Polyacrylate alkali-soluble resin as well as preparation method and application thereof

Abstract

The invention provides polyacrylate alkali-soluble resin as well as a preparation method and application thereof. The polyacrylate alkali-soluble resin has a structure as shown in a general formula (VI). According to the polyacrylate alkali-soluble resin provided by the invention, the six-membered cyclic anhydride with a rigid structure is introduced into a main chain, and the characteristics of the rigid structure and ester groups of the cyclic anhydride are utilized, so that the etching resistance and the adhesion to a copper substrate can be effectively enhanced, and the problems of short circuit and open circuit in a circuit board manufacturing process are reduced; the photosensitive dry film prepared from the photosensitive resin composition has the advantages of excellent adhesive force, high resolution ratio, high film stripping speed and no large film residue residue.

Description

Technical Field

[0001] The present invention belongs to the technical field of photolithography materials, and relates to a polyacrylate alkali-soluble resin and a preparation method and application thereof, and specifically relates to a polyacrylate alkali-soluble resin and a preparation method thereof, a photosensitive resin composition, and a obtained photosensitive dry film with high adhesion, high resolution, and excellent etching resistance. Background Art

[0002] Printed circuit boards (PCBs) are one of the most important industries in the electronic information industry chain. They are the bridge and cornerstone for terminal products to realize various functions. As midstream products, they are widely used in high-end technology fields such as computers, consumer electronics, automobiles, aerospace, etc. According to the different structures of PCB products, they can be divided into five types: rigid boards, flexible circuit boards (FPCs), high-density boards (HDIs), metal substrates, and package substrates (ICs). As various downstream electronic products develop in the direction of "precision, small, light, thin, and flexible", the requirements for the line fineness of PCB board patterns are becoming more and more stringent. In order to adapt to this development trend, in recent years, high-end products such as HDI boards and carrier-like boards have gradually used laser direct imaging (LDI) technology to replace traditional UV and LED exposure machines, and the corresponding requirements for the performance of photosensitive dry film lithography materials are getting higher and higher.

[0003] Photosensitive dry film is a photosensitive film material that acts as a medium to transfer the pre-designed graphics and circuits in the software to the PCB board in a photocuring manner under the exposure of the excitation light source. For HDI boards and similar substrates, the line conductive width requirements are relatively high, and the accuracy is generally required to be in the range of 10 to 20um; for IC substrates, the requirements are even higher, and the line width is generally required to be less than 10um. Therefore, the resolution of the photosensitive dry film photolithography material that acts as a graphic transfer must be very good after the exposure and development process. In addition, good adhesion between the photosensitive dry film photolithography material and the copper substrate is also very important. Excellent adhesion can ensure that it can withstand the erosion of acid and alkaline solutions during the etching and electroplating processes, reduce or avoid short circuits and open circuits between etching lines, and is a reliable guarantee for achieving the goals of high-density and high integration of high-end PCB board lines.

[0004] Polyacrylate with a certain acid value is an alkali-soluble resin. It is the main component of photosensitive dry film materials, accounting for about 40-60% of the total mass. Its components mainly play a skeleton role and have a decisive influence on the various properties of dry film materials. In order to improve the resolution, adhesion, etching resistance and other properties of photosensitive dry film, the traditional practice is to introduce functional groups with benzene ring structures into the side chains of polyacrylate resins, such as using benzyl methacrylate or styrene as comonomer units during polymerization. The introduction of benzene rings and benzyl esters with aromatic ring structures has improved the resolution and adhesion of photosensitive dry films to a certain extent, but it needs to be further enhanced. Due to the introduction of this structure into the resin, the resulting photosensitive dry film material is prone to poor flexibility, and side etching and permeation problems will occur in etching and electroplating processes.

[0005] Therefore, in the art, it is expected to develop a polyacrylate alkali-soluble resin, which can be used for a photosensitive dry film, so that the photosensitive dry film has high adhesion, high resolution, and excellent etching resistance. Summary of the invention

[0006] In view of the deficiencies of the prior art, the object of the present invention is to provide a polyacrylate alkali-soluble resin and a preparation method and application thereof.

[0007] In order to improve the product technology capability in the application of manufacturing high-end PCB boards, the present invention develops a polyacrylate alkali-soluble resin for photosensitive dry film, into which a certain proportion of six-membered cyclic anhydride structure is introduced. When the photosensitive dry film prepared by using the resin is used as a photolithography material, it has excellent etching resistance and has the characteristics of high circuit resolution and high adhesion.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a polyacrylate alkali-soluble resin, wherein the polyacrylate alkali-soluble resin has a structure represented by the following general formula (VI):

[0010]

[0011] Wherein, R1 is independently a hydrogen atom or a C1~C 10 (e.g. C1, C2, C3, C4, C5, C6, C7, C8, C9 or C 10 ) of an alkyl group;

[0012] R2 is a hydrogen atom or a methyl group, and R3 is a C1-C 10 (e.g. C1, C2, C3, C4, C5, C6, C7, C8, C9 or C 10 ) of a straight or branched alkyl group, C4~C 10 (e.g. C4, C5, C6, C7, C8, C9 or C 10) of cycloalkyl, C1~C 10 (e.g. C1, C2, C3, C4, C5, C6, C7, C8, C9 or C 10 ) any one of the alkoxy groups;

[0013] R4 is a hydrogen atom or a methyl group, R5 is a C1-C5 (e.g., C1, C2, C3, C4 or C5) alkoxy group or an ester group, and the number of substituents on the benzene ring is 0-3 (0, 1, 2 or 3);

[0014] R6 is a hydrogen atom or a methyl group, R7 is a C1-C5 alkoxy group or an ester group, and the number of substituents on the benzyl group is 0-3 (0, 1, 2 or 3);

[0015] a and b are each independently an integer of 5 to 500 (e.g., 5, 8, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280, 300, 320, 340, 360, 380, 400, 420, 440, 460, 480, 500, etc.);

[0016] c and d are each independently an integer of 0 to 500 (e.g., 0, 1, 2, 3, 4, 5, 8, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280, 300, 320, 340, 360, 380, 400, 420, 440, 460, 480, 500, etc.);

[0017] n is an integer from 1 to 50 (e.g., 1, 2, 3, 4, 5, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, etc.); and a ≥ n;

[0018] When b, c, d are integers ≥ 2, multiple R2, R3, R4, R5, R6, and R7 are the same or different, for example, multiple R2 are the same or different, for example, multiple R3 are the same or different, etc., which will not be repeated.

[0019] The polyacrylate alkali-soluble resin provided by the present invention can effectively enhance its etching resistance and adhesion to a copper substrate by introducing a rigid six-membered cyclic anhydride (six-membered cyclopentanedianhydride) in the main chain and utilizing the rigid structure and ester group characteristics of the cyclic anhydride, thereby reducing the short circuit and open circuit problems encountered in the circuit board manufacturing process; the polyacrylate alkali-soluble resin is used in a photosensitive resin composition, and the prepared photosensitive dry film has excellent adhesion, high resolution, fast film stripping speed, and no large film residue residue.

[0020] Preferably, the acid value of the polyacrylate alkali-soluble resin is 90 to 240 mg KOH / g, for example, 90 mg KOH / g, 100 mg KOH / g, 120 mg KOH / g, 140 mg KOH / g, 160 mg KOH / g, 180 mg KOH / g, 200 mg KOH / g, 220 mg KOH / g, 240 mg KOH / g, etc., preferably 110 to 160 mg KOH / g.

[0021] Preferably, the weight average molecular weight of the polyacrylate alkali-soluble resin is 10,000 to 150,000, for example, 10,000, 20,000, 30,000, 40,000, 50,000, 60,000, 70,000, 80,000, 90,000, 100,000, 110,000, 120,000, 130,000, 140,000, 150,000, etc. When the weight average molecular weight of the resin is less than 10,000, the developer resistance tends to decrease; when the weight average molecular weight of the resin is greater than 150,000, the film stripping time tends to increase, preferably 20,000 to 100,000.

[0022] Preferably, the molecular weight distribution index (M w / M n ) is 1.0 to 3.0, for example, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.4, 2.6, 2.8, 3.0, etc. When the molecular weight distribution index of the resin is greater than 3.0, there is a problem of decreased resolution, and it is preferably 1.2 to 2.0.

[0023] In a second aspect, the present invention provides a method for preparing the polyacrylate alkali-soluble resin as described in the first aspect, the preparation method comprising the following steps:

[0024] (1) mixing an (alkyl) acrylic acid monomer having a structure represented by the following general formula (I), a (meth) acrylic acid ester monomer having a structure represented by the following general formula (II), and optionally a styrene and / or styrene derivative monomer having a structure represented by the following general formula (III), and optionally a (meth) acrylic acid benzyl ester monomer having a structure represented by the following general formula (IV), and obtaining an alkali-soluble resin precursor through a solution free radical polymerization reaction;

[0025]

[0026] In the general formula (I), R1 is a hydrogen atom or a C1-C 10 (e.g. C1, C2, C3, C4, C5, C6, C7, C8, C9 or C 10 ) of an alkyl group;

[0027] In the general formula (II), R2 is a hydrogen atom or a methyl group, and R3 is selected from C1 to C 10 (e.g. C1, C2, C3, C4, C5, C6, C7, C8, C9 or C 10 ) of a straight or branched alkyl group, C4~C 10 (e.g. C4, C5, C6, C7, C8, C9 or C 10 ) of cycloalkyl, C1~C 10 (e.g. C1, C2, C3, C4, C5, C6, C7, C8, C9 or C 10 ) of an alkoxy group;

[0028] In the general formula (III), R4 is a hydrogen atom or a methyl group, R5 is selected from an alkoxy group or an ester group of C1 to C5 (e.g., C1, C2, C3, C4 or C5), and the number of substituents on the benzene ring is 0 to 3 (0, 1, 2 or 3);

[0029] In the general formula (IV), R6 is a hydrogen atom or a methyl group, R7 is selected from an alkoxy group or an ester group of C1 to C5 (e.g., C1, C2, C3, C4 or C5), and the number of substituents on the benzyl group is 0 to 3 (0, 1, 2 or 3);

[0030] (2) The alkali-soluble resin precursor and the condensation agent are mixed and reacted to obtain the polyacrylate alkali-soluble resin.

[0031] The present invention uses a post-modification strategy to carry out a condensation dehydration reaction on the adjacent carboxyl groups of the side chain of the alkali-soluble resin precursor obtained in step (1) to obtain a new polyacrylate alkali-soluble resin with a certain proportion of hexacyclopentanedianhydride in the polymer main chain. The rigid hexacyclic ring structure is introduced into the resin, which can significantly enhance the etching resistance. At the same time, the hexacyclopentanedianhydride contains an ester group and a ring structure, which can be tightly combined with the surface of the copper substrate after a synergistic effect, and can also significantly enhance the tolerance to etching liquid and electroplating liquid. During film stripping, the anhydride group can undergo a hydrolysis reaction under the action of a sodium hydroxide aqueous solution, and the generated carboxyl group can further react with a hydroxide to accelerate the peeling of the dry film from the surface of the copper substrate. The photosensitive dry film photolithography material prepared by using the polyacrylate alkali-soluble resin of the present invention has excellent high resolution, adhesion and etching resistance, and a fast and clean film stripping response speed.

[0032] According to the preparation method provided by the present invention, the polyacrylate alkali-soluble resin precursor can easily generate a new six-membered cyclic anhydride with a rigid structure on the resin main chain through a condensation reaction, and the reaction conditions are mild, the operation is simple and convenient, and the feasibility is high.

[0033] Preferably, based on the total mass of the monomers of the structures represented by the general formula (I) to (IV) as 100%, the amount of the (alkyl) acrylic acid monomer represented by the general formula (I) is 20% to 40% (for example, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, etc.), and the amount of the (meth) acrylic acid ester monomer represented by the general formula (II) is 20% to 70% (for example, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50%, 52%, 54%, 56%, 58%, 60%, 62%, 64%, 66%, 68%, etc.). , 70%, etc.), the amount of styrene and / or styrene derivative monomers of the structure represented by the general formula (III) is 0-30% (for example, 0, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, etc.), and the amount of benzyl (meth)acrylate monomers of the structure represented by the general formula (IV) is 0-40% (for example, 0, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, etc.).

[0034] Preferably, the solvent for the solution free radical polymerization reaction in step (1) comprises butanone.

[0035] Preferably, the solution free radical polymerization reaction in step (1) is carried out under the initiation of an initiator.

[0036] Preferably, the initiator comprises azobisisobutyronitrile (AIBN).

[0037] Preferably, the temperature of the free radical polymerization reaction in step (1) is 80-90°C, for example 80°C, 85°C, 90°C, etc., and the time is 8-12h, for example 8h, 9h, 10h, 11h, 12h, etc.

[0038] Preferably, the alkali-soluble resin precursor obtained in step (1) has a structure represented by the following general formula (V):

[0039]

[0040] In the general formula (V), the values ​​of R1 to R7 and a to d are the same as those in the first aspect.

[0041] Taking the case where all monomers of the structures represented by general formula (I) to general formula (IV) participate in the reaction as an example, the synthetic route diagram of step (1) is as follows:

[0042]

[0043] Preferably, the condensation agent in step (2) comprises dicyclohexylcarbodiimide (DCC).

[0044] Preferably, the reaction temperature in step (2) is 40-60°C, for example, 40°C, 45°C, 50°C, 55°C, 60°C, etc., and the reaction time is 4-6h, for example, 4h, 4.5h, 5h, 5.5h, 6h, etc.

[0045] Preferably, the reaction in step (2) is a reaction until 1 wt% to 10 wt% (e.g., 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, etc.) of the carboxylic acid groups of the alkali-soluble resin precursor are removed. The reaction in step (2) is a condensation reaction, and 1 to 10 wt% of the carboxylic acid groups in the alkali-soluble resin precursor can be converted into a rigid structure hexacyclopentane dianhydride after condensation reaction.

[0046] The synthetic route of step (2) is as follows:

[0047]

[0048] In a third aspect, the present invention provides a photosensitive resin composition, wherein the photosensitive resin composition comprises the following components by weight percentage:

[0049]

[0050] The polyacrylate alkali-soluble resin includes the polyacrylate alkali-soluble resin as described in the first aspect or the polyacrylate alkali-soluble resin prepared according to the preparation method as described in the second aspect.

[0051] Preferably, the amount of the polyacrylate alkali-soluble resin in the photosensitive resin composition can be 30%, 32%, 34%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50%, 52%, 54%, 56%, 58%, 60%, etc., by weight percentage. When the weight percentage is less than 30%, the edge glue flow phenomenon is easy to occur during the storage of the photosensitive dry film; when the weight percentage is greater than 60%, there is a phenomenon of insufficient sensitivity during exposure and affecting the resolution analysis capability.

[0052] Preferably, the amount of photopolymerizable unsaturated monomer in the photosensitive resin composition can be 25%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50%, etc., calculated by weight percentage. If the weight percentage is less than 25%, the produced photosensitive dry film will have problems of low sensitivity and low resolution; if the weight percentage is greater than 50%, the photosensitive layer of the photosensitive dry film will have edge glue flow and short storage time.

[0053] Preferably, the photosensitive resin composition may contain 0.1%, 0.3%, 0.5%, 0.8%, 1%, 2%, 3%, 4%, 5% or the like of the photopolymerization initiator in terms of weight percentage.

[0054] Preferably, the amount of the additive in the photosensitive resin composition can be 0.5%, 0.6%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, 16%, 18%, 20%, etc., calculated by weight percentage.

[0055] Preferably, the photopolymerizable unsaturated monomer includes any one or a combination of at least two of isobornyl ester, octadecyl (meth)acrylate, nonylphenol (meth)acrylate, phenoxyethyl (meth)acrylate, bisphenol A di(meth)acrylate, ethoxylated (propoxylated) nonylphenol acrylate, ethoxylated dimethacrylate, ethoxylated (propoxylated) bisphenol A di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethoxylated (propoxylated) trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, alkoxylated pentaerythritol tetra(meth)acrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate, and preferably any one or a combination of at least two of ethoxylated (propoxylated) bisphenol A di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane triacrylate, bisphenol A dimethacrylate, and bisphenol A dimethacrylate.

[0056] Preferably, the photopolymerization initiator includes 2-(o-chlorophenyl)-4,5-diphenylbiimidazole, 2,4-bis-(o-chlorophenyl)-5-(3,4-dimethoxyphenyl)-diphenylbiimidazole, 9-phenylacridine, N-phenylglycine, bisacridylheptane, 9-(p-methylphenyl)acridine, 9,10-dibutoxyanthracene, 9,10-diethoxyanthracene, 7-diethylamino-4-methylcoumarin, benzophenone, 4,4'-bis(diethylamino)benzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 1-phenyl-3-(4-tert-butyl-phenyl)- Any one of 5-(4-tert-butyl-phenyl)-pyrazoline, 1-(4-(benzoxazol-2-yl)phenyl)-3-(4-tert-butyl-phenylvinyl)-5-(4-tert-butyl-phenyl)-pyrazoline, 2,6-di-tert-butyl-p-cresol, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-biimidazole, or a combination of at least two thereof.

[0057] Preferably, the additives include any one or a combination of at least two of a photochromic agent, a dye, a plasticizer, a stabilizer, an antioxidant, a defoamer, a leveling agent, an inhibitor, and a deodorant. These additives can be used alone or in combination of two or more, but are not limited to the use of the above additives.

[0058] Preferably, the photochromic agent includes tribromophenyl sulfone, invisible crystal violet and the like.

[0059] Preferably, the dye includes brilliant green, malachite green, diamond green and the like.

[0060] Preferably, the plasticizer includes p-toluenesulfonamide, dibutyl phthalate and the like.

[0061] Preferably, the stabilizer includes methoxyphenol, hydroquinone and the like.

[0062] Preferably, the antioxidant includes 2,6-di-tert-butyl-p-cresol, trinonylphenyl phosphite, and the like.

[0063] Preferably, the deodorant includes hydrogenated polydecene, polyoxyethylene lauryl (dodecyl) ether and the like.

[0064] In a fourth aspect, the present invention provides a photosensitive dry film, wherein the photosensitive dry film comprises the photosensitive resin composition as described in the third aspect.

[0065] Compared with the prior art, the present invention has the following beneficial effects:

[0066] The polyacrylate alkali-soluble resin provided by the present invention can effectively enhance its etching resistance and adhesion to the copper substrate by introducing a six-membered cyclic anhydride with a rigid structure into the main chain and utilizing the rigid structure and ester group characteristics of the cyclic anhydride, thereby reducing the short circuit and open circuit problems encountered in the circuit board manufacturing process; the polyacrylate alkali-soluble resin is used in a photosensitive resin composition, and the prepared photosensitive dry film has excellent adhesion, high resolution, fast film stripping speed, and no large film residue residue. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 The infrared spectra of the alkali-soluble resin precursor (A1) obtained in step (1) of Example 1 reacted with the condensing agent DCC at 0 h, 0.5 h, 2 h, and 4 h.

[0068] Figure 2 This is the GPC test chart of the product of the alkali-soluble resin precursor (A1) obtained in step (1) of Example 1 reacted with the condensation agent DCC for 0h, 0.5h, 2h, and 4h. DETAILED DESCRIPTION

[0069] Alkali-soluble resin plays a decisive role in the photosensitive resin composition and is the core component of the system. By introducing specific functional groups into the resin structure, many properties of the photosensitive resin composition, such as adhesion, etching resistance and circuit resolution, can be significantly improved.

[0070] The invention provides a polyacrylate alkali-soluble resin and a preparation method thereof, as well as a high-adhesion, high-resolution, and etching-resistant photosensitive resin composition prepared from the resin.

[0071] 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.

[0072] Example 1

[0073] In this embodiment, a polyacrylate alkali-soluble resin is provided, and the preparation method comprises the following steps:

[0074] (1) Synthesis of alkali-soluble resin precursor

[0075] In a four-mouth reaction flask, after configuring a stirring device, a reflux device and a thermometer, 100g of the reaction monomer is mixed evenly according to the calculated mass ratio (as shown in Table 1) and added to a 250mL clean beaker, and then 1g of initiator AIBN and 50g of butanone solvent are added, mixed evenly and set aside. Stirring is turned on, 50mL of butanone is added to the flask, the reaction system is sealed after nitrogen protection, and the oil bath is heated to 80°C. After the temperature stabilizes, a constant flow pump is used to drip the mixed solution containing the monomer to the reaction system, and the dripping is completed in 4 hours, and the reaction is kept warm for 3 hours. Then the temperature is raised to 85°C, and 0.3g of AIBN (dissolved in 20g of butanone) is added by a constant flow pump, and the dripping is completed in 0.5 hours. After the dripping is completed, the reaction is continued for 3 hours, and the reaction is terminated to obtain an alkali-soluble resin precursor (referred to as A1), and its weight average molecular weight and distribution, solid content and acid value are measured. The results are shown in Table 1.

[0076] (2) Synthetic polyacrylate alkali-soluble resin

[0077] In a three-mouth reaction flask, after configuring a stirring device, a reflux device and a thermometer, 50g of alkali-soluble resin precursor (A1) and 2.5L of pyridine were accurately weighed in sequence, and a stirring device was turned on. After the precursor was completely dissolved, 75mL of triethylamine was added, and the oil bath was heated to 50°C. After the temperature stabilized, 60g of dicyclohexylcarbodiimide (DCC) was added at one time, and the closed system began to react. After reacting for 5 hours, the reaction device was placed in an ice bath to terminate the reaction. After the reaction solution was precipitated with n-hexane, filtered and dried, the polyacrylate alkali-soluble resin (denoted as B1) was obtained, and its weight-average molecular weight, distribution and acid value were measured, and the results are shown in Table 2.

[0078] Embodiments 2 to 6

[0079] In Examples 2 to 6, a polyacrylate alkali-soluble resin is provided respectively, which is different from Example 1 only in that the types and proportions of the reaction monomers in step (1) are different. As shown in Table 1, the alkali-soluble resin precursors synthesized in Examples 2 to 6 are respectively denoted as A2 to A6, and the synthesized polyacrylate alkali-soluble resins are respectively denoted as B2 to B6.

[0080] Table 1

[0081]

[0082] Table 2

[0083]

[0084] Taking the P-(MAA-co-MMA-co-St) alkali-soluble resin precursor (A1) obtained in step (1) of Example 1 as the reaction raw material, the target polyacrylate alkali-soluble resin was prepared under the action of the condensation agent DCC as an example, samples were taken at 0h, 0.5h, 2h, and 4h of the reaction, and then the samples were subjected to a series of operations such as precipitation in a poor solvent, washing, drying, filtering, and drying, and the progress and changes of the reaction were monitored by infrared spectroscopy. The results are as follows: Figure 1 As shown. Figure 1 It can be seen that when the reaction time is 0h, the 1850~1750cm -1 There is no absorption in the range. When the reaction is carried out for 0.5h, at 1761.99cm -1 and 1802.19cm -1 Two new characteristic peaks appeared. These two new peaks are characteristic peaks after the formation of hexacyclopentane dianhydride, corresponding to the stretching and shearing vibration peaks of the anhydride carbonyl group, indicating that the technical route of using the carboxyl group of the side group of the alkali-soluble resin precursor to form hexacyclopentane dianhydride is successful. As the reaction time increases, that is, after 2h and 4h, the two new peaks are compared with the vibration peak of the carbonyl group in the carboxyl group at 1729.62cm -1 The relative intensity gradually increases, indicating that the condensation reaction is taking place during this reaction time.

[0085] The alkali-soluble resin precursor (A1) obtained in step (1) of Example 1 was reacted under the action of a condensing agent, DCC, and samples were taken at 0 h, 0.5 h, 2 h, and 4 h of reaction, and GPC tests were performed. The results are as follows: Figure 2 As shown, from Figure 2 It can be seen that compared with the GPC flow curve of the alkali-soluble resin precursor with a reaction time of 0h, the molecular weight and its distribution of the GPC flow curves of the alkali-soluble resin obtained under sampling at 0.5h, 2h, and 4h of reaction time are not much different, with only a slight increasing trend, indicating that the condensation reaction of the pendant carboxyl groups only occurs within the resin polymer molecules, and no condensation reaction of carboxyl coupling occurs between polymer molecules.

[0086] In summary, three conclusions can be drawn. First, through infrared spectrum monitoring, it is proved that the preparation method of polyacrylate alkali-soluble resin provided by the present invention is feasible; second, the proportion of hexacyclic pentanediol anhydride in the main chain of polymer resin can be controlled by condensation reaction time and reaction degree; third, through GPC monitoring, no coupling reaction between resin polymers occurs. This proves the feasibility and efficiency of the preparation method of polyacrylate alkali-soluble resin provided by the present invention.

[0087] Unless otherwise specified, the raw material information used in the following application examples and comparative application examples of the present invention is as follows:

[0088] (1) Alkali-soluble resin precursors: A1 and A4, obtained by step (1) of Example 1 and Example 4, respectively;

[0089] (2) polyacrylate alkali-soluble resin: B1 to B6, provided in Examples 1 to 6;

[0090] (3) Photopolymerizable unsaturated monomers

[0091] C1: ethoxylated trimethylolpropane triacrylate, molecular weight 428 (Sartomer);

[0092] C2: bisphenol A dimethacrylate, molecular weight 364 (Sartomer);

[0093] C3: ethoxylated dimethacrylate, molecular weight 598 (Meiyuan);

[0094] (4) Photopolymerization initiator

[0095] D1: 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole (Suzhou Weisipu New Materials Co., Ltd.);

[0096] D2: 9-phenylacridine (Suzhou Weisipu New Materials Co., Ltd.);

[0097] (5) Additives

[0098] E1: invisible crystal violet (Shanghai Bailingwei Chemical Technology Co., Ltd.);

[0099] E2: Diamond Green GH (Shanghai TCI Chemical Industry Development Co., Ltd.);

[0100] E3: tribromomethylphenyl sulfone (Shanghai TCI Chemical Industry Development Co., Ltd.);

[0101] E4: p-Toluenesulfonamide (Adamas reagent);

[0102] E5: 2,6-di-tert-butyl-p-cresol (Shanghai Bailingwei Chemical Technology Co., Ltd.).

[0103] Application Examples 1 to 6, Comparative Application Examples 1 to 2

[0104] In Application Examples 1 to 6 and Comparative Application Examples 1 to 2, a photosensitive resin composition is provided respectively. The components and amounts (parts by weight) of the photosensitive resin composition are shown in Table 3.

[0105] Table 3

[0106]

[0107]

[0108] Preparation of photosensitive dry film

[0109] According to the components and proportions of the photosensitive resin composition provided in each application example and comparative application example in Table 3, accurately weigh and pour into a container, then add acetone, and then mix thoroughly with a stirring device to obtain a resin composition slurry with a solid content of 40%. Use a laboratory-level small coating device and select a wire rod to evenly coat the above slurry on the surface of a 15μm thick PET film, bake in a 95℃ oven for 9 minutes, and obtain a photosensitive dry film (thickness of 25μm). After cooling, a 18μm thick PE film is attached to the surface of the photosensitive dry film.

[0110] The above-mentioned photosensitive dry film was sampled and tested for performance, as follows:

[0111] Sample preparation method

[0112]

Film

[0113] The copper surface of the copper clad laminate was deeply polished using a grinder, and after washing and drying, a bright, uniform and clean copper surface was obtained. Then a laminator was used to perform heat lamination and lamination under standard pressure, with the roller temperature set at 110°C and the transmission speed at 1.6m / min.

[0114]

exposure

[0115] After lamination, the sample was placed on a horizontal surface for more than 20 minutes, and was exposed using a Suzhou Tianzhun TZDI series laser direct imaging (LDI) exposure machine, and a stouffer 21-grid exposure ruler was used for photosensitivity testing.

[0116]

development

[0117] After exposure, the sample was left to stand for more than 20 minutes, the developing temperature was 30°C, and the pressure was 1.2Kg / cm 2 , prepare a 1% mass concentration of sodium carbonate aqueous solution as a developer, and take the minimum time required for the complete dissolution of the unexposed part of the photosensitive dry film as the minimum developing time. The developing time is 1.5 times the minimum developing time. After development, wash and dry.

[0118]

Removal of film

[0119] Prepare a 3% mass concentration of NaOH aqueous solution as the film stripping solution, the film stripping temperature is 60℃, and the pressure is 1.2Kg / cm 2 The minimum time required for the exposed part of the photosensitive dry film to completely dissolve is taken as the minimum stripping time. The stripping time is 1.5 times the minimum stripping time. After stripping, the film is washed and dried.

[0120] Evaluation Method

[0121]

Evaluation of electroplating resistance

[0122] The temperature was set to 40°C, and the developed substrate was immersed in a 10% acidic degreasing solution for 10 minutes, then washed with water for 5 minutes, microetched with a sodium sulfate solution, and then immersed in a 10% sulfuric acid aqueous solution at 25°C for 2 minutes. The substrate was then immersed in a pre-configured copper plating solution and electroplated for 60 minutes; then immersed in a 10% sulfuric acid aqueous solution at 25°C for 2 minutes, and then immersed in a pre-configured tin plating solution and electroplated for 10 minutes. After washing with water, the cured dry film was removed, and the morphology of the dry film sample was observed using a high-resolution scanning electron microscope to observe whether permeation occurred.

[0123]

Resolution evaluation

[0124] Exposure was performed using a mask having a wiring pattern with a width of 1:1 between the exposed portion and the unexposed portion, and after development for 1.5 times the minimum development time, the minimum mask width at which a cured resist line was normally formed was taken as the resolution value.

[0125]

Adhesion evaluation

[0126] A photosensitive dry film resist was laminated on a copper plate by hot pressing, and exposed using a mask having a wiring pattern with a width of n:400 between the exposed and unexposed parts. After development for 1.5 times the minimum development time, the minimum mask width at which a cured resist line was normally formed was taken as the adhesion value.

[0127]

Etching resistance evaluation

[0128] The developed copper plate was subjected to an etching process, with cupric chloride as the etching solution, an etching temperature of 50°C, an acidity of 2 mol / L, and a copper ion of 140 g / L.

[0129]

Adhesion after etching

[0130] The developed copper plate is subjected to etching process, the etching solution is cupric chloride, the etching speed is 1.0m / min, the etching temperature is 50℃, the acidity is 2mol / L, and the copper ion is 140g / L. Observe with a magnifying glass, and take the minimum mask width of the cured resist line as the value of the adhesion after etching, requiring that the edge of the resist line has no floating or warping phenomenon.

[0131]

Evaluation of film stripping speed

[0132] The stripping speed is measured by testing the stripping time, that is, the shorter the stripping time, the faster the stripping speed.

[0133]

Flexibility evaluation

[0134] After lamination, exposure and development, fold the flexible substrate 20 times from different angles to observe whether the dry film cracks, count the number of cracks, and express the result with a number. The smaller the number, the better the flexibility of the dry film. (Good: the dry film cracks 0-1 times after folding; Average: the dry film cracks 2-5 times after folding; Poor: the dry film cracks more than 5 times after folding.)

[0135] The evaluation results are shown in Table 4.

[0136] Table 4

[0137]

[0138]

[0139] As can be seen from Table 4, application examples 1 to 6 all obtained resin compositions with resistance to electroplating, high resolution, high adhesion, good flexibility and fast film stripping speed. By comparing with comparative application examples 1 to 2, it is found that by introducing a certain amount of cyclic rigid hexacyclic pentanediol structure into the main chain of the resin in application examples 1 to 6, the etching resistance of the photosensitive dry film is significantly enhanced. At the same time, the introduction of rigid groups also has a significant effect on improving the resolution and adhesion performance of the dry film. In comparative application examples 1 to 2, the resolution and adhesion performance are acceptable, but compared with application examples 1 to 6, the performance is significantly reduced, and the anti-electroplating ability, anti-etching performance and flexibility are poor.

[0140] In summary, the present invention provides a photosensitive dry film prepared from a photosensitive resin composition with high resolution, high adhesion, etching resistance and fast film stripping speed, which provides a new solution and method for the research and development and production of high-end dry film products.

[0141] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the polyacrylate alkali-soluble resin and its preparation method and application, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials selected by 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 polyacrylate alkali-soluble resin, characterized in that: The polyacrylate alkali-soluble resin has a structure shown in the following general formula (VI): Wherein, R1 is independently a hydrogen atom or a C1~C 10 The alkyl group; R2 is a hydrogen atom or a methyl group, and R3 is a C1-C 10 Straight or branched alkyl, C4~C 10 Cycloalkyl, C1~C 10 Any one of the alkoxy groups; R4 is a hydrogen atom or a methyl group, R5 is a C1-C5 alkoxy group or an ester group, and the number of substituents on the benzene ring is 0-3; R6 is a hydrogen atom or a methyl group, R7 is a C1-C5 alkoxy group or an ester group, and the number of substituents on the benzyl group is 0-3; a and b are each independently an integer of 5 to 500; c and d are each independently an integer from 0 to 500; n is an integer from 1 to 50; and a≥n; When b, c, and d are integers ≥ 2, multiple R2, R3, R4, R5, R6, and R7 are the same or different.

2. The polyacrylate alkali-soluble resin according to claim 1, characterized in that: The acid value of the polyacrylate alkali-soluble resin is 90 to 240 mg KOH / g, preferably 110 to 160 mg KOH / g; Preferably, the weight average molecular weight of the polyacrylate alkali-soluble resin is 10,000 to 150,000, preferably 20,000 to 100,000; Preferably, the molecular weight distribution index of the polyacrylate alkali-soluble resin is 1.0 to 3.0, preferably 1.2 to 2.

0.

3. A method for preparing the polyacrylate alkali-soluble resin according to claim 1 or 2, characterized in that: The preparation method comprises the following steps: (1) mixing an (alkyl) acrylic acid monomer having a structure represented by the following general formula (I), a (meth) acrylic acid ester monomer having a structure represented by the following general formula (II), and optionally a styrene and / or styrene derivative monomer having a structure represented by the following general formula (III), and optionally a (meth) acrylic acid benzyl ester monomer having a structure represented by the following general formula (IV), and obtaining an alkali-soluble resin precursor through a solution free radical polymerization reaction; In the general formula (I), R1 is a hydrogen atom or a C1-C 10 The alkyl group; In the general formula (II), R2 is a hydrogen atom or a methyl group, and R3 is selected from C1 to C 10 Straight or branched alkyl, C4~C 10 Cycloalkyl, C1~C 10 Alkoxyl groups; In the general formula (III), R4 is a hydrogen atom or a methyl group, R5 is selected from a C1-C5 alkoxy group or an ester group, and the number of substituents on the benzene ring is 0-3; In the general formula (IV), R6 is a hydrogen atom or a methyl group, R7 is selected from a C1-C5 alkoxy group or an ester group, and the number of substituents on the benzyl group is 0-3; (2) The alkali-soluble resin precursor and the condensation agent are mixed and reacted to obtain the polyacrylate alkali-soluble resin.

4. The preparation method according to claim 3, characterized in that: Based on the total mass of the monomers of the structures represented by the general formulas (I) to (IV) as 100%, the amount of the (alkyl) acrylic acid monomer represented by the general formula (I) is 20% to 40%, the amount of the (meth) acrylic acid ester monomer represented by the general formula (II) is 20% to 70%, the amount of the styrene and / or styrene derivative monomer represented by the general formula (III) is 0% to 30%, and the amount of the (meth) acrylic acid benzyl ester monomer represented by the general formula (IV) is 0% to 40%; Preferably, the solvent for the solution free radical polymerization reaction in step (1) comprises butanone; Preferably, the solution free radical polymerization reaction in step (1) is carried out under the initiation of an initiator; Preferably, the initiator comprises azobisisobutyronitrile; Preferably, the temperature of the free radical polymerization reaction in step (1) is 80-90° C. and the time is 8-12 hours.

5. The preparation method according to claim 3 or 4, characterized in that: The alkali-soluble resin precursor obtained in step (1) has a structure shown in the following general formula (V): In the general formula (V), the values ​​of R1 to R7 and a to d are the same as those in claim 1.

6. The preparation method according to any one of claims 3 to 5, characterized in that: The condensation agent in step (2) includes dicyclohexylcarbodiimide (DCC); Preferably, the reaction temperature in step (2) is 40-60° C., and the reaction time is 4-6 hours; Preferably, the reaction in step (2) is carried out until 1 wt % to 10 wt % of the carboxylic acid groups of the alkali-soluble resin precursor are reacted away.

7. A photosensitive resin composition, characterized in that: The photosensitive resin composition comprises the following components by weight percentage: The polyacrylate alkali-soluble resin includes the polyacrylate alkali-soluble resin according to claim 1 or 2 or the polyacrylate alkali-soluble resin prepared according to the preparation method according to any one of claims 3 to 6.

8. The photosensitive resin composition according to claim 7, characterized in that: The photopolymerizable unsaturated monomer includes any one or a combination of at least two of isobornyl ester, octadecyl (meth)acrylate, nonylphenol (meth)acrylate, phenoxyethyl (meth)acrylate, bisphenol A di(meth)acrylate, ethoxylated (propoxylated) nonylphenol acrylate, ethoxylated dimethacrylate, ethoxylated (propoxylated) bisphenol A di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethoxylated (propoxylated) trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, alkoxylated pentaerythritol tetra(meth)acrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate, and is preferably any one or a combination of at least two of ethoxylated (propoxylated) bisphenol A di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane triacrylate, bisphenol A dimethacrylate, and bisphenol A dimethacrylate; Preferably, the photopolymerization initiator includes 2-(o-chlorophenyl)-4,5-diphenylbiimidazole, 2,4-bis-(o-chlorophenyl)-5-(3,4-dimethoxyphenyl)-diphenylbiimidazole, 9-phenylacridine, N-phenylglycine, bisacridylheptane, 9-(p-methylphenyl)acridine, 9,10-dibutoxyanthracene, 9,10-diethoxyanthracene, 7-diethylamino-4-methylcoumarin, benzophenone, 4,4'-bis(diethylamino)benzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 1-phenyl-3-(4-tert-butyl-phenyl)- Any one of 5-(4-tert-butyl-phenyl)-pyrazoline, 1-(4-(benzoxazol-2-yl)phenyl)-3-(4-tert-butyl-phenylvinyl)-5-(4-tert-butyl-phenyl)-pyrazoline, 2,6-di-tert-butyl-p-cresol, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-biimidazole, or a combination of at least two thereof.

9. The photosensitive resin composition according to claim 7 or 8, characterized in that: The additives include any one of a photochromic agent, a dye, a plasticizer, a stabilizer, an antioxidant, a defoaming agent, a leveling agent, an inhibitor, and a deodorant, or a combination of at least two of them.

10. A photosensitive dry film, characterized in that: The photosensitive dry film comprises the photosensitive resin composition according to any one of claims 7 to 9.

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