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CN-121974829-A - Alkali-soluble photo-curing epoxy resin containing hindered urea structure, photo-curing solder resist ink and application method thereof

CN121974829ACN 121974829 ACN121974829 ACN 121974829ACN-121974829-A

Abstract

The invention provides an alkali-soluble photo-curing epoxy resin containing hindered urea structure, photo-curing solder resist ink and application method thereof, wherein the alkali-soluble photo-curing epoxy resin is prepared by nucleophilic addition reaction of binary aromatic compound containing amino or phenolic hydroxyl and diisocyanate compound, after epoxidation of amino or phenolic hydroxyl in the reaction product, ring opening reaction is carried out on the epoxy resin matrix and acrylic acid, esterification reaction is carried out on partial hydroxyl groups generated by the reaction and unsaturated anhydride, and finally the rest hydroxyl groups and unsaturated monomers containing hindered urea structures are connected by using diisocyanate compounds. According to the invention, a hindered urea structure is introduced, rearrangement of a cross-linked network is realized through heat treatment, and the hindered urea bond is broken and reconnected under the action of heat treatment to react and connect part of free carboxyl in the system to the cross-linked network, so that the influence of a large steric hindrance side group on the material performance in a cured network is reduced, and the glass transition temperature of a solder resist coating is increased.

Inventors

  • LI MINGHUI
  • LIU WENQI
  • DONG YAN
  • ZHANG JUNHUA

Assignees

  • 广东炎墨方案科技股份有限公司

Dates

Publication Date
20260505
Application Date
20251211

Claims (10)

  1. 1. An alkali-soluble photo-curing epoxy resin containing a hindered urea structure is characterized by having the following chemical structural formula: , Or (b) 。
  2. 2. A preparation method of alkali-soluble photo-curing epoxy resin containing hindered urea structure is characterized in that after nucleophilic addition reaction of binary aromatic compound containing amino or phenolic hydroxyl and diisocyanate compound, epoxidation of amino or phenolic hydroxyl in reaction product is carried out, ring-opening reaction is carried out on epoxy resin matrix and acrylic acid, esterification reaction is carried out on part of hydroxyl groups generated by reaction and unsaturated anhydride, and finally diisocyanate compound is utilized to connect the rest of hydroxyl groups and unsaturated monomer containing hindered urea structure, thus obtaining photo-curing alkali-soluble resin ink containing hindered urea structure.
  3. 3. The preparation method according to claim 2, characterized by comprising the steps of: (1) Under inert atmosphere, dissolving a binary aromatic compound containing amino or phenolic hydroxyl into an organic solvent A, adding a diisocyanate compound, stirring for reaction, and performing epoxidation treatment on the amino or phenolic hydroxyl of the obtained product to prepare a polyurethane epoxy resin matrix; (2) Dissolving the polyurethane epoxy resin matrix obtained in the step (1) in an organic solvent B, adding an acrylic acid, a cyclic ester ring-opening catalyst and a polymerization inhibitor, regulating the temperature to 100-120 ℃, and stirring and reacting for 8-12 hours to obtain an epoxy resin solution containing acrylate bonds; (3) Adding unsaturated anhydride and polymerization inhibitor into the epoxy resin solution containing acrylate bonds obtained in the step (2), and continuing stirring and reacting for 3-5 hours at the temperature of 90-100 ℃ to obtain alkali-soluble photo-curing epoxy resin; Wherein the molar ratio of the epoxy resin containing acrylate bonds to unsaturated anhydride is 1 (0.8-1.2); (4) Under inert atmosphere, dissolving unsaturated monomers containing a hindered urea structure in an organic solvent A, adding diisocyanate compounds, stirring and reacting, adding the alkali-soluble photo-curing epoxy resin obtained in the step (3), stirring and reacting for 3-5 hours at 50-80 ℃ to obtain the alkali-soluble photo-curing epoxy resin containing the hindered urea structure; wherein the unsaturated monomer containing the hindered urea structure is 2- (tertiary butyl amino) ethyl methacrylate.
  4. 4. The method according to claim 3, wherein the organic solvent A in the steps (1) and (4) comprises any one of tetrahydrofuran, methylene chloride, N-dimethylformamide, dimethyl sulfoxide and ethyl acetate; The organic solvent B in the step (2) comprises at least one of N-methyl pyrrolidone, dibasic acid ester solvent, ethylene glycol diethyl ether acetate, ethylene glycol butyl ether acetate, diethylene glycol diethyl ether acetate, diethylene glycol butyl ether acetate, propylene glycol methyl ether propionate, dipropylene glycol methyl ether, propylene glycol methyl ether, trimethylbenzene and tetramethylbenzene.
  5. 5. The method according to claim 3, wherein the amino group-or phenolic hydroxyl group-containing binary aromatic compound in the step (1) comprises at least one of p-phenylenediamine, m-phenylenediamine, 4' -diaminodiphenyl ether, hydroquinone, resorcinol, p-aminophenol and tyramine.
  6. 6. The process according to claim 3, wherein the diisocyanate compound in the step (1) or (4) comprises at least one of hexamethylene diisocyanate, isophorone diisocyanate, toluene diisocyanate, dimethylbenzene diisocyanate, o-toluene diisocyanate, p-phenylene diisocyanate, toluene-2, 4-diisocyanate, toluene-2, 6-diisocyanate, and 1, 3-phenylene diisocyanate.
  7. 7. The method of claim 3, wherein the step (1) is characterized in that the step (1) is performed by adding an excessive amount of epichlorohydrin and tetrabutylammonium bromide into the obtained product, stirring and reacting for 3-4 hours at the temperature of 80-100 ℃, adjusting the temperature to 40 ℃ after the time is reached, adding sodium hydroxide, and continuing stirring and reacting for 2 hours at the temperature of 40 ℃ to obtain the polyurethane epoxy resin matrix.
  8. 8. A photo-curing solder resist ink is characterized by comprising the following raw materials in parts by weight: 100 parts of alkali-soluble photo-curing epoxy resin containing hindered urea structure, 1-10 Parts of a photoinitiator; The alkali-soluble photo-curing epoxy resin containing the hindered urea structure is the alkali-soluble photo-curing epoxy resin containing the hindered urea structure as claimed in claim 1 or the alkali-soluble photo-curing epoxy resin containing the hindered urea structure prepared by the preparation method as claimed in claim 2.
  9. 9. The light-curable solder resist ink according to claim 8, wherein the raw materials comprise, in parts by weight: 100 parts of alkali-soluble photo-curing epoxy resin containing hindered urea structure, 3-5 Parts of a photoinitiator, 20-50 Parts of a filler, 5-30 Parts of a reactive diluent, 1-25 Parts of an additive.
  10. 10. The method of using the photo-curable solder resist ink according to claim 8, wherein the photo-cured coating film is further thermally cured by a heat treatment at 150 to 170 ℃ after development of 1 to h.

Description

Alkali-soluble photo-curing epoxy resin containing hindered urea structure, photo-curing solder resist ink and application method thereof Technical Field The invention relates to the technical field of photo-curing epoxy resin and photo-curing solder resist ink, and relates to alkali-soluble photo-curing epoxy resin containing a hindered urea structure, photo-curing solder resist ink and an application method thereof, in particular to alkali-soluble photo-curing epoxy resin containing a hindered urea structure and a preparation method thereof, and the photo-curing solder resist ink prepared by using the alkali-soluble photo-curing epoxy resin and the application method for further improving the glass transition temperature by heat treatment after photo-curing. Background A printed circuit board (Printed circuit board, abbreviated as PCB), which is a substrate for modern electrical installation and connection elements, is an important basic assembly in the electronics industry. The photo-curing solder resist ink is one of key materials of a Printed Circuit Board (PCB), and is a coating for a solder resist coating covered on a printed circuit copper wire, and is used for preventing circuit corrosion and disconnection, preventing short circuit between wires caused by a plurality of welding points, adjusting the attachment amount of soldering tin, reducing the dissolution pollution of copper in the welding lines, saving soldering tin, reducing the weight of an instrument, increasing the high density of wiring, avoiding false soldering and improving the inspection speed. With the advent of high frequency communications, PCB substrates have also evolved to high density and fine, with higher and higher performance requirements for solder resist coatings. Typically, the PCB is processed through lead soldering process at a temperature of 260 ℃ or higher, so that the cured solder resist ink has high electrical insulation performance and can resist soldering heat treatment. The glass transition temperature of the traditional solder resist ink prepared based on bisphenol A epoxy resin or phenolic epoxy resin is generally 120-140 ℃, and the solder resist ink is difficult to meet the requirement of higher heat resistance, for example, the glass transition temperature reaches more than 140 ℃. Therefore, increasing the glass transition temperature of solder resist ink materials is one of the important research objectives in the related art. Conventional photo-curable solder resist ink is typically composed of a photosensitive oligomer, a photoinitiator, a reactive diluent, a filler, and the like. The photosensitive oligomer is generally composed of a resin matrix, is a main component of the ink, is generally a photo-curable and thermosetting resin oligomer, is commonly epoxy acrylic resin, and has the advantages of good photo-curability, developability and the like. Because the photosensitive oligomer is usually a single resin component, a cured network formed after curing is similar to a single-layer structure, in order to improve the glass transition temperature of the whole material, methods of adjusting the compactness of the single-layer network structure, increasing the rigidity of the network structure and the like are generally adopted, for example, increasing the density of carbon-carbon double bonds in a resin matrix structure, introducing rigid elements such as benzene rings and the like, and the like. Research and exploration for the above-described methods has been mature and comprehensive in the prior art literature and patent technology, For example, the inventor of the present invention previously issued the patent "a high heat-resistant high crosslinking degree photo-curing solder mask ink and its preparation method" (CN 110527350B) by increasing the hydroxyl density of the system, increasing the unsaturated double bond density in the system, and increasing the crosslinking density after curing, so that the cured product has good heat resistance. However, in the above technical solution, it is obvious that in order to increase the density of unsaturated double bonds in the system, on one hand, it is necessary to replace acrylic acid on the photo-curing epoxy resin by selecting dihydroxy group carboxylic acid with longer carbon chain and more branched chain, and on the other hand, it is necessary to add unsaturated anhydride with double molar quantity corresponding to more hydroxyl groups, so as to achieve higher double bond density, and further, the product has higher crosslinking density. In the specific production practice of the prior patent, when the content of the added unsaturated anhydride is larger than a certain value (the threshold values of different systems possibly differ), the double bond content is overlarge in the resin synthesis process, the air resistance effect in the system is enhanced, the gel phenomenon easily occurs in the preparation process, the reaction is failed, the preparation