WO2025148605A1 - Alkali-soluble resin and use thereof - Google Patents

Abstract

An alkali-soluble resin and a use thereof. The alkali-soluble resin comprises a compound represented by general formula (1) and a compound represented by general formula (2), wherein the diamine residue in general formula (2) comprises at least two structural units, one of which is represented by general formula (3) or (4). By introducing a phenolic hydroxyl group, a sulfonyl group, or a combination thereof, and the structural unit represented by general formula (3) or (4) into an alkali-soluble resin structure, a fluorine-element-free alkali-soluble resin having a good organic solvent solubility is obtained. The alkali-soluble resin can be applied to a photosensitive resin composition to prepare a photosensitive curing film having good transmittance and heat resistance.

Description

Alkali-soluble resin and its application

Cross-references

This application claims priority to Chinese Patent Application No. 202410037523.7 filed on January 10, 2024, entitled “An Alkali-Soluble Resin and Its Application,” all disclosures of which are incorporated herein by reference in their entirety.

Technical Field

The invention relates to the field of polymer materials, and in particular to an alkali-soluble resin and application thereof.

Background Art

Polyimide, due to its unique aromatic ring conjugation and imide ring structure, has good heat resistance, high insulation, chemical resistance and good mechanical properties, and is widely used in surface passivation layers, stress buffer layers and interlayer insulation layers of semiconductor devices; it also has important application value in signal line distribution, α-particle shielding layers, micro-solder ball processes, stress buffer layers of plastic-sealed circuits, flexible packaging substrates, etc. in semiconductor advanced packaging (BGA, CSP, SiP, WLP, etc.); at the same time, in display devices such as organic EL display devices or liquid crystal display devices, photosensitive polyimide resins are widely used in the flat layer and pixel definition layer of the display device to improve interlayer insulation and reduce display color difference.

The unique aromatic ring conjugated structure in the polyimide structure leads to the formation of intramolecular and intermolecular charge transfer complexes (CTC), which greatly affects the light transmittance of polyimide (PI) films, and presents a brown-yellow color and poor light transmittance, limiting the development of PI films in the optoelectronic field. In order to achieve good organic solvent solubility and excellent optical properties (such as transmittance), fluorine elements or fluorine-containing structures are often introduced to destroy the conjugation in the polyimide structure to improve optical performance.

However, with the international community's regulation of PFAS (full name: polymerized perfluoroalkane sulfonates) in recent years, the demand for fluorine-free materials has become increasingly apparent.

Summary of the invention

The invention provides an alkali-soluble resin for solving the problems of poor solubility in organic solvents, low transmittance and poor heat resistance in the prior art without fluorine element.

The present invention also provides application of the alkali-soluble resin.

In a first aspect, the present invention provides an alkali-soluble resin, comprising a compound represented by general formula (1) and a compound represented by general formula (2),

Wherein, in the general formula (1), Ar ₁ represents a dianhydride residue; Ar ₂ represents a diamine residue, and Ar ₁ and Ar ₂ contain at least one phenolic hydroxyl group or one sulfonyl group; R ₁ represents a fluorine-free organic group having 1 to 10 H or C atoms; m is an integer of 10 to 10000, and r is an integer of 0 to 2;

Wherein, in the general formula (2), Ar ₃ represents a dianhydride residue; Ar ₄ represents a diamine residue, and the diamine residue Ar ₄ comprises at least two structural units, one of which is as shown in the general formula (3) or the general formula (4);

Wherein, in the general formula (3), R ₂ and R ₃ are the same or different and independently represent -(CH ₂ )- or -(CH ₂ CH ₂ )-; L ₁ , L ₂ , L ₃ and L ₄ are the same or different and independently represent H or a non-fluorine halogen element;

Wherein, in the general formula (4), R ₄ and R ₅ are the same or different and independently represent -(CH ₂ )- or -(CH ₂ CH ₂ )-; L ₅ , L ₆ , L ₇ and L ₈ are the same or different and independently represent H or a non-fluorine halogen element;

Ar ₁ , Ar ₂ , Ar ₃ and Ar ₄ do not contain fluorine element.

It should be noted that the "non-fluorine halogen elements" mentioned in the above technical solution refer to chlorine, bromine or iodine.

The dianhydride residue (Ar ₁ and Ar ₃ ) refers to the residue obtained by removing two anhydride groups from the dianhydride. The dianhydride includes but is not limited to the following dianhydrides, such as pyromellitic dianhydride (PMDA), 3,3,3',4'-biphenyltetracarboxylic dianhydride (s-BPDA), 2,3,3',4'-biphenyltetracarboxylic dianhydride (α-BPDA), 4,4'-oxydiphthalic anhydride (ODPA), 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), p-phenylene-triphenylene dianhydride (TAHQ), 3,3',4 , one or more of 4'-diphenylsulfonetetracarboxylic dianhydride (BSDA), cyclobutanetetracarboxylic dianhydride (CBDA), cyclohexanetetracarboxylic dianhydride (HPMDA), N-[5-[3-[(1,3-dioxy-2-benzofuran-5-carbonyl)amino]-4-hydroxyphenyl]sulfonyl-2-hydroxyphenyl]-1,3-dioxy-2-benzofuran-5-carboxamide and 3,3,4,4-diphenylsulfonetetracarboxylic dianhydride (DSDA).

The diamine residue (Ar ₂ and Ar ₄ ) refers to a residue obtained by removing two amino groups from a diamine. The diamine includes but is not limited to the following diamines, such as 2,2-bis(4-hydroxy-3-aminophenyl)propane (BAP), 3,3'-diamino-4,4'-dihydroxydiphenyl sulfone (BAHS), N,N'-[(1-methylethylidene)bis(6-hydroxy-3,1-phenylene)]bis[3-aminobenzamide, 4,4'-bis(3-aminophenoxy)diphenyl sulfone, 2,2-bis[3-(4-aminobenzamido)-4-hydroxyphenyl]propane, 2,2-bis [3-(4-aminobenzamide)-4-hydroxyphenyl]sulfone, 2,2-bis[3-(4-aminobenzamide)-4-hydroxyphenyl]ether, N-(2-hydroxy-5-amino)phenyl-3-aminobenzamide, N-(5-amino-2-hydroxyphenyl)-4-[2-[4-[(4-aminophenyl)carbamoyl]phenyl]-propane-2-yl]benzamide, N-(5-amino-2-hydroxyphenyl)-4-[2-[4-[(4-aminophenyl)carbamoyl]phenyl]-propane-2-yl]benzamide ]phenyl]-sulfone-2-yl]benzamide, N-(5-amino-2-hydroxyphenyl)-4-[2-[4-[(4-aminophenyl)carbamoyl]phenyl]-ether-2-yl]benzamide, 1,4-p-phenylenediamine (PDA), m-phenylenediamine (m-PDA), o-phenylenediamine (o-PDA), 4,4'-diaminodiphenyl ether (ODA), 4,4'-diamino-p-terphenyl (DATP), 4,4'-diaminodiphenylmethane (MDA), 2,2'- One or more of dimethyl-4,4'-diaminobiphenyl (m-TB), p-aminophenyl para-aminobenzoate (APAB), 1,4-bis(4'-aminophenoxy)benzene (1,4,4-APB), 1,3,4-APB:1,3-bis(4'-aminophenoxy)benzene (1,3,4-APB), 1,3-bis(3'-aminophenoxy)benzene (1,3,3-APB) and 2,2-bis(4-(4-aminophenoxy)phenyl)propane (BAPP).

Ar ₁ and Ar ₂ contain at least one phenolic hydroxyl group or one sulfonyl group (-S(=O) ₂ -); in other words, among the raw materials dianhydride and diamine used to form the general formula (1), at least one raw material monomer contains a phenolic hydroxyl group or a sulfonyl group (-S(=O) ₂ -) structure, or both structures may be present, and the two structures may appear simultaneously on one monomer or on different monomers. In the process of preparing the compound represented by the general formula (1), the weight proportion of the monomer containing a phenolic hydroxyl group, a sulfonyl group or a combination of the two is ≥20% of the total monomers.

It should be noted that when _R1 represents H, the alkali-soluble resin is a polyamic acid soluble in an alkaline aqueous solution; when _R1 represents a fluorine-free organic group having 1 to 10 C atoms, the alkali-soluble resin is a polyamide ester soluble in an alkaline aqueous solution, and preferably, the organic group is an alkyl group.

The present invention has found that when the structure contains phenolic hydroxyl groups, the obtained alkali-soluble resin has better alkali solubility; when the structure contains sulfonyl groups (-S(=O) ₂ -) and alicyclic structures, the obtained alkali-soluble resin has better organic solvent solubility and better optical transmittance.

In a specific embodiment of the present invention, good alkali solubility is achieved by adjusting the structural ratio of general formula (1) and general formula (2); by introducing phenolic hydroxyl group, sulfonyl group (-S(=O) ₂ -) or a combination of the two, and structural units represented by general formula (3) or general formula (4) into the alkali-soluble resin structure, an alkali-soluble resin with good organic solvent solubility is obtained under the condition of not containing fluorine element.

Specifically, the alkali-soluble resin has good solubility in organic solvents, which is embodied in that it is soluble in one or more of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, tetrahydrofuran, propylene glycol methyl ether, propylene glycol monoethyl ether, ethylene glycol monomethyl ether, γ-butyrolactone, methyl lactate, ethyl lactate, propyl lactate and butyl lactate.

In some embodiments of the present invention, the proportion of the compound represented by general formula (1) to the sum of the mass of the compound represented by general formula (1) and the compound represented by general formula (2) is 10% to 50%.

The present invention has found that the higher the specific gravity of the compound represented by the general formula (1) in the alkali-soluble resin, the better. If the specific gravity is too high, it is difficult to achieve good organic solvent solubility and light transmittance, and if the specific gravity is too low, it is difficult to achieve alkali dissolution.

To further improve the transmittance, during the preparation of the compound represented by general formula (2), the proportion of the diamine monomers of general formula (3) and the diamine monomers of general formula (4) to the total mass of the diamine monomers (Ar ₄ is connected to an amino group at both ends) is ≥50%.

In some embodiments of the present invention, the diamine forming the general formula (3) is selected from the group consisting of the following structures:

In some embodiments of the present invention, the diamine structure forming the general formula (4) is as follows:

The preparation method of the alkali-soluble resin of the present invention comprises the following steps:

(1) preparing the desired diamine (a diamine represented by two amino groups connected at both ends of the general formula (3) or (4)) according to the self-designed structure and process, and performing purification and other post-treatments for use;

(2) Under the protection of inert gas, materials such as phenolic hydroxyl group, sulfonyl group (-S(＝O) ₂ -) monomer, other diamine (optionally added) and dianhydride (optionally added) are successively dissolved in an organic solvent, and a polyimide precursor solution 1 with a solid content of 10-50% is obtained by polymerization reaction, or a diester solution is obtained by esterification of dianhydride and alcohol, and then further reacted with diamine after chlorination or DCC treatment to obtain a polyimide precursor solution 1 with a solid content of 10-50%; alicyclic diamine (a diamine represented by two amino groups connected at both ends of the general formula (3) or (4), other diamine (optionally added) and dianhydride (optionally added) are successively dissolved in an organic solvent, and a polyimide solution 2 with a solid content of 10-50% is obtained by high-temperature polymerization reaction; the two are mixed and stirred at room temperature to obtain a polyimide resin solution (a small amount of copolymerization occurs under room temperature mixing);

(3) using a precipitant to precipitate the resin, and obtaining the target alkali-soluble resin after filtering, washing and drying.

In a second aspect, the present invention provides a photosensitive resin composition, comprising (a) an alkali-soluble resin, (b) a photosensitizer, (c) a cross-linking agent, (d) an adhesion modifier and (e) a solvent; the (a) alkali-soluble resin comprises the above-mentioned alkali-soluble resin of the present invention.

In some embodiments of the present invention, the (b) photosensitizer is a naphthoquinone azide photosensitizer.

The naphthoquinone azido type photosensitizer is an esterification product of a phenolic hydroxyl compound and naphthoquinone azido sulfonyl chloride. The phenolic hydroxyl compound is selected from one or more of Bis-Z, BisP-EZ, BisOPP-Z, BisP-CP, BisP-EZ, TekP-4HBPA, TrisP-HAP, TrisP-PA, Tris-PHBA, TrisP-SA, TrisOCR-PA, BisOCHP-Z, BisP-MZ, and BisP-PZ (trade names, manufactured by Honshu Chemical Industry Co., Ltd.).

In some embodiments of the present invention, the cross-linking agent (c) has no special requirements, and can be a heat-crosslinkable compound that can undergo a cross-linking reaction with the alkali-soluble resin. Specifically, the cross-linking agent (c) can be selected from one or more of epoxy compounds, alkoxymethylol compounds, and alkoxymethylol triazine ring compounds; the functionality of the cross-linking agent (c) is greater than or equal to 2.

Wherein, the epoxy compound is selected from one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, and propylene glycol diglycidyl ether.

The alkoxymethylol compound is selected from polyalkoxymethylolated phenolic hydroxyl compounds, wherein the phenolic hydroxyl compound is selected from one or more of Bis-Z, BisP-EZ, BisOPP-Z, BisP-CP, BisP-EZ, TekP-4HBPA, TrisP-HAP, TrisP-PA, Tris-PHBA, TrisP-SA, TrisOCR-PA, BisOCHP-Z, BisP-MZ, and BisP-PZ (trade names, manufactured by Honshu Chemical Industry Co., Ltd.).

The alkoxy hydroxymethyl triazine ring compound is selected from one or more compounds represented by general formula (5);

Wherein, R ₈ and R ₉ each independently represent H, CH ₂ OCH ₃ or CH ₂ OCH ₂ CH ₃ , and not all of them are H.

In some embodiments of the present invention, the (d) adhesion modifier includes but is not limited to one or more of the following: γ-glycidyloxypropyltrimethoxysilane (KH560), γ-aminopropyltriethoxysilane (KH550), γ-aminopropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, p-aminophenyltrimethoxysilane, 3-(m-aminophenoxy)trimethoxysilane, 3-mercaptomethyltrimethoxysilane, and 3-mercaptopropyltriethoxysilane.

In some embodiments of the present invention, the (e) solvent is one or more of ketone solvents, ester solvents, ether solvents, aromatic hydrocarbon solvents and other solvents.

By way of example but not limitation, the ketone solvent is one of acetone, methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone, cyclopentanone and cyclohexanone.

The ester solvent is one or more of ethyl acetate, butyl acetate, n-propyl acetate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, propylene glycol methyl ether acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate and gamma-butyrolactone.

The ether solvent is one or more of propylene glycol methyl ether, propylene glycol monoethyl ether and ethylene glycol monomethyl ether.

The aromatic hydrocarbon solvent may be one or more of toluene and xylene.

The other solvents are one or more of N-methylpyrrolidone, tetrahydrofuran, dioxane, N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide.

In a third aspect, the present invention provides a photosensitive cured film formed by curing any one of the above-mentioned photosensitive resin compositions.

It is understood by those skilled in the art that the curing of the above-mentioned photosensitive resin composition to form a cured film usually includes some pre-treatments, such as coating, hot plate drying, exposure, and development before curing. Among them, each step adopts conventional operation means in the art. For example, a rotational viscometer is used for coating, hot plate drying is used for drying, and curing is performed by heat curing under nitrogen.

Due to the specific structure of the alkali-soluble resin in the photosensitive resin composition, the photosensitive cured film of the present invention has good light transmittance and heat resistance; the average light transmittance of the photosensitive cured film at 380-780nm is ≥70%; and the thermal weight loss temperature T5% is ≥300°C.

The photosensitive cured film of the present invention can be applied to a surface protective film and an interlayer insulating film of a semiconductor element, an insulating layer of an organic electroluminescent element, and an insulating layer of a thin film transistor.

The present invention provides an alkali-soluble resin and its application. By introducing a phenolic hydroxyl group, a sulfonyl group or a combination of the two, and a structural unit represented by the general formula (3) or the general formula (4) into the structure of the alkali-soluble resin, an alkali-soluble resin having good solubility in an organic solvent without the presence of fluorine element is provided. The alkali-soluble resin can be applied to a photosensitive resin composition to prepare a photosensitive cured film having good transmittance and heat resistance.

DETAILED DESCRIPTION

In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Unless otherwise specified, the technical means used in the embodiments of the present invention are conventional means well known to those skilled in the art. Unless otherwise specified, the materials and reagents used in the embodiments of the present invention can be obtained through regular commercial channels.

The abbreviations of the compounds in the following examples are:
PDA: p-phenylenediamine
BAP:2,2-bis(4-hydroxy-3-aminophenyl)propane
BAHS:3,3'-diamino-4,4'-dihydroxydiphenyl sulfone
ODPA:4,4'-oxydiphthalic anhydride
DSDA:3,3,4,4-Diphenylsulfone tetracarboxylic dianhydride
DMFDEA: N,N'-dimethylformamide diethyl acetal
MAP: meta-aminophenol
TrisP-HAP: 1,1,1-Tris(4-hydroxyphenyl)ethane

Synthesis Example 1 Synthesis of diamines (I-1) and (I-2)

The synthesis route is as follows:

(1) Synthesis of Compound I-1

Add 25.4 g of compound I-1-1 and 200 ml of tetrahydrofuran to the reactor, pass ammonia gas to a pressure of 0.5-1.0 MPa at room temperature, raise the temperature to 200 ° C and react for 6 hours, cool and reduce the pressure, quench the reaction with saturated sodium bicarbonate aqueous solution, carry out conventional post-treatment, and recrystallize from n-heptane to obtain 25.1 g of an off-white solid (compound I-1), HPLC: 99.6%, yield 87.2%.

The obtained white solid compound I-1 was analyzed by GC-MS, and the m/z of the product was 246.2 (M+).

(2) Synthesis of Compound I-2

Compound I-2 was prepared using the same mechanism as above, but the yield was low, so the subsequent synthesis example 9 is currently in the laboratory stage.

Synthesis Example 2 Synthesis of diamine (I-3)

The synthesis route is as follows:

(1) Synthesis of Compound I-3-2

Under nitrogen protection, 36.0 g of compound I-3-1 and 200 ml of tetrahydrofuran were added to the reaction bottle, and 68.3 g of hydrofluoric acid pyridine was added dropwise at a temperature of -10 to 0 ° C. After the addition, the reaction was kept warm for 2 hours, and a saturated aqueous sodium bicarbonate solution was added to quench the reaction. After conventional post-treatment, 30.5 g of light yellow solid (compound I-3-2) was obtained by recrystallization from n-heptane, HPLC: 99.3%, yield 72.6%.

(2) Synthesis of Compound I-3

Under nitrogen protection, 14.2 g of ammonium formate, 200 ml of methanol, 30.0 g of compound I-3-2, 10 ml of acetic acid, and 0.001 g of iridium catalyst (Ir-3) were added to the reaction bottle, and the reaction was refluxed for 8 hours at a temperature of 75 ° C. The temperature was cooled to room temperature, and saturated aqueous sodium hydroxide solution was added to quench, and then conventional post-treatment operations were performed, dissolved and separated by dichloromethane, purified by chromatography, and recrystallized from a mixed solution of n-heptane and toluene in a volume ratio of 3: 1 to obtain 23.7 g of a white solid (compound I-3), HPLC: 99.8%, yield: 78.5%.

The obtained white solid compound I-3 was analyzed by GC-MS, and the m/z of the product was 246.2 (M+).

Synthesis Example 3 Synthesis of photosensitizer (PAC-1)

The reaction vessel was vented with nitrogen in advance. After 30 minutes, 260 g of dioxane (water was removed with molecular sieves 24 hours in advance), and then 10.60 g (0.025 mol) of TrisP-PA (trade name, made by Honshu Chemical) and 20.1 g (0.075 mol) of naphthoquinone azidosulfonyl chloride were added respectively. A mixed solution of triethylamine (6.3 g) and dioxane (20 g) was slowly added dropwise. The temperature was controlled below 30°C. After the addition was completed, the mixture was kept at 30°C for 2 hours. The mixture was filtered, washed with deionized water for 3 times, rinsed with dilute hydrochloric acid and deionized water for 3 times respectively, and dried under vacuum at 60°C for 24 hours.

Synthesis Example 4 Synthesis of photosensitizer (PAC-2)

The photosensitizer PAC-2 was prepared by a similar synthesis method to that in Synthesis Example 3, except that TrisP-PA (trade name, manufactured by Honshu Chemical) was replaced by Trisp-HAP (trade name, manufactured by Honshu Chemical).

Synthesis Example 5 Synthesis of Crosslinking Agent (C-1)

The reaction vessel was vented with nitrogen in advance. After 30 minutes, 200 g of water was added, and then 20 g (0.5 mol) of NaOH and 25.8 g (0.1 mol) of 1,1,1-tris(4-hydroxyphenyl)ethane were added respectively. After fully dissolved, 18 eq of formaldehyde solution was slowly added dropwise, and the temperature was controlled within 20°C. After the addition was completed, the temperature was kept at 20°C for 24 hours. Sulfuric acid and water were added to neutralize the product to obtain a white product, which was washed with deionized water for 3 times and dried under vacuum at 50°C for 72 hours.

The dried white product was further reacted with methanol at room temperature for 24 hours, and the methanol was removed by distillation under reduced pressure to obtain the cross-linking agent C-1.

Synthesis Example 6 Synthesis of Crosslinking Agent (C-2)

Crosslinking agent C-2 was prepared by a similar synthesis method to that in Synthesis Example 5 except that Trisp-HAP (trade name, manufactured by Honshu Chemical) was replaced with melamine.

Synthesis Example 7 Synthesis of Polyimide Resin A-1

The reaction vessel was vented with nitrogen in advance. After 30 minutes, 86.25 g of N-methylpyrrolidone (NMP, dehydrated with molecular sieves 24 hours in advance) was added, and then 5.17 g (0.02 mol) of BAP were added, and stirred at 25°C until completely dissolved; then 8.96 g (0.025 mmol) of compound DSDA was added, and the reaction was stirred at room temperature for 12 hours, and 1.09 g (0.01 mol) of MAP was added, and the reaction was kept warm for 12 hours; 11.66 g of DMFDEA was added, the temperature was raised to 60°C, kept warm for 4 hours, and then cooled to room temperature to obtain resin solution A-1-1;

Use nitrogen to vent the reaction container in advance. After 30 minutes, add 78.82g N-methylpyrrolidone (NMP, use molecular sieve to remove water 24 hours in advance), then add 6.16g (0.025mol) I-1, stir at 25°C until completely dissolved, then add 7.75g (0.025mmol) compound ODPA, stir at room temperature for 12 hours, add 16g toluene, heat to 160°C, reflux to separate water, keep warm for 4 hours and cool to room temperature to obtain resin solution A-1-2;

The resin solutions A-1-1 and A-1-2 were mixed and stirred at room temperature for 12 hours to obtain a polyimide resin A-1 solution, which was then added into 3 L of deionized water, precipitated, filtered, and washed three times; and vacuum dried at 80° C. for 72 hours to obtain a polyimide resin A-1.

Synthesis Examples 8 to 12 Synthesis of Polyimide Resins A-2 to A-6

As shown in Table 1, 40 parts of BAP were replaced by 40 parts of BAHS or PDA respectively and the same formula and process as resin solution A-1-1 were used to prepare resin solutions A-2-1, A-3-1, A-4-1, A-5-1, and A-6-1;

Resin solutions A-2-2, A-3-2, A-4-2, A-5-2, and A-6-2 were prepared by replacing 50 parts of I-1, I-2, I-3, PDA, and PDA with 50 parts of I-1, and replacing 50 parts of DSDA with 50 parts of ODPA, respectively, according to the same formula and process as resin solution A-2-1;

In the same manner as A-1-2 and A-2-2, the mixtures were stirred at room temperature for 12 hours to obtain polyimide resin A-2 to A-6 solutions, and then added into 3L of deionized water, precipitated, filtered and washed three times; vacuum dried at 80°C for 72 hours to obtain polyimide resins A-2 to A-6.

Synthesis Example 13 Synthesis of Polyimide Resin A-7

As shown in Table 1, resin solution A-7 was prepared by replacing 40 parts of BAP with 90 parts of PDA, replacing 50 parts of ODPA and 50 parts of DSDA with 100 parts of ODPA and using the same formula and process as resin solution A-1-1;

The reaction was continued under stirring at room temperature for 12 h to obtain a polyimide resin A-7 solution, which was then added into 3 L of deionized water, precipitated, filtered, and washed three times; and vacuum dried at 80° C. for 72 h to obtain a polyimide resin A-7.

Table 1

Example 1

10 g of polyimide resin A-1 prepared in Synthesis Example 7, 1 g of PAC-1 prepared in Synthesis Example 3, 2 g of PAC-2 prepared in Synthesis Example 4, 0.1 g of silane coupling agent γ-glycidyloxypropyltrimethoxysilane, 0.8 g of cross-linking agent C-1 prepared in Synthesis Example 5 and 0.2 g of cross-linking agent C-2 prepared in Synthesis Example 6 were dissolved in 30 g of γ-butyrolactone, and the mixture was thoroughly mixed to obtain a photosensitive resin composition.

Embodiments 2 to 4

In Examples 2 to 4, polyimide resins A-2 to A-4 were used to replace polyimide resin A-1, respectively, and photosensitive resin compositions were prepared in the same manner as in Example 1.

Comparative Examples 1 to 3

In Comparative Examples 1 to 3, polyimide resins A-5 to A-7 were used to replace polyimide resin A-1, respectively, and the photosensitive resin compositions were prepared in the same manner as in Example 1.

The solubility of resins A-1 to A-7 obtained in Synthesis Examples 7 to 13 in organic solvents was tested. 1 g of resin was weighed and dissolved in 9 g of solvent, and the solubility was observed after stirring for 12 h. The results are summarized in Table 2. Among them, amides: N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide; ethers: propylene glycol methyl ether, propylene glycol monoethyl ether, ethylene glycol monomethyl ether; esters: γ-butyrolactone, methyl lactate, ethyl lactate, propyl lactate, butyl lactate.

Table 2

The photosensitive resin compositions obtained in the examples and comparative examples were used to prepare photosensitive cured films according to the following preparation methods, and the properties of the obtained photosensitive cured films were measured according to the following methods. The results are summarized in Table 3.

Preparation of photosensitive curing film: Use a rotational viscometer (Mikasa: MS-B150+DA-60S) for wet film coating, pre-dry on a hot plate, and then transfer to a nitrogen drying for further curing after exposure and development. Curing at 150-250°C for 30-180 minutes, cool to room temperature and take out.

(1) Transmittance (T%)

The results were obtained by using Agilent UV-Vis spectrophotometer Cary4000 in transmission mode.

(2) Thermal weight loss temperature (T5%)

The thermal decomposition temperature was measured using a thermogravimetric analyzer (model TGA-55) with a heating rate of 10°C/min and a sample size of 3 to 5 mg; the temperature range was R.T. to 500°C.

Table 3

It can be seen from the data in Table 2 that the alkali-soluble resin provided by the present invention has good solubility in organic solvents, and can be well soluble in solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, tetrahydrofuran, propylene glycol methyl ether, propylene glycol monoethyl ether, ethylene glycol monomethyl ether, γ-butyrolactone, methyl lactate, ethyl lactate, propyl lactate and butyl lactate, and is suitable for an alkali-soluble resin solution with good organic solvent solubility without fluorine element; and provides an environmentally friendly photosensitive resin composition solution.

It can be seen from the data in Table 3 that the photosensitive resin composition, after being coated with a rotational viscometer, dried on a hot plate, exposed, developed and thermally cured under nitrogen, has a photosensitive cured film that exhibits excellent light transmittance and good heat resistance; the average light transmittance (380-780nm) is ≥70%; the thermal weight loss temperature T5% is ≥300°C; and it is suitable for surface protection films and interlayer insulating films of semiconductor elements, insulating layers of organic electroluminescent elements and insulating layers of thin film transistors.

However, the ratio of the structures of the general formula (1) and the general formula (2) needs to be controlled. Good alkali solubility can be achieved by adjusting the ratio of the structures of the general formula (1) and the general formula (2). When the ratio of the structures of the general formula (1) exceeds 50%, it is difficult to achieve good organic solvent solubility and transmittance. When the ratio is too low, it is difficult to achieve alkali solubility. At the same time, by introducing phenolic hydroxyl group, sulfonyl group (-S(＝O) ₂ -) or a combination of the two, and the structural unit represented by the general formula (3) or the general formula (4) into the alkali-soluble resin structure, it can be used to solve the problems of poor organic solvent solubility, low transmittance and poor heat resistance in the prior art without fluorine element.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Industrial Applicability

The present invention relates to the field of polymer materials and provides an alkali-tolerant resin and an application thereof. The present invention provides an alkali-soluble resin having good solubility in organic solvents without fluorine element by introducing phenolic hydroxyl group, sulfonyl group or a combination of the two and a structural unit represented by general formula (3) or general formula (4) into the structure of the alkali-soluble resin. The alkali-soluble resin can be applied to a photosensitive resin composition to prepare a photosensitive cured film having good transmittance and heat resistance.

Claims (10)

An alkali-soluble resin, characterized in that it comprises a compound represented by general formula (1) and a compound represented by general formula (2),
Wherein, in the general formula (1), Ar ₁ represents a dianhydride residue; Ar ₂ represents a diamine residue, and Ar ₁ and Ar ₂ contain at least one phenolic hydroxyl group or one sulfonyl group; R ₁ represents a fluorine-free organic group having 1 to 10 H or C atoms; m is an integer of 10 to 10000, and r is an integer of 0 to 2;
Wherein, in the general formula (2), Ar ₃ represents a dianhydride residue; Ar ₄ represents a diamine residue, and the diamine residue Ar ₄ comprises at least two structural units, one of which is as shown in the general formula (3) or the general formula (4);
Wherein, in the general formula (3), R ₂ and R ₃ are the same or different and independently represent -(CH ₂ )- or -(CH ₂ CH ₂ )-; L ₁ , L ₂ , L ₃ and L ₄ are the same or different and independently represent H or a non-fluorine halogen element;
Wherein, in the general formula (4), R ₄ and R ₅ are the same or different and independently represent -(CH ₂ )- or -(CH ₂ CH ₂ )-; L ₅ , L ₆ , L ₇ and L ₈ are the same or different and independently represent H or a non-fluorine halogen element; Ar ₁ , Ar ₂ , Ar ₃ and Ar ₄ do not contain fluorine element. The alkali-soluble resin according to claim 1 is characterized in that the ratio of the compound represented by the general formula (1) to the total mass of the compound represented by the general formula (1) and the compound represented by the general formula (2) is 10% to 50%. The alkali-soluble resin according to claim 1 or 2, characterized in that, in the process of preparing the compound represented by general formula (1), the mass ratio of monomers containing phenolic hydroxyl groups, sulfonyl groups or a combination of the two to the total monomers is ≥20%. The alkali-soluble resin according to any one of claims 1 to 3, characterized in that, in the process of preparing the compound represented by general formula (2), the proportion of the diamine monomers formed by general formula (3) and the diamine monomers formed by general formula (4) in the total mass of the diamine monomers is ≥50%. The alkali-soluble resin according to any one of claims 1 to 4, characterized in that the diamine forming the general formula (3) is selected from the group consisting of the following structures:
And/or, the diamine structure of the general formula (4) is as follows:
The alkali-soluble resin according to any one of claims 1 to 5, characterized in that the alkali-soluble resin has good solubility in organic solvents and is soluble in one or more of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, tetrahydrofuran, propylene glycol methyl ether, propylene glycol monoethyl ether, ethylene glycol monomethyl ether, γ-butyrolactone, methyl lactate, ethyl lactate, propyl lactate and butyl lactate. A photosensitive resin composition, characterized in that it comprises (a) an alkali-soluble resin, (b) a photosensitizer, (c) a cross-linking agent, (d) an adhesion modifier and (e) a solvent; the (a) alkali-soluble resin comprises the alkali-soluble resin according to any one of claims 1 to 6. A photosensitive cured film, characterized in that it is formed by curing the photosensitive resin composition according to claim 7. The photosensitive cured film according to claim 8, characterized in that the average light transmittance of the photosensitive cured film at 380-780nm is ≥70%; and the thermal weight loss temperature T5% is ≥300°C. The photosensitive cured film according to claim 9 is characterized in that the photosensitive cured film is suitable for use as a surface protection film and an interlayer insulating film of a semiconductor element, an insulating layer of an organic electroluminescent element, and an insulating layer of a thin film transistor.