JP7371813B2 - Laminated substrate, laminate, method for manufacturing a laminate, laminate with electronic device member, method for manufacturing an electronic device - Google Patents

Description

The present invention relates to a laminate substrate, a laminate, a method for manufacturing a laminate, a laminate with a member for an electronic device, and a method for manufacturing an electronic device.

Electronic devices such as solar cells (PV); liquid crystal panels (LCD); organic EL panels (OLED); reception sensor panels that detect electromagnetic waves, X-rays, ultraviolet rays, visible light, and infrared rays; and other electronic devices are becoming thinner and lighter. are doing. Along with this, substrates such as polyimide resin substrates used in electronic devices are becoming thinner. If the strength of the substrate is insufficient due to thinning, the handling properties of the substrate deteriorate, and problems may occur in the step of forming an electronic device member on the substrate (member forming step).

Therefore, recently, in order to improve the handling properties of the substrate, a technique using a laminate in which a polyimide resin substrate is placed on a support base material has been proposed (Patent Document 1). More specifically, in Patent Document 1, a polyimide varnish is applied on a cured layer of a thermosetting resin composition to form a resin varnish cured film (corresponding to a polyimide film), and then a resin varnish cured film (corresponding to a polyimide film) is formed. It is disclosed that precision elements can be placed. In the technique of Patent Document 1, the cured resin varnish film can be easily peeled off from the cured thermosetting resin composition layer and used as a polyimide resin substrate.

Japanese Patent Application Publication No. 2018-193544

When the present inventors produced a polyimide film using the technique described in Patent Document 1, they found that the polyimide film peeled off from the thermosetting resin composition cured layer that functions as a silicone resin layer that adsorbs and holds the polyimide film. Optical unevenness was confirmed. Since polyimide films are sometimes applied to transparent electronic devices as polyimide resin substrates, improvement in optical unevenness is required.

An object of the present invention is to provide a laminated substrate that can produce a polyimide film with less optical unevenness when a polyimide varnish is applied on the surface of a silicone resin layer and then peeled off. shall be.
Another object of the present invention is to provide a laminate having the above-mentioned laminate substrate, a method for manufacturing the laminate, a laminate with a member for an electronic device, and a method for manufacturing an electronic device.

As a result of intensive studies, the present inventors have found that the above-mentioned problems can be solved by the following configuration.

[1] A glass base material having a first surface and a second surface opposite to the first surface,
a silicone resin layer disposed on the second surface of the glass base material,
The variation in surface roughness Ra of the surface of the silicone resin layer opposite to the glass substrate is 1.00 nm or less,
A multilayer substrate, wherein the silicone resin layer has a thickness variation of 1.5 μm or less.
[2] The multilayer substrate according to [1], wherein the silicone resin layer has an average thickness of 50.0 μm or less.
[3] The multilayer substrate according to [1] or [2], wherein a removable protective film is disposed on the silicone resin layer.
[4] A laminate comprising the laminate substrate according to any one of [1] to [3] and a polyimide film disposed on the silicone resin layer of the laminate substrate.
[5] On the silicone resin layer of the multilayer substrate according to any one of [1] to [3], apply a polyimide varnish containing polyimide or its precursor and a solvent to form a polyimide film on the silicone resin layer. A method for manufacturing a laminate, comprising: forming a laminate including the glass substrate, the silicone resin layer, and the polyimide film.
[6] The laminate according to [4],
A laminate with an electronic device member, comprising: an electronic device member disposed on the polyimide film in the laminate.
[7] Forming an electronic device member on the polyimide film of the laminate according to [4],
a member forming step for obtaining a laminate with members for electronic devices;
A method for producing an electronic device, comprising a separation step of obtaining an electronic device having the polyimide film and the electronic device member from the electronic device member-attached laminate.

According to the present invention, when a polyimide varnish is applied on the surface of a silicone resin layer and then peeled off from the silicone resin layer to produce a polyimide film, a polyimide film with less optical unevenness can be produced. can be provided.
According to the present invention, it is possible to provide a laminate having the above-mentioned laminate substrate, a method for manufacturing a laminate, a laminate with an electronic device member, and a method for manufacturing an electronic device.

FIG. 1 is a cross-sectional view schematically showing an embodiment of a multilayer substrate of the present invention. 1 is a cross-sectional view schematically showing an embodiment of a laminate of the present invention. FIG. 3 is a diagram for explaining a member forming process. It is a figure for explaining a separation process.

Embodiments of the present invention will be described below with reference to the drawings. However, the following embodiments are illustrative for explaining the present invention, and the present invention is not limited to the embodiments shown below. Note that various modifications and substitutions can be made to the following embodiments without departing from the scope of the present invention.

The meanings of terms in the present invention are as follows.
The variation in surface roughness Ra is determined by measuring the surface roughness Ra at 10 arbitrary locations on the target surface (measurement area: 940 μm vertically x 700 μm horizontally), and calculating the maximum and minimum values of the 10 measured values. This is the difference between

The average value of the surface roughness Ra is the arithmetic mean value of 10 measured values measured by the above procedure.
The surface roughness Ra is measured using, for example, a non-contact surface/layer cross-sectional shape measuring system "Vertscan R3300-lite" manufactured by Ryoka System Co., Ltd.

The film thickness variation is the difference between the maximum value and the minimum value among the 10 measured values obtained by measuring the film thickness at 10 arbitrary locations on the object.

The average value of the film thickness is the arithmetic mean value of the 10 measurement values obtained by measuring the above-mentioned film thickness variations.
However, in the case of the film thickness of the silicone resin layer, the measurement range excludes a peripheral region of 3 mm from the peripheral edge of the silicone resin layer toward the center.
The film thickness is measured using, for example, a contact-type film thickness measuring device.

A numerical range expressed using "~" means a range that includes the numerical values written before and after "~" as lower and upper limits.

<Laminated board>
FIG. 1 is a cross-sectional view schematically showing an embodiment of a multilayer substrate of the present invention.
The laminated substrate 10 includes a glass base material 12 having a first surface 12a and a second surface 12b opposite to the first surface 12a, and a silicone resin layer disposed on the second surface 12b of the glass base material 12. 14.

Although details will be described later, polyimide varnish is applied onto the silicone resin layer 14 of the laminated substrate 10, and then a polyimide film is formed. An electronic device member is formed on this polyimide film, and then the polyimide film (ie, electronic device) on which the electronic device member is formed is separated. In this way, an electronic device is manufactured.

In the multilayer substrate 10 shown in FIG. 1, the variation in surface roughness Ra of the surface 14a of the silicone resin layer 14 on the side opposite to the glass substrate 12 defined below is 1.00 nm or less.

If the variation in surface roughness Ra of the surface 14a of the silicone resin layer 14 on the side opposite to the glass base material 12 is 1.00 nm or less, it is possible to , a polyimide film with less optical unevenness can be produced.

The variation in surface roughness Ra of the surface 14a of the silicone resin layer 14 on the side opposite to the glass substrate 12 is preferably 0.70 nm or less, more preferably 0.40 nm or less. The lower limit of the variation in surface roughness Ra of the surface 14a of the silicone resin layer 14 on the side opposite to the glass substrate 12 is 0.00 nm.

In the multilayer substrate 10 shown in FIG. 1, the variation in the thickness of the silicone resin layer 14 is 1.5 μm or less.
If the variation in the film thickness of the silicone resin layer 14 is 1.5 μm or less, a polyimide film with less optical unevenness can be produced by forming a polyimide film on the silicone resin layer 14 of the multilayer substrate 10 and then peeling it off. can.
The variation in the thickness of the silicone resin layer 14 is preferably 1.2 μm or less, more preferably 1.0 μm or less. The lower limit of the variation in the thickness of the silicone resin layer 14 is 0.0 μm.

Below, each layer (glass base material 12, silicone resin layer 14) which constitutes laminated substrate 10 is explained in detail, and then a manufacturing method of laminated substrate 10 is explained in detail.

(Glass base material)
The glass base material 12 is a member that supports and reinforces the polyimide film.
As the type of glass, alkali-free borosilicate glass, borosilicate glass, soda lime glass, high silica glass, and other oxide glasses containing silicon oxide as a main component are preferred. As the oxide glass, a glass having a silicon oxide content of 40 to 90% by mass in terms of oxide is preferable.

More specifically, the glass substrate includes a glass substrate made of alkali-free borosilicate glass (trade name "AN100" manufactured by AGC Corporation).

A method for manufacturing a glass substrate is usually obtained by melting glass raw materials and forming the molten glass into a plate shape. Such a molding method may be a general method, and examples thereof include a float method, a fusion method, and a slot down-draw method.

The shape of the glass substrate 12 (the shape of the main surface) is not particularly limited, but a rectangular shape is preferred.

It is preferable that the glass substrate 12 is not flexible. Therefore, the thickness of the glass base material 12 is preferably 0.3 mm or more, more preferably 0.5 mm or more.
On the other hand, the thickness of the glass base material 12 is preferably 1.0 mm or less.

(Silicone resin layer)
The silicone resin layer 14 is a film for preventing the polyimide film disposed on the silicone resin layer 14 from peeling off.
The silicone resin layer 14 is arranged on the glass substrate 12.

A silicone resin is a resin containing a predetermined organosiloxy unit, and is usually obtained by curing curable silicone. Curable silicones are classified into addition reaction silicones, condensation reaction silicones, ultraviolet curable silicones, and electron beam curable silicones depending on their curing mechanism, and any of them can be used. Among the silicone resins, condensation reaction type silicones are particularly preferred.

Condensation reaction type silicones include hydrolyzable organosilane compounds as monomers or mixtures thereof (monomer mixtures), or partially hydrolyzed condensates obtained by subjecting monomers or monomer mixtures to a partial hydrolytic condensation reaction (organopolysiloxanes). can be suitably used.
Using this condensation reaction type silicone, a silicone resin can be formed by proceeding with a hydrolysis/condensation reaction (sol-gel reaction).

The silicone resin layer 14 is preferably formed using a curable composition containing curable silicone.

The curable composition may contain, in addition to the curable silicone, a solvent, a platinum catalyst (if an addition reaction silicone is used as the curable silicone), a leveling agent, a metal compound, and the like. Examples of the metal elements contained in the metal compound include 3d transition metals, 4d transition metals, lanthanoid metals, bismuth (Bi), aluminum (Al), and tin (Sn). The content of the metal compound is not particularly limited and may be adjusted as appropriate.

It is preferable that the silicone resin layer 14 has a hydroxy group. Hydroxy groups can appear when some of the Si--O--Si bonds constituting the silicone resin of the silicone resin layer 14 are broken. Further, when a condensation reaction type silicone is used, its hydroxyl group can become the hydroxyl group of the silicone resin layer 14.

The average thickness of the silicone resin layer 14 is preferably 50.0 μm or less, more preferably 30.0 μm or less, and even more preferably 12.0 μm or less. On the other hand, the average thickness of the silicone resin layer 14 is preferably more than 1 μm, and more preferably 6.0 μm or more for better foreign matter embedding properties.

Note that "having excellent foreign matter embedding properties" means that even if there is a foreign matter between the glass base material 12 and the silicone resin layer 14, the foreign matter is embedded by the silicone resin layer 14.

Excellent foreign matter embedding properties make it difficult for foreign matter to form protrusions in the silicone resin layer, reducing the risk of wire breakage in electronic device parts due to protrusions when electronic device parts are formed on polyimide films. be done. In addition, since the voids formed when the above-mentioned convex portions are generated are observed as bubbles, the foreign matter embedding ability can be evaluated based on the presence or absence of bubble generation.

The average surface roughness Ra of the surface 14a of the silicone resin layer 14 is preferably 50.00 nm or less, more preferably 30.00 nm or less, even more preferably 15.00 nm or less, and particularly preferably 5.00 nm or less. If the average value of the surface roughness Ra of the surface 14a is within the above range, the surface roughness of the polyimide film produced by forming it on the silicone resin layer 14 of the multilayer substrate 10 and then peeling it off is reduced.

Further, the average value of the surface roughness Ra of the surface 14a of the silicone resin layer 14 is preferably 0.10 nm or more, and 0.30 nm or more in order to maintain a state in close contact with the polyimide film formed on the silicone resin layer 14. is more preferable.

When a polyimide film is formed on the glass substrate 12 and subjected to high-temperature heat treatment, the polyimide film turns yellow, making it difficult to apply it to transparent electronic devices. However, although the mechanism is unknown, by forming the silicone resin layer 14 on the glass substrate 12 and forming the polyimide film on the silicone resin layer 14, yellowing of the polyimide film due to high temperature heat treatment can be suppressed.

(Protective film)
In the laminated substrate 10, a removable protective film may be disposed on the silicone resin layer 14.
The protective film is a film that protects the surface of the silicone resin layer 14 until a polyimide varnish, which will be described later, is applied onto the silicone resin layer 14.

Examples of the material constituting the protective film include polyimide resin, polyester resin (eg, polyethylene terephthalate, polyethylene naphthalate), polyolefin resin (eg, polyethylene, polypropylene), and polyurethane resin. Among the materials constituting the protective film, polyester resin is preferred, and polyethylene terephthalate is more preferred.

The average thickness of the protective film is preferably 20 μm or more, more preferably 30 μm or more, and even more preferably 50 μm or more, in order to reduce the influence of external forces. The average thickness of the protective film is preferably 500 μm or less, more preferably 300 μm or less, and even more preferably 100 μm or less.

The protective film may further have an adhesive layer on the surface on the silicone resin layer 14 side.

As the adhesive layer, a known adhesive layer can be used. Examples of the adhesive constituting the adhesive layer include (meth)acrylic adhesive, silicone adhesive, and urethane adhesive.

Further, the adhesive layer may be made of resin, and examples of the resin include vinyl acetate resin, ethylene-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate copolymer resin, (meth)acrylic resin, and butyral resin. , polyurethane resin, and polystyrene elastomer.

The average value of the surface roughness Ra of the protective film is preferably 50 nm or less, more preferably 30 nm or less, and even more preferably 15 nm or less, since the peeling force when peeling the protective film is reduced. Moreover, the average value of the surface roughness Ra of the protective film is preferably 0.1 nm or more, more preferably 0.5 nm or more, since the protective film and the silicone resin layer can maintain a close contact state.

<Manufacturing method of laminated board>
The method for manufacturing the laminated substrate is not particularly limited, and known methods may be used.
Among these, in terms of productivity, a transfer film having a temporary support and a precursor film that becomes a silicone resin layer after heat treatment is prepared, and the precursor in the transfer film is Examples include a method in which a film is bonded to a predetermined position on a glass substrate and a laminate having the obtained glass substrate, precursor film, and temporary support is subjected to heat treatment. A silicone resin layer is formed by heat treatment.

After bonding the above transfer film to the glass substrate, the resulting laminate may be washed with an alkaline detergent. Further, after cleaning with an alkaline detergent, rinsing with pure water may be performed as necessary. Furthermore, after rinsing the laminate with pure water, it may be drained using an air knife, if necessary. After the air knife, the laminate may be dried by heating. In addition, cleaning may be performed by applying a brush to the laminate. The temperature of the alkaline detergent used for cleaning and the temperature of pure water used for rinsing are preferably 20°C or higher, more preferably 40°C or higher, from the viewpoint of detergency.

The heat treatment (annealing step) for forming the silicone resin layer is preferably performed while applying pressure. Specifically, it is preferable to carry out the heat treatment and pressure treatment using an autoclave.

The heating temperature during the heat treatment is preferably 50°C or higher, more preferably 55°C or higher, and even more preferably 60°C or higher. The heating temperature during the heat treatment is preferably 350°C or lower, more preferably 300°C or lower, and even more preferably 250°C or lower. The heating time is preferably 10 minutes or more, more preferably 20 minutes or more. The heating time is preferably 60 minutes or less, more preferably 40 minutes or less.

The pressure during the pressure treatment is preferably 0.5 to 1.5 MPa, more preferably 0.8 to 1.0 MPa.

Further, the heat treatment may be performed multiple times. When heat treatment is performed multiple times, the heating conditions for each may be changed.
For example, when performing heat treatment multiple times, the heating temperature may be changed. For example, when heat treatment is performed twice, the first heat treatment may be performed at a temperature of less than 200°C, and the second heat treatment may be performed at a temperature of 200°C or higher.

Furthermore, when heat treatment is performed multiple times, the presence or absence of pressure treatment may be changed. For example, when heat treatment is performed twice, pressure treatment may be performed in the first heat treatment, and pressure treatment may not be performed in the second heat treatment.

Note that when manufacturing a laminated substrate using a transfer film, the above heat treatment may be performed after peeling off the temporary support, or the heat treatment may be performed while the temporary support is placed on the silicone resin layer. may be implemented. Furthermore, when heat treatment is performed multiple times, the temporary support may be peeled off between each heat treatment. For example, after performing the first heat treatment, the temporary support may be peeled off and the second heat treatment may be performed.

When peeling off the temporary support, a notch portion may be formed in the temporary support in order to facilitate peeling. Alternatively, a part of the end of the temporary support may be peeled off from the precursor film or silicone resin layer to form a folded part, which may be used as a starting point for peeling. Further, a pull tape may be attached to the temporary support. In addition, in order to facilitate the peeling of the temporary support, the temporary support is made larger than the precursor film or silicone resin layer so that the temporary support protrudes, and the protruding part of the temporary support is grasped to temporarily support the temporary support. The body may be exfoliated.

When peeling off the temporary support, 180 degree peeling is preferred because there is less risk of damage to the precursor film or silicone resin layer resulting in defects.
Further, in order to prevent dust adhesion due to peeling electrification, it is preferable to use an ionizer or to humidify the peeling environment.

A heating furnace such as a circulation furnace or an infrared furnace can be used for the heat treatment. The heating furnace is preferably evacuated to remove gas generated from the silicone resin layer during the heat treatment. The cleanliness inside the heating furnace is preferably class 10,000 or lower.

The surface of the silicone resin layer of the multilayer substrate may be subjected to surface treatment.
Examples of the surface treatment include corona treatment, atmospheric pressure plasma treatment, UV ozone treatment, and excimer UV treatment, with corona treatment and atmospheric pressure plasma treatment being preferred.

The water contact angle on the surface 14a of the silicone resin layer 14 after surface treatment is preferably 10 degrees or less, more preferably 5 degrees or less.

Using the above-described laminated substrate 10, a structure including a glass base material 12, a silicone resin layer 14, and a supported material in this order can be manufactured. Materials other than the polyimide film 18 can also be laminated as the supported material.

Examples of supported materials include polyimide resin films, epoxy resin films, photosensitive resists, polyester resin films (e.g., polyethylene terephthalate, polyethylene naphthalate), polyolefin resin films (e.g., polyethylene, polypropylene), polyurethane resin films, and metals. Foil (e.g. copper foil, aluminum foil), sputtered film (e.g. copper, titanium, aluminum, tungsten, silicon nitride, silicon oxide, amorphous silicon), TGV substrate, thin glass substrate, thin glass substrate with sacrificial layer, ABF, Examples include sapphire substrates, silicon substrates, TSV substrates, LED chips, display panels (eg, LCDs, OLEDs, μ-LEDs), artificial diamonds, interleaving paper, and the like.

<Laminated body and its manufacturing method>
Using the above-described multilayer substrate 10, a multilayer body 16 having a glass base material 12, a silicone resin layer 14, and a polyimide film 18 shown in FIG. 2 can be manufactured. The laminate 16 includes a polyimide film 18 disposed on the silicone resin layer 14 of the laminate substrate 10.

Specifically, the method for manufacturing the laminate 16 includes applying a polyimide varnish containing polyimide and a solvent onto the silicone resin layer 14 of the laminate substrate 10 to form a polyimide film 18 on the silicone resin layer 14. , a method of forming a laminate including a glass substrate 12, a silicone resin layer 14, and a polyimide film 18 in this order.
Below, the above manufacturing method will be explained in detail, and then the structure of the polyimide film 18 will be explained in detail.

(Polyimide varnish)
Polyimide varnish contains polyimide or its precursor and a solvent.

Polyimide is usually obtained by polycondensing tetracarboxylic dianhydride and diamine and imidizing the resultant. It is preferable that the polyimide has solvent solubility.

Examples of the tetracarboxylic dianhydride used include aromatic tetracarboxylic dianhydride and aliphatic tetracarboxylic dianhydride. Examples of diamines used include aromatic diamines and aliphatic diamines.

Examples of the aromatic tetracarboxylic dianhydride include pyromellitic anhydride (1,2,4,5-benzenetetracarboxylic dianhydride), 4,4'-(hexafluoroisopropylidene) diphthalic anhydride , 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetra Carboxylic dianhydride, 4,4'-benzophenonetetracarboxylic dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride Acid dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 2,2',3,3 '-Biphenyltetracarboxylic dianhydride, methylene-4,4'-diphthalic dianhydride, 1,1-ethylidene-4,4'-diphthalic dianhydride, 2,2-propylidene-4,4' -diphthalic dianhydride, 1,2-ethylene-4,4'-diphthalic dianhydride, 1,3-trimethylene-4,4'-diphthalic dianhydride, 1,4-tetramethylene-4, 4'-diphthalic dianhydride, 1,5-pentamethylene-4,4'-diphthalic dianhydride, 4,4'-oxydiphthalic dianhydride, thio-4,4'-diphthalic dianhydride , sulfonyl-4,4'-diphthalic dianhydride, 1,3-bis(3,4-dicarboxyphenyl)benzene dianhydride, 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,3-bis[2-(3,4-dicarboxyphenyl)-2-propyl]benzene dianhydride, 1, 4-bis[2-(3,4-dicarboxyphenyl)-2-propyl]benzene dianhydride, bis[3-(3,4-dicarboxyphenoxy)phenyl]methane dianhydride, bis[4-( 3,4-dicarboxyphenoxy)phenyl]methane dianhydride, 2,2-bis[3-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, 2,2-bis[4-(3, 4-dicarboxyphenoxy)phenyl]propane dianhydride, bis(3,4-dicarboxyphenoxy)dimethylsilane dianhydride, bis(3,4-dicarboxyphenoxy)dimethylsilane dianhydride, 1,3-bis (3,4-dicarboxyphenyl)-1,1,3,3-tetramethyldisiloxane dianhydride, 4,4'-biphenylbis(trimellitic acid monoester acid anhydride), 2,2-bis( 3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, bis(3 ,4-dicarboxyphenyl)sulfone dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3, 4-dicarboxyphenyl)methane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2-bis (2,3-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, 1,3-bis[(3,4-dicarboxy)benzoyl]benzene dianhydride, 1,4-bis[(3,4-dicarboxy)benzoyl]benzene dianhydride, 2,2-bis{4-[4-(1,2-dicarboxy)phenoxy]phenyl}propane dianhydride, 2 ,2-bis{4-[3-(1,2-dicarboxy)phenoxy]phenyl}propane dianhydride, bis{4-[4-(1,2-dicarboxy)phenoxy]phenyl}ketone dianhydride , bis{4-[3-(1,2-dicarboxy)phenoxy]phenyl}ketone dianhydride, 4,4'-bis[4-(1,2-dicarboxy)phenoxy]biphenyl dianhydride, 4 , 4'-bis[3-(1,2-dicarboxy)phenoxy]biphenyl dianhydride, bis{4-[4-(1,2-dicarboxy)phenoxy]phenyl}ketone dianhydride, bis{4 -[3-(1,2-dicarboxy)phenoxy]phenyl}ketone dianhydride, bis{4-[4-(1,2-dicarboxy)phenoxy]phenyl}sulfone dianhydride, bis{4-[ 3-(1,2-dicarboxy)phenoxy]phenyl}sulfone dianhydride, bis{4-[4-(1,2-dicarboxy)phenoxy]phenyl}sulfide dianhydride, bis{4-[3- (1,2-dicarboxy)phenoxy]phenyl}sulfide dianhydride, 2,2-bis{4-[4-(1,2-dicarboxy)phenoxy]phenyl}-1,1,1,3,3 , 3-hexafluoropropane dianhydride, 2,2-bis{4-[3-(1,2-dicarboxy)phenoxy]phenyl}-1,1,1,3,3,3-propane dianhydride , 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1 , 2,3,4-benzenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2 , 7,8-phenanthrenetetracarboxylic dianhydride, 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-cyclohexene -1,2 dicarboxylic acid anhydride and pyromellitic dianhydride.

Examples of aliphatic tetracarboxylic dianhydrides include cyclic or acyclic aliphatic tetracarboxylic dianhydrides, and examples of cyclic aliphatic tetracarboxylic dianhydrides include 1, 2, 3, 4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, cyclohexane-1,2,3,4-tetracarboxylic dianhydride, 1,2,4, 5-cyclohexanetetracarboxylic dianhydride, 1,1'-bicyclohexane-3,3',4,4'-tetracarboxylic acid-3,4,3',4'-dianhydride, carbonyl-4, 4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, 1,2-ethylene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, 1,1-ethylidene- 4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, 2,2-propylidene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, oxy-4, 4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, thio-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, sulfonyl-4,4'-bis(cyclohexane) -1,2-dicarboxylic dianhydride, bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, rel-[1S,5R,6R] -3-Oxabicyclo[3,2,1]octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 4-(2,5-dioxotetrahydrofuran- Examples include acyclic Examples of the aliphatic tetracarboxylic dianhydride include ethylenetetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride, and 1,2,3,4-pentanetetracarboxylic dianhydride. Examples include.

Examples of aromatic diamines include p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, 2,4-diaminotoluene, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'- Dimethyl-4,4'-diaminobiphenyl, 3,3'-diethyl-4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl, 2,2 ',5,5'-tetrachloro-4,4'-diaminobiphenyl, 3,7-diamino-dimethyldibenzothiophene-5,5-dioxide, 4,4'-bis(4-aminophenyl) sulfide, 1, 3-bis[2-(4-aminophenoxyethoxy)]ethane, 9,9-bis(4-aminophenyl)fluorene, 9,9-bis(4-aminophenoxyphenyl)fluorene, 5(6)-amino- 1-(4-aminomethyl)-1,3,3-trimethylindane, 2,5-bis(4-aminophenoxy)biphenyl, 2,2-bis[4-(4-aminophenoxyphenyl)]propane, 2 , 2-bis(4-aminophenoxyphenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 4,4'-methylene-bis(2-chloroaniline), 9,10-bis(4-aminophenyl)anthracene, o-tolidine sulfone, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide , 3,4'-diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfide, 3,3'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 3,3' -Diaminobenzophenone, 4,4'-diaminobenzophenone, 3,4'-diaminobenzophenone, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2-di( 3-aminophenyl)propane, 2,2-di(4-aminophenyl)propane, 2-(3-aminophenyl)-2-(4-aminophenyl)propane, 1,1-di(3-aminophenyl) -1-phenylethane, 1,1-di(4-aminophenyl)-1-phenylethane, 1-(3-aminophenyl)-1-(4-aminophenyl)-1-phenylethane, 1,3- Bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 1, 3-bis(3-aminobenzoyl)benzene, 1,3-bis(4-aminobenzoyl)benzene, 1,4-bis(3-aminobenzoyl)benzene, 1,4-bis(4-aminobenzoyl)benzene, 1,3-bis(3-amino-α,α-dimethylbenzyl)benzene, 1,3-bis(4-amino-α,α-dimethylbenzyl)benzene, 1,4-bis(3-amino-α, α-dimethylbenzyl)benzene, 1,4-bis(4-amino-α,α-dimethylbenzyl)benzene, 2,6-bis(3-aminophenoxy)benzonitrile, 2,6-bis(3-aminophenoxy) ) pyridine, 4,4'-bis(3-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, bis[4-(3-aminophenoxy)phenyl]ketone, bis[4-( 4-aminophenoxy)phenyl]ketone, bis[4-(3-aminophenoxy)phenyl]sulfide, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[4-(3-aminophenoxy)phenyl]sulfone , bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)phenyl]ether, 2,2-bis[4 -(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 1,3-bis[4-(3-aminophenoxy)benzoyl]benzene, 1,3 -bis[4-(4-aminophenoxy)benzoyl]benzene, 1,4-bis[4-(3-aminophenoxy)benzoyl]benzene, 1,4-bis[4-(4-aminophenoxy)benzoyl]benzene , 1,3-bis[4-(3-aminophenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-aminophenoxy)-α,α-dimethylbenzyl]benzene, 1 , 4-bis[4-(3-aminophenoxy)-α,α-dimethylbenzyl]benzene, 1,4-bis[4-(4-aminophenoxy)-α,α-dimethylbenzyl]benzene, 4,4 '-bis[4-(4-aminophenoxy)benzoyl]diphenyl ether, 4,4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]benzophenone, 4,4'-bis[4- (4-amino-α,α-dimethylbenzyl)phenoxy]diphenylsulfone, 4,4'-bis[4-(4-aminophenoxy)phenoxy]diphenylsulfone, 3,3'-diamino-4,4'-di Phenoxybenzophenone, 3,3'-diamino-4,4'-dibiphenoxybenzophenone, 3,3'-diamino-4-phenoxybenzophenone, 3,3'-diamino-4-biphenoxybenzophenone, 6,6'-bis (3-aminophenoxy)-3,3,3',3'-tetramethyl-1,1'-spirobiindane, 6,6'-bis(4-aminophenoxy)-3,3,3',3'- Tetramethyl-1,1'-spirobiindane, 1,4-diamino-2-fluorohenzene, 1,4-diamino-2,3-difluorobenzene, 1,4-diamino-2,5-difluorobenzene, 1, 4-diamino-2,6-difluorobenzene, 1,4-diamino-2,3,5-trifluorobenzene, 1,4-diamino-2,3,5,6-tetrafluorobenzene, 1,4-diamino -2-(trifluoromethyl)henzene, 1,4-diamino-2,3-bis(trifluoromethyl)benzene, 1,4-diamino-2,5-bis(trifluoromethyl)benzene, 1,4- Diamino-2,6-bis(trifluoromethyl)benzene, 1,4-diamino-2,3,5-tris(trifluoromethyl)benzene, 1,4-diamino, 2,3,5,6-tetrakis( trifluoromethyl)benzene, 2,2'-dimethylbenzidine, 2-fluorobenzidine, 3-fluorobenzidine, 2,3-difluorobenzidine, 2,5-difluorobenzidine, 2,6-difluorobenzidine, 2,3,5 -Trifluorobenzidine, 2,3,6-trifluorobenzidine, 2,3,5,6-tetrafluorobenzidine, 2,2'-difluorobenzidine, 3,3'-difluorobenzidine, 2,3'-difluorobenzidine , 2,2',3-trifluorobenzidine, 2,3,3'-trifluorobenzidine, 2,2',5-trifluorobenzidine, 2,2',6-trifluorobenzidine, 2,3', 5-trifluorobenzidine, 2,3',6,-trifluorobenzidine, 2,2',3,3'-tetrafluorobenzidine, 2,2',5,5'-tetrafluorobenzidine, 2,2' ,6,6'-tetrafluorobenzidine, 2,2',3,3',6,6'-hexafluorobenzidine, 2,2',3,3',5,5',6,6'-octa Fluorobenzidine, 2-(trifluoromethyl)benzidine, 3-(trifluoromethyl)benzidine, 2,3-bis(trifluoromethyl)benzidine, 2,5-bis(trifluoromethyl)benzidine, 2,6-bis (trifluoromethyl)benzidine, 2,3,5-tris(trifluoromethyl)benzidine, 2,3,6-tris(trifluoromethyl)benzidine, 2,3,5,6-tetrakis(trifluoromethyl)benzidine , 2,2'-bis(trifluoromethyl)benzidine, 3,3'-bis(trifluoromethyl)benzidine, 2,3'-bis(trifluoromethyl)benzidine, 2,2',3-bis(trifluoromethyl)benzidine, fluoromethyl)benzidine, 2,3,3'-tris(trifluoromethyl)benzidine, 2,2',5-tris(trifluoromethyl)benzidine, 2,2',6-tris(trifluoromethyl)benzidine, 2,3',5-tris(trifluoromethyl)benzidine, 2,3',6,-tris(trifluoromethyl)benzidine, 2,2',3,3'-tetrakis(trifluoromethyl)benzidine, 2 , 2',5,5'-tetrakis(trifluoromethyl)benzidine, 2,2',6,6'-tetrakis(trifluoromethyl)benzidine, 1,4-diaminobenzene, 1,3-diaminobenzene. It will be done.

Examples of aliphatic diamines include hexamethylene diamine, polyethylene glycol bis(3-aminopropyl) ether, polypropylene glycol bis(3-aminopropyl) ether, bis(aminomethyl) ether, bis(2-aminoethyl) ether, Bis(3-aminopropyl) ether, bis[(2-aminomethoxy)ethyl]ether, bis[2-(2-aminoethoxy)ethyl]ether, bis[2-(3-aminoprotoxy)ethyl]ether, 1,2-bis(aminomethoxy)ethane, 1,2-bis(2-aminoethoxy)ethane, 1,2-bis[2-(aminomethoxy)ethoxy]ethane, 1,2-bis[2-(2 -aminoethoxy)ethoxy]ethane, ethylene glycol bis(3-aminopropyl) ether, diethylene glycol bis(3-aminopropyl) ether, triethylene glycol bis(3-aminopropyl) ether, ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1, 11-diaminoundecane, 1,12-diaminododecane, 1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, trans-1,4-diaminocyclohexane, 1,2-di(2- aminoethyl)cyclohexane, 1,3-di(2-aminoethyl)cyclohexane, 1,4-di(2-aminoethyl)cyclohexane, bis(4-aminocyclohexyl)methane, 2,6-bis(aminomethyl) ) Bicyclo[2.2.1]heptane, acyclic aliphatic diamines such as 2,5-bis(aminomethyl)bicyclo[2.2.1]heptane, 4,4'-diaminodicyclohexylmethane, 4,4 '-Diamino-3,3'-dimethylcyclohexylmethane, 4,4'-diamino-3,3',5,5'-tetramethylcyclohexylmethane, 1-amino-3-aminomethyl-3,5,5- Trimethylcyclohexane, 2,2-bis(4,4'-diaminocyclohexyl)propane, 1,3-bisaminomethylcyclohexane, 1,4-bisaminomethylcyclohexane, 2,3-diaminobicyclo [2.2.1] Heptane, 2,5-diaminobicyclo[2.2.1]heptane, 2,6-diaminobicyclo[2.2.1]heptane, 2,7-diaminobicyclo[2.2.1]heptane, 2,5 -bis(aminomethyl)-bicyclo[2.2.1]heptane, 2,6-bis(aminomethyl)-bicyclo[2.2.1]heptane, 2,3-bis(aminomethyl)-bicyclo[2] .2.1] Heptane, 3(4),8(9)-bis(aminomethyl)-tricyclo[5.2.1.02,6]decane, 2,5-bis(aminomethyl)-bicyclo[2 .2.1] Heptane, 1,3-bis(3-aminopropyl)tetramethyldisiloxane, 1,3-bis(4-aminobutyl)tetramethyldisiloxane, α,ω-bis(3-aminopropyl) Cycloaliphatic diamines such as polydimethylsiloxane, α,ω-bis(3-aminobutyl)polydimethylsiloxane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, norbornanediamine, etc. In addition, hydrogenated products of the above-mentioned aromatic diamines may be mentioned.

Further, specific examples of polyimides include those containing a structural unit A derived from a tetracarboxylic dianhydride and a structural unit B derived from a diamine, where the structural unit A is represented by the following formula (a-1). and a structural unit (A-2) derived from a compound represented by the following formula (a-2), and the structural unit B is derived from the following formula (b-1). ) and a structural unit (B-2) derived from a compound represented by the following formula (b-2).

In formula (a-2), L is a single bond or a divalent linking group, and in formula (b-2), R is each independently a hydrogen atom, a fluorine atom, or a methyl group.

<Constituent unit A>
Structural unit A is a structural unit derived from tetracarboxylic dianhydride, and is represented by structural unit (A-1) derived from a compound represented by formula (a-1) and formula (a-2). Contains a structural unit (A-2) derived from a compound.

The compound represented by formula (a-1) is norbornane-2-spiro-α-cyclopentanone-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic dianhydride. It is a thing.

In formula (a-2), L is a single bond or a divalent linking group. The divalent linking group is preferably a substituted or unsubstituted alkylene group, more preferably -CR ₁ R ₂ - (wherein R ₁ and R ₂ are each independently a hydrogen atom or a substituted or unsubstituted alkylene group). is a substituted alkyl group, or R ₁ and R ₂ are bonded to each other to form a ring).

L is preferably selected from the group consisting of a single bond, a group represented by the following formula (L-1), and a group represented by the following formula (L-2).

In formula (L-1) and formula (L-2), * is a bond.

The structural unit (A-2) is preferably a structural unit (A-2-1) derived from a compound represented by the following formula (a-2-1), a structural unit represented by the following formula (a-2-2), At least one selected from the group consisting of a structural unit (A-2-2) derived from a compound represented by the following formula (A-2-3) and a structural unit (A-2-3) derived from a compound represented by the following formula (a-2-3). and more preferably at least one selected from the group consisting of structural unit (A-2-1) and structural unit (A-2-2).

The compound represented by formula (a-2-1) is biphenyltetracarboxylic dianhydride, and specific examples thereof include 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2 , 3,3',4'-biphenyltetracarboxylic dianhydride, and 2,2',3,3'-biphenyltetracarboxylic dianhydride.

The compound represented by formula (a-2-2) is 9,9'-bis(3,4-dicarboxyphenyl)fluorene dianhydride.

The compound represented by formula (a-2-3) is 4,4'-(hexafluoroisopropylidene) diphthalic anhydride.

The content of the structural unit (A-1) in the structural unit A is preferably 50 mol% or more, more preferably 55 mol% or more, even more preferably 60 mol% or more, and particularly preferably 75 mol% or more. The content of the structural unit (A-1) in the structural unit A is preferably 95 mol% or less.

The content of the structural unit (A-2) in the structural unit A is preferably 50 mol% or less, more preferably 45 mol% or less, even more preferably 40 mol% or less, particularly preferably 25 mol% or less. The lower limit of the content of the structural unit (A-2) in the structural unit A is preferably 5 mol% or more.

The total content of the structural unit (A-1) and the structural unit (A-2) in the structural unit A is preferably 55 mol% or more, more preferably 60 mol% or more, even more preferably 65 mol% or more, Particularly preferred is 80 mol% or more. The upper limit of the total content of the structural unit (A-1) and the structural unit (A-2) is not particularly limited, that is, it is 100 mol% or less. The structural unit A may consist only of the structural unit (A-1) and the structural unit (A-2).

The structural unit A may include structural units other than structural units (A-1) and (A-2).
The tetracarboxylic dianhydride forming such a structural unit is not particularly limited, but includes aromatic tetracarboxylic dianhydrides such as pyromellitic dianhydride (however, those represented by formula (a-2) alicyclic tetracarboxylic dianhydrides such as 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1,2,4,5-cyclohexanetetracarboxylic dianhydride , excluding the compound represented by formula (a-1)); and aliphatic tetracarboxylic dianhydrides such as 1,2,3,4-butanetetracarboxylic dianhydride.

Note that aromatic tetracarboxylic dianhydride refers to tetracarboxylic dianhydride containing one or more aromatic rings, and alicyclic tetracarboxylic dianhydride refers to tetracarboxylic dianhydride containing one or more alicyclic rings and containing one or more aromatic rings. It means a tetracarboxylic dianhydride that does not contain a ring, and an aliphatic tetracarboxylic dianhydride means a tetracarboxylic dianhydride that does not contain an aromatic ring or an alicyclic ring.

The number of structural units optionally included in structural unit A (ie, structural units other than structural units (A-1) and (A-2)) may be one type or two or more types.

<Constituent unit B>
Structural unit B is a structural unit derived from a diamine, and is derived from a structural unit (B-1) derived from a compound represented by formula (b-1) and a compound represented by formula (b-2). Contains the structural unit (B-2). The structural unit (B-1) improves mechanical properties and dimensional stability, and the structural unit (B-2) improves heat resistance.

The compound represented by formula (b-1) is 2,2'-bis(trifluoromethyl)benzidine.
In formula (b-2), each R is independently selected from the group consisting of a hydrogen atom, a fluorine atom, and a methyl group, and is preferably a hydrogen atom. Examples of the compound represented by formula (b-2) include 9,9-bis(4-aminophenyl)fluorene, 9,9-bis(3-fluoro-4-aminophenyl)fluorene, and 9,9-bis(4-aminophenyl)fluorene. Examples include (3-methyl-4-aminophenyl)fluorene, and 9,9-bis(4-aminophenyl)fluorene is preferred.

The content of the structural unit (B-1) in the structural unit B is preferably 20 mol% or more, more preferably 45 mol% or more, and even more preferably 50 mol% or more. The content of the structural unit (B-1) in the structural unit B is preferably 90 mol% or less, more preferably 85 mol% or less, even more preferably 80 mol% or less.

The content of the structural unit (B-2) in the structural unit B is preferably 10 mol% or more, more preferably 15 mol% or more, and even more preferably 20 mol% or more. The content of the structural unit (B-2) in the structural unit B is preferably 80 mol% or less, more preferably 55 mol% or less, and even more preferably 50 mol% or less.

The total content of the structural unit (B-1) and the structural unit (B-2) in the structural unit B is preferably 30 mol% or more, more preferably 60 mol% or more, and even more preferably 70% or more. The upper limit of the total content of the structural unit (B-1) and the structural unit (B-2) is not particularly limited, that is, it is 100 mol% or less. The structural unit B may consist only of the structural unit (B-1) and the structural unit (B-2).

The structural unit B may include structural units other than the structural units (B-1) and (B-2). Diamines forming such structural units are not particularly limited, but include the aromatic diamines described above (excluding compounds represented by formula (b-1) and compounds represented by formula (b-2)). ), the above-mentioned alicyclic diamines, and the above-mentioned aliphatic diamines.

The number of structural units optionally included in structural unit B, ie, structural units other than structural units (B-1) and (B-2), may be one type or two or more types.

In addition, 9-bis(4-aminophenyl)fluorene and 9,9-bis(4-aminophenoxyphenyl)fluorene have a negative intrinsic birefringence in their fluorene skeleton, so for the purpose of adjusting the retardation of a polyimide film, Polyimide may have structural units derived from these.

Also, 2,2'-bis(trifluoromethyl)benzidine, 3,3'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 2,2'-bis[3(3-aminophenoxy)phenyl ] Hexafluoropropane, 2,2'-bis[4(4-aminophenoxy)phenyl]hexafluoropropane, 2,2'-bis(3-aminophenyl)hexafluoropropane, 2,2'-bis(4- (aminophenyl)hexafluoropropane can suppress the formation of charge transfer complexes between polyimide molecules by introducing bulky steric hindrance of fluorine atoms. Therefore, in order to lower the yellow index (YI) of the polyimide film, the polyimide may have repeating units derived from these.

The polyimide precursor means polyamic acid (so-called polyamic acid and/or polyamic acid ester) in a state before being imidized.

Specific examples of the polyimide precursor include polyimide precursors containing 50 mol% or more of the structural unit represented by the following formula (1A) based on the total structural units, and structural units represented by the following formula (1A). and a polyimide precursor containing 50 mol% or more of the structural unit represented by the following formula (2A) based on the total structural units.

In the formula, R ₁ and R ₂ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms.

In the formula, R ₃ and R ₄ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms.

Specific examples of the polyimide precursor include a polyimide precursor containing a structural unit represented by the following formula (3A), preferably 90 mol% or more, more preferably 95 mol% or more, based on the total structural units; A polyimide precursor containing a structural unit represented by the following formula (3A) and a structural unit represented by the following formula (4A), based on the total structural units, preferably 90 mol% or more, more preferably 95 mol% or more One example is the body.

In the formula, A ₁ is a divalent group having an aromatic ring, and R ₅ and R ₆ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkyl group having 3 to 9 carbon atoms. It is a silyl group.

In the formula, A ₂ is a divalent group having an aromatic ring, and R ₇ and R ₈ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkyl group having 3 to 9 carbon atoms. It is a silyl group.

The structural unit represented by formula (1A) is a structural unit represented by formula (3A) in which A ₁ is a group represented by formula (D-1) below.
The structural unit represented by the formula (2A) is a structural unit represented by the formula (4A) in which A ₂ is a group represented by the following formula (D-1).

A ₁ in formula (3A) and A ₂ in formula (4A) other than the group represented by formula (D-1) are divalent groups having an aromatic ring having 6 to 40 carbon atoms. is preferable, and a group represented by the following formula (A-1) is more preferable.

In the formula, m independently represents 0 to 3, and n represents 0 to 3. Y ₁ , Y ₂ , and Y ₃ each independently represent one selected from the group consisting of a hydrogen atom, a methyl group, and a trifluoromethyl group, and Q and R each independently represent a direct bond, Alternatively, it represents one selected from the group consisting of groups represented by the formula: -NHCO-, -CONH-, -COO-, and -OCO-.

Examples of the tetracarboxylic acid component that provides the structural unit represented by the formula (1A) and the structural unit represented by the above formula (3A) include 1,2,3,4-cyclobutanetetracarboxylic acids. Examples of the tetracarboxylic acids include tetracarboxylic acids and tetracarboxylic acid derivatives such as tetracarboxylic dianhydrides, tetracarboxylic acid silyl esters, tetracarboxylic acid esters, and tetracarboxylic acid chlorides.

As the tetracarboxylic acid component providing the structural unit represented by formula (2A), trans-endo-endo-norbornane-2-spiro-α-cyclopentanone-α'-spiro-2"-norbornane-5,5 ",6,6"-tetracarboxylic acids, cis-endo-endo-norbornane-2-spiro-α-cyclopentanone-α'-spiro-2"-norbornane-5,5",6,6"-tetra Examples include norbornane-2-spiro-α-cyclopentanone-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acids such as carboxylic acids.

As the diamine component that provides the structural unit represented by the formula (1A) and the structural unit represented by the formula (2A), for example, 2,2'-dimethyl-4,4'-diaminobiphenyl (m-tolidine) is used. be.

A structural unit of formula (3A) in which A ₁ is a group represented by formula (A-1), and a structural unit of formula (4A) in which A ₂ is a group represented by formula (A-1). The diamine component to be provided has an aromatic ring, and when it has a plurality of aromatic rings, the aromatic rings are each independently connected to each other by a direct bond, an amide bond, or an ester bond. The bonding position between aromatic rings is not particularly limited, but bonding at the 4-position to an amino group or a linking group between aromatic rings may result in a linear structure, and the resulting polyimide may have low linear thermal expansion. . Further, the aromatic ring may be substituted with a methyl group or a trifluoromethyl group. Note that the substitution position is not particularly limited.

A structural unit of formula (3A) in which A ₁ is a group represented by formula (A-1), and a structural unit of formula (4A) in which A ₂ is a group represented by formula (A-1). The diamine components to be given include p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, benzidine, 3,3'-diamino-biphenyl, 2,2'-bis(trifluoromethyl)benzidine, 3,3'- Bis(trifluoromethyl)benzidine, 4,4'-diaminobenzanilide, 3,4'-diaminobenzanilide, N,N'-bis(4-aminophenyl)terephthalamide, N,N'-p-phenylenebis (p-aminobenzamide), 4-aminophenoxy-4-diaminobenzoate, bis(4-aminophenyl) terephthalate, biphenyl-4,4'-dicarboxylic acid bis(4-aminophenyl) ester, p-phenylene bis(p -aminobenzoate), bis(4-aminophenyl)-[1,1'-biphenyl]-4,4'-dicarboxylate, [1,1'-biphenyl]-4,4'-diylbis(4-amino benzoate), etc.

The diamine component that provides the structural unit of formula (3A) or formula (4A) may be other than the diamine component that provides the structure of formula (D-1) or formula (A-1) in which A ₁ or A ₂ is aromatic diamines can be used.

Other diamine components include, for example, 4,4'-oxydianiline, 3,4'-oxydianiline, 3,3'-oxydianiline, p-methylenebis(phenylenediamine), 1,3-bis( 4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4 '-bis(3-aminophenoxy)biphenyl, 2,2-bis(4-(4-aminophenoxy)phenyl)hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, bis(4- aminophenyl) sulfone, 3,3'-bis(trifluoromethyl)benzidine, 3,3'-bis((aminophenoxy)phenyl)propane, 2,2'-bis(3-amino-4-hydroxyphenyl)hexa Fluoropropane, bis(4-(4-aminophenoxy)diphenyl)sulfone, bis(4-(3-aminophenoxy)diphenyl)sulfone, octafluorobenzidine, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dichloro-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, 6,6'-bis(3-aminophenoxy)-3,3,3', 3'-tetramethyl-1,1'-spirobiindane, 6,6'-bis(4-aminophenoxy)-3,3,3',3'-tetramethyl-1,1'-spirobiindane, etc. and derivatives thereof A tetracarboxylic acid component containing 1,2,3,4-cyclobutanetetracarboxylic acids, or 1,2,3,4-cyclobutanetetracarboxylic acids and norbornane-2-spiro-α-cyclo A tetracarboxylic acid component including pentanone-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acids, and 2,2'-dimethyl-4,4'-diaminobiphenyl ( Examples include polyimide precursors obtained from diamine components containing m-tolidine).

The solvent may be any solvent that dissolves polyimide or its precursor, such as phenolic solvents (e.g. m-cresol), amide solvents (e.g. N-methyl-2-pyrrolidone, N,N-dimethylformamide), etc. , N,N-dimethylacetamide), lactone solvents (for example, γ-butyrolactone, δ-valerolactone, ε-caprolactone, γ-crotonolactone, γ-hexanolactone, α-methyl-γ-butyrolactone, γ- valerolactone, α-acetyl-γ-butyrolactone, δ-hexanolactone), sulfoxide solvents (e.g. N,N-dimethylsulfoxide), ketone solvents (e.g. acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone), esters Examples include solvents such as methyl acetate, ethyl acetate, butyl acetate, and dimethyl carbonate.

The polyimide varnish preferably contains 5 to 40% by mass, more preferably 10 to 30% by mass of polyimide resin or its precursor. The viscosity of the polyimide varnish is preferably 1 to 200 Pa·s, more preferably 5 to 150 Pa·s.

(procedure)
The method of applying polyimide varnish to the silicone resin layer 14 side of the laminated substrate 10 is not particularly limited, and known methods may be used. Examples include slit coating, curtain coating, spray coating, die coating, spin coating, dip coating, roll coating, bar coating, screen printing, and gravure coating.

After coating, a heat treatment (curing step) may be performed as necessary.
The temperature conditions for the heat treatment are preferably 50 to 500°C, more preferably 50 to 450°C. The heating time is preferably 10 to 300 minutes, more preferably 20 to 200 minutes.
Further, the heat treatment may be performed multiple times. When heat treatment is performed multiple times, the heating conditions for each may be changed.

Further, in order to flatten particles and convex portions, the surface of the polyimide film after formation may be polished.

The laminated substrate may be cleaned with an alkaline detergent before applying the polyimide varnish. Further, after cleaning with an alkaline detergent, rinsing with pure water may be performed as necessary. Furthermore, after rinsing with pure water, the water may be drained using an air knife, if necessary. After air knife, heat drying may be performed. Since the surface of the silicone resin layer may be damaged by contact with a brush, it is preferable to perform cleaning without applying a brush.

The surface quality of the laminated substrate before applying the polyimide varnish may be inspected in the same manner as the glass substrate.

(laminate)
As shown in FIG. 2, the laminate 16 includes a glass base material 12, a silicone resin layer 14, and a polyimide film 18.
The structures of the glass base material 12 and the silicone resin layer 14 are as described above.

Polyimide film 18 is placed on silicone resin layer 14 .

The average thickness of the polyimide film 18 is preferably 1 μm or more, more preferably 5 μm or more. In terms of flexibility, the thickness is preferably 1 mm or less, more preferably 0.2 mm or less.

The variation in the thickness of the polyimide film 18 is preferably 0.5 μm or less, more preferably 0.2 μm or less. The lower limit is 0 μm.

The polyimide film 18 may be a single film or a multilayer film of two or more layers.

In order to form high-definition wiring for electronic devices on the polyimide film 18, the surface of the polyimide film 18 is preferably smooth. Specifically, the average value of the surface roughness Ra of the polyimide film 18 is preferably 50 nm or less, more preferably 30 nm or less, and even more preferably 10 nm or less. The lower limit is 0 nm.

It is preferable that the polyimide film 18 has a smaller difference in thermal expansion coefficient from the glass substrate 12 because warping of the laminate 16 after heating or cooling can be suppressed. Specifically, the difference in thermal expansion coefficient between the polyimide film 18 and the glass substrate 12 is preferably 0 to 90×10 ⁻⁶ /°C, more preferably 0 to 30×10 ⁻⁶ /°C.

The area of the polyimide film 18 is not particularly limited, but is preferably 300 cm ² or more from the viewpoint of productivity of electronic devices.

The yellow index (YI) of the polyimide film 18 is preferably small. The YI of the polyimide film 18 is preferably 10.0 or less, more preferably 5.0 or less, even more preferably 3.5 or less, and particularly preferably 1.5 or less. The lower limit is 0.
YI is measured in accordance with JIS K7361-1.

The light transmittance of the polyimide film 18 in the visible light region is preferably 80% or more. The upper limit is less than 100%.

The laminate may have a gas barrier film on the polyimide film 18. When the polyimide film 18 is a laminated film, a gas barrier film may be provided between two or more layers.

The gas barrier film is, for example, an inorganic material film such as a silicon oxide film or a silicon nitride film. Further, the gas barrier film may be a multilayer film in which a layer of an organic material such as a thermoplastic resin or an organosilicon compound and a layer of an inorganic material such as silicon oxide or silicon nitride are laminated. The film forming method is not particularly limited, and known methods may be used. Examples include methods such as plasma CVD and sputtering.

The laminate 16 can be used for various purposes, such as manufacturing electronic components such as display panels, PV, thin film secondary batteries, semiconductor wafers with circuits formed on the surface, and reception sensor panels, which will be described later. Can be mentioned. In these applications, the laminate may be exposed to high temperature conditions (for example, 450° C. or higher) under atmospheric conditions (for example, for 20 minutes or longer).

Panels for display devices include LCDs, OLEDs, electronic paper, plasma display panels, field emission panels, quantum dot LED panels, micro LED display panels, MEMS shutter panels, and the like.

The receiving sensor panel includes an electromagnetic wave receiving sensor panel, an X-ray receiving sensor panel, an ultraviolet receiving sensor panel, a visible light receiving sensor panel, an infrared receiving sensor panel, and the like. The substrate used for the receiving sensor panel may be reinforced with a reinforcing sheet made of resin or the like.

<Method for manufacturing electronic devices>
Using the laminate, an electronic device including a polyimide film and an electronic device member described below is manufactured.

For example, as shown in FIGS. 3 and 4, the electronic device manufacturing method includes forming an electronic device member 20 on the surface of the polyimide film 18 of the laminate 16 on the side opposite to the silicone resin layer 14 side, and manufacturing the electronic device. This method includes a member forming step for obtaining a laminate 22 with a member for electronic device use, and a separation step for obtaining an electronic device 24 having a polyimide film 18 and an electronic device member 20 from the laminate 22 for an electronic device member.

Hereinafter, the process of forming the electronic device member 20 will be referred to as a "member forming process", and the process of separating the electronic device 24 and the glass substrate 26 with a silicone resin layer will be referred to as a "separating process".
The materials and procedures used in each step are detailed below.

(Component forming process)
The member forming step is a step of forming an electronic device member on the polyimide film 18 of the laminate 16. More specifically, as shown in FIG. 3, an electronic device member 20 is formed on the surface of the polyimide film 18 on the side opposite to the silicone resin layer 14 side, to obtain a laminate 22 with an electronic device member. The electronic device member-attached laminate 22 includes the laminate 16 and the electronic device member 20 disposed on the polyimide film 18 in the laminate 16.
First, the electronic device member 20 used in this step will be explained in detail, and the procedures of subsequent steps will be explained in detail.

(Electronic device parts)
The electronic device member 20 is a member that constitutes at least a portion of an electronic device formed on the polyimide film 18 of the laminate 16.

More specifically, the electronic device member 20 is used for display device panels, solar cells, thin film secondary batteries, electronic components such as semiconductor wafers with circuits formed on the surface, reception sensor panels, etc. Members (for example, members for display devices such as LTPS, members for solar cells, members for thin film secondary batteries, circuits for electronic components, members for reception sensors), for example, US Patent Application Publication No. 2018/0178492 Examples include solar cell members described in paragraph [0192] of the book, thin film secondary battery members described in the same paragraph [0193], and electronic component circuits described in the same paragraph [0194].

(Process steps)
The method for manufacturing the above-described electronic device member-attached laminate 22 is not particularly limited, and the electronic device can be formed on the polyimide film 18 of the laminate 16 by a conventionally known method depending on the type of the component of the electronic device member. A member 20 for use is formed.

The electronic device member 20 may be a part of the entire member (hereinafter referred to as a "partial member") rather than the entire member finally formed on the polyimide film 18 (hereinafter referred to as the "all member"). good. The substrate with partial members peeled off from the silicone resin layer 14 can also be made into a substrate with all the members (corresponding to an electronic device described later) in a subsequent process.

Other electronic device members may be formed on the peeled surface of the substrate with all the materials peeled off from the silicone resin layer 14. Furthermore, the electronic device members 20 of the two electronic device member-attached laminates 22 are made to face each other, and the two are pasted together to assemble a laminate with all the materials, and then the two silicone An electronic device can also be manufactured by peeling off the resin layer-coated glass substrate.

For example, in the case of manufacturing an OLED, in order to form an organic EL structure on the surface of the polyimide film 18 of the laminate 16 on the side opposite to the silicone resin layer 14 side, a transparent electrode is formed. Furthermore, various layer formations are performed, such as depositing a hole injection layer, hole transport layer, light emitting layer, electron transport layer, etc. on the surface on which the transparent electrode is formed, forming a back electrode, and sealing using a sealing plate. processing is performed. Specific examples of these layer formations and treatments include film formation treatment, vapor deposition treatment, and sealing plate adhesion treatment.

(separation process)
In the separation step, as shown in FIG. 4, the electronic device member 20 is separated from the electronic device member-attached laminate 22 obtained in the member forming step by using the interface between the silicone resin layer 14 and the polyimide film 18 as a peeling surface. In this step, the polyimide film 18 laminated with the polyimide film 18 and the silicone resin layer-coated glass substrate 26 are separated to obtain the electronic device member 20 and the electronic device 24 including the polyimide film 18.

If the electronic device component 20 on the stripped polyimide film 18 is part of the formation of all necessary components, the remaining components can also be formed on the polyimide film 18 after separation.

The method of peeling off the polyimide film 18 and the silicone resin layer 14 is not particularly limited. For example, a sharp knife-like object is inserted into the interface between the polyimide film 18 and the glass substrate 12 to trigger peeling, and then a mixed fluid of water and compressed air can be sprayed to peel the film. Alternatively, a laser lift-off method may be used.

Preferably, as a method for peeling off the polyimide film 18 and the silicone resin layer 14, the electronic device member-attached laminate 22 is placed on a surface plate so that the glass base material 12 is on the upper side and the electronic device member 20 side is on the lower side. The electronic device member 20 side is vacuum-adsorbed onto a surface plate, and in this state, a knife-like object is first penetrated into the interface between the polyimide film 18 and the glass base material 12. Thereafter, the glass substrate 12 side is suctioned with a plurality of vacuum suction pads, and the vacuum suction pads are raised in order from the vicinity of the point where the knife-like object is inserted. Then, the silicone resin layer-coated glass base material 26 can be easily peeled off.

Furthermore, when the polyimide film 18 and the silicone resin layer 14 are peeled off, if the electronic device member 20 is manufactured for each cell, the electronic device 24 having the polyimide film 18 and the electronic device member 20 is separated for each cell. After cutting, the polyimide film 18 and silicone resin layer 14 may be separated for each cut cell. Examples of the method of cutting each cell include a method of cutting with a laser beam and a method of cutting with a cutting machine such as a dicing saw.

When separating the electronic device 24 from the electronic device member-attached laminate 22, by controlling the spraying with an ionizer and the humidity, electrostatic adsorption of pieces of the silicone resin layer 14 to the electronic device 24 can be further suppressed. .

The electronic device manufacturing method described above is suitable, for example, for manufacturing the display device described in paragraph [0210] of U.S. Patent Application Publication No. 2018/0178492, and the electronic device 24 is, for example, Examples include those described in [0211].

Moreover, before implementing the above-mentioned separation step, the region of the laminate where the electronic device member is not arranged may be cut and removed.

A protective film may be bonded to the surface of the electronic device member 20 of the separated electronic device 24 on the side opposite to the polyimide film 18 side.

Moreover, a protective film may be bonded to the surface of the polyimide film 18 of the separated electronic device 24 on the side opposite to the electronic device member 20 side. Note that, before bonding the protective film to the polyimide film 18, the surface of the polyimide film 18 may be subjected to surface treatment, if necessary. Examples of the surface treatment include corona treatment, atmospheric pressure plasma treatment, UV ozone treatment, and excimer UV treatment. The water contact angle on the surface of the polyimide film 18 after surface treatment is preferably 10 degrees or less, more preferably 5 degrees or less.

The silicone resin layer-attached glass base material 26 separated from the electronic device member-attached laminate 22 may be recycled as a glass raw material.

Furthermore, by cleaning the surface of the silicone resin layer 14 of the separated silicone resin layer-attached glass substrate 26 and further surface modification, it may be used again as a laminated substrate for forming a polyimide film.

Alternatively, the silicone resin layer 14 of the separated glass base material 26 with a silicone resin layer may be removed and reused as a glass base material. Examples of methods for removing the silicone resin layer include a method of dissolving the silicone resin layer in a solvent, and a method of mechanically grinding or polishing the silicone resin layer.

EXAMPLES The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to these Examples.
In the following, a glass substrate made of alkali-free borosilicate glass (linear expansion coefficient 38×10 ⁻⁷ /° C., trade name “AN100” manufactured by AGC Corporation) was used as the glass substrate.
Examples 1 to 4, 9 and 10 are examples, and examples 5 to 8 and 11 to 15 are comparative examples.

(Preparation of curable silicone 1)
Triethoxymethylsilane (179 g), toluene (300 g), and acetic acid (5 g) were added to a 1 L flask, and the mixture was stirred at 25° C. for 20 minutes, then further heated to 60° C. and reacted for 12 hours. After cooling the obtained reaction crude liquid to 25° C., the reaction crude liquid was washed three times with water (300 g). Chlorotrimethylsilane (70 g) was added to the washed reaction crude liquid, and the mixture was stirred at 25° C. for 20 minutes, then further heated to 50° C. and reacted for 12 hours. After cooling the obtained reaction crude liquid to 25° C., the reaction crude liquid was washed three times with water (300 g).

Toluene was distilled off under reduced pressure from the washed reaction crude liquid to form a slurry, which was then dried overnight in a vacuum dryer to obtain curable silicone 1, which is a white organopolysiloxane compound. In curable silicone 1, the number of T units: the number of M units = 87:13 (mole ratio). Curable silicone 1 had a molar ratio of M units to T units of 13:87, all organic groups were methyl groups, and the average number of OX groups was 0.02. The average number of OX groups is a numerical value representing how many OX groups (X is a hydrogen atom or a hydrocarbon group) are bonded to one Si atom on average. Note that the M unit means a monofunctional organosiloxy unit represented by (R) ₃ SiO _1/2 . The T unit means a trifunctional organosiloxy unit represented by RSiO _3/2 (R represents a hydrogen atom or an organic group).

(Preparation of curable composition 1)
Curable silicone (20 g), zirconium octylate compound ("Orgatics ZC-200", manufactured by Matsumoto Fine Chemical Co., Ltd.) (0.16 g) as a metal compound, and cerium (III) 2-ethylhexanoate (Alfa Aesar) (manufactured by TonenGeneral Sekiyu Co., Ltd.) (0.17 g) and Isoper G (manufactured by Tonen General Sekiyu Co., Ltd.) (19.7 g) as a solvent, and the resulting mixture was filtered through a filter with a pore size of 0.45 μm. A curable composition 1 was obtained by filtering the mixture using the following methods.

(Preparation of curable silicone 2)
Curable silicone 2 was obtained by mixing organohydrogensiloxane and alkenyl group-containing siloxane. The composition of curable silicone 2 is as follows: the molar ratio of M units, D units, and T units is 9:59:32, the molar ratio of methyl groups to phenyl groups as organic groups is 44:56, and all alkenyl groups to all silicon atoms. The molar ratio (hydrogen atom/alkenyl group) to the hydrogen atom bonded to was 0.7, and the average number of OX groups was 0.1.

(Preparation of curable composition 2)
Platinum (0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane (CAS No. 68478-92-2) was added to curable silicone 2 so that the platinum element content was 120 ppm. , mixture A was obtained. Mixture A (200 g) was mixed with diethylene glycol diethyl ether ("Hysolve EDE", manufactured by Toho Chemical Industries, Ltd.) (84.7 g) as a solvent, and the resulting mixed solution was filtered using a filter with a pore size of 0.45 μm. By doing so, curable composition 2 was obtained.

<Example 1>
(Preparation of a laminated substrate consisting of a glass base material and a silicone resin layer)
A PET film (manufactured by Toyobo Co., Ltd., Cosmoshine A4160, thickness 50 μm) was prepared as a release film (corresponding to a temporary support). This film has a flat surface and an uneven surface, and a silicone resin layer was formed by coating the prepared curable composition 1 on the flat surface side and heating it at 140° C. for 10 minutes using a hot plate.

Next, a 200 mm x 200 mm, 0.5 mm thick glass base material "AN100" (glass base material) was washed with a water-based glass cleaning agent ("PK-LCG213" manufactured by Parker Corporation) and then with pure water. A PET film (size: 190 mm x 190 mm) on which a silicone resin layer was formed was laminated to produce a laminate in which a glass substrate, a silicone resin layer, and a PET film were arranged in this order.

Next, the obtained laminate was placed in an autoclave and heated at 60° C. and 1 MPa for 30 minutes. Thereafter, the PET film was peeled off, and the obtained laminate was placed in an oven preheated to 250°C and annealed for 30 minutes to produce a laminate substrate consisting of a glass base material and a silicone resin layer (annealing process). .

The film thickness of the silicone resin layer after the annealing treatment was measured at ten arbitrary locations using a film thickness measurement system ("F20" manufactured by Filmetrics Co., Ltd.). As a measurement range, a peripheral region of 3 mm from the peripheral edge of the silicone resin layer toward the center was excluded. The average value of the film thickness of 10 measurements was 7.2 μm. The maximum thickness of the silicone resin layer was 7.4 μm, and the minimum thickness was 7.1 μm. Further, the difference between the maximum value and the minimum value of the film thickness was defined as the film thickness variation. The film thickness variation was 0.3 μm.

The surface roughness (Ra) of ten arbitrary locations of the silicone resin layer after the annealing treatment was measured using a non-contact surface/layer cross-sectional shape measurement system ("Vertscan R3300-lite" manufactured by Ryoka System Co., Ltd.). As a measurement range, a peripheral region of 3 mm from the peripheral edge of the silicone resin layer toward the center was excluded. The measurement area at one location was 940 μm in length×700 μm in width. The average value of the surface roughness of 10 measurements was 0.81 nm. The maximum value of the surface roughness was 0.87 nm, and the minimum value was 0.72 nm. In addition, the difference between the maximum value and the minimum value of surface roughness was defined as surface roughness variation. The surface roughness variation was 0.15 nm.

When measuring the thickness and surface roughness of the silicone resin layer, if foreign matter such as lint or glass cullet was observed on the surface of the silicone resin layer, it was not adopted as measurement data and the measurement was performed again.

(Preparation of laminate)
After corona treatment was applied to the silicone resin layer of the laminated substrate obtained above, a colorless polyimide varnish ("Neoprim H230" manufactured by Mitsubishi Gas Chemical Co., Ltd.) was applied, and then heated at 80°C for 20 minutes using a hot plate. did. Subsequently, the mixture was heated at 400° C. for 30 minutes in a nitrogen atmosphere using an inert gas oven to obtain a laminate having a glass substrate, a silicone resin layer, and a colorless polyimide film (thickness: 7 μm) in this order.

(Formation of gas barrier film and heat resistance test)
A silicon nitride film (SiN film) with a thickness of 50 nm was formed on the surface of the colorless polyimide film of the laminate obtained above (fabrication of laminate) using a plasma CVD apparatus. Next, using an inert gas oven, a laminate including a glass substrate, a silicone resin layer, a colorless polyimide film, and a silicon nitride film in this order was heated at 400° C. for 1 hour in a nitrogen atmosphere (heat resistance test).

(Peeling of colorless polyimide film)
After the heat resistance test, the colorless polyimide film on the surface of which the SiN film was formed was peeled off from the laminate by pinching the edge of the colorless polyimide film of the laminate with fingers and pulling up vertically.

<Example 2 to Example 6, Example 9 to Example 13>
Evaluation samples were prepared in the same manner as in Example 1, except that the curable composition, release film, and annealing conditions shown in Table 1 were used.

<Example 7>
(Preparation of a laminated substrate consisting of a glass base material and a silicone resin layer)
After cleaning with a water-based glass cleaning agent (“PK-LCG213” manufactured by Parker Corporation), spin on a 190 mm x 190 mm, 0.5 mm thick glass substrate “AN100” (glass substrate) that has been cleaned with pure water. Curable composition 1 was applied using a coater. A silicone resin layer was formed by heating at 140° C. for 10 minutes using a hot plate. A laminated substrate consisting of a glass base material and a silicone resin layer was placed in an oven preheated to 250° C. and annealed for 30 minutes (annealing step).

The film thickness at 10 arbitrary locations on the silicone resin layer after annealing was measured using a film thickness measurement system (“F20” manufactured by Filmetrics Co., Ltd.) (the measurement range was from the edge to the center of the silicone resin layer). except for the peripheral area of 3 mm towards the end). The average value of the film thickness of 10 measurements was 7.0 μm. The maximum value of the film thickness was 9.5 μm, and the minimum value was 6.8 μm. Further, the film thickness variation, which is the difference between the maximum value and the minimum value of the film thickness, was 2.7 μm.

The surface roughness (Ra) of ten arbitrary locations of the silicone resin layer after the annealing treatment was measured using a non-contact surface/layer cross-sectional shape measurement system ("Vertscan R3300-lite" manufactured by Ryoka System Co., Ltd.). As the measurement range, a peripheral area of 3 mm from the end of the silicone resin layer toward the center was excluded. The measurement area at one location was 940 μm×700 μm. The average value of the surface roughness of 10 measurements was 0.42 nm. The maximum value of the surface roughness was 0.47 nm, and the minimum value was 0.40 nm. Further, the surface roughness variation, which is the difference between the maximum value and the minimum value of surface roughness, was 0.07 nm.

When measuring the thickness and surface roughness of the silicone resin layer, if foreign matter such as lint or glass cullet was observed on the surface of the silicone resin layer, it was not adopted as measurement data and the measurement was performed again.

(Preparation of laminate)
After corona treatment was applied to the silicone resin layer of the laminated substrate obtained above, a colorless polyimide varnish ("Neoprim H230" manufactured by Mitsubishi Gas Chemical Co., Ltd.) was applied, and then heated at 80°C for 20 minutes using a hot plate. did. Subsequently, it was heated at 400° C. for 30 minutes in a nitrogen atmosphere using an inert gas oven (curing step) to obtain a laminate having a glass substrate, a silicone resin layer, and a colorless polyimide film (thickness: 7 μm) in this order.

(Formation of gas barrier film and heat resistance test)
As a gas barrier film, a silicon nitride film (SiN film) with a thickness of 50 nm was formed on the surface of the colorless polyimide film of the laminate obtained in the above (fabrication of laminate) using a plasma CVD apparatus.
Next, as a heat resistance test, a laminate including a glass substrate, a silicone resin layer, a colorless polyimide film, and a silicon nitride film in this order was heated at 400° C. for 1 hour in a nitrogen atmosphere using an inert gas oven.

(Peeling of colorless polyimide film)
After the heat resistance test, the colorless polyimide film (with a SiN film on the surface) was peeled off from the laminate by pinching the end of the colorless polyimide film of the laminate with fingers and pulling up vertically.

<Example 8, Example 14, Example 15>
Evaluation samples were prepared in the same manner as in Example 7, except that the curable composition, silicone resin layer formation method, and annealing conditions shown in Table 1 were used.

<Evaluation of unevenness of colorless polyimide film>
The peeled colorless polyimide film was visually observed to evaluate the optical non-uniformity (unevenness) of the colorless polyimide film. The evaluation area was 184 mm x 184 mm, and evaluation was made according to the following evaluation criteria.
◎: No unevenness is observed over the entire surface 〇: Unevenness is observed in an area of less than 10% of the evaluated area ×: Unevenness is observed in an area of 10% or more of the evaluated area

Table 2 shows the results of the unevenness evaluation.
In Table 2, the "Average" column in the "Silicone resin layer thickness [μm]" column represents the arithmetic mean value of 10 film thickness measurements of the silicone resin layer, and the "Maximum" column represents the 10 film thickness measurements. The maximum value among the measured thickness values is represented, the "minimum" column represents the minimum value among the ten film thickness measurements, and the "variation" column represents the difference between the maximum value and the minimum value.

In Table 2, the "average" column in the "Surface roughness Ra [nm] of silicone resin layer" column represents the arithmetic mean value of 10 surface roughness measurements of the silicone resin layer, and the "maximum" column represents 10 The ``Minimum'' column represents the minimum value among the 10 surface roughness measurements, and the ``Dispersion'' column represents the maximum and minimum values. represents the difference.

Comparing Examples 1 to 4, 9, and 10 with Examples 5, 6, and 11 to 13, it is clear that if the variation in surface roughness Ra of the silicone resin layer is 1.00 nm or less, optical nonuniformity is observed. It was found that a colorless polyimide film with less unevenness can be obtained.
Furthermore, by comparing Examples 1 to 4, Examples 9, and 10 with Examples 7, 8, 14, and 15, it was found that if the variation in the thickness of the silicone resin layer is 1.5 μm or less, there is no optical problem. It was found that a colorless polyimide film with less uniformity (unevenness) could be obtained.
Further, by comparing Examples 1 to 4 with Examples 9 and 10, it was confirmed that the effect is more excellent when the variation in surface roughness Ra is 0.40 nm or less.

<Manufacture of organic EL display devices (corresponding to electronic devices)>
Organic EL display devices were manufactured using the laminates obtained in Examples 1 to 4, Example 9, and Example 10 according to the following procedure.

First, silicon nitride, silicon oxide, and amorphous silicon were deposited in this order on the surface of the polyimide film of the multilayer substrate on the side opposite to the glass substrate side by plasma CVD. Next, a low concentration of boron was implanted into the amorphous silicon layer using an ion doping device, and heat treatment was performed to perform dehydrogenation treatment. Next, the amorphous silicon layer was crystallized using a laser annealing device. Next, low concentration phosphorus was injected into the amorphous silicon layer using an etching and ion doping device using photolithography to form N-type and P-type TFT areas.

Next, on the opposite side of the polyimide film from the glass substrate side, a silicon oxide film is formed by plasma CVD to form a gate insulating film, and then molybdenum is formed by sputtering and photolithography is used. A gate electrode was formed by etching. Next, using a photolithography method and an ion doping device, highly concentrated boron and phosphorus were implanted into desired areas of each of the N type and P type to form a source area and a drain area.

Next, on the side of the polyimide film opposite to the glass substrate, an interlayer insulating film is formed by forming a silicon oxide film by plasma CVD, and a TFT electrode is formed by forming an aluminum film by sputtering and etching using photolithography. Formed. Next, after performing heat treatment and hydrogenation treatment in a hydrogen atmosphere, a passivation layer was formed by forming a silicon nitride film by plasma CVD.

Next, an ultraviolet curable resin was applied to the side of the polyimide film opposite to the glass substrate side, and a flattening layer and contact holes were formed by photolithography. Next, a film of indium tin oxide was formed by sputtering, and a pixel electrode was formed by etching using photolithography. Subsequently, 4,4',4''-tris(3-methylphenylphenylamino)triphenylamine as a hole injection layer and a hole transport layer are formed on the opposite side of the polyimide film from the glass substrate side by vapor deposition. bis[(N-naphthyl)-N-phenyl]benzidine as the light-emitting layer, and 2,6-bis[4-[N-(4-methoxyphenyl)-N-phenyl] in the 8-quinolinol aluminum complex (Alq ₃ ) as the emissive layer. A mixture of 40% by volume of [aminostyryl]naphthalene-1,5-dicarbonitrile (BSN-BCN) and Alq ₃ as an electron transport layer were formed in this order.Next, aluminum was formed into a film by a sputtering method, A counter electrode was formed by etching using photolithography.

Next, another glass substrate was bonded to the opposite side of the polyimide film from the glass substrate side with an ultraviolet curable adhesive layer interposed therebetween for sealing. An organic EL structure was formed on the polyimide film by the above procedure. A structure having an organic EL structure on a polyimide film (hereinafter referred to as panel A) is a laminate with members for an electronic device.

Next, the sealing body side of panel A was vacuum-adsorbed on a surface plate, and a stainless steel knife with a thickness of 0.1 mm was inserted into the interface between the polyimide film and the glass substrate at the corner of panel A to remove the polyimide film. This caused delamination at the interface between the glass substrate and the glass substrate. Then, after adsorbing the surface of the glass substrate of panel A with a vacuum suction pad, the suction pad was raised. Here, the knife was inserted while spraying static eliminating fluid from an ionizer (manufactured by Keyence Corporation) onto the interface.

Next, the vacuum suction pad was pulled up while continuing to spray the static eliminating fluid from the ionizer toward the formed gap and pouring water into the separation front. As a result, it was possible to peel off the glass substrate with the silicone resin layer, leaving only the polyimide film on which the organic EL structure was formed on the surface plate.

Next, the separated polyimide film is cut using a laser cutter or scribe-break method to divide it into a plurality of cells, and then the polyimide film on which the organic EL structure is formed and a counter substrate are assembled to form a module. The steps were carried out to produce an organic EL display device.

Although various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to such examples. It is clear that those skilled in the art can come up with various changes or modifications within the scope of the claims, and these naturally fall within the technical scope of the present invention. Understood. Further, each of the constituent elements in the above embodiments may be arbitrarily combined without departing from the spirit of the invention.

Note that this application is based on a Japanese patent application (Japanese Patent Application No. 2021-072745) filed on April 22, 2021, the contents of which are incorporated as a reference in this application.

10 Laminated substrate 12 Glass base material 14 Silicone resin layer 16 Laminated body 18 Polyimide film 20 Member for electronic device 22 Laminated body with member for electronic device 24 Electronic device 26 Glass base material with silicone resin layer

Claims (7)

a glass base material having a first surface and a second surface opposite to the first surface;
a silicone resin layer disposed on the second surface of the glass base material,
The variation in surface roughness Ra of the surface of the silicone resin layer opposite to the glass substrate is 1.00 nm or less,
A laminated substrate, wherein the silicone resin layer has a thickness variation of 1.5 μm or less. The laminated substrate according to claim 1, wherein the silicone resin layer has an average thickness of 50.0 μm or less. The laminated substrate according to claim 1 or 2, wherein a removable protective film is disposed on the silicone resin layer. A laminate comprising the laminate substrate according to claim 1 or 2 and a polyimide film disposed on the silicone resin layer of the laminate substrate. A polyimide varnish containing polyimide or a precursor thereof and a solvent is applied onto the silicone resin layer of the multilayer substrate according to claim 1 or 2 to form a polyimide film on the silicone resin layer, and the glass base A method for producing a laminate, the method comprising: forming a laminate including a polyimide film, the silicone resin layer, and the polyimide film. The laminate according to claim 4,
A laminate with a member for an electronic device, comprising: a member for an electronic device disposed on the polyimide film in the laminate. A member forming step of forming an electronic device member on the polyimide film of the laminate according to claim 4 to obtain a laminate with an electronic device member;
A method for manufacturing an electronic device, comprising: a separation step of obtaining an electronic device having the polyimide film and the electronic device member from the laminate with the electronic device member.

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