CN115903386A - Alkali soluble composition, product, preparation method and application - Google Patents

Abstract

The invention provides an alkali-soluble composition, a product, a preparation method and application. Wherein the alkali soluble composition comprises: alkali soluble resin and residue in the process of preparing the alkali soluble resin, wherein the residue comprises a monomer, a thermal initiator and a solvent, and the content of the thermal initiator is 10-50,000ppm. Can solve the problems of poor peeling and adhesion performance of subsequent products of the alkali-soluble composition in the prior art, and is suitable for the field of printed materials of circuit boards.

Description

Alkali soluble composition, product, preparation method and application

Technical Field

The invention relates to the field of printed materials of circuit boards, in particular to an alkali-soluble composition, a product, a preparation method and application.

Background

In the manufacturing process of printed wiring boards, pattern transfer is generally performed using a photoresist, i.e., a dry film resist. The prior art dry film photoresist is generally divided into three layers, which are a protective layer, an intermediate photosensitive layer (photosensitive resin composition) and a bottom support layer in this order from top to bottom. When the polymer circuit pattern is used, the protective film is removed, the polymer circuit pattern is firmly attached to a processed copper-clad plate through a film attaching machine, then photopolymerization, namely exposure, is carried out by utilizing ultraviolet or laser illumination, then a required circuit pattern is obtained by utilizing sodium carbonate solution for development, and the stable polymer circuit pattern can realize the function of blocking electroplating liquid and etching liquid.

In the photoresist dry film, the photosensitive resin composition of the middle layer is a core technology part and mainly comprises the following raw materials: alkali soluble compositions, ethylenically photopolymerizable unsaturated monomers, photoinitiators and related additives. The alkali-soluble composition as an important component can be synthesized by the means known in the prior art, and can be prepared by solution polymerization, suspension polymerization, emulsion polymerization, living polymerization and the like. The thermal initiator used in the polymerization process and the inevitable residues of monomers (including acid functional group-containing monomers and non-acidic monomers) in the alkali-soluble composition enter the dry film of the photoresist through the raw material mixing and compounding process. The prior art does not disclose the effect of residues such as thermal initiators on the properties of the product.

Disclosure of Invention

The invention mainly aims to provide an alkali-soluble composition, a product, a preparation method and application, and aims to solve the problems of poor peeling and adhesion performance of subsequent products of the alkali-soluble composition in the prior art.

In order to achieve the above object, according to a first aspect of the present invention, there is provided an alkali-soluble composition comprising: alkali-soluble resin and residue in the process of preparing the alkali-soluble resin, wherein the residue comprises a monomer, a thermal initiator and a solvent, and the content of the thermal initiator is 10-50,000ppm.

Further, in the alkali-soluble composition, the total residual rate of the monomers is 0.01% to 15%.

Further, the monomers include acid functional group-containing monomers and/or non-acid monomers.

Further, the acid value of the alkali-soluble composition is 90 to 300mgKOH/g.

Further, the alkali-soluble resin has a weight average molecular weight of 30,000 to 200,000.

In order to achieve the above object, according to a second aspect of the present invention, there is provided a method for producing an alkali-soluble composition, the method comprising: dissolving a monomer and a thermal initiator in a solvent to obtain a mixed solution; heating and stirring part of the mixed solution to react to obtain a prepolymer; supplementing the residual mixed solution into the prepolymer for further polymerization reaction to obtain a polymer solution; a thermal initiator was additionally added to the polymer solution to obtain an alkali-soluble composition.

Further, the monomers comprise acid functional group-containing monomers and non-acidic monomers, and the mixed solution comprises 15 to 25 parts of acid functional group-containing monomers, 75 to 85 parts of non-acidic monomers and 0.5 to 2.0 parts of thermal initiator.

Further, the mass ratio of the thermal initiator in the mixed solution to the thermal initiator additionally added is 100: (1-100).

Furthermore, the reaction temperature of the polymerization reaction is 75-100 ℃, and the reaction time of the polymerization reaction is 3-14 h.

Further, the reaction time of the mixed solution is 2-4 h, and the reaction temperature is 75-95 ℃; after the mixed solution is reacted, adding a thermal initiator additionally, adjusting the reaction temperature to 85-100 ℃, and continuing to react for 1-10 h.

Further, a thermal initiator additionally added was added in portions to the polymer solution.

Further, the acid functional group-containing monomer includes one or more of a monocarboxylic acid, a dicarboxylic acid, or an anhydride; monocarboxylic acids include acrylic acid and/or methacrylic acid; the monocarboxylic acid comprises one or more of maleic acid, fumaric acid or citraconic anhydride; the acid anhydride comprises one or more of phthalic anhydride, maleic anhydride or citraconic anhydride.

Further, the non-acidic monomer comprises one or more of alkyl (meth) acrylate, hydroxy (meth) acrylate or styrene compounds; the alkyl (meth) acrylate includes one or more of methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, N-butyl (meth) acrylate, isobutyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, glycidyl (meth) acrylate, ethyl N, N-dimethyl (meth) acrylate, ethyl N, N-diethyl (meth) acrylate, propyl N, N-diethyl (meth) acrylate, butyl N, N-dimethyl (meth) acrylate, or butyl N, N-diethyl (meth) acrylate; the (meth) acrylic acid hydroxy esters include one or more of 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, or 4-hydroxybutyl (meth) acrylate; the styrene compound comprises one or more of styrene, benzyl (methyl) acrylate, (methyl) acrylonitrile or alpha-methyl styrene; non-acidic monomers include styrene or benzyl (meth) acrylate; the thermal initiator comprises benzoyl peroxide and/or azobisisobutyronitrile.

In order to achieve the above object, according to a third aspect of the present invention, there is provided a photosensitive resin composition comprising an alkali-soluble composition, an ethylenically photopolymerizable unsaturated monomer, a photoinitiator, and an additive, wherein the alkali-soluble composition is an alkali-soluble composition obtained by the above production method, or the above alkali-soluble composition.

Further, the method for preparing the photosensitive resin composition comprises: mixing 40-65wt% of alkali-soluble composition, 30-57wt% of ethylenic photo-polymerization unsaturated monomer, 0.1-5wt% of photoinitiator and 0.1-5wt% of additive to prepare photosensitive resin composition; dissolving the photosensitive resin composition in an organic solvent, and mixing to form a photosensitive resin composition solution; the organic solvent comprises one or more of ethanol, toluene, butanone or acetone; the solid content of the photosensitive resin composition solution is 35-60%; the photosensitive resin composition solution has a viscosity of 1000 to 8000mpa.s at 25 ℃.

In order to achieve the above object, according to a fourth aspect of the present invention, there is provided a dry film resist comprising a protective layer, an intermediate photosensitive layer and a bottom support layer, which are disposed in this order from top to bottom, the intermediate photosensitive layer comprising the above photosensitive resin composition, or the photosensitive resin composition prepared by the above preparation method.

Furthermore, the bonding force between the protective layer and the middle photosensitive layer is smaller than that between the middle photosensitive layer and the bottom supporting layer; the binding force between the middle photosensitive layer and the bottom supporting layer is smaller than that between the middle photosensitive layer and the contact surface; the protective layer comprises a polyethylene film or a polypropylene film; the thickness of the protective layer is 10-20 μm; the bottom supporting layer comprises one or more of a polyethylene terephthalate film, a polyvinyl alcohol film, a polyvinyl chloride film, a vinyl chloride copolymer film, a polyvinylidene chloride film, a vinylidene chloride copolymer film, a polymethyl methacrylate copolymer film, a polystyrene film, a polyacrylonitrile film, a styrene copolymer film, a polyamide film or a cellulose derivative film; the thickness of the bottom supporting layer is 5-25 μm.

In order to achieve the above object, according to a fifth aspect of the present invention, there is provided a use of the above alkali-soluble composition, the preparation method, the photosensitive resin composition, or the dry film resist in a printed circuit board.

The technical scheme of the invention provides the alkali soluble composition with low thermal initiator residue, the alkali soluble composition is used for preparing the light resistance dry film product, the peeling and adhesion problems of subsequent products in use are favorably improved, and the photosensitive resin composition and the light resistance dry film prepared by the alkali soluble composition have strong analysis adhesion performance, excellent peeling performance and lower oil outlet risk, and are favorable for playing better use effects in the fields of circuit board printing and the like.

Detailed Description

It should be noted that, in the present application, the embodiments and features of the embodiments may be combined with each other without conflict. The present invention will be described in detail with reference to examples.

As mentioned in the background, thermal initiators inevitably remain in the alkali-soluble composition during the preparation of the alkali-soluble composition and enter the subsequent product. However, it is not clear in the prior art what effect the residue of thermal initiator has on the properties of the subsequent product. There is no requirement for precise control of residual amounts in actual production. The photosensitive resin composition and the dry film resist in the prior art have problems of poor peeling performance and poor adhesion performance when performing etching and plating operations of a printed circuit board and the like, and for solving such problems, it is not clear to those skilled in the art how to process the photosensitive resin composition or the raw material thereof can solve such technical problems.

In the present application, the inventors have found that the content of residual thermal initiator in the alkali-soluble composition can have an effect on the properties of the subsequently prepared product (see example table 3 of the present application). Therefore, the inventor regulates and controls the residual quantity of the thermal initiator, and provides an alkali soluble composition with low residual quantity of the thermal initiator, and provides a series of protection schemes of the application on the basis of the alkali soluble composition.

In a first exemplary embodiment of the present application, there is provided an alkali-soluble composition comprising: alkali-soluble resin and residue in the process of preparing the alkali-soluble resin, wherein the residue comprises a monomer, a thermal initiator and a solvent, and the content of the thermal initiator is 10-50,000ppm, including but not limited to 10, 20, 30, 50, 100, 200, 300, 500, 800, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 6000, 7000, 8000, 10000, 20000, 30000, 40000, 50000ppm. The alkali-soluble resin is polymerized from monomers.

It has been found that residual thermal initiator in the alkali-soluble composition affects the properties of the alkali-soluble composition and subsequent products. Taking thermal initiator AIBN (azobisisobutyronitrile) as an example, if the AIBN residual quantity is higher than 50,000ppm, after a photoresist dry film is prepared by glue coating, the stripping performance of the photoresist dry film is excellent, and the oil-out risk is lower. If the AIBN residual amount is more than 10ppm, the adhesion property of the photo-resist dry film is promoted to some extent. Thermal initiators include, but are not limited to, AIBN, BPO or other commonly used thermal initiators. The product prepared from the alkali-soluble composition having a low residual amount of thermal initiator has better properties than the product prepared from the alkali-soluble composition in the prior art.

The initiator residue can be accurately measured by High Performance Liquid Chromatography (HPLC), and the specific implementation mode is as follows: (1) preparing initiator standard solutions with different gradient concentrations, testing the prepared initiator solutions with different concentrations by using HPLC, and establishing a standard curve of the initiator peak area and the initiator concentration; (2) the alkali-soluble copolymer resin is precipitated in a precipitant, i.e., a poor solvent, the alkali-soluble copolymer resin is removed by filtration, and the filtrate is concentrated to obtain an initiator solution not containing the alkali-soluble copolymer resin. (3) And testing the solution by using HPLC to obtain corresponding peak area, and then substituting the peak area into a standard curve formula to calculate to obtain the corresponding initiator residual quantity.

Solvents include, but are not limited to, one or more of ethanol, butanone, toluene, or acetone.

In a preferred embodiment, the residual amount of thermal initiator is from 50ppm to 8,000ppm, more preferably from 50ppm to 5,000ppm; preferably, the method of detecting the residual amount comprises high performance liquid chromatography.

In a preferred embodiment, the total residual monomer content in the alkali soluble composition is from 0.01% to 15%, including but not limited to 0.01%, 0.05%, 0.1%, 0.2%, 0.5%, 1%, 2%, 3%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 15%, preferably from 0.01% to 5%; preferably, the monomers include acid functional group-containing monomers and/or non-acid monomers; preferably, the method of detecting the total residual rate comprises gas chromatography, more preferably gas chromatography internal standard method.

The total residual rate can be accurately determined by Gas Chromatography (GC) and an internal standard method, and the specific implementation mode is as follows: (1) preparing standard solutions with different gradient concentrations of different alkali-soluble copolymer resin monomers (including acid functional group-containing monomers or non-acid monomers), testing the prepared standard solutions with the gradient concentrations of different monomers by using a GC (gas chromatography), recording peak positions and peak areas, and establishing peak areas and concentration standard curves of different monomers; (2) selecting a proper internal standard substance, preparing a standard solution with gradient concentration, and injecting samples under the same test conditions to obtain an internal standard solution standard curve; (3) dissolving alkali soluble copolymer resin in an organic solvent for dilution and dissolution, adding a certain amount of internal standard solution, injecting the solution under the same test condition, contrasting the peak emergence time of different alkali soluble copolymer monomers to obtain corresponding peak areas, then substituting the peak areas into respective standard curve formulas for calculation to obtain residual quantity, and calculating according to 100% of the total quantity to obtain the total residual rate. The total residual rate refers to the sum of the residual rates of all monomers (including acid functional group-containing monomers and non-acid monomers). Conversion was also obtained by subtraction on a total of 100%. The total residual rate of the monomer is low, which means that the conversion rate of the monomer is high, and the content of alkali-soluble resin in the alkali-soluble composition is high, thereby being beneficial to improving the performance of subsequent products.

In a preferred embodiment, the acid value of the alkali-soluble composition is from 90 to 300mgKOH/g, preferably from 115 to 185mgKOH/g; preferably, the weight average molecular weight of the alkali-soluble resin is 30,000 to 200,000, more preferably 50,000 to 110,000.

The carboxyl group in the alkali-soluble composition imparts solubility and releasability to the dry film resist in an alkali aqueous solution, and the acid value is preferably 115 to 185mgKOH/g from the viewpoint of the developability, the adhesiveness and the releasability in combination. The alkali-soluble resin has a weight average molecular weight of 30,000 to 200,000. If the weight average molecular weight is too low, the hole masking performance of the photoresist dry film is poor, the risk of glue overflow is caused, and the storage stability is low. When the weight average molecular weight is too high, the resolution of the dry resist film is significantly reduced, and the development time tends to be long. The weight average molecular weight was measured by Gel Permeation Chromatography (GPC) and converted to a calibration curve using a standard polymethyl methacrylate PMMA. Preferably, the weight average molecular weight is 50,000 to 110,000.

In a second exemplary embodiment of the present application, there is provided a method of preparing an alkali-soluble composition, the method comprising: dissolving a monomer containing acid functional groups, a non-acid monomer and a thermal initiator in a solvent to obtain a mixed solution; heating and stirring part of the mixed solution to react to obtain a prepolymer; supplementing the residual mixed solution into the prepolymer for further reaction to obtain a polymer solution; a thermal initiator is additionally added to the polymer solution to obtain an alkali-soluble composition. The volume of part of the mixed solution accounts for 20-60% of the volume of the mixed solution.

The volume of the part of the mixed solution to be reacted first is 20 to 60%, preferably 30 to 40%, including but not limited to 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60% of the volume of the total mixed solution.

In the preparation method of the alkali-soluble composition, firstly, a mixed solution containing acid functional group-containing monomer, non-acid monomer and thermal initiator is heated and stirred to carry out free radical polymerization reaction, so as to obtain a prepolymer; adding the rest of the mixed solution into the prepolymer to further carry out free radical polymerization reaction, thereby improving the monomer conversion rate and obtaining a polymer solution with high polymerization efficiency; and then, a thermal initiator is additionally added into the polymer solution for continuous reaction, so that the alkali soluble composition with low residual quantity of the thermal initiator can be prepared, and the method is favorable for practical production and application. The solvent in the mixed solution can be added and mixed together in the mixing stage of the monomer and the thermal initiator, or the solvent can be added after the monomer and the thermal initiator are mixed. The "adding the remaining mixed solution" includes adding the remaining mixed solution to the prepolymer in one or more additional additions (including but not limited to dropwise addition or one-time addition) for reaction.

In a preferred embodiment, the mixed solution comprises 15 to 25 parts of acid functional group-containing monomer, 75 to 85 parts of non-acidic monomer and 0.5 to 2.0 parts of thermal initiator; preferably, the mass ratio of the thermal initiator in the mixed solution to the additionally added thermal initiator is 100: (1 to 100), preferably 100: (10 to 50), more preferably 100: (15-40); preferably, the reaction temperature of the polymerization reaction is 75-100 ℃; preferably, the reaction time of the polymerization reaction is 3 to 14 hours.

In the above preparation method, the reactions of preparing the prepolymer, the polymer solution, and replenishing the thermal initiator to obtain the alkali-soluble composition are all polymerization reactions.

In a preferred embodiment, the reaction time of the mixed solution is 2-4 h, and the reaction temperature is 75-95 ℃; after the mixed solution is reacted, adding a second solution, adjusting the reaction temperature to 85-100 ℃, and continuing to react for 1-10 h; preferably, in the reaction of the mixed solution, part of the solution in the mixed solution reacts first, and then the rest part of the mixed solution is dripped to react; preferably, the additionally added thermal initiator is added to the mixed solution in portions.

After the polymer solution is obtained, the conversion rate of the monomers in the alkali-soluble composition can be improved by supplementing the thermal initiator, and simultaneously, after the thermal initiator is supplemented, the reaction temperature is further increased, and the reaction time is further prolonged, so that the decomposition of the thermal initiator is accelerated, the conversion rate of the monomers is improved, the residual thermal initiator is reduced, the thermal initiator and the reaction monomers in the solution can be further consumed, and the residual thermal initiator and the reaction monomers are reduced. The purpose of adding additional initiator at the initial stage of compounding is to initiate the polymerization reaction, primarily for controlling the resin molecular weight. The initiator is added later to increase the monomer conversion, and if the initiator is not added later, the monomer remains in the resin and influences the dry film performance.

The thermal initiator is added into the mixed solution, and adding methods such as fractional addition and dropwise addition can be selected, so that the contact area of the thermal initiator and the mixed solution is increased, uniform mixing is facilitated, and the reaction is complete. By adjusting the reaction time, the reaction temperature, the ratio of the mixed solution to the thermal initiator additionally added, the reaction and decomposition of the thermal initiator can be promoted, thereby reducing the residual amount of the thermal initiator in the alkali-soluble composition obtained by the preparation.

In a preferred embodiment, the acid functional group-containing monomer comprises one or more of a monocarboxylic acid, a dicarboxylic acid, or an anhydride; preferably, the monocarboxylic acid comprises acrylic acid and/or methacrylic acid; preferably, the monocarboxylic acid comprises one or more of maleic acid, fumaric acid, or citraconic anhydride; preferably, the anhydride comprises one or more of phthalic anhydride, maleic anhydride or citraconic anhydride.

In a preferred embodiment, the non-acidic monomer comprises one or more of alkyl (meth) acrylates, hydroxy (meth) acrylates, or styrenic compounds; preferably, the alkyl (meth) acrylate includes one or more of methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, N-butyl (meth) acrylate, isobutyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, glycidyl (meth) acrylate, ethyl N, N-dimethyl (meth) acrylate, ethyl N, N-diethyl (meth) acrylate, propyl N, N-diethyl (meth) acrylate, butyl N, N-dimethyl (meth) acrylate, or butyl N, N-diethyl (meth) acrylate; preferably, the hydroxy (meth) acrylates include one or more of 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, or 4-hydroxybutyl (meth) acrylate; preferably, the styrenic compound comprises one or more of styrene, benzyl (meth) acrylate, (meth) acrylonitrile, or alpha-methylstyrene; preferably, the non-acidic monomer comprises styrene or benzyl (meth) acrylate.

The ratio of methacrylic acid is particularly preferably 15wt% or more from the viewpoint of maintaining developability. The ratio of methacrylic acid is particularly preferably 30wt% or less from the viewpoint of storage stability and resolution of the resist. From the viewpoint of the overall properties of the resist such as resolution, adhesion, flexibility and developing speed, the contents of methyl methacrylate, butyl acrylate and styrene in the alkali-soluble copolymer resin are particularly preferably as follows: 20-50wt%,20-40wt%,1-10wt%.

In a preferred embodiment, the thermal initiator comprises benzoyl peroxide and/or Azobisisobutyronitrile (AIBN).

AIBN is preferably used in the examples of the present application because it is stable in initiation, free from side reactions, and suitable and well controlled in reaction temperature.

The alkali-soluble composition includes the alkali-soluble composition prepared by the above-described preparation method.

In a third exemplary embodiment of the present application, there is provided a photosensitive resin composition including: an alkali-soluble composition, an ethylenically photopolymerizable unsaturated monomer, a photoinitiator, and an additive, wherein the alkali-soluble composition includes an alkali-soluble composition obtained by the above-described preparation method, or the above-described alkali-soluble composition.

In a preferred embodiment, the method of preparing the photosensitive resin composition comprises: mixing 40-65wt% of alkali-soluble composition, 30-57wt% of ethylenically photopolymerizable unsaturated monomer, 0.1-5wt% of photoinitiator, and 0.1-5wt% of additive to prepare a photosensitive resin composition.

In a preferred embodiment, the photosensitive resin composition is dissolved in an organic solvent and mixed to form a photosensitive resin composition solution; preferably, the organic solvent comprises one or more of ethanol, butanone, toluene, or acetone; preferably, the solid content of the photosensitive resin composition solution is 35 to 60%; preferably, the photosensitive resin composition solution has a viscosity of 1000 to 8000mpa.s at 25 ℃.

In a preferred embodiment, the ethylenically photopolymerizable unsaturated monomer includes one or more of (meth) acrylate of bisphenol a structure, polyethylene glycol-based di (meth) acrylate, polypropylene glycol-based di (meth) acrylate, polyethylene oxide propylene oxide-based di (meth) acrylate, alkyl (meth) acrylate, trimethylolpropane tri (meth) acrylate, alkoxylated trimethylolpropane triacrylate, pentaerythritol tri (meth) acrylate, alkoxylated pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, alkoxylated pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, alkoxylated dipentaerythritol tetra (meth) acrylate, nonylphenol (meth) acrylate, alkoxylated nonylphenol (meth) acrylate, phenoxyethyl (meth) acrylate, or alkoxylated phenoxyethyl (meth) acrylate; preferably, the ethylenically photopolymerizable unsaturated monomer includes polyethylene glycol-based di (meth) acrylate, polypropylene glycol-based di (meth) acrylate, polyethylene oxide-propylene oxide-based di (meth) acrylate, bisphenol a-structured (meth) acrylate, or alkoxylated nonylphenol (meth) acrylate; preferably, the (meth) acrylate of bisphenol a structure comprises a (meth) acrylate obtained by alkylene oxide modification of bisphenol a.

From the viewpoint of flexibility, resolution and adhesiveness, polyethylene glycol based di (meth) acrylate is preferable; polypropylene glycol-based di (meth) acrylate; polyethylene oxide propylene oxide based di (meth) acrylates. From the viewpoint of adhesion and resolution, a (meth) acrylate containing a bisphenol a structure is preferable. Further, these (meth) acrylate compounds obtained by modifying bisphenol a with an alkylene oxide are useful from the viewpoint of improving resolution, adhesion, and flexibility. From the viewpoint of dry film peeling property and flexibility of the resist, alkoxylated nonylphenol (meth) acrylate is preferred.

In a preferred embodiment, the photoinitiator comprises one or more of a benzoin ether compound, a benzophenone derivative, a thioxanthone-based compound (including but not limited to 2-isopropyl thioxanthone), an anthraquinone derivative, a thioxanthone-based compound, an N-aryl- α -amino acid compound, a hexaaryl bisimidazole-based compound, or a halogen compound; preferably, the benzoin ether compound includes one or more of benzoin methyl ether, benzoin ethyl ether, or benzoin phenyl ether; preferably, the benzophenone derivative comprises one or more of benzophenone, N ' -tetramethyl-4, 4' -diaminobenzophenone, N ' -tetraethyl-4, 4' -diaminobenzophenone, or 4-methoxy-4 ' -dimethylaminobenzophenone; preferably, the anthraquinone derivative includes one or more of 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, octaethylanthraquinone, 1, 2-benzoanthraquinone, 2, 3-benzoanthraquinone, 2-phenylanthraquinone, 2, 3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1, 4-naphthoquinone, 9, 10-phenanthrenequinone, 2-methyl-1, 4-naphthoquinone, 2, 3-dimethylanthraquinone or 3-chloro-2-methylanthraquinone; preferably, the thioxanthone series of compounds includes one or more of 2, 4-diethylthioxanthone, 2, 4-diisopropylthioxanthone, or 2-chlorothioxanthone; preferably, the N-aryl-a-amino acid compound comprises one or more of N-phenylglycine, N-methyl-N-phenylglycine, or N-ethyl-N-phenylglycine, more preferably N-phenylglycine; preferably, the hexaarylbisimidazole series compounds include 2,2', 4-tris (2-chlorophenyl) -5- (3, 4-dimethoxyphenyl) -4',5' -diphenyl-1, 1' -diimidazole, 2- (o-chlorophenyl) -4, 5-diphenylbiimidazole, 2', 5-tris (o-chlorophenyl) -4- (3, 4-dimethoxyphenyl) -4',5' -diphenylbiimidazole, 2, 4-bis- (o-chlorophenyl) -5- (3, 4-dimethoxyphenyl) -diphenylbiimidazole, 2,4, 5-tris (o-chlorophenyl) -diphenylbiimidazole, 2- (o-chlorophenyl) -bis-4, 5- (3, 4-dimethoxyphenyl) -biimidazole, 2' -bis- (2-fluorophenyl) -4,4',5,5' -tetrakis- (3-methoxyphenyl) -biimidazole, 2' -bis- (2, 3-difluoromethylphenyl) -4,4', 5' -tetrakis- (3-methoxyphenyl) -biimidazole, 2' -bis- (2, 4-difluorophenyl) -4,4',5,5' -tetrakis- (3-methoxyphenyl) -biimidazole, 2' -bis- (2, 5-difluorophenyl) -4,4', 5' -tetrakis- (3-methoxyphenyl) -biimidazole, 2' -bis- (2, 6-difluorophenyl) -4,4',5,5' -tetrakis- (3-methoxyphenyl) -biimidazole, 2' -bis- (2, 3, 4-trifluorophenyl) -4,4', 5' -tetrakis- (3-methoxyphenyl) -biimidazole, 2' -bis- (2, 3, 5-trifluorophenyl) -4,4', 5' -tetrakis- (3-methoxyphenyl) -biimidazole, 2' -bis- (2, 3, 6-trifluorophenyl) -4,4',5,5' -tetrakis- (3-methoxyphenyl) -biimidazole, 2' -bis- (2, 4, 5-trifluorophenyl) -4,4', 5' -tetrakis- (3-methoxyphenyl) -biimidazole, 2' -bis- (2, 4, 6-trifluorophenyl) -4,4', one or more of 5,5' -tetrakis- (3-methoxyphenyl) -biimidazole, 2' -bis- (2, 3,4, 5-tetrafluorophenyl) -4,4', 5' -tetrakis- (3-methoxyphenyl) -biimidazole, 2' -bis- (2, 3,4, 6-tetrafluorophenyl) -4,4', 5' -tetrakis- (3-methoxyphenyl) -biimidazole, or 2,2' -bis- (2, 3,4,5, 6-pentafluorophenyl) -4,4', 5' -tetrakis- (3-methoxyphenyl) -biimidazole, more preferably 2,2', 4-tris (2-chlorophenyl) -5- (3, 4-dimethoxyphenyl) -4',5 '-diphenyl-1, 1' -diimidazole; the halogen compound includes one or more of amyl bromide, isoamyl bromide, bromoisobutylene, vinyl bromide, diphenylmethyl bromide, benzyl bromide, dibromomethane, tribromomethylphenylsulfone, carbon tetrabromide, tris (2, 3-dibromopropyl phosphate), trichloroacetamide, amyl iodide, isobutyl iodide, 1-trichloro-2, 2-bis (p-chlorophenyl) ethane, a triazine chloride compound or a diallylium iodide compound, more preferably tribromomethylphenylsulfone.

Among them, the photoinitiator is preferably N-phenylglycine having a high sensitizing effect; or preferably 2,2', 4-tris (2-chlorophenyl) -5- (3, 4-dimethoxyphenyl) -4',5 '-diphenyl-1, 1' -diimidazole, which has excellent properties with respect to sensitivity, resolution and cured film strength of the resist dry film;

in a preferred embodiment, the additive comprises one or more of a colorant, a developer, a plasticizer, a defoamer, a polymerization inhibitor or an antioxidant; preferably, the coloring agent comprises one or more of phthalocyanine green, malachite green, brilliant green, methyl violet, crystal violet, methyl green, victoria blue B, basic green, rhodamine B, or methyl orange; preferably, the colour developer comprises tris (4-dimethylaminophenyl) methane (leuco crystal violet) and/or bis (4-dimethylaminophenyl) phenylmethane (leuco malachite green); preferably, the plasticizer includes one or more of phthalic acid-based compounds such as diethyl phthalate, sulfonamide-based compounds such as o-toluenesulfonamide, p-toluenesulfonamide, citric acid-based compounds such as tributyl citrate, triethyl citrate, acetyl tri-n-propyl citrate, acetyl tri-n-butyl citrate, polyethylene glycol, polypropylene glycol, polyethylene glycol alkyl ether or polypropylene glycol alkyl ether; preferably, the inhibitor comprises one or more of p-methoxyphenol, hydroquinone, pyrogallol, t-butylcatechol, or N-nitrosophenylhydroxylamine aluminium salt.

The developer can develop the color of the exposed portion of the dry film resist, increasing the visibility, and is also more advantageous when the inspection machine reads the alignment mark for the exposure position. From the viewpoint of improving the contrast, leuco crystal violet is preferably used as the coloring dye, and the contrast is improved.

The photosensitive resin composition comprises the photosensitive resin composition prepared by the preparation method.

In a fourth exemplary embodiment of the present application, there is provided a dry film resist comprising a protective layer, an intermediate photosensitive layer and a bottom support layer arranged in this order from top to bottom, the intermediate photosensitive layer comprising the above photosensitive resin composition or the photosensitive resin composition prepared by the above preparation method.

In a preferred embodiment, the bonding force of the protective layer to the intermediate photosensitive layer is smaller than the bonding force of the intermediate photosensitive layer to the bottom support layer; preferably, the binding force between the middle photosensitive layer and the bottom supporting layer is smaller than that between the middle photosensitive layer and the contact surface; preferably, the protective layer comprises a polyethylene film or a polypropylene film; preferably, the thickness of the protective layer is 10 to 20 μm; preferably, the support layer includes a polyethylene terephthalate film, a polyvinyl alcohol film, a polyvinyl chloride film, a vinyl chloride copolymer film, a polyvinylidene chloride film, a vinylidene chloride copolymer film, a polymethyl methacrylate copolymer film, a polystyrene film, a polyacrylonitrile film, a styrene copolymer film, a polyamide film, or a cellulose derivative film; preferably, the thickness of the support layer is 5 to 25 μm.

The contact surface comprises a copper surface. The protective layer can be easily torn off in the film sticking process of the photoresist dry film, and the supporting layer can be easily torn off after film sticking and before development.

In a fifth exemplary embodiment of the present invention, there is provided an alkali-soluble composition, a method for preparing the alkali-soluble composition, a photosensitive resin composition, or a dry film resist, as described above, for use in etching and developing a printed circuit board or the like.

The advantageous effects of the present application will be explained in further detail below with reference to specific examples.

Example 1

1. Synthetic alkali soluble compositions

The preparation of resins of the A1 and A2 series by means of free radical solution polymerization comprises the following steps:

uniformly mixing methacrylic acid MAA, methyl methacrylate MMA, butyl acrylate BA and styrene ST according to a certain mass ratio, adding an initiator AIBN (azodiisobutyronitrile) and butanone, stirring for dissolving, adding a mixed solution with the mass fraction of about 35% into a three-neck flask which is protected by nitrogen and is provided with a condensation reflux device through a peristaltic pump, heating to 80 ℃ in an oil bath, stirring for reacting for 1h, slowly dropwise adding the rest mixed solution, and finishing the addition within 3 h. And after the heat preservation reaction is continued for 4 hours, heating to 90 ℃, replenishing butanone solution for dissolving a small amount of initiator AIBN twice at an interval of 1 hour, preserving heat and stirring for 4 hours after the dropwise addition is finished, and ending the reaction to obtain the alkali-soluble resin.

A series of comonomers are obtained according to different mass ratios of MAA, MMA, BA and ST, and corresponding dry resins with different properties (the dry resins are resins with solvent removed) are shown in Table 1.

TABLE 1 alkali soluble composition Performance Table

TABLE 1

2. Preparation of photosensitive resin composition

According to the mass ratio scheme of the components of the photosensitive resin composition, all the components are mixed according to the ratio, butanone and ethanol are added, and the mixture is stirred at a high speed by a high-speed dispersion machine to fully and uniformly mix all the components until the components are completely dissolved, so that the photosensitive resin composition with the solid content of 36% is prepared.

3. Preparation of a Dry film resist

The photosensitive resin composition solution prepared in Table 2 was coated on a PET film of 14 to 17 μm using a coater with selecting an appropriate wire bar and coating speed, and dried in an oven for 8min. After cooling, a PE film having a thickness of 18 μm was thermally laminated at a certain pressure and temperature using a hot rubber nip roller, thereby obtaining a photo resist dry film having a thickness of 38 μm of the photosensitive resin composition.

Examples 2 to 16

A photosensitive resin composition and a dry film resist were prepared using the A-series comonomers prepared in example 1, in the same manner as in example 1, and the specific ratios are shown in Table 2.

TABLE 2 quality ratio table of components of photosensitive resin composition

TABLE 2

Wherein, B-1 is ethoxylated trimethylolpropane triacrylate (sartomer monomer SR454, the number of ethoxy units is 3);

b-2, ethoxylated bisphenol A diacrylate (sartomer SR602, number of ethoxy units 10);

b-3, ethoxy nonyl phenol acrylate (Changzhou powerful new material, the number of ethoxy is 8);

b-4, polyethylene oxide-propylene oxide dimethacrylate (Changzhou powerful new material TM2203, the total number of ethoxy repeating units is 6, and the total number of propoxy repeating units is 12);

c-1;

c-2;

d-1, malachite green (Shanghai ladder loving chemical industry);

d-2 tribromomethyl phenyl sulfone (Shanghai ladder loving chemical industry);

d-3, p-toluenesulfonamide (Shanghai ladder Seai chemical industry).

Example 17

Preparation of A-3 resin: uniformly mixing methacrylic acid MAA, methyl methacrylate MMA, butyl acrylate BA and styrene ST according to a certain mass ratio, adding an initiator AIBN (azodiisobutyronitrile) and butanone, stirring for dissolving, adding a mixed solution with the mass fraction of about 35% into a three-neck flask which is protected by nitrogen and is provided with a condensation reflux device through a peristaltic pump, heating to 80 ℃ in an oil bath, stirring for reacting for 1h, slowly dropwise adding the rest mixed solution, and finishing the addition within 3 h. And (3) after continuing the heat preservation reaction for 4 hours, heating to 90 ℃, continuing the heat preservation stirring for 4 hours, and ending the reaction to obtain the alkali-soluble resin A-3. The photosensitive resin composition and the dry film resist were prepared using the alkali-soluble resin a-3 in the same manner as in example 1, and the specific formulation is shown in table 2.

Example 18

A-4 resin preparation method: uniformly mixing methacrylic acid MAA, methyl methacrylate MMA, butyl acrylate BA and styrene ST according to a certain mass ratio, adding an initiator AIBN (azodiisobutyronitrile) and butanone, stirring for dissolving, adding a mixed solution with the mass fraction of about 35% into a three-neck flask which is protected by nitrogen and is provided with a condensation reflux device through a peristaltic pump, heating to 65 ℃ in an oil bath, stirring for reacting for 1h, slowly dropwise adding the rest mixed solution, and finishing the addition within 3 h. And after the heat preservation reaction is continued for 4 hours, heating to 75 ℃, replenishing butanone solution for dissolving a small amount of initiator AIBN twice at an interval of 1 hour, preserving heat and stirring for 4 hours after the dropwise addition is finished, and ending the reaction to obtain the alkali-soluble resin A-4. The photosensitive resin composition and the dry film resist were prepared using the alkali-soluble resin A-4 in the same manner as in example 1, and the specific formulation is shown in Table 2.

Example 19

A-5 resin preparation method: uniformly mixing methacrylic acid MAA, methyl methacrylate MMA, butyl acrylate BA and styrene ST according to a certain mass ratio, adding an initiator AIBN (azodiisobutyronitrile) and butanone, stirring for dissolving, adding a mixed solution with the mass fraction of about 35% into a three-neck flask which is protected by nitrogen and is provided with a condensation reflux device through a peristaltic pump, heating to 65 ℃ in an oil bath, stirring for reacting for 0.5h, slowly dropwise adding the rest mixed solution, and finishing adding within 2 h. And after the reaction is continued for 2 hours, heating to 90 ℃, supplementing butanone solution for dissolving a small amount of initiator AIBN twice at an interval of 1 hour, stirring for 1 hour under heat preservation after the dropwise addition is finished, and finishing the reaction to obtain the alkali-soluble resin A-5. The photosensitive resin composition and the dry film resist were prepared using the alkali-soluble resin A-5 in the same manner as in example 1, and the specific formulation is shown in Table 2.

The evaluation results for the photosensitive resin compositions prepared in examples 2 to 19 above are shown in Table 3.

The following describes the sample preparation method (including film application, exposure, and development), the sample evaluation method, and the evaluation results in the examples.

[ FILM-APPLICATION ]

And polishing the copper surface of the copper-clad plate by a grinder, washing with water, and wiping to obtain a bright and fresh copper surface. The press roll temperature of a film sticking machine is set to be 110 ℃, the conveying speed is 1.5m/min, and heat sticking is carried out under standard pressure.

[ Exposure ] to light

Exposure was carried out using a Saint technologies model M-522 exposure machine and photosensitivity test was carried out using a stouffer 41 th order exposure ruler.

[ DEVELOPING ]

Gradually increasing the line width/line distance of the film selected by developing from 10 mu m to 100 mu m; the developing solution was 1% by weight of sodium carbonate aqueous solution, the developing temperature was 30 deg.C, the developing pressure was 1.8bar, the developing speed was 1.5m/min, and the developing machine model was Yunsu science XY-430. The minimum time required for the resist layer of the unexposed portion to be completely dissolved is taken as the minimum development time (MD).

[ evaluation of resolution ]

The photosensitive resin composition was laminated on the copper plate by a heating press roller. Here, the resolution was evaluated by the minimum value of the line width that can completely remove the unexposed portion and remain without twisting or chipping of the line by exposing the resist pattern to light through a mask having a wiring pattern with a width of 1 (10 to 100 μm) of the exposed portion and the unexposed portion, developing the resist pattern 2 times the developing removal time, and observing the resist pattern through a magnifying glass, and the smaller the value, the better the resolution.

[ evaluation of adhesion ]

The adhesion was evaluated by exposing and developing a resist pattern with a photomask of a wiring pattern of different Line widths at an equal Line pitch of Line/Space = n/400 μm (n ranges from 15 to 51, and is increased by 3 at each time), developing and drying the resist pattern for a 2-fold minimum development time, and observing the resist pattern with a magnifying glass, and the adhesion was evaluated by the minimum value of the Line width which can completely remove the unexposed portion and which remains without distortion and chipping of the lines.

[ evaluation of film-removing Properties ]

Laminating the photosensitive resin composition on a copper plate by using a heating and pressing roller, exposing the whole plate surface without any film, developing the exposed plate surface by using 2 times of minimum development time, drying the developed plate surface, and cutting the plate surface into squares with the size of 4cm multiplied by 4cm by a plate cutting machine. Preparation of 300mL of NaOH aqueous solution as a stripping solution 3%, placing in a 50 ℃ water bath and keeping the temperature constant. And (3) placing the 4cm multiplied by 4cm small plate in the membrane removing solution by using a pair of tweezers, slightly stirring by using a stirrer, pressing a stopwatch for timing, pausing the stopwatch when the whole photoresist dry film is separated from the surface of the substrate, and recording the film removing time. And taking out the substrate, rapidly stirring the photoresist dry film for one minute, gently taking out the film fragments by using tweezers, putting the film fragments in water, and measuring the length and the width of the film fragments by using a graduated scale.

[ evaluation of storage stability ]

And (3) respectively placing the cut photoresist dry film rolls in a constant-temperature constant-humidity aging box at room temperature (5-25 ℃) and 50 ℃, controlling the relative humidity of the two to be between 40% and 70%, and observing the side edge glue overflow condition of the photoresist dry film rolls after a period of time.

Storage at room temperature:

1: no glue flow after 6 months of placement;

2: slight gummosis appeared after 6 months of standing;

3: slight gummosis appeared after 3 months of standing;

4: severe gummosis occurred after 3 months of storage.

[ evaluation of development oil contamination ]

Weighing 18g of photoresist dry film to dissolve in 1000mL 1% ₃ In the developing solution, after foaming by using a foaming machine and standing for 3 days, the oil stain condition of the liquid surface is observed:

o: no visible oil stain is generated;

excellent: a small amount of oil stain;

● : and is very greasy.

[ evaluation results ]

The evaluation results for the dry film resists prepared in examples 2-19 above are shown in table 3:

TABLE 3

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TABLE 3

And (4) analyzing results: from the comparison between examples 2 and 3 and examples 4 to 8, it can be seen that the addition amount of the thermal initiator is small, the residual amount of the thermal initiator in the alkali-soluble composition is small, the monomer conversion rate is insufficient, the minimum development time of the dry film is prolonged, the desorption adhesion performance is affected, the storage stability of the dry film is reduced, and the risk of developing oil exists. In addition, with the increase of the residual quantity of AIBN, the adhesion performance of a dry film is improved to a certain extent, and if the residual quantity of AIBN is too much and exceeds 8000ppm, the film removing speed is greatly influenced, and the film removing time is prolonged.

From examples 9-12, comparative analysis was conducted to ensure that the residual amount of AIBN initiator was about 2500ppm and monomer conversion was greater than 95% in resins of different acid numbers, the storage stability of the dry film was superior and the risk of developing oil was low.

Comparative analysis is performed from examples 13 to 16, and the influence of the addition amount of different resin contents on the dry film MD, the analytic adhesion, the stripping performance and the storage stability is large, and if the resin content is too low, the dry film has good fluidity and poor storage stability, and the dry film is easy to flow.

In example 17, no additional initiator was added; in example 18, the reaction temperature was low and the initiator was replenished in excess; in example 19, too low a reaction temperature and too short a reaction time result in insufficient monomer conversion, and the residual amount of the initiator is out of the appropriate range, which seriously affects the overall properties of the dry film.

From the above description, it can be seen that the above-described embodiments of the present invention achieve the following technical effects: in the prior art, there is no investigation or limitation of the content of thermal initiators in alkali soluble compositions. The applicant has unexpectedly found in practical production operations that the alkali-soluble composition with a residual amount of thermal initiator of 10-50,000ppm, and the alkali-soluble composition and the photosensitive resin composition and the dry film resist prepared subsequently have better properties, including but not limited to short minimum development time of the dry film, strong desorption adhesion property, excellent stripping property, high storage stability and low risk of developing oil. The alkali-soluble composition containing a proper amount of thermal initiator residue can be prepared by the preparation method of the alkali-soluble composition, and products prepared by the alkali-soluble composition, including photosensitive resin compositions in photoresist dry films, have better performance and are beneficial to actual production and application.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (13)

1. An alkali-soluble composition, comprising:

alkali-soluble resin and residues from the preparation of the alkali-soluble resin,

wherein the residue comprises monomers, thermal initiator and solvent,

the content of the thermal initiator is 10-50,000ppm;

in the alkali-soluble composition, the total residual rate of the monomers is 0.01-15%.

2. The alkali soluble composition according to claim 1, wherein the thermal initiator is present in an amount of 50 to 8000ppm.

3. A method of making an alkali soluble composition, the method comprising:

dissolving a monomer and a thermal initiator in a solvent to obtain a mixed solution;

heating and stirring part of the mixed solution to carry out polymerization reaction to obtain a prepolymer;

supplementing the residual mixed solution into the prepolymer for further polymerization reaction to obtain a polymer solution;

supplementing and adding the thermal initiator to the polymer solution to obtain the alkali-soluble composition;

part of the mixed solution accounts for 20-60% of the volume of the mixed solution.

4. The method of claim 3, wherein the monomers include an acid functional group-containing monomer and a non-acid monomer, and the mixed solution includes 15 to 25 parts of the acid functional group-containing monomer, 75 to 85 parts of the non-acid monomer, and 0.5 to 2.0 parts of the thermal initiator.

5. The preparation method according to claim 3, wherein the mass ratio of the thermal initiator in the mixed solution to the thermal initiator additionally added is 100: (1-100).

6. The method according to claim 3, wherein the polymerization reaction is carried out at a reaction temperature of 75 to 100 ℃ for 3 to 14 hours.

7. The preparation method according to claim 6, wherein the reaction time of the mixed solution is 2 to 4 hours, and the reaction temperature is 75 to 95 ℃; and after the reaction of the mixed solution is finished, supplementing and adding the thermal initiator, adjusting the reaction temperature to 85-100 ℃, and continuing the reaction for 1-10 h.

8. The method of claim 4, wherein the acid functional group-containing monomer comprises one or more of a monocarboxylic acid, a dicarboxylic acid, or an anhydride;

the non-acidic monomer comprises one or more of alkyl (meth) acrylate, hydroxy (meth) acrylate or styrene compounds;

the thermal initiator comprises benzoyl peroxide and/or azobisisobutyronitrile.

9. A photosensitive resin composition comprising an alkali-soluble composition, an ethylenically photopolymerizable unsaturated monomer, a photoinitiator, and an additive,

wherein the alkali-soluble composition is an alkali-soluble composition produced by the production method described in any one of claims 3 to 8, or an alkali-soluble composition described in claim 1 or 2.

10. The photosensitive resin composition according to claim 9, wherein said method for preparing a photosensitive resin composition comprises:

mixing 40-65wt% of alkali-soluble composition, 30-57wt% of ethylenic photo-polymerization unsaturated monomer, 0.1-5wt% of photoinitiator and 0.1-5wt% of additive to prepare the photosensitive resin composition;

dissolving the photosensitive resin composition in an organic solvent, and mixing to form a photosensitive resin composition solution;

the organic solvent comprises one or more of ethanol, toluene, butanone or acetone;

the solid content of the photosensitive resin composition solution is 35-60%;

the photosensitive resin composition solution has a viscosity of 1000 to 8000mpa.s at 25 ℃.

11. A dry film photoresist is characterized in that the dry film photoresist comprises a protective layer, a middle photosensitive layer and a bottom supporting layer which are arranged from top to bottom in sequence,

the intermediate photosensitive layer includes the photosensitive resin composition described in claim 9 or 10, or a photosensitive resin composition obtained by the production method described in any one of claims 3 to 8.

12. The dry film resist according to claim 11, wherein the bonding force of the protective layer to the intermediate photosensitive layer is smaller than the bonding force of the intermediate photosensitive layer to the bottom support layer;

the bonding force between the middle photosensitive layer and the bottom supporting layer is smaller than the bonding force between the middle photosensitive layer and the contact surface;

the protective layer comprises a polyethylene film or a polypropylene film; the thickness of the protective layer is 10-20 μm;

the bottom supporting layer comprises one or more of a polyethylene glycol terephthalate film, a polyvinyl alcohol film, a polyvinyl chloride film, a vinyl chloride copolymer film, a polyvinylidene chloride film, a vinylidene chloride copolymer film, a polymethyl methacrylate copolymer film, a polystyrene film, a polyacrylonitrile film, a styrene copolymer film, a polyamide film or a cellulose derivative film;

the thickness of the bottom supporting layer is 5-25 μm.

13. Use of the alkali-soluble composition of claim 1 or 2, the method of preparing any one of claims 3 to 8, the photosensitive resin composition of claim 9 or 10, or the dry film resist of claim 11 or 12 in a printed circuit board.