Method for detecting imide structure content in photosensitive polyimide precursor resin

Abstract

The present invention belongs to the technical field of imide structure content detection, and specifically discloses a method for testing the imide structure content in a polyimide precursor resin: preparing a photosensitive polyimide precursor resin sample; spin-coating the sample on a potassium bromide tablet; baking the sample, and tableting the obtained pre-cured sample; detecting using infrared spectroscopy to obtain an absorption value A1 of the benzene ring carbon-carbon double bond and an absorption value B1 of the amide bond; curing the pre-cured sample tablet to obtain a cured sample tablet; detecting using infrared spectroscopy to obtain an absorption value A2 of the benzene ring carbon-carbon double bond and an absorption value B2 of the amide bond; processing the absorption peaks of the benzene ring carbon-carbon double bond and the amide bond before and after curing to obtain the imide structure content. This method can accurately obtain the imide structure content in the photosensitive polyimide precursor resin, does not require the use of a highly toxic good solvent, and has the advantages of simplicity, fast analysis speed, high accuracy, low error, low detection cost, safety and environmental protection.

Description

Technical Field

[0001] The invention relates to the technical field of imide structure content detection, and in particular to a method for detecting the imide structure content in a photosensitive polyimide precursor resin. Background Art

[0002] Polyimide (PI) refers to a class of polymers containing an imide ring (-CO-NR-CO-) in their backbone. These polymers are soluble and can be formulated into heat-resistant photoresists. Their backbone contains both rigid aromatic rings and flexible ether bonds, resulting in high thermal stability and toughness. Polyimide offers numerous advantages, making it an excellent polymer material for various functions, including heat resistance and photosensitivity. The content of various components in its precursor resin is crucial for determining the outcome of resin synthesis, but existing techniques are unable to measure the imide content. Summary of the Invention

[0003] The purpose of the present invention is to provide a new method for detecting the imide structure content in a photosensitive polyimide precursor resin.

[0004] To achieve the above objectives and other related objectives, the present invention provides the following technical solutions.

[0005] A method for detecting the imide structure content in a photosensitive polyimide precursor resin comprises the following steps:

[0006] 1) Under yellow light conditions, dissolving a photosensitive polyimide precursor resin in an organic solvent and filtering through a filter membrane to obtain a photosensitive polyimide precursor resin sample;

[0007] 2) Spin-coating a photosensitive polyimide precursor resin sample on a potassium bromide pellet and baking the pellet at 80° C. to 120° C. to obtain a pre-cured sample pellet;

[0008] 3) using infrared spectroscopy to detect the sample pellet before curing to obtain the absorption value A1 of the benzene ring carbon-carbon double bond and the absorption value B1 of the amide bond;

[0009] 4) pressing the uncured sample into a tablet and curing it at 150-350° C. to obtain a cured sample tablet;

[0010] 5) using infrared spectroscopy to detect the pressed tablet of the cured sample to obtain the absorption value A2 of the carbon-carbon double bond of the benzene ring and the absorption value B2 of the amide bond;

[0011] 6) The absorption peaks of the carbon-carbon double bond of the benzene ring and the amide bond before and after curing are calculated according to the formula: The treatment is performed to obtain an imide structure content W.

[0012] Furthermore, the photosensitive polyimide precursor resin is formed by ring-opening, dehydration and esterification of aromatic dianhydride and aromatic diamine.

[0013] Preferably, the aromatic dianhydride and the aromatic diamine undergo a ring-opening reaction in an aprotic solvent to generate polyamic acid, which is then activated and dehydrated to form polyisoimide, and finally the polyisoimide is esterified to form polyamide ester.

[0014] Preferably, the synthetic route is:

[0015]

[0016] Furthermore, in step 1), the organic solvent is at least one of N-methylpyrrolidone, N,N-dimethylformamide or γ-butyrolactone.

[0017] Furthermore, in step 1), the mass fraction of the photosensitive polyimide precursor resin in the photosensitive polyimide precursor resin sample is 20%-40%, preferably 35%.

[0018] Furthermore, the filter membrane is a polypropylene filter membrane.

[0019] Furthermore, the pore size of the filter membrane is less than or equal to 1 μm.

[0020] Furthermore, the spin coating in step 2) includes two spin coatings, the first spin coating has a rotation speed of 500-800 r / min and a time of 10-30 s; the second spin coating has a rotation speed of 1000-3000 r / min and a time of 30-60 s.

[0021] Furthermore, in step 2), the diameter of the potassium bromide tablet is 25-100 mm and the thickness is 4-10 mm.

[0022] Preferably, the potassium bromide tablet has a diameter of 25 mm and a thickness of 4 mm.

[0023] Furthermore, in step 4), the curing is carried out under nitrogen or argon inert gas conditions.

[0024] Furthermore, the curing includes three curing steps, the first curing step is at 150°C for 30 minutes, the second curing step is at 250°C for 30 minutes, and the third curing step is at 350°C for 1 hour.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] This application designs a method for testing the imide structure content in a photosensitive polyimide precursor resin, which solves the method gap of testing the imide structure content in a photosensitive polyimide precursor resin. A uniform film is obtained by spin coating, and the imide peak and benzene ring C=C absorption peak in the polyimide precursor resin before curing are obtained by infrared scanning. After curing, the imide peak and benzene ring C=C absorption peak in the cured polyimide precursor resin are obtained by infrared scanning. The imide peak before curing is compared with the imide peak after curing. Because the film shrinks after curing, resulting in a change in the absorption value, while the benzene ring structure does not change before and after curing, the absorption of the benzene ring C=C before and after curing is compared to eliminate the effect of film thickness loss caused by curing. This method can accurately obtain the imide structure content in the photosensitive polyimide precursor resin, and does not require the use of highly toxic good solvents. It has the advantages of simplicity, fast analysis speed, high accuracy, small error, low detection cost, safety and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is the infrared spectrum of the sample tablet before curing in Example 1;

[0028] Figure 2 This is the infrared spectrum of the sample tablet after curing in Example 1;

[0029] Figure 3 This is the infrared spectrum of the sample tablet before curing in Example 2;

[0030] Figure 4 This is the infrared spectrum of the sample tablet after curing in Example 2;

[0031] Figure 5 This is the infrared spectrum of the sample tablet before curing in Example 3;

[0032] Figure 6 This is the infrared spectrum of the sample tablet after curing in Example 3;

[0033] Figure 7 This is the infrared spectrum of the sample tablet before curing in Example 4;

[0034] Figure 8 This is the infrared spectrum of the sample tablet after curing in Example 4. DETAILED DESCRIPTION

[0035] Unless otherwise indicated, implied from the context, or customary in the art, all parts and percentages in this application are based on weight, and the test and characterization methods used are current as of the filing date of this application. Where applicable, the contents of any patents, patent applications, or publications referred to in this application are incorporated herein by reference in their entirety, and their equivalent patent families are also incorporated by reference, especially with respect to definitions of synthetic techniques, product and processing designs, polymers, comonomers, initiators, or catalysts disclosed in these documents in the art. If the definition of a specific term disclosed in the prior art is inconsistent with any definition provided in this application, the definition of the term provided in this application shall prevail.

[0036] Numerical ranges in this application are approximate values, so unless otherwise indicated, they may include numerical values ​​outside the scope. Numerical ranges include all numerical values ​​from the lower limit to the upper limit increased by 1 unit, provided that there is an interval of at least 2 units between any lower value and any higher value. For example, if the description component, physical or other properties (such as molecular weight, melt index, etc.) is 100 to 1000, it means that all individual numerical values ​​are clearly enumerated, such as 100, 101, 102, and all subranges, such as 100 to 166, 155 to 170, 198 to 200, etc. For a numerical value less than 1 or a scope comprising a fraction greater than 1 (such as 1.1, 1.5, etc.), 1 unit is appropriately considered to be 0.0001, 0.001, 0.01 or 0.1. For ranges containing single-digit numbers less than 10 (e.g., 1 to 5), one unit is generally considered to be 0.1. These are merely specific examples of what is intended, and all possible combinations of numerical values ​​between the lowest value and the highest value enumerated are to be considered expressly stated in this application. The numerical ranges within this application provide, among other things, calcium-containing filler content, stirring temperature, and various characteristics and properties of these components.

[0037] When used with respect to chemical compounds, unless expressly stated otherwise, the singular includes all isomeric forms and vice versa (e.g., "hexane" includes all isomers of hexane, individually or collectively). In addition, nouns using "a," "an," or "the" also include their plural forms unless expressly stated otherwise.

[0038] The terms "comprising", "including", "having" and their derivatives do not exclude the presence of any other components, steps or processes and are irrelevant to whether these other components, steps or processes are disclosed in this application. To eliminate any doubt, all compositions using the terms "comprising", "including", or "having" in this application may include any additional additives, excipients or compounds unless expressly stated otherwise. In contrast, the term "essentially consisting of" excludes any other components, steps or processes from the scope of any description of the term below, except those necessary for operational performance. The term "consisting of" does not include any components, steps or processes that are not specifically described or listed. Unless expressly stated otherwise, the term "or" refers to the listed members alone or in any combination thereof.

[0039] Example

[0040] The embodiments of the present invention will be described in detail below. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0041] The general structural formula of the photosensitive polyimide precursor is:

[0042]

[0043] Example 1

[0044] Purchase a known photosensitive polyimide precursor structure with an imide structure content of 7.62%

[0045] Under yellow light conditions, the photosensitive polyimide precursor was dissolved in N-methylpyrrolidone to obtain a mixed solution with a solid content of 35%. Then it was allowed to stand for more than one day to allow it to fully dissolve. The dissolved mixed solution was filtered through a 1um polypropylene (PP) filter membrane. The filtered mixed solution was allowed to stand for a photosensitive polyimide precursor resin sample. It was allowed to stand for defoaming to avoid bubbles in the subsequent operation that would affect the experiment.

[0046] Place a 25mm diameter, 4mm thick potassium bromide sheet on a spin coater. Then, drop the treated photosensitive polyimide precursor resin sample onto the sheet. Set the spin coater program to spin coat at 500 rpm for 10 seconds in the first step, and at 2000-3000 rpm for 30 seconds in the second step. Start the spin coater and continue spin coating. Remove the coated potassium bromide sheet and place it on a baking sheet. Bake at 90°C for 5 minutes to obtain the uncured sample sheet.

[0047] Place the pre-cured sample on an infrared spectrometer for testing. Obtain the infrared spectrum by infrared scanning. Switch the infrared spectrum viewing mode to absorbance. Record the absorption value at a wavelength of 1500 as A1, and the absorption value at a wavelength of 1377 as B1. Figure 1 As shown, the absorption peak A1=0.281 of the benzene ring carbon-carbon (C=C) double bond is at 1500, and the absorption peak B1=0.112 of the amide bond is at 1377.

[0048] Press the pre-cured sample into a high-temperature curing oven. Set the curing program to heat to 150°C, hold for 30 minutes, then to 250°C, hold for 30 minutes, and finally to 350°C, hold for 1 hour. The heating rate is 10°C / min. Start the curing program under a nitrogen atmosphere. Press the cured sample into a tablet.

[0049] After the curing process is completed, wait for it to cool naturally to room temperature and then take out the sample. Press the cured sample into a tablet and test it using an infrared spectrometer. Obtain the infrared spectrum by infrared scanning. Switch the infrared spectrum viewing mode to absorbance. Record the absorption value at a wavelength of 1500 as A2 and the absorption value at a wavelength of 1377 as B2. Figure 2 As shown, the absorption peak A2=0.191 of the C=C double bond of the benzene ring is at 1500, and the absorption peak B2=1.01 of the amide bond is at 1377.

[0050] Process the data and calculate the imide structure content according to the formula based on the absorption peaks of the carbon-carbon double bond of the benzene ring and the absorption peaks of the amide bond before and after curing:

[0051] Example 2

[0052] Purchase a known photosensitive polyimide precursor with an imide structure content of 27.50%

[0053] Under yellow light conditions, the photosensitive polyimide precursor is dissolved in N-methylpyrrolidone to obtain a mixed solution with a solid content of 35%. Then let it stand for more than one day to allow it to fully dissolve. The dissolved mixed solution is filtered through a 1um PP filter membrane. The filtered mixed solution is allowed to stand for a photosensitive polyimide precursor resin sample. Let it stand for defoaming to avoid bubbles in subsequent operations that may affect the experiment.

[0054] Place a 25mm diameter, 4mm thick potassium bromide sheet on a spin coater. Then, drop the treated photosensitive polyimide precursor resin sample onto the sheet. Set the spin coater program to spin coat at 500 rpm for 10 seconds in the first step, and at 2000-3000 rpm for 30 seconds in the second step. Start the spin coater and continue spin coating. Remove the coated potassium bromide sheet and place it on a baking sheet. Bake at 90°C for 5 minutes to obtain the uncured sample sheet.

[0055] Place the pre-cured sample on an infrared spectrometer for testing. Obtain the infrared spectrum by infrared scanning. Switch the infrared spectrum viewing mode to absorbance. Record the absorption value at a wavelength of 1500 as A1, and the absorption value at a wavelength of 1377 as B1. Figure 3 As shown, the absorption peak A1=0.333 of the benzene ring carbon-carbon (C=C) double bond is at 1500, and the absorption peak B1=0.487 of the amide bond is at 1377.

[0056] Press the pre-cured sample into a high-temperature curing oven. Set the curing program to heat to 150°C, hold for 30 minutes, then to 250°C, hold for 30 minutes, and finally to 350°C, hold for 1 hour. The heating rate is 10°C / min. Start the curing program under a nitrogen atmosphere. Press the cured sample into a tablet.

[0057] After the curing process is completed, wait for it to cool naturally to room temperature and then take out the sample. Press the cured sample into a tablet and test it using an infrared spectrometer. Obtain the infrared spectrum by infrared scanning. Switch the infrared spectrum viewing mode to absorbance. Record the absorption value at a wavelength of 1500 as A2 and the absorption value at a wavelength of 1377 as B2. Figure 4 As shown, the absorption peak A2=0.164 of the C=C double bond of the benzene ring is at 1500, and the absorption peak B2=1.42 of the amide bond is at 1377.

[0058] Process the data and calculate the imide structure content according to the formula based on the absorption peaks of the carbon-carbon double bond of the benzene ring and the absorption peaks of the amide bond before and after curing:

[0059] Example 3

[0060] Purchase a known photosensitive polyimide precursor with an imide structure content of 26.03%

[0061] Under yellow light, the photosensitive polyimide precursor was dissolved in N-methylpyrrolidone to obtain a mixed solution with a solid content of 35%. The solution was then allowed to stand for at least one day to allow for full dissolution. The dissolved mixed solution was then filtered through a 1 μm PP filter membrane. The filtered mixed solution was allowed to stand for defoaming to prevent bubbles from forming during subsequent operations and affecting the experiment.

[0062] Place a 25mm diameter, 4mm thick potassium bromide sheet on a spin coater. Then, drop the treated photosensitive polyimide precursor resin sample onto the sheet. Set the spin coater program to spin coat at 500 rpm for 10 seconds in the first step, and at 2000-3000 rpm for 30 seconds in the second step. Start the spin coater and continue spin coating. Remove the coated potassium bromide sheet and place it on a baking sheet. Bake at 90°C for 5 minutes to obtain the uncured sample sheet.

[0063] Place the pre-cured sample on an infrared spectrometer for testing. Obtain the infrared spectrum by infrared scanning. Switch the infrared spectrum viewing mode to absorbance. Record the absorption value at a wavelength of 1500 as A1, and the absorption value at a wavelength of 1377 as B1. Figure 5 As shown, the absorption peak A1=0.489 of the benzene ring carbon-carbon (C=C) double bond is at 1500, and the absorption peak B1=0.463 of the amide bond is at 1377.

[0064] Press the pre-cured sample into a high-temperature curing oven. Set the curing program to heat to 150°C, hold for 30 minutes, then to 250°C, hold for 30 minutes, and finally to 350°C, hold for 1 hour. The heating rate is 10°C / min. Start the curing program under a nitrogen atmosphere. Press the cured sample into a tablet.

[0065] After the curing process is completed, wait for it to cool naturally to room temperature and then take out the sample. Press the cured sample into a tablet and test it using an infrared spectrometer. Obtain the infrared spectrum by infrared scanning. Switch the infrared spectrum viewing mode to absorbance. Record the absorption value at a wavelength of 1500 as A2 and the absorption value at a wavelength of 1377 as B2. Figure 6 As shown, the absorption peak A2=0.282 of the C=C double bond of the benzene ring is at 1500, and the absorption peak B2=1.03 of the amide bond is at 1377.

[0066] Process the data and calculate the imide structure content according to the formula based on the absorption peaks of the carbon-carbon double bond of the benzene ring and the absorption peaks of the amide bond before and after curing:

[0067] Example 4

[0068] A known photosensitive polyimide precursor was purchased, and its imide structure content was 36.75%.

[0069] Under yellow light, the photosensitive polyimide precursor P4 was dissolved in N-methylpyrrolidone to obtain a mixed solution with a solid content of 35%. The solution was then allowed to stand for at least one day to allow for full dissolution. The dissolved mixed solution was then filtered through a 1 μm PP filter membrane. The filtered mixed solution was allowed to stand for defoaming to prevent bubbles from forming during subsequent operations and affecting the experiment.

[0070] Place a 25mm diameter, 4mm thick potassium bromide sheet on a spin coater. Then, drop the treated photosensitive polyimide precursor resin sample onto the sheet. Set the spin coater program to spin coat at 500 rpm for 10 seconds in the first step, and at 2000-3000 rpm for 30 seconds in the second step. Start the spin coater and continue spin coating. Remove the coated potassium bromide sheet and place it on a baking sheet. Bake at 90°C for 5 minutes to obtain the uncured sample sheet.

[0071] Place the pre-cured sample on an infrared spectrometer for testing. Obtain the infrared spectrum by infrared scanning. Switch the infrared spectrum viewing mode to absorbance. Record the absorption value at a wavelength of 1500 as A1, and the absorption value at a wavelength of 1377 as B1. Figure 7 As shown, the absorption peak A1=0.287 of the benzene ring carbon-carbon (C=C) double bond is at 1500, and the absorption peak B1=0.257 of the amide bond is at 1377.

[0072] Press the pre-cured sample into a high-temperature curing oven. Set the curing program to heat to 150°C, hold for 30 minutes, then to 250°C, hold for 30 minutes, and finally to 350°C, hold for 1 hour. The heating rate is 10°C / min. Start the curing program under a nitrogen atmosphere. Press the cured sample into a tablet.

[0073] After the curing process is completed, wait for it to cool naturally to room temperature and then take out the sample. Press the cured sample into a tablet and test it using an infrared spectrometer. Obtain the infrared spectrum by infrared scanning. Switch the infrared spectrum viewing mode to absorbance. Record the absorption value at a wavelength of 1500 as A2 and the absorption value at a wavelength of 1377 as B2. Figure 8 As shown, the absorption peak A2=0.101 of the C=C double bond of the benzene ring is at 1500, and the absorption peak B2=0.243 of the amide bond is at 1377.

[0074] Process the data and calculate the imide structure content according to the formula based on the absorption peaks of the carbon-carbon double bond of the benzene ring and the absorption peaks of the amide bond before and after curing:

Claims

1. A method for detecting the imide structure content in a photosensitive polyimide precursor resin, characterized in that: The following steps are involved: 1) Under yellow light conditions, dissolving a photosensitive polyimide precursor resin in an organic solvent and filtering through a filter membrane to obtain a photosensitive polyimide precursor resin sample; 2) Spin-coating a photosensitive polyimide precursor resin sample on a potassium bromide pellet and baking the pellet at 80° C. to 120° C. to obtain a pre-cured sample pellet; 3) using infrared spectroscopy to detect the sample pellet before curing to obtain the absorption value A1 of the benzene ring carbon-carbon double bond and the absorption value B1 of the amide bond; 4) pressing the uncured sample into a tablet and curing it at 150-350° C. to obtain a cured sample tablet; 5) using infrared spectroscopy to detect the pressed tablet of the cured sample to obtain the absorption value A2 of the carbon-carbon double bond of the benzene ring and the absorption value B2 of the amide bond; 6) The absorption peaks of the carbon-carbon double bond of the benzene ring and the amide bond before and after curing are calculated according to the formula: The treatment is performed to obtain an imide structure content W. 2 . The method for detecting the imide structure content in a photosensitive polyimide precursor resin according to claim 1 , wherein the photosensitive polyimide precursor resin is formed by ring-opening, dehydrating, and esterifying aromatic dianhydride and aromatic diamine.

3. The method for detecting the imide structure content in the photosensitive polyimide precursor resin according to claim 1, wherein: In step 1), the organic solvent is selected from at least one of N-methylpyrrolidone, N,N-dimethylformamide or γ-butyrolactone.

4. The method for detecting the imide structure content in the photosensitive polyimide precursor resin according to claim 1, wherein: In step 1), the mass fraction of the photosensitive polyimide precursor resin in the photosensitive polyimide precursor resin sample is 20%-40%.

5. The method for detecting the imide structure content in the photosensitive polyimide precursor resin according to claim 1, wherein: In step 1), the filter membrane is a polypropylene filter membrane.

6. The method for detecting the imide structure content in a photosensitive polyimide precursor resin according to claim 1 or 5, wherein: The pore size of the filter membrane is less than or equal to 1 μm.

7. The method for detecting the imide structure content in the photosensitive polyimide precursor resin according to claim 1, characterized in that: In step 2), the spin coating includes two spin coatings, the first spin coating has a rotation speed of 500-800 r / min and a time of 10-30 s; the second spin coating has a rotation speed of 1000-3000 r / min and a time of 30-60 s.

8. The method for detecting the imide structure content in the photosensitive polyimide precursor resin according to claim 1, characterized in that: In step 2), the diameter of the potassium bromide tablet is 25-100 mm and the thickness is 4-10 mm.

9. The method for detecting the imide structure content in a photosensitive polyimide precursor resin according to claim 1, wherein: In step 4), the curing is carried out under nitrogen or argon inert gas conditions.

10. The method for detecting the imide structure content in the photosensitive polyimide precursor resin according to claim 1, wherein: In step 4), the curing includes three curing steps, wherein the first curing step is at 150° C. for 15-45 minutes, the second curing step is at 250° C. for 15-45 minutes, and the third curing step is at 350° C. for 45-75 minutes.

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