent organic group, preferably an organic group which may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group, and the above formulas (20), (21), (22) and (23) , A group in which two non-adjacent groups are substituted with a hydrogen atom among the bonds of the group represented by formula (24), formula (25), formula (26), formula (27), formula (28) or formula (29), and C6 or less chain hydrocarbon group is illustrated.

A, A ¹ , A ² , and A ³ are all divalent organic groups, preferably an organic group which may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group, and the following formulas (30), (31), A group represented by formula (32), formula (33), formula (34), formula (35), formula (36), formula (37) or formula (38); Groups in which they are substituted by a methyl group, a fluoro group, a chloro group or a trifluoromethyl group and a chain hydrocarbon group having 6 or less carbon atoms are exemplified. In the formula, * represents a bond, and Z ¹ , Z ² and Z ³ each independently represent a single bond, -O-, -CH _2- , -CH ₂ -CH _2- , -CH (CH ₃ )- , -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -SO ₂ -or -CO-. One example is that Z ¹ and Z ³ are -O-, and Z ² is -CH _2- , -C (CH ₃ ) _2- , -C (CF ₃ ) ₂ -or -SO _2- . It is preferable that Z <^1> and Z <^2> and Z <^2> and Z <^3> are a meta position or a para position with respect to each ring, respectively.

[Formula 3]

The polyamide of this invention is a polymer which mainly uses the repeating structural unit represented by said Formula (13). Preferred examples and specific examples are the same as those of G ³ and A ³ in the polyimide polymer. G ³ and / or A ³ may include a structure represented by two or more types of formulas (13).

The polyimide polymer is obtained by, for example, polycondensation of a diamine and a tetracarboxylic acid compound (tetracarboxylic dianhydride, etc.), for example, JP-A-2006-199945 or JP-A It can synthesize | combine according to the method described in Unexamined-Japanese-Patent No. 2008-163107. As a commercial item of a polyimide, Neopulim etc. by Mitsubishi Gas Chemical Co., Ltd. are mentioned.

As tetracarboxylic acid compound used for the synthesis | combination of a polyimide, aliphatic tetracarboxylic acid compounds, such as aromatic tetracarboxylic dianhydride, and aliphatic tetracarboxylic acid compounds, such as aliphatic tetracarboxylic dianhydride, are mentioned. The tetracarboxylic acid compound may be used independently or may use 2 or more types together. The tetracarboxylic acid compound may be a tetracarboxylic acid compound flexible body such as an acid chloride compound, in addition to the anhydride.

Specific examples of the aromatic tetracarboxylic dianhydride include 4,4'-oxydiphthalic dianhydride, 3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride, 2,2', 3,3'-benzophenone Tetracarboxylic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 3,3 ', 4,4 '-Diphenylsulfontetracarboxylic acid dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, 2,2 -Bis (3,4-dicarboxyphenoxyphenyl) propane dianhydride, 4,4 '-(hexafluoro isopropylidene) diphthalic dianhydride, 1,2-bis (2,3-dicarboxyphenyl) ethane 2 anhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,2-bis (3,4-dicarboxyphenyl) ethane dianhydride, 1,1-bis (3,4-di Carboxyphenyl) ethane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, 4,4 '-(p-phenylene Oxy) diphthalic dianhydride, 4,4 '- there may be mentioned (m- phenylenedimaleimide oxy) diphthalic acid dianhydride and 2,3,6,7-naphthalene tetracarboxylic dianhydride. These can be used individually or in combination of 2 or more types.

As aliphatic tetracarboxylic dianhydride, a cyclic or acyclic aliphatic tetracarboxylic dianhydride is mentioned. Cyclic aliphatic tetracarboxylic dianhydride is tetracarboxylic dianhydride which has alicyclic hydrocarbon structure, As a specific example, 1,2,4,5-cyclohexane tetracarboxylic dianhydride, 1,2,3,4-cyclo Cycloalkanetetracarboxylic dianhydride, such as butanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene-2,3,5 And 6-tetracarboxylic dianhydride, dicyclohexyl 3,3 ', 4,4'-tetracarboxylic dianhydride and positional isomers thereof. These can be used individually or in combination of 2 or more types. Specific examples of the acyclic aliphatic tetracarboxylic dianhydride include 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-pentanetetracarboxylic dianhydride, and the like, and these alone or It can be used in combination of 2 or more type.

Among the tetracarboxylic dianhydrides, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene-2,3, from the viewpoint of high transparency and low colorability Preference is given to 5,6-tetracarboxylic acid dianhydride and 4,4 '-(hexafluoroisopropylidene) diphthalic dianhydride.

In addition, the polyimide-based polymer of the present invention, in addition to the anhydrides of tetracarboxylic acid used for the above-mentioned polyimide synthesis, in the range that does not impair the various physical properties of the resulting polyimide-based polymer film, tetracarboxylic acid, tricar The reaction may be performed by further reacting the main acid and the dicarboxylic acid and their anhydrides and derivatives.

Examples of the tricarboxylic acid compound include aromatic tricarboxylic acid, aliphatic tricarboxylic acid, their flexible acid chloride compounds, and acid anhydrides, and two or more kinds thereof may be used in combination. Specific examples include anhydrides of 1,2,4-benzenetricarboxylic acid; 2,3,6-naphthalenetricarboxylic acid-2,3- anhydride; And phthalic anhydride and benzoic acid are linked by a single bond, -O-, -CH _2- , -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -SO ₂ -or a phenylene group. .

As a dicarboxylic acid compound, aromatic dicarboxylic acid, aliphatic dicarboxylic acid, those flexible acid chloride compounds, an acid anhydride, etc. are mentioned, You may use 2 or more types together. Specific examples include terephthalic acid; Isophthalic acid; Naphthalenedicarboxylic acid; 4,4'-biphenyldicarboxylic acid; 3,3'-biphenyldicarboxylic acid; The dicarboxylic acid compound of the chain hydrocarbon having 8 or less carbon atoms and the two benzoic acids are a single bond, -O-, -CH _2- , -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -SO ₂ -or The compound connected by the phenylene group is mentioned.

As a diamine used for the synthesis | combination of a polyimide, aliphatic diamine, aromatic diamine, or a mixture thereof may be sufficient. In addition, in this embodiment, "aromatic diamine" represents the diamine which the amino group couple | bonded with the aromatic ring directly, and may contain the aliphatic group or other substituent in a part of the structure. The aromatic ring may be monocyclic or condensed ring, and examples thereof include, but are not limited to, benzene ring, naphthalene ring, anthracene ring, fluorene ring and the like. Among these, Preferably they are a benzene ring. Moreover, "aliphatic diamine" shows the diamine which the amino group couple | bonded with the aliphatic group directly, and may contain the aromatic ring and other substituent in a part of the structure.

Examples of the aliphatic diamines include acyclic aliphatic diamines such as hexamethylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, norbornanediamine, and 4,4. Cyclic aliphatic diamines, such as "-diamino dicyclohexyl methane, etc. are mentioned, These can be used individually or in combination of 2 or more types.

Examples of the aromatic diamine include p-phenylenediamine, m-phenylenediamine, 2,4-toluenediamine, m-xylylenediamine, p-xylylenediamine, 1,5-diaminonaphthalene, 2 Aromatic diamine having one aromatic ring, such as 6-diaminonaphthalene, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, and 4,4'-diaminodiphenyl ether , 3,4'-diaminodiphenylether, 3,3'-diaminodiphenylether, 4,4'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 3,3'- Diaminodiphenylsulfone, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] Propane, 2,2'-dimethylbenzidine, 2,2'-bis (trifluoromethyl) benzidine, 4,4'-bis (4-aminophenoxy) biphenyl, 9,9-bis (4-aminophenyl ) Ple Orene, 9,9-bis (4-amino-3-methylphenyl) fluorene, 9,9-bis (4-amino-3-chlorophenyl) fluorene, 9,9-bis (4-amino-3-fluor Aromatic diamine which has two or more aromatic rings, such as rophenyl) fluorene, is mentioned, These can be used individually or in combination of 2 or more types.

Among the diamines, from the viewpoint of high transparency and low colorability, it is preferable to use one or more selected from the group consisting of aromatic diamines having a biphenyl structure. Consisting of 2,2'-dimethylbenzidine, 2,2'-bis (trifluoromethyl) benzidine, 4,4'-bis (4-aminophenoxy) biphenyl and 4,4'-diaminodiphenylether It is more preferable to use one or more selected from the group, and more preferably 2,2'-bis (trifluoromethyl) benzidine is included.

The polyimide polymer and polyamide which are polymers containing at least 1 type of repeating structural unit represented by Formula (10), Formula (11), Formula (12), or Formula (13) are a diamine, a tetracarboxylic acid compound ( Tetracarboxylic acid compound flexible body such as acid chloride compound and tetracarboxylic dianhydride), tricarboxylic acid compound (tricarboxylic acid compound flexible body such as acid chloride compound and tricarboxylic acid anhydride) and dicarboxylic acid compound (acid chloride compound) It is a condensation type polymer which is a polycondensation product with at least 1 type of compound contained in the group which consists of dicarboxylic acid compound flexible bodies, such as these. In addition to these, a dicarboxylic acid compound (including flexible bodies, such as an acid chloride compound) may be used as a starting raw material. The repeating structural unit represented by Formula (11) is usually derived from diamines and tetracarboxylic acid compounds. The repeating structural unit represented by the formula (12) is usually derived from a diamine and a tricarboxylic acid compound. The repeating structural unit represented by the formula (13) is usually derived from a diamine and a dicarboxylic acid compound. Specific examples of the diamine and tetracarboxylic acid compound are as described above.

The weight average molecular weight in terms of the standard polystyrene of the polyimide polymer and polyamide of the present invention is preferably 10,000 to 500,000, more preferably 50,000 to 500,000, still more preferably 100,000 to 450,000, particularly preferably 100,000 to 400,000 to be. The larger the weight average molecular weight of the polyimide-based polymer and polyamide, the more likely it is to express high flex resistance when filmed. However, if the weight average molecular weight of the polyimide-based polymer and polyamide is too large, the viscosity of the resin varnish increases, There exists a tendency for workability to fall. You may use a polyimide type polymer in mixture of 2 or more types.

By containing a fluorine-containing substituent, the polyimide polymer and the polyamide tend to reduce the YI value while improving the elastic modulus when forming a film. If the elastic modulus of the film is high, the occurrence of scratches and wrinkles tends to be suppressed. From the viewpoint of transparency of the film, the polyimide polymer and the polyamide preferably have a fluorine-containing substituent. As a specific example of a fluorine-containing substituent, a fluoro group and a trifluoromethyl group are mentioned.

The content of the fluorine atom in the polyimide polymer and the polyamide is preferably 1% by mass or more and 40% by mass or less, more preferably 5% by mass or more and 40% by mass with respect to the mass of the polyimide polymer or the polyamide. % Or less

The resin varnish may further contain inorganic materials such as inorganic particles in addition to the above polyimide polymer and / or polyamide.

As an inorganic material, Preferably, a silicon compound, such as a quaternary alkoxysilane, such as a silica particle and tetraethyl ortho silicate, is mentioned, From a viewpoint of varnish stability, Preferably, a silica particle is mentioned.

The average primary particle diameter of a silica particle becomes like this. Preferably it is 10-100 nm, More preferably, it is 20-80 nm. When the average primary particle diameter of a silica particle exists in the said range, transparency tends to improve, and since cohesion force of a silica particle becomes weak, it tends to be easy to handle.

The silica particles in the present invention may be a silica sol obtained by dispersing the silica particles in an organic solvent or the like, or may be a silica particle powder produced by a gas phase method. However, since the handling is easy, the silica particles are preferably silica sol.

The average primary particle diameter of the silica particle in the obtained resin film can be calculated | required by observation with a transmission electron microscope (TEM). The particle size distribution of the silica particle before forming a transparent resin film can be calculated | required with a commercially available laser diffraction type particle size distribution meter.

In the resin film of this invention, content of an inorganic material becomes like this. Preferably it is 0 mass% or more and 90 mass% or less with respect to the mass of a resin film, More preferably, it is 10 mass% or more and 60 mass% or less, More preferably, It is 20 mass% or more and 50 mass% or less. When the compounding ratio of the polyimide polymer and the polyamide and the inorganic material is within the above range, there is a tendency to make the transparency and mechanical strength of the resin film compatible.

The resin film may further contain other components in addition to the components described above. As other components, antioxidant, a mold release agent, a stabilizer, a bluing agent, a flame retardant, a lubricating agent, and a leveling agent are mentioned, for example.

Content of components other than a resin component and an inorganic material becomes like this. Preferably it is more than 0 mass% and 20 mass% or less, More preferably, it is more than 0 mass% and 10 mass% or less with respect to the mass of a resin film.

The resin varnish used in the present invention is, for example, a reaction solution of a polyimide-based polymer and / or polyamide obtained by selecting from the tetracarboxylic acid compound, the diamine and the other raw materials, and / or a polyamide, and a solvent. It can prepare by mixing and stirring the said other components used according to the above. Instead of a reaction solution such as a polyimide polymer, a solution such as a purchased polyimide polymer or a solution such as a purchased polyimide polymer may be used.

The solvent used for the resin varnish may be one that dissolves or disperses the resin component. For example, amide solvents such as N, N-dimethylformamide and N, N-dimethylacetamide, γ-butyrolactone, and γ Lactone solvents such as valerolactone, sulfur solvents such as dimethyl sulfone, dimethyl sulfoxide, and sulfolane; and carbonate solvents such as ethylene carbonate and propylene carbonate. The amount of the solvent is selected so that the resin varnish can be handled, and the amount of the solvent is not particularly limited. For example, the amount of the solvent is usually 70 to 95 mass%, preferably 80 to 90 mass% with respect to the entire resin varnish.

Formation of the resin varnish is manufactured by mixing the component of the said resin film with a solvent. Mixing is performed using a normal mixing apparatus.

When manufacturing the resin film containing an inorganic material, an inorganic material is added, it is stirred and mixed, and the resin varnish (dispersion liquid) in which an inorganic material was disperse | distributed uniformly is prepared.

After forming a resin varnish, it moves to a pre film forming process, as shown in FIG. In the pre-film forming step, the resin varnish is applied onto the support by a coating device, and simply dried to form a layer of a resin film on the support. The support may be, for example, a resin film substrate or a steel substrate (for example, an SUS belt). As a resin film base material, a polyethylene terephthalate (PET) film is mentioned, for example. In the case where the support is a resin film base material, the thickness thereof is not particularly limited, but is preferably 50 to 250 μm, more preferably 100 to 200 μm. The thinner side tends to be suppressed in cost, and the thicker side tends to be able to suppress curls which may occur in the process of removing a part of the solvent.

As mentioned above, in a pre-film forming process, although the layer of a resin film is formed on a support body, a protective film is further formed on a resin film normally. As a protective film, a film, such as polyester-based films, such as polyolefin type films, such as polyethylene and a polypropylene, and a polyethylene terephthalate, is used as a film for protecting a resin film. Therefore, in a pre-film forming process, the layer of a resin film is formed on a support body, and the laminated | multilayer film in which the protective film was formed on the layer of a resin film is further formed.

The following process of the pre-film forming process of FIG. 1 is a support body peeling process. A support body peeling process is a process of peeling a support body so that there may be no peeling trace from a resin film layer before passing through the following drying process. The resin film at this point has not yet undergone a drying step, and a large amount of solvent remains, and it is necessary to carefully peel off the support before passing through the drying step, thereby providing this support peeling step. The resin film obtained here consists of two layers of a protective film and a resin film, and is usually wound up in roll shape. A roll can wind a laminated body around the winding pipe | tube (plastic core, a metal roll, etc.) of outer diameter 50-200 mm, for example, and can roll a laminated body. As a winding tube, you may use a commercially available 3 inch and 6 inch diameter plastic core. This roll can be used for the roll which winds up a laminated | multilayer film also in the drying process of FIG.

The drying process is shown typically in FIG. 2 specifically. The laminated film of the two layers of the resin film and protective film obtained by the previous pre-film forming process is shown by FIG. 2 in the form of the roll 1. As shown in FIG. The laminated | multilayer film sent out from the roll 1 winds up a protective film in the protective film winding roll 2, and sets only the resin film 3 on the some guide roll 5 in the drying furnace 4 Drive. After the guide roll is sufficiently dried in the drying furnace 4 during traveling, the guide roll 9 is passed through and wound around the second roll 6. Also when winding up on this 2nd roll 6, a protective film is normally sent out from the protective film roll 7, and it coat | covers with a protective film. The arrow shown by 8 in FIG. 2 shows the flow direction (vertical direction) of a resin film.

In this invention, in the said drying process, before the resin film 3 peels from a support body, the ring support surface side which was not in contact with the support body surface is made to contact a guide roll. In FIG. 2, although the resin film 3 is in contact with the guide roll 5 and the guide roll 9 after drying in the drying furnace 4, since the contacted surface is a side which peeled off the protective film, it is in contact with a support surface. The ring retardation surface, which was not present, is brought into contact with the guide rolls 5 and 9.

In the present invention, when it is dried in the drying furnace 4, it is confirmed that micro scratches are generated when contacting the guide rolls 5 and 9, but the ring was not in contact with the support surface before the resin film was peeled off from the support. When the retardation surface side is brought into contact with the guide rolls 5 and 9, fine scratches are reduced. In the present invention, since the solvent is volatilized by the drying in the previous step, the ring retaining surface, which is not in contact with the support surface before the resin film is peeled off from the support, has a guide roll (5). And 9), the micro scratches are not formed or are greatly reduced even if they are formed.

In the resin film after peeling a support body, in a support body surface and a ring support surface, the ring support surface side has high hardness. If a large amount of solvent remains, the solvent acts as a plasticizer and the hardness is reduced. In the drying in the pre-film forming step, since the solvent is volatilized from the ring retaining surface side, a large amount of solvent may remain on the support surface side. For this reason, it is preferable to make the surface which contacts a guide roll into the ring support surface side.

The drying in the drying furnace 4 may heat a coating film as needed for the drying which removes a solvent from a coating film. For example, heating temperature can be adjusted in the range of 40-240 degreeC, and heating time in 10 to 180 minutes, Preferably it is 10 to 120 minutes. In the case of drying (removal of a solvent) by hot air, the wind speed of hot air can be adjusted in the range of 0-15 m / sec. At the time of removal of a solvent, you may heat a coating film under conditions of inert atmosphere or reduced pressure. The diameter of the guide roll in the drying furnace 4 becomes like this. Preferably it is 10-300 mm, More preferably, it is 30-250 mm, More preferably, it is 50-200 mm. Moreover, the surface roughness Rmax of the guide roll measured based on JIS B0601 becomes like this. Preferably it is 0.01 or more and 1.0 or less, More preferably, it is 0.03 or more and 0.9 or less, More preferably, it is 0.05 or more and 0.7 or less. If the surface roughness Rmax of the guide roll is larger than 0.01, the resistance at the time of contact with the resin film is small, and if smaller than 1.0, the shape of the guide roll surface is hard to be transferred to the resin film. Moreover, the preferable Vickers hardness of the guide roll measured based on JISZ2244 becomes like this. Preferably it is 500 or more and 2,000 or less, More preferably, it is 520 or more and 1,500 or less, More preferably, it is 550 or more and 1,300 or less. As a surface treatment method of a metal roll, nickel plating, electroless nickel plating, nickel-boron plating, hard chromium plating, parker plating, etc. are mentioned, Preferably, hard chromium plating is mentioned.

Although the thickness of the resin film obtained is adjusted suitably according to the various device to which a resin film is applied, Preferably it is 10-500 micrometers, More preferably, it is 15-200 micrometers, More preferably, it is 20-100 micrometers. The resin film of such a structure can have especially the outstanding flexibility.

In addition, in this specification, a "microscopic flaw" means the dot defect which can be recognized visually by irradiating the light of 3,000 lumens or more, for example, 3,400 lumens of illumination from the flow direction (namely, a longitudinal direction) of a film. And the size refers to a size of 40 to 400 μm. The photograph of the micro scratches on the surface of the resin film is shown in FIG.

The occurrence of minute scratches is related to the amount of solvent remaining in the resin film in the step after film formation of the resin film. When there is much quantity of the residual solvent in a resin film, a film surface becomes soft and a micro flaw is easy to produce. Remaining solvent in the resin film after the said pre-film forming is 5-30 mass% normally with respect to the mass of a resin film, Preferably it is about 5-20 mass%, The quantity of a remaining solvent is a mass with respect to the mass of a resin film after a drying process. 0-10 mass% normally, Preferably it is 0-5 mass%. When the amount of residual solvent after a drying process exists in the said range, it is thought that the risk of generation | occurrence | production of the micro scratches during conveyance of a resin film will become very small.

The measurement of the amount of residual solvent in the said resin film can be performed by "TG-DTA measurement." As a measuring device of TG-DTA, "TG / DTA6300" by Hitachi High-Tech Science Co., Ltd. can be used. The order of measurement is as follows:

About 20 mg of sample is acquired from the produced polyimide film.

The sample collected was heated to a temperature increase rate of 10 ° C./min from room temperature to 120 ° C., held at 120 ° C. for 5 minutes, and then heated to 400 ° C. under conditions of increasing the temperature at a temperature increase rate of 10 ° C./min, Measure the change in mass of the sample.

From the TG-DTA measurement result, the mass reduction rate L (%) from 120 degreeC to 250 degreeC is computed by the following formula, and it is set as the amount of residual solvent.

L (%) = 100- (W ₁ / W ₀ ) × 100

(In the formula, W ₀ denotes the mass of the sample after the look out for 5 minutes at 120 ℃,

W ₁ represents the mass of the sample at 250 ° C.)

In this invention, Furthermore, it is a resin film which consists of polyimide, polyamide, or polyamideimide,

The said resin film has the generation | occurrence | production area | region where the micro scratches of the size of 40-400 micrometers in size exist in the frequency of 100-1,000 piece / cm <2>,

Said micro scratch is a defect which can be visually recognized by irradiating the light of illumination intensity higher than 3,000 lumens from the flow direction of a film, and

The area | region where the said micro flaws generate | occur | produce provides the resin film characterized by the above-mentioned with respect to the area of the whole film.

Specifically, the resin film of this invention consists of polyimide, polyamide, or polyamideimide, and has the generation | occurrence | production area | region where there are few micro-wounds, ie, micro-wounds exist in the frequency of 100-1,000 pieces / cm <2>, and micro The area | region where a flaw generate | occur | produces is 10% or less with respect to the area of the whole film. When the area where the micro scratches are generated exceeds 10% with respect to the area of the film as a whole, there are fewer areas where there are no micro scratches, for example, when the resin film has a long shape, the sheet can be cut out from this. It is not preferable that the resin film of) decreases.

In the polyamide-based resin film of the present invention, the micro scratches can hardly be visually recognized and can be used for optical applications.

In addition, the weight average molecular weight measurement of polyimide-type resin and polyamide is performed by the following method by gel permeation chromatography (GPC) measurement.

(1) pretreatment method

The sample was dissolved in γ-butyrolactone (GBL) to a 20% by mass solution, diluted 100-fold with N, N-dimethylformamide (DMF) eluent, and filtered through a 0.45 μm membrane filter as a measurement solution. do.

(2) measurement conditions

Apparatus: LC-10Atvp manufactured by Shimadzu Corporation

Column: TSKgel Super AWM-H × 2 + SuperAW2500 × 1 (6.0 mm I.D. × 150 mm × 3 pieces)

Eluent: DMF (with 10 mM lithium bromide)

Flow rate: 0.6 mL / min.

Detector: RI Detector

Column temperature: 40 ℃

Injection volume: 20 μL

Molecular Weight Standard: Standard Polystyrene

EXAMPLE

An Example is given to the following and this invention is demonstrated further more concretely. However, this invention is not limited to these Examples.

Example 1

The polyimide ("KPI-MX300F" by Kawamura Industries Co., Ltd.) whose weight average molecular weight is 360,000 was prepared. This polyimide was dissolved in a 9: 1 mixed solvent of N, N-dimethylacetamide and γ-butyrolactone to prepare a resin varnish (concentration 20% by mass). This resin varnish was apply | coated to 870 mm in width by the casting method on the elongate polyethylene terephthalate (PET) film base material of thickness 188 micrometers, and width 900mm, and formed into a film. The solvent is removed from the resin varnish by passing the film-formed resin varnish through a furnace having a length of 0.4 m / min. A film (thickness 80 μm) was formed. Thereafter, a protective film (&quot; 7332 &quot; manufactured by Toray Film Processing Co., Ltd., a polyolefin protective film having a weak adhesive strength) is bonded to the resin film, and the film is composed of a protective film, a resin film, and a PET film. The shape laminate was wound up to a roll core to obtain a roll shape (250 m).

The PET film base material was peeled off, unwinding the laminated body wound up in roll shape as mentioned above, and the laminated body comprised from a resin film and a protective film was wound up.

The resin film was introduced into the drying furnace at a tension of 80.5 N / m and further dried while peeling off the protective film while unwinding the laminated body wound in the roll shape at a tension of 30 N (33.3 N / m). In the drying furnace, the resin film after peeling off the protective film is made of metal 100 mm in diameter and surface roughness on the surface (semi-support surface) side on the side opposite to the surface (support surface) side on which the resin film after contact with the PET film base material before peeling off. (Rmax) It conveyed in contact with 10 guide rolls of hard chromium plating of 0.6 S and Vickers hardness 850. The temperature of the drying furnace was 200 degreeC, the conveyance speed was 0.4 m / min, and the drying time was 30 minutes. The resin film after drying in the drying furnace bonded the protective film (Toray Film Processing Co., Ltd. product "7332", the polyolefin protective film of weak adhesive force) on both surfaces, and wound up to the roll core (200m acquisition).

With respect to the resin film after drying obtained in Example 1, the protective film of both surfaces was peeled off and it cut out randomly 1 m from the 200 m roll, and evaluated the micro flaw as follows.

Evaluation of Smile Scratches

Polarlion light ("PS-X1" manufactured by Polarion) (3,400 lumens) was irradiated from the flow direction (ie, longitudinal direction) from the support surface side. In that case, it irradiated at the lying angle of about 20-70 degrees with respect to the film surface. The direction to visually recognize was from about immediately above (an angle of 90 degrees from a resin film surface) of the surface of the resin film to evaluate, and evaluated with the human eye. About the area visually recognized, the square was drawn so that the whole group of micro scratches may be included, and the area was put together, and it was set as the generation area | region (it is called a "micro scratch area."). However, when the square was not separated from the neighboring one by 0.5 cm or more, it was set as the same generating area.

Evaluation of the micro scratches was performed as follows.

(Circle): The area | region where the microscratches seen with eyes are less than 5% of the total area

(Triangle | delta): 5% or more and 10% or less of the whole area | region where the micro-scratches which were seen by eyes were seen

X: The area | region where the microscratches seen with eyes exceeded 10% of the total area

Evaluation in the said measurement of the micro scratches of the resin film obtained in Example 1 was (circle). The results of Example 1 are shown in Table 1. In Table 1, it described also about the contact surface with a guide roll, a micro flaw area (cm <2>), and the micro scratch rate (%) in the whole film. In addition, the inspection film area is 87x100 = 8,700 cm <2>, and it is the minute scratch rate (%) in the whole film which divided and divided 100 micro scratch area (cm <2>) by inspection film area (8,700 cm <2>).

Measurement of Elastic Modulus

The obtained resin film was dried at 200 degreeC for 20 minutes, and it cut out to 10 mm x 100 mm of vertical rectangular shape using the dumbbell cutter, and obtained the sample. Using the Autograph AG-IS manufactured by Shimadzu Corporation, the elastic modulus of this sample was measured on an SS curve under conditions of a distance of 500 mm between chucks and a tensile speed of 20 mm / minute, and from the inclination of the optical film. The elastic modulus was calculated. The results are shown in Table 1.

Measurement of residual solvent amount

The measurement of the amount of residual solvent in the obtained resin film was performed by "TG-DTA measurement." The measurement procedure was as follows:

About 20 mg of sample was obtained from the produced resin film.

The sample sample was heated at a temperature increase rate of 10 ° C./min from room temperature to 120 ° C., held at 120 ° C. for 5 minutes, and then heated to 400 ° C. under conditions of increasing the temperature at a temperature increase rate of 10 ° C./min. The change was measured by the measuring apparatus of TG-DTA: "TG / DTA6300" by Hitachi High-Tech.

From the TG-DTA measurement result, the mass reduction rate L (%) over 120 ° C to 250 ° C is expressed by the following equation:

L (%) = 100- (W ₁ / W ₀ ) × 100

(In the formula, W ₀ denotes the mass of the sample after the look out for 5 minutes at 120 ℃,

W ₁ represents the mass of the sample at 250 ° C.)

It calculated from and set it as the amount of residual solvent. The amount of residual solvent was measured about the resin film before drying and the resin film after drying, respectively, and the result was shown in Table 1.

Comparative Example 1

In the drying furnace, a resin film was obtained in the same manner as in Example 1 except that the side on which the PET film base material was laminated was brought in contact with the guide roll. In the same manner as in Example 1, micro scratches of the resin film were evaluated, and the results are shown in Table 1. In Table 1, similarly to Example 1, the contact surface with the guide roll, the micro scratch area (cm 2), the micro scratch ratio (%) in the entire film, the residual solvent amount (before drying) and the residual solvent amount (after drying) Also described. In addition, the inspection film area is 8,700 cm <2> similarly to Example 1.

As is apparent from Table 1 above, when the contact surface with the guide roll is placed on the anti-retardant surface in the drying step, the evaluation of the micro scratches is improved. On the contrary, when the contact surface with the guide roll is the support surface, the evaluation of the micro scratches is deteriorated. It turned out. Moreover, the white point part shown in FIG. 3 is a micro scratch.

In the method for producing a resin film of the present invention, a small scratch (particularly, by contacting a guide roll with a ring support surface side, which is not in contact with the support surface before the resin film is separated from the support, at the time of drying at the time of manufacturing the transparent resin film), Micro-scratches) can be prevented and can be widely applied to the production of films requiring transparency.

One … role
2 … Protective film winding roll
3…. Resin film
4 … Drying furnace
5…. Guide roll
6. 2nd roll
7. Protective film roll
8 … Flow direction (portrait direction)
9. Guide roll

Claims (3)

In the process of peeling the resin film obtained by apply | coating a resin varnish on a support body after peeling from a support body, resin which makes only a ring support surface side which was not in contact with a support body surface before contacting the guide roll before peeling from the support body resin Method for producing a film. The method of claim 1,
The said resin varnish contains the at least 1 sort (s) of polymer chosen from the group which consists of a polyimide, polyamideimide, and polyamide, The manufacturing method of the resin film. delete