A crosslinking agent, a photosensitive resin composition and its use

Abstract

The present invention relates to a crosslinking agent, a photosensitive resin composition and its use, wherein the crosslinking agent has a structure shown in formula (I) or formula (II), the crosslinking agent contains at least 3 benzyl ether groups or benzyl alcohol groups substituted on an aromatic group, and at least 2 oxyethylene groups, the photosensitive resin composition comprises the crosslinking agent, and also comprises a solvent, a photoacid generator and a hydroxyl-containing polyimide resin, and the use of the photosensitive resin composition, wherein the photosensitive resin composition is used for an OLED display panel. The photosensitive resin composition comprising the crosslinking agent provided by the present invention has good resolution and development film retention rate, and also has high anti-stripping performance, mechanical strength, and low small molecule volatility.

Description

Technical Field

[0001] The present invention relates to the technical field of photolithography, and in particular to a crosslinking agent, a photosensitive resin composition and applications thereof. Background Art

[0002] Polyimide materials have good thermal stability, mechanical properties, electrical properties and chemical corrosion resistance, and are often used to prepare high-temperature resistant and highly insulating photosensitive compositions. The commonly used technical solution at present is a composition composed of a polyimide precursor (polyamic acid or its partially esterified product, referred to as polyamic acid (ester)) and a diazonaphthoquinone sulfonate compound (PAC) and other additives. The main problem of this solution is that the carboxyl alkali solubility in polyamic acid (ester) is too high, and PAC has poor inhibition of alkali solubility of resin, resulting in a high film reduction rate during the development process, which is not conducive to improving material utilization; in addition, polyamic acid (ester) needs to undergo high-temperature cyclization and cross-linking reactions (above 200°C) in the process technology to form a cross-linked polyimide to obtain the required properties. This process will cause further film reduction and overflow of a large amount of small molecular volatiles (outgas), resulting in thermal film shrinkage of the material and high residual stress, affecting the stability of the device.

[0003] CN104678697B discloses a positive photosensitive resin composition, a photosensitive resin film prepared therefrom, and a display device. The positive photosensitive resin composition comprises an alkali-soluble resin, a photosensitive diazoquinone compound, a thermosetting crosslinking agent represented by the following chemical formula 1, and a solvent;

[0004]

[0005] R 1 To R 4 are independently hydrogen, substituted or unsubstituted C1 to C20 alkyl, substituted or unsubstituted C3 to C20 cycloalkyl, or substituted or unsubstituted C6 to C20 aryl, and R 2 and R 3 At least one of them is hydrogen, and the positive photosensitive resin composition has improved heat resistance, chemical resistance and mechanical properties, and reduces the amount of outgassing generated. However, when the cross-linking agent is used for cross-linking of alkali-soluble resins, the degree of cross-linking of the product is not high, so that the peeling resistance and mechanical properties of the photosensitive resin composition after curing are poor.

[0006] CN104730861A discloses a positive photosensitive resin composition, a photosensitive resin film prepared using the same, and a display device. The present invention discloses a positive photosensitive resin composition, comprising an alkali-soluble resin, a photosensitive diazoquinone compound, a crosslinking agent, a thermal acid generator, a phenolic compound, and an organic solvent, wherein the crosslinking agent and the thermal acid generator are contained in a weight ratio of 1:50 to 50:1, the crosslinking agent can be a melamine crosslinking agent, a hydroxymethyl crosslinking agent, or a combination thereof, the alkali-soluble resin can be a polybenzoxazole precursor, a polyimide precursor, or a combination thereof, the composition needs to be cured at a higher temperature, has a high residual stress, affects the stability of the device, and contains a large amount of small molecule volatiles.

[0007] CN106842819A discloses a positive photosensitive polyimide resin composition with an acetylenic monomer end-capping agent and flexible developer selection, which contains an alkali-soluble polyimide, a photosensitizer, a cross-linking agent, an additive and an organic solvent; the weight percentage of the alkali-soluble polyimide, the photosensitizer, the cross-linking agent, the additive and the organic solvent is 100:10-40:0-10:10-20:500-1000. The alkali-soluble polyimide is prepared by a one-step two-stage method, using a polycondensation and thermal imidization method, which has the advantages of simple process and simple operation compared with the two-step method; the positive photosensitive resin composition provided by the invention has a low thermal expansion coefficient, high mechanical strength, high heat resistance and excellent photosensitivity, but the introduction of an acetylenic monomer end-capping agent means that curing needs to be achieved at high temperature, which will cause high residual stress, affect the stability of the device, and contain a large amount of small molecule volatiles.

[0008] Therefore, it is urgent to study in this field how to improve the stripping performance, mechanical strength and small molecule volatility while ensuring that the photosensitive resin composition has good resolution and development retention rate. Summary of the invention

[0009] The object of the present invention is to provide a crosslinking agent, which is used in a photoresist and can make the photoresist have good resolution and development film retention rate while improving the stripping performance, mechanical strength and small molecule volatility.

[0010] To achieve this object, the present invention adopts the following technical solutions:

[0011] The present invention provides a cross-linking agent having a structure shown in formula (I) or formula (II);

[0012]

[0013] In formula (I) or formula (II), Ar1, Ar2 and Ar3 are each independently selected from substituted or unsubstituted C6-C40 aryl groups;

[0014] In formula (I) or formula (II), R1 is -CH2-OC i H 2i+1 , 0≤i<8, such as 1, 2, 3, 4, 5, 6, 7, etc., wherein R1 is directly connected to the aromatic group;

[0015] In formula (I) or formula (II), R2 is -OC j H 2j -O-CH=CH2, wherein j is an integer of 1 to 4, such as 1, 2, 3, 4, and R2 is directly connected to the aromatic group;

[0016] In formula (I), g is 0 or 1;

[0017] In formula (I) or formula (II), s, r, t, k, m and n are all natural numbers;

[0018] Formula (I) contains at least 3 R1 and at least 2 R2, such as 4 R1, 5 R1, 6 R1, 7 R1, 8 R1, 3 R2, 4 R2, 5 R2, 6 R2, etc.;

[0019] Formula (II) contains at least 3 R1 and at least 2 R2, such as 4 R1, 5 R1, 6 R1, 7 R1, 8 R1, 3 R2, 4 R2, 5 R2, 6 R2, etc.;

[0020] In formula (I), L1 is selected from any one of a single bond, a C6-C30 organic group containing an aromatic group, a C1-C12 alkyl group, a C3-C12 cycloalkyl group, and a C1-C12 halogenated hydrocarbon group, and L1 does not contain any group defined by R1 and R2;

[0021] In formula (II), L2 is selected from any one of a C6-C30 organic group containing an aromatic group, a C1-C12 alkyl group, a C3-C12 cycloalkyl group, and a C1-C12 halogenated hydrocarbon group;

[0022] When the above-mentioned groups have substituents, the substituents are selected from one of cyano, halogen, C1-C10 chain alkyl or cycloalkyl, C2-C10 alkenyl, C1-C6 alkoxy or thioalkoxy, C6-C30 monocyclic aromatic hydrocarbon group or condensed aromatic hydrocarbon group, C3-C30 monocyclic heteroaromatic hydrocarbon group or condensed heteroaromatic hydrocarbon group.

[0023] The groups or numbers represented by the same symbols in formula (I) and formula (II) have the same definition.

[0024] The "C6-C30 organic group containing an aromatic group" in the present invention includes an aromatic group and a group formed by connecting an aromatic group with other organic groups. The connection position of the C6-C30 organic group containing an aromatic group with other groups may be on the aromatic group or not on the aromatic group. For example, it may be wait.

[0025] The dashed lines in the structural formula of the substituents in the present invention are Both represent the access position of the group.

[0026] The crosslinking agent provided by the present invention contains at least three benzyl ether groups or benzyl alcohol groups (R1) substituted on the aromatic group, and at least two oxyethylene groups (R2), wherein the oxyethylene groups can react with the active hydroxyl groups in the polyimide during the pre-baking of the photoresist to form a micro-crosslinking structure, thereby reducing the alkali dissolution rate of the non-exposed area during the development process, which is beneficial to improving the development film retention rate and resolution. The benzyl ether groups or benzyl alcohol groups react with the polyimide during the curing of the photoresist to further crosslink and expand the molecular weight of the polymer. In addition, the present invention selects a specific number of two active groups, and the same compound can be crosslinked twice in succession to finally form a specific body network structure, thereby improving the stripping performance and mechanical properties, while reducing the volatility of small molecules.

[0027] Preferably, formula (I) contains at least 3 to 6 R1 and at least 2 to 3 R2.

[0028] Preferably, formula (II) contains at least 3 to 6 R1 and at least 2 to 3 R2.

[0029] In the present invention, it is preferred that the cross-linking agent contains at least 3 to 6 benzyl ether groups or benzyl alcohol groups, and at least 2 to 3 oxyethylene groups. The specific number of the two substituents is set so that the two cross-linkings cooperate with each other to form a better cross-linking network, further improving the stripping resistance and mechanical properties of the photoresist. Too many benzyl ether groups or benzyl alcohol groups may lead to insufficient cross-linking reaction due to intermolecular or intramolecular steric hindrance effects. Uncross-linked benzyl ether groups or benzyl alcohol groups are easily decomposed at high temperatures, resulting in poor thermal stability and outgas performance of the photoresist. The same is true for oxyethylene groups. In addition, too many oxyethylene groups may also cause overly dense cross-linking, and more photoacid generators need to be added to decompose the cross-linking after exposure, which is not conducive to improving material stability.

[0030] Preferably, g is 1.

[0031] Preferably, Ar1, Ar2 and Ar3 are all benzene rings.

[0032] Preferably, j is 2.

[0033] Preferably, 1≤i<8.

[0034] In the present invention, R1 is preferably a benzyl ether group, which can cross-link with polyimide at a relatively low temperature (170-190° C.) to achieve low-temperature curing and reduce the residual stress of the photoresist.

[0035] Preferably, s, r and t are all 2, and m, n and k are all 1;

[0036] Furthermore, the present invention preferably contains 2 to 3 aromatic groups substituted with cross-linking groups in the cross-linking agent, and at the same time, each aromatic group is selected to contain 2 benzyl ether groups or benzyl alcohol groups and 1 oxyethylene group. The distribution of the substitution positions of the two cross-linking groups can further optimize the cross-linking structure and improve the stripping resistance and mechanical properties of the photoresist.

[0037] Preferably, the cross-linking agent has a structure shown in formula (IV) or formula (V);

[0038]

[0039] The L1, L2, R1, and R2 have the same defined ranges as above.

[0040] Preferably, the cross-linking agent has any one of the following structures:

[0041]

[0042] The second object of the present invention is to provide a photosensitive resin composition, which comprises the crosslinking agent, solvent, photoacid generator and hydroxyl-containing polyimide resin (PHI) described in the first object.

[0043] The photosensitive resin composition of the present invention adds polyimide instead of polyamic acid or polyamide ester, which eliminates the need for high-temperature imidization, thereby avoiding defects such as increased residual stress and increased small molecule volatility caused by high temperature. In combination with the use of the cross-linking agent of the present invention, the resolution, mechanical properties and stripping resistance of the photoresist can be further improved.

[0044] Preferably, the hydroxyl-containing polyimide resin comprises at least one structural unit represented by formula (III);

[0045]

[0046] In formula (III), p and q are each independently an integer of 0 to 4, and p and q are not 0 at the same time;

[0047] In formula (III), the (OH) p and (OH) q All are directly attached to the aromatic group;

[0048] In formula (III), R3 is selected from any one of a C6-C40 organic group containing an aromatic group and a C4-C20 cycloalkyl group;

[0049] In formula (III), R4 is selected from any one of an organic group containing an aromatic group of C6 to C40, an aliphatic hydrocarbon group of C2 to C12, a polysiloxane group having a weight average molecular weight of 200 to 2000 (e.g., 220, 250, 300, 350, 400, 500, 600, 800, 100, 1500, 1800, etc.), and a cycloalkane group of C4 to C12.

[0050] The siloxane group in the present invention is defined by the weight average molecular weight because the siloxane group is generally obtained by reacting an amino-terminated polysiloxane compound, and the polysiloxane group is usually defined by the weight average molecular weight.

[0051] In the present invention, the dotted lines on the structural formula represent the access sites of the groups to other groups.

[0052] Preferably, the weight average molecular weight of the hydroxyl-containing polyimide resin is 2000-50000, for example, 2100, 2500, 2800, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 7000, 8000, 9000, 10000, 12000, 15000, 20000, 25000, 30000, 35000, 40000, 45000, 48000, etc., preferably 5000-30000.

[0053] Preferably, the R3(OH) p Any one selected from the following groups:

[0054]

[0055] Preferably, the R4(OH) q Any one selected from the following groups:

[0056]

[0057]

[0058] Preferably, the crosslinking agent accounts for 0.4wt.% to 10wt.% of the total mass of the photosensitive resin composition, for example, 0.5wt.%, 1wt.%, 2wt.%, 3wt.%, 4wt.%, 5wt.%, 6wt.%, 7wt.%, 8wt.%, 9wt.%, etc.

[0059] Preferably, the hydroxyl-containing polyimide resin accounts for 4wt.% to 40wt.% of the total mass of the photosensitive resin composition, for example, 5wt.%, 6wt.%, 7wt.%, 8wt.%, 9wt.%, 10wt.%, 12wt.%, 15wt.%, 18wt.%, 20wt.%, 22wt.%, 25wt.%, 27wt.%, 29wt.%, 30wt.%, 32wt.%, 35wt.%, 38wt.%, etc., preferably 5wt.% to 30wt.%.

[0060] Preferably, the cross-linking agent accounts for 5wt.% or more of the mass of the hydroxyl-containing polyimide resin, for example, 6wt.%, 7wt.%, 8wt.%, 9wt.%, 10wt.%, 12wt.%, 13wt.%, 14wt.%, 15wt.%, 16wt.%, 17wt.%, 18wt.%, 19wt.%, 20wt.%, 21wt.%, 22wt.%, 23wt.%, 25wt.%, etc., preferably 10wt.% and more, further preferably 15wt.% to 20wt.%.

[0061] The present invention preferably comprises a specific mass percentage of the crosslinking agent in the hydroxyl-containing polyimide resin. If the added amount is too small, the difference in alkali dissolution rate between the exposed area and the non-exposed area will be too small due to the low crosslinking density, making it difficult to produce high-resolution graphics. When the amount is 10wt.% or more, the effect is better, and 15wt.% to 20wt.% has the best effect.

[0062] When the cross-linking agent accounts for 15wt.% to 20wt.% of the hydroxyl-containing polyimide resin, the moisture absorption rate of the photosensitive resin composition is 1.0-1.2%, the compatibility rate difference during exposure is 38-55nm / s, the small molecule volatilization amount is 100-350ppm, the residual stress is 12-16MPa, the film thickness reduction before and after etching is 0.008-0.082μm, the tensile strength is 100-130MPa, and the elongation at break is 10-16%.

[0063] Preferably, the photoacid generator accounts for 0.4wt.% to 10wt.% of the total mass of the photosensitive resin composition, for example, 0.5wt.%, 1wt.%, 2wt.%, 3wt.%, 4wt.%, 5wt.%, 6wt.%, 7wt.%, 8wt.%, 9wt.%, etc.

[0064] Preferably, the photoacid generator accounts for 5wt.% or more of the mass of the hydroxyl-containing polyimide resin, for example 6wt.%, 7wt.%, 8wt.%, 9wt.%, 10wt.%, 12wt.%, etc. If the content is lower than this, it is difficult to generate enough protons, resulting in insufficient acid hydrolysis reaction and difficulty in development.

[0065] Preferably, the photoacid generator includes any one of sulfonium salts, iodonium salts, and diazonium salts, or a combination of at least two of them.

[0066] Preferably, the photoacid generator includes any one or a combination of at least two of diazonium sulfate, diazonium hydrochloride, diazonium sulfonate, diazonium fluoroborate, diazonium fluorophosphate, diazonium fluoroantimonate, diazonium perchlorate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium trifluoromethanesulfonic acid, bis(p-toluenesulfonyl)diazomethane, di(cyclohexylsulfonyl)diazomethane and ditolyl iodonium trifluoromethanesulfonic acid.

[0067] Preferably, the solvent accounts for 40wt.% to 95wt.% of the total weight of the photosensitive resin composition, for example, 42wt.%, 45wt.%, 48wt.%, 50wt.%, 52wt.%, 55wt.%, 58wt.%, 60wt.%, 65wt.%, 70wt.%, 75wt.%, 80wt.%, 85wt.%, 88wt.%, 90wt.%, etc., preferably 50wt.% to 90wt.%.

[0068] The solvent includes but is not limited to γ-butyrolactone, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether formate, propylene glycol monoethyl ether formate, ethyl lactate, nitrogen methyl pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide and the like.

[0069] Preferably, the photosensitive resin composition also includes an auxiliary agent, and the auxiliary agent accounts for 0.01wt.% to 0.5wt.% of the total mass of the photosensitive resin composition, for example, 0.02wt.%, 0.05wt.%, 0.09wt.%, 0.1wt.%, 0.15wt.%, 0.20wt.%, 0.25wt.%, 0.30wt.%, 0.35wt.%, 0.40wt.%, 0.45wt.%, 0.48wt.%, etc.

[0070] Preferably, the auxiliary agent includes a leveling agent and / or a coupling agent.

[0071] The leveling agent includes a fluorine-containing or silicon-containing surfactant, and specifically, polydimethylsiloxane and / or modified organic siloxane can be selected.

[0072] The coupling agent includes any one or a combination of at least two of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane and anilinemethyltriethoxysilane.

[0073] The third object of the present invention is to provide a use of the photosensitive resin composition described in the second object, wherein the photosensitive resin composition is used for an OLED display panel.

[0074] Compared with the prior art, the present invention has the following beneficial effects:

[0075] The crosslinking agent provided by the present invention contains at least three benzyl ether groups or benzyl alcohol groups (R1) substituted on the aromatic group, and at least two oxyethylene groups (R2), wherein the oxyethylene groups can react with the active hydroxyl groups in the polyimide during the pre-baking of the photoresist to form a micro-crosslinking structure, thereby reducing the alkali dissolution rate of the non-exposed area during the development process, which is beneficial to improving the development film retention rate and resolution. The benzyl ether groups or benzyl alcohol groups react with the polyimide during the curing of the photoresist to further crosslink and expand the molecular weight of the polymer. In addition, the present invention selects a specific number of two active groups, and the same compound can be crosslinked twice in succession to finally form a specific body network structure, thereby improving the stripping performance and mechanical properties, while reducing the volatility of small molecules, and reacting off the hydroxyl groups on the polyimide chain to reduce the hygroscopicity of the material.

[0076] The photosensitive resin composition provided by the present invention has a moisture absorption rate of 1.0-1.2%, a compatible rate difference during exposure of 35-55 nm / s, a small molecule volatilization amount of 100-350 ppm, a residual stress of 12-20 MPa, a film thickness reduction before and after etching of 0.008-0.431 μm, a tensile strength of 100-130 MPa, and an elongation at break of 10-16%. DETAILED DESCRIPTION

[0077] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0078] The synthesis method of the cross-linking agent provided by the present invention is prior art, and those skilled in the art can select a synthesis method based on the prior art and actual conditions.

[0079] The raw materials used in the following preparation examples can all be purchased commercially, for example, from Suzhou Sisuo New Materials Co., Ltd., Bohai Chemical, Xiens Reagent Co., Ltd., etc.

[0080] Exemplarily, the specific preparation process of the following representative cross-linking agent is given:

[0081] Preparation Example 1

[0082] Synthetic crosslinker 1

[0083] Weigh 40.45g (0.1mol) of compound 1 into a 250mL three-necked round-bottom flask, and add 40mL 2-chloroethyl vinyl ether (CEVE) and 50mL toluene. After the mixture is stirred evenly and fully dissolved, weigh 10g sodium hydroxide (0.25mol) and add it to the three-necked flask. Heat the mixture to 80°C, keep constant temperature for 30min, add 10mL of tetrabutylammonium bromide CEVE (50mL, 0.493mol) solution into the reaction system, heat to 95°C for 3h and then cool to room temperature. Add 100mL of deionized water to the reaction mixture, mix thoroughly and separate the liquids, collect the upper organic phase, extract with deionized water 3 times, and distill at 108°C to remove the residual water, solvent and CEVE. After vacuum drying, the crude product is recrystallized to obtain a white crystalline crosslinker 1.

[0084] Structural characterization: Method: Fourier transform infrared spectroscopy (the instrument used for Fourier transform infrared spectroscopy characterization in the present invention is Spectrum One infrared spectrometer from Perkin Elmer, USA), characteristic peak 2850~2960cm -1 The characteristic peaks of methyl, methylene and vinyl are at 3400cm -1 The broad peak disappeared, indicating that the hydroxyl group was replaced.

[0085]

[0086] Preparation Example 2

[0087] Synthetic crosslinker 2

[0088] The difference from Preparation Example 1 is that Compound 1 is replaced by an equal amount of Compound 2.

[0089]

[0090] Structural characterization: Method: Fourier transform infrared spectroscopy, characteristic peak 2850~2960cm -1 The characteristic peaks of methyl, methylene and vinyl are at 3400cm -1 The broad peak disappeared, indicating that the hydroxyl group was replaced.

[0091] Preparation Example 3

[0092] Synthetic crosslinker 3

[0093] The difference from Preparation Example 1 is that Compound 1 is replaced by an equal amount of Compound 3.

[0094]

[0095] Structural characterization: Method: Fourier transform infrared spectroscopy, characteristic peak 2850~2960cm -1 The characteristic peaks of methyl, methylene and vinyl are at 3400cm -1 The broad peak disappeared, indicating that the hydroxyl group was replaced.

[0096] Preparation Example 4

[0097] Synthetic crosslinker 4

[0098] The difference from Preparation Example 1 is that Compound 1 is replaced by an equal amount of Compound 4.

[0099]

[0100] Structural characterization: Method: Fourier transform infrared spectroscopy, characteristic peak 2850~2960cm -1 The characteristic peaks of methyl, methylene and vinyl are at 3400cm -1 The broad peak disappeared, indicating that the hydroxyl group was replaced.

[0101] Preparation Example 5

[0102] Synthetic crosslinker 5

[0103] Weigh 57.07g (0.1mol) of compound 5 into a 250mL three-necked round-bottom flask, and add 60mL of 2-chloroethyl vinyl ether (CEVE) and 60mL of toluene. After the mixture is stirred evenly and fully dissolved, weigh 15g of sodium hydroxide (0.375mol) and add it to the three-necked flask. Heat the mixture to 80°C, keep constant temperature for 30min, add 15mL of tetrabutylammonium bromide CEVE solution (75mL, 0.740mol in total) into the reaction system, heat to 95°C for 3h and then cool to room temperature. Add 100mL of deionized water to the reaction mixture, mix thoroughly and separate the liquids, collect the upper organic phase, extract it with deionized water 3 times, and distill at 108°C to remove the residual water, solvent and CEVE in the organic phase. After vacuum drying, the crude product is recrystallized to obtain a white crystalline crosslinker 5.

[0104]

[0105] Structural characterization: Method: Fourier transform infrared spectroscopy, characteristic peak 2850~2960cm -1 The characteristic peaks of methyl, methylene and vinyl are at 3400cm -1 The broad peak disappeared, indicating that the hydroxyl group was replaced.

[0106] Preparation Example 6

[0107] Synthetic crosslinker 6

[0108] The difference from Preparation Example 5 is that Compound 5 is replaced by an equal amount of Compound 6.

[0109]

[0110] Structural characterization: Method: Fourier transform infrared spectroscopy, characteristic peak 2850~2960cm -1 The characteristic peaks of methyl, methylene and vinyl are at 3400cm -1 The broad peak disappeared, indicating that the hydroxyl group was replaced.

[0111] Preparation Example 7

[0112] Synthetic crosslinker 7

[0113]

[0114] The difference from Preparation Example 5 is that Compound 5 is replaced by an equal amount of Compound 7.

[0115] Structural characterization: Method: Fourier transform infrared spectroscopy, characteristic peak 2850~2960cm -1 The characteristic peaks of methyl, methylene and vinyl are at 3400cm -1 The broad peak disappeared, indicating that the hydroxyl group was replaced.

[0116] Comparative Preparation Example 1

[0117] Synthetic crosslinker D1

[0118] The difference from Preparation Example 1 is that Compound 1 is replaced with an equal amount of bisphenol A (BPA) to obtain a crosslinking agent D1.

[0119]

[0120] Structural characterization: Method: Fourier transform infrared spectroscopy, comparison with compound BPA, 3400cm -1 The broad peak disappeared, indicating that the hydroxyl group was replaced.

[0121] Comparative Preparation Example 2

[0122] Synthetic crosslinker D2

[0123] The difference from Preparation Example 1 is that Compound 1 is replaced with an equal amount of Compound 8 to obtain a crosslinking agent D2.

[0124]

[0125] Structural characterization: Method: Fourier transform infrared spectroscopy, comparison with compound 8, 3400 cm -1The broad peak disappeared, indicating that the hydroxyl group was replaced.

[0126] Exemplarily, the following synthesis method of hydroxy dianhydride-containing monomer is provided:

[0127] Preparation Example 8

[0128] Synthesis of hydroxyl dianhydride monomer 1:

[0129]

[0130] Under nitrogen protection, 21.6 g (0.1 mol) of 3.3'-dihydroxybenzidine was dissolved in 100 g of γ-butyrolactone (solution 1), cooled to -15°C, then 44.2 g of 1,2,4-trimellitic anhydride chloride was dissolved in 100 g of -butyrolactone and added dropwise to solution 1, keeping the reaction temperature below -5°C. After the addition was completed, the reaction was continued for 4 hours.

[0131] The reaction product was concentrated using a rotary evaporator, and then the concentrate was poured into 1 L of toluene to obtain a hydroxyl dianhydride monomer 1.

[0132] Structural characterization: Method: Fourier transform infrared spectroscopy, characteristic peak: 1850cm -1 The characteristic peak of the anhydride group is at 3400cm -1 The characteristic peak of -OH is 1650cm -1 The peak is the characteristic peak of amide group.

[0133] Preparation Example 9

[0134] Synthesis of hydroxyl dianhydride monomer 2

[0135]

[0136] The difference from Preparation Example 7 is that 3,3'-dihydroxybenzidine is replaced with an equal amount of 5,5'-(1,4-phenylenebis(oxy))bis(2-aminophenol) to obtain hydroxyl-containing dianhydride monomer 2.

[0137] Structural characterization: Method: Fourier transform infrared spectroscopy, characteristic peak: 1850cm -1 The characteristic peak of the anhydride group is at 3400cm -1 The characteristic peak of -OH is 1650cm -1 The peak is the characteristic peak of amide group.

[0138] Exemplarily, the following synthesis method of hydroxyl diamine monomer is provided:

[0139] Preparation Example 10

[0140] Synthesis of hydroxyl-containing diamine monomer 1

[0141]

[0142] Under nitrogen protection, 12.2 g (0.1 mol) of 4-hydroxybenzaldehyde was weighed into a 100 mL three-necked flask, and 27.9 g (0.3 mol) of aniline was weighed into the three-necked flask. The temperature was raised to 150°C for reaction for 3 h. After cooling to room temperature, the purple product was recrystallized with ethanol to obtain diamine monomer 1.

[0143] Structural characterization: Method: Fourier transform infrared spectroscopy, characteristic peak: 3100~3400cm -1 The broad peak at 3250cm is the characteristic peak of hydroxyl group. -1 The -NH2 characteristic peak is at .

[0144] Preparation Example 11

[0145] Synthesis of hydroxyl-containing diamine monomer 2

[0146]

[0147] Under nitrogen protection, 12.2 g (0.1 mol) of 4-hydroxybenzaldehyde was weighed into a 100 mL three-necked flask, and 36.9 g (0.3 mol) of o-anisidine was weighed and added into the three-necked flask. The temperature was raised to 150°C for reaction for 3 h. The product was recrystallized with ethanol and then azeotroped with hydroiodic acid for 2 h. Sodium bicarbonate was then added to neutralize the hydroiodic acid. The precipitate was collected to obtain hydroxyl-containing diamine monomer 2.

[0148] Structural characterization: Method: Fourier transform infrared spectroscopy, characteristic peak: 3100~3400cm -1 The broad peak at 3250cm is the characteristic peak of hydroxyl group. -1 The -NH2 characteristic peak is at .

[0149] Preparation Example 12

[0150] Synthesis of hydroxyl-containing diamine monomer 3

[0151]

[0152] The difference from Preparation Example 10 is that 4-hydroxybenzaldehyde is replaced with an equal amount of 2'-(trifluoromethyl)-[1,1'-biphenyl]-4-carboxaldehyde to obtain hydroxyl-containing diamine monomer 3

[0153] Structural characterization: Method: Fourier transform infrared spectroscopy, characteristic peak: 3350cm -1 The characteristic peak of hydroxyl group is 3250cm -1 The characteristic peak of -NH2 is 1350cm -1 The -CF3 characteristic peak is at .

[0154] Preparation Example 13

[0155] Synthesis of hydroxyl-containing diamine monomer 4

[0156]

[0157] The difference from Preparation Example 10 is that 4-hydroxybenzaldehyde is replaced with an equal amount of 4'-methoxy-[1,1'-biphenyl]-4-carboxaldehyde to obtain a hydroxyl-containing diamine monomer 4.

[0158] Structural characterization: Method: Fourier transform infrared spectroscopy, characteristic peak: 3100~3400cm -1 The broad peak at 3250cm is the characteristic peak of hydroxyl group. -1 The -NH2 characteristic peak is at .

[0159] Exemplarily, the following method for synthesizing a hydroxyl-containing polyimide precursor resin is provided:

[0160] Preparation Example 14

[0161] Synthetic PHI-1

[0162] Weigh 29.3g (0.08mol) of 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane and dissolve it in 100g of N-methylpyrrolidone (NMP) under nitrogen protection, and cool down to 4°C under mechanical stirring. Weigh 32.4g (0.10mol) of 3,3',4,4'-dibenzhydrol tetracarboxylic dianhydride and mix it with 35g of NMP, quickly add it to the reaction system, continue stirring and reacting for 8h, install a Dean-Stark water separator in the reaction device, and heat it to 160°C. While heating, add 80mL of NMP and 50mL of toluene to the reaction system, react at 160°C for 3h, and separate the generated water through the water separator and collect it in a single-mouth bottle. Cool the reaction system naturally to room temperature, add 100mL of deionized water to the product, stir and mix evenly, filter, collect the precipitate and vacuum dry it at 80°C for 24h to obtain PHI-1. Molecular weight 6000.

[0163] Preparation Example 15

[0164] Synthetic PHI-2

[0165] The difference from Preparation Example 13 is that 3,3',4,4'-benzhydrol tetracarboxylic dianhydride is replaced with an equal amount of dianhydride monomer 1.

[0166] Preparation Example 16

[0167] Synthetic PHI-3

[0168] The difference from Preparation Example 13 is that 3,3',4,4'-benzhydrol tetracarboxylic dianhydride is replaced with an equal amount of dianhydride monomer 2.

[0169] Preparation Example 17

[0170] Synthetic PHI-4

[0171] Weigh 32.23g (0.1mol) of hydroxyl diamine monomer 1 and dissolve it in 100g N-methylpyrrolidone (NMP) under nitrogen protection, and cool down to 4°C under mechanical stirring. Weigh 32.6g (0.105mol) of 3,3',4,4'-diphenyl ether dianhydride (ODPA) and mix it with 35g NMP, quickly add it to the reaction system, continue stirring and reacting for 8h, install a Dean-Stark water separator in the reaction device, and heat it to 160°C. While heating, add 80mL NMP and 50mL toluene to the reaction system, react at 160°C for 3h, and separate the generated water through the water separator and collect it in a single-mouth bottle. Cool the reaction system naturally to room temperature, add 100mL of deionized water to the product, stir and mix evenly, filter, collect the precipitate and vacuum dry it at 80°C for 24h to obtain PHI-4. Molecular weight 10000.

[0172] Preparation Example 18

[0173] Synthetic PHI-5

[0174] The difference from Example 17 is that the hydroxyl-containing diamine monomer 1 is replaced by the hydroxyl-containing diamine monomer 2 in an equal amount.

[0175] Preparation Example 19

[0176] Synthetic PHI-6

[0177] The difference from Example 17 is that the hydroxyl-containing diamine monomer 1 is replaced by the hydroxyl-containing diamine monomer 3 in an equal amount.

[0178] Preparation Example 20

[0179] Synthetic PHI-7

[0180] The difference from Example 17 is that the hydroxyl-containing diamine monomer 1 is replaced by the hydroxyl-containing diamine monomer 4 in an equal amount.

[0181] The following examples provide a specific method for preparing the photosensitive resin composition:

[0182] Example 1

[0183] 10 g of PHI-1 was weighed and dissolved in 100 mL of a mixed solvent consisting of 60% γ-butyrolactone, 20% ethyl lactate, and 20% N,N-dimethylformamide, 1.5 g of crosslinker 1, 1.5 g of diphenyliodonium 5-hydroxy-1-naphthalenesulfonate, 0.01 g of a silane coupling agent, and 0.01 g of a fluorinated surfactant were added and fully dissolved, and then the composition was filtered through a 0.45 μm filter.

[0184] Example 2

[0185] The difference from Example 1 is that the cross-linking agent 1 is replaced by the cross-linking agent 2 of the same mass.

[0186] Example 3

[0187] The difference from Example 1 is that the cross-linking agent 1 is replaced by the cross-linking agent 3 of the same mass.

[0188] Example 4

[0189] The difference from Example 1 is that the cross-linking agent 1 is replaced by the cross-linking agent 4 of the same mass.

[0190] Example 5

[0191] The difference from Example 1 is that the cross-linking agent 1 is replaced by the cross-linking agent 5 of the same mass.

[0192] Example 6

[0193] The difference from Example 1 is that the cross-linking agent 1 is replaced by the cross-linking agent 6 of the same mass.

[0194] Example 7

[0195] The difference from Example 1 is that PHI-1 is replaced by PHI-2 of equal mass.

[0196] Example 8

[0197] The difference from Example 1 is that PHI-1 is replaced by PHI-3 of equal mass.

[0198] Example 9

[0199] The difference from Example 1 is that PHI-1 is replaced by PHI-4 of equal mass.

[0200] Example 10

[0201] The difference from Example 1 is that PHI-1 is replaced by PHI-5 of equal mass.

[0202] Embodiment 11

[0203] The difference from Example 1 is that PHI-1 is replaced by PHI-6 of equal mass.

[0204] Example 12

[0205] The difference from Example 1 is that PHI-1 is replaced by PHI-7 of equal mass.

[0206] Example 13

[0207] 10 g of PHI-1 was weighed and dissolved in 100 mL of a mixed solvent consisting of 60% γ-butyrolactone, 20% ethyl lactate, and 20% N,N-dimethylformamide, 2 g of crosslinker 1, 1.0 g of diphenyliodonium 5-hydroxy-1-naphthalenesulfonate, 0.01 g of a silane coupling agent, and 0.01 g of a fluorinated surfactant were added and fully dissolved, and then the composition was filtered through a 0.45 μm filter.

[0208] Embodiment 14

[0209] 10 g of PHI-1 was weighed and dissolved in 100 mL of a mixed solvent consisting of 60% γ-butyrolactone, 20% ethyl lactate, and 20% N,N-dimethylformamide, 1.0 g of crosslinker 1, 1.0 g of diphenyliodonium 5-hydroxy-1-naphthalenesulfonate, 0.01 g of a silane coupling agent, and 0.01 g of a fluorinated surfactant were added and fully dissolved, and then the composition was filtered through a 0.45 μm filter.

[0210] Embodiment 15

[0211] The difference from Example 1 is that the cross-linking agent 1 is replaced by the cross-linking agent 7 in an equal amount.

[0212] Example 16

[0213] The difference from Example 14 is that the added amount of the cross-linking agent is 1.5 g.

[0214] Comparative Example 1

[0215] The difference from Example 1 is that the crosslinking agent 1 is replaced by the crosslinking agent D1 in an equal amount.

[0216] Comparative Example 2

[0217] The difference from Example 1 is that the crosslinking agent 1 is replaced by the crosslinking agent D2 in an equal amount.

[0218] Comparative Example 3

[0219] The difference from Example 1 is that the cross-linking agent 1 is replaced by the compound 1 in an equal amount.

[0220] Comparative Example 4

[0221] The difference from Example 1 is that the cross-linking agent 1 is replaced by a mixture of 1.0 g of the cross-linking agent D1 and 1.1 g of the compound 1.

[0222] Lithography performance test:

[0223] The prepared photosensitive resin composition was coated on a 5-inch square glass substrate by spin coating, pre-baked at 130° C. for 180 seconds to remove most of the solvent and cause pre-crosslinking, then exposed under a 365nm UV exposure machine, post-baked at 130° C. for 90 seconds after the exposure, and developed with 2.38% tetramethylammonium hydroxide (2.38wt.% TMAH) for 60 seconds to 180 seconds to obtain a photolithography pattern with a sensitivity of the minimum exposure required to develop a complete pattern within a development time of 60 seconds.

[0224] Alkali dissolution rate test:

[0225] The prepared photosensitive resin composition is coated on a glass substrate by a spin coating method, pre-baked at 130° C. for 180 seconds to remove most of the solvent and cause pre-crosslinking, and then exposed under a 365nm UV exposure machine (half of the mask area is light-transmitting and the other half is opaque), and post-baked at 130° C. for 90 seconds after the exposure is completed. The substrate is then cut into exposed and non-exposed areas, and the alkali dissolution rates of the exposed and non-exposed areas are tested respectively. The alkali dissolution rates are tested separately using an RDA 760 (or similar equipment) ADR testing device, and the developer is 2.38% TMAH, to obtain the alkali dissolution rates of the exposed and non-exposed areas.

[0226] Outgas test:

[0227] Sample preparation: The prepared photosensitive resin composition was coated on a 5-inch square glass substrate by spin coating (250 rpm), pre-baked at 120°C for 180s to remove most of the solvent, and then the coated glass substrate was placed in a 250°C clean oven under nitrogen protection (oxygen concentration <500ppm) for curing for 1h, the film was scraped off and vacuum-sealed for storage.

[0228] Thermogravimetric analysis test: Test atmosphere: nitrogen, heating program: keep at 40℃ for 30min, then heat to 250℃ at 5K / min, keep at this temperature for 30min, calculate the mass loss during the 250℃ keeping process.

[0229] Residual stress performance test:

[0230] Sample preparation: The prepared photosensitive resin composition is coated on a 6-inch circular ITO glass (or other materials such as silicon wafers, and its curvature is tested by FLX-2320 (or other similar equipment) before coating) by spin coating, and pre-baked at 120°C for 180s to remove most of the solvent. Then, the coated substrate is placed in a clean oven for curing for 1h, the substrate curvature is tested, and the residual stress is calculated by the software attached to the equipment.

[0231] The above performance test results are shown in Table 1.

[0232] Anti-peeling performance test:

[0233] The prepared photosensitive resin composition was applied to a 5-inch square glass substrate by spin coating (250 rpm), pre-baked at 120°C for 180s to remove most of the solvent, and the film thickness t was measured. The coated glass substrate was then placed in a 250°C clean oven under nitrogen protection (oxygen concentration <500ppm) for curing for 1h, and the film thickness (t1) was measured using an ellipsometer. The coated glass substrate was immersed in a 65°C TOK106 stripping solution and etched for 150s. After being taken out, it was quickly rinsed with deionized water, and then cured for 30min in a 230°C clean oven under nitrogen protection (oxygen concentration <500ppm). The film thickness t2 was measured using an ellipsometer, and the film thickness change Δt=t2-t1 before and after etching was calculated.

[0234] Mechanical properties test:

[0235] The photosensitive resin composition was poured into a mold of 150 mm × 10 mm × 0.5 mm (length × width × depth), placed on a horizontal platform, dried at room temperature until semi-dry, placed in a nitrogen oven, and cured according to a temperature program of 100°C (30 min) - 130°C (30 min) - 150°C (30 min) - 200°C (30 min) - 250°C (60 min) - naturally cooled to room temperature to obtain a test standard specimen with a film thickness of 20 μm. The mechanical properties were tested using a universal material testing machine at a displacement rate of 5 mm / min, an environment of 23°C, and a humidity of 50±5%.

[0236] The test results of anti-peeling performance and mechanical properties are shown in Table 2.

[0237] Table 1

[0238]

[0239]

[0240] In Table 1, — represents that development is not possible.

[0241] Table 2

[0242]

[0243]

[0244] As can be seen from Table 1 and Table 2, the photosensitive resin composition provided in the embodiment has a lower alkali dissolution rate in the non-exposed area during the development process, and a higher alkali dissolution rate in the exposed area, which can make the photoresist have good resolution and development retention rate, and at the same time have strong stripping performance and mechanical strength after curing, and have small residual stress and small small molecule volatility; while Comparative Example 1 uses a cross-linking agent without benzyl ether group or benzyl alcohol group, the small molecule volatility is greatly increased, the residual stress is increased, and the stripping performance and mechanical strength are significantly reduced; Comparative Example 2 uses a cross-linking agent containing only two benzyl ether groups and two oxyethylene groups, and the small molecule volatility is increased. The crosslinking agent containing no ethylene oxide is high, the residual stress increases, and the peel strength and mechanical strength are significantly reduced; Comparative Example 3 uses a crosslinking agent that does not contain ethylene oxide, the compatibility rate of the non-exposed area increases, it cannot be developed, the amount of small molecule volatility increases, and the mechanical strength is also reduced; Comparative Example 4 adds a crosslinking agent containing only ether groups and a crosslinking agent containing only ethylene oxide groups to the composition at the same time, the amount of small molecule volatility increases, and the residual stress increases, and the peel strength and mechanical strength are also reduced, indicating that only by introducing these two groups into the same compound at the same time can a more dense body crosslinking network be formed, thereby achieving the technical effect of the present invention. The above results prove that when the crosslinking agent provided by the present invention is used for photoresist, it can make the photoresist have good resolution rate and development film retention rate, while improving the stripping performance, mechanical strength, and reducing residual stress and small molecule volatility.

[0245] Comparing Examples 13, 14 and 16, when the mass percentage of the cross-linking agent to the resin is 15wt.% to 20wt.% (Examples 13 and 16), the small molecule volatility, residual stress, anti-peeling performance and mechanical properties are further improved compared to the 10wt.% (Example 14). This proves that the new cross-linking agent provided by the present invention is combined with the specific proportion of the resin to optimize the various properties of the photoresist.

[0246] The present invention illustrates the detailed method of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed method, that is, it does not mean that the present invention must rely on the above-mentioned detailed method to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A cross-linking agent, characterized in that The cross-linking agent has a structure shown in formula (I) or formula (II); In formula (I) or formula (II), Ar1, Ar2 and Ar3 are each independently selected from substituted or unsubstituted C6-C40 aryl groups; In formula (I) or formula (II), R1 is -CH2-OC i H 2i+1 , 0≤i<8, the R1 is directly connected to the aromatic group; In formula (I) or formula (II), R2 is -OC j H 2j -O-CH=CH2, j is an integer of 1 to 4, and R2 is directly connected to the aromatic group; In formula (I), g is 0 or 1; In formula (I) or formula (II), s, r, t, k, m and n are all natural numbers; Formula (I) contains at least 3 R1 and at least 2 R2; Formula (II) contains at least 3 R1 and at least 2 R2; In formula (I), L1 is selected from any one of a single bond, a C6-C30 organic group containing an aromatic group, a C1-C12 alkyl group, a C3-C12 cycloalkyl group, and a C1-C12 halogenated hydrocarbon group, and L1 does not contain any group defined by R1 and R2; In formula (II), L2 is selected from any one of a C6-C30 organic group containing an aromatic group, a C1-C12 alkyl group, a C3-C12 cycloalkyl group, and a C1-C12 halogenated hydrocarbon group; When the above-mentioned groups have substituents, the substituents are selected from one of cyano, halogen, C1-C10 chain alkyl or cycloalkyl, C2-C10 alkenyl, C1-C6 alkoxy or thioalkoxy, C6-C30 monocyclic aromatic hydrocarbon group or condensed aromatic hydrocarbon group, C3-C30 monocyclic heteroaromatic hydrocarbon group or condensed heteroaromatic hydrocarbon group.

2. The crosslinking agent according to claim 1, characterized in that Formula (I) contains 3 to 6 R1 and 2 to 3 R2.

3. The crosslinking agent according to claim 1, characterized in that Formula (II) contains 3 to 6 R1 and 2 to 3 R2.

4. The crosslinking agent according to claim 1, characterized in that The g is 1.

5. The cross-linking agent according to claim 1, characterized in that Ar1, Ar2 and Ar3 are all benzene rings.

6. The crosslinking agent according to claim 1, characterized in that The j is 2.

7. The cross-linking agent according to claim 1, characterized in that 1≤i<8。 8. The cross-linking agent according to claim 4, characterized in that The s, r and t are all 2, and the m, n and k are all 1.

9. The cross-linking agent according to claim 5, characterized in that The cross-linking agent has a structure shown in formula (IV) or formula (V); The L1, L2, R1, and R2 have the same definition range as that of claim 5.

10. The cross-linking agent according to claim 1, characterized in that The cross-linking agent has any one of the following structures:

11. A photosensitive resin composition, characterized in that: The photosensitive resin composition comprises the cross-linking agent according to any one of claims 1 to 10, a solvent, a photoacid generator, and a hydroxyl-containing polyimide resin.

12. The photosensitive resin composition according to claim 11, characterized in that: The hydroxyl-containing polyimide resin comprises at least one structural unit represented by formula (III); In formula (III), p and q are each independently an integer of 0 to 4, and p and q are not 0 at the same time; In formula (III), R3 is selected from any one of a C6-C40 organic group containing an aromatic group and a C4-C20 cycloalkyl group; In formula (III), R4 is selected from any one of a C6-C40 organic group containing an aromatic group, a C2-C12 aliphatic hydrocarbon group, a polysiloxane group having a weight average molecular weight of 200-2000, and a C4-C12 cycloalkane hydrocarbon group; In formula (III), the (OH) p and (OH) q are directly connected to the aromatic group.

13. The photosensitive resin composition according to claim 12, characterized in that: The weight average molecular weight of the hydroxyl-containing polyimide resin is 2,000 to 50,000.

14. The photosensitive resin composition according to claim 12, characterized in that: The weight average molecular weight of the hydroxyl-containing polyimide resin is 5,000 to 30,000.

15. The photosensitive resin composition according to claim 12, characterized in that: The R3(OH) p Any one selected from the following groups:

16. The photosensitive resin composition according to claim 12, characterized in that: The R4(OH) q Any one selected from the following groups:

17. The photosensitive resin composition according to claim 11, characterized in that: The crosslinking agent accounts for 0.4 wt. % to 10 wt. % of the total mass of the photosensitive resin composition.

18. The photosensitive resin composition according to claim 11, characterized in that: The hydroxyl-containing polyimide resin accounts for 4 wt.% to 40 wt.% of the total mass of the photosensitive resin composition.

19. The photosensitive resin composition according to claim 18, characterized in that: The hydroxyl-containing polyimide resin accounts for 5 wt.% to 30 wt.% of the total mass of the photosensitive resin composition.

20. The photosensitive resin composition according to claim 11, characterized in that: The cross-linking agent accounts for 5wt.% or more of the mass of the hydroxyl-containing polyimide resin.

21. The photosensitive resin composition according to claim 20, characterized in that: The cross-linking agent accounts for 10 wt.% or more of the mass of the hydroxyl-containing polyimide resin.

22. The photosensitive resin composition according to claim 20, characterized in that: The cross-linking agent accounts for 15 wt.% to 20 wt.% of the mass of the hydroxyl-containing polyimide resin.

23. The photosensitive resin composition according to claim 11, characterized in that: The photoacid generator accounts for 0.4 wt. % to 10 wt. % of the total mass of the photosensitive resin composition.

24. The photosensitive resin composition according to claim 11, characterized in that: The photoacid generator accounts for 5wt.% or more of the mass of the hydroxyl-containing polyimide resin.

25. Use of the photosensitive resin composition according to any one of claims 11 to 24, characterized in that: The photosensitive resin composition is used for an OLED display panel.

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