WO2022203067A1

WO2022203067A1 - Curable resin composition and cured resin layer using same

Info

Publication number: WO2022203067A1
Application number: PCT/JP2022/014625
Authority: WO
Inventors: 博貴木下; 智史永縄
Original assignee: リンテック株式会社
Priority date: 2021-03-26
Filing date: 2022-03-25
Publication date: 2022-09-29
Also published as: JPWO2022203067A1; TW202307016A

Abstract

Provided are: a curable resin composition having low thermal shrinkage and excellent heat resistance; and a cured resin layer which is a cured product of said curable resin composition. The present invention provides a curable resin composition and a cured resin layer which is a cured product thereof, the curable resin composition containing a polymer component (A) and a curable monomer (B), wherein the polymer component (A) contains a polyimide resin, and the weight-average molecular weight of the polyimide resin is 100,000-230,000.

Description

Curable resin composition and cured resin layer using the same

The present invention relates to a curable resin composition and a cured resin layer using the same.

In recent years, various electronic devices, including display devices such as liquid crystal displays and organic electroluminescence (EL) displays, thermoelectric conversion elements, etc., have been configured to achieve thinness, weight reduction, flexibility, etc. As a member for supporting, it is being studied to use a thin transparent plastic film instead of a conventional rigid substrate such as glass or ceramics.
However, plastic films are generally inferior to glass in heat resistance. For example, when a transparent plastic film is used as a support substrate for the electronic device or the like, it often undergoes a heat history at high temperatures during the manufacturing process. At that time, mechanical damage or the like is received, which acts on the elements inside the electronic device, and causes problems such as the occurrence of a short circuit, which degrades the device performance and shortens the life of the device.
For example, Patent Literature 1 relating to a gas barrier laminate used for display devices and the like describes a cured product of a curable resin composition containing a polymer component (A) and a curable monomer (B) as a plastic film. An underlayer is disclosed which consists of:

WO2020/138206

However, although the use of a polyimide resin is described as the polymer component (A) contained in the curable resin composition constituting the underlayer in Patent Document 1, regarding thermal deformation due to heat history at high temperatures, polyimide It has not been sufficiently studied from the viewpoint of the weight average molecular weight of the resin.

In view of the above, an object of the present invention is to provide a curable resin composition having a low thermal shrinkage rate and excellent heat resistance, and a cured resin layer that is a cured product of the curable resin composition.

The present inventors have made intensive studies to solve the above problems, and as a result, the cured resin layer is composed of a polymer component (A) containing a polyimide resin having a specific weight average molecular weight and a curable monomer (B) The present inventors have found that the above problems can be solved by forming a layer made of a cured product of a curable resin composition containing and, and completed the present invention.
That is, the present invention provides the following [1] to [8].
[1] A curable resin composition containing a polymer component (A) and a curable monomer (B), wherein the polymer component (A) contains a polyimide resin, and the weight average molecular weight of the polyimide resin is 100,000 or more and 230,000 or less.
[2] The curable resin composition according to [1] above, wherein the polymer component (A) has a glass transition temperature of 250°C or higher.
[3] The curable resin composition according to [1] above, wherein the polyimide resin is soluble in methyl ethyl ketone.
[4] The curable resin composition according to [1] or [3] above, wherein the polyimide resin has a fluoro group in its molecule.
[5] A cured resin layer comprising a cured product of the curable resin composition according to any one of [1] to [4] above, wherein the cured resin layer has a thickness of 20 μm or less.
[6] The cured resin layer according to [5] above, wherein the cured resin layer has a thermal shrinkage of 0.08% or less when heat-treated at 100° C. for 2 minutes.
[7] The cured resin layer according to [6] above, wherein the in-plane retardation of the cured resin layer is 2.0 nm or less.
[8] A laminate comprising a functional layer on the cured resin layer according to any one of [5] to [7] above.

According to the present invention, it is possible to provide a curable resin composition having a low thermal shrinkage rate and excellent heat resistance, and a cured resin layer that is a cured product of the curable resin composition.

It is a sectional view showing an example of a cured resin layer of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram which shows an example of the laminated body using the cured resin layer of this invention.

In the present specification, the definition of being preferred can be arbitrarily selected, and it can be said that a combination of the definitions of being preferred is more preferred.
In this specification, the description "XX to YY" means "XX or more and YY or less".
In this specification, for preferred numerical ranges (for example, ranges of content etc.), the lower and upper limits described stepwise can be independently combined. For example, from the statement "preferably 10 to 90, more preferably 30 to 60", combining "preferred lower limit (10)" and "more preferred upper limit (60)" to "10 to 60" can also
In this specification, for example, "(meth)acrylic acid" indicates both "acrylic acid" and "methacrylic acid", and the same applies to other similar terms.

[Curable resin composition]
The curable resin composition of the present invention is a curable resin composition containing a polymer component (A) and a curable monomer (B), wherein the polymer component (A) contains a polyimide resin, The weight average molecular weight of the polyimide resin is 100,000 or more and 230,000 or less.
In the present invention, when the curable resin composition containing the polymer component (A) and the curable monomer (B) is made into a cured product, the residual shrinkage stress associated with the curing reaction of the monomer component The internal stress can be reduced by adjusting the weight average molecular weight of the polyimide resin in the polymer component (A) to 100,000 or more and 230,000 or less. As a result, in the cured resin layer, thermal deformation is further suppressed, leading to a reduction in thermal shrinkage.

<Polymer component (A)>
The curable resin composition of the present invention contains a polymer component (A) containing a polyimide resin. Polyimide resins have a high Tg and excellent heat resistance, and are readily soluble in general-purpose organic solvents while exhibiting good heat resistance.
In addition, by using a polyimide resin (amorphous thermoplastic resin) as the polymer component (A), it becomes easier to obtain a cured resin layer with excellent transparency. In addition, since it is easily soluble in an organic solvent as described above, a cured resin layer composed of a cured product of the curable resin composition can be efficiently formed by using a solution casting method, as described later.
Here, the amorphous thermoplastic resin means a thermoplastic resin whose melting point is not observed in differential scanning calorimetry.

The glass transition temperature of the polymer component (A) is preferably 250°C or higher, more preferably 290°C or higher, still more preferably 320°C or higher. By using the polymer component (A) having a Tg of 250°C or higher, it is possible to impart sufficient heat resistance to the cured resin layer. In this case, the cured resin layer is affected by heating (including solvent drying, etc.) during coating of the coating film, and deformation, etc., is suppressed, and as a result, the function that the functional layer of the laminate originally has is suppressed. can be fully demonstrated.
A coating film is a film obtained by coating a coating material on a base material or an object and, if necessary, performing a treatment such as drying or curing by heating. When the functional layer is a coating film, the coating material containing the component forming the functional layer described later is applied on the cured resin layer, and cured by either or both of drying, heating, irradiation of active energy rays, etc. It is a film obtained by processing.
Here, Tg is the maximum point of tan δ (loss modulus/storage modulus) obtained by viscoelasticity measurement (measurement in tensile mode in the range of 0 to 400° C. at a frequency of 10 Hz and a heating rate of 3° C./min). means temperature.

The weight average molecular weight (Mw) of the polyimide resin in the polymer component (A) is 100,000 or more and 230,000 or less. If the weight-average molecular weight (Mw) is less than 100,000, the mechanical strength is lowered, for example, the toughness tends to be lowered and the elongation at break is lowered. If it exceeds 230,000, the mobility of the molecular chains in the curing system will not be sufficiently high when the resin composition is naturally cooled after curing, so the shrinkage stress accompanying the curing reaction of the monomer component will increase. It becomes difficult to reduce the internal stress derived from Further, by using the polymer component (A) having a weight average molecular weight (Mw) of 100,000 or more, the molecular chains of the polymer component (A) are sufficiently entangled with each other, and the toughness of the cured resin layer can be ensured. can. It is preferably 100,000 or more and 220,000 or less, more preferably 100,000 or more and 210,000 or less, and still more preferably 100,000 or more and 200,000 or less. When the weight average molecular weight (Mw) is in this range, for example, when forming a functional layer or the like contained in a laminate described later from a coating film, before and after heating (including solvent drying etc.) during coating of the coating film The heat shrinkage of the cured resin layer is suppressed, and as a result, the original function of the functional layer of the laminate can be fully exhibited.
Also, the molecular weight distribution (Mw/Mn) is preferably in the range of 1.0 to 5.0, more preferably 1.2 to 3.0.
A weight average molecular weight (Mw) and a molecular weight distribution (Mw/Mn) are polystyrene equivalent values measured by a gel permeation chromatography (GPC) method.

The polyimide resin is not particularly limited as long as it does not impair the effects of the present invention. For example, aromatic polyimide resin, aromatic (carboxylic acid component) - cycloaliphatic (diamine component) polyimide resin, cyclic Group (carboxylic acid component)-aromatic (diamine component) polyimide resins, cycloaliphatic polyimide resins, fluorinated aromatic polyimide resins, and the like can be used. In particular, a polyimide resin having a fluoro group in its molecule, which will be described later, is preferred.
Specifically, a polyimide resin obtained by polymerization to polyamic acid and chemical imidization reaction using an aromatic diamine compound and a tetracarboxylic dianhydride is preferred.

The aromatic diamine compound is a polyimide that is soluble in a common solvent (for example, N,N-dimethylacetamide (DMAC)) and has a certain level of transparency by reacting with the tetracarboxylic dianhydride that is used together. Any aromatic diamine compound can be used as long as it provides the aromatic diamine compound. Specifically, m-phenylenediamine, p-phenylenediamine, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide, 3,4' -diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminobenzophenone, 3 , 3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(3-aminophenyl)propane, 2 -(3-aminophenyl)-2-(4-aminophenyl)propane, 2,2-bis(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 2,2- bis(3-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 2-(3-aminophenyl)-2-(4-aminophenyl)-1,1,1,3, 3,3-hexafluoropropane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(3-aminophenoxy)benzene, 1,4 -bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 3,3'-bis(4-aminophenoxy)biphenyl, 3,4'-bis(3-aminophenoxy) Biphenyl, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[3-(4-aminophenoxy)phenyl]sulfide, bis[4-(3-aminophenoxy)phenyl]sulfide, bis[3-(4 -aminophenoxy)phenyl]sulfide, bis[3-(3-aminophenoxy)phenyl]sulfide, bis[3-(4-aminophenoxy)phenyl]sulfone, bis[4-(4-aminophenyl)]sulfone, bis [3-(3-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenyl)]sulfone, bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(4-amino phenoxy)phenyl] ether, bis[3-(3-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)phenyl]methane, bis[4-(4-aminophenoxy)phenyl L]methane, bis[3-(3-aminophenoxy)phenyl]methane, bis[3-(4-aminophenoxy)phenyl]methane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[3-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy) Phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoro Propane, 2,2-bis[3-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[3-(4-aminophenoxy)phenyl ]-1,1,1,3,3,3-hexafluoropropane, 1,3-bis[4-(4-amino-6-trifluoromethylphenoxy)-α,α-dimethylbenzyl]benzene, 1, 3-bis[4-(4-amino-6-fluoromethylphenoxy)-α,α-dimethylbenzyl]benzene, 2,2′-dimethyl-4,4′-diaminobiphenyl, 3,3′-dimethyl-4 ,4'-diaminobiphenyl, 3,3'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and the like. .

These aromatic diamine compounds may be used alone, or two or more aromatic diamine compounds may be used. From the viewpoint of transparency and heat resistance, preferable aromatic diamine compounds include 2,2-bis(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 2,2 -bis(3-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 2-(3-aminophenyl)-2-(4-aminophenyl)-1,1,1,3 ,3,3-hexafluoropropane, 2,2-bis[4-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[4- (4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[3-(3-aminophenoxy)phenyl]-1,1,1,3, 3,3-hexafluoropropane, 2,2-bis[3-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 1,3-bis[4-( 4-amino-6-trifluoromethylphenoxy)-α,α-dimethylbenzyl]benzene, 3,3′-bis(trifluoromethyl)-4,4′-diaminobiphenyl, 2,2′-bis(trifluoro Examples include aromatic diamine compounds having a fluoro group such as methyl)-4,4'-diaminobiphenyl, and at least one of the aromatic diamine compounds used is preferably an aromatic diamine compound having a fluoro group, particularly 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl is preferred. By using an aromatic diamine compound having a fluoro group, it becomes easy to obtain transparency, heat resistance, and solubility in a solvent.

As the tetracarboxylic dianhydride, a tetracarboxylic acid that is soluble in a common solvent (eg, N,N-dimethylacetamide (DMAC)) and gives a polyimide having a predetermined transparency, like the aromatic diamine compound. Any dianhydride can be used, and specifically, 4,4′-(1,1,1,3,3,3-hexafluoropropane-2,2-diyl)diphthalic acid di anhydride, pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 1,4-hydroquinonedibenzoate-3,3',4,4'-tetracarboxylic acid Acid dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 3,3′,4,4′-diphenylethertetracarboxylic dianhydride and the like are exemplified. These tetracarboxylic dianhydrides may be used alone, or two or more kinds of tetracarboxylic dianhydrides may be used. 4,4′-(1,1,1,3,3,3-hexafluoropropane-2,2-diyl)diphthalic dianhydride and the like from the viewpoint of transparency, heat resistance and solubility in solvents , preferably a tetracarboxylic dianhydride having at least one fluoro group.

Polymerization into polyamic acid can be carried out by reacting the above aromatic diamine compound and tetracarboxylic dianhydride while dissolving in a solvent in which the resulting polyamic acid is soluble. Solvents used for polymerization to polyamic acid include solvents such as N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, and dimethylsulfoxide. can be used.

The polymerization reaction to polyamic acid is preferably carried out while stirring in a reaction vessel equipped with a stirring device. For example, a method of dissolving a predetermined amount of an aromatic diamine compound in the above solvent, adding tetracarboxylic dianhydride while stirring to react, and obtaining polyamic acid, dissolving the tetracarboxylic dianhydride in the solvent. A method of obtaining polyamic acid by adding an aromatic diamine compound while stirring and reacting, a method of obtaining polyamic acid by alternately adding an aromatic diamine compound and a tetracarboxylic dianhydride and reacting them, etc. is mentioned.

The temperature of the polymerization reaction to polyamic acid is not particularly limited, but it is preferably carried out at a temperature of 0 to 70°C, more preferably 10 to 60°C, and even more preferably 20 to 50°C. By performing the polymerization reaction within the above range, it is possible to obtain a high-molecular-weight polyamic acid with little coloration and excellent transparency.

In addition, the aromatic diamine compound and the tetracarboxylic dianhydride used for polymerization into polyamic acid are generally used in equimolar amounts. It is also possible to change the molar amount of the compound/the molar amount (molar ratio) of the aromatic diamine compound within the range of 0.95 to 1.05. The molar ratio of the tetracarboxylic dianhydride and the aromatic diamine compound is preferably in the range of 1.001-1.02, more preferably 1.001-1.01. By making the tetracarboxylic dianhydride slightly excessive relative to the aromatic diamine compound in this way, the degree of polymerization of the resulting polyamic acid can be stabilized, and the unit derived from the tetracarboxylic dianhydride can be It can be placed at the end of the polymer, and as a result, it is possible to obtain a polyimide with little coloration and excellent transparency.

The concentration of the polyamic acid solution to be produced is preferably adjusted to an appropriate concentration (for example, about 10 to 30% by mass) so that the viscosity of the solution can be properly maintained and handling in the subsequent steps can be facilitated.

An imidizing agent is added to the resulting polyamic acid solution to carry out a chemical imidization reaction. As the imidizing agent, carboxylic acid anhydrides such as acetic anhydride, propionic anhydride, succinic anhydride, phthalic anhydride, and benzoic anhydride can be used. Preference is given to using acetic acid. The equivalent of the imidizing agent to be used is at least the equivalent of the amide bond of the polyamic acid that performs the chemical imidization reaction, preferably 1.1 to 5 times the equivalent of the amide bond, and 1.5 to 4 times. is more preferable. By using the imidizing agent in a slightly excess amount with respect to the amide bond in this way, the imidization reaction can be efficiently carried out even at a relatively low temperature.

For the chemical imidization reaction, aliphatic, aromatic or heterocyclic tertiary amines such as pyridine, picoline, quinoline, isoquinoline, trimethylamine and triethylamine can be used as imidization accelerators. By using such amines, the imidization reaction can be efficiently carried out at a low temperature, and as a result, it becomes possible to suppress coloring during the imidization reaction, making it easier to obtain a more transparent polyimide.

Although there are no particular restrictions on the chemical imidization reaction temperature, it is preferably carried out at 10°C or higher and lower than 50°C, more preferably at 15°C or higher and lower than 45°C. By performing the chemical imidization reaction at a temperature of 10° C. or more and less than 50° C., coloration during the imidization reaction can be suppressed, and a polyimide having excellent transparency can be obtained.

After that, if necessary, a poor solvent for polyimide is added to the polyimide solution obtained by the chemical imidization reaction to precipitate polyimide to form powder, which is powderization and drying.

The polyimide resin is preferably soluble in low-boiling organic solvents such as benzene and methyl ethyl ketone. In particular, it is preferably soluble in methyl ethyl ketone. When it is soluble in methyl ethyl ketone, it is possible to easily form a curable resin layer, which will be described later, comprising a cured product of the curable resin composition by coating and drying.

A polyimide resin containing a fluoro group is particularly preferable from the viewpoint that it is easily dissolved in a general-purpose organic solvent having a low boiling point such as methyl ethyl ketone and that a curable resin layer is easily formed by a coating method.
The polyimide resin having a fluoro group is preferably an aromatic polyimide resin having a fluoro group in the molecule, and preferably has a skeleton represented by the following chemical formula in the molecule.

A polyimide resin having a skeleton represented by the above chemical formula has an extremely high Tg exceeding 300°C due to the high rigidity of the skeleton. Therefore, the heat resistance of the cured resin layer can be greatly improved. In addition, the skeleton is linear and has relatively high flexibility, which facilitates increasing the breaking elongation of the curable resin layer. Furthermore, the polyimide resin having the above skeleton can dissolve in general-purpose low-boiling organic solvents such as methyl ethyl ketone due to the presence of fluoro groups. Therefore, the coating can be performed using a solution casting method to form a curable resin layer as a coating film, and the solvent can be easily removed by drying. The polyimide resin having a skeleton represented by the above chemical formula includes 2,2′-bis(trifluoromethyl)-4,4′-diaminobiphenyl and 4,4′-(1,1,1,3,3,3 -Hexafluoropropane-2,2-diyl)diphthalic dianhydride can be obtained by polymerization and imidization reaction of the polyamic acid described above.

The polymer component (A) may further contain other components.
A polyarylate resin is a resin composed of a polymer compound obtained by reacting an aromatic diol with an aromatic dicarboxylic acid or a chloride thereof. The polyarylate resin also has a relatively high Tg, similarly to the polyimide resin, and has relatively good elongation properties. The polyarylate resin is not particularly limited, and known ones can be used.

Examples of aromatic diols include bis(4-hydroxyphenyl)methane [bisphenol F], bis(3-methyl-4-hydroxyphenyl)methane, 1,1-bis(4′-hydroxyphenyl)ethane, 1, 1-bis(3'-methyl-4'-hydroxyphenyl)ethane, 2,2-bis(4'-hydroxyphenyl)propane [bisphenol A], 2,2-bis(3'-methyl-4'-hydroxy bis(hydroxyphenyl)alkanes such as phenyl)propane, 2,2-bis(4'-hydroxyphenyl)butane, 2,2-bis(4'-hydroxyphenyl)octane; 1,1-bis(4'- bis(hydroxyphenyl)cyclopentane, 1,1-bis(4'-hydroxyphenyl)cyclohexane [bisphenol Z], 1,1-bis(4'-hydroxyphenyl)-3,3,5-trimethylcyclohexane, etc. phenyl)cycloalkanes; bis(4-hydroxyphenyl)phenylmethane, bis(3-methyl-4-hydroxyphenyl)phenylmethane, bis(2,6-dimethyl-4-hydroxyphenyl)phenylmethane, bis(2, 3,6-trimethyl-4-hydroxyphenyl)phenylmethane, bis(3-t-butyl-4-hydroxyphenyl)phenylmethane, bis(3-phenyl-4-hydroxyphenyl)phenylmethane, bis(3-fluoro- 4-hydroxyphenyl)phenylmethane, bis(3-bromo-4-hydroxyphenyl)phenylmethane, bis(4-hydroxyphenyl)-4-fluorophenylmethane, bis(3-fluoro-4-hydroxyphenyl)-4- Fluorophenylmethane, bis(4-hydroxyphenyl)-4-chlorophenylmethane, bis(4-hydroxyphenyl)-4-bromophenylmethane, bis(3,5-dimethyl-4-hydroxyphenyl)-4-fluorophenylmethane , 1,1-bis(4′-hydroxyphenyl)-1-phenylethane [bisphenol P], 1,1-bis(3′-methyl-4′-hydroxyphenyl)-1-phenylethane, 1,1- Bis(3′-t-butyl-4′-hydroxyphenyl)-1-phenylethane, 1,1-bis(3′-phenyl-4′-hydroxyphenyl)-1-phenylethane, 1,1-bis( 4′-hydroxyphenyl)-1-(4′-nitrophenyl)ethane, 1,1-bis(3′ -bromo-4′-hydroxyphenyl)-1-phenylethane, 1,1-bis(4′-hydroxyphenyl)-1-phenylpropane, bis(4-hydroxyphenyl)diphenylmethane, bis(4-hydroxyphenyl)di bis(hydroxyphenyl)phenylalkanes such as benzylmethane; bis(hydroxyphenyl)ethers such as bis(4-hydroxyphenyl)ether and bis(3-methyl-4-hydroxyphenyl)ether; bis(4-hydroxyphenyl) ) ketones, bis (hydroxyphenyl) ketones such as bis (3-methyl-4-hydroxyphenyl) ketone; bis (4-hydroxyphenyl) sulfide, bis (3-methyl-4-hydroxyphenyl) sulfide and other bis ( hydroxyphenyl) sulfides; bis(4-hydroxyphenyl) sulfoxide, bis(3-methyl-4-hydroxyphenyl) sulfoxide and other bis(hydroxyphenyl) sulfoxides; bis(4-hydroxyphenyl) sulfone [bisphenol S], Bis(hydroxyphenyl)sulfones such as bis(3-methyl-4-hydroxyphenyl)sulfone; 9,9-bis(4′-hydroxyphenyl)fluorene, 9,9-bis(3′-methyl-4′- bis(hydroxyphenyl)fluorenes such as hydroxyphenyl)fluorene;

Examples of aromatic dicarboxylic acids or chlorides thereof include phthalic acid, isophthalic acid, terephthalic acid, 4,4′-biphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid, diphenyl ether 4,4′-dicarboxylic acid, 4,4′- diphenylsulfonedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, chlorides thereof, and the like. Further, the polyarylate-based resin to be used may be a modified polyarylate-based resin. Among these, the polyarylate-based resin is preferably a resin composed of a polymer compound obtained by reacting 2,2-bis(4'-hydroxyphenyl)propane with isophthalic acid.

The polymer component (A) can be used singly or in combination of two or more. Also, the polymer component (A) and the polymer component (A') having a glass transition temperature of less than 250°C may be used in combination. Examples of the polymer component (A′) include polyamide resins and polyarylate resins having a Tg of less than 250° C. Polyamide resins are preferred.

As the polyamide resin, one that is soluble in an organic solvent is preferable, and a rubber-modified polyamide resin is preferable. As the rubber-modified polyamide resin, for example, those described in JP-A-2004-035638 can be used.

As the polymer component (A) and the polymer component (A'), one using a single type of polyimide resin, one using a plurality of different types of polyimide resin, and polyimide resin with polyamide resin and polyarylate resin It is preferable to add at least one of them from the viewpoint of adjusting the elongation characteristics and the viewpoint of solvent resistance.

When adding a polyamide resin or a polyarylate resin having a Tg of less than 250 ° C. to the polyimide resin, the amount of the resin to be added is 100 parts by mass of the polyimide resin from the viewpoint of imparting moderate flexibility while maintaining a high Tg. , preferably 100 parts by mass or less, more preferably 70 parts by mass or less, even more preferably 50 parts by mass or less, still more preferably 30 parts by mass or less, and preferably 1 part by mass or more, more preferably It is 3 parts by mass or more.

<Curable monomer (B)>
The curable resin composition of the present invention contains a curable monomer (B).
A curable monomer (B) is a monomer having a polymerizable unsaturated bond, and is a monomer that can participate in a polymerization reaction or a polymerization reaction and a cross-linking reaction. In this specification, the term "curing" means a broad concept including this "polymerization reaction of monomers" or "polymerization reaction of monomers and subsequent cross-linking reaction of polymers".

The molecular weight of the curable monomer (B) is generally 3,000 or less, preferably 150-2,000, more preferably 150-1,000.
The number of polymerizable unsaturated bonds in the curable monomer (B) is not particularly limited. The curable monomer (B) is a monofunctional monomer having one polymerizable unsaturated bond, or a multifunctional monomer such as a bifunctional or trifunctional monomer having a plurality of polymerizable unsaturated bonds. There may be.

Examples of the monofunctional monomers include monofunctional (meth)acrylic acid derivatives.
The monofunctional (meth)acrylic acid derivative is not particularly limited, and known compounds can be used. Examples include monofunctional (meth)acrylic acid derivatives having a nitrogen atom, monofunctional (meth)acrylic acid derivatives having an alicyclic structure, and monofunctional (meth)acrylic acid derivatives having a polyether structure. .

Examples of monofunctional (meth)acrylic acid derivatives having a nitrogen atom include compounds represented by the following formula.

In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R ² and R ³ each independently represent a hydrogen atom or an organic group having 1 to 12 carbon atoms, and R ² and R ³ may combine to form a ring structure, and R ⁴ represents a divalent organic group.
Examples of the alkyl group having 1 to 6 carbon atoms represented by R ¹ include a methyl group, an ethyl group, a propyl group and the like, and a methyl group is preferred.
Examples of organic groups having 1 to 12 carbon atoms represented by R ² and R ³ include alkyl groups having 1 to 12 carbon atoms such as methyl group, ethyl group and propyl group; cycloalkyl groups having 3 to 12 carbon atoms; aromatic groups having 6 to 12 carbon atoms such as phenyl, biphenyl and naphthyl groups; These groups may have a substituent at any position. Also, R ² and R ³ may combine to form a ring, and the ring may further have a nitrogen atom or an oxygen atom in its skeleton.
Divalent organic groups represented by R ⁴ include groups represented by -(CH ₂ ) _m - and -NH-(CH ₂ ) _m -. Here, m is an integer of 1-10.

Among these, the (meth)acryloylmorpholine represented by the following formula is preferred as the monofunctional (meth)acrylic acid derivative having a nitrogen atom.

By using a monofunctional (meth)acrylic acid derivative having a nitrogen atom as the curable monomer (B), a cured resin layer with more excellent heat resistance can be formed.

Examples of monofunctional (meth)acrylic acid derivatives having an alicyclic structure include compounds represented by the following formulas.

In the formula, R ¹ has the same meaning as above, and R ⁵ is a group having an alicyclic structure.
The group having an alicyclic structure represented by R ⁵ includes cyclohexyl group, isobornyl group, 1-adamantyl group, 2-adamantyl group, tricyclodecanyl group and the like.

Specific examples of monofunctional (meth)acrylic acid derivatives having an alicyclic structure include isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, 1-adamantyl (meth)acrylate, 2-adamantyl (meth)acrylate and the like. mentioned.

By using a monofunctional (meth)acrylic acid derivative having an alicyclic structure as the curable monomer (B), a cured resin layer with more excellent optical properties can be formed.

The monofunctional (meth)acrylic acid derivative having a polyether structure includes compounds represented by the following formula.

In the formula, R ¹ has the same meaning as above, and R ⁶ represents an organic group having 1 to 12 carbon atoms. Examples of the organic group having 1 to 12 carbon atoms represented by R ⁶ include alkyl groups having 1 to 12 carbon atoms such as methyl group, ethyl group and propyl group; A cycloalkyl group; an aromatic group having 6 to 12 carbon atoms such as a phenyl group, a biphenyl group and a naphthyl group; j represents an integer from 2 to 20;

Specific examples of monofunctional (meth)acrylic acid derivatives having a polyether structure include ethoxylated o-phenylphenol (meth)acrylate, methoxypolyethyleneglycol (meth)acrylate, phenoxypolyethyleneglycol (meth)acrylate, and the like. .

By using a monofunctional (meth)acrylic acid derivative having a polyether structure as the curable monomer (B), a cured fat layer with excellent toughness can be formed.

Examples of the polyfunctional monomers include polyfunctional (meth)acrylic acid derivatives.
The polyfunctional (meth)acrylic acid derivative is not particularly limited, and known compounds can be used. Examples thereof include di- to hexa-functional (meth)acrylic acid derivatives.
Bifunctional (meth)acrylic acid derivatives include compounds represented by the following formulas.

In the formula, R ¹ has the same meaning as above, and R ⁷ represents a divalent organic group. Examples of the divalent organic group represented by R ⁷ include groups represented by the following formulae.

(Wherein, s represents an integer of 1 to 20, t represents an integer of 1 to 30, u and v each independently represent an integer of 1 to 30, and "-" at both ends is represents a bond.)

Specific examples of the bifunctional (meth)acrylic acid derivative represented by the above formula include tricyclodecanedimethanol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propoxylated ethoxylated bisphenol A di(meth)acrylate. , ethoxylated bisphenol A di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 9,9-bis[4-(2-acryloyloxyethoxy) phenyl]fluorene and the like. Among these, from the viewpoint of heat resistance and toughness, in the above formula, such as tricyclodecanedimethanol di(meth)acrylate, those in which the divalent organic group represented by ^R7 has a tricyclodecane skeleton, propoxy In the above formula, such as ethoxylated bisphenol A di(meth)acrylate and ethoxylated bisphenol A di(meth)acrylate, the divalent organic group represented by ^R7 has a bisphenol skeleton, 9,9-bis [4-(2-Acryloyloxyethoxy)phenyl]fluorene, etc., in which the divalent organic group represented by R ⁷ in the above formula preferably has a 9,9-bisphenylfluorene skeleton.

Further, bifunctional (meth)acrylic acid derivatives other than these include neopentyl glycol adipate di(meth)acrylate, neopentylglycol hydroxypivalate di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, Ethylene oxide-modified phosphoric acid di(meth)acrylate, di(acryloxyethyl)isocyanurate, allylated cyclohexyl di(meth)acrylate and the like can be mentioned.

Trifunctional (meth)acrylic acid derivatives include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propionic acid-modified dipentaerythritol tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate. ) acrylate, tris(acryloxyethyl) isocyanurate, and the like.
Examples of tetrafunctional (meth)acrylic acid derivatives include pentaerythritol tetra(meth)acrylate.
Pentafunctional (meth)acrylic acid derivatives include propionic acid-modified dipentaerythritol penta(meth)acrylate.
Examples of hexafunctional (meth)acrylic acid derivatives include dipentaerythritol hexa(meth)acrylate and caprolactone-modified dipentaerythritol hexa(meth)acrylate.

A cyclization-polymerizable monomer may be used as the curable monomer (B). A cyclization-polymerizable monomer is a monomer that has the property of being radically polymerized while being cyclized. Cyclopolymerizable monomers include non-conjugated dienes, for example, α-allyloxymethyl acrylic acid-based monomers can be used, 2-allyloxymethyl acrylic acid alkyl esters having 1 to 4 carbon atoms, Cyclohexyl 2-(allyloxymethyl)acrylate is preferred, C 1-4 alkyl esters of 2-allyloxymethylacrylic acid are more preferred, and methyl 2-(allyloxymethyl)acrylate is even more preferred.
In addition, dimethyl-2,2'-[oxybis(methylene)]bis-2-propenoate, diethyl-2,2'-[oxybis(methylene)]bis-2-propenoate, di(n-propyl)-2,2 '-[oxybis(methylene)]bis-2-propenoate, di(i-propyl)-2,2'-[oxybis(methylene)]bis-2-propenoate, di(n-butyl)-2,2'- [oxybis(methylene)]bis-2-propenoate, di(n-hexyl)-2,2'-[oxybis(methylene)]bis-2-propenoate, dicyclohexyl-2,2'-[oxybis(methylene)]bis Cyclopolymerizable monomers such as -2-propenoate can also be used.

The curable monomer (B) can be used singly or in combination of two or more.
Among these, the curable monomer (B) is preferably a polyfunctional monomer because a cured resin layer having excellent heat resistance and solvent resistance can be obtained. As the polyfunctional monomer, a bifunctional (meth)acrylic acid derivative is preferable from the viewpoints that it is easily mixed with the polymer component (A) and that curing shrinkage of the polymer hardly occurs and curling of the cured product can be suppressed. .
More preferably, the curable monomer (B) contains a polyfunctional (meth)acrylate compound and a cyclopolymerizable monomer. By using these together, it becomes easy to adjust the breaking elongation of the cured resin layer while appropriately adjusting the heat resistance of the cured resin layer.
When the curable monomer (B) contains a polyfunctional monomer, the content thereof is preferably 40% by mass or more in the total amount of the curable monomer (B), and 50 to 100% by mass. more preferred.

The curable resin composition of the present invention is prepared by mixing the polymer component (A), the curable monomer (B), and optionally the polymerization initiator and other components described later, and dissolving or dispersing them in an appropriate solvent. It can be prepared by

The total content of the polymer component (A) and the curable monomer (B) in the curable resin composition is preferably 40 to 99 with respect to the total mass of the curable resin composition excluding the solvent. .5% by mass, more preferably 60 to 99% by mass, still more preferably 80 to 98% by mass.

The content of the polymer component (A) and the curable monomer (B) in the curable resin composition is preferably the mass ratio of the polymer component (A) and the curable monomer (B) is polymer component (A):curable monomer (B)=20:80 to 90:10, more preferably 30:70 to 70:30.
In the curable resin composition, when the mass ratio of the polymer component (A) to the curable monomer (B) is within this range, the thermal shrinkage rate of the cured resin layer before and after heat treatment at a high temperature tends to decrease. , the elongation at break is easily maintained.
Further, the content of the polyimide resin in the polymer component (A) is preferably 70 to 100% by mass, more preferably 80 to 100% by mass, based on the total mass of the polymer component (A) excluding the solvent. , more preferably 95 to 100% by mass.

As the polymer component (A), when using a combination of a plurality of resins with different solvent solubility, such as a combination of the polyimide resin described above and a polyamide resin or a polyarylate resin, first, the resin is added to a solvent suitable for each. After dissolving, it is preferable to add a solution in which another resin is dissolved to the low boiling point organic solvent in which the resin is dissolved.

The curable resin composition can optionally contain a polymerization initiator. Any polymerization initiator can be used without particular limitation as long as it initiates the curing reaction. Examples thereof include thermal polymerization initiators and photopolymerization initiators.

Thermal polymerization initiators include organic peroxides and azo compounds.
Examples of organic peroxides include dialkyl peroxides such as di-t-butyl peroxide, t-butylcumyl peroxide and dicumyl peroxide; diacyl peroxides such as acetyl peroxide, lauroyl peroxide and benzoyl peroxide. ; ketone peroxides such as methyl ethyl ketone peroxide, cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone peroxide and methyl cyclohexanone peroxide; peroxyketals such as 1,1-bis(t-butylperoxy)cyclohexane ; t-butyl hydroperoxide, cumene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2, Hydroperoxides such as 5-dihydroperoxide; esters; and the like.
Azo compounds include 2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis(2-cyclopropylpropionitrile), 2,2′-azobis(2 ,4-dimethylvaleronitrile), azobisisobutyronitrile, 2,2′-azobis(2-methylbutyronitrile), 1,1′-azobis(cyclohexane-1-carbonitrile), 2-(carbamoylazo ) isobutyronitrile, 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile and the like.

Photoinitiators include 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxy-cyclohexyl-phenylketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one , 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-[4-[4-(2-hydroxy-2 -methyl-propionyl)-benzyl]phenyl]-2-methyl-propan-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethyl Amino-1-(4-morpholinophenyl)-butanone-1,2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone Alkylphenone-based photopolymerization initiators such as; -Phosphorus-based photoinitiators such as phenylphosphinate and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide; bis(η ⁵ -2,4-cyclopentadien-1-yl) )-Bis[2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl]titanium titanocene-based photopolymerization initiator; 1,2-octanedione-1-[4-(phenylthio)- 2-(O-benzoyloxime)], ethanone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime) and other oxime esters Photopolymerization initiator; benzophenone, p-chlorobenzophenone, benzoylbenzoic acid, o-methylbenzoylbenzoate, 4-methylbenzophenone, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4'-methyl-diphenyl benzophenones such as sulfide, 3,3′-dimethyl-4-methoxybenzophenone, 2,4,6-trimethylbenzophenone, 4-(13-acryloyl-1,4,7,10,13-pentoxatridecyl)-benzophenone Photopolymerization initiator; thioxanthone, 2-chlorothioxanthone, 3-methylthioxanthone, 2,4-dimethylthioxanthone thioxanthone-based photopolymerization initiators such as tilthioxanthone, 2,4-diisopropylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, and 4-isopropylthioxanthone; are mentioned.

Among the above photoinitiators, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, ethyl(2,4,6-trimethylbenzoyl)- Phosphorus-based photopolymerization initiators such as phenylphosphinate and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide are preferred.
When the polymer component (A) is a thermoplastic resin having an aromatic ring such as the polyimide resin used in the present invention, the polymer component (A) absorbs ultraviolet rays, and as a result, the curing reaction may be difficult to occur. However, by using the above phosphorus-based photopolymerization initiator, it is possible to efficiently proceed the curing reaction using light of a wavelength that is not absorbed by the polymer component (A).
A polymerization initiator can be used individually by 1 type or in combination of 2 or more types.

The content of the polymerization initiator is preferably 0.05 to 15% by mass, more preferably 0.05 to 10% by mass, and still more preferably 0.05 to 5% by mass, relative to the entire curable resin composition.

In addition, the curable resin composition contains a polymer component (A), a curable monomer (B), and a polymerization initiator, as well as triisopropanolamine and photopolymerization such as 4,4′-diethylaminobenzophenone. It may contain an initiation aid.

The solvent used for preparing the curable resin composition is not particularly limited, and examples thereof include aliphatic hydrocarbon solvents such as n-hexane and n-heptane; aromatic hydrocarbon solvents such as toluene and xylene; and dichloromethane. , ethylene chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane, monochlorobenzene and other halogenated hydrocarbon solvents; methanol, ethanol, propanol, butanol, propylene glycol monomethyl ether and other alcohol solvents; acetone, methyl ethyl ketone, 2 - ketone solvents such as pentanone, isophorone and cyclohexanone; ester solvents such as ethyl acetate and butyl acetate; cellosolve solvents such as ethyl cellosolve; ether solvents such as 1,3-dioxolane;

The content of the solvent in the curable resin composition is not particularly limited, but is usually 0.1 to 1,000 g, preferably 1 to 100 g, per 1 g of polymer component (A). By appropriately adjusting the amount of the solvent, the viscosity of the curable resin composition can be appropriately adjusted.

In addition, the curable resin composition may further contain known additives such as plasticizers, antioxidants, and ultraviolet absorbers within a range that does not impair the objects and effects of the present invention.

<Cured resin layer>
The cured resin layer consists of a cured product of a curable resin composition containing a polymer component (A) containing a polyimide resin and a curable monomer (B).
FIG. 1 is a cross-sectional view showing an example of the cured resin layer of the present invention. The cured resin layer 1 may be a single layer or multiple layers.
The method for forming the cured resin layer will be described in detail in the method for manufacturing a laminate, which will be described later.

The cured resin layer of the present invention exhibits heat shrinkability (shrinks when heated). The thermal shrinkage rate when heat-treated at 100° C. for 2 minutes is preferably 0.08% or less, more preferably 0.05% or less, and still more preferably 0.01% or less. When the heat shrinkage of the cured resin layer is within this range, the cured resin layer has high heat resistance. Therefore, for example, as described above, a functional layer, which will be described later, is formed on the cured resin layer by coating and heat drying. When a manufacturing process involving heating is performed after forming a cured resin layer, such as a laminate, heat shrinkage is suppressed, and mechanical deformation (e.g., warpage, peeling, wrinkles, etc.) of the functional layer is less likely to occur. The predetermined function inherent in the functional layer can be exhibited sufficiently.
The thermal shrinkage rate was measured by the method described in Examples described later.

The breaking elongation of the cured resin layer is preferably 2.5% or more, more preferably 3.0% or more, and still more preferably 3.5% or more. When the breaking elongation of the cured resin layer is in this range, for example, if it is 2.5% or more, it becomes easy to adjust the breaking elongation of the laminate to about 2% or more, resulting in excellent flexibility. A laminated body is easily obtained. The breaking elongation was measured by the method described in Examples described later.

The in-plane retardation of the cured resin layer is preferably 2 nm or less, preferably 1.5 nm or less, more preferably 1.0 nm or less, even more preferably 0.5 nm or less, and even more preferably 0.3 nm or less. be. The retardation in the thickness direction is usually −500 nm or less, preferably −450 nm or less. Further, the value (birefringence) obtained by dividing the in-plane retardation by the thickness of the cured resin layer is usually 100×10 ⁻⁵ or less, preferably 20×10 ⁻⁵ or less.
If the in-plane retardation, the thickness direction retardation, and the birefringence of the cured resin layer are within the above ranges, the cured resin layer is excellent in optical isotropy and can be preferably used as a member for optical applications.
The in-plane retardation was measured by the method described in Examples described later.

The thickness of the cured resin layer is not particularly limited, and may be appropriately adjusted, for example, according to the purpose of the laminate having a functional layer, which will be described later. The thickness of the cured resin layer is usually 50 μm or less, preferably 20 μm or less, more preferably 0.1 to 20 μm, even more preferably 0.1 to 15 μm, particularly preferably 0.2 to 10 μm.
When the thickness of the cured resin layer is within this range, it is possible to prevent the thickness of the laminate to be described later from becoming large, and it is possible to obtain a thin laminate. A thin laminate is preferable because the laminate does not cause an increase in the thickness of the entire applicable device in applications such as devices that require thinner devices. Furthermore, the amount of stretching strain of the outermost layer can be reduced when the laminate is bent, and the flexibility of the laminate can be improved. Moreover, if the laminate is thin, flexibility after mounting of the laminate can be secured.

The cured resin layer of the present invention is excellent in solvent resistance. Because of its excellent solvent resistance, even when an organic solvent is used to form another layer on the surface of the cured resin layer, the surface of the cured resin layer is hardly dissolved. Therefore, for example, even when the functional layer is formed on the surface of the cured resin layer using a resin solution containing an organic solvent, the components of the cured resin layer are less likely to penetrate into the functional layer. is difficult to decrease.
From the above viewpoint, the gel fraction of the cured resin layer is preferably 80% or higher, more preferably 85% or higher, even more preferably 87% or higher, and particularly preferably 90% or higher. A cured resin layer having a gel fraction of 80% or more has excellent solvent resistance. It is possible to easily obtain a laminate having a surface that hardly dissolves and having excellent solvent resistance.
Here, for example, the gel fraction is obtained by performing the following operations (a), (b), and (c), and comparing the weight of the measured structure after drying to the structure before immersion in MEK (methyl ethyl ketone) solvent Calculated by dividing by body weight.
(a) The cured resin layer was wrapped with a mesh (α_UX SCREEN 150-035/380TW manufactured by NBC Meshtec) and stapled to form a structure, and the weight of the structure was measured. (b) Methyl ethyl ketone (MEK) solvent was added. After the composition is immersed in the filled bottle, it is sealed and left at 25°C for 36 hours. (c) The composition is removed from the solvent, dried at 100°C for 60 minutes, and the weight of the composition after drying is measured.

(Laminate)
As one aspect of the present invention, it is preferable to provide a functional layer on the cured resin layer.
FIG. 2 is a schematic cross-sectional view showing an example of a laminate using the cured resin layer of the present invention. In FIG. 2, a laminate 11 is, for example, a laminate of a functional layer 2 on a cured resin layer 1, and the cured resin layer 1 can be used as a layer or a substrate on which the functional layer 2 is provided.
Moreover, as another aspect of the present invention, the laminate may include a process film, a cured resin layer, and a functional layer in this order. When the laminate is actually used, the process film is peeled off from the laminate, and the laminate is attached to an electronic device such as a predetermined display.
Since the cured resin layer of the present invention has a low thermal shrinkage rate at high temperatures and is excellent in heat resistance, it is more preferably used in a manufacturing process or the like having a heat treatment step at high temperatures.

The functional layer is not particularly limited, but includes, for example, a conductive layer, an adhesive layer, an adhesive layer, an adhesive layer, a gas barrier layer, an impact absorption layer, a hard coat layer, an antireflection layer, and the like. In addition, the arrangement position of the functional layer is not particularly limited.

For example, materials constituting the conductive layer (electrode, transparent conductive layer, etc.) used as the functional layer include metals, alloys, metal oxides, electrically conductive compounds, mixtures thereof, and the like. In transparent conductive layers, for example, antimony-doped tin oxide (ATO); fluorine-doped tin oxide (FTO); tin oxide, germanium-doped zinc oxide (GZO), zinc oxide, indium oxide, indium tin oxide ( ITO), semi-conductive metal oxides such as indium zinc oxide (IZO); metals such as gold, silver, chromium, nickel; mixtures of these metals and conductive metal oxides; inorganic materials such as copper iodide and copper sulfide conductive substances; organic conductive materials such as polyaniline, polythiophene, and polypyrrole; and the like.
Methods for forming the conductive layer include, for example, a printing method, a vapor deposition method, a sputtering method, an ion plating method, a thermal CVD method, a plasma CVD method, and the like.
The thickness of the conductor layer may be appropriately selected according to its use. It is usually 10 nm to 50 μm, preferably 20 nm to 20 μm.

The adhesive layer is a layer used, for example, when attaching the laminate to an adherend or the like. The material for forming the adhesive layer is not particularly limited, and known adhesives or adhesives such as acrylic, silicone, rubber, epoxy, etc., heat sealing materials, etc. can also be used. Epoxy-based adhesive is preferable as the material constituting the .
Similarly, the pressure-sensitive adhesive layer is a layer used, for example, when attaching the laminate to an adherend or the like. Examples of adhesives used for the adhesive layer include acrylic adhesives, urethane adhesives, silicone adhesives, rubber adhesives, and the like. Among these, acrylic pressure-sensitive adhesives and urethane-based pressure-sensitive adhesives are preferred from the viewpoints of adhesive strength, transparency, and handleability. Also, a pressure-sensitive adhesive capable of forming a crosslinked structure is preferred. The adhesive may be in any form such as a solvent-type adhesive, an emulsion-type adhesive, a hot-melt-type adhesive, or the like.

The thickness of the laminate can be determined as appropriate depending on the intended use, such as an adherend or an electronic device. A substantial thickness of the laminate is preferably 0.3 to 50 μm, more preferably 0.5 to 25 μm, and more preferably 0.7 to 12 μm from the viewpoint of handleability.
In addition, "substantial thickness" means the thickness in the state of use. That is, the laminate may have a process film, etc. as described above, but the thickness of the portion (process film, etc.) that is removed during use is not included in the "substantial thickness". do not have.

(Laminate manufacturing method)
The laminate of the present invention can be produced using a process film as one aspect. By using the process film, the laminate can be produced efficiently and easily.

The method for producing a laminate of the present invention includes the following (Step 1) to (Step 3).
(Step 1): A step of forming a curable resin layer (coating film) on a process film using a curable resin composition containing a polymer component (A) and a curable monomer (B) (step 2): Step of curing the curable resin layer (coating film) obtained in step 1 to form a cured resin layer (step 3): Forming a functional layer on the cured resin layer obtained in step 2 process

The method of applying the curable resin composition onto the process film is not particularly limited, and may be spin coating, spray coating, bar coating, knife coating, roll coating, blade coating, die coating, or gravure coating. A known coating method such as a method can be used.

The method for drying the obtained coating film is not particularly limited, and conventionally known drying methods such as hot air drying, hot roll drying, and infrared irradiation can be used.
The drying temperature of the coating film is usually 30 to 150°C, preferably 50 to 130°C.

The curable resin layer (coating film) obtained in step 1 is cured to form a cured resin layer.
A method for curing the curable resin layer (coating film) is not particularly limited, and a known method can be employed. For example, when the curable resin layer (coating film) is formed using a curable resin composition containing a thermal polymerization initiator, the curable resin layer (coating film) is cured by heating. The resin layer (coating film) can be cured. The heating temperature is usually 30 to 150°C, preferably 50 to 130°C.
Further, when the curable resin layer (coating film) is formed using a curable resin composition containing a photopolymerization initiator, the curable resin layer (coating film) is irradiated with an active energy ray. Thus, the curable resin layer (coating film) can be cured. Active energy rays can be applied using a high-pressure mercury lamp, an electrodeless lamp, a xenon lamp, or the like.

The wavelength of the active energy ray is preferably 200-400 nm, more preferably 350-400 nm. The illuminance of the active energy rays is usually in the range of 50-1,000 mW/cm ² , preferably 100-600 mW/cm ² . The amount of active energy rays is in the range of 50 to 5,000 mJ/cm ² , preferably 300 to 4,000 mJ/cm ² . The irradiation time is usually 0.1 to 1,000 seconds, preferably 1 to 500 seconds, more preferably 10 to 100 seconds. In consideration of the heat load of the light irradiation process, the irradiation may be performed multiple times in order to satisfy the aforementioned light amount.

In this case, in order to prevent deterioration of the polymer component (A) and coloration of the cured resin layer due to irradiation with active energy rays, a filter that absorbs light of wavelengths unnecessary for the curing reaction is interposed, and the active energy rays are applied. The curable resin composition may be irradiated. According to this method, the filter absorbs light of a wavelength that is unnecessary for the curing reaction and degrades the polymer component (A). It becomes easy to obtain a resin.
A resin film such as a polyethylene terephthalate film can be used as the filter. When using a resin film, it is preferable to provide a step of laminating a resin film such as a polyethylene terephthalate film on the curable resin layer between

steps

1 and 2 . The resin film is usually peeled off after step 2.

The curable resin layer (coating film) can also be cured by irradiating the curable resin layer (coating film) with an electron beam. In the case of electron beam irradiation, the curable resin layer (coating film) can be cured usually without using a photopolymerization initiator. When irradiating with an electron beam, an electron beam accelerator or the like can be used. The irradiation dose is usually in the range of 10 to 1,000 krad. The irradiation time is usually 0.1 to 1,000 seconds, preferably 1 to 500 seconds, more preferably 10 to 100 seconds.

The curing of the curable resin layer (coating film) may be performed under an inert gas atmosphere such as nitrogen gas, if necessary. Curing in an inert gas atmosphere makes it easier to prevent oxygen, moisture, and the like from interfering with curing.

A desired functional layer is formed on the cured resin layer obtained in step 2.
As a method for forming the functional layer, the method described above can be appropriately adopted.

When the laminate has a process film, the laminate may have the process film on one side or both sides. In the latter case, it is preferable to use two types of process films and make the process film to be peeled off first easier to peel.
The process film is preferably sheet-like or film-like. The term "sheet-like" or "film-like" includes not only a long one but also a short flat plate-like one.
Process films include paper base materials such as glassine paper, coated paper, and fine paper; laminated paper obtained by laminating these paper base materials with thermoplastic resins such as polyethylene and polypropylene; Those subjected to filling treatment with alcohol, acrylic-styrene resin, etc.; plastic films such as polyester films such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate, and polyolefin films such as polyethylene and polypropylene; and glass.
Further, the process film may be a paper substrate or a plastic film having a release agent layer provided thereon from the viewpoint of ease of handling. The release layer can be formed using conventionally known release agents such as silicone release agents, fluorine release agents, alkyd release agents, and olefin release agents.
The thickness of the release agent layer is not particularly limited, but is usually 0.02 to 2.0 μm, more preferably 0.05 to 1.5 μm.
The thickness of the process film is preferably 1 to 500 μm, more preferably 5 to 300 μm, from the viewpoint of ease of handling.
Moreover, the process film is usually peeled off in a predetermined process depending on the use of the laminate.

Thus, the manufacturing method including the above (Step 1) to (Step 3) forms a cured resin layer using a process film, and the laminate obtained by this method has a process film. may or may not have.
According to the above-described method for manufacturing a laminate, the laminate according to one aspect of the present invention can be efficiently, continuously, and easily produced.

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited by these examples.

The thermal change rate (thermal shrinkage rate), in-plane retardation, and elongation at break of the cured resin layers produced in Examples and Comparative Examples were evaluated by the following methods.

(1) Thermal change rate (heat shrinkage rate)
Eight cured resin layers obtained in Examples and Comparative Examples, from which polyethylene terephthalate (PET) films as process films were peeled off, were laminated to form a laminate having a total thickness of 40 μm. Next, cut into a test piece of 5 mm × 30 mm, set the distance between chucks to 20 mm using a thermomechanical analyzer (manufactured by NETZSCH Japan, model name "TMA4000SE"), and laminate the cured resin layer. I grabbed my body. Next, the laminate of the cured resin layers was heated from 25°C to 100°C at a heating rate of 5°C/min, held for 2 minutes, and then cooled to 25°C at a cooling rate of 5°C/min. The rate of change in displacement in the longitudinal direction before and after heating and cooling (a value expressed as a percentage of the amount of displacement with respect to the chuck-to-chuck distance of 20 mm) was defined as the rate of thermal change. When the obtained value takes a negative value, it means that the cured resin layer has shrunk (heat shrinkage), and when it takes a positive value, it means that the cured resin layer has elongated.
(2) In-plane phase difference The cured resin layers obtained in Examples and Comparative Examples were measured using a phase difference measuring device (manufactured by Oji Scientific Instruments Co., Ltd., model name “KOBRA-WR”, wavelength: 589 nm). The in-plane retardation (retardation value) was measured under the condition of 23°C.
(3) Breaking Elongation The cured resin layers obtained in Examples and Comparative Examples were cut into test pieces of 15 mm×150 mm, and the breaking elongation was measured according to JIS K7127:1999. Specifically, the test piece was subjected to a tensile test at a speed of 200 mm/min after setting the distance between chucks to 100 mm using a tensile tester (manufactured by Shimadzu Corporation, Autograph). %) was measured. When the test piece did not have a yield point, the tensile breaking strain was taken as the breaking elongation.

(Example 1)
- Formation of cured resin layer A curable resin composition was prepared as follows.
As the polymer component (A), 100 parts by mass of polyimide resin (PI) pellets (manufactured by Kawamura Sangyo Co., Ltd., product name “KPI-MX300F”, Tg = 354 ° C., weight average molecular weight 190,000) to methyl ethyl ketone (MEK) By dissolving, a 15% by mass solution of PI was prepared. Next, in this solution, 122 parts by weight of tricyclodecanedimethanol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., A-DCP, molecular weight 304.4) as a curable monomer (B), and a polymerization initiator, (2,4,6-trimethylbenzoyl)-phenylphosphine oxide (OMNIRAD TPO manufactured by IGM Resins) (5 parts by mass) was added and mixed to prepare a curable resin composition. The curable monomer (B) and the polymerization initiator used in the present examples and comparative examples do not contain a solvent and are all raw materials having a solid content of 100%.
Next, as a process film, a polyethylene terephthalate (PET) film (manufactured by Toyobo Co., Ltd., PET100A-4100, thickness 50 μm) having an easy-adhesion layer on one side was used. A curable resin composition was applied to the surface, and the resulting coating film was dried by heating at 90° C. for 2 minutes.
Using a high-pressure mercury lamp (manufactured by Eyegraphics, product name “H04-L41”), the illuminance at a light wavelength of 365 nm was 130 mW/cm ² and the amount of light was 700 mJ/cm ² (manufactured by Heraus, UV photometer, UV Power Puck). Under the conditions of (registered trademark) II), a curing reaction was performed by irradiating ultraviolet rays in a nitrogen atmosphere to form a cured resin layer having a thickness of 5 μm.
The thermal shrinkage rate, in-plane retardation and breaking elongation of the obtained cured resin layer were evaluated. Table 1 shows the results.

(Comparative example 1)
Pellets of the polyimide resin (PI) of the polymer component (A) in the curable resin composition of Example 1 were replaced with pellets of a polyimide resin (PI) having a higher weight average molecular weight (manufactured by Kawamura Sangyo Co., Ltd., product name "KPI- MX300F”, Tg=354° C., weight average molecular weight 280,000) was used to form a cured resin layer having a thickness of 5 μm in the same manner as in Example 1.
The thermal shrinkage rate, in-plane retardation and breaking elongation of the obtained cured resin layer were evaluated. Table 1 shows the results.

The chemical structural formula of the curable monomer (B) used in Examples and Comparative Examples is shown below.

As the polymer component (A) constituting the curable resin composition, the cured resin layer of Example 1 using a polyimide resin having a weight average molecular weight of 190,000 has a weight average molecular weight of Compared to the cured resin layer of Comparative Example 1 using a polyimide resin of 280,000, the thermal shrinkage rate is one order lower, and the elongation at break (toughness) usually decreases as the weight average molecular weight decreases. is expected, but contrary to this, it can be seen that the breaking strength is maintained.

According to the curable resin composition of the present invention, the cured resin layer made of the cured product has a low thermal shrinkage rate at high temperatures, so it is possible to suppress the occurrence of curls and wrinkles. It has excellent toughness (toughness), has optical isotropy, and is thin and flexible, so it is required to be manufactured at high temperature. For example, antireflection hard coat films, polarizing plate protective films for polarizing plates used in liquid crystal displays, ITO base films used in touch panels, etc., and other members such as flexible organic EL elements and flexible thermoelectric conversion elements. expected to be applied.

1: Cured resin layer 2: Functional layer 11: Laminate

Claims

A curable resin composition containing a polymer component (A) and a curable monomer (B), wherein the polymer component (A) contains a polyimide resin, and the polyimide resin has a weight average molecular weight of 100, 000 or more and 230,000 or less, a curable resin composition.
The curable resin composition according to claim 1, wherein the polymer component (A) has a glass transition temperature of 250°C or higher.
The curable resin composition according to claim 1, wherein the polyimide resin is soluble in methyl ethyl ketone.
The curable resin composition according to claim 1 or 3, wherein the polyimide resin has a fluoro group in its molecule.
A cured resin layer comprising a cured product of the curable resin composition according to any one of claims 1 to 4, and having a thickness of 20 μm or less.
The cured resin layer according to claim 5, wherein the cured resin layer has a thermal shrinkage rate of 0.08% or less when heat-treated at 100°C for 2 minutes.
The cured resin layer according to claim 6, wherein the in-plane retardation of the cured resin layer is 2.0 nm or less.
A laminate comprising a functional layer on the cured resin layer according to any one of claims 5 to 7.