A pH-responsive acrylic resin, preparation method and application thereof

Abstract

The application discloses a kind of acrylic resin responding to PH and preparation method and application, take hydroxyethyl methacrylate and 1 / 2 toluene into reaction vessel, temperature is raised to first temperature, take epoxy polymethylsiloxane, remaining toluene and organic base catalyst, after being mixed uniformly, obtain mixed solution, by first time dropwise adding mixed solution reaction, obtain HEMA-DMS monomer;HEMA-DMS monomer is taken, and reaction monomer, mixed solvent and chain transfer agent are placed in reaction vessel;Take initiator and dissolve in dilution solvent, every time interval is added to the dilution solvent containing initiator reaction vessel, incubation;After reaction, dilution solvent is added in reaction vessel, stirring, obtain high adhesion acrylic resin.The application is grafted into acrylic resin polymer by introducing monomer responding to PH rapidly, with the increase of PH value, the greater the response degree, the greater the stress between its polymer molecules, the higher the swelling rate, the stronger the alkali solubility.

Description

Technical Field

[0001] This invention belongs to the field of resin preparation, and relates to the preparation of acrylic resin, and more particularly to an acrylic resin that responds to pH, its preparation method and application. Background Technology

[0002] PCB dry film adhesive is composed of acrylic resin, photoreactive monomers, photoinitiators, solvents, and other additives. The dry film adhesive is coated onto a PET film, dried, laminated with a PE film, and then wound up to obtain the dry film.

[0003] Customers use dry film, which is hot-pressed onto the PCB board, exposed by an exposure machine, then developed with sodium carbonate, etched with an etching solution, and finally removed with sodium hydroxide solution to form the desired circuitry.

[0004] Currently, the acrylic resins used in dry film adhesives are designed primarily by adjusting the resin's molecular weight, Tg, acid value, and functional modifications. However, these target parameters are difficult to comprehensively consider the specific requirements of dry films, such as development speed, acid etching resistance, and film removal speed.

[0005] The developing solution and the stripping solution are alkaline solutions of sodium carbonate and sodium hydroxide, respectively. Generally, the dry film is required to have good alkaline solubility. The alkaline etching solution is also an alkaline solution, and is generally required to have poor alkaline solubility.

[0006] In existing PCB dry film preparation methods, dry films cannot achieve good alkali solubility and resistance to alkaline etching solutions. Summary of the Invention

[0007] To address the aforementioned problems, this invention provides a pH-responsive acrylic resin, its preparation method, and its application. This invention introduces a monomer that responds rapidly to pH and grafts it into the acrylic resin polymer. As the pH value increases, the degree of response increases, the intermolecular stress of the polymer increases, the swelling rate increases, and the alkali solubility increases.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] This invention first provides a method for preparing a pH-responsive acrylic resin, the method comprising the following steps:

[0010] 1) Add hydroxyethyl methacrylate and 1 / 2 toluene to a reaction vessel, heat to the first temperature, take epoxy polymethylsiloxane, the remaining toluene and organic base catalyst, mix them evenly to obtain a mixture, and react by adding the mixture dropwise at the first time to obtain HEMA-DMS monomer;

[0011] 2) Take HEMA-DMS monomer, reactant monomer, mixed solvent and chain transfer agent and place them in a reaction vessel, introduce nitrogen gas and raise the temperature to the second temperature;

[0012] 3) Dissolve the initiator in a diluted solvent, and add diluted solvent containing the initiator to the reaction vessel at regular intervals, keeping it at a constant temperature;

[0013] 4) After the reaction is complete, add diluent to the reaction vessel and stir to obtain an acrylic resin that responds to pH.

[0014] The reaction monomers include methacrylic acid, methyl methacrylate, and butyl acrylate.

[0015] As a preferred embodiment of the present invention, in step 1), by weight, 75-85 parts of hydroxyethyl methacrylate, 15-26 parts of toluene, 15-25 parts of epoxy polymethylsiloxane, 0.3-0.8 parts of organic base catalyst, the first temperature is 40-50℃, and the first time is 7.5-8.5h.

[0016] As a preferred embodiment of the present invention, in step 2), the reaction monomers contain 30-40 parts of methacrylic acid, 40-50 parts of methyl methacrylate and 8-15 parts of butyl acrylate by weight, and 8-12 parts of HEMA-DMS monomer are added; the mixed solvent contains 25-35 parts of toluene, 15-25 parts of ethyl acetate and 15-25 parts of methanol by weight.

[0017] As a preferred embodiment of the present invention, in step 2), the second temperature is 70-90°C, and the chain transfer agent is dodecyl mercaptan, with 0.05-0.15 parts of chain transfer agent added by weight.

[0018] As a preferred embodiment of the present invention, in step 3), the initiator is azobisisobutyronitrile, and the diluent is ethyl acetate. Each time, 0.3-0.8 parts of azobisisobutyronitrile are dissolved in 8-15 parts of the diluent ethyl acetate.

[0019] As a preferred embodiment of the present invention, in step 3), a diluted solvent containing an initiator is added three times every 1.5-2.5 hours.

[0020] As a preferred embodiment of the present invention, in step 4), the stirring time is 1.5-2.5h, and 25-35 parts by weight of diluent are added.

[0021] The present invention also provides a pH-responsive acrylic resin prepared by the above preparation method.

[0022] The present invention also provides the application of the above-mentioned pH-responsive acrylic resin in PCB dry film.

[0023] As a preferred embodiment of the present invention, the method for preparing PCB dry film includes:

[0024] a) By weight, take 80 parts of the pH-responsive acrylic resin of claim 8 and add them to the reaction vessel, add 10 parts of the photoreactive monomer TMPTA, 5 parts of the photoreactive monomer LA and 5 parts of the photoreactive monomer IBOA, and heat in a water bath at 40°C for 4.5-5.5 hours.

[0025] b) Take 0.1 parts of photoinitiator 1173 and 0.2 parts of photoinitiator 184, dissolve them in 1 part of ethyl acetate, mix them evenly, and then add them to the reaction system of step a); take 0.05 parts of dye OP powder, dissolve it in 0.1 parts of ethyl acetate, mix them evenly, and then add it to the reaction system of step a); stir evenly for 1.5-2.5 hours to obtain PCB dry film adhesive solution;

[0026] c) The PCB dry film adhesive obtained in step b) is coated onto a PET film, dried in an oven, laminated with a PE protective film, and then wound up to obtain the PCB dry film.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1) This invention introduces a monomer that responds rapidly to pH and grafts it into an acrylic resin polymer. As the pH value increases, the degree of response increases, the stress between polymer molecules increases, the swelling rate increases, and the alkali solubility increases.

[0029] 2) The dry film of this invention exhibits different response speeds in solutions with different pH values. The prepared dry film has faster development and removal speeds, and excellent resistance to alkali-soluble etching lines. Detailed Implementation

[0030] To facilitate understanding of the technical means, creative features, objectives, and effects of this invention, the invention is further described below with reference to specific embodiments. However, the following embodiments are merely preferred embodiments of this invention and not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments described herein without creative effort are all within the scope of protection of this invention. Unless otherwise specified, the experimental methods in the following embodiments are conventional methods, and the materials and reagents used in the following embodiments are commercially available unless otherwise specified.

[0031] The PET film used in the preparation of the PCB dry film in this invention is purchased from the market, and the PE film used in the protective film layer is also purchased from the market.

[0032] In this invention, the photoreactive monomers include photoreactive monomer TMPTA, photoreactive monomer LA, and photoreactive monomer IBOA; the photoinitiators include photoinitiator 1173 and photoinitiator 184; and the dye is OP powder, all of which are commercially available.

[0033] Example 1

[0034] This embodiment discloses a method for preparing a pH-responsive acrylic resin, comprising:

[0035] 1: Synthesis of HEMA-DMS:

[0036] Weigh 80g of hydroxyethyl acrylate and 10g of toluene, and pour them into a four-necked flask equipped with a condenser, stirrer, thermometer, and constant pressure funnel. Heat the flask to 45℃, weigh 20g of epoxy polymethylsiloxane, 0.5g of organic base catalyst tetramethylguanidine, and 10g of toluene, stir to dissolve, and start adding dropwise over 8 hours. After the addition is complete, HEMA-DMS monomer is obtained.

[0037] 2: Preparation of pH-responsive acrylic resins:

[0038] Weigh out 10g, 35g, 45g, and 10g of HEMA-DMS monomer, methacrylic acid, methyl methacrylate, and butyl acrylate, respectively, and weigh out 0.1g of chain transfer agent dodecyl mercaptan. Pour these into a four-necked flask equipped with a condenser, stirrer, thermometer, and constant pressure funnel. Weigh out 30g of toluene, 20g of ethyl acetate, and 20g of methanol, and pour them into the four-necked flask. Purge with nitrogen, stir, and heat to 85℃. Weigh out 0.5g of azobisisobutyronitrile (AIB) and dissolve it in 10g of ethyl acetate solvent to prepare three ethyl acetate solutions containing AIB. Add these solutions to the four-necked flask in three portions, every 2 hours. After the reaction is complete, weigh out 30g of ethyl acetate and pour it into the four-necked flask. Dilute and stir for two hours to obtain an acrylic resin that responds to pH.

[0039] Example 2

[0040] This embodiment discloses a method for preparing a pH-responsive acrylic resin, comprising:

[0041] 1: Synthesis of HEMA-DMS:

[0042] Weigh 75g of hydroxyethyl acrylate and 7.5g of toluene, and pour them into a four-necked flask equipped with a condenser, stirrer, thermometer, and constant pressure funnel. Heat the flask to 40℃, weigh 15g of epoxy polymethylsiloxane, 0.3g of the organic base catalyst tetramethylguanidine, and 7.5g of toluene, stir to dissolve, and begin dropwise addition. The addition takes 7.5 hours. After the addition is complete, HEMA-DMS monomer is obtained.

[0043] 2: Preparation of pH-responsive acrylic resins:

[0044] Weigh out 8g, 30g, 40g, and 8g of HEMA-DMS monomer, methacrylic acid, methyl methacrylate, and butyl acrylate, respectively, and weigh out 0.05g of chain transfer agent dodecyl mercaptan. Pour these into a four-necked flask equipped with a condenser, stirrer, thermometer, and constant pressure funnel. Weigh out 25g of toluene, 15g of ethyl acetate, and 15g of methanol, and pour them into the four-necked flask. Purge with nitrogen, stir, and heat to 70℃. Weigh out 0.3g of azobisisobutyronitrile (AIB) and dissolve it in 8g of ethyl acetate solvent to prepare three ethyl acetate solutions containing AIB. Add these solutions to the four-necked flask in three portions, every 1.5 hours. After the reaction is complete, weigh out 25g of ethyl acetate, pour it into the four-necked flask, dilute, and stir for 1.5 hours to obtain a pH-responsive acrylic resin.

[0045] Example 3

[0046] This embodiment discloses a method for preparing a pH-responsive acrylic resin, comprising:

[0047] 1: Synthesis of HEMA-DMS:

[0048] Weigh 85g of hydroxyethyl acrylate and 13g of toluene, and pour them into a four-necked flask equipped with a condenser, stirrer, thermometer, and constant pressure funnel. Heat the flask to 50°C, weigh 25g of epoxy polymethylsiloxane, 0.8g of the organic base catalyst tetramethylguanidine, and 13g of toluene, stir to dissolve, and begin dropwise addition. The process takes 8.5 hours. After the dropwise addition is complete, HEMA-DMS monomer is obtained.

[0049] 2: Preparation of pH-responsive acrylic resins:

[0050] Weigh out 12g, 40g, 50g, and 15g of HEMA-DMS monomer, methacrylic acid, methyl methacrylate, and butyl acrylate, respectively, and weigh out 0.15g of chain transfer agent dodecyl mercaptan. Pour these into a four-necked flask equipped with a condenser, stirrer, thermometer, and constant pressure funnel. Weigh out 35g of toluene, 25g of ethyl acetate, and 25g of methanol, and pour them into the four-necked flask. Purge with nitrogen, stir, and heat to 90℃. Weigh out 0.8g of azobisisobutyronitrile (AIB) and dissolve it in 15g of ethyl acetate solvent to prepare three ethyl acetate solutions containing AIB. Add these solutions to the four-necked flask in three portions every 2.5 hours. After the reaction is complete, weigh out 35g of ethyl acetate, pour it into the four-necked flask, dilute, and stir for 2.5 hours to obtain a pH-responsive acrylic resin.

[0051] Example 4

[0052] This embodiment discloses the preparation of PCB dry film:

[0053] 1) Weigh 80 parts of the pH-responsive acrylic resin prepared in Example 1 and add them to a four-necked flask. Weigh TMPTA, LA, and IBOA separately, and add them to the four-necked flask in proportions of 10 parts, 5 parts, and 5 parts, respectively. Heat in a water bath and stir evenly at 40°C for about 5 hours. Weigh photoinitiator 1173 and photoinitiator 184, and dissolve them in 1 part of ethyl acetate solvent in proportions of 0.1 parts and 0.2 parts, respectively. After dissolution, pour them into the four-necked flask. Weigh 0.05 parts of dye OP powder, dissolve it in 0.1 parts of ethyl acetate solvent, and pour it into the four-necked flask. Stir evenly for about 2 hours to obtain the PCB dry film adhesive solution.

[0054] 2) Preparation of PCB dry film: The above-prepared PCB dry film adhesive solution is coated on PET film, passed through an oven, laminated with PE protective film, and wound up to obtain PCB dry film.

[0055] The conventional dry film and the PCB dry film prepared in Example 4 were tested, and the test results are shown in Table 1.

[0056] Table 1. Test Results

[0057]

[0058]

[0059] As can be seen, this invention introduces a monomer that responds rapidly to pH and grafts it into an acrylic resin polymer. As the pH value increases, the response becomes greater, the intermolecular stress of the polymer increases, the swelling ratio increases, and the alkali solubility becomes stronger. The dry film of this invention exhibits different response rates in solutions with different pH values. The prepared dry film has fast development and removal speeds and excellent resistance to alkali-soluble etching lines.

[0060] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any form or substance. It should be noted that those skilled in the art can make various improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention. Any modifications, alterations, and equivalent changes made by those skilled in the art based on the above-disclosed technical content without departing from the spirit and scope of the present invention are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing an acrylic resin that responds to pH, characterized in that, The preparation method includes the following steps: 1) Add hydroxyethyl methacrylate and 1 / 2 toluene to a reaction vessel, heat to the first temperature, take epoxy polymethylsiloxane, the remaining toluene and organic base catalyst, mix them evenly to obtain a mixture, and react by adding the mixture dropwise at the first time to obtain HEMA-DMS monomer; 2) Take HEMA-DMS monomer, reactant monomer, mixed solvent and chain transfer agent and place them in a reaction vessel, introduce nitrogen gas and raise the temperature to the second temperature; 3) Dissolve the initiator in a diluent, and add the diluent containing the initiator to the reaction vessel at regular intervals, while keeping it at a constant temperature; 4) After the reaction is complete, add diluent to the reaction vessel and stir to obtain an acrylic resin that responds to pH. The reaction monomers include methacrylic acid, methyl methacrylate and butyl acrylate; In step 1), by weight, there are 75-85 parts of hydroxyethyl methacrylate, 15-26 parts of toluene, 15-25 parts of epoxy polymethylsiloxane, and 0.3-0.8 parts of organic base catalyst. The first temperature is 40-50℃ and the first time is 7.5-8.5h. In step 2), by weight, the reactant monomers contain 30-40 parts methacrylic acid, 40-50 parts methyl methacrylate and 8-15 parts butyl acrylate, and 8-12 parts HEMA-DMS monomer are added; by weight, the mixed solvent contains 25-35 parts toluene, 15-25 parts ethyl acetate and 15-25 parts methanol. In step 2), the second temperature is 70-90℃, and the chain transfer agent is dodecyl mercaptan, with 0.05-0.15 parts by weight of chain transfer agent added.

2. The method for preparing a pH-responsive acrylic resin according to claim 1, characterized in that, In step 3), the initiator is azobisisobutyronitrile, and the diluent is ethyl acetate. Each time, 0.3-0.8 parts by weight of azobisisobutyronitrile are dissolved in 8-15 parts of the diluent ethyl acetate.

3. The method for preparing a pH-responsive acrylic resin according to claim 1, characterized in that, In step 3), the diluted solvent containing the initiator is added three times every 1.5-2.5 hours.

4. The method for preparing a pH-responsive acrylic resin according to claim 1, characterized in that, In step 4), the stirring time is 1.5-2.5 hours, and 25-35 parts by weight of dilution solvent are added.

5. An acrylic resin that responds to pH, characterized in that, pH-responsive acrylic resin prepared by the preparation method according to any one of claims 1-4.

6. The application of the pH-responsive acrylic resin according to claim 5, characterized in that, The application of the pH-responsive acrylic resin in PCB dry film.

7. The application of the pH-responsive acrylic resin according to claim 6, characterized in that, Methods for preparing PCB dry film include: a) Take 80 parts by weight of the pH-responsive acrylic resin as described in claim 5 and add it to the reaction vessel, along with 10 parts of the photoreactive monomer TMPTA, 5 parts of the photoreactive monomer LA and 5 parts of the photoreactive monomer IBOA, and heat in a water bath at 40°C for 4.5-5.5 hours. b) Take 0.1 parts of photoinitiator 1173 and 0.2 parts of photoinitiator 184, dissolve them in 1 part of ethyl acetate, mix them evenly, and then add them to the reaction system of step a); take 0.05 parts of dye OP powder, dissolve it in 0.1 parts of ethyl acetate, mix them evenly, and then add it to the reaction system of step a); stir evenly for 1.5-2.5 hours to obtain PCB dry film adhesive solution; c) The PCB dry film adhesive obtained in step b) is coated onto a PET film, dried in an oven, laminated with a PE protective film, and then wound up to obtain the PCB dry film.

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