JP7211374B2 - Film laminate manufacturing method and film laminate manufacturing apparatus - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method and an apparatus for manufacturing a film laminate by coating a long film with a reactive liquid and immediately laminating the film.

Silane coupling agents are widely used at the interface between inorganic materials such as glass and polymer resins to improve the wettability and adhesiveness between the two. The silane coupling agent has a strong adsorptive power to inorganic materials, and at the same time, tends to cause a self-condensation reaction. As a result, condensate particles are formed in the treatment liquid and the coating liquid, and these particles often cause foreign matter defects on the coated and treated surfaces.

In order to solve this problem, for example, Patent Document 1 discloses a technique of coating a substrate with a silane coupling agent in a vapor phase state. According to such a method, it is possible to realize an extremely thin silane coupling agent layer with few defects. However, since the low-defect silane coupling agent coating layer obtained by such a method is extremely thin, even if a foreign object is pinched on the coating surface, even if it is minute, the silane coupling agent coating surface will be damaged. interfering with the reaction.
This problem is not limited to the case of using a silane coupling agent, but is a problem related to all films coated with a reactive compound layer, particularly a reactive compound that is liquid at room temperature.

JP 2015-178237 A

As a result of intensive studies by the present inventors in order to solve the above problems, it was found that a long film laminate with less blister defects can be produced by immediately laminating a film coated with a reactive compound to another film and winding the film. Found it. In addition, by advancing the reaction between the layers at a temperature at which the winding core of the laminate deforms above a certain value, the adhesion between the films during the reaction is maintained, and a higher quality long film laminate is produced. In addition, the present inventors have found that this method can be applied to a wide range of film laminates formed via reactive compounds, and have arrived at the present invention.

That is, the present invention consists of the following configurations.
[1] A method for producing a polyimide film laminate,
(1) applying a reactive liquid to at least one side of the first polyimide film;
(2) A step of continuously laminating a second polyimide film using a roll laminator on the surface of the first polyimide film coated with the reactive liquid within 5 minutes after applying the reactive liquid to obtain a laminated film. ,
(3) A step of winding the obtained laminated film around a core made of a material having a CTE of 20 ppm/° C. or more and 150 ppm/° C. or less;
A method for producing a polyimide film laminate, comprising at least:
[2]
A method for producing a polyimide film laminate,
(1) applying a reactive liquid to both sides of the first polyimide film;
(2) After applying the reactive liquid,
A step of simultaneously and continuously laminating a second polyimide film and a third polyimide film on both sides of the first polyimide film using a roll laminator within 5 minutes to obtain a laminated film;
(3) A step of winding the obtained laminated film around a core made of a material having a CTE of 25 ppm/° C. or more and 100 ppm/° C. or less;
A method for producing a polyimide film laminate, comprising at least:
[3] A heat treatment method for a polyimide film laminate, wherein the polyimide film laminate roll obtained by the method [1] or [2] is treated at a temperature at which the change length of the core thickness is 0.02 mm or more. A method for producing a polyimide film laminate, characterized by:
[4] An apparatus for manufacturing a polyimide film laminate,
unwinding portion of the first long base material,
a height adjusting roll for the unwound long base material,
liquid application mechanism,
an unwinding portion of at least one of the second and third elongated substrates;
a pressurizing unit downstream of the liquid applying mechanism;
winding section,
and the liquid applying mechanism unit has at least
an inlet for introducing a long base material;
a lead-out port for leading out the elongate base material;
reactive liquid supply,
A roll directly contacts the reactive liquid coated surface of the long substrate between the downstream side of the long substrate introduction port and the pressure unit of the reactive liquid coating mechanism. An apparatus for manufacturing a polyimide film laminate, characterized in that it is constructed so as not to

The laminate manufacturing method of the present invention can suppress foreign matter from being sandwiched between the film on which the thin film of the reactive liquid is formed on the surface and the other film. It is possible to obtain a high-quality long film laminate with less.
In addition, after applying the reactive liquid, bonding and heat treatment are performed in a short period of time before foreign substances such as crystal nuclei and gels are generated due to a dark reaction in the applied reactive liquid, so that a high-quality laminate can be obtained. can be done.

In the present invention, the reaction between the layers of the film laminate obtained in a roll form is allowed to proceed at a temperature at which the winding core is deformed to a certain value or more, so that the adhesion between the films during the reaction is maintained, and the floating is prevented. It is possible to obtain a high-quality long film laminate with little peeling.

FIG. 1 is a schematic diagram showing an example of the laminate manufacturing apparatus of the present invention. FIG. 2 is a schematic diagram showing an example of the laminate manufacturing apparatus of the present invention. FIG. 3 is a schematic diagram of a silane coupling agent treatment apparatus. FIG. 4 is a schematic diagram of the winding section of the laminate manufacturing apparatus of the present invention.

<Polyimide film>
The thickness of the polyimide film of the present invention is preferably 3 μm or more, more preferably 11 μm or more. Although the upper limit of the thickness of the polyimide film is not particularly limited, it is preferably 250 μm or less, more preferably 150 μm or less, and even more preferably 90 μm or less, in view of requirements as a flexible electronic device.
The area of the polyimide film of the present invention is preferably large from the viewpoint of production efficiency and cost of laminates and flexible electronic devices. It is preferably 1000 square cm or more, more preferably 1500 square cm or more, and even more preferably 2000 square cm or more.

In the present invention, aromatic polyimide, alicyclic polyimide, polyamideimide, polyetherimide, etc. can be used as the polyimide film. More preferably, it refers to a polymer containing 50% or more of a polyimide skeleton.

In general, a polyimide film is prepared by coating a polyamic acid (polyimide precursor) solution obtained by reacting diamines and tetracarboxylic acids in a solvent on a support for producing a polyimide film and drying it to form a green film (precursor film ” or “polyamic acid film”), and further subjected to a dehydration ring closure reaction by subjecting the green film to a high-temperature heat treatment on a polyimide film-producing support or in a state peeled off from the support.

The diamines constituting the polyamic acid are not particularly limited, and aromatic diamines, aliphatic diamines, alicyclic diamines and the like which are commonly used in polyimide synthesis can be used. From the viewpoint of heat resistance, aromatic diamines are preferred, and among aromatic diamines, aromatic diamines having a benzoxazole structure are more preferred. The use of aromatic diamines having a benzoxazole structure makes it possible to exhibit high heat resistance, high elastic modulus, low thermal shrinkage, and low coefficient of linear expansion. Diamines may be used alone or in combination of two or more.

Aromatic diamines having a benzoxazole structure are not particularly limited, and examples include 5-amino-2-(p-aminophenyl)benzoxazole, 6-amino-2-(p-aminophenyl)benzoxazole, 5 -amino-2-(m-aminophenyl)benzoxazole, 6-amino-2-(m-aminophenyl)benzoxazole, 2,2'-p-phenylenebis(5-aminobenzoxazole), 2,2' -p-phenylenebis(6-aminobenzoxazole), 1-(5-aminobenzoxazolo)-4-(6-aminobenzoxazolo)benzene, 2,6-(4,4'-diaminodiphenyl)benzo [1,2-d:5,4-d′]bisoxazole, 2,6-(4,4′-diaminodiphenyl)benzo[1,2-d:4,5-d′]bisoxazole, 2, 6-(3,4′-diaminodiphenyl)benzo[1,2-d:5,4-d′]bisoxazole, 2,6-(3,4′-diaminodiphenyl)benzo[1,2-d: 4,5-d']bisoxazole, 2,6-(3,3'-diaminodiphenyl)benzo[1,2-d:5,4-d']bisoxazole, 2,6-(3,3' -diaminodiphenyl)benzo[1,2-d:4,5-d']bisoxazole and the like.

Examples of aromatic diamines other than the above aromatic diamines having a benzoxazole structure include 2,2′-dimethyl-4,4′-diaminobiphenyl, 1,4-bis[2-(4-aminophenyl )-2-propyl]benzene (bisaniline), 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl, 4,4 '-bis(4-aminophenoxy)biphenyl, 4,4'-bis(3-aminophenoxy)biphenyl, bis[4-(3-aminophenoxy)phenyl]ketone, bis[4-(3-aminophenoxy)phenyl ] sulfide, bis[4-(3-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl ]-1,1,1,3,3,3-hexafluoropropane, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, 3,3′- Diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfoxide, 3,4'-diaminodiphenyl sulfoxide, 4,4' -diaminodiphenyl sulfoxide, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4, 4'-diaminobenzophenone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, bis[4-(4-aminophenoxy)phenyl]methane, 1,1-bis[ 4-(4-aminophenoxy)phenyl]ethane, 1,2-bis[4-(4-aminophenoxy)phenyl]ethane, 1,1-bis[4-(4-aminophenoxy)phenyl]propane, 1, 2-bis[4-(4-aminophenoxy)phenyl]propane, 1,3-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl] Propane, 1,1-bis[4-(4-aminophenoxy)phenyl]butane, 1,3- bis[4-(4-aminophenoxy)phenyl]butane, 1,4-bis[4-(4-aminophenoxy)phenyl]butane, 2,2-bis[4-(4-aminophenoxy)phenyl]butane, 2,3-bis[4-(4-aminophenoxy)phenyl]butane, 2-[4-(4-aminophenoxy)phenyl]-2-[4-(4-aminophenoxy)-3-methylphenyl]propane , 2,2-bis[4-(4-aminophenoxy)-3-methylphenyl]propane, 2-[4-(4-aminophenoxy)phenyl]-2-[4-(4-aminophenoxy)-3 ,5-dimethylphenyl]propane, 2,2-bis[4-(4-aminophenoxy)-3,5-dimethylphenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]-1 , 1,1,3,3,3-hexafluoropropane, 1,4-bis(3-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,4-bis(4-amino phenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]ketone, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[4- (4-aminophenoxy)phenyl]sulfoxide, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)phenyl] ether, 1,3-bis[4-(4-aminophenoxy)benzoyl]benzene, 1,3-bis[4-(3-aminophenoxy)benzoyl]benzene, 1,4-bis[4-(3-amino phenoxy)benzoyl]benzene, 4,4'-bis[(3-aminophenoxy)benzoyl]benzene, 1,1-bis[4-(3-aminophenoxy)phenyl]propane, 1,3-bis[4-( 3-aminophenoxy)phenyl]propane, 3,4′-diaminodiphenyl sulfide, 2,2-bis[3-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane , bis[4-(3-aminophenoxy)phenyl]methane, 1,1-bis[4-(3-aminophenoxy)phenyl]ethane, 1,2-bis[4-(3-aminophenoxy)phenyl]ethane , bis[4-(3-aminophenoxy)phenyl]sulfoxide, 4,4′-bis[ 3-(4-aminophenoxy)benzoyl]diphenyl ether, 4,4'-bis[3-(3-aminophenoxy)benzoyl]diphenyl ether, 4,4'-bis[4-(4-amino-α,α-dimethyl benzyl)phenoxy]benzophenone, 4,4′-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]diphenylsulfone, bis[4-{4-(4-aminophenoxy)phenoxy}phenyl]sulfone , 1,4-bis[4-(4-aminophenoxy)phenoxy-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-aminophenoxy)phenoxy-α,α-dimethylbenzyl]benzene , 1,3-bis[4-(4-amino-6-trifluoromethylphenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-amino-6-fluorophenoxy)- α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-amino-6-methylphenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-amino- 6-cyanophenoxy)-α,α-dimethylbenzyl]benzene, 3,3′-diamino-4,4′-diphenoxybenzophenone, 4,4′-diamino-5,5′-diphenoxybenzophenone, 3,4 '-diamino-4,5'-diphenoxybenzophenone, 3,3'-diamino-4-phenoxybenzophenone, 4,4'-diamino-5-phenoxybenzophenone, 3,4'-diamino-4-phenoxybenzophenone, 3 ,4'-diamino-5'-phenoxybenzophenone, 3,3'-diamino-4,4'-dibiphenoxybenzophenone, 4,4'-diamino-5,5'-dibiphenoxybenzophenone, 3,4'-diamino -4,5'-dibiphenoxybenzophenone, 3,3'-diamino-4-biphenoxybenzophenone, 4,4'-diamino-5-biphenoxybenzophenone, 3,4'-diamino-4-biphenoxybenzophenone, 3 ,4'-diamino-5'-biphenoxybenzophenone, 1,3-bis(3-amino-4-phenoxybenzoyl)benzene, 1,4-bis(3-amino-4-phenoxybenzoyl)benzene, 1,3 -bis(4-amino-5-phenoxybenzoyl)benzene, 1,4-bis(4-amino-5-phenoxybenzoyl)benzene, 1,3-bis(3-amino-4-biphenyl noxybenzoyl)benzene, 1,4-bis(3-amino-4-biphenoxybenzoyl)benzene, 1,3-bis(4-amino-5-biphenoxybenzoyl)benzene, 1,4-bis(4- amino-5-biphenoxybenzoyl)benzene, 2,6-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]benzonitrile, and some of the hydrogen atoms on the aromatic rings of the above aromatic diamines or all of which are halogen atoms, alkyl or alkoxyl groups having 1 to 3 carbon atoms, cyano groups, or halogens having 1 to 3 carbon atoms in which some or all of the hydrogen atoms of an alkyl or alkoxyl group are substituted with halogen atoms and aromatic diamines substituted with alkyl groups or alkoxyl groups.

Examples of the aliphatic diamines include 1,2-diaminoethane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,8-diaminooctane and the like.
Examples of the alicyclic diamines include 1,4-diaminocyclohexane and 4,4'-methylenebis(2,6-dimethylcyclohexylamine).
The total amount of diamines other than aromatic diamines (aliphatic diamines and alicyclic diamines) is preferably 20% by mass or less, more preferably 10% by mass or less, and still more preferably 5% by mass or less of all diamines. is. In other words, aromatic diamines are preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more of all diamines.

Tetracarboxylic acids constituting polyamic acid include aromatic tetracarboxylic acids (including their acid anhydrides), aliphatic tetracarboxylic acids (including their acid anhydrides), and alicyclic tetracarboxylic acids, which are commonly used in polyimide synthesis. Acids (including anhydrides thereof) can be used. Among them, aromatic tetracarboxylic anhydrides and alicyclic tetracarboxylic anhydrides are preferable, aromatic tetracarboxylic anhydrides are more preferable from the viewpoint of heat resistance, and alicyclic anhydrides are preferable from the viewpoint of light transmittance. Group tetracarboxylic acids are more preferred. When these are acid anhydrides, one or two anhydride structures may be present in the molecule, but preferably those having two anhydride structures (dianhydrides) are good. Tetracarboxylic acids may be used alone, or two or more of them may be used in combination.

Examples of alicyclic tetracarboxylic acids include alicyclic tetracarboxylic acids such as cyclobutanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, and 3,3′,4,4′-bicyclohexyltetracarboxylic acid. Carboxylic acids, and their acid anhydrides. Among these, dianhydrides having two anhydride structures (for example, cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3′,4,4 '-bicyclohexyltetracarboxylic dianhydride) are preferred. The alicyclic tetracarboxylic acids may be used alone, or two or more of them may be used in combination.
The alicyclic tetracarboxylic acid is, for example, preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more of the total tetracarboxylic acids when transparency is important.

The aromatic tetracarboxylic acid is not particularly limited, but is preferably a pyromellitic acid residue (that is, having a structure derived from pyromellitic acid), more preferably an acid anhydride thereof. Examples of such aromatic tetracarboxylic acids include pyromellitic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 4,4′-oxydiphthalic dianhydride, 3 ,3′,4,4′-benzophenonetetracarboxylic dianhydride, 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride, 2,2-bis[4-(3,4-di carboxyphenoxy)phenyl]propanoic anhydride and the like.
The aromatic tetracarboxylic acid is, for example, preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more of the total tetracarboxylic acids when heat resistance is important.

The polyimide film of the present invention preferably has a glass transition temperature of 250° C. or higher, preferably 300° C. or higher, more preferably 350° C. or higher, or preferably has no glass transition temperature in the region of 500° C. or lower. The glass transition temperature in the invention is determined by differential thermal analysis (DSC).

The coefficient of linear expansion (CTE) of the polyimide film of the present invention is preferably -5 ppm/K to +20 ppm/K, more preferably -5 ppm/K to +15 ppm/K, still more preferably 1 ppm/K to +10 ppm. /K. When the CTE is within the above range, the difference in coefficient of linear expansion with a general support can be kept small, and even when subjected to a process of applying heat, it is possible to avoid peeling of the polyimide film and the support made of an inorganic substance. . In addition, the linear expansion coefficient of the polyimide film in question in the present invention uses an average value between 30 and 200 ° C., but depending on the application, the temperature range of interest changes, and considering the process at high temperature, When examining the range of 30°C to 400°C, it may be in the range of 100°C to 400°C. In some cases, the range of °C may be emphasized.

The breaking strength of the polyimide film in the present invention is 60 MPa or more, preferably 120 MPa or more, more preferably 240 MPa or more. Although the upper limit of breaking strength is not limited, it is practically less than about 1000 MPa. Here, the breaking strength of the polyimide film refers to the average value in the length direction and width direction of the polyimide film.

The thickness unevenness of the polyimide film in the present invention is preferably 20% or less, more preferably 12% or less, still more preferably 7% or less, and particularly preferably 4% or less. If the thickness unevenness exceeds 20%, it tends to be difficult to apply to narrow areas. The uneven thickness of the film can be obtained by measuring the thickness of the film by randomly extracting about 10 positions from the film to be measured using, for example, a contact-type film thickness meter, and calculating the thickness according to the following formula.
Film thickness unevenness (%)
= 100 x (maximum film thickness - minimum film thickness) / average film thickness

The polyimide film in the present invention is preferably obtained in the form of being wound as a long polyimide film having a width of 300 mm or more and a length of 10 m or more at the time of production, and the polyimide roll wound around the winding core Film forms are more preferred.

In the polyimide film, in order to ensure handleability and productivity, it is preferable to add or contain a lubricant (particles) in the film to provide fine unevenness to the surface of the polyimide film to ensure slipperiness. The lubricating material (particles) is preferably fine particles made of an inorganic substance, and includes metals, metal oxides, metal nitrides, metal carbides, metalates, phosphates, carbonates, talc, mica, clay, and others. Particles made of clay minerals, etc. can be used. Preferably, metal oxides such as silicon oxide, calcium phosphate, calcium hydrogen phosphate, calcium dihydrogen phosphate, calcium pyrophosphate, hydroxyapatite, calcium carbonate, glass filler, phosphates and carbonates can be used. Only one type of lubricant may be used, or two or more types may be used.

The volume average particle size of the lubricant (particles) is usually 0.001 to 10 μm, preferably 0.03 to 2.5 μm, more preferably 0.05 to 0.7 μm, and still more preferably 0.05 to 0.7 μm. 0.3 μm. The volume average particle size is based on the measured value obtained by the light scattering method. If the particle size is less than the lower limit, industrial production of the polyimide film becomes difficult, and if the particle size exceeds the upper limit, the unevenness of the surface becomes too large and the adhesion strength becomes weak, which may impede practical use.

The amount of the lubricant added is 0.02 to 50% by mass, preferably 0.04 to 3% by mass, more preferably 0.08 to 1.2%, based on the polymer component in the polyimide film. % by mass. If the amount of the lubricant added is too small, it is difficult to expect the effect of adding the lubricant, and it may interfere with the production of the polyimide film because the lubricity is not sufficiently ensured. Even if lubricity is ensured, problems such as deterioration of smoothness, reduction in breaking strength and breaking elongation of the polyimide film, and increase in CTE may be caused.

When a lubricant (particles) is added or contained in a polyimide film, it may be a single-layer polyimide film in which the lubricant is uniformly dispersed. A lubricant concentration gradient type polyimide film may be used in which the other surface is composed of a polyimide film containing no lubricant or containing a small amount of lubricant even if it does. In such a lubricant concentration gradient type film, fine unevenness is imparted to the surface of one layer (film) so that the layer (film) can ensure slipperiness, and good handling properties and productivity can be achieved. can be secured.

Lubricant concentration gradient type polyimide film, in the case of a film produced by the melt-stretching film-forming method, for example, is first formed into a film using a polyimide film raw material that does not contain a lubricant. It can be obtained by applying a resin layer containing a lubricant. Of course, on the contrary, it is also possible to form a film using a polyimide film raw material containing a lubricant and apply a polyimide film raw material that does not contain a lubricant during the process or after the film formation is completed to obtain a film. I can.
The same is true for a polyimide film obtained using a solution film forming method such as a polyimide film. .5 μm) is 0.02% to 50% by mass (preferably 0.04 to 3% by mass, more preferably 0.08 to 1.2% by mass) relative to the polymer solid content in the polyamic acid solution. and a polyamic acid solution containing no or a small amount of lubricant (preferably less than 0.02% by weight, more preferably less than 0.01% by weight based on polymer solids in the polyamic acid solution) It can be manufactured using certain two types of polyamic acid solutions.

The lubricant concentration gradient type (lamination) method of the lubricant concentration gradient type polyimide film is not particularly limited as long as there is no problem in the adhesion of both layers, and the adhesion is achieved without an adhesive layer or the like. I wish I had.
In the case of a polyimide film, for example, i) a method of imidizing by continuously applying the other polyamic acid solution on the polyimide film after producing one polyimide film, and ii) casting one polyamic acid solution. After producing a polyamic acid film, the other polyamic acid solution is continuously applied on the polyamic acid film and then imidized, iii) a method by coextrusion, iv) containing no lubricant or having a lubricant content For example, a polyamic acid solution containing a large amount of lubricant is applied onto a film formed from a small amount of a polyamic acid solution by spray coating, T-die coating, or the like to imidize the film. In the present invention, the methods i) to ii) are preferably used.

The ratio of the thickness of each layer in the lubricant concentration gradient type polyimide film is not particularly limited, but the polymer layer (a) containing a large amount of lubricant is the layer, and the lubricant is not contained or the content is small. When the polymer layer is layer (b), the ratio of (a) layer/(b) layer is preferably 0.05 to 0.95. When the (a) layer/(b) ratio exceeds 0.95, the smoothness of the (b) layer tends to be lost, while when it is less than 0.05, the effect of improving the surface properties is insufficient and the slipperiness is lost. sometimes

<Surface activation treatment of polyimide film>
It is preferable to subject the polyimide film used in the present invention to a surface activation treatment. By the surface activation treatment, the surface of the polyimide film is modified into a state in which functional groups are present (so-called activated state), thereby improving affinity with the silane coupling agent.
The surface activation treatment in the present invention is dry or wet surface treatment. As the dry treatment of the present invention, treatment of irradiating the surface with active energy rays such as ultraviolet rays, electron beams and X-rays, corona treatment, vacuum plasma treatment, normal pressure plasma treatment, flame treatment, Itro treatment, etc. can be used. . Examples of wet processing include processing in which the film surface is brought into contact with an acid or alkaline solution. The surface activation treatment preferably used in the present invention is plasma treatment, which is a combination of plasma treatment and wet acid treatment.

Plasma treatment is not particularly limited, but includes RF plasma treatment in vacuum, microwave plasma treatment, microwave ECR plasma treatment, atmospheric pressure plasma treatment, corona treatment, gas treatment containing fluorine, ion Also included are source-based ion implantation treatments, treatments using the PBII method, flame treatments exposed to thermal plasma, itro treatments, and the like. Among these, RF plasma treatment in vacuum, microwave plasma treatment, and atmospheric pressure plasma treatment are preferred.

Appropriate plasma processing conditions include plasma known to have a high chemical etching effect, such as oxygen plasma, plasma containing fluorine such as CF4 and C2F6, or physical etching such as Ne, Ar, Kr, and Xe. It is preferable to use plasma, which is highly effective in physically etching the polymer surface by imparting a large amount of energy to the polymer surface. It is also preferable to add plasma such as CO2, CO, H2, N2, NH4, CH4, a mixed gas thereof, and water vapor. In addition to these, OH, N2, N, CO, CO2, H, H2, O2, NH, NH2, NH3, COOH, NO, NO2, He, Ne, Ar, Kr, Xe, CH2O, Si(OCH3)4, It is necessary to create a plasma containing at least one component selected from the group consisting of Si(OC2H5)4, C3H7Si(OCH3)3, C3H7Si(OC2H5)3 as a gas or as a decomposed product in the plasma. When aiming for short-time processing, plasma with high energy density, high kinetic energy of ions in plasma, and plasma with high number density of active species is desirable. There is a limit to increasing the density. When oxygen plasma is used, surface oxidation progresses, which is good in terms of generating OH groups. Adhesion is also deteriorated.
In addition, in plasma using Ar gas, purely physical collision effects occur on the surface, and in this case also, surface roughness increases. Considering these comprehensively, microwave plasma processing, microwave ECR plasma processing, plasma irradiation with an ion source that easily implants high-energy ions, PBII method, and the like are desirable.

Such surface activation treatments clean the polymer surface and generate more active functional groups. The generated functional groups are bound to the coupling agent layer by hydrogen bonding or chemical reaction, making it possible to firmly bond the polyimide film layer and the coupling agent layer.
The effect of etching the surface of the polyimide film can also be obtained in the plasma treatment. In particular, in a polyimide film containing a relatively large amount of lubricant particles, protrusions due to the lubricant may inhibit adhesion between the film and the inorganic substrate. In this case, the surface of the polyimide film is thinly etched by plasma treatment to partially expose the lubricant particles, and then treated with hydrofluoric acid to remove the lubricant particles in the vicinity of the film surface.

The surface activation treatment may be applied to only one side of the polyimide film, or may be applied to both sides. When plasma treatment is performed on one side, plasma treatment can be performed only on the side of the polyimide film that is not in contact with the electrode by placing a polyimide film in contact with the electrode on one side in plasma treatment with parallel plate electrodes. can. Plasma treatment can be performed on both sides of the polyimide film by placing the polyimide film in the space between the two electrodes in an electrically floating state. In addition, plasma treatment can be performed on one side of the polyimide film with a protective film attached to one side of the polyimide film. As the protective film, a PET film with an adhesive, an olefin film, or the like can be used.

<Surface roughness of polyimide film>
The surface roughness Ra of the polyimide film in the present invention is desirably 70 nm or less, more desirably 30 nm or less, and even more desirably 1.5 nm or less. When Ra is larger than 70 nm, when a plurality of polyimide films are laminated via a silane coupling agent layer, it causes uneven coating of the silane coupling agent and uneven peeling due to it.

<Reactive liquid>
The reactive liquid in the present invention means a compound having an unsaturated double bond, a compound having an epoxy group, a compound having an amino group, a compound having a carboxyl group, a compound having a hydroxyl group, an isocyanate compound, a compound having a silanol group, etc. can be exemplified. The present invention is preferably applicable to reactive compounds which are preferably liquid at 25°C.

A silane coupling agent can be used as the reactive liquid preferably used in the present invention. Silane coupling agents can be used singly or in combination of multiple types. It can also be used as a solution of alcohol, water, or various solvents.

<Silane coupling agent>
The silane coupling agent in the present invention refers to a compound having a silicon element in its molecule, physically and chemically interposing between polyimide films, and having an effect of increasing the adhesion between the two.
Preferred specific examples of the silane coupling agent include N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-( aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, 2- (3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycid xypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, 3-ureidopropyltriethoxysilane , 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis(triethoxysilylpropyl)tetrasulfide, 3-isocyanatopropyltriethoxysilane, tris-(3-trimethoxysilane silylpropyl)isocyanurate, chloromethylphenethyltrimethoxysilane, chloromethyltrimethoxysilane, aminophenyltrimethoxysilane, aminophenethyltrimethoxysilane, aminophenylaminomethylphenethyltrimethoxysilane, hexamethyldisilazane and the like.

Silane coupling agents that can be used in the present invention include, in addition to the above, n-propyltrimethoxysilane, butyltrichlorosilane, 2-cyanoethyltriethoxysilane, cyclohexyltrichlorosilane, decyltrichlorosilane, diacetoxydimethylsilane, Ethoxydimethylsilane, dimethoxydimethylsilane, dimethoxydiphenylsilane, dimethoxymethylphenylsilane, dodecyltrichlorosilane, dodecyltrimethoxysilane, ethyltrichlorosilane, hexyltrimethoxysilane, octadecyltriethoxysilane, octadecyltrimethoxysilane, n-octyltrichlorosilane , n-octyltriethoxysilane, n-octyltrimethoxysilane, triethoxyethylsilane, triethoxymethylsilane, trimethoxymethylsilane, trimethoxyphenylsilane, pentyltriethoxysilane, pentyltrichlorosilane, triacetoxymethylsilane, trichloro Hexylsilane, Trichloromethylsilane, Trichlorooctadecylsilane, Trichloropropylsilane, Trichlorotetradecylsilane, Trimethoxypropylsilane, Allyltrichlorosilane, Allyltriethoxysilane, Allyltrimethoxysilane, Diethoxymethylvinylsilane, Dimethoxymethylvinylsilane, Trichlorovinylsilane , triethoxyvinylsilane, vinyltris(2-methoxyethoxy)silane, trichloro-2-cyanoethylsilane, diethoxy(3-glycidyloxypropyl)methylsilane, 3-glycidyloxypropyl(dimethoxy)methylsilane, 3-glycidyloxypropyltrimethoxysilane, etc. can also be used.

Further, other alkoxysilanes such as tetramethoxysilane and tetraethoxysilane may be appropriately added to the silane coupling agent.

In addition, when other alkoxylans such as tetramethoxysilane, tetraethoxylan, etc. are appropriately added to the silane coupling agent, or even when they are not added, the reaction can be slightly affected by adding mixing and heating operations. You can use it after proceeding.

Among such silane coupling agents, the silane coupling agent preferably used in the present invention is preferably a coupling agent having a chemical structure having one silicon atom per molecule.
In the present invention, particularly preferred silane coupling agents include N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2 -(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, aminophenyl trimethoxysilane, aminophenethyltrimethoxysilane, aminophenylaminomethylphenethyltrimethoxysilane, and the like. If the process requires particularly high heat resistance, it is desirable to have an aromatic group connecting Si and an amino group.
In the present invention, a phosphorus-based coupling agent, a titanate-based coupling agent, or the like may be used in combination, if necessary.

A diamine can be used as the reactive liquid preferably used in the present invention. A diamine compound can be used individually or in combination of multiple types. It can also be used as a solution of alcohol, water, or various solvents. Also, the diamine in solution may be mixed with a reactive liquid other than the diamine.

Diamines that can be used in the present invention include 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9- nonanediamine, 1,10-decanediamine, 1,2-hexanediamine, 1,3-hexanediamine, 1,4-hexanediamine, 1,5-hexanediamine, 1,2-pentanediamine, 1,3-pentanediamine , 1,4-pentanediamine and the like.

<Method of applying silane coupling agent>
In general, silane coupling agent treatment refers to a treatment for forming a thin film layer composed of a silane coupling agent or a condensate of the silane coupling agent on the surface of an object.
In the silane coupling agent treatment, the silane coupling agent is generally used as a solution such as alcohol and applied to the object, or the object is applied by means such as immersion in the silane coupling agent solution, and then dried and heated to remove the silane. By condensing the coupling agent and simultaneously chemically bonding it to the surface of the object.
A spin coating method, a spray coating method, a capillary coating method, a dipping method, and the like are generally used as methods for applying the silane coupling agent.
The silane coupling agent treatment is performed on one side or both sides of the polyimide film as required.

In the present invention, coater coating can be used as a method of applying the silane coupling agent to the polyimide film. In that case, the concentration of the silane coupling agent in the coating liquid is desirably 0.1 wt % or more. A low concentration of the silane coupling agent causes coating unevenness. Moreover, the distance between the polyimide film and the coating blade or bar is preferably 15 μm or more and 50 μm or less. If the distance between the polyimide film and the coating blade or bar is 15 μm or less, the surface of the polyimide film is likely to be scratched. becomes.

In the present invention, preferably, the silane coupling agent application step can be performed through the gas phase. Dissolving the gas phase is a method of exposing the polyimide film to a vaporized silane coupling agent. Vaporization refers to the vaporization of the silane coupling agent, that is, the state in which the silane coupling agent is in a substantially gaseous state or in a fine particle state. The term "exposure" here refers to bringing the polyimide film into contact with an atmosphere containing the vaporized silane coupling agent. Since the silane coupling agent has a certain vapor pressure, a certain amount of gaseous silane coupling agent exists even in a room temperature atmosphere. By heating the liquid silane coupling agent to a temperature between 40° C. and the boiling point of the silane coupling agent, vapor of the silane coupling agent with a higher concentration can be obtained. Due to the dew point, the vaporized silane coupling agent may be misted and exist in the form of fine particles in the gas. Such a state can also be used in the present invention. Also, it is possible to add an operation to increase the vapor density by manipulating the temperature and pressure. The boiling point of the silane coupling agent varies depending on the chemical structure, but generally ranges from 100 to 250°C. However, heating at 200° C. or higher is not preferable because it may cause a side reaction on the side of the organic group of the silane coupling agent.
The environment in which the silane coupling agent is heated may be under pressure, under normal pressure, or under reduced pressure, but in the case of promoting vaporization of the silane coupling agent, under substantially normal pressure or under reduced pressure is preferable. Since many silane coupling agents are flammable liquids, it is preferable to carry out the vaporization operation in a sealed container, preferably after replacing the inside of the container with an inert gas. However, from the viewpoint of improving production efficiency and reducing production equipment costs, it is desirable to apply the silane coupling agent in an environment that does not use a vacuum. The silane coupling agent deposition method that does not use a vacuum in the present invention does not use a vacuum only during deposition, but rather sets the polyimide film in a normal atmospheric atmosphere, then replaces the carrier gas with a silane coupling agent. from the time of deposition until the state of no silane coupling agent is returned to approximately atmospheric pressure.
Although the time for exposing the polyimide film to the silane coupling agent is not particularly limited, it is within 60 minutes, preferably within 20 minutes, and more preferably within 10 minutes. The exposure time is a process design value determined by the relationship between the concentration of the silane coupling agent and the required coating amount of the silane coupling agent. The lower limit of the exposure time is not particularly limited, but in order to reduce unevenness in the coating amount that occurs industrially, it is better to provide a time of about 10 seconds or more, preferably about 30 seconds or more.

The polyimide film temperature during exposure of the polyimide film to the silane coupling agent is controlled to an appropriate temperature between -50°C and 200°C depending on the type of silane coupling agent and the desired thickness of the silane coupling agent layer. is preferred.
The polyimide film exposed to the silane coupling agent is preferably heated to 70°C to 200°C, more preferably 75°C to 150°C after exposure. Such heating causes the hydroxyl groups on the surface of the polyimide film to react with the alkoxy groups and silazane groups of the silane coupling agent, thus completing the treatment with the silane coupling agent. The time required for heating is from 10 seconds to 10 minutes. If the temperature is too high or the time is too long, the coupling agent may deteriorate. On the other hand, if it is too short, the treatment effect cannot be obtained. If the temperature of the substrate during exposure to the silane coupling agent is already 80° C. or higher, subsequent heating can be omitted.

In the present invention, it is preferable to expose the polyimide film to the silane coupling agent vapor while holding the surface of the polyimide film coated with the silane coupling agent downward. In the conventional method of applying a solution of a silane coupling agent, the coating surface of the polyimide film inevitably faces upward during and before and after coating, which reduces the possibility of deposition of floating contaminants in the working environment on the inorganic substrate surface. Undeniable. However, in the present invention, by holding the polyimide film downward, it is possible to greatly reduce the adhesion of foreign matter in the environment.
Further, when the gas containing the vaporized silane coupling agent is introduced into the room where the polymer substrate is exposed, the gas is first separated into two or more and introduced, and the two or more gases collide in the room. It is also effective to make the distribution of the silane coupling agent uniform by generating a turbulent flow.
As a method for vaporizing the silane coupling agent, a method of introducing gas into the silane coupling agent liquid to generate bubbles can be used in addition to vaporization by heating. This is hereinafter called bubbling. Regarding bubbling, simply put a pipe through which gas passes into the silane coupling agent liquid, attach a porous body to the tip of the pipe so that many fine bubbles are emitted, superimpose ultrasonic waves, and vaporize It is also effective to encourage

The vaporized silane coupling agent may not only be exposed, but may also be sprayed onto the polyimide film. In that case, it is desirable that the spray angle is 10° or more with respect to the transported film. If the spraying angle is 10° or less, there is a possibility that a sufficient amount of the silane coupling agent cannot be applied to the polyimide film surface being transported.

Also, the vaporized silane coupling agent may be charged. Using this effect, a large amount of silane coupling agent can be deposited in a short time by applying an electric field to the film during exposure, and the silane coupling agent has kinetic energy, so the deposited film becomes an island-like film. can be suppressed. Further, it is known that if the carrier gas used contains water, a reaction between the water and the silane coupling agent begins. Therefore, a low dew point is effective. Desirably, the dew point is 15° C. or lower, more preferably 10° C. or lower, and even more preferably 5° C. or lower.
The number of silicon-containing foreign substances having a major diameter of 10 μm or more existing in the silane coupling agent layer of the silane coupling agent layer-laminated polyimide film is 2000/m2 or less, preferably 1000/m2 or less, and further 500/m2 or less. is a preferred form of the invention. Also, by combining the above operations, the number of silicon-containing foreign substances can be achieved.

The coating amount of the silane coupling agent depends on the thickness of the silane coupling agent condensate layer. If the coupling agent layer is too thick, the amount of decomposition products generated upon exposure to high temperature increases, which may hinder adhesion between polyimide films. The thickness of the silane coupling agent condensate layer of the present invention is preferably 0.1 nm or more and 300 nm or less, more preferably 0.5 nm or more and 200 nm or less. Furthermore, the upper limit of the thickness is preferably less than 200 nm, preferably 150 nm or less, more preferably 100 nm or less for practical use, more preferably 70 nm or less, and even more preferably 50 nm or less. If it is in the range of 0.1 nm or less, the coupling agent may exist in the form of clusters rather than as a uniform coating film, which is not preferable.
The film thickness of the silane coupling agent condensate layer is obtained by polishing the cross section perpendicular to the film surface of the polyimide film laminate, making an ultra-thin section with a microtome, photographing the cross section with a transmission electron microscope, and obtaining the actual measurement value. It was obtained by calculating back from the enlargement magnification.

<Method of applying diamine>
Generally, diamine treatment refers to treatment for forming a thin film layer made of diamine on the surface of an object.
The diamine treatment, like the silane coupling agent treatment, is performed by coating or immersing an object with alcohol or the like as a solvent, and then chemically bonding it to the surface of the object by drying and heating.
Common methods for applying diamine include spin coating, spray coating, capillary coating, dipping, coating using a coater, and vapor phase.
Diamine treatment is performed on one side or both sides of the polyimide film as required.

<Film lamination conditions>
In the present invention, a polyimide film laminate in which polyimide film layers and silane coupling agent condensate layers are alternately laminated is obtained by laminating polyimide films through silane coupling agent layers.
Lamination of the polyimide films is carried out by stacking and pressing the polyimide films such that the surfaces treated with the silane coupling agent are positioned between the polyimide film layers. A combination of pressure and heat is effective.
The pressure treatment may be performed, for example, under an atmospheric pressure atmosphere or in a vacuum by pressing, laminating, roll laminating, or the like while heating. Alternatively, a method of pressurizing and heating while being placed in a flexible bag can also be applied. From the viewpoint of improving productivity and reducing processing costs brought about by high productivity, press or roll lamination in an air atmosphere is preferred, and a method using rolls (roll lamination, etc.) is particularly preferred.

When a laminate is produced by roll lamination, it is desirable that at least one of the upper and lower rolls used for lamination is a roll made of a flexible material. The roll made of a flexible material as used herein refers to a silicone rubber roll having an elastic modulus of 300 MPa or less. If at least one of the rolls used for lamination is made of a flexible material, it is possible to produce a high-quality film laminate with less inclusion of air bubbles.

The pressure for pressurization is preferably 1 MPa to 30 MPa, more preferably 3 MPa to 25 MPa. If the pressure is too high, the support may be damaged, and if the pressure is too low, some portions may not adhere to each other, resulting in insufficient adhesion. The temperature during the pressure treatment is within a range that does not exceed the heat resistance temperature of the polyimide film used. In the case of a non-thermoplastic polyimide film, treatment at 10°C to 400°C, more preferably 150°C to 350°C is preferred.
The pressurizing treatment can be performed in an atmosphere of atmospheric pressure as described above, but is preferably performed in a vacuum in order to obtain a stable adhesive strength over the entire surface. At this time, the degree of vacuum obtained by a normal oil rotary pump is sufficient, and a degree of vacuum of about 10 Torr or less is sufficient.
As an apparatus that can be used for pressure heating treatment, for example, "11FD" manufactured by Imoto Seisakusho Co., Ltd. can be used for pressing in a vacuum, and a roll-type film laminator in a vacuum or a vacuum is used. For vacuum lamination using a film laminator or the like that applies pressure to the entire glass surface at once with a thin rubber film, for example, "MVLP" manufactured by Meiki Seisakusho Co., Ltd. can be used.

In the present invention, the inner diameter of the core used for winding the laminate is desirably 3 inches or more, more desirably 6 inches or more. If the inner diameter of the core and, in turn, the outer diameter of the core are too small, the laminate will warp when the number of layers increases, or the stress applied to the reactive liquid layer between the polyimide films will increase, causing the polyimide films to separate. cause.

In the present invention, the CTE of the core material used for winding is preferably 150 ppm/°C or less, preferably 100 ppm/°C or less. If the CTE of the core material is above a given range, the core may deform significantly during the heating process for reacting the reactive liquid. The lower limit of the CTE of the core material is preferably 20 ppm/°C, more preferably 25 ppm/°C. If the CTE is lower than the lower limit, the pressure applied to the laminated film may be insufficient and the interlayer adhesive strength of the laminate may decrease.
Core materials preferably used in the present invention can be metals with a relatively high CTE, such as polymer materials such as aluminum or aluminum alloys, ABS resins and polypropylene.

In the present invention, the angle θ between the laminate and the tangent line of the core at the winding start point of the laminate is preferably 40° or less. If θ is greater than 40°, winding may become unstable.

In the present invention, the unwinding tension of the polyimide film is desirably 2N or more and 15N or less. If the unwinding tension is less than 2N, the film tends to wrinkle when it enters the laminating roller, and if it is greater than 15N, vertical wrinkles tend to form between the unwinding and laminating rollers. goes down.

The storage environment of the laminate of the present invention before the heat treatment is preferably 15° C. or less, more preferably 5° C. or less, still more preferably −5° C. or less, further preferably −15. ℃ or less.

As a condition for heat-treating the polyimide film laminate roll in the present invention and reacting the reactive liquid between the films, a temperature at which the thickness change length of the core used for winding is 0.02 mm or more is desirable. By heat-treating at a temperature at which the change in length during heat-treatment is 0.02 mm or more, the core expands during heat-treatment, the adhesion between films is improved, and a high-quality laminate can be obtained.

The adhesive strength between the polyimide film layers of the polyimide film laminate in the present invention after heat treatment is 0.4 N / cm or more and 20 N / cm or less, preferably 0.4 N / cm or more and 18 N / cm, more preferably 0.4 N/cm or more and 15 N/cm or less.

In the laminate manufacturing apparatus of the present invention, between the unwinding section and the winding section for the first long base material, the height adjusting roll for the long base material, the liquid coating mechanism section, and the second and third long base materials are arranged. By repeatedly arranging the unwinding part of at least one of the length substrates and the pressure part downstream of the liquid applying mechanism part, a laminate of three or more layers can be manufactured.

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples. Methods for evaluating physical properties in the following examples are as follows.

<Number of blisters>
The number of blisters with a diameter of 0.2 mm or more was counted in a laminate of 10 cm x 10 cm. A blister is a type of defect in which a gap is formed between a long polymer film and an inorganic substrate, and is sometimes called a float, an air bubble, a bubble, or the like. The number of blisters was counted so that n=5 for each sample, and rounded off to the nearest whole number. For the three-layer laminate, the total number of blisters having a diameter of 0.2 mm or more existing in an area of 10 cm x 10 cm was multiplied by 0.5 to convert it into the number of blisters as the two-layer laminate.

<Coefficient of linear expansion (CTE)>
A plastic core to be measured was cut into a size of 5 mm×5 mm using a tabletop abrasive cutting machine (manufactured by AS ONE, RC-120). In the thickness direction of the core, the expansion ratio is measured under the following conditions, and the expansion ratio/temperature is measured at intervals of 15°C from 30°C to 45°C, 45°C to 60°C, and so on, and this measurement is performed up to 120°C. The average value of all measured values was calculated as CTE.
Equipment name; TMA4000SA made by BRUKER
Sample size; 5mm x 5mm
Sample thickness; 5mm
Heating start temperature; 25°C
Heating end temperature; 150°C
Temperature rise rate; 5°C/min
atmosphere; argon

<Change in core thickness>
The thickness change of the core was obtained by the following equation.
Core thickness change = core linear expansion coefficient x core thickness at room temperature x (heat treatment temperature - room temperature)

<Delamination strength>
The adhesive strength between the polyimide film layers of the polyimide film laminate was determined according to the 90 degree peeling method of JISK6854-1.
Device name: Autograph AG-IS manufactured by Shimadzu Corporation
Measurement temperature; room temperature Peeling speed; 50mm/min
Atmosphere; air Measurement sample width; 1 cm
The sample was measured by cutting the surface of a square polyimide film laminate with one side of 100 mm to a depth corresponding to 120% of the thickness of the outermost polyimide film, and peeling off the outermost polyimide film from the edge of the laminate. .
Adhesion strength was measured after heat treatment.

[Manufacturing example]
(Preparation of polyamic acid solution)
After purging the inside of a reaction vessel equipped with a nitrogen inlet tube, a thermometer, and a stirring bar, 223 parts by mass of 5-amino-2-(p-aminophenyl)benzoxazole (DAMBO) and 4416 parts by mass of N,N-dimethylacetamide. and completely dissolved by adding 217 parts by mass of pyromellitic dianhydride (PMDA), and a dispersion obtained by dispersing colloidal silica as a lubricant in dimethylacetamide (manufactured by Nissan Chemical Industries, Ltd. "Snowtex ( (registered trademark) DMAC-ST30") and silica (lubricant) are added so that the total amount of polymer solids in the polyamic acid solution is 0.12% by mass), and stirred at a reaction temperature of 25 ° C. for 24 hours, A brown and viscous polyamic acid solution V1 was obtained.

(Preparation of polyimide film)
Polyamic acid solution V1 obtained above is applied to the smooth surface (no lubricant surface) of a long polyester film ("A-4100" manufactured by Toyobo Co., Ltd.) with a width of 1050 mm using a slit die, and the final film thickness (imide After drying at 105° C. for 20 minutes, it was peeled off from the polyester film to obtain a self-supporting polyamic acid film with a width of 920 mm.
After obtaining the polyamic acid film obtained above, imidization is performed by heat treatment with a pin tenter at 150° C. for 5 minutes at the first stage, 220° C. for 5 minutes at the second stage, and 495° C. for 10 minutes at the third stage. , and the pin gripped portions at both ends were dropped by slits to obtain a long polyimide film F1 (1000 m roll) having a width of 850 mm.

<Vacuum plasma treatment of polyimide film>
As a pre-process for treating the polyimide film with a silane coupling agent, the polyimide film was subjected to a vacuum plasma treatment. Vacuum plasma treatment uses a long film apparatus, evacuates the vacuum chamber to 1 × 10 ^-3 Pa or less, introduces argon gas into the vacuum chamber, discharge power 100 W, frequency 15 kHz conditions. for 20 seconds at argon gas plasma treatment. In the following examples and comparative examples, wide polyimide films after plasma treatment were slit and used.

<Silane coupling agent treatment>
A silane coupling agent was applied to a polyimide film under the following conditions using an apparatus for generating a silane coupling agent vapor schematically shown in FIG.
A polyimide film having a width of 220 mm was passed through a chamber of 750 mm×20 mm×10 mm having a slit of 20 mm×250 mm at a speed of 240 mm/min.
A container containing 100 g of a silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd. "KBM-903": 3-aminopropyltrimethoxysilane) was heated to 40 ° C., and then nitrogen gas was bubbled at 20 L / min. Nitrogen gas containing the generated silane coupling agent vapor was introduced into the chamber through a pipe, and both sides of the polyimide film were exposed to the gas for 3 minutes to obtain a silane coupling agent-coated polyimide film roll.

<Comparative Example 1>
Three of the obtained silane coupling agent-treated substrates were stacked, sandwiched between a release sheet, and temporarily bonded by applying a pressure of 100 Pa to decompress using a vacuum press. Then, the obtained temporarily bonded laminate was placed in a clean oven and heated at 100° C. for 20 hours in a nitrogen atmosphere to obtain a polyimide film laminate.

<Comparative Example 2>
A polyimide film was laminated using a laminate manufacturing apparatus schematically shown in FIG. 1, and the polyimide film laminate wound around a 6-inch polypropylene core (manufactured by Chiyoda Kogyo Co., Ltd.) was heat-treated at 60° C. for 20 hours and evaluated.

<Comparative Example 3>
In the same manner as in Comparative Example 2, a three-layered polyimide film was wound around a 3-inch polyethylene core (manufactured by Kurimoto Polymer Co., Ltd.), heat-treated at 80° C. for 20 hours, and evaluated.

<Example 1>
As in Comparative Example 2, a three-layered polyimide film was wound around a 6-inch polypropylene core, heat-treated at 100° C. for 20 hours, and evaluated.

<Example 2>
A polyimide film was laminated using a laminate manufacturing apparatus schematically shown in FIG. 2, and the polyimide film laminate wound around a 6-inch polypropylene core (manufactured by Chiyoda Kogyo Co., Ltd.) was heat-treated at 100° C. for 20 hours and evaluated.

<Example 3>
Using the laminate manufacturing apparatus schematically shown in FIG. 2, a polyimide film coated with diamine ("2-methyl-1-5-diaminopentane" manufactured by Tokyo Chemical Industry Co., Ltd.) is laminated, and the same as in Example 2. was heat treated and evaluated. Table 1 shows the results obtained from the above comparative examples and examples.

INDUSTRIAL APPLICABILITY As described above, the method and apparatus for producing a film laminate of the present invention continuously perform the steps from applying a reactive compound to the film surface to laminating a long film with few blister defects. Laminates can be made. As exemplified, the present invention is a thermosetting compound epoxy resin, a photocurable compound (meth) acrylate, and a case where a film laminate is produced using various reactive compounds such as a silane coupling agent. and can be used in various industrial fields.

REFERENCE SIGNS LIST 11 film unwinding section 12 coating liquid supply section 13 coating liquid discharge section 14 coating liquid vapor exhaust port 15 long base material unwinding section 16 pressurizing section 17 winding section 18 height adjustment of long base material Roll 21 film unwinding part 22 coating liquid supply part 23 coating liquid discharging part 24 wire bar 25 long base material unwinding part 26 pressurizing part 27 winding part 28 height adjustment roll for long base material 31 film winding Dispensing part 32 Coating liquid supply part 33 Coating liquid discharge part 34 Vapor outlet for coating liquid vapor 35 Film winding part 36 Interleaving paper supply roll 41 Film laminate 42 Winding part

Claims (2)

A method for producing a polyimide film laminate,
(1) applying a reactive liquid to at least one side of the first polyimide film;
(2) A step of continuously laminating a second polyimide film on the surface of the first polyimide film coated with the reactive liquid using a roll laminator within 5 minutes after the application of the reactive liquid to obtain a laminated film. ,
(3) winding the obtained laminated film around a core made of a material having an inner diameter of 6 inches or more and a CTE of 20 ppm/° C. or more and 150 ppm/° C. or less;
Then, treatment at a temperature at which the change length of the core thickness is 0.02 mm or more
A method for producing a polyimide film laminate, comprising at least: A method for producing a polyimide film laminate,
(1) applying a reactive liquid to both sides of the first polyimide film;
(2) After applying the reactive liquid,
A step of simultaneously and continuously laminating a second polyimide film and a third polyimide film on both sides of the first polyimide film using a roll laminator within 5 minutes to obtain a laminated film;
(3) winding the obtained laminated film around a core made of a material having an inner diameter of 6 inches or more and a CTE of 25 ppm/° C. or more and 100 ppm/° C. or less;
Then, treatment at a temperature at which the change length of the core thickness is 0.02 mm or more
A method for producing a polyimide film laminate, comprising at least:

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