WO2022210945A1

WO2022210945A1 - Curable resin composition, laminated structure, cured product, and electronic component

Info

Publication number: WO2022210945A1
Application number: PCT/JP2022/016206
Authority: WO
Inventors: 悠斗小田桐; 裕横山; 直之小池; 一善米田; 英和宮部
Original assignee: 太陽インキ製造株式会社
Priority date: 2021-03-31
Filing date: 2022-03-30
Publication date: 2022-10-06
Also published as: TWI833191B; TW202342577A; TW202307056A; KR20230163369A

Abstract

[Problem] To provide a curable resin composition that has good resolution in a resultant dried coating film and exhibits minimal adhesion even if cured products are stacked after heat curing and stored in a high temperature environment. [Solution] A curable resin composition that enables alkaline development and forms a cured film when subjected to exposure and heat treatment. If a dried coating film having a thickness of 2–100 μm is formed from this curable resin composition, the arithmetic mean roughness Ra of the dried coating film is less than 0.1 μm, and the arithmetic mean roughness Ra of a cured film obtained by heat curing the dried coating film is 0.1–1 μm. This curable resin composition has characteristics such that the obtained dried coating film has good resolution, and there is minimal adhesion even if cured products are stacked after heat curing and stored in a high temperature environment. [Selected drawing] None

Description

Curable resin composition, laminated structure, cured product and electronic component

TECHNICAL FIELD The present invention relates to a curable resin composition, a laminate structure of resin layers formed from the curable resin composition, a cured product thereof, and an electronic component having an insulating film formed from the cured product, and particularly to an alkali-developable structure. It has a curable resin composition that forms a cured film by exposure and heat treatment, a laminated structure of resin layers formed from the curable resin composition, a cured product thereof, and an insulating film composed of the cured product. Regarding electronic components.

Conventionally, a non-photosensitive resin structure formed by applying a thermosetting adhesive to a film such as polyimide has been used as a protective film for a flexible printed wiring board. As a method of patterning such a non-photosensitive resin structure and forming it on a flexible printed wiring board, conventionally, a method of forming holes by punching and then thermocompression bonding on the flexible printed wiring board has been adopted. Alternatively, a method has also been adopted in which a solvent-soluble thermosetting resin composition is directly pattern-printed on a flexible printed wiring board and thermally cured to form a pattern. In particular, polyimide films have been used as suitable materials for flexible printed wiring boards because they are flexible and have excellent heat resistance, mechanical properties, and electrical properties (see, for example, Patent Document 1).
However, with the above-mentioned conventional method, the shape of the pattern ends is lost due to the bleeding of the resin during coating or thermocompression bonding. However, it has been difficult to form a fine pattern to be used.

WO2012/133665

On the other hand, it is also conceivable to apply a photosensitive solder resist, which is known as a permanent circuit protective film that can be microfabricated, as a coverlay for flexible printed wiring boards. A photosensitive solder resist in a flexible printed wiring board requires a low crosslinking density in order to impart flexibility. Since flexible substrates are thin and easily bent, they are often stacked and fixed, stored, and transported. Due to its storage and transportation environment, it is exposed to high temperatures. When a photosensitive solder resist is applied to the coverlay, the area that protects the flexible printed wiring board becomes wider. They may stick together.

Also, in recent years, there has been an increasing demand for thinner films in fields that use rigid substrates. Not only flexible substrates, but also thin substrates such as rigid substrates with a thickness of 0.1 mm, the phenomenon of sticking of coating films to each other may occur.

In order to solve this problem, if the surface roughness of the coating film is increased, the contact surface area will become smaller and sticking will not occur. However, when a coating film having a large surface roughness is patterned by photolithography, halation occurs on the coating film surface, and sufficient resolution cannot be obtained.

The first object of the present invention in view of the above problems is that the resolution of the dried coating film is good, the flexibility of the resulting cured product is good, and sticking is not caused when stored in a stack. An object of the present invention is to provide a curable resin composition having small properties.

Further, the second object of the present invention in view of the above problems is that the dry coating film has good developability, the obtained cured product has good heat resistance and flexibility, and the obtained cured product To provide a curable resin composition having a characteristic of little sticking when stored in a pile.

The present inventors have diligently studied to achieve the above first purpose. As a result, it is possible to maintain a small surface roughness (arithmetic mean roughness) at the time of the dried coating film, and use a curable resin composition that increases the surface roughness (arithmetic mean roughness) after heat curing. The inventors have found that both high resolution of the film and flexibility and low sticking property of the thermosetting film can be achieved, and have completed the present invention. In this specification, the term "resolution" refers to the ability to express fine details of an image obtained by exposing a resin layer comprising the curable resin composition of the present invention to light and developing with an alkali.

That is, the first object of the present invention is
A curable resin composition that is alkali developable and forms a cured film by exposure and heat treatment,
When a dry coating film having a thickness of 2 to 100 μm is formed from the curable resin composition, the arithmetic mean roughness Ra of the dry coating film is less than 0.1 μm, and after heat curing of the dry coating film It is achieved by a curable resin composition (hereinafter also referred to as the curable resin composition of the first aspect of the present invention) in which the cured film has an arithmetic mean roughness Ra of 0.1 μm or more and 1 μm or less. It was found that

In this specification, the term "resolution" refers to the expressiveness of fine details of an image obtained when a resin layer made of the curable resin composition of the first aspect of the present invention is pattern-exposed and alkali-developed. and

Further, in the curable resin composition of the first aspect of the present invention, when a dry coating film having a thickness of 2 to 100 μm is formed from the curable resin composition, the dry coating film has an arithmetic mean roughness Ra of It is preferably less than 0.05 μm, and the arithmetic mean roughness Ra of the cured film after thermal curing of the dried coating film is preferably 0.1 μm or more and 0.5 μm or less.

Further, it preferably contains (A) an alkali-soluble polyamide-imide resin, (B) a photobase generator, (C) a thermosetting compound, and (D) a cellulose derivative.

Also, (C) the thermosetting compound is preferably an epoxy resin.

Moreover, the first object of the present invention is a laminate structure in which at least one side of a resin layer formed from the curable resin composition of the present invention is supported or protected by a film,
It can also be achieved by the curable resin composition of the present invention, the cured product of the resin layer of the laminated structure of the present invention, and the electronic component having an insulating film made of the cured product of the present invention.

In addition, the present inventors have diligently studied to achieve the above second purpose. As a result, it was found that by blending a cellulose derivative into the curable resin composition and adding an alkali-soluble polyimide resin to a predetermined blend, sticking between the resulting cured products is reduced. was completed.

That is, the second object of the present invention is
(A) an alkali-soluble polyamideimide resin;
(B) a photobase generator;
(C) a thermosetting compound;
(D) a cellulose derivative (hereinafter also referred to as the curable resin composition of the second aspect of the present invention).

In addition, (A) the alkali-soluble polyamide-imide resin preferably has a carboxyl group, and (A) the alkali-soluble polyamide-imide resin preferably has a carboxyl group and a phenolic hydroxyl group.

Furthermore, it is preferable that the curable resin composition of the second aspect of the present invention further contains (E) an alkali-soluble polyimide resin.

In addition, (C) the thermosetting compound is preferably an epoxy resin.

Furthermore, the second object of the present invention can also be achieved by a cured product obtained from the curable composition of the present invention and an electronic component having an insulating film made of this cured product.

According to the curable resin composition of the first aspect of the present invention, the resolution of the obtained dried coating film is good, and the flexibility of the cured product after thermosetting is also good. Even when cured products are stacked and stored in a high-temperature environment, sticking is minimal.
In addition, the dry coating film of the curable composition of the second aspect of the present invention has good developability, and the cured product obtained from the curable composition of the second aspect of the present invention has heat resistance. , which has good flexibility and little sticking when stored in a pile.

It is explanatory drawing of the MIT test which performed the evaluation board|substrate produced in the Example as a test piece.

<Curable resin composition of the first aspect of the present invention>
The curable resin composition of the first aspect of the present invention is
A curable resin composition that is alkali developable and forms a cured film by exposure and heat treatment,
When a dry coating film having a thickness of 2 to 100 μm is formed from the curable resin composition, the dry coating film has an arithmetic mean roughness Ra of less than 0.1 μm, and a cured film after heat curing of the dry coating film. has an arithmetic mean roughness Ra of 0.1 μm or more and 1 μm or less.

In order for the curable resin composition of the first aspect of the present invention to be alkali-developable and to form a cured film by exposure and heat treatment, the constituents thereof must contain alkali-soluble functional groups (hereinafter referred to as alkali a compound having a soluble group) (hereinafter also referred to as an alkali-soluble compound), (B) a photobase generator, and (C) a thermosetting compound, which will be described later.

Among these, (B) the photobase generator changes its molecular structure by irradiation with light such as ultraviolet light or visible light, or the molecule is cleaved, thereby forming an alkali-soluble compound and (C) a thermosetting It functions as a catalyst for addition reactions with compounds.

Examples of alkali-soluble compounds include compounds having a phenolic hydroxyl group, compounds having a carboxyl group, and compounds having a phenolic hydroxyl group and a carboxyl group. Preferably, the alkali-soluble compound is (A) an alkali-soluble polyamide-imide resin described later. Among them, it is preferable to use a polyamideimide resin having a structure represented by the following general formula (1) and a structure represented by the following general formula (2) as (A) the alkali-soluble polyamideimide resin.

When a dry coating film having a thickness of 2 to 100 μm, more preferably 3 to 80 μm from the viewpoint of improving resolution is formed from the curable resin composition of the first aspect of the present invention, the arithmetic mean of this dry coating film The roughness Ra is less than 0.1 μm, preferably less than 0.05 μm, and the arithmetic average roughness Ra of the cured film after thermal curing of the dry coating film is 0.1 μm or more and 1 μm or less, preferably 0.1 μm or more and 0.1 μm or more. 5 μm or less.

When the dry coating film has an arithmetic mean roughness Ra of less than 0.1 μm, diffused reflection of the light applied to the coating film during exposure is suppressed, resulting in good resolution. Further, after thermal curing, the cured film has an arithmetic mean roughness Ra of 0.1 μm or more and 1 μm or less, so that small unevenness is generated on the cured film. The unevenness reduces the contact area between the stacked cured films and contributes to the reduction of sticking.

The phenomenon that the unevenness of the dried coating film is small in the state of the dry coating film before heat curing, and the unevenness on the cured film after heat curing is increased is due to the fact that the curable resin composition of the present invention is the above (C) It is considered that this is caused by including a polymer component having a different compatibility with a thermosetting compound or an alkali-soluble compound. That is, it is presumed that the polymer components dispersed in the dry coating film before heat curing migrate to the film surface during the heat curing reaction.

As this polymer component, it is preferable to blend (D) a cellulose derivative.

The curable resin composition of the first aspect of the present invention preferably includes (A) an alkali-soluble polyamideimide resin, (B) a photobase generator, (C) a thermosetting compound, and (D ) a cellulose derivative.

<Curable resin composition of the second aspect of the present invention>
The curable resin composition of the second aspect of the present invention is
(A) an alkali-soluble polyamideimide resin;
(B) a photobase generator;
(C) a thermosetting compound;
(D) a cellulose derivative.

Furthermore, it is preferable that the curable resin composition of the second aspect of the present invention contains (E) an alkali-soluble polyimide resin.

In addition, (C) the thermosetting compound is preferably an epoxy resin.

[(A) alkali-soluble polyamideimide resin]
(A) The alkali-soluble polyamide-imide resin is a preferred example of the alkali-soluble photocurable compound. (A) The alkali-soluble polyamide-imide resin contains alkali-soluble groups (one or more of phenolic hydroxyl groups and carboxyl groups). The curable resin composition of the first aspect of the present invention preferably contains (A) an alkali-soluble polyamideimide resin, and the curable resin composition of the second aspect of the present invention comprises (A) an alkali Contains soluble polyamide-imide resin.

Such an alkali-soluble polyamide-imide resin is, for example, a resin obtained by reacting a carboxylic acid anhydride component and an amine component to obtain an imidized product, and then reacting the obtained imidized product with an isocyanate component. etc. Here, the alkali-soluble group is introduced by using an amine component having a carboxyl group or a phenolic hydroxyl group. Further, the imidization may be carried out by thermal imidization or by chemical imidization, and these may be used in combination.

Examples of the carboxylic anhydride component include tetracarboxylic anhydrides and tricarboxylic anhydrides, but are not limited to these acid anhydrides. Acid anhydride groups that react with amino groups and isocyanate groups and Any compound having a carboxyl group can be used, including its derivatives. Also, these carboxylic acid anhydride components may be used alone or in combination.

As the amine component, diamines such as aliphatic diamines and aromatic diamines, polyvalent amines such as aliphatic polyetheramines, diamines having a carboxyl group, diamines having a phenolic hydroxyl group, and the like can be used. The amine component is not limited to these amines, but it is necessary to use an amine capable of introducing at least one functional group out of phenolic hydroxyl groups and carboxyl groups. Also, these amine components may be used alone or in combination.

As the isocyanate component, diisocyanates such as aromatic diisocyanates and their isomers and polymers, aliphatic diisocyanates, alicyclic diisocyanates and their isomers, and other general-purpose diisocyanates can be used. It is not limited. Also, these isocyanate components may be used alone or in combination.

(A) When an alkali-soluble polyamideimide resin is contained in the curable resin composition of the present invention, the alkali solubility (developability) of the polyamideimide resin and the mechanical properties of the cured product of the resin composition containing the polyamideimide resin From the viewpoint of improving the balance with other properties such as properties, the acid value (solid content acid value) is preferably 30 mgKOH/g or more, more preferably 30 mgKOH/g to 150 mgKOH/g, Especially preferred is 50 mg KOH/g to 120 mg KOH/g. Specifically, when the acid value is 30 mgKOH/g or more, the alkali solubility, that is, the developability, is improved, and the crosslink density with the thermosetting component after light irradiation is increased, resulting in sufficient development. You can get contrast. In addition, by setting the acid value to 150 mgKOH/g or less, it is possible to suppress so-called heat fogging, especially in the PEB (POST EXPOSURE BAKE) process after light irradiation, which will be described later, and to increase the process margin.

Further, the molecular weight of the alkali-soluble polyamideimide resin (A) is preferably 20,000 or less, and preferably 1,000 to 17,000, in consideration of developability and cured coating properties. More preferably, 2,000 to 15,000 is even more preferable. When the molecular weight is 20,000 or less, the alkali-solubility of the unexposed area is increased and the developability is improved. On the other hand, when the molecular weight is 1,000 or more, sufficient development resistance and cured physical properties can be obtained in the exposed area after the exposure/PEB process.

(A) When an alkali-soluble polyamideimide resin is contained in the curable resin composition of the present invention, in particular, a polyamide having a structure represented by the following general formula (1) and a structure represented by the following general formula (2) It is more preferable to use an imide resin from the viewpoint of further improving developability and improving flexibility and adhesion. It should be noted that the structure represented by the general formula (1) and the structure represented by the following general formula (2) are not limited to (A) when contained in one molecule of an alkali-soluble polyamideimide resin, (A) It suffices if it is contained in the alkali-soluble polyamide-imide resin.

(In the general formula (1), X ₁ is a residue of an aliphatic diamine (a) derived from a dimer acid having 24 to 48 carbon atoms (also referred to herein as "dimer diamine (a)"),
In general formula ( ₂ ), X2 is a residue of aromatic diamine (b) having a carboxyl group (also referred to herein as "carboxyl group-containing diamine (b)"). In general formulas (1) and (2), each Y is independently cyclohexane or an aromatic ring. )

By including the structure represented by the general formula (1) and the structure represented by the general formula (2), even when a mild alkaline solution such as a 1.0% by mass sodium carbonate aqueous solution is used, It can be a polyamide-imide resin excellent in alkali solubility that can dissolve also. Moreover, a cured product of a curable resin composition containing such a polyamideimide resin can have excellent dielectric properties.

The dimer diamine (a) can be obtained by reductively aminating the carboxyl group in the dimer of aliphatic unsaturated carboxylic acid having 12 to 24 carbon atoms. That is, dimer diamine (a), which is an aliphatic diamine derived from dimer acid, is obtained by polymerizing unsaturated fatty acids such as oleic acid and linoleic acid to form dimer acid, reducing this, and then aminating it. . As such an aliphatic diamine, commercially available products such as PRIAMINE 1073, 1074, and 1075 (manufactured by Croda Japan Co., Ltd., trade names), which are diamines having a skeleton of 36 carbon atoms, can be used. The dimer diamine (a) may be preferably derived from a dimer acid having 28 to 44 carbon atoms, and more preferably derived from a dimer acid having 32 to 40 carbon atoms.

Specific examples of the carboxyl group-containing diamine (b) include 3,5-diaminobenzoic acid, 3,4-diaminobenzoic acid, 5,5'-methylenebis(anthranilic acid), benzidine-3,3'-dicarboxylic acid, and the like. is mentioned. The carboxyl group-containing diamine (b) may be composed of one type of compound, or may be composed of a plurality of types of compounds. From the viewpoint of raw material availability, the carboxyl group-containing diamine (b) preferably contains 3,5-diaminobenzoic acid and 5,5'-methylenebis(anthranilic acid).

The relationship between the content of the structure represented by the general formula (1) and the content of the structure represented by the general formula (2) in the polyamideimide resin is not limited. The content of dimer diamine (a) (unit: % by mass) is preferably 20 to 60 mass %, more preferably 30 to 50 mass %. In the present specification, the "content of dimer diamine (a)" refers to the charged amount of dimer diamine (a), which is positioned as one of raw materials for producing polyamide-imide resin, of the produced polyamide-imide resin. It means ratio to mass. Here, the "mass of the produced polyamide-imide resin" is the amount of water (H ₂ O) produced by imidization and carbon dioxide gas (CO ₂ ) is the value after subtracting the theoretical amount.

From the viewpoint of increasing the alkali solubility of the polyamideimide resin, the portion represented by Y in the general formulas (1) and (2) preferably has a cyclohexane ring. From the viewpoint of improving the balance between the alkali solubility of the polyamideimide resin and other properties such as the mechanical properties of the cured product of the resin composition containing the polyamideimide resin, the aromatic ring and the cyclohexane ring in the portion represented by Y above. The molar ratio of the cyclohexane ring content to the aromatic ring content is preferably 85/15 to 100/0, more preferably 90/10 to 99/1, It is more preferably 90/10 to 98/2.

The method for producing the above (A) alkali-soluble polyamide-imide resin is not limited, and it can be produced through an imidization step and an amidimidation step using a known and commonly used method.

In the imidization step, from dimer diamine (a), carboxyl group-containing diamine (b), and cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride (c) and trimellitic anhydride (d) An imidized product is obtained by reacting one or two selected from the group consisting of:

The amount of the dimer diamine (a) to be charged is preferably such that the content of the dimer diamine (a) is 20 to 60% by mass, and more preferably the amount is such that the content of the dimer diamine (a) is 30 to 50% by mass. . The definition of the content of the dimer diamine (a) is as described above.

If necessary, other diamines may be used together with the dimer diamine (a) and the carboxyl group-containing diamine (b). Specific examples of other diamines include 2,2-bis[4-(4-aminophenoxy)phenyl]propane, bis[4-(3-aminophenoxy)phenyl]sulfone, bis[4-(4-aminophenoxy) )phenyl]sulfone, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, bis[4-(4-aminophenoxy)phenyl]methane, 4,4′-bis(4-aminophenoxy ) biphenyl, bis[4-(4-aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)phenyl]ketone, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis( 4-aminophenoxy)benzene, 2,2′-dimethylbiphenyl-4,4′-diamine, 2,2′-bis(trifluoromethyl)biphenyl-4,4′-diamine, 2,6,2′,6 '-tetramethyl-4,4'-diamine, 5,5'-dimethyl-2,2'-sulfonyl-biphenyl-4,4'-diamine, 3,3'-dihydroxybiphenyl-4,4'-diamine, (4,4'-diamino)diphenyl ether, (4,4'-diamino)diphenylsulfone, (4,4'-diamino)benzophenone, (3,3'-diamino)benzophenone, (4,4'-diamino)diphenylmethane , (4,4′-diamino)diphenyl ether, (3,3′-diamino)diphenyl ether, hexamethylenediamine, octamethylenediamine, decamethylenediamine, dodecamethylenediamine, octadecamethylenediamine, Aliphatic diamines such as 4,4′-methylenebis(cyclohexylamine), isophoronediamine, 1,4-cyclohexanediamine and norbornenediamine are included.

From the viewpoint of increasing the alkali solubility of the polyamideimide resin, it is preferable to use cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride (c) in the imidization step. The molar ratio of the amount of cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride (c) used to the amount of trimellitic anhydride (d) used should be 85/15 to 100/0. is preferred, 90/10 to 99/1 is more preferred, and 90/10 to 98/2 is even more preferred.

Amount of diamine compound (specifically, dimer diamine (a), carboxyl group-containing diamine (b), and other diamines used as necessary) used to obtain imidized product and acid anhydride (Specifically, it means one or two selected from the group consisting of cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride (c) and trimellitic anhydride (d). ) is not limited. The amount of the acid anhydride used is preferably such that the molar ratio with respect to the amount of the diamine compound used is 2.0 or more and 2.4 or less, and the amount is such that the molar ratio is 2.0 or more and 2.2 or less. It is more preferable to have

In the amidization step, the imidized product obtained in the above imidization step is reacted with a diisocyanate compound to obtain a polyamideimide resin containing a substance having a structure represented by the general formula (3) described later.

The specific type of diisocyanate compound is not limited. The diisocyanate compound may be composed of one type of compound, or may be composed of a plurality of types of compounds.

Specific examples of diisocyanate compounds include 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, o-xylylene diisocyanate, m-xylylene diisocyanate aromatic diisocyanates such as isocyanate and 2,4-tolylene dimer; aliphatic diisocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate and norbornene diisocyanate; (A) From the viewpoint of improving both the alkali solubility of the alkali-soluble polyamideimide resin and the light transmittance of the polyamideimide resin, the diisocyanate compound preferably contains an aliphatic isocyanate, and the diisocyanate compound is an aliphatic isocyanate. It is more preferable to have

The amount of diisocyanate compound used in the amidimidation process is not limited. From the viewpoint of imparting moderate alkali solubility to the polyamide-imide resin, the amount of the diisocyanate compound used is 0.3 or more and 1.0 or less as a molar ratio with respect to the amount of the diamine compound used to obtain the imide compound. , more preferably 0.4 or more and 0.95 or less, and particularly preferably 0.50 or more and 0.90 or less.

The polyamideimide resin thus produced has the following general formula (3)

(In the above general formula (3), X is each independently a diamine residue (a residue of a diamine compound), Y is each independently an aromatic ring or a cyclohexane ring, Z is a residue of a diisocyanate compound. n is a natural number. ) includes substances having the structure shown in

(A) The total amount of the alkali-soluble polyamideimide resin and the alkali-soluble polyimide resin (E), which is an optional component described later, is based on 100 parts by mass of the curable resin composition of the present invention, for example , 10 to 85 parts by mass, preferably 15 to 80 parts by mass, particularly preferably 20 to 75 parts by mass.

[(B) Photobase generator]
The curable resin composition of the first aspect of the present invention includes (A) an alkali-soluble polyamideimide resin (and an optional component (E) an alkali-soluble polyimide resin described later), and (C) a thermosetting It preferably contains a compound and (B) a photobase generator, and the curable resin composition of the second aspect of the present invention contains (B) a photobase generator. (B) The photobase generator is a catalyst for the addition reaction between the polyimide resin having a carboxyl group and the thermosetting component when the molecular structure changes or the molecule is cleaved by irradiation with light such as ultraviolet light or visible light. It is a compound that produces one or more basic substances that can function as

Examples of basic substances include secondary amines and tertiary amines.

Examples of photobase generators include α-aminoacetophenone compounds, oxime ester compounds, acyloxyimino groups, N-formylated aromatic amino groups, N-acylated aromatic amino groups, nitrobenzylcarbamate groups, alkoxybenzyl A compound having a substituent such as a carbamate group is included. Among them, oxime ester compounds and α-aminoacetophenone compounds are preferred. As α-aminoacetophenone compounds, those having two or more nitrogen atoms are particularly preferred.

Other photobase generators include WPBG-018 (trade name: 9-anthrylmethylN,N'-diethylcarbamate), WPBG-027 (trade name: (E)-1-[3-(2-hydroxyphenyl)-2-propenoyl ]piperidine), WPBG-082 (trade name: guanidinium2-(3-benzoylphenyl)propionate), WPBG-140 (trade name: 1-(anthraquinon-2-yl)ethyl imidazolecarboxylate), etc. (Fuji Film Wako Pure Chemical Industries, Ltd. ) can also be used. The α-aminoacetophenone compound has a benzoin ether bond in its molecule, and when exposed to light, it undergoes intramolecular cleavage to produce a basic substance (amine) that acts as a curing catalyst.

Specific examples of α-aminoacetophenone compounds include (4-morpholinobenzoyl)-1-benzyl-1-dimethylaminopropane (Omnirad 369, trade name, manufactured by IGM Resins) and 4-(methylthiobenzoyl)- 1-methyl-1-morpholinoethane (Omnirad 907, trade name, manufactured by IGM Resins), 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4 -morpholinyl)phenyl]-1-butanone (Omnirad 379, trade name, manufactured by IGM Resins) or a commercially available compound or a solution thereof can be used.

Any compound can be used as the oxime ester compound as long as it is a compound that generates a basic substance upon irradiation with light. As such an oxime ester compound, an oxime ester photobase generator having a group represented by the following general formula (4) is preferable.

(In the formula, R ₁ is a hydrogen atom, an unsubstituted or C 1-6 alkyl group, a phenyl group or a phenyl group substituted with a halogen atom, an unsubstituted C 1 group substituted with one or more hydroxyl groups, -20 alkyl groups, said alkyl groups interrupted by one or more oxygen atoms, unsubstituted or C5-8 cycloalkyl groups substituted with C1-6 alkyl groups or phenyl groups, unsubstituted or an alkanoyl group having 2 to 20 carbon atoms or a benzoyl group substituted with an alkyl group having 1 to 6 carbon atoms or a phenyl group, and R ₂ is unsubstituted or an alkyl group having 1 to 6 carbon atoms, a phenyl group or a halogen A phenyl group substituted with an atom, an alkyl group having 1 to 20 carbon atoms unsubstituted or substituted with one or more hydroxyl groups, the alkyl group interrupted by one or more oxygen atoms, unsubstituted or having 1 to 1 carbon atoms a cycloalkyl group having 5 to 8 carbon atoms substituted with an alkyl group of 6 or a phenyl group, an alkanoyl group having 2 to 20 carbon atoms or a benzoyl group unsubstituted or substituted with an alkyl group having 1 to 6 carbon atoms or a phenyl group; represents.)
Examples of commercially available oxime ester photobase generators include IRGACURE OXE01 and IRGACURE OXE02 manufactured by BASF Japan, N-1919 and NCI-831 manufactured by ADEKA. Compounds having two oxime ester groups in the molecule, which are described in Japanese Patent No. 4344400, can also be preferably used.

In addition, JP 2004-359639, JP 2005-097141, JP 2005-220097, JP 2006-160634, JP 2008-094770, JP 2008-509967, Examples include carbazole oxime ester compounds described in JP-T-2009-040762 and JP-A-2011-80036.

Such photobase generators may be used singly or in combination of two or more. The amount of the photobase generator (B) in the curable resin composition of the present invention is (A) relative to 100 parts by mass of the alkali-soluble polyamideimide resin, or when the alkali-soluble polyimide resin is included In (A) the total amount of the alkali-soluble polyamideimide resin and the alkali-soluble polyimide resin is 100 parts by mass, for example, 0.1 parts by mass or more and 40 parts by mass or less, preferably 0.2 It is more than 20 parts by mass and less than 20 parts by mass.

When the amount is 0.1 part by mass or more, a good contrast of development resistance between the light-irradiated area and the non-irradiated area can be obtained. Moreover, when it is 40 parts by mass or less, the properties of the cured product are improved.

[(C) thermosetting compound]
The curable resin composition of the first aspect of the present invention preferably contains (C) a thermosetting compound from the viewpoint of imparting heat resistance and chemical resistance to the cured product after thermosetting. The curable resin composition of the second aspect contains (C) a thermosetting compound.

(C) Thermosetting compounds include epoxy resins, urethane resins, polyester resins, hydroxyl group-, amino- or carboxyl-containing polyurethanes, polyesters, polycarbonates, polyols, phenoxy resins, acrylic copolymer resins, vinyl resins, oxazine resins, A known and commonly used thermosetting resin such as a cyanate resin can be used.

Above all, from the viewpoint of heat resistance and chemical resistance, (C) the thermosetting compound is preferably an epoxy resin.

Specific examples of epoxy resins include jER828 manufactured by Mitsubishi Chemical Corporation, EHPE3150 manufactured by Daicel Corporation, EPICLON840 manufactured by DIC Corporation, Epotote YD-011 manufactured by Nippon Steel Chemical & Materials, and D.I. E. R. 317, bisphenol A type epoxy resins such as Sumiepoxi ESA-011 (both trade names) manufactured by Sumitomo Chemical; , Dow Chemical Company D.I. E. R. 542, brominated epoxy resins such as Sumiepoxy ESB-400 (both trade names) manufactured by Sumitomo Chemical; jER152 manufactured by Mitsubishi Chemical; E. N. 431, DIC's EPICLON N-730, Nippon Steel Chemical & Materials' Epotato YDCN-701, Nippon Kayaku's EPPN-201, Sumitomo Chemical's Sumiepoxy ESCN-195X, etc. (all are trade names) novolak type epoxy resin; EPICLON830 manufactured by DIC Corporation, jER807 manufactured by Mitsubishi Chemical Corporation, Epotote YDF-170, YDF-175, YDF-2004 manufactured by Nippon Steel Chemical & Materials Co., Ltd. (all trade names) Bisphenol F type epoxy Resin: Hydrogenated bisphenol A type epoxy resin such as Epotato ST-2004 (trade name) manufactured by Nippon Steel Chemical &Materials; Glycidylamine type epoxy resin such as Sumiepoxy ELM-120 (both are trade names); Trihydroxyphenylmethane type epoxy resin such as EPPN-501 (all trade names) manufactured by Mitsubishi Chemical Corporation; type epoxy resins or mixtures thereof; EBPS-200 manufactured by Nippon Kayaku, EPX-30 manufactured by ADEKA, bisphenol S type epoxy resins such as EXA-1514 (trade name) manufactured by DIC; jER157S manufactured by Mitsubishi Chemical Corporation ( Bisphenol A novolac type epoxy resins such as bisphenol A novolak type epoxy resins such as TEPIC manufactured by Nissan Chemical Co., Ltd. (both are trade names); biphenyl novolak type epoxy resins; ESN-190 and DIC manufactured by Nippon Steel Chemical & Materials naphthalene group-containing epoxy resins such as HP-4032 manufactured by DIC Corporation; and epoxy resins having a dicyclopentadiene skeleton such as HP-7200 manufactured by DIC Corporation.

(C) The thermosetting compound may be in any amount, but (A) the alkali-soluble polyamideimide resin and the equivalent ratio (alkali-soluble It is preferred that the ratio of 1:0.1 to 1:10 of the functional group: thermosetting group such as epoxy group) be obtained.

[(D) cellulose derivative]
The curable resin composition of the first aspect of the present invention contains (D) a cellulose derivative as a polymer component different in compatibility with the (C) thermosetting compound or alkali-soluble photocurable compound. Preferably, the curable resin composition of the second aspect of the present invention contains (D) a cellulose derivative. When the cellulose derivative (D) is contained in the curable resin composition of the present invention, the cellulose derivative (D) is preferably soluble in an organic solvent and has a high glass transition temperature (Tg). (D) Cellulose derivatives include cellulose ethers, carboxymethyl celluloses, cellulose esters, etc., which will be described later.

Cellulose ethers include ethyl cellulose, hydroxyalkyl cellulose and the like, and commercial products of ethyl cellulose include Ethocel (registered trademark) 4, Ethocel 7, Ethocel 10, Ethocel 14, Ethocel 20, Ethocel 45, Ethocel 70, Ethocel 100 and Ethocel. 200, Ethocel 300 (all trade names manufactured by Dow Chemical Company), and commercial products of hydroxyalkyl cellulose include Metolose SM, Metolose 60SH, Metolose 65SH, Metolose 90SH, Metolose SEB, and Metolose SNB (all of which are Shin-Etsu Chemical Co., Ltd. ( (trade name) manufactured by Co., Ltd.).

In addition, commercial products of carboxymethyl cellulose include CMCAB-641-0.2 (trade name manufactured by Eastman Chemical Co.), Sunrose F, Sunrose A, Sunrose P, Sunrose S, and Sunrose B (all product name of Nippon Paper Industries Co., Ltd.) and the like.

A more preferable cellulose derivative is a cellulose ester obtained by esterifying the hydroxyl group of cellulose with an organic acid.

(In formula (5), R ₁ , R ₂ and R ₃ are each independently hydrogen, an acyl group, or

(In formula (6), R4 is hydrogen or a methyl group, and R5 is hydrogen, a methyl group, an ethyl group, or a glycidyl group.), and at least one of R ₁ , R ₂ and R ₃ is hydrogen, n is an integer of 1 or more, and its upper limit is regulated by the molecular weight described later. ) can be mentioned.

In the cellulose ester represented by the above formula (5), the acyl group content relative to the cellulose resin is in the range of more than 0 to 60 wt% or less, preferably in the range of 5 to 55 wt%.

In the cellulose ester represented by the above formula (5), the hydroxyl group content relative to the cellulose resin is 0 to 6 wt%, the acetyl group content as the acyl group is 0 to 40 wt%, and the propionyl group or/and butyryl group content is 0. 55 wt %, and the content of the group represented by formula (6) is preferably in the range of 0 to 20 wt %. As used herein, "wt%" is the weight percent of hydrogen, acyl groups, or groups represented by formula (6) relative to the weight of cellulose.

Commercial products of such cellulose esters include cellulose acetates such as CA-398-3, CA-398-6, CA-398-10, CA-398-30, CA-394-60S, and cellulose acetate butyrate. As, CAB-551-0.01, CAB-551-0.2, CAB-553-0.4, CAB-531-1, CAB-500-5, CAB-381-0.1, CAB-381- CAP-504-0.0.5, CAB-381-2, CAB-381-20, CAB-381-20BP, CAB-321-0.1, CAB-171-15, etc. as cellulose acetate propionates. 2, CAP-482-0.5, CAP-482-20 (all of the above cellulose derivatives are trade names manufactured by Eastman Chemical Co.), and the like. Among these, cellulose acetate butyrate and cellulose acetate propionate are preferable from the viewpoint of solubility in solvents.
In addition, the above cellulose acetate, cellulose acetate butyrate, and cellulose acetate propionate are treated with (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, ( A cellulose derivative containing a group represented by the formula (6) can be obtained by reacting with glycidyl meth)acrylate or the like. By using the cellulose derivative containing the group represented by the formula (6), the evaluation result of sticking property becomes better.

Although the number average molecular weight of (D) the cellulose derivative is not particularly limited, it is preferably 5,000 to 500,000, more preferably 10,000 to 100,000, still more preferably 10,000 to 30,000. When the molecular weight is within the above range, sticking is small, that is, the evaluation result of sticking property is good, and the viscosity of the curable resin composition falls within an appropriate range.

The glass transition temperature Tg referred to in this specification refers to the glass transition temperature measured by thermomechanical analysis (DSC) according to the method described in JIS C 6481:1996, "5.17.5 DSC method".

The cellulose derivative used in the present invention is preferably derived from natural products from the viewpoint of fossil fuel depletion. Furthermore, the starting material used for the cellulose derivative of the present invention can be produced from recycled products such as regenerated pulp, and it is possible to provide a composition that is preferable from the environmental aspect of CO ₂ reduction.

(D) A cellulose derivative can be used individually or in mixture of 2 or more types. (D) The amount of the cellulose derivative is, for example, 0.5 parts by mass or more and 20 parts by mass per 100 parts by mass of the (A) alkali-soluble polyamideimide resin (and an optional alkali-soluble polyimide resin described later). It is not more than 1 part by mass, preferably 1 part by mass or more and 15 parts by mass or less, more preferably 4 parts by mass or more and 10 parts by mass or less. When it is in the above range, the surface roughness (arithmetic mean roughness Ra) can be less than 0.1 μm at the time of the dry coating film, and the sticking is small, that is, the evaluation result of the sticking property is good. , the viscosity of the curable resin composition is in an appropriate range.
This is because (A) the alkali-soluble polyamideimide resin, (C) the thermosetting compound, and (D) the cellulose derivative have good compatibility before heat curing, and the polymer component is dispersed in the dried coating film. presumably because it exists.
In addition, after heat curing, the polymer components dispersed in the dry coating migrate to the film surface during the heat curing reaction, resulting in the surface roughness of the cured film after heat curing (arithmetic It is thought that the average roughness Ra) is larger than that of the dry coating film before heat curing. The thickness Ra) can also be set to 0.1 μm or more and 1 μm or less.

[(E) alkali-soluble polyimide resin]
From the viewpoint of heat resistance, the curable resin composition of the present invention preferably contains (E) an alkali-soluble polyimide resin.

(E) The alkali-soluble polyimide resin has an alkali-soluble functional group (hereinafter also referred to as an alkali-soluble group). The alkali-soluble functional group is a functional group that enables the curable resin composition of the present invention to be developed with an alkaline solution, and includes, for example, a carboxyl group and a phenolic hydroxyl group.

Such (E) alkali-soluble polyimide resins include, for example, resins obtained by reacting a carboxylic anhydride component with an amine component and/or an isocyanate component. Here, the alkali-soluble group is introduced by using an amine component having a carboxyl group or a phenolic hydroxyl group. Further, the imidization may be carried out by thermal imidization or by chemical imidization, and these may be used in combination.

In the synthesis of such (E) alkali-soluble polyimide resin, a known and commonly used organic solvent can be used. As such an organic solvent, there is no problem as long as it does not react with the carboxylic acid anhydrides, amines, and isocyanates that are raw materials and dissolves these raw materials, and its structure is not particularly limited. In particular, aprotic solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethylsulfoxide, and γ-butyrolactone are preferred because of their high solubility of raw materials.

(E) The alkali-soluble polyimide resin preferably has a carboxyl group as an alkali-soluble group, and particularly preferably has both a carboxyl group and a phenolic hydroxyl group as an alkali-soluble group.

(E) Alkali-soluble polyimide resin, the alkali solubility (developability) of the polyimide resin, the viewpoint of improving the balance with other properties such as mechanical properties of the cured product of the curable resin composition containing the polyimide resin Therefore, the acid value (solid content acid value) is preferably 20 to 200 mgKOH/g, particularly preferably 60 to 150 mgKOH/g.

Further, the molecular weight of the alkali-soluble polyimide resin is preferably a mass average molecular weight Mw of 100,000 or less, more preferably 1,000 to 100,000, in consideration of developability and cured coating film properties. ,000 to 50,000 are more preferred.

(E) When an alkali-soluble polyimide resin is blended, from the viewpoint of improving heat resistance and developability, the blending ratio of (A) an alkali-soluble polyamideimide resin and (E) an alkali-soluble polyimide resin can have a mass ratio of 98:2 to 50:50, preferably 95:5 to 50:50, more preferably 95:5 to 70:30.

The curable resin composition of the present invention may further contain the following components as necessary.

[Polymer resin]
The curable resin composition of the present invention can be blended with a known and commonly used polymer resin for the purpose of improving the flexibility and dryness to the touch of the resulting cured product. Examples of such polymer resins include polyester-based polymers, phenoxy resin-based polymers, polyvinylacetal-based polymers, polyvinyl butyral-based polymers, polyamide-based polymers, elastomers, and the like. Such polymer resins may be used singly or in combination of two or more.

[Inorganic filler]
The curable resin composition of the present invention can contain an inorganic filler in order to suppress curing shrinkage of the cured product and improve properties such as adhesion and hardness. Examples of such inorganic fillers include barium sulfate, amorphous silica, fused silica, spherical silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, silicon nitride, aluminum nitride, boron nitride, and Neuburg Silicious Earth.

[Coloring agent]
The curable resin composition of the present invention can contain known and commonly used colorants such as red, orange, blue, green, yellow, white and black. Any of pigments, dyes, and dyes may be used as such a coloring agent.

[Organic solvent]
The curable resin composition of the present invention can be blended with an organic solvent for preparing the resin composition or for adjusting the viscosity for application to a substrate or carrier film. Examples of such organic solvents include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, and petroleum solvents. Such organic solvents may be used singly or as a mixture of two or more.

[Other ingredients]
The curable resin composition of the present invention may further contain components such as mercapto compounds, adhesion promoters, antioxidants and ultraviolet absorbers, if necessary. Known and commonly used materials can be used as these materials.

In addition, known and commonly used thickeners such as finely divided silica, hydrotalcite, organic bentonite, and montmorillonite, antifoaming agents and/or leveling agents such as silicone-based, fluorine-based, and polymer-based agents, silane coupling agents, and rust inhibitors. Known and commonly used additives such as these can be blended.

<Laminated structure>
In the laminated structure of the present invention, at least one surface of the resin layer formed from the curable resin composition of the present invention is supported or protected by a film.

The resin layer may be a single layer or may have a laminated structure of two or more resin layers. In the case of a laminated structure of two or more resin layers, for example, a resin layer formed of the curable resin composition of the present invention may be laminated, or a resin layer formed of the curable resin composition of the present invention. and a resin layer formed of a curable resin composition not according to the present invention.

When the latter laminated structure is adopted, the laminated structure includes, for example, a resin layer (A) provided on a substrate such as a flexible printed wiring board, a resin layer (B) provided on the resin layer (A), At least one side of the resin layer having a laminated structure of is supported or protected by the film. The resin layer (A) is made of, for example, an alkali-developable resin composition containing an alkali-soluble resin and a heat-reactive compound.

The laminated structure can be manufactured, for example, as follows.

That is, first, on a carrier film (support film), the curable resin composition of the present invention constituting the resin layer is diluted with an organic solvent to adjust the viscosity to an appropriate value. Apply by method. When the resin layer has a laminated structure, the coating operation is repeated with or without changing the resin composition to be applied. Thereafter, it is usually dried at a temperature of 50 to 130° C. for 1 to 30 minutes to form a dry coating film of a resin layer in a B-stage state (semi-cured state) on the carrier film, and the laminated structure of the present invention. You can make a body. The resin layer of this laminated structure is a so-called dry film. A peelable cover film (protective film) can be further laminated on the dry film for the purpose of preventing dust from adhering to the surface of the dry coating film. As the carrier film and the cover film, conventionally known plastic films can be appropriately used. Regarding the cover film, when the cover film is peeled off, the adhesion force between the resin layer and the carrier film should be smaller. preferable. The thickness of the carrier film and cover film is not particularly limited, but is generally selected appropriately within the range of 10 to 150 μm.

<Cured product>
The cured product of the present invention is obtained by curing the curable resin composition of the present invention or the resin layer of the laminate structure of the present invention.

<Electronic parts>
The curable resin composition of the present invention and the resin layer of the laminate structure of the present invention can be effectively used for electronic components such as flexible printed wiring boards. Specifically, a layer of the curable resin composition of the present invention or a resin layer of a laminated structure is formed on a flexible printed wiring base material, patterned by light irradiation, and an insulation formed by forming a pattern with a developer. Examples include flexible printed wiring boards having a cured film.

The method for manufacturing the flexible printed wiring board will be specifically described below.

<Method for manufacturing flexible printed wiring board>
An example of manufacturing a flexible printed wiring board using the curable resin composition of the present invention or the resin layer of the laminate structure of the present invention is shown below. That is, the step of forming a resin layer by applying the curable resin composition of the present invention on a flexible printed wiring substrate on which a conductive circuit is formed, or by attaching the resin layer of the laminated structure of the present invention (layer forming step ), a step of patternwise irradiating the resin layer with active energy rays (exposure step), and a step of alkali-developing the exposed resin layer to form a patterned resin layer image (development step). It is a manufacturing method including. Further, if necessary, after alkali development, further photocuring or heat curing (post-curing step) is performed to completely cure the resin layer, form a cured film, and obtain a highly reliable flexible printed wiring board. be able to.

In addition, the production of a flexible printed wiring board using the curable resin composition of the present invention or the resin layer of the laminated structure of the present invention can also be carried out according to other procedures. That is, the step of forming a resin layer by applying the curable resin composition of the present invention on a flexible printed wiring substrate on which a conductive circuit is formed, or by attaching the resin layer of the laminated structure of the present invention (layer forming step ), a step of irradiating the resin layer with an active energy ray in a pattern (exposure step), a step of heating the resin layer after exposure (heating (PEB) step), and alkali development of the resin layer after heating. and a step of forming a patterned resin layer image (developing step). Further, if necessary, after alkali development, further photocuring or heat curing (post-curing step) is performed to completely cure the resin layer, form a cured film, and obtain a highly reliable flexible printed wiring board. be able to.

The present invention will be specifically described below with reference to examples, but the present invention is not limited only to these examples. In addition, "part" shall mean the mass part of solid content unless there is particular notice below.

((A) Synthesis of alkali-soluble polyamideimide resin)
[Synthesis Example 1]
In a four-necked 300 mL flask equipped with a nitrogen gas inlet tube, a thermometer, and a stirrer, an aliphatic diamine derived from a dimer acid having 36 carbon atoms as a dimer diamine (a) (manufactured by Croda Japan, product name PRIAMINE 1075) 28 0.61 g (0.052 mol), 4.26 g (0.028 mol) of 3,5-diaminobenzoic acid as a carboxyl group-containing diamine (b), and 85.8 g of γ-butyrolactone were charged and dissolved at room temperature.

Next, 30.12 g (0.152 mol) of cyclohexane-1,2,4-tricarboxylic anhydride (c) and 3.07 g (0.016 mol) of trimellitic anhydride (d) were added, and the mixture was stirred at room temperature for 30 minutes. held. Further, 30 g of toluene was charged, the temperature was raised to 160° C., water generated together with toluene was removed, the mixture was held for 3 hours, and the mixture was cooled to room temperature to obtain a solution containing an imidized compound.

14.30 g (0.068 mol) of trimethylhexamethylene diisocyanate as a diisocyanate compound was added to the solution containing the obtained imidized product, maintained at a temperature of 160° C. for 32 hours, and diluted with 21.4 g of cyclohexanone. (A) A solution (A-1) containing an alkali-soluble polyamideimide resin was obtained. The resulting polyamideimide resin had a mass average molecular weight Mw of 5250, a solid content of 41.5% by mass, an acid value of 63 mgKOH/g, and a dimer diamine (a) content of 40.0% by mass.

[Synthesis Example 2]
In a four-necked 300 mL flask equipped with a nitrogen gas inlet tube, a thermometer, and a stirrer, an aliphatic diamine derived from a dimer acid having 36 carbon atoms as a dimer diamine (a) (manufactured by Croda Japan, product name PRIAMINE 1075) 29 49 g (0.054 mol), 4.02 g (0.026 mol) of 3,5-diaminobenzoic acid as a carboxyl group-containing diamine (b), and 73.5 g of γ-butyrolactone were charged and dissolved at room temperature.

Next, 31.71 g (0.160 mol) of cyclohexane-1,2,4-tricarboxylic anhydride (c) and 1.54 g (0.008 mol) of trimellitic anhydride (d) were added, and the mixture was stirred at room temperature for 30 minutes. held. Further, 30 g of toluene was charged, the temperature was raised to 160° C., water generated together with toluene was removed, the mixture was held for 3 hours, and the mixture was cooled to room temperature to obtain a solution containing an imidized compound.

6.90 g (0.033 mol) of trimethylhexamethylene diisocyanate and 8.61 g (0.033 mol) of dicyclohexylmethane diisocyanate as diisocyanate compounds were added to the solution containing the obtained imidized product, and the mixture was heated at 160° C. for 32 hours. By holding and diluting with 36.8 g of cyclohexanone, a solution (A-2) containing (A) alkali-soluble polyamide-imide resin was obtained. The resulting polyamideimide resin had a mass average molecular weight Mw of 5840, a solid content of 40.4% by mass, an acid value of 62 mgKOH/g, and a dimer diamine (a) content of 40.1% by mass.

[Synthesis Example 3]
6.98 g of 2,2′-bis[4-(4-aminophenoxy)phenyl]propane, 3,5-diaminobenzoic acid and 3.5-diaminobenzoic acid were placed in a four-necked 300 mL flask equipped with a nitrogen gas inlet tube, a thermometer and a stirrer. 80 g, 8.21 g of polyether diamine (manufactured by Huntsman, product name Elastamine RT1000, molecular weight 1025.64), and 86.49 g of γ-butyrolactone were charged and dissolved at room temperature.

Next, 17.84 g of cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride and 2.88 g of trimellitic anhydride were charged and kept at room temperature for 30 minutes. Further, 30 g of toluene was charged, the temperature was raised to 160° C., and after removing the water generated together with the toluene, the mixture was held for 3 hours and cooled to room temperature to obtain an imidized compound solution.

9.61 g of trimellitic anhydride and 17.45 g of trimethylhexamethylene diisocyanate were added to the obtained imidized product solution and kept at a temperature of 160° C. for 32 hours. Thus, (A) an alkali-soluble polyamide-imide resin solution (A-3) containing carboxyl groups was obtained. The solid content was 40.1% by mass and the acid value was 83 mgKOH/g.

((E) Synthesis of alkali-soluble polyimide resin)
[Synthesis Example 4]
22.4 g of 3,3′-diamino-4,4′-dihydroxydiphenylsulfone, 2,2′-bis[4 8.2 g of -(4-aminophenoxy)phenyl]propane, 30 g of NMP, 30 g of γ-butyrolactone, 27.9 g of 4,4'-oxydiphthalic anhydride, and 3.8 g of trimellitic anhydride were added, Under nitrogen atmosphere, the mixture was stirred at room temperature and 100 rpm for 4 hours. Next, 20 g of toluene was added, and the mixture was stirred for 4 hours at a silicone bath temperature of 180° C. and 150 rpm while toluene and water were distilled off to obtain a polyimide resin solution (PI-1) having phenolic hydroxyl groups and carboxyl groups.

The resulting resin (solid content) had an acid value of 18 mg KOH, an Mw of 10,000, and a hydroxyl equivalent of 390.

((D) Synthesis of cellulose derivative)
[Synthesis Example 5]
A flask equipped with a stirrer, a thermometer and a reflux condenser was charged with 64 g of methyl ethyl ketone and 16 g of CAB-553-0.4 (cellulose acetate derivative, manufactured by Eastman Chemical Co.) and stirred at 75° C. for 1 hour. Then, a mixture obtained by premixing 15 g of methyl methacrylate and 1 g of benzoyl peroxide was added dropwise over 3 hours. After the dropwise addition was completed, a mixture obtained by previously mixing 0.5 g of benzoyl peroxide and 5 g of methyl ethyl ketone was added dropwise over 1 hour while maintaining the temperature at 75°C. Stirring was further continued at 75° C. for 3 hours and then cooled. 61 g of methyl ethyl ketone was added to the mixture and stirred to obtain a resin solution (CA-1). The content of resin solution CA-1 after heating was 20.0% by mass.

[Synthesis Example 6]
A flask equipped with a stirrer, a thermometer and a reflux condenser was charged with 64 g of methyl ethyl ketone and 16 g of CAB-553-0.4 (cellulose acetate derivative, manufactured by Eastman Chemical Co.) and stirred at 75° C. for 1 hour. Then, a mixture obtained by premixing 15 g of glycidyl methacrylate and 1 g of benzoyl peroxide was added dropwise over 3 hours. After the dropwise addition was completed, a mixture obtained by previously mixing 0.5 g of benzoyl peroxide and 5 g of methyl ethyl ketone was added dropwise over 1 hour while maintaining the temperature at 75°C. Stirring was further continued at 75° C. for 3 hours and then cooled. 61 g of methyl ethyl ketone was added to the mixture and stirred to obtain a resin solution (CA-2). The content of resin solution CA-2 after heating was 20.0% by mass.

[Example of the curable resin composition of the first aspect of the present invention]
<1-1. Preparation of curable resin compositions of Examples 1-1 to 1-12 and Comparative Examples 1-1 to 1-3>
According to the component composition shown in Table 1 below, the materials of the curable resin compositions of Examples 1-1 to 1-12 and Comparative Examples 1-1 to 1-3 were blended, respectively, and premixed with a stirrer. , and kneaded in a three-roll mill to prepare each curable resin composition for forming a resin layer. In addition, the value in Table 1 is the mass part of solid content, unless there is particular notice.

For each curable resin composition, a B-stage (semi-cured) resin layer (dry coating film) was formed for each curable resin composition, and the resolution was evaluated. Furthermore, as will be described later, the flexible wiring board having the resin layer in the B-stage state (semi-cured state) and the flexible wiring board having the cured product of the resin layer are classified into the B-stage state (semi-cured state)/after heat curing. The surface roughness of each coating film was evaluated. In addition, heat resistance (solder heat resistance), gold plating resistance (chemical resistance), flexibility and sticking properties were also evaluated for the flexible wiring board having the cured resin layer. Table 1 shows the results.

<1-2. Formation of Resin Layer>
A flexible printed wiring substrate on which a circuit with a copper thickness of 18 μm is formed was prepared and pretreated using CZ-8100 manufactured by MEC. Thereafter, each curable resin composition obtained in Examples 1-1 to 1-12 and Comparative Examples 1-1 to 1-3 was applied to the pretreated flexible printed wiring substrate, and the film thickness after drying was coated so as to have the film thickness shown in Table 1. Then, it was dried at 90° C. for 30 minutes in a hot air circulating drying oven to form a B-stage (semi-cured) resin layer (dry coating film).

<1-3. Preparation of Evaluation Board>
For the uncured resin layer on each flexible printed wiring substrate on which the resin layer is formed as described above, first, an exposure device (HMW-680-GW20: manufactured by Oak Manufacturing Co., Ltd.) equipped with a metal halide lamp is used to pass through a negative mask. A pattern exposure was performed so as to form an opening with a diameter of 200 μm at 300 mJ/cm ² . After that, a PEB process was performed at 90° C. for 30 minutes, followed by development (30° C., 0.2 MPa, 1 mass % Na ₂ CO ₃ aqueous solution) for 60 seconds, and curing by heat curing at 150° C. for 60 minutes. A flexible printed wiring board (evaluation board) having a resin layer (cured coating film) formed thereon was produced.

<1-4. Evaluation of Surface Roughness>
<1-2. Formation of resin layer>, a B-stage (semi-cured) resin layer (dry coating film) formed on a flexible printed wiring substrate as described in <1-3. Preparation of Evaluation Substrate>, the arithmetic mean surface roughness Ra was measured for the resin layer on the evaluation substrate after thermal curing, which was prepared as described in the above. The measured value was the average value of arbitrary 5 points in the observation range of 100×100 μm. A shape measuring laser microscope (VK-X100 manufactured by Keyence Corporation) was used to measure the arithmetic mean surface roughness Ra. Shape measurement laser microscope (same VK-X100) Main body (control unit) and VK observation application (Keyence VK-H1VX) After starting, support film with an intermediate layer to be measured on the xy stage (the surface having the intermediate layer is the top) was placed. Rotate the lens revolver of the microscope (VK-X110 manufactured by KEYENCE CORPORATION) to select an objective lens with a magnification of 10x, and roughly adjust the focus and brightness in the image observation mode of the VK observation application (same VK-H1VX). did. By operating the xy stage, the part of the sample surface to be measured was adjusted to be in the center of the screen. The 10x objective lens was replaced with a 100x objective lens, and the surface of the sample was brought into focus using the autofocus function in the image observation mode of the VK observation application (same as VK-H1VX). The simple mode of the shape measurement tab of the VK observation application (same as VK-H1VX) was selected, the measurement start button was pressed, the surface shape of the sample was measured, and a surface image file was obtained. A VK analysis application (VK-H1XA manufactured by KEYENCE CORPORATION) was started to display the obtained surface image file, and then tilt correction was performed.

The observation measurement range (horizontal) in measuring the surface shape of the sample was 100 μm×100 μm. Display the line roughness window, select JIS B 0601-1994 in the parameter setting area, select the horizontal line from the measurement line button, display the horizontal line anywhere in the surface image, and press the OK button. obtained the numerical value of the arithmetic mean surface roughness Ra. Further, horizontal lines were displayed at four different locations in the surface image, and numerical values of the arithmetic mean surface roughness Ra were obtained. The average value of the obtained five numerical values was calculated and used as the arithmetic mean surface roughness Ra value of the surface of each resin layer.

<1-5. Evaluation of resolution>
<1-2. Formation of Resin Layer> Regarding the B-stage state (semi-cured state) resin layer (dried coating film) formed on the flexible printed wiring substrate as described in <1-4. Evaluation of Surface Roughness>, the arithmetic average roughness Ra of each dry coating film was measured, and the dry coating films of each example, Comparative Example 1-1 and Comparative Example 1-3 were 0. was less than 0.1 μm. The dry coating film of Comparative Example 1-2 had an arithmetic mean roughness Ra of 0.1 or more. An exposure apparatus (HMW-680-GW20: manufactured by Oak Manufacturing Co., Ltd.) equipped with a metal halide lamp was first used on each of these dry coating films to form openings of 150 μm and 200 μm in diameter through a negative mask at 300 mJ/cm ² . Pattern exposure. The substrate having the resin layer after exposure was heat-treated at 90° C. for 30 minutes.

After that, the substrate was immersed in a 1% by mass sodium carbonate aqueous solution at 30° C. and developed for 1 minute, and the state of pattern formation was observed to evaluate the resolution. Evaluation criteria are as follows.

⊚: An opening pattern of 150 µm is well formed.
◯: An opening pattern of 200 μm is well formed, but an opening pattern of 150 μm is slightly defective.
x: The unexposed area exhibits developability, but there is a defect in the formation of a 200 μm opening pattern (insufficient resolution).

<1-6. Evaluation of heat resistance (solder heat resistance)>
<1-3. Preparation of evaluation substrate> A rosin-based flux is applied to the evaluation substrate prepared as described in, and immersed in a solder bath set to 260 ° C. in advance for 20 seconds (10 seconds x 2 times) to form a cured coating film. Blistering and peeling were observed, and heat resistance (solder heat resistance) was evaluated. Evaluation criteria are as follows.

⊚: There was no swelling or peeling even after being immersed twice for 10 seconds.
◯: No swelling or peeling occurred even after immersion for 10 seconds×1 time, but peeling occurred in the second immersion.
x: Swelling and peeling occurred when immersed once for 10 seconds.

<1-7. Evaluation of Gold Plating Resistance (Chemical Resistance)>
<1-3. Production of Evaluation Substrate>, evaluation was performed by the following method using an evaluation substrate manufactured as described above.

Using commercially available electroless nickel plating baths and electroless gold plating baths, the substrates for evaluation were plated with 5 μm of nickel and 0.05 μm of gold at 80 to 90° C. The substrate and the cured coating were observed. Plating resistance (chemical resistance) was evaluated. Evaluation criteria are as follows.

◯: No permeation between the substrate and the cured coating film.
Δ: Penetration is confirmed between the substrate and the cured coating film.
x: Part of the cured coating film is peeled off.

<1-8. Flexibility (MIT test) >
<1-3. Preparation of Evaluation Board> Using each evaluation board prepared as described in MIT folding fatigue tester D type (manufactured by Toyo Seiki Seisakusho), the film is regarded as paper in accordance with JIS P8115. A test was performed to evaluate flexibility. Specifically, as shown in FIG. 1, the test piece 1 is attached to the device, and a load F (0.5 kgf) is applied. Bending was performed at 135 degrees and a speed of 175 cpm, and the number of reciprocating bendings (times) until breakage was measured. The test environment was 25° C., and the radius of curvature was R=0.38 mm. Evaluation criteria are as follows.

A: It was bent 200 times or more, and the cured coating film at the bent portion did not crack.
◯: It was bent 170 to 199 times, and similarly no crack occurred.
Δ: It was bent 150 to 169 times, and no crack was generated.
x: Cracks occurred when the number of times of bending was 149 or less.

<1-9. Adhesion>
<1-2. Formation of Resin Layer> Regarding the resin layer in the B-stage state (semi-cured state) on each flexible printed wiring substrate on which the resin layer was formed as described in <1-4. Evaluation of Surface Roughness>, the arithmetic average roughness Ra of each dry coating film was measured, and the dry coating films of each example, Comparative Example 1-1 and Comparative Example 1-3 were 0. was less than 0.1 μm. The dry coating film of Comparative Example 1-2 had an arithmetic mean roughness Ra of 0.1 or more. Each of these dry coating films was first subjected to solid exposure at 300 mJ/cm ² through a negative mask using an exposure apparatus equipped with a metal halide lamp (HMW-680-GW20: manufactured by ORC Manufacturing Co., Ltd.). After that, a PEB process was performed at 90° C. for 30 minutes, followed by development (30° C., 0.2 MPa, 1% by mass Na ₂ CO ₃ aqueous solution) for 60 seconds, and heat curing at 150° C. for 60 minutes to obtain a cured coating. A flexible printed wiring board (evaluation board) on which a film was formed was produced. For each cured coating film, <1-4. Evaluation of surface roughness>, the arithmetic average roughness Ra of each dry coating film was measured, and the dry coating films of each example, Comparative Examples 1-2 and 1-3 were 0. .1 μm or more and 1 μm or less. The dry coating film of Comparative Example 1-1 had an arithmetic mean roughness Ra of less than 0.1.

The obtained evaluation substrates were cut into 2 cm squares, 10 sheets were stacked, left at temperatures of 20, 30, 40, and 60°C for 72 hours, and then the presence or absence of sticking was checked. Evaluation criteria are as follows.

◎: No sticking at 60 ° C. ○: No sticking at 40 ° C. or lower, but slight sticking at 60 ° C. △: No sticking at 30 ° C. or lower, but sticking at 40 ° C. or higher ×: Any temperature But you can see the sticking

The details of the ingredients in Table 1 are as follows.

A-1: Polyamideimide resin-containing solution produced by [Synthesis Example 1] of ((A) synthesis of alkali-soluble polyamideimide resin) described above A-2: The above-described ((A) alkali-soluble Polyamideimide resin-containing solution prepared by [Synthesis Example 2] in Synthesis of polyamideimide resin) A-3: Produced by [Synthesis Example 3] in ((A) Synthesis of alkali-soluble polyamideimide resin) Polyamideimide resin-containing solution PI-1: Alkali-soluble polyimide resin solution produced by [Synthesis Example 4] of ((E) Synthesis of alkali-soluble polyimide resin) described above P7-532: Polyurethane acrylate , acid value 47 mgKOH / g (manufactured by Kyoeisha Chemical Co., Ltd.)
IRGACURE OXE02: oxime photopolymerization initiator (manufactured by BASF)
CAB-553-0.4: Cellulose acetate derivative, number average molecular weight 20,000, 20 wt% DPM solution (manufactured by Eastman Chemical Co.) (parts in Table 1 indicate mass parts of solid content of 20 wt% DPM solution) )
CAB-504-0.2: Cellulose acetate derivative, number average molecular weight 15,000, 20 wt% DPM solution (manufactured by Eastman Chemical Co.) (parts in Table 1 indicate mass parts of solid content of 20 wt% DPM solution) )
JER828: bisphenol A type epoxy resin, epoxy equivalent 190, mass average molecular weight 380 (manufactured by Mitsubishi Chemical Corporation)
B-30: barium sulfate (manufactured by Sakai Chemical Industry Co., Ltd.)

As shown in Table 1, a dry coating film having a thickness of 2 to 100 μm was formed from a curable resin composition that was alkali-developable and formed a cured film by exposure and heat treatment from a comparison of Examples and Comparative Examples. In the case, when the arithmetic mean roughness Ra of the dry coating film is less than 0.1 μm and the arithmetic mean roughness Ra of the cured film after thermal curing of the dry coating film is 0.1 μm or more and 1 μm or less , The formed resin layer (dry coating film) has excellent resolution, and the cured coating film (cured product) after heat curing is not only excellent in heat resistance, gold plating resistance and flexibility, but also has excellent adhesion after high temperature storage. It was confirmed that the attachment was small.

Also, from the comparison between Examples 1-1, 1-2, 1-4, 1-9 to 1-11 and Examples 1-3, 1-5 to 1-8, 1-12, the dry coating film The film thickness is 3 μm or more and 80 μm or less, the arithmetic average roughness Ra of the dry coating film is less than 0.05 μm, and the ratio of the arithmetic average roughness Ra of the cured film after heat curing to the arithmetic average roughness Ra of the dry coating film ( When the arithmetic mean roughness Ra of the cured film after heat curing/the arithmetic mean roughness Ra of the dry coating film) is 6 or more, the resolution of the formed resin layer (dry coating film) is greatly improved, In addition, it was found that the cured coating film (cured product) after thermosetting is less sticky after storage at high temperatures.

[Example of the curable resin composition of the second aspect of the present invention]
<2-1. Preparation of curable resin compositions of Examples 2-1 to 2-8 and Comparative Examples 2-1 to 2-2>
According to the component composition shown in Table 2 below, the materials of the curable resin compositions of Examples 2-1 to 2-8 and Comparative Examples 2-1 to 2-2 were blended, respectively, and premixed with a stirrer. , and kneaded in a three-roll mill to prepare each curable resin composition for forming a resin layer. In addition, the value in Table 2 is the mass part of solid content, unless there is particular notice.

For each curable resin composition, as shown below, a resin layer (dry coating film) in a B-stage state (semi-cured state) of each curable resin composition is formed, and developability (alkali solubility) is evaluated. evaluated. Furthermore, as described later, a flexible printed wiring board having a cured product of this resin layer was formed, and heat resistance (solder heat resistance), gold plating resistance (chemical resistance), flexibility and adhesion were evaluated. Table 2 shows the results.

<2-2. Formation of Resin Layer>
A flexible printed wiring substrate on which a circuit with a copper thickness of 18 μm is formed was prepared and pretreated using CZ-8100 manufactured by MEC. Thereafter, each curable resin composition obtained in Examples 2-1 to 2-8 and Comparative Examples 2-1 to 2-2 was applied to the pretreated flexible printed wiring base material, and each film thickness after drying was applied so that the thickness was 30 μm. Then, it was dried at 90° C. for 30 minutes in a hot air circulating drying oven to form a B-stage (semi-cured) resin layer (dry coating film).

<2-3. Preparation of Evaluation Board>
First, an exposure device (HMW-680-GW20) equipped with a metal halide lamp is applied to the resin layer (dried coating film) in the B stage state (semi-cured state) on each flexible printed wiring substrate on which the resin layer is formed as described above. (manufactured by Oak Manufacturing Co., Ltd.), pattern exposure was performed through a negative mask at 300 mJ/cm ² so as to form an opening with a diameter of 200 μm. After that, a PEB process was performed at 90° C. for 30 minutes, followed by development (30° C., 0.2 MPa, 1 mass % Na ₂ CO ₃ aqueous solution) for 60 seconds, and curing by heat curing at 150° C. for 60 minutes. A flexible printed wiring board (evaluation board) having a resin layer (cured coating film) formed thereon was produced.

<2-4. Evaluation of developability (alkali solubility)>
<2-2. Formation of Resin Layer> First, an exposure apparatus (HMW-680- GW20 (manufactured by Oak Manufacturing Co., Ltd.), pattern exposure was performed through a negative mask at 300 mJ/cm ² so as to form an opening with a diameter of 200 μm. The substrate having the resin layer after exposure was heat-treated at 90° C. for 30 minutes.

After that, the substrate was immersed in a 1% by mass sodium carbonate aqueous solution at 30°C and developed for 1 minute, the state of pattern formation was observed, and developability (alkali solubility) was evaluated. Evaluation criteria are as follows.

◯: The exposed area exhibited developability, the unexposed area exhibited developability, and pattern formation was good.
x: The unexposed area exhibits developability, but resolution pattern formation is poor (insufficient resolution).

<2-5. Evaluation of heat resistance (solder heat resistance)>
<2-3. Preparation of evaluation substrate> A rosin-based flux is applied to the evaluation substrate prepared as described in, and immersed in a solder bath set to 260 ° C. in advance for 20 seconds (10 seconds x 2 times) to form a cured coating film. Blistering and peeling were observed, and heat resistance (solder heat resistance) was evaluated. Evaluation criteria are as follows.
⊚: There was no swelling or peeling even after being immersed twice for 10 seconds.
◯: No swelling or peeling occurred even after immersion for 10 seconds×1 time, but peeling occurred in the second immersion.
x: Swelling and peeling occurred when immersed once for 10 seconds.

<2-6. Evaluation of Gold Plating Resistance (Chemical Resistance)>
<2-3. Production of Evaluation Substrate>, evaluation was performed by the following method using an evaluation substrate manufactured as described above.

<2-7. Flexibility (MIT test)>
<2-3. Preparation of Evaluation Board> Using each evaluation board prepared as described in MIT folding fatigue tester D type (manufactured by Toyo Seiki Seisakusho), the film is regarded as paper in accordance with JIS P8115. A test was performed to evaluate flexibility. Specifically, as shown in FIG. 1, the test piece 1 is attached to the device, and a load F (0.5 kgf) is applied. Bending was performed at 135 degrees and a speed of 175 cpm, and the number of reciprocating bendings (times) until breakage was measured. The test environment was 25° C., and the radius of curvature was R=0.38 mm. Evaluation criteria are as follows.

<2-8. Adhesion>
<2-2. Formation of resin layer> First, an exposure device equipped with a metal halide lamp is applied to the resin layer (dried coating film) in the B stage state (semi-cured state) on each flexible printed wiring substrate on which the resin layer is formed as described in (HMW-680-GW20: manufactured by ORC Manufacturing Co., Ltd.), solid exposure was performed at 300 mJ/cm ² through a negative mask. After that, a PEB process was performed at 90° C. for 30 minutes, followed by development (30° C., 0.2 MPa, 1 mass % Na ₂ CO ₃ aqueous solution) for 60 seconds, and curing by heat curing at 150° C. for 60 minutes. A flexible printed wiring board (evaluation board) having a resin layer (cured coating film) formed thereon was produced.

Details of the components in Table 2-1 are as follows.

PI-1: Alkali-soluble polyimide resin solution produced by [Synthesis Example 4] of ((E) Synthesis of alkali-soluble polyimide resin) described above A-3: Alkali-soluble polyimide resin solution A-3: Alkali-soluble polyimide resin solution Polyamideimide resin-containing solution A-1 produced by [Synthesis Example 3] of (Synthesis of polyamideimide resin): Manufactured by [Synthesis Example 1] of ((A) Synthesis of alkali-soluble polyamideimide resin) Polyamideimide resin-containing solution P7-532: Polyurethane acrylate, acid value 47 mgKOH/g (manufactured by Kyoeisha Chemical Co., Ltd.)
IRGACURE OXE02: oxime photobase generator (manufactured by BASF)
CAB-553-0.4: Cellulose acetate derivative, number average molecular weight 20,000, 20 wt% DPM solution (manufactured by Eastman Chemical Co.) (parts in Table 2 indicate mass parts of solid content of 20 wt% DPM solution) )
CAB-504-0.2: Cellulose acetate derivative, number average molecular weight 15,000, 20 wt% DPM solution (manufactured by Eastman Chemical Co.) (parts in Table 2 indicate mass parts of solid content of 20 wt% DPM solution) )
CA-1: CAB-553-0.4 modified with methyl methacrylate, number average molecular weight 24,000, 20 wt% MEK solution (table The number of parts in 2 indicates the mass part of the solid content of the 20 wt% MEK solution)
CA-2: CAB-553-0.4 modified with glycidyl methacrylate, number average molecular weight 25,000, 20 wt% MEK solution (table The number of parts in 2 indicates the mass part of the solid content of the 20 wt% MEK solution)
jER828: bisphenol A type epoxy resin, epoxy equivalent 190, mass average molecular weight 380 (manufactured by Mitsubishi Chemical Corporation)

As shown in Table 2, from the comparison between Examples and Comparative Examples, the curable resin composition contains (A) an alkali-soluble polyamideimide resin, (C) a thermosetting compound, and (B) a photobase generator. By including (D) a cellulose derivative, the formed resin layer has good developability, and the resin layer after curing not only has excellent heat resistance, gold plating resistance, and flexibility, but also has little sticking. was done.

In addition, from the comparison between Examples 2-1 to 2-2 and Examples 2-3 to 2-8, (A) alkali-soluble polyamideimide resin was blended more than (E) alkali-soluble polyimide resin. It was shown that the heat resistance is further improved in the case of In addition, from the comparison between Example 2-3 and Examples 2-7 and 2-8, by using a cellulose derivative (D) containing a group represented by formula (6), the sticking property was further improved. It was found that the smaller the value, the better the evaluation result of sticking property. Further, from a comparison of Examples 2-3 and 2-6, (A) as an alkali-soluble polyamideimide resin, a polyamideimide having a structure represented by the formula (1) and a structure represented by the formula (2) It was found that the use of a resin also improves flexibility and adhesion.

Claims

A curable resin composition that is alkali developable and forms a cured film by exposure and heat treatment,
When a dry coating film having a thickness of 2 to 100 μm is formed from the curable resin composition, the arithmetic mean roughness Ra of the dry coating film is less than 0.1 μm, and after heat curing of the dry coating film A curable resin composition, wherein the cured coating film has an arithmetic mean roughness Ra of 0.1 μm or more and 1 μm or less.
When a dry coating film having a thickness of 2 to 100 μm is formed from the curable resin composition, the arithmetic mean roughness Ra of the dry coating film is less than 0.05 μm, and after heat curing of the dry coating film 2. The curable resin composition according to claim 1, wherein the cured coating film has an arithmetic mean roughness Ra of 0.1 [mu]m or more and 0.5 [mu]m or less.
(A) an alkali-soluble polyamide-imide resin, (B) a photobase generator, (C) a thermosetting compound, and (D) a cellulose derivative. The curable resin composition according to .
The curable resin composition according to claim 3, wherein the (C) thermosetting compound is an epoxy resin.
A laminated structure, characterized in that at least one side of a resin layer formed from the curable resin composition according to claim 1 is supported or protected by a film.
The curable resin composition according to claim 1 or the cured product of the resin layer according to claim 5.
An electronic component comprising an insulating film made of the cured product according to claim 6.
(A) an alkali-soluble polyamideimide resin;
(B) a photobase generator;
(C) a thermosetting compound;
(D) a curable resin composition comprising a cellulose derivative;
The curable resin composition according to claim 8, wherein the (A) alkali-soluble polyamide-imide resin has a carboxyl group.
The curable resin composition according to claim 9, wherein the (A) alkali-soluble polyamide-imide resin has a carboxyl group and a phenolic hydroxyl group.
The curable resin composition according to claim 8, further comprising (E) an alkali-soluble polyimide resin.
The curable resin composition according to claim 8, wherein (C) the thermosetting compound is an epoxy resin.
A cured product obtained from the curable resin composition according to claim 8.
An electronic component comprising an insulating film made of the cured product according to claim 13.